Social interaction is known to alter behavior and emotional responses to various events. It has been reported that when fear-conditioned animals are put in a fear extinction paradigm with non-fearful conspecifics (pair-exposure), freezing behavior decreases compared to a solitary situation. However, it remains unclear whether pair-exposure during fear extinction is persistently effective in reducing the freezing response. In this study, we examined whether the effect of pair-exposure could be persistently effective on cued and contextual fear extinction. The reduction of the fear compared to the solitary condition was transiently observed only in the cued fear extinction with no difference in the subsequent recall session. We also found that the correlation between corticosterone levels and freezing behavior during extinction was disrupted in the pair-exposure situation. These results suggest that pair-exposure reduces freezing behavior in cued fear extinction, although this fear response reduction is

Sex differences in learned fear expression and extinction involve the medial prefrontal cortex (mPFC). We recently demonstrated that enhanced learned fear expression during auditory fear extinction and its recall is linked to persistent theta activation in the prelimbic (PL) but not infralimbic (IL) cortex of female rats. Emerging evidence indicates that gamma oscillations in mPFC are also implicated in the expression and extinction of learned fear. Therefore we re-examined our in vivo electrophysiology data and found that females showed persistent PL gamma activation during extinction and a failure of IL gamma activation during extinction recall. Altered prefrontal gamma oscillations thus accompany sex differences in learned fear expression and its extinction. These findings are relevant for understanding the neural basis of post-traumatic stress disorder, which is more prevalent in women and involves impaired extinction and mPFC dysfunction.. ...

We combined classical fear conditioning with patch-clamp electrophysiology to explore the cellular mechanisms of prefrontal control over the expression of conditioned fear. We showed for the first time that: (1) fear conditioning depressed IL intrinsic excitability and increased the sAHP; (2) extinction returned IL excitability and sAHP to preconditioning levels; and (3) extinction also decreased the fAHP and introduced a bursting component not seen in the untrained group. These findings indicate that conditioning and extinction alter the intrinsic excitability of IL projection neurons in opposite directions to modulate differentially the expression of conditioned fear responses.. Previous studies have suggested that IL activity is necessary for the recall of extinction memory but not for conditioning. Electrolytic lesions or pharmacological inactivation of IL had no effect on conditioning or extinction training but impaired subsequent recall of extinction memory (Morgan et al., 1993; Quirk et ...

Memories are not always worth keeping. People who suffer from post-traumatic stress disorder, for example, wrestle to suppress thoughts and feelings that take a heavy emotional toll. Unfortunately, it is not always possible to purge bad memories, but as scientists begin to understand the biology behind memory extinction, there is a glimmer of hope that they might find a therapeutic approach that helps. In this weeks Nature Neuroscience online, researchers led by Li-Huei Tsai at MIT reveal one aspect of memory extinction that may be amenable to manipulation. They report that in mice, contextual fear extinction is impaired by Cdk5, a kinase best known for its role in the developing nervous system. Cdk5 has also been implicated in the pathology of Alzheimer disease and other neurodegenerative disorders (see ARF related news story).. Memory extinction is often measured in mice using a fear conditioning paradigm, where animals learn to associate a condition, such as a specific cage or environment, ...

Little is known about the neural correlates of fear learning in adolescents, a population at increased risk for anxiety disorders. Healthy adolescents (mean age 16.26) and adults (mean age 29.85) completed a fear learning paradigm across two stages during functional magnetic resonance imaging (fMRI). Stage 1 involved conditioning and extinction, and stage 2 involved extinction recall, re-conditioning, followed by re-extinction. During extinction recall, we observed a higher skin conductance response to the CS+ relative to CS- in adolescents compared to adults, which was accompanied by a reduction in dorsolateral prefrontal cortex (dlPFC) activity. Relative to adults, adolescents also had significantly reduced activation in the ventromedial PFC, dlPFC, posterior cingulate cortex (PCC), and temporoparietal junction (TPJ) during extinction recall compared to late extinction. Age differences in PCC activation between late extinction and late conditioning were also observed. These results show for ...

The main finding of this study is that CB1R signaling critically modulates memory reconsolidation processes necessary for subsequent drug context-induced cocaine-seeking behavior in an instrumental model of drug relapse. Furthermore, memory retrieval induces CB1R-dependent changes in IEG expression, glutamate receptor subunit phosphorylation, and excitatory synaptic transmission in the BLA during memory reconsolidation.. Systemic CB1R antagonism during cocaine-memory reconsolidation (i.e., immediately after memory retrieval) reduced drug context-induced cocaine-seeking behavior 3 d later, relative to VEH (Fig. 1). The CB1R antagonist, AM251 does not alter inhibitory avoidance (Gobira et al., 2013) or grooming behaviors (Hodge et al., 2008) at similar doses, suggesting it is not aversive. Furthermore, AM251 alone did not alter the expression of drug-seeking behavior despite its long half-life (i.e., 22 h; McLaughlin et al., 2003; Fig. 2). These observations suggest that CB1R signaling is ...

Fingerprint Dive into the research topics of Functional deficit in hippocampal activity during fear extinction recall in the single prolonged-stress model of PTSD in male rats. Together they form a unique fingerprint. ...

ABSTRACT. The end-Permian extinction event is regarded as the most severe of the five major extinction events in the history of life. Recent work in the Karoo Basin of South Africa suggests that the extinctions at the Permo-Triassic boundary (PTB) may have been followed by a second pulse of extinctions, one that claimed the few species that crossed the PTB and thus survived the first extinction pulse. We report here a new specimen of the procolophonoid reptile, Sauropareion anoplus, which was known heretofore only from a single specimen from Lower Triassic strata of the Palingkloof Member, Balfour Formation. The new specimen comes from the lower part of the overlying Katberg Formation and serves as the last appearance datum for the stratigraphic range of S. anoplus. It indicates that S. anoplus survived the second pulse of PTB extinctions and reinforces the hypothesis that procolophonoid evolution was not seriously perturbed by extinctions that mark the beginning of the Triassic Period.. ...

