cssi/SciSciGPT-SciSciNet huggingface dataset:
V3 Loop Truncations in HIV-1 Envelope Impart Resistance to Coreceptor Inhibitors and Enhanced Sensitivity to Neutralizing Antibodies

The V1/V2 region and the V3 loop of the human immunodeficiency virus type I (HIV-1) envelope (Env) protein are targets for neutralizing antibodies and also play an important functional role, with the V3 loop largely determining whether a virus uses CCR5 (R5), CXCR4 (X4), or either coreceptor (R5X4) to infect cells. While the sequence of V3 is variable, its length is highly conserved. Structural studies indicate that V3 length may be important for interactions with the extracellular loops of the coreceptor. Consistent with this view, genetic truncation of the V3 loop is typically associated with loss of Env function. We removed approximately one-half of the V3 loop from three different HIV-1 strains, and found that only the Env protein from the R5X4 strain R3A retained some fusion activity. Loss of V1/V2 (ΔV1/V2) was well tolerated by this virus. Passaging of virus with the truncated V3 loop resulted in the derivation of a virus strain that replicated with wild-type kinetics. This virus, termed TA1, retained the V3 loop truncation and acquired several adaptive changes in gp120 and gp41. TA1 could use CCR5 but not CXCR4 to infect cells, and was extremely sensitive to neutralization by HIV-1 positive human sera, and by antibodies to the CD4 binding site and to CD4-induced epitopes in the bridging sheet region of gp120. In addition, TA1 was completely resistant to CCR5 inhibitors, and was more dependent upon the N-terminal domain of CCR5, a region of the receptor that is thought to contact the bridging sheet of gp120 and the base of the V3 loop, and whose conformation may not be greatly affected by CCR5 inhibitors. These studies suggest that the V3 loop protects HIV from neutralization by antibodies prevalent in infected humans, that CCR5 inhibitors likely act by disrupting interactions between the V3 loop and the coreceptor, and that altered use of CCR5 by HIV-1 associated with increased sensitivity to changes in the N-terminal domain can be linked to high levels of resistance to these antiviral compounds.
Potential Mechanisms of Progranulin-deficient FTLD

Frontotemporal lobar dementia (FTLD) is the most common cause of dementia in patients younger than 60 years of age, and causes progressive neurodegeneration of the frontal and temporal lobes usually accompanied by devastating changes in language or behavior in affected individuals. Mutations in the progranulin (GRN) gene account for a significant fraction of familial FTLD, and in the vast majority of cases, these mutations lead to reduced expression of progranulin via nonsense-mediated mRNA decay. Progranulin is a secreted glycoprotein that regulates a diverse range of cellular functions including cell proliferation, cell migration, and inflammation. Recent fundamental discoveries about progranulin biology, including the findings that sortilin and tumor necrosis factor receptor (TNFR) are high affinity progranulin receptors, are beginning to shed light on the mechanism(s) by which progranulin deficiency causes FTLD. This review will explore how alterations in basic cellular functions due to PGRN deficiency, both intrinsic and extrinsic to neurons, might lead to the development of FTLD.
Nonsurgical interventional therapies for low back pain: a review of the evidence for an American Pain Society clinical practice guideline.

Study Design. Systematic review. Objective. To systematically assess benefits and harms of nonsurgical interventional therapies for low back and radicular pain. Summary of Background Data. Although use of certain interventional therapies is common or increasing, there is also uncertainty or controversy about their efficacy. Methods. Electronic database searches on Ovid MEDLINE and the Cochrane databases were conducted through July 2008 to identify randomized controlled trials and systematic reviews of local injections, botulinum toxin injection, prolotherapy, epidural steroid injection, facet joint injection, therapeutic medial branch block, sacroiliac joint injection, intradiscal steroid injection, chemonucleolysis, radiofrequency denervation, intradiscal electrothermal therapy, percutaneous intradiscal radiofrequency thermocoagulation, Coblation nucleoplasty, and spinal cord stimulation. All relevant studies were methodologically assessed by 2 independent reviewers using criteria developed by the Cochrane Back Review Group (for trials) and by Oxman (for systematic reviews). A qualitative synthesis of results was performed using methods adapted from the US Preventive Services Task Force. Results. For sciatica or prolapsed lumbar disc with radiculopathy, we found good evidence that chemonucleolysis is moderately superior to placebo injection but inferior to surgery, and fair evidence that epidural steroid injection is moderately effective for short-term (but not long-term) symptom relief. We found fair evidence that spinal cord stimulation is moderately effective for failed back surgery syndrome with persistent radiculopathy, though device-related complications are common. We found good or fair evidence that prolotherapy, facet joint injection, intradiscal steroid injection, and percutaneous intradiscal radiofrequency thermocoagulation are not effective. Insufficient evidence exists to reliably evaluate other interventional therapies. Conclusion. Few nonsurgical interventional therapies for low back pain have been shown to be effective in randomized, placebo-controlled trials.
Comparison of Adult-Initiated vs. Child-Initiated Interaction Styles with Handicapped Prelanguage Children

