cssi/SciSciGPT-SciSciNet huggingface dataset:
Application of PWM techniques to realize a 2MHz off-line switching regulator, with hybrid implementation

A high frequency, 2Mhz, off-line switching regulator intended for applications in military use environments, has been implemented with PWM techniques. This paper describes the design trade-offs made in selecting the PWM approach for this relatively high frequency application, and provides an overview of the performance characteristics of the circuit and key critical components. This is an off-line power supply which must operate over a wide range of MIL-STD-704 aircraft prime power interface conditions. This power supply delivers three output voltages, each f u l l y regulated, at up to 50 watts total delivered power. The design will be implemented in a high density, hybrid configuration of approximately 10 watts per cubic inch, and will include the power processor and all filtering and bypass functions, except for rectification of the AC input lines, which is done external to the module. The circuits and components used to implement the power processing stage, the feedback control and stabilization network, and the overall supervisory circuit are discussed. Performance under high frequency load conditions is covered, as well as general regulator performance. A brief comparison of operating characteristics and complexity between this topology and an equivalent series resonant circuit is also given. This paper concludes with highlights of advanced packaging techniques similar to those to be used to implement this circuit in the high density configuration.
Designing the Electronic Classroom: Applying Learning Theory and Ergonomic Design Principles.

This article applies learning theory and ergonomic principles to the design of effective learning environments for library instruction. It discusses features of electronic classroom ergonomics, including the ergonomics of the physical space, environmental factors, and the workstations. Includes classroom layouts.
Prenatal cocaine exposure and the development of the human eye.

Purpose: The use of cocaine during pregnancy has been associated with congenital abnormalities of the developing eye. The authors report a prospective, controlled study of 40 cocaine-exposed and 40 nonexposed (control) preterm and full-term infants. Methods: Detailed maternal and obstetric histories were obtained by chart review and interview. Infants with a positive urine toxicology screen for cocaine at birth or whose mothers tested positive for cocaine were recruited into the exposed group. Nonexposed infants were recruited at random from newborns admitted to the authors' nurseries. Mothers of these infants received routine prenatal care in the authors' clinics, and nonexposure was documented by maternal history and/or negative urine toxicologies that were available in 30% of these mother-infant pairs. General physical and ocular examinations, including measurement of axial length and intraocular pressure, were performed on all infants. Results: Forty infants were recruited in each group, with gestational ages ranging from 25 to 42 weeks. Twenty-nine of the exposed infants and 26 of the control infants were full-term (gestational age, 37 weeks or older). A total of 160 eyes were examined. No differences were seen in the incidence of congenital anomalies, subconjunctival hemorrhages, retinal hemorrhages, or optic nerve abnormalities between the two groups. No differences in mean axial length (16.9 ± 0.6 mm [exposed group] versus 17.1 ± 0.7 mm [control group]) or intraocular pressure (15.4 ± 3.8 mmHg [exposed group] versus 15.0 ± 3.0 mmHg [control group]) were seen between full-term infants in both groups. Axial length correlated strongly with gestational age, birth weight, head circumference, and body length over the range of gestational ages evaluated in both groups. No effect of cocaine exposure on these correlations was demonstrated. The range of axial length was 12.1 to 18.0 mm in the exposed group and 12.4 to 18.6 mm in the control group. Conclusion: In this study group, no significant effect of prenatal cocaine exposure was seen on the infant eye. In both exposed and nonexposed groups, axial length measurements agreed closely with known statistical norms and correlated closely with other parameters of fetal growth.
Oral class III antiarrhythmics: what is new?

Purpose of reviewThis review describes the latest developments in the clinical usage of class III antiarrhythmics. It also discusses some new studies providing insight into the mechanism of action of these drugs.Recent findingsNew data suggest that amiodarone is one of the most effective drugs for m
Searching for hemostatic modifier genes affecting the phenotype of mice with very low levels of FVII.

Abstract FVII tTA/− mice are heterozygous for the FVII − null allele and a gene-targeted allele expressing very low levels of FVII. Approximately half the FVII tTA/− in a mixed C57Bl/6:129x1/SVJ background survive much longer than mice in a C57Bl/6 background, suggesting that genetic background affects the survival of mice expressing very low levels of FVII. A lineage of long-term surviving FVII tTA/− mice in a predominantly C57Bl/6 background was generated by selecting 16 weeks or older FVII tTA/− males and breeding them with C57Bl/6 FVII +/− females. It is postulated that these mice maintain 129x1/SVJ alleles at putative hemostatic modifier loci necessary for the survival of mice expressing very low levels of FVII. A SNP genomic scan was performed on DNA from long-term surviving FVII tTA/− mice. The scan identified 8 regions enriched for 129x1/SVJ sequences that might contain putative hemostatic modifier genes.
Electrical engineering curricula in a changing world

IN THE LAST DECADE, important changes have taken place in the education of electrical engineers. These in part, have come in response to new needs. A factor, however, has been an underlying dissatisfaction with the inadequacies of the typical training of the prewar electrical engineer.
Stability of difference methods for initial-value type partial differential equations

