cssi/SciSciGPT-SciSciNet huggingface dataset:
Time-dependent thermal convection in dilute solutions of 3 He in superfluid 4 He

Time-dependent thermal convection can occur in a unity-aspect-ratio Rayleigh-Benard convection cell containing a dilute solution of 3He in superfluid 4He when the fluid is heated from above. Results are presented primarily for a 0.24 mole % He solution at 0.925 K. Means is provided for introducing heat at the top and separately for a central plug and an outer ring such that both are at a constant temperature gDT above the bottom. A critical temperature difference δT cfor convection can be defined above which both steady and time-dependent convection occur. The time-dependent effects include a region of δT. near δT cand characterized only by excessive noise, a region of somewhat higher δT where there are intermittent major changes in the plug heating rate with a time distribution like that for random events, and a region at still higher δT where periodic but nonsinusoidal variation of the heat flow is observed. When a long enough time, several months, has elapsed after cooling down the apparatus, time-dependent states no longer occur, and the heat flow above δT cis limited to steady convection. Briefly raising the temperature of the apparatus to 77 K is sufficient to restore the possibility of time-dependent states.
Low-lying disordered states in the presence of long-range order.

A Comment on the Letter by S. Liang, B. Doucot, and P. W. Anderson, Phys. Rev. Lett. 61, 365 (1988).
Magnetic resonance venography for the detection of deep venous thrombosis: Comparison with contrast venography and duplex Doppler ultrasonography

Abstract Purpose: Contrast venography is the gold standard for diagnosis in deep venous thrombosis (DVT); however, this technique is invasive and requires the use of potentially hazardous contrast agents. Although duplex Doppler ultrasonography is accurate in the evaluation of lower extremity DVT, it is less accurate in the assessment of the pelvic and intraabdominal veins. Magnetic resonance venography (MRV) has recently been developed, and our purpose was to determine whether MRV could accurately demonstrate DVT when compared with duplex scanning and contrast venography. Methods: Eighty-five patients underwent contrast venography and MRV from the inferior vena cava to the popliteal veins to rule out DVT. Thirty-three of these patients also underwent duplex scanning. Blinded readings of these studies were compared for the presence or absence and extent of venous thrombosis. Results: DVT was documented by contrast venography in 27 (27%) venous systems. Results of MRV and contrast venography were identical in 98 (97%) of 101 venous systems, whereas results of duplex scanning and contrast venography were identical in 40 (98%) of 41 venous systems. All DVTs identified by contrast venography were detected by MRV and duplex scanning. The discrepancies were due to false-positive MRV (3) and duplex scanning (1) results. When compared with contrast venography, MRV had a sensitivity of 100%, specificity of 96%, positive predictive value of 90%, and negative predictive value of 100%. For duplex scanning the sensitivity was 100%, specificity was 96%, positive predictive value was 94%, and negative predictive value was 100%. Conclusions: It is concluded that MRV is an accurate noninvasive venographic technique for the detection of DVT. (J VASC SURG 1993;18:734-41.)
S1649 The Role of Prostaglandin E2 (PGE2) in Toll-Like Receptor-4 (TLR4)-Mediated Colitis-Associated Neoplasia

Background We have previously found that TLR4-deficient (TLR4-/-) mice demonstrate decreased expression of mucosal PGE 2 and are protected against colitis-associated neoplasia. However, it is still unclear whether PGE 2 is the central factor downstream of TLR4 signaling that promotes intestinal tumorigenesis. To further elucidate critical downstream pathways involving TLR4-mediated intestinal tumorigenesis, we examined the effects of exogenously administered PGE 2 in TLR4-/- mice to see if PGE 2 bypasses the protection from colitis-associated tumorigenesis.
In Vivo and in Vitro Incorporation of Phosphorus-32 into Deoxyribonucleic Acid (DNA), Spermatozoa and Seminal Plasma of the Fowl

Abstract INTRODUCTION The uptake of phosphorus-32 by whole semen and its various fractions has been a subject of interest to several workers. Patrick et al. (1962) injected New Hampshire cocks with a series of seven injections of 50μc. of phosphorus-32 each. They reported that the intact spermatozoa had increasing levels of radioactivity until a maximum level was reached at 28 days from the time of the initial injection. Patrick et al. (1965) reported on another experiment in which New Hampshire cocks were each administered 200 μc.of phosphorus-32 in a single injection. They discovered that the spermatozoa, semen, DNA and the protein increased in levels of radioactivity until a peak level was reached at 26 days of spermatozoa, semen and DNA, while the protein fraction of the spermatozoa exhibited a peak at 16 days. After such times as the peaks were reached, all the fractions began to decline in radioactivity. Saeki et…
Are you close with me? are you nearby?: investigating social groups, closeness, and willingness to share

