Disrupted White Matter Microstructure of the Cerebellar Peduncles in Scholastic Athletes After Concussion.

Concussion, or mild traumatic brain injury (mTBI), is a major public health concern, linked with persistent post-concussive syndrome, and chronic traumatic encephalopathy. At present, standard clinical imaging fails to reliably detect traumatic axonal injury associated with concussion and post-concussive symptoms. Diffusion tensor imaging (DTI) is an MR imaging technique that is sensitive to changes in white matter microstructure. Prior studies using DTI did not jointly investigate white matter microstructure in athletes, a population at high risk for concussive and subconcussive head traumas, with those in typical emergency room (ER) patients. In this study, we determine DTI scalar metrics in both ER patients and scholastic athletes who suffered concussions and compared them to those in age-matched healthy controls. In the early subacute post-concussion period, athletes demonstrated an elevated rate of regional decreases in axial diffusivity (AD) compared to controls. These regional decreases of AD were especially pronounced in the cerebellar peduncles, and were more frequent in athletes compared to the ER patient sample. The group differences may indicate differences in the mechanisms of the concussive impacts as well as possible compound effects of cumulative subconcussive impacts in athletes. The prevalence of white matter abnormality in cerebellar tracts lends credence to the hypothesis that post-concussive symptoms are caused by shearing of axons within an attention network mediated by the cerebellum, and warrant further study of the correlation between cerebellar DTI findings and clinical, neurocognitive, oculomotor, and vestibular outcomes in mTBI patients

Temperature Controlled Stacked Board Cavity

This publication describes techniques and apparatuses that decrease the temperature variation in a cavity created by an interposer that stacks two or more boards inside a smartphone. When operating electrical components, heat generation is inevitable. A way to minimize temperature variation is by embracing and managing a safe rise in temperature in and/or around the electrical components inside the cavity of the interposer. A safe rise in temperature may be a temperature between +25°C and +85°C (e.g., +55°C). That way, when the smartphone shifts from an idle state to normal operation, the cavity of the interposer and the electrical components inside the cavity do not experience a large temperature variation—the cavity is pre-warmed. Less temperature variation enables the smartphone to use less complex software and lookup tables that are limited to one temperature (e.g., +55°C) instead of a wide range of temperatures, such as from -40°C to +85°C. Limiting temperature variation by keeping the cavity of the interposer above room temperature and below the maximum temperature offers consistent smartphone performance, better space utilization, and decreased manufacturing and/or operational cost

Individual Differences in Distinct Components of Attention are Linked to Anatomical Variations in Distinct White Matter Tracts

Inter-subject variations in white matter tract properties are known to correlate with individual differences in performance in cognitive domains such as attention. The specificity of such linkages, however, is largely unexplored at the level of specific component operations of attention associated with distinct anatomical networks. This study examines individual performance variation within three functional components of attention – alerting, orienting, and conflict processing – identified by the Attention Network Task (ANT), and relates each to inter-subject variation in a distinct set of white matter tract regions. Diffusion tensor imaging data collected at 3T was used to calculate average fractional anisotropy within a set of individualized a priori defined regions of interest using the Reproducible Objective Quantification Scheme (ROQS) (Niogi and McCandliss, 2006; Niogi et al., 2007). Results demonstrate three functionally distinct components of attention that each correlate distinctly with three white matter tract regions. Structure–function correlations were found between alerting and the anterior limb of the internal capsule, orienting and the splenium of the corpus callosum, and conflict and the anterior corona radiata. A multiple regression/dissociation analysis demonstrated a triple dissociation between these three structure-function relationships that provided evidence of three anatomically and functionally separable networks. These results extend previous findings from functional imaging and lesion studies that suggest these three components of attention are subserved by dissociable networks, and suggest that variations in white matter tract microstructure may modulate the efficiency of these cognitive processes in highly specific ways

Recreating the perivascular niche ex vivo using a microfluidic approach

Stem cell niches are composed of numerous microenvironmental features, including soluble and insoluble factors, cues from other cells, and the extracellular matrix (ECM), which collectively serve to maintain stem cell quiescence and promote their ability to support tissue homeostasis. A hallmark of many adult stem cell niches is their proximity to the vasculature in vivo, a feature common to neural stem cells, mesenchymal stem cells (MSCs) from bone marrow and adipose tissue, hematopoietic stem cells, and many tumor stem cells. In this study, we describe a novel 3D microfluidic device (MFD) as a model system in which to study the molecular regulation of perivascular stem cell niches. Endothelial cells (ECs) suspended within 3D fibrin gels patterned in the device adjacent to stromal cells (either fibroblasts or bone marrow-derived MSCs) executed a morphogenetic process akin to vasculogenesis, forming a primitive vascular plexus and maturing into a robust capillary network with hollow well-defined lumens. Both MSCs and fibroblasts formed pericytic associations with the ECs but promoted capillary morphogenesis with distinct kinetics. Biochemical assays within the niche revealed that the perivascular association of MSCs required interaction between their Α6Β1 integrin receptor and EC-deposited laminin. These studies demonstrate the potential of this physiologically relevant ex vivo model system to study how proximity to blood vessels may influence stem cell multipotency. Biotechnol. Bioeng. 2010;107: 1024–1032. © 2010 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78244/1/22891_ftp.pd

