cssi/SciSciGPT-SciSciNet huggingface dataset:
Insulin Receptor Substrate-2 Deficiency Impairs Brain Growth and Promotes Tau Phosphorylation

Insulin resistance and diabetes might promote neurodegenerative disease, but a molecular link between these disorders is unknown. Many factors are responsible for brain growth, patterning, and survival, including the insulin-insulin-like growth factor (IGF)-signaling cascades that are mediated by tyrosine phosphorylation of insulin receptor substrate (IRS) proteins. Irs2 signaling mediates peripheral insulin action and pancreatic β-cell function, and its failure causes diabetes in mice. In this study, we reveal two important roles for Irs2 signaling in the mouse brain. First, disruption of the Irs2 gene reduced neuronal proliferation during development by 50%, which dissociated brain growth from Irs1-dependent body growth. Second, neurofibrillary tangles containing phosphorylated tau accumulated in the hippocampus of old Irs2 knock-out mice, suggesting that Irs2 signaling is neuroprotective. Thus, dysregulation of the Irs2 branch of the insulin-Igf-signaling cascade reveals a molecular link between diabetes and neurodegenerative disease.
New horizons for the use of porous materials as catalysts

Abstract The diversity in porous materials has steadily expanded over the past decade and the ensuing new properties have provided opportunities for application as heterogeneous catalysts. Three areas of importance are described herein. First, efforts are currently underway to create uniform pore sizes in the 10-20dgA and this region is being approached from sizes both above and below the desired range. Second, atomic arrangements in porous solids can be used to provide unique active sites and the coupling of the atomic arrangement with the control of the hydrophobicity of the local, porous environment provides novel catalytic centers. These effects are illustrated using titanosilicates as catalysts for liquid-phase epoxidation with peroxides as oxidants. Finally, the area of organic-inorganic, hybrid, porous solids is discussed.
Respiratory-induced venous blood flow effects using flexible retrospective double-gating.

Background To demonstrate a novel velocity sensitive acquisition and retrospective cardiorespiratory double-gated reconstruction scheme to examine respiratory effect on venous blood flow in healthy volunteers. Methods Radial two dimensional (2D) phase contrast MR is performed at 3 Tesla in the internal jugular vein (IJV) of healthy volunteers (n = 6). Data are retrospectively partitioned based on respiratory waveforms using three schemes: moving average for respiration plateaus, gradient for active respiration, and ten respiratory phases that are cardiac time-averaged. A single 4D flow MR scan is performed in the neck of a healthy volunteer. After gradient operation, blood velocity measurements are made along the IJV length. Percent changes from expiration to inspiration for moving average and gradient techniques are statistically compared with paired t-tests. Results Percent change increase in summed IJV mean and peak blood flow during active inspiration versus active expiration in 2D was significant (mean flow: 11.5 ± 8.0%, peak flow: 11.9 ± 5.9%, P < 0.01). Smallest cross-sectional area and largest blood velocity are seen during inspiration phases (phase number: area-6.5 ± 3.6, velocity-6.2 ± 3.2). Significant increase in mean velocity along the length of the IJV was observed in 3D, with increasing percent changes more proximal to the chest (mean, 39 ± 30%; range, 0–93%, P = 0.001). Conclusion With a radial acquisition, this pilot study demonstrates feasibility of simultaneous retrospective cardiorespiratory gating in IJV flow. Greatest differences in flow occur between active respiration phases, increasing in magnitude more proximal to the chest. J. Magn. Reson. Imaging 2015;42:211–216. © 2014 Wiley Periodicals, Inc.
The safety and effectiveness of a dural sealant system for use with nonautologous duraplasty materials: Clinical article

Object The DuraSeal dural sealant system, a polyethylene glycol hydrogel, has been shown to be safe and effective when used with commercial and autologous duraplasty materials. The authors report on the safety and effectiveness of this sealant when used in conjunction with nonautologous duraplasty materials. Methods In this retrospective, nonrandomized, multicenter study, the safety and efficacy of a dural sealant system was assessed in conjunction with primarily collagen-based nonautologous duraplasty materials in a sample of 66 patients undergoing elective cranial procedures at 3 institutions. This cohort was compared with 50 well-matched patients from the DuraSeal Pivotal Trial who were treated with this sealant system and autologous duraplasty material. Results The key end points of the study were the incidences of CSF leaks, surgical site infections, and meningitis 90 days after surgery. The incidence of postoperative CSF leakage was 7.6% in the study group (retrospective population) and 6.0% in the ...
Simulation in the health services and biomedicine

Computer simulation can be used to evaluate complex health services and biomedical systems in situations where traditional methodologies are difficult or too costly to employ. The construction of a computer simulation model involves the development of a model that represents important aspects of the system under evaluation. Once validated, the model can be used to study the effects of variations in system inputs, differences in initial conditions and changes in the structure of the system. The modeling process is described followed by a review of examples where computer simulation has been utilized in health care policy making, health services planning, biomedical applications from the systems to the cellular and genetic level, and education.
The establishment of a district treatment facility for problem drug takers.