As ubiquitous computing becomes increasingly mobile and social, personal information sharing will likely increase in frequency, the variety of friends to share with, and range of information that can be shared. Past work has identified that whom you share with is important for choosing whether or not to share, but little work has explored which features of interpersonal relationships influence sharing. We present the results of a study of 42 participants, who self-report aspects of their relationships with 70 of their friends, including frequency of collocation and communication, closeness, and social group. Participants rated their willingness to share in 21 different scenarios based on information a UbiComp system could provide. Our findings show that (a) self-reported closeness is the strongest indicator of willingness to share, (b) individuals are more likely to share in scenarios with common information (e.g. we are within one mile of each other) than other kinds of scenarios (e.g. my location wherever I am), and (c) frequency of communication predicts both closeness and willingness to share better than frequency of collocation.
Chemotactic behavior of mutants of the nematode Caenorhabditis elegans that are defective in their attraction to NaCl

Wild-type C. elegans and 16 derivative strains previously selected for defective attraction to NaCl and shown to carry single-gene mutations were tested for their responses to nine chemical stimuli to which the wild-type responds. These were the attractants Na+, Cl−, OH−, cyclic AMP, CO2 in borate buffer, and pyridine and the repellents D-tryptophan, CO2 in phosphate buffer, and acid. All together 563 measurements were performed. Most strains were defective in most responses but responded normally to some chemical stimuli. In a few cases mutant strains avoided a chemical that attracted the wild-type. Analysis of the patterns of defective responses among these mutants indicates that there are probably at least four different receptors. If results previously reported are included, the minimum number of receptors is increased to six. These mutations appear to have rather discrete effects on behavior.
Performance analysis and enhancement for the current and future IEEE 802.11 MAC protocols

The IEEE 802.11 specifications provide up to 54 Mbps data rates, respectively. The industry is seeking Higher Data Rates (HDR's) over 100Mbps for IEEE 802.11a extension. However, the medium access control (MAC), which they are based upon, is the same. In this paper, we explore the overhead of HDR's to find out whether the MAC is good enough for the increasing data rates and what to expect as the industry seeks higher data rates. We prove that a theoretical throughput upper limit and a theoretical delay lower limit exist for IEEE 802.11 protocols. The existence of such limits indicates that the overhead must be reduced to get good performance for HDR's. Otherwise, the enhanced performance of HDR's is limited and bounded even when the data rate becomes infinitely high. Both reducing overhead and pursuing HDR's are therefore necessary and important. In order to reduce overhead, we propose a burst transmission and acknowledgement (BTA) mechanism, in which, instead of acknowledging each frame, a burst of frames is received first, and then the whole burst is acknowledged one time. Our study shows that with the BTA mechanism, overhead has been greatly reduced and performance has been greatly improved.
Theoretical considerations on the effects of bulk charge on VMOST characteristics

A linear approximation to the bulk-charge effect in short-channel VMOS devices is presented which allows for an explicit solution to the volt-ampere characteristics in the presence of velocity saturation effects. The results are shown to agree closely with the more complex exact analysis.
Antipredator Responses by Native Mosquitofish to Non‐Native Cichlids: An Examination of the Role of Prey Naiveté

The strong impact of non-native predators in aquatic systems is thought to relate to the evolutionary naivete of prey. Due to isolation and limited dispersal, this naivete may be relatively high in freshwater systems. In this study, we tested this notion by examining the antipredator response of native mosquitofish, Gambusia holbrooki, to two non-native predators found in the Everglades, the African jewelfish, Hemichromis letourneuxi, and the Mayan cichlid, Cichlasoma urophthalmus. We manipulated prey naivete by using two mosquitofish populations that varied in their experience with the recent invader, the African jewelfish, but had similar levels of experience with the longer-established Mayan cichlid. Specifically, we tested these predictions: (1) predator hunting modes differed between the two predators, (2) predation rates would be higher by the novel jewelfish predator, (3) particularly on the naive population living where jewelfish have not invaded yet, (4) antipredator responses would be stronger to Mayan cichlids due to greater experience and weaker and/or ineffective to jewelfish, and (5) especially weakest by the naive population. We assayed prey and predator behavior, and prey mortality in lab aquaria where both predators and prey were free-ranging. Predator hunting modes and habitat domains differed, with jewelfish being more active search predators that used slightly higher parts of the water column and less of the habitat structure relative to Mayan cichlids. In disagreement with our predictions, predation rates were similar between the two predators, antipredator responses were stronger to African jewelfish (except for predator inspections), and there was no difference in response between jewelfish-savvy and jewelfish-naive populations. These results suggest that despite the novelty of introduced predators, prey may be able to respond appropriately if non-native predator archetypes are similar enough to those of native predators, if prey rely on general antipredator responses or predation cues, and/or show neophobic responses.
The measurement of the Half Life of plutonium-239 by the U.S. Half-Life evaluation committee

Abstract The half life of plutonium-239 was measured by member laboratories of the U.S. Half-Life Evaluation Committee. Eight separate determinations were made using three different measurements techniques (calorimetry, mass spectrometry and alpha-particle counting). From these measurements, the committee recommends a value of 24,119± 26 yr for the half life of plutonium-239.
Can silicon dimers form logic gates