The molecular mechanisms underlying drug extinction remain largely unknown, although a role for medial prefrontal cortex (mPFC) glutamate neurons has been suggested. Considering that the mPFC sends glutamate efferents to the ventral tegmental area (VTA), we tested whether the VTA is involved in methamphetamine (METH) extinction via conditioned place preference (CPP). Among various METH-CPP stages, we found that the amount of phosphoGluR1/Ser845 increased in the VTA at behavioral extinction, but not the acquisition or withdrawal stage. Via surface biotinylation, we found that levels of membrane GluR1 were significantly increased during METH-CPP extinction, while no change was observed at the acquisition stage. Specifically, the number of dendritic spines in the VTA was increased at behavioral extinction, but not during acquisition. To validate the role of the mPFC in METH-CPP extinction, we lesioned the mPFC. Ibotenic acid lesioning of the mPFC did not affect METH-CPP acquisition,

It is generally believed that fear extinction is a form of new learning that inhibits rather than erases previously acquired fear memories. Although this view has gained much support from behavioural and electrophysiological studies, the hypothesis that extinction causes the partial erasure of fear …

The efficacy of many proposed kill mechanisms, such as synchronous sea surface and atmospheric temperature increase, rapid rise in pCO2, and flooding of shelf areas with anoxic and euxinic waters, depends on rate of change and on precisely when they occur relative to the onset of extinction (9, 34, 35). For example, it is crucial to know whether the ∼10 °C increase in sea surface temperature close to the extinction interval slightly predates or postdates the onset of the mass extinction (9, 33) (Fig. S1). More detailed study of the relationship between temperature increase and extinction is needed from less condensed sections than Meishan to evaluate whether temperature leads or lags the extinction and the relationship between temperature rise and changes in the carbonate carbon isotopic record. Using the maximum extinction duration of ∼60 ka, this suggests an ∼1 °C increase per 6,000 y, comparable to the rate and magnitude of the increase at the Paleocene-Eocene Thermal Maximum (PETM) ...

After fear conditioning, presenting the conditioned stimulus (CS) alone yields a context-specific extinction memory; fear is suppressed in the extinction context, but renews in any other context. The context-dependence of extinction is mediated by a brain circuit consisting of the hippocampus, prefrontal cortex (PFC) and amygdala. In the present work, we sought to determine at what level of this circuit context-dependent representations of the CS emerge. To explore this question, we used cellular compartment analysis of temporal activity by fluorescent in situ hybridization (catFISH). This method exploits the intracellular expression profile of the immediate early gene (IEG), Arc, to visualize neuronal activation patterns to two different behavioral experiences. Rats were fear conditioned in one context and extinguished in another; 24 h later, they were sequentially exposed to the CS in the extinction context and another context. Control rats were also tested in each context, but were never ...

Present -day risk assessment would have predicted the extinction of the passenger pigeon (Ectopistes migratorius). Stanton, J,C., 2014, Present -day risk assessment would have predicted the extinction of the passenger pigeon (Ectopistes migratorius). Biological Conservation, v 180, p 11-20, doi:10.1016/j.biocon.2014.09.023. Abstract. The precipitous decline and extinction of the passenger pigeon one century ago helped galvanize implementation of national policies and international cooperation on wildlife management. Having a clear understanding of past conservation failures will aid in preventing future unanticipated extinctions. Simulations from a population model developed for this species indicate that while habitat loss contributed to decline, the main cause of the extinction was an unregulated commercial harvest. Hindcast application of the IUCNs Red Listing criteria to modeled population trajectories show that the species would have been listed as threatened for decades prior to ...

WONG, Heidi and WANG, Steve C., Mathematics and Statistics, Swarthmore College, 500 College Ave, Swarthmore, PA 19081, [email protected]. In the past few decades, there has been much interest in determining whether mass extinction events were simultaneous or gradual. This task, however, is complicated by the incompleteness of the fossil record. Using statistical methods, a number of authors have accounted for such Signor-Lipps effects in testing whether a pattern of fossil occurrences is consistent with a simultaneous extinction. In such tests, the null hypothesis is typically that the extinction was simultaneous, with the alternative hypothesis being that the extinction was gradual. If the record of fossil occurrences does not strongly contradict the null hypothesis, we conclude the extinction could have been simultaneous. However, even if the null hypothesis is not rejected, it is incorrect to infer that the null hypothesis must therefore be true. In fact, any set of fossil occurrences ...

Urban also made the surprising discovery that the varying research methods employed didnt matter - the different papers all pointed towards similar estimates of extinction risk. Studies that built statistical models that correlate environmental factors to the distribution and abundance of species, produced on average the same results as mechanistic or process-based models that simulate populations of species. Very different techniques were producing the same magnitudes of extinction risk.. However, there were some key factors in Urbans analysis that were associated with large uncertainty. The biggest differences in extinction risk were associated with different carbon emissions scenarios. This will be largely up to us to determine - how much of the existing reserves of coal, oil and gas are we willing to burn off? The second most important factor was the extinction debt - the unavoidable extinction of species - as a consequence of habitat loss.. If a species of tree frog can only reproduce in ...

Studies of species-area curves and of the spatial correlation of biogeographic ranges with climatic variables may allow some crude prediction of amount of extinction over large regions in the face of major environmental change. However, these approaches tell little about the proximate causes of species loss. The contention that failure of metapopulation dynamics is at the root of many species extinctions is so far not borne out by observed rates of inter-population movement. Rather, most species that have a metapopulation structure seem to have central source populations and peripheral sink populations. Much of the extinction recorded in the ecological literature is probably of such peripheral populations and their loss has little to do with species extinctions. The disappearance of central, source populations is more important but its causes are not well documented. Habitat loss is the single greatest ultimate cause of current extinction. However, disappearance of the very last individuals of ...

Extinction risk in vertebrates has been linked to large body size, but this putative relationship has only been explored for select taxa, with variable results. Using a newly assembled and taxonomically expansive database, we analyzed the relationships between extinction risk and body mass (27,647 species) and between extinction risk and range size (21,294 species) for vertebrates across six main classes. We found that the probability of being threatened was positively and significantly related to body mass for birds, cartilaginous fishes, and mammals. Bimodal relationships were evident for amphibians, reptiles, and bony fishes. Most importantly, a bimodal relationship was found across all vertebrates such that extinction risk changes around a body mass breakpoint of 0.035 kg, indicating that the lightest and heaviest vertebrates have elevated extinction risk. We also found range size to be an important predictor of the probability of being threatened, with strong negative relationships across ...

Stress modulates instrumental action in favor of habit processes that encode the association between a response and preceding stimuli and at the expense of goal-directed processes that learn the association between an action and the motivational value of the outcome. Here, we asked whether this stress-induced shift from goal-directed to habit action is dependent on noradrenergic activation and may therefore be blocked by a β-adrenoceptor antagonist. To this end, healthy men and women were administered a placebo or the β-adrenoceptor antagonist propranolol before they underwent a stress or a control procedure. Shortly after the stress or control procedure, participants were trained in two instrumental actions that led to two distinct food outcomes. After training, one of the food outcomes was selectively devalued by feeding participants to satiety with that food. A subsequent extinction test indicated whether instrumental behavior was goal-directed or habitual. As expected, stress after placebo ...