Multi-disciplinary teams in treatment centres were envisaged by the Second Brain Committee in 1965 (1) as the most appropriate means of treating problem drug takers. Since then the problem has changed and expanded so that treatment facilities need to exist outside the hospital-based units, but the concept of treatment by a team of different professionals remains intact.In Wolverhampton we have produced a local treatment unit that is firmly based on the multi-disciplinary concept; it is readily accessible to those who need its services; it is not staffed by full time ‘specialists' and yet has built into it safeguards against problems that ‘non-specialists' have produced.The need for local treatment facilities will continue and it is possible that others may find Wolverhampton's experience helpful in planning their own provisions for problem drug takers.
Clouds and Water Vapor in the Tropical Tropopause Transition Layer over Mesoscale Convective Systems

AbstractObservations from A-Train satellites and other datasets show that mesoscale convective systems (MCSs) affect the water vapor and ice content of the tropical tropopause transition layer (TTL). The largest MCSs with radar reflectivity characteristics consistent with the presence of large stratiform and anvil regions have the greatest impact. Most MCSs are associated with clouds in the TTL. Composites in MCS-relative coordinates indicate enhanced cloudiness and ice water content (IWC) extending toward the cold-point tropopause (CPT), particularly in large and connected MCSs. Widespread anvils in the lower TTL are evident in the peak cloudiness diverging outward at those levels. Upper-tropospheric water vapor concentrations are enhanced near MCSs. Close to the centers of MCSs, water vapor is suppressed at TTL base, likely because of the combined effects of reduced moistening or dehydration at the higher TTL relative humidities and subsidence above cloud top. Weak moistening is observed near the CPT, c...
Influence of branched‐chain amino acids and branched‐chain keto acids on protein synthesis in isolated hepatocytes

We investigated the effects of the branched-chain amino acids--valine, leucine and isoleucine--or their keto analogs, the branched-chain keto acids--alpha-ketoisovaleric acid, alpha-ketoisocaproic acid and alpha-keto-beta-methylvaleric acid--on protein synthesis and secretion by monolayers of rabbit hepatocytes incubated with [35S] methionine in pulse-chase and steady-state experiments. The branched-chain amino acids (2.0 mM or 1.0 mM), in the presence or absence of insulin (2 X 10(-4) IU per dish) and in both types of experiments, reduced the trichloroacetic acid-precipitable 35S-protein secreted into the medium. The branched-chain keto acids (2.0 mM or 1.0 mM) had a stimulatory effect on secreted trichloroacetic acid-precipitable 35S-protein which was observed only by the pulse-chase technique in the presence of insulin. Immunoaffinity chromatography of medium demonstrated a slight inhibition by branched-chain amino acids and a slight stimulation by branched-chain keto acids on secretion of 35S-albumin and no effect of either treatment on secretion of 35S-fibrinogen. ELISA analysis of total (i.e., 35S-labeled and unlabeled) secreted albumin revealed an inhibitory effect of the branched-chain amino acids in both pulse-chase and steady-state experiments, and a small stimulatory effect, in steady-state experiments, of the branched-chain keto acids; both effects were insulin-dependent. Total secreted fibrinogen, under steady-state conditions, was increased by the branched-chain keto acids in the presence of insulin, while transferrin production was unaffected by any treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
Temporal processing in inferior colliculus and auditory cortex affected by high doses of salicylate

Speech recognition and language learning can be affected by both peripheral and central auditory system impairment. However, whether sensorineural hearing loss would affect central auditory processing is not clear. Recent studies found that salicylate not only affects outer hair cell motility in the cochlea, but also blocks GABAergic neuron activities in central nervous systems. This provides a good animal model to evaluate the role of sensorineural hearing loss and central inhibition in auditory temporal processing. In this study, gap prepulse inhibition (gap-PPI) of the acoustic startle reflex was used to measure effects of salicylate on gap detection acuity. Salicylate administration (250 mg/kg) resulted in a significant reduction in gap-PPI amplitude and an increased gap detection threshold at 50 dB SPL, but not at 60 or 80 dB SPL. To identify the physiological effects of salicylate on central auditory system function, the inferior colliculus (IC) and auditory cortex (AC) responses were measured from conscious rats with chronically implanted electrodes. Salicylate induced a significant increase of the gap-detection threshold in AC-evoked potentials, but not in the IC-evoked potentials. The AC gap-detection threshold shift was diminished measured at an equal sensational level. These results suggest that salicylate-induced temporal processing deficits may be due to peripheral hearing loss, not central disinhibition.
Persistent heterogeneity and sustainable innovation

