cssi/SciSciGPT-SciSciNet huggingface dataset:
Agonist administration in ovo down-regulates cerebellar GABAA receptors in the chick embryo

Chick embryos with an undeveloped blood-brain barrier were used to examine the down-regulation of GABAA receptors in vivo. The GABAA receptor agonist isoguvacine (5 mumol) was applied to the vascularized chorioallantoic membrane of 8 day embryos. This treatment was repeated on embryonic days 11, 14, and 17, and the embryos were sacrificed on day 18 (stage 42). Isoguvacine administration reduced the clonazepam-displaceable binding of [3H]flunitrazepam to washed cerebellar membranes by 34.0 +/- 3.0% compared to vehicle-treated controls. Binding reductions of lower magnitude were found in membranes from the cerebrum and optic lobes. Administration of isoguvacine had no significant effect on the wet weights of whole embryos or cerebella, the yield of cerebellar membranes, or the binding of [3H]N-methylscopolamine. The reduction of [3H]flunitrazepam binding to cerebellar membranes was dose-dependent, allowing a half saturation value of 8 microM isoguvacine to be estimated. Scatchard analysis showed that the Bmax for [3H]flunitrazepam binding was reduced by 28.3 +/- 6.7% compared to controls, without a change in the Kd. Embryonic exposure to isoguvacine also caused a reduction of 43.6 +/- 6.0% in the binding of the GABAA receptor channel ligand [35S]t-butylbicyclophosphorothionate to washed cerebellar membranes. Taken together, these results indicate that isoguvacine induces a down-regulation of the receptor subunits in vivo. However, measurements of cerebellar GABAA receptor mRNAs for the alpha 1, beta 2L, beta 2S, beta 4, gamma 1, gamma 2L, and gamma 2S subunits by reverse transcriptase-polymerase chain reaction (RT-PCR) revealed no significant alterations by isoguvacine administration. The data suggest that translational or post-translational mechanisms, rather than those modulating the synthesis or stability of subunit mRNAs, take precedence in establishing GABAA receptor down-regulation.
Key position of catecholamines in functional and degenerative cardiovascular pathology.

Abstract The catecholamines, norepinephrine and epinephrine, occupy a prominent position in the dynamic, metabolic and structural pathogenic mechanisms of the most common functional and degenerative cardiovascular disorders, such as angina pectoris, myocardial degeneration and failure, arterial hypertension and atherogenesis. Although they are essential constituents of physiologic cardiovascular regulation, their potentially oxygen-wasting, efficiency-impairing, hypoxiating, necrotizing and vasoconstrictor properties become greatly accentuated by certain abnormal circumstances, such as: (1) excessive formation, liberation and local accumulation of catecholamines in cardiovascular tissues; (2) deterioration of sympatho-inhibitory and cholinergic counter-regulatory mechanisms; and (3) coexisting overactivity of other hormones (adrenal corticoids, thyroid hormone) which potentiate the injurious metabolic effects of the catecholamines on heart and blood vessels, in part possibly by way of derangements of the transmembrane cationic gradient. Many effective therapeutic measures are based on quantitative diminution and/or appropriate functional inactivation of the catecholamines.
Toxicokinetics, covalent binding and histopathological features of [14C]2-chloro-4-acetotoluidide toxicity in the starling after intravenous administration

Abstract The toxicokinetics and subcellular covalent binding of the avicide 2-chloro-4-acetotoluidide (CAT) were examined in the starling. Intravenous administration of 4.5 mg/kg ringlabeled [ 14 C]-CAT produced biphasic decay curves of the radioactivity in plasma and other tissues. The alpha phase of the decay curves ranged from 17 min to 1 hr while the beta phase of the decay curves varied widely from 4 hr up to 23 hr. Significant amounts of tissue covalent binding were found only in the plasma, liver, and kidney. The amount of covalently bound material found in plasma and liver varied from 30 to 55 pmole/mg protein and from 800 to 1100 pmole/mg protein in the kidney. A subcellular distribution study indicated that there is a high affinity for covalently bound radioactivity in the light mitochondrial and microsomal fractions of the liver and kidney. The kidneys of treated birds, 18 hr postinjection, had areas of necrosis, swelling of the proximal tubule epithelium, and dilation of the distal tubules. No lesions were found in the livers of these birds.
Perturbation solution for the interaction of Lamb waves with localized surface defects

We present an analytical solution of the transmitted and reflected wave fields due to the interaction of Lamb waves with localized, small-scale defects on late surfaces. The surface defect is represented by a distribution of surface sources, and the overall solution is obtained as a superposition of the incident wave field plus the 'small' wave field associated with the surface sources. The reflection and transmission coefficients of various Lamb modes are also determined. It is shown that the scattered field consists of a superposition of various possible modes at the frequency of the incident mode. For the fundamental modes, it is found that the reflection coefficients are periodic functions of the defect width with the period and magnitude being dependent on the surface defect profile. The transmission coefficient for the converted mode is also found to be a periodic function of the defect width while that corresponding to the incident mode does not deviate significantly from unity. A parametric study has also shown that to this approximation the numerical values of the reflection and transmission coefficients are not sensitive to the maximum slope of the defect profile.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Correlation between findings on MRCP and gadolinium-enhanced MR of the liver and a survival model for primary sclerosing cholangitis

