cssi/SciSciGPT-SciSciNet huggingface dataset:
Intravascular β-amyloid infusion increases blood pressure: implications for a vasoactive role of β-amyloid in the pathogenesis of Alzheimer's disease

Hypertension has been recognized as a risk factor for Alzheimer's disease (AD). Moreover, serum beta-amyloid (A beta) levels are elevated in several mutations linked to familial AD, as well as in some sporadic AD individuals. To determine the in vivo effects of A beta on blood pressure, A beta(1-40) was infused intra-arterially into anesthetized rats. For all animals, strong correlations exist between pre-infusion mean arterial blood pressure (MA beta) and post-arterial infusion increases in blood pressure. In spontaneously hypotensive animals, A beta infusion resulted in substantial increases in MA beta compared to vehicle distilled water infusion. A beta(1-40) was also able to accelerate MA beta return from induced hypotension, but infusion of A beta(1-42), or rat amylin had no such effect. These results provide evidence that circulating A beta(1-40) can exert vasopressor actions in vivo. Moreover, they suggest a pathophysiologic role for vascular A beta in AD that precedes A beta deposition and dementia onset.
Peeking into the black box: New biomarkers for acute kidney injury

The development of effective therapies for acute kidney injury (AKI) has been hindered by delayed diagnosis in the clinical setting, varying definitions of AKI, and limited prognostic information. In a study by Portilla et al. , elevations in liver fatty acid-binding protein (L-FABP) were found to predict AKI in children undergoing cardiac surgery. New biomarkers offer the promise of earlier and more accurate diagnosis of AKI. Before they can be deemed clinically useful, however, they must undergo rigorous validation in multiple cohorts.
Comparative nutrient pathways to the flexor profundus tendons in zone II of various experimental animals

Abstract The role of diffusion and vascular perfusion as nutrient pathways to Zone II of the flexor profundus tendon of various experimental animals was studied by measuring the uptake of tritiated proline by tendon segments. The uptake by the flexor profundus tendon of the chicken resembled the uptake by that of the monkey in that both diffusion and perfusion effectively provided nutrients to the tendon. In contrast, the uptake by the dog and rabbit profundus tendon differed from the primate; although the uptake by diffusion resembled that of the monkey, the uptake by vascular perfusion was poor. Clinical relevance : These results challenge the use of the dog and rabbit as appropriate experimental animals when vascular perfusion of the profundus tendon in Zone II is an essential component of study.
The Role of the Caregiver in the Drug Treatment of Dementia

Summary Although dementia is common among the institutionalised elderly, the majority of patients with dementia are cared for at home by nonprofessional caregivers, usually a spouse or adult child, As dementia progresses, the role of the caregiver expands from assistance with meal preparation, financial planning and medication administration to include personal care and decision making responsibilities. The chronic burden of these caregiver responsibilities affects the emotional and physical health of the caregiver and, as a result, can affect the patient. It is often caregivers who first seek a diagnosis and treatment for patients with dementia. Medication is becoming a more important part of the treatment of these patients. Tacrine is now available forthe treatment of Alzheimer’s disease in some countries, and other drugs are being investigated. Drugs have also been shown to be effective in modifying the risk factors for vascular dementia and in the treatment of behavioural problems associated with dementia. The administration of medication, monitoring of effectiveness and identification of adverse reactions are important aspects of caregiving and require interaction between the caregiver and the prescriber. The role of the caregiver in assessing the efficacy and adverse effects of medication and the impact of such medication on caregiver burden should be considered in the development of new treatments. There are instruments available to quantify the observations of caregivers, but few have demonstrated sensitivity or responsiveness to change in disease severity over time. Very little is known about the validity and reliability of caregiver observations. Further research needs to be done to develop and test instruments to capture information related to the function of patients with dementia and to caregiver quality of life.
Dilepton radiation from high temperature nuclear matter.

The general features of electron-positron emission from high temperature nuclear matter are discussed. Estimates are made of the production rates arising from incoherent nucleon-nucleon scattering and from two-pion annihilation. It may be possible to infer the pion dispersion relation in hot and dense nuclear matter by measuring the invariant mass distribution of back-to-back electrons and positrons in the center of mass frame in high energy nucleus-nucleus collisions.
Fat digestion in patients with bile acid malabsorption but minimal steatorrhea.

Patients with an interrupted enterohepatic circulation of bile acids and minimal or no steatorrhea were studied to determine if their fat absorption was aided by compensatory mechanisms which delivered increased amounts of lipid to the aqueous phase of postprandial duodenal fluid. The data suggested that the molar stoichiometry of association of fatty acid and bile acid in an aggregated (micelle) form was reduced in the patients (0.8) as compared to normals (1.4). Each patient had either normal sized or undetectable micelles; one patient had a large fatty acid-rich aggregated species. The bile acid composition of the whole duodenal fluid was found to have an increased proportion of dihydroxy bile acids which were conjugated with glycine. There was a selective precipitation of dihydroxy bile acids from the aqueous phase, such that the patients had a normal proportion of these bile acids in the aqueous phase. We were unable to identify a consistent compensatory mechanism whereby these patients could increase the concentration of lipid in the aqueous phase which would have led to a better understanding of their minimal steatorrhea. We believe that the reduced stoichiometry of aggregated fatty acid to aggregated bile acid is in part due to the altered bile acid pool composition of these patients.
Faserverstärkte SiC-Keramik: Eigenschaften und Anwendungen