We have performed density functional theory calculations to show how a tungsten scanning probe can mediate the interactions between bistable Si(100) surface dimers. Interpreting the state of each dimer as a bit of information, we demonstrate the use of this mediated interaction to construct a NOR logic gate.
Snails and Changes in Sea-Level

IN NATURE of April 7, 1923, p. 464, I directed attention to the great changes in sea-level assumed by some geologists to have occurred during Pleistocene times. Reference was made to the small I. de Cima, close to Porto Santo, in the Madeira group. This islet has a very distinct species of snail, in great abundance, and if the postulated changes in sea-level actually occurred, it is hard to understand why the snail did not reach the main island, or, at another time, perhaps perish beneath the waves.
Using enhanced dasymetric mapping techniques to improve the spatial accuracy of sea level rise vulnerability assessments

This article reports on the application of dasymetric mapping techniques to interpolate and disaggregate block group population counts to smaller areal units (i.e., tax parcels) and derive surface population models with more realistic representations of population distributions in our residential study area in Miami-Dade, Florida. Three methods of dasymetric interpolation were tested: (i) binary, (ii) three-class, and (iii) limiting variable. Our enhanced limiting variable approach introduced an adjustment factor for parcel vacancy rates in the dasymetric calculations, and applied dasymetric mapping techniques to disaggregate future population projections to the tax lot level of analysis. The limiting variable interpolation generated the lowest coefficient of variation (0.188), followed by the three-class interpolation (0.645). We also found that population densities vary substantially within land use classes of single family, medium density and high density classes, and these variations also highlighted the importance of incorporating vacancy rates when interpolating population counts to categorical land use data. Overall, the enhanced dasymetric mapping technique is particularly useful for examining the impact of sea-level rise as its derivatives are compatible with high resolution LiDAR and orthoimagery data. Coastal counties can also benefit from such high resolution surface population models to enhance the accuracy of hazard-related vulnerability assessments and to guide the development of relevant shore zone conservation and adaptation strategies.
Mechanisms in cardiovascular regulation following chronic exposure of male rats to inorganic mercury

Abstract In this study we verified the possibility that chronic exposure to inorganic mercury may induce hemodynamic changes in the rat by affecting some neurogenic and/or humoral mechanisms regulating cardiovascular function. For this reason, aortic blood pressure, maximum rate of rise of the left ventricular pressure, heart rate, and electrocardiogram were monitored under pentothal anesthesia in rats which received 50 μg/ml of mercury (as HgCL 2 ) in drinking water for 320 days and in control rats. No pressor or electrocardiographic changes were found in mercury-treated animals, which showed increase of cardiac inotropism and decrease of the pressor and inotropic responses to bilateral carotid occlusion. Cardiovascular responses to bilateral vagotomy and iv hexamethonium under vagotomy were unchanged in the mercury-exposed rats. In these animals both pressor and inotropic responses to iv norepinephrine and to higher doses of epinephrine were reduced, while the vascular beta-adrenergic response to 0.125 μg/kg of iv epinephrine was potentiated. cardiovascular responses to acetylcholine, angiotensin I, angiotensin II, bradykinin, histamine, and serotonin did not differ in the two groups of rats. These results indicated that chronic mercury exposure affects cardiovascular function by interfering with the baroreflex mechanisms and/or the reactivity to catecholamines. Higher amounts of mercury were found in kidney, but the metal was significantly accumulated also in urine, blood, and brain. Mercury exposure greatly increased the levels of copper and zinc, but not that of iron, in brain and kidney. The increased accumulation of copper and zinc in tissues may be related in part to the mercury-induced synthesis of metallothionein, a protein able to bind these essential metals. It may be suggested that zinc and copper interact with mercury in inducing cardiovascular changes.
Contract or coincidence: George Herbert Mead and Adam Smith on self and society

Although a number of commentators have remarked upon the simi larities between aspects of George Herbert Mead's social psychology and Adam Smith's Theory of Moral Sentiments, there has been no sys ...
Consumer-perceived risk in e-commerce transactions

A major promise of the Internet is its potential for online shopping and its benefits in the form of cost reduction, for consumers and businesses alike. For example, according to Penton Research (www.penton.com), using the Web site as a marketing tool provides a compelling means for cost reduction in terms of cost per contact statistics (Internet: $0.98, direct mail: $1.68, telemarketing: $31.16, tradeshows: $162). Yet the new medium is far from the true electronic marketplace of the future. This is due largely to the reluctance of consumers to engage in transactions over the Internet. In their study, Hoffman, Novak and Peralta found that consumers, on the Web, may fear providing credit card information to any commercial Web provider and that consumers simply do not trust most Web providers enough to engage in exchange relationships involving money [4]. This perceived risk among consumers translates into their reluctance to use debit and/or credit card information over the Internet resulting in their disengagement from electronic transactions. Most sites on the Internet today do not focus on building and nurturing trust as part of an ongoing relationship with their customers [7, 9]. Millions of consumers browse thousands of Web vendor sites everyday with the intention of buying products and services. Yet, the majority of these consumers opt for buying the products or services from a brick-andmortar facility rather than completing the purchase process online. Reliable encryption and authentication methods are available. But we believe that secure technological infrastructure is only a necessary foundation and by itself not sufficient for creating the level of trust needed for spontaneous electronic transactions over the Internet. This is due to the fact that secure transaction methods using encryption and
Microbiologic evaluation of needleless and needle-access devices

