Comparison of triploid and diploid rainbow trout (Oncorhynchus mykiss) fine-scale movement, migration and catchability in lowland lakes of western Washington

Fisheries managers stock triploid (i.e., infertile, artifcially produced) rainbow trout Oncorhynchus mykiss in North American lakes to support sport fsheries while minimizing the risk of genetic introgression between hatchery and wild trout. In Washington State, the Washington Department of Fish and Wildlife (WDFW) allocates approximately US $3 million annually to stock hatchery-origin rainbow trout in>600 lakes, yet only about 10% of them are triploids. Many lakes in Washington State drain into waters that support wild anadromous steelhead O. mykiss that are listed as threatened under the U.S. Endangered Species Act. As a result, there is a strong interest in understanding the costs and benefts associated with stocking sterile, triploid rainbow trout as an alternative to traditional diploids. The objectives of this study were to compare triploid and diploid rainbow trout in terms of: (1) contribution to the sport fshery catch, (2) fne-scale movements within the study lakes, (3) rate of emigration from the lake, and (4) natural mortality. Our results demonstrated that triploid and diploid trout had similar day-night distribution patterns, but triploid trout exhibited a lower emigration rate from the lake and lower catch rates in some lakes. Overall, triploid rainbow trout represent a viable alternative to stocking of diploids, especially in lakes draining to rivers, because they are sterile, have comparable home ranges, and less often migrat

Diet Composition and Body Condition of Northern Continental Divide Grizzly Bears, Montana

From 2009–2013, we documented apparent population health by investigating food use and physiological condition of grizzly bears (Ursus arctos) in the Northern Continental Divide Ecosystem (NCDE), Montana.  We used stable isotope analysis upon hair and blood tissue to obtain information on percent terrestrial meat and plant matter in the diets of NCDE bears.  We also assessed body fat content of grizzly bears via bioelectrical impedance analysis.  Adult females used less meat compared to subadults and adult males (P < 0.0001).  Bears within regions on the southwestern, southern, and eastern periphery of the ecosystem consumed a significantly higher proportion of meat than those in the interior or northwestern periphery (P < 0.0001).  Diets of bears in the Whitefish Mountains and North and South Fork of the Flathead River were, on average, composed of 70% less meat than those on the East Front.  Adult males had significantly higher den entrance body fat contents than adult females and subadults (P < 0.0001).  Average body fat of adult females varied significantly between those in areas of high consumption of meat and those otherwise.  However, we find adult females across all regions enter dens at mean fat levels above those thought to be critical for cub production (i.e., > 20%).  We conclude that, within each region, the quantity and quality of foods appear adequate to meet the needs of reproductively-active adult females.  As truly opportunistic omnivores, grizzly bears in each region of the NCDE exploit diverse combinations of food items to arrive at productive body conditions

Estimation of Sustainable Mortality Thresholds for Grizzly Bears in the Northern Continental Divide Ecosystem

Habitat management and limits on mortality have led to population growth and sizable range expansion for the federally-listed grizzly bear population in the Northern Continental Divide Ecosystem (NCDE), Montana.  Human-caused mortality has coincidentally increased, but it is not clear what level of human-caused mortality would cause the population to decline. A record of annual documented mortalities of independent (?2 years old) bears is maintained for the NCDE, from which an estimate of the total number of mortalities is generated.  Our goal was to estimate sustainable survival rates for independent bears and to develop realistic thresholds for sustainable mortality, which could be applied to these annual estimates.  We estimated survival and recruitment rates using 662 bear-years of telemetry data, performed stochastic modeling, and estimated the annual growth rate as 1.023 and annual population size as 765–960 during 2004–2014.  We then evaluated minimum independent survival rates consistent with a stable to increasing trend, and integrated these sustainable rates with model-estimated population size and mean estimates of total annual independent bear mortality to establish mortality thresholds.  During 2004–2014, estimates of total annual mortality were highly variable, but averaged 13.8 for females and 16.4 for males.  For females and males, respectively, these estimates accounted for only 69% (range 28–168%) and 62% (28–121%) of sustainable mortality thresholds, indicating that approximately 6 and 10 additional annual mortalities could have been sustained without the population declining.  Application and periodic reevaluation of mortality thresholds will help managers reach or maintain a target population size for grizzly bears in the NCDE

Trends in waterbird diversity at Banzi, Shokwe and Nyamithi pans, Ndumo Game Reserve, South Africa

