Extinction Processes Research Articles

Locus coeruleus input-modulated reactivation of dentate gyrus opioid-withdrawal engrams promotes extinction.

Extinction training during the reconsolidation window following memory recall is an effective behavioral pattern for promoting the extinction of pathological memory. However, promoted extinction by recall-extinction procedure has not been universally replicated in different studies. One potential reason for this may relate to whether initially acquired memory is successfully activated. Thus, the methods for inducing the memory into an active or plastic condition may contribute to promoting its extinction. The aim of this study is to find and demonstrate a manipulatable neural circuit that engages in the memory recall process and where its activation improves the extinction process through recall-extinction procedure. Here, naloxone-precipitated conditioned place aversion (CPA) in morphine-dependent mice was mainly used as a pathological memory model. We found that the locus coeruleus (LC)-dentate gyrus (DG) circuit was necessary for CPA memory recall and that artificial activation of LC inputs to the DG just prior to initiating a recall-extinction procedure significantly promoted extinction learning. We also found that activating this circuit caused an increase in the ensemble size of DG engram cells activated during the extinction, which was confirmed by a cFos targeted strategy to label cells combined with immunohistochemical and in vivo calcium imaging techniques. Collectively, our data uncover that the recall experience is important for updating the memory during the reconsolidation window; they also suggest a promising neural circuit or target based on the recall-extinction procedure for weakening pathological aversion memory, such as opioid withdrawal memory and fear memory.

A Systematic Review of Fear Learning, Extinction Learning, and Reversal Learning in Obsessive-Compulsive Disorder: Implications for Treatment.

Objective: Given the implications in the etiology and treatment of obsessive-compulsive disorder (OCD), this systematic review examined fear acquisition, extinction learning, and reversal learning processes in individuals with OCD.Data Sources: In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, PubMed (1946-October 26, 2021), PsycInfo, and Embase were searched for empirical studies utilizing classical or reversal learning paradigms to compare learning and extinction processes in individuals with and without OCD.Study Selection: A total of 15,603 articles (7,761 from PubMed, 1,128 from PsycInfo, 6,711 from Embase, 3 from citation review) were identified. Articles were screened for duplicates and inclusion/exclusion criteria. Eleven studies met all inclusion/exclusion criteria.Results: Across studies, minimal evidence of abnormal fear learning was found. However, developmental differences emerged for extinction learning. Youth with OCD displayed impaired extinction learning and safety signal discrimination. Meanwhile, adults largely showed deficits in extinction recall. Conflicting findings emerged regarding impairments in reversal learning. Across learning processes, neuroimaging data implicated the importance of the ventromedial prefrontal cortex (vmPFC).Conclusions: The physiological and neuroimaging data suggest that extinction learning impairment varies across development. Notably, key associative learning processes remain largely unexamined. Findings underlying abnormalities in extinction learning suggest the potential of novel therapeutic approaches, such as neuromodulation and psychotherapy augmentation strategies (ie, attention bias modification training), to precisely target and resolve identified deficits.

Manifesto: Fertilizing mourning – Global South’s offering to a world in flames

This manifesto takes the coincidence of Peru’s and Greece’s bicentennials of independence, and their overlap with the COVID-19 pandemic, as a departure point, in order to propose a different understanding of mourning from the Global South. The article is an open invitation to reinforce mourning’s capacity to be a reproductive life force, responding to contemporary experiences of loss in the face of the COVID-19 pandemic and the accelerated processes of extinction, especially in resource extraction zones, like the Amazon. Taking inspiration from ancient Indigenous techniques for soil regeneration, fertilizing mourning is a call to merge traditional knowledge, collective practices and non-anthropocentric world-views that resist individualism and capitalism both in the Global South and in places that defend communal life in the north of the planet. This manifesto proposes that to transform prevalent colonial, modern structures, it is necessary to develop a different relationship with nature, by reconsidering the entanglements between life, death and regeneration.

