cssi/SciSciGPT-SciSciNet huggingface dataset:
Involvement of sensory neuron-TRPV4 in acute and chronic itch behaviors

ABSTRACT Itch, particularly chronic itch, negatively impacts patients’ physical, social, and psychological well-being, leading to deterioration in their quality of life. Limited understanding of itch mechanisms hinders the development of effective antipruritic treatments.TRPV4, a multimodally activated nonselective cation channel, has been detected in sensory neurons of dorsal root and trigeminal ganglion (DRG, TG) and skin cells (e.g. keratinocytes, mast cells, and macrophages). Recent evidence from experimental and clinical relevant studies has implicated that TRPV4 in skin cells plays an important role in both acute and chronic itch. In contrast, little is known whether TRPV4 in sensory neurons directly contributes to scratching behaviors. Here we used sensory neuron-Trpv4 conditional knockout (cKO) mice to address this question. Our results showed that TRPV4 in sensory neurons contributes to scratching behavior evoked by histaminergic (histamine and 48/80) and partial histaminergic (5-HT), but not non-histaminergic (SLIGRL and CQ) pruritogens. Moreover, we observed that TRPV4 in sensory neurons is required for dry skin, but not allergic contact dermatitis, -associated chronic itch. These findings suggest that neuronal-TRPV4 might be specific for some forms of acute and chronic itch.
The Synechocystis ORF slr0201 product is involved in succinate dehydrogenase-mediated cyclic electron transfer around PSI

The Synechocystis sp. PCC 6803 open reading frame (ORF) slr0201 was originally annotated as heterodisulfide reductase B subunit (HdrB). The slr0201 encodes a 301-amino acid hypothetical protein with the predicted amino acid sequence significantly homologous to not only the HdrB from methanogenic bacteria, but also some novel succinate dehydrogenase C subunit (SdhC) found in Archaea and Campylobacter. Genetic manipulation via knocking-out approach created a{Delta} slr0201 mutant showing a{Delta} sdhB-like phenotype that was characterized by impaired succinate-dependent DCPIP reduction activities, reduced SDH-mediated respiratory electron transports, lower cellular contents of succinate and fumarate, slower KCN-induced increases in Chl fluorescence yield in the dark, and weak state 2/strong state 1 transitions, being indicative of a more oxidized PQ pool. In addition, slower re-reductions of the photosystem (PS) I reaction center P700 upon light-off were also monitored in the{Delta} slr0201, indicating functional involvements of Slr0201 in cyclic electron transfer around PSI. Both photoautptrophical and photomixotrophical growth rates of the{Delta} slr0201 strain resembled to those of the wild type, but substantial growth deteriorations occurred when arginine ([~]25 mM) or other two urea-cycle relevant amino acids (citrulline and ornithine) were added, which were attributed to generations and accumulations of certain hazardous metabolites. Based on the{Delta} sdhB-resembling phenotype, in conjunction with its high sequence similarities to some archaeal SdhC, we proposed that the slr0201 encodes a SDH function-relevant protein and is most likely the SdhC, a membrane anchoring subunit, which, while being genetically distinct from those in traditional bacterial SDH, belongs to the C subunit of novel archaeal SDH.
Mechanical Compression Creates a Quiescent Muscle Stem Cell Niche

Abstract Skeletal muscles can regenerate throughout life time from resident Pax7-expressing (Pax7+) muscle stem cells (MuSCs)1–3. Pax7+ MuSCs are normally quiescent and localized at a niche in which they are attached to the extracellular matrix basally and compressed against the myofiber apically3–5. Upon muscle injury, MuSCs lose apical contact with the myofiber and re-enter cell cycle to initiate regeneration. Prior studies on the physical niche of MuSCs focused on basal elasticity6,7, and significance of the apical force exerted on MuSCs remains unaddressed. Here we simulate MuSCs’ mechanical environment in vivo by applying physical compression to MuSCs’ apical surface. We demonstrate that compression drives activated MuSCs back to a quiescent stem cell state, even when seeded on different basal elasticities. By mathematical modeling and manipulating cell tension, we conclude that low overall tension combined with high edge tension generated by compression lead to MuSC quiescence. We further show that apical compression results in up-regulation of Notch downstream genes, accompanied by increased levels of nuclear Notch. The compression-induced nuclear Notch is ligand-independent, as it does not require the canonical S2-cleavage of Notch by ADAM10/17. Our results fill the knowledge gap on the role of apical tension for MuSC fate. Implications to how stem cell fate and activity are interlocked with the mechanical integrity of its resident tissue are discussed.
Barriers and facilitators for adopting a healthy lifestyle among Latina cancer survivors: A qualitative descriptive study.