Abstract A systematic way to formulate stable difference expressions for initial and mixed boundary value problems is presented. It is shown that difference schemes must satisfy “invariants” in order to be stable, consistent approximations to the partial differential equation. An open loop technique is presented to choose a stable time step, Δt .
A comparison of logistic regression and Mantel-Haenszel procedures for detecting differential item functioning

The Mantel-Haenszel (MH) procedure is sensitive to only one type of differential item functioning (DIF). It is not designed to detect DIF that has a non uniform effect across trait levels. By gener...
Pure and Applied Consciousness in Valéry and Sartre

To speak of the ‘death of the subject’ today might seem anachronistic, even irrelevant. There are flagrant signs, however, of the ‘return of the subject’ in contemporary French literature, suggesting its persistence. Besides, unprecedented innovations in philosophy and literature galvanized precisely by the death of the subject have not produced tangible changes in the world, except perhaps for the rhetoric of diversity. These observations oblige a return to the fundamental question: what is the subject, or, rather, what must the subject be in order for an authentic intersubjective rapport to be freshly conceivable? Long before the subject was declared ‘dead’ in the 1960s, two thinkers for whom this question was a central concern were Valery and Sartre. Tracing their earliest conceptions of pure consciousness and of its application in the world, this article seeks to go beyond the usual opposition drawn between Sartrean humanism and Valeryan inhumanism . I argue that their strikingly similar conceptions of pure consciousness based on its dual characteristics — negativity and impersonality — bind the two thinkers, and that the notion of pure consciousness serves each as a theoretical foundation to envision the transformation of society by means, paradoxically, of the negation of human subjectivity.
Lipid Tilt Regulates Ripple Phase Behavior in Lipid Bilayer

Continuum modeling of lipid bilayers provides insight into the physics underlying geometric changes to the shape of the membrane in response to biological processes. The Helfrich model has been the gold standard for many years and applies only to length scales larger than that of the thickness of the bilayer. For small length scale processes, orientation of the lipid, characterized by ‘lipid tilt’, is a suitable fundamental degree of freedom. In this work, we develop a continuum model with lipid tilt as the key degree of freedom. Using local force balance, we derive the equations of motion associated with the membrane. We use this model to study the characteristics of ripple phases in bilayers. Comparing the continuum model to coarse-grained simulations, we find that the tilt degree of freedom is important to allow for ripple formation in bilayer membranes.
The Penetration and Diffusion of Co 60 Gamma-Rays in Water Using Spherical Geometry

Ionization and Geiger-M\"uller counter measurements of ${\mathrm{Co}}^{60}$ gamma-rays were made in effectively spherical geometry up to a distance of 252.8 cm (16 mean free paths of the primary radiation) corresponding to an exponential attenuation of the primary radiation by a factor of 8.8\ifmmode\times\else\texttimes\fi{}${10}^{6}$. The "build-up factor" was observed to climb up to 33.8 and approached closely the theoretically predicted trend of asymptotic variation ${r}^{1.4}$. Preliminary information on the spectral distribution of the radiation is included.
Bacterial Endotoxin Enhances the Hepatotoxicity of Allyl Alcohol

Lipopolysaccharide (LPS), or bacterial endotoxin, causes liver damage at relatively large doses in rats. Smaller doses, however, may influence the response to other hepatotoxicants. The purpose of these studies was to examine the effect of exposure to relatively small doses of LPS on the hepatotoxic response to allyl alcohol, which causes periportal necrosis in laboratory rodents through an unknown mechanism. Rats were pretreated with LPS (100 μg/kg) 2 hr before treatment with a minimally toxic dose of allyl alcohol (30 mg/kg), and liver toxicity was assessed 18 hr later from activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in plasma and from histologic changes in liver sections. Plasma ALT and AST activities were not elevated significantly in rats treated with vehicle, LPS, or allyl alcohol alone, but pronounced increases were observed in rats treated with LPS and allyl alcohol. Significant liver injury occurred as early as 2 hr after allyl alcohol treatment in LPS-pretreated rats and peaked at 6 hr. LPS treatment did not affect the activity of alcohol dehydrogenase and did not affect the rate of production of NADH in isolated livers perfused with allyl alcohol; thus, LPS does not appear to increase the metabolic bioactivation of allyl alcohol into acrolein. On the other hand, pretreatment with 4-methylpyrazole, an inhibitor of alcohol dehydrogenase, abolished the hepatotoxicity of allyl alcohol in LPS-treated rats, indicating that production of acrolein was needed for LPS enhancement of the toxicity of allyl alcohol. Pretreatment of rats with gadolinium chloride (10 mg/kg), a known inactivator of Kupffer cell phagocytic function, decreased LPS augmentation of the response to allyl alcohol. These data indicate that LPS markedly enhances the hepatotoxic response to allyl alcohol. Furthermore, the results suggest that the LPS-induced enhancement of allyl alcohol hepatotoxicity occurs through a Kupffer cell-dependent mechanism.
Developing a complexity measure for project schedules

