The widespread use of neonicotinoid insecticides in recent years has led to increasing environmental concern, including impacts to avian populations. In Texas and across their range, Northern ...bobwhite (Colinus virginianus) habitat frequently overlaps cultivated cropland protected by neonicotinoids. To address the effects of neonicotinoid use on bobwhites in Texas, we conducted a historical analysis from 1978-2012 in Texas' ecological regions using quail count data collected from North American Breeding Bird Survey and Texas Parks and Wildlife Department, and neonicotinoid use data from the U.S. Geological Survey. We considered bobwhite abundance, neonicotinoid use, climate, and land-use variables in our analysis. Neonicotinoid use was significantly (p<0.05) negatively associated with bobwhite abundance in the High Plains, Rolling Plains, Gulf Coast Prairies & Marshes, Edwards Plateau, and South Texas Plains ecological regions in the time periods following neonicotinoid introduction (1994-2003) or after their widespread use (2004-2012). Our analyses suggest that the use of neonicotinoid insecticides may negatively affect bobwhite populations in crop-producing regions of Texas.
Northern bobwhites (
Colinus virginianus
) have been declining across the range of the species primarily due to habitat loss and habitat fragmentation. There is increasing concern regarding effects ...related to elevated environmental contaminants, including pesticides and metals. Elevated concentrations of some metals are known to have adverse effects on reproduction, development, and survival in birds; however, little research has been conducted on metal exposure in wild bobwhites. We analyzed metal concentrations in the feathers of 60 bobwhites from 3 ecoregions in Texas and evaluated differences between age-class, gender, and location with the objective of determining if bobwhites in Texas are at increased risk of exposure to elevated metal concentrations. We found feather Pb concentrations above the established effect threshold of 4.0 µg/g dry weight at which sublethal and reproductive effects have been reported in birds. More than 25% (
n
= 16) of the samples analyzed had Pb concentrations above the effect threshold, including four that were five times above the threshold. We also observed slightly elevated feather Cd concentrations, above 0.1 µg/g dry weight, in 17% (
n
= 11) of the bobwhites analyzed. On average, juvenile bobwhites had higher concentrations of Ba, Co, Fe, Mn, Sr, and V compared to adults (
p
< 0.05). Additionally, concentrations of Al, Be, Co, Fe, Hg, Ni, Se, Sr, and Tl differed significantly between sampling locations, indicating a potential relationship between metal levels and local agricultural practices. The results of our study indicate a potential risk of sublethal effects of Pb and to a lesser extent Cd in bobwhites in Texas.
Abstract Observed evolution of the total mass distribution with redshift is crucial to testing galaxy evolution theories. To measure the total mass distribution, strong gravitational lenses ...complement the resolved dynamical observations that are currently limited to z ≲ 0.5. Here we present the lens models for a pilot sample of seven galaxy-scale lenses from the ASTRO3D Galaxy Evolution with Lenses ( AGEL ) survey. The AGEL lenses, modeled using HST/WFC3-F140W images with Gravitational Lens Efficient Explorer ( GLEE ) software, have deflector redshifts in the range 0.3 < z defl < 0.9. Assuming a power-law density profile with slope γ , we measure the total density profile for the deflector galaxies via lens modeling. We also measure the stellar velocity dispersions ( σ obs ) for four lenses and obtain σ obs from SDSS - BOSS for the remaining lenses to test our lens models by comparing observed and model-predicted velocity dispersions. For the seven AGEL lenses, we measure an average density profile slope of −1.95 ± 0.09 and a γ – z relation that does not evolve with redshift at z < 1. Although our result is consistent with some observations and simulations, it differs from other studies at z < 1 that suggest the γ – z relation evolves with redshift. The apparent conflicts among observations and simulations may be due to a combination of (1) systematics in the lensing and dynamical modeling; (2) challenges in comparing observations with simulations; and (3) assuming a simple power law for the total mass distribution. By providing more lenses at z defl > 0.5, the AGEL survey will provide stronger constraints on whether the mass profiles evolve with redshift as predicted by current theoretical models.
Background:
Cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC) are the two major constituents of cannabis with contrasting mechanisms of action. THC is the major psychoactive, addiction-promoting, ...and psychotomimetic compound, while CBD may have opposite effects. The brain effects of these drugs alone and in combination are poorly understood. In particular, the striatum is implicated in the pathophysiology of several psychiatric disorders, but it is unclear how THC and CBD influence striato-cortical connectivity.