The molecular mechanism underlying the extinction of lipoprotein lipase (LPL) expression in rat liver during development was investigated. A mouse (BWTG3) and a rat (7777) hepatoma, both of which exhibit characteristics of fetal hepatocytes, were found to contain LPL mRNA, whereas the more differentiated human (Hep G2 and Hep 3B) or rat (Fa32) hepatoma cell lines did not. Somatic cell hybrids between LPL-producing hepatoma cells and non-LPL-producing cells, such as adult rat hepatocytes or fibroblasts, exhibited extinction of LPL gene expression. Assay of expression of nested deletions in the 5 regulatory sequences of the LPL gene in the Hep G2 cell line and in BWTG3 cells localized sequences involved in the suppression of LPL production to a region between -591 and -288 relative to the transcription initiation site. A site with sequence homology to a glucocorticoid responsive element (GRE) was shown not to play an important role in the extinction process. A novel transcription factor, termed RF-1-LPL,

A global analysis published in Nature Ecology and Evolution collates all plant extinction records documented from across the world. The unique dataset shows how many plant species have gone extinct in the last 250 years.. Dr Bjorn Robroek, Lecturer in Ecology, University of Southampton, said:. This is an interesting piece of work. The science seems sound and thorough. The finding that extinction rates are highest in biodiversity hotspots that are at risk due to land-use change is alarming and echoes the message put forward by the recent IPBES report (https://www.ipbes.net) that current losses in suitable habitat should be high on the political agenda. Indeed, extinction rates are likely still underestimated and more effort needs to go in getting good estimates about extinction rates in underrepresented ecosystems (not only biodiverse systems as the authors state) and plant groups, including algae. That the authors found no clear pattern in evolutionary-closely-related plants regarding ...

The number of extinct animals in 2017 is on the rise. The continuation and rapid speed of extinction and threat to extinction are causing the biodiversity loss which has negative impacts on the balance and whole ecosystems globally.

Evolution, mass extinctions and mass speciations are the result of ionizing radiation, magnetic field reversals, and other factors of an activated planet. The resulting rearrangment of genetic material leads to new species and the extinction of the older species, and this is why mass extinctions are followed by mass speciations.

We demonstrate that more branches from the tree-of-life are pruned when extinction is phylogenetically non-random, but that the loss of their summed lengths is no greater than expected by chance. Furthermore, in some cases (e.g. Artiodactyla), non-random extinction can reduce the loss of branch lengths, presumably because threatened species tend to cluster within young, species-rich clades, while the number of branches being pruned may still be greater than random expectations. We suggest that number of branches, rather than branch lengths, might be important if trait variation accumulates in bursts at speciation events (represented by the nodes in the phylogenetic tree), as would be expected under a model of punctuated equilibrium [26]. If evolution follows a speciational model (and this may be the case for body size in mammals; [27]), short branches separating rapidly diverging lineages might capture as much feature diversity as longer branches in more slowly diversifying clades, although ...

It is important to emphasize that the reduction in robustness caused by the inclusion of parasites did not result from parasite-induced extinctions of hosts (an outcome not possible in our topological approach). Instead, the decrease in robustness was due to the higher sensitivity of parasites to secondary extinction. This finding was only possible when considering that each life stage in a trematode life cycle has a potentially different set of hosts. Had we simply lumped all life stages, the trematodes would have appeared to have had a wide host range and to have been relatively invulnerable to secondary extinction.. Empirical studies in this system reveal more subtle dependencies of parasites on the host community. For instance, a decrease in the diversity and abundance of birds at a particular site directly decreases the diversity and abundance of trematodes using C. californica (Hechinger & Lafferty 2005). Furthermore, the trematode assemblage at a particular location depends on the ...

Jay Williams1 tells about an old woman who was living out the last days of her life. Surrounded by white walls, upon a white bed, in care of doctors and nurses, this dark-skinned relict fought off death with all her primitive vitality. She rebuked her attendants and intermittently broke forth in song and chants. But inevitably she collapsed onto her pillows and whispered, Bury me behind the mountains. And so she died, but her skeleton was placed instead in a city museum, for she was the last of her kin. With her passing, the Tasmanian people became extinct.. Extinction is like that. It is the absolute terminus for a formerly recognized group of organisms. When mortality exceeds natality for a sufficient time to bring the total number of individuals of a species to zero or one (for those organisms which reproduce sexually), then extinction is pronounced.2. Since life began, many organisms have been lost from the biosphere through extinction. Some people feel that this is a normal expectation of ...

A new model of delayed species loss (extinction debt) within isolated communities is applied to a large data set of terrestrial vertebrate assemblages (n = 188) occupying habitat fragments or islands varying greatly in size and age. The model encapsulates previous approaches based on diversity-dependent (DD) extinction rates while allowing for a more flexible treatment of temporal dynamics. Three important results emerge. First, species loss rate slows down with the age of the isolate, a strong and general pattern largely unnoticed so far. Secondly, while being good candidates in the light of previous works, DD models fail to account for this pattern, a result that necessitates a search for other mechanisms. Thirdly, a simple diversity-independent model based on area (converted into population size) and age explains 97% of the variability in species loss rate and appears to be a promising predictive tool to handle extinction debt following habitat loss ...

Our study was inspired by the observation that young individuals suffering from psychiatric diseases such as PTSD have an increased risk to develop AD as they age (Yaffe et al, 2010; Burri et al, 2013; Weiner et al, 2013). We reasoned that one possible way to begin elucidating this phenomenon would be to select genes that have been implicated with age‐associative memory decline and to test whether these genes may also play a role in the development of PTSD‐like phenotypes, which we analyzed in mice via fear extinction as a commonly used and robust paradigm. Nevertheless, we like to reiterate that results from animal models of neuropsychiatric diseases have to be interpreted with care, and while impaired fear extinction in rodents may point to the mechanisms that underlie increased susceptibility for PTSD, it does not fully recapitulate the phenotypes observed in PTSD patients. We observed that deficits in fear extinction precede memory decline in Fmn2−/− mice, and moreover, Fmn2 ...

A new report has urged the federal government to take action, after it was revealed Australia has lost more mammals to extinction than any other country.

...Athens Ga. What if there were a way to predict when a species was ab...Findings from a study by John M. Drake associate professor in the Uni...The paper Early warning signals of extinction in deteriorating envir... This is the first experimental demonstration of critical slowing down...,Study,may,help,predict,extinction,tipping,point,for,species,biological,biology news articles,biology news today,latest biology news,current biology news,biology newsletters

...Scientists have uncovered a lot about the Earths greatest extinction ... No one had ever looked to see if mercury was a potential culprit. Thi...Dr. Benoit Beauchamp professor of geology at the University of Calgar... Geologists including myself should be taking notes and taking anothe...,Earths,massive,extinction:,The,story,gets,worse,biological,biology news articles,biology news today,latest biology news,current biology news,biology newsletters

Transformers: Age of Extinction is the fourth film in director Michael Bays global blockbuster franchise. Mark Wahlberg, Stanley Tucci, Li Bingbing , Kelsey Grammer, Sophia Myles, T. J. Miller, Nicola Peltz, Jack Reynor and Titus Welliver star. The film begins after an epic battle that left a great city torn, but with the world saved. As humanity picks up the pieces, a shadowy group reveals itself in an attempt to control the direction of history… while an ancient, powerful new menace sets Earth in its crosshairs. With help from a new cast of humans, Optimus Prime (voiced by Peter Cullen) and the Autobots rise to meet their most fearsome challenge yet. In an incredible adventure, they are swept up in a war of good and evil, ultimately leading to a climactic battle across the world. Transformers: Age of Extinction is in theaters 06.27.14

You probably already know the planet is experiencing an extinction crisis; scientists estimate well lose up to 50 percent of current species during the next 20 years. But did you know theres also an extinction crisis of gut bacteria happening among civilized humans?The modern diet, which is high in processed foods, meats and sugars but…

As the need increases for sound estimates of impending rates of animal and plant species extinction, scientists must have a firm grounding in the qualitative and quantitative methods required to make the best possible predictions. Extinction Rates offers the most wide-ranging and practical introduction to those methods available.

