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Immune activation is an important feature in the development and progression and nonalcoholic fatty liver disease (NAFLD). Macrophages are the most abundant immune cell type in the liver and are implicated in this process. However, intra-hepatic macrophages are a heterogeneous and dynamic population. They can be classified based on ontogeny into : yolk sac-derived tissue-resident macrophages, commonly referred to as Kupffer cells (KCs), and bone marrow (BM) monocyte-derived macrophages.

In terms of fish dynamic population, reproduction is a process related with corporal size of each population member, which is tied with the spawning time and number of eggs produced. In order to relate the size of female little tuny (Euthynnus alletteratus), located in the southwest Gulf of Mexico, and its contribution in reproductive process, cycle and reproductive characteristics were analyzed by different size groups. Biological data were obtained by the artisanal fishing fleet of Antón Lizardo Veracruz community (Mexico). A total of 480 fish were caught from December 2009 to November 2012. Size structure, gonadosomatic index and duration and intensity spawning index (IDI) were determined. The gonadosomatic index showed a decrease in the population after April and July. Nevertheless, these months and the fraction of spawning female may vary depending on size groups. According with the IDI, the individuals with the highest contribution in reproductive process belong to sizes from 44 to 56 cm. Therefore, in order to guarantee the conservation of this species, it is imperative to mainly direct the management measures towards the females from these sizes.

Italian ryegrass (Lolium multiflorum Lam.) is a troublesome weed widely found in temperate Brazilian fields with several herbicide-resistant populations. Soil seed bank is the main source of future infestations and can be strongly affected by agricultural practices, such as crop rotation and tillage system. Therefore, this study evaluated the long-term effects of different crop rotation and tillage systems on the seed bank of Italian ryegrass. Data were collected in 2012 and 2013 in a field managed since 1985 under conventional-tillage and no-tillage and subjected to three cropping systems (monoculture, total, and partial rotation) compared to the control plot. The samples were collected at three soil depths (0-5, 5-10, and 10-20 cm) using a cylindrical soil sampler, and infestations in the field were evaluated with a sample frame of 1 m2. All cropping systems reduced the soil seed bank of Italian ryegrass, regardless of soil management and sampling depths comparing to the control plot. Total and partial rotation were more effective than soil tillage to reduce the seed bank. A larger number of seeds was observed on the surface layer (0-5 cm) for all cropping systems with more uniform distribution in the soil profile in conventional-tillage. Infestation of Italian ryegrass was greater for monoculture under no-tillage in both years, whereas in total and partial rotation, regardless of soil tillage, infestations remained below 40 seedlings m−2. Thus, strategies to reduce the soil seed bank and infestations of Italian ryegrass should focus on cropping systems with crop rotation and no-tillage.

Ancient genomes anchor genealogies in directly observed historical genetic variation, and contextualise ancestral lineages with archaeological insights into their geography and lifestyles. We introduce an extension of theRelatealgorithm to incorporate ancient genomes and reconstruct the joint genealogies of 14 previously published high-coverage ancients and 278 present-day individuals of the Simons Genome Diversity Project. As the majority of ancient genomes are of lower coverage and cannot be directly built into genealogies, we additionally present a fast and scalable method,Colate,for inferring coalescence rates between low-coverage genomes without requiring phasing or imputation. Our method leverages sharing patterns of mutations dated using a genealogy to construct a likelihood, which is maximised using an expectation-maximisation algorithm. We applyColateto 430 ancient human shotgun genomes of >0.5x mean coverage. UsingRelateandColate,we characterise dynamic population structure, such as repeated partial population replacements in Ireland, and gene-flow between early farmer and European hunter-gatherer groups. We further show that the previously reported increase in the TCC/TTC mutation rate, which is strongest in West Eurasians among present-day people, was already widespread across West Eurasia in the Late Glacial Period ~10k - 15k years ago, is strongest in Neolithic and Anatolian farmers, and is remarkably well predicted by the coalescence rates between other genomes and a 10,000-year-old Anatolian individual. This suggests that the driver of this signal originated in ancestors of ancient Anatolia >14k years ago, but was already absent by the Mesolithic and may indicate a genetic link between the Near East and European hunter-gatherer groups in the Late Paleolithic.

The comprehension of the underlying mechanisms of the interactions within microbial communities represents a major challenge to be faced to control their outcome. Joint efforts of in vitro, in vivo and ecological models are crucial to controlling human health, including chronic infections. In a broader perspective, considering that polymicrobial communities are ubiquitous in nature, the understanding of these mechanisms is the groundwork to control and modulate bacterial response to any environmental condition. The reduction of the complex nature of communities of microorganisms to a single bacterial strain could not suffice to recapitulate the in vivo situation observed in mammals. Furthermore, some bacteria can adapt to various physiological or arduous environments embedding themselves in three-dimensional matrices, secluding from the external environment. Considering the increasing awareness that dynamic complex and dynamic population of microorganisms (microbiota), inhabiting different apparatuses, regulate different health states and protect against pathogen infections in a fragile and dynamic equilibrium, we underline the need to produce models to mimic the three-dimensional niches in which bacteria, and microorganisms in general, self-organize within a microbial consortium, strive and compete. This review mainly focuses, as a case study, to lung pathology-related dysbiosis and life-threatening diseases such as cystic fibrosis and bronchiectasis, where the co-presence of different bacteria and the altered 3D-environment, can be considered as worst-cases for chronic polymicrobial infections. We illustrate the state-of-art strategies used to study biofilms and bacterial niches in chronic infections, and multispecies ecological competition. Although far from the rendering of the 3D-environments and the polymicrobial nature of the infections, they represent the starting point to face their complexity. The increase of knowledge respect to the above aspects could positively affect the actual healthcare scenario. Indeed, infections are becoming a serious threat, due to the increasing bacterial resistance and the slow release of novel antibiotics on the market.

