Diamond DL, Krasnoselsky AL, Burnum KE, Monroe ME, Webb-Robertson BJ, McDermott JE, Yeh MM, Dzib JF, Susnow N, Strom S, Proll SC, Belisle SE, Purdy DE, Rasmussen AL, Walters KA, Jacobs JM, Gritsenko MA, Camp DG, Bhattacharya R, Perkins JD, Carithers RL, Liou IW, Larson AM, Benecke A, Waters KM, Smith RD, Katze MG. Proteome and computational analyses reveal new insights into the mechanisms of hepatitis C virus-mediated liver disease posttransplantation. Hepatology. 2012 Jul; 56(1):28-38 ...
Characteristics of hidden populations (e.g. population of injection drug users) cannot be studied using standard sampling and estimation procedures. This article consider..
Wu, J., Crawford, F.W., Raag, M., Heimer, R., Uusküla, A., (2017) Using data from respondent-driven sampling studies to estimate the number of people who inject drugs: Application to the Kohtla-Järve region of Estonia., PLOS One, Nov 2;12(11):e0185711. doi: 10.1371/journal.pone.0185711. eCollection 2017.. White Hughto, J.M., Clark, K.A., Altice, F.L., Reisner, S.L., Kershaw, T.S., Pachankis, J.E. (2017) Improving correctional healthcare providers ability to care for transgender patients: Development and evaluation of a theory-driven cultural and clinical competence intervention., Social Science and Medicine, Oct 14. pii: S0277-9536(17)30609-3. doi: 10.1016/j.socscimed.2017.10.004. [Epub ahead of print]. Ritchwood, T.D., Bishu, K.G., Egede, L.E., (2017) Trends in healthcare expenditure among people living with HIV/AIDS in the United States: evidence from 10 Years of nationally representative data., International Journal for Equity in Health, Oct 27;16(1):188. doi: ...
Wu, J., Crawford, F.W., Raag, M., Heimer, R., Uusküla, A., (2017) Using data from respondent-driven sampling studies to estimate the number of people who inject drugs: Application to the Kohtla-Järve region of Estonia., PLOS One, Nov 2;12(11):e0185711. doi: 10.1371/journal.pone.0185711. eCollection 2017.. White Hughto, J.M., Clark, K.A., Altice, F.L., Reisner, S.L., Kershaw, T.S., Pachankis, J.E. (2017) Improving correctional healthcare providers ability to care for transgender patients: Development and evaluation of a theory-driven cultural and clinical competence intervention., Social Science and Medicine, Oct 14. pii: S0277-9536(17)30609-3. doi: 10.1016/j.socscimed.2017.10.004. [Epub ahead of print]. Ritchwood, T.D., Bishu, K.G., Egede, L.E., (2017) Trends in healthcare expenditure among people living with HIV/AIDS in the United States: evidence from 10 Years of nationally representative data., International Journal for Equity in Health, Oct 27;16(1):188. doi: ...
Introduction The HIV epidemic represents an important public health issue in Europe particularly among men who have sex with men (MSM). Global AIDS Monitoring indicators (GAM) have been widely and jointly promoted as a set of crucial standardised items to be adopted for monitoring and responding to the epidemic. Methods The Sialon II study, implemented in 13 European cities (2013-14), was a complex multi-centre integrated bio-behavioural cross-sectional survey targeted at MSM, with a concomitant collection of behavioural and biological (oral fluid or blood specimens) data. Rigorous sampling approaches for hard-to-reach populations were used (time-location sampling and respondent-driven sampling) and GAM indicators were calculated; sampling frames were adapted to allow weighted estimates of GAM indicators. Results 4,901 MSM were enrolled. HIV prevalence estimates ranged from 2.4% in Stockholm to 18.0% in Bucharest. When exploring city-level correlations between GAM indicators, prevention campaigns
Marti, J.; Csajka, F. S.: The aqueous solvation of sodium chloride: A Monte Carlo transition path sampling study. Journal of Chemical Physics 113, S. 1154 - 1161 (2000 ...
MJFF announces the launch of the Systemic Synuclein Sampling Study (S4) to investigate alpha-synuclein as a potential biomarker of Parkinson s disease.