PURPOSE Cancer is the leading cause of death among Hispanics/Latinos in the USA. Latina cancer survivors experience higher symptom burden than other cancer survivors. A healthy lifestyle can decrease recurrent cancer risk, increase well-being, and may decrease symptom burden in cancer survivors. The purpose of this study was to explore the barriers and facilitators for adopting healthy lifestyle behaviors among Latina cancer survivors. METHODS Using the Health Belief Model as the theoretical framework, qualitative descriptive methodology was used for secondary analysis of data from a previously conducted randomized clinical trial. Transcripts from the telephone health coaching calls, analyzed in the original language (English or Spanish), were used for this qualitative analysis. RESULTS Intervention telephone call transcript data from Latina cancer survivors (n = 14) were analyzed. Major themes were as follows: Perceived susceptibility to other chronic illnesses, perceived benefits of a healthy lifestyle, and perceived barriers and facilitators of adopting a healthy lifestyle. Lack of knowledge about healthy lifestyle behaviors could prevent participants from adopting a healthy lifestyle; gaining new knowledge about healthy lifestyle behaviors was a facilitator for changing lifestyle. Family responsibility and wearable technology could both prevent and motivate the participants to adopt a healthy lifestyle. CONCLUSION Developing culturally appropriate interventions for Latina cancer survivors is vital to decrease symptom burden and health risks, as well as improve health outcomes in this population.
Genes for asymmetry easily overruled

The hermit crab Clibanarius vittatus inhabits empty gastropod shells and is highly asymmetric. I have found that this asymmetry does not depend on initial possession of a shell, but can be lost within a few moults in the absence of shells, suggesting that the morphology has a genetic component but is environmentally regulated. The loss of dependence on shells has been implicated in the evolution of the nearly symmetrical, fully armoured king crabs and coconut crabs from hermit crab ancestors1,2. The first steps of such a transformation may thus have been much easier than previously thought3,4.
An Internet-Based Communication Network for Information Transfer During Patient Transitions from Skilled Nursing Facility to the Emergency Department

OBJECTIVES: To determine whether the implementation of an Internet-based communication system improves the amount of essential information conveyed between a skilled nursing facility (SNF) and the emergency department (ED) during patient care transitions. DESIGN: Interventional; before and after. SETTING: ED of an urban teaching hospital with approximately 55,000 visits per year and a 55-bed subacute free-standing rehabilitation facility (the SNF). PARTICIPANTS: All patients transferred from the SNF to the ED over 16 months. INTERVENTION: An Internet-based communication network with SNF–ED transfer form for communication during patient care transitions. MEASUREMENTS: Nine elements of patient information assessed before and after intervention through chart review. Secondary outcomes: changes in efficiency of information transfer and staff satisfaction. RESULTS: Two hundred thirty-four of 237 preintervention and all 276 postintervention care transitions were reviewed. The Internet communication network was used in 78 (26%) of all care transitions, peaking at 40% by the end of the study. There was more critical patient information (1.85 vs 4.29 of 9 elements; P<.001) contained within fewer pages of transfer documents (24.47 vs 5.15; P<.001) after the intervention. Staff satisfaction with communication was higher among ED physicians after the intervention. CONCLUSION: The use of an Internet-based system increased the amount of information communicated during SNF–ED care transitions and significantly reduced the number of pages in which this information was contained.
3-D Seismic Exploration Project, Ute Indian Tribe, Uintah and Ouray Reservation, Uintah County, Utah

The objectives of this North Hill Creek 3-D seismic survey were to: (1) cover as large an area as possible with available budget; (2) obtain high quality data throughout the depth range of the prospective geologic formations of 2,000' to 12,000' to image both gross structures and more subtle structural and stratigraphic elements; (3) overcome the challenges posed by a hard, reflective sandstone that cropped out or was buried just a few feet below the surface under most of the survey area; and (4) run a safe survey.
Two Methods for Load Balanced Distributed Adaptive Integration

Parallel subregion-adaptive integration often exhibits sequential behavior when applied to functions with difficult local problems such as boundary singularities. To correct this, one needs to balance the loads of the processors by providing all of them with a reasonably difficult part of the problem. In this paper, we present two distributed adaptive integration methods: one based on a global heap priority queue (distributed over the processors) which remains load balanced and assures that the subregions are processed according to their (global) priority (size of error) and one based on a local heap priority queue enhanced by receiverinitiated load balancing. We report results of both methods.
Longitudinal Impact of a Targeted Simulation Experience on High-Stakes Examination Outcomes

Abstract Background This study provides a longitudinal vantage point to demonstrate how a research-based approach to human patient simulation (HPS) utilization may affect didactic learning in nursing education. Methods The study used a quantitative, experimental, longitudinal, repeated measures design with baccalaureate nursing students (n = 94) who were enrolled in an adult health course. Results The data revealed an increase in Health Education Systems Incorporated© examination scores for students who participated in a content specific HPS versus those who did not. Conclusion The findings from this study provide quantitative evidence that HPS may be an effective teaching method for undergraduate nurse education.
Distinctive Properties of β-Glucosidases and Related Enzymes Derived from a Commercial Aspergillus niger Cellulase

