cssi/SciSciGPT-SciSciNet huggingface dataset:
Increased glutamate uptake and glutamine synthetase activity in neuronal cell cultures surviving chronic hypoxia.

Abstract To examine the neurochemical effects of chronic hypoxia on immature nervous tissue in vitro, mixed neuronal-glial cell cultures derived from fetal mice were exposed to 5% O2 for 24 or 48 h. Those cultures subjected to longer hypoxia manifested improved neuronal survival compared to those with the shorter insult, both with respect to neuronal morphology and also cell counts. Neurochemical assays were performed on living cells in situ to determine the possible basis for differential cell survival. After both exposure conditions. Ro5-4864-displaceable benzodiazepine (BDZ) binding, reflecting nonneuronal BDZ binding sites, was either not reduced or was elevated. Although initially reduced, binding of the excitatory amino acid (EAA) glutamate was progressively increased after both insults and, within 2 days after return to normoxia, was increased relative to control values (121 and 128% of controls, P less than 0.05). The most impressive neurochemical differences between the two conditions related to changes in the predominantly or exclusively glial functions of glutamate uptake and glutamine synthetase activity. In those cultures with relatively preserved neuronal morphology: 1) high affinity uptake of glutamate was elevated compared to the shorter hypoxic insult by 3 days of recovery (104 vs 70%, P less than 0.001) and 2) glutamine synthetase, an enzyme localized primarily within astrocytes, was significantly elevated even when compared to absolute control values (148%, P less than 0.001). These data suggest that longer periods of hypoxia may be less deleterious to neurons than shorter hypoxic events because of a time-dependent stimulation of specific glial cell functions which relate to increased metabolism of potentially neurotoxic EAAs such as glutamate.
Neurogenic goblet cell secretion and bronchoconstriction in guinea pigs sensitised to trimellitic anhydride.

Abstract Trimellitic anhydride is a cause of occupational asthma in humans. We have previously found that tracheal instillation of trimellitic anhydride conjugated to guinea pig serum albumin induces acute bronchoconstriction and airway plasma exudation in sensitised animals, responses mediated primarily via histamine release. In the present study, neural mechanisms mediating bronchoconstriction and goblet cell secretion were determined in trimellitic anhydride-sensitised guinea pigs using the ganglionic blocker hexamethonium to eliminate efferent reflex mechanisms, pretreatment with capsaicin to eliminate afferent mechanisms, or cimetidine and mepyramine to eliminate histamine-mediated mechanisms. The magnitude of secretion of intracellular mucus from tracheal goblet cells was quantified morphometrically as a mucus score which is inversely related to the degree of discharge. Guinea pigs were injected intradermally either with 0.1 ml 0.3% trimellitic anhydride in corn oil or with corn oil alone as control. Fourteen to eighteen days later all sensitised animals had developed specific immunoglobulin (Ig) G1 antibodies whereas the controls had not. Tracheal instillation of conjugated trimellitic anhydride in anaesthitised animals significantly increased airway lung resistance ( R L ) 24-fold in sensitised guinea pigs (34.3 ± 7.9 cm H 2 O · ml −1 · s) compared with controls (1.4 ± 0.1 cm H 2 O · ml −1 · s). Mucus score was significantly reduced by 51% (indicating goblet cell secretion) in sensitised guinea pigs (183 ± 22 mucus score units) compared with controls (372 ± 41 mucus score units). The antihistamines significantly inhibited conjugated trimellitic anhydride-induced bronchoconstriction by 89%, but did not significantly affect goblet cell discharge. Hexamethonium alone did not significantly affect conjugated trimellitic anhydride-induced bronchoconstriction or goblet cell secretion. Capsaicin pretreatment (in combination with hexamethonium) significantly inhibited golet cell discharge (by 80%) but had no significant effect on bronchoconstriction. We conclude that conjugated trimellitic anhydride challenge of trimellitic anhydride-sensitised guinea pigs induces goblet cell discharge and bronchoconstriction via different mechanisms with activation of capsaicin-sensitive sensory nerves responsible for secretion and histamine release responsible for airway constriction. The guinea pig model of trimellitic anhydride-induced occupational asthma may prove useful in examination of mechanisms of goblet cell secretion in allergic diseases.
Fishing the Fermi sea

Sophocles had it right, the Rolling Stones made a friendly amendment and Linus Pauling detailed the conceptual mechanism for finding novel materials that will define and revolutionize the future.
Effects of Perchlorate on Growth and Behavior of a Granivorous Passerine, the Zebra Finch ( Taeniopygia guttata)

