cssi/SciSciGPT-SciSciNet huggingface dataset:
Adolescent and adult responsiveness to the incentive value of cocaine reward in mice: Role of neuronal nitric oxide synthase (nNOS) gene

A major concern in adolescent psychostimulant abuse is the long-term consequence of this practice, because early drug exposure may cause long-term adaptations, which render the organism more susceptible to drug abuse later in life. The incentive value of drug and natural reward in rodents is commonly assessed by the conditioned place preference (CPP) paradigm, which involves Pavlovian learning. The aims of the present study were to investigate: a) the acquisition, expression, maintenance and reinstatement of cocaine CPP from periadolescence (PD24-45) through adulthood (PD70); b) potential sexual dimorphism in adolescence and adulthood in response to cocaine-induced CPP; and c) the role of the neuronal nitric oxide synthase (nNOS) gene in long-term neural plasticity underlying responsiveness to cocaine and cocaine-associated cues. Adolescent wild type (WT) mice acquired significant cocaine (20 mg/kg) CPP that was maintained from PD24 through PD43. Upon extinction, CPP was reinstated in adulthood (PD70) following a priming injection of cocaine (5 mg/kg). In contrast, cocaine CPP acquired between PD26 and PD31 in adolescent nNOS knockout (KO) mice, was neither maintained nor reinstated by cocaine. There was no sexual dimorphism in adolescent WT and KO mice. Genotype differences and sexual dimorphism were observed in adult mice. Cocaine CPP in adult WT males (PD89-94) was maintained for 4 weeks post training, and subsequently reinstated by cocaine priming; the magnitude of CPP in adult WT males was lower than in female counterparts. CPP in adult KO males (PD88-93) was neither maintained nor reinstated by cocaine priming; in contrast, CPP in adult KO females was not significantly different from adult WT females. Results suggest that the nNOS gene is essential during adolescence of both sexes for the development of long-term neural plasticity underlying responsiveness to the incentive value of cocaine reward. Sexual dimorphism in response to cocaine CPP emerges in adulthood; nNOS contribution to long-term plasticity is therefore sexually dimorphic and age-dependent in female but not in male subjects.
A profile sheet for the clinical interpretation of the Holtzman Inkblot Technique.

Summary It is suggested that the clinical interpretation of Holtzman Inkblot Technique scores would be facilitated by the use of T-score profile sheets analogous to those used for the MMPI and CPI. Using Holtzman et al.'s normative data for average adults, two such profile sheets were devised, one listing the 22 scales in their usual order and a Clinical Form in which the scales were divided into six clusters reflecting I: Reactions to the Stimuli, II: Manner of approach and organization of the blot, III: Reality contact and Communality, IV: Intelligence and Maturity, V: Emotional Responsivity, and VI: Psychopathology. The clinical interpretation of the HIT profile was discussed and illustrated.
EVOLUTION OF CARDIOVASCULAR BARORECEPTOR CONTROL

Summary During animal evolution the circulatory system has shown a progressive modification in structure, function and short-term control. Short-term circulatory control has evolved from the limitation of a rising blood pressure via a reflex bradycardia to bidirectional control of blood pressure by appropriate reflex changes in heart rate, vascular resistance and impedance. Relevant experimental data ranges from extensive in mammals to nugatory in invertebrates. Baroreceptor research in intervening animal groups is varied, being particularly sparse in birds. This research is reviewed. There are few interspecies comparisons of baroreceptor physiology. Available data is complicated by variation in the techniques employed for assessing baroreceptor function. In non-mammalian research the correlation of heart rate changes to pharmacologically induced changes in blood pressure predominate. In mammalian baroreceptor research methods based upon the ability of discrete baroreceptor sites to effect changes in the peripheral vasculature are more prevalent. All methods are susceptible to modification by other experimental variables, particularly the anaesthetic state of the animal. Available evidence shows a consistent response of a decreasing heart rate to baroreceptor loading throughout the vertebrates, with a progressive increase in the ability of the baroreceptors to change peripheral vascular resistance. These findings are consistent with the known, progressive trend from cholinergic to adrenergic control of the vascular system during evolution. Known baroreceptor sites appear to be located so as to protect the end-organ or-organs primarily at risk from inappropriate blood pressure changes; namely the gill vasculature in the fish, pulmonary circulation in the Amphibia and Reptilia, and the brain and heart in higher animal groups. It is postulated that the carotid sinus baroreceptors have developed in the Mammalia as a second functional baroreceptor site to provide extra protection against hypoperfusion of vital organs, particularly the heart and brain. In humans the dynamic aspects of cardiovascular carotid sinus control, particularly of skeletal muscle flow and integration with cardiopulmonary baroreceptors, may represent a specific response to the adoption of an upright stance. Extremes of environmental stress encountered in contemporary life may exceed the limitation of baroreceptor function in humans, as, for example, during gravitational loading particularly following periods of weightlessness and modification by endurance training.
Modeling of a simple motor task in man: motor output dependence on sensory input

