cssi/SciSciGPT-SciSciNet huggingface dataset:
Accounting for Wage and Employment Changes in the U.S. from 1968-2000: A Dynamic Model of Labor Market Equilibrium, Second Version

In this paper, we present a unified treatment of and explanation for the evolution of wages and employment in the U.S. over the last 30 years. Specifically, we account for the pattern of changes in wage inequality, for the increased relative wage and employment of women, for the emergence of the college wage premium and for the shift in employment from the goods to the service-producing sector. The underlying theory we adopt is neoclassical, a two-sector competitive labor market economy in which the supply of and demand for labor of heterogeneous skill determines spot market skill-rental prices. The empirical approach is structural. The model embeds many of the features that have been posited in the literature to have contributed to the changing U.S. wage and employment structure including skill-biased technical change, capital-skill complementarity, changes in relative product-market prices, changes in the productivity of labor in home production and demographics such as changing cohort size and fertility.
Activating mutations in p110δ cause human immunodeficiency and reveal important roles of PI3K in T cell senescence and homeostatic cell death (HUM2P.334)

The p110δ subunit of phosphatidylinositol-3-kinase (PI3K) is selectively expressed in leukocytes and plays critical roles in lymphocyte biology. We have identified 14 patients from 7 families who were heterozygous for one of three different germline, gain-of-function mutations in PIK3CD (which encodes p110δ) and suffered from sinopulmonary infections, lymphadenopathy, nodular lymphoid hyperplasia, and viremia due to cytomegalovirus and/or Epstein-Barr virus. Strikingly, hyperactivation of PI3K signaling caused significant skewing of peripheral blood CD8 T cells toward an effector phenotype with exaggerated effector characteristics in vitro. Mechanistically, T cell blasts harboring gain-of-function mutations in p110δ exhibited constitutively hyperactive Akt and mTORC1 signaling with enhanced glucose uptake. These changes promoted marked terminal effector cell differentiation and senescence of CD8 T cells. Notably, treatment of patients with rapamycin to inhibit mTOR activity in vivo partially restored the abundance of naive T cells, largely ‘rescued’ the in vitro T cell defects, and greatly improved clinical course. In addition to enhanced effector characteristics, in vitro analyses of patient T cell blasts also revealed a greater susceptibility to TCR restimulation-induced cell death. Indeed, in an independent chemical genetics screen, PI3K stood out as a critical pro-death kinase whose downstream signaling connected with caspase activation upon TCR restimulation.
Mining Diagnostic Assessment Data for Concept Similarity

This paper introduces a method for mining multiple-choice assessment data for similarity of the concepts represented by the multiple choice responses. The resulting similarity matrix can be used to visualize the distance between concepts in a lower-dimensional space. This gives an instructor a visualization of the relative difficulty of concepts among the students in the class. It may also be used to cluster concepts, to understand unknown responses in the context of previously identified concepts.
The Effects Of Different Sections And Students Pre-Course Interest On An Instructors Teaching Evaluations

This study has identified two important factors, unrelated to an instructor’s teaching ability, which can affect an instructor’s teaching evaluations. The first factor, which has never been examined in any prior studies, is the section effect. This study finds that teaching evaluations differ significantly across sections of the same course taught by the same instructor. This section effect cannot be explained by six student-related variables. The second factor, which is students’ pre-course interest measured at the beginning of a course, is found to be positively related to teaching evaluations. These findings suggest that higher-education administrators may want to consider the section effect and the students’ pre-course interest when they evaluate an instructor’s teaching effectiveness for promotion, tenure and merit decisions.
DNA glycosylases search for and remove oxidized DNA bases.

The following mini review summarizes recent research from the Author’s laboratory as presented to the Environmental Mutagen Society in October 2012. It provides an overview of the DNA glycosylases that recognize oxidized DNA bases using the Fpg/Nei family of DNA glycosylases as models for how structure can inform function. For example, even though human NEIL1 and the plant and fungal orthologs lack the zinc finger shown to be required for binding, DNA crystal structures revealed a “zincless finger” with the same properties. Also the “lesion recognition loop” is not involved in lesion recognition rather stabilization of 8-oxoG in the active site pocket. Unlike the other Fpg/Nei family members, Neil3 lacks two of the three void-filling residues that stabilize the duplex and interact with the opposite strand which may account for its preference for lesions in single stranded DNA. We also showed, using single molecule approaches, that DNA glycosylases search for their substrates in a sea of undamaged DNA by using a wedge residue that is inserted into the DNA helix to probe for the presence of damage.
Mycobacterium tuberculosis bacteraemia: experience from a non-endemic urban centre.