Perchlorate (ClO 4 − ) is a thyroid hormone inhibitor and persistent environmental contaminant that has been shown to impair thyroid function and growth in ground-dwelling birds. In this study, we used the zebra finch (Taeniopygia guttata) as a model to examine the effects of environmentally relevant perchlorate concentrations on growth and behavior of a granivorous passerine. On post-hatch days (PHDs) 3–14, finch chicks were orally dosed once per day with either 0, 10, 100, or 1000 μg sodium perchlorate/g body mass, and multiple endpoints of growth and behavior were examined in birds up to 72 days of age. Mean (±SE) body mass and tibiotarsal length were significantly reduced in the 100 and 1000 μg/g dose groups from PHDs 3–14, and this reduction persisted until PHD 40. Mean liver mass (PHD 15) in the 100 and 1000 μg/g dose groups were significantly greater than controls. Mean brain mass and mean nuclear volume of the song control nucleus area X in brains of 72-day-old males did not differ among dose groups. All endpoints of finch behavior were significantly influenced by perchlorate exposure at the highest dose level. Compared to controls, birds in this dose group exhibited a greater begging intensity, decreased motivation for spontaneous movement (e.g., attempts to fly), and reduced capacity to wean themselves from parental care. On PHD 15, flight attempts were also significantly reduced in the 10 and 100 μg/g dose groups, and the proportion of perchlorate-dosed birds attempting flight was less than half that in the control group. This study demonstrates a dose-dependent alteration of multiple growth and behavioral endpoints in zebra finches exposed to environmentally relevant concentrations of perchlorate. Comparable exposures in the wild may also affect normal development and behavior in similarly sensitive avian granivores.
MECHANISMS OF INITIAL ENDPLATE FAILURE IN THE HUMAN VERTEBRAL BODY

Endplate failure occurs frequently in osteoporotic vertebral fractures and may be related to the development of high tensile strain. To determine whether the highest tensile strains in the vertebra occur in the endplates, and whether such high tensile strains are associated with the material behavior of the intervertebral disc, we used micro-CT-based finite element analysis to assess tissue-level strains in 22 elderly human vertebrae (81.5 ± 9.6 years) that were compressed through simulated intervertebral discs. In each vertebra, we compared the highest tensile and compressive strains across the different compartments: endplates, cortical shell, and trabecular bone. The influence of Poisson-type expansion of the disc on the results was determined by compressing the vertebrae a second time in which we suppressed the Poisson expansion. We found that the highest tensile strains occurred within the endplates whereas the highest compressive strains occurred within the trabecular bone. The ratio of strain to assumed tissue-level yield strain was the highest for the endplates, indicating that the endplates had the greatest risk of initial failure. Suppressing the Poisson expansion of the disc decreased the amount of highly tensile-strained tissue in the endplates by 79.4 ± 11.3%. These results indicate that the endplates are at the greatest risk of initial failure due to the development of high tensile strains, and that such high tensile strains are associated with the Poisson expansion of the disc. We conclude that initial failure of the vertebra is associated with high tensile strains in the endplates, which in turn are influenced by the material behavior of the disc.
Electron microscopy of mouse preimplantation embryos and isolated blastomeres immobilized on coverslips

In this report we describe a new method of immobilizing intact mouse preimplantation embryos and their dissociated blastomeres on a flat substrate so that they may be processed en masse for electron microscopy. The embryos can be arranged so that they will be coplanar and grouped together closely enough to be included within the same plane of section. The substrate consists of Thermonex plastic coverslips that have been coated with a layer of fibroblasts or with fibronectin. The plant lectin phytohemaggiutinin (PHA) is used as a ligand to adhere the embryos onto the coverslips. This method is compatible with other ligands and with a variety of immunocytochemical procedures and can be used with live or fixed embryos.
The link between resources and type of diversification: Theory and evidence

In this paper we theoretically and empirically investigate the idea that firms diversify in part to utilize productive resources which are surplus to current operations. Knowledge of these resources allows us to make predictions about the direction of a firm's expansion. In particular, we suggest that excess physical resources, most knowledge-based resources, and external financial resources are associated with more related diversification, while internal financial resources are associated with more unrelated diversification.
Successful supersymmetric dark matter with thermal over/under-abundance from late decay of a visible sector scalar

We present an explicit model where the decay of an $R$-parity-even scalar $S$ with $\mathcal{O}(\mathrm{TeV})$ mass is the origin of nonthermal dark matter. The correct relic abundance can be produced for both large and small annihilation rates in accordance with the Fermi constraints on the annihilation cross section. This scenario has advantages over that of nonthermal dark matter from modulus decay. First, the branching ratio for production of $R$-parity odd particles can be made quite small by a combination of $S$ couplings to matter fields and kinematic suppression, enabling us to obtain the observed dark matter relic density in cases of thermal underproduction as well as overproduction. Second, gravitino production is naturally suppressed by the virtue of a decaying scalar belonging to the visible sector. The decaying scalar can also successfully generate the baryon asymmetry of the Universe, and may provide an explanation for the baryon---dark matter coincidence puzzle.
Biwetted ultrafine solids and structure formation in oil sands fine tailings

A high water holding capacity of oil sands fine tailing has been attributed to the presence of ultrafine (< 0.2 μm) clay fractions. On the basis of hydrophobic character two major types of ultrafines are recognized: biwetted, associated with a significant coverage or organic matter and preferentially hydrophilic solids. The effect of biwetted solids on the colloidal stability of ultrafine clays in aqueous suspensions has been studied by dynamic light scattering and 2 H n.m.r. methods. The organic matter associates with the surfaces of the biwetted solids is believed to be responsible for their accelerating effect on aggregation. The results indicate that prevention, or reduction, of the amount of biwetted solids entering the tailings pond could be beneficial.
Deep punching PMMA