Eight highly purified beta-glucosidases from Aspergillus niger were compared enzymatically, chemically, and immunologically. Ultraviolet spectra, pH-activity responses, substrate specificities, thermal stabilities, kinetic changes in the viscosity of substrate, Michaelis-Menten parameters, adsorption characteristics on cellulose, and exclusion characteristics on dextran gels were determined. The data indicate that the several components represent distinctly different enzymes in terms of mode of attack on substrate. The concept of partial denaturation of a single enzyme precursor is unable to explain the heterogeneity observed. Comparison of the effect of pH on hydrolysis of carboxymethylcellulose and cellohexaose suggests that a negative charge center on the substrate has a pronounced inhibitory effect on the enzymes.
State‐of‐Art Numerical Simulation of Glass Melting Furnaces

Le modele mathematique permet de decrire les processus suivant: la fonte du melange vitrifiable, la circulation du verre, le transfert de chaleur et l'affinage et l'homogeneisation
Electrodeposited Al―Mn alloys with microcrystalline, nanocrystalline, amorphous and nano-quasicrystalline structures

Abstract Al–Mn alloys with Mn content ranging from 0 to 15.8 at.% are prepared by electrodeposition from an ionic liquid at room temperature, and exhibit a remarkably broad range of structures. The alloys are characterized through a combination of techniques, including X-ray diffraction, electron microscopy and calorimetry. For alloys with Mn content up to 7.5 at.%, increasing Mn additions lead to a decrease in grain size of single-phase microcrystalline face-centered cubic (fcc) Al(Mn). Between 8.2 and 12.3 at.% Mn, an amorphous phase appears, accompanied by a dramatic reduction in the size of the coexisting fcc crystallites to the ∼2–50 nm level. At higher Mn contents, the structure nominally appears entirely amorphous, but is shown to contain order in the form of pre-existing nuclei of the icosahedral quasicrystalline phase. Additionally, nanoindentation tests reveal that the nanostructured and amorphous specimens have very high hardnesses that exhibit complex trends with Mn content.
Modeling Gas Hydrate Phase Equilibria in Laboratory and Natural Porous Media

A method to predict hydrate phase behavior in laboratory-prepared and natural porous media is presented. This model extends both the van der Waals and Platteeuw (vdWP) approach and our fugacity-based approach to porous media by accounting for the effects of both surface energy and pore size distribution. Our fugacity approach quantitatively predicts the equilibrium pressure−temperature relation for hydrates in laboratory porous media above the normal freezing point of water without any empirical corrections to the surface contact parameters, as have previously been required with the vdWP model. A pore size distribution model that depends on the soil type and pressure is developed and then used to predict methane hydrate formation in natural porous environments. The maximum depth of ocean hydrates using our fugacity-based model with the pore size correction is calculated for seven drilling sites. Our predictions for the hydrate depth have an average deviation of 4.9% compared to the experimental data, whic...
Divorce Among Sociologists Married to Sociologists

In a study of correlates of divorce in a sample of American sociologists, male sociologists whose first wives were sociology majors were found to be substantially more likely to have been divorced than male sociologists whose first wives had degrees in other fields. This finding rules out the categorical validity of the generalization that common interests are conducive to stability of marriages. Prevalence of an unusually secular orientation among sociology major wives is offered as a tentative explanation.
Effect of cosolvent additives on relative rates of photooxidation on semiconductor surfaces

The effect of solvent additives on the course of TiO2 photocatalyzed oxygenation of α-methylstyrene has been studied. While the addition of small amounts of nonhalogenated alcohols to TiO2 powders suspended in acetonitrile was found to decrease the rate of photooxygenation, added halogenated alcohols increase the rate of reaction. In addition, the solvent additives affect the observed product distribution.
Characterization of pore size distribution of packing materials used in perfusion chromatography using a network model

Abstract A network model is used to represent the porous structure existing in a column packed with perfusive stationary phase. By matching model simulations with experimental mercury intrusion data, characteristics of the pore size distribution (PSD) of perfusive particles can be calculated quantitatively. It was found that the distribution is biomodal, consisting of an interconnected porous structure of macropores (pore diameters of the order of 1000 A) and micropores (pore diameters of the order of 100 A). Two different types of perfusive packings (POROS I and Ii) were compared in terms of capacity and throughput capabilities with respect to their PSD. The sensitivity and validity of the model was corroborated by simulating intrusion experiments on blends of the perfusive packings. The simulated results compared very well with the experimental data. The network model was used to elucidate partinent parameters using perfusive packing such as surface area accessibility of various proteins and size-exclusion chromatography of polystyrene molecules. The agreement between experimental data and model predictions are excellent in both studies.
Money in Colonial Transition: Cowries and Francs in West Africa

For about five decades, the French colonial government in the Volta region of West Africa failed in its repeated attempts to replace the local monetary form of cowry shells with its own monetary system of francs, largely because of local opposition. This article provides an account of these events and explores the reasons for the opposition and why the opposition was successful. Despite government prohibition, the cowries even acquired increased vitality as they became the main money in the emerging urban market. Government measures were partly motivated by practical difficulties that stemmed from the conflicts that the colonial system and monetary policy generated. The article ends with a critical discussion of how money and the colonial transition are treated in anthropology.
A Newly Discovered Function for C1 Inhibitor, Removal of the Entire C1qr2s2Complex from Immobilized Human IgG Subclasses

