Environmental factors shaping ungulate abundances in Poland

Peer reviewedPublisher PD

Czynniki kształtujące płodność samic jelenia (Cervus elaphus) w północno-wschodniej Polsce

Reproduction of mammalian females plays a key role in the population dynamics. Reproductive performance, however, depends on the broad set of extrinsic (weather conditions, food availability, predation, parasites) and intrinsic (population density, age of an individual, body condition, prior reproductive activity) factors. The highest significance is attributed to food availability, which is the main determinant of females’ body condition and their readiness for reproduction. Forage supply, on the other hand, is strongly dependent on the habitat quality and weather conditions. The main aims of this study, conducted in Augustów, Knyszyn and Białowieża Forests (north-eastern Poland) in 2006-2011, were to quantify the reproductive parameters of red deer (Cervus elaphus) females and to determine the factors affecting their fertility. Furthermore, I aimed at assessing the role of the reproductive input in the observed population dynamics under the existing mortality level. Finally, I conducted meta-analysis of the published data to compare some reproduction parameters of deer females from NE Poland with the available literature on other European populations. Reproduction parameters, body condition and the age of red deer females were determined based on 541 samples (female reproductive tracks and jaws) collected in the surveyed woodlands of NE Poland. Fertility of females was assessed by macroscopic examination of ovaries and uteri, while their age was determined based on tooth cementum. Body condition was described by two indices: dressed body mass and percentage of mandible marrow fat. In addition, information on the lactation status of hinds was obtained. Red deer population density in the studied forests was estimated based on drive counts. Environmental factors, which expressed habitat productivity and weather conditions were calculated in GIS from the available data sets (Corine Land Cover 2006, MODIS, GSMap). Finally, the association between reproductive parameters and intrinsic and extrinsic factors was established by incorporating of the statistical techniques including: regression models, correlations, analysis of variance (ANOVA), and generalized linear models (GLMs). Compared to other European populations, red deer in NE Poland occurred at relatively low densities (3.6-6.8 ind./km2), and hinds exhibited high reproductive potential, which was reflected in the high fertility rate (85%), low age of the first reproduction (1.5-year-olds) and lack of reproductive senescence. A clear negative effect of the population density on the hind fertility rate was evidenced at biogeographic scale. The strength of density-dependence in female fertility rates decreased with females’ age. At the population level in the studied woodlands, the body condition and the fertility rate of yearling females was significantly lower compared to older age classes (p < 0.001). Pregnant females had significantly higher body mass and percentage of mandible marrow fat than non-pregnant hinds (p < 0.001). At individual level, probability of hinds to be fertile was affected by their age and body condition. The positive effect of the body mass declined with the mother’s age, while the opposite relationship was proved for the mandible fat content – its effect increased with the age of hinds. The probability of fertility in yearlings was positively associated with the body mass. The probability of fertility in adult females (2-19-year-olds) increased with the growing percentage of marrow fat, and the effect of this factor increased with the female’s age. Environmental factors (low temperature and abundant precipitation in summer) could have a negative, indirect effect on fertility through the body condition of females. The foetus sex ratio was male-biased (1:0.68). Age-specific differences in the body condition of pregnant females showed a tendency that females in better body condition had more males among foetuses, which supported the Trivers-Willard hypothesis. The mortality rate of offspring in the first 6 months of lives was high (41%) and positively associated with the mother’s age (p = 0.02). This could have been the first sign of the reproductive senescence in mothers. Life expectancy of females at birth was low (4.3 years), which was most probably caused by a high level of mortality enforced by wolf (Canis lupus) and lynx (Lynx lynx), other natural factors and hunting harvest. The mortality rate was stable across the female age classes. Younger age classes (1-3 years old females) had the highest contribution to reproduction (46%). On average, females were supposed to produce more male than female offspring during the course of their lives. The reproductive potential of females balanced the losses imposed by mortality factors. Hence, the population of red deer in NE Poland is supposed to be stable. Findings of this study are expected to have practical significance in the deer management and decision making regarding hunting bags.Celem badań, przeprowadzonych w Puszczach Augustowskiej, Knyszyńskiej i Białowieskiej (północno-wschodnia Polska) w latach 2006-2011, było określenie parametrów rozrodczych samic jelenia szlachetnego (Cervus elaphus) oraz czynników kształtujących ich płodność. Parametry rozrodcze określono w oparciu o analizę narządów rozrodczych samic. Łącznie we wszystkich objętych badaniami kompleksach leśnych zebrano 541 prób. W porównaniu z innymi europejskimi populacjami, jelenie w badanych kompleksach leśnych występowały w niskich zagęszczeniach, łanie wykazywały duży potencjał rozrodczy, który był wyrażony wysokim poziomem płodności (85%), wczesnym przystępowaniem do rozrodu (1,5-roczne samice) oraz brakiem spadku płodności z wiekiem. W skali biogeograficznej wykazano, iż poziom płodności łań był ujemnie skorelowany z zagęszczeniem populacji. W północno-wschodniej Polsce prawdopodobieństwo płodności samic wzrastało z ich wiekiem i kondycją. Czynniki środowiskowe (niskie temperatury i obfite opady latem) mogły mieć pośredni, negatywny wpływ na płodność poprzez kondycję samic. Wśród płodów wykazano większy udział płodów męskich (1:0.68). Zależne od wieku różnice w kondycji fizycznej samic wykazywały tendencję, w której łanie w lepszej kondycji fizycznej miały większy udział płodów męskich, co potwierdzałoby hipotezę Triversa Willarda. Poziom śmiertelności cieląt w pierwszych 6 miesiącach życia był wysoki (41%) i wzrastał wraz z wiekiem samic. Oczekiwana długość życia nowo narodzonych samic wynosiła 4,3 roku. Wykazano zbliżony, niezależny od wieku, poziom śmiertelności samic. Młode samice (1-3-letnie) miały największy wkład w rozrodczość populacji (46%). W latach badań rozrodczość bilansowała ubytki powodowane przez śmiertelność, dlatego przewiduje się stabilizację badanej populacji jeleni. Uzyskane wyniki mogą mieć praktyczne zastosowanie w zarządzaniu populacjami jelenia i planowaniu wielkości odstrzałów łowieckich