The authors performed deep punching experiments on PMMA (polymethyl methacrylate) using cylindrical-shaped punches with conical and hemispherical noses. The test samples cracked when no lateral confinement was provided. Application of proper lateral confinement suppressed the cracks. The punching force recorded from the experiments correlates very well with cavity expansion theory. Because the use of a single friction coefficient gives excellent agreement between theory and experiments for two different-shaped punches, the authors propose deep punching as a new technique to measure the friction coefficient.
The Use of the Milne-Eddington Absorption Coefficient for Radiative Heat Transfer in Combustion Systems

The applicability of the Milne-Eddington absorption coefficient approximation is discussed in relation to the calculation of radiative transport involving the two distinct types of species produced in combustion systems: gases and soot particles. The approximation is found to apply well to hydrocarbon soot particles and as a result analytical closed-form solutions are derived for the radiative heat transfer inside one-dimensional slab shaped soot clouds. (The applicability of the gray approximation to soot is also discussed.) For the calculation of total band radiation from gases, however, the Milne-Eddington approximation is found to be questionable. The meaning of its assumption is discussed in light of an established Curtis-Godson wide band scaling approximation. Its usefulness for real gases is then assessed through the calculation and comparison of slab radiation by both techniques.
RHESSI AND HINODE X-RAY OBSERVATIONS OF A PARTIALLY OCCULTED SOLAR FLARE

This Letter presents X-ray observations of a partially limb-occulted solar flare taken by the Reuven Ramaty High-Energy Solar Spectroscopic Imager and the X-ray telescope on board Hinode. Thermal emission originates from a simple loop at the western limb that rises slowly (~7 km s−1) until the flare peak time. Above 18 keV, faint nonthermal emission with a hard/flat spectrum (γ ~ 4) and fast time variations (of the order of tens of seconds) is seen that comes from a loop slightly above (~2000 km) the thermal loop, if compared at the same time. However, the nonthermal loop agrees well in altitude with the thermal flare loop seen later, at the soft X-ray peak time. This is consistent with simple flare models where nonthermal electrons in a flare loop produce thin-target hard X-ray emission in the corona as they travel to the loop footpoints. There they lose all their energy and heat chromospheric plasma that fills the loop earlier seen in nonthermal hard X-rays. This suggests that electron acceleration in solar flares occurs in the corona.
Hearing Loss After Radiotherapy for Pediatric Brain Tumors: Effect of Cochlear Dose

Purpose To determine the effect of cochlear dose on sensorineural hearing loss in pediatric patients with brain tumor treated by using conformal radiation therapy (CRT). Patients and Methods We studied 78 pediatric patients (155 ears) with localized brain tumors treated in 1997–2001 who had not received platinum-based chemotherapy and were followed up for at least 48 months. They were evaluated prospectively by means of serial pure-tone audiograms (250 Hz–8 kHz) and/or auditory brainstem response before and every 6 months after CRT. Results Hearing loss occurred in 14% (11 of 78) of patients and 11% (17 of 155) of cochleae, with onset most often at 3–5 years after CRT. The incidence of hearing loss was low for a cochlear mean dose of 30 Gy or less and increased at greater than 40–45 Gy. Risk was greater at high frequencies (6–8 kHz). In children who tested abnormal for hearing, average hearing thresholds increased from a less than 25 decibel (dB) hearing level (HL) at baseline to a mean of 46 ± 13 (SD) dB HL for high frequencies, 41 ± 7 dB HL for low frequencies, and 38 ± 6 dB HL for intermediate frequencies. Conclusions Sensorineural hearing loss is a late effect of CRT. In the absence of other factors, including ototoxic chemotherapy, increase in cochlear dose correlates positively with hearing loss in pediatric patients with brain tumor. To minimize the risk of hearing loss for children treated with radiation therapy, a cumulative cochlear dose less than 35 Gy is recommended for patients planned to receive 54–59.4 Gy in 30–33 treatment fractions.
Macrophages create an acidic extracellular hydrolytic compartment to digest aggregated lipoproteins.

A critical event in atherogenesis is the interaction of macrophages with subendothelial lipoproteins. Although most studies model this interaction by incubating macrophages with monomeric lipoproteins, macrophages in vivo encounter lipoproteins that are aggregated. The physical features of the lipoproteins require distinctive mechanisms for their uptake. We show that macrophages create an extracellular, acidic, hydrolytic compartment to carry out digestion of aggregated low-density lipoproteins. We demonstrate delivery of lysosomal contents to these specialized compartments and their acidification by vacuolar ATPase, enabling aggregate catabolism by lysosomal acid hydrolases. We observe transient sealing of portions of the compartments, allowing formation of an “extracellular” proton gradient. An increase in free cholesterol is observed in aggregates contained in these compartments. Thus, cholesteryl ester hydrolysis can occur extracellularly in a specialized compartment, a lysosomal synapse, during the interaction of macrophages with aggregated low-density lipoprotein. A detailed understanding of these processes is essential for developing strategies to prevent atherosclerosis.
Applying idealized scientific theories to engineering