Abstract A new function for C1 Inhibitor (C1 INH) is reported. C1 inhibitor dislodged the entire activated C1 complex (C1qr 2 s 2 ) from immobilized human IgG. C1 binding to doses of immobilized human IgG3, IgG1, or IgG2 was quantified as a function of time. When human serum, as a source of C1qr 2 s 2 , was added to relatively low doses of immobilized IgG, C1q binding peaked at 1.0 min then gradually decreased. However when purified C1q was applied to immobilized IgG, C1q binding did not diminish with time. The removal of C1q was duplicated by adding purified C1 INH to C1qr 2 s 2 which had been bound to immobilized IgG. The dislodgement of C1q from immobilized IgG required the presence of intact C1qr 2 s 2 and of C1 INH. This removal of C1q by purified C1 INH was prevented when activated C1s was used to neutralize C1 INH function or when relatively high levels of IgG were immobilized.
Cyanosis, interatrial communication, and normal pulmonary vascular resistance in adults.

Abstract We report 4 patients with atrial septal defect (ASD) and cyanosis who had otherwise normal intracardiac anatomy and normal pulmonary vascular resistance. Each patient underwent successful surgical repair, emphasizing the importance of thorough investigation of the adult patient with cyanosis secondary to ASD.
Shell structure in Difflugia Lobostoma observed by scanning and transmission electron microscopy.

Abstract Observations by scanning and transmission electron microscopy provide information about shells of Difflugia lobostoma which suggests a complex activity in shell construction. As observed by scanning microscopy, the shell consists of a single layer of sand grains which are organized into rosettes. The sand grains of the rosettes are different in size from those of flat areas between rosettes suggesting that the organism sorts these stones and places them according to size. Hydrofluoric acid treatment dissolves the sand but leaves a web of cement material intact. Examination of such acid treated specimens by transmission microscopy shows structure in the cement material of the shell, and granules of similar structure in the cell body. The rosette pattern observed differs from shell patterns in other species of Difflugia , and this suggests that shell structure may be species specific.
Thermodynamics of electrolyte mixtures. Activity and osmotic coefficients consistent with the higher-order limiting law for symmetrical mixing

The parameters for symmetrical mixing of ions of the same sign in the virial-coefficient (Pitzer) system are evaluated from literature data for 25°C in a manner consistent with the higher-order limiting law of Friedman. Twenty-four systems involve cation mixing with a common anion and fourteen involve anion mixing with a common cation. Heat of mixing data were similarly treated in a recent publication; the results give the temperature coefficients of some of these same parameters. The combined results yield the mixing parameters as functions of temperature on a basis both self-consistent and in accord with the limiting law. The results also yield, for a few systems without a common ion, predicted values in good agreement with experimental data.
A review of toxoplasmosis in cattle

Worldwide reports of natural and experimentally-induced Toxoplasma gondii infections in cattle are reviewed and tabulated. Serologic tests employed in most studies in the past are of suboptimal sensitivity for the diagnosis of T. gondii infection in cattle; therefore data need to be interpreted with caution. From the evidence available it is concluded that: T. gondii is probably not important in causing abortion or clinical illness in cattle but further experimental studies are desirable; T. gondii is eliminated quickly from bovine tissues; Whether beef plays a part in the epidemiology of toxoplasmosis is unresolved; Milk from T. gondii-infected cows is of negligible importance in the epidemiology of toxoplasmosis.
Trafficking of FoxP3 + regulatory T cells: myths and facts

Fork head box P3 (FoxP3+) regulatory T cells (Tregs) are specialized T cells for prevention of hyperimmune responses and autoimmunity. Tumors and pathogens can hijack FoxP3+ Tregs to evade host immune responses. There is an increasing body of evidence that trafficking of FoxP3+ Tregs is important for their effective suppression of target cells. Because of their distinctive functions and gene expression phenotype, the migratory behavior of FoxP3+ Tregs has been somewhat mystified. The myths are that they have unique trafficking receptors and migratory behaviors that are different from those of conventional T cells. Another related myth is that FoxP3+ regulatory T cell subsets have a fixed trafficking behavior from the time they are generated in the thymus. The recent progress in trafficking receptors and migratory behavior of FoxP3+ Tregs is reviewed here and the validity of these myths is examined.
Common cold viruses

Abstract The structure of a human common cold (rhinovirus) serotype, human rhinovirus 14 (HRV14) is providing extensive information on viral assembly, stability, neutralization by antibodies and antiviral agents as well as the site of receptor attachment.
Intrinsic religiosity buffers the longitudinal effects of peer victimization on adolescent depressive symptoms.

