cssi/SciSciGPT-SciSciNet huggingface dataset:
A structured model for vegetative growth and sporulation in Bacillus thuringiensis

A mathematical model has been developed for the delta-endotoxin producing Bacillus thuringiensis. The structure of the model involves the processes taking place during vegetative growth, those leading to the initiation of sporulation under conditions of carbon and/or nitrogen limitation, and the sporulation events. The key features in the model are the pools of compounds, such as PRPP, IMP, ADP/ATP, GDP/GTP, pyrimidine nucleotides, NAD/NADH2, amino acids, nucleic acids, cell wall, and vegetative and sporulation proteins. These, along with sigma-factors that control the nature of RNA-polymerase during the different phases, effectively stimulate the vegetative growth and sporulation. The initiation of sporulation is controlled by the intracellular concentration of GTP. Results of simulation of vegetative growth, initiation of sporulation, spore protein formation, and production of delta-endotoxin under C- or N-limitation are presented.
Extracellular ATP induces stellation and increases glial fibrillary acidic protein content and DNA synthesis in primary astrocyte cultures

A number of factors appear to be involved in the proliferative and hypertrophic processes which characterize reactive astrocytosis. We have investigated the possibility that ATP, an agent that is released by injured cells following tissue destruction, may be one such factor. For this purpose, we utilized primary cultures of astrocytes derived from cerebral cortices of neonatal rats to study the effect of extracellular ATP on properties associated with astrogliosis. Light microscopic studies disclosed marked stellation of astrocytes after 30-60 min of exposure to 100 microM-1 mM ATP. In addition, the content of the astrocyte-specific intermediate filament, glial fibrillary acidic protein (GFAP), was increased 35-40% following 60-min exposure to ATP; this effect persisted for 1-3 days of exposure to 100 microM ATP. [3H]Thymidine incorporation increased progressively from 1-3 days; a 3.6-fold increase in DNA synthesis was observed following 3 days of exposure to 1 mM ATP, suggesting stimulation of cellular proliferation. These findings show that high micromolar to low millimolar concentrations of extracellular ATP reproduce several features associated with reactive gliosis and suggest that extracellular ATP may be involved in the activation of astrocytes following CNS injury.
My biomass, your biomass, our solution†

The USA is pursuing an array of renewable energy sources to reduce reliance on imported fossil fuels and to reduce greenhouse gas emissions. Biomass energy and biomass ethanol are key components in this pursuit. Vast amounts of biomass feedstock will be needed to produce sufficient ethanol to meet any of the numerous target production goals. The Billion Ton Vision suggests one billion tons of biomass is needed annually to meet the ‘30x30’ goal (to replace 30% of 2004 levels of fossil transportation fuel use with ethanol by the year 2030). Great advances in technology will be required to produce this enormous quantity of biomass sustainably. These advances will not come about through ill–coordinated, competitive efforts. On the contrary, the problem of sustainably meeting the biofuel feedstock demand while continuing to meet traditional demands for agricultural output is so great that we need to focus all our energies on establishing complementary public energy policy based on facts and candid analysis; on crafting cooperative, coordinated energy goals across agencies; and on creating enthusiastic, dedicated teams of researchers and educators to develop and deploy existing and new technologies. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd
DETECTION OF CHICKEN FLESH IN BEEF SAUSAGES

Antisera to chicken troponin were produced in rabbits and were effective, in agar gel diffusion reactions, for the identification of chicken flesh in those beef sausages which by law should contain no chicken. Antisera to chicken troponin were reacted with extracts of heated beef sausages containing 1, 3 and 5% chicken flesh. The results indicate that such antisera can detect chicken flesh in beef sausages adulterated at the 1, 3 and 5% levels. Species specificity was demonstrated by a lack of reactivity between rabbit antiserum to chicken troponin, beef sausages and heated pork and lamb flesh. Chances of species cross-reactivity may increase with prolonged immunization. It is recommended that each antiserum be tested for species specificity before “pooling.”
Differences in substance-related risk behavior between dual and triple diagnosed severely mentally ill adults

The purpose of this study was to determine whether differences exist between adults with dual and triple diagnoses with regard to substance-related risk behaviors. This secondary analysis was a cross-sectional study. There were 252 subjects with dual and triple diagnoses recruited from residential crisis programs in San Francisco. Using descriptive and logistic regression analyses, subjects in the two groups were compared with regard to demographic data, types of substances, and routes of administration used in the previous 30 days to determine risk for exposure and/or transmission of human immunodeficiency virus/hepatitis C virus. When compared to the dual diagnosis group, subjects with triple diagnoses were four times more likely to have engaged in injection drug use (IDU) (p = 0.001) and 2.6 times more likely to use amphetamines (p = 0.05). They also reported using more types of substances over the lifetime (p < 0.0001). But with regard to other risk behaviors such as alcohol use to intoxication and co...
Fabrication of silica nanocomposite-cups using electrospraying