The relationship between the movement's parameters and the motor output during the execution of certain intentional motor tasks subsequent to a ballistically initiated movement is determined. The two tasks considered are to arrest the movement and to accelerate it as fast as possible. These experiments are the same as described in the preceding paper (Viviani and Terzuolo, 1973). It is shown that the motor output is dependent on sensory input in normal subjects and that this dependence is absent in cerebellar patients. The phase relations between motor output and angular displacement in normal subjects indicate the likelihood of fusimotor dynamic activity to the muscle spindles when the task is to arrest the movement. Instead, when normal subjects are instructed to accelerate the movement, an appropriately timed fusimotor static activity, i.e. alpha-gamma linkage, is indicated. The appropriately timed switching of fusimotor static and dynamic activation is attributed to the presence of cerebellar activities.
IODINE-131 TOSITUMOMAB (BEXXAR) IN A RADIATION ONCOLOGY ENVIRONMENT

Iodine-131 (I-131) tositumomab (Bexxar; GlaxoSmithKline, Research Triangle Park, NC) is one of two recently approved radiolabeled antibodies directed against the CD20 surface antigen found on normal B cells and in more than 95% of B cell non-Hodgkin’s lymphoma. The compound itself is formulated as an IgG2a immunoglobulin radiolabeled with the mixed beta/gamma emitter I-131. Multicenter clinical trials have repeatedly shown impressive clinical responses (20–40% complete response rates and 60–80% overall response rates) in the patient groups for whom this treatment is indicated. Treatment-related toxicity is generally extremely mild and typically involves only reversible hematopoietic suppression and (in some cases) a risk of treatment-induced hypothyroidism. Owing to the radiation safety concerns necessitated by the clinical use of this targeted radiopharmaceutical, it is important for radiation oncology departments wishing to participate in the care of these patients to establish methodologies and standard operating procedures for safe and efficient departmental use. This summary reviews the pertinent background information related to the current clinical experience with I-131 tositumomab and highlights some of the major opportunities for the participation of radiation oncology in the patient evaluation and treatment process. I-131 tositumomab provides an excellent example of the way in which the increasingly important new field of “targeted therapy” intersects with the practice of clinical radiotherapy. The author contends that it will be worth the time and effort involved in establishing a firm basis for the development of a comprehensive program for systemic targeted radiopharmaceutical therapies (STaRT) within the radiation medicine domain.
Bivalves as bathymetric indicators

Abstract Water depth does not directly control the distribution of marine bivalve molluscs, but bathymetric inferences may sometimes be made by relating water depth to environmental variables known to limit bivalve distribution, such as temperature, salinity, and nature of the substratum. When contemporaneous stenothermal and eurythermal (or stenohaline and euryhaline) bivalve associations are found in the same general area , the more tolerant associations (eurythermal or euryhaline) will usually be found in shallower water than less tolerant (stenothermal or stenohaline) associations. Similarly, associations dominated by epifaunal and boring bivalves would normally be expected in relatively shallow water where hard substrata are most abundant. Burrowing infaunal bivalves are present at all depths, but infaunal deposit-feeding bivalves are most common in subtidal, quiet water muds. Observations on Recent infaunal benthonic associations suggest that organisms adapted for deep vertical burrowing are common only in intertidal and shallow subtidal environments where stress conditions at the sediment-water interface are most severe. In contrast, infaunal organisms adapted for horizontal burrowing just below the sediment surface predominate in deeper subtidal environments. In situ associations of fossil bivalves adapted for these two modes of burrowing should therefore be reliable indicators of relative water depth. These burrowing patterns may also be determined directly from biogenic sedimentary structures, and thus this paleobathymetric tool may be applied to many unfossiliferous sedimentary rocks.
Electrically heated converters for automotive emission control: determination of the best size regime for the heated element

Abstract In view of the significant cold-start hydrocarbon emission reduction potential of the electrically heated converter (EHC) technology demonstrated in recent studies, there is considerable interest in better understanding the behavior and design aspects of an EHC during the cold-start portion of actual vehicle emission tests. Computer simulations based on the EHC model developed previously (Oh et al., 1993, Industrial and Engineering Chemistry Research 32, 1560–1567) show that although decreasing the volume of an electric heater generally improves the emission performance of the EHC system, there is a critical heater volume below which no significant emission benefit is obtained. This paper examines the EHC sizing issue in more detail by analyzing a simplified version of the EHC model to investigate why the emission benefit of decreasing electric heater volume eventually disappears and how the critical heater volume where this occurs is related to system parameters. Analysis of the simplified EHC model identifies this critical volume, Vh, which is proportional to the exhaust flow rate through the EHC and inversely proportional to the product of the interphase (gas–solid) heat transfer coefficient within the heated element and its geometric surface area per unit volume. It is shown that the recommended heater size regime must be where the physical heater volume, V, and Vh are comparable in magnitude. When V≫Vh, the electric heater is clearly too large because the emission performance suffers from the slow heat-up rate caused by the large thermal mass. Also, decreasing the heater volume to values much smaller than Vh (i.e., V≪Vh) is not desirable because it would simply lead to unnecessarily higher (potentially damaging) solid-phase temperatures without producing additional emission reductions. In this smallest size regime, the emission performance of the EHC system becomes insensitive to heater size variation because the higher solid-phase temperatures within the smaller heater tend to be compensated by its poor interphase (solid-to-gas) heat transfer arising from the insufficient heat transfer area available.
Measuring the surface inhomogeneity of metals on accreting white dwarfs

