cssi/SciSciGPT-SciSciNet huggingface dataset:
Structural characterization of the human respiratory syncytial virus fusion protein core

Human respiratory syncytial virus (HRSV) is a major cause of a number of severe respiratory diseases, including bronchiolitis and pneumonia, in infants and young children. The HRSV F protein, a glycoprotein essential for viral entry, is a primary target for vaccine and drug development. Two heptad-repeat regions within the HRSV F sequence were predicted by the computer program learncoil-vmf. These regions are thought to form trimer-of-hairpins-like structures, similar to those found in the fusion proteins of several enveloped viruses. The hairpin structure likely brings the viral and cellular membranes into close apposition, thereby facilitating membrane fusion and subsequent viral entry. Here, we show that peptides, denoted HR-N and HR-C, corresponding to the heptad-repeat regions from the N-terminal and C-terminal segments of the HRSV F protein, respectively, form a stable alpha-helical trimer of heterodimers. The HRSV N/C complex was crystallized and its x-ray structure was determined at 2.3-A resolution. As anticipated, the complex is a six-helix bundle in which the HR-N peptides form a three-stranded, central coiled coil, and the HR-C peptides pack in an antiparallel manner into hydrophobic grooves on the coiled-coil surface. There is remarkable structural similarity between the HRSV N/C complex and the fusion protein core of other viruses, including HIV-1 gp41. In addition, earlier work has shown that HRSV HR-C peptides, like the HIV-1 gp41 C peptides, inhibit viral infection. Thus, drug discovery and vaccine development strategies aimed at inhibiting viral entry by blocking hairpin formation may be applied to the inhibition of HRSV.
Assessing the impact of teacher professional development on science instruction in the early elementary grades in rural US schools

This study examined the extent to which significant changes after one year of a longitudinal, state-funded teacher professional development program were sustained during the second year. Participants taught in elementary schools located in small, rural school districts in the state of California in the United States. The research examined changes in early elementary teachers’ science content knowledge; self-efficacy in teaching science; instructional practices in science; and contextual factors. Data sources included a teacher survey, self-efficacy assessment, content knowledge tests, interviews and classroom observations. Teachers experienced a significant increase in their knowledge of earth science in the second year. Their overall self-efficacy scores also increased significantly in the second year. Changes in instructional practices in science were largely sustained during the second year but were influenced by contextual factors such as resources, curricular demands, administrators’ support and supp...
The effect of static and dynamic spatially structured disturbances on a locally dispersing population

Previous models of locally dispersing populations have shown that in the presence of spatially structured fixed habitat heterogeneity, increasing local spatial autocorrelation in habitat generally has a beneficial effect on such populations, increasing equilibrium population density. It has also been shown that with large-scale disturbance events which simultaneously affect contiguous blocks of sites, increasing spatial autocorrelation in the disturbances has a harmful effect, decreasing equilibrium population density. Here, spatial population models are developed which include both of these spatially structured exogenous influences, to determine how they interact with each other and with the endogenously generated spatial structure produced by the population dynamics. The models show that when habitat is fragmented and disturbance occurs at large spatial scales, the population cannot persist no matter how large its birth rate, an effect not seen in previous simpler models of this type. The behavior of the model is also explored when the local autocorrelation of habitat heterogeneity and disturbance events are equal, i.e. the two effects occur at the same spatial scale. When this scale parameter is very small, habitat fragmentation prevents the population from persisting because sites attempting to reproduce will drop most of their offspring on unsuitable sites; when the parameter is very large, large-scale disturbance events drive the population to extinction. Population levels reach their maximum at intermediate values of the scale parameter, and the critical values in the model show that the population will persist most easily at these intermediate scales of spatial influences. The models are investigated via spatially explicit stochastic simulations, traditional (infinite-dispersal) and improved (local-dispersal) mean-field approximations, and pair approximations.
Degradation of Oxide Properties Caused by Low-Level Metallic Contamination

In this work SiO 2 on silicon was contaminated with metal-containing solutions after it was grown. Significant deleterious electrical effects are shown to develop following oxide surface contamination with part per billion, ppB, levels of metals from solution. The objective was to address the risk that unintentional contamination, such as may occur during routine manufacturing processes, posed to oxide electrical performance. Accordingly, high temperature or ion implantation-based contamination process environments, typical of previous studies, were not used in this work. Two low-energy methods were developed to introduce the contamination to the oxide and they are referred to as unintentional contamination mimic and plasma mimic processes, respectively. Equilibrium current density vs oxide stress field, J-E OX , capacitor measurements were used to assess the degradation in oxide quality caused by exposure to either cobalt, copper, nickel, or iron containing solutions. Cobalt was observed to act in a fashion different from other metals at low ppB contamination levels for capacitor structures, suggesting a different behavior of this metal when applied to oxide relative to the other metals considered. Further, a strong correlation is demonstrated between capacitor measurement results and noncontact oxide stress-induced-leakage-current, measurements that do not require capacitor fabrication.
Photopolymerization of nematic liquid crystal monomers for structural applications: molecular order and orientation dynamics