We have investigated a new process for the fabrication of nanocomposite cups by electrospraying blended polymer–sol–gel solutions followed by calcination. Due to the low viscosity and high surface tension of the blended polymer–sol–gel solutions, the electrostatically extruded continuous liquid jet from the spray source became tiny droplets with diameters of less than 1 µm. These droplets dried in transit and were collected at the counter electrode. To eliminate polymers, as well as cross-link sol–gel material, they were calcined at 850 °C for 3 h. We also investigated a probable method to control the morphology of the nanocups by changing the ionic concentration of the polymer solution. This is a simple and efficient approach for producing nanocomposite cups, which cannot be made by the aggregation method. These nanocomposite cups may find applications in drug delivery and filtration media.
Pharmacokinetic/Pharmacodynamic Modelling in Diabetes Mellitus

Diabetes mellitus is a major health risk in many countries, and the incidence rates are increasing. Diverse therapeutic agents are applied to treat this condition. Since 1960, numerous mathematical models have been developed to describe the glucose-insulin system, analyse data from diagnostic tests and quantify drug effects. This review summarizes the present state-of-the-art in diabetes modelling, with a focus on models describing drug effects, and identifies major strengths and limitations of the published models. For diagnostic purposes, the minimal model has remained the most popular choice for several decades, and numerous extensions have been developed. Use of the minimal model is limited for applications other than diagnostic tests. More mechanistic models that include glucose-insulin feedback in both directions have been applied. The use of biophase distribution models for the description of drug effects is not always appropriate. More recently, the effects of various antidiabetic agents on glucose and insulin have been modelled with indirect response models. Such models provide good curve fits and mechanistic descriptions of the effects of antidiabetic drugs on glucose-insulin homeostasis. These and other types of models were used to describe secondary drug effects on glucose and insulin, and effects on ancillary biomarkers. Modelling of disease progression in diabetes can utilize indirect response models as a disturbance of homeostasis. Future needs are to include glucose-insulin feedback more often, develop mechanistic models for new drug groups, consider dual drug effects on complementary subsystems, and incorporate elements of disease progression.
Telomeric repeat sequences are not associated with Tec1 elements in euplotes crassus

Summary The micronuclear genome of Euplotes crassus contains a large number of Tec 1 transposons that are eliminated during the formation of the macronucleus after mating. Other ciliated protozoa possess repetitive DNA elements that undergo developmental elimination, but these elements differ from known Tecl elements in that they are associated with telomeric repeat sequences. We have carried out hybridization screenings of an E. crassus micronuclear recombinant library to determine if some Tec 1 elements in E. crassus might also be associated with telomeric repeat sequences. This analysis indicated that the vast majority of micronuclear Tec 1 elements are not associated with telomeric repeat sequences. In the few cases where micronuclear clones were identified that contained both a Tecl element(s) and telomeric repeat sequences, further analyses demonstrated that they were not directly associated.
A SIMULTANEOUS PLANNING MODEL FOR PRODUCTION AND WORKING CAPITAL

A simultaneous model is proposed for the planning of production, inventory, workforce, and working capital levels over several periods. By exploiting the capabilities of linear programming, the model provides relevant information more efficiently than would be typical of the more traditional approach, in which planning is decomposed along functional lines. A detailed example is presented in order to illustrate the advantages of the simultaneous model.
The Teacher of Teachers Talks about Learning to Learn: An Interview with Wilbert (Bill) J. McKeachie

Wilbert J. McKeachie has been the president of the American Psychological Association (APA), the American Association of Higher Education, the American Psychological Foundation, the Division of Edu...
An algorithm for the simulation of electrohydrodynamic rigid particulate flows

In this communication, a numerical technique for electrohydrodynamic rigid particulate flows is presented. The proposed algorithm takes advantage of a specialized rigid particle formulation, thus enabling an efficient computational approach. The approach is tested for all the basic dielectrophoretic behaviors expected in DC and AC fields. This tool has potential use in several micro- and nano-scale fabrication processes that rely on electrohydrodynamic self-assembly of particles. Copyright © 2009 John Wiley & Sons, Ltd.
Inflaming hypothalamic neurons raises blood pressure.

Obesity and hypertension are strongly associated, and neural dysfunction has been implicated in both. The hypothalamus integrates signals regulating blood pressure and energy homeostasis. A recent paper in Nature Medicine (Purkayastha et al., 2011) suggests that obesity and hypertension are caused by inflammation in distinct hypothalamic neuronal populations.
Treatment‐induced diabetic neuropathy: A reversible painful autonomic neuropathy