Peer victimization is a common and potentially detrimental experience for many adolescents. However, not all youth who are exposed to peer victimization experience maladaptive outcomes, such as depression. Thus, greater attention to potential moderators of peer victimization is particularly important. The current study examined the potential moderating effect of intrinsic religiosity and religious attendance on the longitudinal association between physical and relational victimization and depressive symptoms. A diverse sample of adolescents (N = 313; Mage = 17.13 years; 54% female; 49% Caucasian, 24% African American, 19% Latino, 8% mixed race/other; 80% Christian religious affiliation) were recruited from a rural, low-income setting. Adolescents completed self-report measures of religious attendance and intrinsic religiosity, and two forms of victimization (i.e., physical and relational) were assessed using sociometric procedures in 11th grade. Depressive symptoms were measured in both 11th and 12th grad...
Optimization of the fabrication of novel stealth PLA-based nanoparticles by dispersion polymerization using D-optimal mixture design

AbstractPurpose: Nanoparticle size is important in drug delivery. Clearance of nanoparticles by cells of the reticuloendothelial system has been reported to increase with increase in particle size. Further, nanoparticles should be small enough to avoid lung or spleen filtering effects. Endocytosis and accumulation in tumor tissue by the enhanced permeability and retention effect are also processes that are influenced by particle size. We present the results of studies designed to optimize cross-linked biodegradable stealth polymeric nanoparticles fabricated by dispersion polymerization.Methods: Nanoparticles were fabricated using different amounts of macromonomer, initiators, crosslinking agent and stabilizer in a dioxane/DMSO/water solvent system. Confirmation of nanoparticle formation was by scanning electron microscopy (SEM). Particle size was measured by dynamic light scattering (DLS). D-optimal mixture statistical experimental design was used for the experimental runs, followed by model generation (S...
Successful intra-arterial basilar artery thrombolysis in a patient with bilateral vertebral artery occlusion: technical case report.

OBJECTIVE AND IMPORTANCE: Basilar artery occlusion is a clinical event with an exceedingly high mortality rate. Improved survival is closely associated with successful recanalization of the occluded basilar artery. Bilateral vertebral artery occlusion (BVAO) is a unique disease entity that effectively denies any direct access to the basilar artery for endovascular rescue therapy. We report a case of successful intra-arterial basilar artery thrombolysis in a patient with BVAO. CLINICAL PRESENTATION: A 78-year-old man was transferred to our hospital after intravenous administration of tissue plasminogen activator and with deteriorating neurological status requiring intubation. His clinical presentation was highly suggestive of acute basilar artery thrombosis. The cerebral angiogram showed a BVAO and collateral flow reconstituting both distal extracranial vertebral arteries but with significant contrast stasis. There was no retrograde filling of the basilar artery through the only angiographically visible posterior communicating artery. TECHNIQUE (see video at website): Selective catheterizations of the left occipital artery and the left ascending cervical branch of the thyrocervical trunk were performed to deliver a total of 12 mg of tissue plasminogen activator. At that point, the patient showed significant neurological improvement. The post-tissue plasminogen activator angiogram showed improved flow through the basilar artery. The patient was independent and well at his 1-year follow-up visit. CONCLUSION: Knowledge of potential collateral pathways is important when direct access to the main intracranial vessels is not available. Basilar artery thrombolysis through collateral vessels is clinically effective when a direct approach to the artery is not feasible.
A Fully Automated Method for Quantifying and Localizing White Matter Hyperintensities on MR Images

White matter hyperintensities (WMH), commonly found on T2-weighted FLAIR brain MR images in the elderly, are associated with a number of neuropsychiatric disorders, including vascular dementia, Alzheimer's disease, and late-life depression. Previous MRI studies of WMHs have primarily relied on the subjective and global (i.e., full-brain) ratings of WMH grade. In the current study we implement and validate an automated method for quantifying and localizing WMHs. We adapt a fuzzy-connected algorithm to automate the segmentation of WMHs and use a demons-based image registration to automate the anatomic localization of the WMHs using the Johns Hopkins University White Matter Atlas. The method is validated using the brain MR images acquired from eleven elderly subjects with late-onset late-life depression (LLD) and eight elderly controls. This dataset was chosen because LLD subjects are known to have significant WMH burden. The volumes of WMH identified in our automated method are compared with the accepted gold standard (manual ratings). A significant correlation of the automated method and the manual ratings is found (P<0.0001), thus demonstrating similar WMH quantifications of both methods. As has been shown in other studies (e.g. [Taylor, W.D., MacFall, J.R., Steffens, D.C., Payne, M.E., Provenzale, J.M., Krishnan, K.R., 2003. Localization of age-associated white matter hyperintensities in late-life depression. Progress in Neuro-Psychopharmacology and Biological Psychiatry. 27 (3), 539-544.]), we found there was a significantly greater WMH burden in the LLD subjects versus the controls for both the manual and automated method. The effect size was greater for the automated method, suggesting that it is a more specific measure. Additionally, we describe the anatomic localization of the WMHs in LLD subjects as well as in the control subjects, and detect the regions of interest (ROIs) specific for the WMH burden of LLD patients. Given the emergence of large NeuroImage databases, techniques, such as that described here, will allow for a better understanding of the relationship between WMHs and neuropsychiatric disorders.
Two Crystal Structures of the Isochorismate Pyruvate Lyase from Pseudomonas aeruginosa

