cssi/SciSciGPT-SciSciNet huggingface dataset:
Identification and Characterization of a Novel Plant Phospholipase D That Requires Polyphosphoinositides and Submicromolar Calcium for Activity in Arabidopsis

Phospholipase D (PLD; EC 3.1.4.4) has been proposed to be involved in a number of cellular processes including transmembrane signaling and membrane deterioration. PLD previously described from various plant sources generally requires millimolar ranges of calcium for optimal activity. In this study, we genetically suppressed the expression of this conventional PLD in Arabidopsis by introducing an antisense PLD cDNA. However, both the antisense transgenic and wild-type plants showed comparable PLD activity in the presence of submicromolar concentrations of calcium and phosphatidylinositol 4, 5-bisphosphate using phosphatidylcholine as a substrate. This new PLD activity was partially stimulated by phosphatidylinositol 4-phosphate, but not by other phospholipids, including phosphatidylinositol, phosphatidylserine, phosphatidylglycerol, phosphatidic acid, or phosphatidylcholine. Its requirement for polyphosphoinositides was further supported by its ability to be inhibited by neomycin. The polyphosphoinositide-dependent PLD requires calcium for activity, but no magnesium. The calcium stimulation was observed in the nanomolar range and reached a plateau at 5 microM calcium. The findings of this study demonstrate the presence of different PLDs that are regulated in a distinct manner in plants. The potential significance of a PLD that is regulated by polyphosphoinositides and physiological concentrations of Ca2+ is discussed.
Certification-cognizant scheduling of tasks with pessimistic frequency specification

In modern embedded platforms, safety-critical functionalities that must be certified correct to very high levels of assurance may co-exist with less critical software that are not subject to certification requirements. Upon such platforms one seeks to satisfy two, sometimes contradictory, goals: (i) being able to certify the safety-critical functionalities under very conservative assumptions, and (ii) ensuring high utilization of platform resources even when actual run-time behavior does not live up to such pessimistic expectations. This paper describes efforts at designing scheduling algorithms that balance these two requirements, when scheduling recurrent tasks that are triggered by external events of unknown exact frequency.
Treatment and outcome of patients with chest wall recurrence after mastectomy and breast reconstruction

Abstract Background Chest wall recurrence (CWR) in the setting of previous mastectomy and breast reconstruction can pose complex management dilemmas for clinicians. We examined the impact of breast reconstruction on the treatment and outcomes of patients who subsequently developed a CWR. Methods Between 1988 and 1998, 155 breast cancer patients with CWR after mastectomy were evaluated at our center. Of these patients, 27 had previously undergone breast reconstruction (immediate in 20; delayed in 7). Clinicopathologic features, treatment decisions, and outcomes were compared between the patients with and without previous breast reconstruction. Nonparametric statistics were used to analyse the data. Results There were no significant differences between the reconstruction and no-reconstruction groups in time to CWR, size of the CWR, number of nodules, ulceration, erythema, and association of CWR with nodal metastases. In patients with previous breast reconstruction, surgical resection of the CWR and repair of the resulting defect tended to be more complex and was more likely to require chest wall reconstruction by the plastic surgery team rather than simple excision or resection with primary closure (26% [7 of 27] versus 8% [10 of 128], P = 0.013). Risk of a second CWR, risk of distant metastases, median overall survival after CWR, and distant-metastasis-free survival after CWR did not differ significantly between patients with and without previous breast reconstruction. Conclusions Breast reconstruction after mastectomy does not influence the clinical presentation or prognosis of women who subsequently develop a CWR. Collaboration with a plastic surgery team may be beneficial in the surgical management of these patients.
Wages, union membership, and public sector bargaining legislation: Simultaneous equations with an ordinal qualitative variable

A simultaneous equations model of teachers’ wages and unionization is constructed. The exogenous impact of collective bargaining legislation is captured by conditioning the wage-union system on an ordinal qualitative variable. A new estimation method involving N-chotomous probit and two-stage least squares is developed. The estimation results are consistent with a private interest theory of regulation, predicting that legislators will avoid direct subsidization of teacher wages. By comparison it is also shown that a conventional dummy variable specification of the qualitative legislative outcomes will yield misleading results.
EM Algorithm for Mapping Quantitative Trait Loci in Multivalent Tetraploids

Multivalent tetraploids that include many plant species, such as potato, sugarcane, and rose, are of paramount importance to agricultural production and biological research. Quantitative trait locus (QTL) mapping in multivalent tetraploids is challenged by their unique cytogenetic properties, such as double reduction. We develop a statistical method for mapping multivalent tetraploid QTLs by considering these cytogenetic properties. This method is built in the mixture model-based framework and implemented with the EM algorithm. The method allows the simultaneous estimation of QTL positions, QTL effects, the chromosomal pairing factor, and the degree of double reduction as well as the assessment of the estimation precision of these parameters. We used simulated data to examine the statistical properties of the method and validate its utilization. The new method and its software will provide a useful tool for QTL mapping in multivalent tetraploids that undergo double reduction.
2009 Special Issue: Valuation of uncertain and delayed rewards in primate prefrontal cortex

