Stability and reactivity of dimethylethoxysilane

The chemistry of the compound dimethylethoxysilane (DMES) is discussed especially as it relates to waterproofing silica surfaces. Some of the desirable properties of this compound are that it readily reacts with silica in the vapor phase, it is a low boiling point liquid (54 C), and the by-product of its reaction with silica is the rather inert substances ethanol. It is currently used by NASA to re-waterproof the HRSI shuttle tiles before relaunching the vehicle. Very little information is available on this particular compound in the literature or even on related silane compounds that have both a hydride group and an alkoxy group. Since the close proximity of two groups often drastically affects the chemical behavior of each group, chemical reactions were carried out in the laboratory with DMES to verify the expected behavior of these two functional groups located on DMES. Some of the reactions tested would be potentially useful for quantitative or qualitative measurements on DMES. To study the reactions of DMES with silica surfaces, cabosil was used as a silica substrate because of its high surface area and the ease of detection by infrared spectroscopy as well as other techniques

Percutaneous Transfemoral Renal Artery Occlusion in the Management of Advanced Renal Carcinoma

This report describes renal artery occlusion as a therapeutic alternative to nephrectomy and chemotherapy in treating patients with metastatic renal carcinoma. Using a combination of Gelfoam and the Gianturco stainless steel coil, embolization was performed on 75 patients at the University of Texas System Cancer Center, M.D. Anderson Hospital and Tumor Institute with promising results. Its use is recommended 1) to facilitate surgical removal of large and difficult tumors, 2) to control local symptoms (pain, bleeding, etc), and 3) as part of a planned therapeutic program consisting of infarction, nephrectomy and progestins for patients with minimal to moderate metastatic disease

Comparing Fixed-amount and Progressive-amount DRO Schedules for Tic Suppression in Youth with Chronic Tic Disorders

Chronic tic disorders (CTDs) involve motor and/or vocal tics that often cause substantial distress and impairment. Differential reinforcement of other behavior (DRO) schedules of reinforcement produce robust, but incomplete, reductions in tic frequency in youth with CTDs; however, a more robust reduction may be needed to affect durable clinical change. Standard, fixed‐amount DRO schedules have not commonly yielded such reductions, so we evaluated a novel, progressive‐amount DRO schedule, based on its ability to facilitate sustained abstinence from functionally similar behaviors. Five youth with CTDs were exposed to periods of baseline, fixed‐amount DRO (DRO‐F), and progressive‐amount DRO (DRO‐P). Both DRO schedules produced decreases in tic rate and increases in intertic interval duration, but no systematic differences were seen between the two schedules on any dimension of tic occurrence. The DRO‐F schedule was generally preferred to the DRO‐P schedule. Possible procedural improvements and other future directions are discussed

SNTF immunostaining reveals previously undetected axonal pathology in traumatic brain injury

Diffuse axonal injury (DAI) is a common feature of severe traumatic brain injury (TBI) and may also be a predominant pathology in mild TBI or “concussion”. The rapid deformation of white matter at the instant of trauma can lead to mechanical failure and calcium-dependent proteolysis of the axonal cytoskeleton in association with axonal transport interruption. Recently, a proteolytic fragment of alpha-II spectrin, “SNTF”, was detected in serum acutely following mild TBI in patients and was prognostic for poor clinical outcome. However, direct evidence that this fragment is a marker of DAI has yet to be demonstrated in either humans following TBI or in models of mild TBI. Here, we used immunohistochemistry (IHC) to examine for SNTF in brain tissue following both severe and mild TBI. Human severe TBI cases (survival <7d; n = 18) were compared to age-matched controls (n = 16) from the Glasgow TBI archive. We also examined brains from an established model of mild TBI at 6, 48 and 72 h post-injury versus shams. IHC specific for SNTF was compared to that of amyloid precursor protein (APP), the current standard for DAI diagnosis, and other known markers of axonal pathology including non-phosphorylated neurofilament-H (SMI-32), neurofilament-68 (NF-68) and compacted neurofilament-medium (RMO-14) using double and triple immunofluorescent labeling. Supporting its use as a biomarker of DAI, SNTF immunoreactive axons were observed at all time points following both human severe TBI and in the model of mild TBI. Interestingly, SNTF revealed a subpopulation of degenerating axons, undetected by the gold-standard marker of transport interruption, APP. While there was greater axonal co-localization between SNTF and APP after severe TBI in humans, a subset of SNTF positive axons displayed no APP accumulation. Notably, some co-localization was observed between SNTF and the less abundant neurofilament subtype markers. Other SNTF positive axons, however, did not co-localize with any other markers. Similarly, RMO-14 and NF-68 positive axonal pathology existed independent of SNTF and APP. These data demonstrate that multiple pathological axonal phenotypes exist post-TBI and provide insight into a more comprehensive approach to the neuropathological assessment of DAI

Plant phenology supports the multi-emergence hypothesis for ebola spillover events