To prevent extinction, banks have to stop funding it. - Portfolio Earth Thats according to Bankrolling Extinction, a new report published Wednesday by Portfolio Earth, an initiative seeking to challenge the financial industrys role in ecological devastation. The report shows Big Banks lent ...

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Otto: Any age.. Stage setting: A closed space with leaks in the ceiling. The rear part of a car with a television. Kitchen with a gas tap.. Summary: A married couple lives a strange and routine enclosure. The son comes to realize his revenge upon them. The mother plays out a different relationship in her head.. Type of theater: An ironic tragic-comedy on family and enclosure.. Aa puzzle halfway between amusement, playfulness and criticism.. Hey, do you know a more sinister institution than the family?. It combines the caustic with the intimate, the desperate with the comic.. The family has humor in it, it will soon disappear.. The humor conditions the style whose undercurrent hides a notable violence.. An amusing and efficient play.. The four black (or white) beasts of my inspiration run loose.. The time has come to eradicate their common denominator: monotheism.. I am fed up with the world.. Productions: ...

Croatian marine biologists are struggling to save the largest Mediterranean clam from extinction after a precipitious fall in numbers which they say was probably caused by a deadly pathogen.

Whether you are in the mood for some catfish from Oleans, crap legs from Red Lobster or some good old fashion sushi, seafood seems to be that type of food that appears to always be around; there are four oceans and numerous lakes and rivers.. But, have we bitten off more than we can chew?. I know 2048 may seem like a long way down the line, but for the future generations, seafood may become a rare delicacy.According to an article posed on http://cnn.com, crab cakes, swordfish, clambakes and even fish sticks could soon be considered a thing of the past. Some ecologists believe that if the current trends of over fishing and pollution continue, almost all seafood will face extinction by 2048. The aforementioned seafood dishes could be little more than a fond memory in a few decades. Whether we looked at tide pools or studies over the entire worlds ocean, we saw the same picture emerging. In losing species we lose the productivity and stability of entire ecosystems, said lead author of an ...

Dawn of Extinction had planned to start this 2021 with the release of a new EP that would be a continuation of their successful Welcome to the New Century. However, the pandemic we are all suffering has taken this and many other great plans with it, causing the deadlines to be lengthened and the dates postponed.. But the group did not want to leave their fans without any new material, and for that reason they have set to work to launch Lost Paradise. This single, which will not be included in any release, shows a new face of the more relaxed and intimate group, but equally direct. A song that is out of the ordinary patterns to which we are accustomed and that will surely put them on the radar of many new listeners. ...

Evidence trapped in 250-million-year-old sediments may help researchers pin the ultimate blame for the massive extinctions that occurred then on the impact of an extraterrestrial object about 9 kilometers across.

Ancient teeth from Italy suggest the arrival of modern humans in Western Europe coincided with the demise of Neanderthals there, suggesting man played a role in this extinction.

Environmental stress has played a major role in the evolution of living organisms (Hoffman AA, Parsons PA. 1991. Evolutionary genetics and environmental stress. Oxford: Oxford University Press; Parsons PA. 2005. Environments and evolution: interactions between stress, resource inadequacy, and energetic efficiency. Biol Rev Camb Philos Soc. 80:589 610). This is reflected by the massive and background extinctions in evolutionary time (Nevo E. 1995a. Evolution and extinction. Encyclopedia of Environmental Biology. New York: Academic Press, Inc. 1:717 745). The interaction between organism and environment is central in evolution. Extinction ensues when organisms fail to change and adapt to the constantly altering abiotic and biotic stressful environmental changes as documented in the fossil record. Extreme environmental stress causes extinction but also leads to evolutionary change and the origination of new species adapted to new environments. I will discuss a few of these global, regional, and ...

By Peter Moyle In case you hadnt noticed, one of Californias most spectacular fish is leaving us. The coho salmon, silvery favorites of fishermen and essential components of our coastal rainforest ecosystems, are headed for extinction in the state. This projection was made abundantly clear, at least to me, in a recent (August 16) State…

Human impact can explain ninety-six percent of all mammal species extinctions of the last hundred thousand years, according to a new study published in the scientific journal Science Advances.

As the Extinction Rebellion protesters target the London Underground, there is already chaos on the tubes for commuters this morning.

The Evolution and Extinction of the Dinosaurs by David E. Fastovsky, 9780521811729, available at Book Depository with free delivery worldwide.

Read independent reviews on OPUS - Ultrasonic extinction sensor for particle characterisation in highly concentrated suspensions and emulsions for process or laboratory application from below 0.1 µm to 3,000 µm from Sympatec GmbH on SelectScience

Finally to make sure the effects of reinforcement/punishment werent specific to learning an operant task the mice were also tested for place preference. In a place preference test an imaginary line divides the cage in half and only one side of the cage activates illumination.. The results were consistent with the previous findings with operant training; the reinforced dMSN mice learned faster and gave stronger responses as well as proved to be far more resistant during the extinction test. Like with the operant task, punished iMSN mice lost all preference during the extinction trial.. In short, reinforced (dMSN) mice learned faster, showed stronger responses, were more resistant to extinction. The punishment mediated pathway (iMSN) gave weak responses between trials and within trials, it was the behavior was prone to extinction.. If you must choose then choose wisely.. REFERENCES. Kravitz, A., Tye, L., & Kreitzer, A. (2012). Distinct roles for direct and indirect pathway striatal neurons in ...

These experiments examined the effects of posttrial peripheral and intra-amygdala injections of the cholinergic muscarinic receptor agonist oxotremorine on memory consolidation underlying extinction of amphetamine conditioned place preference (CPP) behavior. Male Long-Evans rats were initially trained and tested for an amphetamine (2 mg/kg) CPP. Rats were subsequently given limited extinction training, followed by immediate posttrial peripheral or intrabasolateral amygdala injections of oxotremorine. A second CPP test was then administered, and the amount of time spent in the previously amphetamine-paired and saline-paired apparatus compartments was recorded. Peripheral (0.07 or 0.01 mg/kg) or intra-amygdala (10 etag/0.5 microL) postextinction trial injections of oxotremorine facilitated CPP extinction. Oxotremorine injections that were delayed 2 h posttrial training did not enhance CPP extinction, indicating a time-dependent effect of the drug on memory consolidation processes. The findings ...