Bonefish (Albula vulpes) are popular fish for sports anglers in South Florida. Despite the implementation of catch and release policies, there is concern that numbers are declining. Previous work found a significant downward trend for Bonefish CPUE from 1980 to 2014, and a structural breakpoint in the year 2000. Our objective was to develop and use an age-structured model to explore the relative role of recruitment and changes to adult mortality to explain the decline. Parameters for Bonefish growth, mortality, fecundity and recruitment were compiled from previous research and literature. The CPUE time series from 1980 to 2014 was used to fit the model. Recruit survivorship was responsible for explaining most of the variation in the CPUE time series, while adult survivorship had a significant downward trend. There was no statistically significant structural breakpoint in the survivorship time series, but there was a shift in the mean values in 1998 for adult survivorship and 2008 for recruit survivorship. The shift in adult survivorship is close to the CPUE breakpoint and thus interpreted as driving that change. The fact that there is also a shift in recruit survivorship is cause for concern and warrants continued monitoring of Bonefish populations and research into spawning and recruitment. There is a need to identify biophysical, climatological and habitat variables that are responsible for recruitment and mortality anomalies, and the time series estimates generated in this study will be useful for the analysis of management and conservation decisions in relation to these variables.

Paused RNA polymerase II (Pol II) that piles up near most human promoters is the target of mechanisms that control entry into productive elongation. Whether paused Pol II is a stable or dynamic target remains unresolved. We report that most 5′ paused Pol II throughout the genome is turned over within 2 min. This process is revealed under hypertonic conditions that prevent Pol II recruitment to promoters. This turnover requires cell viability but is not prevented by inhibiting transcription elongation, suggesting that it is mediated at the level of termination. When initiation was prevented by triptolide during recovery from high salt, a novel preinitiated state of Pol II lacking the pausing factor Spt5 accumulated at transcription start sites. We propose that Pol II occupancy near 5′ ends is governed by a cycle of ongoing assembly of preinitiated complexes that transition to pause sites followed by eviction from the DNA template. This model suggests that mechanisms regulating the transition to productive elongation at pause sites operate on a dynamic population of Pol II that is turning over at rates far higher than previously suspected. We suggest that a plausible alternative to elongation control via escape from a stable pause is by escape from premature termination.

Microbiota is an essential community of microorganisms that colonize from birth in different areas of the human body predominantly gut, oral and nasal mucosa, vaginal tract, etc. Is a dynamic population of over a trillion of microbes that include bacteria belonging to the different families, viruses and fungi that interact one with the other, with the local habitat and environment.

This study aimed to assess the applicability of freeze-dried E. faecium NRRL B-2354 (FDE) to evaluate the inactivation efficiency of radio-frequency (RF) pasteurization on wheat flour. FDE was prepared by adding equal volume of 10% skim milk solution as a protectant. Microstructure of FDE was evaluated by scanning and transmission electron microscopy. Thermal resistance parameters of FDE in wheat flour were determined at 75 °C, 80 °C, and 85 °C. A 6 kW, 27.12 MHz RF heating system was used to rapidly pasteurize 3.0 kg wheat flour at 75 °C, 80 °C, and 85 °C, respectively. Population reduction of FDE in the geometric center of flour samples were compared with survivor counts and predicted model. Flour samples were equilibrated to water activity 0.45 measured at 25 °C. The results showed that FDE protected by skim milk were well maintained with repeatable D-values D75°C = 14.27 ± 0.85 min, D80°C = 5.92 ± 0.39 min, and D85°C = 2.79 ± 0.15 min, and z-value of 13.1 °C. RF treatment at 75 °C, 80 °C, and 85 °C for 10 min achieved 1.0-, 2.5-, and 4.9-log reduction of FDE, respectively. In RF pasteurization process, the dynamic population reduction of FDE can be predicted by a model based on F-value. RF treatment provides an effective and rapid approach to inactivate target microorganism in flour samples.