Speech-language pathologists are increasingly providing intervention to younger and more severely handicapped children. The methods and strategies that the adult uses in interacting with this population are important considerations in treatment. The results of this study comparing adult-initiated vs. child-initiated interaction styles indicate that prelanguage children engage in a greater frequency and higher developmental level of communicative behaviors when the interaction is child-initiated.
Linking atmospheric and hydrologic models at the basin scale

Abstract This paper describes the development of a modeling system that provides a physically based robust model chain to link global, decade-scale climate inputs to vegetation change and river basin flow studies. The regional climate model, RegCM2 (Giorgi et al., 1993a and 1993b), is downscaled with the orographic microscale model, ZOOM, to create a model estimate at the point of interest in space. We have completed RegCM2 runs at 50 km resolution using ECMWF observational analysis input data over the Western U.S. for 16 years (1 Dec 1978 through 12 Dec 1994). We performed a “box analysis” (250 sq. km box) of 50 km RegCM2 runs, each having averaged model and observed data, comparing the two for temperatures and precipitation. ZOOM provides data at distributed points within the watershed to better represent the hydrologic processes in the watershed. The Climate Vegetation Hydrologic Model (CVHM) is a daily time-step hydrologic model based on the hydrologic response unit (Sikka, 1993), which requires inputs at points within each HRU, provided by ZOOM. This paper presents six years of the nested model runs for both the atmospheric (RegCM2, ZOOM) and the basin models (CVHM).
Distance Sensing Using Constant-Amplitude Wavelength-Swept Semiconductor Lasers

The frequency modulated continuous wave (FMCW) technique1, which was developed and used in radar systems, has recently been applied to optical sources in interferometric sensors. Applications of this technique include remote distance sensing2, fiber evaluation1, and characterization of the source itself. The use of single frequency lasers is especially attractive because the optical frequency can be directly modulated over a large range by injection current modulation. The resolution of such systems3 often suffers from intensity modulation accompanying the frequency modulation. The range of measured distances is limited by the short coherence length of semiconductor lasers. These problems have been alleviated in the present work by using two-section constant amplitude tunable lasers and external cavities for linewidth narrowing.
Errors in magnetic direction finding due to nonvertical lightning channels

A theory showing that errors in lightning magnetic direction finding due to nonvertical source orientations are minimized by detecting the field from the lowest possible channel section is presented. For 99 cloud-to-ground lightning channels photographed in Arizona, 45 exhibited a bottom few hundred meters within about 8 deg of the vertical, the standard deviation of the distribution of lower-channel tilt angles being about 18 deg. These experimental results, coupled with theory, suggest that if a wideband gated direction finder is used, polarization errors due to nonvertical sources can be kept less than 1 deg for lightning beyond 10 km.
Predicting late-successional fire refugia pre-dating European settlement in the Wenatchee Mountains

Abstract Fires occur frequently in dry forests of the Inland West. Fire effects vary across the landscape, reflecting topography, elevation, aspect, slope, soils, and vegetation attributes. Patches minimally affected by successive fires may be thought of as ‘refugia’, islands of older forest in a younger forest matrix. Refugia support species absent within the landscape matrix. Our goal was to predict the occurrence of pre-settlement refugia using physiographic and topographic variables. We evaluated 487 plots across a 47000 ha landscape using three criteria to identify historical fire refugia: different structure from surrounding matrix; different fire regime from surrounding matrix; presence of old individuals of fire-intolerant tree species. Several combinations of aspect, elevation, and topography best predicted refugial presence. Less than 20% of the pre-settlement landscape was identified as historical fire refugia. Refugia were not connected except by younger stands within the matrix. Current management goals of increasing amounts and connectivity of old, refugia-like forests for the benefit of species associated with late-successional habitat increase the risk of insect and pathogen outbreaks and catastrophic wildfires.
Hydraulics of Sediment Movement in Urban Drainage Systems

JO In order to implement its objective, the Task Committee organized technical sessions at the 1999 WRPM conference in Tempe, Arizona, the 2000 EWRI conference in Minneapolis, and the 2001 EWRI conference in Orlando, Florida. Because of the important European advances in this field, many of the invited speakers came from across the Atlantic. The presented papers were published in the proceedings of those conferences. The authors were then invited to submit refined and extended journal papers. These refined and extended papers were then submitted to the rigorous review of ASCE journals. This special issue represents the culmination of that effort. The papers can be classified into four categories: ~1! review of recent research and practice in the U.S.; ~2! review of recent research and practice in Europe; ~3! new design methodologies for self-cleansing sewers; and ~4! specialized aspects having to do with the detail of the sediment transport in sewers and the impact of the sediments on the pollution in the receiving streams. In the first category, Fan et al. present a historical summary of the sewer sediment control projects carried out by the WetWeather Flow Research Program of the U.S. Environmental Protection Agency. Among the researches presented are studies of the causes of sewer solid deposition and methods to prevent sewer sediment accumulations. The use of an integrated approach including solid source management, in-sewer control, and treatment facilities is advocated and sewer flushing is presented as a method of sewer sediment control. Pisano et al. discuss further flushing experiences in Cambridge, Massachusetts, and report on automated flushing techniques used in France and Germany. In the second category on European research, Ashley et al. summarize the very extensive research into sewer sediments and associated processes that has taken place in Europe during the last two decades. In fact, European research on this subject has been
Early relationships and the development of aggression in children.