Mit Verbundkeramiken ist eine Werkstoffklasse entstanden, bei denen sich verschiedene Herstellverfahren mit unterschiedlichen Qualitaten entwickelt haben [1]. Es wird eine Verbundkeramik mit C- bzw. SiC-Fasern und SiC-Matrix vorgestellt, die uber die Infiltration der Fasern mit dem CVI-Verfahren (Chemical Vapour Infiltration) hergestellt wird [2]. Die Eigenschaften werden bestimmt durch die Qualitat der Einbettung der Fasern in die Matrix. Nur eine schwache Ankopplung zwischen Fasern und Matrix erlaubt es, Festigkeit und Dehnbarkeit der Fasern auszunutzen. Die gemessenen Risswiderstande solcher Verbundkeramiken liegen im Bereich von Metallen wie zum Beispiel Grauguss. Anwendungen konzentrieren sich bisher auf Gebiete, in denen die bekannten Werkstoffe nicht eingesetzt werden konnen. Grunde hierfur sind zum Beispiel zu hohe Temperaturen, Thermoschock- und Sprodbruchverhalten und Verschleis. Beispiele sind Steuerklappen aus dem Bereich der Raumfahrt, die beim Wiedereintritt in die Erdatmosphare Temperaturen uber 1600 °C ausgesetzt sind, und hoch belastete Gleitlager fur Grospumpen, in denen Verbundkeramik seit uber zehn Jahren als Wellenschutzhulse eingesetzt wird.
Repair of the radiation-induced vaginal fistula utilizing the Martius technique.

The radiation-induced vaginal fistula is an extremely difficult rehabilitative challenge to the surgeon. Historically there has been a sense of frustration about prospects for success with these defects and many patients have been managed by either permanent colostomy or permanent urinary diversion. This report reviews a personal experience of 25 radiation-induced vaginal fistulas in 22 patients utilizing the Martius bulbocavernosus-labial fat flap technique. Successful closure was accomplished in 84.2% of the rectovaginal fistulas and 50% of the vesicovaginal fistulas. Only 1 patient required a second surgical effort for successful closure. There was no surgical mortality and no significant surgical morbidity. No patient with a rectovaginal fistula closure required subsequent colostomy for stricture. These results, coupled with the relative simplicity of the procedure, allow us to recommend this technique as firstline therapy for these difficult management problems. The majority of patients will be rewarded with successful rehabilitation.
Environmental Issues for the Poultry Industry: Processing

Abstract The water flow and waste loading patterns of a modern broiler processing plant (260,000 birds per day) were studied. The study was conducted in two phases. The first phase examined the water flow and waste-loading patterns during a 24-h period. The second phase studied flow and waste-loading patterns from five major process functions of the plant. The first phase study showed that 84% of the water flow of the plant was used for processing and the remaining 16% for plant sanitation. Based on received water, this plant used 5.08 gal (1 gal = .379 L) per bird. Analysis of the waste stream from five process functions determined that 72% of the plant flow came from the evisceration operation. The feather flow operation and the offal truck contributed 83% of the NH3 N discharged by the plant. Definition of flow and waste-loading patterns provides valuable information for enhancing water conservation and waste minimization.
Stage- and position-related changes in chondrogenic response of chick embryonic wing mesenchyme to treatment with dibutyryl cyclic AMP.

The responsiveness of high-density cell cultures (micromass) prepared from different stages or different regions of chick embryonic wings to treatment with dibutyryl cyclic AMP (dbcAMP) and related compounds is used to define cellular heterogeneity and steps in cartilage differentiation. Cultures of stage 19 wing mesenchyme form aggregates (areas of greater cell density than adjacent areas), but not cartilage nodules. Treatment with dbcAMP (1 mM) results in the aggregates differentiating into cartilage nodules. Cultures from stage 21–24 wings form aggregates which spontaneously differentiate into cartilage nodules. Treatment with dbcAMP or cholerotoxin for only 12 hr results in the formation of a continuous sheet of cartilage, as defined by Alcian blue stainign, 35SO42− autoradiography, and immunofluorescence with antibodies to cartilage-specific proteoglycan. The peripheral, normally nonchondrogenic region of the stage 24 limb and the distal 0.5 mm of the stage 24–26 wing in micromass culture respond to dbcAMP similarly of the whole stage 24 limb. On the other hand, cultures from whole wings or cross-sectional slices from the midregion of stage 26 wings behave like stage 19 wings, except for the additional presence of small scattered clusters of cartilage cells. These results suggest the existence of at least four subpopulations of limb mesenchyme cells (non-chondrogenic cells, dbcAMP-responsive aggregate cells, dbcAMP-responsive nonaggregate cells, and spontaneously chondrogenic cells). The proportions of cells having these properties change temporally and spatially in a manner which is correlated with cartilage histogenesis.
Potentiometric method for subatrate analysis using immobilized NAD+‐dependent oxidoreductase enzymes

