Life Cycle Stages: The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.Schistosomatidae: A family of blood flukes of the class Trematoda which is found in animals and man. It Includes the genera Heterobilharzia, Schistosomatium, Schistosoma, Ornithobilharzia, Bilharziella, Trichobilharzia, Pseudobilharzia, and Austrobilharzia.Trypanosoma brucei brucei: A hemoflagellate subspecies of parasitic protozoa that causes nagana in domestic and game animals in Africa. It apparently does not infect humans. It is transmitted by bites of tsetse flies (Glossina).Protozoan Proteins: Proteins found in any species of protozoan.DNA, Helminth: Deoxyribonucleic acid that makes up the genetic material of helminths.Sporozoites: The product of meiotic division of zygotes in parasitic protozoa comprising haploid cells. These infective cells invade the host and undergo asexual reproduction producing MEROZOITES (or other forms) and ultimately gametocytes.RNA, Protozoan: Ribonucleic acid in protozoa having regulatory and catalytic roles as well as involvement in protein synthesis.Cell Cycle: The complex series of phenomena, occurring between the end of one CELL DIVISION and the end of the next, by which cellular material is duplicated and then divided between two daughter cells. The cell cycle includes INTERPHASE, which includes G0 PHASE; G1 PHASE; S PHASE; and G2 PHASE, and CELL DIVISION PHASE.Tsetse Flies: Bloodsucking flies of the genus Glossina, found primarily in equatorial Africa. Several species are intermediate hosts of trypanosomes.Host-Parasite Interactions: The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.RNA, Ribosomal, 28S: Constituent of the 60S subunit of eukaryotic ribosomes. 28S rRNA is involved in the initiation of polypeptide synthesis in eukaryotes.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Trypanosoma cruzi: The agent of South American trypanosomiasis or CHAGAS DISEASE. Its vertebrate hosts are man and various domestic and wild animals. Insects of several species are vectors.Quality of Life: A generic concept reflecting concern with the modification and enhancement of life attributes, e.g., physical, political, moral and social environment; the overall condition of a human life.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Plasmodium falciparum: A species of protozoa that is the causal agent of falciparum malaria (MALARIA, FALCIPARUM). It is most prevalent in the tropics and subtropics.Estrous Cycle: The period of cyclic physiological and behavior changes in non-primate female mammals that exhibit ESTRUS. The estrous cycle generally consists of 4 or 5 distinct periods corresponding to the endocrine status (PROESTRUS; ESTRUS; METESTRUS; DIESTRUS; and ANESTRUS).Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Menstrual Cycle: The period from onset of one menstrual bleeding (MENSTRUATION) to the next in an ovulating woman or female primate. The menstrual cycle is regulated by endocrine interactions of the HYPOTHALAMUS; the PITUITARY GLAND; the ovaries; and the genital tract. The menstrual cycle is divided by OVULATION into two phases. Based on the endocrine status of the OVARY, there is a FOLLICULAR PHASE and a LUTEAL PHASE. Based on the response in the ENDOMETRIUM, the menstrual cycle is divided into a proliferative and a secretory phase.Cell Cycle Proteins: Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.Mitosis: A type of CELL NUCLEUS division by means of which the two daughter nuclei normally receive identical complements of the number of CHROMOSOMES of the somatic cells of the species.DNA, Kinetoplast: DNA of kinetoplasts which are specialized MITOCHONDRIA of trypanosomes and related parasitic protozoa within the order KINETOPLASTIDA. Kinetoplast DNA consists of a complex network of numerous catenated rings of two classes; the first being a large number of small DNA duplex rings, called minicircles, approximately 2000 base pairs in length, and the second being several dozen much larger rings, called maxicircles, approximately 37 kb in length.Estrus: The period in the ESTROUS CYCLE associated with maximum sexual receptivity and fertility in non-primate female mammals.Nuclear Transfer Techniques: Methods of implanting a CELL NUCLEUS from a donor cell into an enucleated acceptor cell.G1 Phase: The period of the CELL CYCLE preceding DNA REPLICATION in S PHASE. Subphases of G1 include "competence" (to respond to growth factors), G1a (entry into G1), G1b (progression), and G1c (assembly). Progression through the G1 subphases is effected by limiting growth factors, nutrients, or inhibitors.Genes, Protozoan: The functional hereditary units of protozoa.Cytokinesis: The process by which the CYTOPLASM of a cell is divided.Cell Nucleus: Within a eukaryotic cell, a membrane-limited body which contains chromosomes and one or more nucleoli (CELL NUCLEOLUS). The nuclear membrane consists of a double unit-type membrane which is perforated by a number of pores; the outermost membrane is continuous with the ENDOPLASMIC RETICULUM. A cell may contain more than one nucleus. