cssi/SciSciGPT-SciSciNet huggingface dataset:
Correction: Exploring secondary interactions and the role of temperature in moisture-contaminated polymer networks through molecular simulations.

Leveraging the state of absorbed moisture within a polymer network to identify physical and chemical features of the host material is predicated upon a clear understanding of the interaction between the polymer and a penetrant water molecule; an understanding that has remained elusive. Recent work has revealed that a novel damage detection method that exploits the very low baseline levels of water typically found in polymer matrix composites (PMC) may be a valuable tool in the composite NDE arsenal, provided that a clear understanding of polymer–water interaction can be obtained. Precise detection, location, and possible quantification of the extent of damage can be performed by characterizing the physical and chemical states of moisture present in an in-service PMC. Composite structures have a locally elevated dielectric constant near the damage sites due to a higher fraction of bulk (“free”) water, which has a higher dielectric constant when compared to water molecules bound to the polymer network through secondary bonding interactions. In this study, we aim to get a clear atomistic scale picture of the interactions which drive the dielectric signature variations necessary for tracking damage. Molecular Dynamics (MD) simulations were used to explore the effect of temperature on the state of moisture in two epoxy matrices with identical chemical constituents but different morphologies. The motivation was to understand whether higher polarity binds a greater fraction of moisture even at higher temperatures, leading to suppressed dielectric activity. Consequently, the influence of secondary bonding interactions was investigated to understand the impact of temperature on the absorbed water molecules in a composite epoxy matrix.
Is Milan for kids?: The Milan System for Reporting Salivary Gland Cytology in pediatric patients at an academic children's hospital with cytologic-histologic correlation.

Background The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) provides a useful framework for the diagnosis of salivary gland fine-needle aspiration (FNA) biopsies. In this study, the MSRSGC was applied to salivary gland FNAs in pediatric patients to assess its usefulness and look at pitfalls. Methods The laboratory information system was queried over a 15-year period for all salivary gland FNAs in patients 18 years old or younger. Patient demographics, FNA diagnosis categorized according to the MSRSGC, and follow-up surgical pathology diagnoses were examined and correlated. Results Thirty-two cases were identified, with an average age of 12 years (range, 0.6-18 years). A majority of the cases (84.4%) were from the parotid region. Twenty of 32 cases (62.5%) had follow-up resection. MSRSGC recategorization diagnoses of the 32 FNA cases were 34% benign neoplasm, 31% nonneoplastic, 16% nondiagnostic, 9% atypia of undetermined significance, 3% salivary neoplasm of uncertain malignant potential, 3% suspicious for malignancy, and 3% malignant. Overall, the sensitivity and specificity were 100% and 80%, respectively. On follow-up resection, 55% were neoplastic: pleomorphic adenomas (n = 6; 55%), pilomatricoma (n = 3; 28%), mucoepidermoid carcinoma (n = 1; 9%), schwannoma (n = 1; 9%), and myofibroma (n = 1; 9%). Conclusions The MSRSGC performed fairly well in the pediatric population with a low overall risk of malignancy (6%) and high sensitivity. Although the majority of pediatric salivary gland FNAs were benign, 55% of resected cases were positive for a neoplasm, with benign neoplasms outnumbering malignancy. Challenging entities included inflammatory conditions, like immunoglobulin G4-related sialadenitis, and skin and soft tissue lesions near the salivary gland.
Electronic control of strong magnetic anisotropy in Co-based single-molecule magnets

The observation of large swings in the magnetic anisotropy in ligated ${\mathrm{Co}}_{2}$ dimers has motivated further calculations on single-center Co qubits in quasitetrahedral and quasioctahedral symmetries. In all cases our results indicate that it is the creation of an unquenched orbital moment due to a half-occupied frontier state at the Co center that directly drives large changes in the magnetic anisotropy barriers regardless of whether it is through symmetry breaking, a change in the charge state, or orbital energy reordering. While these observations are computationally demonstrated through our results on both monomers and dimers, the origin of orbital reordering at the Fermi level is not describable in terms of single physical changes. For example, in ligated ${\mathrm{Co}}_{2}$ the appearance of an unquenched orbital moment in one of the Co centers is correlated with a change from antiferromagnetic to ferromagnetic ordering at an energy that is uncharacteristically high for such transitions. Because this raises the spector of electromagnetically switchable quantum devices that operate at higher temperatures relative to that of the first-generation magnetic qubits, we carefully discuss subtle details associated with single-center qubits in realistic atomistic environments.
Assessing the Contemporary Role of Cytoreductive Nephrectomy in Metastatic Renal Cell Carcinoma: Another Step in the Right Direction.