Phylodynamics of Crimean Congo Hemorrhagic fever virus (CCHFV) genotype V in South Russia was analyzed using 244 partial (452–571 nt) sequences in all three genomic segments and 38 complete genomic sequences. Despite increased number of sequences, the Russian lineage of the European genotype V (commonly termed GtVa) was distinct from GtV isolates from Turkey and the Balkan countries. No geographic pattern was observed in phylogenetic subgrouping of CCHFV within South Russia. Identical isolates could be found at distant locations spaced by hundreds of kilometers, while relatively divergent viruses circulated in the same region. Full genome analysis indicated that reassortment events within GtVa occurred every few decades (median half-life of a non-reassortant node 30–40 years) and involved M and S segments. Therefore, in South Russia CCHFV represents a highly dynamic population of frequently reassorting viruses.

Prioritizing habitats for conservation is a challenging task, particularly for species with fluctuating populations and seasonally dynamic habitat needs. Although the use of resource selection models to identify and prioritize habitat for conservation is increasingly common, their ability to characterize important long-term habitats for dynamic populations are variable. To examine how habitats might be prioritized differently if resource selection was directly and dynamically linked with population fluctuations and movement limitations among seasonal habitats, we constructed a spatially explicit individual-based model for a dramatically fluctuating population requiring temporally varying resources. Using greater sage-grouse (Centrocercus urophasianus) in Wyoming as a case study, we used resource selection function maps to guide seasonal movement and habitat selection, but emergent population dynamics and simulated movement limitations modified long-term habitat occupancy. We compared priority habitats in RSF maps to long-term simulated habitat use. We examined the circumstances under which the explicit consideration of movement limitations, in combination with population fluctuations and trends, are likely to alter predictions of important habitats. In doing so, we assessed the future occupancy of protected areas under alternative population and habitat conditions. Habitat prioritizations based on resource selection models alone predicted high use in isolated parcels of habitat and in areas with low connectivity among seasonal habitats. In contrast, results based on more biologically-informed simulations emphasized central and connected areas near high-density populations, sometimes predicted to be low selection value. Dynamic models of habitat use can provide additional biological realism that can extend, and in some cases, contradict habitat use predictions generated from short-term or static resource selection analyses. The explicit inclusion of population dynamics and movement propensities via spatial simulation modeling frameworks may provide an informative means of predicting long-term habitat use, particularly for fluctuating populations with complex seasonal habitat needs. Importantly, our results indicate the possible need to consider habitat selection models as a starting point rather than the common end point for refining and prioritizing habitats for protection for cyclic and highly variable populations.

The middle-temporal area (MT) of primate visual cortex is critical in the analysis of visual motion. Single-unit studies suggest that the response dynamics of neurons within area MT depend on stimulus features, but how these dynamics emerge at the population level, and how feature representations interact, is not clear. Here, we used multivariate classification analysis to study how stimulus features are represented in the spiking activity of populations of neurons in area MT of marmoset monkey. Using representational similarity analysis we distinguished the emerging representations of moving grating and dot field stimuli. We show that representations of stimulus orientation, spatial frequency, and speed are evident near the onset of the population response, while the representation of stimulus direction is slower to emerge and sustained throughout the stimulus-evoked response. We further found a spatiotemporal asymmetry in the emergence of direction representations. Representations for high spatial frequencies and low temporal frequencies are initially orientation dependent, while those for high temporal frequencies and low spatial frequencies are more sensitive to motion direction. Our analyses reveal a complex interplay of feature representations in area MT population response that may explain the stimulus-dependent dynamics of motion vision. NEW & NOTEWORTHY Simultaneous multielectrode recordings can measure population-level codes that previously were only inferred from single-electrode recordings. However, many multielectrode recordings are analyzed using univariate single-electrode analysis approaches, which fail to fully utilize the population-level information. Here, we overcome these limitations by applying multivariate pattern classification analysis and representational similarity analysis to large-scale recordings from middle-temporal area (MT) in marmoset monkeys. Our analyses reveal a dynamic interplay of feature representations in area MT population response.

Se realizó un estudio serológico en busca de anticuerpos contra agentes etiológicos comunes, en gallinas de patio (Gallus gallus) de la aldea El Caoba (AEC), situada en la zona de amortiguamiento de la Reserva de la Biosfera Maya, en Petén, Guatemala. Se tomaron aleatoriamente, muestras de sangre de 39 gallinas. Se buscaron anticuerpos contra el virus de influenza aviar tipo A (VIA), el virus de la enfermedad de Newcastle (VENC), el virus de la enfermedad de Gumboro (VEG), la bacteria Mycoplasma gallisepticum (MG) y la bacteria Salmonella pullorum (SP). El 46%de las gallinas estudiadas portaba anticuerpos contra el VIA; el 51% contra el VENC y el 95% contra el VEG. No se detectaron anticuerpos contra MG ni contra SP. Los anticuerpos contra el VENC se detectaron únicamente durante el muestreo del mes de septiembre. El 31% de las gallinas muestreadas portaba, de manera concomitante, anticuerpos contra tres patógenos (VIA, VENC y VEG) y el 15% contra dos patógenos (VENC y VEG). Se considera que la población dinámica de gallinas de patio de la AEC representa una potencial amenaza para la avicultura artesanal, la avicultura tecnificada, las aves silvestres y la población humana.