The development of abnormally aggressive human behavior is complex and multifactorial. Aggressive patterns of behavior often begin early in life and, once established, are notorious for their resis...
MEASURES OF DURATION

Macaulay's measure of “duration” and Hicks' “average maturity” of an income stream, sometimes used to compare different assets, is an index number. It is shown in this paper that many such indexes can be defined and that the appropriate one depends on an investor's objective and his subjective view of future prices (or yields).
Corporate response to social pressures: A typology

The paper deals briefly with several definitional issues; discusses the concept of “image” as it determines the way managers see the world; as one aspect of the image, examines the contrasting views of conflict and cooperation in social and organizational relationships; and then presents a typology of corporate responses to pressures for socially responsible behavior: authoritarian, manipulative and bargaining. This typology was developed on the basis of the analysis of a large number of case histories of environmental conflicts, a number of which are included for purposes of illustration. Several historical examples are cited. The inference drawn from this study is that decisions become more responsible as decision-makers come under the scrutiny of and pressure from those affected by the decisions.
The Meaning of Parenteral Hydration to Family Caregivers and Patients With Advanced Cancer Receiving Hospice Care

Abstract Context In the U.S., patients with advanced cancer who are dehydrated or have decreased oral intake almost always receive parenteral hydration in acute care facilities but rarely in the hospice setting. Objectives To describe the meaning of hydration for terminally ill cancer patients in home hospice care and for their primary caregivers. Methods Phenomenological interviews were conducted at two time points with 85 patients and 84 caregivers enrolled in a randomized, double-blind, controlled trial examining the efficacy of parenteral hydration in patients with advanced cancer receiving hospice care in the southern U.S. Transcripts were analyzed hermeneutically by the interdisciplinary research team until consensus on the theme labels was reached. Results Patients and their family caregivers saw hydration as meaning hope and comfort. Hope was the view that hydration might prolong a life of dignity and enhance quality of life by reducing symptoms such as fatigue and increasing patients' alertness. Patients and caregivers also described hydration as improving patients' comfort by reducing pain; enhancing the effectiveness of pain medication; and nourishing the body, mind, and spirit. Conclusion These findings differ from traditional hospice beliefs that dehydration enhances patient comfort, given that patients and their families in the study viewed fluids as enhancing comfort, dignity, and quality of life. Discussion with patients and families about their preferences for hydration may help tailor care plans to meet specific patient needs.
Scarcity and Growth: How Does It Look Today?

Twelve years ago, in a book entitled Scarcity and Growth, Barnett and Morse demonstrated that the labor and capital required to extract most resources had declined strikingly since 1870. The economics profession, intent at the time on accelerating our economy faster than competing socialist models, cited this analysis when asked why Keynesian systems were constructed without natural resource constraints. The continued existence of New
Intraneural perineurioma of the radial nerve visualized by 3.0 Tesla MRI

A progressive radial neuropathy of unknown etiology despite 1.5T magnetic resonance imaging (MRI) and surgical exploration was identified as an intraneural perineurioma by a localized Tinel's sign, an enlarged radial nerve at the spiral groove by 3.0T MRI, and a fascicular biopsy. The distinction between the initial diagnoses of inflammatory, demyelinating polyneuropathy and perineurioma was made by immunohistochemistry and electron microscopy. A slowly progressing, localized mononeuropathy should include perineurioma in the differential diagnosis.
Molecular basis of mechanotransduction in living cells

The simplest cell-like structure, the lipid bilayer vesicle, can respond to mechanical deformation by elastic membrane dilation/thinning and curvature changes. When a protein is inserted in the lip...
No Intrinsic Deficiencies in CD8+ T Cell-Mediated Antitumor Immunity with Aging