5-HT1B receptors (5-HT1BRs) modulate behavioral effects of cocaine. Here we examined the effects of the 5-HT1BR agonist CP94253 on spontaneous and cocaine-induced locomotion and on cocaine-primed reinstatement of conditioned place preference (CPP) in male mice given daily repeated injections of either saline or cocaine (15 mg/kg, IP) for 20 days. In the locomotor activity experiment, testing occurred both 1 and 20 days after the final injection. In the CPP experiment, mice underwent conditioning procedures while receiving the last of their daily injections, which were given either during or ≥2 h after CPP procedures. The CPP procedural timeline consisted of baseline preference testing (days 12-13 of the chronic regimen), conditioning (days 14-19, 2 daily 30-min sessions separated by 5 h), CPP test (day 21), extinction (days 22-34; no injections), CPP extinction test (day 35; no injections), and reinstatement test (day 36). Mice that had not extinguished received additional extinction sessions prior to

Blackburn et al. (2009) suggest that if the relationship between variables is as expected at random, then it is uninteresting. In fact, if extinctions of bird species on islands were as expected at random with respect to species richness it would be fairly easy and accurate to predict the number of extinctions from the size of the original bird fauna, a useful and interesting prediction to say the least. At random, one would expect to see a strong association of the size of the bird fauna and the number of extinctions. This would suggest that a random draw of species from the islands provides an explanation for the number of species that have gone extinct. However, the size of the avifauna has a significantly poor association with the number of extinctions (Karels et al., 2008). This means that something is causing deviation from the random expectation, an interesting result that we suggest may be partly due to heavily impacted islands being large enough to support agriculture, which in turn ...

Climate change this century is forecast to cause imminent and delayed extinctions for frogs in the AWT. We show that these delayed extinctions are likely to occur at time lags greater than 100 years, following the disappearance of climatically suitable areas and associated habitat loss. This has important implications for mitigating climate-driven biodiversity loss, because long lag times (decades to centuries) provide conservation practitioners with more time for intervention.. The widespread practice of coupling BEMs with SARs to infer extinctions due to climate change has been criticized on technical grounds [11], and more detailed (but data-demanding) mechanistic approaches have been offered as a solution [8]. However, until now, no study has compared the likelihood of inferred extinction rates from BEM-SAR approaches with more direct mechanistic estimates, to better understand the proportion of climate-driven extinctions that are delayed, and as importantly, the lag times for these delays. ...

There is considerable evidence that Alcohol Use Disorders (AUDs) can be understood as a form of dysregulated learning and are influenced by classical conditioning. This is based on numerous studies indicating that conditioned contextual cues influence craving for alcohol consumption. As a result, there has been considerable interest in extinction-based treatments for AUDs (i.e., treatments that focus on extinguishing the associations between alcohol cues and motivation to drink), referred to as cue exposure treatment To date, extinction-based treatment for AUDs has resulted in disappointing outcomes in clinical trials and there is considerable interest in improving this form of treatment. One novel strategy is the use of pharmacological adjuncts to enhance extinction. Medications that maximize extinction may minimize subsequent reactions to alcohol cues and, in turn, subsequent clinical outcomes. This study is examining whether the medication d-cycloserine (DCS) can enhance extinction to alcohol ...

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While we cover animal species extinctions a lot in ODP, but plants are also struggling to survive in a world thats rapidly being altered by climate change. According to a new study published in the journal Nature Ecology and Evolution, 600 plant extinctions have taken place of the past two and a half centuries. As the Guardian explained, The number of plants that have disappeared from the wild is more than twice the number of extinct birds, mammals and amphibians combined. The new figure is also four times the number of extinct plants recorded in the International Union for Conservation of Natures red list.Surprise! Humans at Fault: Plant extinction today is occurring at a rate that is 500 times greater than before the Industrial Revolution-and the researchers warn that this number could be an understatement. Our activity such as clear-cutting forests for mining, logging and agriculture is the primary driver of this mass extinction. In fact, were killing so many plants that many of them may ...

TY - JOUR. T1 - Fuse measurements of far-ultraviolet extinction. II. Magellanic cloud sight lines. AU - Cartledge, Stefan I.B.. AU - Clayton, Geoffrey C.. AU - Gordon, Karl D.. AU - Rachford, Brian L.. AU - Draine, B. T.. AU - Martin, P. G.. AU - Mathis, John S.. AU - Misselt, K. A.. AU - Sofia, Ulysses J.. AU - Whittet, D. C.B.. AU - Wolff, Michael J.. PY - 2005/9/1. Y1 - 2005/9/1. N2 - We present an extinction analysis of nine reddened/comparison star pairs in the Large and Small Magellanic Clouds (LMC and SMC) based on Far-Ultraviolet Spectroscopic Explorer (FUSE) FUVobservations. To date, just two LMC sight lines have probed dust grain composition and size distributions in the Magellanic Clouds using spectral data for wavelengths as short as 950 Å. We supplement these two with data from four regions distinguished by their IR through UV extinction curves and grouped as LMCAvg, LMC2, SMC bar, and SMC wing. Despite the distinct characters of extinction in the Clouds and Milky Way, our results ...

The reasons of the popularity of the concept of Near Term Extinction are a fascinating subject in themselves. One reason could be that many of us are truly fed up with the many awful things we are doing to this planet (and to ourselves). So much, that human extinction doesnt look so bad; it actually becomes almost a relief. But near term extinction could be seen as an extreme form of BAU-ism. That is, some people seem unable to conceive that there could be life for humankind in forms different than the present one. Some of them take refuge in a form of technological BAU, hoping that the present society can be maintained forever by means of technological progress. Others seem to realize the impossibility of the technological dream and hence take refuge in self-annihilation. It is a little like the many Japanese citizens who committed suicide after the surrender of Japan at the end of the second world war. They couldnt conceive a world where Japan had been defeated, and so they decided to ...