The problem for the scientist created by using idealizations is to determine whether failures to achieve experimental fit are attributable to experimental error, falsity of theory, or of idealization. Even in the rare case when experimental fit within experimental error is achieved, the scientist must determine whether this is so because of a true theory and fortuitously canceling idealizations, or due to a fortuitous combination of false theory and false idealizations. For the engineer, the problem seems rather different. Experiment for the engineer reveals the closeness of predictive fit that can be achieved by theory and idealization for a particular case. If the closeness of fit is good enough for some practical purpose, the job is done. If not, or there are reasons to consider variation, then the engineer needs to know how well the experimentally determined closeness of fit will extrapolate to new cases. This paper focuses on engineering measures of closeness of fit and the projectibility of those measures to new cases.
Zone-Melting Recrystallization of Silicon on Alumina

Polysilicon-on-alumina films have been zone-melt recrystallized with a graphite strip heater. High levels of in-plane stress and stress concentrations due to alumina grain pull-outs cause tensile failure at high temperature. This can be avoided by phosphorus incorporation into an SiOo layer between the polysilicon film and the alumina substrate. The glass layer provides high-temperature viscoelastic strain relief and planarizes the alumina substrate. Double-crystal diffractometry and anisotropic etch techniques indicate that the recrystallized silicon-on-alumina film texture is (100).
Instrumentation for future parallel computing systems

This book contains chapters relating to parallel computing systems. Included are the following chapters: Parallel applications performance methodology, Monitoring experimental parallel machines, and Parallel processing a real code - a case history.
Biocompatible and pH-Sensitive PLGA Encapsulated MnO Nanocrystals for Molecular and Cellular MRI

Inorganic manganese-based particles are becoming attractive for molecular and cellular imaging, due to their ability to provide bright contrast on MRI, as opposed to the dark contrast generated from iron-based particles. Using a single emulsion technique, we have successfully fabricated pH-sensitive poly(lactic-co-glycolic acid) (PLGA)-encapsulated manganese oxide (MnO) nanocrystals. Two classes of particles were fabricated at ∼140 nm and 1.7 μm and incorporated 15 to 20 nm MnO nanocrystals with high encapsulation efficiencies. Intact particles at physiological pH cause little contrast in MRI, but following endocytosis into low pH compartments within the cells, the particles erode and MnO dissolves to release Mn(2+). This causes the cells to appear bright on MR images. The magnitude of the change in MRI properties is as high as 35-fold, making it the most dynamic "smart" MRI contrast agent yet reported. Possible applications of these MnO particles include slow release Mn(2+), tumor targeting, and confirmation of cell uptake.
Stimulation of cholinergic receptor mediated secretion from the bovine adrenal medulla by neuropeptide Y

The bovine adrenal medulla has been shown to possess binding sites for neuropeptide Y (NPY) and to release NPY in response to nicotinic receptor stimulation. Therefore we chose to investigate the influence of this peptide on adrenomedullary secretion using the retrogradely perfused bovine adrenal gland. The secretion of enkephalin-like peptides, norepinephrine and epinephrine was monitored after nicotinic cholinergic receptor stimulation in the presence and absence of NPY. NPY, alone, had no effect on secretion from the adrenal gland but produced a dose dependent increase in the secretion of enkephalin-like peptides and catecholamines when the cholinergic agonist, 1,1 dimethyl-4-phenylpiperizinium iodide, was present. The increase was significant at 1 X 10(-8) M when compared to release in the absence of NPY. The stimulatory action of other cholinergic agonists (nicotine and acetylcholine) was likewise potentiated by the addition of the neuropeptide. Peptide YY and pancreatic polypeptide did not mimic the effect of NPY when examined at the same concentration. In contrast to the potentiation observed in the perfused adrenal gland, NPY (1 X 10(-8) M) inhibited the cholinergic mediated release of enkephalin-like peptides and catecholamines from cultured bovine chromaffin cells. These data suggest that NPY may have the capacity to augment cholinergic receptor mediated secretion from the bovine adrenal gland.
Screening for Malignancy in Primary Sclerosing Cholangitis (PSC)

Primary sclerosing cholangitis (PSC) is a frequently progressive and fatal disease. Death from cancer occurs in a significant subset of patients with PSC. Patients with PSC have a 10 to 15 % lifetime risk of developing cholangiocarcinoma (CCA). About one third of CCAs are present in the first year after a diagnosis of PSC; the remainder are present with a frequency of about 1.5 % each year. Patients with concomitant PSC and inflammatory bowel disease (IBD) have a 4-fold higher risk of colorectal cancer (CRC) than patients with IBD alone and a 10-fold higher risk of CRC than the general population. The risk does not diminish with liver transplantation. This patient population also has a high frequency of carcinoma in gallbladder mass lesions. The risk for hepatocellular carcinoma (HCC) in the presence of cirrhosis is uncertain—two large cohort studies suggest that HCC is not as common as in other causes of cirrhosis. Although AASLD guidelines do not recommend routine screening for liver tumors in patients with PSC, we recommend MRI/MRCP and serum CA 19-9 levels in patients with PSC every 6 months to screen for CCA, HCC, pancreatic cancer, and gallbladder cancer. Screening colonoscopy at the diagnosis of PSC and surveillance colonoscopies every 1–2 years should be performed in those with PSC and IBD.
Gonadal differentiation and effects of temperature on sex determination in southern flounder (Paralichthys lethostigma)

