Socio-geographic analysis of the demographic situation in Vinnytsia Oblast: current condition and peculiarities of development

The article contains analysis of the current demographic situation in Vinnytsia Oblast. We determined causes and factors influencing the development of the demographic situation in Vinnytsia Oblast. The paper reveals the specifics of development of the demographic processes in Vinnytsia Oblast according to the data of the Main Statistic Service in Vinnytsia Oblast for the period from 1959 to January 1, 2020. We determined how the totals of the urban and rural populations have changed. Based on the analysis of statistical and literature sources, we researched the specifics of natural movement of population, its sex and age structure, migration, distribution of the employed population and unemployment rate. We provide characteristics of specifics of the territorial differentiation of parameters of birth, death rates, natural increment (decline), migration, sex and age structure in Vinnytsia Oblast. We analyzed the specifics of employment of population in Vinnytsia Oblast, levels of economic activity and unemployment. We etermined modern tendencies of natural movement of the population, its impact on the prospects of further changes. We found out the problems of current demographic development in Vinnytsia Oblast based on determining modern specifics of the demographic parameters of the population in the researched area. The paper suggests ways to improve the demographic situation in Vinnytsia Oblast in the immediate future. As a result of the research, the demographic situation in Vinnytsia oblast was found to be negative. We observed a number of negative tendencies and patterns, including decrease in the rural population; decrease in the birth rate in the period from 1995 to 2020; high death rates due to diseases of blood circulation and malignant tumors; high parameters of aging of the population, especially in rural areas; decrease in the number of the employable population in the Oblast, etc.

Historical Accounts Provide Inference into Population Dynamics of American Kestrels (Falco sparverius) in the Northeastern USA

ABSTRACT American Kestrels (Falco sparverius) are declining across much of North America, yet the initial timing of the population decrease is unclear. In an attempt to elucidate when kestrel declines began, we examined historical descriptions of abundance within the northeastern United States. Within The Peregrine Fund's research library, we found 54 descriptions of kestrel abundance in northeastern states dating from 1839 to 2013. Our analysis indicates a cubic trend in descriptions of kestrel abundance with a peak occurring in 1951. After that peak, the population began its current decline, yet the population appears to have been stable beforehand. That the current decline is apparent in our data set lends credence to our methodology and suggests that populations were likely secure until approximately 1951. Our results thus suggest that populations of American Kestrels in the northeastern United States began declining before systematic monitoring began in 1966. Future research should thus examine what environmental changes occurred around the early- to mid-20th century in the northeastern USA to cause population declines of American Kestrels.

Visualizing Antineoplastic Activity with a Whole Organism Drosophila melanogaster Screen

Cancer is a disease characterized by high mitosis rates with a loss of regulation. Many antineoplastics, those drugs used to treat cancer, act by slowing or halting mitosis. We are developing a whole-organism screening protocol to identify novel antineoplastics. After exposing Drosophila melanogaster eggs and larva to a compound, their growth rate and population decrease if mitosis inhibition or arrest occur. We screened several compounds from the National Cancer Institute’s (NCI) Developmental Therapeutics Program (DTP). Our screen successfully identified two compounds, toyocamycin and stictic acid, previously identified as possible antineoplastics. Toyocamycin killed a fraction of the population proportional to the dose concentration resulting in full mortality at 100 and 200 µM. At low doses, toyocamycin also slowed larval development by a mean of one day. RNAseq showed that no genes were differentially expressed in mature flies after toyocamycin exposure was halted. Stictic acid delayed larval growth by an equal or greater margin compared to toyocamycin. These results demonstrate that decreases in Drosophila growth or population can predict a compound’s antineoplastic activity and toxicity.

