cssi/SciSciGPT-SciSciNet huggingface dataset:
Hostile Mood and Social Strain during Daily Life: A Test of the Transactional Model

Background Hostility is a multidimensional construct related to cardiovascular (CV) disease risk. Daily hostile mood and social interactions may precipitate stress-related CV responses in hostile individuals.
Assessing the impact of differential measurement error on estimates of fine particle mortality.

ABSTRACT In air pollution epidemiology, error in measurements of correlated pollutants has been advanced as a reason to distrust regressions that find statistically significant weak associations. Much of the related debate in the literature and elswhere has been qualitative. To promote quantitative evaluation of such errors, this paper develops an air pollution time-series model based on correlations among unit-normal variables. Assuming there are no other sources of bias present, the model shows the expected amount of relative bias in the regression coefficients of a bivariate regression of coarse and fine particulate matter measurements on daily mortality. The model only requires information on instrumental error and spatial variability, along with the observed regression coefficients and information on the true fine-course correlation. Analytical results show that if one pollutant is truly more harmful than the other, then it must be measured more precisely than the other in order not to bias the ratio...
Tracing the roots of ion channels

Two sets of recent findings draw our attention to questions concerning the origin of ion channels. First, there is sequence similarity among five classes of channels: voltage-gated channels, a putative Ca(2+)-activated K+ channel, cyclic nucleotide-gated cation channels, a putative Ca2+ channel for phosphoinositide-mediated Ca2+ entry, and a plant K+ channel/transporter. Like voltage-gated K+ channels, the most recently identified members of the superfamily share the basic design of one set of six potential membrane-spanning segments plus the H5 sequence; as such, they may resemble more closely the ancestral channel, which is likely to predate the separation of the animal and plant kingdoms. Second, several members of the ABC superfamily function as ion channels, even though they were previously known as transporters or enzymes. Did some ancestral enzymes subsequently acquire channel/transporter function? Or could it be the other way around? Aside from evolutionary considerations, enzymes and ion channels can no longer be treated as separate and nonoverlapping groups of proteins. When one molecule exhibits both functions, there are interesting mechanistic questions: How might the enzyme activity such as ATP hydrolysis be coupled to activation/regulation of the intrinsic channel activity? How might interactions between the permeant ions and the channel pore in turn regulate the enzymatic function of the same molecule? It seems possible that the latter is an extension of the observed coupling between permeant ions and the gating machinery of an ion channel (Swenson and Armstrong, 1981). Finally, the potential cross-regulation between channel activity and enzyme activity within the same molecule offers many intriguing possibilities for the integration of different cellular functions.
The localization of spectra with respect to homology

IN [8] WE studied localizations of spaces with respect to homology, and we now develop the analogous stable theory. Let Ho” denote the stable homotopy category of CW-spectra. We show that each spectrum E E Ho” gives rise to a natural E*localization functor ( )E: Ho” -+HoS and n : 1 +( )E. For A E Ho”, v:A-+AE is the terminal example of an E*-equivalence going out of A in Ho”. After proving the existence of ES-localizations, we develop their basic properties and discuss in detail the cases where E is connective and E = K. Using EJocalization theory, we obtain results on the convergence of the E*-Adams spectral sequence, and on the class A(Ho”) of acyclicity types of spectra, see [9]. The paper is sectioned as follows: 91. E*-localizations and E*-acyclizations of spectra; 42. Localizations with respect to Moore spectra; 93. General examples of E*-localizations; 34. K-theoretic localizations of spectra; 05. The E*-Adams spectral sequence and the E-nilpotent completion; 06. Convergence theorems for the E*Adams spectral sequence; P7. Duality in &Ho”). E*-localizations of spectra were previously studied by Adams, who sketched a useful outline of the subject in 141. However, the first complete existence proof for such localizations was obtained by the author as an immediate corrollary of work on EJocalizations of spaces, see [8]. The relevant proofs in [81 may be stabilized by using Kan’s semi-simplicial spectra in place of simplicial sets. That approach also shows the existence of “ES-factorizations” for maps of spectra and leads to a Quillen model category framework for “stable homotopy theory with respect to Es.” To make the present exposition more understandable we omit these topics and work in the homotopy category of CW-spectra. This paper grew out of an attempt to understand Doug Ravenel’s work on localizations of spectra with respect to certain periodic homology theories [17], and we are indebted to him for explaining his ideas. We are also indebted to Mark Mahowald and Haynes Miller for supplying the homotopy theoretic theorem underlying our approach to K*-localizations, and we have been significantly influenced by Guido Mislin’s work on K*-localizations of spaces [ 161. We understand that various results in this paper, particularly in 54, were obtained by Frank Adams and David Baird in earlier unpublished work, and that some have been obtained independently by W. Dwyer (unpublished). We essentially use the notation and terminology of [4]. However, we let Ho” be the category of CW-spectra and homotopy classes of maps of degree 0, see [4], p. 144. Thus HO” is an additive category equipped with an equivalence C : Ho” --f Ho” induced by the “shift” suspension for CW-spectra. We let [X, Y] be the group of morphisms
Discrepancies in the crystal structures assigned to precipitated zirconia