Humans and animals often must choose between rewards that differ in their qualities, magnitudes, immediacy, and likelihood, and must estimate these multiple reward parameters from their experience. However, the neural basis for such complex decision making is not well understood. To understand the role of the primate prefrontal cortex in determining the subjective value of delayed or uncertain reward, we examined the activity of individual prefrontal neurons during an inter-temporal choice task and a computer-simulated competitive game. Consistent with the findings from previous studies in humans and other animals, the monkey's behaviors during inter-temporal choice were well accounted for by a hyperbolic discount function. In addition, the activity of many neurons in the lateral prefrontal cortex reflected the signals related to the magnitude and delay of the reward expected from a particular action, and often encoded the difference in temporally discounted values that predicted the animal's choice. During a computerized matching pennies game, the animals approximated the optimal strategy, known as Nash equilibrium, using a reinforcement learning algorithm. We also found that many neurons in the lateral prefrontal cortex conveyed the signals related to the animal's previous choices and their outcomes, suggesting that this cortical area might play an important role in forming associations between actions and their outcomes. These results show that the primate lateral prefrontal cortex plays a central role in estimating the values of alternative actions based on multiple sources of information.
Functional outcome of collagenase injections compared with fasciectomy in treatment of Dupuytren’s contracture

Background This study was designed to provide comparative information on the safety and efficacy of injection with collagenase clostridium histolyticum (CCH) and fasciectomy for patients with Dupuytren’s contracture (DC).
Detection of a Severe Isolate of Impatiens Necrotic Spot Virus Infecting Lisianthus in Florida.

In May 1997, inclusions typical of a tospovirus were visualized by light microscopy in leaf tissue of lisianthus (Eustoma grandiflorum) exhibiting stunting, necrotic ringspots, leaf distortion, and systemic necrosis. Wilting and plant death were the final symptoms observed. Affected plants occurred at low incidence (<0.1%) in greenhouse-grown lisianthus in Manatee County, FL. Symptomatic tissue tested positive for impatiens necrotic spot virus (INSV) and negative for tomato spotted wilt virus (TSWV) with enzyme-linked immunosorbent assay (ELISA; Agdia, Elkhart, IN). Mechanical transmission of the virus to lisianthus and tomato was attempted by triturating 1 g of symptomatic leaf tissue in 7 ml of a buffer consisting of 0.01 M Tris and 0.01 M sodium sulfite, pH 7.3. Six plants of lisianthus cv. Maurine Blue and three of tomato (Lycopersicon esculentum) cv. Lanai at the second true-leaf stage were inoculated following abrasion of leaves with Carborundum. An equal number of controls were inoculated with buffer alone. Plants were maintained in a controlled environment chamber with a 12-h photoperiod, day/night temperatures of 21/16°C, and light intensity of 120 μE · s-l · m-2. Transmission rates were 100 and 0% to lisianthus and tomato, respectively. Chlorotic local lesions followed by chlorotic ringspots were observed in inoculated lisianthus leaves 4 days after inoculation. Stunting, leaf distortion, and necrotic ringspots appeared in noninoculated leaves of lisianthus plants within 3 to 4 weeks after inoculation. Buffer-inoculated lisianthus and all tomato plants remained symptomless and tested negative for INSV by ELISA. All symptomatic lisianthus tested positive for INSV by ELISA. The symptoms we observed in lisianthus due to infection by INSV were more severe than those previously reported in this host (1,2). The occurrence of such strains of INSV at high incidences could pose a significant threat for commercial lisianthus production. References: (1) M. K. Hausbeck et al. Plant Dis. 76:795, 1992. (2) H. T. Hsu and R. H. Lawson. Plant Dis. 75:292,1991.
Positron annihilation gamma rays from novae

The potential for observing annihilation gamma rays from novae is investigated. These gamma rays, a unique signature of the thermonuclear runaway models of novae, would result from the annihilation of positrons emitted by beta(+)-unstable nuclei produced near the peak of the runaway and carried by rapid convection to the surface of the nova envelope. Simple models, which are extensions of detailed published models, of the expansion of the nova atmospheres are evolved. These models serve as input into investigations of the fate of nearby Galactic fast novae could yield detectable fluxes of electron-positron annihilation gamma rays produced by the decay of N-13 and F-18. Although nuclear gamma-ray lines are produced by other nuclei, it is unlikely that the fluxes at typical nova distances would be detectable to present and near-future instruments.
The Interaction of Thioredoxin with Txnip: Evidence for Formation of a Mixed Disulfide by Disulfide Exchange