Abstract Objective: This study was carried out to determine whether needleless intravenous access devices are more likely to allow microorganisms to enter the fluid pathway than intravenous needle-access devices. Methods: A laboratory study was conducted with two needleless and one intravenous needle-access devices and Enterococcus faecium as a bacterial challenge. Inocula of E. faecium were prepared on the basis of the numerical estimates of 1000 to 10,000 colony-forming units (CFU/cm2 of bacterial flora on dry regions of skin (arms, legs, and hands). The septum of each access device was inoculated with 10 to 20 μl of a 104 to 105 CFU/ml challenge suspension, which was allowed to dry on the surface of the septum. In the first part of the experiment, the needleless or needle-access cannula of each device was used to puncture the corresponding septum without previously disinfecting the top of the septum. In the second part, the contaminated septum was punctured after disinfecting the septum with a 70% isopropyl alcohol wipe. After each puncture, trypticase soy broth was flushed through the fluid pathway of the intravenous access device, collected, and cultured by the membrane filtration technique. The septum of each injection-site cap and the needless or needle-access cannula were sampled with sterile premoistened swabs. Swabs were cultured on blood agar plates. Results: The rate of fluid pathway contamination was 100% ( 40 40 ) for one of the needleless intravenous access devices and 80% ( 20 25 ) for the other when septa were contaminated with E. faecium and not disinfected before puncture. The rate for the intravenous needle-access device was 72% ( 18 25 ). When the septa of the three different devices tested were disinfected with 70% isopropyl alcohol, E. faecium was isolated on only one septum from all devices tested in part two ( 1 74 , 1.3%). Conclusions: These laboratory studies demonstrate that there is no statistically significant difference in the rate of fluid pathway contamination between needleless and intravenous needle-access devices. However, if the septa of either needleless or needle systems are not disinfected before puncture, a high rate of fluid pathway contamination may occur.
Place and Time: On the Interplay of Historical Points of View

A historian’s account of a past action must take into account the agent’s point of view, and that point of view may differ radically from that of the historian. This difference of points of view, I argue, may extend to the very place and time of the action in question. In this paper, by exploring the spatial and temporal aspects of action, agency, and the description of past action, I try to describe the interplay of points of view between historian and historical agent. Because of these differences, actions may be embedded in radically different realities for agent and historian, different conceptions of the spatially and temporally real. This is especially true of time: an action may have a very different future for the agent from the future it has in retrospect. These discrepancies, I claim, do not constitute an obstacle that can be overcome, but are structural features of the relation between description and action. This is because they are merely extensions into a particular domain of certain features of relations between persons. I try to show that these features also have implications for the concepts of narrative and of counterfactual history.
A constitutive model for consolidation of granular materials

Abstract A version of endochronic theory is presented and applied to describe the mechanical behavior of granular materials, including metal powders and cohesionless sands. The model is applicable to the consolidation of powder materials. The volumetric and deviatoric deformations, and the shearing-induced densification under monotonic and cyclic loading conditions are discussed. A quadratic form of Gibbs free energy in conjunction with three internal state variables and intrinsic times are adequate to describe the generic behavior of granular materials. Data from the literature, including Atomet 28 iron powder and tungsten carbide powder, and data of Alcoa pure aluminum powder are examined for the isotropic consolidation test under monotonic and reversed loadings. Air-dried Toyoura sand is employed to illustrate the deviatoric and densification responses. Both monotonic and cyclic loadings under ring-type torsion tests are described for initial density ranging from 20% to 64%.
Proton Flux during the Great Aurora of 3-4 September 1959

Photoelectric measurements of the H beta intensity from the aurora observed on September 3-4, 1959, show that it continued to increase after a corona formed, and reached a maximum as the corona broke up into rays, decreasing rapidly to nearly zero within the next 10 minutes. The maximum flux of protons incident on the earth during the aurora, deduced from these measures, was at least 1.4 x 10/sup 8/ auroral protond per square centimeter, per second. (auth)
A cell-penetrating ester of the neural metabolite lanthionine ketimine stimulates autophagy through the mTORC1 pathway: Evidence for a mechanism of action with pharmacological implications for neurodegenerative pathologies