While chronic neuropathic pain occurs frequently in diabetic patients, acute severe neuropathic pain is rarely encountered. Several different acute painful syndromes occur: 1) Pain may appear shortly after the initiation of intensive glycemic control, sometimes referred to as ‘insulin neuritis’ or treatment induced neuropathy.1-3 Characteristically, the painful neuropathy is preceded by rapid glycemic control. 2) Additional cases present in association with severe weight loss with or without a change in glycemic control, a disorder referred to as ‘diabetic neuropathic cachexia’.4-6 The weight loss in these patients is unintentional. 3) Pain may also present with intentional weight loss unrelated to changes in glucose control, a condition called “diabetic anorexia”.7 4) Rarely, an acute painful neuropathy may present with no apparent underlying cause.8-11 Treatment induced neuropathy was first described by Caravati in 1933. He reported a diabetic woman with numbness, tingling, and shooting pains in the lower extremities that appeared four weeks after the initiation of insulin.1 The pain increased despite the use of analgesics and sedatives, but resolved within 3 days of stopping insulin concurrent with severe hyperglycemia. Further attempts at insulin use resulted in similar levels of pain. He called the condition “insulin neuritis”.1 Recent reports have described treatment induced neuropathy in individuals with type 1 and type 2 diabetes treated with oral hypoglycemic agents or with insulin. Pre-treatment glycosylated hemoglobin (A1C) is typically high and glycemic control rapid. Pain, the most prominent symptom of treatment induced neuropathy, may occur distally in a length-dependent fashion or be more generalized and involve proximal sites including the trunk.2-4 Reports of treatment induced neuropathy have been predominantly small observational case studies with variable follow-up.2-5, 12, 13 In this manuscript, we report a cohort of 16 patients with the sudden onset of pain, autonomic dysfunction and microvascular complications after rapid glycemic control without associated weight loss. We provide the largest case-series, first detailed report of autonomic testing, autonomic symptoms, intra-epidermal nerve fiber density, concomitant microvascular complications and longitudinal follow-up of patients with treatment induced neuropathy.
Technical communique: A stability and contractiveness analysis of discrete-time Markovian jump linear systems

We propose performance criteria for discrete-time linear systems with Markov jumping parameters. Exact convex conditions for internal stability and contractiveness of such systems are expressed in terms of linear matrix inequalities. These conditions are of the same form as that in the Kalman-Yacubovich-Popov lemma.
Shock tube studies of gas phase reactions preceding the soot formation process

Abstract Various shock tube techniques have been employed to investigate the kinetics and thermodynamics that are pertinent to the thermal decompositions of acyclic and aromatic fuels. The goal of these studies is to formulate mechanisms that may be applied to the reactions of fuels over a wide range of temperatures and pressures. The process by which the first aromatic rings are formed or ruptured involves a complex sequence of chemical reactions. Measurements of soot yields have identified several key fuels and it is the elucidation of their respective pyrolytic reaction pathways that is the primary focus of this review.
Monitoring degradation of matrix metalloproteinases-cleavable PEG hydrogels via multiple particle tracking microrheology

The design of hydrogel matrices for cell encapsulation and tissue regeneration has become increasingly complex. Oftentimes, researchers seek to recapitulate specific biophysical and biochemical cues critical for the resident cell population and an in depth understanding of changes in the local microstructure and rheological properties of the synthetic matrix during enzymatic degradation would be extremely beneficial. Multiple particle tracking microrheology (MPT) enables simultaneous characterization of rheological properties and visualization of the microstructure in an evolving hydrogel scaffold. MPT measures the Brownian motion of fluorescently labeled probe particles embedded in the material, which is directly related to rheological properties using the Generalized Stokes–Einstein Relation (GSER). Here, we study a hydrogel scaffold consisting of a four-arm poly(ethylene glycol) (PEG) end functionalized with norbornene that is cross-linked with both a nondegradable PEG–dithiol and a matrix metalloproteinase (MMP) degradable peptide sequence (KCGPQG↓IWGQCK) using thiol–ene chemistry. The material degradation is measured as a function of time and extent of degradability, focusing on measuring the gel–sol transition. Using time–cure superposition, we determine the critical degradation time and critical extent of degradability for this specific gel formulation as tc = 1.85 h and pc = 0.589, respectively, and the critical relaxation exponent, n = 0.16. Finally, spatial information gained by MPT measurements quantifies the heterogeneity within the scaffold showing that these hydrogels degrade homogeneously when collagenase is introduced in solution at a concentration of 0.1–0.3 mg mL−1. Understanding the microstructural and rheological properties of a material near the gel–sol transition enables researchers to improve their insight as to how cells remodel their microenvironment when encapsulated in gels, and more precisely design and manipulate this parameter to improve three-dimensional culture systems.
Results of Tests on a New Drift Chamber to Be Used as a Trigger for the Time Projection Chamber

A new drift chamber is being designed to trigger the Time Projection Chamber. Two candidate designs have been tested in a high-pressure, high-field environment. Resolutions and efficiencies for various running conditions are presented.
The Attitudes of State Legislators and State Medicaid Policies Related to AIDS

As the Medicaid programs become increasingly important payers of AIDS-related care, state governments will face difficult policy choices in allocating limited Medicaid resources among many competing health needs. The state legislatures will play a critical role in these allocation decisions. This research presents the results of an analysis of attitudes concerning Medicaid coverage of AIDS-related care among state legislators serving on health-related committees in all 50 states. The model employed includes characteristics of the state legislators, their districts, and their states to explain the legislators' allocation choices and attitudes relating to Medicaid coverage of AIDS-related care. The relationship of these factors to the actualization of AIDS-related state policy also is examined. The model identified political ideology, party affiliation, and sex of the state legislator as the most important predictors of attitudes about AIDS-related Medicaid policies. AIDS prevalence, constituency characteristics, and legislator attitudes are the most important predictors of actual state policies.
Four wave mixing effects in gain-equalized distributed fiber raman amplifiers