Abstract Southern flounder ( Paralichthys lethostigma ) support valuable North American fisheries and show great promise for aquaculture. Because females grow faster and reach larger adult sizes than males, monosex culture of females is desirable for commercial operations. A detailed understanding of sexual development and its timing is critical to control sex and optimize culture. Structural and cellular sex-distinguishing markers were identified histologically, and then used to describe ovarian development in female and testicular development in male flounder. In presumptive ovaries of southern flounder, development of an ovarian cavity first occurs in fish ranging from 75 to 100 mm total length (TL). This is considerably delayed relative to that observed in the Japanese congener, Paralichthys olivaceus , where an ovarian cavity is seen in fish as small as 40 mm TL. The smallest southern flounder that possessed primary oocytes in the early perinucleolus stage was 115 mm TL. In presumptive testes, the formation of seminiferous tubules first occurs in fish of approximately 100 mm TL. Spermatogonia remained quiescent until most fish were over 100 mm TL. Overall, gonads from southern flounder greater than 120 mm TL commonly possess gonial cells undergoing meiosis, clearly differentiating sex. The effect of temperature on sex determination in southern flounder was addressed in a separate experiment. Juvenile southern flounder were grown at 18, 23, or 28°C for 245 days. High and low temperatures induced phenotypic sex reversal in juvenile southern flounder, producing a higher proportion of males (96% males at high temperature, P P P. olivaceus , but possibly shifted towards warmer temperatures. These findings indicate that sex differentiation in southern flounder is distinguishable in most fish by 100–120 mm TL and that sex determination is sensitive to temperature. This information is critical to the development of strategies to maximize the number of faster-growing females for commercial flounder culture.
The Unfolded Protein Response Modulates Toxicity of the Expanded Glutamine Androgen Receptor

Kennedy disease, a degenerative disorder caused by an expanded glutamine tract, is mediated by misfolding of the mutant androgen receptor (AR) protein, a process that may disrupt proteasome function. We hypothesized that this might lead to endoplasmic reticulum (ER) stress and induction of the unfolded protein response (UPR), a complex physiologic pathway that regulates cell survival. To test this hypothesis, we used aminoterminal fragments of wild type (AR16Q) or mutant (AR112Q) AR that triggered glutamine length-dependent cell death and activated an ER stress-inducible promoter. To evaluate the role of the UPR, we examined the contributions of three proximal sensors of ER stress: activating transcription factor 6 (ATF6), inositol requiring 1 (IRE1), and PKR-like endoplasmic reticulum kinase (PERK). AR112Q toxicity was significantly increased by a dominant negative ATF6 mutant and significantly decreased by a constitutively active ATF6 mutant, indicating that ATF6 promoted cell survival. In contrast, co-transfection with three separate IRE1α dominant negative mutants failed to alter glutamine length-dependent toxicity, suggesting that this arm of the UPR did not significantly affect AR112Q induced cell death. Activation of PERK, an ER transmembrane protein that functions as the third proximal UPR sensor, promoted glutamine length-dependent toxicity. Although nuclear localization sequence- and nuclear export sequence-targeted proteins both activated the UPR, this pathway more potently influenced toxicity when proteins were targeted to the cytoplasm. Taken together, our data demonstrate that the UPR is activated in cells expressing long glutamine tracts and that this pathway modulates polyglutamine toxicity.
Acceptance and Commitment Therapy for the Treatment of Posttraumatic Stress Among Adolescents

The number of individuals who meet diagnostic criteria for posttraumatic stress disorder (PTSD) is a small percentage of those exposed to trauma; many youth who do not meet criteria for PTSD continue to experience problematic posttraumatic stress (PTS) symptomology. Acceptance and commitment therapy (ACT) has shown preliminary effectiveness in the treatment of adult PTSD, but its effectiveness in treating PTS in youth is unknown. Using a multiple-baseline design, this study investigated the effectiveness of 10 weeks of ACT to treat PTS in youth. Four adolescents from a community sample and three adolescents from a residential sample participated. The Clinician Administered PTSD Scale for Children and Adolescents (CAPS-CA), Child PTSD Symptom Scale (CPSS), and Comprehensive Quality of Life Scale were completed at pretreatment, posttreatment, and 3-month follow-up. Individuals reported baseline data for 7 to 66 days. Symptom and process measures were completed at each session. Results revealed a decrease in PTS symptomology across both samples with mean reductions in self-reported PTS symptomology at posttreatment of 69% and 81% for the community and residential samples, respectively, and an overall 68% and 84% respective reduction at follow-up. Reductions in clinician rated measures of PTSD were observed for all participants with mean reductions of 57% and 61% in the community and residential samples at posttreatment, and 71% and 60% at follow-up, respectively. Results provide preliminary support for ACT as a treatment for adolescent PTS. Empirical and clinical implications as well as limitations and future directions are discussed.
ELASTOMERS IN THE OIL FIELD