Aims:
To examine effects of THC, CBD, and THC + CBD on functional connectivity of striatal sub-divisions (associative, limbic and sensorimotor).
Method:
Resting-state functional Magnetic Resonance Imaging (fMRI) was used across two within-subjects, placebo-controlled, double-blind studies, with a unified analysis approach.
Results:
Study 1 (N = 17; inhaled cannabis containing 8 mg THC, 8 mg THC + 10 mg CBD or placebo) showed strong disruptive effects of both THC and THC + CBD on connectivity in the associative and sensorimotor networks, but a specific effect of THC in the limbic striatum network which was not present in the THC + CBD condition. In Study 2 (N = 23, oral 600 mg CBD, placebo), CBD increased connectivity in the associative network, but produced only relatively minor disruptions in the limbic and sensorimotor networks.
Outcomes:
THC strongly disrupts striato-cortical networks, but this effect is mitigated by co-administration of CBD in the limbic striatum network. Oral CBD administered has a more complex effect profile of relative increases and decreases in connectivity. The insula emerges as a key region affected by cannabinoid-induced changes in functional connectivity, with potential implications for understanding cannabis-related disorders, and the development of cannabinoid therapeutics.
Cannabidiol (CBD) and Δ
-tetrahydrocannabinol (THC) are the two major constituents of cannabis with contrasting mechanisms of action. THC is the major psychoactive, addiction-promoting, and ...psychotomimetic compound, while CBD may have opposite effects. The brain effects of these drugs alone and in combination are poorly understood. In particular, the striatum is implicated in the pathophysiology of several psychiatric disorders, but it is unclear how THC and CBD influence striato-cortical connectivity.
To examine effects of THC, CBD, and THC + CBD on functional connectivity of striatal sub-divisions (associative, limbic and sensorimotor).
Resting-state functional Magnetic Resonance Imaging (fMRI) was used across two within-subjects, placebo-controlled, double-blind studies, with a unified analysis approach.
Study 1 (
= 17; inhaled cannabis containing 8 mg THC, 8 mg THC + 10 mg CBD or placebo) showed strong disruptive effects of both THC and THC + CBD on connectivity in the associative and sensorimotor networks, but a specific effect of THC in the limbic striatum network which was not present in the THC + CBD condition. In Study 2 (
= 23, oral 600 mg CBD, placebo), CBD increased connectivity in the associative network, but produced only relatively minor disruptions in the limbic and sensorimotor networks.
THC strongly disrupts striato-cortical networks, but this effect is mitigated by co-administration of CBD in the limbic striatum network. Oral CBD administered has a more complex effect profile of relative increases and decreases in connectivity. The insula emerges as a key region affected by cannabinoid-induced changes in functional connectivity, with potential implications for understanding cannabis-related disorders, and the development of cannabinoid therapeutics.
Observed evolution of the total mass distribution with redshift is crucial to testing galaxy evolution theories. To measure the total mass distribution, strong gravitational lenses complement the ...resolved dynamical observations currently limited to \(z \lesssim 0.5\). Here we present the lens models for a pilot sample of seven galaxy-scale lenses from the ASTRO3D Galaxy Evolution with Lenses (AGEL) survey. The AGEL lenses, modeled using HST/WFC3-F140W images with Gravitational Lens Efficient Explorer (GLEE) software, have deflector redshifts between \(0.3 < z_{\rm defl} < 0.9\). Assuming a power-law density profile with slope \(\gamma\), we measure the total density profile for the deflector galaxies via lens modeling. We also measure the stellar velocity dispersions (\(\sigma_{\rm obs}\)) for four lenses and obtain \(\sigma_{\rm obs}\) from SDSS-BOSS for the remaining lenses to test our lens models by comparing observed and model-predicted velocity dispersions. For the seven AGEL lenses, we measure an average density profile slope of \(-1.95 \pm 0.09\) and a \(\gamma\)--\(z\) relation that does not evolve with redshift at \(z<1\). Although our result is consistent with some observations and simulations, it differs from other studies at \(z<1\) that suggest the \(\gamma\)--\(z\) relation evolves with redshift. The apparent conflicts among observations and simulations may be due to a combination of 1) systematics in the lensing and dynamical modeling; 2) challenges in comparing observations with simulations; and 3) assuming a simple power-law for the total mass distribution. By providing more lenses at \(z_{\rm defl} > 0.5\), the AGEL survey will provide stronger constraints on whether the mass profiles evolve with redshift as predicted by current theoretical models.
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