Primary sclerosing cholangitis is a chronic, progressive disease of inflammation and fibrosis of the bile ducts. The ability to predict survival is important for appropriate management and treatment decisions. The purpose of this study was to examine the relationship between specific findings on the enhanced magnetic resonance imaging (MRI) examination of the liver and the corresponding magnetic resonance cholangiopancreatogram (MRCP) and a survival model for primary sclerosing cholangitis (PSC), the Mayo Risk Score. During a five-year period, 47 patients with primary sclerosing cholangitis were identified who had a complete MRI/MRCP examination. The extent of anatomical changes of the biliary tree and the degree of peribiliary enhancement in the hepatic parenchyma were compared with the Mayo Risk Score for each patient. Peribiliary enhancement was present to a varying extent in 38 of 47 cases of PSC. Peribiliary enhancement 3 min after gadolinium administration had a weak correlation with the Mayo Risk Score (analysis of variance P < 0.01, Pearson correlation r = 0.37). No statistically significant relationship between the severity of extrahepatic or intrahepatic duct changes and the Mayo Risk Score was found (analysis of variance P = 0.24, P = 0.38, respectively). Although biliary tree changes on MRCP aid in the diagnosis of PSC, they do not correlate with survival, as predicted by the Mayo Risk Score. Peribiliary enhancement on MRI of the liver is a finding occurring to a variable extent in primary sclerosing cholangitis but does not correlate significantly with survival.
Fans whose hyperspace of subcontinua are cones

Abstract It is proved that if F is a fan, then the hyperspace of subcontinua of F is homeomorphic to a cone over a continuum if and only if F is homeomorphic to a cone over a compact metric space.
Extraction of threshold voltage degradation modeling due to Negative Bias Temperature Instability in circuits with I/O measurements

Negative Bias Temperature Instability (NBTI) is a serious reliability issue for pMOS transistors. Normally, degradation due to NBTI is modeled based on test structure data or ring oscillators embedded within product die. In this paper, we present a new method to determine the NBTI model parameters through I/O circuit measurements. We determine a relationship between Δ V th and signature signal degradation and fit a model to the simulation results. The signature signal involves the calculation of the degradation in the voltage signature, measured as delay and amplitude shifts. Given an estimate of Δ V th we find NBTI model parameters. Then, using the NBTI parameters at test conditions, we scale to use conditions and calculate lifetime. The methodology enables the extraction of NBTI model parameters for individual chips, not just for the manufacturing process, and hence it becomes possible to identify chips that are more vulnerable to NBTI.
Cyclopolymerization of ether dimers of α-(hydroxymethyl)acrylic acid and its alkyl esters: substituent effect on cyclization efficiency and microstructures

Abstract Free-radical cyclopolymerization of six ether dimers of α-(hydroxymethyl)acrylic acid and its alkyl esters was kinetically investigated to evaluate the factors that control the cyclopolymerizability. A strong effect of ester substituent on cyclopolymerizability was observed and cyclization efficiency at 80°C increased in the following order: methyl, ethyl, isobornyl, t-butyl and adamantyl esters. That is, cyclization efficiency is found to be affected by the number of carbons linked to the central ester carbon (which defines the ‘effective’ bulkiness) rather than by the ‘apparent’ bulkiness, which encompasses the total mass or size of the whole substituent. Kinetic considerations of the temperature dependence of cyclization efficiency indicated that a strong contribution of the steric factor for bulky substituents (which inhibits intermolecular monomer addition) resulted in high cyclization efficiency despite a disadvantage in activation energy for cyclization. A linear relationship between the difference of activation energies ( E c − E i ) and the logarithm of the ratio of collision frequency factors ( ln ( A c A i ) ) observed for various esters led to recognition of an iso-efficiency point at which all esters show the same cyclization efficiency ( k c k i = 2.0 mol l −1 at −45°C). This phenomenon is caused by the fact that both parameters change in proportion to the bulkiness of the ester substituent. The ether dimer of α-(hydroxymethyl)acrylic acid showed unexpectedly high cyclization efficiency (intermediate between secondary and tertiary esters) despite having the lowest substituent bulkiness. The kinetic parameters obtained showed some deviation from the linearity observed for the ester derivatives. The large A c A i obtained was attributed to the capability of hydrogen-bond formation between acid groups, which causes a favourable conformation for cyclization. Microstructures of the cyclopolymers were investigated by observation of carbonyl carbon peaks in the 13 C nuclear magnetic resonance spectra. The peaks observed were assigned to four microstructures based on the combination of trans/cis configuration of the tetrahydropyran ring and racemic/meso configuration between the rings. Both the trans and racemic ratios increased with the bulkiness of the ester substituent. The values of E cis − E trans and A trans A cis for the t-butyl ester cyclopolymer indicated that trans formation is slightly favourable in both activation energy and steric factor, a result similar to that reported for the racemic/meso ratio in radical polymerization of some alkyl methacrylates. On the other hand, racemic formation between rings was suggested to be sterically unfavourable by the A racemic A meso ratio = 0.55 . The glass transition temperatures for the cyclopolymers were found to be much higher than for the corresponding acrylates or methacrylates, and the thermal stabilities of some of the derivatives, especially the adamantyl compound, were also high.
Average core structures and variability measures for protein families: application to the immunoglobulins.

