Variation of annual apparent survival and detection rates with age,year and individual identity in male Weddell seals (Leptonychotes weddellii) from long-term mark-recapture data

Exploring age- and sex-specific survival rates provides insight regarding population behavior and life-history trait evolution. However, our understanding of how age-specific patterns of survival, including actuarial senescence, compare between the sexes remains inadequate. Using 36 years of mark-recapture data for 7,516 male Weddell seals (Leptonychotes weddellii) born in Erebus Bay, Antarctica, we estimated age-specific annual survival rates using a hierarchical model for mark-recapture data in a Bayesian framework. Our male survival estimates were moderate for pups and yearlings, highest for 2-year-olds, and gradually declined with age thereafter such that the oldest animals observed had the lowest rates of any age. Reports of senescence in other wildlife populations of species with similar longevity occurred at older ages than those presented here. When compared to recently published estimates for reproductive Weddell seal females, we found that peak survival rates were similar (males: 0.94, 95% CI = 0.92–0.96; females: 0.92, 95% CI = 0.93–0.95), but survival rates at older ages were lower in males. Age-specific male Weddell seal survival rates varied across years and individuals, with greater variation occurring across years. Similar studies on a broad range of species are needed to contextualize these results for a better understanding of the variation in senescence patterns between the sexes of the same species, but our study adds information for a marine mammal species to a research topic dominated by avian and ungulate species.     

A non‐canonical rhodopsin‐mediated insulin receptor signaling pathway in retinal photoreceptor neurons

We previously reported a ligand‐independent and rhodopsin‐dependent insulin receptor (IR) neuroprotective signaling pathway in both rod and cone photoreceptor cells, which is activated through protein–protein interaction. Our previous studies were performed with either retina or isolated rod or cone outer segment preparations and the expression of IR signaling proteins were examined. The isolation of outer segments with large portions of the attached inner segments is a technical challenge. Optiprep? density gradient medium has been used to isolate the cells and subcellular organelles, Optiprep? is a non‐ionic iodixanol‐based medium with a density of 1.320 g/mL. We employed this method to examine the expression of IR and its signaling proteins, and activation of one of the downstream effectors of the IR in isolated photoreceptor cells. Identification of the signaling complexes will be helpful for therapeutic targeting in disease conditions.     

The Ability of Tetrahymena utriculariae (Ciliophora,Oligohymenophorea) to Colonize Traps of Different Species of Aquatic Carnivorous Utricularia

The host specificity of the recently described ciliate species Tetrahymena utriculariae was tested in a greenhouse growth experiment, which included 14 different species of aquatic Utricularia as potential host plants. We confirmed the high specificity of the interaction between U. reflexa and T. utriculariae, the former being the only tested host species able to maintain colonization for prolonged time periods. We conclude that this plant–microbe relationship is a unique and specialized form of digestive mutualism and the plant–microbe unit a suitable experimental system for future ecophysiological studies.     

Spatial synchrony in the response of a long range migratory species (Salmo salar) to climate change in the North Atlantic Ocean

A major challenge in understanding the response of populations to climate change is to separate the effects of local drivers acting independently on specific populations, from the effects of global drivers that impact multiple populations simultaneously and thereby synchronize their dynamics. We investigated the environmental drivers and the demographic mechanisms of the widespread decline in marine survival rates of Atlantic salmon (Salmo salar) over the last four decades. We developed a hierarchical Bayesian life cycle model to quantify the spatial synchrony in the marine survival of 13 large groups of populations (called stock units, SU) from two continental stock groups (CSG) in North America (NA) and Southern Europe (SE) over the period 1971–2014. We found strong coherence in the temporal variation in postsmolt marine survival among the 13 SU of NA and SE. A common North Atlantic trend explains 37% of the temporal variability of the survivals for the 13 SU and declines by a factor of 1.8 over the 1971–2014 time series. Synchrony in survival trends is stronger between SU within each CSG. The common trends at the scale of NA and SE capture 60% and 42% of the total variance of temporal variations, respectively. Temporal variations of the postsmolt survival are best explained by the temporal variations of sea surface temperature (SST, negative correlation) and net primary production indices (PP, positive correlation) encountered by salmon in common domains during their marine migration. Specifically, in the Labrador Sea/Grand Banks for populations from NA, 26% and 24% of variance is captured by SST and PP, respectively and in the Norwegian Sea for populations from SE, 21% and 12% of variance is captured by SST and PP, respectively. The findings support the hypothesis of a response of salmon populations to large climate‐induced changes in the North Atlantic simultaneously impacting populations from distant continental habitats.     

Temperature and precipitation at migratory grounds influence demographic trends of an Arctic‐breeding bird

Anthropogenic climate disruption, including temperature and precipitation regime shifts, has been linked to animal population declines since the mid‐20th century. However, some species, such as Arctic‐breeding geese, have thrived during this period. An increased understanding of how climate disruption might link to demographic rates in thriving species is an important perspective in quantifying the impact of anthropogenic climate disruption on the global state of nature. The Greenland barnacle goose (Branta leucopsis) population has increased tenfold in abundance since the mid‐20th century. A concurrent weather regime shift towards warmer, wetter conditions occurred throughout its range in Greenland (breeding), Ireland and Scotland (wintering) and Iceland (spring and autumn staging). The aim of this study was to determine the relationship between weather and demographic rates of Greenland barnacle geese to discern the role of climate shifts in the population trend. We quantified the relationship between temperature and precipitation and Greenland barnacle goose survival and productivity over a 50 year period from 1968 to 2018. We detected significant positive relationships between warmer, wetter conditions on the Icelandic spring staging grounds and survival. We also detected contrasting relationships between warmer, wetter conditions during autumn staging and survival and productivity, with warm, dry conditions being the most favourable for productivity. Survival increased in the latter part of the study period, supporting the possibility that spring weather regime shifts contributed to the increasing population trend. This may be related to improved forage resources, as warming air temperatures have been shown to improve survival rates in several other Arctic and northern terrestrial herbivorous species through indirect bottom‐up effects on forage availability.     