Two coenzyme-dependent oxidoreductases, glucose dehydrogenase and alcohol dehydrogenase, were immobilized in polyacrylamide gel over a platinum grid matrix and used as enzyme electrodes to measure their substrate concentrations in buffered aqueous solutions. The immobilized enzymes were used to oxidize their substrates in the presence of NAD +. Ferricyanide was used as the redox mediator and electroactive species. The determinations of glucose and ethanol were utilized to demonstrate and evaluate the performance of the system. The described methodology should be readily applicable to the analysis of numerous other substrates of coenzyme-dependent oxidoreductases.
Differential conductance fluctuations in silicon nanowire transistors caused by quasiballistic transport and scattering induced intersubband transitions

Calculations based on the multisubband Boltzmann transport equation with relevant microscopic scattering mechanisms predict abrupt differential conductance fluctuations (kinks) in the drain current versus drain voltage curves of silicon nanowire transistors at room temperature. The kink originates from the change of series resistance at the drain extension related to the interplay between quasiballistic transport and intersubband transitions of electrons caused by elastic interactions with acoustic phonons, surface roughness, and ionized impurities. The kink occurs when the energy of the second subband in the drain extension is aligned with the peak of the net electron flux distribution in the first subband. This bias condition yields a large series resistance in the drain extension because those quasiballistic electrons in the first subband which reach the drain can scatter isotropically into the second subband.
OA03-06 LB. Unique stimulatory properties of myeloid dendritic cells in individuals with "elite" HIV-1 control

Methods Functional properties of freshly isolated myeloid dendritic cells were analyzed in mixed lymphocyte reactions. Surface expression of costimulatory molecules and myelomonocytic receptors was analyzed by multiparameter flow cytometry. Targeted si-RNA mediated gene knockout was used to determine the impact of specific functional effects mediated by regulatory myelomonocytic receptors. Assays were performed in elite controllers (n=11) and HIV-1 progressors (n=11) or healthy HIV-1 uninfected persons (n=12) as reference cohorts.
Ludwig's angina: Case report and review

Modern dental care and use of antibiotics for oral infections have made Ludwig's angina rare. To avoid acute airway obstruction, emergency physicians must be able to rapidly recognize and treat this condition. A typical case of Ludwig's angina is presented, followed by a review of clinical findings and therapeutic modalities. Emphasis is made on airway management, antibiotics, and surgical drainage.
Polarizable empirical force field for alkanes based on the classical Drude oscillator model.

Recent extensions of potential energy functions used in empirical force field calculations have involved the inclusion of electronic polarizability. To properly include this extension into a potential energy function it is necessary to systematically and rigorously optimize the associated parameters based on model compounds for which extensive experimental data are available. In the present work, optimization of parameters for alkanes in a polarizable empirical force field based on a classical Drude oscillator is presented. Emphasis is placed on the development of parameters for CH3, CH2, and CH moieties that are directly transferable to long chain alkanes, as required for lipids and other biomolecules. It is shown that a variety of quantum mechanical and experimental target data are reproduced by the polarizable model. Notable is the proper treatment of the dielectric constant of pure alkanes by the polarizable force field, a property essential for the accurate treatment of, for example, hydrophobic solv...
The World of Juvenile Justice According to the Numbers.

Intended to be an instructive, yet sobering, introduction to the complex and disturbing nature of the juvenile justice system, this article details the “numbers,” including selected percentages, ratios, and dollar amounts, that are relevant to developing a better understanding of the juvenile justice system. General statistics about juvenile and adult correctional systems in the United States are compared with similar data for U.S. public schools (e.g., prevalence of learning and behavior disabilities among school-aged children and those who are incarcerated). Lastly, the benefits of providing educational services for incarcerated juveniles, along with statistics related to recidivism and potential costs to our society, are included.
Flash photolysis study of 5-nitroquinoline

Abstract Flash photolysis of 5-nitroquinoline in 50% isopropyl alcohol-water solutions containing hydrochloric acid provides evidence that electron transfer to its π,π * triplet is the primary process leading to the known photoreduction, which terminates in formation of a chlorinated 5-amino-quinoline. A transient having a wavelength maximum at 550 nm and a lifetime of 5.3 ± 0.3 ms is assigned as the 5-nitro-quinolinium radical anion. A second absorption appearing at 410 nm with a lifetime of 1.1 ± 0.1 ms is believed to arise from an irreversible reaction of the protonated radical anion with the solvent. A comparison of the flash data with photochemical quantum yields suggests that both transients contribute to the observed photoreduction.
The High Price of Success: Costs of Mating Effort in Male Primates

While males are generally the low investing sex when it comes to offspring care, males of many species experience intense and persistent mating effort. Mating effort incurs a variety of costs which are expected to have non-negligible effects on fitness, as well as how reproductive tactics are selected and investment in mating activity is moderated over time. This special issue features contributions investigating the costs of male mating effort across primate species. Here, we place these exciting new works in context, addressing the specific types of mating effort expected for male primates and the significance of these costs for our understanding of primate life histories and socioecology.
Single n-gram stemming