A variety of methods are currently available for creating multiple alignments, and these can be used to define and characterize families of related proteins, such as the globins or the immunoglobulins. We have developed a method for using a multiple alignment to identify an average structural "core", a subset of atoms with low structural variation. We show how the means and variances of core-atom positions summarize the commonalities and differences with a family, making them particularly useful in compiling libraries of protein folds. We show further how it is possible to describe the rotation and translation relating two core structures, as in two domains of a multi-domain protein, in a consistent fashion in terms of a "mean" transformation and a deviation about this mean. Once determined, our average core structures (with their implicit measure of structural variation) allow us to define a measure of structural similarity more informative than the usual root-mean-square (RMS) deviation in atomic position, i.e. a "better RMS." Our average structures also permit straightforward comparisons between variation in structure and sequence at each position in a family. We have applied our core-finding methodology in detail to the immunoglobulin family. We find that the structural variability we observe just within the VL and VH domains anticipates the variability that others have observed throughout the whole immunoglobulin superfamily; that a core definition based on sequence conservation, somewhat surprisingly, does not agree with one based on structural similarity; and that the cores of the VL and VH domains vary about 5 degrees in relative orientation across the known structures.
Use of Sequence Data Generated in the Bayer TruGene Genotyping Assay To Recognize and Characterize Non-Subtype-B Human Immunodeficiency Virus Type 1 Strains

Human immunodeficiency virus type 1 (HIV-1) protease (PR) and reverse transcriptase (RT) gene sequences obtained during antiretroviral resistance testing with a commercial genotyping assay (TruGene; Bayer Corp.) were analyzed to assess the utility of these data for detecting and characterizing non-subtype-B HIV-1 strains. A total of 125 viral sequences obtained from patients believed to have acquired their HIV-1 infection in Africa were analyzed, of which 121 were determined to belong to non-B subtypes. Utilizing TruGene sequence data alone, 92 (76%) of these viruses could be subtyped by conventional phylogenetic analysis. The addition of supplemental RT sequence data enabled a further 28 (23.1%) viruses to be classified, while one (0.9%) sample could not be classified conclusively. Two internet-accessible databases that generate HIV-1 subtypes from PR and RT sequences (HIV-SEQ and Geno2Pheno) were also evaluated, and both achieved 88% concordance (106/120) with phylogenetic analysis. Non-subtype-B and B-subtype HIV-1 sequences could be readily discriminated by tallying silent polymorphisms listed on the TruGene research report. The mean number of silent polymorphisms in the non-B HIV-1 sequences identified in this study was 58.3 (95% confidence interval [CI], 41.1 to 75.5), compared with 20.7 (95% CI, 9.9 to 31.5) for the four subtype B viruses in the study cohort and 118 case-matched B-subtype controls. Sequence data generated in the TruGene HIV-1 genotyping assay could, therefore, provide a ready means of tracking the prevalence and identity of non-B subtypes in HIV-1-infected populations undergoing routine antiretroviral resistance testing.
Delamination Growth in Graphite/Epoxy Composites Subjected to Cyclic Mode III Loading:

A study was conducted to characterize the delamination growth behavior in a brittle graphite/epoxy composite under a tearing mode III condition. For this purpose, split canti lever beam specimens were tested under static and fatigue loadings. The static tests pro vided the critical strain energy release rate, GIIIC, for mode III. From the fatigue tests, the relationships between delamination growth rate and the corresponding strain energy release rate, GIII, were established for two displacement ratios. The results of the present study under the mode III condition are discussed and compared with their counterparts from previous studies involving mode I and mode II. The present results are also discussed in terms of damage tolerance and durability design considerations in composite structures.
The clinical potential of proteasome inhibition

Abstract The development of the proteasome inhibitor bortezomib is a prime example of successful bench-to-bedside research. NF-κB is implicated in the pathogenesis of multiple myeloma (MM), and bortezomib blocks NF-κB activation and its sequelae. Additional bortezomib mechanisms include interactions at the MM cell surface and mitochondrial level and in downstream apoptotic signaling. In the pivotal bortezomib study, the response rate was 35%; time to progression (TTP), 7 months; and median duration of response, 14.3 months. Responses were associated with improvements in quality of life, increases in laboratory parameters, and decreased transfusions. Bortezomib is thus indicated in the US for patients with relapsed, progressive MM and recommended for approval in Europe. The confirmatory phase III trial has been stopped early due to a significant improvement in TTP with bortezomib. The success of bortezomib in MM demonstrates the utility of targeting the tumour:host interaction and BM milieu, in addition to the tumour itself.
Hypersexual Behavior in Frontotemporal Dementia: A Comparison with Early-Onset Alzheimer’s Disease