Effect of membrane integrity on survival competition of Botrytis cinerea upon QoI fungicide pyraclostrobin

Botrytis cinerea, the causal agent of the grey mould disease, developed resistance to multiple fungicides. However, the role of cell membrane in survival competition of B. cinerea upon quinone outside inhibitor (QoI) fungicide has not yet been elucidated. In this paper, the enhancement of cystamine, a transglutaminase inhibitor, on membrane integrity of B. cinerea was determined, and the effect of the enhancement on the sensitivity of B. cinerea to pyraclostrobin was investigated. The results showed that pyraclostrobin inhibited mycelial growth with EC₅₀ as 1.122 and 3.042 μg/ml at 24 and 48 hr, respectively. In the treatment of 5 and 50 μg/ml pyraclostrobin, membrane integrity of B. cinerea was broken, causing high permeability, lipid peroxidation, flocculent and malformed surface with vague septum and abundant agglomerates inside and outside the mycelia. Cystamine even at 50 and 200 μg/ml had little inhibitory effect on mycelial growth. However, in presence of 50 or 200 μg/ml cystamine, the mycelia from pyraclostrobin treatment possessed a significantly reduced leakage, lower MDA content, and a revived fibrous and transparent surface. Meanwhile, SEM images showed that membrane integrity of the mycelia was significantly improved and the agglomerates were dramatically disappeared. Synergy assays further revealed that B. cinerea regained less sensitivity to pyraclostrobin inhibition. In conclusion, membrane integrity controls mycelia sensitivity and is required for survival competition of B. cinerea upon pyraclostrobin.     

Reintroduced wolves and hunting limit the abundance of a subordinate apex predator in a multi-use landscape

Top-down effects of apex predators are modulated by human impacts on community composition and species abundances. Consequently, research supporting top-down effects of apex predators occurs almost entirely within protected areas rather than the multi-use landscapes dominating modern ecosystems. Here, we developed an integrated population model to disentangle the concurrent contributions of a reintroduced apex predator, the grey wolf, human hunting and prey abundances on vital rates and abundance of a subordinate apex predator, the puma. Increasing wolf numbers had strong negative effects on puma fecundity, and subadult and adult survival. Puma survival was also influenced by density dependence. Overall, puma dynamics in our multi-use landscape were more strongly influenced by top-down forces exhibited by a reintroduced apex predator, than by human hunting or bottom-up forces (prey abundance) subsidized by humans. Quantitatively, the average annual impact of human hunting on equilibrium puma abundance was equivalent to the effects of 20 wolves. Historically, wolves may have limited pumas across North America and dictated puma scarcity in systems lacking sufficient refugia to mitigate the effects of competition.     

Lasting the distance: The survival of alien birds shipped to New Zealand in the 19th century

Invasive alien species are a major threat to biodiversity and human activities, providing a strong incentive to understand the processes by which alien invasion occurs. While it is important to understand the determinants of success at each of several invasion stages—transport, introduction, establishment, and spread—few studies have explored the first of these stages. Here, we quantify and analyze variation in the success of individual animals in surviving the transport stage, based on shipping records of European passerines destined for New Zealand. We mined the original documents of Acclimatisation Societies, established in New Zealand for the purpose of introducing supposedly beneficial alien species, in combination with recently digitized newspaper archives, to produce a unique dataset of 122 ships that carried passerines from Europe to New Zealand between 1850 and 1885. For 37 of these shipments, data on the survival of individual species were available. Using generalized linear mixed models, we explored how survival was related to characteristics of the shipments and the species. We show that species differed greatly in their survival, but none of the tested traits accounted for these differences. Yet, survival increased over time, which mirrors the switch from early haphazard shipments to larger organized shipments. Our results imply that it was the quality of care received by the birds that most affected success at this stage of the invasion process.     

Minibrain-related kinase/dual-specificity tyrosine-regulated kinase 1B implication in stem/cancer stem cells biology

Dual-specificity tyrosine phosphorylation-regulated kinase 1B (DYRK1B), also known as minibrain-related kinase (MIRK) is one of the best functionally studied members of the DYRK kinase family. DYRKs comprise a family of protein kinases that are emerging modulators of signal transduction pathways, cell proliferation and differentiation, survival, and cell motility. DYRKs were found to participate in several signaling pathways critical for development and cell homeostasis. In this review, we focus on the DYRK1B protein kinase from a functional point of view concerning the signaling pathways through which DYRK1B exerts its cell type-dependent function in a positive or negative manner, in development and human diseases. In particular, we focus on the physiological role of DYRK1B in behavior of stem cells in myogenesis, adipogenesis, spermatogenesis and neurogenesis, as well as in its pathological implication in cancer and metabolic syndrome. Thus, understanding of the molecular mechanisms that regulate signaling pathways is of high importance. Recent studies have identified a close regulatory connection between DYRK1B and the hedgehog (HH) signaling pathway. Here, we aim to bring together what is known about the functional integration and cross-talk between DYRK1B and several signaling pathways, such as HH, RAS and PI3K/mTOR/AKT, as well as how this might affect cellular and molecular processes in development, physiology, and pathology. Thus, this review summarizes the major known functions of DYRK1B kinase, as well as the mechanisms by which DYRK1B exerts its functions in development and human diseases focusing on the homeostasis of stem and cancer stem cells.