Several factors contribute to the complexity of project schedules, including the number of activities, the level of detail, and the shape of the project network. This paper presents a measure that assesses the complexity of project schedules in terms of the connectivity of the activities. Unlike similar complexity measures, the proposed complexity measure does not consider redundant relationships in the project's schedule. In addition, the measure is expressed as a percentage and therefore has the advantage of being intuitively understand by project managers. The measure considers the degree of interrelationships between the activities in the project's schedule. The measure has been implemented in a computerized tool to help managers assess the complexity of their projects. The tool is developed as an add-in to popular commercial scheduling software like MS Project.
Response of the Inner Radiation Belt to the Violent Sun-Earth Connection Events of October-November 2003

We report observations of the response of the low-altitude radiation population below L = 3 during and after the strong solar energetic particle events and geomagnetic disturbances of late October and early November 2003, and we place this response in the context of observations throughout the 12-year SAMPEX mission. We find that on 29 October 2003, at the approximately 600 km altitude of SAMPEX, the usual belt of energetic protons (above 19 MeV) around L = 2 almost completely disappeared, recovering only after several months. We also observed the appearance of a new belt of ultrarelativistic (above 10 MeV) electrons centered around L = 2. In the previous twelve years, we have never observed such a large decrease of the energetic protons at low altitude. An injection of very high energy electrons like this has not been seen since February 1994.
Structural characterization of surface glycans from Clostridium difficile

Abstract Whole-cell high-resolution magic angle spinning (HR-MAS) NMR was employed to survey the surface polysaccharides of a group of clinical and environmental isolates of Clostridium difficile. Results indicated that a highly conserved surface polysaccharide profile among all strains studied. Multiple additional peaks in the anomeric region were also observed which prompted further investigation. Structural characterization of the isolated surface polysaccharides from two strains confirmed the presence of the conserved water soluble polysaccharide originally described by Ganeshapillai et al. which was composed of a hexaglycosyl phosphate repeat consisting of [→6)-β- d -Glcp-(1-3)-β- d -GalpNAc-(1-4)-α- d -Glcp-(1-4)-[β- d -Glcp(1-3]-β- d -GalpNAc-(1-3)-α- d -Manp-(1-P→]. In addition, analysis of phenol soluble polysaccharides revealed a similarly conserved lipoteichoic acid (LTA) which could be detected on whole cells by HR-MAS NMR. Conventional NMR and mass spectrometry analysis indicated that the structure of this LTA consisted of the repeat unit [→6)-α- d -GlcpNAc-(1-3)-[→P-6]-α- d -GlcpNAc-(1-2)- d -GroA] where GroA is glyceric acid. The repeating units were linked by a phosphodiester bridge between C-6 of the two GlcNAc residues (6-P-6). A minor component consisted of GlcpN-(1-3) instead of GlcpNAc-(1-3) in the repeat unit. Through a 6–6 phosphodiester bridge this polymer was linked to →6)-β- d -Glcp-(1-6)-β- d -Glcp-(1-6)-β- d -Glcp-(1-1)-Gro, with glycerol (Gro) substituted by fatty acids. This is the first report of the utility of HR-MAS NMR in the examination of surface carbohydrates of Gram positive bacteria and identification of a novel LTA structure from Clostridium difficile.
Improving parallel scalability for edge plasma transport simulations with neutral gas species

Simulating the transport of multi-species plasma and neutral species in the edge region of a tokamak magnetic fusion energy device is computationally intensive and difficult due to coupling among various components, strong nonlinearities and a broad range of temporal scales. In addition to providing boundary conditions for the core plasma, such models aid in the understanding and control of the associated plasma/material–wall interactions, a topic that is essential for the development of a viable fusion power plant. The governing partial differential equations are discretized to form a large nonlinear system that typically must be evolved in time to obtain steady-state solutions. Fully implicit techniques using preconditioned Jacobian-free Newton–Krylov methods with parallel domain-based preconditioners are shown to be robust and efficient for the plasma components. Inclusion of neutral gas components, however, increases the condition number of the system to the point where improved parallel preconditioning is needed. Standard algebraic preconditioners that provide sufficient coupling throughout the global domain to handle the neutrals are not generally scalable. We present a new preconditioner, termed FieldSplit, which exploits the character of the neutral equations to improve the scalability of the combined plasma/neutral system.
Clinical outcomes after reirradiation of paraspinal tumors

Objective:We present our experience with reirradiation of locally recurrent paraspinal tumors using image-guided intensity modulated radiotherapy (IG-IMRT).Methods:We performed a retrospective review of 37 patients who were reirradiated using IG-IMRT for recurrent paraspinal tumors between 2000 and
Serum biomarker panels for the detection of pancreatic cancer.