One of the concerns with strategy as a field is that its goal (durable profits) appears at odds with that of microeconomics (homogeneous firms with zero profits). Thus even if we can find sources of durable profits, maybe we shouldn't—because doing so comes at the expense of social welfare. In this sense, strategy is an ‘economic bad.’ Probably the most vivid evidence of this tension is the fact that Porter's Competitive Strategy (1982) is Industrial Organization turned on its head—exploiting indications of anti-competitive behavior to create prescriptions for durable profits. This study presents a parallax view in which the field of strategy is an economic good. In this view, heterogeneity stimulates innovation and economic growth. The underlying logic is that heterogeneity fuels diffusion; diffusion erodes leaders' shares; the loss of shares stimulates innovation, which in turn fuels new diffusion. I develop this view through a simple model of firms embedded in an industry, and then evaluate the model via simulation. The key issue for the model is whether there are steady states that sustain heterogeneity and innovation. Results indicate that heterogeneity persists in roughly half the industry conditions I examined. Furthermore innovation and growth are sustained under those conditions. What is comforting about the set of conditions is that they accommodate (and indeed require) all the things we hold dear: industrial policy, and strategic as well as routine behavior by firms. The new insights are as follows: (1) heterogeneity fuels growth (thus ‘strategy’ is an economic good, rather than anathema to allocative efficiency); (2) persistent heterogeneity is feasible even in the presence of spillovers (without isolating mechanisms); (3) but this heterogeneity (while persistent) requires managers to actively preserve the inherent value of their resource advantages—firms can't rest on their laurels; (4) policy prescriptions differ from those of prior innovation models. Copyright © 2003 John Wiley & Sons, Ltd.
Effective electrode array in mapping karst hazards in electrical resistivity tomography

When conducting environmental and engineering investigations in karst terranes, engineers and geologists often supplement exploratory borehole results with data gathered from surface geophysics to reduce the site-characterization cost and establish the most useful locations for borings or samples. When conducting resistivity investigations, a frequently occurring problem is the need to determine which of the many existing electrode configurations will respond best to the material changes in karst features. Each array has its advantages and disadvantages in terms of depth of investigation, sensitivity to horizontal or vertical variations, and signal strength. In the application presented in this paper, numerical forward modeling was conducted of dipole–dipole, Schlumberger, and Wenner arrays, and they produced markedly different anomaly shapes for a conceptual model of the development of a cover-collapse sinkhole. The resolution of the three above-mentioned arrays was further evaluated along a section of I-70 near Frederick, Maryland, where a sinkhole had occurred in the median of the highway. The image from the dipole–dipole array appeared to be better than those from the Wenner and Schlumerger arrays in displaying the sinkhole collapse area. However, they are all less effective than a mixed array, in which apparent resistivities from all the three arrays are combined and processed together in the model. Because the mixed array requires a significant increase in data collection, the dipole–dipole array appears to be the most effective and less costly configuration in mapping karst hazards areas. This conclusion was then confirmed by two case studies.
The aerobic CO dehydrogenase from Oligotropha carboxidovorans

We review here the recent literature dealing with the molybdenum- and copper-dependent CO dehydrogenase, with particular emphasis on the structure of the enzyme and recent advances in our understanding of the reaction mechanism of the enzyme.
Dissection of QTLs for hull silicon content on the short arm of rice chromosome 6.

Abstract The QTL qHUS6 for hull silicon content in rice was previously located on the short arm of rice chromosome 6. By using an F2:3 population segregating in the RM587–RM19784 region harboring qHUS6 in an isogenic background, two QTLs for hull silicon content were detected, of which qHUS6-1 was located in the distal region and qHUS6-2 in the region proximal to the centromere. Three rice plants carrying small heterozygous segments in the target region were selected, of which two covered the qHUS6-1 region and the other covered the qHUS6-2 region. Three F2:3 populations were derived from the selfed seeds of the three plants, respectively. QTL mapping was performed using the two populations segregating in the qHUS6-1 region, and qHUS6-1 was delimited to a 147.0-kb region flanked by the markers RM510 and RM19417. Five groups of F3 lines with different genotypic compositions in the qHUS6-2 region were selected from the other F2:3 population. Two QTLs were separated with two-way ANOVA, of which qHUS6-2a was located in the interval defined by RM19706–RM19795 and qHUS6-2b in the interval RM314–RM19665.
Differentiation and characterization of isomeric polychlorinated biphenyls by gas-liquid chromatography coupled with electron impact and chemical ionization mass spectrometry.

Abstract This report describes the utilization of gas-liquid chromatography coupled with chemical ionization and electron impact mass spectrometry for the characterization and isomeric differentiation of polychlorinated biphenyls (PCB's) from numerous sources. By a comparison of model compounds with very complex mixtures, one is able to gain significant information about the o,o′-chlorine interaction of PCB's as monitored by mass spectrometry. The abudance of the specific (M − Cl)+ ion assisted greatly in the isomeric differentiation of dichloro-, hexachloro-, and heptachlorobiphenyls. Furthermore, by the indepth characterization by mass spectrometry of the Ullman reaction products formed in the preparation of 14C-labeled PCB′s, one may conclude that a very complex mixture of dichloro- and trichlorobiphenyls is formed from a specific pure isomeric iodomonochlorobenzene during the Ullman reaction. As revealed by the use of gas-liquid chromatography coupled with electron impact mass spectrometry, care must be exercised in choosing the type of organic synthetic reactions for the preparations of polychlorinated biphenyls which will be used for biological testing in order to minimize isomeric contamination.
Enzymatic conversion of cholest-8(14)-en-3β,15α-diol and cholest-8(14)-en-3β,15β-diol to cholesterol