Mapping species diversification metrics in macroecology: Prospects and challenges

The intersection of macroecology and macroevolution is one of today’s most active research in biology. In the last decade, we have witnessed a steady increment of macroecological studies that use metrics attempting to capture macroevolutionary processes to explain present-day biodiversity patterns. Evolutionary explanations of current species richness gradients are fundamental for understanding how diversity accumulates in a region. Although multiple hypotheses have been proposed to explain the patterns we observe in nature, it is well-known that the present-day diversity patterns result from speciation, extinction, colonization from nearby areas, or a combination of these macroevolutionary processes. Whether these metrics capture macroevolutionary processes across space is unknown. Some tip-rate metrics calculated directly from a phylogenetic tree (e.g., mean root distance -MRD-; mean diversification rate -mDR-) seem to return very similar geographical patterns regardless of how they are estimated (e.g., using branch lengths explicitly or not). Model-based tip-rate metrics —those estimated using macroevolutionary mixtures, e.g., the BAMM approach— seem to provide better net diversification estimates than only speciation rates. We argue that the lack of appropriate estimates of extinction and dispersal rates in phylogenetic trees may strongly limit our inferences about how species richness gradients have emerged at spatial and temporal scales. Here, we present a literature review about this topic and empirical comparisons between select taxa with several of these metrics. We implemented a simple null model approach to evaluate whether mapping of these metrics deviates from a random sampling process. We show that phylogenetic metrics by themselves are relatively poor at capturing speciation, extinction, and dispersal processes across geographical gradients. Furthermore, we provide evidence of how parametric biogeographic methods can improve our inference of past events and, therefore, our conclusions about the evolutionary processes driving biodiversity patterns. We recommend that further studies include several approaches simultaneously (e.g., spatial diversification modeling, parametric biogeographic methods, simulations) to disentangle the relative role of speciation, extinction, and dispersal in the generation and maintenance of species richness gradients at regional and global scales.

Interactions between a propagating detonation wave and circular water cloud in hydrogen/air mixture

Interactions between a propagating hydrogen/air detonation wave and circular water cloud are studied. Eulerian-Lagrangian method involving two-way gas-droplet coupling is applied. Different droplet (diameter, concentration) and cloud (diameter) properties are considered. Results show that droplet size, concentration and cloud radius have significant effects on peak pressure trajectory of the detonation wave. Three propagation modes are identified: perturbed propagation, leeward re-detonation, and detonation extinction. Leeward re-detonation is analyzed from unsteady evolutions of gas and liquid droplet quantities. The detonation is re-initiated by a local hot spot from shock focusing of upper and lower diffracted detonations. Disintegration of water droplets proceeds when the detonation wave crosses the cloud. In addition, detonation extinction is featured by quickly fading peak pressure trajectories when the detonation wave passes the larger cloud, and no local autoignition occurs in the shock focusing area. Evolutions of thermochemical structures from the shocked area in an extinction process are also studied. The transfer rates of mass, energy and momentum of detonation success and failure are analyzed. Moreover, parametric studies demonstrate that the critical cloud size to quench a detonation decreases when the droplet concentration is increased. However, when the droplet concentration is beyond 0.84 kg/m3, the critical cloud size is negligibly influenced due to small droplets. Two-phase fluid interfacial instability is observed, and the mechanism of cloud evolution is studied with the distributions of droplet, vorticity, density / pressure gradient magnitudes, and gas velocity. Analysis confirms that velocity difference (due to two-phase momentum exchange) dominates the formation of large-scale vortices from the southern and northern poles, corresponding to Kelvin–Helmholtz instability. Moreover, the influences of effective Atwood number on the evolutions of cloud morphology, vorticity, and gas velocity are evaluated. Results show that higher droplet concentration results in wider droplet dispersion range due to larger vortices.

The Shape of Phylogenies Under Phase-Type Distributed Times to Speciation and Extinction