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)S Phase: Phase of the CELL CYCLE following G1 and preceding G2 when the entire DNA content of the nucleus is replicated. It is achieved by bidirectional replication at multiple sites along each chromosome.Life: The state that distinguishes organisms from inorganic matter, manifested by growth, metabolism, reproduction, and adaptation. It includes the course of existence, the sum of experiences, the mode of existing, or the fact of being. Over the centuries inquiries into the nature of life have crossed the boundaries from philosophy to biology, forensic medicine, anthropology, etc., in creative as well as scientific literature. (Random House Unabridged Dictionary, 2d ed; Dr. James H. Cassedy, NLM History of Medicine Division)Cell Division: The fission of a CELL. It includes CYTOKINESIS, when the CYTOPLASM of a cell is divided, and CELL NUCLEUS DIVISION.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Cell Line: Established cell cultures that have the potential to propagate indefinitely.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.RNA Interference: A gene silencing phenomenon whereby specific dsRNAs (RNA, DOUBLE-STRANDED) trigger the degradation of homologous mRNA (RNA, MESSENGER). The specific dsRNAs are processed into SMALL INTERFERING RNA (siRNA) which serves as a guide for cleavage of the homologous mRNA in the RNA-INDUCED SILENCING COMPLEX. DNA METHYLATION may also be triggered during this process.Transcription, Genetic: The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.G2 Phase: The period of the CELL CYCLE following DNA synthesis (S PHASE) and preceding M PHASE (cell division phase). The CHROMOSOMES are tetraploid in this point.DNA, Protozoan: Deoxyribonucleic acid that makes up the genetic material of protozoa.Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.DNA Replication: The process by which a DNA molecule is duplicated.Progesterone: The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Flow Cytometry: Technique using an instrument system for making, processing, and displaying one or more measurements on individual cells obtained from a cell suspension. Cells are usually stained with one or more fluorescent dyes specific to cell components of interest, e.g., DNA, and fluorescence of each cell is measured as it rapidly transverses the excitation beam (laser or mercury arc lamp). Fluorescence provides a quantitative measure of various biochemical and biophysical properties of the cell, as well as a basis for cell sorting. Other measurable optical parameters include light absorption and light scattering, the latter being applicable to the measurement of cell size, shape, density, granularity, and stain uptake.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Breeding: The production of offspring by selective mating or HYBRIDIZATION, GENETIC in animals or plants.Reference Standards: A basis of value established for the measure of quantity, weight, extent or quality, e.g. weight standards, standard solutions, methods, techniques, and procedures used in diagnosis and therapy.Quercus: A plant genus of the family FAGACEAE that is a source of TANNINS. Do not confuse with Holly (ILEX).Trees: Woody, usually tall, perennial higher plants (Angiosperms, Gymnosperms, and some Pterophyta) having usually a main stem and numerous branches.Sunlight: Irradiation directly from the sun.Photosynthesis: The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide using energy obtained from light rather than from the oxidation of chemical compounds. Photosynthesis comprises two separate processes: the light reactions and the dark reactions. In higher plants; GREEN ALGAE; and CYANOBACTERIA; NADPH and ATP formed by the light reactions drive the dark reactions which result in the fixation of carbon dioxide. (from Oxford Dictionary of Biochemistry and Molecular Biology, 2001)Seeds: The encapsulated embryos of flowering plants. They are used as is or for animal feed because of the high content of concentrated nutrients like starches, proteins, and fats. Rapeseed, cottonseed, and sunflower seed are also produced for the oils (fats) they yield.Life Support Care: Care provided patients requiring extraordinary therapeutic measures in order to sustain and prolong life.