Abstract Reduction of 3β-benzoyloxy-cholest-8(14)-en 13-one with lithium aluminum hydride yielded two epimers (at C-15) of cholest-8(14)-en-3β,15-diol. Reduction with lithium aluminum tritide yielded [15α-3H]-cholest-8(14)-en-3β,15β-diol and [15β-3H]-cholest-8(14)-en-3β,155-diol. Both labeled compounds served as efficient substrates for cholesterol formation in rat liver homogenate preparations.
Quercetin 3-O-galactosyl-(1 → 6)-glucoside, a compound from narrowleaf vetch with antibacterial activity

Abstract A new flavonol glycoside, quercetin 3- O -galactosyl-(1 → 6)-glucoside, has been isolated from above-ground parts of narrowleaf vetch, Vicia angustifolia . Its antibacterial activity against Pseudomonas maltophilia and Enterobacter cloacae is compared with that of several other flavonol glycosides.
I-Xe studies of the Acapulco meteorite: Absolute I-Xe ages of individual phosphate grains and the Bjurböle standard

We have measured Kr and Xe by laser volatilization of seventeen individual neutron-irradiated phosphate grains (nine apatite and eight merrillite) separated from the (reclassified) A-chondrite Acapulco. Radiogenic 129Xe from now-extinct 129I is only observed in the apatites, which all formed simultaneously (8.1 ± 1.2 Ma) after Xe closure in the Bjurbole (L4) standard. This relative closure time, when coupled with the Pb-Pb age of Acapulco phosphates (4.557 ± 0.002 Ga) provides an absolute I-Xe age for these apatites, for Bjurbole and for all samples previously referenced to the Bjurbole standard, subject to the assumptions implicit in I-Xe dating. We have also measured Kr and Xe by stepwise heating of irradiated and unirradiated whole-rock samples of Acapulco and of unirradiated phosphate concentrates. Iodine-derived xenon in the irradiated whole-rock sample does not yield an I-Xe isochron, consistent with the presence of multiple iodine host phases previously observed. Xenon from the spontaneous fission of now-extinct 244Pu is observed in the single phosphate grains and the inferred initial (244Pu/238U)0 ratios reflect fractionation of the actinides favoring plutonium in the merrillites and uranium in the apatites.
Determinants of Soil Microbial Communities: Effects of Agricultural Management, Season, and Soil Type on Phospholipid Fatty Acid Profiles

Phospholipid fatty acid (PLFA) profiles were measured in soils from organic, low-input, and conventional farming systems that are part of the long term Sustainable Agriculture Farming Systems (SAFS) Project. The farming systems differ in whether their source of fertilizer is mineral or organic, and in whether a winter cover crop is grown. Sustained increases in microbial biomass resulting from high organic matter inputs have been observed in the organic and low-input systems. PLFA profiles were compared to ascertain whether previously observed changes in biomass were accompanied by a change in the composition of the microbial community. In addition, the relative importance of environmental variables on PLFA profiles was determined. Redundancy analysis ordination showed that PLFA profiles from organic and conventional systems were significantly different from April to July. On ordination plots, PLFA profiles from the low-input system fell between organic and conventional systems on most sample dates. A group of fatty acids (i14:0, a15:0, 16:1ω7c, 16:1ω5c, 14:0, and 18:2ω6c) was enriched in the organic plots throughout the sampling period, and another group (10Me16:0, 2OH 16:1 and 10Me17:0) was consistently lower in relative abundance in the organic system. In addition, another group (15:0, a17:0, i16:0, 17:0, and 10Me18:0) was enriched over the short term in the organic plots after compost incorporation. The relative importance of various environmental variables in governing the composition of microbial communities could be ranked in the order: soil type > time > specific farming operation (e.g., cover crop incorporation or sidedressing with mineral fertilizer) > management system > spatial variation in the field. Measures of the microbial community and soil properties (including microbial biomass carbon and nitrogen, substrate induced respiration, basal respiration, potentially mineralizable nitrogen, soil nitrate and ammonium, and soil moisture) were seldom associated with the variation in the PLFA profiles.
Mind, meaning, and behavior

NOTES 1 "On Observing and Perceiving," Philosophical Studies, 2:92-93 (1951). This paper appeared in reply to my "Reichenbach on Observing and Perceiving," Philosophical Studies, 2:45-48 (1951). My paper was a criticism of Reichenbach's Elements of Symbolic Logic, pp. 274-76. 2 Professor Reichenbach's analysis is stated more exactly in his "On Observing and Perceiving"; the general problem is stated more exactly in the other two works cited above.
Reactions of aromatic heterocycles with uranium alkyl complexes.