Stemming can improve retrieval accuracy, but stemmers are language-specific. Character n-gram tokenization achieves many of the benefits of stemming in a language independent way, but its use incurs a performance penalty. We demonstrate that selection of a single n-gram as a pseudo-stem for a word can be an effective and efficient language-neutral approach for some languages.
A time and hydration dependent viscoplastic model for polyelectrolyte membranes in fuel cells

Ionomers are co-polymers with ionic groups. One of the interesting applications of ionomer membranes is as electrolytes in proton exchange membrane (PEM) fuel cells. The most commonly used membranes in PEM fuel cells are perfluorosulfonic acid (PFSA) membranes, e.g., Nafion® from DuPontTM. Besides its dependency on temperature and hydration due to phase inversion and cluster formation, Nafion® as a polymer, exhibits strong time and rate effects. In this work, the stress–strain behavior of Nafion® at different strain rates has been obtained in an environmental chamber for various temperatures and hydrations. After a certain strain was reached in each test, stress relaxation was performed for an hour to observe the relaxation behavior of Nafion®. We attempted to use a nonlinear, time-dependent constitutive model to predict the hygro-thermomechanical behavior of Nafion®. Because a substantial component of the response is unrecoverable, a viscoplastic model was employed. The proposed two-layer viscoplasticity model consisted of an elastoplastic network that was in parallel with an elastic-viscous network (Maxwell model) which separates the rate-dependent and rate-independent behavior of the material. After obtaining the necessary parameters for different hydrations, this model showed reasonably accurate success in predicting the stress–strain behavior at different strain rates, and matched the relaxation test results. Finite element simulations based on the proposed two-layer viscoplasticity model were in good agreement with test results and can be used to study the stress–strain state of the ionomer membranes in fuel cell configurations.
Proactive recovery in a Byzantine-fault-tolerant system

This paper describes an asynchronous state-machine replication system that tolerates Byzantine faults, which can be caused by malicious attacks or software errors. Our system is the first to recover Byzantine-faulty replicas proactively and it performs well because it uses symmetric rather than public-key cryptography for authentication. The recovery mechanism allows us to tolerate any number of faults over the lifetime of the system provided fewer than 1/3 of the replicas become faulty within a window of vulnerability that is small under normal conditions. The window may increase under a denial-of-service attack but we can detect and respond to such attacks. The paper presents results of experiments showing that overall performance is good and that even a small window of vulnerability has little impact on service latency.
McDowell's Kantianism*

In recent work, John McDowell has urged that we resurrect the Kantian thesis that concepts without intuitions are empty. I distinguish two forms of the thesis: a strong form that applies to all concepts and a weak form that is limited to empirical concepts. Because McDowell rejects Kant's philosophy of mathematics, he can accept only the weaker form of the thesis. But this position is unstable. The reasoning behind McDowell's insistence that empirical concepts can have content only if they are actualizable in passive experience makes it mysterious how the concepts of pure mathematics can have content. In fact, historically, it was anxiety about the possibility of mathematical content, and not worries about the “Myth of the Given,” that spurred the retreat from Kantian views of empirical content. McDowell owes us some more therapy on this score.
An EEG correlate of autonomic discrimination

In a forced choice procedure, Ss can identify the presence or absence of their own spontaneous GSRs. Correctly and incorrectly discriminated GSRs are preceded by opposing patterns of 5 cps EEG activity. It is suggested that discriminable GSRs are produced by the same central events which serve as cues for the discrimination.
Adolescents' Clothing Conformity, Awareness, and Peer Acceptance1

The observed similarity in the clothing and appearance of adolescents from the same school led to the hypothesis that awareness of and conformity to the modal pattern of dress would be associated with social acceptance by peers. Filmed observations of the clothing of 121 boys and 110 girls from a high school sophomore class and reactions from a questionnaire concerning what “most were wearing” were analyzed and related to general peer acceptance. Significant positive relationships were found to exist between awareness of and conformity to the clothing mode and peer acceptance. Awareness of the mode and conformity to the mode were significantly related to each other. These findings indicate that clothing and adornment may serve a strategic function in the socialization of high school students.
Comment on ``BCS Superconductivity of Dirac Electrons in Graphene Layers''

Comment on "BCS superconductivity of Dirac fermions in graphene layers" by N. B. Kopnin and E. B. Sonin [arXiv:0803.3772; Phys. Rev. Lett. 100, 246808 (2008)].
Phylogeny, genetic diversity and phylogeography of the genus Codoma (Teleostei, Cyprinidae)