Characterizing optimal hierarchical policy inference on graphs via non-equilibrium thermodynamics

Hierarchies are of fundamental interest in both stochastic optimal control and biological control due to their facilitation of a range of desirable computational traits in a control algorithm and the possibility that they may form a core principle of sensorimotor and cognitive control systems. However, a theoretically justified construction of state-space hierarchies over all spatial resolutions and their evolution through a policy inference process remains elusive. Here, a formalism for deriving such normative representations of discrete Markov decision processes is introduced in the context of graphs. The resulting hierarchies correspond to a hierarchical policy inference algorithm approximating a discrete gradient flow between state-space trajectory densities generated by the prior and optimal policies.Comment: NIPS 2017 Workshop on Hierarchical Reinforcement Learning. 8 pages, 1 figur

Prolonged ventilation post cardiac surgery - tips and pitfalls of the prediction game

<p>Abstract</p> <p>Background</p> <p>Few available models aim to identify patients at risk of prolonged ventilation after cardiac surgery. We compared prediction models developed in ICU in two adjacent periods of time, when significant changes were observed both in population characteristics and the perioperative management.</p> <p>Methods</p> <p>We performed a retrospective review of two cohorts of patients in our department in two subsequent time periods (July 2007 - December 2008, n = 2165; January 2009 - July 2010, n = 2192). The study was approved by the Institutional Ethics Committee and the individual patient consent was not required. Patients were divided with regard to ventilation time of more or less than 48 hours. Preoperative and procedure-related variables for prolonged ventilation were identified and multivariate logistic regression analysis was performed separately for each cohort.</p> <p>Results</p> <p>Most recent patients were older, with more co-morbidities, more frequently undergoing off-pump surgery. At the beginning of 2009 we also changed the technique of postoperative ventilation. Percentage of patients with prolonged ventilation decreased from 5.7% to 2.4% (p < 0.0001).Preoperative and procedure-related variables for prolonged ventilation were identified. Prediction models for prolonged ventilation were different for each cohort. Most recent significant predictors were: aortic aneurysm surgery (OR 12.9), emergency surgery (OR 5.3), combined procedures (OR 5.1), valve procedures (OR 3.2), preoperative renal dysfunction (OR 2.9) and preoperative stroke or TIA (OR 2.8).</p> <p>Conclusions</p> <p>Prediction models for postoperative ventilation should be regularly updated, particularly when major changes are noted in patients' demographics and surgical or anaesthetic technique.</p

On data collection time by an electronic nose

We use electronic nose data of odor measurements to build machine learning classification models. The presented analysis focused on determining the optimal time of measurement, leading to the best model performance. We observe that the most valuable information for classification is available in data collected at the beginning of adsorption and the beginning of the desorption phase of measurement. We demonstrated that the usage of complex features extracted from the sensors’ response gives better classification performance than use as features only raw values of sensors’ response, normalized by baseline. We use a group shuffling cross-validation approach for determining the reported models’ average accuracy and standard deviation

How do genetic relatedness and spatial proximity shape African swine fever infections in wild boar?