The reactivity of a uranium dibenzyl complex supported by a ferrocenediamide ligand toward aromatic N-heterocycles was investigated. The uranium dibenzyl complex reacted with 1 equiv of pyridine or picoline to give the respective ortho-metalated product. In turn, the η2-N,C-pyridyl complexes reacted with benzoxazole or benzothiazole, leading to a cascade of transformations that involves C−C coupling of the two heterocyclic rings, ring opening, and alkyl transfer. A similar cascade was previously reported for 1-methylimidazole. The present results provide support for the mechanism proposed earlier and attest to the generality of the reaction cascade described.
Dynamical response of antiferromagnets in an oblique magnetic field: Application to surface magnons

We discuss the dynamical response of the two-sublattice, uniaxial Heisenberg antiferromagnet, for the case where an external magnetic field is applied in arbitrary direction relative to the easy axis. For the case where the external field is perpendicular to this axis, we obtain simple expressions for the nonzero elements of the magnetic-susceptibility tensor. These are used to discuss the properties of spin waves on the surface of an antiferromagnet, for the case where both the easy axis and the external magnetic field are parallel to the surface, but mutually perpendicular.
Vibration reduction in rotorcraft using active control - A comparison of various approaches

This paper presents a concise review of the state of the art for vibration reduction in rotorcraft using active controls. The principal approaches to vibration reduction in helicopters described in the paper are 1) higher harmonic control, 2) individual blade control, 3) vibration reduction using an actively controlled flap located on the blade, and 4) active control of structural response. The special attributes of the coupled rotor/flexible fuselage vibration reduction problem are also briefly discussed to emphasize that vibration reduction at the hub is not equivalent to acceleration reduction at specific fuselage locations. Based on the comparison of the various approaches, it appears that the actively controlled flap has remarkable potential for vibration reduction.
Effect of Tissue Dehydration on Smooth Muscle Cell Contractility, Collagen Matrix Structure and Overall Artery Biomechanics

Applications involving freeze-thaw in arteries such as cryoplasty and cryopreservation alter the arterial biomechanics significantly [1]. Tissue dehydration or bulk water loss is observed following freeze-thaw in native arteries as well as other artificial tissues [1, 2]. It is hypothesized that tissue dehydration observed during freeze-thaw is an important mechanism underlying the biomechanical changes in arteries. In order to test this hypothesis, dehydration was induced in arteries (without changing temperature or phase) by treating them with different concentrations of hyperosmotic mannitol solutions. Changes to smooth muscle cell (SMC) contractility, collagen matrix structure and overall artery biomechanics were studied following tissue dehydration. SMC contractility and relaxation were measured by studying the response of arteries to norepinephrine (NE) and acetylcholine (AC) respectively. Collagen matrix structure was assessed by studying the thermal denaturation of collagen due to heating using Fourier transform infrared (FTIR) spectroscopy and the overall artery biomechanics through uniaxial tensile tests.© 2008 ASME
Metal complexation with pyrimidine derivatives—II Spectrophotometric studies

Abstract Ultra-violet light absorption studies were made on a number of pyrimidine derivatives in water or deuterium oxide both as a function of pH and in the absence or presence of metal ions. The pyrimidine compounds studied included: uracil-5-carboxylic acid (iso-orotic acid), 2-ethylthio-iso-orotic acid, uracil-6-carboxylic acid (orotic acid), 5-nitro-orotic acid and their corresponding esters. Iso-orotic acid was found to be very pH sensitive in water and deuterium oxide. Identical spectral curves were obtained in both solvent systems. A lowering of the extinction coefficient at pH 6, as compared with pH 1, could indicate an ionization effect rather than enolization since no appreciable wavelength shift was observed. However, enolization is predominant in the region of pH 12. A confirmation that p K 2 in iso-orotic acid refers to proton dissociation from an enolic species was obtained by determining the p K 2 of iso-orotic acid in water and in deuterium oxide. In the presence of Cu(II) ions at pH 3, there was noted a slight shift towards the visible in the region of the uracil absorption band of iso-orotic acid. This slight shift is attributed to complexing through the ketonic oxygen and carboxyl group. Very little shift in the uracil lactam band occurred in going from the acidic to neutral region for orotic acid and a slight shift to longer wavelengths resulted when approaching the region of pH 12. Ultra-violet absorption spectra obtained in deuterium oxide indicated that even up to pH 12, orotic acid was still predominantly mono or diketonic. Deuterium iostope studies indicate at least one monoketonic form at pH 10. Spectral curves show that in the presence of Zn(II), Co(II) and Mn(II), orotic acid forms weak complexes. However, in the presence of Cu(II) and Ni(II) ions strong complexing is observed. A deuterium isotope effect was noted with orotic acid and Ni(II) ions in deuterium oxide resulting from the cleavage of the DN 1 bond and verifying complexation through the carboxyl group and nitrogen in the 1-position. The nitro group in 5-nitro-orotic acid appears to considerably modify the lactam-lactim equilibria in the pyrimidine nucleus, favouring enolization in the neutral and high pH regions. It was found that 5-nitro-orotic acid complexes strongly with Cu(II) at pH 6, but is almost independent of Ni(II) ions. The ethylthio group in 2-ethylthio-iso-orotic acid appears to cause enhanced enolization of the carbonyl group in the 4-position. Complexing with Cu(II) ions is quite similar to iso-orotic acid in magnitude.
Ischemia and excitotoxins in development