The isolation of Mycobacterium tuberculosis from blood culture specimens has been associated with human immunodeficiency virus (HIV) co-infection with variable impact on tuberculosis (TB) mortality reported. The overwhelming majority of M. tuberculosis bacteraemia cases were described in developing countries. We present a nested case–control analysis of clinical, sociodemographic and behavioural risk factors in patients with positive M. tuberculosis blood cultures compared with patients with negative blood cultures from a 9-year population-based active TB surveillance study conducted in Houston, Texas. There were 42 patients with M. tuberculosis bacteraemia, 47 blood culture negative patients and 3573 patients for whom no mycobacterial blood culture was requested. HIV infection was more common in patients for whom a mycobacterial blood culture was requested (79.8% versus 15.1% p <0.001). Of the patients with M. tuberculosis bacteraemia, six were HIV negative or had no documentation of HIV status, including five with immunosuppressive conditions other than HIV. Patients with M. tuberculosis bacteraemia were more likely than patients with negative blood cultures to be deceased at diagnosis or to die while on TB therapy (50.0% versus 17.0%, p <0.01), to report men-who-have-sex-with-men behaviour (31.7% versus 13.0%, p 0.03), to have renal failure (28.6% versus 6.4%, p 0.01), and to have HIV RNA levels higher than 500 000 copies/mL (61.9% versus 17.2%, p ≤0.01). Requests for mycobacterial culture of blood specimens were more common in HIV-infected individuals, and the presence of M. tuberculosis bacteraemia was associated with a significant increase in mortality.
Correction of numerical error in kinematical differential equations when one direction cosine is known

Abstract If a direction cosine matrix represents a two-axis rotation, one of the direction cosines remains zero. It is shown how one can take advantage of this knowledge to improve the correction of numerical errors in the parametrizing variables of the matrix. The cases of Euler parameters and six-parameter representations are considered, as well as Euler-Rodrigues parameters for which there is no traditional correction process because they normally do not satisfy any kinematical constraint. Improvement in the matrix estimates can be gotten in all cases, but only for the six-parameter method is it substantial.
Quantum cryptography: An emerging technology in network security

The uses of computer communications networks technologies have increased the incidents of computer abuse. Because of these incidents, most organizations facing pressure to protect their assets. Most digital networks generally rely on modern cryptosystems to secure the confidentiality and integrity of traffic carried across the network. The current modern cryptosystems based on mathematical model introduce potential security holes related to technological progress of computing power, the key refresh rate and key expansion ratio, the most crucial parameters in the security of any cryptographic techniques. For that reason efforts have been made to establish new foundation for cryptography science in the computer communications networks. One of these efforts has led to the development of quantum cryptography technology, whose security relies on the laws of quantum mechanics [1,2,3,20, 24]. This research paper concentrates on quantum cryptography, and how this technology contributes to the network security. The scope of this research paper is to cover the weaknesses, and the security pitfalls in modern cryptography, fundamental concepts of quantum cryptography, the real — world application implementation of this technology, finally the future direction in which the quantum cryptography is headed forwards.
Diurnal observations on the behavioral ecology of Gymnothorax moringa (Cuvier) and Muraena miliaris (Kaup) on a Caribbean coral reef

Activities of muraenids, primarilyGymnothorax moringa andMuraena miliaris, were observed on a Caribbean coral reef with a view to further understanding their role in the reef ecosystem. Other muraenid species included in the total of 198 sightings wereEchidna catenata, Enchelycore nigricans, and an unidentified brown moray. The five species were unequally distributed among three basic habitats (sand, coral head, reef rock) available on the reef. Nine particular holes accounted for 52.5% of the total sightings, although hundreds of other seemingly appropriate sites were available. The eels (exceptM. miliaris) were transient with respect to given holes and particular sections of the reef. While someG. moringa were sighted in the same holes for several consecutive days,M. miliaris individuals remained in the same coral heads throughout the 6-week study period. Muraenids observed in this study showed high tolerances for and were tolerated by other fishes (including other morays) and invertebrates on the reef. They appeared to be opportunistic, roving predators and were not strictly nocturnal. Distinct behavioral interactions and displays between muraenids and reef fish were observed.
Hydroxylation and deglycosylation of 2'-deoxyguanosine in the presence of magnesium and nickel.

Abstract Nickel (Ni), a carcinogenic and genotoxic metal, has been shown to enhance deglycosylation and hydroxylation of 2′-deoxyguanosine (dG) that has been caused by ascorbic acid and H2O2. There is evidence that Mg is a competitive antagonist of the toxicological effects of Ni. A factorial design was used to examine the interactive influence of Mg and Ni on the deglycosylation and hydroxylation of dG under a range of pH conditions in which ascorbate (Ascb) and H2O2 were added. Formation of guanine (Gu) (deglycosylation) and 8-hydroxy-2′-deoxyguanosine (8-OH-dG) (hydroxylation) appeared in large amounts in samples in which both H2O2 and Ascb were present. The largest amounts of Gu appeared where both Ni or magnesium (Mg) were present. When Mg alone was present, the amounts of Gu was intermediate between these two. Slightly less 8-OH-dG was formed where only Mg was present. The reaction mixtures were more sensitive to the pH than to the respective presence or absence of metals. At slightly acid or neutral pH (6.2–7.0) large amounts of both Gu and 8-OH-dG were formed. Gu formation decreased dramatically between pH 7.0 and 7.2. There was no 8-OH-dG formed at pH 7.8 and only small amounts at pH 7.6. The formation of 8-OH-dG was generally less where Mg was present. When Ni was absent, 8-OH-dG formation was greater in the pH 6.8 mixtures. The formation of Gu and 8-OH-dG from 2′-deoxyguanosine are directly a function of pH. Slight changes in pH greatly effected the formation of these biomarkers of oxidatively damaged DNA. Additional research is needed to determine if this is a cause or effect, i.e. does pH enhance toxicity conditions, thus permitting formation of 8-OH-dG, or does pH permit the reaction to proceed.
Persistence filter-based control for systems with time-varying control gains