Thermal Shock and Ciprofloxacin Act Orthogonally on Pseudomonas aeruginosa Biofilms

Bacterial biofilm infections are a major liability of medical implants, due to their resistance to both antibiotics and host immune response. Thermal shock can kill established biofilms, and some evidence suggests antibiotics may enhance this efficacy, despite having an insufficient effect themselves. The nature of this interaction is unclear, however, complicating efforts to integrate thermal shock into implant infection treatment. This study aimed to determine whether these treatments were truly synergistic or simply orthogonal (i.e., independent). Pseudomonas aeruginosa biofilms of different architectures and stationary-phase population density were subjected to various thermal shocks, antibiotic exposures, or combinations thereof, and examined either immediately after treatment or after subsequent reincubation. Population decreases from the combination treatment matched the product of the decreases of individual treatments, indicating their orthogonality. However, reincubation showed binary behavior, where biofilms with an immediate population decrease beyond a critical factor (~104) died off completely during reincubation, while biofilms with a smaller immediate decrease regrew. This critical factor was independent of the initial population density and the combination of treatments that achieved the immediate decrease. While antibiotics do not appear to enhance thermal shock directly, their contribution to achieving a critical population decrease for biofilm elimination can make the treatments appear strongly synergistic, strongly decreasing the intensity of thermal shock needed.

Histology and structure of the testicles in three species of Atelopus frogs (Anura: Bufonidae) endemic to the Sierra Nevada de Santa Marta, Colombia

Introduction: Testicular histology constitutes one of the least explored aspects in frogs of the genus Atelopus. This taxonomic group shows an alarming population decline; therefore, its reproductive biology is one of the greatest topics of interest for its conservation. Objective: To describe the testicular morphology and the spermatogenetic lineage cells in adult males of Atelopus laetissimus, Atelopus nahumae, and Atelopus carrikeri in the Sierra Nevada de Santa Marta, Colombia. Methods: During June – July 2017 and 2018, sampling was conducted in the localities of San Lorenzo and Páramo Cebolletas, Sierra Nevada de Santa Marta (SNSM), to collect 15 adult males, 5 per species. Testes samples were fixed in Bouin to be processed by the standard paraffin-embedding technique. Histological sections (3 mμ) were stained with Hematoxylin-eosin and Mallory-Heidenhain-Azan-Gomori's. For the description and photographic register of the germ cells, the photonic microscopy technique was used with the differential interference contrast system. Results: The testes are oval organs, compact, light yellow color, and with little vascularization. Externally, they are surrounded by a thin albuginea tunic constituted by regular dense connective tissue. Inside this layer, they are composed of numerous seminiferous tubules of hexagonal contour, in which germ cell cysts are distinguished at different stages of spermatogenesis (spermatogonia I and II, spermatocyte I and II, and early and late spermatids) and spermiogenesis (spermatozoa in fascicles and free spermatozoa). Separating the seminiferous structures is the interstitial tissue in which Leydig cells and blood vessels stand out. Additionally, in the cranial part of the testis, the Bidder's organ was found, formed by two distinguishable regions, the cortex and the medulla. In the cortex, there are previtellogénic oocytes of different sizes surrounded by a monolayer of flat follicular cells. For its part, the medullary region is the connective tissue that nourishes the oocytes and is constituted by blood capillaries. Conclusions: The gonads of the three species analyzed present a cystic cellular organization similar to other anurans, where all stages of spermatogenesis and spermiogenesis were identified, possibly indicating a continuous reproductive activity. Likewise, the Bidder’s organ is reported for the first time in the three Atelopus species, which allows suggesting a possible sexual reversion in case of a population decrease of females as a reproductive strategy.

Hurricane-induced population decrease in a Critically Endangered long-lived reptile

Catastrophic events, like hurricanes, bring lethal conditions that can have population-altering effects. The threatened Caribbean dry forest occurs in a region known for its high-intensity hurricane seasons and high species endemism, highlighting the necessity to better understand hurricane impacts as fragmentation and clearing of natural habitat continues. However, such studies remain rare, and for reptiles are mostly restricted to Anolis. Here we used single-season occupancy modeling to infer the impact of the intense 2017 Atlantic hurricane season on the critically endangered Lesser Antillean Iguana, Iguana delicatissima. We surveyed 30 transects across eight habitats on St. Eustatius during 2017-2019, which resulted in 344 individual surveys and 98 iguana observations. Analyses of abundance and site occupancy indicated both measures for 2018 and 2019 were strongly reduced compared to the pre-hurricane 2017 state. Iguanas at higher elevations were affected more profoundly, likely due to higher wind speeds, tree damage and extensive defoliation. Overall, our results indicate a decrease in population estimates (23.3-26.5%) and abundance (22-23.8%) for 2018 and 2019, and a 75% reduction in the number of opportunistic sightings of tagged iguanas between 2017-2018. As only small and isolated I. delicatissima populations remain, our study further demonstrates their vulnerability to stochastic events. Considering the frequency and intensity of hurricanes are projected to increase, our results stress the urgent need for population-increasing conservation actions in order to secure the long-term survival of I. delicatissima throughout its range.