Due to the short settling times of metals in DA white dwarf atmospheres, any white dwarfs with photospheric metals must be actively accreting. It is therefore natural to expect that the metals may not be deposited uniformly on the surface of the star. We present calculations showing how the temperature variations associated with white dwarf pulsations lead to an observable diagnostic of the surface metal distribution, and we show what constraints current data sets are able to provide.
Review of the adipose derived stem cell secretome.

Abstract Recent advances in protein detection and analysis have lead to multiple in depth studies that analyze the adipose-derived stem cell (ASC) secretome. These studies differ significantly in their methods of secretome preparation and analysis. Most of them use a pro-differentiation or pro-inflammatory stimulus to observe differential expression of secreted proteins. In spite of the variance in methodologies used, 68 proteins are reported to be commonly expressed in a majority of the studies and may serve as potential candidates for conserved secretome proteins. Multiple recent clinical and basic science studies demonstrate the beneficial role played by secreted proteins in augmenting ASC effects in scenarios involving angiogenesis, wound healing, tissue regeneration and immunomodulation. Furthermore, 3-D formulations of ASCs that preserve the niche environment of cells and their secreted proteins have also shown enhanced clinical effects. In light of the lack of uniformity in prior secretome-analysis studies, and the growing clinical importance of the ASC secretome, more in depth studies that use uniform and standardized means of protein detection and analysis are necessary.
Dual-Mode Combustion of Hydrogen in a Mach 5, Continuous-Flow Facility

Results of an experimental and numerical study of a dual-mode scramjet combustor are reported. The experiment consisted of a direct-connect test of a Mach 2 hydrogen-air combustor with a single unswept-ramp fuel injector. The flow stagnation enthalpy simulated a flight Mach number of 5. Measurements were obtained using conventional wall instrumentation and a particle-imaging laser diagnostic technique. The particle imaging was enabled through the development of a new apparatus for seeding fine silicon dioxide particles into the combustor fuel stream. Numerical simulations of the combustor were performed using the GASP code. The modeling, and much of the experimental work, focused on the supersonic combustion mode. Reasonable agreement was observed between experimental and numerical wall pressure distributions. However, the numerical model was unable to predict accurately the effects of combustion on the fuel plume size, penetration, shape, and axial growth.
Understanding relativistic electron losses with BARREL

Abstract The primary scientific objective of the Balloon Array for RBSP Relativistic Electron Losses (BARREL) is to understand the processes responsible for scattering relativistic electrons into Earth's atmosphere. BARREL is the first Living with a Star Geospace Mission of Opportunity, and will consist of two Antarctic balloon campaigns conducted in the 2012 and 2013 Austral summer seasons. During each campaign, a total of 20 small ( ∼ 20 kg ) balloon payloads will be launched, providing multi-point measurements of electron precipitation in conjunction with in situ measurements from the two RBSP spacecraft, scheduled to launch in May 2012. In this paper we outline the scientific objectives of BARREL, highlighting a few key science questions that will be addressed by BARREL in concert with other ILWS missions in order to understand loss processes in the radiation belts. A summary of observations from the 2008/2009 BARREL test flight is also presented. Electron precipitation was observed during a geomagnetic storm on February 14–18, 2009. This storm, though relatively weak (Dst=−36 nT), was remarkably effective in increasing the trapped electron population.
Exact solutions of the cubic–quintic Swift–Hohenberg equation and their bifurcations

Many systems of physical interest may be modelled by the bistable Swift–Hohenberg equation with cubic–quintic nonlinearity. We construct a two-parameter family of exact meromorphic solutions of the time-independent equation and use these to construct a one-parameter family of exact periodic solutions on the real line. These are of two types, differing in their symmetry properties, and are connected via an exact heteroclinic solution. We use these exact solutions as initial points for numerical continuation and show that some of these lie on secondary branches while others fall on isolas. The approach substantially enhances our understanding of the solution space of this equation.
Introduction to the special issue on learning and computational game theory