The paper addresses the generic problem of devising stabilizing control laws for systems with time-varying control gains and unstable drift terms. Specifically, a large class of single-input, linear, control affine systems are considered wherein the control gains (coefficients) can become singular at certain instants in time or stay singular for large time intervals, thus amounting to pointwise-in-time loss of controllability. The time-varying components of the control gains are assumed to be sufficiently smooth and possess certain structure expressed in terms of persistent excitation conditions. A novel persistence filter construction is developed which helps achieve stabilization objectives. Some preliminary results on bounded trajectory tracking are also provided.
Seasonality of peak metabolic rate in non-migrant tropical birds

Birds that are year-round residents of temperate and tropical regions have divergent life histories. Tropical birds have a slower ‘ pace of life ’ , one characteristic of which includes lower peak metabolic rate and daily activity levels. Temperate resident birds are faced with seasonal variation in thermogenic demand. Th is challenge is met with seasonally increased peak metabolic rate during winter. Th ese thermogenic demands are much lower in birds that are year-round tropical residents. By measuring peak (summit) metabolic rate in tropical and temperate resident bird species during summer and winter, we asked whether tropical birds exhibit seasonality in peak metabolic rate, and if the direction of seasonality diff ers between tropical and temperate species. We measured summit metabolism in seven tropical and one temperate species during the winter and during the summer breeding season to test the hypothesis that summit metabolism of tropical residents would change seasonally. We consider whether metabolic seasonality is associated with breeding season for tropical species. We found that summit metabolism was signifi cantly greater during the summer for most tropical residents, while the temperate resident matched several previous reports with higher summit metabolism in winter. We conclude that metabolic seasonality occurs in tropical residents and diff ers from temperate residents, suggesting that breeding during the summer may be driving relatively higher metabolism as compared to winter thermogenesis in temperate birds.
Priority interventions from the NIC and expected results from the NOC in patients with a nursing diagnosis of Ineffective breathing pattern

Abstract The aim of the study was to validate the priority interventions from the Nursing Interventions Classification (NIC) and the expected results from the Nursing Outcomes Classification (NOC) in patients hospitalized in an intensive care unit, with a nursing diagnosis of ineffective breathing pattern . Twenty experts helped with the verification of the priority interventions and expected results. They assigned scores to individual interventions and results, using a Likert scale. During testing, the experts had to indicate with the help of the Likert scale how they perform the various activities in the selected NIC and how they evaluate different indicators in the selected NOC. They could select from the following scale: 1 = not at all, 2 = seldom, 3 = sometimes, 4 = many times, 5 = always. The data were consequently analysed by assigning a value to each of the responses (1 = 0; 2 = 0.25; 3 = 0.5; 4 = 0.75; 5 = 1). The maximum value that could be achieved in the evaluated field was 1, and the minimum was 0. Activities (for NIC) and indicators (for NOC) which were assigned a value of ≥0.8, were identified as priority use, and when they were assigned a value of ≤0.5, they were excluded on the grounds that the nurses performed them minimally or not at all. Others were taken as commonly used. Based on an analysis of the related NIC (specifically: respiratory monitoring 3350, ventilation assistance 3390, chest physiotherapy 3230, airways suctioning 3160 and airways management 3140), we concluded that only 62 activities from a total number of 158 were used by nurses. In the NOC, from a total number of 83, 50 indicators were assessed and 32 can be considered typically rated. On the basis of the results, our experts considered most of the NIC interventions unusable. On the other hand, more than half of the NOC indicators were rated as useful. The results of the study point to the fact that the introduction of the classification systems NIC and NOC would require further testing in clinical practice in the Czech Republic in order for them to be used effectively.
Penile prosthesis infections