The basis of hypersexual behavior among patients with dementia is not entirely clear. Hypersexual behavior may be a particular feature of behavioral variant frontotemporal dementia (bvFTD), which affects ventromedial frontal and adjacent anterior temporal regions specialized in interpersonal behavior. Recent efforts to define hypersexual disorder indicate an increasing awareness of heightened sexual activity as a source of personal distress and functional impairment, and clarification of hypersexuality in bvFTD could contribute to understanding the neurobiology of this behavior. This study reviewed 47 patients with bvFTD compared to 58 patients with Alzheimer’s disease (AD) for the presence of heightened sexual activity to the point of distress to caregivers and others. Hypersexual behavior occurred in 6 (13 %) bvFTD patients compared to none of the AD patients. Caregivers judged all six bvFTD patients with hypersexual behavior as having a dramatic increase in sexual frequency from premorbid levels. All had general disinhibition, poor impulse control, and actively sought sexual stimulation. They had widened sexual interests and experienced sexual arousal from previously unexciting stimuli. One patient, with early and predominant right anterior temporal involvement, was easily aroused by slight stimuli, such as touching her palms. Although previously considered to be predominantly disinhibited sexual behavior as part of generalized disinhibition, these patients with dementia illustrate varying degrees of increased sexual desire. We conclude that bvFTD is uniquely associated with hypersexuality; it is more than just cognitive impairment with frontal disinhibition but also involves alterations in sexual drive, possibly from right anterior temporal- limbic involvement in this disease.
4D flow CMR in assessment of valve-related ascending aortic disease.

Blood flow imaging with 3-dimensional time-resolved, phase-contrast cardiac magnetic resonance (4-dimensional [4D] Flow) is an innovative and visually appealing method for studying cardiovascular disease that allows quantification of important secondary vascular parameters including wall shear stress. The hypothesis of this pilot study is that 4D Flow will become a powerful tool for characterizing the relationship of aortic valve–related flow dynamics, especially with bicuspid aortic valve (BAV), and progression of ascending aortic (AsAo) dilation. We identified 46 patients previously studied with 4D Flow: tricuspid aortic valve patients without valvular disease (n = 20), and BAV patients with either normal flow (n = 7) or eccentric systolic jets resulting in abnormal right-handed helical AsAo flow (n = 19). The subgroup of patients with BAV and eccentric systolic AsAo blood flow was found to have significantly and asymmetrically elevated wall shear stress. This increased hemodynamic burden may place them at risk for AsAo aneurysm.
Electrophoresis and fractionation of wheat gluten.

Abstract Electrophoretic patterns of wheat gluten previously reported in the literature are asymmetric with respect to the ascending and descending boundaries. Primary objective of the present work was to find electrophoresis conditions that would give symmetrical diagrams. Such patterns would aid in establishing the number of components in gluten and their relative concentrations. An analytical tool also would be provided for following the progress of fractionation experiments. Lack of such a tool has been a handicap in previous attempts to fractionate gluten. Several suitable buffer systems were found. They include sodium chloroacetate-chloroacetic acid, sodium acetate-hydrochloric acid, sodium phosphate-phosphoric acid, all at pH 3.1 and nominal ionic strengths of about 0.03, and aluminum lactate-lactic acid at pH 3.1 and nominal ionic strengths of 0.03–0.12. Electrophoretic patterns obtained in these buffers demonstrate that gluten of bread wheats is composed of at least four major and one minor components representing, in order of decreasing mobility, relative concentrations among themselves of approximately 44, 22, 15, 16, and 3 %. There is evidence that the peak containing 15 % of the total gluten is composed of two components. In addition, the patterns show the presence of a small amount of relatively fast-moving material believed to be either globulin or albumin rather than true gluten protein. While aluminum lactate-lactic acid buffer does not resolve the two faster moving components, the excellent symmetry of the patterns obtained in this medium at relatively high gluten concentration recommends its use for following the progress of fractionation experiments and for investigating the effect on gluten composition of such variables as gluten quality and method of preparation. A partial separation of the electrophoretic components was obtained by precipitation of gluten from acid solution by increasing pH or ionic strength. The relationships between electrophoretic pattern and gluten quality and method of preparation were also studied.
Magnetoresistance and electrical noise in silver chalcogenide Ag 2 Te