Aging is associated with a decline in immune function, particularly within the T cell compartment. Because CD8(+) T cells are critical mediators of protective immunity against cancer, which arises more frequently with advancing age, it is important to understand how aging affects T cell-based antitumor responses. We used our DUC18 T cell/CMS5 tumor model system to examine the ability of both aged APCs and aged, tumor-specific CD8(+) T cells to mount protective responses to tumors in vivo. An assessment of aged DUC18 T cells in vitro showed a naive phenotype, but impaired proliferation in response to anti-CD3 and anti-CD28 stimulation. We found that DCs from young and old recipient mice are comparable phenotypically, and endogenous APCs in these mice are equally able to prime adoptively transferred young DUC18 T cells. Even when aged DUC18 T cells are transferred into aged CMS5-challenged mice, Ag-specific proliferation and CD25 expression are similar to those found when young DUC18 T cells are transferred into young mice. Although trafficking to tumor sites appears unequal, old and young DUC18 T cells reject primary CMS5 challenges to the same degree and with similar kinetics. Overall, we found no loss of endogenous APC function or intrinsic defects in CD8(+) DUC18 T cells with advanced age. Therefore, when young and old tumor-specific T cell populations are equivalently sized, CD8(+) T cell-mediated antitumor immunity in our system is not impaired by age, a finding that has positive implications for T cell-based immunotherapies.
U.S. Latino Population Composition Change and Comprehensive Cancer Centers

Background . We describe a typology characterizing population trends of U.S. Latinos/Hispanics from 1990 to 2000 with respect to National Cancer Institute-designated comprehensive cancer centers (CCCs) and corresponding consolidated metropolitan statistical or metropolitan statistical areas (CMSA/MSAs). Methods . Using U.S. Census Bureau data, we constructed population pyramids to analyze population growth and composition for each CMSA/MSA with a CCC. Results . We identified four types of population growth and composition: Type I—Very Fast and Unstable; Type II—Fast and Unstable; Type III— Somewhat Fast and Stable; Type IV—Slow and Stable. Conclusions . The CCCs in areas with Types I and II population growth face the greatest challenges because of the lack of infrastructure for reaching medically underserved Latinos. In contrast, CCCs in areas with Types III and IV population growth may have significant infrastructure but must quickly develop interventions to reach and provide access to aging Latinos to reduce health disparities in cancer mortality and morbidity.
Tourism as Science and Science as Tourism Environment, Society, Self, and Other in Papua New Guinea

The experience of villagers in Maimafu, in the Crater Mountain Wildlife Management Area of the Eastern Highlands of Papua New Guinea, calls attention to two forms of social interaction between rural people and outsiders that have been little examined in the anthropological literature. One of these is scientific research and the other is scientific tourism, a form of ecotourism that is linked not to science but to self‐fashioning and individual gain. Scientific tourists may be seeking an educational adventure that they can turn into symbolic capital on their return home, a way into the world of science, or an experience that can be turned into economic capital through publication in popular magazines. For both researchers and scientific journalists, New Guinea combines the exotic, the about‐to‐be‐lost, the primitive, the untouched, and the spectacular and is therefore a powerful space for imaginary and representational practice.
Did send-down experience benefit youth? A reevaluation of the social consequences of forced urban–rural migration during China’s Cultural Revolution ☆

During China’s Cultural Revolution, a large proportion of urban youth were forced to go to the countryside as a result of the state’s “send-down” policy. Past research has been ambivalent about the long-term social consequences for the Chinese youth who experienced send-down. Some scholars have suggested that the send-down experience may have yielded beneficial effects. To test this claim, we analyze data from the Survey of Family Life in Urban China, which we conducted in three large cities in 1999. Questions available in this data set allow us to ascertain the send-down experience of both the respondent and a sibling and educational attainment at the times of send-down and return. Our analyses of the new data show that the send-down experience does not seem to have benefited the affected Chinese youth. Differences in social outcomes between those who experienced send-down and those who did not are either non-existent or spurious due to other social processes.
Variations of Major Chemical Constituents across the Central Sierra Nevada Batholith

A study of 193 chemical analyses of plutonic rocks from 132 localities in the central Sierra Nevada shows convincingly that K2O decreases systematically westward and suggests that Fe2O3 and TiO2 may also decrease westward and that FeO, MgO, and CaO may increase. The ratio K2O/SiO2 obviously decreases westward across six of eight provisionally established sequences of granitic rocks. Plots of analyses of rocks from each sequence form discrete fields that are strongly elongate toward zero K2O at 40 to 45 percent SiO2. The boundaries between fields on these plots and between fields on plots of normative minerals on triangular diagrams are sharp. Compositional trends within sequences are different than the compositional changes that take place across the batholith—rocks in the western Sierra Nevada probably are not compositionally identical with rocks that are present at depth beneath the eastern Sierra Nevada. Progressive decrease of K2O in the Paleozoic and Mesozoic country rocks westward across the batholith is consistent with the anatectic model for its origin. However, it also is consistent with the hypothesis developed to explain chemical patterns in volcanic island arcs—that K2O increases toward continental land masses because of increasing depth of magma generation along landward-dipping seismic (Benioff) zones. The seismic-zone hypothesis encounters several difficulties, but it cannot be ruled out.
Characterization of the Secondary Structure and Membrane Interaction of the Putative Membrane Anchor Domains of Prostaglandin I2Synthase and Cytochrome P450 2C1