ABSTRACT Even before Spindletop “gushered” in the great Texas oil boom in 1901, rubber chemistry and technology played a key role in the pressure and flow control of hydrocarbons from petroleum reservoirs. This key role for rubber in the oil field continues today, where the cost of construction of an oil or gas well can exceed a billion dollars. Almost all equipment used in downhole drilling and completion operations currently depends on elastomers and other sealing materials to provide steady, reliable performance during service. Although the cost of the individual seals used downhole in a well represents only a fraction of the total well cost, the seals are critical to well performance and safety. Sealing mechanisms are at the heart of any drilling, completion, or production system and are the primary components on which the functional success and longevity of the system rests. Modern drilling systems, with their significant use of onboard electronic components and sensors, rely heavily on nonmetallic s...
Highly efficient integration of the viral portal proteins from different types of phages into planar bilayers for the black lipid membrane analysis

The planar lipid bilayer technology is a technique that yields incredibly useful structural function information about a single channel protein. It is also currently actively utilized as a powerful platform using biological protein nanopores for the development of single-molecule nanopore sensing technology, as well as ultrafast DNA sequencing technology. The portal protein, GP10, from the bacteriophage Φ29 was the first phage portal protein shown to be successfully inserted into planar bilayer membranes, thereby it may inspire more researchers to apply the techniques to portal proteins from the other bacteriophages. However, the technology is far from perfect since the insertion of the channel proteins into planar bilayer membranes is not only technically difficult but also time-consuming. For the fusion of phage portal proteins, vesicles are typically needed to be reconstituted with the portal proteins to form proteoliposomes. However, most of the phage portal proteins have low solubility, and may self-aggregate during the preparation of the proteoliposomes. Furthermore, the fusion of the formed proteoliposomes is sporadic, unpredictable and varied from person to person. Due to the lack of experimental consistency between labs, the results from different methodologies reported for generating fusible proteoliposomes are highly variable. In this research, we propose a new method for the preparation of the fusible proteoliposomes containing portal proteins from bacteriophages, to circumvent the problems aforementioned. Compared to the conventional methods, this method was able to avoid the protein aggregation issues during the vesicle preparation by eliminating the need for detergents and the subsequent time-consuming step for detergent removal. The proteoliposomes prepared by the method were shown to be more efficiently and rapidly inserted into planar bilayer membranes bathed in different conducting buffer solutions including those with nonelectrolytes such as glycerol and PEG. In addition, the method of forming proteoliposomes has significantly extended the shelf life of the proteoliposomes. To further explore its potentials, we have successfully applied the method to the insertion of a mutant portal protein, GP20, from T4 bacteriophage, a hydrophobic portal protein that has not been explored using the planar lipid bilayer membrane technique. The results suggest that this method could be used to prepare proteoliposomes formed by hydrophobic portal proteins from other bacteriophages.
Comparing tourists crime victimization.

This Department publishes research notes, conference reports, reports on the work of public agencies and associations, field (industry) reports, and other relevant topics and timely issues. Contributions to this department are submitted to its two Associate Editors: Research Notes to Juergen Gnoth (Department of Marketing, University of Otago, Dunedin, New Zealand. Email jgnoth@commerce.otago.ac.nz ) and Conference Reports to Russell Smith (Hospitality and Tourism, Nanyang Technological University, Singapore 639798, Rep. of Singapore. Email arasmith@ntu.edu.sg ). Unsolicited conference and agency reports will not be accepted.
A 75µW, 16-channel neural spike-sorting processor with unsupervised clustering

We describe a neural spike-sorting processor that provides unsupervised clustering simultaneously for 16 channels. The use of a two-stage clustering algorithm, noise-tolerant distance metric, and selectively clocked high-V T register arrays makes online clustering feasible for implementation. The spike-sorting processor has a power consumption of 75µW at 270mV and an area of 2.45mm2 in a 65nm CMOS.
Distinguishing surface effects of calcium ion from pore-occupancy effects in Na+ channels

The effects of calcium ion on the Na+ activation gate were studied in squid giant axons. Saxitoxin (STX) was used to block ion entry into Na+ channels without hindering access to the membrane surface, making it possible to distinguish surface effects of calcium from pore-occupancy effects. In the presence of STX, gating kinetics were measured from gating current (Ig). The kinetic effects of external calcium concentration changes were small when STX was present. In the absence of STX, lowering the calcium concentration (from 100 to 10 mM) slowed the closing of Na+ channels (measured from INa tails) by more than a factor of 2. Surprisingly, the voltage sensitivity of closing kinetics changed with calcium concentration, and it was modified by STX. Voltage sensitivity apparently depends in part on the ability of calcium to enter and block the channels as voltage is driven negative. In external medium with no added calcium, INa tail current initially increases in amplitude severalfold with the relief of calcium block, then progressively slows and gets smaller, as calcium diffuses out of the layers investing the axon. INa tails seen just before the current disappears suggest that closing in the absence of channel block is very slow or does not occur. INa amplitude and kinetics are completely restored when calcium is returned. The results strongly suggest that calcium occupancy is a requirement for channel closing and that nonoccupied channels fold reversibly into a nonfunctional conformation.
Childhood Precursors of Adult Interpartner Violence