ABSTRACT The relatively large and linear magnetoresistance found in nonstoichiometric silver chalcogenides makes them attractive candidates for studying the mechanisms of linear magnetoresistance and for field sensing applications. After a brief review of the magnetoresistive properties of these materials, we report on the intrinsic electrical noise in bulk, polycrystalline Ag 2+ Te. Low-frequency noise is due to resistance fluctuations having a 1/ f-like power spectrum. The temperature dependence of the noise magnitude and its spectral slope indicate thermally activated kinetics which we attribute to some form of charge trapping-detrapping process occurring in or near the intergranular regions. The effective magnetic field noise in Ag 2+ Te is also compared to other materials systems used in field sensing applications. Keywords: magnetoresistance, semiconductor, 1/ f noise, charge trapping 1. INTRODUCTION Narrow-gap semiconductors are generally considered to be the weaker sibling in the family of semiconducting materials, ranking behind normal semiconductors such as silicon and gallium arsenide. The most renowned narrow-gap semiconductors are from the II-VI compounds such as mercury-cadmium-telluride (HgCdTe) which has found applications in a variety of fields, including: medicine and astronomy. Less celebrated are the class of I-VI semiconductors of which the silver chalcogenides are an example. The scientific and technological interest in these materials stems from the extremely high sensitivity of their band structure to external effects such as magnetic field, light, temperature, pressure, impurities, etc. Silver telluride is a member of the silver chalcogenide family of non-magnetic, self-doped, degenerate, narrow band gap semiconductors. Although the stoichiometric material ( -Ag
An all-optical polymer fiber cantilever

There is a long history of using light to change the shape of a material. More than a decade ago, our group proposed and demonstrated that the length of an optical fiber should change due to a guided mode in analogy to the refractive index change due to the Optical Kerr Effect. The mechanisms that we postulated as being responsible included photothermal heating and photoisomerization. In the present studies, we report on a polymer optical fiber cantilever, which is excited by launching a light beam off-axis into the fiber. In measurements of the degree of bending as a function of time after the light beam is turned on or turned off, we find that there are two distinct time responses, each of different magnitude. We show that the dynamics of photobending is consistent with coupling between the photothermal heating and photoisomerization mechanisms. More interestingly, we find that a collective release of stress must be invoked to describe the observations. We propose new kinetic models of the phenomena, and show that they are consistent with the data.
Atmospheric effects on infrared imaging systems

Radiometric infrared camera systems are often used at test ranges to characterize the IR signature of targets such as aircraft or rockets through significant air columns that reduce the received signal through a combination of absorption and scattering. The dominant effect in clear air is molecular resonant absorption which is particularly strong in the midwave IR band (3-5 microns) for carbon dioxide and water vapor. Tactical targets can be imaged at standoff distances up to 1000km or more, but there are many cases where these targets are within a 1km range, as is the case with a close-in flyby at a test range. Therefore it is useful to model the short-range atmospheric transmission to predict its effect on radiometric measurements. Many industrial processes that occur in large outdoor facilities also lend themselves to radiometric measurement for standoff ranges of tens or hundreds of meters. This paper compares experimental radiometric data taken at ranges under 1km to a theoretical model of the atmosphere, and describes a simple method for correcting for air column effects at these relatively short ranges. The data were collected in the 3-5 micron band using an indium antimonide staring-array camera and a long focal length lens combined with radiometric analysis software. The system was calibrated to measure target radiances, but can also be used to estimate target temperatures in cases where the in-band emissivity of the target is well understood. The radiometric data are compared to a model built on MODTRAN code, with conclusions about the attenuation introduced by the atmosphere for standard medium-range imaging systems in "typical" observing conditions. Effects caused by the MTF of the lens system are studied briefly, and used to set limits on the minimum number of pixels the target can subtend and still have an accurately measurable radiance.
Detector time jitter in He3 and BF3 proportional counters

Abstract The delayed-coincidence technique has been used to measure the electronic time jitter for a number of neutron-detecting proportional counters. A selection of BF3 counters with filling pressures of 1–2 atm and cathode diameters of one and two inches were investigated. Several 1″ diameter He3 counters with fillings of helium and various polyatomic gas additives in pressures up to 12 atm were also studied. Procedures for the use of these results in the design of neutron time-of-flight detectors are discussed.
Mouse lacking NAD+-linked glycerol phosphate dehydrogenase has normal pancreatic beta cell function but abnormal metabolite pattern in skeletal muscle.

We surveyed the BALB/cHeA mouse, which lacks cytosolic glycerol phosphate dehydrogenase an enzyme that catalyzes a reaction in the glycerol phosphate shuttle. The other enzyme of this shuttle, mitochondrial glycerol phosphate dehydrogenase, is abundant in skeletal muscle and pancreatic islets suggesting that the shuttle's activity is high in these tissues. Levels of glycerol phosphate (low) and dihydroxyacetone phosphate (high) were very abnormal in nonislet tissue, especially in skeletal muscle. Intermediates situated before the triose phosphates in the glycolysis pathway were increased and those after the triose phosphates were generally low, depending on the tissue. The lactate/pyruvate ratio in muscle was low signifying a low cytosolic NAD/NADH ratio. This suggests that a nonfunctional glycerol phosphate shuttle caused a block in glycolysis at the step catalyzed by glyceraldehyde phosphate dehydrogenase. When exercised, mice were unable to maintain normal ATP levels in skeletal muscle. Blood glucose, serum insulin levels, and pancreatic islet mass were normal. In isolated pancreatic islets insulin release, glucose metabolism and ATP levels were normal, but lactate levels and lactate/pyruvate ratios with a glucose load were slightly abnormal. The BALB/cHeA mouse can maintain NAD/NADH ratios sufficient to function normally under most conditions, but the redox state is not normal. Glycerol phosphate is apparently formed at a slow rate. Skeletal muscle is severely affected probably because it is dependent on the glycerol phosphate shuttle more than other tissues. It most likely utilizes glycerol phosphate rapidly and, due to the absence of glycerol kinase in muscle, is unable to rapidly form glycerol phosphate from glycerol. Glycerol kinase is also absent in the pancreatic insulin cell, but this cell's function is essentially normal probably because of redundancy of NAD(H) shuttles.
Egg-mimicry as a mating strategy in the fantail darter, Etheostoma flabellare: females prefer males with eggs