Enzymatic systems that exploit pericyclic reaction mechanisms are rare. A recent addition to this class is the enzyme PchB, an 11.4-kDa isochorismate pyruvate lyase from Pseudomonas aeruginosa. The apo and pyruvate-bound structures of PchB reveal that the enzyme is a structural homologue of chorismate mutases in the AroQα class despite low sequence identity (20%). The enzyme is an intertwined dimer of three helices with connecting loops, and amino acids from each monomer participate in each of two active sites. The apo structure (2.35 A resolution) has one dimer per asymmetric unit with nitrate bound in an open active site. The loop between the first and second helices is disordered, providing a gateway for substrate entry and product exit. The pyruvate-bound structure (1.95 A resolution) has two dimers per asymmetric unit. One has two open active sites like the apo structure, and the other has two closed active sites with the loop between the first and second helices ordered for catalysis. Determining the structure of PchB is part of a larger effort to elucidate protein structures involved in siderophore biosynthesis, as these enzymes are crucial for bacterial iron uptake and virulence and have been identified as antimicrobial drug targets.
Plant‐derived differences in the composition of aphid honeydew and their effects on colonies of aphid‐tending ants

In plant-ant-hemipteran interactions, ants visit plants to consume the honeydew produced by phloem-feeding hemipterans. If genetically based differences in plant phloem chemistry change the chemical composition of hemipteran honeydew, then the plant's genetic constitution could have indirect effects on ants via the hemipterans. If such effects change ant behavior, they could feed back to affect the plant itself. We compared the chemical composition of honeydews produced by Aphis nerii aphid clones on two milkweed congeners, Asclepias curassavica and Asclepias incarnata, and we measured the responses of experimental Linepithema humile ant colonies to these honeydews. The compositions of secondary metabolites, sugars, and amino acids differed significantly in the honeydews from the two plant species. Ant colonies feeding on honeydew derived from A. incarnata recruited in higher numbers to artificial diet, maintained higher queen and worker dry weight, and sustained marginally more workers than ants feeding on honeydew derived from A. curassavica. Ants feeding on honeydew from A. incarnata were also more exploratory in behavioral assays than ants feeding from A. curassavica. Despite performing better when feeding on the A. incarnata honeydew, ant workers marginally preferred honeydew from A. curassavica to honeydew from A. incarnata when given a choice. Our results demonstrate that plant congeners can exert strong indirect effects on ant colonies by means of plant-species-specific differences in aphid honeydew chemistry. Moreover, these effects changed ant behavior and thus could feed back to affect plant performance in the field.
On internal reflection from an absorbing surface layer

Abstract An explicit expression is derived for the reflection coefficient associated with internal reflection from an absorbing surface layer. The curves presented were calculated using the resulting expression for the reflection coefficient. The results demonstrate several characteristics of internal reflection from an absorbing surface layer, and allow transmission measurements to be directly related to the surface absorption coefficient.
The average hamiltonian view of low-energy scattering by a vibrating molecule

Abstract The average hamiltonian theory is used to examine the effect of molecular vibration on low-energy scattering. When the relative motion of the colliding molecules is slow on the timescale of molecular vibration, it is appropriate to transform the problem into an oscillating reference frame and to describe the collision in that frame by the average hamiltonian over one period of oscillation. The first-order result is identical to the distorted-wave Born approximation. High-order corrections introduce phase shifts for elastic scattering due to molecular vibration and provide transition amplitudes for inelastic scattering. The extent to which the higher-order corrections modify the distorted waves establishes criteria for the validity of the DWA. These criteria are used to examine recent distorted-wave calculations of V-V energy transfer rate constants.
A Non-Gaussian Ensemble Filter Update for Data Assimilation

Abstract A deterministic square root ensemble Kalman filter and a stochastic perturbed observation ensemble Kalman filter are used for data assimilation in both linear and nonlinear single variable dynamical systems. For the linear system, the deterministic filter is simply a method for computing the Kalman filter and is optimal while the stochastic filter has suboptimal performance due to sampling error. For the nonlinear system, the deterministic filter has increasing error as ensemble size increases because all ensemble members but one become tightly clustered. In this case, the stochastic filter performs better for sufficiently large ensembles. A new method for computing ensemble increments in observation space is proposed that does not suffer from the pathological behavior of the deterministic filter while avoiding much of the sampling error of the stochastic filter. This filter uses the order statistics of the prior observation space ensemble to create an approximate continuous prior probability dis...
Model systems for exploring electron correlation effects in the buckling of SiSi dimers on the Si(100) surface

Si2H4 and Si7H8 cluster models are constructed for studying the role of high-order electron correlation effects on the buckling of SiSi dimers on the Si(100) surface. CASPT3, multi-reference coupled-pair functional, and the diffusion Monte Carlo methods are used to examine whether correlation effects not recovered in CASPT2 calculations are important for the buckling of the dimers. The calculations show that such high-order correlation effects are indeed important for determining the relative stability of the buckled and unbuckled structures.
Size-frequency estimates of secondary production by Mysis relicta in Lakes Michigan and Huron