Zirconia exists in three well-known polymorphic forms: monoclinic, tetragonal and cubic structures [1, 2], besides the one recently reported as a high-pressure orthorhombic phase [3]. Whereas the monoclinic phase is quite stable at low temperatures, the tetragonal and cubic phases are high temperature (> 1000 °C) stable phases. However, these latter polymorphs can be made stable or metastable even at room temperature by manipulating the preparation procedures or by the addition of rareearth oxides in appropriate proportions. Apart from the usage of additives as stabilizers, it was reported by Garvie [4, 5] that the tetragonal phase can be stabilized at temperatures well below 500 °C if the crystallite size was < 30 nm. Other data were not consistent with size as the stabilizing factor [6-10]. The stabilization of the tetragonal phase in zirconia at low temperatures has been attributed to chemical factors involved in the precipitation methods [11-13]. It was reported that the zirconia precipitated at a pH of 13.5 exhibited tetragonal symmetry. However, recent papers by Benedetti et al. [14, 15] have evoked interesting arguments about the assignment of crystal symmetries to the zirconia precipitated at a pH of 13.5. These authors [14, 15] indicate that 3 wt % Na incorporated in the precipitation step stabilizes the cubic form. In this letter the questions raised by Benedetti et al. [14, 15] are addressed. A zirconia solution (0.3 M) was prepared using anhydrous ZrCI4. Precipitation was effected at a pH of 13.5 by rapidly adding excess 4 M NaOH. The gels were thoroughly stirred. Sample A was washed three times and sample B was washed exhaustively (about eight times). Sample A contained 3 wt % Na, whereas sample B had < 0 . 5 w t % Na, as determined by atomic absorption analysis. The two samples were calcined at 500 °C for 4 h. The X-ray diffractometer (XRD), the Raman spectrometer and the experimental conditions used to collect Raman spectra are described in detail elsewhere [16]. Clearfield [6] found that by refluxing zirconyl chloride in NHeOH, monoclinic hydrous zirconia could be obtained; refluxing in a 20% NaOH solution resulted in the formation of tetragonal hydrous zirconia. Katz [17], however, reported that the precipitate formed from a zirconyl chloride solution with NaOH addition led to a metastable cubic phase when the hydrous oxide was heated at 285 °C; at 300 °C the splitting of some of the cubic lines indicated the onset of a c ~ t transformation
Multispectral satellite observations for arid land studies

Multispectral satellite data when properly calibrated and standardized can be used synergistically for a quantitative analysis of processes and surface characteristics, and for quantifying land surface change. Relationships among multispectral satellite data (visible reflectance, surface temperature and polarization difference of microwave emission at 37 GHz frequency) have been used to develop hypotheses concerning the relative sensitivity of these data to varied land surface characteristics, which needs to be verified by field observations. Radiative transfer models have also been developed to understand these multispectral data. Interannual variations of visible reflectance and polarization difference for the period 1982-1986 over the Sahel and the Sudan zones of Africa show a lagged response with respect to the rainfall deficit during recovery from drought, which needs to be understood in terms of biophysical parameters.
The Immunologic Basis for Neonatal Immunizations

After completing this article, readers should be able to: 1. Describe the immunologic basis of the recommendations for immunization in infants. 2. Address parental concerns regarding controversies surrounding immunization. 3. Understand and outline the current recommendations for immunizing preterm and low-birthweight infants against hepatitis B. 4. Describe the current immunizations administered to infants. At birth, the human immune system is principally passive. Transplacental passage of maternal immunoglobulin (Ig) G occurs predominantly in the third trimester and, therefore, quantitatively correlates with gestational age. The immunologic status of the mother and her antibody (Ab) repertoire are critical components of the quality and specificity of transferred Ab. Human milk prolongs the passive transfer of IgG and provides IgA. These preformed Abs provide the neonate with protection against bacterial and viral pathogens if the mother was immune prior to either the birth of the baby or the provision of human milk. Such passive immunity, although protective against potential pathogens, does not result in immunologic memory and the consequent logarithmically increased production of high-avidity Ab, both of which define the ability of an infant to respond to an immunization. Minimal in utero antigen (Ag) exposure results in B- and T-cell repertoires in the infant that are relatively naive. This naive lymphocyte repertoire expands quickly because of the massive Ag exposure that begins at birth. Within several hours of birth, many infants have experienced enteral nutrition, and myriad bacterial species colonize the gastrointestinal tract. The ability of human B- and T-cell repertoires to expand clonally and for these cells to undergo specialized differentiation is crucial in the development of an active immunologic response. This active response is the cornerstone of successful immunization. The immaturity of this active response determines both the efficacy and the safety of various immunizations in infancy. Bacterial polysaccharides (PSs) form the capsules of several bacterial species …
Performance metrics based on signal intensity for ion mobility spectrometry – based explosive trace detectors using inkjet printed materials