Understanding the adaptive responses of individual bacterial strains is crucial for microbiome engineering approaches that introduce new functionalities into complex microbiomes, such as xenobiotic compound metabolism for soil bioremediation. Adaptation requires metabolic reprogramming of the cell, which can be captured by multi-omics, but this data remains formidably challenging to interpret and predict. Here we present a new approach that combines genome-scale metabolic modeling with transcriptomics and exometabolomics, both of which are common tools for studying dynamic population behavior. As a realistic demonstration, we developed a genome-scale model of Pseudomonas veronii 1YdBTEX2, a candidate bioaugmentation agent for accelerated metabolism of mono-aromatic compounds in soil microbiomes, while simultaneously collecting experimental data of P. veronii metabolism during growth phase transitions. Predictions of the P. veronii growth rates and specific metabolic processes from the integrated model closely matched experimental observations. We conclude that integrative and network-based analysis can help build predictive models that accurately capture bacterial adaptation responses. Further development and testing of such models may considerably improve the successful establishment of bacterial inoculants in more complex systems.

The relatively rapid shift from consuming preagricultural wild foods for thousands of years, to consuming postindustrial semi-processed and ultra-processed foods endemic of the Western world less than 200 years ago did not allow for evolutionary adaptation of the commensal microbial species that inhabit the human gastrointestinal (GI) tract, and this has significantly impacted gut health. The human gut microbiota, the diverse and dynamic population of microbes, has been demonstrated to have extensive and important interactions with the digestive, immune, and nervous systems. Western diet-induced dysbiosis of the gut microbiota has been shown to negatively impact human digestive physiology, to have pathogenic effects on the immune system, and, in turn, cause exaggerated neuroinflammation. Given the tremendous amount of evidence linking neuroinflammation with neural dysfunction, it is no surprise that the Western diet has been implicated in the development of many diseases and disorders of the brain, including memory impairments, neurodegenerative disorders, and depression. In this review, we discuss each of these concepts to understand how what we eat can lead to cognitive and psychiatric diseases.

Fringescale sardine (Sardinella fimbriata) is one of important species caught in Prigi waters, Trenggalek, East Java. The existence of fringescale sardine as marine fisheries commodity plays an important role in Prigi fisheries community. This research was conducted in Prigi waters from December 2018 to July 2019 aimed to determine the biological aspects, to illustrate some dynamic population parameters, and to identify food composition. This study applied a descriptive method and random sampling for data collection. There were 1,375 fish have been assessed with total length (TL) ranging from 10 cm to 20.4 cm. Results indicated that growth patterns of the fish was negative allometric with length weight relationship equation was W = 0.014L2.804. Sex ratio of male and female obtained was 1: 1. The gonad maturity level analysis found that proportion of mature and immature fish was equal. The gonadosomatic index value was ranged from 0.57% to 2.42%. The values of length at first capture and length at first mature were 15.35 cm and 16.07 cm, respectively. The growth rate equation obtained in this study was Lt = 26.75 (1-e0.92 (t+0.178)). Mortality rates, total and fishing were 1.709 and 0.286, respectively, while the exploitation rate was 0.167. Additional assessment showed that the main food of the fringescale sardine was phylum Arthropods with index of preponderance (IP) value was 61.5%. It can be concluded that the fish was a plankton feeder and status of the stock was in over fishing condition.

Roughneck Grunt (Haemulopsis corvinaeformis Steindachner, 1868) is the second most important species caught as bycatch of the shrimp fishery in Pernambuco, Northeastern Brazil. However, the population dynamic of this species is poorly known in the region. The aim of this study was to describe aspects of the population structure and reproductive biology of the H. corvinaeformis, providing important information for the development of sustainable management practices. Specimens were collected monthly from August 2011 to July 2012 and quarterly from October 2012 to June 2014. A total of 1,140 individuals was collected; 340 males (29.8%), 391 females (34.3%), and 409 were immature and could not be sexed (35.9%). Total length ranged from 7 to 25 cm. In general, total length of females [12.85 ± 2.49 cm (mean± SD)] and males [12.72 ± 2.46 cm (mean ± SD)] were similar (p > 0.05). The proportion of males and females was similar along the year, except in March. The relationship between total length and total weight was statistically significant (p< 0.05), showing an isometric growth. The (GSI) coupled with the distribution of maturational stages suggests that females reproduce all year around, with a peak during October-November. The length at first maturity (L50) was estimated at 11.88 cm for females and 11 cm for males. RESUMO: O coró branco (Haemulopsis corvinaeformis Steindachner, 1868) é a segunda espécie mais importante capturada como fauna acompanhante na pesca de camarão em Pernambuco, nordeste do Brasil. No entanto, a dinâmica populacional é pouco conhecida na região. O objetivo do estudo foi descrever aspectos da estrutura populacional e biologia reprodutiva da espécie, fornecendo informações importantes para o desenvolvimento de práticas de manejo sustentáveis. Espécimes foram coletados mensalmente de agosto de 2011 a julho de 2012, e a cada três meses de outubro de 2012 a junho de 2014. Um total de 1.140 espécimes foi coletado; 340 machos (29,8%), 391 fêmeas (34,3%), e 409 imaturos cujo sexo não pode ser identificado (35,9%). O comprimento total variou entre 7 e 25 cm. De maneira geral, o comprimento total das fêmeas [12,85 ± 2,49 cm (média ± DP)] e machos [12,72 ± 2,46 cm (média ± DP)] foram similares (p > 0.05). A proporção de machos e fêmeas foi similar, com exceção de março. As relações entre comprimento total e peso total foram estatisticamente significantes (p< 0.05), mostrando um crescimento isométrico. O índice gonadossomático (GSI) associado com a distribuição dos estágios maturacionais sugerem que as fêmeas reproduzem durante todo o ano, com um pico durante outubro-novembro. O tamanho de primeira maturação foi estimado em 11.88 cm para fêmeas e 11 cm para machos.