The RD114/simian type D retrovirus receptor is a neutral amino acid transporter. (1/1132)

The RD114/simian type D retroviruses, which include the feline endogenous retrovirus RD114, all strains of simian immunosuppressive type D retroviruses, the avian reticuloendotheliosis group including spleen necrosis virus, and baboon endogenous virus, use a common cell-surface receptor for cell entry. We have used a retroviral cDNA library approach, involving transfer and expression of cDNAs from highly infectable HeLa cells to nonpermissive NIH 3T3 mouse cells, to clone and identify this receptor. The cloned cDNA, denoted RDR, is an allele of the previously cloned neutral amino acid transporter ATB0 (SLC1A5). Both RDR and ATB0 serve as retrovirus receptors and both show specific transport of neutral amino acids. We have localized the receptor by radiation hybrid mapping to a region of about 500-kb pairs on the long arm of human chromosome 19 at q13.3. Infection of cells with RD114/type D retroviruses results in impaired amino acid transport, suggesting a mechanism for virus toxicity and immunosuppression. The identification and functional characterization of this retrovirus receptor provide insight into the retrovirus life cycle and pathogenesis and will be an important tool for optimization of gene therapy using vectors derived from RD114/type D retroviruses.  (+info)

Spontaneous heterosis in larval life-history traits of hemiclonal frog hybrids. (2/1132)

European water frog hybrids Rana esculenta (Rana ridibunda x Rana lessonae) reproduce hemiclonally, transmitting only their ridibunda genome to gametes. We compared fitness-related larval life-history traits of natural R. esculenta from Poland with those of the two sympatric parental species and of newly generated F1 hybrids. Compared with either parental species, F1 hybrid offspring had higher survival, higher early growth rates, a more advanced developmental stage by day 49, and earlier metamorphosis, but similar mass at metamorphosis. R. esculenta from natural lineages had trait values intermediate between those of F1 offspring and of the two parental species. The data support earlier observations on natural R. esculenta that had faster larval growth, earlier metamorphosis, and higher resistance to hypoxic conditions compared with either parental species. Observing larval heterosis in F1 hybrids in survival, growth rate, and time to metamorphosis, however, at an even higher degree than in hybrids from natural lineages, demonstrates that heterosis is spontaneous and results from hybridity per se rather than from subsequent interclonal selection; in natural lineages the effects of hybridity and of clonal history are confounded. This is compelling evidence for spontaneous heterosis in hybrid clonals. Results on hemiclonal fish hybrids (Poeciliopsis) showed no spontaneous heterosis; thus, our frog data are not applicable to all hybrid clonals. Our data do show, however, that heterosis is an important potential source for the extensively observed ecological success of hybrid clonals. We suggest that heterosis and interclonal selection together shape fitness of natural R. esculenta lineages.  (+info)

Evaluation of life-cycle herd efficiency in cow-calf systems of beef production. (3/1132)

A deterministic beef efficiency model (BEM) was used to evaluate life-cycle herd efficiency (LCHE) in cow-calf beef production systems using four breed groups of beef cattle. The breed groups were Beef Synthetic #1 (SY1), Beef Synthetic #2 (SY2), Dairy Synthetic (DS), and purebred Hereford (HE). The LCHE was defined over the lifetime of the herd as the ratio of total output (lean meat equivalent) to total input (feed equivalent). Breed differences in LCHE were predicted with the larger/slower maturing DS being most efficient at each age of herd disposal and reproductive rate. This was mainly because, at any average age at culling, the dams of DS breed group were less mature and so had been carrying relatively lower maintenance loads for shorter periods and positively influencing LCHE. Higher LCHE was predicted with improvement in reproductive performance if there were no associated extra costs. However, this declined markedly if there was a delay in marketing of offspring. As average age at culling increased from 4 to 6 yr, efficiency declined sharply, but it began to recover beyond this age in most breed groups. We concluded that the slower maturing DS breed group may be more efficient on a herd basis in cow-calf systems and that improvements in reproductive rate not associated with extra costs improve life-cycle efficiency. Culling cows soon after their replacements are produced seems efficient.  (+info)

Population biology of human onchocerciasis. (4/1132)