Visual extinction after right parietal damage involves a loss of awareness for stimuli in the contralesional field when presented concurrently with ipsilesional stimuli, although contralesional stimuli are still perceived if presented alone. However, extinguished stimuli can still receive some residual on-line processing, without awareness. Here we examined whether such residual processing of extinguished stimuli can produce implicit and/or explicit memory traces lasting many minutes. We tested four patients with right parietal damage and left extinction on two sessions, each including distinct study and subsequent test phases. At study, pictures of objects were shown briefly in the right, left, or both fields. Patients were asked to name them without memory instructions (Session 1) or to make an indoor/outdoor categorization and memorize them (Session 2). They extinguished most left stimuli on bilateral presentation. During the test (up to 48 min later), fragmented pictures of the previously exposed

Posttraumatic stress disorder (PTSD) results when individuals are exposed to a life threatening event, assault, serious injury, or other traumatic incident. Individuals with PTSD are impaired in their ability to extinguish fear memories, resulting in intrusive symptoms that impair their ability to live otherwise healthy lives. It remains unclear why some individuals exposed to traumatic events develop PTSD while others do not. Acetylcholine has been shown to play a critical role in fear learning, but its role in fear extinction is not well understood. This study utilized a rat model of fear learning and extinction to determine if individual differences in fear and extinction learning are correlated with markers of cholinergic signaling. This study examined M1 muscarinic acetylcholine receptor (M1 mAChR) and acetylcholinesterase (AChE), both heavily expressed in the basolateral amygdala (BLA), a region that has been heavily implicated in the acquisition, consolidation, and recall of fear and extinction

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Abstract. Multi-axis differential optical absorption spectroscopy (MAX-DOAS) measurements were performed in the urban environment of Madrid, Spain, from March to September 2015. The O4 absorption in the ultraviolet (UV) spectral region was used to retrieve the aerosol extinction profile using an inversion algorithm. The results show a good agreement between the hourly retrieved aerosol optical depth (AOD) and the correlative Aerosol Robotic Network (AERONET) product, with a correlation coefficient of R = 0.87. Higher AODs are found in the summer season due to the more frequent occurrence of Saharan dust intrusions. The surface aerosol extinction coefficient as retrieved by the MAX-DOAS measurements was also compared to in situ PM2.5 concentrations. The level of agreement between both measurements indicates that the MAX-DOAS retrieval has the ability to characterize the extinction of aerosol particles near the surface. The retrieval algorithm was also used to study a case of severe dust intrusion ...

The discrepancy may be down to the strengths and weaknesses of the two methods. Schoenes offers greater precision, but instead of dating lava flows directly, it dates the formation of zircon crystals in the lava, which may occur in magma chambers before the eruption.. We still dont know what the relative contributions of the Deccan Traps and the asteroid impact were to the extinction, says Schoene. But having a more precise timeline helps us get closer. Before, we had no record with enough detail from the volcanic rock to compare to the climate records, he says.. Although her results suggest most of the lava erupted after the extinction, Sprain still thinks volcanism played an important role. Fossils and temperature records show that changes in the climate and signs of ecological stress coincided with the start of the volcanic activity, some 400,000 years before the impact and the extinction.. The Deccan Traps likely weakened late Cretaceous ecosystems to make them susceptible to the rapid ...

We combine optical remote sensing with computed tomography to determine simultaneously (a) the concentration and (b) the size distribution of particles at every pixel in a plane that slices through an aerosol. Light-extinction measurements are made along intersecting paths that pass through the plane. The spatial distribution of extinction coefficients at multiple wavelengths is obtained by an algebraic image-reconstruction technique (ART3). The size distribution of the aerosol at every pixel in the plane is obtained by inversion of the Fredholm integral equation. Computer simulations of this procedure were conducted. Extinction coefficients were found at all pixels in the plane at multiple wavelengths. Aerosol size distributions were retrieved at four pixels. Results of this analysis show that four projection angles were sufficient for reconstruction of extinction coefficient distributions in the plane. The technique can tolerate up to 10% random, normally distributed noise in the measurements. ...

The Late Pleistocene global extinction of many terrestrial mammal species has been a subject of intensive scientific study for over a century, yet the relative contributions of environmental changes and the global expansion of humans remain unresolved. A defining component of these extinctions is a bias toward large species, with the majority of small-mammal taxa apparently surviving into the present. Here, we investigate the population-level history of a key tundra-specialist small mammal, the collared lemming (Dicrostonyx torquatus), to explore whether events during the Late Pleistocene had a discernible effect beyond the large mammal fauna. Using ancient DNA techniques to sample across three sites in North-West Europe, we observe a dramatic reduction in genetic diversity in this species over the last 50,000 y. We further identify a series of extinction-recolonization events, indicating a previously unrecognized instability in Late Pleistocene small-mammal populations, which we link with ...

The extinction coefficient is present in the beer-lambert law (A=ECL). However, how would I calculate the extinction coefficient from a graph where concentration is on the x-axis and optical density on the y-axis? Would I have to work out a gradient? And so, where do I go next to work out the extinction coefficient ...

Countdown to Extinction: Live is a live album by American heavy metal band Megadeth, released on September 24, 2013, through Dave Mustaines Tradecraft label in Blu-ray, DVD, and CD formats. It was recorded during the bands Countdown to Extinction 20th Anniversary Tour at a show at Fox Theatre in Pomona, California, on December 7, 2012,[1] and features the band performing the entire Countdown to Extinction album. The album debuted at number 119 on the Billboard 200. ...

Traditionally, discussion of the cause of their extinction has focused on the antler size (rather than on their overall body size), which may be due more to their impact on the observer than any actual property. Some have suggested hunting by humans was a contributing factor in the demise of the Irish elk, as may have been the case with other prehistoric megafauna, even assuming that the large antler size restricted the movement of males through forested regions or that it was by some other means a maladaptation.[18] Others assume the ultimate cause of extinction may have been the adaptations for mineral metabolism that were beneficial to the Irish elk until vegetation changed.[17] But given the difficulty of recovering quantitative records of human hunting impacts from the sub-fossil record alone, the role of humans in the extinction of the Irish elk is not yet clear. Some research has suggested that a lack of sufficient high-quality forage caused the extinction of the elk. According to an ...

Fear inhibition learning induces plasticity and remodeling of circuits within the amygdala. Most studies examine these changes in nondiscriminative fear conditioning paradigms. Using a discriminative fear, safety, and reward conditioning task, Sangha et al. (2013) have previously reported several ne …

This is one of the only questions we cannot answer. When Alice gets opened up towards the middle of the movie, Peter is dumbstruck to see what his wife is. Miles asks Peter if he really didnt realize what he was.. In some of the flashbacks, we find out that Peter and Alice are synthetics tasked with menial jobs. Peter is an engineer and Alice is a cleaner. Its throughout these flashbacks we begin to learn of the rising tension between the humans and the AIs. Its also around this time we know that the synths are evolving to develop emotions and free-thought. To begin with, Peter is relatively robotic and lifeless but as the movie progresses he becomes more human-like.. ...

2 March 2004 Almost 440 million years ago, some 85 percent of marine animal species were wiped out in the earths first known mass extinction. Roughly 367 million years ago, once again many species of fish and 70 percent of marine invertebrates perished in a major extinction event. Then about 245 million years ago, up to 95 percent of all animals nearly the entire animal kingdom were lost in what is thought to be the worst extinction in history. ... After each extinction, it took upwards of 10 million years for biological richness to recover. Yet once a species is gone, it is gone forever. The consensus among biologists is that we now are moving toward another mass extinction that could rival the past big five. This potential sixth great extinction is unique in that it is caused largely by the activities of a single species. It is the first mass extinction that humans will witness firsthand and not just as innocent bystanders. [More EPI at EcoVaria.com]. MACAL RIVER VALLEY FACES DAM ...