The thioredoxin system plays an important role in maintaining a reducing environment in the cell. Recently, several thioredoxin binding partners have been identified and proposed to mediate aspects of redox signaling, but the significance of these interactions is unclear in part due to incomplete understanding of the mechanism for thioredoxin binding. Thioredoxin-interacting protein (Txnip) is critical for regulation of glucose metabolism, the only currently known function of which is to bind and inhibit thioredoxin. We explored the mechanism of the Txnip-thioredoxin interaction and present evidence that Txnip and thioredoxin form a stable disulfide-linked complex. We identified two Txnip cysteines that are important for thioredoxin binding and showed that this interaction is consistent with a disulfide exchange reaction between oxidized Txnip and reduced thioredoxin. These cysteines are not conserved in the broader family of arrestin domain-containing proteins, and we demonstrate that the thioredoxin-binding property of Txnip is unique. These data suggest that Txnip is a target of reduced thioredoxin and provide insight into the potential role of Txnip as a redox-sensitive signaling protein.
The Membrane Potential and its Representation by a Constant Electric Field in Computer Simulations

A theoretical framework is elaborated to account for the effect of a transmembrane potential in computer simulations. It is shown that a simulation with a constant external electric field applied in the direction normal to the membrane is equivalent to the influence of surrounding infinite baths maintained to a voltage difference via ion-exchanging electrodes connected to an electromotive force. It is also shown that the linearly-weighted displacement charge within the simulation system tracks the net flow of charge through the external circuit comprising the electromotive force and the electrodes. Using a statistical mechanical reduction of the degrees of freedom of the external system, three distinct theoretical routes are formulated and examined for the purpose of characterizing the free energy of a protein embedded in a membrane that is submitted to a voltage difference. The W-route is constructed from the variations in the voltage-dependent potential of mean force along a reaction path connecting two conformations of the protein. The Q-route is based on the average displacement charge as a function of the conformation of the protein. Finally, the G-route considers the relative charging free energy of specific residues, with and without applied membrane potentials. The theoretical formulation is illustrated with a simple model of an ion crossing a vacuum slab surrounded by two aqueous bulk phases and with a fragment of the voltage-sensor of the KvAP potassium channel.
Differential behavioral and neurochemical effects of exercise, reboxetine and citalopram with the forced swim test.

Abstract Aims In this study, we investigated whether short-term exercise, known to promote hippocampal brain-derived neurotrophic factor (BDNF) expression, would also enhance activity in the Porsolt forced swim test (FST), a model for assessing antidepressant efficacy. We also wished to determine whether exercise combined with antidepressants would be more effective at modifying behavior in the FST than either intervention alone. In parallel with this, we also expected that these interventions would preserve post-stress levels of BDNF, and that antidepressants designed to selectively enhance noradrenergic or serotonergic neurotransmission (reboxetine or citalopram, respectively) would have differential effects on behavior and BDNF expression. Main methods Male Sprague-Dawley rats were treated with exercise (voluntary wheel running), reboxetine, citalopram, or the combination of exercise and each antidepressant, for 1 week. At the end of this period, a subset of animals from each treatment group underwent the FST. Post-stress levels of hippocampal BDNF mRNA were then quantified via in situ hybridization. Key findings Our results indicate that while both exercise and antidepressant treatment preserved post-stress levels of hippocampal BDNF mRNA, each intervention led to a unique behavioral profile in the FST. We found that antidepressant treatment increased swimming time in the FST, but that exercise decreased swimming time. While the combination of reboxetine-plus-exercise led to an increase in climbing and diving, citalopram-plus-exercise reduced these behaviors. Significance It is possible that active behaviors during the FST, though specific to antidepressant medications, may not reflect increased hippocampal BDNF expression or other survival- associated benefits.
Variations in Bull Semen and their Relation to Fertility

Summary 1. A study of the semen of ten bulls used in the University of Missouri dairy herd has been made and the semen properties compared with the bulls’ breeding records. 2. The property of the semen most nearly correlated with fertility was the time of survival with vigorous motility hi semen stored at 40° Fahrenheit. 3. Among the different bulls, other properties of the semen such as pH, concentration, volume, percentage of abnormal spermatozoa, and initial motility were not correlated with the bull's fertility or time of survival with good motility except in the case of one bull of poor fertility which produced semen very high in abnormalities and very low in initial motility. 4. Among separate ejaculates from the same bull initial motility was roughly correlated with viability in storage. 5. Wide variations in all properties of the semen were observed, among ejaculates of different bulls as well as among ejaculates of the same bull. 6. It is proposed that a bull's fertility should be rated from examinations of at least five semen samples collected over a period of at least two weeks, and that the suitability for use or storage of a sample of semen from a fertile bull can best be determined at time of collection by examination for motility.
A note on the predictive validity of the CETSCALE

Consumers’ perceptions of the morality of buying foreign products, or consumer ethnocentric tendencies, are becoming an increasingly important issue for marketers in the global environment. The predictive validity of Shimp and Sharma’s (1987) CETSCALE was tested in a nationwide mail survey. The scale is shown to be a much stronger predictor of import buying behavior than are demographic variables. The ability of the scale to predict purchase behavior does not, however, appear to be consistent across the two products tested.
Professional portrait studio for amateur digital photography