There are three important clinical questions regarding whether cytoreductive nephrectomy (CN) should be performed in metastatic renal cell carcinoma (mRCC): (1) Does CN extend survival in the average patient in the targeted therapy era? (2) Is the timing of CN important (ie, before or after targeted therapy)? (3) Could we do a better job at selecting CN candidates? The first two questions are being addressed with two level 1–evidence ongoing randomized clinical trials (CARMENA [NCT0093033] and SURTIME [NCT01099423]). In this month’s issue of European Urology, Gershman et al [1] reported their retrospective large single-center study addressing the third question. They examined the association of clinicopathologic features with postoperative complications (30 d), prolonged length of stay, and delay in the receipt of systemic therapy (ST) among 294 mRCC patients treated with CN between 1990 and 2009. In this selected cohort, the authors found an overall low rate of postoperative complications (12%) and only a 5% rate of grade 3 complications. Median time to ST was 56 d after CN. Despite the low rate of postoperative complications, up to 61% of patients did not receive ‘‘timely ST,’’ which was defined as ST within 60 d of surgery. Gershman et al [1] should be congratulated for addressing an important topic in the surgical management of mRCC. Based on their report, some aspects deserve specific mention. First, the cohort they relied on represents a highly selected population in terms of baseline tumor burden after surgery. Indeed, only 36% of the patients had more than
A review: Recent work on inflatable structures

Abstract Contributions to the theory of pressure-stabilized inflatable structures are reviewed. Some recent work on the mechanical behavior of fabrics is surveyed.
Control of Trace Element Releases from High-Sulphur Coal Preparation Wastes: Technology and Costs

Abstract The aqueous drainage from coal piles and coal refuse dumps is frequently contamined with acids and various inorganic constituents. The Los Alamos National Laboratory has conducted research on the quantitative assessment of the source, nature, and magnitude of the aqueous release of trace elements from high-sulfur preparation wastes to evaluate existing control technologies, to identify new and effective technologies, and to evaluate costs of field implementation of these technologies. Our research shows that in terms of effectiveness and economics the most promising environmental control technology (ECT) for dealing with high-sulfur coal wastes from the United States consists of sequential slurry coating of the waste with lime and limestone. In the configuration tested (0.35% lime and 1.1% limestone), this technique controlled the waste effluent quality for 4 months. The effluent pH remained between 7.3 and 7.6, and the trace element concentrations (aluminium, calcium, manganese, iron, cobalt, nickel, and copper) were within acceptable limits. This treatment offers a potentially viable approach disposal of these wastes. Costs of 10 alternative ECTs were calculated for three hypothetical and three actual coal-cleaning plants, and the cost of lime-limestone slurry coating was analyzed.
Hydrocephalus-induced ischemia relating to VEGF-R2 and blood vessel density in hippocampus

Meeting abstracts - A single PDF containing all abstracts in this supplement is available here .
Evaluation of a preparatory community-based prostate health education program.

Abstract Background. Medical organizations are divided on the issue of screening for prostate cancer, yet there is agreement that men should be educated about prostate health. Shared decision making involves patients and practitioners in this process, yet some men need preparatory education prior to the physician encounter. This study assessed the effectiveness of a community prostate health awareness program, focusing on men at risk for prostate cancer. Methods. Participants were given a pretest and a posttest to assess knowledge gains and impact on short‐term intentions to address their prostate health. Results. There was a statistically significant increase in knowledge. Short‐term intentions increased for those participants meeting the inclusion criteria. Discussion. Community outreach programs remain an excellent vehicle to educate the public and complement the efforts of health care providers.
Tactile mapping for breast cancer diagnosis

This paper presents the development of a prototype tactile mapping device (TMD) system comprised mainly of a tactile sensor array probe, a 3D camera and a force/torque sensor, which can provide the means to produce tactile maps of the breast lumps during a breast palpation. Focusing on the key tactile topology features from breast palpation such as spatial location, size and shape of the detected lesion, and the force levels used to demonstrate the palpable abnormalities, these maps can record the results of clinical breast examination with a set of pressure distribution profiles and force sensor measurements due to detected lesion. The vision based knowledge, neural networks and tactile sensing technology are integrated for the investigation of soft tissue interaction with tactile/force sensor, where the hard inclusion (breast cancer) can be characterized through the neural network learning capability, instead of using a simplified complex biomechanics model with many heuristic assumptions. These maps will serve as an objective documentation of palpable lesions for future comparative examinations. Preliminary results of simulated experiments of the TMD prototype have validated our hypothesis and provided solid promising data showing the feasibility of the TMD in real clinical applications.
Datum Planes Based on a Constrained L1 Norm

This paper has two major goals. First, we present an algorithm for establishing planar datums suitable for a default in tolerancing standards. The algorithm is based on a constrained minimization search based on the L1 (L1) norm after forming a convex surface from the original surface or sampled points. We prove that the problem reduces to a simple minimization search between the convex surface and its centroid. The data points in the discrete case do not need to have any corresponding weights provided with them, as appropriate weighting is part of the algorithm itself, thereby making the algorithm largely insensitive to nonuniformly sampled data points. Terse mathematica code is included for the reader. The code is sufficient for primary and secondary planar datum fitting as well as a 3-2-1 datum reference frame generation. The second goal of this paper is to compare this new method with several other possible means for establishing datum planes, ultimately showing several appealing characteristics of the proposed algorithm. Since both the International Organization for Standardization (ISO) and American Society of Mechanical Engineers (ASME) standardization efforts are actively working to establish datum plane definitions, the timing of such a study is opportune.
Physiology of Thermophilic Bacteria