Abstract This paper is concerned with the molecular orientation in liquid crystal (LC) monomers and the retention of orientation in cross-linked network polymers subsequently formed by photopolymerization. This is of importance because anisotropic mechanical properties can be beneficial in certain structural applications. We have been using LC monomers for forming structural polymers via stereolithography, a novel rapid prototyping process where three-dimensional objects are built layer-by-layer using a laser to scan the surface of a liquid monomer. To this end the magnetic alignment of liquid crystal photo-monomers was investigated with dielectric measurements. Using the permittivity data, an extrapolation method based on the isotropic transition temperature provided an estimate of the order parameter as a function of temperature. The dielectric permittivity was also measured as a function of time after reorientation of an external magnetic field. The calculated change in monomer orientation angle followed an exponential time dependence with two distinct time constants. The faster of the two time regimes was attributed to bulk reorientation and obeyed an Arrhenius type of temperature dependence. The slower time regime was attributed to inhibition caused by impurities and surface interaction with the electrodes. Finally, dynamic mechanical analysis data showed that the molecular anisotropy induced by the magnetic field was retained after polymerization. © 1997 Elsevier Science Ltd.
Effects of gangliosides on the activity of the plasma membrane Ca2+-ATPase.

Abstract Control of intracellular calcium concentrations ([Ca 2 + ] i ) is essential for neuronal function, and the plasma membrane Ca 2 + -ATPase (PMCA) is crucial for the maintenance of low [Ca 2 + ] i . We previously reported on loss of PMCA activity in brain synaptic membranes during aging. Gangliosides are known to modulate Ca 2 + homeostasis and signal transduction in neurons. In the present study, we observed age-related changes in the ganglioside composition of synaptic plasma membranes. This led us to hypothesize that alterations in ganglioside species might contribute to the age-associated loss of PMCA activity. To probe the relationship between changes in endogenous ganglioside content or composition and PMCA activity in membranes of cortical neurons, we induced depletion of gangliosides by treating neurons with d -threo-1-phenyl-2-decanoylamino-3-morpholino-1-propanol ( d -PDMP). This caused a marked decrease in the activity of PMCA, which suggested a direct correlation between ganglioside content and PMCA activity. Neurons treated with neuraminidase exhibited an increase in GM1 content, a loss in poly-sialoganglioside content, and a decrease in PMCA activity that was greater than that produced by d -PDMP treatment. Thus, it appeared that poly-sialogangliosides had a stimulatory effect whereas mono-sialogangliosides had the opposite effect. Our observations add support to previous reports of PMCA regulation by gangliosides by demonstrating that manipulations of endogenous ganglioside content and species affect the activity of PMCA in neuronal membranes. Furthermore, our studies suggest that age-associated loss in PMCA activity may result in part from changes in the lipid environment of this Ca 2 + transporter.
RECOVERY FROM THE INHIBITORY EFFECT OF X-RADIATION ON URETHAN LUNG ADENOMAGENESIS.

Male (C2HfBiHe x Alele)F1 mice irradiated with 500 R 24 h prior to urethan treatment developed fewer lung adenomas than non-irradiated, urethan-treated mice. When irradiation was given two weeks before irrethan treatment, adenoma incidence was the some as in non-irradiaetd controls, suggesting recovery fromthe tumorinhibitory effrect of radiation. The recovery was not prevented by thymectomy prior to irradiation. Irradiation of female (C3HfBiHe × AjHe)F1 mice with 500 R did no significantly reduce the numver of adenomas induced by urethan. RENVERSEMENT DE L'INHIBITION PAR IRRADIATION DE L'ADENOMAGENESE DUE A L'URETHANE Nous avons etudie l'induction d'adenomes pulmonaires par l'urethane chez trois groupes de souris mǎles (C3HfB/He x A/He)F1; les premier et deuxieme groupes avaient recu une irradiation de 500 R respectivement quinze jours et un jour avant le traitement; le traisieme groupe n'etait pas irradie. Chez les souris irradiees 24 heures avant le traitement a l'urethane, l'incidence des adenomes etait plus faible que chez les souris non irradiees ou irradiees 15 jours plus tǒt, ce qui nous porte a conclure a la possibilite d'un renversement de l'inhibition par irradiation de l'adenomagenese. Le renversement depend de la dose de rayons et non pas du thymus. Nous n'avons pas pu deceler d'inhibition de l'adenomagenese chez des femelles (C3HfB/He x A/He)F1 apres une irradiation de 500 R.
Bifurcations and Strange Behavior in Instability Saturation by Nonlinear Mode Coupling

A simple model for the nonlinear saturation of an instability is studied via numerical solution of the resonant three-wave coupling equations in the case where the high-frequency wave is linearly unstable and the two lower-frequency waves are linearly damped. The solutions are shown to undergo interesting qualitative cahnges as the damping rate of the stable waves is increased. These changes include bifurcations to increasingly complicated periodic motions and the appearance of apparently chaotic motions, possibly indicative of the presence of a strange attractor.
“Cation-cation” complexes of pentavalent actinides—II Spectrophotometric study of complexes of Am(V) with UO22+ and NpO22+ in aqueous perchlorate solution

