Impacts of Man-Made Structures on Avian Community Metrics in 4 State Parks in Northwestern Arkansas

Avian community metrics often differ between areas with no human disturbance and areas with high levels of human disturbance. However, the relationships between avian community metrics and smaller-scale disturbances are not as clear. Our goal was to investigate if avian abundance, richness, evenness, and diversity differed in areas with and without small-scale human developments. We used fixed-radius 50-m avian point counts to compare points which contained a man-made structure (n = 47), such as a picnic area, road, or campsite to those that did not contain a man-made structure (n = 181) at 4 state parks in Arkansas during 18 May – 7 August 2015. We used paired t-tests to compare points at the park scale and one-way ANOVAs or Kruskal-Wallis tests to investigate differences among the hiking and biking trails within parks. At the park scale, avian abundance (t₃ = -1.44, P = 0.246), richness (t₃ = ˗0.86, P = 0.453), diversity (t₃= 2.02, P = 0.137), and evenness (t₃ =˗0.37, P = 0.733) did not differ between points containing man-made structures and points without man-made structures. Species richness (F1,11 = 5.03, P= 0.047) and diversity (X^2₁ = 4.20, P = 0.040) were higher at points with man-made structures (Simpson’s D mean = 0.13 ± 0.01SE; S mean = 8.99 ± 0.70SE) at Pinnacle Mountain than points without man-made structures (Simpson’s D mean = 0.18 ± 0.03SE; S mean = 7.17 ± 0.47SE); abundance (F₁, ₁₁ = 1.43, P =0.257) and evenness (F₁, ₁₁ = 0.16, P = 0.695) did not differ among points. Within the 3 remaining parks, abundance (F₁,7-9 = 0.11 – 2.59, P = 0.152 – 0.748), richness (χ^2 ₁ = 0.300 – 1.68, P = 0.195 – 0.584), diversity (χ2 = 0.300 – 1.05, P = 0.305 – 0.584; F₁,7 =1.82, P = 0.219) and evenness (F₁,7-9 = 0.35 – 4.28, P =0.077 – 0.570) did not differ between points with and without man-made structures. Given the results of our analyses both at the park scale and within parks, it appears that small-scale man-made disturbances may have limited or no impact on avian community metrics

Attributes Preferred and Premiums Offered for Naturally Produced Beef Cattle

A growing number of beef cattle producers in the US are using limited information to determine whether or not it would be economical for them to grow naturally produced cattle. The objective was to discover the attributes that marketing companies prefer for the naturally produced cattle they purchase, and to elicit the price premiums being offered for cattle that possess these attributes. Results of a phone survey of companies that purchase natural cattle show that 27 out of 32 companies report their willingness to pay a premium of $5.95/cwt for cattle that have never received antibiotics, ionophores, hormones or animal by-products.Key words: attributes, beef, cattle, naturally produced, premiums, Agribusiness, Food Consumption/Nutrition/Food Safety, Livestock Production/Industries, Marketing,

Grass Tetany.

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Grass Tetany.

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Handling Newly Purchased Feeder Pigs.

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Diffusion-Based smoothers for spatial filtering of gridded geophysical data

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Grooms, I., Loose, N., Abernathey, R., Steinberg, J. M., Bachman, S. D., Marques, G., Guillaumin, A. P., & Yankovsky, E. Diffusion-Based smoothers for spatial filtering of gridded geophysical data. Journal of Advances in Modeling Earth Systems, 13(9), (2021): e2021MS002552, https://doi.org/10.1029/2021MS002552.We describe a new way to apply a spatial filter to gridded data from models or observations, focusing on low-pass filters. The new method is analogous to smoothing via diffusion, and its implementation requires only a discrete Laplacian operator appropriate to the data. The new method can approximate arbitrary filter shapes, including Gaussian filters, and can be extended to spatially varying and anisotropic filters. The new diffusion-based smoother's properties are illustrated with examples from ocean model data and ocean observational products. An open-source Python package implementing this algorithm, called gcm-filters, is currently under development.I.G. and N.L. are supported by NSF OCE 1912332. R.A. is supported by NSF OCE 1912325. J.S. is supported by NSF OCE 1912302. S.B. and G.M. are supported by NSF OCE 1912420. A.G. and E.Y. are supported by NSF GEO 1912357 and NOAA CVP NA19OAR4310364

Loss of alkyladenine DNA glycosylase alters gene expression in the developing mouse brain and leads to reduced anxiety and improved memory