Purpose: Serum–biomarker based screening for pancreatic cancer could greatly improve survival in appropriately targeted high-risk populations. Experimental Design: Eighty-three circulating proteins were analyzed in sera of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC, n = 333), benign pancreatic conditions ( n = 144), and healthy control individuals ( n = 227). Samples from each group were split randomly into training and blinded validation sets prior to analysis. A Metropolis algorithm with Monte Carlo simulation (MMC) was used to identify discriminatory biomarker panels in the training set. Identified panels were evaluated in the validation set and in patients diagnosed with colon ( n = 33), lung ( n = 62), and breast ( n = 108) cancers. Results: Several robust profiles of protein alterations were present in sera of PDAC patients compared to the Healthy and Benign groups. In the training set ( n = 160 PDAC, 74 Benign, 107 Healthy), the panel of CA 19–9, ICAM-1, and OPG discriminated PDAC patients from Healthy controls with a sensitivity/specificity (SN/SP) of 88/90%, while the panel of CA 19–9, CEA, and TIMP-1 discriminated PDAC patients from Benign subjects with an SN/SP of 76/90%. In an independent validation set ( n = 173 PDAC, 70 Benign, 120 Healthy), the panel of CA 19–9, ICAM-1 and OPG demonstrated an SN/SP of 78/94% while the panel of CA19–9, CEA, and TIMP-1 demonstrated an SN/SP of 71/89%. The CA19–9, ICAM-1, OPG panel is selective for PDAC and does not recognize breast (SP = 100%), lung (SP = 97%), or colon (SP = 97%) cancer. Conclusions: The PDAC-specific biomarker panels identified in this investigation warrant additional clinical validation to determine their role in screening targeted high-risk populations. Clin Cancer Res; 17(4); 805–16. ©2010 AACR .
Perceived effects of instructional pornography on the self, partner, and others

People tend to perceive socially undesirable media, such as pornography, as having a more negative effect on others than on themselves. This study examined how this phenomenon, called the third-person effect, manifests when the pornography has positive connotations, as with instructional pornography. Participants (n = 229) were asked to rate how instructional adult films would affect them, their partner, and other people. Unlike non-instructional pornography, participants perceived instructional pornography as having a positive effect. Participants perceived other men and women as more positively affected by informational pornography than themselves, but perceived themselves as more positively affected than their closest friend. Participants with partners reported that they and their partner would be equally positively affected by instructional pornography. Findings are discussed in light of genre-specific pornography effects and the possible use of instructional pornography as an educational tool.
The effects of impurity redistribution of the subthreshold leakage current in CMOS n-channel transistors

A study of subthreshold leakage current in n-channel transistors on low threshold voltage CMOS circuits has been made. Redistribution of impurities at the silicon surface during thermal oxidation is shown to be the main cause of excess subthreshold leakage current. Processing techniques to minimize this leakage have been developed.
A Simple Approach to Testing Homogeneity of Order-Constrained Means

Abstract The likelihood-ratio test for equality of partially ordered means, first proposed by Bartholomew, is known to possess power characteristics that are generally superior to those of competing procedures. A limitation of this test, however, is that the null distribution of the test statistic is heavily dependent on both the specific form of the order restriction and the group sample sizes. It is not readily available for most orderings, especially when the group sample sizes are unequal. Furthermore, computation of the test statistics often involves intricate algorithms. We propose a class of procedures based upon classical methods for combining independent tests. These procedures are generally applicable and easily implemented. A study of the power functions of the competing tests indicates that the power of the test based on Fisher's combination method compares reasonably with that of the likelihood-ratio test. It is concluded that the procedure based on Fisher's combination method is an effective...
Catalysis in abiotic structured media: an approach to selective synthesis of biopolymers

Micro- and nanoenvironments formed by amphiphile self-assembled structures, water-ice lattices and minerals have well-defined, repeating, chemical and physical properties that can be used for selective synthesis of biopolymers, such as RNAs and proteins. The advances made in the development of polymerization supported by these micro- and nanosystems are reviewed here. In particular, it is shown that these systems promote non-enzymatic biopolymerization, yielding long polymers whose sequence composition is determined by the interactions between monomers and the supporting environment. When used to compartmentalize enzymatic biopolymerization, micro- and nanostructures allow the implementation of molecular selection and evolution schemes, which are difficult in homogeneous medium, yielding very active molecules. Thus, micro- and nanoenvironment approaches to the synthesis and selection of biopolymers could be developed into a new biotechnological tool for the production of biopolymers with novel functions.
Cuspidal Representations Associated to (GL(n), O(n)) over Finite Fields andp-Adic Fields

Abstract Whenris an irreducible cuspical representation ofḠ = GL(n, q) andHis an orthogonal group associated to a symmetric matrix inḠthen the space ofH-fixed vectors forris shown to have dimension at most one. Such a representationrinduces an irreducible supercuspidal representation π ofG = GL(n, E), whereEis ap-adic field whose residue field has orderq. The space of those linear forms on the space of π which are invariant under an orthogonal group is computed. For the corresponding group of orthogonal similitudes, it is shown that the dimension of the space of invariant linear forms is always at most one.
Protein modification during biological aging: selective tyrosine nitration of the SERCA2a isoform of the sarcoplasmic reticulum Ca2+-ATPase in skeletal muscle.