Autophagy is a fundamental cellular recycling process vulnerable to compromise in neurodegeneration. We now report that a cell-penetrating neurotrophic and neuroprotective derivative of the central nervous system (CNS) metabolite, lanthionine ketimine (LK), stimulates autophagy in RG2 glioma and SH-SY5Y neuroblastoma cells at concentrations within or below pharmacological levels reported in previous mouse studies. Autophagy stimulation was evidenced by increased lipidation of microtubule-associated protein 1 light chain 3 (LC3) both in the absence and presence of bafilomycin-A1 which discriminates between effects on autophagic flux versus blockage of autophagy clearance. LKE treatment caused changes in protein level or phosphorylation state of multiple autophagy pathway proteins including mTOR; p70S6 kinase; unc-51-like-kinase-1 (ULK1); beclin-1 and LC3 in a manner essentially identical to effects observed after rapamycin treatment. The LKE site of action was near mTOR because neither LKE nor the mTOR inhibitor rapamycin affected tuberous sclerosis complex (TSC) phosphorylation status upstream from mTOR. Confocal immunofluorescence imaging revealed that LKE specifically decreased mTOR (but not TSC2) colocalization with LAMP2+ lysosomes in RG2 cells, a necessary event for mTORC1-mediated autophagy suppression, whereas rapamycin had no effect. Suppression of the LK-binding adaptor protein CRMP2 (collapsin response mediator protein-2) by means of shRNA resulted in diminished autophagy flux, suggesting that the LKE action on mTOR localization may occur through a novel mechanism involving CRMP2-mediated intracellular trafficking. These findings clarify the mechanism-of-action for LKE in preclinical models of CNS disease, while suggesting possible roles for natural lanthionine metabolites in regulating CNS autophagy.
On arithmetic subgroups of simple algebraic groups

Abstract Arithmetic subgroups of simple isotropic algebraic groups are described as subgroups full of root elements.
Energetic ion observations of the Earth’s magnetic cusps during an extended geomagnetically quiescent period in April 2001 using detectors on S/C ISTP/Polar

Abstract We present a method of polar cusp identification using high charge state heavy ions. There is reason to think that these ions would constitute shocked solar wind ions such as doubly charged helium ions, He 2+ , and multiply charged oxygen ions, O (3−8)+ , that appear to have relatively easy access to one or both of the polar cusps essentially at all times. The observations made with the ISTP/POLAR spacecraft were mostly obtained during geomagnetically non-storm times in April 2001 when the spacecraft orbit allowed northern cusp encounters with low trajectory angle between the spacecraft velocity vector and the overall cusp magnetic field orientation. We also show one extended cusp crossing during the modest magnetic storm of April 22, 2001 (with D st ∼−103 nT). It is found that during the study period, 1–10 keV high charge state ions are present in the cusp region at virtually all times, during storm or quiet. We also found that what appears to be the interior of the northern polar magnetic cusp region can be rather turbulent both in the local magnetic field direction and in the energetic charged particle kinetic flow characteristics. There is some evidence for temporally varying turbulent acceleration processes, either within the cusp domain itself or in the surrounding magnetosphere. In terms of the present ion observations, there is little to distinguish the dayside low latitude boundary layer (LB) ion signatures from those of the interior of the polar cusp region (high charge state ions, abundant 1–10 keV ion fluxes).
Effect of unilateral ovariectomy, gonadotropin stimulation and immunization against a synthetic peptide of the inhibin α-subunit on follicular development and oocyte recovery in cattle

Nulliparous Holstein cows were randomly distributed among 4 treatment groups to test the effects of treatments, including unilateral ovariectomy, anti-inhibin immunization and gonadotropin stimulation on ovarian follicle population and oocyte recovery. The Control treatment consisted of intact cows (I-Control). Unilaterally ovariectomized cows were included in the 3 remaining treatments consisting of ovariectomy alone (U-Control), cows immunized against a synthetic peptide of the alpha(c)-subunit of bovine inhibin (alpha(c)I; U-IH), and cows stimulated with FSH (Super-Ov; 75 units/female/week) and also immunized with alpha(c)I as in the previous treatment (U-IH/FSH). Oocytes were collected by transvaginal ultrasound-guided aspiration on a weekly basis from cows in each treatment for 5 consecutive weeks. Intact Control cows had a greater (P or = 3 mm per female (4.7) than the U-Control and U-IH cows (2.6 and 2.9, respectively), and had a similar number of follicles as the U-IH/FSH treatment group (3.5). The numbers of follicles aspirated (2.7 to 3.6) and oocytes recovered/cow (1.6 to 2.6) were similar for cows in the I-Control, U-IH and U-IH/FSH treatment groups. Cows in the U-Control treatment group had a lower (P<0.05) number of aspirated follicles (2.0) and recovered oocytes (1.1) than the I-Control cows. Cows in the U-IH/FSH and U-IH treatments had follicles with larger (P<0.01) diameters (8.7 and 8.2 mm, respectively) than cows in the I-Control (6.6 mm) and U-Control (5.7 mm) treatments. In conclusion, unilateral ovariectomy did not result in compensatory increase of follicle number or size in the intact ovary; cows in the U-IH/FSH treatment group had a greater number of follicles aspirated than the U-Control cows. In addition, the anti-alpha(c)I immunization may have played a role in increasing the number and diameter of the follicles. None of the treatments evaluated in this study improved oocyte retrieval over that of the intact, nontreated cows.
Diagnostic concordance of DSM-III-R, DSM-IV, and ICD-10 inhalant use disorders