Publisher Summary The chapter discusses the physiology of thermophilic bacteria. Thermophilic microorganisms have all of the properties normally found in mesophilic microorganisms. These include metabolic pathways, regulatory mechanisms such as allosteric or feedback control, repression and induction of protein synthesis, growth yields and metabolic rates. The main difference between thermophiles and mesophiles is the former's capacity to grow at high temperatures. The basis for this capacity is the thermophile's capability to synthesize proteins, complex structures, and membranes that are stable or are stabilized and functional at thermophilic temperatures. It is proposed that the maximum and minimum growth temperatures are normally determined by properties associated with proteins, and that the membrane plays a lesser role in determining these temperatures. Enzymes and other proteins from thermophiles, except for having higher thermostability, are very similar to corresponding proteins from mesophiles. The higher thermostability is generally dependent on subtle changes in the composition and sequence of the amino acids and rarely dependent on non-proteinaceous factors. Although over 100 proteins have been purified from thermophiles and compared with corresponding proteins from mesophiles, the exact nature of the higher thermostability has yet to be determined in a protein from a thermophile.
Low Cost Testing of Low Power Wireless Transceivers

Parallel low cost testing of low power wireless RF transceivers is realized using a low cost RF mixed signal tester. Special design for test (DFT) considerations for the transceiver has made the implementation of low cost multisite RF testing possible with reduced test time and test development effort and improved throughput. Careful load board design considerations have reduced load board cross talk, signal noise coupling, and susceptibility for electromagnetic interference.
Differential Vertical Tectonics: Insights from Models Composed of Sandstone and Limestone Deformed at Confining Pressure: ABSTRACT

Rock models (12 × 3 × 3 cm, 4 × 1 × 1 in.) composed of a precut forcing block of sandstone beneath a 1-cm thick, multilithologic layered veneer of sandstone and limestone or of uncemented sand, have been deformed room-dry, at 100-MPa confining pressure, room temperature, and a strain rate of 10-4 sec-1. Upon frictional sliding along the lubricated precut (inclined at 30° to 90° to the intact veneer) the forcing blocks deform the layered veneer into a faulted drape fold. Thin sections cut parallel to the dip and to the strike of the precut and major fault in the veneer are studied to provide detailed maps of the induced deformation (microfractures, faults, intragranular strains, "bedding" thickness changes, brittle versus ductile behavior, and nature of the folding and hinge formation). In addition, dynamic fabric analyses of faults, microfractures, and calcite twin lamellae yield stress trajectory diagrams that serve to test the applicability of corresponding numerical or analytical solutions. Insights gained from the models primarily deal with (a) brittle or ductile behavior of the limestone depending upon location within the faulted drape fold; (b) nature of the deformation concentrated in the leading edge of the "upthrown" forcing block; (c) configuration and sequence of faulting associated with the major "upthrust" in the veneer; (d) location and significance of associated precursive microfracturing; (e) cataclastic thinning of veneers to the point where discrete layers are "tectonically eliminated" in the major fault zones; (f) hinge formation within the veneer; and (g) the role of "bedding-plane slip" in the folding process. Deformation features in these models are used to interpret the geometry and genesis of the large scale structures at the Clark's Fork Corner of the Beartooth Block and at Rattlesnake Mountain near Cody, Wyoming; at Colorado National Monument near Grand Junction, Colorado; at the Yampa drape fold, Dinosaur National Monument; and in the subsurface along the Oak Ridge fault, Ventura basin, California. Collectively, these features are criteria for, and hence help define, the differential-vertical-tectonic style. End_of_Article - Last_Page 1337------------
FAB-MS spectra from Teflon® surface: peak pattern development with increasing bombarding dose

Abstract The potential of FAB-MS for characterization of Teflon® surface is investigated and the character of the spectra compared with SIMS results from several different experiments. The change in the spectral peak pattern with increasing atom bombarding dose is examined in light of the radiation damage accumulation in the surface layer of the polymer and surface morphology development at higher atom bombarding doses. The correlation of the fragment ion yield with surface morphology shows that the overall change of the bombarding geometry plays an important role in the decrease of signal intensity with time. An irregular development of the relative ion fragment yields with increasing bombarding dose indicates that processes in the surface region are more complicated than a simple radiation damage accumulation of the polymer fragments created by a polymer chain scissoring mechanism.
Head and neck soft tissue sarcomas: a multivariate analysis of outcomes.