The degradation of the performance of distributed fiber Raman amplifiers (DFRAs) is shown to be dependent on the interaction between pump-pump four-wave mixing (FWM) and stimulated Raman scattering (SRS), by means of numerical simulations. We verify that FWM processes, including depletion and parametric gain, generate new sources of SRS and a redistribution of the pump power along the fiber. Results show impairments on the performance of DFRAs such as loss of flatness on the spectral gain and reduction on the Raman gain and presence of FWM products within the transmission band.
A study of communities and influence in blogosphere

Blogging becomes a popular way for a Web user to publish information on the Web. Bloggers write blog posts, share likes and dislikes, voice opinions, provide suggestions, and report news. In this work we study influential bloggers in both community as well as individual blogs. We synthesize virtual communities by aggregating individual blogs with similar interests. We formulate the problem for identifying influential bloggers and synthesizing virtual communities from individual blogs, present a preliminary model, discuss the challenges, and pave the way for building a robust model that allows finding various types of the influentials. To illustrate these issues, we conduct experiments with data from a real-world blog site, evaluate multi-facets of the problem, and discuss unique challenges. We conclude with interesting findings and future work.
SHAPE SENSITIVITIES FOR NONLINEAR DYNAMIC THERMOELASTIC STRUCTURES

Explicit shape sensitivities are formulated for a general functional associated with a nonlinear, dynamic, thermoelastic system. Uncoupled thermoelastic response and s111al1-defor~~~ation behavior are assumed. The forlnulation uses the Lagrange multiplier method to define an adjoint system, the convolution operator to incorporate transient effects, and domain parameterization to describe shape variations. Variations of the functional are expressed in explicit form with respect to perturbations in structural shape. The functional is defined in terms of the design fields (material properties, applied loads, prescribed boundary conditions, and initial conditions) and t,he implicit response fields (displacement,, t,en~perature, st,rnin, temperature gradient, stress, heat flux vector, reaction force, and, reaction surface flux). In an example problem, the finite element method is used to evaluate the real and adjoint responses and the shape sensitivities for a stress measure used in a tank design problem. The tank is modeled an a nonlinear, quasi-static, uncoupled, thermoelastic system.
Suppression of void coalescence in thermal aging of tin-silver-copper-X solder joints

Addressing the potential for drop impact failure of Pb-free interconnects, the shear ductility after extensive aging of Sn-Ag-Cu (SAC) solders has been improved radically by Co or Fe modifications. Several other SAC+X candidates (X=Mn, Ni, Ge, Ti, Si, Cr, and Zn) now have been tested. Solder joint microstructures and shear strength results show that new SAC+X alloys also suppress void formation and coalescence at the Cu (substrate)/Cu3Sn interface (and embrittlement) after aging at 150°C for up to 1,000 h. Microprobe measurements of 1,000 h aged samples suggest that Cu substitution by X is usually accentuated in the intermetallic layers, consistent with X=Co and Fe results.
Buspirone and dexmedetomidine synergistically reduce the shivering threshold in humans

Hypothermia may be therapeutically beneficial in stroke victims; however, it provokes vigorous shivering. Buspirone, a partial serotonin 1A antagonist, and dexmedetomidine, an α2 agonist, linearly reduce the shivering threshold (triggering core temperature) with minimal sedation and respiratory depression. We tested the hypothesis that buspirone and dexmedetomidine synergistically reduce the shivering threshold without producing substantial sedation or respiratory depression.
E-063 Physicians Use Perfusion Imaging to Aid in Diagnosis and Treatment Decisions for Acute Ischemic Stroke

Background Recently, perfusion imaging has been utilised to provide visualization of at risk ischemic tissue that would benefit from revascularization treatment; however, current research differs in recommendations on the use of perfusion. The purpose of our study was to evaluate whether perfusion imaging helped guide diagnosis and treatment of ischemic strokes. Methods and materials We conducted a retrospective review for patients who received perfusion imaging and/or treatment for ischemic stroke over a three-year period. We reviewed the progression of diagnosis, treatment or lack of, complications of treatment, and whether the imaging played a role in the treatment plan. Results The majority of patients in this study had treatment that was influenced by perfusion imaging. This was most evident in our population of patients that received intra-arterial therapy as 95% of these patients received treatment based on the results of imaging. There was an impact in the decision to not treat patients who had completed strokes on perfusion imaging, preventing unnecessary treatment and complications. In addition, our perfusion imaged patients were found to have a significantly longer time to treat than those that did not receive imaging, extending beyond the three-hour treatment window with an average of 4.88 h without an increased risk of complications or decrease in clinical outcome. Conclusion Perfusion imaging can be used in the real world setting as a tool to guide patient diagnosis and treatment, to select patients with salvageable tissue to receive intra-arterial treatment outside the standard intravenous time window. Disclosures K. Seifert: None. J. Wiener: None. D. DeOrchis: None.
In Defense of Clarity in the Study of Personal Epistemology

Andrew Elby (this issue) argues that researchers in the field of personal epistemology should beware insistence on a narrow definition of epistemology to guide this work. His argument is a response to suggestions (Hofer & Pintrich, 1997; Sandoval, 2005) that the study of personal epistemology should focus on people's views about knowledge and knowing and not conflate those with views about learning. His main concern is that learners' views about knowledge and their views about learning may, in fact, be conflated and that an insistence on definitional clarity could lead to a mischaracterization of cognitive structures. In this response I argue that clarity in the definition of theoretical constructs does not imply exclusion of views about learning from the study of personal epistemology. Furthermore, given the history of this area of research, failing to more clearly define our constructs makes real theoretical progress difficult.
Hematopoietic stem cell transplantation for severe Crohn's disease