In this retrospective review we looked at infection rates and risk factors in penile prosthesis recipients. Computer registry records of patients implanted with three-piece inflatable prostheses from April 1986 to March 1999 were reviewed. Bacteriological culture report data were obtained from the medical records. There were 491 three-piece inflatable penile prosthesis recipients with follow-up ranging from 1 to 168 months (mean 83). All patients were implanted more than 1 y ago. There were 10 infections in 491 recipients (2.0%). In 285 primary prosthesis recipients there were seven infections (2.5%). In 206 secondary prosthesis recipients there were three infections (1.5%). Seven infections occurred in 354 non-diabetics (2.0%) and three infections occurred in 137 diabetics (2.2%). None of these differences were statistically significant. Explants for infection were performed in 8 weeks or less following implantation in eight patients. In two patients explants occurred at 17 and 26 months following implantation. Cultures from the periprosthetic space grew E. coli (four), Proteus mirabilis (two), Staph. aureus (two), and bacteroides (two). Infections occurred in 2.0% of three-piece inflatable penile prosthesis recipients. There were no statistically significant differences in infection rates between first time and repeat prosthesis recipients and between diabetic and non-diabetic recipients. Eight of the 10 infections occurred 8 weeks or less following implantation.
Genetic Characterization of 2 Novel Feline Caliciviruses Isolated from Cats with Idiopathic Lower Urinary Tract Disease

Feline caliciviruses (FCVs) are potential etiologic agents in feline idiopathic lower urinary tract disease (I-LUTD). By means of a modified virus isolation method, we examined urine obtained from 28 male and female cats with nonobstructive I-LUTD, 12 male cats with obstructive I-LUTD, and 18 clinically healthy male and female cats. All cats had been routinely vaccinated for FCV. Two FCVs were isolated; 1 (FCV-U1) from a female cat with nonobstructive I-LUTD, and another (FCV-U2) from a male cat with obstructive I-LUTD. To determine the genetic relationship of FCV-U1 and FCV-U2 to other FCVs, capsid protein gene RNA was reverse transcribed into cDNA, amplified, and sequenced. Multiple amino acid sequence alignments and phylogenetic trees were constructed for the entire capsid protein, hypervariable region E, and the more conserved (nonhypervariable) regions A, B, D, and F. When compared to 23 other FCV isolates with known biotypes, the overall amino acid sequence identity of the capsid protein of FCV-U1 and FCV-U2 ranged from 83 to 96%; identity of hypervariable regions C and E ranged from 58 to 85%. Phylogenetically, FCV-U1 clearly separated from other FCV strains in phenograms based on nonhypervariable regions. In contrast, FCV-U2 consistently segregated with the Urbana strain in all phenograms. Clustering of isolates by geographic origin was most apparent in phenograms based on nonhypervariable regions. No clustering of isolates by biotype was apparent in any phenograms. Our results indicate that FCV-U1 and FCV-U2 are genetically distinct from other known vaccine and field strains of FCV.
LKB1/Mo25/STRAD Uniquely Impacts Sarcomeric Contractile Function and Posttranslational Modification

The myocardium undergoes extensive metabolic and energetic remodeling during the progression of cardiac disease. Central to remodeling are changes in the adenine nucleotide pool. Fluctuations in these pools can activate AMP-activated protein kinase (AMPK), the central regulator of cellular energetics. Binding of AMP to AMPK not only allosterically activates AMPK but also promotes phosphorylation of AMPK by an upstream kinase complex, LKB1/Mo25/STRAD (liver kinase B 1, mouse protein 25, STE-related adaptor protein). AMPK phosphorylation by the LKB1 complex results in a substantial increase in AMPK activity. Molecular targeting by the LKB1 complex depends on subcellular localization and transcriptional expression. Yet, little is known about the ability of the LKB1 complex to modulate targeting of AMPK after activation. Accordingly, we hypothesized that differing stoichiometric ratios of LKB1 activator complex to AMPK would uniquely impact myofilament function. Demembranated rat cardiac trabeculae were incubated with varying ratios of the LKB1 complex to AMPK or the LKB1 complex alone. After incubation, we measured the Ca2+ sensitivity of tension, rate constant for tension redevelopment, maximum tension generation, length-dependent activation, cooperativity, and sarcomeric protein phosphorylation status. We found that the Ca2+ sensitivity of tension and cross-bridge dynamics were dependent on the LKB1 complex/AMPK ratio. We also found that the LKB1 complex desensitizes and suppresses myofilament function independently of AMPK. A phospho-proteomic analysis of myofilament proteins revealed site-specific changes in cardiac Troponin I (cTnI) phosphorylation, as well as a unique distribution of cTnI phosphospecies that were dependent on the LKB1 complex/ AMPK ratio. Fibers treated with the LKB1 complex alone did not alter cTnI phosphorylation or phosphospecies distribution. However, LKB1 complex treatment independent of AMPK increased phosphorylation of myosin-binding protein C. Therefore, we conclude that the LKB1/AMPK signaling axis is able to alter muscle function through multiple mechanisms.
Phase control of Y2BaCuO5 in high-Tc superconducting YBa2Cu3O7 ceramics prepared by rapid solidification processing

Abstract It has recently been reported that Y 2 BaCuO 5 (2-1-1 phase) plays an important role in improving critical current density in bulk superconducting YBa 2 Cu 3 O 7 (1-2-3). We have found that it is possible to incorporate a controlled amount of 2-1-1 in 1-2-3 by post-annealing a precursor prepared by rapid solidification. The phase volume ratio [ 2-1-1 (1-2-3 + 2-1-1) ] can be controlled in the range of 10% to 100% by post-annealing between 900 and 1020°C. Also, CuO precipitates ranging in size from approximately 2 μm to 20 μm were observed in the 1-2-3 phase and a mixture of BaO and CuO was found around these CuO precipitates by SEM and EDX. Samples made by this process show T c ( ρ = 0) of 91.5 K and a sharp superconducting transition, ΔT c = 0.4 K.
Diagnosis of urinoma by MAG3 scintigraphy in a renal transplant patient.