Human onchocerciasis (river blindness) is the filarial infection caused by Onchocerca volvulus and transmitted among people through the bites of the Simulium vector. Some 86 million people around the world are at risk of acquiring the nematode, with 18 million people infected and 600,000 visually impaired, half of them partially or totally blind. 99% of cases occur in tropical Africa; scattered foci exist in Latin America. Until recently control programmes, in operation since 1975, have consisted of antivectorial measures. With the introduction of ivermectin in 1988, safe and effective chemotherapy is now available. With the original Onchocerciasis Control Programme of West Africa coming to an end, both the new African Programme for Onchocerciasis Control and the Onchocerciasis Elimination Programme for the Americas, rely heavily on ivermectin self-sustained mass delivery. In consequence, the need for understanding the processes regulating parasite abundance in human and simuliid populations is of utmost importance. We present a simple mathematical framework built around recent analyses of exposure- and density-dependent processes operating, respectively, within the human and vector hosts. An expression for the basic reproductive ratio, R0, is derived and related to the minimum vector density required for parasite persistence in localities of West Africa in general and northern Cameroon in particular. Model outputs suggest that constraints acting against parasite establishment in both humans and vectors are necessary to reproduce field observations, but those in humans may not fully protect against reinfection. Analyses of host age-profiles of infection prevalence, intensity, and aggregation for increasing levels of endemicity and intensity of transmission in the Vina valley of northern Cameroon are in agreement with these results and discussed in light of novel work on onchocerciasis immunology.  (+info)

Infection status of dragonflies with Plagiorchis muris metacercariae in Korea. (5/1132)

Plagiorchis muris has been found in both house and field rats as well as in humans. The infection status of the second intermediate hosts of P. muris is prerequisite in understanding their biological features in an ecosystem. Six species of dragonflies were caught in a wide range of areas in Korea; and they were Sympetrum darwinianum, S. eroticum, S. pedomontanum, S. infuscatum, Pantala flavoscens, Calopteryx atrata, and Orthetrum albistylum speciosum. The occurrence of P. muris metacercariae in dragonflies was nationwide with various infection rates. The metacercarial burden of P. muris in the surveyed areas was the highest in S. eroticum followed by S. darwinianum, S. pedomontanum, and C. atrata. The highest infection rate by P. muris metacercariae was found in S. darwinianum followed by S. eroticum. The metacercarial burden was particularly heavy in the dragonflies found in Hamyang-gun and Kosong-gun, Kyongsangnam-do. It is, therefore, likely that dragonflies play a significant role as the second intermediate host in the life cycle of P. muris in Korea.  (+info)

The effect of Plasmodium yoelii nigeriensis infection on the feeding persistence of Anopheles stephensi Liston throughout the sporogonic cycle. (6/1132)

Vector-borne parasites such as malaria have been shown to modify the feeding behaviour of their invertebrate hosts so as to increase the probability of transmission. However, evolutionary consideration of developmental changes in malaria within Anopheles mosquitoes suggests that the nature of altered feeding by mosquitoes should differ depending on the developmental stage of the parasite. We present laboratory evidence that the feeding persistence of female Anopheles stephensi towards a human host is decreased in the presence of Plasmodium yoelii nigeriensis oocysts (which cannot be transmitted), but increased when the malaria has developed into transmissible sporozoites in the salivary glands. In ten-minute trials, 33% of uninfected mosquitoes gave up their feeding attempt before the test period had ended, 53% of those harbouring oocysts had given up, but only 20% of those infected with sporozoites gave up by this time. We conclude that changes in feeding behaviour of mosquitoes mediated by parasite infection are sensitive to the developmental stage of the parasite and that these changes have important implications for malaria epidemiology.  (+info)

Stage-specific expression of a Schistosoma mansoni polypeptide similar to the vertebrate regulatory protein stathmin. (7/1132)

The ubiquitous vertebrate protein stathmin is expressed and phosphorylated in response to a variety of external and internal signals. Stathmin, in turn, controls cell growth and differentiation through its capacity to regulate microtubule assembly dynamics. This is the first report on the molecular cloning and characterization of a stathmin-like protein (SmSLP) in an invertebrate, the human blood fluke Schistosoma mansoni. SmSLP is first synthesized at high levels in the intermediate molluscan host and completely disappears 48 h after penetration into the mammalian host. The protein is preferentially iodinated in intact immature parasites using the Bolton-Hunter reagent, can be quantitatively extracted in high salt buffers, and remains soluble after boiling. Native SmSLP was partially sequenced, and its complete structure was derived from the cloning and sequencing of its cDNA. The sequence is up to 26% identical to vertebrate stathmin sequences and contains two potential phosphorylation sites. Native SmSLP is indeed phosphorylated because phosphatase digestion shifts its mobility in electrofocusing gels. SmSLP associates with tubulin, as suggested by immune co-precipitation results. In vitro experiments demonstrated that SmSLP inhibits tubulin assembly and causes the depolymerization of preassembled microtubules, thus probably fulfilling regulatory roles in critical steps of schistosome development.  (+info)