In some species of fishes with paternal care, females prefer to spawn with males already defending eggs. Such female preference appears to have resulted in adoption of unrelated eggs as a male mating strategy in several species. Page and Swofford (1984) proposed that such female preference may have also resulted in the evolution of male egg-mimics in several species of darters (Percidae); however, their hypothesis has not been tested. We examined female preference in the fantail darter (Etheostoma flabellare) and found that females preferred males with eggs over males without eggs, and males with egg-mimics over males without egg-mimics. Thus it appears that female preference for males already guarding eggs may have led to the evolution of specialized egg-mimicking morphology in males.
Evaluating Regional Environmental Governance in Northeast Asia

Abstract Since the early 1990s, many regional and subregional environmental frameworks and programs have been created in Northeast Asia. In this article, the author assesses the extent to which these schemes have translated into a higher level of environmental governance. He argues that despite remarkable institutional development, regional environmental governance is at an embryonic stage. Its weakness stems from three factors in particular: (1) the primacy of national governments and the limited role of nonstate actors, (2) the lack of a coordinating mechanism among overlapping environmental initiatives, and (3) the lack of tangible outcomes in terms of mitigating environmental degradation.
Ultrastructure of aerial stalk formation by the ciliated protozoanSorogena stoianovitchae

Sorogena stoianovitchaeBradbury andOlive is an unusual kinetophragminophoran ciliate characterized by the aggregation of individual trophic cells to form a multicellular sorogen that rises aerially from the medium surface to produce a sorocarp. A light and electron microscope study of sorogenesis revealed how the sorogenic cells produce the stalk. The feeding ciliates contain numerous subpellicular expansions of rough endoplasmic reticulum cisternae that are only one element of the secretory system necessary for stalk formation. Upon aggregation, the stalk secretory system develops further, initially with the proliferation of the subpellicular expansions. Then, during later aggregation and early sorogenesis, other secretory elements appear: stalk material vesicles, dense granule vesicles, and electron lucent vacuoles. These are all derived from the rough endoplasmic reticulum. Only the subpellicular expansions and stalk material vesicles appear to add to the stalk matrix. The dense granule vesicles could be precursors of the stalk material vesicles; the electron lucent vacuoles, which can be demonstrated to contain fibrillar material, are perhaps by-products of the secretory process. Sorogenesis inSorogena occurs by a mechanism unique among the stalk-producing protists that have been studied.
Cell nucleus in context.

The molecular pathways that participate in regulation of gene expression are being progressively unraveled. Extracellular signals, including the binding of extracellular matrix and soluble molecules to cell membrane receptors, activate specific signal transducers that convey information inside the cell and can alter gene products. Some of these transducers when translocated to the cell nucleus may bind to transcription complexes and thereby modify the transcriptional activity of specific genes. However, the basic molecules involved in the regulation of gene expression are found in many different cell and tissue types; thus the mechanisms underlying tissue-specific gene expression are still obscure. In this review, we focus on the study of signals that are conveyed to the nucleus. We propose that the way in which extracellular signals are integrated may account for tissue-specific gene expression. We argue that the integration of signals depends on the structural organization of cells ( i.e., extracellular matrix, cell membrane, cytoskeleton, nucleus) which a particular cell type within a tissue. Putting the nuclei in context allows us to envision gene expression as being regulated not only by the communication between the extracellular environment and the nucleus, but also by the influence of organized assemblies of cells on extracellular-nuclear communications.
Renal acidification during chronic hypercapnia in the conscious dog.