Ischemia in the developing brain triggers a series of events that cause damage after a threshold of severity and duration are reached. Release of glutamate, the major excitatory amino acid neurotransmitter in the brain, is one of the primary events in this cascade of injury. Release of glutamate combined with reversal of glutamate uptake pumps in nerve terminals causes glutamate levels to increase from 10–1000x baseline levels in the brain's extracellular space during ischemia, traumatic brain injury, and hypoglycemia in animal models and in humans. High levels of extracellular glutamate trigger opening of N-methyl-D-asparate (NMDA) and non-NMDA glutamate channels, allowing calcium and sodium to flood into neurons. Energy failure in mitochondria facilitates opening of NMDA channels by lowering the membrane potential and reducing their blockade by magnesium that resides within the channel at normal membrane potentials. Calcium entry into the cytoplasm triggers several events including activation of lipases, proteases, and nucleases that can destroy the neuron's cellular machinery. Generation of reactive oxygen free radicals including the messenger molecule nitric oxide can have additional destructive effects. Drugs that block glutamate receptors and the “excitotoxic cascade” of downstream events can protect the brain from injury and show promise for clinical application in infants and children. © 1995 Wiley-Liss, Inc.
The effect of flow and morphology on boundary layers in the scleractinians Dichocoenia stokesii (Milne-Edwards and Haime) and Stephanocoenia michilini (Milne-Edwards and Haime).

Mass transfer characteristics of scleractinian corals are affected by their skeletal morphology and the concentration gradients that develop as a consequence of the interactions of their morphology and biomass with the overlying seawater. These interactions can have a profound effect on coral metabolism. In this study, boundary layer characteristics were compared between different size colonies of the corals Dichocoenia stokesii and Stephanocoenia michilini to determine the relative roles of colony size and corallite structures (i.e. surface roughness) in mass transfer. Colonies of both species were rounded in shape, but differed in small-scale roughness as measured by the elevation of corallites. Additionally, D. stokesii had a greater aspect ratio than S. michilini, and their colonies were slightly taller for a given diameter. Boundary layers were characterized by placing dead coral skeletons in a flow tank and estimating shear velocities (u(*)) at different flow speeds. The effects of flow speed, size, and roughness on shear velocities were estimated for two juvenile size classes (10-20 and 30-40 mm diameter) of each species that were exposed to unidirectional flow regimes (4 and 17 cm s(-1)). Shear velocities were significantly greater in high, compared to low flow, and there was a significant interaction between colony size and surface roughness; the interaction was caused by a difference in magnitude, rather than direction, of the effect of roughness and size on u(*). Thus, there was a greater degree of turbulence at high flow compared to low flow, regardless of roughness or size, and the greatest turbulence occurred over large colonies of D. stokesii at high flow. Together, these results suggest that boundary layers around small corals are heavily influenced by upstream roughness elements, and more strongly affected by flow regimes than skeletal features. The relationship between colony morphology (i.e. aspect ratio and, possibly, surface roughness) and boundary layer characteristics may be non-linear in small corals.
Improved learning by use of a video knowledge-base

Increased mastery of basic computing theory in the introductory computer science class is the subject of on-going research at the University of South Alabama. Previous and continuing projects have considered tools, labs and complexity of assignments. The focus of this study is the role of video media presentations and rehearsal. The role and benefit of video in the course will be discussed; strategies for the evaluation of the effectiveness will be proposed.
Initial Colonization of the Zebra Mussel (Dreissena polymorpha) in Saginaw Bay, Lake Huron: Population Recruitment, Density, and Size Structure

The various life stages of the zebra mussel (Dreissena polymorpha) were examined during the initial years (1991–93) of the mussel's invasion into Saginaw Bay, Lake Huron. Yearly trends in densities of larvae, newly-settled juveniles, and adults were poorly related. Larval densities were lowest in 1991 and increased each year, but the number of settled juveniles was highest in 1991. Adults increased between 1991 and 1992 and then declined in 1993. Mean adult densities at sites with hard substrates were 11,700, 33,200, and 4,100/m2 in each of the 3 years, respectively. Year-to-year variation at individual sites was high and likely a result of recruitment dynamics and spatial patchiness of available substrate. By 1993, densities on hard substrates were generally similar throughout the bay, but length-frequency distributions in the inner and outer bay were quite different. The 1991-cohort was not distinguishable in the inner bay in 1993 either because of poor growth or a limited life span, but this cohort was readily distinguishable in the outer bay. In addition, ash-free dry weight of a standard 15-mm mussel in the inner bay declined 65% between 1991 and 1993. Although food concentrations (chlorophyll and particulate organic carbon) declined to low levels in 1993 and both densities and soft-tissue weight of Dreissena declined, it is not clear whether populations in the bay have peaked and are now at equilibrium with the surrounding environment.
The quantitative impact of the mesopore size on the mass transfer mechanism of the new 1.9 μm fully porous Titan-C18 particles II--analysis of biomolecules