It is clear that some patients with severe Crohn's disease (CD) fail to respond favorably to the standard treatment, including antibody to Tumor Necrosis Factor alpha (TNFalpha), We have embarked on a unique therapy for this group of patients, intense immune suppression followed by autologous hematopoietic stem cell transplantation (HSCT). The response to this approach in our first four patients has been excellent, with there being no significant untoward event from the transplantation and with each patient entering clinical remission in terms of the Crohn's Disease Activity Index off all therapy for CD and no diarrhea or abdominal pain. However, some evidence of minor laboratory abnormalities and slight inflammation of the colon on colonoscopic evaluation persist up to 1 year post-transplant. It is suggested that HSCT should be considered a reasonable option for patients who have failed standard CD therapy, although long-term follow-up will be necessary to confirm the duration of the induced clinical remission.
Crystal orientation relaxation studies of polyethylene

Wide-angle x-ray relaxation studies were performed on films of low- and high-density polyethylene (PE). The samples were rapidly stretched by a pneumatic stretcher and held at a fixed length. The rate of crystal reorientation was monitored by measuring diffracted intensity changes using a count-rate meter with output displayed on a storage oscilloscope as well as a digital counter-timer. Experiments were completed at several temperatures and activation energies comparable to those reported for the α1 relaxation in PE were obtained.
Diverse lavas from closely spaced volcanoes drawing from a common parent: Emmons Lake Volcanic Center, Eastern Aleutian Arc

Abstract Emmons Lake Volcanic Center (ELVC) on the lower Alaskan Peninsula is one of the largest and most diverse volcanic centers in the Aleutian Arc. Since the Middle Pleistocene, eruption of ~ 350 km3 of basalt through rhyolite has produced a 30 km, arc front chain of nested calderas and overlapping stratovolcanoes. ELVC has experienced as many as five major caldera-forming eruptions, the most recent, at ~ 27 ka, produced ~ 50 km3 of rhyolitic ignimbrite and ash fall. These violent silicic events were interspersed with less energetic, but prodigious, outpourings of basalt through dacite. Holocene eruptions are mostly basaltic andesite to andesite and historically recorded activity includes over 40 eruptions within the last 200 yr, all from Pavlof volcano, the most active site in the Aleutian Arc. Geochemical and geophysical observations suggest that although all ELVC eruptions derive from a common clinopyroxene + spinel + plagioclase fractionating high-aluminum basalt parent in the lower crust, magma follows one of two closely spaced, but distinct paths to the surface. Under the eastern end of the chain, magma moves rapidly and cleanly through a relatively young (~ 28 ka), hydraulically connected dike plexus. Steady supply, short magma residence times, and limited interaction with crustal rocks preserve the geochemistry of deep crustal processes. Below the western part of the chain, magma moves haltingly through a long-lived (~ 500 ka) and complex intrusive column in which many generations of basaltic to andesitic melts have mingled and fractionated. Buoyant, silicic melts periodically separate from the lower parts of the column to feed voluminous eruptions of dacite and rhyolite. Mafic lavas record a complicated passage through cumulate zones and hydrous silicic residues as manifested by disequilibrium phenocryst textures, incompatible element enrichments, and decoupling of REEs and HFSEs ratios. Such features are absent in mafic lavas from the younger part of the chain, highlighting the importance of plumbing architecture and longevity in creating petrologic diversity. Supplemental Data include 156 major element (XRF) and 128 trace element (ICP-MS) whole-rock analyses, 23 new 40Ar/39Ar ages, a generalized geologic map with associated unit descriptions and field photographs, and photomicrographs of key petrographic features.
Pharmacokinetics and acute renal effects of continuously infused carboplatin

Carboplatin was given as a 24-hour infusion at high doses to pediatric patients with cancer (n = 11) and pharmacokinetic parameters and renal effects were determined. Median carboplatin clearance for course 1 (151 ml/min per 1.73 m2;) was not significantly different from clearance for course 2 (144 ml/min per 1.73 m2; p = 0.33). The median glomerular filtration rate measured before (159 ml/min per 1.73 m2) and after course 1 (161 ml/min per 1.73 m2) did not differ significantly (p = 0.4). Binding was time dependent but modest with a median free fraction at the end of infusion of 0.82. Pharmacokinetic parameters for continuous-infusion carboplatin are similar to those reported for short infusions, but the median dose of 817 mg/m2 required to achieve an acceptable systemic exposure in these patients was 45% greater than the previously suggested maximum tolerated dosage. Continuous infusion carboplatin did not alter carboplatin clearance or adversely effect glomerular filtration rate during a second course, showing the feasibility of this alternative dosage strategy to enhance therapeutic effects. Clinical Pharmacology and Therapeutics (1993) 54, 374–380; doi:10.1038/clpt.1993.163
LpxI: A Novel Phosphosaccharolipid Hydrolase