Technetium-99m MAG3 is a new renal tracer that has been proposed to replace combination of 1-131 orthoiodohippurate and Tc-99m DTPA in the evaluation of patients with renal transplants. One concern raised in the literature is that diagnosing urine leaks may be hampered by the fact that MAG3 may be excreted in the gut, simulating a urine leak. Attention should be directed to the fact that a minimal amount of MAG3 is excreted with bile and appears first in the upper small bowel-a pattern distinctly different from a transplant urine leak or urinoma. The authors present a typical example of urinoma appearance on MAG3 scintigraphy. The high urinary concentration of the tracer facilitated prompt and facile identification of the urinoma
Pyloric stenosis following ingestion of potassium permanganate

A case of pyloric stenosis following ingestion of potassium permanganate has been described. This is a rare cause of pyloric stenosis.
Predicting institutional misconduct using the Youth Level of Service/ Case Management Inventory

Offender assessment in corrections has advanced considerably over the last several decades. Currently, it is not uncommon to find correctional professionals using any number of objective standardized assessment instruments. While many of these instruments possess face validity as well as statistical predictive validity, more work is needed to test classification protocol on new populations, and in various correctional environments. The current paper investigates the predictive validity of the Youth Level of Service/Case Management Inventory (YLS/CMI) within an institutional setting. Specifically, the composite score rendered from the YLS/CMI is used to predict institutional misconduct. The YLS/ CMI was found to effectively differentiate between two levels of offender risk/ need, and was significantly related to outcome using several different statistical techniques.
Marked sensitivity of insect cell lines to Fungizone (amphotericin B)

Abstract Two insect cell lines, one of the mosquito Aedes aegypti L. and the other of the Asian moth Antheraea eucalypti Scott, are intolerant to Fungizone, a commercial preparation of the polyene amphotericin B. The mosquito cells exhibited cytopathology in 1 μg/ml and the moth cells in 2 μg/ml. Recovery of moth cultures was reduced by treatment with 6 μg/ml; no mosquito cultures tolerated 3 μg/ml. Because the effect of amphotericin B on other organisms is attributed to competitive inhibition of sterols, the intolerance of insect cell lines to this polyene supports the hypothesis that insects do not synthesize sterols. The use of Fungizone as an antifungal agent in insect tissue culture is of limited value because some common fungi are less susceptible than are insect cells.
Effects of a Restrictive Blood Transfusion Policy on Outcomes in Children with Burn Injury

A restrictive blood transfusion policy decreases blood utilization and improves outcomes in critically ill adults, but the impact of a restrictive blood transfusion policy in critically ill children is unclear. The study purpose was to compare the effects of a restrictive with a traditional blood transfusion policy in children with major burn injury. A retrospective review of all blood transfusions administered in a pediatric burn center during a 5-year period was conducted. Children in the traditional group (January 1, 2000, to June 30, 2002), were transfused at a hemoglobin level of less than 10 g/dl. Children in the restrictive group (January 1, 2003, to June 30, 2005, 6 months after the adoption of a restrictive protocol) were transfused at a hemoglobin level of less than 7 g/dl. Patient groups were compared for demographics, ventilator requirements, blood transfusion number, transfusion costs, and outcomes. Of the 1140 patients studied, 266 (24%) received a total of 2577 units of blood. There was no difference in age, TBSA burn, sex, inhalation injury, or mortality between groups. Patients in the traditional group received more blood than the restrictive group (12.3 +/- 1.8 vs 7.2 +/- 1.2 units/patient, P < .001). The mean cost of blood per patient was $2781 for the traditional group and $1489 for the restrictive group. A restrictive transfusion policy in children with burn injury decreases the amount of blood transfused, does not adversely impact patient outcome, and results in significant cost savings to the institution.
The effector interactions of p21ras

Genetic, physical and biochemical methods have been used successfully to identify discrete regions of the p21ras protein involved in protein-protein interactions. Of special interest are the effector residues of p21ras, which are essential for downstream signalling. This review details current understanding of what these residues are and how they bind and activate proteins essential to the ras pathway.
Longitudinal Outcomes for Mathematics Achievement for Students with Learning Disabilities