Phylogenetic trees describe relationships between extant species, but beyond that their shape and their relative branch lengths can provide information on broader evolutionary processes of speciation and extinction. However, currently many of the most widely used macro-evolutionary models make predictions about the shapes of phylogenetic trees that differ considerably from what is observed in empirical phylogenies. Here, we propose a flexible and biologically plausible macroevolutionary model for phylogenetic trees where times to speciation or extinction events are drawn from a Coxian phase-type (PH) distribution. First, we show that different choices of parameters in our model lead to a range of tree balances as measured by Aldous’ beta statistic. In particular, we demonstrate that it is possible to find parameters that correspond well to empirical tree balance. Next, we provide a natural extension of the beta statistic to sets of trees. This extension produces less biased estimates of beta compared to using the median beta values from individual trees. Furthermore, we derive a likelihood expression for the probability of observing an edge-weighted tree under a model with speciation but no extinction. Finally, we illustrate the application of our model by performing both absolute and relative goodness-of-fit tests for two large empirical phylogenies (squamates and angiosperms) that compare models with Coxian PH distributed times to speciation with models that assume exponential or Weibull distributed waiting times. In our numerical analysis, we found that, in most cases, models assuming a Coxian PH distribution provided the best fit.

Numerical study on the extinction dynamics of partially premixed meso-scale methane-air jet flames with hydrogen addition

In this paper, a model of partially premixed jet flames that sustained above a meso-scale short tube was established for an individual flame port of domestic gas stoves. The effects of hydrogen addition (volume ratio β = 0%, 10%, 20%, 30%) on the extinction dynamics of CH4-air jet flames were numerically investigated. It is found that flame oscillation occurs once (β = 10% and 20%) or twice (β = 30%) in the extinction process. Moreover, the larger of β, the longer the extinction process can sustain. Analysis was performed in terms of both chemical effect and thermal effect. As to the chemical effect, in the first place, the reaction rate decreases as the inlet velocity is reduced. As a result, the consumption rate of O2 will be less than the supply rate from the incoming mixture, which makes the O2 concentration in the flame center increase. On the other hand, the amount of H radicals increases with the increase of β, and when the O2 content at the flame center reaches a “critical point”, the key elementary reaction “H + O2 ↔ O + OH” will be enhanced and consequently the total reaction rate will also be intensified. After that, the consumption rate of O2 will be larger than the supply rate due to the reduced flow rate of incoming mixture. The total heat release rate will decrease sharply and extinction occurs. As regards the thermal effect, it is revealed that heat recirculation effect (indirect preheating effect) lags behind the variation of the reaction zone (i.e., flame), thus, it has a negligible impact on flame oscillation. In contrast, the preheating temperature in the vicinity of flame front (named as “direct preheating effect”) exhibits a similar variation tendency with the total heat release rate of the flame. And the larger of β, the more remarkable of the direct preheating effect can be. In summary, due to the chemical effect and thermal effect caused by hydrogen addition, the flame can survive for a longer time with fluctuation during the extinction process.

Multispecies coexistence in fragmented landscapes

Spatial dynamics have long been recognized as an important driver of biodiversity. However, our understanding of species' coexistence under realistic landscape configurations has been limited by lack of adequate analytical tools. To fill this gap, we develop a spatially explicit metacommunity model of multiple competing species and derive analytical criteria for their coexistence in fragmented heterogeneous landscapes. Specifically, we propose measures of niche and fitness differences for metacommunities, which clarify how spatial dynamics and habitat configuration interact with local competition to determine coexistence of species. We parameterize our model with a Bayesian approach using a 36-y time-series dataset of three Daphnia species in a rockpool metacommunity covering >500 patches. Our results illustrate the emergence of interspecific variation in extinction and recolonization processes, including their dependencies on habitat size and environmental temperature. We find that such interspecific variation contributes to the coexistence of Daphnia species by reducing fitness differences and increasing niche differences. Additionally, our parameterized model allows separating the effects of habitat destruction and temperature change on species extinction. By integrating coexistence theory and metacommunity theory, our study provides platforms to increase our understanding of species' coexistence in fragmented heterogeneous landscapes and the response of biodiversity to environmental changes.

Impact of hormonal contraceptives on sex differences in fear conditioning and fear extinction in PTSD.