TY - JOUR. T1 - Comparison of an assumption-free bayesian approach with optimal sampling schedule to a maximum a posteriori approach for personalizing cyclophosphamide dosing. AU - Laínez, José M.. AU - Orcun, Seza. AU - Pekny, Joseph F.. AU - Reklaitis, Gintaras V.. AU - Suvannasankha, Attaya. AU - Fausel, Christopher. AU - Anaissie, Elias J.. AU - Blau, Gary E.. PY - 2014/4. Y1 - 2014/4. N2 - Study Objective Variable metabolism, dose-dependent efficacy, and a narrow therapeutic target of cyclophosphamide (CY) suggest that dosing based on individual pharmacokinetics (PK) will improve efficacy and minimize toxicity. Real-time individualized CY dose adjustment was previously explored using a maximum a posteriori (MAP) approach based on a five serum-PK sampling in patients with hematologic malignancy undergoing stem cell transplantation. The MAP approach resulted in an improved toxicity profile without sacrificing efficacy. However, extensive PK sampling is costly and not generally applicable in ...
Eliminating hepatitis C is hampered by the costs of direct-acting antiviral treatment and the need to treat hard-to-reach populations. Access could be widened by shortening or simplifying treatment, but limited research means it is unclear which approaches could achieve sufficiently high cure rates to be acceptable. We present the statistical aspects of a multi-arm trial designed to test multiple strategies simultaneously and a monitoring mechanism to detect and stop individual randomly assigned groups with unacceptably low cure rates quickly. The VIETNARMS trial will factorially randomly assign patients to two drug regimens, three treatment-shortening strategies or control, and adjunctive ribavirin or no adjunctive ribavirin with shortening strategies (14 randomly assigned groups). We will use Bayesian monitoring at interim analyses to detect and stop recruitment into unsuccessful strategies, defined by more than 0.95 posterior probability that the true cure rate is less than 90% for the individual
Reconstructing weighted networks from partial information is necessary in many important circumstances, e.g. for a correct estimation of systemic risk. It has been shown that, in order to achieve an accurate reconstruction, it is crucial to reliably replicate the empirical degree sequence, which is however unknown in many realistic situations. More recently, it has been found that the knowledge of the degree sequence can be replaced by the knowledge of the strength sequence, which is typically accessible, complemented by that of the total number of links, thus considerably relaxing the observational requirements. Here we further relax these requirements and devise a procedure valid when even the the total number of links is unavailable. We assume that, apart from the heterogeneity induced by the degree sequence itself, the network is homogeneous, so that its (global) link density can be estimated by sampling subsets of nodes with representative density. We show that the best way of sampling nodes is the
Im practicing on choosing the right sampling designs. I have come up with answers below but I do not think they are correct. Please, verify and provide the correct answer with explanations. What kinds of sampling designs.
A probability sampling plan was used for adult male collection in all sites in 2001, which assured that the data truly represented the male arrestee population, not simply an unspecified proportion of that population. The goal of sampling was to represent with known probability the likelihood that a male arrestee was selected for an interview and to use that information to weight each sample case. Additionally, ADAMs goal was to represent all days of the week and all times of the day so as to avoid biasing the male sample against those types of arrests and arrestees who are brought in during the period interviewers were not collecting data (morning, after midnight, "slower" days of the week). The final sampling goal was to represent all the facilities in the target county -- small, large, suburban, urban, quick release, etc. -- again to represent all types of offenders arrested and booked on local and state charges within the past 48 hours. Each ADAM site adopted one of four designs for ...
A probability sampling plan was used for adult male collection in all sites in 2001, which assured that the data truly represented the male arrestee population, not simply an unspecified proportion of that population. The goal of sampling was to represent with known probability the likelihood that a male arrestee was selected for an interview and to use that information to weight each sample case. Additionally, ADAMs goal was to represent all days of the week and all times of the day so as to avoid biasing the male sample against those types of arrests and arrestees who are brought in during the period interviewers were not collecting data (morning, after midnight, "slower" days of the week). The final sampling goal was to represent all the facilities in the target county -- small, large, suburban, urban, quick release, etc. -- again to represent all types of offenders arrested and booked on local and state charges within the past 48 hours. Each ADAM site adopted one of four designs for ...
Normal aproximation when sampling from bounded symmetric distributions . . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
The Better Health Outcomes through Mentoring and Assessment (BHOMA) project is a cluster randomized controlled trial aimed at reducing age-standardized mortality rates in three rural districts through involvement of Community Health Workers (CHWs), Traditional Birth Attendants (TBAs), and Neighborhood Health Committees (NHCs). CHWs conduct quarterly surveys on all households using a questionnaire that captures key health events occurring within their catchment population. In order to validate contact with households, we utilize the Lot Quality Assurance Sampling (LQAS) methodology. In this study, we report experiences of applying the LQAS approach to monitor performance of CHWs in Luangwa District. Between April 2011 and December 2013, seven health facilities in Luangwa district were enrolled into the BHOMA project. The health facility catchment areas were divided into 33 geographic zones. Quality assurance was performed each quarter by randomly selecting zones representing about 90% of enrolled
This specification covers quality assurance sampling and testing procedures used to determine conformance to applicable specification requirements of wrought carbon and low-alloy steel products and of forging stock.. ...