ABSTRACT Using longitudinal data from the first 6 waves of the Early Childhood Longitudinal Study–Kindergarten Cohort (ECLS-K), the authors examined mathematics achievement and growth trajectories by learning disability (LD) subgroups. The 2-level (time–student) growth curve model showed that lower levels of mathematics achievement were already evident at kindergarten entry for all subgroups of students identified as LD during the elementary school years. Results indicate that students with LD as a group made smaller gains in mathematics than students without disabilities. This finding underscores the need for early identification combined with frequent assessment of progress and responsive instruction.
An Investigation into the Nature of Inclusion Problem-Solving Teams

This investigation addressed the use of problem-solving teams (PST) to support general education teachers working in inclusive classrooms. Eight teams in a high-poverty elementary school that had recently implemented an inclusive program were the focus of the study. Teachers noted several benefits of PSTs, including social support, learning new instructional approaches, obtaining practical help with problems, and improving practice through reflection. However, there were several problems with the teams, primarily related to the logistics of team meetings. Finally, analysis of teacher dialogue revealed several features of meetings that contributed to meeting productivity. The implications of these findings for practice are discussed.
Stray capacitance and compensation for the converter valves for ultra-high voltage HVDC application

HVDC (High Voltage Direct Current) electric power transmission system uses direct current for bulk transmission of electrical power, and conventional HVDC is based on thyristor converters. The main components in a conventional converter valve include thyristors, gate units, monitoring units, and cooling components. In this paper, an EMTDC simulation-based valve section capacitance determination system has been investigated for the converter valves for a 660kV HVDC transmission system, and it is used to improve the voltage sharing between different parts of the series-connected valve components at steep front impulse voltage type test conditions. Stray capacitances of the valve configuration were obtained by using the proposed analytical methods and verified by comparing to the results obtained using the Boundary Element Method (BEM). It was concluded that the analytical methods of stray capacitance calculations, which give matching results comparing to the numerical method, can be used for the steep front impulse voltage simulation to assess the requirement for valve section capacitor. The studies confirmed that a minimum valve section capacitance of 3nF was required to restrict the steep front impulse voltage stresses across the critical components of the valve configuration.
Relations of the centrolobular region of the glomerulus to the juxtaglomerular apparatus.

Intercapillary or mesangial cells in the centrolobular region of renal glomeruli of rats are similar to and continuous with “lacis” (pseudo-meissnerian) cells of the juxtaglomerular apparatus. They have electron microscopic features which also relate them to the granular epithelioid cells of the juxtaglomerular apparatus and to smooth muscle cells. Their structural features and functions help to differentiate them from adjacent endothelial cells. Intercapillary cells are bathed by a rapid flow of blood plasma through the centrolobular region. They are actively phagocytic and associated with the PAS-positive intercellular substance in normal glomeruli and its increase in disease, with occasional bundles of collagen in the normal glomerulus, and with the formation of collagen in some glomerular diseases in animals and human beings. Intercapillary cells seem to have various mechanisms with which they could supplement the juxtaglomerular apparatus in altering the amount or composition of the urine.
Effects of Gallium on Bone in the Rat

Gallium nitrate lowers the serum calcium in patients with hypercalcemia caused by malignancy and is available for clinical use. The mechanism for the hypocalcemic action is unknown, however. The present studies were undertaken to determine the effects of gallium on bone metabolism. Normal male rats were implanted subcutaneously with mineralized allogeneic bone matrix. Histomorphometry of the implants and of tibiae was determined after three doses of tetracycline administered at intervals of 1 week. Gallium as nitrate was administered daily by intraperitoneal injection at doses of 0.9, 1.8, and 3.6 mg elemental gallium per kg body weight for 21 days in one study and at 3.5 mg/kg for 33 days in a second study. All the gallium-treated rats gained weight. Rats given gallium at doses of 3.5 mg/kg or more grew at a lower rate than untreated controls (-7 and -10% at doses of 3.5 and 3.6 mg/kg, respectively; p < 0.05). At a dose of 0.9 mg/kg, gallium did not inhibit bone resorption or lower serum calcium but inhibited bone formation by 32% and bone apposition by 36% at the endosteal surface of the tibia. At a dose of 1.8 mg/kg, gallium produced modest hypocalcemia, prevented a rise in circulating 1,25-dihydroxyvitamin D [1,25-(OH)2D], inhibited bone resorption in implants, and inhibited bone formation by 19% and bone apposition by 18%. At a dose of 3.5 mg/kg, gallium lowered the serum calcium and serum 1,25-(OH)2D, inhibited growth, and accentuated the antiresorptive and antiformative effects seen at the two lower doses. The results indicate that gallium inhibits bone resorption, produces hypocalcemia, alters vitamin D metabolism, and inhibits bone formation at doses below those that inhibit bone resorption. The mechanism for hypocalcemia may be by direct action on bone and could involve an indirect effect on calcium metabolism mediated by changes in the metabolism of vitamin D.
Indirect Detection of Labile Solute Proton Spectra via the Water Signal Using Frequency-Labeled Exchange (FLEX) Transfer

We report an “exchange-rate-filtered” magnetic resonance approach that allows the detection of exchangeable protons of low-concentration solutes without interference from nonexchanging protons. Thi...
A model to study the phenotypic changes of interstitial cells of Cajal in gastrointestinal diseases.