The kinetic performances of 3.0 × 100 mm columns packed with 1.9 μm Titan-C18 particles with average mesopore sizes of 80 A and 120 A were investigated quantitatively for the analysis of biomolecules. Large mesopores are expected to speed up the rate of diffusivity of high-molecular-weight compounds across the stationary phase and to generate higher plate counts at high velocities. The mass transfer mechanism of bradykinin acetate salt (1060 Da) and insulin (5733 Da) was determined over a range of flow rates from 0.025 to 1.0 mL/min. The pore diffusivities of these two biomolecules were accurately measured from the peak parking method. Even though the gain in column efficiency was not found significant for small molecules such as valerophenone (162 Da), enlarging the average pore size from 80 to 120 A induces a measurable diminution of the reduced plate height, h, of bradykinin (from 17 to 11 or -35% at a reduced velocity of 50) and a significant reduction for insulin (from 43 to 12 or -72% at a reduced velocity of 90). Remarkably, while the increase of the column efficiency for bradykinin is consistent with a faster diffusivity of bradykinin across the 120 A Titan-C18 particles, the higher column efficiencies measured for insulin are mostly due to a faster absorption kinetics into the 120 A than that into the 80 A Titan-C18 particles. This result is supported by the fact that the effective pore diffusivity of insulin is even slightly smaller across the 120 A than that across the 80 A 1.9μm Titan-C18 particles.
Depression of cellular‐mediated immunity in systemic lupus erythematosus

Cellular-mediated immunity was examined in 6 consecutive patients with active SLE, 6 patients with low active SLE 6 patients with DLE, 8 patients with other collagen diseases, and 9 healthy controls. The following parameters were measured: delayed hypersensitivity, in vitro lymphocyte blast transformation, and MIF production after stimulation with five common antigens, DNA, and two nonspecific mitogens (PHA, PWM). The 6 active SLE patients were anergic and had a markedly depressed response in vitro to the specific antigens and PWM (P less than 0.001). When CMI was retested in 5 patients as early as 5 days after the start of prednisone (60 mc/day), the results were significantly improved in 4 who also improved clinically, and they remained unchanged in a fifth patieht who failed to improve. There was a less marked impairment of CMI among the low active SLE group, whereas the DLE and OCD patients did not differ significantly from the control subjects. DNA did not cause significant stimulation of blast transformation in any of the study groups.
Cold Big Bang Nucleogenesis

This paper treats the energetic and nucleosynthetic history of a Friedmann model with low photon-baryon ratio ηγ and positive lepton-baryon ratio ηL. At early times, such a universe is in equilibrium and is energetically dominated by particle Fermi energies; at later times photon release from elementary particle decays probably lifts degeneracy of nucleons but not of leptons. After outlining the early history I present the results of full nucleosynthesis calculations for nondegenerate baryons and degenerate electrons and neutrinos. The results show that, for ηγ 0.01 (consistent with the particle-decay heating), the neutron-proton ratio depends strongly on ηL and that production of sufficient helium to match observations creates large primordial metallicity, in agreement with a previous argument by Carr for the ηγ = 0 case. Excessive metallicity in the cold model is avoided only if ηL is sufficiently high (ηL > 1.5 for ηγ = 0; ηL 5 for ηγ = 0.01) to suppress all nucleosynthesis before the Population III epoch. The calculations also reveal certain combinations of ηγ 100 (corresponding to T0 ~ 0.02) and ηL 5 that produce acceptable helium yields. This result contradicts the widespread notion that astrophysical observations of helium abundance together with nucleosynthesis calculations within a big bang model predict the current radiation background temperature.
Embedding T cells in the matrix

Memory T cells in peripheral tissues such as the lung lie in wait, ready to attack pathogens that try to reinvade the body. Work on mice infected with the influenza virus now identifies a molecule that keeps these T cells in their positions, and prevents them from dying off.
Social networks reveal cultural behaviour in tool-using dolphins

Animal tool use is of inherent interest given its relationship to intelligence, innovation and cultural behaviour. Here we investigate whether Shark Bay bottlenose dolphins that use marine sponges as hunting tools (spongers) are culturally distinct from other dolphins in the population based on the criteria that sponging is both socially learned and distinguishes between groups. We use social network analysis to determine social preferences among 36 spongers and 69 non-spongers sampled over a 22-year period while controlling for location, sex and matrilineal relatedness. Homophily (the tendency to associate with similar others) based on tool-using status was evident in every analysis, although maternal kinship, sex and location also contributed to social preference. Female spongers were more cliquish and preferentially associated with other spongers over non-spongers. Like humans who preferentially associate with others who share their subculture, tool-using dolphins prefer others like themselves, strongly suggesting that sponge tool-use is a cultural behaviour.
We Don't Know What We Don't Study: The Case for Research on Medication Effects in Pregnancy

This Commentary addresses issues related to exposures to teratogens and makes the case for increased research into the safety of medication usage during pregnancy for mothers and fetuses. Not only are medications commonly used during pregnancy, but evidence points to an increasing prevalence and number of drug exposures experienced by the embryo or fetus, particularly during the critical first trimester of pregnancy. Although the first trimester represents a particularly vulnerable period of organogenesis, exposures during other gestational time periods may also be associated with deleterious outcomes. In addition to the changing (and in many cases unknown) risks to a developing fetus, other challenges to studying medication exposures and their effects during pregnancy include the dramatic changes in physiology that occur in pregnant women and the ethical dilemmas posed by including this vulnerable population in randomized controlled trials of safety and efficacy. However, without adequate knowledge of the pharmacokinetics, pharmacodynamics, efficacy, and safety of medication use in pregnancy, women may be under-dosed to minimize exposure or not treated at all, resulting in inadequate treatment and potential harm to the mother and her baby. The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) is undertaking studies on medications and teratogenic exposures during pregnancy, including alcohol, maternal diabetes, oral hypoglycemic agents, and antiviral medications, through several of its research networks. Although this is a start, there is a critical need for further research on medications used during pregnancy, especially their effects on both the mother and her developing child. Published 2011 Wiley-Liss, Inc.
Revisiting the Advertising-Concentration Issue