The accumulation of covalently modified proteins is an important hallmark of biological aging, but relatively few studies have addressed the detailed molecular-chemical changes and processes responsible for the modification of specific protein targets. Recently, Narayanan et al. [Narayanan, Jones, Xu and Yu (1996) Am. J. Physiol. 271 , C1032-C1040] reported that the effects of aging on skeletal-muscle function are muscle-specific, with a significant age-dependent change in ATP-supported Ca 2+ -uptake activity for slow-twitch but not for fast-twitch muscle. Here we have characterized in detail the age-dependent functional and chemical modifications of the rat skeletal-muscle sarcoplasmic-reticulum (SR) Ca 2+ -ATPase isoforms SERCA1 and SERCA2a from fast-twitch and slow-twitch muscle respectively. We find a significant age-dependent loss in the Ca 2+ -ATPase activity (26% relative to Ca 2+ -ATPase content) and Ca 2+ -uptake rate specifically in SR isolated from predominantly slow-twitch, but not from fast-twitch, muscles. Western immunoblotting and amino acid analysis demonstrate that, selectively, the SERCA2a isoform progressively accumulates a significant amount of nitrotyrosine with age (≈ 3.5±0.7 mol/mol of SR Ca 2+ -ATPase). Both Ca 2+ -ATPase isoforms suffer an age-dependent loss of reduced cysteine which is, however, functionally insignificant. In v itro , the incubation of fast- and slow-twitch muscle SR with peroxynitrite (ONOO - ) (but not NO/O 2 ) results in the selective nitration only of the SERCA2a, suggesting that ONOO - may be the source of the nitrating agent in v i v o . A correlation of the SR Ca 2+ -ATPase activity and covalent protein modifications in v itro and in v i v o suggests that tyrosine nitration may affect the Ca 2+ -ATPase activity. By means of partial and complete proteolytic digestion of purified SERCA2a with trypsin or Staphylococcus aureus V8 protease, followed by Western-blot, amino acid and HPLC-electrospray-MS (ESI-MS) analysis, we localized a large part of the age-dependent tyrosine nitration to the sequence Tyr 294 -Tyr 295 in the M4-M8 transmembrane domain of the SERCA2a, close to sites essential for Ca 2+ translocation.
Equation of state and thermodynamic functions of non-metallic crystals

Abstract The Mie–Gruneisen and Hildebrand approximations to the equation of state of cubic solids imply specific restrictions on the functional form of the thermodynamic functions. The validity of these restrictions has been investigated for non-metals within the quasiharmonic approximation, and confirmed in certain ranges of temperature and volume. A method to test the reliability of the quasiharmonic description of the thermodynamic functions of non-metals, and to determine quantitative values for the anharmonic contributions, has been devised and applied to four alkali halides. General theoretical expressions for the temperature dependence at constant volume of the Debye temperatures for the entropy, the thermal internal energy and the heat capacity at constant volume, involving the quasiharmonic contributions and the anharmonic contribution at high temperature, are fitted to the experimental temperature dependence. In the temperature region from 30 to 80°K the three thermodynamic functions are found to yield consistent and accurate values for the moments of the vibrational frequency spectrum. Accurate values for the anharmonic contribution at high temperature are derived from the entropy. These are consistent with the experimental values of the thermal energy, and also with the experimental values of the heat capacity at constant volume, within the uncertainty caused by the CP–CV correction.
Can Hybrid Learning Theory Be Used to Teach Working Sonographers 3D Imaging Technology

Three-dimensional sonography is being cited more frequently as a means of further evaluating the patient and better defining the pathological condition. One of the main limitations of fully implementing 3D imaging in the sonography department is the limited experience and limited time to educate working sonographers on how to fully understand and use this technology. Deliberate and planned educational activities designed to meet the educational needs of working sonographers may be a way to increase the clinical use of 3D technology in the clinical sonography department.
Prognostic value of QT dispersion in acute stroke.

Abstract Central nervous system mediated cardiac injury is a field of growing interest pertaining to brain-heart interactions. Our group previously found higher QT dispersion, calculated as the difference between the maximum and minimum QT intervals on the admission ECG to be predictive of adverse outcomes in patients presenting with neurological events. In another study, absolute changes in QTD were found related to changes in neurological function. Among 70 patients age 71±13 years, (50% male), QTD was significantly greater in patients with elevated cardiac troponin T levels (71±13 msecs vs 42±16 msecs; p
Recovering and Re-Discovering Craft

