EXAMINING WHOOPING CRANE BREEDING SEASON FORAGING BEHAVIOR IN THE EASTERN MIGRATORY POPULATION

Agricultural fields may provide an important supplementary foraging habitat for whooping cranes (Grus americana) in the reintroduced Eastern Migratory Population (EMP). We developed methods and gathered preliminary data regarding whooping crane foraging efficiency and habitat use to better understand the use of agricultural fields by breeding cranes. We generated a simple null hypothesis that cranes would spend more time in the habitat type (wetlands vs. agricultural fields) in which they were able to obtain a higher foraging efficiency to maximize food intake, along with several alternative hypotheses pertaining to reasons cranes may prefer wetlands or agricultural fields during periods of the breeding season regardless of foraging efficiency. We collected habitat use and measures of foraging efficiency (stepping rate, striking efficiency, and capture rate) from videos of 2 pairs of cranes recorded for a concurrent study. Cranes spent more time in the habitat with higher foraging efficiency during the pre-nesting period (wetlands) but more time in the habitat with lower foraging efficiency during the incubation period (also wetlands). There was no significant difference in foraging efficiency post nest-abandonment. Our data imply that cranes are willing to undergo lower foraging efficiencies in order to remain on territory during incubation. However, our data should be considered preliminary due to the small sample size of individuals studied

Shifts in Plankton, Nutrient and Light Relationships in Small Tundra Lakes Caused by Localized Permafrost Thaw

Tundra lakes located in the Mackenzie Delta uplands, NWT, Canada, are increasingly being affected by permafrost thaw in the form of shoreline retrogressive thaw slumping. This form of thaw-induced disturbance is used as a surrogate indicator of landscape-related disturbance linked to regional climate warming. We compared 22 lakes, half affected by thaw slumping and half unaffected, to determine whether water column nutrient concentrations, light availability, and plankton biomass differed between these two lake types. Total phosphorus (TP), total dissolved nitrogen (TDN), dissolved organic carbon (DOC), and chlorophyll a concentrations were higher in unaffected lakes than in slump-affected lakes. Absorbance related to water colour of both UV and photosynthetically active radiation in the water column was also higher in unaffected lakes, but bacterioplankton abundance was not different between lake types. UV light absorbance was found to be the best predictor of pelagic chlorophyll a concentrations in unaffected lakes, whereas TDN (and to a lesser extent TP) were the best predictors of pelagic chlorophyll a in slump-affected lakes. These findings indicate that slumping arising from permafrost thaw produces a shift in tundra lake nutrient, light, and phytoplankton relationships. Given the projections of continued warming, this result has significant implications for the future biogeochemical and ecological states of Arctic tundra lakes.Les lacs de toundra situés dans les hautes terres du delta du Mackenzie, dans les Territoires du Nord-Ouest, au Canada, sont de plus en plus touchés par le dégel du pergélisol en ce sens qu’il y a glissement régressif du littoral dû au dégel. Cette forme de perturbation attribuable au dégel sert d’indicateur auxiliaire en matière de perturbation du paysage liée au réchauffement climatique de la région. Nous avons comparé 22 lacs, dont la moitié était touchée par le glissement dû au dégel et l’autre moitié ne l’était pas, afin de déterminer si les concentrations en nutriments des colonnes d’eau, la disponibilité lumineuse et la biomasse du plancton différaient entre ces deux types de lacs. Les concentrations de phosphore total (PT), d’azote dissous total (ADT), de carbone organique dissous (COD) et de chlorophylle a étaient plus élevées dans les lacs non touchés quand dans les lacs où il y avait glissement du littoral. L’absorbance liée à la couleur de l’eau du rayonnement actif photosynthétique et du rayonnement actif ultraviolet dans les colonnes d’eau était également plus élevée dans les lacs non touchés, mais l’abondance du bactérioplancton ne différait pas d’un type de lac à l’autre. On a déterminé que l’absorbance de lumière ultraviolette était le meilleur prédicteur de concentrations de chlorophylle a pélagique dans les lacs non touchés, tandis que l’ADT (et le PT, dans une moindre mesure) constituaient les meilleurs prédicteurs de chlorophylle a pélagique pour ce qui est des lacs faisant l’objet d’un glissement. Ces constatations indiquent que le glissement attribuable au dégel du pergélisol altère les relations qui existent entre les nutriments, la lumière et le phytoplancton des lacs de toundra. Compte tenu des projections à l’égard d’un réchauffement continuel, ce résultat revêt d’importantes incidences sur les états biogéochimiques et écologiques des lacs de la toundra arctique