We describe how to build a professional portable portrait studio that can be used with any consumer camera. The studio allows effortless off-line chroma-key insertion of backgrounds. Digital consumer cameras are designed for delivering acceptable images in typical outdoor or small room situations. The cameras fail when tungsten filament lamps are used. The built-in flash tube is too weak to fill the background in a studio setting and cannot be used to trigger professional electronic-flash lamps because the camera's firmware computes the exposure under the assumption that only the build-in flash tube supplies light to the scene when it is activated. A further problem is the position of the lamps. In the case of digital cameras the position is much more delicate than for silver halide film cameras because the sensor's dynamic range is very small and unwanted shadows are easily created. We present two different lamp set-ups for different size rooms.© (1998) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Numerical Formulation of the Effective Medium Approximation: Illustrative Examples and Application to Organic Semiconductors

The effective medium approximation (EMA) approach to calculating the macroscopic properties of disordered materials from an average of microscopic interactions is logically divided into two parts. First, an expression based on the microscale physics of constituents embedded in the effective medium is derived. Second, a configurational average of some sort over is performed, leading to an equation for an effective parameter, which is then solved. Based on this division, we present a numerical approach to the EMA in which the effective parameter ξe satisfies (1) % MathType!MTEF!2!1!+- % feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaam4zamaabm % aabaGaeqOVdG3aaSbaaSqaaiaadwgaaeqaaaGccaGLOaGaayzkaaGa % eyypa0ZaaaWaaeaacaWGMbWaaeWaaeaacqaHdpWCcaGGSaGaeqOVdG % 3aaSbaaSqaaiaadwgaaeqaaaGccaGLOaGaayzkaaaacaGLPmIaayPk % JaGaeyypa0Zaa8qaaeaacaWGMbWaaeWaaeaacqaHdpWCcaGGSaGaeq % OVdG3aaSbaaSqaaiaadwgaaeqaaaGccaGLOaGaayzkaaaaleqabeqd % cqGHRiI8aOGaeqyWdi3aaeWaaeaacqaHdpWCaiaawIcacaGLPaaaca % WGKbGaeq4WdmNaeyypa0JaaGimaiaac6caaaa!5AED! $$g\left( {{\xi _e}} \right) = \left\langle {f\left( {\sigma,{\xi _e}} \right)} \right\rangle = \int {f\left( {\sigma,{\xi _e}} \right)} \rho \left( \sigma \right)d\sigma = 0.$$ Here, σ represents possible configurations of the system, i.e. some variable of the physical formulation with respect to which we have knowledge of both i) microscale interactions and ii) the distribution of constituents; f represents our knowledge of the microscale interactions as a function of σ, and ρ represents our knowledge of the distribution of the configurations/constituents with respect to σ. Then g is the expectation of f. The equation says that the average of the microscale interactions embodied in f, which is a function of the effective parameter ξe, over the possible configurations of the system represented by ρ(σ), is zero. This equation allows us to determine the effective parameter ξe, which, for example, we can compare to experiment, or use in a drift/diffusion type of macroscopic simulation. A key point is that our explicit formulation allows specifying ρ and f numerically (e.g. via Monte Carlo simulation). We present both simple illustrative examples, as well as a realistic application to hopping transport in organic photovoltaics simulation. Preliminary results from this numerical EMA match experimental data remarkably well.
Insect Innate Immunity Database (IIID): An Annotation Tool for Identifying Immune Genes in Insect Genomes

The innate immune system is an ancient component of host defense. Since innate immunity pathways are well conserved throughout many eukaryotes, immune genes in model animals can be used to putatively identify homologous genes in newly sequenced genomes of non-model organisms. With the initiation of the “i5k” project, which aims to sequence 5,000 insect genomes by 2016, many novel insect genomes will soon become publicly available, yet few annotation resources are currently available for insects. Thus, we developed an online tool called the Insect Innate Immunity Database (IIID) to provide an open access resource for insect immunity and comparative biology research (http://www.vanderbilt.edu/IIID). The database provides users with simple exploratory tools to search the immune repertoires of five insect models (including Nasonia), spanning three orders, for specific immunity genes or genes within a particular immunity pathway. As a proof of principle, we used an initial database with only four insect models to annotate potential immune genes in the parasitoid wasp genus Nasonia. Results specify 306 putative immune genes in the genomes of N. vitripennis and its two sister species N. giraulti and N. longicornis. Of these genes, 146 were not found in previous annotations of Nasonia immunity genes. Combining these newly identified immune genes with those in previous annotations, Nasonia possess 489 putative immunity genes, the largest immune repertoire found in insects to date. While these computational predictions need to be complemented with functional studies, the IIID database can help initiate and augment annotations of the immune system in the plethora of insect genomes that will soon become available.
Prioritizing Molecular Signatures by Combining ACGH and Global Gene Expression Profiling

aCGH and expression profiling are two major high throughput genomic tools for functional genomics. Although each tool provides invaluable information, full exposition of disease initiation, progression, and manifestation requires synergistic integration of both measurements. In this paper, we will describe an approach to prioritize genomic regions or molecular signatures through the integration of aCGH and expression. Specifically, methods to prioritize genomic regions related to poor survival and related molecular signatures are described. Results obtained by applying our method to a publicly available data set are also presented.
Effects of CCN1 and Macrophage Content on Glioma Virotherapy: A Mathematical Model