Game theory is concerned with the decision making of utility-maximizing individuals in their interactions with one another and their environment. From its earliest days of study, researchers have recognized the important relationship between game theory and learning— using experience from past play to guide future decisions. Recently, there has been a surge in research that applies a computational perspective to learning in general-sum games. The editors have been involved with such projects: for example, deriving finite time bounds on learning algorithms known to converge to game-theoretic equilibria in the limit (Greenwald, Li, & Marks, 2006); and developing computationally efficient models of strategic interactions (Kearns, Littman, & Singh, 2001). Our purpose in editing this special issue on computational issues that pertain to learning in games was to provide an opportunity for sharing results in this rapidly growing area at the intersection of computer science and economics. When facing an unknown opponent, learning plays a central role. As such, there are many ways of applying machine-learning techniques to games. As eloquently argued by Shoham, Powers, and Grenager (2007), it is critical for research in this area to be geared towards solving a precise problem, and that the criteria for judging the success of the work be clearly stated. We selected five articles that followed these important guidelines. Each of the contributions in the special issue spells out what information is available to the individual players (their own actions, the actions of others, utilities of all players, identity of the other players, etc.), how their performance is to be judged (utility of the player, social utility, convergence to equilibrium, stability of learned behavior, etc.), the model of uncertainty (randomized payoffs, noise in action perception, stochastic action effects, etc.), the relevant equilibrium concepts, and any computational concerns.
Fluorescent speckle microscopy, a method to visualize the dynamics of protein assemblies in living cells

Fluorescence microscopic visualization of fluorophore-conjugated proteins that have been microinjected or expressed in living cells and have incorporated into cellular structures has yielded much information about protein localization and dynamics [1]. This approach has, however, been limited by high background fluorescence and the difficulty of detecting movement of fluorescent structures because of uniform labeling. These problems have been partially alleviated by the use of more cumbersome methods such as three-dimensional confocal microscopy, laser photobleaching and photoactivation of fluorescence [2]. We report here a method called fluorescent speckle microscopy (FSM) that uses a very low concentration of fluorescent subunits, conventional wide-field fluorescence light microscopy and digital imaging with a low-noise, cooled charged coupled device (CCD) camera. A unique feature of this method is that it reveals the assembly dynamics, movement and turnover of protein assemblies throughout the image field of view at diffraction-limited resolution. We found that FSM also significantly reduces out-of-focus fluorescence and greatly improves visibility of fluorescently labeled structures and their dynamics in thick regions of living cells. Our initial applications include the measurement of microtubule movements in mitotic spindles and actin retrograde flow in migrating cells.
Acute iron intoxication in a herd of young bulls.

1. Harvey RB, Clark DE, Huff WE, et al.: 1988, Suppression of serum iron-binding capacity and bone marrow cellularity in pigs fed aflatoxin. Bull Environ Contam Toxicol 40:576-583. 2. Harvey RB, Huff WE, Kubena LF, et al.: 1988, Progression of aflatoxicosis in growing pigs. Am J Vet Res 49:482-487. 3. Harvey RB, Kubena LF, Huff WE, et al.: 1989, Effects of mycotoxins: aflatoxin, deoxynivalenol and their combinations in the diets of growing pigs. Am J Vet Res 50:602-607. 4. Harvey RB, Huff WE, Kubena LF, et al.: 1989, Evaluation of diets co-contaminated with aflatoxin and ochratoxin fed to growing pigs. Am J Vet Res 50:1400-1405. 5. Pang VF, Adams JH, Beasley VR, et al.: 1986, Myocardial and pancreatic lesions induced by T-2 toxin, a trichothecene mycotoxin, in swine. Vet Pathol 23:310-319. 6. Pang VF, Swanson SP, Beasley VR, et al.: 1987, The toxicity of T-2 toxin in swine following topical application. I. Clinical signs, pathology, and residue concentrations. Fund Appl Toxicol 9:4149. 7. Weaver GA, Kurtz HJ, Bates FY, et al.: 1978, Acute and chronic toxicity of T-2 mycotoxin in swine. Vet Rec 103:531-535.
DOSAGE REGULATION OF ZEA MAYS HOMEOBOX (ZMHOX) GENES AND THEIR RELATIONSHIP WITH THE DOSAGE-SENSITIVE REGULATORY FACTORS OF SHRUNKEN 1 (SH1) IN MAIZE

In gene dosage studies on the expression of the maize Shrunken I gene several dosage-sensitive regulatory factors were identified that modulate Sh 1 mRNA levels in various aneuploids. ZmHox 1a and 1b have been shown to interact with the Sh1 promoter sequences in vitro. The present study was conducted to test whether these molecularly defined regulatory genes are subject to dosage modulation and to determine whether ZmHox 1a and 1b are involved with the dosage sensitive modification of Sh1 expression. The result was that ZmHox 1a and 1b were affected by several transacting dosage modifiers and that both genes exhibited a structural gene dosage effect but did not modulate Sh1 mRNA levels. For some chromosomal regions, a correlation was found between the dosage regulation of Sh1 and that of ZmHox 1a, while other effects were not correlated. The results suggest that the dosage effects on Sh1 are not mediated by ZmHox 1a or 1b, but interestingly Sh1 and ZmHox 1a share some dosage-regulatory effects. Dev Genet 20:67–73, 1997. © 1997 Wiley-Liss, Inc.
Ball-Obturation of a Spinning Tubular Projectile

