Innervation of the receptors present at the various joints of the pereiopods and third maxilliped of Homarus gammarus (L.) and other macruran decapods (crustacea)

This paper gives a full account of the number and structure of the chordotonal organs present at all joints between the coxopodite and dactylopodite of the pereiopods and 3rd maxilliped of the macruran Homarus gammarus L. ( H. vulgaris M. Ed.). Some comparative data is supplied for other macruran decapods. As the form of the receptors depends to some degree upon the structure of the joint we have included details of musculature, planes of movement and degrees of freedom at each of the joints.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47101/1/359_2004_Article_BF00297736.pd

Fine root chemistry and decomposition in model communities of north-temperate tree species show little response to elevated atmospheric CO 2 and varying soil resource availability

Rising atmospheric [CO 2 ] has the potential to alter soil carbon (C) cycling by increasing the content of recalcitrant constituents in plant litter, thereby decreasing rates of decomposition. Because fine root turnover constitutes a large fraction of annual NPP, changes in fine root decomposition are especially important. These responses will likely be affected by soil resource availability and the life history characteristics of the dominant tree species. We evaluated the effects of elevated atmospheric [CO 2 ] and soil resource availability on the production and chemistry, mycorrhizal colonization, and decomposition of fine roots in an early- and late-successional tree species that are economically and ecologically important in north temperate forests. Open-top chambers were used to expose young trembling aspen ( Populus tremuloides ) and sugar maple ( Acer saccharum ) trees to ambient (36 Pa) and elevated (56 Pa) atmospheric CO 2 . Soil resource availability was composed of two treatments that bracketed the range found in the Upper Lake States, USA. After 2.5 years of growth, sugar maple had greater fine root standing crop due to relatively greater allocation to fine roots (30% of total root biomass) relative to aspen (7% total root biomass). Relative to the low soil resources treatment, aspen fine root biomass increased 76% with increased soil resource availability, but only under elevated [CO 2 ]. Sugar maple fine root biomass increased 26% with increased soil resource availability (relative to the low soil resources treatment), and showed little response to elevated [CO 2 ]. Concentrations of N and soluble phenolics, and C/N ratio in roots were similar for the two species, but aspen had slightly higher lignin and lower condensed tannins contents compared to sugar maple. As predicted by source-sink models of carbon allocation, pooled constituents (C/N ratio, soluble phenolics) increased in response to increased relative carbon availability (elevated [CO 2 ]/low soil resource availability), however, biosynthetically distinct compounds (lignin, starch, condensed tannins) did not always respond as predicted. We found that mycorrhizal colonization of fine roots was not strongly affected by atmospheric [CO 2 ] or soil resource availability, as indicated by root ergosterol contents. Overall, absolute changes in root chemical composition in response to increases in C and soil resource availability were small and had no effect on soil fungal biomass or specific rates of fine root decomposition. We conclude that root contributions to soil carbon cycling will mainly be influenced by fine root production and turnover responses to rising atmospheric [CO 2 ], rather than changes in substrate chemistry.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47710/1/442_2005_Article_191.pd

Racial Microaggressions and Latinxs\u27 Well-being: A Systematic Review

As a form of racism that is both subtle and ubiquitous, racial microaggressions (RMAs) can have cumulatively deleterious physical and emotional effects on people of a specific race or ethnicity. While a significant body of knowledge about RMAs has been developed from a Black-White perspective, this study was undertaken to explore extant empirical research that specifically addresses the physical and emotional effects of racism and RMAs on people who are Latinx-American. Through the implementation of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, we systematically searched multiple databases (PubMed, PsycInfo, Social Services Abstract, and CINAHL) to identify studies that specifically focused on Latinxs’ well-being in response to RMA. Following a systematic search and screening process, nine studies met all of the study’s inclusion criteria. Researchers reviewed studies for content, methods, effect sizes, and risk of bias. Strengths and shortcomings of the existing studies were identified, followed by suggestions for future research

Effects of Atmospheric CO2 Enrichment on Soil CO2 Efflux in a Young Longleaf Pine System