Abstract The “cation-cation” complexes of americyl(V) ions with those of uranyl(VI) and neptunyl(VI) were studied in aqueous perchlorate solution by absorption spectrophotometry. Within the accuracy limits of the experiment, the formation of the Am(V)-U(VI) complex obeys the mass action law. The constant of complexation was calculated to be K = 0.35 (σ K = 18% ). For the weaker Am(V)-Np(VI) complex, the formation constant was estimated to be K = 0.095 ± 0.030.
Differential effects of amphiregulin and TGF-α on the morphology of MDCK cells

Although both amphiregulin and TGF-alpha are known to exert their effects through the EGF receptor, we find that concentrations of recombinant human amphiregulin and TGF-alpha that are equipotent in EGF receptor activation and mitogenesis exhibit markedly different effects on MDCK cell morphology. Amphiregulin induces a spindle-like morphology that is associated with a redistribution of E-cadherin from a Triton-insoluble to Triton-soluble pool. TGF-alpha does not affect epithelial morphology nor does it affect the distribution of the Triton-soluble or -insoluble pool of E-cadherin. The effects of amphiregulin on E-cadherin are associated with actin rearrangement. The morphological and biochemical effects of amphiregulin are prevented by EGF receptor blockade but require Src-family kinase activity and MAPK signaling. These results identify an action of amphiregulin that is distinct from TGF-alpha that may contribute to amphiregulin's participation in the pathogenesis of inflammatory disorders like psoriasis and cancer.
Ion channels and regulation of insulin secretion in human β-cells: A computational systems analysis

In mammals an increase in glucose leads to block of ATP dependent potassium channels in pancreatic β cells leading to membrane depolarization. This leads to the repetitive firing of action potentials that increases calcium influx and triggers insulin granule exocytosis. Several important differences between species in this process suggest that a dedicated human-oriented approach is advantageous as extrapolating from rodent data may be misleading in several respects. We examined depolarization-induced spike activity in pancreatic human islet-attached β-cells employing whole-cell patch-clamp methods. We also reviewed the literature concerning regulation of insulin secretion by channel activity and constructed a data-based computer model of human β cell function. The model couples the Hodgkin-Huxley-type ionic equations to the equations describing intracellular Ca²⁺ homeostasis and insulin release. On the basis of this model we employed computational simulations to better understand the behavior of action potentials, calcium handling and insulin secretion in human β cells under a wide range of experimental conditions. This computational system approach provides a framework to analyze the mechanisms of human β cell insulin secretion.
Longitudinal Validation of the Urgency Traits Over the First Year of College

Research has identified 2 emotion-based dispositions to rash action, referred to as positive urgency and negative urgency. They are thought to reflect tendencies to engage in rash acts when in extremely positive and extremely negative moods, respectively. In this article, we describe the first direct test of this hypothesis. We measured the urgency traits and risky behavior involvement while in extremely positive and negative moods over the course of the first year of college for 292 students. After controlling for sex, typical mood state, and prior mood-based rash behavior, positive urgency predicted increases in positive mood-based rash action, and negative urgency predicted increases in negative mood-based rash action during the first year of college. These results provide further evidence for the validity of the theory of emotion-based rash action and for the measures of positive and negative urgency.
Time-resolved optical-pumping study of hydrogen discharges.

A new technique is described which utilizes optical pumping in a time-resolved mode to study atomic hydrogen produced by a discharge. Initial measurements provide information about the equlibrium atomic-hydrogen density, its temporal evolution, and the diffusion coefficient for hydrogen atoms in molecular hydrogen.
The role of membrane microdomains in shaping β2-adrenergic receptor-mediated cAMP dynamics

Recently, membrane rafts and caveolae have received much attention for their role as signaling platforms, particularly due to their involvement in the pathogenesis of a number of diseases, including HIV as well as neurological and cardiovascular conditions. Signaling mediated by the β-adrenergic receptor (β-AR), a member of the large family of G-protein coupled receptors (GPCRs) that transduce extracellular messages via the ubiquitous second messenger, cAMP, has been a focus of raft studies since multiple components of the pathway are compartmentalized by these membrane microdomains. However, how these membrane rafts behave and regulate signaling dynamics in a cellular context is poorly understood. Here, we describe a live-cell assay based on single-cell, real-time fluorescence imaging, via an improved FRET-based cAMPbiosensor, to monitor raft regulation of second messenger dynamics. Upon cholesterol depletion with methyl-β-cyclodextrin (MβCD), β2-AR-mediated cAMP accumulation was enhanced and prolonged in HEK-293 cells, demonstrating that membrane raft integrity helps shape β-AR signaling. Single-cell imaging in parallel with fractionation studies reveal that the enhancement and change of dynamics are mediated by the receptor and correlated with its redistribution. Finally, the effect of cholesterol depletion is receptor-type specific as MβCD treatment did not show the same effect when the raft-excluded prostaglandin E receptor was stimulated. This study highlights the potential of a live-cell, real-time imaging assay for studying membrane rafts, including high sensitivity and spatiotemporal resolution, to achieve a better understanding of the nuances of membrane microdomains in both healthy and diseased states.
Chest pain of cardiac and noncardiac origin