Abstract Prostaglandin I 2 synthase (PGIS) produces prostaglandin I 2 (PGI 2 ) which has opposite actions on platelet aggregatory and vasoconstrictive properties compared to thromboxane A 2 (TXA 2 ) produced from the same substrate by another P450 enzyme, thromboxane A 2 synthase (TXAS). PGIS and TXAS have only 16% amino acid sequence identity. Hydropathy analysis suggests that the putative NH 2 -terminal membrane anchor domain of PGIS is similar to many other membrane-bound microsomal P450s, which are believed to be anchored by a single transmembrane segment, and thus different from the TXAS anchor, which appears to have two transmembrane segments. To characterize the membrane anchor function of the PGIS NH 2 -terminal region, we have used the peptidoliposome reconstitution assay to identify the membrane anchor segment in the PGIS NH 2 -terminal domain and compared it with the anchor segment of P450 2C1. Four peptides, mimicking putative NH 2 -terminal membrane anchor segments of PGIS and P450 2C1, containing residues 1–28 (PGIS-LP1 and P450 2C1-LP1) or residues 25–54 (PGIS-LP2 and P450 2C1-LP2), were synthesized and their ability to insert in a lipid bilayer was evaluated. The results indicated that both LP1 peptides of PGIS and P450 2C1 became bound to the lipid bilayer, whereas both LP2 peptides did not bind the lipid. The two LP1 peptides were further characterized as to their conformation using CD spectroscopy. Helical structure induced in these peptides by addition of trifluoroethanol, dodecylphosphocholine, or incorporation into liposomes indicated that these segments tend to adopt a helical structure in a hydrophobic environment and thus could function as membrane anchor segments. These results support the hypothesis that PGIS and TXAS interact with the endoplasmic reticulum membrane in different ways, in which the NH 2 -terminal anchor domain of PGIS, as with P450 2C1, appears to have a single transmembrane segment.
Bacteriophage Migration via Nematode Vectors: Host-Parasite-Consumer Interactions in Laboratory Microcosms

Pathogens vectored by nematodes pose serious agricultural, economic, and health threats; however, little is known of the ecological and evolutionary aspects of pathogen transmission by nematodes. Here we describe a novel model system with two trophic levels, bacteriophages and nematodes, each of which competes for bacteria. We demonstrate for the first time that nematodes are capable of transmitting phages between spatially distinct patches of bacteria. This model system has considerable advantages, including the ease of maintenance and manipulation at the laboratory bench, the ability to observe many generations in short periods, and the capacity to freeze evolved strains for later comparison to their ancestors. More generally, experimental studies of complex multispecies interactions, host-pathogen coevolution, disease dynamics, and the evolution of virulence may benefit from this model system because current models (e.g., chickens, mosquitoes, and malaria parasites) are costly to maintain, are difficult to manipulate, and require considerable space. Our initial explorations centered on independently assessing the impacts of nematode, bacterium, and phage population densities on virus migration between host patches. Our results indicated that virus transmission increases with worm density and host bacterial abundance; however, transmission decreases with initial phage abundance, perhaps because viruses eliminate available hosts before migration can occur. We discuss the microbial growth dynamics that underlie these results, suggest mechanistic explanations for nematode transmission of phages, and propose intriguing possibilities for future research.
Creating Developmentally Appropriate, Safe Counseling Environments for Transgender Youth: The Critical Role of School Counselors

This article outlines the role of school counselors at the elementary, middle, and high school levels as they work with transgender youth. The authors take a developmental approach to identify the role and opportunities school counselors have in building a transgender-positive environment in school settings. Important language and terms for working with transgender youth are provided as well as practice recommendations across elementary, middle, and high school counseling levels. In addition, the authors recommend specific advocacy-focused approaches to make school counseling interventions more transgender-positive.
Toward Tractable Computation of the Capacity of Multi-Hop Wireless Networks

By posing the problem of bandwidth allocation as a constrained maximization problem, it is possible to study various features of optimal bandwidth allocation, and hence the capacity of the network. However, since the typical approach to this problem requires optimizing over a space that is exponential in the number of links, the problem has appeared to be computationally intractable for all but small networks. In this paper, the problem of computing optimal bandwidth allocation is examined and a new approach is presented. While the resulting allocation cannot be guaranteed to be optimal, we find that in the networks where checking optimality is computationally feasible (i.e., networks with fewer than 23 links), the performance of the found allocation is indistinguishable from the optimal allocation. In essence, the proposed iterative scheme focuses on the space of useful bandwidth allocations. The Lagrange multipliers are used to find useful allocations.
Generation of a substructure library for the description and classification of protein secondary structure. II. Application to spectra-structure correlations in Fourier transform infrared spectroscopy.