Oncolytic virus (OV) is a genetically engineered virus that can selectively replicate in and kill tumor cells while not harming normal cells. OV therapy has been explored as a treatment for numerous cancers including glioblastoma, an aggressive and devastating brain tumor. Experiments show that extracellular matrix protein CCN1 limits OV therapy of glioma by orchestrating an antiviral response and enhancing the proinflammatory activation and migration of macrophages. Neutralizing CCN1 by antibody has been demonstrated to improve OV spread and tends to increase the time to disease progression. In this paper, we develop a mathematical model to investigate the effects of CCN1 on the treatment of glioma with oncolytic herpes simplex virus. We show that numerical simulations of the model are in agreement with the experimental results and then use the model to explore the anti-tumor effects of combining antibodies with OV therapy. Model simulations suggest that the macrophage content of the tumor is a critical factor to the success of OV therapy and to the reduction in tumor volume gained with the CCN1 antibody.
The influenza virus NS1 protein as a therapeutic target

Nonstructural protein 1 (NS1) of influenza A virus plays a central role in virus replication and blockade of the host innate immune response, and is therefore being considered as a potential therapeutic target. The primary function of NS1 is to dampen the host interferon (IFN) response through several distinct molecular mechanisms that are triggered by interactions with dsRNA or specific cellular proteins. Sequestration of dsRNA by NS1 results in inhibition of the 2'-5' oligoadenylate synthetase/RNase L antiviral pathway, and also inhibition of dsRNA-dependent signaling required for new IFN production. Binding of NS1 to the E3 ubiquitin ligase TRIM25 prevents activation of RIG-I signaling and subsequent IFN induction. Cellular RNA processing is also targeted by NS1, through recognition of cleavage and polyadenylation specificity factor 30 (CPSF30), leading to inhibition of IFN-β mRNA processing as well as that of other cellular mRNAs. In addition NS1 binds to and inhibits cellular protein kinase R (PKR), thus blocking an important arm of the IFN system. Many additional proteins have been reported to interact with NS1, either directly or indirectly, which may serve its anti-IFN and additional functions, including the regulation of viral and host gene expression, signaling pathways and viral pathogenesis. Many of these interactions are potential targets for small-molecule intervention. Structural, biochemical and functional studies have resulted in hypotheses for drug discovery approaches that are beginning to bear experimental fruit, such as targeting the dsRNA-NS1 interaction, which could lead to restoration of innate immune function and inhibition of virus replication. This review describes biochemical, cell-based and nucleic acid-based approaches to identifying NS1 antagonists.
Prediction of school achievement from motivation, personality, and ability measures.

Personality (16 PF), Motivation (MAT) and Ability (CFIQ) tests were given to 169 6th grade and 142 7th grade children. Approximately 3 mo. later the same children were given standardized achievement tests (ETS) in the areas of mathematics, science, social studies, and reading and their performance on these subjects was predicted from the personality, motivation and ability measures. It was concluded that personality, motivation and ability variables each contributed independently and significantly to the prediction of school achievement but that the pattern of relevant predictors varied with the achievement area.
Early fumonisin B1 toxicity in relation to disrupted sphingolipid metabolism in male BALB/c mice

Fumonisin B1 is a mycotoxin produced by Fusarium moniliforme, a common fungus in corn. It is known to cause a variety of diseases, including hepatic and renal degeneration in many species of laboratory and domestic animals. The known biochemical events in fumonisin B1 toxicity involve inhibition of ceramide synthase leading to disruption of sphingolipid metabolism. The effect of fumonisin B1 on ceramide and more complex sphingolipids in mice is not known. Groups of five male BALB/c mice each were injected with fumonisin B1 subcutaneously at doses of 0, 0.25, 0.75, 2.25, and 6.75 mg/kg body weight daily for 5 days. This protocol has been shown to produce a dose-dependent increase in apoptosis in liver and kidney of these animals. In the present study, liver, kidney, and brain were sampled and analyzed for free sphingoid bases and complex sphingolipids one day after the last treatment. A dose-related accumulation of free sphinganine and sphingosine was observed in liver and kidney, but not brain. The maximal increase in free sphinganine in kidney was 10-fold greater than in liver. Total phospholipids increased only in liver, whereas ceramide levels were not consistently altered in liver, kidney, or brain. In liver and kidney, fumonisin B1 treatment increased the sphinganine-containing complex sphingolipids, but no effect was observed on sphingosine-containing complex sphingolipids. No changes in complex sphingolipids were observed in brain. In liver, there was a close correlation between the extent of free sphinganine accumulation, and apoptosis and hepatopathy. This correlation was also evident in kidney but to a lessor extent. Nonetheless, the apoptosis and nephropathy occurred with little or no change in the levels of ceramide or more complex sphingolipids.
Cell biology: shape-shifting protein channel.