Chest pain is one of the most common symptoms driving patients to a physician's office or the hospital's emergency department. In approximately half of the cases, chest pain is of cardiac origin, either ischemic cardiac or nonischemic cardiac disease. The other half is due to noncardiac causes, primarily esophageal disorder. Pain from either origin may occur in the same patient. In addition, psychological and psychiatric factors play a significant role in the perception and severity of the chest pain, irrespective of its cause. Chest pain of ischemic cardiac disease is called angina pectoris. Stable angina may be the prelude of ischemic cardiac disease; and for this reason, it is essential to ensure a correct diagnosis. In most cases, further testing, such as exercise testing and angiography, should be considered. The more severe form of chest pain, unstable angina, also requires a firm diagnosis because it indicates severe coronary disease and is the earliest manifestation of acute myocardial infarction. Once a diagnosis of stable or unstable angina is established, and if a decision is made not to use invasive therapy, such as coronary bypass, percutaneous transluminal coronary angioplasty, or stent insertion, effective medical treatment of associated cardiac risk factors is a must. Acute myocardial infarction occurring after a diagnosis of angina greatly increases the risk of subsequent death. Chest pain in women warrants added attention because women underestimate their likelihood to have coronary heart disease. A factor that complicates the clinical assessment of patients with chest pain (both cardiac and noncardiac in origin) is the relatively common presence of psychological and psychiatric conditions such as depression or panic disorder. These factors have been found to cause or worsen chest pain; but unfortunately, they may not be easily detected. Noncardiac chest pain represents the remaining half of all cases of chest pain. Although there are a number of causes, gastroesophageal disorders are by far the most prevalent, especially gastroesophageal reflux disease. Fortunately, this disease can be diagnosed and treated effectively by proton-pump inhibitors. The other types of non-gastroesophageal reflux disease-related noncardiac chest pain are more difficult to diagnose and treat. In conclusion, the cause of chest pain must be accurately diagnosed; and treatment must be pursued according to the cause, especially if the cause is of cardiac origin.
Factors Associated with Contraceptive Satisfaction in Adolescent Women Using the IUD

Abstract Study Objective To estimate satisfaction and to identify factors contributing to an adolescent woman's satisfaction with the levonorgestrel-containing or copper intrauterine device (IUD). Design Adolescent women presenting to an urban clinic within 1 month of IUD insertion completed survey questionnaires about prior use of contraception, gynecologic/obstetric history, and a pain scale. Participants were contacted at 3 and 6 months post-insertion to complete surveys regarding satisfaction with the IUD, their menstrual bleeding patterns, and pain and cramping due to the IUD. Chi-square test, Fisher exact test, and logistic regression were used for analysis. Setting Mount Sinai Adolescent Health Center in New York City. Participants Seventy-nine adolescent women aged 15-24 y. Interventions None. Main Outcome Measure Satisfaction was measured at 3 and 6 months post-IUD insertion as a 10-point Likert item. Results 82% and 76% percent of participants were available for follow-up at 3 and 6 months, respectively. Satisfaction with the IUD was high overall with 75.4% (49/65) of participants choosing a satisfaction rating of eight or higher on the 10-point scale at 3 months and 76.7 % (46/60) at 6 months. Prior history of pregnancy and selecting the levonorgestrel containing IUD were predictive of higher satisfaction at 3 months, but not at 6 months. Parity and prior use of contraceptive methods were not predictive of satisfaction. Conclusion The finding of high satisfaction across participants supports the current recommendation for the IUD as a first-line contraceptive for adolescents. Nulliparous young women and those who are naive to contraception should be considered as candidates for the IUD.
The Accusing Body

This essay addresses and critiques attempts by politicians to legislate the language used to describe and therefore define women’s experience of sexual assault. What is written from the body changes the body and vice versa; what is performed turns back on itself changing word and body. Rep. Bobby Franklin (R-Marietta) wants to label me “accuser,” thereby erasing my assaulted body unless and until “there’s a conviction in the matter.” There was never a conviction in the matter of my case. So where does that leave me? He doesn’t want me to claim victimage, as if being a victim is somehow a privilege, a legal labeling granted on “proof” of the attack. The assaulted body is changed by the legal replacement of “victim” for “accuser.” The word tries to displace or erase the action from the agent and replace it with a burden of proof. So following a most heinous experience, as “accuser,” the woman must now carry the burden of proving herself, accounting not only for her own experience, but also, that it actually...
Characterization of bombesin/gastrin-releasing peptide receptors in membranes of MKN45 human gastric cancer