Amendment to: populations in environments with a soft carrying capacity are eventually extinct

This sharpens the result in the paper Jagers and Zuyev (J Math Biol 81:845–851, 2020): consider a population changing at discrete (but arbitrary and possibly random) time points, the conditional expected change, given the complete past population history being negative, whenever population size exceeds a carrying capacity. Further assume that there is an $$\epsilon > 0$$ ϵ > 0 such that the conditional probability of a population decrease at the next step, given the past, always exceeds $$\epsilon $$ ϵ if the population is not extinct but smaller than the carrying capacity. Then the population must die out.

Declines and recovery in endangered Galapagos pinnipeds during the El Niño event

Currently, the Galapagos sea lion (GSL, Zalophus wollebaeki) and Galapagos fur seal (GFS, Arctocephalus galapagoensis) are among the most important endemic species for conservation in the Galapagos Archipelago. Both are classified as “Endangered” since their populations have undergone drastic declines over the last several decades. In this study we estimated the abundance of both otariids, and their population trends based using counts conducted between 2014 and 2018 in all their rookeries, and we analyzed the influence of environmental variability on pup production. The GSL population size in 2018 in the archipelago was estimated to be between 17,000 to 24,000 individuals and has increased at an average annual rate of 1% over the last five years after applying correction factors. The highest number of GSL counted in the archipelago was in 2014 followed by a population decline of 23.8% in 2015 that was associated with the El Niño event that occurred during that year. Following this event, the population increased mainly in the northern, central and southeastern rookeries. The GSL pup abundance showed a decreasing trend with the increase in intensity of the El Niño. The GFS population in 2018 was counted in 3,093 individuals and has increased at an annual rate of 3% from 2014 to 2018. A high number of GFS counted in 2014 was followed by a population decrease of 38% in 2015, mainly in the western rookeries. There was interannual population fluctuations and different growth trends among regions of the archipelago. GSL and GFS pup abundance has a strong decreasing tendency with the increase in the subthermocline temperature (ST) and the El Niño 1 + 2 index. Our results provide evidence that both species are highly vulnerable to periodic oceanographic-atmospheric events in the Galapagos Archipelago which impact prey abundance and the flow of energy in the unique Galapagos ecosystem.

Admission and Survival Trends in Hedgehogs Admitted to RSPCA Wildlife Rehabilitation Centres

The hedgehog (Erinaceus europaeus) population is in decline in the UK and they are the most frequently admitted mammal to British Wildlife Rehabilitation Centres (WRCs). Whilst successful, UK rehabilitation is time-consuming and expensive and few large-scale studies into UK WRC admission and survival rates have been published in the last decade. This paper examines admission and survival trends in 19,577 hedgehogs admitted to Royal Society for the Prevention of Cruelty to Animals centres over a 13 year period (2005–2017) to gauge the state of Britain’s hedgehogs in WRCs and to gain indirect insight into the wild population. During the studied period, admissions more than doubled. Admission weights were greater in later than early litter juveniles. The survival improved 26% overall, and 33% in juveniles. Twenty two percent of animals died or were euthanased within 48 h of admission. Kaplan–Meier analysis gave survivor functions of 0.78 at 2 days, 0.66 at 10 days, 0.62 at 20 days, and 0.53 at 80 days. Survival was independent of admission weight in each age category. In particular, survival was greater in early litter juveniles than in adults or late litter juveniles; and across the breeding season diminished in juveniles and increased in adults. These data suggest factors impacting hedgehog survival have remained stable despite population decrease; that care methods have improved; and that late litters are more vulnerable than early. For WRCs this reaffirms that current methods are successful, but that further resources could be directed towards late litters.