Gram-negative bacteria possess an asymmetric outer membrane in which the inner leaflet is composed primarily of phospholipids, while the outer leaflet contains mainly lipopolysaccharide (LPS). LPS forms a structural barrier that protects Gram-negative bacteria from antibiotics and other environmental stressors. LPS is anchored to the outer membrane by lipid A, a unique glucosamine-based saccharolipid. Lipid A biosynthesis is required for bacterial viability and pathogenesis. While most lipid A biosynthetic genes are present in a single copy, one gene, lpxH, encoding a membrane-associated specific UDP-diacylglucosamine hydrolase, is absent in ∼30% of Gram-negative bacteria. We hypothesized that a transformational analogue of lpxH must exist in these organisms. We identified this gene, designated lpxI, in Caulobacter crescentus, and confirmed its ability to cover for a deficiency of lpxH in Eschserichia coli. LpxI lacks homology to any other known enzyme. We over-expressed LpxI, purified it, and obtained protein crystals. We solved the X-ray crystal structure of this peripheral membrane enzyme using a single-wavelength anomalous dispersion (SAD) dataset collected on Se-Met derivatized protein. The structural data reveal two domains, each having a novel fold. Unexpectedly, “apo” LpxI co-purified and co-crystallized stoichiometrically with its product, diacylglucosamine-1-phosphate (lipid X), the saccharolipid precursor of lipid A. We then identified and determined the 2.5 A X-ray crystal structure of an inactive point mutant of Caulobacter crescentus LpxI, which co-purified in a stoichiometric ratio with its substrate, UDP-2,3-diacyglucosamine. The conformation of substrate-liganded LpxI differs significantly from the product -liganded wild-type enzyme. Taken together with analytical unltracentrifugation data, this observation suggests that large-scale domain re-arrangement occurs during LpxI substrate binding and/or catalysis. These data provide an interesting example of lipid-protein interaction, and set the stage for additional structural and mechanistic work.
Characterization of structured and unstructured decentralized fixed modes using transfer matrices

In this paper, structured and unstructured decentralized fixed modes (DFMs) are studied for a decoupled controllable and observable strictly proper linear time-invariant system with distinct poles. The conditions characterizing both structured and unstructured DFMs for the case of three single-input single-output (SISO) control stations are analytically developed, and the results are then interpreted in terms of the system transfer function matrix. It is shown how mutual couplings between local control stations can influence the structured and unstructured DFMs of the overall decentralized system. Supplementary remarks throughout the paper describe the general case with any arbitrary number of SISO control stations.
Iron uptake by cultured lens epithelial cells.

• Background: Transferrin and Fe concentrations increase in the intraocular fluids in pathological conditions and the lens accumulates Fe during ocular inflammation. Tissues take up Fe from transferrin by two mechanisms, receptor-medicated endocytosis of diferric transferrin and a process occurring at the cell membrane which may be mediated by an oxido-reductase. However, Fe metabolism, transport and storage have not been previously investigated in the lens. This study was designed to characterize the uptake of Fe from transferrin by lens epithelial cells in culture. • Methods: Primary, secondary and tertiary cultures of canine lens epithelial cells and cultures obtained from cataractous lenses were studied. Uptake of 59Fe from transferrin by these cultured cells was measured. Transferrin receptor populations were determined in receptor-binding assays. • Results: There was a distinct relationship between the amount of Fe-transferrin added and the amount of Fe taken up, which was linear for the primary cultures but significantly reduced for the secondary, tertiary and cataract cultures (252±21, 169±14, 153±14 and 96±2 ng Fe/mg protein, respectively).
Managerial Status, Sex, and Selected Personality Characteristics

Relationships among managerial status, sex, and the traits of aggression, dominance, achievement-orientation, and nurturance were investigated in an attempt to obtain insight into the validity of the male managerial stereotype. Sixty-six sets of individuals matched by organization and department participated in the study. Each set consisted of a male and female manager and a male and female nonmanager. Results for high achievement, high dominance, and low nurturance support the managerial stereotype. There was little support for the male managerial stereotype, since these traits appear to be associated with both males and females who have attained a managerial position.
Effects of dietary ω3 and ω6 lipids and vitamin E on chemokine levels in autoimmune-prone MRL/MpJ-lpr/lpr mice

Abstract Elevated levels of chemokines, such as Regulated upon Activation, Normal T cell Expressed and Secreted (RANTES), Monocyte Chemotactic Protein-1 (MCP-1), Macrophage Inflammatory Protein-1α (MIP-1α), and Macrophage Inflammatory Protein-1β (MIP-1β) have been found in rheumatoid arthritis (RA) and juvenile arthritis (JA), and they may be associated with the pathogenesis of these diseases. These chemokines are implicated in the migration of specific leukocytes into the joints. Omega-3 (ω3) fatty acid rich-fish oil (FO) and vitamin E may delay the progress of certain autoimmune diseases. The present study was designed to understand the effects of dietary lipids (ω-6 and ω-3 fatty acids) and vitamin E on the production of chemokines in autoimmune-prone MRL/ lpr (a mouse model for RA) and congenic control MRL/++ mice. The MRL mice were fed for 4.5 months ω-6 and ω-3 diets that varied in lipid sources (corn oil; CO and fish oil; FO) and vitamin E levels (269 I.U./kg and 694 I.U./kg diet). Spleen cells were isolated and cultured aseptically in the presence of PHA for 48 h at 37°C and the levels of chemokines (RANTES, JE/MCP-1 and MIP-1α) were determined in the cell-free supernatants. The levels of RANTES and JE/MCP-1 were significantly higher in MRL/ lpr mice compared to MRL/++ mice. The FO had differential effect on RANTES and MCP-1 production by spleen cells. The production of RANTES and JE/MCP-1 by spleen cells in mice fed the FO diets was significantly lower than in mice fed the CO diets ( p p lpr and MRL/++ mice suggest that FO diets containing ω-3 fatty acids are beneficial in decreasing the levels of certain pro-inflammatory chemokines (RANTES and MCP-1) thereby delaying the onset of and severity of autoimmune symptoms in MRL/ lpr mouse model.
Evaluation and Treatment of Agitation in the Intensive Care Unit