Performance improvements in tubular projectiles over conventional rounds are often negated by difficulties in sealing (obturating) the tubular projectiles during their residence in the barrel of the gun. Ball-obturation of a tubular projectile is achieved by the friction-driven gyrodynamic motion of a bored sphere that is mounted loosely within the spinning projectile. In this paper the motion is analyzed by means of solution of the Euler equations of motion, after suitable formulation of the applied moments. A linear form is presented in order to assist in the preliminary design of ball-obturated projectiles and similar systems. The sensitivity of the projectile performance to the various design variables is demonstrated by means of a series of computer experiments.
Teaching NeuroImages:Crossed cerebellar diaschisis in hemispheric status epilepticus

A 36-year-old woman with Sheehan syndrome was found unresponsive. Evaluation was consistent with Addisonian crisis and myxedema coma. Continuous EEG demonstrated right frontotemporal nonconvulsive status initially refractory to multiple antiepileptic drugs (figure 1).
Chronic idiopathic urticaria: Comparison of the clinical features of patients with and without anti-FcϵRI or anti-IgE autoantibodies

Abstract Background: Previous studies defining the clinical features of patients with chronic idiopathic urticaria (CIU) were performed before the identification of functional autoantibodies against FcϵRI and/or IgE, now known to be present in approximately 30% of patients with CIU. Objective: Our purpose was to determine whether there are differences between patients with and those without autoantibodies in the clinical features or severity of CIU. Methods: The clinical features of 107 patients with CIU were evaluated prospectively. Patients were identified as having functional autoantibodies on the basis of the serum-evoked histamine release in vitro from the basophils of 2 healthy donors. Results: Patients with autoantibodies (31%) had more wheals ( P = .005), a wider distribution of wheals ( P = .009), higher itch scores for the most severe episodes of itching ( P = .002), more systemic symptoms ( P = .03), and lower serum IgE levels ( P Conclusion: The presence of autoantibodies indicates a subset of patients with more severe CIU. (J Am Acad Dermatol 1999;40:443-50.)
Rugged Electrical Power Switching in Semiconductors: A Systems Approach

Current status of wide bandgap (WBG) semiconductor material technology is evaluated for developing high-performance and reliable power electronics switching converters. The study takes into account field reliability of silicon power metal-oxide-semiconductor field-effect transistors (MOSFETs) in compact computer/telecom power supplies where residual material defects present in the silicon space-charge region were found to generate local microplasma that eventually caused power MOSFETs to fail under long-term repetitive field-switching conditions. It is shown that silicon power MOSFETs with increased low-level leakage currents are more prone to field failures in high-density power supplies. A new single-event burnout (SEB) stress testing methodology is proposed; the SEB stress test results are shown to correlate well with silicon power MOSFET failures in power supply circuits. Based on these results and the current state of the art of silicon carbide (SiC) and gallium nitride (GaN) power devices, a “reliability-driven” manufacturing approach is recommended for rapid commercialization and market penetration of WBG semiconductor power devices.
Developmental Changes in Interlimb Coordination: Transition to Hands-and-Knees Crawling

A short-term longitudinal study was conducted to assess changes in the patterning of the limbs during infants’ transition to hands-and-knees crawling Six infants were studied using observational and kinematic assessment techniques The results revealed that all 6 infants converged on the same diagonal interlimb pattern for locomoting shortly after developing sufficient muscle strength to support their abdomens above the support surface This finding is significant because forward prone progression could be accomplished using any number of interlimb patterns (e g, moving one limb at a time), yet a diagonal pattern is the most flexible and dynamically efficient The process by which this behavioral pattern emerges appears consistent with recent developmental theories suggesting that new responses are selected to optimize performance following periods of increased variability induced by changing organismic or environmental conditions
Clinical implications of anatomical wear characteristics in slipped capital femoral epiphysis and primary osteoarthritis.

Background This study compares the wear characteristics in slipped capital femoral epiphysis (SCFE) with those of primary osteoarthritis (OA) in adult patients with advanced arthritis. Methods One hundred femoral heads and proximal neck specimens were studied from SCFE patients (16 hips) and from primary OA (84 hips) patients undergoing total hip arthroplasties (THA). Grade 4 chondromalacia was plotted on a 2-dimensional (2-D) paper grid. Computer tomographic scans were used to create 3-D models of the femoral head and neck to trace the wear patterns. Results The SCFE group was characterized by (1) loss of neck-head offset, (2) acetabular neck impingement, and (3) loss of superior peripheral articular cartilage adjacent to superior neck. Whereas the primary OA group showed (1) preservation of head-neck offset, (2) absence of acetabular neck impingement, and (3) preservation of superior peripheral articular cartilage. The 3-D modeling in SCFE specimens demonstrated acetabular impingement on the superior lateral femoral neck causing the femur to externally rotate with flexion. The SCFE patients undergoing THA on average were 11 years younger than those with primary OA. The study strongly suggests that the abnormal rotation of the femoral head in SCFE patients causes thinner superior lateral articular cartilage on the femoral head to articulate with the acetabulum. The pistol-grip deformity of the proximal femur in the SCFE group results in hip impingement, which explains why hip flexion and internal rotation can be restricted. Conclusions There was a premature development of advanced OA of the adult hip joint in SCFE patients. This was associated with hip impingement caused by loss of the head-neck offset and reorientation of the articular cartilage of the femoral head. Unless the femoral head is redirected in patients with SCFE, the benefits of limited hip preservation debridement procedures are not expected to delay the onset and progression of arthritis. Level of evidence Prognostic study.
Crystal Parameters of an Alcohol Dehydrogenase from the Extreme Thermophile Thermoanaerobium brockii