Binding of the radiolabeled bombesin analog [125I-Tyr4]bombesin to crude cell membranes of MKN45 human gastric cancer grown in nude mice was investigated in vitro. Scatchard analyses of multipoint binding data, performed by complete displacement method demonstrated the presence of two classes of [Tyr4]bombesin binding sites. The high-affinity binding sites had a mean dissociation constant (Kd1) of 2.75 nM with a mean maximal binding capacity (Bmax1) of 492 fmol/mg membrane protein, while the low-affinity binding sites showed a mean dissociation constant (Kd2) of 0.41 microM with a mean maximal binding capacity (Bmax2) of 41.4 pmol/mg membrane protein. Binding of [125(1)-Tyr4]bombesin was specific, reversible and linearly related to the protein concentration of tumor membrane. In displacement studies, the binding of radiolabeled [Tyr4]bombesin was inhibited in a dose-dependent manner by gastrin releasing peptide (GRP)(14-27) and two synthetic antagonists of bombesin/GRP, RC-3095 and RC-3950-II. Both antagonists exhibited high affinity in nearly the same concentration range as GRP(14-27). The presence of receptors for bombesin/GRP on human gastric cancer membranes suggests that bombesin-like peptides may play a role in growth of gastric cancer.
Nest-area fidelity of Greater Sage-Grouse in Strawberry Valley, Utah

ABSTRACT. Nest-area fidelity is common among many birds including those in the orders Anseriformes, Ciconiiformes, and Procellariiformes. Successful nesting attempts are often associated with a higher probability that nesting adults will return in a consecutive year. Conversely, unsuccessful birds are often less likely to show fidelity in subsequent years. Despite substantial natural history information from across the range of Greater Sage-Grouse (Centrocercus urophasianus), the prevalence of sage-grouse nest-area fidelity remains unclear. Our objectives were to (1) determine if individual female sage-grouse showed fidelity to nesting areas in subsequent years, (2) test whether successful females were more likely to demonstrate fidelity than unsuccessful females, and (3) examine the distance between nest sites and active leks in Strawberry Valley, Utah. We observed 30 radio-marked females that attempted a nest in consecutive nesting seasons between 1998 and 2010. The mean distance between initial year's ...
The Political Economy of Consumer Protection: an Examination of State Legislation:

SINCE 1976 the locus of regulatory responsibilities has shifted dramatically. With the Carter-sponsored economic deregulation and the Reagan relaxation of enforcement, the federal regulatory effort can be categorized as stable or declining (Ball 1984). Few federal efforts have been cut back as much as consumer protection. The Federal Trade Commission has become more market oriented; the Consumer Product Safety Commission now emphasizes voluntary controls; and the National Highway Traffic Safety Administration has become pro-automaker (Claybrook 1984; Pertschuk 1982). Consumer protection, however, has always been a regulatory policy area in which the federal government shared jurisdiction with the states. As the federal government withdraws from efforts that protect consumers, the activities of state governments may become more important. This research has two purposes: to examine state-to-state variation in the laws regulating consumer transactions, and to offer new indicators of important, but difficult to measure, concepts in policy analysis. Consumer protection policies will be incorporated into a general theory of regulation; policy is hypothesized to be a function of industry pressures, consumer groups, bureaucratic forces, and elected officials. These four factors determine consumer protection policy within a policy environment that is salient but not complex. Hypotheses derived from this theory are subjected to empirical tests with a fifty-state analysis of twenty-two state laws.
Worldwide Prevalence and Trends in Unintentional Drug Overdose: A Systematic Review of the Literature

Background. Drug overdose is an important, yet an inadequately understood, public health problem. Global attention to unintentional drug overdose has been limited by comparison with the scope of the problem. There has been a substantial increase in drug overdose incidence and prevalence in several countries worldwide over the past decade, contributing to both increased costs and mortality.Objectives. The aim of this study was to systematically synthesize the peer-reviewed literature to document the global epidemiological profile of unintentional drug overdoses and the prevalence, time trends, mortality rates, and correlates of drug overdoses. We searched different combinations of Medical Subject Headings (MeSH) terms in PubMed for articles published from 1980 until July 2013, and we organized these results in tabular spreadsheets and compared them. We restricted the search to English-language articles that deal with unintentional overdose, focusing on 1 or more of the following key constructs: prevalence,...
Oncogenic regulators and substrates of the anaphase promoting complex/cyclosome are frequently overexpressed in malignant tumors.

The fidelity of cell division is dependent on the accumulation and ordered destruction of critical protein regulators. By triggering the appropriately timed, ubiquitin-dependent proteolysis of the mitotic regulatory proteins securin, cyclin B, aurora A kinase, and polo-like kinase 1, the anaphase promoting complex/cyclosome (APC/C) ubiquitin ligase plays an essential role in maintaining genomic stability. Misexpression of these APC/C substrates, individually, has been implicated in genomic instability and cancer. However, no comprehensive survey of the extent of their misregulation in tumors has been performed. Here, we analyzed more than 1600 benign and malignant tumors by immunohistochemical staining of tissue microarrays and found frequent overexpression of securin, polo-like kinase 1, aurora A, and Skp2 in malignant tumors. Positive and negative APC/C regulators, Cdh1 and Emi1, respectively, were also more strongly expressed in malignant versus benign tumors. Clustering and statistical analysis supports the finding that malignant tumors generally show broad misregulation of mitotic APC/C substrates not seen in benign tumors, suggesting that a “mitotic profile” in tumors may result from misregulation of the APC/C destruction pathway. This profile of misregulated mitotic APC/C substrates and regulators in malignant tumors suggests that analysis of this pathway may be diagnostically useful and represent a potentially important therapeutic target.
The (positive) effect of macroeconomic crises on the schooling and employment decisions of children in a middle-income country