Our understanding of the timeous changes to pan-associated bird diversity is very important for the conservation of these wetlands. At Ndumo Game Reserve, a Ramsar site located in northern KwaZulu-Natal, seasonal (from March 2005 to January 2006 at Nyamithi Pan) and long-term (1993 to 2008 at Banzi, Shokwe and Nyamithi pans) changes in the composition of waterbird assemblages were investigated. The numbers of waterbirds were determined and their relationship to water level and diet investigated for winter and summer. Banzi Pan was dominated by piscivorous species that used shallow water and the waterbird assemblage of this pan was stable in the long term. At Shokwe Pan, species richness and the overall abundance of waterbirds showed a long-term increase in winter. At this pan, decreasing water levels may have benefited insect-eating, shoreline users, resulting in an increased waterbird population. At Nyamithi Pan, over the short-term, in shallower water the insectivorous shoreline and mudflat users dominated, and in deeper water the larger piscivorous species. Over the long-term, in both summer and winter, variability of bird abundance decreased, although numbers still showed considerable fluctuation. The species composition of waterbirds is different at each of the pans and all are valuable for waterbird conservation.Keywords: diversity, Ndumo Game Reserve, riparian vegetation, waterbirdsOSTRICH 2013, 84(1): 47–6

Factors Influencing Non-Fungible Tokens (NFT) Game Engagement during the COVID-19 pandemic: The Theory of Planned Behavior (TPB) and Hedonic Motivation System Adoption Model (HMSAM) Approach

The prominent form of Non-Fungible Token (NFT) is found in the gaming industry. NFT games received immense attention during the COVID-19 pandemic because of their play-to-earn model. NFT gamers can enjoy and increase their finances in their spare time. Hence, the researchers utilized Structural Equation Modeling (SEM) to investigate the intention and immersive behaviors of 1082 respondents. The modified framework from the Theory of Planned Behavior (TPB) and Hedonic Motivation System Adoption Model (HMSAM) underwent SEM tests. These theories and methods were used to analyze relationships among hypotheses and assess factors influencing NFT game engagement. The results showed that hedonic motivation produced positive and significant influences on perceived usefulness, curiosity, joy, attitude, subjective norms, and perceived behavioral control. Subjective norms significantly influenced perceived ease of use. In due course, perceived ease of use yielded positive and significant effects on perceived usefulness, joy, attitude, and perceived behavioral control. Moreover, perceived usefulness, curiosity, joy, attitude, and perceived behavioral control had significant positive effects on behavioral intention. In addition, perceived usefulness, curiosity, joy, and attitude significantly and positively affected immersion. Meanwhile, only four hypotheses were not supported by the study. These findings were translated into theoretical and managerial implications to contribute to the academe given the strong the change of behavior of users towards NFT games during the pandemic; gaming industry since they will be able to develop, improve and create a new ecosystem in the gaming space, and NFT stakeholders since they will benefit from the development that will influence this study

Grizzly Bear Population Vital Rates and Trend in the Northern Continental Divide Ecosystem, Montana

We estimated grizzly bear (Ursus arctos) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 and 2009 by following radio-collared females and observing their fate and reproductive performance. Our estimates of dependent cub and yearling survival were 0.612 (95% CI = 0.300–0.818) and 0.682 (95% CI = 0.258–0.898). Our estimates of subadult and adult female survival were 0.852 (95% CI = 0.628–0.951) and 0.952 (95% CI = 0.892– 0.980). From visual observations, we estimated a mean litter size of 2.00 cubs/litter. Accounting for cub mortality prior to the first observations of litters in spring, our adjusted mean litter size was 2.27 cubs/litter. We estimated the probabilities of females transitioning from one reproductive state to another between years. Using the stable state probability of 0.322 (95% CI = 0.262–0.382) for females with cub litters, our adjusted fecundity estimate (mx) was 0.367 (95% CI = 0.273–0.461). Using our derived rates, we estimated that the population grew at a mean annual rate of approximately 3% (λ = 1.0306, 95% CI = 0.928–1.102), and 71.5% of 10,000 Monte Carlo simulations produced estimates of λ \u3e 1.0. Our results indicate an increasing population trend of grizzly bears in the NCDE. Coupled with concurrent studies of population size, we estimate that over 1,000 grizzly bears reside in and adjacent to this recovery area. We suggest that monitoring of population trend and other vital rates using radioed females be continued

Grizzly Bear Population Vital Rates and Trend in the Northern Continental Divide Ecosystem, Montana

