cssi/SciSciGPT-SciSciNet huggingface dataset:
Acclimation, shock and hardening in the cold

Abstract Recent articles by Bowler [2005. J. Therm. Biol. 30, 125–130] and Loeschcke and Sorensen [2005. J. Therm. Biol. 30, 255–257] have discussed the relationship between acclimation, hardening and heat shock in ectothermic animals, implying that analogous processes occur at low temperatures. We address this implication using the Drosophila literature. Cold tolerance in Drosophila has been measured in response to hardening (usually 1–3 h) or acclimation (usually days–weeks) using at least 27 different duration–intensity combinations. The metrics of response to these treatments include chill coma recovery or onset, survival and measures of reproductive success. However, it is unclear whether the mechanisms underlying the different metrics are the same, or whether the causes of injury are related over duration–intensity exposures ranging from a few minutes to hundreds of days. Furthermore, whilst there is ample evidence for acclimation and cold hardening in Drosophila, there is no clear evidence for a cold-shock response analogous to the well-characterised heat-shock response.
Analyzing Carbohydrate-Based Regenerative Fuel Cells as a Power Source for Unmanned Aerial Vehicles

Based on current capabilities, we examine the feasibility of creating a carbohydrate-based regenerative fuel cell (CRFC) as the primary power source for unmanned aerial vehicles (UAV) for long endurance missions where station keeping is required. The CRFC power system evaluated in this research is based on a closed-loop construct where carbohydrates are generated from zooxanthellae, algae which create excess carbohydrates during photosynthesis. The carbohydrates are then fed to a carbohydrate fuel cell where electric power is generated for the UAV’s propulsion, flight control, payload, and accessory systems. The waste products from the fuel cell, carbon dioxide and water, are used by the zooxanthellae to create more carbohydrates, therefore mass is conserved in the process of power generation. The overall goal of this research is to examine the potential of CRFCs as a viable power source for UAV systems, to look at scaling issues related to different vehicle sizes and missions, and to identify sensitivities in the CRFC system to different system parameters, indicating the areas where technology improvements may make CRFCs a viable technology. Through simulations, a UAV is sized to determine if greater than 24 hour endurance flight is possible and these results are compared to UAVs using more traditional photo-cell based power systems. The initial results suggest that CRFCs have potential as a power system for long endurance UAVs, and could offer significant improvements to the overall system performance. The final outcome of this research is to identify the most important areas for more detailed follow-on work in designing a production-ready CRFC power system for long endurance UAVs.
An implicature for um: signaling relative expertise

Many scholars characterize um as an involuntary emission that is devoid of meaning. Other scholars classify um as a non-linguistic signal that conveys certain messages or resolves a conversational ...
Linear Atrial Ablation With a Diode Laser and Fiberoptic Catheter

The catheter maze procedure for the treatment of chronic atrial fibrillation requires the creation of transmural, continuous linear atrial lesions. Attempts to drag a conventional radiofrequency ablation catheter across the atria in clinical as well as experimental studies have resulted in discontinuous lesions. Continuous linear lesions have been most difficult to create in trabeculated atrial muscle. Lesion discontinuities or gaps have resulted in reentrant atrial tachyarrhythmias in patients after ablation. We have explored the use of a linear laser catheter for the creation of continuous atrial lesions. A linear laser system may offer a number of potential advantages over conventional radiofrequency catheter ablation: (1) the laser diffuser …
Carpal tunnel syndrome: pathophysiology and clinical neurophysiology

Carpal tunnel syndrome (CTS) is a constellation of symptoms associated with compression of the median nerve at the wrist. The pathophysiology of CTS is not fully understood but mechanical aspects of injury within the carpal tunnel are most likely. The issues of ischemia, mechanical trauma, ectopic impulse generation, demyelination, tendonitis, elevated carpal tunnel pressure, mechanical factors, small and large fiber involvement and the variability of symptoms are presented. Documentation of neurophysiologic abnormalities in the median nerve is helpful to establish the diagnosis for CTS. There are several types of clinical neurophysiologic evaluations of the median nerve across the wrist. Sensory and motor nerve conduction studies (NCS) of the median nerve segment across the wrist compared to another nerve segment that does not go through the carpal tunnel (i.e. median, radial, or ulnar) are the most sensitive and accurate techniques. Other neurophysiologic techniques used to document CTS include vibrometry threshold testing, current perception testing, Semmes-Weinstein monofilament testing and two-point discrimination. These techniques have considerable subjective components and have not been found to be as sensitive as traditional NCS.
Franchise failure: a reassessment of the Bates (1995) results

Franchising is often touted as a safe route to business ownership in the service arena. Yet findings by Bates (J Small Bus Manage 33(2):26–36, 1995) suggest that franchising may be a riskier alternative for prospective business owners than starting a non-franchised business. We contend that this conclusion is inappropriate because flaws in Bates’ study lend themselves to alternative interpretations of his results. The most critical flaws and plausible alternative interpretations are explained, and implications for prospective business owners are discussed.
A Realist's Moral Opposition to War: Han J. Morgenthau and Vietnam