Soft tissue sarcomas of the head and neck region represent a rare group of tumors of which a limited number of published individual- and institution-based experiences exist. We performed an analysis of head and neck sarcoma patients identified from our institution between 1973 and 1999. Exclusion criteria included pediatric rhabdomyosarcomas, sarcomas of the neuromeningeal axis or non–head and neck primary disease sites, and bone sarcomas. All cases underwent pathologic re-review before statistical analysis. After pathologic review, 111 head and neck sarcoma patients remained (mean age, 47 ± 20 years). The median duration of follow-up was 51 months; the actuarial 5-year relapse-free, disease-specific, and overall survivals were 55%, 52%, and 44%, respectively. Forty-six percent remained free of recurrence at the most recent follow-up, and the most common site of recurrence was local followed by distant sites. By multivariate analysis, size and grade significantly influenced relapse-free, disease-specific, and overall survivals, whereas margin status additionally influenced relapse-free survival. Subset analysis of the fibrosarcoma/malignant fibrous histiocytoma and desmoid/dermatofibrosarcoma protuberans histologies was undertaken. Size >5 cm and high-grade histology are considered poor prognostic indicators. Patients with either of these characteristics should be considered for adjuvant trials.
3D automatic anatomy segmentation based on iterative graph-cut-ASM.

Purpose: This paper studies the feasibility of developing an automatic anatomy segmentation (AAS) system in clinical radiology and demonstrates its operation on clinical 3D images.Methods: The AAS system, the authors are developing consists of two main parts: object recognition and object delineation. As for recognition, a hierarchical 3D scale-based multiobject method is used for the multiobject recognition task, which incorporates intensity weighted ball-scale (b-scale) information into the active shape model (ASM). For object delineation, an iterative graph-cut-ASM (IGCASM) algorithm is proposed, which effectively combines the rich statistical shape information embodied in ASM with the globally optimal delineation capability of the GC method. The presented IGCASM algorithm is a 3D generalization of the 2D GC-ASM method that they proposed previously in Chen et al. [Proc. SPIE, 7259, 72590C1–72590C-8 (2009)]. The proposed methods are tested on two datasets comprised of images obtained from 20 patients (10 male and 10 female) of clinical abdominal CT scans, and 11 foot magnetic resonance imaging (MRI) scans. The test is for four organs (liver, left and right kidneys, and spleen) segmentation, five foot bones (calcaneus, tibia, cuboid, talus, and navicular). The recognition and delineation accuracies were evaluated separately. The recognition accuracy was evaluated in terms of translation, rotation, and scale (size) error. The delineation accuracy was evaluated in terms of true and false positive volume fractions (TPVF, FPVF). The efficiency of the delineation method was also evaluated on an Intel Pentium IV PC with a 3.4 GHZ CPU machine.Results: The recognition accuracies in terms of translation, rotation, and scale error over all organs are about 8 mm, 10° and 0.03, and over all foot bones are about 3.5709 mm, 0.35° and 0.025, respectively. The accuracy of delineation over all organs for all subjects as expressed in TPVF and FPVF is 93.01% and 0.22%, and all foot bones for all subjects are 93.75% and 0.28%, respectively. While the delineations for the four organs can be accomplished quite rapidly with average of 78 s, the delineations for the five foot bones can be accomplished with average of 70 s.Conclusions: The experimental results showed the feasibility and efficacy of the proposed automatic anatomy segmentation system: (a) the incorporation of shape priors into the GC framework is feasible in 3D as demonstrated previously for 2D images; (b) our results in 3D confirm the accuracy behavior observed in 2D. The hybrid strategy IGCASM seems to be more robust and accurate than ASM and GC individually; and (c) delineations within body regions and foot bones of clinical importance can be accomplished quite rapidly within 1.5 min.
Broadly permissive intestinal chromatin underlies lateral inhibition and cell plasticity

A study investigating the mechanisms underlying lateral inhibition and lineage plasticity in the mouse small intestine crypts in vivo finds that crypt cells maintain a permissive chromatin state upon which a transcription factor acts to determine lineage specification, and this is the basis of lateral inhibition. Intestinal crypts are the focus of intensive study, stimulated in part by the recent discovery of distinct stem-cell populations and markers. Ramesh Shivdasani and colleagues have studied mechanisms underlying lateral inhibition and lineage plasticity in mouse small intestine crypts in vivo. They find that crypt cells maintain a permissive chromatin state upon which a transcription factor acts to determine lineage specification, and that this is the basis of lateral inhibition. Cells differentiate when transcription factors bind accessible cis-regulatory elements to establish specific gene expression programs. In differentiating embryonic stem cells, chromatin at lineage-restricted genes becomes sequentially accessible1,2,3,4, probably by means of ‘pioneer’ transcription factor activity5, but tissues may use other strategies in vivo. Lateral inhibition is a pervasive process in which one cell forces a different identity on its neighbours6, and it is unclear how chromatin in equipotent progenitors undergoing lateral inhibition quickly enables distinct, transiently reversible cell fates. Here we report the chromatin and transcriptional underpinnings of differentiation in mouse small intestine crypts, where notch signalling mediates lateral inhibition to assign progenitor cells into absorptive or secretory lineages7,8,9. Transcript profiles in isolated LGR5+ intestinal stem cells10 and secretory and absorptive progenitors indicated that each cell population was distinct and the progenitors specified. Nevertheless, secretory and absorptive progenitors showed comparable levels of H3K4me2 and H3K27ac histone marks and DNase I hypersensitivity—signifying accessible, permissive chromatin—at most of the same cis-elements. Enhancers acting uniquely in progenitors were well demarcated in LGR5+ intestinal stem cells, revealing early priming of chromatin for divergent transcriptional programs, and retained active marks well after lineages were specified. On this chromatin background, ATOH1, a secretory-specific transcription factor, controls lateral inhibition through delta-like notch ligand genes and also drives the expression of numerous secretory lineage genes. Depletion of ATOH1 from specified secretory cells converted them into functional enterocytes, indicating prolonged responsiveness of marked enhancers to the presence or absence of a key transcription factor. Thus, lateral inhibition and intestinal crypt lineage plasticity involve interaction of a lineage-restricted transcription factor with broadly permissive chromatin established in multipotent stem cells.
Fleeting moments : nature and culture in American history