This study represents a thorough analysis of Codoma, a monotypic genus endemic to north-western Mexico. A previous morphological analysis of the species concluded that there exists several morphological groups in Codoma ornata, suggesting diversity in Codoma could be underestimated. No studies have examined the genetic diversity in Codoma ornata to test this hypothesis and identify independent lineages. We present a phylogeographic analysis using one mitochondrial and two nuclear genes, and specimens from across nine major drainages in both the Chihuahuan Desert and the Sierra Madre Occidental of western Mexico. All genes and analyses recovered populations of Codoma in a well-supported clade and sister to Tampichthys, and this clade sister to Cyprinella. Analyses of both mitochondrial and nuclear genes indicated Codoma is not monotypic and recover more diversity in the genus than currently recognized. The four (mitochondrial) and five (nuclear) genetically distinct lineages are consistent with those groups outlined in the prior morphological study of the genus. Composition and distribution of these major lineages is also consistent with prior biogeographic hypothesis for other fishes in the region, supporting an ancestral Rio Grande system extending south towards central Mexico. Fragmentation of this paleosystem was followed by allopatric speciation in the Chihuahuan Desert. These results suggest a scenario of long-term isolation in four major regions (upper Conchos, lower Conchos, Nazas, upper Mezquital). Resolution of the diversity and biogeography of these lineages has many implications for various biological disciplines, especially for evolutionary and conservation studies.
The Catalytic Copper of Peptidylglycine α-Hydroxylating Monooxygenase also Plays a Critical Structural Role

Many bioactive peptides require amidation of their carboxy terminus to exhibit full biological activity. Peptidylglycine a-hydroxylating monooxygenase (PHM; EC 1.14.17.3), the enzyme that catalyzes the first of the two steps of this reaction, is composed of two domains, each of which binds one copper atom (CuH and CuM). The CuM site includes Met 314 and two His residues as ligands. Mutation of Met 314 to Ile inactivates PHM, but has only a minimal effect on the EXAFS spectrum of the oxidized enzyme, implying that it contributes only marginally to stabilization of the CuM site. To characterize the role of Met 314 as a CuM ligand, we determined the structure of the Met 314 Ile-PHM mutant. Since the mutant protein failed to crystallize in the conditions of the original wild-type protein, this structure determination required finding a new crystal form. The Met 314 Ile-PHM mutant structure confirms that the mutation does not abolish CuM binding to the enzyme, but causes other structural perturbations that affect the overall stability of the enzyme and the integrity of the CuH site. To eliminate possible effects of crystal contacts, we redetermined the structure of wt-PHM in the Met 314 Ile-PHM crystal form and showed that it does not differ from the structure of wild-type (wt)-PHM in the original crystals. Met 314 Ile-PHM was also shown to be less stable than wt-PHM by differential scanning calorimetry. Both structural and calorimetric studies point to a structural role for the CuM site, in addition to its established catalytic role.
Immigrant Organizing and the New Labor Movement in Los Angeles

This article traces the transformation of Los Angeles, which was considered a showcase of anti-unionism a century ago, into a key site of labor movement revitalization and a model of successful immigrant organizing. It traces the history of unionization in L.A. over time, and analyzes data from the 1990s on the characteristics of L.A.'s union members. Although immigrants are still less likely to be union members than native-born workers, this is because of their sectoral location, not because they are “unorganizable.” On the contrary, in some respects foreign-born workers tend to be more receptive to unionization efforts than their native-born counterparts, despite the vulnerability non-citizens and undocumented immigrants often experience. Here the dynamics of recent immigrant organizing successes in L.A. are analyzed, highlighting the importance of Latino immigrants' propensity for militancy, on the one side, and the key role of the new activist leadership of a number of key unions, on the other. While ...
Maximum energy window with constrained spectral values

Abstract The optimum energy criterion continuous and discrete prolate spheroidal wave function windows had a profound effect on the basic understanding and practical optimization of many problems in communication theory, signal processing, and antenna theory. However, in many situations, there is interest in not only packing maximum window energy in some frequency interval, but also interest in imposing precise spectral window values and spectral nulls over some specified frequencies. We have formulated and solved such an optimization problem in an analytical sense as well as in an efficient computational sense. The problem is first expressed as a constrained maximization of a normalized quadratic form w′Aw/w′w, where A is a positive-definite matrix specified by the window energy concentration interval, w is the window weighting vector, and the constraining subspace is specified by the spectral window values and locations. This problem is then transformed to a nonconstrained maximization of a normalized quadratic form w′ PAPw/w′w, where P is a projection operator onto the orthogonal complement of the original constraining subspace. Persymmetric properties of A and PAP are used to reduce the computational complexity of the solution of the optimum window. Numerical maximization can be readily performed using the iterative power method. Specific examples are presented.
Stratigraphic relations and source areas of ash‐flow sheets of the Black Mountain and Stonewall Mountain Volcanic Centers, Nevada