Enhanced renal acidification during chronic hypercapnia (CH) results in transient augmentation in net acid excretion (NAE) (adaptation phase) and persistent acceleration in renal bicarbonate reclamation (adaptation and steady-state phases). The mechanisms responsible for the return of NAE to control values despite persistent acidemia during the steady state phase of CH remain undefined. In addition, it remains unsettled whether the enhancement of renal ammoniagenesis known to occur during the adaptation phase of CH persists during the steady-state phase. Furthermore it is uncertain if the alteration in whole-kidney acification observed in CH originates from augmentation in the acification of both proximal and distal nephronal segments.
Perceptions of Teachers' Salaries and Non-salary Benefits

Rowsey and Ley asked undergraduate students in education and engineering to estimate the mean salaries for four groups: beginning teachers in Alabama, all teachers in Alabama, beginning teachers in the United States, and all teachers in the United States. Although estimates made by prospective engi neers were generally more accurate than were those made by prospective teachers, both samples underestimated mean salaries for all but one group, be ginning teachers in the United States. Males in both samples generally sub mitted more accurate estimates than did the females. Prospective teachers indi cated that non-salary benefits, such as personal satisfaction of teaching and ad vantages of the school calendar, were important aspects in their decisions to become teachers. Of the engineering students who had once considered teaching, most reported that low salary was the primary reason they did not pur sue a career in education.
Thermal Conductivities of Tungsten and Molybdenum at Incandescent Temperatures

Using an optical pyrometer method, the thermal conductivity of tungsten has been found to vary linearly from 1.170 watts/(cm2 K°/cm) at 1100°K to 1.026 watts/(cm2 K°/cm) at 2000°K. Similarly, the thermal conductivity of molybdenum has been found to vary linearly from 1.083 watts/(cm2 K°/cm) at 1200°K to 0.666 watt/(cm2 K°/cm) at 1900°K. Spectrographic analysis indicated only traces of impurities in samples of the two metals used in the investigation.
Hirschsprung disease in an infant with a contiguous gene syndrome of chromosome 13

Hirschsprung disease is a developmental disorder resulting from the arrest of the craniocaudal migration of enteric neurons from the neural crest along gastrointestinal segments of variable length; see Behrman [Nelson textbook of pediatrics, 1992:954-956]. It is a heterogeneous disorder in which familial cases map to at least three loci whose function is necessary for normal neural crest-derived cell development. Homozygous mutations in the endothelin-B receptor gene (EDNRB) on 13q22 have been identified in humans and mice with Hirschsprung disease type 2 (HSCR2). The auditory pigmentary disorder, Waardenburg-Shah syndrome, comprises Waardenburg syndrome and Hirschsprung disease and has also been mapped to the EDNRB locus. Hirschsprung disease, malrotation, isochromia, a profound sensorineural hearing loss, and several other anomalies were found in an infant with an interstitial deletion of 13q, suggesting the existence of a contiguous gene syndrome involving developmental genes necessary for the normal growth of the neural crest derivatives of the eye, inner ear, and colon. We report on an additional patient with a deletion in 13q and Hirschsprung disease. Congenital anomalies associated with deletions of the distal long arm of chromosome 13 are sufficiently consistent to suggest a clinical syndrome.
Digital Sensing and Sizing of Vesicular Stomatitis Virus Pseudotypes in Complex Media: A Model for Ebola and Marburg Detection

Rapid, sensitive, and direct label-free capture and characterization of nanoparticles from complex media such as blood or serum will broadly impact medicine and the life sciences. We demonstrate identification of virus particles in complex samples for replication-competent wild-type vesicular stomatitis virus (VSV), defective VSV, and Ebola- and Marburg-pseudotyped VSV with high sensitivity and specificity. Size discrimination of the imaged nanoparticles (virions) allows differentiation between modified viruses having different genome lengths and facilitates a reduction in the counting of nonspecifically bound particles to achieve a limit-of-detection (LOD) of 5 × 10(3) pfu/mL for the Ebola and Marburg VSV pseudotypes. We demonstrate the simultaneous detection of multiple viruses in a single sample (composed of serum or whole blood) for screening applications and uncompromised detection capabilities in samples contaminated with high levels of bacteria. By employing affinity-based capture, size discrimination, and a "digital" detection scheme to count single virus particles, we show that a robust and sensitive virus/nanoparticle sensing assay can be established for targets in complex samples. The nanoparticle microscopy system is termed the Single Particle Interferometric Reflectance Imaging Sensor (SP-IRIS) and is capable of high-throughput and rapid sizing of large numbers of biological nanoparticles on an antibody microarray for research and diagnostic applications.
Partially supervised classification with optimal significance testing

The paper addresses the problem of estimating an optimal acceptance probability to be used for significance testing as applied to partially supervised classification where the class definition and corresponding training samples are provided a priori only for one specific class of interest. Considering the effort in both time and man-power required for a well-defined, exhaustive list of classes with their representative training samples even if there is just one class of interest to identify, the "partially" supervised capability would be very desirable, assuming adequate classifier performance can be obtained. The optimal acceptance probability is estimated directly from the data set. Experiments with both simulated and real data show very satisfactory results. >
Agricultural best management practices for water pollution control: current issues

From the first awareness of agricultural sources of water pollution in the US in the 1960s, we finally see in the 1990s a commitment at the national level for agricultural non-point source (NPS) pollution control. This has been occasioned by a growing awareness that, with point sources of some pollutants largely controlled by waste-water treatment, greater attention must be paid to NPS pollution control, a large percentage of which is agricultural. The 1985 Farm Security Act mandated several national erosion control programs that will have some impact on water quality, and there is opportunity to supplement these programs with best management practices (BMPs) specifically designed to address agricultural water pollutants, primarily nitrate, phosphorus and modern pesticides. This paper discusses fundamental processes affecting transport of agricultural pollutants in surface and ground water and suggests how knowledge of these processes can be used to evaluate existing agricultural NPS BMPs and to develop supplemental practices.
Combined hamartoma of the retina and retinal pigment epithelium associated with juvenile nasopharyngeal angiofibroma.