Commercial off-the-shelf (COTS) explosive trace detectors (ETDs) have become an integral part of security practices aimed at protecting the public, transportation, and facilities. Despite their widespread deployment, quality control procedures that can evaluate day-to-day instrument performance or differences among units of the same manufacture are in need for development. In this work, we describe the preparation of test materials (TMs) using inkjet printing that have fixed dosing levels of two explosives; 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and pentaerythritol tetranitrate (PETN). The uncertainty in the mass of dispensed solute is 0.8% (nominal 1 ng RDX and 5 ng or 20 ng PETN depending on ETD). TMs are stable under storage for at least 20 days at temperatures consistent with indoor and outdoor environments, and can be used by field personnel at deployed locations. Inkjet printing is shown to provide the necessary control over the spatial distribution of analyte on the substrate, thus limiting the variability in the signal response due to the sample. Measurements of signal intensities for two COTS ETDs were obtained from TMs over multi-year time spans and for multiple units of each ETD. Reproducibility in the signal response is shown to be between 6% and 15% RSD, or approximately double the within-day variability. The large datasets allow for the first time modeling of signal intensities with respect to normal distributions, which support the use of standard 3-sigma control practices.
A novel approach for creating trust to reduce malicious behavior in MANET

This paper presents a Reputation-Trust (RT) system that can be used to stabilize the performance of the network for the working nodes even in the presence of malicious nodes which intentionally do not route and forward packets send by others correctly. The situation becomes even worst when nodes do not rely on any routing infrastructure but relay packets for each other. We introduce two extensions to the Dynamic Source Routing algorithm (DSR) [1] to mitigate the effects of routing misbehavior: the watchdog and the pathrater. Using these two approaches, the proposed RT system will update the RT table of each node with the ranked values of other nodes. The implementation of the proposed RT system is entirely based on the underlying proposed RT algorithm. Simulation results demonstrate that the RT system can be used to reduce the malicious behavior of mobile nodes and consequently improve the overall performance of MANET.
Computational Simulation of a Semispan Wing in a Wind Tunnel

The computational simulation of wind tunnel tests are central in efforts to improve the accuracy and range of applicability of CFD codes. A validation experiment in solid wall transonic wind tunnel is simulated with the inviscid and viscous tunnel wall computation models. Viscous wall modeling appears to provide the ability to reproduce the experimental conditions fairly well without wall interference corrections but specification of the actual wall geometry is crucial.
Southeastern extent of the North American craton in Texas and northern Chihuahua as revealed by Pb isotopes

The geographic patterns of Pb isotopic compositions of Eocene to Miocene igneous rocks appear to delineate the southeastern edge of the North American Precambrian craton in Trans-Pecos Texas and northern Chihuahua, Mexico. The boundary parallels and lies southeast of the buried fault contact between Ouachita facies thrust sheets and Paleozoic cratonic sedimentary rocks. Lead isotopic data for basalts and granulite xenoliths suggests that the basalts contain a mixture of Pb from mantle and lower-crustal sources. On the northwest side of the boundary, this mixing involves 1.35 to 1.1 Ga cratonic lithosphere and yields linear arrays of 206Pb/204Pb versus 207Pb/204Pb and 208Pb/204Pb. Basaltic magmas on the southeast side of the boundary apparently interacted with more-radiogenic lithosphere accreted during the Ouachita orogeny. Basalts in a 50-km-wide central zone between the northwestern and southeastern provinces have Pb isotopic compositions that are intermediate between those of the northwestern and southeastern sources. In the northwestern province, lead isotopic compositions of intermediate to felsic rocks are less radiogenic than those of associated basalts, whereas in the southeast province they have more radiogenic compositions than the basalts. This isotopic divergence reflects assimilation of contrasting crust of each province. Most felsic Tertiary rocks of the northwestern province have lower 207Pb/204Pb versus 206Pb/204Pb and somewhat elevated 208Pb/204Pb versus 206Pb/204Pb, suggesting assimilation of relatively high Th/U Precambrian crust. The central province also contains low 206Pb/204Pb and 207Pb/204Pb Precambrian components, but few igneous rocks have elevated 208Pb/204Pb. Southeastern-province crust appears dominantly Phanerozoic, although Precambrian basement with Pb isotopic compositions near model average crust may be present. The Pb isotopic zonation observed in West Texas is similar to that found in the Appalachians of the northern United States and Canada and in the Caledonides of Europe: that is, a progression from more-radiogenic outboard terranes to less-radiogenic inboard terranes. Lead isotopic ratios from Tertiary igneous rocks of the northwestern part of Trans-Pecos Texas are similar to those of adjacent New Mexico and southeastern Arizona, although regional basement ages and isotopic characteristics differ. Extending the West Texas isotopic terranes to the southwest holds promise for testing and improving the understanding of the Sonora-Mojave megashear; Precambrian assembly of Gondwana; and correlation of Grenville-Caledonian terranes between the Appalachians, Texas, and eastern to southern Mexico.
A simplified method of estimating noise power spectra

A technique to estimate the radial dependence of the noise power spectrum of images is proposed in which the calculations are conducted solely in the spatial domain of the noise image. The noise power spectrum averaged over a radial spatial-frequency interval is obtained form the variance of a noise image that has been convolved with a small kernel that approximates a Laplacian operator. Recursive consolidation of the image by factors of two in each dimension yields estimates of the noise power spectrum over that full range of spatial frequencies.
Defining BMP functions in the hair follicle by conditional ablation of BMP receptor IA.