Increases in advertising efforts are reasonably well documented among most U.S. industries [Nelson, p.431. Yet the economic controversy relating to the causal linkage between advertising intensity and changing market structures has by no means been settled. Advertising can represent a major barrier to entry via its role in achieving product differentiation. In contrast advertising may enhance competition with the dissemination of information through competitive advertising, While the advertising issues are varied and complex, this paper will setforth additional empirical evidence showing the relationship between advertising intensity and changing industry structure. In particular, the intensity of advertising across industry levels of concentration will be addressed and reference given to the food industries.
Monte Carlo calculations of lunar Regolith thickness distributions

It is pointed out that none of the existing models of lunar regolith evolution take into account the relationship between regolith thickness, crater shape, and volume of debris ejected. The results of a Monte Carlo computer simulation of regolith evolution are presented. The simulation was designed to consider the full effect of the buffering regolith through calculation of the amount of debris produced by any given crater as a function of the amount of debris present at the site of the crater at the time of crater formation. The method is essentially an improved version of the Oberbeck and Quaide (1968) model.
Interstitial faulted dislocation dipole formation in sapphire (α-Al2O3)

While both vacancy and interstitial edge-trapped perfect dislocation dipoles form with equal probability during high temperature basal deformation of sapphire, faulted dipoles are invariably interstitial in character. The most likely origin of this asymmetry is the different energy associated with the point defects needed to be ejected into the bulk crystal for a dipole to be annihilated. Interstitial point defects are much more energetic than vacancy defects, leading to immediate supersaturation, and rapid condensation of the interstitials into a faulted dipole segment, rather than being absorbed by the bulk crystal.
In Vitro Protein Complex Formation with Cytoskeleton-anchoring Domain of Occludin Identified by Limited Proteolysis

Occludin is an essential membrane protein component of cellular tight junctions, participating in both cell-cell adhesion in the paracellular space and anchoring of the junctional complex to the cytoskeleton. The latter function is accomplished through binding of the C-terminal cytoplasmic region to scaffolding proteins that mediate binding to cytoskeletal actin. We isolated a structural domain from both the bacterial-expressed C-terminal cytoplasmic region of human occludin and native cellular occludin, extracted from epithelial (Madin-Darby canine kidney) or endothelial (human brain) cells, by limited proteolysis with trypsin. This human occludin domain contains the last 119 amino acids as identified by N-terminal sequencing and peptide mass fingerprinting using matrix-assisted laser desorption ionization-time of flight mass spectrometry. Based on the sequence and secondary structure prediction, this domain contains 4 of 5 α-helices in the C-terminal region and is linked to the fourth membrane-spanning region by a loosely structured tethering polypeptide. Comparison of circular dichroism spectra of recombinant proteins corresponding to the entire C-terminal region versus only the binding domain region also supports the interpretation that the helical structural elements are concentrated in that domain. Co-immunoprecipitation of this domain with ZO-2 demonstrated preservation of the specificity of the scaffolding protein-binding function, and binding studies with immobilized ZO-2 suggest the presence of multiple ZO-2 binding sites in this domain. These results provide a basis for development of a structural model of the ZO-binding site that can be used to investigate regulation of tight junction anchoring by intracellular signaling events.
Collusion-resilient credit-based reputations for peer-to-peer content distribution

With growing demand for high-quality multimedia content, content providers face enormous pressure to scale the serving capacity. Peer-to-peer content distribution is a natural low cost option to scale system capacity. In a P2P CDN model, content providers serve content using a small number of "official" seeder nodes and rely on participating users to act as individual seeders for others in the system. Although P2P CDNs have the potential to drastically reduce the required serving capacity of official seeders, they must address the challenge of incentivizing users to stay online in the P2P network and act as seeders.
Laser Micromachining Modeling and Laser Machined Surface Errors Prediction for Biomedical Applications

This paper presents an analytical modeling and laser micromachining technique of microchannel and micro-structures for bio-devices manufacturing and biomedical applications. The ablation of the laser micromachining with direct-write method has been modeled and simulated for micro-channels or microstructures in bio-devices microfabrication. In this paper, the analytical model was adapted from the linear function for beam propagation in our previous research by using the Gaussian function to improve modeling accuracy. Basically, the new laser ablation model based on Gaussian distribution, beam propagation modeling and Beer’s law were used to formulate and model the laser ablation phenomenon. After the simulation with MATLAB programming, the actual experiment on laser micromachining has been conducted to compare the simulated results with the actual ones. Finally, the purposed modeling technique can be applied in the surface error analysis and biomedical applications. The example case in this paper showed how the modeling could solve the complex phenomenon of the overlapping in laser micromachining.Copyright © 2012 by ASME