Abstract : The crystal structure of a thermophilic alcohol dehydrogenase (TBAD) has been determined in complex with sec-butanol as substrate to a resolution of 3.0 A. The enzyme is from Thermoanaerobacter brockii, a bacterium isolated from hot springs in Yellowstone National Park. This tetrameric enzyme has a melting temperature of 98 C. The structure consists of two domains, the catalytic domain and the cofactor-binding domain, with the active site located in a deep cleft at the domain interface. Factors important for the thermostability have been deduced by comparison with the crystal structure of a highly homologous mesophilic alcohol dehydrogenase from Clostridium beijerinckii (CBAD). The thermophilic enzyme has a more hydrophilic exterior, a more hydrophobic interior. a smaller surface area, more prolines, alanines, and less serines than CBAD. Furthermore, in the thermophilic enzyme the number of all types of intersubunit interactions is increased: more salt bridges, hydrogen bonds and hydrophobic interactions. All these effects combined can account for the 32 deg C higher melting temperature of the thermophilic enzyme.
The RNA helicase database

RNA helicases are ubiquitous and essential enzymes that function in nearly all aspects of RNA metabolism. The RNA helicase database (www.rnahelicase.org) integrates the wealth of accumulating information on RNA helicases in a readily accessible format. The database is a portal that allows straightforward retrieval of comprehensive information on sequence, structure and on biochemical and cellular functions of all RNA helicases from the most widely used model organisms Escherichia coli, Saccharomyces cerevisiae, Caenorhabditis elegans, Drosophila melanogaster, mouse and human. Also included are RNA helicases from other organisms that are subject to specific investigation. The database is structured according to the most recent helicase classification into helicase superfamilies (SFs) and families, and thus emphasizes phyologenetic relations between RNA helicases as well. Information on individual RNA helicases can be accessed through various browsing routes or through text-based searches of the database.
Taxes, Competition, and Organizational Form

This study examines whether competition from tax-advantaged firms influences the organizational form choice of tax-disadvantaged firms, and explores two consequences of this choice. Using a sample of 5,268 predominantly private commercial U.S. banks during 1997-2010, we find that greater competition from S corporation banks, which are subject to one layer of income tax, increases the likelihood that rival C corporation banks, which are subject to two layers of income tax, convert to S status. We estimate that the aggregate first-year tax savings from conversion exceed $267 million. In terms of consequences, converting banks increase their market share more than non-converting banks, with advertising growth and new bank branches facilitating this increase, while non-converting banks increase their tax avoidance. Our findings provide economic insight into how competition shapes — and is shaped by — taxes and organizational form.
Measurement-based models of delivery and interference in static wireless networks

We present practical models for the physical layer behaviors of packet reception and carrier sense with interference in static wireless networks. These models use measurements of a real network rather than abstract RF propagation models as the basis for accuracy in complex environments. Seeding our models requires N trials in an N node network, in which each sender transmits in turn and receivers measure RSSI values and packet counts, both of which are easily obtainable. The models then predict packet delivery and throughput in the same network for different sets of transmitters with the same node placements. We evaluate our models for the base case of two senders that broadcast packets simultaneously. We find that they are effective at predicting when there will be significant interference effects. Across many predictions, we obtain an RMS error for 802.11a and 802.11b of a half and a third, respectively, of a measurement-based model that ignores interference.
Persistent Bacillus licheniformis bacteremia associated with an intentional injection of organic drain cleaner

In recent years manufacturers have developed several products containing saprophytic bacteria, previously believed to be of minimal pathogenicity. We describe the first case of persistent Bacillus licheniformis bacteremia occurring after intentional injection of a consumer product that includes B. licheniformis spores. We postulate that these spores remained in the tissue, unaffected by antimicrobials, ultimately necessitating soft-tissue debridement of the area surrounding the injection site. On the basis of this case and a review of the literature, we submit that some consumer products contain bacteria with demonstrated pathogenicity. Manufacturers should study these bacteria in detail in order to rapidly provide information such as bacteriologic data and antimicrobial susceptibility data to clinicians.
Acceleration insensitivity of thickness frequencies of doubly rotated quartz crystal disks

Initial fields of displacement gradients and strains caused by steady accelerations of arbitrary direction are calculated from finite-element solutions of R.D. Mindlin's two-dimensional, first-order equations of equilibrium for crystal plates. The frequency equation for incremental thickness vibrations of circular crystal disks under initial stresses is obtained by the extension of a recently obtained solution for energy-trapped thickness vibrations and solved by a perturbation method. Acceleration sensitivity of SC- and AT-cuts of quartz disks are studied symmetrically. >
Role of phonotactic frequency in nonword repetition by children with specific language impairments