Using conditional gene targeting in mice, we show that BMP receptor IA is essential for the differentiation of progenitor cells of the inner root sheath and hair shaft. Without BMPRIA activation, GATA-3 is down-regulated and its regulated control of IRS differentiation is compromised. In contrast, Lef1 is up-regulated, but its regulated control of hair differentiation is still blocked, and BMPRIA-null follicles fail to activate Lef1/β-catenin–regulated genes, including keratin genes. Wnt-mediated transcriptional activation can be restored by transfecting BMPRIA-null keratinocytes with a constitutively activated β-catenin. This places the block downstream from Lef1 expression but upstream from β-catenin stabilization. Because mice lacking the BMP inhibitor Noggin fail to express Lef1, our findings support a model, whereby a sequential inhibition and then activation of BMPRIA is necessary to define a band of hair progenitor cells, which possess enough Lef1 and stabilized β-catenin to activate the hair specific keratin genes and generate the hair shaft.
An RNA Switch at the 5′ Splice Site Requires ATP and the DEAD Box Protein Prp28p

Abstract Pre-mRNA splicing requires dramatic RNA rearrangements hypothesized to be catalyzed by ATP-dependent RNA unwindases of the DExD/H box family. In a rearrangement critical for the fidelity of 5′ splice site recognition, a base-pairing interaction between the 5′ splice site and U1 snRNA must be switched for a mutually exclusive interaction between the 5′ splice site and U6 snRNA. By lengthening the U1:5′ splice site duplex, we impeded this switch in a temperature-dependent manner and prevented formation of the spliceosome's catalytic core. Using genetics, we identified the DExD/H box protein Prp28p as a potential mediator of the switch. In vitro, the switch requires both Prp28p and ATP. We propose that Prp28p directs isomerization of RNA at the 5′ splice site and promotes fidelity in splicing.
SmedGD: the Schmidtea mediterranea genome database

The planarian Schmidtea mediterranea is rapidly emerging as a model organism for the study of regeneration, tissue homeostasis and stem cell biology. The recent sequencing, assembly and annotation of its genome are expected to further buoy the biomedical importance of this organism. In order to make the extensive data associated with the genome sequence accessible to the biomedical and planarian communities, we have created the Schmidtea mediterranea Genome Database (SmedGD). SmedGD integrates in a single web-accessible portal all available data associated with the planarian genome, including predicted and annotated genes, ESTs, protein homologies, gene expression patterns and RNAi phenotypes. Moreover, SmedGD was designed using tools provided by the Generic Model Organism Database (GMOD) project, thus making its data structure compatible with other model organism databases. Because of the unique phylogenetic position of planarians, SmedGD (http://smedgd.neuro.utah.edu) will prove useful not only to the planarian research community, but also to those engaged in developmental and evolutionary biology, comparative genomics, stem cell research and regeneration.
Lithoherms in the Straits of Florida

Along the base of Little Bahama Bank and out into the northeastern Straits of Florida in depths of 600 to 700 m, the research submersible Alvin encountered an extensive area of rocky mounds that are hundreds of metres long and as high as 50 m. The larger mounds are elongated in the direction of northerly bottom flow. They are composed of surface-hardened concentric crusts of submarine-lithified muddy to sandy carbonate sediment upon which a dense and diverse community of benthic organisms such as crinoids, corals, and sponges attach. Many of the organisms grow oriented into the prevailing northward current. The crusts are cemented in varying degree by micritic magnesian calcite and are intensively bored by endolithic organisms. Excavation of the softer undercrust by currents and (or) organisms can produce stromatactoid voids. It appears that these deep mounds are biohermal in nature and constructed in situ by the subsea lithification of successive layers of trapped sediment and deposited skeletal debris. The term “lithoherm” is proposed to describe the mounds. These and the hardgrounds between them indicate that subsea lithification aids in the accretion of the flanks of carbonate platforms. Micritic carbonate build-ups similar to lithoherms have been recognized in the geologic record. The mounds of the Waulsortian bank margin offer one possible ancient analog.
Landscape and Environment: Insights from the Prehispanic Central Andes