This article examines Hans J. Morgenthau's critique of U.S. policies in Vietnam. Morgenthau, renowned for his advocacy of realism in foreign affairs, was one of the few political commentators to raise questions about nation-building efforts in South Vietnam in the 1950s. After full-scale military intervention in the 1960s, he became the foremost academic critic of the war. Morgenthau demonstrated a dramatic evolution in his views. In the 1950s, he expressed reservations about Indochina policies based on pragmatic concerns. Over time, however, his analysis of Vietnam policies focused on their ethical shortcomings. His examination of the ethics of the Vietnam war led him to revise his notion of how national interests should be determined in making foreign policy, from a calculation based on purely strategic factors to one that also takes moral factors into account.
Magnetic field topology variations in plasmas generated by radial foils

Summary form only given. Radial foil implosions on the COrnell Beam Research Accelerator (COBRA) and MAGPIE [1, 2] are used to understand the magneto-hydrodynamics of astrophysical plasma jets. While this configuration shares geometrical similarities with its celestial counterpart, the topology of the magnetic field may exhibit substantial differences. One possible improvement uses external magnetic fields (using permanent magnets or copper coils) to alter the magnetic field generated by the plasma current and recover more realistic dynamics. The other possibility is to change the shape of the pin cathode. The standard setup uses a single straight pin. Since all the discharge current focuses onto that pin, the magnetic field is azimuthally symmetric during the lifetime of the jet, as is the plasma dynamics. However if the pin geometry is changed, the magnetic field becomes fully three-dimensional, as is often the case in astrophysical plasma jets. Using single and multi-pin setups, we will assess how the magnetic field topology can be changed to yield plasma dynamics which matches that of astrophysical jets more closely. In particular, we will look at the impact of three-dimensional magnetic fields on plasma flows and how they influence the actual structure of the jet. Experimental results will be compared to numerical simulations from the 3D PERSEUS extended MHD computer code. The impact of the Hall effect on the plasma dynamics will be highlighted.
GaSb-Based Diode Lasers With Asymmetric Separate Confinement Heterostructure

A design for GaSb-based type-I quantum well diode lasers with an AlGaInAsSb/GaInAsSb active region, GaSb and AlGaAsSb separate confinement layers, and an AlSb/InAs hole stopper is proposed. The suppression of carrier recombination outside of the active region leads to improved laser efficiency and temperature stability. At a heatsink temperature of 17°C, the 2-mm-long, 100-μm-wide, anti-/high-reflection coated devices demonstrate threshold current densities of ~ 350 A/cm2 and emit ~ 220 mW of continuous wave output power at 3.15 μm.
Volcanic ash dispersed in the Wyodak-Anderson coal bed, Powder River Basin, Wyoming

Abstract Minerals derived from air-fall volcanic ash were found in two zones in the upper Paleocene Wyodak-Anderson coal bed of the Fort Union Formation in the Powder River Basin of Wyoming, and are the first reported evidence of such volcanic material in this thick (> 20 m) coal bed. The volcanic minerals occur in zones that are not visually obvious because they contain little or no clay. These zones were located by geophysical logs of the boreholes and X-ray radiography of the cores. The zones correspond to two of a series of incremental core samples of the coal bed that have anomalous concentrations of Zr, Ba, Nb, Sr, and P2O5. Two suites of minerals were found in both of the high-density zones. A primary suite (not authigenic) consists of silt-sized quartz grains, biotite, and minor zircon. A minor suite consists of authigenic minerals, including calcite, pyrite, kaolinite, quartz, anatase, barite, and an alumino-phosphate (crandallite?). The original volcanic ash is inferred to have consisted of silica glass containing phenocrysts of quartz, biotite, zircon, and possibly, associated feldspars, pyroxenes, and amphiboles. The glass, as well as the less stable minerals, probably dissolved relatively quickly and contributed to the minor authigenic mineral suite or was removed from the peat as a result of the prevailing hydrologic conditions present in a raised peat formation. This type of volcanic ash suggests that suggests that volcanic material could have rained on the peat; this fallout may have also had a fertilizing effect on the peat by providing nutrients essential for plant growth thus contributing to the thick accumulations of the Wyodak-Anderson bed. Notwithstanding, the presence of these minerals provides evidence for the contribution by volcanic sources to the mineral content of coal, but not as tonsteins.
Optimum mixing of hypergolic propellants in an unlike doublet injector element

Optimum penetration and separation mixing of unlike doublet injector element with hypergolic hydrazine and nitrogen tetroxide propellants
Epicardial activation in human left anterior fascicular block