Newly made proteins are moved across cellular membranes through a protein channel. The crystal structure of this channel is now revealed and confirms expectations that it must change shape to allow proteins to pass.
Utilization of Shallow-Water Seagrass Detritus by Carribbean Deep-Sea Macrofauna: δ 13 C Evidence

Abstract Three dives were made using the DSRV Alvin in the deep-sea basin north of St. Croix, Virgin Islands. Detrital seagrasses and macrofaunal distributions at 2455 to 3950 m depth were assessed quantitatively. Counts of the manatee grass Syringodium filiforme (ca. 5 to 100 blades m−2) contrasted sharply with those of the turtle grass Thalassia testudinum (ca. 0.1 to 2.0 blades m−2), reflecting an abundance proportional to previously reported export rates of the same species from Tague Bay, a nearby shallow source lagoon. Of the macrofaunal consumers that could potentially utilize this detrital nutrient source, three species of holothurians (Mesothuria verrilli, Psychropotes semperiana, and Benthodytes linqua) and two species of sea urchins (Hygrosoma petersi and Salencidaris profundi) were collected and/or observed. Gut content analyses revealed that all three holothurians deposit-feed on sediment and at least one species of sea urchin (H. petersi) feeds almost exclusively on Syringodium. Carbon: nitrogen analyses of naturally occurring abyssal Thalassia detritus showed very low nitrogen content (0.21% N) and a high C:N ratio (214.8), thus yielding a loo nutritional value. Fresh Thalassia blades held in a litter bag experiment (by R. D. Turner) at 3950 m changed little in nitrogen content and C:N ratio after four years. A comparison was made of the stable carbon isotope ratios of 13C:12C for abyssal seagrass detritus and other potential carbon sources with those for tissues from the holothurian and urchin consumers. The results indicate that a significant proportion of the nutrition of both groups is derived from detrital seagrasses either by direct consumption (sea urchins) or indirectly by deposit-feeding on sediments enriched by decomposed seagrasses (holothurians).
Transcriptional profiling of gastric epithelial cells infected with wild type or arginase-deficient Helicobacter pylori

Background: Helicobacter pylori causes acute and chronic gastric inflammation induced by proinflammatory cytokines and chemokines secreted by cells of the gastric mucosa, including gastric epithelial cells. Previous studies have demonstrated that the bacterial arginase, RocF, is involved in inhibiting T cell proliferation and CD3ζ expression, suggesting that arginase could be involved in a more general dampening of the immune response, perhaps by down-regulation of certain pro-inflammatory mediators. Results: Global transcriptome analysis was performed on AGS gastric epithelial cells infected for 16 hours with a wild type Helicobacter pylori strain 26695, an arginase mutant (rocF- )o r arocF + complemented strain. H. pylori infection triggered altered host gene expression in genes involved in cell movement, death/growth/proliferation, and cellular function and maintenance. While the wild type strain stimulates host inflammatory pathways, the rocF- mutant induced significantly more expression of IL-8. The results of the microarray were verified using real-time PCR, and the differential levels of protein expression were confirmed by ELISA and Bioplex analysis. MIP-1B was also significantly secreted by AGS cells after H. pylori rocF- mutant infection, as determined by Bioplex. Even though not explored in this manuscript, the impact that the results presented here may have on the development of gastritis, warrant further research to understand the underlying mechanisms of the relationship between H. pylori RocF and IL-8 induction.
Platelets orchestrate remote tissue damage after mesenteric ischemia-reperfusion.

Ischemia-reperfusion (I/R) injury is a leading cause of morbidity and mortality. A functional role for platelets in tissue damage after mesenteric I/R is largely unknown. The hypothesis that mesent...
Loading salts from solutions into nanopores: Model and its test

Abstract A model has been derived to estimate the fullness of nanopores loaded with salts from their solutions. The fullness is defined as a fraction of the filled volume to the total available volume of the nanopores and expressed as a function of the solution concentration and the number of loadings. The model has been tested on silica samples of 6–30 nm pore diameters loaded with ammonium chloride and ammonium nitrate. An assumption of cylindrical pore shape allows the model to be used for estimating the height of the layer deposited on the pore walls.
CNS monoamine levels and the effect of DSP4 on ethanol sensitivity in LS and SS mice.