The impact of macroeconomic crises on parents' investments in the human capital of their children is a widely contested issue. The author analyzes the effects of the profound macroeconomic crisis in Peru in 1988-92 on the schooling and employment decisions made by urban school-age children. He arrives at two basic findings: First, the crisis had no effect on the attendance rates of school-age children. But the share of children who were both employed and in school fell significantly during the crisis. Second, mean educational attainment was significantly higher for children who were exposed to the crisis than for those who were not. THe author argues that these findings may be related: children who are not employed have more time available and may therefore put more effort into school. He concludes with a discussion of the implications of his findings for the design of appropriate social protection policies.
Presynaptic ryanodine receptor-CamKII signaling is required for activity-dependent capture of transiting vesicles.

Activity elicits capture of dense-core vesicles (DCVs) that transit through resting Drosophila synaptic boutons to produce a rebound in presynaptic neuropeptide content following release. The onset of capture overlaps with an increase in the mobility of DCVs already present in synaptic boutons. Vesicle mobilization requires Ca2+-induced Ca2+ release by presynaptic endoplasmic reticulum (ER) ryanodine receptors (RyRs) that in turn stimulates Ca2+/calmodulin-dependent kinase II (CamKII). Here we show that the same signaling is required for activity-dependent capture of transiting DCVs. Specifically, the CamKII inhibitor KN-93, but not its inactive analog KN-92, eliminated the rebound replacement of neuropeptidergic DCVs in synaptic boutons. Furthermore, pharmacologically or genetically inhibiting neuronal sarco-endoplasmic reticulum calcium ATPase to deplete presynaptic ER Ca2+ stores or directly inhibiting RyRs prevented the capture response. These results show that the presynaptic RyR–CamKII pathway, which triggers mobilization of resident synaptic DCVs to facilitate exocytosis, also mediates activity-dependent capture of transiting DCVs to replenish neuropeptide stores.
Using the Common Criteria to Elicit Security Requirements with Use Cases

The common criteria is often too confusing and technical for non-security specialists to understand and therefore properly use. At the same time, it is essential that security critical IT products under development be validated according to such standards not after but rather during the software engineering process. To help address these issues, this paper presents an approach to eliciting security requirements for IT systems with use cases using common criteria methodologies. The approach involves using actor profiles to derive threats, mapping derived threats to security objectives, and mapping objectives to security requirements using a CC toolbox data set. Our aim is to ensure that security issues are considered early during requirements engineering while making the common criteria more readily available to end-users in an understandable context. Violet, an open source UML diagram modeling tool, has been extended to implement the approach from a use case textual description perspective
Curse of digital polar transmission: Precise delay alignment in amplitude and phase modulation paths

Radio transmitters using the polar scheme utilize a CO-ORDInate Calculator (CORDIC) to transform the often interpolated baseband data in Cartesian format to its polar equivalent. This non-linear transmission typically results in an increased bandwidth for amplitude and phase modulated signals. In case of digital implementation, each of these amplitude and phase/frequency modulation paths are realized using segmented modulators, with fine resolution achieved by techniques such as sigma-delta modulation. This paper first describes the structure of a digital polar transmitter. This is followed by a study on the impact of the increased bandwidth in the polar domain on the timing alignment accuracy requirements between the amplitude and phase modulation paths. Furthermore, for each high-resolution modulation path the timing accuracy between the integer and the sigma-delta fractional path split is also analyzed.
Different modes of binding of mono-, di-, and trihalogenated phenols to the hemoglobin dehaloperoxidase from Amphitrite ornata.

The hemoglobin dehaloperoxidase (DHP), found in the coelom of the terebellid polychaete Amphitrite ornata, is a dual-function protein that has the characteristics of both hemoglobins and peroxidases. In addition to oxygen transport function, DHP readily oxidizes halogenated phenols in the presence of hydrogen peroxide. The peroxidase activity of DHP is high relative to that of wild-type myoglobin or hemoglobin, but the most definitive difference in DHP is a well-defined substrate-binding site in the distal pocket, which was reported for 4-iodophenol in the X-ray crystal structure of DHP. The binding of 2,4,6-trihalogenated phenols is relevant since 2,4,6-tribromophenol is considered to be the native substrate and 2,4,6-trichlorophenol also gives high turnover rates in enzymatic studies. The most soluble trihalogenated phenol, 2,4,6-trifluorophenol, acts as a highly soluble structural analogue to the native substrate 2,4,6-tribromophenol. To improve our understanding of substrate binding, we compared the m...
Millimeter-Wave Solid-State Exciter-Modulator-Amplifier Module for Gigabit Data-Rate