Attention to human–environment relationships in the central Andes has a long history. Although the area is not a neat microcosm of the globe, wholly representative of worldwide trends in the archaeology of human–environment interactions, it has been the site of both seminal investigations in archaeology and a substantial body of recent work that investigates themes of broad archaeological relevance. Specifically, central Andean environments have been variously conceived as structuring, modified, and sacred. These approaches to some extent reflect broad trends in archaeology, while also suggesting directions in which the archaeology of human–environment interactions is moving and highlighting archaeology’s relevance to discussions of contemporary human–environment interactions. This article characterizes concepts that are key for describing central Andean environments and considers the ways in which the particular ecology of the central Andes has informed archaeological research in the region. The example of the central Andes highlights the importance of understanding environments as dynamic, considering both geomorphic and anthropogenic contributors to that dynamism, and examining both ecological (“environment”) and ideological (“landscape”) implications of archaeological landscapes.
Capturing Place: A Comparison of Site Recording Methods

When designers document locations for site-specific projects, how do tools affect recording of visual data? We observed design students visiting future project locations with sketchbooks, cameras and video and analysed the resulting Web-based field reports by tallying images according to scale and content. The study describes how tools shape place-recording phases and explains how field reports can contribute to understanding the tools. Examining reports from different classes exposed the importance of objectives and setting characteristics in shaping data collection. A refined approach for studying new place-recording tools is suggested.
What Students Really do in the Library: An Observational Study

The authors observed 730 collegiate students in the library and recorded their study (or non-study) activities. Approximately 60% of behaviors were study related. The most commonly observed behavior was reading print material (18.8%). The second most common behavior was the use of social media (11.4%). These results have implications for understanding how students learn and study in the pervasive digital world.
Attachment Style in Marriage: Adjustment and Responses to Interaction:

This study examined the association between attachment style and marital functioning, focusing on cognition as a key explanatory link. Married spouses completed measures of anxious and avoidant attachment, negative attributions, and perceived marital support and conflict. Attachment style was related to marital adjustment and to attribution style, with anxious attachment being a stronger predictor than avoidant attachment. The interaction of husbands' and wives' attachment styles also predicted marital functioning. In some cases, the tendency to make negative attributions for spouse behavior mediated the effects of attachment style on marital adjustment. Couples also participated in a marital interaction task involving two social situation manipulations - an agency threat (i.e., evaluation) and a communion threat (i.e., disagreement with one's spouse). Following the task, participants completed a measure assessing their appraisals of their spouses' behavior. Attachment style interacted with the social sit...
hCG and hyperglycosylated hCG in the establishment and evolution of hemochorial placentation

The evolution of regular chorionic gonadotropin (CG) and hyperglycosylated CG are linked with the evolution of hemochorial placentation in primates. Recent research with humans shows that regular CG promotes spiral artery angiogenesis and hyperglycosylated CG controls invasion by implanting trophoblast cells. It is inferred that the evolution of regular CG and hyperglycosylated CG in early simian primates, the first species to produce these CG forms, established hemochorial placentation in this species. The circulating half-lives, and thus the circulating concentrations, of regular CG and hyperglycosylated CG increased in advanced simian primates and increased further in humans, seemingly causing greater myometrial invasion and superior angiogenesis in hemochorial placentation in advanced primates and humans. Advanced hemochorial placentation is associated with relatively high proportions of pregnancy failures in humans. This can be explained by considering human implantation inadequate in terms of invasion requirements. The demanding implantation required by the human embryo is seemingly dependent on adequate production of hyperglycosylated CG. Failures in hemochorial placentation invasion lead to anoxia and cause preeclampsia and eclampsia uniquely in humans, which can also be attributed to inadequate hyperglycosylated CG signaling. We propose here that inadequate regular CG and hyperglycosylated CG molecules are the evolutionary causes of these obstetric complications in humans.
Modeling of Fuel Jet Spread for CFD Simulation of Aircraft Fuel Dumping

An analytical jet spread model has been developed for determining the boundary of an axisymmetric jet ejecting into a two -fluid, co -flowing st ream. By assuming that the circumferential velocity of the jet is small, the model can be coupled with the conventional CFD method for simulating the f uel dumping from an aircraft. Application of the model is demonstrated by consider ing the fuel dumping off a V-22 aircraft flying at Mach 0.345 and angles of attack from 7 and 16 degrees. The model provides a first -order correction to the CFD results with the jet dispersion boundaries to yield an overall solution that represents a re alistic aircraft fuel dumping environment.
When Harry Met Harri: Cross-lingual Name Spelling Normalization

Foreign name translations typically include multiple spelling variants. These variants cause data sparseness problems, increase Out-of-Vocabulary (OOV) rate, and present challenges for machine translation, information extraction and other NLP tasks. This paper aims to identify name spelling variants in the target language using the source name as an anchor. Based on word-to-word translation and transliteration probabilities, as well as the string edit distance metric, target name translations with similar spellings are clustered. With this approach tens of thousands of high precision name translation spelling variants are extracted from sentence-aligned bilingual corpora. When these name spelling variants are applied to Machine Translation and Information Extraction tasks, improvements over strong baseline systems are observed in both cases.
A model for turbulent hydraulic fracture and application to crack propagation at glacier beds