Recent work has resulted in major changes in the stratigraphic correlations and source-area assignments of ash-flow sheets of the late Miocene Black Mountain and Stonewall Mountain volcanic centers, southern Nevada. Ash-flow tuffs exposed around Stonewall Mountain have different trace element patterns and thermoremanent magnetization directions than do ash-flow sheetsof the Thirsty Canyon Tuff, erupted from the Black Mountain center, with which they were previously correlated. Hafnium concentrations are particularly useful in distinguishing the megascopically and petrographically similar tuffs ofthe two centers. The ash-flow sheet overlyingthe Spearhead Member in the Stonewall Mountainarea, herein named the Civet Cat Canyon Member, can be traced northward continuously from outflow facies south of Stonewall Mountain to near-vent facies on the southern flank of Stonewall Mountain. This, in conjunction with distribution, thickness, and facies relations show that these units are the outflow sheets of the Stonewall Mountain volcanic center; they are herein assigned to a new formation, the Stonewall Flat Tuff of late Miocene age. Tuffs previously mapped near Black Mountain as the Labyrinth Canyon Member (herein abandoned) are correlated on the basis of trace-element, paleomagnetic, petrographic, and radiometric age data with the type Spearhead Member at Goldfield. Tuffs previously assigned to the Spearhead Member in the Black Mountain frea are reassigned to the Pahute Mesa Member (new) of the Thirsty Canyon Tuff. The Stonewall Mountain volcanic center is thus slightly younger than the Black Mountain center, and the period of time over which the Black Mountain center was active probably was appreciably shorter than was previously inferred. Recognition of the Stone-wall Flat Tuff as a separate stratigraphic and genetic entity enables us to explain a number of geological inconsistencies, including the marked asymmetric distribution previously attributed to the Thirsty Canyon Tuff. Moreover, the inferred original volume of the Thirsty Canyon Tuff is significantly reduced, increasing the importance of lava relative to tuff in the eruptive history of the Black Mountain center.
A calmodulin-sensitive adenylate cyclase in the prothoracic glands of the tobacco hornworm, Manduca sexta.

Abstract The Ca 2+ /calmodulin (CaM) dependence of adenylate cyclase activity in Manduca sexta prothoracic glands was investigated. Membrane fractions from two developmental stages were used, day 3 of the last larval instar and day 0 of the pupal stage, both of which respond to the neuropeptide prothoracicotropic hormone (PTTH) with increased cAMP production dependent on extracellular Ca2+ The data revealed that both larval and pupal prothoracic gland membrane fractions have a Ca 2+ /CaM-dependent adenylate cyclase which is inhibited by CaM antagonists and EGTA. The larval adenylate cyclase shows a multiphasic response to Ca 2+ /CaM, with a 2-fold stimulation between 0.02 and 0.1 μM, a further increase in adenylate cyclase activity at concentrations > 2 μM and a potentiation of NaF-stimulated activity at doses > 0.1 μm Ca 2+ /CaM. Pupal prothoracic gland membrane fractions exhibit only the second phase of stimulation. Stimulation by the GTP analogs GTP-γ-S and Gpp(NH)p is dependent on CaM in larval, but not in pupal membrane fractions, suggesting a role for CaM in Gs protein-mediated regulation of adenylate cyclase. However, adenylate cyclase activity in glands from both stages is dependent on CaM, supporting our initial premise that Ca 2+ is required for cAMP synthesis in the prothoracic glands.
An ideal observer model for identifying the reference frame of objects

The object people perceive in an image can depend on its orientation relative to the scene it is in (its reference frame). For example, the images of the symbols × and + differ by a 45 degree rotation. Although real scenes have multiple images and reference frames, psychologists have focused on scenes with only one reference frame. We propose an ideal observer model based on nonparametric Bayesian statistics for inferring the number of reference frames in a scene and their parameters. When an ambiguous image could be assigned to two conflicting reference frames, the model predicts two factors should influence the reference frame inferred for the image: The image should be more likely to share the reference frame of the closer object (proximity) and it should be more likely to share the reference frame containing the most objects (alignment). We confirm people use both cues using a novel methodology that allows for easy testing of human reference frame inference.
Trade and the adoption of a universal language

Abstract This paper investigates long-run consequences of international trade between two economies inhabited by two distinct races using different languages. If wages are not equal in autarky, free trade encourages the workers of the low-wage country to learn the language of the high-wage country. As the bilingual population increases in the low-wage country, products are increasingly produced in the dominant-language version. In the long run the language of the high-wage country becomes universally adopted.
Following the Teacher's Lead in Professional Development to Improve Classroom Talk Around Texts

This study examines the process of teacher learning in the context of highly responsive, ongoing professional development centered on classroom talk around texts. A classroom teacher and a university researcher met weekly to view, analyze, and discuss videos of reading instruction recorded in the teacher's fifth-grade classroom. The professional development sessions were framed as teacher-driven action research. This article traces the evolution of the intensive professional development activity across one semester and describes the process by which the teacher-researcher appropriated practical and conceptual tools for facilitating class discussions of texts. Results highlight the value of positioning teachers as intellectually capable and honoring their agendas for professional development. Insights are offered regarding a model of professional development that can support teacher agency, address local problems of practice, and simultaneously leverage professional developer expertise to build new practic...
Object oriented parallel architecture simulator

We introduce a general purpose object oriented simulation environment which enables the study of different architectural configurations for servers. The simulation environment has been built on the top of AWESIME which provides a process oriented discrete event simulation environment. On the top of AWESIME, the simulator provides the base class definitions for major components required to build large scale high-performance computer systems, and a more advanced model of any particular component can be derived from these base classes and easily replaced with the old one. This feature enables rapid evaluation of alternatives in simulating different architectures. In addition this design allows studying a component of interest in various degrees of detail while keeping the other components at a coarse-level for a faster simulation time.
Autocatalytic pathways to cell death: A new analysis of the tuna burn problem.