Although childhood exposure to violence in one's family of origin is one of the most consistent correlates of later adult domestic violence, little is known about the developmental pathways or specific mechanisms of in-tergenerational transmission. This article (a) reviews the current knowledge regarding early exposure to domestic violence as precursor of later domestic violence, (b) identifies developmental considerations related to the impact of exposure, and (c) describes several conceptual models of the influence of early exposure. Research on both adults and children is reviewed. Implications for research focus on operational definitions, sex differences, life-span development, relational dynamics, typologies, and mediating processes. Implications for clinical practice focus on early socialization experience in adult treatment, and the development of early prevention programs. Language: en
High Performance RF FETs Using High-k Dielectrics on Wafer-Scale Quasi-Free-Standing Epitaxial Graphene

We explore the effect of processing on graphene/metal ohmic contact resistance, the integration of high-κ dielectric seeds and overlayers on carrier transport in epitaxial graphene, and directly demonstrate the importance of buffer elimination at the graphene/SiC(0001) interface for high frequency applications. We present a robust method for forming high quality ohmic contacts to graphene, which improves the contact resistance by nearly 6000x compared to untreated metal/graphene interfaces. Optimal specific contact resistance for treated Ti/Au contacts is found to average -7 Ohm-cm2. Additionally, we introduce a novel seeding technique for depositing dielectrics by ALD that utilizes direct deposition of high-κ seed layers and can lead to an increase in Hall mobility up to 70% from as-grown. Finally, we demonstrate that buffer elimination at the graphene/SiC(0001) results in excellent high frequency performance of graphene transistors with fT > 130 GHz at 75 nm gate lengths.
Real men don’t eat (vegetable) quiche: Masculinity and the justification of meat consumption.

As arguments become more pronounced that meat consumption harms the environment, public health, and animals, meat eaters should experience increased pressure to justify their behavior. Results of a first study showed that male undergraduates used direct strategies to justify eating meat, including endorsing pro-meat attitudes, denying animal suffering, believing that animals are lower in a hierarchy than humans and that it is human fate to eat animals, and providing religious and health justifications for eating animals. Female undergraduates used the more indirect strategies of dissociating animals from food and avoiding thinking about the treatment of animals. A second study found that the use of these male strategies was related to masculinity. In the two studies, male justification strategies were correlated with greater meat consumption, whereas endorsement of female justification strategies was correlated with less meat and more vegetarian consumption. These findings are among the first to empirically verify Adams’s (1990) theory on the sexual politics of meat linking feminism and vegetarianism. They suggest that to simply make an informational appeal about the benefits of a vegetarian diet may ignore a primary reason why men eat meat: It makes them feel like real men.
A new approach for prediction of tumor sensitivity to targeted drugs based on functional data

The success of targeted anti-cancer drugs are frequently hindered by the lack of knowledge of the individual pathway of the patient and the extreme data requirements on the estimation of the personalized genetic network of the patient’s tumor. The prediction of tumor sensitivity to targeted drugs remains a major challenge in the design of optimal therapeutic strategies. The current sensitivity prediction approaches are primarily based on genetic characterizations of the tumor sample. We propose a novel sensitivity prediction approach based on functional perturbation data that incorporates the drug protein interaction information and sensitivities to a training set of drugs with known targets. We illustrate the high prediction accuracy of our framework on synthetic data generated from the Kyoto Encyclopedia of Genes and Genomes (KEGG) and an experimental dataset of four canine osteosarcoma tumor cultures following application of 60 targeted small-molecule drugs. We achieve a low leave one out cross validation error of <10% for the canine osteosarcoma tumor cultures using a drug screen consisting of 60 targeted drugs. The proposed framework provides a unique input-output based methodology to model a cancer pathway and predict the effectiveness of targeted anti-cancer drugs. This framework can be developed as a viable approach for personalized cancer therapy.
An invariant-based approach to the design of hybrid control systems

In this paper, a methodology for hybrid control design is presented. The hybrid systems of interest are characterized by a feedback architecture of a continuous nonlinear plant with a discrete-event controller. The natural invariants of the continuous dynamics are used to partition the state space into regions and to synthesize simple and efficient control laws. The paper contains a complete description of the approach including a description of the hybrid control system modelling, of the invariant-based approach for the design of the partition, and of the controller synthesis methodology illustrated by examples. The implementation and optimization of the approach are also discussed. The approach presented in this paper not only describes a viable methodology to hybrid design, but also addresses fundamental issues in hybrid system theory that arise in reachability analysis and verification approaches that are based on partitions of the continuous state space. Copyright © 2001 John Wiley & Sons, Ltd.
Resonance Raman Spectroscopy