Sex differences in the neurobiological mechanisms involved in fear conditioning and extinction have been suggested to contribute to differential vulnerability for the development of posttraumatic stress disorder (PTSD) in women compared with men. Reproductive hormones, such as estradiol, have been shown to facilitate fear conditioning and extinction learning and may explain some of these differences. However, the effect of commonly used hormonal contraceptives on the neurobiological mechanisms of fear conditioning and extinction is poorly understood. A laboratory study was conducted in trauma-exposed men and women with and without full or partial PTSD to examine effects of sex and use of hormonal birth control on fear conditioning, fear extinction learning, and extinction retention. Participants underwent fear conditioning with stimuli that were paired (CS+) or unpaired (CS−) with shock. Extinction learning occurred 72 h later, and extinction retention was tested 1 wk after extinction. Women on hormonal contraceptives (HCs) demonstrated enhanced acquisition of fear conditioning and enhanced extinction of fear as compared with women off hormonal birth control and men. While clinical implications have yet to be determined, these results suggest that hormonal contraceptives may facilitate learning during both fear acquisition and extinction. Understanding the impact of sex and hormones on fear conditioning and extinction processes may lead to new insights into the pathophysiology of PTSD and result in advancements in treatment that may vary by sex.

Extinction and hybridization in a neutral model of speciation

Evolution is usually pictured as a tree where ancient species branch into new ones and eventually disappear. In this simplified view, the balance between speciation and extinction fully determines the diversity of life. Hybridization, however, introduces another level of complexity, allowing neighboring branches of the tree to interact, mixing their genetic content. This generates further diversity leading to reticulated trees. In this paper we study processes of speciation, extinction and hybridization using a genetically and spatially explicit neutral model of diversification. The model is based on the Derrida–Higgs formulation, where the genome of haploid individuals is represented by binary strings and reproduction is constrained by genetic similarity. Tracking all events of speciation, extinction and hybridization throughout the evolutionary process allows us to compute complete and exact phylogenetic trees. We found that genome size played a key role in these processes, increasing the extinction rate and decreasing the hybridization rate. Only in the limit of large genomes the simplified picture of a branching tree is recovered. Most hybridization events occurred between relatively abundant species, discarding lack of sexual partners or small population sizes as potential causes. We found that hybridization occurred mostly because of opportunity (genetic similarity and spatial proximity) between recently branched species, when the number of accumulated mutations is not yet too large.

The Recruitment of a Neuronal Ensemble in the Central Nucleus of the Amygdala During the First Extinction Episode Has Persistent Effects on Extinction Expression

BackgroundAdaptive behavior depends on the delicate and dynamic balance between acquisition and extinction memories. Disruption of this balance, particularly when the extinction of memory loses control over behavior, is the root of treatment failure of maladaptive behaviors such as substance abuse or anxiety disorders. Understanding this balance requires a better understanding of the underlying neurobiology and its contribution to behavioral regulation. MethodsWe microinjected Daun02 in Fos-lacZ transgenic rats following a single extinction training episode to delete extinction-recruited neuronal ensembles in the basolateral amygdala (BLA) and central nucleus of the amygdala (CN) and examined their contribution to behavior in an appetitive Pavlovian task. In addition, we used immunohistochemistry and neuronal staining methods to identify the molecular markers of activated neurons in the BLA and CN during extinction learning or retrieval. ResultsCN neurons were preferentially engaged following extinction, and deletion of these extinction-activated ensembles in the CN but not the BLA impaired the retrieval of extinction despite additional extinction training and promoted greater levels of behavioral restoration in spontaneous recovery and reinstatement. Disrupting extinction processing in the CN in turn increased activity in the BLA. Our results also show a specific role for CN PKCδ+ neurons in behavioral inhibition but not during initial extinction learning. ConclusionsWe showed that the initial extinction-recruited CN ensemble is critical to the acquisition-extinction balance and that greater behavioral restoration does not mean weaker extinction contribution. These findings provide a novel avenue for thinking about the neural mechanisms of extinction and for developing treatments for cue-triggered appetitive behaviors.

Impact of demographic variability on the disease dynamics for honeybee model.