During capture and storage of tuna, a small but significant number of fish display a characteristic muscle degeneration termed tuna burn. Based on detailed amino acid analyses and on previous studies of metabolite changes during online swimming of tuna, a new model of the etiology of burnt muscle is developed. According to this model oxygen-lack to white muscle (developing initially during capture) leads to a metabolic collapse, to a drop in ATP concentration, to a consequent opening of ATP-dependent K+ channels, with an efflux of K+, and thus to a collapse of membrane potential. When the membrane potential falls far enough to open voltage-dependent Ca+ + channels, Ca+ + influx occurs leading to elevated Ca+ + concentrations in the cytosol. This process is augmented by simultaneous movement of Ca+ + from sarcoplasmic reticulum (SR) and from mitochondria into the cytosol. At high intracellular concentrations Ca+ + can be devastating. One of its more notable effects involves the activation of Ca+ +-dependent proteases, which preferentially target key components of the contractile machinery (troponins, tropomyosin, C-protein, Mprotein, Z-discs, a-actinin) and thus cause disassembly of myofilaments prior to any significant hydrolysis of myosin or actin. This process is autocatalytic in the sense that Ca+ +-activated proteases may act upon SR, thus increasing Na+/Ca+ + exchange, and ultimately adding more Ca+ + to the cytosolic pool. According to this model, the difference between burnt and unburnt regions of the myotome is simply due to how far each region has moved along this self-destructive, autocatalytic pathway. The model is helpful in explaining previously perplexing data and in making useful (Le. measurable) predictions for further studies of this important problem.
The effect of hospital staff training on management of obstetrical patients referred by traditional birth attendants

A hospital staff training program was conducted in Guatemala to improve outcomes for patients with obstetrical and neonatal complications. This study examines the effect of the training program on the subset of women referred to the hospital by traditional birth attendants (TBAs). The program's goals were to institute standards of care for obstetrical and neonatal patients as well as to improve relations between hospital staff and TBAs. The training program was evaluated by comparing changes in the number of referrals, patient satisfaction, patient management, as well as Apgar scores and perinatal mortality. Evaluations were based on 756 questionnaires administered to TBA referred mothers. There was a significant increase in the overall numbers of referred women as well as improvement in patient satisfaction and decreased waiting time between admission and treatment. Apgar scores and perinatal mortality also improved, but changes were not statistically significant.
Mediastinal lymph node sampling following positron emission tomography with fluorodeoxyglucose imaging in lung cancer staging.

Objectives To evaluate the predictive accuracy as well as the rates of false-positive and false-negative results of CT and positron emission tomography (PET)-fluorodeoxyglucose (FDG) imaging in detecting the metastatic intrathoracic lymph nodes in patients with suspected or proven non-small cell lung cancer (NSCLC). Our other objective was to determine the need for routine invasive sampling procedure in confirming PET/CT staging results. Methods The results of CT and PET-FDG scanning in 77 patients with suspected or proven NSCLC were correlated with the histologic findings of hilar/mediastinal lymph node sampling using mediastinoscopy, open biopsy, thoracotomy, or thoracotomy with resection. Patients were then classified into resectable and unresectable groups based initially on PET results and compared to histologic findings. Results The sensitivity, specificity, and accuracy of CT and PET for detecting metastatic lymphadenopathy were 68%, 61%, 63%, and 87%, 91%, and 82%, respectively. A change of management with routine sampling following PET was seen in five of six patients (83%) with false-positive findings (13%) but in none of four patients (9%) with false-negative findings. Conclusion The false-positive findings of PET-FDG imaging affected selection of treatment in 83% of patients. However, false-negative results did not change management in any patient. This could potentially prevent unnecessary invasive thoracotomy, mediastinoscopy, or other sampling procedures in patients with negative PET results.
CRF enhancement of GIRK channel-mediated transmission in dopamine neurons.

Dopamine neurons in the ventral midbrain contribute to learning and memory of natural and drug-related rewards. Corticotropin-releasing factor (CRF), a stress-related peptide, is thought to be involved in aspects of relapse following drug withdrawal, but the cellular actions are poorly understood. This study investigates the action of CRF on G-protein-linked inhibitory postsynaptic currents (IPSCs) mediated by GIRK (Kir3) channels in dopamine neurons. CRF enhanced the amplitude and slowed the kinetics of IPSCs following activation of D2-dopamine and GABAB receptors. This action was postsynaptic and dependent on the CRF1 receptor. The enhancement induced by CRF was attenuated by repeated in vivo exposures to psychostimulants or restraint stress. The results indicate that CRF influences dopamine- and GABA-mediated inhibition in the midbrain, suggesting implications for the chronic actions of psychostimulants and stress on dopamine-mediated behaviors.
SEROTONERGIC MECHANISMS IN AMYOTROPHIC LATERAL SCLEROSIS