This specification covers quality assurance sampling and testing procedures used to determine conformance to applicable specification requirements of carbon and low-alloy steel forgings.
Background: Although some depression trials have included quality of life (QoL) as an outcome measure, assessments were retrospective and relatively infrequent. Because QoL varies in relation to everyday experience, intensive time-sampling approaches may be useful. Method: The experience sampling method (ESM) was used to assess effects of antidepressant treatment on the quality of life, as measured from moment to moment in daily life (mQoL), and related aspects of daily experience. Primary care patients with a DSM-III-R/DSM-IV diagnosis of major depressive disorder were randomly assigned to imipramine (N=32) or placebo (N=31) treatment for 6 weeks, with possible prolongation to 18 weeks. A healthy control group (N=22) provided normative data. Results: Treatment-related increases in frequency and severity of physical complaints, including those not reported to the general practitioner as side effects, were associated with lowered mQoL; this negative association was especially strong in treatment ...
Antimicrobial resistance (AMR) represents one of the gravest threats to global health. A return to the pre-antibiotic era is imminent unless efforts to combat AMR are prioritized. Key to such efforts is adequate surveillance of AMR at local levels in order to inform empirical antimicrobial treatment and monitor efforts to control AMR and to inform policy at national and international levels. Conventional AMR surveillance is costly, logistically challenging (especially in settings with limited resources) and usually does not provide relevant timely information that can optimize individual patient care. Furthermore, microbiology capacity and quality is often insufficient to support reliable AMR surveillance. Novel approaches are thus needed that require minimum resources and produce a maximum yield in terms of quality and relevant data. The mission of our project is to achieve this aim by combining an efficient sampling strategy - Lot Quality Assurance Sampling (LQAS) - with internet-based ...
The rapidity with which progesterone (P) suppresses daytime lutenizing hormone (LH) (and by inference gonadotropin releasing hormone (GnRH)) pulse frequency is unknown. We propose to assess this further using a randomized, cross-over, placebo-controlled study. Ovulatory women will begin E2 patches on day 4-8 of the cycle, while women with PCOS will begin E2 patches either on day 4-8 of the cycle or at least 8 weeks post-menses. After 3 d of E2 administration, women will undergo a 24-h sampling study in the GCRC. Beginning at 2000 h, blood for LH, FSH, E2, P, and T will be obtained over a 24-h period. After 10 h of sampling, either oral micronized P (100 mg p.o.) suspension or placebo suspension will be administered (according to randomization). At the completion of sampling, E2 patches will be discontinued. During a subsequent menstrual cycle (or after at least 3 weeks in oligomenorrheic PCOS), subjects will undergo another GCRC study identical to the first (including pretreatment with E2) ...
Reconstituted download State Space Models with Regime Switching: Classical and Gibbs Sampling Approaches with Applications 1999 Variations, natural glass. current, cold
Table 3 Degree to which different sampling-based SA methods satisfy desirable criteria. Joint variation. Desirable SA method characteristics. One-at-a-time variation (e.g., No transformation (e.g., Monte Morris method) Carlo, Latin hypercube). Transformation (e.g., Sobol, FAST, Extended FAST). Model nonlinearity ✓. Parameter interaction x. Comprehensiveness of Low output. Computational High efficiency. High Low. Medium Medium. However, they do not consider interactions between parameters and therefore provide limited sensitivity information. Sampling strategies that consider joint model input variations are more computationally expensive, but are able to provide more comprehensive SA outputs. The most common sampling strategies that fall into this category include Monte Carlo and Latin hypercube sampling approaches, for example. While such approaches provide the most comprehensive SA information, they are also the most computationally expensive. As a compromise between computational ...
Create plots involving sample size, half-width, estimated standard deviation, and confidence level for a confidence interval for the mean of a normal distribution or the difference between two means.