Biology of Triatoma pallidipennis stal 1945 (Hemiptera: Reduviidae:Triatominae) under laboratory conditions. (8/1132)

Aspects related to hatching, life time, mortality, feeding behaviour and fecundity for each stage of Triatoma pallidipennis life-cycle were evaluated. The hatching rate observed for 200 eggs was 60% and the average time of hatching was 18 days. Eighty nymphs (N) (40%) completed the cycle and the average time from NI to adult was 168. 7+/-11.7days. The average span in days for each stage was 18.0 for NI, 18.5 for NII, 30.0 for NIII, 35.7 for NIV and 50.1 for NV. The number of bloodmeals at each nymphal stage varied from 1 to 5. The mortality rate was 9.17 for NI, 5.5 for NII, 6.8 for NIII 4.17 for NIV and 13.04 for NV nymphs. The average number of eggs laid per female in a 9-month period was 498.6. The survival rates of adults were 357+/-217.9 and 262.53+/-167.7 for males and females respectively.  (+info)

  • using a structured methodology for the assessment of maintenance and inspection activities, we can help operators optimise an asset's workload and workforce during late life. (
  • Now, I don't know when I started living the scientific life, but I surprisingly can remember some of my earliest experiments as a little child. (
  • Through early engagement, while an asset is still producing, we begin the process towards an effective decommissioning culture, while at the same time we aim to reduce operating costs, and where possible, extend the asset life to push out the decommissioning liability for as long as possible and maximise planning and preparation. (
  • We offer an integrated capability supporting the late life landscape - from studies and production enhancement activities, brownfield engineering and operations to planning and well plugging and abandonment. (
  • a model focused on helping our clients effectively push out the cessation of production date and extend asset life. (
  • Using our asset management software, BuildME™, we can ensure that safety, environmental and business risks are addressed throughout the asset life cycle by managing maintenance and inspection activities as required. (
  • Over at A blog around the clock Bora summarizes a recent paper which shows the importance of glucocorticoids (cortisol) in the regulation of circadian cell cycle rhythms. (
  • While the details vary with each species, the general life cycle stages are: Egg Discharged either in open water or in intestine of definitive host. (
  • In some species, the redial stage is omitted, and sporocysts produce cercariae. (
  • Instead of the regular yearly cycle of ovulation of most mammal species, rabbits ovulate upon copulation. (
  • To overcome this critical gap, we developed assays to measure activity of antimalarials against all life stages of malaria parasites, using a diverse set of human and nonhuman parasite species, including male gamete production (exflagellation) in Plasmodium falciparum, ookinete development in P. berghei, oocyst development in P. berghei and P. falciparum, and the liver stage of P. yoelii. (
  • To investigate this in the clinically relevant sub-species, Trypanosoma brucei gambiense, which is the causative agent of the fatal human disease African sleeping sickness, we have compared the transcriptome of two different life cycle stages, the potentially human-infective bloodstream forms with the non-human-infective procyclic stage using digital gene expression (DGE) analysis. (
  • Some bird species explicitly mature in this stage, while some don't. (
  • Several closely related webworm species have similar lifecycles and damage symptoms. (
  • The fascinating world of butterflies, and their unique life cycle, exploring specifically the four stages of a butterfly's life, all species of butterflies go through the process of total metamorphosis. (
  • Hinging on, the species of butterfly, the life cycle of a butterfly is possible to be a month, to the complete 12 months. (
  • However, little is known on how those mechanisms and their associated effects on native species change across different life-cycle stages. (
  • Thus, the effect of C. solstitialis on Baccharis species depended on the life-cycle stage at which the interactions occurred. (
  • Trypanosoma brucei developed a sophisticated life cycle to adapt to different host environments. (
  • Here we describe the metabolic labeling of cultured Trypanosoma brucei cells in either the bloodstream or procyclic life cycle stage using stable isotope labeling of amino acids in cell culture (SILAC), and the production of samples suitable for analysis by liquid chromatography tandem mass spectrometry. (
  • The evolutionarily ancient parasite, Trypanosoma brucei, is unusual in that the majority of its genes are regulated post-transcriptionally, leading to the suggestion that transcript abundance of most genes does not vary significantly between different life cycle stages despite the fact that the parasite undergoes substantial cellular remodelling and metabolic changes throughout its complex life cycle. (