For the last few years, annual honeybee colony losses have been center of key interest for many researchers throughout the world. The spread of the parasitic mite and its interaction with specific honeybee viruses carried by Varroa mites has been linked to the decline of honeybee colonies. In this investigation, we consider honeybee-virus and honeybee-infected mite-virus models. We perform sensitivity analysis locally and globally to see the effect of the parameters on the basic reproduction number for both models and to understand the disease dynamics in detail. We use the continuous-time Markov chain model to develop and analyze stochastic epidemic models corresponding to both deterministic models. By using the disease extinction process, we compare both deterministic and stochastic models. We have observed that the numerically approximated probability of disease extinction based on 30 000 sample paths agrees well with the calculated probability using multitype branching process approximation. In particular, it is observed that the disease extinction probability is higher when infected honeybees spread the disease instead of infected mites. We conduct a sensitivity analysis for the stochastic model also to examine how the system parameters affect the probability of disease extinction. We have also derived the equation for the expected time required to reach disease-free equilibrium for stochastic models. Finally, the effect of the parameters on the expected time is represented graphically.

Direct observation of the build-up and extinction of similaritons in an all-normal dispersion fiber laser

Similaritons have attracted considerable attention thanks to their outstanding output performance in recent years. In this paper, we explored the entire dynamic evolution process of similaritons in an all-normal dispersion fiber laser through the time-stretch dispersive Fourier transform technique. Particularly, the narrow-band spectral filtering effect on the pulse evolution dynamics has been discovered. The “memory” ability in the relaxation oscillation state has disappeared in similariton fiber lasers compared with the traditional soliton mode-locked fiber lasers, and the build-up time is much shorter than other fiber lasers mode-locked by the nonlinear polarization evolution. Furthermore, the extinction process of the similariton fiber laser is observed and evaluated for the first time as well. An unstable time period accompanied by a high spectral peak over the spectrum is captured during the extinction process, and then the damped relaxation oscillation state is observed. These results can provide new perspectives into the ultrafast transient process of similaritons in all-normal dispersion fiber lasers and the dynamics of sophisticated nonlinear systems.

Numerical investigation on the characteristics of leakage and dispersion of cryogenic liquid oxygen in open environment

Liquid oxygen/liquid hydrogen and liquid oxygen/liquid methane are widely used as cryogenic propellants in the field of aerospace launch. Numerical research is carried out for the potential liquid oxygen leakage caused by damage of tanks or rupture of pipelines. The Mixture multiphase flow model is used, where the slip velocity between the gas–liquid phases and the phase change of water vapor are considered. The development process of the temperature and oxygen concentration distribution after the leakage and the extinction process after the leakage stops are investigated. What's more, the influences of ambient temperature, spill rate, cofferdam, and wind direction on the temperature and concentration distribution are analyzed. The results show that, after about 90 s of continuous liquid oxygen leakage, the oxygen cloud reaches a quasi-steady state. The volume fraction of oxygen in the air reduces to 23% at 60 s after stopping the leakage. As the ambient temperature increases from 253 K to 308 K, the hazardous temperature region is reduced while the maximum oxygen concentration increases from 0.422 to 0.471. An increase in spill rate significantly increases the hazardous regions of temperature and concentration. In contrast, increasing the angle in the horizontal plane between the wind direction and the direction of leakage or building a cofferdam can reduce the extent of the hazardous region. The results of this paper can provide references for the development of liquid oxygen leakage experiments, the development of related standards, and the emergency treatment of accidents.

Targeted Memory Reactivation During REM Sleep in Patients With Social Anxiety Disorder.

BackgroundSocial anxiety disorder (SAD) is characterized by a significant amount of fear when confronted to social situations. Exposure therapy, which is based on fear extinction, does not often lead to full remission. Here, based on evidence showing that rapid eye movement (REM) sleep promotes the consolidation of extinction memory, we used targeted memory reactivation (TMR) during REM sleep to enhance extinction learning in SAD.MethodsForty-eight subjects with SAD were randomly assigned to two groups: control or TMR group. All patients had two successive exposure therapy sessions in a virtual reality (VR) environment, where they were asked to give a public talk in front of a virtual jury. At the end of each session, and only in the TMR group (N = 24), a sound was paired to the positive feedback phase of therapy (i.e., approval of their performance), which represented the memory to be strengthened during REM sleep. All participants slept at home with a wearable headband device which automatically identified sleep stages and administered the sound during REM sleep. Participants' anxiety level was assessed using measures of parasympathetic (root mean square of successive differences between normal heartbeats, RMSSD) and sympathetic (non-specific skin conductance responses, ns-SCRs) activity, and subjective measures (Subjective Units of Distress Scale, SUDS), during the preparation phase of their talks before (T1) and after (T2) one full-night's sleep and after 1 week at home (T3). Participants also filled in a dream diary.ResultsWe observed an effect of time on subjective measures of anxiety (SUDS). We did not find any difference in the anxiety levels of the two groups after 1 week of TMR at home. Importantly, the longer the total duration of REM sleep and the more stimulations the TMR group had at home, the less anxious (increased RMSSD) these participants were. Finally, fear in dreams correlated positively with ns-SCRs and SUDS at T3 in the TMR group.ConclusionTMR during REM sleep did not significantly modulate the beneficial effect of therapy on subjective anxiety. Yet, our results support that REM sleep can contribute to extinction processes and substantiate strong links between emotions in dreams and waking stress levels in these patients.