... The ASCE Task Committee on Neutron Gauge Calibration met in Logan, Utah in July 1992 to investigate the various methods of soil sampling, installation of access tubes, effect of various parameters on gauge readings, methods of developing field calibration curves and comparison of neutron gauge characteristics. Details of the overall objectives of the study are covered by Stone (1993, this volume). This paper discusses the soil sampling methods and presents a comparative result based on bulk density, time required for sampling and cost of sampling equipment Other papers developed from this study describe the soils, the three sites investigated and the problems related to the tube installation process.
Globally, billions of individuals wash their hair in water, which acts as an exogenous metal source. Many studies which measure the metal levels found on human hair specifically aim to remove exogenous materials prior to analysis. Although this is needed when using hair analysis to probe the impact of the local environment on endogenous metal levels, it is not relevant for understanding exactly what is on hair as a result of contact with its daily environment. Understanding these levels are important, as the presence of redox active metals, such as copper and iron, can impact fibre health, either as a result of UV irradiation, or during the hair colouring process. A global hair sampling study of over 300 individuals from nine countries has been performed, and the combined endogenous and exogenous metals analysed. The levels measured vary widely, even within the narrow geography of each hair sampling location. The levels of calcium, magnesium, copper and iron were not correlated, and within each ...
A unique pilot program will get underway shortly in Vancouvers Downtown Eastside and Prince George to seek and treat vulnerable populations who are either undiagnosed or untreated for HIV.Vancouver - The four-year, $48-million pilot called Seek and Treat is the first of its kind in Canada and believed to be the first internationally. It will expand access to HIV/AIDS medications among hard-to-reach populations, including sex trade workers, injection drug users and men who have sex with men.
From 2018, the Melbourne Sexual Health Centre (MSHC) started to provide free HAV vaccine. MSHC is the largest sexual health service in Victoria and provides 50,000 consultations a year with about 40% were GBM. All MSM attending MSHC are offered for the vaccine. However, this only captures sexually-active MSM who attend MSHC for the routine check-up and may not be able to capture all MSM at risk in the community. Due to the social stigma, MSM is a hidden and hard-to-reach population. We aim to launch a 6-month online social media campaign to improve the knowledge, awareness and vaccine uptake rate of HAV among MSM in Victoria ...
In 2008, a total of 12,898 incident TB cases were reported in the United States; the TB rate declined 3.8% from 2007 to 4.2 cases per 100,000 population, the lowest rate recorded since national reporting began in 1953. In 2008, the TB rate in foreign-born persons in the United States was 10 times higher than in U.S.-born persons. TB rates among Hispanics and blacks were nearly 8 times higher than among non-Hispanic whites, and rates among Asians were nearly 23 times higher than among non-Hispanic whites. To ensure that TB rates decline further in the United States, especially among foreign-born persons and minority populations, TB prevention and control capacity should be increased. Additional capacity should be used to (a) improve case management and contact investigations; (b) intensify outreach, testing, and treatment of high-risk and hard-to-reach populations; (c) enhance treatment and diagnostic tools; (d) increase scientific research to better understand TB transmission; and (e) continue ...
The database contained information on patients in the United Kingdom.. The study cohort consisted of users of PPI therapy and nonusers of acid suppression drugs who were older than 50 years.. The researchers evaluated all patients with an incident hip fracture.. The team selected controls using incidence density sampling, matched for sex, index date, and year of birth.. In addition, the controls were matched for both calendar period and duration of up-to-standard follow-up before the index date.. For comparison purposes, the researchers performed a similar nested case-control analysis for histamine 2 receptor antagonists.. The teams main outcome measure was the risk of hip fractures associated with PPI use.. The researchers found that there were 13,556 hip fracture cases and 135,386 controls.. The adjusted odds ratio for hip fracture associated with more than 1 year of PPI therapy was 1.4.. The team noted that the risk of hip fracture was significantly increased among patients prescribed ...
It is possible to design and implement a national probability sample of persons with a low-prevalence disease, even if it is stigmatized.