TY - JOUR. T1 - Reversible inactivations of the cerebellum prevent the extinction of conditioned nictitating membrane responses in rabbits. AU - Ramnani, N.. AU - Yeo, C. H.. N1 - Using Smart Source Parsing Aug 15. PY - 1996. Y1 - 1996. KW - Behavior, Animal drug effects. KW - Cerebellum drug effects. KW - Conditioning PsychologyPsychologydrug effects. KW - Extinction Psychology drug effects. KW - Muscimol pharmacology Rabbits. M3 - Article. VL - 495. SP - 159. EP - 168. JO - Journal of Physiology JF - Journal of Physiology SN - 0022-3751. IS - Pt 1. ER - ...

Introduction Impaired inhibition of dread in the current presence of basic safety cues and a insufficiency in the extinction of dread cues are increasingly regarded as important biological markers of Posttraumatic Tension Disorder (PTSD). females (20 PTSD+ 21 PTSD?) recruited from Grady Memorial Medical center in Atlanta GA. We utilized a Move/NoGo method with useful magnetic resonance imaging (fMRI) within a high-resolution 3T scanning device. Participants had been instructed to press a key whenever an X or O made an appearance on the display screen however not if a crimson square made an appearance behind the notice. Individuals were assessed for stress history and PTSD analysis and completed a fear-potentiated startle and extinction paradigm. Results We found stronger activation in the ventromedial prefrontal cortex (vmPFC) in traumatized subjects without PTSD compared to those with PTSD in the NoGo greater than Proceed contrast condition. Activation in the vmPFC was negatively correlated ...

Background: Contact with cocaine-associated stimuli sets off a sturdy rise in circulating glucocorticoid amounts. the basolateral amygdala or the overlying posterior caudate-putamen (anatomical control area). Instantly thereafter, drug-seeking behavior (i.e., nonreinforced lever presses) was evaluated in the previously cocaine-paired framework and locomotor activity was evaluated in a book framework. Outcomes: Intra-basolateral amygdala, however, not intra-posterior caudate-putamen, mifepristone dose-dependently attenuated medication context-induced cocaine-seeking behavior in accordance with vehicle, in a way that responding was very similar to that seen in the extinction framework. On the other hand, mifepristone treatment didnt alter locomotor activity. Conclusions: These results claim that basolateral amygdala glucocorticoid receptor arousal is essential for medication context-induced motivation to get cocaine. (Institute of Lab Animal Assets on Lifestyle Sciences, 2011) and had been ...

Abstract: Operant renewal is the reemergence of a previously extinguished behavior due to a change in stimulus context after extinction. Renewal is problematic in the context of the treatment of severe behavior disorders because destructive behavior may reemerge from simply transitioning from a treatment context to another context (e.g., home). In the current study, we examined a modified ABA renewal procedure in a translational format with analogue tasks. First, we reinforced target responding in Context A. Next, we concurrently extinguished target responding and differentially reinforced an alternative response in Context B. Finally, we tested for renewal of target responding in a return to Context A while extinction and differential reinforcement remained in place for target and alternative responding, respectively. Participants (diagnosed with ASD or other developmental disabilities) were exposed to both a typical ABA renewal procedure and the modified renewal procedure. For some ...

Thats news to me. I opened up my intro biology text, which is more a philosophy and history of biology book, and found 23 pages dedicated to discussing extinctions. Its been my experience that most textbooks will mention at least the Permian and K/T extinctions; theyll include quite a bit of material on modern extinctions; and theyll always discuss mechanisms of extinctions. Its as if these people have never even cracked a biology book, yet feel perfectly comfortable in declaring precisely whats inside.. Even weirder, OLeary goes on to quote a section from David Raups excellent book, Extinction (damn those evilutionists: theyre always trying to hide the facts by writing books with titles that say exactly what theyre about. Douglas Erwin also has a book titled Extinction - were trying so hard to avoid discussing in any detail these subjects, you see.) Raup wrote a book in which he documented the importance of chance events in evolutionary history, arguing that some major events, such ...

The strong selectivity of the end-Permian biotic crisis for animal metabolic rate/physiology, the evidence for ocean acidification, and the dramatically increased terrestrial and marine temperature all point to anomalously high atmospheric Pco2 as a critical driver of both terrestrial and marine biotic crises (5, 6, 36). Critical to understanding the roles of gases and aerosols in the environment are estimates of flux. Although volatile/aerosol flux estimates from the Siberian Traps LIP are variable because of uncertainty in eruption rates/volumes and the efficiency of volatile delivery, the rapid downturn in carbon isotopes from an exponentially growing pool and the short-duration extinction followed by an increase in seawater temperatures suggest that massive amounts of CH4/CO2 were introduced into the atmosphere/oceans over a restricted interval of LIP magmatism [251.999 ± 0.039 Ma to 251.880 ± 0.037 Ma (4)].. In the case of the end-Triassic extinction and Central Atlantic Magmatic Province ...

Last week I lectured in Connecticut and Washington DC; in Bridgeport Naturopathic Medical School and George Washington University, for their fourth year premed students. We had a blast! Last week I promised we will look further at Phyto Power, but lets look first at why we need it, which was what the lectures were all about. Here are a few points I would like to share with you.. In our lecture, we posited and then discussed two main ideas. One is that we are headed toward the next mass extinction within the biosphere. As many of you know, I call this phenomenon the de-evolution of the planet. And the second is, if we can collectivity, on a global-local level, focus on getting our global-local food system right-we not only can avert this pending doom, but create a world of abundance.. Important resources for you and your patients to read are The Sixth Extinction by Richard Leakey (1995); The Flooded Earth by Peter Ward (2010); Sustaining Life by Eric Chivian and Aaron Bernstein (2008); Stuffed ...

For most people, extinction means gone forever. And sometimes it does. But with extraordinary efforts, unusual resources, and dedication, extinction doesnt have to be a death sentence.. Take, for example, those animals you rushed past in a hurry to get to the pandas. Did you see something that looked a bit like a white deer out by parking lot A? You might have stopped to marvel at its long, arching horns, but you probably didnt stay long. Thats a scimitar-horned oryx and may be the animal that inspired the legend of the unicorn.. The oryx is a fascinating species. Native to the sub-Saharan grasslands, theyre adapted to make do with very little water. Back in 1988, only a handful lived in the wild, and none have been seen since then.. However, the species survived in private hands, in zoos, and in conservation centers. Careful management, including strategic breeding and research on oryx biology, is helping bring the species back from the brink.. In addition to the oryx at the Zoo, 15 oryx ...