Many studies have shown that craft involves know-how, practice and problem solving that represents activities that can be recovered by study of various artifact assemblages and contexts within archaeological sites. The types of conclusions differ with nature of the research question, sample size and its variability, methods of study and organization of collecting in the field, as well as the results of areal study: ethnographic information, resource survey and landscape reconstruction. Questions generated through analysis of materials, processes and properties often generate questions that can only be answered by replicative experiments of all aspects of a chaine operatoire, only part of it or only those critical aspects about which questions remain. The integration of the laboratory/workshop results with the archaeological evidence, both objects and context, can lead to a re-discovery of craft. The conjectured details of materials composition and structure, sequence of processing, properties, performance or use essentially reverse engineer the typical way that modern materials research is conducted. This paper aims at developing a widening dialogue about craft know-how among materials scientists working in museums and artist-craftsmen. To learn about our history and the human condition is not just to analyze and preserve the objects and artifacts, but also to investigate and understand the knowledge and skills used to produce and use them— essentially this is the preservation of intangible cultural heritage and culture history.
Bottom-up computation of sparse and Iceberg CUBE

We introduce the Iceberg-CUBE problem as a reformulation of the datacube (CUBE) problem. The Iceberg-CUBE problem is to compute only those group-by partitions with an aggregate value (e.g., count) above some minimum support threshold. The result of Iceberg-CUBE can be used (1) to answer group-by queries with a clause such as HAVING COUNT(*) >= X, where X is greater than the threshold, (2) for mining multidimensional association rules, and (3) to complement existing strategies for identifying interesting subsets of the CUBE for precomputation.We present a new algorithm (BUC) for Iceberg-CUBE computation. BUC builds the CUBE bottom-up; i.e., it builds the CUBE by starting from a group-by on a single attribute, then a group-by on a pair of attributes, then a group-by on three attributes, and so on. This is the opposite of all techniques proposed earlier for computing the CUBE, and has an important practical advantage: BUC avoids computing the larger group-bys that do not meet minimum support. The pruning in BUC is similar to the pruning in the Apriori algorithm for association rules, except that BUC trades some pruning for locality of reference and reduced memory requirements. BUC uses the same pruning strategy when computing sparse, complete CUBEs.We present a thorough performance evaluation over a broad range of workloads. Our evaluation demonstrates that (in contrast to earlier assumptions) minimizing the aggregations or the number of sorts is not the most important aspect of the sparse CUBE problem. The pruning in BUC, combined with an efficient sort method, enables BUC to outperform all previous algorithms for sparse CUBEs, even for computing entire CUBEs, and to dramatically improve Iceberg-CUBE computation.
Inactivation of Cryptosporidium parvum oocysts with ozone

Ozone inactivation rates for Cryptosporidium parvum (C. parvum) oocysts were determined with an in vitro excystation method based on excysted sporozoite counts. Results were consistent with published animal infectivity data for the same C. parvum strain. The inactivation kinetics for C. parvum were characterized by a lag phase followed by pseudo-first order kinetics. Both the magnitudes of the lag phase and the pseudo-first order rate constant were found to be different for C. parvum oocysts from two different sources, and to obey Arrhenius law for the experimental temperature range of 5–30°C. CT requirements for C. parvum inactivation were found to increase by an average factor of approximately three for every 10°C decrease in temperature.
Iterative deblurring for CT metal artifact reduction

Iterative deblurring methods using the expectation maximization (EM) formulation and the algebraic reconstruction technique (ART), respectively, are adapted for metal artifact reduction in medical computed tomography (CT). In experiments with synthetic noise-free and additive noisy projection data of dental phantoms, it is found that both simultaneous iterative algorithms produce superior image quality as compared to filtered backprojection after linearly fitting projection gaps. Furthermore, the EM-type algorithm converges faster than the ART-type algorithm in terms of either the I-divergence or Euclidean distance between ideal and reprojected data in the authors' simulation. Also, for a given iteration number, the EM-type deblurring method produces better image clarity but stronger noise than the ART-type reconstruction. The computational complexity of EM- and ART-based iterative deblurring is essentially the same, dominated by reprojection and backprojection. Relevant practical and theoretical issues are discussed.
Recovering dynamically independent coordinates for time-delay-embedded product systems

Phase space embeddings, time-delay or otherwise, do not preserve the natural decoupled description of a product system's state variables. The authors show, invoking a genericity argument, that for a restricted class of diffeomorphic transformations the images of independent manifolds can be isolated in the embedded phase space without knowledge of the underlying dynamical description. Several applications of this results are suggested, including the separation of signals originating from independent dynamical systems. Some of the estimation problems that must be resolved before this technique realizes its full potential are mentioned. >
A wholly defined Agilent microarray spike-in dataset

Motivation: Spike-in datasets provide a valuable resource for assessing and comparing among competing microarray analysis strategies. Our previous wholly defined spike-in datasets, the Golden and Platinum Spikes, have provided insights for the analysis of Affymetrix GeneChips. However, a similar dataset, in which all cRNA identities and relative levels are known prospectively, has not been available for two-color platforms. Results: We have generated a wholly defined spike-in dataset for Agilent microarrays consisting of 12 arrays with more than 2000 differentially expressed, and approximately 3600 background, cRNAs. The composition of this ‘Ag Spike’ dataset is identical to that of our previous Platinum Spike dataset and therefore allows direct cross-platform comparison. We demonstrate here the utility of the Ag Spike dataset for evaluating different analysis methods designed for two-color arrays. Comparison between the Ag Spike and Platinum Spike studies shows high agreement between results obtained using the Affymetrix and Agilent platforms. Availability: The Ag Spike raw data can be accessed at http://www.ccr.buffalo.edu/halfon/spike/index.html and through NCBI's Gene Expression Omnibus (GEO; accession GSE24866). Contact:qzhu@buffalo.edu; mshalfon@buffalo.edu. Supplementary information:Supplementary data are available at Bioinformatics online.
Aerosol Effects on Cloud Emissivity and Surface Longwave Heating in the Arctic