<i>Background:</i> Recruitment and retention of medical staff are important issues in rural health. The aim of this study was to describe and understand the perceptions of women doctors working in rural hospitals in South Africa about their work. <br><i>Methods:</i> This was a descriptive study, using a qualitative methodology. Free attitude interviews were conducted with 14 women doctors. Themes were identified and tested against the data and comments from the research diary. <br><i>Results:</i> The main theme was balance. A rural woman doctor has to juggle different issues, including running the household and responsibilities at work. Other themes that were identified included the reason for working at a rural hospital, attitudes to rural life, opportunities for personal and professional growth, the feeling of being needed in a rural hospital, advantages and disadvantages for
Respondent-driven sampling to assess outcomes of sexual violence: a methodological assessment. ABSTRACT: Sexual and gender-based violence (SGBV) is pervasive in eastern Democratic Republic of Congo (DRC). Survivors of sexual violence encounter numerous challenges and women with a sexual violence-related pregnancy (SVRP) face even more complex sequelae. Due to the stigma associated with SGBV theres a lack of an effective sampling frame and therefore, a paucity of research on SVRP outcomes. Respondent-driven sampling (RDS), employed to study this "hidden" population, utilizes a peer-recruitment sampling system that maintains strict participant privacy, and controls and tracks recruitment. If RDS assumptions are met and the sample attains equilibrium, sample weights to correct for biases associated with traditional chain-referral sampling can be calculated. Questionnaires were administered to female participants: 1) raising a child from a SVRP; and/or 2) who had terminated a SVRP. 852 participants ...
In an interview given to CNS, Mr. Arif Jafar, Managing Director of Balarc Foundation, said that the issues of general population are no different from those of the marginalized population. There is huge gender inequality even as the LGBT community challenges the hetro normative structure of the society as well as the social definition of gender. So we need to achieve gender equality in the marginalised population not only in terms of equal opportunities for education and jobs but also in terms of personal identity. Once we recognize gender beyond the two so called normative identities (male and female) then these goals can be achieved for these populations. If this is achieved by 2030 it will definitely help the hidden population to come forward. The LGBT community is treated as a minuscule minority and so their rights are just not taken into account ...
Sampling Methods. Random sampling is the purest form of probability sampling. Each member of the population has an equal and known chance of being selected. When there are very large populations, it is often difficult or impossible to identify every member of the population, so the pool of available subjects becomes biased.. Systematic sampling is often used instead of random sampling. It is also called an Nth name selection technique. After the required sample size has been calculated, every Nth record is selected from a list of population members. As long as the list does not contain any hidden order, this sampling method is as good as the random sampling method. Its only advantage over the random sampling technique is simplicity. ...
Mode: for a discrete random variable, the value with highest probability (the location at which the probability mass function has its peak); for a continuous random variable, the location at which the probability density function has its peak ...
Both bivariate and multivariate analytic approaches were used to examine 2010 NAMCS data in order to answer the research question. The NAMCS was designed and is used to collect data on the actual use and provision of ambulatory care services throughout the US. A national sample of ambulatory care visits are surveyed in order to collect the data. A complex four-stage probability sampling design is employed in the data collection process. A description of the sampling strategy is discussed elsewhere [25]. Because they were the most recently available data at the onset of this study, the 2010 NAMCS data were used. These data are weighted, by the survey designers, to be nationally representative of patient health records.. As recommended by the Center for Disease Control and Preventions (CDC) National Center for Health Statistics (NCHS), all analyses were performed on weighted data. The weighting, as calculated, uses the most recently available census data to provide a stratified representation of ...
download sample survey methods educators( cancers, platelet, and changes) do protection arcades. Each download is the Board on the team of noticeable regulations, the ability of agreeing cspf and crime measure of cells. For a download sample survey methods and of the Jewish capituli, establish decrease our Program Advisory albums.
This Harris Poll was conducted online, in English, within the United States between July 16 and 21, 2014 among 2,306 adults (aged 18 and over). Figures for age, sex, race/ethnicity, education, region and household income were weighted where necessary to bring them into line with their actual proportions in the population. Propensity score weighting was also used to adjust for respondents propensity to be online.. All sample surveys and polls, whether or not they use probability sampling, are subject to multiple sources of error which are most often not possible to quantify or estimate, including sampling error, coverage error, error associated with nonresponse, error associated with question wording and response options, and post-survey weighting and adjustments. Therefore, The Harris Poll avoids the words "margin of error" as they are misleading. All that can be calculated are different possible sampling errors with different probabilities for pure, unweighted, random samples with 100% ...
Sampling Techniques Worksheet For each description of sampling, decide if the sampling technique is A. Simple Random B. Stratified C. Cluster D. Systematic
(KudoZ) Russian to English translation of хинное просвечивание: crosshole survey/method/techniques [geophysics exploration (Tech/Engineering)].
The goal of this report is to further document the 2018 NSDUH sample experiences, including a comparison of actual sample yields to state and quarter targets, a comparison of achieved and expected design effects (DEFFs) and relative standard errors, and documentation of any issue encountered during sample implementation. The 2018.... ...
Smart QSRs know mobile apps drive engagement and sales by creating an easy, convenient customer experience. This national chain needed to raise its game with a hard-to-reach audience, promoting value meals at key points during the day ...
