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One of the responses to the demands of graduate education in the United States has been the development of faculty directors of graduate programs within academic departments. The title for this position varies widely, but it is most commonly called Graduate Program Director (GPD). The GPD serves at the departmental level and is key in the administration of graduate programs in the U.S. and in a number of other countries. However, little scholarly attention has been brought to examination of these positions although there has been acknowledgement that the faculty members holding them play key roles in student recruitment, socialization, retention, and program completion. This article is the first presentation of multi-institutional survey data on faculty members serving in this role. The survey found that the role is only partially formalized. About half of the survey respondents reported that there were written job descriptions and university-wide policies related to this role. Survey respondents reported a wide range of responsibilities, but rather limited resources to assist them in this role.

Biochar is a promising source of renewable carbon that potentially can serve the same purpose as carbon black (sourced from fossil fuels) to reinforce rubber composites. Pistachio shells are a prolific agricultural waste product that is a suitable feedstock for biochar. Unlike many other agricultural residues, pistachio shells are a feedstock that yields biochar with a high concentration of carbon (>80%) and low concentration of ash (<5%), which is necessary to replace carbon black without detrimental effects to the final composite. Filler blends of pistachio shell biochar and carbon black were explored to see how much carbon black could be replaced before composite properties were affected. Pistachio shell biochar was able to replace up to 40% of the carbon black while improving the tensile strength, elongation, and toughness of the rubber composites, but a reduction in modulus was observed. Based on the results obtained, pistachio shell biochar would be suitable for partially replacing carbon black in applications like hoses, seals, belts, and gloves, thereby enabling a new application for this sustainable, agricultural waste product that will help reduce dependence on fossil fuels. [ABSTRACT FROM AUTHOR]

Antlers are genetically coded to have bilateral symmetry. However, environmental stressors cause asymmetries between antlers. Previous studies have investigated fluctuating asymmetries on harvested white-tailed deer (Odocoileus virginianus Zimmermann, 1780). Cast antlers provide underutilized metrics that are not available prior to shedding. The objectives of this study were to quantify relative fluctuating asymmetry (RFA) between age groups and identify the best age-specific pre- and post-cast antler metrics to confirm an antler pair. We hypothesized lower RFA values for post-cast measurements than pre-cast measurements due to a lessened chance for damage when atop the head. Additionally, younger individuals were hypothesized to have higher RFA values due to greater susceptibility to environmental stressors. Cast antler pairs from 196 white-tailed deer were collected in Nebraska. We measured 14 available antler metrics per cast antler side classified by age group. The most symmetric measurements between antler sides included pedicle seal area, main beam length, and circumference. Antlers of older deer were consistently more symmetric than younger deer. When combining the top metrics and testing against random antler pairs, we found an 81.9–92.3% match rate for 1.5 and ≥2.5-year-olds, respectively. Our findings provided a quantifiable method to assign antler pair classifications more confidently while documenting decreased symmetry in younger individuals. [ABSTRACT FROM AUTHOR]

The chemokine receptors CCR1 and CCR5 display overlapping expression patterns and ligand dependency. Here we find that ligand activation of CCR5, not CCR1, is dependent on N-terminal receptor O-glycosylation. Release from O-glycosylation dependency is obtained by increasing CCR5 N-terminus acidity to the level of CCR1. Ligand activation of CCR5, not CCR1, drastically improves in the absence of glycosaminoglycans (GAGs). Ligand activity at both CCR1 and CCR5 is boosted by positively charged/basic peptides shown to interact with acidic chemokine receptor N-termini. We propose that receptors with an inherent low N-terminus acidity rely on post-translational modifications (PTMs) to efficiently compete with acidic entities in the local environment for ligand capture. Although crucial for initial ligand binding, strong electrostatic interactions between the ligand and the receptor N-terminus may counteract following insertion of the ligand into the receptor binding pocket and activation, a process that seems to be aided in the presence of basic peptides. Basic peptides bind to the naked CCR1 N-terminus, not the CCR5 N-terminus, explaining the loss of boosting of ligand-induced signaling via CCR5 in cells incapable of glycosylation. [ABSTRACT FROM AUTHOR]

Managing ecosystems to maintain biodiversity may be one approach to ensuring their dynamic stability, productivity, and delivery of vital services. The applicability of this approach to industrial ecosystems that harness the metabolic activities of microbes has been proposed but has never been tested at relevant scales. We used a tag-sequencing approach with bacterial small subunit rRNA (16S) genes and eukaryotic internal transcribed spacer 2 (ITS2) to measuring the taxonomic composition and diversity of bacteria and eukaryotes in an open pond managed for bioenergy production by microalgae over a year. Periods of high eukaryotic diversity were associated with high and more-stable biomass productivity. In addition, bacterial diversity and eukaryotic diversity were inversely correlated over time, possibly due to their opposite responses to temperature. The results indicate that maintaining diverse communities may be essential to engineering stable and productive bioenergy ecosystems using microorganisms.

Known for its distinct metamorphic behavior, XCL1 interconverts between a canonical chemokine folded monomer (XCL1mon) that interacts with the receptor, XCR1, and a unique dimer (XCL1dim) that interacts with glycosaminoglycans and inhibits HIV-1 activity. This study presents the first detailed analysis of the GAG binding properties of XCL1dim. Basic residues within a conformationally selective dimeric variant of XCL1 (W55D) were mutated and analyzed for their effects on heparin binding. Mutation of Arg23 and Arg43 greatly diminished the level of heparin binding in both heparin Sepharose chromatography and surface plasmon resonance assays. To assess the contributions of different GAG structures to XCL1 binding, we developed a solution fluorescence polarization assay and correlated affinity with the length and level of sulfation of heparan sulfate oligosaccharides. It was recently demonstrated that the XCL1 GAG binding form, XCL1dim, is responsible for preventing HIV-1 infection through interactions with gp120. This study defines a GAG binding surface on XCL1dim that includes residues that are important for HIV-1 inhibition.