Neurodevelopment is a tightly coordinated process, during which the genome is exposed to spectra of endogenous agents at different stages of differentiation. Emerging evidence indicates that DNA damage is an important feature of developing brain, tightly linked to gene expression and neuronal activity. Some of the most frequent DNA damage includes changes to DNA bases, which are recognized by DNA glycosylases and repaired through base excision repair (BER) pathway. The only mammalian DNA glycosylase able to remove frequent alkylated DNA based is alkyladenine DNA glycosylase (Aag, aka Mpg). We recently demonstrated that, besides its role in DNA repair, AAG affects expression of neurodevelopmental genes in human cells. Aag was further proposed to act as reader of epigenetic marks, including 5-hydroxymethylcytosine (5hmC), in the mouse brain. Despite the potential Aag involvement in the key brain processes, the impact of Aag loss on developing brain remains unknown. Here, by using Aag knockout (Aag-/-) mice, we show that Aag absence leads to reduced DNA break levels, evident in lowered number of γH2AX foci in postnatal day 5 (P5) hippocampi. This is accompanied by changes in 5hmC signal intensity in different hippocampal regions. Transcriptome analysis of hippocampi and prefrontal cortex, at different developmental stages, indicates that lack of Aag alters gene expression, primarily of genes involved in regulation of response to stress. Across all developmental stages tested aldehyde dehydrogenase 2 (Aldh2) emerged as one of the most prominent genes deregulated in Aag-dependent manner. In line with the changes in hippocampal DNA damage levels and the gene expression, adult Aag-/- mice exhibit altered behavior, evident in decreased anxiety levels determined in the Elevated Zero Maze and increased alternations in the Elevated T Maze tests. Taken together these results suggests that Aag has functions in modulation of genome dynamics during brain development, important for animal behavior.publishedVersio

Relating Coral Skeletal Structures at Different Length Scales to Growth, Light Availability to Symbiodinium, and Thermal Bleaching

Light scattering of coral skeletons and tissues increases light availability to photosynthetic endosymbionts to form one of the most efficient biological collectors of solar radiation. Rapid increases in light availability during thermally-induced symbiont loss (bleaching) impair photosynthetic performance of the remaining Symbiodinium and precipitate a more severe bleaching response (optical feedback-loop hypothesis). Here we focus on light scattering of the skeleton, which is determined by light interaction with skeletal components assembled in a hierarchical fractal-like structure from tens of nanometers (e.g., calcium carbonate nanograins) to micro- and milli-meters (septa, corallites, and coenosteum) to centimeters and higher (colony form). We examined the association between skeletal structures, their role in light scattering, and species-specific bleaching responses for 88 coral species using phylogenetically-corrected analysis. We also explored the effect of growth on light scattering by modeling the fractal-like accretive growth of the skeleton (assuming a diffusion limited process of biomineralization) as a function of skeletal density, size of nanograins, fractal range of biomineralized clusters, and overall mass-fractal dimension, and validated the model with experimental data. Our results show that differences in light scattering from the top ~200 μm (micro-μs′) of the skeleton, and not from the whole skeleton (bulk-μs′), are related to bleaching susceptibility. We also demonstrate how differences in micro-μs′ of corallites and coenosteum could explain, in part, the heterogeneous light environment between polyp and coenosarc. The average effective light transport distance of coenosteum measured in 14 coral species indicates that coenosteum could transport light to the corallites, which could then function as “light-trapping devices” where photons are scattered multiple times by septa and corallite walls until absorbed by Symbiodinium. Furthermore, our fractal skeletal growth model suggests that corals that grow faster typically have lower mass-fractal dimension, denser skeletons, lower skeletal micro-μs′, and higher bleaching susceptibility. Finally, our results demonstrate that several skeletal structures of varying length scales known to modulate the light microenvironment of Symbiodinium in coral tissue are not associated with bleaching susceptibility. This work provides evidence of the relationship between skeletal growth, light scattering, and bleaching, and further supports the optical feedback-loop hypothesis of coral bleaching

Parameterizing the Impact of Unresolved Temperature Variability on the Large-Scale Density Field: 2. Modeling

Ocean circulation models have systematic errors in large-scale horizontal density gradients due to estimating the grid-cell-mean density by applying the nonlinear seawater equation of state to the grid-cell-mean water properties. In frontal regions where unresolved subgrid-scale (SGS) fluctuations are significant, dynamically relevant errors in the representation of current systems can result. A previous study developed a novel and computationally efficient parameterization of the unresolved SGS temperature variance and resulting density correction. This parameterization was empirically validated but not tested in an ocean model. In this study, we implement deterministic and stochastic variants of this parameterization in the pressure-gradient force term of a coupled ocean-sea ice configuration of the community Earth system model-modular ocean model version 6 and perform a suite of hindcast sensitivity experiments to investigate the ocean response. The parameterization leads to coherent changes in the large-scale ocean circulation and hydrography, particularly in the Nordic Seas and Labrador Sea, which are attributable in large part to changes in the seasonally varying upper-ocean exchange through Denmark Strait. In addition, the separated Gulf Stream strengthens and shifts equatorward, reducing a common bias in coarse-resolution ocean models. The ocean response to the deterministic and stochastic variants of the parameterization is qualitatively, albeit not quantitatively, similar, yet qualitative differences are found in various regions. &nbsp;</p