Data from five Great Lakes studies of Mysis relicta populations were reanalyzed to calculate secondary production estimates using the size-frequency method. Production estimates (P) ranged from 0.25 to 3.2 g dry weight m-2 yr-1. Average annual biomass (\(\overline B \)) and mean annual density (\(\overline D \)) were 0.11–1.11 g dry weight/ m2 and 25–434 animals/m2, respectively. P:\(\overline B \) ratios varied only between 2.2 and 3.3. Maximum and minimum biomass values within a study varied by a factor of 519 for one study but by less than 17 for the others. Highest estimates of P, \(\overline B \) and \(\overline D \) were calculated for collections from a 50-m station in Lake Michigan despite the larger populations suspected to be present at greater depths sampled in the other studies. These conservative estimates provide a basis for scaling trophic interactions involving M. relicta and emphasize findings by previous workers that night-time sampling with vertical net hauls is the best available technique for quantitative studies of M. relicta populations in the Great Lakes.
Software for evaluating sediment-induced stratification in open-channel flows

Open channel flow containing sediment suspension subjects itself to a density gradient in the vertical direction, i.e. density self-stratification, due to the tendency for suspended sediment to settle. Velocity and concentration profiles under the effect of density stratification may differ significantly from the conventional logarithmic and Rousean distributions associated with open channel flow. It is hence important to include this effect into flow computations in order to accurately predict flow characteristics such as the resistance coefficient, near-bed sediment concentration, flow and sediment discharge. In this study we introduce a software, StratSedOC, for such purpose. The application contains a user-friendly interface which allows users to evaluate and visualize the differences in the velocity, concentration and eddy viscosity profiles when stratification effects are taken into account. In addition to the standard logarithmic/Rousean formulation, the model uses three turbulence closures, i.e. an algebraic model (Smith-McLean) and two differential models (k-@e and Mellor-Yamada). The software application can also be used to study the effect of sediment mixtures on flow stratification under different boundary conditions for near-bed sediment concentration. Comparison among the model and experimental results suggests that the Mellor-Yamada model predicts a damping effect on the eddy viscosity which is similar to the Smith-McLean model, while the k-@e model consistently predicts weaker stratification effects. Based on this result, a modified boundary condition for the k-@e model is then proposed.
DB-HReduction: A data preprocessing algorithm for data mining applications

Data preprocessing is an important and critical step in the data mining process and it has a huge impact on the success of a data mining project. In this paper, we present an algorithm DB-HReduction, which discretizes or eliminates numeric attributes and generalizes or eliminates symbolic attributes very efficiently and effectively. This algorithm greatly decreases the number of attributes and tuples of the data set and improves the accuracy and decreases the running time of the data mining algorithms in the later stage.
Theory of defects and defect processes in silicon dioxide

Abstract Defects and defect processes are of particular importance in the thin SiO2 films that form an integral part of silicon-based metal-oxide-semiconductor (MOS) electronic systems. To understand such effects, we have carried out total-energy electronic structure calculations on large clusters of atoms chosen to simulate particular defects and their reactions. Here we consider two examples. (1) Electrical switching experiments in thin oxides have been interpreted by a model in which a metastable state of the oxygen vacancy has a longer lifetime than seems theoretically reasonable. We suggest that this might be explained by different time scales for local and longer-range atomic relaxations. (2) A serious problem occurs if boron diffuses from the polysilicon gate through the oxide in MOS devices. It has been found that hydrogen enhances and nitrogen inhibits the boron diffusion. We use the results of our calculations to discuss several possible explanations for these effects.
Rearticulating Caste: The Global Cottonseed Commodity Chain and the Paradox of Smallholder Capitalism in South India

Cottonseed is an aspirational crop for smallholders newly incorporated in the global cottonseed commodity chain as own-account cultivators in South India. The labor to produce cottonseeds, which are hybrids, in the field is excessive. Multinational and Indian corporations depend on hybridization to protect their intellectual property rights in branded seeds. As wage rates rise and seed prices do not, the outsourcing of cottonseed production to smallholders is attractive to capital. It is mostly the unpaid, family labor of smallholders which now generates exchange value. While smallholders dream of spectacular gains and some success stories seem to support this, growing cottonseed is a risky business and, at times, the returns to smallholders are so low that the very costs of reproducing family labor are unmet; many go into debt. Yet, smallholders from a formerly untouchable caste, or Dalit, community, who just a short while ago worked as ‘cottonseed children’ for rich farmers are, for the first time, prou...
Effect of Oligosaccharide-Free Soybean Meal on True Metabolizable Energy and Fiber Digestion in Adult Roosters