Glaciological observations of under-flooding suggest that fluid-induced hydraulic fracture of an ice sheet from its bed sometimes occurs quickly, possibly driven by turbulently flowing water in a broad sheet flow. Taking the approximation of a fully turbulent flow into an elastic ice medium with small fracture toughness, we derive an approximate expression for the crack-tip speed, opening displacement and pressure profile. We accomplish this by first showing that a Manning-Strickler channel model for resistance to turbulent flow leads to a mathematical structure somewhat similar to that for resistance to laminar flow of a power law viscous fluid. We then adapt the plane-strain asymptotic crack solution of Desroches et al. (1994) and the power law self-similar solution of Adachi and Detournay (2002) for that case to calculate the desired quantities. The speed of crack growth is shown to scale as the overpressure (in excess of ice overburden) to the power 7/6, inversely as ice elastic modulus to the power 2/3, and as the ratio of crack length to wall roughness scale to the power 1/6. We tentatively apply our model by choosing parameter values thought appropriate for a basal crack driven by the rapid drainage of a surface meltwater lake near the margin of the Greenland Ice Sheet. Making various approximations perhaps relevant to this setting, we estimate fluid inflow rate to the basal fracture and vertical and horizontal surface displacements and find order-of-magnitude agreement with observations by Das et al. (2008) associated with lake drainage. Finally, we discuss how these preliminary estimates could be improved.
Cross-talk between excitatory and inhibitory amino acids in the regulation of luteinizing hormone-releasing hormone secretion

Inhibitory (IAA) and excitatory amino acid (EAA) neurotransmitters appear to play an important role in regulating reproductive functions. L-Glutamic acid (GLU), the major representative of the EAA system, stimulates LHRH release from arcuate nucleus-median eminence (AN-ME) fragments in vitro. Several studies have provided evidence for considering gamma-aminobutyric acid (GABA), a major IAA neurotransmitter, as another regulator of LHRH secretion. Recent reports have indicated that a cross-talk between GABA and GLU participates in the regulation of synaptic transmission in the brain. In concert with this notion, we present evidence indicating that this cross-talk between GABA and GLU appears to be also involved in neuroendocrinological paradigms. In this respect, bicuculline, a GABA-A receptor antagonist, blocked GLU-evoked LHRH secretion from AN-ME fragments in vitro without affecting basal LHRH release. In addition, activation of GABA-A receptors by muscimol (MUS) stimulated basal LHRH secretion. Interestingly, when MUS and GLU were added together to the incubation medium, an additive, stimulatory effect was observed. These observations clearly indicate that a GABAergic mechanism participates, via GABA-A receptors, in GLU-induced LHRH secretion from terminals of the ME. Furthermore, GABA-B receptors appear to negatively modulate the effects of GLU. Activation of GABA-B receptors by baclofen (BAC) blocked GLU-induced LHRH secretion, while phaclofen, a GABA-B receptor antagonist, reversed this effect. In summary, our data provide evidence for a cross-talk between EAA and IAA systems in the regulation of LHRH release, and, therefore, in the control of gonadal function.
More risk factors affecting heart failure outcomes! Time for hope or despair?

Tremendous progress has been made over the last two decades in the management of patients with heart failure due to left ventricular dysfunction. Recent large randomized beta-blocker trials in these patients have shown a single-digit annual mortality rate (range 7.2% to 8.8%) and a reduction in
Trends in the management of pelvic fractures, 2008-2010.

Abstract Background Bleeding from pelvic fractures can be lethal. Angioembolization (AE) and external fixation (EXFIX) are common treatments to control bleeding, but it is not known how frequently they are used. We hypothesized that AE would be increasingly more common compared with EXFIX over time. Methods The National Trauma Data Bank for the years from 2008–2010 were used. Patients were included in the study if they had an International Classification of Diseases, ninth edition, Clinical Modification codes for pelvic fractures and were aged ≥18 y. Patients were excluded if they had isolated acetabular fractures, were not admitted, or had minor injuries. Outcomes included receiving a procedure and in-hospital mortality. Results A total of 22,568 patients met study criteria. AE and EXFIX were performed in 746 (3.3%) and 663 (2.9%) patients, respectively. AE was performed more often as the study period progressed (2.5% in 2007 to 3.7% in 2010; P P = 0.008). Having a procedure was associated with higher mortality in unadjusted analyses compared with those with no procedure (11.0% for no procedure versus 20.5% and 13.4% for AE or EXFIX, respectively; P P Conclusions AE in severely injured pelvic fracture patients is increasing. AE is associated with higher mortality, which may reflect the fact that it is used for patients at higher risk of death. The role of AE for bleeding should be examined in future studies.
US-guided Biopsy of Neck Lesions: The Head and Neck Neuroradiologist’s Perspective