Single doses of a highly selective inhibitor of phosphodiesterase 1 (lenrispodun) in healthy volunteers: a randomized pharmaco-fMRI clinical trial.

Lenrispodun is a potent and highly selective inhibitor of phosphodiesterase (PDE) type 1, which is thought to prolong intracellular second messenger signaling within cortical and subcortical dopaminergic brain regions. This is the first study of a PDE1 inhibitor in healthy volunteers using behavioral and neuroimaging approaches to examine its effects on neural targets and to provide a safety and tolerability assessment. The primary objectives were to determine whether lenrispodun induces changes in BOLD fMRI signals in the inferior frontal gyrus (IFG) during the stop signal task, and the dorsal anterior insula (dAI) during the extinction phase of a fear conditioning/extinction task. Using a double-blind, placebo-controlled, within-subjects design, 26 healthy individuals (22 completed all fMRI sessions) received in random order a single oral dose of placebo, lenrispodun 1.0 milligram (mg) or lenrispodun 10.0 mg and completed several tasks in the scanner including the stop signal (n = 24) and fear conditioning/extinction tasks (n = 22). Prespecified region-of-interest analyses for the IFG and dAI were computed using linear mixed models. Lenrispodun induced increases in IFG activity during the stop signal task at 1.0 mg (Cohen's d = 0.63) but not 10.0 mg (Cohen's d = 0.07) vs. placebo. Lenrispodun did not induce changes in dAI activity during fear extinction at either dose. Exploratory outcomes revealed changes in cardiac interoception. Lenrispodun administration was well-tolerated. These results provide evidence that 1.0 mg lenrispodun selectively improved neural inhibitory control without altering fear extinction processing. Future investigations should determine whether lenrispodun improves inhibitory control in target populations such as individuals with attention deficit hyperactivity disorder. Trial registration: ClinicalTrials.gov identifier: NCT03489772.

Biogeography and diversification of bare‐eyes, an endemic Amazonian clade

AbstractAimBiotic interchange, speciation and extinction processes drive biotas assembling. However, the evolutionary outcomes of those mechanisms are complex and difficult to discriminate. Here, we investigate how these processes affect avian diversification in tropical forest regions and test the relative roles of vicariant speciation and biotic interchange on the assemblage of Amazonian biota through the reconstruction of the biogeographical history of bare‐eyes using molecular markers.LocationAmazon.TaxonPhlegopsis (Aves: Thamnophilidae).MethodsWe carried out a phylogenetic reconstruction of Phlegopsis based on four mtDNA and nuclear markers of 52 individuals from 21 localities representing all recognized taxa in the genus. We estimated phylogenetic relationships using both gene tree and species tree methods, demographic history, gene flow and divergence time to reconstruct the biogeographical history of the genus.ResultsPhylogenetic analyses recovered nine lineages delimited by some of the largest Amazonian rivers. Molecular dating and biogeographical studies showed that (1) most of the diversification in the genus occurred during the Quaternary; (2) vicariance was the most critical biogeographical process driving the history of this group and (3) two lineages are expanding their ranges, with one of them (P. n. nigromaculata) crossing the boundaries of areas of endemism.Main conclusionsOur results reinforce the notion that continental biotas are assembled by alternating dispersal and vicariance events. In Phlegopsis, vicariance shaped the distribution and differentiation of most lineages, but one event of post‐speciation dispersal made two lineages sympatric in Western Amazonia. Dispersal events within the Amazon are not random but are constrained by the characteristics of the species that are expanding their ranges and the features of the places that receive such species. Although most of the speciation events of Phlegopsis occurred during the Quaternary, there is no reason to assume that such events were driven by climatic‐vegetation changes associated with the Milankovitch cycles.