Fourier transform infrared spectroscopy has become well known as a sensitive and informative tool for studying secondary structure in proteins. Present analysis of the conformation-sensitive amide I region in protein infrared spectra, when combined with band narrowing techniques, provides more information concerning protein secondary structure than can be meaningfully interpreted. This is due in part to limited models for secondary structure. Using the algorithm described in the previous paper of this series, we have generated a library of substructures for several trypsin-like serine proteases. This library was used as a basis for spectra–structure correlations with infrared spectra in the amide I′ region, for five homologous proteins for which spectra were collected. Use of the substructure library has allowed correlations not previously possible with template-based methods of protein conformational analysis. © 1992 Wiley-Liss, Inc.
Estimating the Total Number of Alleles Using a Sample Coverage Method

Previously reported methods for estimating the number of different alleles at a single locus in a population have not described a useful general result. Using the number of alleles observed in a sample gives an underestimate for the true number of alleles. The similar problem of estimating the number of species in a population was first investigated in 1943. In this article we use the sample coverage method proposed by Chao and Lee in 1992 to estimate the number of alleles in a population when there are unequal allele frequencies. Simulation studies under the recurrent mutation model show that, for reasonable sample sizes, a significantly better estimate of the true number can be obtained than that using only the observed alleles. Results under the stepwise mutation model and infinite-allele model are presented. Possible applications include improving the characterization of the prior distribution for the allele frequencies, adjusting the estimates of genetic diversity, and estimating the range of microsatellite alleles.
Propagation of the radiofrequency ground wave transient over a finitely conducting plane earth

The introduction of precision radio navigation systems employing pulse techniques and the ever increasing interest in spherics have stimulated considerable interest in the propagation of the ground wave transient over the surface of the earth. The theory of the propagation of a transient radio frequency ground wave over a finitely conducting plane earth is presented for the particular case of theNorton surface wave by a consideration of a wave, interrupted abruptly at one point in time (t=0), a wave interrupted abruptly at two points in time (t=0,T2) and a wave interrupted at one point in time followed by an exponential decay. The first case is illustrated by several numerical examples of a cosine current wave applied to a vertical electric dipole source. It is apparent that the method of the inverse Ľaplace transform for the particular cases considered yields some simple mathematical formulas.
Soil-plant nitrogen dynamics following incorporation of a mature rye cover crop in a lettuce production system

Winter non-leguminous cover crops are included in crop rotations to decrease nitrate (NO 3 -N) leaching and increase soil organic matter. This study examined the effect of incorporating a mature cover crop on subsequent N transformations. A field trial containing a winter cover crop of Merced rye and a fallow control was established in December 1991 in Salinas, California. The rye was grown for 16 weeks, so that plants had headed and were senescing, resulting in residue which was difficult to incorporate and slow to decompose. Frequent sampling of the surface soil (0-15 cm) showed that net mineralizable N (anaerobic incubation) rapidly increased, then decreased shortly after tillage in both treatments, but that sustained increases in net mineralizable N and microbial biomass N in the cover-cropped soils did not occur until after irrigation, 20 days after incorporation. Soil NO 3 -N was significantly reduced compared to winter-fallow soil at that time. A 15 N experiment examined the fate of N fertilizer, applied in cylinders at a rate of 12 kg 15 N/ha at lettuce planting, and measured in the soil, microbial biomass and lettuce plants after 32 days. In the cover-cropped soil, 59% of the 15 N was recovered in the microbial biomass, compared to 21 % in the winter-bare soil. The dry weight, total N and 15 N content of the lettuce in the cover-cropped cylinders were significantly lower; 28 v. 39% of applied 15 N was recovered in the lettuce in the cover-cropped and winter-bare soils, respectively. At harvest, the N content of the lettuce in the cover-cropped soil remained lower, and microbial biomass N was higher than in winter-bare soils. These data indicate that delayed cover crop incorporation resulted in net microbial immobilization which extended into the period of high crop demand and reduced N availability to the crop
Destroying the Opposition’s Livelihood: Pathways to Violence in Bolivia since 2000

During the first decade of the 2000s, Bolivia occasionally turned violent. Yet the causes of these episodes of sustained violence have not yet been identified. To this end, this article tests which mechanisms theorized by existing scholarship produced two prolonged episodes of violence. It concludes that both episodes emerged from the same causal pathway: the national government provoked violence by seeking to raze the economic foundations of well-organized sectors – sectors that represented the mass bases of ascendant political oppositions. This finding not only sheds light on political order in Bolivia, but also opens up new directions in research on violent confrontation in Latin America.
Classifiability based omnivariate decision trees

Decision trees represent a simple and powerful method of induction from labeled examples. Univariate decision trees consider the value of a single attribute at each node, leading to the splits that are parallel to the axes. In linear multivariate decision trees, all the attributes are used and the partition at each node is based on a linear discriminate (a hyperplane). Nonlinear multivariate decision trees are able to divide the input space arbitrarily based on higher order parameterizations of the discriminate, though one should be aware of the increase of the complexity and the decrease in the number of examples available as moves further down the tree. In omnivariate decision trees, the decision node may be univariate, linear, or nonlinear. Such architecture frees the designer from choosing the appropriate tree type for a given problem. In this paper, we propose to do the model selection at each decision node based on a novel classifiability measure when building omnivariate decision trees. The classifiability measure captures the possible sources of misclassification with relative ease and is able to accurately reflect the complexity of subproblems at each node. The proposed approach does not require the time consuming statistic tests at each node and therefore does not suffer from as high computational burden as typical model selection algorithm. Our simulation results over several data sets indicate that our approach can achieve at least as good classification accuracy as statistical tests based model select algorithms, but in much faster speed.
Laparoscopic cholecystectomy in a patient with an implantable left ventricular assist device