Ebola virus disease outbreaks in animals (including humans and great apes) start with sporadic host switches from unknown reservoir species. The factors leading to such spillover events are little explored. Filoviridae viruses have a wide range of natural hosts and are unstable once outside hosts. Spillover events, which involve the physical transfer of viral particles across species, could therefore be directly promoted by conditions of host ecology and environment. In this report we outline a proof of concept that temporal fluctuations of a set of ecological and environmental variables describing the dynamics of the host ecosystem are able to predict such events of Ebola virus spillover to humans and animals. We compiled a dataset of climate and plant phenology variables and Ebola virus disease spillovers in humans and animals. We identified critical biotic and abiotic conditions for spillovers via multiple regression and neural networks based time series regression. Phenology variables proved to be overall better predictors than climate variables. African phenology variables are not yet available as a comprehensive online resource. Given the likely importance of phenology for forecasting the likelihood of future Ebola spillover events, our results highlight the need for cost-effective transect surveys to supply phenology data for predictive modelling efforts

Effect Of Shock Tunnel Geometry On Shockwave And Vortex Ring Formation, Propagation, And Head On Collision

Vortex ring research primarily focuses on the formation from circular openings. Consequently, the role of tunnel geometry is less understood, despite there being numerous research studies using noncircular shock tunnels. This experimental study investigated shockwaves and vortex rings from different geometry shock tunnels from formation at the tunnel opening to head on collision with another similarly formed vortex ring using schlieren imaging and statistical analysis. The velocity of the incident shockwave was found to be consistent across all four shock tunnel geometries, which include circle, hexagon, square, and triangle of the same cross-sectional area. The velocity was 1.2 ± 0.007 Mach and was independent of the tunnel geometry. However, the velocities of the resulting vortex rings differed between the shapes, with statistical analysis indicating significant differences between the triangle and hexagon vortex velocities compared to the circle. Vortex rings from the square and circle shock tunnels were found to have statistically similar velocities. All vortex rings slowed as they traveled due to corner inversion and air drag. All shock tunnels with corners produce a wobble in the vortex rings. Vortex rings interact with opposing incident shockwaves prior to colliding with each other. Vortex velocity before and after shock-vortex interaction was measured and evaluated, showing statistically similar results. Shock-vortex interaction slows the shockwave upon interaction, while the shock-shock interaction resulted in no change in shock velocity. Although the vortex rings travel at different velocities, all head-on vortex ring collisions produce a perpendicular shockwave that travels at 1.04 ± 0.005 Mach

Emerging Near-Real Time Forage Monitoring Technology with Application to Large Herbivore Management in Mongolia

Large herbivore livestock and wildlife in Mongolia depend almost entirely for substance on forage standing crop produced each year on natural pastureland. Consequently, both livestock and wildlife are continuously subject to environmental risk, especially drought and severe winter storms, while livestock are also subject to financial risk. As consumption-based livestock production changes to commercialized livestock production, steps taken by the livestock herder to avert both environmental and financial risk to livestock can increase environmental risk to large wild herbivores. A realistic and workable pastureland and risk management system will be critical for conservation of large herbivore habitat. New technologies are becoming available to facilitate understanding of risk and resource allocation. Texas A&M University has developed a suite of innovative technologies that facilitate resolving risk and resource allocation issues. A pre-parameterized rangeland model (i.e., PHYGROW) provides daily estimates of forage available to a mixed population of herbivores. Near Infra-Red Spectroscopy (NIRS) allows prediction of diet quality of free-ranging large herbivores via fecal scans which, when coupled with advanced nutritional management software (i.e., NUTBAL), can predict performance of animals. Oregon State University has developed a computerized multi-criteria decision-making tool (i.e., KRESS) that can take landscape parameters and determine the suitability of each cell or unit of the landscape for use by large herbivores. Emerging near real-time technologies can help clarify habitat needs, identify habitat improvements, and enable better management of large herbivore wildlife and livestock

Emerging Near-Real Time Forage Monitoring Technology with Application to Large Herbivore Management in Mongolia

Large herbivore livestock and wildlife in Mongolia depend almost entirely for substance on forage standing crop produced each year on natural pastureland. Consequently, both livestock and wildlife are continuously subject to environmental risk, especially drought and severe winter storms, while livestock are also subject to financial risk. As consumption-based livestock production changes to commercialized livestock production, steps taken by the livestock herder to avert both environmental and financial risk to livestock can increase environmental risk to large wild herbivores. A realistic and workable pastureland and risk management system will be critical for conservation of large herbivore habitat. New technologies are becoming available to facilitate understanding of risk and resource allocation. Texas A&M University has developed a suite of innovative technologies that facilitate resolving risk and resource allocation issues. A pre-parameterized rangeland model (i.e., PHYGROW) provides daily estimates of forage available to a mixed population of herbivores. Near Infra-Red Spectroscopy (NIRS) allows prediction of diet quality of free-ranging large herbivores via fecal scans which, when coupled with advanced nutritional management software (i.e., NUTBAL), can predict performance of animals. Oregon State University has developed a computerized multi-criteria decision-making tool (i.e., KRESS) that can take landscape parameters and determine the suitability of each cell or unit of the landscape for use by large herbivores. Emerging near real-time technologies can help clarify habitat needs, identify habitat improvements, and enable better management of large herbivore wildlife and livestock