Abstract PURPOSE: To report a patient who had concomitant combined hamartoma of the retinal pigment epithelium and retina and juvenile nasopharyngeal angiofibroma. METHOD: Case report. RESULTS: An 18-year-old man presented with a juvenile nasopharyngeal angiofibroma and a combined hamartoma of the retina and retinal pigment epithelium in the ipsilateral eye. The diagnosis of juvenile nasopharyngeal angiofibroma was confirmed by histopathology, and the diagnosis of combined hamartoma was established by typical ophthalmoscopic and fluorescein angiographic findings. CONCLUSION: Juvenile nasopharyngeal angiofibroma may be associated with combined hamartoma of the retina and retinal pigment epithelium.
Sulfur Cycling in the Terrestrial Subsurface: Commensal Interactions, Spatial Scales, and Microbial Heterogeneity

Microbiological, geochemical, and isotopic analyses of sediment and water samples from the unconsolidated Yegua formation in east-central Texas were used to assess microbial processes in the terrestrial subsurface. Previous geochemical studies suggested that sulfide oxidation at shallow depths may provide sulfate for sulfate-reducing bacteria (SRB) in deeper aquifer formations. The present study further examines this possibility, and provides a more detailed evaluation of the relationship between microbial activity, lithology, and the geochemical environment on meter-to-millimeter scales. Sediment of varied lithology (sands, silts, clays, lignite) was collected from two boreholes, to depths of 30 m. Our findings suggest that pyrite oxidation strongly influences the geochemical environment in shallow sediments (∼5 m), and produces acidic waters (pH 3.8) that are rich in sulfate (28 mM) and ferrous iron (0.3 mM). Sulfur and iron-oxidizing bacteria are readily detected in shallow sediments; they likely play an indirect role in pyrite oxidation. In consistent fashion, there is a relative paucity of pyrite in shallow sediments and a low 34S/32S-sulfate ratio (0.2‰) (reflecting contributions from 34S-depleted sulfides) in shallow regions. Pyrite oxidation likely provides a sulfate source for both oxic and anoxic aquifers in the region. A variety of assays and direct-imaging techniques of 35S-sulfide production in sediment cores indicates that sulfate reduction occurs in both the oxidizing and reducing portions of the sediment profile, with a high degree of spatial variability. Narrow zones of activity were detected in sands that were juxtaposed to clay or lignite-rich sediments. The fermentation of organic matter in the lignite-rich laminae provides small molecular weight organic acids to support sulfate reduction in neighboring sands. Consequently, sulfur cycling in shallow sediments, and sulfate transport represent important mechanisms for commensal interaction among subsurface microorganisms by providing electron donors for chemoautotrophic bacteria and electron acceptors for SRB. The activity of SRB is linked to the availability of suitable electron donors from spatially distinct zones.
Network Awareness for Mobile Agents on Ad Hoc Networks

This paper introduces a state description for mobile agent systems on ad hoc networks, allowing agents to reason about how they communicate over the agent system's underlying network. The ability to make intelligent decisions about communications allows agents to achieve their goals more efficiently, and increase the security and survivability of an agent system. One application of this model includes a formal representation of information assurance for agent messaging on dynamic networks with possibly redundant routes. We use this framework to study the "compromised host" problem - specifically, how agents should react after an intruder has been detected. This is done by first quantifying the effect of the compromised host on the integrity of messages among agents; and then selecting a routing policy with respect to message integrity and the compromised host (e.g., rerouting to avoid the host or continuing to communicate through it). We provide examples of how this technique can be used to improve information assurance for agent-to-agent communications and information distribution in sensor networks. Empirical validation in the SecureWireless Agent Testbed (SWAT) shows network awareness improves the survivability and efficiency of mobile agent systems.
Bridged interface cracks in anisotropic bimaterials

Abstract The bonding strength between dissimilar materials in composites is often relatively weak. Interface debonding and cracking are of common occurrence. As an effective method to minimize such failures, fibre stitching is used to enhance the bonding strength when joining layers in polymer composites. With the presence of the reinforcing fibre, the overall elastic response for each component of the composite is, in general, anisotropic. This paper investigates the elastic behaviour of bridged interface cracks in anisotropic bimaterials. From the equilibrium of the interface crack, a system of Cauchy integral equations for the required distributed dislocation density is obtained. When the bridging force depends linearly on the crack-opening displacement, explicit solutions are given in terms of a series of Jacobi polynomials. For illustration, a bridged interface crack in isotropic bimaterials is examined in detail. Results suggest that bridging fibres effectively enhance the toughness of the compositi...