Background & Aims Interstitial cells of Cajal (ICC) express the receptor tyrosine kinase, KIT, the receptor for stem cell factor. In the gastrointestinal (GI) tract, ICC are pacemaker cells that generate spontaneous electrical slow waves, and mediate inputs from motor neurons. Absence or loss of ICC are associated with GI motility disorders, including those consequent of diabetes. Studies of ICC have been hampered by the low density of these cells and difficulties in recognizing these cells in cell dispersions. Methods Kit +/copGFP mice harboring a copepod super green fluorescent protein ( copGFP ) complementary DNA, inserted at the Kit locus, were generated. copGFP + ICC from GI muscles were analyzed using confocal microscopy and flow cytometry. copGFP + ICC from the jejunum were purified by a fluorescence-activated cell sorter and validated by cell-specific markers. Kit +/copGFP mice were crossbred with diabetic Lep +/ob mice to generate compound Kit +/copGFP ;Lep ob/ob mutant mice. copGFP + ICC from compound transgenic mice were analyzed by confocal microscopy. Results copGFP in Kit +/copGFP mice colocalized with KIT immunofluorescence and thus was predominantly found in ICC. In other smooth muscles, mast cells were also labeled, but these cells were relatively rare in the murine GI tract. copGFP + cells from jejunal muscles were Kit + and free of contaminating cell-specific markers. Kit +/copGFP ; Lep ob/ob mice displayed ICC networks that were dramatically disrupted during the development of diabetes. Conclusions Kit +/copGFP mice offer a powerful new model to study the function and genetic regulation of ICC phenotypes. Isolation of ICC from animal models will help determine the causes and responses of ICC to therapeutic agents.
The determinants of jail use across large US cities: an assessment of racial, ethnic, and economic threat explanations

While empirical research on jails is not as neglected as it once was, there is no study that systematically tests theoretical assumptions on the use of this type of punishment. The present study fills this gap by examining theoretically based determinants of jail admission rates across 157 US cities. The consensus perspective assumes that the legal order reflects a widely held consensus about social harms that require punishment and that the use of formal crime-control mechanisms is a natural response to infractions of this order. Alternatively, the conflict perspective assumes that the legal order reflects the interests of the powerful and that the size of the state punishment apparatus is a response to perceived threats to these interests. Two prominent threat hypotheses are used to assess this approach. Racial and ethnic threat theories suggest that incarceration is more likely in areas with the most blacks or Hispanics. Economic threat theories claim that the rate of incarceration will be greatest where economic differences are the most pronounced. This study uses classical regression to test these perspectives with data from the 1983 Census of Local Jails. With the crime rate, measures of disorder, the size of the police force, the presence of young males, jail capacity, and regional effects held constant, the results provide strong support for the conflict perspective. Income differences between African-Americans and whites, and the size of both the African-American and Hispanic populations are found to explain variations in jail use across large US cities. The findings supporting the threat hypotheses are strengthened in supplemental analyses that restrict the sample of cities to those with a sizable minority population and another that uses updated data from the 1999 Jail Census. Additionally, some models show a quadratic association between residential segregation and the rate of jail admissions providing some support for the contact hypothesis.
Predicting Participation in Environmental Treaties: A World‐System Analysis*

Which countries tend to sign international environmental treaties and why? This study tests the ability of quantitative cross-national political and economic analysis to predict participation in international environmental agreements over the period 1963–1987. Cross-sectional ordinary least squares regressions suggest that poor, highly indebted countries that are dependent on very few trading partners and that have repres-sive regimes are far more likely to be nonsignatories. The results suggest strategies for increasing the likelihood that nations will ratify hture environmental treaties.
Multilevel monolithic inductors in silicon technology

Multilevel monolithic inductors implemented in a standard BiCMOS technology are presented. Use of top metal layers shunted with vias provides Q values approaching 10 at 2.4 GHz and above 6 at 900 MHz for a 2 nH inductor. There is no modification to the conventional wiring metallurgy and no need for extra processing steps.
Identifying and mapping stakeholders: an industry case study

Purpose – The paper seeks to identify and map groups, organizations, and individuals chief executive officers refer to in annual report letters, and propose a method for identifying those appearing to be stakeholders. Identifying who those stakeholders are could provide clues to competitors' corporate strategies or other issues drawing the attention of executive managers.Design/methodology/approach – Annual report letters of all 19 public restaurant franchisors on the 2007 Franchise Times top 200 list were analyzed with concordance software. Stakeholders were identified and mapped according to their linkages with franchisors.Findings – Significant differences were found between international and domestic franchisors. An industry‐specific approach was used.Research limitations/implications – A small sample, focused on a single industry, was used. The study could be replicated using the procedures discussed.Practical implications – Groups, organizations, and individuals referred to in annual reports are ide...
TUNABLE COHERENT RADIATION FROM TERAHERTZ TO MICROWAVE BY MIXING TWO INFRARED FREQUENCIES IN A 47-MM-LONG GaSe CRYSTAL