Functional and Homeostatic impact of Age-Related Changes in Lymph node Stroma

Adults over 65 years of age are more vulnerable to infectious disease and show poor responses to vaccination relative to those under 50. A complex set of age-related changes in the immune system is believed to be largely responsible for these defects. These changes, collectively termed immune senescence, encompass alterations in both the innate and adaptive immune systems, in the microenvironments where immune cells develop or reside, and in soluble factors that guide immune homeostasis and function. While age-related changes in primary lymphoid organs (bone marrow, and, in particular, the thymus, which involutes in the first third of life) have been long appreciated, changes affecting aging secondary lymphoid organs, and, in particular, aging lymph nodes (LNs) have been less well characterized. Over the last 20 years, LN stromal cells have emerged as key players in maintaining LN morphology and immune homeostasis, as well as in coordinating immune responses to pathogens. Here, we review recent progress in understanding the contributions of LN stromal cells to immune senescence. We discuss approaches to understand the mechanisms behind the decline in LN stromal cells and conclude by considering potential strategies to rejuvenate aging LN stroma to improve immune homeostasis, immune responses, and vaccine efficacy in the elderly.113Ysciescopu

Atomic Representations of Local and Global Chemistry in Complex Alloys

The exceptional properties observed in complex concentrated alloys (CCAs) arise from the interplay between crystalline order and chemical disorder at the atomic scale, complicating a unique determination of properties. In contrast to conventional alloys, CCA properties emerge as distributions due to varying local chemical environments and the specific scale of measurement. Currently there are few ways to quantitatively define, track, and compare local alloy compositions (versus a global label, i.e. equiatomic) contained in a CCA. Molecular dynamics is used here to build descriptive metrics that connect a global alloy composition to the diverse local alloy compositions that define it. A machine-learned interatomic potential for MoNbTaTi is developed and we use these metrics to investigate how property distributions change with excursions in global-local composition space. Short-range order is examined through the lens of local chemistry for the equiatomic composition, demonstrating stark changes in vacancy formation energy with local chemistry evolution.Comment: Version 2: editing and figure improvements, overall content unchanged. 15 pages, 6 main figures, 1 supplemental figur

Defective Transcriptional Programming of Effector CD8 T Cells in Aged Mice Is Cell-Extrinsic and Can Be Corrected by Administration of IL-12 and IL-18

In response to infection with intracellular microorganisms, old mice mobilize decreased numbers of antigen-specific CD8 T cells with reduced expression of effector molecules and impaired cytolytic activity. Molecular mechanisms behind these defects and the cell-intrinsic (affecting naïve CD8 T cells themselves) vs. extrinsic, microenvironmental origin of such defects remain unclear. Using reciprocal transfer experiments of highly purified naïve T cells from adult and old transgenic OT-1 mice, we decisively show that the dominant effect is cell-extrinsic. Naïve adult OT-1 T cells failed to expand and terminally differentiate in the old organism infected with Listeria-OVA. This defect was preceded by blunted expression of the master transcription factor T-bet and impaired glycolytic switch when T cells are primed in the old organism. However, both old and adult naïve CD8 T cells proliferated and produced effector molecules to a similar extent when stimulated in vitro with polyclonal stimuli, as well as when transferred into adult recipients. Multiple inflammatory cytokines with direct effects on T cell effector differentiation were decreased in spleens of old animals, particularly IL-12 and IL-18. Of note, in vivo treatment of mice with IL-12 and IL-18 on days 4–6 of Listeria infection reconstituted cytotoxic T cell response of aged mice to the level of adult. Therefore, critical cytokine signals which are underproduced in the old priming environment can restore proper transcriptional programming of old naïve CD8 T cells and improve immune defense against intracellular microorganisms

A Preliminary Comparison of Firefighter Candidates\u27 Biddle Physical Ability Test Performance and Success Based on Training Class Participation

International Journal of Exercise Science 15(4): 1627-1640, 2022. The Biddle Physical Ability Test (BPAT) was developed to identify candidates who possess the physical ability to become structural firefighters. The test must be completed in ≤ 9:34 min:s before a candidate is admitted to an academy. Some community colleges offer semester-long training classes for candidates. This study analyzed whether candidates who completed a training class could perform the BPAT more effectively. Retrospective analysis of 30 males and 2 females who attempted the BPAT was conducted. BPAT tasks were: dry and charged hose drag; halyard raise, roof walk, and attic crawl; roof ventilation and victim removal; ladder removal and carry; stair climb with hose bundle; crawling search and tower exit; stair climb with air bottles; hose hoist; and return to ground floor with air bottles. Independent samples t-tests or Mann-Whitney U tests (p \u3c 0.05) and effect sizes calculated BPAT time differences between candidates who completed a training class or not. Twenty-nine candidates passed the BPAT; 6 completed a training class. The 3 candidates (2 males, 1 female) who failed did not complete a class. There were no significant between-group differences in BPAT times (p = 0.054-0.829). There were moderate effects for faster roof ventilation and victim removal, ladder removal and carry, and hose hoist times for candidates who attended a class (d = 0.74-0.95). While training classes may not be necessary for all candidates, physically demanding BPAT tasks were finished faster by candidates who completed a class. For candidates who find the BPAT physicality difficult, participation in a task-specific fitness and skills class may prove beneficial