Left ventricular assist devices (LVADs) provide mechanical support for left ventricular ejection in the failing heart. We describe the anaesthetic management of a patient with an LVAD requiring laparoscopic cholecystectomy. A 51-yr-old female patient with severe heart disease had a Heartmate II LVAD implanted 4 months before this proposed elective surgery. Maintaining haemodynamic stability in the perioperative period is essential in such patients. The case was managed successfully using invasive monitoring and anaesthesia with sevoflurane and remifentanil. The potential problems in management of patients with LVADs are highlighted and discussed. A team approach is essential.
Depletion of Ascorbic Acid Restricts Angiogenesis and Retards Tumor Growth in a Mouse Model

Angiogenesis requires the deposition of type IV collagen by endothelial cells into the basement membrane of new blood vessels. Stabilization of type IV collagen triple helix depends on the hydroxylation of proline, which is catalyzed by the iron-containing enzyme prolyl hydroxylase. This enzyme, in turn, requires ascorbic acid to maintain the enzyme-bound iron in its reduced state. We hypothesized that dietary ascorbic acid might be required for tumor angiogenesis and, therefore, tumor growth. Here, we show that, not surprisingly, ascorbic acid is necessary for the synthesis of collagen type IV by human endothelial cells and for their effective migration and tube formation on a basement membrane matrix. Furthermore, ascorbic acid depletion in mice incapable of synthesizing ascorbic acid (Gulo-/-) dramatically restricts the in vivo growth of implanted Lewis lung carcinoma tumors. Histopathological analyses of these tumors reveal poorly formed blood vessels, extensive hemorrhagic foci, and decreased collagen and von Willebrand factor expression. Our data indicate that ascorbic acid plays an essential role in tumor angiogenesis and growth, and that restriction of ascorbic acid or pharmacological inhibition of prolyl hydroxylase may prove to be novel therapeutic approaches to the treatment of cancer.
Emergency Pretreatment for Contrast Allergy Before Direct Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction

Patients with previous adverse contrast reactions occasionally present with ST-segment elevation myocardial infarction. Whether they can undergo catheterization safely using current contrast and medications is unknown. We reviewed catheterization laboratory records of all 501 patients (January 2005 to December 2006) presenting with ST-segment elevation myocardial infarction who underwent emergency coronary angiography. Six patients (1.2%) reported a previous contrast reaction including rash, acute bronchospasm, or anaphylaxis. All received a combination of intravenous steroids and H1 and H2 blockers in the emergency department or catheterization laboratory before catheterization. None of these had complications or evidence of allergy in any patient. In conclusion, some patients with previous contrast reaction may undergo emergency catheterization without adverse consequences, although the safety of this approach has not been proved.
Flood extent mapping for Namibia using change detection and thresholding with SAR

A new method for flood detection change detection and thresholding (CDAT) was used with synthetic aperture radar (SAR) imagery to delineate the extent of flooding for the Chobe floodplain in the Caprivi region of Namibia. This region experiences annual seasonal flooding and has seen a recent renewal of severe flooding after a long dry period in the 1990s. Flooding in this area has caused loss of life and livelihoods for the surrounding communities and has caught the attention of disaster relief agencies. There is a need for flood extent mapping techniques that can be used to process images quickly, providing near real-time flooding information to relief agencies. ENVISAT/ASAR and Radarsat-2 images were acquired for several flooding seasons from February 2008 to March 2013. The CDAT method was used to determine flooding from these images and includes the use of image subtraction, decision-based classification with threshold values, and segmentation of SAR images. The total extent of flooding determined for 2009, 2011 and 2012 was about 542 km 2 , 720 km 2 , and 673 km 2 respectively. Pixels determined to be flooded in vegetation were typically <0:5% of the entire scene, with the exception of 2009 where the detection of flooding in vegetation was much greater (almost one third of the total flooded area). The time to maximum flooding for the 2013 flood season was determined to be about 27 days. Landsat water classification was used to compare the results from the new CDAT with SAR method; the results show good spatial agreement with Landsat scenes.
Performance evaluation of the IEEE 802.15.4 MAC for low-rate low-power wireless networks