Increases in anthropogenic aerosols in the atmosphere tend to increase the reflectance of solar (shortwave) radiation from water clouds, which can lead to lower surface temperatures. Here an opposing effect whereby aerosols increase the longwave emissivity of thin clouds that adds to the warming of the earth’s surface, is discussed. The latter effect may be particularly important in the Arctic, especially during the winter and early spring when thin stratus clouds are ubiquitous, relatively high levels of anthropogenic pollution are common, and there is little solar radiation.
Basement Membrane Macromolecules: Insights from Atomic Force Microscopy

The major macromolecules of basement membranes-collagen IV, laminin-1, and heparan sulfate proteoglycan (HSPG)-have been analyzed by atomic force microscopy (AFM), both individually and in combination with each other. The positions of laminin binding to collagen IV were mapped and compared with the positions of imperfections in the amino acid sequence of collagen IV; the apparent molecular volumes of the HSPG proteoglycans were measured and used to estimate the corresponding molecular weights. Even the thin, thread-like strands of the polyanion heparan sulfate can be visualized with AFM without staining, coating, or fixation. These strands are single polysaccharide chains and are thus thinner than single-stranded DNA. The heparan sulfate strands in HSPG are necessary for protein filtration in kidney basement membranes. We propose that these thin strands filter proteins by functioning as an entropic brush-i.e., that they filter proteins by their constant thermally driven motion in the basement membrane. These AFM analyses in air are a step toward AFM analyses under fluid of basement membrane macromolecules interacting with each other.
A Self-Aligned InGaAs HEMT Architecture for Logic Applications

In this paper, we present a novel self-aligned process for future III-V logic FETs. Using this process, we have demonstrated enhancement-mode 90-nm-gate-length InGaAs HEMTs with excellent logic figures of merit. We have carried out a detailed analysis of this device architecture to determine its future scaling capabilities. We find that, as the insulator is scaled to achieve enhancement mode, the performance of the device is limited by degradation of the I ON/I OFF ratio due to gate leakage current. By use of TLM test structures, we have determined that the barrier resistance dominates the source resistance. We use a trilayer TLM model to predict the expected evolution of the contact resistance as it is scaled to realistic VLSI dimensions and find that the current technology results in resistance values that are two orders of magnitude higher than the desired target for sub-22-nm nodes. Using the model, we explore different options for device redesign. Both I ON/I OFF and source-resistance limitations imply that the use of a high-k gate dielectric will be required for future device implementations.
Animal-to-Animal Variation in Fecal Microbial Diversity among Beef Cattle

The intestinal microbiota of beef cattle are important for animal health, food safety, and methane emissions. This full-length sequencing survey of 11,171 16S rRNA genes reveals animal-to-animal variation in communities that cannot be attributed to breed, gender, diet, age, or weather. Beef communities differ from those of dairy. Core bovine taxa are identified.
Histone H1 is essential for mitotic chromosome architecture and segregation in Xenopus laevis egg extracts

During cell division, condensation and resolution of chromosome arms and the assembly of a functional kinetochore at the centromere of each sister chromatid are essential steps for accurate segregation of the genome by the mitotic spindle, yet the contribution of individual chromatin proteins to these processes is poorly understood. We have investigated the role of embryonic linker histone H1 during mitosis in Xenopus laevis egg extracts. Immunodepletion of histone H1 caused the assembly of aberrant elongated chromosomes that extended off the metaphase plate and outside the perimeter of the spindle. Although functional kinetochores assembled, aligned, and exhibited poleward movement, long and tangled chromosome arms could not be segregated in anaphase. Histone H1 depletion did not significantly affect the recruitment of known structural or functional chromosomal components such as condensins or chromokinesins, suggesting that the loss of H1 affects chromosome architecture directly. Thus, our results indicate that linker histone H1 plays an important role in the structure and function of vertebrate chromosomes in mitosis.
Social Affiliation and the Demand for Health Services: Caste and Child Health in South India

Abstract This paper assesses the role of social affiliation, measured by caste, in shaping investments in child health. The special setting that we have chosen for the analysis – tea estates in the South Indian High Range – allows us to control nonparametrically for differences in income, access to health services, and patterns of morbidity across low caste and high caste households. In this controlled setting, low caste households spend more on their children's health than high caste households, reversing the pattern we would expect to find elsewhere in India. Moreover, health expenditures do not vary by gender within either caste group, in contrast once again with the male preference documented throughout the country. A simple explanation, based on differences in the returns to human capital across castes in the tea estates, is proposed to explain these striking results.
Dielectric Properties of Multi-Layer High-K Polymer Composite Films