Nanostructured particles possess unique chemical and physical properties, making them excellent candidates for air purification, smoke clearing, and obscuration. This research was conducted to investigate the aerodynamic, charging, and infrared (IR) extinction properties of nanostructured particles. Specific objectives were to: (1) measure the size distribution and concentration of aerosolized nanostructured particles; (2) evaluate their IR extinction properties; (3) determine their relative chargeability; and (4) numerically model their transport in enclosed rooms. The size distribution and concentration of two nanostructured particles (NanoActive® MgO and MgO plus) were measured in an enclosed room. The particles differed in size distribution and concentration; for example, the geometric mean diameters of NanoActive® MgO and MgO plus were 3.12 and 11.1 [Mu]m, respectively. The potential of nanostructured particles as IR obscurants was determined and compared with other particles. Four groups ...

Guest post by Dr. Craig Loehle Last year, Willis Eschenbach had a WUWT post about extinction rates being exaggerated in the literature. I offered to help him get this published, and it is now out. We conclude that the extinction crisis for birds and mammals is very specific to island fauna which are uniquely sensitive…

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marian at micro.ifas.ufl.edu (Marian Buszko) writes: ,Is there a software program available to calculate the extinction coefficient ,of a protein at 280 nm if the complete sequence of the protein is known? ,If so, I would be interested in obtaining this program. ========== GPMAW, from the American Chemical Society (I believe), does calculate the extinction coefficient for a protein, or fragment, at 280. Its an ancillary part of the program (and probably not worth the cost of the program to gain this feature). If you have a need to do MALDI, though, then GPMAW is a decent program to own (invaluable for calculating the mol. wt. of peptide fragments). -- Eric Larson , University of Illinois at Urbana-Champaign USDA/Agronomy , 190 PABL; 1201 W. Gregory; Urbana, IL 61801 elarson at ux1.cso.uiuc.edu , Voice 217.244.3079 Fax 217.244.4419 Fidonet: 1:233/4.1 , My opinions are my own, but correct ...

Earth has suffered five big extinctions and innumerable little ones. A potential sixth mass extinction, the only one created by the planets own

Interrelationships between volume extinction oefficient, ice water content (IWC), and effective radius (Reff), each dependent upon the particle size distribution (PSD) and temperature (T), are developed using in-situ microphysical measurements at low and midlatitudes, remote sensing data, and model results. The ratio IWC/extinxtion, proportional to Reff, increases with T. Lower values of [IWC/extinction] are observed near cloud top and base than within a cloud layer, although [IWC/extinction] changes more with temperature than relative height within the cloud. For equivalent radar reflectivities (Ze) below about 28 dB, the minimum detectable with forthcoming spaceborne cloud radar, [IWC/extinxtion] is a nearly constant value. IWC increases almost linearly with extinction, with a temperature-dependence noted ...

The article below may contain offensive and/or incorrect content.. Theories of functioning in the medial prefrontal cortex are distinct across appetitively and aversively motivated procedures. In the appetitive domain, it is argued that the medial prefrontal cortex is important for producing adaptive behavior when circumstances change. This view advocates a role for this region in using higher-order information to bias performance appropriate to that circumstance. Conversely, literature born out of aversive studies has led to the theory that the prelimbic region of the medial prefrontal cortex is necessary for the expression of conditioned fear, whereas the infralimbic region is necessary for a decrease in responding following extinction. Here, the argument is that these regions are primed to increase or decrease fear responses and that this tendency is gated by subcortical inputs. However, we believe the data from aversive studies can be explained by a supraordinate role for the medial ...

Amphibians the world over are facing probably the worlds most serious extinction crisis. What are your thoughts on the future prospects for amphibian conservation and preventing further extinctions? Extinctions are part and parcel of the natural process and have always taken place in this planets long history, but

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Alternative Behavior Strategies Earns Behavioral Health Center of Excellence DistinctionUtah and California Autism Treatment Center Named as Top National Behavioral Service Provider

Surely yet more reasons for legalisation. Remove the profit as you are NEVER going to eradicate the market. This from The Times (UK): May 19, 2007 Exile and extinction face a tribe that lost...

How to study dinosaur extinction: dating rock strata, examining the fossil record, and analyzing the rocks chemical and mineral anomalies.

How to study dinosaur extinction: dating rock strata, examining the fossil record, and analyzing the rocks chemical and mineral anomalies.

The Sixth Extinction: An Unnatural History by Elizabeth Kolbert The sixth extinction referred to in the title is of course the extinction Homo sapiens are bringing about through the agency of climate change. Situating our extinction in a cosmic context sets an entirely different tone from say, the panic engendered by the recent report from the U.N.s…

Theres a nice conversation on twitter that is raising some great points that I thought may be worth including here (Im not a big fan of 140 character limit and navigating byzantine twitter conversation threads).. One question that has come up is whether the option for computing extinction probabilities that we used in our paper (i.e., the combineExtinctionAtNodes = random option) is implemented in BAMM. This is indeed one of the options implemented in BAMM, but it is not the default option in BAMM v.2.5-we note, however, that using this option does not require altering any source code. The default option (as of v.2.5) for computing extinction probabilities is the combineExtinctionAtNodes = if_different option, which computes extinction probabilities at nodes by taking the product of extinction probabilities of descendant branches if they are different (as described above in the blog post).. A second question is Why wouldnt you use the default option (i.e., the combineExtinctionAtNodes = ...

Our world is currently in the midst of a mass extinction, with species declining and disappearing at alarming rates. However, not all are faring so poorly. While many populations and species are disappearing, others are maintaining their numbers, or even becoming more abundant, and a critical question is why: why are some species and populations more vulnerable to decline and extinction than others?. Many researchers have identified that body size predicts vulnerability to population decline and species extinction. Populations and species with larger individuals are more likely to decline and go extinct than those with smaller individuals. However, this relationship between body size and population decline and extinction is probably because larger animals tend to have other life-history traits - like lower rates of reproduction, slower growth rates and delayed sexual maturity - which make them less able to recover when the mortality rate increases. There is a great deal of variation in ...

By combining fractional amounts of an assumed standard Arctic methane fountain/torch/plume with a global warming potential of 1000 (which equals a 16 oC temperature rise (4 - 20 oC) over one year - 2010 - 2011) with the mean global temperature curve (from IPCC 2007 - gradient data) it was possible to closely match the 5 visually and mathematically determined best estimates of the global extinction gradients shown in Figure 6 (a to e). Because the thermal radiant flux from the earth into space is a function of its area (Lide and Fredrickse, 1995) we can roughly determine how many years it will take for the methane to spread globally by getting the ratio of the determined fraction of the mean global temperature curve to the fraction of the Arctic methane fountain/torch/plume curve, as the latter is assumed to represent only one year of methane emissions. In addition as the earths surface area is some 5.1*10^8 square kilometres (Lide and Fredrickse, 1995) a rough estimate of the average area of ...