Serotonin (5-HT) has been intimately linked with global regulation of motor behavior, local control of motoneuron excitability, functional recovery of spinal motoneurons as well as neuronal maturation and aging. Selective degeneration of motoneurons is the pathological hallmark of amyotrophic lateral sclerosis (ALS). Motoneurons that are preferentially affected in ALS are also densely innervated by 5-HT neurons (e.g., trigeminal, facial, ambiguus, and hypoglossal brainstem nuclei as well as ventral horn and motor cortex). Conversely, motoneuron groups that appear more resistant to the process of neurodegeneration in ALS (e.g., oculomotor, trochlear, and abducens nuclei) as well as the cerebellum receive only sparse 5-HT input. The glutamate excitotoxicity theory maintains that in ALS degeneration of motoneurons is caused by excessive glutamate neurotransmission, which is neurotoxic. Because of its facilitatory effects on glutaminergic motoneuron excitation, 5-HT may be pivotal to the pathogenesis and therapy of ALS. 5-HT levels as well as the concentrations 5-hydroxyindole acetic acid (5-HIAA), the major metabolite of 5-HT, are reduced in postmortem spinal cord tissue of ALS patients indicating decreased 5-HT release. Furthermore, cerebrospinal fluid levels of tryptophan, a precursor of 5-HT, are decreased in patients with ALS and plasma concentrations of tryptophan are also decreased with the lowest levels found in the most severely affected patients. In ALS progressive degeneration of 5-HT neurons would result in a compensatory increase in glutamate excitation of motoneurons. Additionally, because 5-HT, acting through presynaptic 5-HT1B receptors, inhibits glutamatergic synaptic transmission, lowered 5-HT activity would lead to increased synaptic glutamate release. Furthermore, 5-HT is a precursor of melatonin, which inhibits glutamate release and glutamate-induced neurotoxicity. Thus, progressive degeneration of 5-HT neurons affecting motoneuron activity constitutes the prime mover of the disease and its progression and treatment of ALS needs to be focused primarily on boosting 5-HT functions (e.g., pharmacologically via its precursors, reuptake inhibitors, selective 5-HT1A receptor agonists/5-HT2 receptor antagonists, and electrically through transcranial administration of AC pulsed picotesla electromagnetic fields) to prevent excessive glutamate activity in the motoneurons. In fact, 5HT1A and 5HT2 receptor agonists have been shown to prevent glutamate-induced neurotoxicity in primary cortical cell cultures and the 5-HT precursor 5-hydroxytryptophan (5-HTP) improved locomotor function and survival of transgenic SOD1 G93A mice, an animal model of ALS.
A rapid probability estimator and binary arithmetic coder

We present a new integrated algorithm for binary arithmetic coding and probability estimation, competitive in speed and compression performance with state-of-the-art algorithms such as the QM-coder and Z-coder. The chief innovation is representing the bracketing interval width both directly and by a logarithmic approximation. Performance is evaluated by experiments using bilevel-image data sets. An open-source software version is available.
Inversion of polynomial matrices

A new algorithm for the inversion of polynomial matrices is presented in this paper. As a by-product, the minimal polynomial or the determinant of the polynomial matrix can be computed as well.
Adult diapause in Chrysopa carnea: stages sensitive to photoperiodic induction.

In this study, Chrysopa carnea adults showed at least three levels of diapause intensity. Differences in the degree of intensity, as measured by diapause duration, resulted from both a change in photoperiod (LD 16 : 8 to LD 12 : 12) and the particular stage experiencing this change. The least enduring diapause resulted when the entire life cycle experienced LD 12 : 12 or when either the egg or first instar was transferred to LD 12 : 12. Diapause of intermediate length occurred after the second instar or freeliving third instar experienced the change in photoperiod. The longest diapause occurred after the third instar within the cocoon or the pupa underwent the change in photoperiod, and we therefore consider that sensitivity to photoperiodic stimuli was greatest during these stages. Pupal sensitivity to photoperiodic induction has not been reported previously for any insect. Transfer of newly emerged adults produced diapause; however, the relative sensitivity of this stage to the photoperiodic stimuli remains a question. Only the period between the larval-pupal ecdysis and the pupal-adult ecdysis showed an apparently slower developmental rate under LD 12 : 12 than under LD 16 : 8.
Recent climate anomalies and their impact on snow chemistry at South Pole, 1987 - 1994

Three 2-m deep snowpits sampled at South Pole in 1994 provide detailed (2-cm resolution) profiles of the concentrations of soluble ionic species for the period 1987–1994. The most prominent feature is a large concentration spike of SO4= in snow deposited in 1992 reflecting fallout from the eruptions of Pinatubo and Hudson in 1991. Concentrations of MSA and values of the MSA/(non-sea-salt SO4=) ratio are elevated for about three years centered on the prominent volcanic signal. These changes appear to be due to the extended 1991–1993 El Nino. The overlapping effects of the volcanic eruptions and El Nino circulation preclude partitioning the enhanced deposition of SO4= into volcanic and biogenic fractions. Nitrate concentration profiles show no relation to the severity of O3 depletion in the Antarctic stratosphere during the period of record. Rather, the profiles show a progressive decline of the annual peak concentrations over the top 0.5–1.0 m of each pit. This behavior is attributed to post-deposition loss of NO3−, presumably by reemission of HNO3 into the atmosphere.