The diagnostic concordance of DSM-III-R, DSM-IV, and ICD-10 inhalant use disorders was assessed using the sample of lifetime inhalant users (n=76) participating in the DSM-IV Field Trial for Substance Use Disorders. Substantially smaller proportions of lifetime inhalant users met DSM-IV inhalant abuse or dependence criteria than met comparable DSM-III-R or ICD-10 criteria. DSM-III-R and ICD-10 performed similarly, although DSM-III-R tended to be more inclusive vis-a-vis diagnoses of inhalant dependence. Kappa coefficients indicated a moderate degree of concordance between the three nosologies for inhalant use disorder diagnosis rates. Inclusion of possible withdrawal symptomatology criteria (that are not normally included) in the DSM-IV and ICD-10 criteria sets for inhalant dependence exerted little effect on diagnosis rates.
Characterization of striatal neurons expressing high levels of glutamic acid decar☐ylase messenger RNA

Two types of labelled cells are detected in sections of rat and mouse striata processed for in situ hybridization histochemistry with35S-radiolabelled RNA probes complementary to the messenger RNA (mRNA) encoding glutamic acid decar☐ylase (GAD), the synthesis enzyme for γ-aminobutyric acid (GABA): numerous lightly, and fewer very densely labelled neurons. In order to determine whether the densely labelled cells correspond to the striatal somatostatinergic neurons with which they share morphological characteristics, the presence of GAD mRNA was examined in brain sections processed successively for dihydronicotinamide adenine dinucleotide phosphate (NADPH) diaphorase histochemistry, a marker of striatal somatostatinergic neurons, and in situ hybridization histochemistry. In addition, the distribution of GABAergic interneurons was analysed with regard to striatal compartments (striosomes) indicated by patches of dense opiate binding sites. The results show that NADPH diaphorase activity and GAD mRNA do not co-exist in striatal neurons. Furthermore, in contrast to the somatostatinergic neurons which are almost exclusively located in the extrastriosomal matrix, densely labelled GAD cells were present both in the striosomes and the matrix, further suggesting that GABAergic and somatostatinergic neurons form two distinct interneuronal systems in the striatum of rats and mice.
Differential Effects of Complement Activation Products C3a and C5a on Cardiovascular Function in Hypertensive Pregnant Rats

Early-onset pre-eclampsia is characterized by decreased placental perfusion, new-onset hypertension, angiogenic imbalance, and endothelial dysfunction associated with excessive activation of the innate immune complement system. Although our previous studies demonstrated that inhibition of complement activation attenuates placental ischemia–induced hypertension using the rat reduced uterine perfusion pressure (RUPP) model, the important product(s) of complement activation has yet to be identified. We hypothesized that antagonism of receptors for complement activation products C3a and C5a would improve vascular function and attenuate RUPP hypertension. On gestational day (GD) 14, rats underwent sham surgery or vascular clip placement on ovarian arteries and abdominal aorta (RUPP). Rats were treated once daily with the C5a receptor antagonist (C5aRA), PMX51 (acetyl-F-[Orn-P-(D-Cha)-WR]), the C3a receptor antagonist (C3aRA), SB290157 (N2-[(2,2-diphenylethoxy)acetyl]-l-arginine), or vehicle from GD 14–18. Both the C3aRA and C5aRA attenuated placental ischemia–induced hypertension without affecting the decreased fetal weight or decreased concentration of free circulating vascular endothelial growth factor (VEGF) also present in this model. The C5aRA, but not the C3aRA, attenuated placental ischemia–induced increase in heart rate and impaired endothelial-dependent relaxation. The C3aRA abrogated the acute pressor response to C3a peptide injection, but it also unexpectedly attenuated the placental ischemia–induced increase in C3a, suggesting nonreceptor-mediated effects. Overall, these results indicate that both C3a and C5a are important products of complement activation that mediate the hypertension regardless of the reduction in free plasma VEGF. The mechanism by which C3a contributes to placental ischemia–induced hypertension appears to be distinct from that of C5a, and management of pregnancy-induced hypertension is likely to require a broad anti-inflammatory approach.
DIFFERENCES IN COTTONWOOD GROWTH BETWEEN A LOSING AND A GAINING REACH OF AN ALLUVIAL FLOODPLAIN