CONDUCTING ACTIONS ON CONTROLLING THE SPREAD OF QUARANTINE PEST TYPES IN THE AGROBIOCENOSIS OF KARAKALPAKSTAN

Due to the fact that the Republic of Karakalpakstan is situated in the northern part of Uzbekistan, where the climate is sharp and the territory is extra-arid, changes of ecological factors in recent years, in the first place bringing into the decrease of the amount of plant types, yields of agricultural crops, which are being sown in the biotopes. As a result, rapid change of pest types of agricultural crops, which appear in biocenosis, was being observed. While the process of extinction of some types is appeared, there is an opportunity for rapid appearance of types, which did not exist in the past and coming into the ranks of the main pests. It is required to indicate these types of pests as inner and outer quarantine object and carrying out controlling actions in order to prevent them from spreading. Although these types of pests are appearing in the region in recent years, it can be stated as an example potato moth, which is damaging potato and tomato moth, which is the main pest of potato. Nowadays, it is an actual problem to create scientific basics of controlling actions which influence in maximum degree by defining biological peculiarities, developing dynamics, damaging degree in order to carry out effective controlling actions of the types which are spread in the agrobiocenosis.

Trajectory to local extinction of an isolated dugong population near Okinawa Island, Japan

A small animal population becomes extinct owing to demographic and environmental stochasticity after declining below the minimum viable population (MVP). However, the actual process of extinction derived by stochastic factors after crossing MVP has not been recorded for long-lived marine mammals. Here, we reconstructed the declining history of a small, isolated population of dugongs in Okinawa over 125 years. The initial population size of approximately 280–420 in the nineteenth century declined to approximately < 100 in 1917 because of overfishing, < 70 in 1979, 11 in 1997, 3 after 2006, and all known individuals disappeared or died by 2019. After 1979, a decline in the natural growth rate has led to extinction. Long-lived animals may persist for a few decades after the population falls below the MVP, at which time active conservation measures, such as captive breeding, should be implemented.

Multi-season site occupancy of Eastern Whip-poor-wills (Antrostomus vociferus) in New York

Multi-year monitoring of species distribution is important for conservation planners to understand population trajectories. In New York, USA, the Eastern Whip-poor-will (Antrostomus vociferus) is among several bird species that have been documented to be declining and has been monitored for several years through large-scale surveys such as the Breeding Bird Atlas and Breeding Bird Survey. We implemented a study to assess trends in site occupancy at 19 survey routes during 2014–2018 breeding seasons. We surveyed for Eastern Whip-poor-wills following the Center of Conservation Biology Nightjar Survey Network methodology and used these data to estimate yearly relative abundance, factors that may influence the probability of detection, probability of a site being occupied and potentially important landscape features, and dynamic processes of site colonization and extinction. The mean relative abundance ranged from 0.54 in 2016 to 0.89 in 2014, with all yearly estimates having 95% confidence intervals that overlapped. The probability of detection was negatively affected by the greatest wind speeds recorded (12.87–28.97 kph, [8–18 mph]). Site occupancy was relatively low each year ranging from 26% to 32% across all years. We observed a negative effect on site occupancy with survey sites located in the Adirondack ecozone of New York. We additionally found support for a negative effect of median elevation and a positive effect of area of hay and pasture on site occupancy within 675 m of survey sites. The probability of a site becoming colonized ranged from 0.05 to 0.14 and the probability of a site going extinct ranged from 0.14 to 0.42. Overall, we did not find support for a decreasing trend in site occupancy. The yearly relative abundance estimates and site occupancy estimates were small but did not decrease over time and the dynamic processes did not suggest increasing extinction or decreasing colonization rates. Occupied survey locations may represent some of the most suitable and stable habitat for these birds within the state. Important landscape characteristics of lower elevation and area of hay and pasture may be representative of forest mosaics that include open areas with forest edges at lower elevation, which has been documented in other studies.