  • The activity of genes required to undergo the next stage in cell cycle is checked at these checkpoints by factors called cyclins and are aided by Cyclin-dependent kinases (Cdks), a type of enzymes. (
  • The study of the HPV-16 life cycle and the role of the various viral genes in the life cycle has been hindered by the lack of a cell culture system which supports the viral life cycle. (
  • DGE analysis is extremely sensitive for detecting gene expression differences, revealing firstly that a far greater number of genes are stage-regulated than had previously been identified and secondly and more importantly, this analysis has revealed the existence of several differentially expressed clusters of genes present on what appears to be the same polycistronic units, a phenomenon which had not previously been observed in microarray studies. (
  • Microarray analysis of gene expression during the T. cruzi life-cycle could be a valuable means of identifying drug and vaccine targets based on their appropriate expression patterns, but results from previous microarray studies in T. cruzi and related kinetoplastid parasites have suggested that the transcript abundances of most genes in these organisms do not vary significantly between life-cycle stages. (
  • In contrast to previous microarray studies in kinetoplastids, we observed that relative transcript abundances for over 50% of the genes detected on the T. cruzi microarrays were significantly regulated during the T. cruzi life-cycle. (
  • Thus, microarray analysis is a valuable screening tool for identifying stage-regulated T. cruzi genes and metabolic pathways. (
  • Bucephalus polymorphus Trematode infection Apicomplexa lifecycle stages "2. (
  • As IN plays a pivotal role in establishing infection during the early stages of the retroviral life cycle, it is an attractive target for therapeutic intervention. (
  • Metacercariae set the stage for an infection in animals such as sheep and cattle and in human beings. (
  • A final molt to the sexually immature adult stage occurs approximately 2 months (50 to 70 days) after infection. (
  • Moreover, isoenzyme studies have detected strain makers that in some circumstances permitted to trace back the flow of T. cruzi populations among the domestic and sylvatic infection cycles. (
  • Time-of-addition and synchronized infection assays revealed that POS targets an early stage of the PeV-A3 life cycle. (
  • For both the ancestral strain and two single-substitution strains with down-regulated transcription, we measured seven phenotypic components of fitness (attachment, ejection, eclipse, virion assembly, latent period, lysis rate and burst size) during a single cycle of infection at each of two temperatures. (
  • To understand how these substitutions are improving fitness at the adaptive temperature, we have compared the phenotypic components of fitness during a single cycle of infection between strains that carried single adaptive substitutions and the ancestral strain. (
  • Anthozoa Polyp only Metamorphosis Simple - one free living adult stage, no larval stages Complex - multiple free living adult and / or larval stages (differ in morphology) can be sexually or asexually produced can be 1n or 2n Benthic Polyp (2 n) male female meiosis gametes (n) gametes (n) asex. (
  • Product life cycle management (or PLCM) is the succession of strategies used by business management as a product goes through its developmental life cycle. (
  • Organizational life - cycle: The characteristics of developmental stages in Russian companies created from scratch ," Journal of East European Management Studies , Rainer Hampp Verlag, vol. 14(1), pages 65-85. (
  • All developmental stages in the copepod had unpaired nuclei (were haplophasic), starting with the sporoplasms from the meiospore, continuing as a succession of schizonts undergoing binary division and ending with sporulation, producing a second type of uninucleate spore. (
  • We are primarily interested in small manufacturing plants and problems of development in the early stages of the life cycle. (
  • Intracellular expression of single-chain variable fragments to inhibit early stages of the viral life cycle by targeting human immunodeficiency virus type 1 integrase. (
  • During a panel discussion on challenges that startups typically grapple with in their early stages, Pratyush Jalan, Founder, BoxMySpace, opined that if one's goals aren't laughable, they're not good enough. (
  • To shuttle between these two hosts, trypanosomes differentiate from the so-called bloodstream form (BSF) 1 in the mammalian host to the procyclic form (PCF), which is adapted to life in the insect vector ( 1 ). (
  • At a microscopic level, however, another aspect of the plant life cycle occurs in two distinct stages, known as the diploid sporophyte and haploid gametophyte generations. (
  • Classic economic theory dissects the economic cycle into four distinct stages: Accumulation, Markup, Distribution, and Decline. (
  • Now a team of investigators from the Salk Institute for Biological Studies has illuminated key differences in the mechanisms behind nuclear pores formed at two distinct stages in the cell cycle. (