IEEE 802.15.4 is a new standard to address the need for low-rate low-power low-cost wireless networking. We provide in this paper one of the first simulation-based performance evaluations of the new medium access protocol in IEEE 802.15.4, focusing on its beacon-enabled mode for a star-topology network. We describe its key features such as the superframe structure, which allows devices to access channels in a contention access period (CAP) or a collision free period (CFP) and the beacon-based synchronization mechanism. Our performance evaluation study reveals some of the key throughput-energy-delay tradeoffs inherent in this MAC protocol. We provide an analysis comparing the energy costs of beacon tracking and non-tracking modes for synchronization, showing that the optimum choice depends upon the combination of duty cycles and data rates.
The Relative Importance of Global, Country and Sector Risks

We construct a state-dependent trivariate GARCH-M model to extract state-dependent risk-aversion coefficients around the 1997-1999 financial meltdown. These coefficients are further used to decompose sector risk into global (systematic), country-specific (diversifiable through global country allocation) and sector-specific (diversifiable through domestic sector allocation) risk measures. Our investigation shows that diversification benefits of sector-based allocation have increased as a result of the Asian meltdown. Nevertheless, the importance of country factors persists. Finally, we find that sector-specific effects are as important as country effects and increase slightly over the period of study.
Ionosphere-thermosphere (IT) response to solar wind forcing during magnetic storms

Air Force Office of Scientific Research under Grants LRIR 14 RV11COR and FA9550-14-1-0280; National Science Foundation under Grant NSF Grant AGS-1259508.
Unclear results for the use of botulinum toxin therapy for TMD pain.

Data sources A comprehensive search was carried out on major databases such as PubMed, EMBASE and Cochrane CENTRAL. Reference lists of the included studies were explored along with journals likely to contain studies relevant to the topic. The search was restricted to the English language. Study selection The inclusion criteria included randomised and quasi-randomised controlled trials including parallel or cross-over studies comparing botulinum toxin therapy (BTX) versus any alternative intervention or placebo. Data extraction and synthesis Quality assessment and data extraction were done following the Cochrane risk of bias tool and recommendations. All of the steps in the review, including the search and selection process, were done independently by two reviewers. Disagreements were discussed with one another until consensus was reached. Results Five relevant studies were included in the review, which consisted of 117 participants. Two trials revealed a significant inter-group difference in myofascial pain reduction. Another trial that compared BTX with fascial manipulation showed no significant difference in pain relief for temporomandibular disorders (TMDs), while the remaining two trials showed no significant difference between the BTX and placebo groups. Meta-analysis was not performed due to the considerable variation in study methods and evaluation of the results. All five studies were targeted primarily on the masseter and temporalis muscles and most of them administered injections at bilateral muscle sites. The methods used to find the muscles to target were all based on physical examination, with three studies using electromyography (EMG) as guidance. The dose of BTX ranged from 70U to 300U, the majority used being 100-150U. All studies gave a single session of BTX and re-evaluated participants at least one month following the injection. Conclusions No consensus could be reached on the therapeutic benefit of BTX on TMDs.
Some Observations on the Electrical Characterization of the Heteroepitaxially Grown Cubic SiC

This paper re-examines the electrical characterization of thin layers of cubic SiC, grown on (100) Si substrates. The resistivity and Hall coefficient for undoped SiC layers were measured between 10 K and 500 K. Electron spin resonance (ESR) and secondary ion mass spectrometry (SIMS) were used to identify and determine the nitrogen concentrations, which were higher than 1017/cm3. In all the samples examined the Hall measurements indicated impurity band conduction. Therefore, the temperature dependence of the resistivity has been used to derive an activation energy el. The value of el found to be in the range of 0.032−0.025 eV. The observed decrease in activation energy has been correlated with an increase in nitrogen concentration. The presence of substantial nitrogen leads to impurity band conduction and it is the most likely reason for the conflicting values reported for the dominant donor ionization energy by Hall and PL measurements.
Miniaturized silicon apertures for lipid bilayer reconstitution experiments

Ion channels reconstituted into lipid bilayer membranes can be used as a very sensitive and selective platform for high-throughput drug screening applications. In order to employ suspended lipid bilayer membranes for these experiments in form of a “lab-on-a-chip” configuration, a robust and affordable platform is required. In our study, we investigated the feasibility of hosting lipid bilayer membranes across micron-size apertures ranging from 5 μm–50 μm in silicon. On these substrates, lipid bilayers were formed and characterized concerning their seal resistance, capacitance and breakdown voltage. Seal resistance values of up to 60 GΩ could be achieved repeatedly on these substrates.
Professional ethics and professional morality in the assessment of competence for execution: A response to Bonnie.

Four psychological perspectives need to be considered in response to the Richard Bonnie outlook on competence for execution. The first perspective is the degree to which the task itself is ambiguous and thus allows individual clinicians' values to leak through. The second perspective is that prisoners' choices to opt for execution instead of appeal are murky and often irrational. The third perspective is that even rational decisions for execution instead of appeal are often not founded on informed judgments, in part because of the situational influences of living on death row. The fourth perspective is that clinicians' judgments to participate in such legal-psychological activities are not only a matter of individual morality but also part of evolving professional ethics.