Next-generation whole genome sequencing data is currently being utilised to explore Mycobacterium tuberculosis genetic diversity. Studies have focused in particular on the evolution of drug resistance, and have revealed a surprising degree of dynamic population heterogeneity, with implications for transmission studies, treatment regimens and new drug target development.

The critique by Hargrove et al. (Popul Ecol, 2011) of our recently published paper on a tsetse population model (Barclay and Vreysen in Popul Ecol 53:89–110, 2011) has made some good points but has also misinterpreted the intent of some of our results as we presented them. Hargrove et al. rightly say that there is a mismatch between the size of the unit cells in the model (1 ha) and the iteration rate of the model (every 5 days), yielding too low a dispersal rate to simulate reality. However, they have misconstrued several of our results that we presented as examples to imply that those results were a necessary condition for control of tsetse, especially using traps and targets.

Materials of preliminary investigations of the life strategy of mykiss Parasalmo mykiss and trout Salmo trutta introduced to water bodies of Chili are considered. Analysis of the structure of scales demonstrated that, in mykiss and trout, the estuarine and riverine-estuarine types of life strategy prevail. This seems to be related to good feeding conditions in fjords. The hypothesis is suggested that, in the area of Chilean fjords, the successful introduction to rivers and artificial rearing in cages in brackish water resulted in the formation of a peculiar and highly dynamic population system. Elements of this system are from both fish of natural self-reproducing populations and fish grown in cages. There is a continuous exchange with genetic information between them as the fish that have escaped from cages attain maturity, arrive to rivers for spawning, and reproduce together with wild fish.

Consider a dynamic population system in which the species are competing for finite resources. Due to demographic stochasticity, the system is inevitably forced to extinction, regardless of the initial count of species. Extinction is the event when either all resources are exhausted or all the competing species disappear. By collecting noisy and sporadic measurements of the quantity of available resources over a certain period of time, we can predict theoretically the probability density function of extinction time. This problem is cast in the framework of a stochastic, multipredator, single-prey Lotka-Volterra (LV) system, whose parameters are estimated using the particle Markov Chain Monte Carlo (pMCMC) method. The proposed algorithm is illustrated by numerical simulations involving three competing predators.

It is often difficult to estimate abundance for a dynamic population, i.e., one that is moving through the survey area or in which birth or mortality rates are high. One approach is to estimate the proportion of animals present during each survey, using a model that estimates the dynamics of the survey proportion of the population. However, this can increase the uncertainty of the estimates if the dynamics parameters are not well estimated. Here we approached this problem by developing methods using hierarchical model structures, which allow us to share information on the dynamics parameters across years. We applied this modeling approach to the estimation of residence time and spawning biomass for New Zealand hoki (Macruronus novaezelandiae) in Cook Strait spawning grounds. By sharing parameters across years, we obtained better parameter estimates than by the traditional assumption that the dynamics in one year are independent of those of other years. By integrating the estimation of residence time into ...

Almost all influenza surveillance systems of temperate countries report a single influenza illness peak each winter. Although several strains of different types or subtypes may co-circulate, they exceptionally lead to two distinct illness peaks during the same winter. We hypothesize that cross-protection between the different strains can, by itself, explain this absence of succeeding illness peaks. We used a dynamic population model to describe the spread of two influenza strains during one season. Cross-protection is included through a parameter defined as the reduction of host risk of infection to one strain after infection with another strain. Different scenarios are performed with two strains emerging with different time-lags, for different levels of cross-protection. We show that a cross-protection of 50% between the two strains is sufficient to explain why we observe a single influenza illness peak in temperate countries.

Summary 1. Dispersal parameters are critical for modelling spatially dynamic populations yet remain among the most difficult to quantify. Linyphiid spider aerial dispersal by ‘ballooning’ on silk threads is dependent on meteorological factors and amenable to analysis and quantification. 2. Spider aerial activity was measured during consecutive 10-min periods for up to 11 h a day. Aerial density was measured at four heights using sticky traps. The time intervals between successive flights were measured by observing spiders landing and taking-off. 3. Meteorological measurements (wind speeds and temperatures) were taken simultaneously with the collection of airborne spiders, and used to calculate Richardson numbers to estimate atmospheric turbulence. 4. Numbers of airborne spiders on any given day, and their vertical density profile on different days, were significantly correlated with Richardson numbers. 5. Single flight distances were modelled using estimates of ascent and descent rates, the vertical density profile of airborne spiders and the wind speeds they experience aloft. The distributions of single flight distances and the time spent between successive flights were combined in an alternating renewal process to model the number of flights and the total daily dispersal distances of ballooning spiders as a function of available dispersal time. 6. On a day with, for example, 6 h of suitable weather, linyphiid spiders can potentially disperse a mean distance of approximately 30 km downwind. 7. Synthesis and applications . We have developed a dispersal model of linyphiid spiders that is central to the further development of spatially dynamic population models of these spiders in agricultural landscapes. It could also be adapted for application to other wind-borne organisms. Such models have a key role in the future management of sustainable agricultural systems where natural predators are seen as major components of pest control.