We estimated grizzly bear (Ursus arctos) population vital rates and trend for the Northern Continental Divide Ecosystem (NCDE), Montana, between 2004 and 2009 by following radio-collared females and observing their fate and reproductive performance. Our estimates of dependent cub and yearling survival were 0.612 (95% CI = 0.300–0.818) and 0.682 (95% CI = 0.258–0.898). Our estimates of subadult and adult female survival were 0.852 (95% CI = 0.628–0.951) and 0.952 (95% CI = 0.892– 0.980). From visual observations, we estimated a mean litter size of 2.00 cubs/litter. Accounting for cub mortality prior to the first observations of litters in spring, our adjusted mean litter size was 2.27 cubs/litter. We estimated the probabilities of females transitioning from one reproductive state to another between years. Using the stable state probability of 0.322 (95% CI = 0.262–0.382) for females with cub litters, our adjusted fecundity estimate (mx) was 0.367 (95% CI = 0.273–0.461). Using our derived rates, we estimated that the population grew at a mean annual rate of approximately 3% (λ = 1.0306, 95% CI = 0.928–1.102), and 71.5% of 10,000 Monte Carlo simulations produced estimates of λ \u3e 1.0. Our results indicate an increasing population trend of grizzly bears in the NCDE. Coupled with concurrent studies of population size, we estimate that over 1,000 grizzly bears reside in and adjacent to this recovery area. We suggest that monitoring of population trend and other vital rates using radioed females be continued

Comparison of triploid and diploid rainbow trout (Oncorhynchus mykiss) fine-scale movement, migration and catchability in lowland lakes of western Washington

Abstract Fisheries managers stock triploid (i.e., infertile, artificially produced) rainbow trout Oncorhynchus mykiss in North American lakes to support sport fisheries while minimizing the risk of genetic introgression between hatchery and wild trout. In Washington State, the Washington Department of Fish and Wildlife (WDFW) allocates approximately US $3 million annually to stock hatchery-origin rainbow trout in > 600 lakes, yet only about 10% of them are triploids. Many lakes in Washington State drain into waters that support wild anadromous steelhead O. mykiss that are listed as threatened under the U.S. Endangered Species Act. As a result, there is a strong interest in understanding the costs and benefits associated with stocking sterile, triploid rainbow trout as an alternative to traditional diploids. The objectives of this study were to compare triploid and diploid rainbow trout in terms of: (1) contribution to the sport fishery catch, (2) fine-scale movements within the study lakes, (3) rate of emigration from the lake, and (4) natural mortality. Our results demonstrated that triploid and diploid trout had similar day-night distribution patterns, but triploid trout exhibited a lower emigration rate from the lake and lower catch rates in some lakes. Overall, triploid rainbow trout represent a viable alternative to stocking of diploids, especially in lakes draining to rivers, because they are sterile, have comparable home ranges, and less often migrate

High-throughput screening of human induced pluripotent stem cell-derived brain organoids

[Display omitted] •Organoid models can be optimized for use in high-throughput screens to study disease relevant phenotypes.•High-throughput imaging can be used for morphological analyses in neural organoids.•MEA recordings are multiplexed with high-throughput imaging to analyze neuronal circuits at network and single-cell levels. The need for scalable high-throughput screening (HTS) approaches for 3D human stem cell platforms remains a central challenge for disease modeling and drug discovery. We have developed a workflow to screen cortical organoids across platforms. We used serum-free embryoid bodies (SFEBs) derived from human induced pluripotent stem cells (hiPSCs) and employed high-content imaging (HCI) to assess neurite outgrowth and cellular composition within SFEBs. We multiplexed this screening assay with both multi-electrode arrays (MEAs) and single-cell calcium imaging. HCI was used to assess the number of excitatory neurons (VGlut+) in experimental replicates of hiPSC-derived SFEBs, demonstrating experiment-to-experiment consistency. Neurite detection using HCI was applied to assess neurite morphology. MEA analysis showed that firing and burst rates in SFEBs decreased with blockade of NMDARs and AMPARs and increased with GABAR blockade. We also demonstrate effective combination of both MEA and HCI to analyze VGlut+ populations surrounding electrodes within MEAs. HCI-based (Ca2+) transient analysis revealed firing in individual cells surrounding active MEA electrodes. Current methods to generate neural organoids show high degrees of variability, and often require sectioning or special handling for analysis. The protocol outlined in this manuscript generates SFEBs with high degree of consistency making them amenable to complex assays combining HTS and electrophysiology allowing for an in-depth, unbiased analysis. SFEBs can be used in combination with HTS to compensate for experimental variability common in 3D cultures, while significantly decreasing processing speed, making this an efficient starting point for phenotypic drug screening