Interstitial flow of river (hyporheic) water influences algal productivity, benthic assemblages, and locations of fish spawning. However, little is known of the effects of hyporheic flow on the growth of riparian vegetation. By increasing water availability and nutrient delivery, regional upwelling of hyporheic water may increase the growth of terrestrial vegetation. We tested and accepted the hypothesis that cottonwood trees (Populus trichocarpa) in a gaining reach of an alluvial floodplain grow faster than trees in a losing reach by comparing basal areas and ages on an expansive floodplain in western Montana (USA). Trees in the gaining reach had basal areas twice the size of the trees in the losing reach, after correcting for tree age. In addition, the carbon-to-nitrogen ratios in leaves were 16% lower in the gaining reach. Lower cottonwood stem densities, deeper layers of fine sediments, and a higher water table occurred in the gaining compared to the losing reach. Each of these variables was significa...
Potential U.S. contributions to in-reactor experiments for fast reactor surveillance systems

Abstract It is maintained that special features of FFTF make it an ideal system to test sodium boiling detection techniques by acoustic/neutronic methods and to test the response of acoustic/neutronic sensors to vibrations. It is shown that accumulated research results indicate that such tests in FFTF are feasible, predictable, promising and safe.
The Psychopharmacology of Hallucinogens

Hallucinogenic drugs have been inhaled, ingested, worshipped, and reviled since prehistory. With the purification and synthesis of bontanical preparations and the ensuing discovery of chemically unique agents, hope was raised regarding their therapeutic potential, but this hope has been clouded by an epidemic of abuse and an inventory of adverse effects. This review examines aspects of that controversy, including the history of hallucinogens, epidemiology of current hallucinogen abuse, the association of LSD use with prolonged psychoses and hallucinogen persisting perception disorder, and the efforts to demonstrate the drug's therapeutic efficacy. Human subject ramifications in hallucinogen experimentation are discussed. Future lines of research are suggested in human, animal, and tissue culture paradigms.
The impact of the stent era on the management strategy for acute myocardial infarction: A population-based perspective.

We determined trends in the use of invasive diagnostic and revascularization strategies from a multihospital community-wide perspective for patients suffering acute myocardial infarction (AMI). Comparing 3,824 patients treated in the prestent era (1986-1993) to 1,915 patients hospitalized during the stent era (1995-1997), there was a significant increase in the use of invasive procedures and revascularization techniques across a broad spectrum of AMI patients during their index hospitalization. This resulted in a higher-risk profile of patients referred for invasive management of AMI in the stent era. Cathet. Cardiovasc. Intervent. 51:255-258, 2000.
Optimizing Traffic in DSM Clusters: Fine-Grain Memory Caching versus Page Migration / Replication

In this paper we compare and contrast two techniques to improve capacity/conflict miss traffic in CC-NUMA DSM clusters. Page migration/replication optimizes read-write accesses to a page used by a single processor by migrating the page to that processor and replicates all read-shared pages in the sharers' local memories. R-NUMA optimizes read-write accesses to any page by allowing a processor to cache that page in its main memory. Page migration/replication requires less hardware complexity compared with R-NUMA, but has limited applicability and incurs much higher overheads even with tuned hardware/software support. In this paper we compare and contrast page migration/replication and R-NUMA on simulated clusters of symmetric multiprocessors executing shared-memory applications. Our results show that: (1) both page migration/replication and R-NUMA significantly improve the system performance over "first-touch" migration in many applications, (2) page migration/replication has limited opportunity and cannot eliminate all the capacity/conflict misses even with fast hardware support and unlimited amount of memory, (3) R-NUMA always performs best given a page cache large enough to fit an application's primary working set and subsumes page migration/replication, (4) R-NUMA benefits more from hardware support to accelerate page operations than page migration/replication, and (5) integrating page migration/replication into R-NUMA to help reduce the hardware cost requires sophisticated mechanisms and policies to select candidates for page migration/replication
Treatment and chemoprevention of NSAID-associated gastrointestinal complications.

The use of non-steroidal anti-inflammatory drugs has become ubiquitous worldwide and remains a common source of gastrointestinal morbidity. Antisecretory medications, particularly proton pump inhibitors, are effective in the treatment and prevention of NSAID-related gastrointestinal complications, including peptic ulcer disease and non-ulcer dyspepsia. A careful assessment of patients’ risk factors for developing NSAID-related gastrointestinal complications should be undertaken prior to initiation of any NSAIDs. Patients who are considered at risk for developing gastrointestinal complications should receive concurrent antisecretory medical therapy to minimize the risk for GI complications.
Add-on therapy for hypercholesterolemia: a pilot comparison of two gastrointestinally-acting agents in statin-treated patients