Gunther Barth's book focuses on the relation between nature and culture in American history. He begins with the search for a Northwest Passage by Spanish and English explorers and describes how they learned about American natural phenomena. There is a section showing how nature was adapted to urban settings in cemeteries and in city parks like New York's Central Park and San Francisco's Golden Gate Park.
Russian folk discourse on problem drinking

Cultural discourse analysis was used to explore the data from 77 interviews with Russian respondents in order to describe and interpret what representatives of Russian culture understand by problematic alcohol consumption. The study identified two clusters of cultural terms that define problem drinking as either ‘to get drunk at one sitting’ (‘napit'sia’ – напиться) or ‘to consume alcohol in a regular and patterned way’ (‘pit’ – пить). The two term clusters were analyzed and compared as functioning in the folk discourse according to communication norms that are constituted by code and normative rules. Cultural propositions developed on the foundation of term clusters helped to formulate statements reflecting folk logic in defining problem drinking. Further analysis revealed a key cultural premise about problem drinking in Russian culture: it is dangerous to consume large quantities of alcohol at one sitting, but alcohol intake does not carry substantial long-term damage unless it acquires a regular, ident...
Automated protocol analysis

Over the past 8 years, The TextLab Research Group within the Department of Computer Science at the University of North Carolina has developed a collection of tools and techniques for recording users' interactions with graphics-based direct manipulation computer systems in machine-readable form and for automatically analyzing and displaying those data. This article describes these tools, discusses their methodological context, and considers their implications for software design and studies of human-computer interaction. Tools discussed include the following: tracking users' behaviors and producing a machine-recorded protocol at the level of users' actions, replaying users' sessions from the protocol data, modeling users' strategies using formal cognitive grammars, analyzing user sessions by parsing them with the grammars, and displaying results in visual form-both static and animated--to facilitate interpretation and understanding by researchers. These tools are placed in a methodological context by reviewing issues associated with concurrent think-aloud, keystroke, X-Windows, and video protocols; other support systems for working with these forms of protocol data are also reviewed. The discussion concludes with our reflections on the methodology and its application to computer systems and research objectives different from our own.
Role of treatment alliance in the clinical management of bipolar disorder: Stronger alliances prospectively predict fewer manic symptoms

The strength of the treatment alliance between patients and their clinicians may play a unique role in the management of bipolar disorder. However, few empirical studies have examined the alliance in bipolar disorder or its effects on patient outcomes. This study investigates variables associated with a strong treatment alliance in bipolar disorder, and the prospective effects of treatment alliance on patients' mood symptoms and treatment attitudes. Participants were 58 longitudinally followed individuals with Bipolar I disorder. We found that alliance ratings covaried with depressive symptoms, such that alliance strength increased as depressive symptoms decreased, and stronger alliances were associated with more social support. Tests of temporal association indicated that stronger alliances predicted fewer manic symptoms 6 months later. Stronger alliances also predicted less negative attitudes about medication and less of a sense of stigma about bipolar disorder. Thus, a strong treatment alliance may help to reduce manic symptoms over time. It may be that a strong treatment alliance encourages patients' greater acceptance of bipolar disorder and psychopharmacological interventions, and thus contributes to improved medication adherence and clinical outcomes. Considered in sum, these findings suggest that the treatment alliance is an integral component of the long-term management of bipolar disorder.
Free and forced oscillations of a class of mechanical systems

Abstract It is shown that oscillations of a broad class of mechanical systems are governed by a differential equation of the form q + p 2 q(1 + aq 2 + bq 2 ) = Ω 2 cos ωt which includes the Duffing equation as a special case. A first integral of this equation, for Ω = 0, is used to explore the relationship between the amplitude and the period of free vibrations, and forced oscillations are discussed by reference to response curves obtained by the method of Kryloff and Bogoliuboff.
Comparison of k independent, zero-heavy lognormal distributions