Role of particle size and surface functionalisation on the flexibility behaviour of switchable metal-organic framework DUT-8(Ni)

Flexible MOF nanoparticles, i.e. MOF nanoparticles that change their structure upon external stimuli such as guest uptake, are promising for numerous applications including advanced gas adsorption, drug delivery and sensory devices. However, the properties of MOFs are typically characterised based on the bulk material with no consideration of how the particle size and external surface influences their performance. This combined computational and experimental contribution investigates the influence of the particle size and surface functionalisation on the flexibility of DUT-8(Ni) (Ni2 (2,6-ndc)2 dabco, ndc = naphthalene dicarboxylate, dabco = 1,4-diazabicyclo[2.2.2]octane, DUT=Dresden University of Technology). DUT-8 nanoparticles remain rigid in their open pore form while microparticles, synthesised under slightly different conditions, undergo gate opening upon nitrogen adsorption suggesting that the particle size has an important role to play in the flexibility of DUT-8. While the adsorption environment at the surface capped with modulators smaller than the 2,6-ndc ligand is very different compared to the bulk of the crystal with considerably weaker guest-framework interaction, simulations reveal that the nanoparticles should close. We conclude that the size of the nanoparticles is not the major contributor for keeping DUT-8 nanoparticles open but that it is more likely that defects or nucleation barriers dominate. Moreover, our work reveals for the first time that functionalising the external surface of nanoparticles with different modulators or capping groups offers the opportunity to manipulate the gate opening / closing pressure. This principle is generally applicable and could be exploited to tune the gate openig / closing pressure for the application of interest

Does habitat stability structure intraspecific genetic diversity? It’s complicated...

Regional phylogeographic studies have long been conducted in the southeastern United States for a variety of species. With some exceptions, many of these studies focus on single species or single clades of organisms, and those considering multiple species tend to focus on deep historical breaks causing differentiation. However, in many species more recent factors may be influencing genetic diversity. To understand the roles of historic and contemporary processes in structuring genetic diversity, we reanalyzed existing genetic data from Southeast of North America using approaches gleaned from phylogeographic and landscape genetic literature that were implemented across species including AMOVAs, PCoAs, Species Distribution Modelling, and tests of isolation by distance, environment, and habitat instability. Genetic variance was significantly partitioned by ecoregions, watersheds, and across phylogeographic breaks in the majority of species. Similarly, genetic variation was significantly associated with some combination of geographic or environmental distance or habitat instability in most species. Patterns of genetic variation were largely idiosyncratic across species. While habitat instability over time is significantly correlated with genetic diversity in some species, it appears generally less important than isolation by geographic or environmental distance. Our results suggest that many factors, both historical and contemporary, impact genetic diversity within a species, and more so, that these patterns aren’t always similar in closely related species. This supports the importance of species- specific factors and cautions against assumptions that closely related species will respond to historical and contemporary forces in similar ways

Vitrification within a nanoliter volume : oocyte and embryo cryopreservation within a 3D photopolymerized device

Open Access funding enabled and organized by CAUL and its Member Institutions. KRD is supported by a Mid-Career Fellowship from the Hospital Research Foundation (C-MCF-58–2019). KD acknowledges funding from the UK Engineering and Physical Sciences Research Council (grants EP/P030017/1). This study was funded by the Australian Research Council (ARC) Centre of Excellence for Nanoscale BioPhotonics (CE140100003).Purpose Vitrification permits long-term banking of oocytes and embryos. It is a technically challenging procedure requiring direct handling and movement of cells between potentially cytotoxic cryoprotectant solutions. Variation in adherence to timing, and ability to trace cells during the procedure, affects survival post-warming. We hypothesized that minimizing direct handling will simplify the procedure and improve traceability. To address this, we present a novel photopolymerized device that houses the sample during vitrification. Methods The fabricated device consisted of two components: the Pod and Garage. Single mouse oocytes or embryos were housed in a Pod, with multiple Pods docked into a Garage. The suitability of the device for cryogenic application was assessed by repeated vitrification and warming cycles. Oocytes or early blastocyst-stage embryos were vitrified either using standard practice or within Pods and a Garage and compared to non-vitrified control groups. Post-warming, we assessed survival rate, oocyte developmental potential (fertilization and subsequent development) and metabolism (autofluorescence). Results Vitrification within the device occurred within ~ 3 nL of cryoprotectant: this volume being ~ 1000-fold lower than standard vitrification. Compared to standard practice, vitrification and warming within our device showed no differences in viability, developmental competency, or metabolism for oocytes and embryos. The device housed the sample during processing, which improved traceability and minimized handling. Interestingly, vitrification-warming itself, altered oocyte and embryo metabolism. Conclusion The Pod and Garage system minimized the volume of cryoprotectant at vitrification—by ~ 1000-fold—improved traceability and reduced direct handling of the sample. This is a major step in simplifying the procedure.Publisher PDFPeer reviewe