Background Both colesevelam hydrochloride (colesevelam) and ezetimibe monotherapy have been reported to lower low-density lipoprotein cholesterol (LDL-C) approximately 15–17% in patients with hypercholesterolemia. When statin therapy is inadequate to reach desired LDL-C goals, the choice of add-on therapy, while multifactorial, must consider efficacy of additional LDL-C reduction. Objective To provide pilot study data in assessing the relative potential of ezetimibe or colesevelam to further reduce LDL-C in statin-treated patients. Methods Fourteen patients with hypercholesterolemia, who at baseline were on treatment with a stable regimen of low- to moderate-dose statin therapy, were randomized to receive colesevelam HCl 3.75 g/day or ezetimibe 10 mg/day as add-on therapy (AOT). At the end of 6 weeks, each patient was crossed over to the alternative AOT. Results LDL cholesterol fell an additional 21.0% on colesevelam ( P P P P P P P P P P Conclusion Colesevelam HCl and ezetimibe are both effective AOTs in patients on statin therapy. The superior further improvement in the lipid panel with ezetimibe compared to colesevelam was demonstrated in this placebo uncorrected crossover pilot study.
Toward a More Appropriate Conceptualization of Research on School Effects: A Three-Level Hierarchical Linear Model

Two aspects of educational research--that children's learning is typically the object of inquiry and that this learning usually occurs in organizational settings of classrooms and schools--locate educational research at the nexus of two of the most troublesome and persistent methodological problems in the social sciences: the measurement of change and the "unit-of-analysis" problems. Over the past several years, a satisfactory solution to these problems has been developed through the use of hierarchical linear models. This article summarizes these developments and shows how these techniques have already been used to illuminate important substantive questions about the effects of school organization and children's language development. In the final section of the article, the authors introduce a three-level hierarchical model that they argue should constitute the basic paradigm for future quantitative research on student learning.
Minimization of Errors in a Calibration-Surface-Derived Scanning Probe Microscope Model

In this paper, we present a method to choose operating parameters to minimize intrinsic error in a newly developed scanning probe microscope (SPM) modeling method. This modeling method uses the probe-sample interaction signal to develop a model for the SPM dynamics — it is noted that this is especially advantageous when sensor information is either unavailable or unreliable. Despite the method’s advantages, the choice of operating parameters affect the accuracy of the model. The main contribution of this paper is a complete error analysis of the modeling method and the application of multi-objective optimization to determine SPM operating parameters that minimize this error.Copyright © 2010 by ASME
Effects of insulator ablation on the operation of a quasi-steady MPD arc

Multimegawatt operation of quasi-steady MPD arcjets can involve serious ablation of the insulator surfaces within the arc discharge chamber. Various degrees of insulator ablation manifest themselves by significantly perturbing the voltage-current characteristics and the exhaust velocity profiles. Voltage-current characteristics for two different insulator materials, Plexiglas and boron nitride, are interpreted in terms of an empirical Ohm's law. Use of the refractory insulator material eliminates the ablation-dominated nature of the terminal voltage, but the exhaust stream is still disturbed by insulator material. An Alfven critical velocity model can be applied to this influence of insulator ablation on exhaust velocity. Appropriate changes in the propellant injection geometry eliminate this influence and result in arcjet operation which is independent of insulator material. A particular combination of propellant injection geometries reduces the terminal voltage for a given current and mass flow while maintaining insulator-independent operation, thus implying an improvement in the overall efficiency of the device.
Legal Reform in Child Abuse Reporting A Time Series Analysis

The followmg study evaluates the impact of a legal reform on child abuse reporting in the District of Columbia. A multiple time series design is used to assess and compare the effects of legislative change on the reporting behavior of two groups. The results suggest that reporting legislation can play a useful role in reform efforts by extending reporting requirements to new groups of reporters and by precipitating efforts to implement legal requirements of those already required to report.
Measurements and calculations of neutron detector efficiencies

Abstract Neutron detector absolute efficiencies measured in our laboratory for several organic scintillators are reported. A substantially revised version of Kurz's neutron detector efficiency computer program has been used to calculate efficiencies for new and previous measurements. Good agreement has been obtained for various scintillators.
What is the best treatment for patients with acute type B aortic dissections--medical, surgical, or endovascular stent-grafting?

Abstract Background Controversy continues regarding treatment for patients with acute type B aortic dissection. Methods One hundred eighty-nine patients with acute type B aortic dissection managed over a 36-year period were analyzed retrospectively for three outcome endpoints: survival; freedom from reoperation, and freedom from late aortic-related complications or late death. Risk factors for death were identified using a multivariable Cox proportional hazards model. Then to account for patient selection bias, heterogeneity of the population, and continuous evolution in techniques, propensity score analysis was used to identify risk-matched cohorts (quintiles I and II) in which the results of medical (n = 111) or surgical (n = 31) therapy were compared more comprehensively. Results The two main determinants of death were shock (hazard ratio [HR] = 14.5, 95% confidence level [CL] 4.7, 44.5; p p Conclusions The poor long-term prognosis of patients with acute type B aortic dissection is determined primarily by dissection-related and patient-specific risk factors, which are not readily modifiable. Whether the outlook in the future will be improved using stent-grafts remains to be determined.
Designing for Mars: Mitigating Habitability Factors to Support Crew Performance

This presentation provides an overview of the habitability factors that affect the design of space habitats for long-duration spaceflight missions. Components of habitability that affect human adap...