  • We were able to show for the first time that there are two distinct mechanisms behind how these large protein complexes assemble to accommodate cell cycle-dependent differences in nuclear membrane topology," says Hetzer. (
  • Nymphs are vulnerable as prey to other large predators such as the bats, birds and spiders, and not all nymphs survive this stage. (
  • One unfortunate menopause symptom that many people fall prey to is the belief that life is over after menopause. (
  • The productive stage of the HPV-16 life cycle occurs in the postmitotic suprabasal layers of the epithelium, where the virus amplifies its DNA to high copy number, synthesizes the capsid proteins (L1 and L2), encapsidates the HPV-16 genome, and releases virion particles as the upper layer of the epithelium is shed. (
  • In this layer of the epithelium, the nonproductive stage of the HPV life cycle occurs, where the virus establishes itself as a low-copy-number episome by synthesizing its DNA on average once per cell cycle via a bidirectional theta mode ( 1a , 8 , 12 , 30 ). (
  • The productive stage of the HPV life cycle occurs in the suprabasal layers of the epithelium, where the virus amplifies its DNA to a high copy number. (
  • The host DNA replication machinery is readily available in the proliferating basal layer of the epithelium where the nonproductive stage of the HPV life cycle occurs. (
  • This stage occurs just before winter. (
  • For most women, this stage begins at 10 to 16 years of age, when the first period occurs, to the last normal period, which usually occurs in a woman's 40s or 50s. (
  • Results In this study, we used whole genome, oligonucleotide microarrays to globally determine the extent to which T. cruzi regulates mRNA relative abundances over the course of its complete life-cycle. (
  • T. cruzi is not a homogeneous population and is composed rather by a pool of strains which circulate in both the domestic and sylvatic cycles involving humans, vectors and animal reservoirs of the parasite. (
  • Quantitative comparison of 4364 protein groups identified many proteins previously not known to be stage-specifically expressed. (
  • Methods and Findings: Little is known about the wider stage-specific activities of current antimalarials that were primarily designed to alleviate symptoms of malaria in the blood stage. (
  • By dividing menopause into separate stages, it is easier to identify and address the health issues and symptoms unique to each. (
  • and the graph ends in the decline stage. (
  • Demand takes a downward turn in the decline stage as competing brands or newer products gain market share from yesterday's big sellers. (
  • A DEAD-box RNA helicase, which is highly up-regulated in the bloodstream form of this parasite and which is essential for viability and proper cell cycle progression in this stage is described as an example. (
  • Thus, many stage-specifically expressed proteins are important for infectivity of the mammalian host and are of medical interest as putative drug targets against the parasite. (
  • After stage 2 the small intestine wall is penetrated by the fluke parasite and it enters into the peritoneal cavity. (
  • While effective therapies are available, if malaria is to be eradicated a broader range of small molecule therapeutics that are able to target the liver and the transmissible sexual stages are required. (
  • Although this has previously been extensively analyzed by transcriptomics ( 3 , 4 ), the genomic organization of trypanosomes suggests that transcriptome studies will not reveal a complete picture of adaption of the two life stages. (
  • Demand levels off the maturity stage as most of a product's target market is aware of its availability and has formed their opinions of it. (
  • Here we investigated the effect of a similar mutation isoleucine to phenylalanine (M-I36F) in the prM ectodomain on the virus life cycle of Japanese Encephalitis (JEV) and West Nile (WNV) viruses. (
  • It was not until the 1980s, when the full genetic sequences of viruses began to be unraveled, that researchers began to learn how viruses worked in detail, and exactly what chemicals were needed to thwart their reproductive cycle. (
  • The goal of this study is to investigate the environmental impact from a stage performance in the Göteborg Opera and a stage performance in the Regionteater Väst. (
  • The first three stages occur in water, but the adult is an active flying insect. (
  • To understand how such an extreme change in gene expression might lead to an almost two-fold increase in fitness at the adaptive temperature, we focused on stages in the life cycle of the phage that occur before and after the initiation of transcription. (
  • Down-regulating transcription affects several steps in the phage life cycle, and all of these occur after the initiation of transcription. (
  • After a few days in the pupal stage, the ladybug we are familiar with will emerge. (
  • A mature tree measures more than 30.5 cm (12 inches) in diameter and has begun its reproductive stage. (