Agitation in the intensive care unit (ICU) patient is a complication of severe medical illness that requires prompt attention and treatment. The first step in managing an agitated ICU patient is a ...
Venus: absence of a phase effect at a 2-centimeter wavelength.

Observations of Venus made during 1967 and 1968 at a frequency of 15.4 gigahertz set an upper limits of 5 percent for the variation of brightness temperature with phase. This negative result appears to contradict earlier detections of a phase effect. By comparison with Virg A (3C 274), which has an assumed flux density of 29 x 10 -26 watt per square meter per hertz, the brightness temperature of Venus at this frequency is 485 + 60, -40°K (mean error).
Enhanced gain coefficient in Raman amplifier based on silicon nanocomposites

Abstract In this paper, silicon nanoparticles dispersed into a silica phase by sol–gel processing has been investigated by structural and nonlinear-optical characterization. The structural characterization has been performed by energy filtered and scanning transmission electron microscopy. A silicon nanoparticles mean radius of about 49 nm and a nanoparticle density of about 1.62 × 108 dots/cm2 have been obtained. Regarding nonlinear optics characterization, the observation of stimulated Raman scattering and the realization of a Raman amplifier based on silicon nanocomposites are described. Using a 1427 nm cw pump laser, amplification of Stokes signal, at 1542.2 nm, up to 1.4 dB/cm is demonstrated. A preliminary valuation of approximately a fivefold enhancement of the gain coefficient a significant reduction of threshold power are reported. Our findings have a potential interest for silicon-based Raman lasers.
Hydrogen and hydrogen-neon promoted field ionization of helium

Abstract Hydrogen promoted helium field ion images of refractory metals, such as molybdenum, tungsten, iridium and platinum, were studied. The addition of a small amount of neon to the helium-hydrogen mixed gas lowered the imaging field of the promoted images. The neon effect is quite significant for iridium. The migration of hydrogen on these metals was seen by the resulting field induced chemical reaction, the promoted field evaporation. The surface disorders induced by the reaction are field and temperature dependent. A novel phenomenon is a strongly localized surface disorder at a field below the hydrogen imaging field in the presence of the hydrogen-neon mixed gas.
Metabolic preconditioning of mammalian cells: mimetic agents for hypoxia lack fidelity in promoting phosphorylation of pyruvate dehydrogenase.

Induction of HIF-1α by oxygen limitation promotes increased phosphorylation and catalytic depression of mitochondrial pyruvate dehydrogenase (PDH) and an enhanced glycolytic poise in cells. Cobalt chloride and desferrioxamine are widely used as mimics for hypoxia because they increase the levels of HIF-1α. We evaluated the ability of these agents to elicit selected physiological responses to hypoxia as a means to metabolically precondition mammalian cells, but without the detrimental effects of hypoxia. We show that, while CoCl2 does increase HIF-1α in a dose-dependent manner, it unexpectedly and strikingly decreases PDH phosphorylation at E1α sites 1, 2, and 3 (Ser293, Ser300, and Ser232, respectively) in HepG2 cells. This same effect is also observed for site 1 in mouse NIH/3T3 fibroblasts and J774 macrophages. CoCl2 unexpectedly decreases the mRNA expression for PDH kinase-2 in HepG2 cells, which likely explains the dephosphorylation of PDH observed. And nor does desferrioxamine promote the expected increase in PDH phosphorylation. Dimethyloxaloylglycine (a prolyl hydroxylase inhibitor) performs better in this regard, but failed to promote the stronger effects seen with hypoxia. Consequently, CoCl2 and desferrioxamine are unreliable mimics of hypoxia for physiological events downstream of HIF-1α stabilization. Our study demonstrates that mimetic chemicals must be chosen with caution and evaluated thoroughly if bona fide cellular outcomes are to be promoted with fidelity.
Can an Algorithm Predict Appropriate Utilization of Emergency Venous Studies