The structure, and assumed parameter values, of a recent dynamic population model for tsetse (Diptera: Glossinidae) render it unable to fit published data on tsetse control programs using odor-baited targets, insecticide-treated cattle and the sterile insect technique (SIT). The underlying problem is a mismatch between the small size of the mapped cells (1 ha) and the long time-step, which allows flies to move only once every 5 days, and then only to an adjacent cell. Assumed rates of tsetse dispersal and killing by odor-baited targets are consequently at least an order of magnitude lower than observed in the field. Suggestions that Glossina pallidipes could be eradicated more rapidly with SIT, than using hundreds of targets per km2, is contradicted both by the field data and by three other independent modeling studies.

Research into the genomics of schizophrenia promises much, but so far is resplendent with failures to replicate, and has yielded little of therapeutic potential. Within our bodies resides a dynamic population of gut microbes forming a symbiotic superorganism comprising a myriad of bacteria of approximately 10(14) cells, containing 100 times the number of genes of the human genome and weighing approximately the same as the human brain. Recent preclinical investigations indicate that these microbes majorly impact on cognitive function and fundamental behavior patterns, such as social interaction and stress management. We are pivotally dependent on the neuroactive substances produced by such bacteria. The biological diversity of this ecosystem is established in the initial months of life and is highly impacted upon by environmental factors. To date, this vast quantity of DNA has been largely ignored in schizophrenia research. Perhaps it is time to reconsider this omission.

Demographic composition and dynamics of animal and human populations are important determinants for the transmission dynamics of infectious disease and for the effect of infectious disease or environmental disasters on productivity. In many circumstances, demographic data are not available or of poor quality. Since 1999 Switzerland has been recording cattle movements, births, deaths and slaughter in an animal movement database (AMD). The data present in the AMD offers the opportunity for analysing and understanding the dynamic of the Swiss cattle population. A dynamic population model can serve as a building block for future disease transmission models and help policy makers in developing strategies regarding animal health, animal welfare, livestock management and productivity. The Swiss cattle population was therefore modelled using a system of ordinary differential equations. The model was stratified by production type (dairy or beef), age and gender (male and female calves: 0-1 year, heifers and young bulls: 1-2 years, cows and bulls: older than 2 years). The simulation of the Swiss cattle population reflects the observed pattern accurately. Parameters were optimized on the basis of the goodness-of-fit (using the Powell algorithm). The fitted rates were compared with calculated rates from the AMD and differed only marginally. This gives confidence in the fitted rates of parameters that are not directly deductible from the AMD (e.g. the proportion of calves that are moved from the dairy system to fattening plants).

Studies have focused on the roles of the gonadotrope subsets defined by cytochemical and morphological tools. The evidence points to groups of gonadotropes that may be stimulated to mature and secrete to support surge activity. We postulate that these gonadotropes stem from the medium-sized subset. Other gonadotropes may more involved with maintenance functions. Perhaps these come from the larger cell pools. Monohormonal gonadotropes may play unique roles, such as FSH secretion early in estrus. Some may be immature, others may be regulatory and play both paracrine or autocrine roles in the pituitary cell population. We also recognize that one of the limitations of the current-day cytochemical techniques is that it does not define the entire gonadotrope population in any given two-label protocol. Nevertheless, based on past cytochemical studies, assumptions are made about the extent to which the cells express both hormones or behave in a uniform manner. These assumptions have led researchers to focus on one subset of the gonadotrope population. In their attempts to simplify the population to be studied, they may have eliminated important regulatory, secretory, or monohormonal gonadotropes from the pool. The approach is valid, as long as they recognize that they are studying a subset of a complex and dynamic population.

Consider a uniformly mixing population which grows as a super-critical linear birth and death process. At some time an infectious disease (of SIR or SEIR type) is introduced by one individual being infected from outside. It is shown that three different scenarios may occur: 1) an epidemic never takes off, 2) an epidemic gets going and grows but at a slower rate than the community thus still being negligible in terms of population fractions, or 3) an epidemic takes off and grows quicker than the community eventually leading to an endemic equilibrium. Depending on the parameter values, either scenario 1 is the only possibility, both scenario 1 and 2 are possible, or scenario 1 and 3 are possible., 11 pages

A method for predicting response to selection and inbreeding depression in a dynamic population for amount of inbreeding was derived and illustrated with an example of selection under full-sib mating.