A module consisting of an IMPATT diode oscillator, a PIN diode bi-phase modulator, and an IMPATT diode power amplifier operated at a gigabit data-rate in-V-band frequency range is described.
Surgical Treatment of Tibial Plafond Fractures

Intra-articular fractures of the tibial plafond are typically the result of rotational or axial loading forces, and both mechanisms of injuries can result in an associated fibula fracture. Rotational distal tibial plafond fractures are typically of lower energy and are associated with less articular injury and chondral impaction, whereas axial load injuries of the distal tibial plafond are associated with a higher incidence of intra-articular and soft tissue injury. The goal of this article is to review the mechanisms of injury, fracture patterns, and potential complications associated with the most common presentations of tibial plafond fractures.
Bulk Power System Reliability Assessment Experience with the RECS Program

This paper describes the philosophy, objectives, and experience in bulk power system reliability assessment using the RECS program. RECS stands for Reliability Evaluation Via Contingency Simulation. It is a modular and expandible program for assessing the reliability of the combined (generation/transmission) power system. The paper describes the concepts, models, computational techniques, and data reqquirements of the program. Emphasis is placed on the experience gained using this program for reliability studies of the Southern Company System. Studies of three subsystems of the Southern Company System are presented and discussed. Finally, future needs and developments are outlined.
Pathology of locoweed poisoning in sheep.

The poisoning of livestock by locoweeds (plants of the genera Astragahs and Oxytropis) in the United States was first reported in 187315. Since that time, numerous reports have been published on various aspects of the disease such as the clinical signs in domestic animals, the sequelae of loco poisoning, the species of plants involved, and substances in locoweeds that might induce the signs of poisoning2-6% 8% 10912-18,209 22. Although many clinical signs have been reported from locoweed intoxication, such reports have not always agreed. MARSH reported slow, staggering gait, rough coat, staring look, emaciation, lack of muscular coordination, and extreme nervousness15. JAMES et al.8 have emphasized the abortive and teratogenic consequences in sheep and cattle. These clinical signs might be more explicitly expressed as : central nervous impairment resulting in diminished or lost control of motor function and proprioception, emaciation, and reproductive disorders resulting in abortion or teratogenesis. An adequate description is lacking of the lesions of locoweed intoxication in sheep. MATHEWS17 described various gross changes and a generalized neuronal degeneration. OEHME et al.18 reported vacuolar degeneration of neurons in horses poisoned under field conditions. They did not attempt extensive histochemical studies to determine the nature of the lesions. Our own study of tissues collected from field cases of locoweed poisoning in sheep indicated severe vacuolar degenerative changes in the parenchymal cells of central nervous system, liver, kidney, and various endocrine organs. This study was designed to induce locoweed poisoning in sheep
Herding in Queues with Waiting Costs: Rationality and Regret

We study how consumers with waiting cost disutility choose between two congested services of unknown service value. Consumers observe an imperfect private signal indicating which service facility may provide better service value as well as the queue lengths at the service facilities before making their choice. If more consumers choose the same service facility because of their private information, longer queues will form at that facility and indicate higher quality. On the other hand, a long queue also implies more waiting time. We characterize the equilibrium queue-joining behavior of arriving consumers and the extent of their learning from the queue information in the presence of such positive and negative externalities. We find that when the arrival rates are low, utility-maximizing rational consumers herd and join the longer queue, ignoring any contrary private information. We show that even when consumers treat queues as independently evolving, herd behavior persists with consumers joining longer queues above a threshold queue difference. However, if the consumers seek to minimize ex post regret when making their decisions, herd behavior may be dampened.
Personal Advertisements: Sources of Data about Relationships:

Personal advertisements are a growing means of meeting other people and establishing relationships. The variety of these advertisements makes them an excellent source of data for social science research, but this interesting resource is presently underutilized. This article attempts to persuade more social scientists to use personal ads as a source of research data and it discusses the positive features of this data source and outlines various research methods possible with them. Existing studies using personal advertisements as a source of data are reviewed as illustrations of the methods presented.
Pomo Indian Basket Weavers: Their Baskets and the Art Market

POMO INDIAN BASKET WEAVERS: THEIR BASKETS AND THE ART MARKET. National Museum of the American Indian, New York, N.Y. (May 9, 1999—August 15,1999).
Optical Alignment Support Of The Magnetic Field Satellite (MAGSAT) Vector Magnetometer Calibration

The Magnetic Field Satellite (MAGSAT) was launched into low earth orbit on October 30, 1979, and reentered on June 11, 1980. It included a vector magnetometer which was successfully used to accurate-ly map the magnitude and direction of the magnetic field over most of the surface of the earth. To achieve the accuracy sought required arc second precision determination of the relative orientations of the three sensor axes in a coordinate system defined by optical references attached to the magnetometer. The calibration procedure consisted basically of accurate and repeatable positioning of the vector magnetometer within a unique magnetic test facility which nulls the earth's magnetic field, then generates magnetic fields of selected orientations and strengths. Analysis of the magnetometer sensor outputs together with data on the accurate positioning and optical reference alignment gave the axes orientations. We used precision theodolites and methods related to surveying techniques to do the accurate positioning and optical component alignment measurements.
An exploration of transactional states and cessation-related social variables within adolescent smokers

Background Given the high rate of adolescent smoking, cessation remains a vital public health priority. This study explored archival data using a structured phenomenological framework known as Reversal Theory (RT). In order to better understand aspects of adolescent tobacco use we compared the transactional, psychological states described by RT to the factor structure of adolescents’ self-reported social environment influencing tobacco use.
The innate immune protein Nod2 binds directly to MDP, a bacterial cell wall fragment.