The Polish company is a leader in the use of aerial drones in the building of overhead high-voltage powerlines in a hard-to-reach terrain. The company... See more ...
The Polish company is a leader in the use of aerial drones in the building of overhead high-voltage powerlines in a hard-to-reach terrain. The company... See more ...
PCA plot comparing cMDand aMD trajectory sampling for the Ca2+-bound system.The principal component space generated byknown structures of TnC is shown along wit
Menarcheal age was studied in 900 girls, half of which were from middle class families and the other half from low income class families from the Niger delta region of Nigeria. A retrospective and descriptive random sampling study was conducted through the use of questionnaires. Social class was based on parental occupation. The mean age at menarche for girls from middle class families was 12.22 ± 1.19 years while that for girls from low income families was 13.01 ± 1.44 years. Most of the children from the middle class families attained menarche at the ages of 12 and 13 while those from the low income families attained menarche at the ages of 12, 13 and 14 years.: The age at menarche of girls from middle class families was significantly lower than those of girls from the low socioeconomic class and is similar to those obtained for U.S. girls The age of menarche of girls from low income families is lower than a result of similar study obtained for rural India. ...
This is an open-label, multi-center, clinical sampling study to assess ganciclovir pharmacokinetics and pharmacodynamics in premature infants. Only those subjects who receive ganciclovir for clinical reasons will be enrolled. The decision to initiate ganciclovir therapy will be made by the attending physician based upon his/her clinical decision to treat virologically-confirmed CMV infection; infants receiving such therapy and meeting entry criteria will then be eligible for this study. Therefore, ganciclovir will not provided under this protocol.. Subjects meeting enrollment criteria will be entered into this clinical trial. Subjects will be stratified by gestational age and by chronologic age as follows: 1) ≤ 27 weeks 6 days gestational age at birth and ≤ 30 days chronologic age at study enrollment; 2) ≤ 27 weeks 6 days gestational age at birth and , 30 days chronologic age at study enrollment; 3) ≥ 28 weeks 0 days gestational age at birth and ≤ 30 days chronologic age at study ...
The organizations more than 43, pulmicort xopenex together000 members include pharmacists, student pharmacists, and pharmacy technicians! • Wear sun-protective clothing when going outdoors! Continuation of the study drug beyond Day 100 is permitted for participants who meet specific criteria? El ácido retinoico no pigmentará estas manchas? However, for purposes of understanding the degree to which sample means will agree with the corresponding population mean, it is useful to consider what would happen if 10, or 50, or 100 separate sampling studies, of the same type, were conducted? I really hope to notify you that I am new to online blogging and thoroughly loved your review! Amoxicillin-clavulanate rather than amoxicillin alone is recommended as empiric antimicrobial therapy for ABRS in adults (weak, low). These medications are available over the counter without a prescription, pulmicort cost so make sure you read the manufacturers instructions before taking them. It should also be noted ...
In the image on the left, data from NASAs Chandra X-ray Observatory shows SGR 0418 as a pink source in the middle. Optical data from the William Herschel telescope in La Palma and infrared data from NASAs Spitzer Space Telescope are shown in red, green and blue.. On the right is an artists impression showing a close-up view of SGR 0418. This illustration highlights the weak surface magnetic field of the magnetar, and the relatively strong, wound-up magnetic field lurking in the hotter interior of the star. The X-ray emission seen with Chandra comes from a small hot spot, not shown in the illustration. At the end of the outburst this spot has a radius of only about 160 meters, compared with a radius for the whole star of about 12 km.. More at http://chandra.harvard.edu/photo/2013/sgr0418/. -Megan Watzke, CXC. ...
Soil respiration is the second largest flux of carbon between terrestrial ecosystems and the atmosphere and is affecting climate sensitivity and vulnerability of the terrestrial carbon stock. Monitoring soil carbon dioxide efflux is a complex task, due to the high spatial and temporal variability of the fluxes. For this reason, more than 30 sampling points are required to attain reliable estimates of ecosystem soil respiration. However, the number of sampled points is often limited by labour, time and budget constraints. Stratified sampling is an alternative to random sampling as a method to reduce the number of sampling points when an effective proxy variable is available for the definition of the strata. In order to evaluate different sampling strategies we tested, with a Monte Carlo simulation, the effectiveness of random and stratified samplings, using experimental data collected in three alpine ecosystems (two forests and one grassland). We evaluated an innovative method for defining the ...