Abstract Brain area monoamine levels were determined in selectively-bred ethanol sensitive (LS) and insensitive (SS) mice. Norepinephrine, dopamine and serotonin were measured using high performance liquid chromatography coupled with electrochemical detection. Brain regions studied included cerebellum, brain stem, striatum, frontal cortex, hippocampus and hypothalamus. LS and SS mice exhibited similar regional monamine levels with the exception of differences in brain stem and cerebellar norepinephrine levels. The role of norepinephrine in regulating ethanol sensitivity of these mice was investigated using the neurotoxin, DSP4 (selectively lesions central noradrenergic pathways). Treatment with DSP4 did not alter ethanol sensitivitiy in the LS or SS mice, measured by duration of righting response loss and blood ethanol concentration at its recovery. Differences in brain stem and cerebellar norepinephrine levels between the LS and SS mice were considerably smaller than the large decreases in levels produced in both lines by DSP4. It is concluded that although synaptically-released monoamines may influence ethanol responses, norepinephrine probably does not directly mediate differences in behavioral sensitivity to ethanol between these mouse lines.
An Analysis of the Sources of Earnings Variation among Brazilian Males.

Abstract The paper uses data from the 1980 Brazilian census to analyse the sources of earnings variation among males with emphasis on the role of education, labor market segmentation, geographic location and sector of economic activity. The results indicate a sizeable private rate of return to investment in education across labor market “segments”, especially among rural workers and the self-employed. Such a finding is upheld after econometric corrections for dependent variable (earnings) truncation and selectivity bias regarding who enters a particular economic sector. However, regional earnings differentials persist even after adjustment for a set of personal and job characteristics. Thus, internal migration still has a role to play towards reducing regional earnings disparities.
Computational study of tin-catalyzed Baeyer-Villiger reaction pathways using hydrogen peroxide as oxidant

Density functional theory has been used to study several possible reaction mechanisms for tin-catalyzed Baeyer−Villiger oxidation of the model ketone acetone with hydrogen peroxide. The tin catalyst has been modeled with unconstrained single coordination sphere clusters using a B3LYP/ECP methodology. The Baeyer−Villiger reaction mechanism involves two principal steps: (1) addition of the hydrogen peroxide oxidant and the ketone substrate to form the Criegee intermediate and (2) Baeyer−Villiger rearrangement of the Criegee intermediate to yield the ester product. The Gibbs activation barriers for the addition and rearrangement steps in the noncatalyzed mechanism are 39.8 and 41.7 kcal/mol, respectively. In the absence of solvent coordination, tin activates hydrogen peroxide to produce a tin hydroperoxo (SnOOH) intermediate with a Gibbs activation barrier of 15.4 kcal/mol. Water molecules coordinating the tin active site facilitate proton transfer and lower the Gibbs activation barrier for tin hydroperoxo ...
Interaction of thrombin with human platelets.

Summary The first step in thrombin-induced aggregation of blood platelets is binding of thrombin to specific receptors on the platelet membrane. Elucidation of the nature of this receptor in human platelets was attempted using radioactively labelled thrombin. In disc gel electrophoresis an extract of thrombin-treated platelets showed one peak of radioactivity near the origin. Gel filtration of the platelet extract through Sephadex G-200 showed mainly one protein peak at the void volume which contained radioactivity. After column fractionation the final isolate reacted with antiserum to thrombosthenin but did not react with antiserum to serum, fibrinogen or soluble platelet proteins. Gel electrophoresis of the reduced isolate in the presence of sodium dodecyl sulphate showed a pattern similar to thrombosthenin. To explore the possibility that thrombosthenin might be the receptor of thrombin, attempts were made to complex the receptor sites with thrombosthenin antibody or its univalent fragment. It was observed that complexing these receptors potentiates, rather than inhibits, platelet aggregation by thrombin or by adenosine diphosphate. Univalent fragment of antibody to albumin failed to cause this potentiation. Thus, blocking of the thrombosthenin sites is necessary for sensitization of platelets.
The transcription factor, Lmx1b, is necessary for the development of the principal trigeminal nucleus-based lemniscal pathway

Little is known of transcriptional mechanisms underlying the development of the trigeminal (V) principal sensory nucleus (PrV), the brainstem nucleus responsible for the development of the whisker-to-barrel cortex pathway. Lmx1b, a LIM homeodomain transcription factor, is expressed in embryonic PrV. In Lmx1b knockout ((-)(/)(-)) mice, V primary afferent projections to PrV are normal, albeit reduced in number, whereas the PrV-thalamic lemniscal pathway is sparse and develops late. Excess cell death occurs in the embryonic Lmx1b(-)(/)(-) PrV, but not in Lmx1b/Bax double null mutants. Expression of Drg11, a downstream transcription factor essential for PrV development and pattern formation, is abolished in PrV, but not in the V ganglion. Consequently, whisker patterns fail to develop in PrV by birth. Rescued PrV cells in Lmx1b/Bax double (-)(/)(-)s failed to rescue whisker-related PrV pattern formation. Thus, Lmx1b and Drg11 may act in the same genetic signaling pathway that is essential for PrV pattern formation.
SEX DIFFERENCES IN THE SERUM CHOLESTEROL RESPONSE TO STRESS IN MONKEYS.