Lachenbruch (1976, 2001) introduced two-part tests for comparison of two means in zero-inflated continuous data. We are extending this approach and compare k independent distributions (by comparing their means, either overall or the departure from equal proportion of zeros and equal means of nonzero values) by introducing two tests: a two-part Wald test and a two-part likelihood ratio test. If the continuous part of the distributions is lognormal then the proposed two test statistics have asymptotically chi-square distribution with degrees of freedom. A simulation study was conducted to compare the performance of the proposed tests with several well-known tests such as ANOVA, Welch (1951), Brown & Forsythe (1974), Kruskal–Wallis, and one-part Wald test proposed by Tu & Zhou (1999). Results indicate that the proposed tests keep the nominal type I error and have consistently best power among all tests being compared. An application to rainfall data is provided as an example. The Canadian Journal of Statistics 39: 690–702; 2011. © 2011 Statistical Society of Canada Lachenbruch (1976, 2001) a introduit un test en deux parties pour comparer deux moyennes pour des donnees provenant du modele continu augmente en zero. Nous generalisons cette approche en comparant k distributions independantes (en comparant leur moyenne globale, ou l'ecart par rapport a une proportion egale de zeros ou encore l'egalite des moyennes des valeurs non nulles) en presentant deux tests: un test de Wald en deux parties ou un test du rapport de vraisemblance aussi en deux parties. Si la partie continue des distributions est log-normale, alors les deux statistiques de test proposees suivent asymptotiquement une distribution khi-deux avec degres de liberte. Une etude de simulation a ete faite afin de comparer la performance des tests proposes avec plusieurs tests bien connus tels que : l'analyse de la variance, les tests de Welch (1951), Brown & Forsythe (1974), de Kruskal–Wallist et le test de Wald en une partie propose par Tu et Zhou (1999). Les resultats de cette etude indiquent que les tests proposes maintiennent l'erreur de type I et ils ont systematiquement une meilleure puissance parmi tous les tests consideres. Un exemple est donne a l'aide de donnees de precipitations. La revue canadienne de statistique 39: 690–702; 2011. © 2011 Societe statistique du Canada
An alternative approach to the refined duality theory of geometric programming

Abstract The refined, or strong duality theory of posynomial geometric programming is a comprehensive duality theory which does not depend on the Kuhn-Tucker theorem or on the superconsistency of the primal. It is also used to classify geometric programs into categories that possess certain distinctive attributes. In this paper an alternative and mathematically simpler approach to this theory is presented. The approach is based upon a reformulation of the dual as a generalized linear program, and the derivation of the results is based primarily upon principles in linear optimization.
Is losing sleep making us obese

Summary Obesity has become pandemic. In America, as obesity has increased, the amount of sleep Americans get per night has decreased, and studies are now showing an association. Epidemiological studies on short sleep duration (SSD) and obesity have been conducted in children and adults, and show an overall positive association. Leptin and ghrelin, two hormones that control appetite, have been studied as a mechanism for SSD causing obesity. Low leptin and high ghrelin levels have been seen in sleep deprivation, the effect of which is an increase in appetite that could be linked to obesity. Decreasing media use, namely television and computers, could be one way to increase nightly sleep and potentially help people lose weight. Paediatric studies have shown an association with bedroom media use and shorter sleep duration. Adult studies are lacking in this area. Limitations in the literature include self-report in a majority of sleep studies and only a suggested causal link between SSD and obesity among all of the epidemiological studies. In conclusion, obesity is a global problem with great complexity. Encouraging people to get more sleep could be one part of the solution to help them lose weight and gain health.
Resampling methods revisited: advancing the understanding and applications in educational research

Resampling methods including randomization test, cross‐validation, the jackknife and the bootstrap are widely employed in the research areas of natural science, engineering and medicine, but they lack appreciation in educational research. The purpose of the present review is to revisit and highlight the key principles and developments of resampling methods to advance the understanding and applications of resampling methods in educational research. The present review also intends to provide resources for educational researchers to identify specific resampling methods that may be unitized to solve research problems in education. The procedures of each resampling technique are illustrated by empirical examples. The recent developments and further directions of resampling methods are also discussed.
Geologic settings of Martian gullies: Implications for their origins