Purpose Recent work suggests that specific language impairment (SLI) results from a primary deficit in phonological processing. This deficit is most striking in nonword repetition tasks, where sema...
X-ray microprobe for the microcharacterization of materials

The unique properties of X rays offer many advantages over those of electrons and other charged particles for the microcharacterization of materials. X rays are more efficient in exciting characteristic X-ray fluorescence and produce higher fluorescent signal-to-background ratios than obtained with electrons. Detectable limits for X rays are a few parts per billion which are 10 −3 to 10 −5 lower than for electrons. Energy deposition in the sample from X rays is 10–3 to 10–4 less than for electrons for the same detectable concentration. High-brightness storage rings, especially in the 7 GeV class with undulators, will have sources as brilliant as the most advanced electron probes. The highly collimated X-ray beams from undulators simplify the X-ray optics required to produce submicron X-ray probes with fluxes comparable to electron sources. Such X-ray microprobes will also produce unprecedentedly low levels of detection in diffraction, EXAFS, Auger, and photoelectron spectroscopies for structural and chemical characterization and elemental identification. These major improvements in microcharacterization capabilities will have wide-ranging ramifications not only in materials science but also in physics, chemistry, geochemistry, biology, and medicine.
A Randomized Trial of Epidural Glucocorticoid Injections for Spinal Stenosis

Background Epidural glucocorticoid injections are widely used to treat symptoms of lumbar spinal stenosis, a common cause of pain and disability in older adults. However, rigorous data are lacking regarding the effectiveness and safety of these injections. Methods In a double-blind, multisite trial, we randomly assigned 400 patients who had lumbar central spinal stenosis and moderate-to-severe leg pain and disability to receive epidural injections of glucocorticoids plus lidocaine or lidocaine alone. The patients received one or two injections before the primary outcome evaluation, performed 6 weeks after randomization and the first injection. The primary outcomes were the score on the Roland–Morris Disability Questionnaire (RMDQ, in which scores range from 0 to 24, with higher scores indicating greater physical disability) and the rating of the intensity of leg pain (on a scale from 0 to 10, with 0 indicating no pain and 10 indicating “pain as bad as you can imagine”). Results At 6 weeks, there were no significant between-group differences in the RMDQ score (adjusted difference in the average treatment effect between the glucocorticoid– lidocaine group and the lidocaine-alone group, −1.0 points; 95% confidence in terval [CI], −2.1 to 0.1; P = 0.07) or the intensity of leg pain (adjusted difference in the average treatment effect, −0.2 points; 95% CI, −0.8 to 0.4; P = 0.48). A prespecified secondary subgroup analysis with stratification according to type of injection (interlaminar vs. transforaminal) likewise showed no significant differences at 6 weeks. Conclusions In the treatment of lumbar spinal stenosis, epidural injection of glucocorticoids plus lidocaine offered minimal or no short-term benefit as compared with epidural injection of lidocaine alone. (Funded by the Agency for Healthcare Research and Quality; ClinicalTrials.gov number, NCT01238536.)
Life and death of a cardiac calcium spark

Calcium sparks in cardiac myocytes are brief, localized calcium releases from the sarcoplasmic reticulum (SR) believed to be caused by locally regenerative calcium-induced calcium release (CICR) via couplons, clusters of ryanodine receptors (RyRs). How such regeneration is terminated is uncertain. We performed numerical simulations of an idealized stochastic model of spark production, assuming a RyR gating scheme with only two states (open and closed). Local depletion of calcium in the SR was inevitable during a spark, and this could terminate sparks by interrupting CICR, with or without assumed modulation of RyR gating by SR lumenal calcium. Spark termination by local SR depletion was not robust: under some conditions, sparks could be greatly and variably prolonged, terminating by stochastic attrition–a phenomenon we dub “spark metastability.” Spark fluorescence rise time was not a good surrogate for the duration of calcium release. Using a highly simplified, deterministic model of the dynamics of a couplon, we show that spark metastability depends on the kinetic relationship of RyR gating and junctional SR refilling rates. The conditions for spark metastability resemble those produced by known mutations of RyR2 and CASQ2 that cause life-threatening triggered arrhythmias, and spark metastability may be mitigated by altering the kinetics of the RyR in a manner similar to the effects of drugs known to prevent those arrhythmias. The model was unable to explain the distributions of spark amplitudes and rise times seen in chemically skinned cat atrial myocytes, suggesting that such sparks may be more complex events involving heterogeneity of couplons or local propagation among sub-clusters of RyRs.
Developmental expression of chemokine receptor genes in the human fetus