The southeastern landscape is composed of agricultural and forest systems that can store carbon (C) in standing biomass and soil. Research is needed to quantify the effects of elevated atmospheric carbon dioxide (CO2) on terrestrial C dynamics including CO2 release back to the atmosphere and soil sequestration. Longleaf pine savannahs are an ecologically and economically important, yet understudied, component of the southeastern landscape. We investigated the effects of ambient and elevated CO2 on soil CO2 efflux in a young longleaf pine system using a continuous monitoring system. A significant increase (26.5%) in soil CO2 efflux across 90 days was observed under elevated CO2; this occurred for all weekly and daily averages except for two days when soil temperature was the lowest. Soil CO2 efflux was positively correlated with soil temperature with a trend towards increased efflux response to temperature under elevated CO2. Efflux was negatively correlated with soil moisture and was best represented using a quadratic relationship. Soil CO2 efflux was not correlated with root biomass. Our data indicate that, while elevated CO2 will increase feedback of CO2 to the atmosphere via soil efflux, terrestrial ecosystems will remain potential sinks for atmospheric CO2 due to greater biomass production and increased soil C sequestration

Cognitive Impairments, Neuroinflammation and Blood–Brain Barrier Permeability in Mice Exposed to Chronic Sleep Fragmentation during the Daylight Period

Obstructive sleep apnea (OSA) is a chronic condition characterized by intermittent hypoxia (IH) and sleep fragmentation (SF). In murine models, chronic SF can impair endothelial function and induce cognitive declines. These deficits are likely mediated, at least in part, by alterations in Blood–brain barrier (BBB) integrity. Male C57Bl/6J mice were randomly assigned to SF or sleep control (SC) conditions for 4 or 9 weeks and in a subset 2 or 6 weeks of normal sleep recovery. The presence of inflammation and microglia activation were evaluated. Explicit memory function was assessed with the novel object recognition (NOR) test, while BBB permeability was determined by systemic dextran-4kDA-FITC injection and Claudin 5 expression. SF exposures resulted in decreased NOR performance and in increased inflammatory markers and microglial activation, as well as enhanced BBB permeability. Explicit memory and BBB permeability were significantly associated. BBB permeability remained elevated after 2 weeks of sleep recovery (p < 0.01) and returned to baseline values only after 6 weeks. Chronic SF exposures mimicking the fragmentation of sleep that characterizes patients with OSA elicits evidence of inflammation in brain regions and explicit memory impairments in mice. Similarly, SF is also associated with increased BBB permeability, the magnitude of which is closely associated with cognitive functional losses. Despite the normalization of sleep patterns, BBB functional recovery is a protracted process that merits further investigation

Influence of Elevated CO\u3csub\u3e2\u3c/sub\u3e, Nitrogen, and \u3ci\u3ePinus elliottii\u3c/i\u3e Genotypes on Performance of the Redheaded Pine Sawfly, \u3ci\u3eNeodiprion lecontei\u3c/i\u3e

Slash pine (Pinus elliottii Engelm. var. elliottii) seedlings were grown in open-top chambers receiving ambient or elevated atmospheric CO2 (-365 or -720 μL.L-1). Seedlings received low or high soil nitrogen treatments (0.02 or 0.2 mg N.g-1) and represented three families varying in resistance to fusiform rust (Cronartium quercuum (Berk.) Miyabe ex Shirai f. sp. fusiforme (Hedgc. & N. Hunt) Burdsall & G. Snow). Following 18 months of exposure to treatment conditions, current-year needles were fed to larvae of the redheaded pine sawfly (Neodiprion lecontei (Fitch)). Needle N concentration and water content were lower in elevated-CO2 and in low-N treatments. Total phenolics increased under high-CO2 and low-N conditions and were highest in the resistant family. Condensed tannins did not vary on the basis of CO2 or N but were higher in needles from the resistant family. Alterations in needle chemistry were associated with variations in sawfly growth and development. Larvae performed most poorly on the family most resistant to fusiform rust, suggesting that the mechanism for resistance was similar in both cases. Relative consumption rates increased with CO2-enriched needle diets but were depressed for resistant needles, suggesting deterrence from the higher total phenolics in this family. Diets using CO2-enriched needles or resistant needles or needles from low-N fertilization treatments resulted in lower relative growth rates for the larvae. Days to pupation increased for larvae fed CO2-enriched and low-N needles. These results suggest that the redheaded pine sawfly could suffer as the level of atmospheric CO2 continues to rise