The importance of social and spatial structuring of wildlife populations for disease spread, though widely recognized, is still poorly understood in many host-pathogen systems. In particular, system-specific kin relationships among hosts can create contact heterogeneities and differential disease transmission rates. Here, we investigate how distance-dependent infection risk is influenced by genetic relatedness in a novel host-pathogen system: wild boar (Sus scrofa) and African swine fever (ASF).We hypothesized that infection risk would correlate positively with proximity and relatedness to ASF-infected individuals but expected those relationships to weaken with the distance between individuals due to decay in contact rates and genetic similarity.We genotyped 323 wild boar samples (243 ASF-negative and 80 ASF-positive) collected in north-eastern Poland in 2014–2016 and modelled the effects of geographic distance, genetic relatedness and ASF virus transmission mode (direct or carcass-based) on the probability of ASF infection. Infection risk was positively associated with spatial proximity and genetic relatedness to infected individuals with generally stronger effect of distance. In the high-contact zone (0–2 km), infection risk was shaped by the presence of infected individuals rather than by relatedness to them. In the medium-contact zone (2–5 km), infection risk decreased but was still associated with relatedness and paired infections were more frequent among relatives. At farther distances, infection risk further declined with relatedness and proximity to positive individuals, and was 60% lower among un-related individuals in the no-contact zone (33% in10–20 km) compared among relatives in the high-contact zone (93% in 0–2 km). Transmission mode influenced the relationship between proximity or relatedness and infection risk. Our results indicate that the presence of nearby infected individuals is most important for shaping ASF infection rates through carcass-based transmission, while relatedness plays an important role in shaping transmission rates between live animals

Contemporary genetic structure, phylogeography and past demographic processes of wild boar <i>Sus scrofa</i> population in central and eastern Europe

The wild boar (Sus scrofa) is one of the most widely distributed mammals in Europe. Its demography was affected by various events in the past and today populations are increasing throughout Europe. We examined genetic diversity, structure and population dynamics of wild boar in Central and Eastern Europe. MtDNA control region (664 bp) was sequenced in 254 wild boar from six countries (Poland, Hungary, Belarus, Ukraine, Moldova and the European part of Russia). We detected 16 haplotypes, all known from previous studies in Europe; 14 of them belonged to European 1 (E1) clade, including 13 haplotypes from E1-C and one from E1-A lineages. Two haplotypes belonged respectively to the East Asian and the Near Eastern clade. Both haplotypes were found in Russia and most probably originated from the documented translocations of wild boar. The studied populations showed moderate haplotype (0.714 &#177;0.023) and low nucleotide diversity (0.003 &#177;0.002). SAMOVA grouped the genetic structuring of Central and Eastern European wild boar into three subpopulations, comprising of: (1) north-eastern Belarus and the European part of Russia, (2) Poland, Ukraine, Moldova and most of Belarus, and (3) Hungary. The multimodal mismatch distribution, Fu's Fs index, Bayesian skyline plot and the high occurrence of shared haplotypes among populations did not suggest strong demographic fluctuations in wild boar numbers in the Holocene and pre-Holocene times. This study showed relatively weak genetic diversity and structure in Central and Eastern European wild boar populations and underlined gaps in our knowledge on the role of southern refugia and demographic processes shaping genetic diversity of wild boar in this part of Europe

Odkrywanie w\u142a\u15bciwo\u15bci sieci neuronowych: przy u\u17cyciu program\uf3w w j\u119zyku C#

S\u142owa kluczowe: sieci neuronowe; modelowanie cybernetyczne ludzkiego m\uf3zgu \u2013 neuronowe metody przetwarzania informacji i systemy modeluj\u105ce struktur\u119 ludzkiego m\uf3zgu i zachowanie cz\u142owieka; logika matematyczna; automatyczne rozpoznawanie obraz\uf3w; programy w j\u119zyku C