The objective of this research was to investigate the dynamics of population, productivity, and output of Bali cattle in region of Kepulauan Yapen Regency, Papua Province. The research was carried out for 3 months, started inJuly until September 2009. The materials included 103 farmers as the respondent and 211 heads of Bali cattle. The result showed that reproductive efficiency (RE) was 88.38%, natural increase (NI) 18.18% and net replacement ratevalue (NRR) of Bali cattle male and female were 234.28% and 189.59% each. The potency and compotition of Bali cattle being exported every year without disturbing the existing population was about 13.11% equal to 354 cattle,consist of the remains of replacement stock (male cattle) about 4.27% equal to 115 cattle, culled not productive cattle of 3.18% male equal to 86 cattle and 5.67% for female equal to 153 cattle. Dynamic population of Bali cattle from 2004 until 2008 increased 6.6% per year in average and in 2013 population is estimated to be 3,028 cattle with the potency of about 2,153 cattle.(Keywords: Male Bali cattle, Population dynamics, Productivity)

The intestinal microbiota, which is a complex and dynamic population of different bacterial species, represents an important contribution to the health of the host. This microbiota plays a key role by promoting the integrity of the epithelial barrier and the development of mucosal immunity. However, under some stressful situations, such as after gastrointestinal surgery, infectious complications may originate from the intestinal microbiota of the patient. This phenomenon is known as the gut origin of sepsis hypothesis. However, the supply of probiotics has beneficial effects under similar conditions despite some controversial results. Therefore, it is important to carefully assess the efficacy of probiotics in the prevention and treatment of complications in surgical patients and to evaluate the safety of its use. This review provides an overview of the proposed mechanisms of probiotic action and the significant progress in this field, mainly concerning gastrointestinal surgery.

Adult stem cells of the mammary gland (MaSCs) are a highly dynamic population of cells that are responsible for the generation of the gland during puberty and its expansion during pregnancy. In recent years significant advances have been made in understanding how these cells are regulated during these developmentally important processes both in humans and in mice. Understanding how MaSCs are regulated is becoming a particularly important area of research, given that they may be particularly susceptible targets for transformation in breast cancer. Here, we summarize the identification of MaSCs, how they are regulated and the evidence for their serving as the origins of breast cancer. In particular, we focus on how changes in MaSC populations may explain both the increased risk of developing aggressive ER/PR(-) breast cancer shortly after pregnancy and the long-term decreased risk of developing ER/PR(+) tumors.

Consider a community of various species newly introduced into a stable environment. Evolutionary processes acting on this community will produce, over time, a community of surviving species. Methods for predicting the evolutionarily stable strategies (ESSs) used by the surviving species are now available for a large class of dynamic population models. Here we expand a previously developed evolutionary game theory, which can be used to predict ESSs in a large class of models, by introducing strategy dynamics. By so doing, a more complete description of the evolutionary process is obtained. One not only obtains a convenient way of determining evolutionarily stable strategies, but interesting features about the evolutionary process itself can be observed. Of particular interest here, we show that the number of strategies which are evolutionarily stable can change as certain environmental factors involved with the model change. The process by which the ESS is formed is examined in terms of an "adaptive landscape" formed by our fitness generating function ( G -function). The G -function has properties that enhance the likelihood that the various adaptive peaks will be occupied.

A method to determine the mortality effects of a hydrophobic chemical on a population is proposed. The ecotoxicological protocol is based on individual organism response and is derived from the static theory of “survival of the fattest.” This study, focusing upon effects of mortality and the effects of toxicant stress on population succession, examines the static assessment survival of the fattest in a dynamic population model. A premise in this approach is that risk assessment should not be based solely upon chemical properties of the toxicant and that the biology of the exposed organisms is an important factor in the determination of effects.

Study of biology and population dynamic of banana shrimp (Penaeus merguiensis) in Tarakan waters, East Borneo was carried out from January to November 2012. The aim of this research was to identify the biological aspects and population dynamics of banana shrimp. For estimating dynamic population, data were analysed using FiSAT II. The result showed that length at first capture (Lc) of banana shrimp by mini trawl (pukat hela) was 35 mm and the size at first maturity (Lm) was 33,86 mm in carapace length. Spawning occured all year around and reached it’s peak in March. The growth coefficient (K) of banana shrimp was 1,45/year with carapace asymptotic length (CL”) of 80 mm. Total mortality rate (Z) and natural mortality rate (M) were 4,85/year and 1,76/year. While fishing mortality rate (F) and exploitation rate (E) were 3,09/year and 0,64, respectively. The exploitation rate of banana shrimp in Tarakan waters tended to be overexploited so that it needed to be managed wisely and carefully by reducing the fishing effort and fishing season especially on spawning season. The recruitment peak of banana shrimp occured in May.