Adult Leghorn roosters were precision-fed 44% protein soybean meal (SBM) or 80% ethanol-extracted soybean meal (ESBM) to determine nutritional differences due to the removal of oligosaccharides. Dry-matter digestibility and TMEn as well as apparent hemicellulose and cellulose digestion were determined. The transit time, rate of passage, and pH of the cecal contents were also established with roosters that had consumed a .3% chromic-oxide diet that contained SBM or ESBM. The protein content of the SBM and the ESBM was 46.1 and 64.4%, respectively. The true-dry matter digestibility of SBM was 54%. The TMEn of the SBM on a dry-matter basis was 2,794 kcal per kg; and the apparent hemicellulose and cellulose digestibility was 9% and 0%, respectively. The true dry-matter digestibility of the ESBM was 67%. On a dry-matter basis, the TMEn of the ESBM was 3,368 kcal per kg; and the apparent hemicellulose and cellulose digestibility was 62% and 35%, respectively. Oligosaccharide digestion occurred mainly anterior to the ileo-cecal junction. Hemicellulose and cellulose digestion occurred predominantly in the lower gastrointestinal tract. The transit time for the ESBM diet was 115 min, compared to 71 min for the SBM diet. Based on a 16-h collection of excreta, the rate of passage was approximately 50% slower for the ESBM diet than for the SBM diet. The pH of the cecal contents from roosters consuming the ESBM diet was 7.21 versus 6.51 for the SBM diet.
Solutions to hidden terminal problems in wireless networks

The floor acquisition multiple access (FAMA) discipline is analyzed in networks with hidden terminals. According to FAMA, control of the channel (the floor) is assigned to at most one station in the network at any given time, and this station is guaranteed to be able to transmit one or more data packets to different destinations with no collisions. The FAMA protocols described consist of non-persistent carrier or packet sensing, plus a collision-avoidance dialogue between a source and the intended receiver of a packet. Sufficient conditions under which these protocols provide correct floor acquisition are presented and verified for networks with hidden terminals; it is shown that FAMA protocols must use carrier sensing to support correct floor acquisition. The throughput of FAMA protocols is analyzed for single-channel networks with hidden terminals; it is shown that carrier-sensing FAMA protocols perform better than ALOHA and CSMA protocols in the presence of hidden terminals.
Organic Phosphorus Compounds 61. Esterification and chlorination of nitrilo-tri(methylene-phosphonic acid), N(CH2PO3H2)3, and hydroxyethylidenediphosphonic acid, H2O3PC(OH)(CH3)PO3H2, and the corresponding esters†

Nitrilo-tri(methylenephosphonic acid) and hydroxyethylidenediphosphonic acid are esterified in high yield when treated with excess orthoformic acid ester under reflux. Because of the high temperature necessary to effect esterification a partial isomerization of hydroxyethylidenediphosphonate to the phosphate-phosphonate isomer V takes place. Chlorination of N(CH2PO3H2)3 or a mixture of the ester and the acid with PCl5 yields tris(chloromethyl)amine, N(CH2Cl)3. Interaction of N(CH2Cl)3 and (EtO)3P yields nitrilo-tri(methylenephosphonate), which on hydrolysis with HCl conc. produces N(CH2PO3H2)3. Chlorination of a mixture of hydroxyethylidene-diphosphonic acid and the corresponding ethyl ester IV which contained the phosphate-phosphonate isomer V gave the products VII to XI. Chlorination of the acid III with PCl5 gave 4 products, i.e., VIII, IX, XI and Cl2(O)POP(O)Cl2. The 1H- and 31P-NMR. spectra of the products are discussed.
An AOP-based Performance Evaluation Framework for UML Models

Performance is a key aspect of non-functional software requirements. While performance cross-cuts much of the software functionality, it is frequently difficult to express in traditional software development representations. In this paper we propose a framework for evaluating software performance using aspect-oriented programming (AOP) and examine its strengths and limitations. The framework provides a mechanism for supporting software performance evaluation prior to final software release. AOP is a promising software engineering technique for expressing cross-cutting characteristics of software systems. We consider software performance as a cross-cutting concern since it is not confined only a few modules, but often spread over multiple functional and non-functional elements. A key strength of our framework is the use of a code instrumentation mechanism of AOP - AspectJ code for performance analysis is separated from Java code for functional requirements. Java code is executable regardless of Aspect J code and can be woven together with AspectJ code when performance is evaluated. Our performance evaluation modules, written in AspectJ are semi-automatically or automatically generated from the UML [1] models with annotated performance profiles. The AspectJ code generator facilitates performance evaluation by allowing performance requirements that have been specified in UML models to be analyzed. The UML diagrams can then be improved by reflecting the feedback from the results of the performance analysis.
Implications of domain‐general “psychological support skills” for transfer of skill and acquisition of expertise

The article proposes that individuals who acquire certain psychological support skills may experience accelerated learning and enhanced performance in many domains. In support of this proposal, we present evidence that these skills enhance learning and performance, that they are domain-general in that they can be applied in a variety of domains, and that they can be taught and learned. We also discuss two implications of the skills for current theories of expertise. The first is that any observed transfer of expertise between domains might result as much from the support supplied by application of the skills during learning and performance as from any direct transfer achieved due to two domains sharing similar task elements. The second is that use of these skills might contribute to an understanding of how performers sustain the motivation necessary for the extended period of deliberate practice required to maximize skill acquisition.