By mixing two infrared radiations near 1 μm in a 47-mm-long GaSe crystal, we efficiently generated a monochromatic radiation which has frequency tunability from 4.51 THz down to 53 GHz. The highest peak power produced by us is 389 W at 203 μm (1.48 THz), which corresponds to the photon conversion efficiency of 19% (the power conversion efficiency of 0.098%).
Analysis of exhaust waste heat recovery from a dual fuel low temperature combustion engine using an Organic Rankine Cycle

Abstract This paper examines the exhaust waste heat recovery potential of a high-efficiency, low-emissions dual fuel low temperature combustion engine using an Organic Rankine Cycle (ORC). Potential improvements in fuel conversion efficiency (FCE) and specific emissions (NO x and CO 2 ) with hot exhaust gas recirculation (EGR) and ORC turbocompounding were quantified over a range of injection timings and engine loads. With hot EGR and ORC turbocompounding, FCE improved by an average of 7 percentage points for all injection timings and loads while NO x and CO 2 emissions recorded an 18 percent (average) decrease. From pinch-point analysis of the ORC evaporator, ORC heat exchanger effectiveness ( ɛ ), percent EGR, and exhaust manifold pressure were identified as important design parameters. Higher pinch point temperature differences (PPTD) uniformly yielded greater exergy destruction in the ORC evaporator, irrespective of engine operating conditions. Increasing percent EGR yielded higher FCEs and stable engine operation but also increased exergy destruction in the ORC evaporator. It was observed that hot EGR can prevent water condensation in the ORC evaporator, thereby reducing corrosion potential in the exhaust piping. Higher ɛ values yielded lower PPTD and higher exergy efficiencies while lower ɛ values decreased post-evaporator exhaust temperatures below water condensation temperatures and reduced exergy efficiencies.
Design of Laminar Flow Restrictors for Damping Pneumatic Vibration Isolators

Pneumatic isolators provide excellent isolation of machine tools and measuring machines from seismic floor disturbances. Damping of the machine mass/air spring behavior becomes essential when automatic height adjustment is added. Air flow from the isolator to a tank can dissipate the oscillatory energy if it is passed through a restrictor. Commercially available isolators use a simple orifice as a restrictor, but flow through an orifice is non-linear with pressure. This non-linearity Insures that the damping is correct at only one amplitude of oscillation which can in turn lead to limit cycles as large as 1 mm. Conventional solutions to this instability problem include lowering the sensitivity of the self leveling valves, increasing the spacing between the isolators and lowering the center of mass of the machine with respect to the isolators. Laminar flow restrictors that provide optimum damping of an all amplitudes can be implemented with shim stock and spacers with no impact on the machine installation. Design formulas that accurately predict the experimental results will be described and some guidelines based on practical experience will be discussed.
The Relationship Among Child Maltreatment, Parental Bonding, and a Lifetime History of Major Depressive Disorder in Latino College Students

This study examined the relationship among child maltreatment, parental bonding, and a lifetime history of major depressive disorder (MDD) in a sample of 119 Latino students. Forty-five students reported a lifetime history of MDD and 74 reported not having a lifetime history of MDD. The results indicated that emotional abuse and maternal overprotection were significantly associated with having a lifetime history of MDD. The findings support the importance of examining these factors among depressed Latinos. Future research should continue to explore both the role of child maltreatment and parental bonding in relation to a lifetime history of MDD in this population.
Shear properties and a stress analysis obtained from vinyl-ester losipescu specimens

The use of losipescu specimens for the determination of the shear properties of a vinyl-ester resin was investigated. The antisymmetric four-point bend and the Adams and Walrath fixtures were studied for their suitability in loading these specimens. Photoelastic and strain-gage data in addition to published finite-element results show that the latter fixture distorts the stress field in the gage section. The antisymmetric four-point bend fixture is found to give the purest shear-stress field in the gage section and to yield the most reliable shear-modulus values. A refined photoelastic analysis shows that the shear-stress distribution between the notch roots is essentially uniform with a relative maximum or minimum at the centroid depending on the depths of the notches. Also, stress risers of up to 30 percent are observed near the notch roots. Except at the roots, finite-element predictions are presented which are in excellent agreement with photoelastic data. The failure mode of this vinyl-ester resin is tensile and the corresponding tensile stress calculated from the average shear stress in the gage section of the losipescu specimen is in excellent agreement with failure data acquired in tension.
The alpha problem & line count configurations

Abstract Motivated by the work of Chudnovsky and the Eisenbud–Mazur Conjecture on evolutions, Harbourne and Huneke give a series of conjectures that relate symbolic and regular powers of ideals of fat points in projective space P n . The conjectures involve both containment statements and bounds for the initial degree in which there is a non-zero form in an ideal. Working with initial degrees, we verify two of these conjectures for special line count configurations in projective 2-space over an algebraically closed field of characteristic 0.