THE investigation reported here was undertaken as an initial step in the assessment of central nervous system influences on the transport of serum lipids, with particular reference to their possible role in the pathogenesis of atherosclerosis. The experimental situation dictated that monkeys be moderately restrained for extended periods of time in order that the neural variables could be manipulated under controlled conditions. It became apparent, however, that such restraint itself was a significant variable affecting the level of cholesterol and other lipids in the serum, hence this study was designed to investigate this aspect of the problem in a detailed fashion.
Substitution of In for Si adatoms and In-induced charge redistribution of the Si(1 1 1)-(7×7) surface

Abstract The adsorption mechanism and the origin of the In-induced surface electronic states of the Si(1 1 1)-(7×7) surface have been studied using bias-dependent scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS). At very low In coverages, bias-dependent STM images show that some of the adatoms have either slightly higher or lower apparent height in the filled-state topographic images, while the empty-state images are completely identical to those of the clean Si(1 1 1)-(7×7). These peculiar features are interpreted as being caused by three different adsorption mechanisms: the substitution of In for Si adatoms in the 7×7 unit cell; In atom adsorption on Si adatoms; and charge redistribution due to the adsorption of In atoms on Si rest-atom dangling bonds (DBs). These mechanisms involve covalent bonding which removes intrinsic metallic surface states caused by partially occupied Si adatom DBs, opening a band gap at the surface and producing a metal–insulator transition.
A case of Cronkhite–Canada syndrome presenting with adenomatous and inflammatory colon polyps

A 72-year-old man was evaluated for dysgeusia, diarrhea and ano-rexia. 3 months earlier he began to experience taste changes, a de-cline in appetite and 3–7 loose, non-bloody stools per day, followed by nausea, lower abdominal cramping and weight loss of 22.68 kg. Cronkhite–Canada syndrome was diagnosed and treatment started with prednisone, a histamine-2-receptor blocker and oral micronutrient supplementation. All visible polyps were removed and subtotal colectomy with end-to-side ileorectostomy per-formed.
Municipal Support of Biomedical Research

ABSTRACTDifficulties in funding promising young researchers at the outset of their careers have led to efforts to find new kinds of sources of support. In the past four years the municipal administration in New York City has funded a program to help support new junior research faculty in the city's
A simulation clock-based solution to the frequency domain experiment indexing problem

Frequency domain experiments (FDEs) were introduced to perform system sensitivity analysis for factor screening in complex simulations. Since then, FDEs have been used in simulation optimization, gradient estimation and several other research areas. Central to all FDEs is the Fourier analysis of a sampled data sequence. The choice of an appropriate oscillation index and associated sampling index for the sampled data sequence has been a much researched topic now known in the FDE literature as the indexing problem. In this paper we address the indexing problem by providing some general guidelines on the selection of the oscillation index and considering the implementation of two different indices: the continuous global simulation clock time and an inherently discrete index such as the job index in a simple queuing system. We show that the choice of a discrete oscillation index has to be made in an application-dependent manner and does not generalize well to different discrete-event simulation scenarios. In contrast, because the notion of time underlies all discrete-event simulations, the global simulation clock time is a natural choice for an FDE indexing scheme. Two different schemes for the global simulation clock time are presented. The results are illustrated via different scenarios commonly found in simulations of queuing networks and manufacturing systems.
Positive drinking consequences among hazardous drinking college students

Negative drinking consequences in college students have been well studied, but emerging evidence points to a role for positive drinking consequences in predicting alcohol related problems. Positive drinking consequences appear to be distinct from other drinking constructs such as drinking expectancies and drinking motives. However, no work has evaluated the role of positive drinking consequences in hazardous drinking college students, a population at high risk for alcohol related problems. The goal of the current study was to examine the effect of positive drinking consequences on problem drinking and alcohol problem recognition in a hazardous drinking college sample. Participants (N=222) were hazardous drinking undergraduate students completing a battery of self-report measures about alcohol use. Findings indicated that positive drinking consequences predicted problem drinking above and beyond other related constructs including positive drinking motives (i.e. enhancement and social). However, positive drinking consequences did not appear to play a significant role in alcohol problem recognition. Future research directions and implications for interventions with hazardous drinking college students are discussed.
Climate shocks and political violence

Abstract The dominant discourse on the security implications of climate change has asserted that acute environmental scarcity—such as that caused by drought—causes political violence. In contrast, we argue that there are good reasons why water scarcity might have a pacifying effect on armed conflict, and that political violence should be more prevalent during periods of comparatively better agro-climatic conditions. Political violence is more prevalent when basic needs are met and when the tactical environment is more conducive to attacks—conditions that hold when water is comparatively abundant. Empirically, this paper explores the relationship between environmental scarcity and political violence in a global sample of countries, 1970–2006. We find that water abundance is positively correlated with political violence, and that this relationship is stronger in less developed, more agriculturally dependent societies. These findings are robust to several different operationalizations of our variables. We conclude with a brief discussion of the policy implications of our findings.