The electrical properties of thin polymer films are key parameters in the design of both smaller and faster circuit devices in the microelectronics industry. In this study, we made a three-layer film structure, ABA', to investigate the dielectric interaction between two high-K dielectric polymer thin films, A and A', as a function of the thickness of the middle B layer. The Cole-Cole plot showed clear changes with the thickness of the middle B layer. The total capacitances were evaluated with a simple serial three capacitances model. This ABA' structure is thought to be very useful for studying mechanical and thermal properties of thin polymer film system.
Autoinhibition of the formin Cappuccino in the absence of canonical autoinhibitory domains

Formins are a conserved family of proteins known to enhance actin polymerization. Most formins are regulated by an intramolecular interaction. The Drosophila formin, Cappuccino (Capu), was believed to be an exception. Capu does not contain conserved autoinhibitory domains and can be regulated by a second protein, Spire. We report here that Capu is, in fact, autoinhibited. The N-terminal half of Capu (Capu-NT) potently inhibits nucleation and binding to the barbed end of elongating filaments by the C-terminal half of Capu (Capu-CT). Hydrodynamic analysis indicates that Capu-NT is a dimer, similar to the N-termini of other formins. These data, combined with those from circular dichroism, suggest, however, that it is structurally distinct from previously described formin inhibitory domains. Finally, we find that Capu-NT binds to a site within Capu-CT that overlaps with the Spire-binding site, the Capu-tail. We propose models for the interaction between Spire and Capu in light of the fact that Capu can be regulated by autoinhibition.
Effect of Channel Material on Water Droplet Dynamics in a PEMFC Gas Channel

Water accumulation in the gas channels affects the gas diffusion to the reaction sites and the overall performance of proton exchange membrane fuel cells (PEMFCs). Understanding water droplet growth and detachment from the gas diffusion layer (GDL) inside the channel is critical in developing better water management strategies. It has been reported that the wettability of the channel affects the droplet-wall interaction. Hence, in this study, the behavior of the liquid water droplet within a channel is experimentally investigated from a fundamental perspective. Experiments were conducted for different air velocities (0.2–2.4 m/s), GDL types and channel wall materials which are commercially used in PEMFCs for automotive applications. Experimental results were analyzed through the Concus-Finn condition using instantaneous dynamic contact angle (IDCA) to determine the corner filling behavior, which is a precursor to channel flooding. Droplet detachment is influenced by air flow within the channel and the contact angle hysteresis (CAH) of the wall and the GDL material. Experiments were also performed on the GDLs that have undergone longer test periods in a fuel cell. Results showed much lower static CA and CAH, and a corresponding change in the droplet dynamics on used
Nitrogen transport and retention in an arid land watershed: influence of storm characteristics on terrestrial-aquatic linkages

Arid ecosystems experience prolonged dry periods, as well as storms that vary in size, intensity and frequency. As a result, nitrogen (N) retention and export patterns may be a function of individual storm characteristics. Our objective was to determine how seasonal patterns in rainfall as well as individual storm characteristics influence N transport and retention on terrestrial hill slopes in a Sonoran Desert watershed. Regression models indicated that variation in runoff ammonium (NH4 +) was best explained by antecedent conditions (cumulative seasonal rainfall, days since last storm) while variation in runoff nitrate (NO3 −) was best explained by single storm characteristics, primarily rain NO3 −. Increases in runoff NO3 − along overland surface flowpaths were balanced by decreases in NH4 + during summer, with no change in dissolved inorganic nitrogen (DIN) concentration; a pattern consistent with nitrification. Nitrate increases along flowpaths were not as strong during winter storms. Results indicate that NH4 + is transported from hillslopes to other parts of the catchment, including streams, and that nitrification occurs along surface flowpaths, particularly during summer storms. These findings suggest that the extent to which a receiving patch is supplied with NH4 + or NO3 − depends on the distance runoff has traveled (flowpath length) and the length of the antecedent dry period. The extent and configuration of fluvial reconnection amongst patches in the landscape following long drought periods likely determines the fate of available N, whether N is processed and retained in the terrestrial or in the aquatic component of the watershed, and the mechanisms involved. The nature of this fluvial reconnection is driven by the size, intensity and sequence of storms in space and time.
Effects of Sucrose and Kinetin on Growth and Chlorophyll Synthesis in Tobacco Tissue Cultures

Investigations were carried out on the effects of various combinations of sucrose and kinetin concentrations on growth and chlorophyll production in a green and a nongreen clone of pith callus of Nicotiana tabacum L. It was found that 2 milligrams per liter or higher amounts of kinetin induced greening in the nongreen tissue. The observations suggested that growth of the callus and synthesis of chlorophyll and soluble protein are controlled by relative concentrations of sucrose and kinetin in the medium. Kinetin was found to be inhibitory for chlorophyll synthesis in the green callus.