Ultrasonographically (US) guided percutaneous biopsy of a neck lesion is a cost-effective, safe, and diagnostically effective procedure without radiation exposure. The benefit of real-time visualization of the needle location allows for instantaneous maneuvering of the needle trajectory for safe and accurate tissue sampling with short procedural time. Effective US-guided biopsy requires technical experience, strong clinical acumen, and skillful biopsy technique. A neuroradiologist's knowledge of head and neck anatomy and pathology allows correlation with cross-sectional imaging and enhances the understanding of US imaging evaluation. Familiarity with a spectrum of neck surgeries and reconstructions and expertise in imaging evaluation of the treated neck are invaluable in accurate identification of the target for biopsy in patients with treatment-related altered anatomy using US guidance. After thyroid nodules, the common adult neck masses are lymphadenopathy, head and neck cancer, salivary neoplasms, nerve sheath tumors, and inflammatory and infectious pseudomasses. Diagnostic expertise in the imaging characteristics of these individual pathologic conditions and their differential diagnoses also play an important role in choosing the biopsy technique and in procuring an adequate sample for diagnosis, including material for ancillary laboratory testing. Using an anatomic zone approach, this article illustrates the practical considerations in patient selection, the methodical analysis of preprocedure cross-sectional imaging and its correlation with real-time US evaluation, general principles for optimizing US instrumentation, and biopsy technique. In skillful hands, the versatility and portability of US make it the valuable modality for histologic sampling of superficial head and neck lesions. Online supplemental material is available for this article.
Thoughts on racial democratic education and moral virtue

The taking of Black life by state authorities is a long-standing tragic tradition in America. However, in recent years, instances of Black death have gained wider media attention. This is a potenti...
Sterols in blood of normal and Smith-Lemli-Opitz subjects

Smith-Lemli-Opitz syndrome (SLOS) is a hereditary disorder in which a defective gene encoding 7-dehydrocholesterol reductase causes the accumulation of noncholesterol sterols, such as 7- and 8-dehydrocholesterol. Using rigorous analytical methods in conjunction with a large collection of authentic standards, we unequivocally identified numerous noncholesterol sterols in 6 normal and 17 SLOS blood samples. Plasma or erythrocytes were saponified under oxygen-free conditions, followed by multiple chromatographic separations. Individual sterols were identified and quantitated by high performance liquid chromatography (HPLC), Ag(+)-HPLC, gas chromatography (GC), GC-mass spectrometry, and nuclear magnetic resonance. As a percentage of total sterol content, the major C(27) sterols observed in the SLOS blood samples were cholesterol (12;-98%), 7-dehydrocholesterol (0.4;-44%), 8-dehydrocholesterol (0.5;-22%), and cholesta-5,7,9(11)-trien-3beta-ol (0.02;-5%), whereas the normal blood samples contained <0.03% each of the three noncholesterol sterols. SLOS and normal blood contained similar amounts of lathosterol (0.05;-0.6%) and cholestanol (0.1;-0.4%) and approximately 0.003;-0.1% each of the Delta(8), Delta(8(14)), Delta(5,8(14)), Delta(5,24), Delta(6,8), Delta(6,8(14)), and Delta(7,24) sterols. The results are consistent with the hypothesis that the Delta(8(14)) sterol is an intermediate of cholesterol synthesis and indicate the existence of undescribed aberrant pathways that may explain the formation of the Delta(5,7,9(11)) sterol. 19-Norcholesta-5,7,9-trien-3beta-ol was absent in both SLOS and normal blood, although it was routinely observed as a GC artifact in fractions containing 8-dehydrocholesterol. The overall findings advance the understanding of SLOS and provide a methodological model for studying other metabolic disorders of cholesterol synthesis.
Complications of Bacterial Rhinosinusitis in Children and their Management

Sinus infection can spread through anastomosing veins or by direct extension to close by structures. Orbital complications of rhinosinusitis were categorized by Chandler et al. [2] into five stages according to their severity. Contiguous spread to the oribital area can cause periorbital cellulitis, subperiosteal abscess, orbital cellulitis, and abscess. Orbital cellulitis can complicate acute ethmoiditis if thrombophlebitis of the anterior and posterior ethmoidal veins spreads to the lateral or orbital side of the ethmoid labyrinth. Sinusitis can also spread intracranially, where it can cause cavernous sinus thrombosis, retrograde meningitis, and epidural, subdural, and brain abscesses [2-5]. Orbital symptoms often precede intracranial extension of the infection [5]. Other complications include sinobronchitis, maxillary osteomyelitis, and frontal bone osteomyelitis [6-10]. Frontal bone osteomyelitis often originates from an extending thrombophlebitis. Frontal sinus periostitis can cause outer membrane osteitis and periostitis, which produces a tender, puffy swelling of the forehead. The most common pathogens causing these complications are those seen in acute and chronic rhinosinusitis, depending on the length and etiology of the primary rhinosinusitis. These include Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcos aureus (including methicillin resistant), anaerobic bacteria (Prevotella, Porphyromonas, Fusobacterium and Peptostreptococcus spp.) and Microaerophilic streptococci [5]. Anaerobic bacteria are mostly found in chronic rhinosinusitis and those associated with dental etiology [11]. Early diagnosis of a complication is of prime importance. Diagnosis is assisted by computed tomography (CT) and nuclear isotope scanning. Prevention of these complications is of great importance. This can be accomplished by administering appropriate empiric antimicrobial therapy, obtaining sinus cultures from those who fail to respond to treatment after 2-4 days and those with severe symptoms who do not respond within 48 hours, and the immunocompromised. These cultures
Flame Spread Experiments in a Simulated Microgravity Flow Environment Using Laminar Planar Couette Flow