Venous duplex evaluation (VDE) has virtually supplanted venography in the diagnosis of deep vein thrombosis (DVT). To control low yield of VDE of ambulatory patients, performed at “off-hours,” we adopted an algorithm to improve the selection process and to increase efficiency. “Off-hours” studies are those performed after the normal daily working hours, weekends, or holidays. From January 1, 1996, through December 31, 1998, we performed 5393 lower extremities VDE, utilizing color duplex imaging with video taping. 2535 studies were done during the eighteen months prior to adoption of the algorithm on July 1, 1997 and 2858 studies were performed during the subsequent eighteen months. During the first 18 months, 314 requests for emergency studies came from the Emergency Department (ED). 132 were “off-hours” and 24 (18.2%) were positive for DVT compared to 427 after adoption of the algorithm, of which 79 were “off-hours” with 24 being positive for DVT (30.3%). Using an algorithm for dealing with requests for VDE originating in the ED on outpatients at “off-hours” resulted in an overall decrease in requests as well as a greater yield of positive studies without apparent compromise of the quality of care.
Spin-wave dispersion and exchange interactions in Y 0.90 Tb 0.10 and Y 0.90 Ho 0.10 alloys

Neutron inelastic scattering experiments carried out on ${\mathrm{Y}}_{0.90}$${\mathrm{Tb}}_{0.10}$ and ${\mathrm{Y}}_{0.90}$${\mathrm{Ho}}_{0.10}$ at 4.7\ifmmode^\circ\else\textdegree\fi{}K show that well-defined spin waves exist in dilute alloys of the heavy rare earths Tb and Ho in yttrium metal. The measured spin-wave dispersion relations are satisfactorily described by a mean-lattice model together with the assumption that the exchange interaction $\mathcal{J}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}})$ is related to the conduction-electron susceptibility $\ensuremath{\chi}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}})$ of yttrium and, hence, is common to both alloys. The $\mathcal{J}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}})$ function deduced from the data possesses a peak, at the wave vector of the helical magnetic structures of the alloys, that is much larger than those measured for the pure rare-earth metals. This result is consistent with theoretical calculations of $\ensuremath{\chi}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{q}})$ by Liu, Gupta, and Sinha from the electronic energy bands for yttrium and with measurements of the magnetic structures of yttrium-rare-earth alloys as a function of composition and applied magnetic field.
Nuclear Size and Magnetic Effects in Bremsstrahlung from Electron-Nucleus Scattering

The distribution in energy and angle of bremsstrahlung from the scattering of electrons by static nuclear charge and magnetic-moment distributions is calculated in Born approximation. As expected, large reductions from point-nucleus cross sections are obtained for bremsstrahlung involving large momentum transfers, and the effects of a magnetic-moment distribution are important for wide-angle bremsstrahlung. Integrations were carried out numerically by computer, using form factors determined by elastic electron scattering, for some representative cases.
Substrate Control of Anisotropic Resistivity in Heteroepitaxial Nanostructured Arrays of Cryptomelane Manganese Oxide on Strontium Titanate

Resistivity and resistance measurements have been carried out for thin films of cryptomelane-type manganese oxide (OMS-2) grown onto (001), (110), and (111)STO single crystals substrates via pulsed laser deposition. While the symmetries of the (001) and (111)STO substrate surfaces give deposits consisting of multiple nanofiber arrays with isotropic in-plane resistivities, only a single nanofiber array is formed on (110)STO giving highly anisotropic electrical properties with very low resistivity values measured parallel to the fibers and similar to the lowest value ever reported.
Enhanced Conduction In Sipos Films With High Oxygen Content

Polysilicon films with high oxygen content (SIPOS) have been prepared by LPCVD. These films have a two-phase structure with silicon crystallites surrounded by amorphous oxide, as confirmed by TEM and HRTEM measurements. Increasing the ratio of nitrous oxide to silane, R, during growth allows us to vary the oxygen concentration. Contrary to expectation, we observe a region where conduction increases as R is increased from 1 to 10. This can be accounted for by deviations from monotonicity in the dependence of silicon volume fraction on R. We also observe some influence of the SIPOS/silicon interface on conduction.
Tnf-α and glucocorticoid receptor interaction in L6 muscle cells : A cooperative downregulation of myosin heavy chain

Sepsis is associated with increased expression of TNF-α with subsequent activation of nuclear factor-kappa B (NF-κB). The glucocorticoid receptor (GR) and NF-κB function as mutual antagonists and induction of the latter is believed to play a major role in the acquired glucocorticoid resistance that occurs in some septic patients. GR expression and function has been reported to be elevated in septic muscle suggesting a limited effect of the activated NF-κB on GR function in this context. In this study, the L6 myocyte cell line was used as an in vitro model for a sepsis-like condition in skeletal muscle. While short or long term treatment with TNF-α had no effect on GR expression, glucocorticoid-dependent downregulation of GR occurred with a kinetic profile that is accelerated relative to that observed in most cells. This downregulation was not affected by co-treatment or prior priming of L6 cells with TNF-α. The synthetic glucocorticoid, dexamethasone (DEX) blunted TNF-α-stimulated NF-κB activation in L6 cells. However, although effective at activating an NF-κB transcriptional response, TNF-α treatment exerted a minimal effect in myoblasts and no effect in myotubes on GR transcriptional activity. This limited impact of TNF-α on GR activity was not universal as TNF-α and DEX exerted an additive effect on the reduction in myosin heavy chain (MHC) protein expression caused by either agent alone. Thus, the selective perseverance of GR function in the presence of increased levels of glucocorticoids and TNF-α during sepsis or other inflammatory states may exacerbate muscle protein breakdown.