Resonance Raman (RR) spectroscopy is an invaluable and widely used probe of structure and bonding for chromophoric transition metal centers in proteins and enzymes. The spectacular increase in detection sensitivity and selectivity of RR spectroscopy for vibrations that are localized in the absorbing center(s) of the molecule has revolutionized the vibrational spectroscopic field of bioinorganic systems. In this article, we explain the characteristics of RR spectra, emphasizing the kind of information that can be obtained and the rules for optimal resonance enhancement. We then discuss the applications of RR scattering to the study of structural dynamics of two different mononuclear metal-cysteinate sites, type-1 copper in cupredoxins and Fe(S-Cys)4 center in rubredoxins, using a combination of site-directed mutagenesis, production of isotopically labeled proteins, and cryogenic-temperature RR methods. These chromophores, involved in biological electron transport, have been very suitable subjects for RR studies because they exhibit strong absorption bands in the visible region due to (Cys)S Cu(II) (∼625 nm) and (Cys)S Fe(III) (∼500–570 nm) charge-transfer electronic transitions that facilitate the observation of resonantly enhanced Cu-and Fe-thiolate vibrations. Keywords: infrared; Raman; resonance Raman; inelastic scattering of light; Stokes radiation; anti-Stokes radiation; Franck-Condon scattering; Herzberg-Teller scattering; vibrational frequency; Raman shift; molecular polarizability; selection rules; metalloproteins; blue copper proteins; cupredoxin; azurin; iron-sulfur proteins; rubredoxin; rubrerythrin
Socializing Messages in Blue-Collar Families: Communicative Pathways to Social Mobility and Reproduction

This study explicitly links processes of anticipatory socialization to social mobility and reproduction. An examination of the socializing messages exchanged between blue-collar parents (n = 41) and their children (n = 25) demonstrate that family-based messages about work and career seldom occur in straightforward, unambiguous ways. Instead, messages take several paths (direct, indirect, ambient, and omission). Further, the content of messages communicated along these paths often is contradictory. That is, sons and daughters receive messages that both encourage and discourage social mobility. Ultimately, these individuals must negotiate the meanings of family-based anticipatory socialization communicated to them through a mix of messages.
Particle methods in the study of fracture

This article reviews particle methods in the study of fracture. It focuses on the exact solution of dynamic cracks in an ideal brittle solid. Topics that arise include Cherenkov radiation of phonons, how calculations in a strip let one connect continuum fracture mechanics to atomic solutions, and the use of Wiener-Hopf techniques for analytical results. Then the article discusses molecular dynamics solutions, focusing on how to set them up making use of insights from the exactly solvable models. The particular case of silicon is discussed in detail. Finally there is a brief discussion of mesoscopic particle models.
A prospective study of platelet function in trauma patients

BACKGROUNDExsanguination associated with acute traumatic coagulopathy is a leading cause of death following injury. While platelets occupy a pivotal role in clot formation, clinical research has been scant because of complexities resulting from the need for rapid handling and complex testing of plat
Necessary Conditions for Polynomial Solutions of Certain Riccati Equations

(1936). Necessary Conditions for Polynomial Solutions of Certain Riccati Equations. The American Mathematical Monthly: Vol. 43, No. 8, pp. 473-476.
Sensitivity of commercial thromboplastins to factor VII.

Seven commercial thromboplastins and one preparation of human brain thromboplastin were tested for sensitivity to factor VII by two different methods. The prothrombin times of a normal control plasma (100% factor VII), an intermediate plasma (7%), and a severely deficient plasma (<1%) were tested by using eight preparations. A wide range of values was obtained. Quantitative assays for factor VII were performed, and the slope of the regression line was calculated. Wide variability in sensitivity to factor VII was shown for each reagent. The implications of this observation for clinical patient management are discussed.
Imagining Anti-Administration’s Anti-Hero (Antagonist? Protagonist? Agonist?)

This article poses an anti-heroic creature of folklore and administrative experience as a potential personification of anti-administration. In these pages, the paradoxical and antagonistic figure of Trickster is offered in comparison and contrast to some protagonists and agonistic ((heroes " of contemporary administrative theory. It is suggested that antagonism has imaginative and anti-administrative uses.
Extended cervical mediastinoscopy

The technique of extended cervical mediastinoscopy is described in detail as well as its indications for use. The author has found extended cervical mediastinoscopy extremely valuable in staging lung carcinoma with regard to level V and VI lymph node involvement if a standard cervical mediastinoscopy fails to demonstrate metastatic disease and a CT scan suggests subaortic lymph node involvement. This technique has been found to be safe and accurate and only adds minimal operating time to a cervical mediastinoscopy without the need for a second incision.
A three-legged MATLAB/SIMULINK transformer model using a fictitious delta winding

This paper proposes a simple MATLAB/ SIMULINK model of a three-phase, three-legged, saturated transformer. A fictitious delta winding is added to three single-phase saturable transformers. The proposed model is simple and fairly accurate to model the nonlinear characteristics of a saturable three-legged transformer including mutual coupling.