Opposed flow flammability experiments are conducted for the first time using a planar Couette Flow Apparatus (CFA). The CFA produces a linear velocity profile above the fuel to mimic in normal gravity the boundary layer encountered by a flame in an actual microgravity fire. Similar apparatuses (e.g., the Narrow Channel Apparatus) have been used to test materials using a parabolic velocity profile, but the purpose of this research is to determine whether or not using a linear velocity profile above the fuel surface will produce different results in the flame spread rate or flame appearance. The apparatus is a 1.1 meter long channel, 8 centimeters wide, and has a height adjustable 0 to 4 cm. The channel consists of a fixed bottom plate, two glass side walls, a moving belt at the top, and a fan at the outlet to help pull air in the inlet to initiate the flow. Images and videos were recorded through windows in the channel to show flame behavior. Air flow in the channel was characterized using hot wire anemometers, and flame speed was determined using image tracking software. The belt velocity, gap height, and velocity gradient were varied to study their effect on flame spread. Comparisons are made to flame spread rate in the Narrow Channel Apparatus with the same average velocity. The results for thin cellulosic fuel indicate that the flame spread rate is affected by gap height and may also be affected by velocity gradient.
Surface Structure of Silica Glasses by Molecular Dynamics Simulations

Molecular dynamics computer simulations were used to study surfaces of pure silica glass. The potentials used here were those previously established to model bulk silica and have been extended to study surface relaxation in a perfect vacuum. A large number of surfaces were made using different starting configurations; system sizes, and cooling procedures. Following “fracture”, many broken bonds rearranged in response to the changes in the net forces in the surface region. After this reconstruction, the simulations showed the expected general features observed experimentally, such as a prevalence of oxygen atoms at the outermost surface, non-bridging oxygens, and strained siloxane bonds. Three fold silicons (similar to e’ centers) were initially present in the “fractured” surfaces but most often were incorporated into the network tetrahedrally after reconstruction. Other defects produced during the reconstruction were five coordinated silicons and more importantly, edge sharing tetrahedra, forming the strained siloxane bonds. Bond angles and bond lengths for each defect were determined, showing good agreement with previously published results as well as providing new information. Finally, estimations for silanol concentrations were made which compare well with experimentally determined coverages. The computer simulation technique used here adequately reproduces many of the structural and dynamic characteristics of silica glass surfaces.
Nutritional Management of the Infant With Severe Bronchopulmonary Dysplasia

Optimal nutrition and growth in patients with severe, established bronchopulmonary dysplasia are complex and require an understanding of the factors and challenges that affect this population. Most publications have reported weight gain as the primary outcome because of ease of measurement, accuracy, and repeatability. There is, however, increasing evidence that linear growth is better correlated with long-term development and pulmonary outcomes. In addition, factors such as stress, inflammation, respiratory support and stability, and medication exposures have a direct influence on achieving nutritional success in infants with severe bronchopulmonary dysplasia. This article reviews concepts related to these challenges and provides recommendations for achieving successful nutrition in this population.
Portfolio theory based sensor selection in Wireless Sensor Networks with unreliable observations

In this paper, we propose a portfolio theory based sensor selection framework in Wireless Sensor Networks (WSNs) with unreliable sensor observations for target localization. Fisher information (FI) is used as the sensor selection metric in our work. Our objective is to find a sensor selection scheme that considers both the expected FI gain and the reliability of the sensors, where we observe that the FI variability captures the reliability of the sensors. Based on portfolio theory, we formulate our sensor selection problem as a multiobjective optimization problem (MOP), which is solved by the normal boundary intersection (NBI) method. Simulation results show the advantages of performing portfolio theory based sensor selection.
Hallucinations as Top-Down Effects on Perception

Abstract The problem of whether and how information is integrated across hierarchical brain networks embodies a fundamental tension in contemporary cognitive neuroscience, and by extension, cognitive neuropsychiatry. Indeed, the penetrability of perceptual processes in a “top-down” manner by higher-level cognition—a natural extension of hierarchical models of perception—may contradict a strictly modular view of mental organization. Furthermore, some in the cognitive science community have challenged cognitive penetration as an unlikely, if not impossible, process. We review the evidence for and against top-down influences in perception, informed by a predictive coding model of perception and drawing heavily on the literature of computational neuroimaging. We extend these findings to propose a way in which these processes may be altered in mental illness. We propose that hallucinations—perceptions without stimulus—can be understood as top-down effects on perception, mediated by inappropriate perceptual priors.