Moisture Accumulation and Its Impact on the Thermal Performance of Pipe Insulation for Chilled Water Pipes in High Performance Buildings

Mechanical pipe insulation systems are commonly applied to cold piping surfaces in most industrial and commercial buildings in order to limit the heat losses and prevent water vapor condensation on the pipe exterior surfaces. Due to the fact that the surface temperature of these pipelines is normally below the ambient dew point temperature, water vapor diffuses inside the pipe insulation systems and often condenses when it reaches the pipe exterior surfaces. The water droplets accumulated in the pipe insulation system increase its overall thermal conductivity by thermal bridging the cells or the fibers of the insulation material. The moisture ingress into pipe insulation threatens the thermal performance and the overall efficiency of the building mechanical system. This phenomenon is also responsible for the mold growth inside occupied spaces and causes the pipelines to be more vulnerable to corrosion. Although a wide range of vapor barriers are used for preventing water vapor penetration into pipe insulation, common experience in the field shows that water vapor will inevitably ingress into the insulation materials from the end joints or from the cracks created during insulation installation. How to account for the moisture ingress on pipe insulation service life and thermal performance is still an open question. Thermal conductivity is one of the most important properties for evaluating the thermal performance of the pipe insulation systems. Using a new test apparatus, the thermal conductivity of pipe insulation systems below ambient temperature and in wet conditions with moisture ingress was measured. Fiberglass and phenolic pipe insulation were tested to investigate the moisture effects on the material thermal conductivity. The data showed that these two types of pipe insulation systems had quite different water absorption rates due to different characteristics of the material and its structure. A serious degradation of fiberglass pipe insulation thermal performance was observed and the thermal conductivity increased by as much as 3 times when the moisture content was about 12 percent in volume. Tested at a different condition, the thermal conductivity of phenolic pipe insulation increased to 1.6 times of the original value and the moisture content was 5% in volume. Considering the gravity effect, the moisture content on the top and bottom C-shells were separately measured and discussed in this paper

Preparation of Gliclazide Nanoparticles via Electrospraying Method and Evaluation of Their Physicochemical Properties

Introduction:  Gliclazide is a second-generation sulfonylurea used in the treatment of non-insulin dependent diabetes mellitus. Gliclazide is practically insoluble in water, therefore, researchers try to find techniques to improve its physicochemical properties. On the other hand, researches has shown that nanoparticles are effective in improving the physicochemical characteristics of poorly water-soluble drugs. There are many methods to prepare nanoparticles, among all, electrospraying as a one-step and cost-benefit technique can  be easily applied in industrial scale. Methods and Results:  Gliclazide and polymer (Eudragit RS100 or PEG6000) were co-dissolved in acetone with drug: polymer ratios of 1:5 and 1:10, so that the polymer solution concentrations were 10, 15 and 20% (w/v). Then these solutions were electosprayed. The particle size and morphology were evaluated using scanning electron microscopy (SEM). The physicochemical characteristics of nanofibers and nanoparticles were evaluated by DSC thermograms, FTIR spectroscopy and X-Ray crystallography. Drug release profiles were studied as well. The size of prepared nanofibers and nanobeads, ranged from 100 nm-500 nm. Based on the physicochemical characteristics, there was a transition from crystalline to amorphous state of Gliclazide. No interaction between drug and polymers were observed in the prepared nanoparticles. In vitro drug release studies revealed that the drug-release patterns were improved in the prepared nanoparticles. Conclusions:  Electrospraying is a simple and low-cost method that can be used to produce Gliclazide nanoparticles in industrial scale and improve physicochemical properties of the drug

Bee-Friendly Beef: Developing Biodiverse Pastures to Increase Ecosystem Services

The capacity of grasslands to provide ecosystem services, such as pollinator resources, is often limited by lack of plant biodiversity. This is true of grasslands in the eastern US that are dominated by tall fescue (Festuca arundinacea) a non-native, cool-season grass that is typically toxic to cattle. This paper summarizes a research project in Virginia, USA exploring the idea that ecosystem services provided by tall fescue-dominated grasslands can be improved by increasing the plant biodiversity available to beef cattle and bees. Within three 6.5 ha tall fescue grasslands, we established 0.8 ha plots with a 17 species mix of native warm-season grasses (NWSGs) and wildflowers. Beginning in 2018, we measured grass and wildflower establishment, attractiveness of wildflowers to bees, abundance and diversity of bee communities in biodiverse pastures and adjacent tall fescue pastures. Many of the 18 species sown established well expect for NWSGs. Competition from wildflowers likely suppressed native grasses and limited forage availability for beef cattle. Cattle largely ignored the wildflowers. This finding suggests that cattle and pollinators can share this biodiverse grassland as their primary foods are mutually exclusive. The total number of bees was almost double in wildflower-enhanced grasslands compared with more typical tall fescue grasslands. We observed most bee landings on purple coneflower (Echinacea purpurea) and anise hyssop (Agastache foeniculum). Several weedy species such as milkweed (Asclepias syriaca) and musk thistle (Carduus nutans) were also attractive to bees. Preliminary analyses identified at least 28 bee morphospecies and a distinct bee community present in wildflower pastures. While these results were promising, more research is needed on ways to establish biodiverse grasslands so that a more optimal balance of grasses and wildflowers can be sustained to benefit both cattle production and pollinators