Abstract Background Chemokines induce cell motility during embryogenesis by activating specific receptors. While the orchestration of organogenesis is complex and requires the interaction of many morphoregulatory molecules that lead to coordinated organ development, limited knowledge exists regarding the human developmental biology of chemokines and their receptors. Such information on chemokine receptor expression could potentially enhance our understanding of organogenesis in the normal human fetus. Aim To determine the distribution of the CXC receptors (CXCR-1, CXCR-2, CXCR-3, and CXCR-4) and SDF-1 in human fetuses. Subjects Tissues from human fetuses 12–15 weeks ( n =5) and 16–19 weeks ( n =5) gestation were studied. Outcome measures Reverse transcription–PCR was performed to simultaneously determine the gene expression of CXCR-1–4 and SDF-1, and immunohistochemical staining of non-hematopoietic tissues was used to determine the specific cellular proteins. Results CXCR-1–4 and SDF-1 mRNA were present in every tissue examined. The expression of CXCR-3 in kidney, liver, and brain was dependent upon gestational age. CXCR-1–4 protein was expressed in non-hematopoietic cells in the brain, heart, intestine, and kidney. Conclusions CXCR-1–4 and SDF-1 genes are widely expressed in the normal human fetus. This suggests that these gene products could influence fetal development.
Obstructive Sleep Apnea Is a Risk Factor for Stroke and Atrial Fibrillation

1helps with the assessment of risk for stroke and thromboembolism in patients with atrial fibrillation (AF). Unfortunately, the Euro Heart Survey did not evaluate patients for obstructive sleep apnea (OSA), which we believe is a signifi cant risk factor. OSA is believed to increase the risk of stroke through endothelial damage and hypercoagulability as well as to increase the risk of AF. OSA with an apnea-hypopnea index (AHI) . 5 is an independent risk factor for stroke, with a hazard ratio of 1.97 when adjusted for race, sex, smoking, alcohol use, BMI, diabetes, AF, hypertension, and lipids. 2 In a metaanalysis of studies on stroke and sleep apnea, we found that 72% of patients with stroke and transient ischemic attack (TIA) have OSA with an AHI . 5, and 38% have OSA with an AHI . 20. 3 Further, we cite studies fi nding that treatment with continuous positive airway pressure (CPAP) reduces the rate of recurrent stroke and mortality in patients with OSA. Among the Sleep Heart Health Study cohort, 4.8% of patients with OSA (AHI . 5) have AF compared with only 0.9% of patients without OSA. 4 OSA increases the 12-month recurrence of AF after cardioversion from 53% of patients without OSA to 82% of patients with untreated OSA vs 42% of those treated with CPAP.
c-Jun NH2-terminal kinase activating kinase 1/mitogen-activated protein kinase kinase 4-mediated inhibition of SKOV3ip.1 ovarian cancer metastasis involves growth arrest and p21 up-regulation.

In many patients without clinical metastases, cancer cells have already escaped from the primary tumor and entered a distant organ. A long-standing question in metastasis research is why some disseminated cancer cells fail to complete steps of metastatic colonization for extended periods of time. Our laboratory identified c-Jun NH2-terminal kinase activating kinase 1/mitogen-activated protein kinase kinase 4 (JNKK1/MKK4) as a metastasis suppressor protein in a mouse xenograft model of experimental i.p. ovarian cancer metastasis. In this model, expression of JNKK1/MKK4 via activation of p38 delays formation of ≥1-mm implants and prolongs animal survival. Here, we elucidate the time course of this delay as well as the biological mechanisms underpinning it. Using the Gompertz function to model the net accumulation of experimental omental metastases, we show that MKK4-expressing implants arise, on average, 30 days later than controls. Quantitative real-time PCR shows that MKK4 expression does not have a substantial effect on the number of cancer cells initially adhering to the omentum, and terminal deoxyribonucleotidyl transferase–mediated dUTP nick end labeling analysis shows that there is no increase in apoptosis in these cells. Instead, immunohistochemical quantitation of cell cycle proteins reveals that MKK4-expressing cells fail to proliferate once they reach the omentum and up-regulate p21, a cell cycle inhibitor. Consistent with the time course data, in vitro kinase assays and in vivo passaging of cell lines derived from macroscopic metastases show that the eventual outgrowth of MKK4-expressing cells is not due to a discrete selection event. Rather, the population of MKK4-expressing cells eventually uniformly adapts to the consequences of up-regulated MKK4 signaling. [Cancer Res 2008;68(7):2166–75]
Islands in Zonal Flow

The impact of a meridional gradient in sea surface temperature (warm toward the equator, cold toward the pole) on the circulation around an island is investigated. The upper-ocean eastward geostrophic flow that balances such a meridional gradient is blocked where the isotherms intersect boundaries. In the case in which the boundaries represent either the eastern or western side of a planetary-scale island, circulation integrals around the island show that some of this eastward transport will flow around both the equatorward and poleward tips of the island. There is also a net downwelling along the western side of the island and a net upwelling along the eastern side of the island. An analytic model of the eastern and western boundary currents is used together with a circulation integral to estimate the fraction of the eastward transport that flows around the equatorward and poleward tips of the island and the net upwelling/downwelling on either side of the island. Calculations with a primitive equation numerical model are in close agreement with the theory. A simple closed-form analytic solution for the transport around the island tips is derived in the limit of strong buoyancy forcing. It is found that, over a wide range of parameter space, a significant fraction of the eastward transport in the upper ocean circulates around the tips of the island from the western basin into the eastern basin.