Martian gullies are found on steep slopes of all origins, on all sorts of terrains of all ages, scattered across nearly all of Mars. Gullies are observed on all manner of substrates (layered, massive, shattered, rubble), with or without nearby mantling deposits. Gullies are most common in the southern midlatitudes but also occur in the northern hemisphere, in near polar terrain, on equatorial volcanoes, and on northern plains. Most gullies in the southern hemisphere are on south-facing slopes, but they occur on slopes of all orientations. Gullies are among the youngest features on Mars but locally are overlain by eolian deposits and cut by faults. Old or eroded gullies are rare, and those found have been partially stripped from slopes, leaving no rock debris behind. Most gully deposits contain no detectable rocks. These data are inconsistent with published hypotheses of gully formation, including seeps and breakouts of water or brine, hydrothermal activity, cryovolcanism, and breakouts from liquid carbon dioxide. The data are consistent with gullies being dry flows of eolian material (dust and silt), comparable to climax snow avalanches on Earth. Eolian sedimentation should be correlated little with underlying geology: cause of slope, age of terrain, type of terrain, or the nature of the rocks. Eolian sedimentation should be correlated with wind deceleration (which will cause suspended sediment to drop), and areas with common gullies are those with strong wind deceleration (predicted by global circulation model). In such areas, sediment will be deposited preferentially in the lee of obstacles; for the gully-rich areas of the southern midlatitudes, winds blow from the NNW, so that sediment is deposited on SSE-facing slopes (i.e., poleward). These predictions are in accord with observations.
COX2 Inhibition Reduces Aortic Valve Calcification In Vivo

Objective— Calcific aortic valve disease (CAVD) is a significant cause of morbidity and mortality, which affects ≈1% of the US population and is characterized by calcific nodule formation and stenosis of the valve. Klotho -deficient mice were used to study the molecular mechanisms of CAVD as they develop robust aortic valve (AoV) calcification. Through microarray analysis of AoV tissues from klotho -deficient and wild-type mice, increased expression of the gene encoding cyclooxygenase 2 (COX2; Ptgs2 ) was found. COX2 activity contributes to bone differentiation and homeostasis, thus the contribution of COX2 activity to AoV calcification was assessed. Approach and Results— In klotho -deficient mice, COX2 expression is increased throughout regions of valve calcification and is induced in the valvular interstitial cells before calcification formation. Similarly, COX2 expression is increased in human diseased AoVs. Treatment of cultured porcine aortic valvular interstitial cells with osteogenic media induces bone marker gene expression and calcification in vitro, which is blocked by inhibition of COX2 activity. In vivo, genetic loss of function of COX2 cyclooxygenase activity partially rescues AoV calcification in klotho -deficient mice. Moreover, pharmacological inhibition of COX2 activity in klotho -deficient mice via celecoxib-containing diet reduces AoV calcification and blocks osteogenic gene expression. Conclusions— COX2 expression is upregulated in CAVD, and its activity contributes to osteogenic gene induction and valve calcification in vitro and in vivo.
Race and Human Rights Violations in the United States: Considerations for Human Rights and Moral Educators.

In the previous article Mary M. Brabeck and Lauren Rogers called for dialogue between moral educators of North America and human rights educators of South America, noting that the latter group has much to offer the former for its work in the United States. In what follows, I posit that moral educators can learn not only from South American human rights workers but also from North Americans who have challenged US human rights violations, especially those occurring within their own national borders. I use race as an analytical device in this article to illustrate human rights abuses, given the blatant nature and institutionalised character of these particular violations as they occur in the United States. In my view, such an examination is useful for investigating other issues of concern for human rights and moral educators. I conclude the article by discussing some of the implications for crossing boundaries between human rights work and moral education, the praxis that Brabeck and Rogers propose for the c...
Active reflectors for high performance lithium niobate on silicon dioxide resonators

This paper reports on the design and demonstration of active reflectors for enhancing the electromechanical coupling (k t 2) and suppressing spurious modes in Laterally Vibrating Resonators (LVRs) based on X-cut ion-sliced Lithium Niobate (LN) thin film on silicon dioxide (SiO 2 ). By adding electroded quarter wavelength (λ/4) regions at the two ends of the resonant plate, active reflectors (since an electrical signal is applied to them) are formed to improve the device performance. Optimized active reflectors that resort to 100% metal coverage of the λ/4 extensions enable: (i) a considerable improvement of k t 2, (ii) spurious mode suppression, and robustness to processing (iii) misalignment and (iv) over/under-etching. 2X improvement in k t 2 and significant suppression of in-band spurious vibrations were attained with respect to the conventional design (without active reflectors) despite 0.5 µm misalignment and more than 0.5 µm overetch in the fabrication process.
A Vocational Preference Rank Technique

The relationship between Kuder Vocational scale positions obtained by a rank order method, and ranks obtained from the Kuder Preference Record Vocational Form CH Profile Sheet, was found for 39 male psychiatric patients at a Veterans Administration Hospital. Correlations were significantly higher for valid than for invalid Preference Record profiles, approaching the level of Kuder test-retest reliability. The V scale may reflect in part the confused thinking of neuropsychiatric patients. Validation of this impression must await further research.
Parametric instabilities and wave coupling in Alfvén simple waves