The oral bacterial community appears to use coaggregation as a major mechanism for interbacterial adhesion and colonization of the host. Methods for measuring and evaluating the specificity of adhesion vary from the visual observation of the phenomenon to quantitative analyses. Not only is aggregation specificity reflected in the choice of partners but also in the fact that many are inhibited by galactosides and sialic acid. Each coaggregation between any two partners within a multigeneric coaggregate is independent of the others and can be shown to be distinct by using the radioactivity-based assay. By using the visual assay, it has been shown that members of the 17 genera of most frequently isolated oral bacteria exhibit coaggregation. With the exception of oral streptococci and a few oral actinomyces, the 17 genera do not exhibit intrageneric coaggregation. As a dynamic population, oral bacteria are in a constant flux of accretion and detachment, which are coupled to growth and death. This ecological community is amenable to intensive study, and the coaggregation assays described here are particularly suited to enhance progress in this study.

Objectives Workers exposed to pigs can develop meningitis, sepsis or endocarditis due to infection with Streptococcus suis transmitted from pigs to man. The aim of our study was to estimate the risk of these diseases in workers exposed to pigs. Methods We used the Occupational Hospital Register (OHR) which holds information about occupation and hospital treatments for all adults in Denmark. A dynamic population of male workers exposed to pigs was identified every year from 1995 to 2006 by occupational and industrial group. First hospital treatment or death in the following year due to meningitis, sepsis or endocarditis was identified by ICD10-codes from the OHR. By comparison with all other economically active men in Denmark, the standardised incidence ratio (SIR) was calculated for these diseases. Results Among those exposed we observed 32 cases of meningitis, sepsis and endocarditis during 140 118 person years. In the reference group we observed 2680 cases during 15 209 394 person years. The SIR of the exposed group was 1.35 (95% CI: 0.95 to 1.92). Among the 32 cases 7 cases of meningitis and sepsis were specified as caused by infection with streptococci. The SIR for these seven cases was 2.4 (95% CI. 1.1 to 5.0). Conclusions Our study did not find that workers exposed to pigs had an overall increased risk of developing meningitis, sepsis or endocarditis.

Genetic models of subdivided populations usually assume highly simplified fixed population structures. Studies of social groups of rhesus monkeys (Macaca mulatta) and hamadryas baboons (Papio hamadryas) indicate that populations of these monkeys possess complex, distinctive, highly dynamic population structures. The lack of correspondence between assumptions of ordinary genetic models and observations on real monkey populations seems sufficiently great that existing genetic models for subdivided populations cannot serve as theories for monkey populations. It is suggested that more adequate representations of genetic structures of populations of social species will be built with formalisms borrowed from linguistic and computer sciences.

Spruce beetles (D. rufipennis) from a population homogeneous with respect to population quality were subjected to different degrees of competition at corresponding stages of their reproductive cycles by varying the spacing of individuals and by varying the time of introduction of individuals into the competitive environment. Competition effects increase with gallery accumulation, as suggested in previous studies, and result in subsequent reduction of gallery production and oviposition. Increase in individual beetle quality, however, confers increased powers of resistance to the competition effects. Initial egg-free length is an unsuitable attribute for comparisons of populations. Expression of reproductive efficiency is a dynamic population characteristic which varies over the reproductive cycle, and which may be readily estimated by measurement of yolk deposition rate. For comparing populations, such measurements would be more valuable when carried out before the onset of competition effects. Individuals with the highest quality at the start of the egg-production cycle exhibit the highest reproductive efficiency as conditions change.

A previous article [1] presents a simulation model for modeling complex interactions between a dynamic population and its environment. In that article alleles are represented by an ordered pair ( a i , x i ) where the first member a i defines an enzyme (or enzymes) and the second member x i defines a “linkage” factor. In the present article, this model is used to study the process of selection on the crossover probabilities in a small population. It is found that strong selective forces are necessary to drive such a population. These include the possibility of a relatively large number of offspring for a given mating and broad mortality procedures. They are necessary in the face of the stochastic effects to which a small population is subject.

A model is presented which describes the effect of sterile male release on a wild population. This model is not subject to restrictions, such as equal competitiveness between normal and sterile males and sperm nor to insect species whose females mate only once. The model is an approximation as it assumes constancy in several dynamic population variables. However, it has application in determining the approximate effects of sterile male release and in decisions on the number of sterile males required for release programs. It also has uses in ecological research.

In this paper a set of more-detailed multiregional population accounts is proposed to specify more realistically the exposure time of populations at risk for various components of population change. The concepts of population-time at risk and forward demographic rates based on the initial population are discussed. The relations of the forward demographic rates defined in this paper with the occurrence-exposure demographic rates are discussed. A more precise and straightforward multiregional population model is developed on the basis of forward demographic rates. The model is also expressed in the familiar matrix form of multiregional cohort-survival models. Some applications of the model are made to data for China. (EXCERPT)

A quantitative analysis of the retinal pigment epithelium (RPE) was accomplished by examining ten eyes obtained postmortem from eight individuals between the ages of four months of gestation and 96 years. The RPE was found to consist of a dynamic population of cells which change in number and dimensions as a function of age and location in the eye. The total number of RPE cells per eye was estimated at 4.2 to 6.1 million with greater numbers in older eyes. The degenerative changes involving the peripheral RPE were postulated to be the result of a disparity between the rate of growth of the RPE and the sclera in this region.