Mammalian Nod2 is an intracellular protein that is implicated in the innate immune response to the bacterial cell wall and is associated with the development of Crohn’s disease, Blau syndrome, and gastrointestinal cancers. Nod2 is required for an immune response to muramyl dipeptide (MDP), an immunostimulatory fragment of bacterial cell wall, but it is not known whether MDP binds directly to Nod2. We report the expression and purification of human Nod2 from insect cells. Using novel MDP self-assembled monolayers (SAMs), we provide the first biochemical evidence for a direct, high-affinity interaction between Nod2 and MDP.
Probability hypothesis density filter for multitarget multisensor tracking

Multiple target tracking techniques require data association that operates in conjunction with filtering. When multiple targets are closely spaced, the conventional approach (MHT/assignment) may not give satisfactory results, mainly due to the difficulty in deciding the number of targets. Recently, the first moment of the "multi-target posterior density", called the probability hypothesis density (PHD), has been proposed to address the multi-target tracking problem. Particle filtering techniques have been applied to implement the PHD based tracking. In this paper, we explain our interpretation of the PHD, and then investigate its performance on the problem of tracking unresolved targets from multiple sensors. In the set-up, there are two different radars, which monitor the targets, and the PHD is fed sequentially by these scans. In the scenario, we investigate 3 different levels of complexity in terms of measurement extraction methodologies of sensors when there are unresolved targets 1) Sensor model reports a measurement with variance /spl sigma//sub mono//sup 2/. (Sensor is not capable of sensing any abnormality in radar return). 2) Sensor model gives a single measurement with a larger variance /spl sigma//sub azi//sup 2//spl ges//spl sigma//sub mono//sup 2/ 3) Sensor model uses a multi-target measurement extractor. Unresolved targets create separate measurements with variance /spl sigma//sub mono//sup 2/. Simulation results for two-dimensional scenario are given to show the performance of the approach. Based on our simulation results, we also discuss difficulties the PHD algorithm seems to encounter, especially as is reflected in the target "death" event.
Targeting abdominal obesity and the metabolic syndrome to manage cardiovascular disease risk

Almost every week there is an article published in a major national newspaper on the epidemic proportions reached by obesity in various countries. The pathophysiology of obesity is complex and some people are more prone to accumulate excess fatness and to develop related metabolic complications than others. However, despite individual differences in genetic susceptibility to body fat accumulation, it has become obvious that the epidemic proportions reached by obesity is partly the result of a pronounced reduction in the level of daily physical activity as we have engineered for ourselves a very comfortable sedentary environment. For example, most of us are now sedentary during working hours and we use transportation devices (cars, trains, planes) to go from one place to another. In addition, what was centuries ago a constant daily struggle (getting access to food, sometimes in limited quantities) has become very easy: we are surrounded by energy dense, refined foods which promote the passive overconsumption of calories. Therefore, an environment favouring minimal energy expenditure but facilitating overeating largely contributes to the worldwide epidemic of obesity. However, although it is generally perceived that obesity causes prejudice to health, this condition has, for a long time, left cardiologists rather perplexed. For example, although epidemiological studies have shown that an excess relative body weight (the most commonly used index being the body mass index (BMI) expressed in kg of body weight divided by height in m2) is associated with increased mortality and comorbidities such as hypertension, dyslipidemia and diabetes,w1–4 obesity assessed by the BMI has often failed to be identified as an independent risk factor for cardiovascular disease (CVD), once adjustments are made for the presence of comorbidities. There are two possible explanations for the weak independent association between obesity and CVD. First of all, it is possible that the …
Mediators of septic lung injury.

Abstract Septic pulmonary injury remains a significant cause of morbidity and mortality among hospitalized patients today and is likely to increase in prevalence as advances in medical technology allow the salvage of more critically ill and immunocompromised hosts. Treatment of the host's underlying disease and even of the infection itself has appeared to redeem septic patients only to have them succumb in increasing numbers to the pulmonary injury reaction. Our understanding of the mechanisms and mediators of lung dysfunction in sepsis is in a rapidly expanding phase. Currently we recognize the contributions of several blood elements, lipids, and peptides to pulmonary injury, although the relative importance and points of interaction and interdependence of these mediators remain to be established. It is hoped that a more complete understanding of the process of pulmonary injury in sepsis will suggest effective means of intervention at a stage in which damage may be reversed or minimized.