A wave coupling formalism for magnetohydrodynamic (MHD) waves in a non-uniform background flow is used to study parametric instabilities of the large-amplitude, circularly polarized, simple plane Alfven wave in one Cartesian space dimension. The large-amplitude Alfven wave (the pump wave) is regarded as the background flow, and the seven small-amplitude MHD waves (the backward and forward fast and slow magnetoacoustic waves, the backward and forward Alfven waves, and the entropy wave) interact with the pump wave via wave coupling coefficients that depend on the gradients and time dependence of the background flow. The dispersion equation for the waves D(k, w) = 0 obtained from the wave coupling equations reduces to that obtained by previous authors. The general solution of the initial value problem for the waves is obtained by Fourier and Laplace transforms. The dispersion function D(k,ω) is a fifth-order polynomial in both the wavenumber k and the frequency ω. The regions of instability and the neutral stability curves are determined. Instabilities that arise from solving the dispersion equation D(k,ω) = 0, both in the form w = w(k), where k is real, and in the form k = k(w), where w is real, are investigated. The instabilities depend parametrically on the pump wave amplitude and on the plasma beta. The wave interaction equations are also studied from the perspective of a single master wave equation, with multiple wave modes, and with a source term due to the entropy wave. The wave hierarchies for short- and long-wavelength waves of the master wave equation are used to discuss wave stability. Expanding the dispersion equation for the different long-wavelength eigenmodes about k = 0 yields either the linearized Korteweg-deVries equation or the Schrodinger equation as the generic wave equation at long-wavelengths. The corresponding short-wavelength wave equations are also obtained. Initial value problems for the wave interaction equations are investigated. An inspection of the double-root solutions of the dispersion equation for k, satisfying the equations D(k, ω) = 0 and ∂D(k, ω)/∂k = 0 and pinch point analysis shows that the solutions of the wave interaction equations for hump or pulse-like initial data develop an absolute instability. Fourier solutions and asymptotic analysis are used to study the absolute instability.
T-bet employs diverse regulatory mechanisms to repress transcription.

Lineage-defining transcription factors are responsible for activating the signature genes required for a given cell fate. They are also needed to repress the genetic programs associated with alternative lineage decisions. The T-box transcription factor T-bet is required for CD4+ T helper 1 (Th1) cell differentiation. Numerous studies have explored the mechanisms by which T-bet activates the Th1 gene profile, but until recently not much was known about the mechanisms that T-bet utilizes to negatively regulate alternative T helper cell differentiation pathways such as the Th2 and Th17 fates. Here, we discuss new advances in the field that highlight the diverse mechanisms that T-bet employs to antagonize the gene programs for alternative T helper cell fates.
Kinetics and inhibition of reductive dechlorination of trichloroethene, cis-1,2-dichloroethene and vinyl chloride in a continuously fed anaerobic biofilm reactor.

Anaerobic bioreactors containing Dehalococcoides spp. can be effective for the treatment of trichloroethene (TCE) contamination. However, reductive dehalogenation of TCE often results in partial co...
Model studies of the dynamics of launch vehicles.

Structural dynamics research on launch vehicles at Langley Research Center, examining analytical method limitations and need for improved mathematical models for vibrational characteristics
Electromigration characteristics of vias in Ti:W/Al-Cu(2 wt.%) multilayered metallization

The electromigration (EM) performance and failure mechanisms for 1.2- mu m vias fabricated in a passivated Ti:W/Al-Cu(2 wt.%) metallization were investigated. Single van der Pauw via structures were stressed at 175 degrees C and 200 degrees C and at accelerated current densities. The via resistance was monitored independently of the metal feed lines and a difference in activation energy, failure mode, and mean time to fail was observed depending on the direction of current flow. When electrons flowed into the via, the via sustained a 20% increase in resistance before failing catastrophically. Conversely, when electrons flowed out of the via, a monotonic increase in resistance was observed, and yet the via remained intact. Concerns of poor aluminum step coverage in the vias were addressed. Reliability comparisons were made between vias and flat metal stripes. >
Phase Homogeneity in Y2O3–MgO Nanocomposites Synthesized by Thermal Decomposition of Nitrate Precursors with Ammonium Acetate Additions

Nanocomposite powders with equal volume fractions of Y2O3 and MgO have been produced by the thermal decomposition of precursor mixtures of yttrium nitrate and magnesium nitrate. Solutions of the precursor salts were mixed with ammonium acetate fuel, dried to form a gel-like substance, and then calcined to give nanocrystalline ceramic powders. The amount of ammonium acetate added to the metal nitrate precursors was varied systematically, and the morphology and distribution of the component phases in consolidated compacts of the resultant ceramic powders were examined by a combination of focused ion beam sectioning, scanning, and transmission electron microscopy. The dispersion of the Y2O3 and MgO phases within the synthesized powders improved, and the sizes of the phase domains reduced, with increasing ammonium acetate content up to the quantity required for a stoichiometric redox reaction with the metal nitrates. The addition of excess ammonium acetate gave no further improvement in phase domain dispersion or reduction in phase domain sizes. These phenomena are related to the thermal characteristics for the decomposition of the precursors and their effect on phase separation during oxide crystallization.