Abstract Four patients with coronary artery disease and chronic marked left axis deviation, defined as a frontal QRS axis more negative than −45 °, were studied with epicardial mapping during coronary bypass surgery. All patients had normal right ventricular and inferior left ventricular epicardial breakthrough sites and activation sequence. Normal breakthrough in the basal anterolateral left ventricular epicardium was absent in all four patients. Two patients had breakthrough in the apical region of the anterolateral left ventricle. In the other two this region was activated from wave fronts emerging in the right ventricle and inferior left ventricle. The latest site of left ventricular activation was the basal segment of the anterolateral wall, a site never found to be the latest activated in our previously studied patients without conduction defects. This site was activated during or slightly after the terminal portion of the QRS complex. It is concluded that marked left axis deviation in patients with coronary artery disease reflects delayed activation of the basal anterolateral left ventricle, and is consistent with the presence of block or delay in the anterior “fascicle” of the left bundle branch.
Correlation between mesh size and equilibrium degree of swelling of polymeric networks

A correlation is established between the mesh size of a swollen cross-linked network and its equilibrium polymer volume fraction, for hydrogels isothermally swollen up to semidilute, dilute, or concentrated conditions. The exponent of this correlation decreases as the water concentration of the hydrogel decreases. Experimental results with hydrogels of poly(vinyl alcohol) and poly(2-hydroxy ethyl methacrylate) are used to verify the new scaling laws.
RNA chain growth rates in Escherichia coli

Abstract The rate of RNA chain growth was measured in vivo in Escherichia coli cultures growing in various media at 29 and 37 °C. For this purpose, the bacteria were allowed to assimilate [ 3 H]uracil or [ 3 H]guanine into their RNA for short time-periods. The RNA was then extracted and hydrolyzed with alkali, and the radioactivity measured in the resulting nucleotides and nucleosides. The data thus obtained allowed the calculation of individual nucleotide step-times in RNA chain growth, the step-time for a particular nucleotide being defined as the average time required for adding the next nucleotide to the end of a nascent RNA chain carrying that particular nucleotide as its growing end. In bacteria growing exponentially in a glucose-Casaminoacids medium at 29 °C with 1.07 cell generations per hour, the uridylic acid step-time was estimated to be 42 msec, the cytidylic acid step-time to be at most 67 msec and the guanylic acid step-time to be 20 msec. Assuming an equality of the step-times of guanylic and adenylic acids, the average RNA chain growth rate was estimated to be 26 nucleotides/second at 29 °C. At 37.5 °C both the generation period as well as the nucleotide step-times were found to be 60% of the corresponding values at 29 °C, giving an average RNA chain growth rate of 43 nucleotides/second. The nucleotide step-times in E. coli growing at 29 °C in a succinate medium with 0.63 cell generation per hour and in a proline medium with 0.33 cell generation per hour were found to be longer than the corresponding step-times during the faster growth in glucose-Casaminoacids medium. The increases in nucleotide step-times with increases in the generation period observed here are not nearly great enough, however, to account for the great variations in the rate of RNA synthesis observed under these three different physiological conditions. Thus bacteria appear to adjust their specific content of RNA according to their physiological needs by varying both the rate of RNA chain growth and the number of nascent RNA molecules under synthesis at any time.
Case report: A subclavian line complication: Embolisation of an arteriovenous fistula

We report a case illustrating the successful non-surgical management of an arteriovenous fistula resulting from central line placement. After diagnosis by angiography transcatheter embolotherapy of the internal mammary artery provided an alternative to thoracotomy in treating this unusual complication.
Resurgent Volcano-Tectonic Depression of Oligocene Age, South-Central New Mexico

The Goodsight-Cedar Hills volcano-tectonic depression in south-central New Mexico formed concurrently with and following deposition of about 550 km 3 of Oligocene volcanic and volcaniclastic rocks. The depression is an asymmetric basin about 80 km long and 38 km wide. It is filled to a maximum depth of about 550 m by early rhyolitic ash-flow tuff, medial epiclastic strata derived partly from marginal raised rims (Bell Top Formation), and late basaltic andesite (Uvas Basalt). Much of the 295 km 3 of effusive rock was erupted from vents located near the center of the depression and from a major subsidence fracture zone along the eastern margin. Subsidence of the depression floor was noncatastrophic and approximately kept pace with basin filling, except along the eastern margin. Following eruption and broad, regional subsidence of the Uvas Basalt, the central floor of the depression was arched upward to form the Sierra de las Uvas dome and adjacent synclinal moat. The fault pattern of the dome and its association with known vents and the thickest part of the volcanic pile suggest that it formed by vertical movement of magma from an underlying chamber. Its development, following subsidence of the Uvas Basalt, suggests that it is essentially resurgent in origin. Although no postdoming volcanism is known, indirect evidence indicates that intrusion of silicic magma probably caused resurgence. It is clear that the Goodsight-Cedar Hills depression is not a resurgent cauldron of the classic Valles or Toba types. Rather, it appears to be a structure transitional in character between a cauldron and a fault trough. Subsidence apparently followed volcanism. Resurgence followed eruption of basaltic andesite rather than the usual ash-flow sequence, and the 10- to 12-m.y. history of the Goodsight-Cedar Hills depression is 5 to 6 times as long as other well-known resurgent cauldron cycles. Locally, deposition in the depression continued without interruption into early late Tertiary time, when extensional faulting occurred. The depression is elongated parallel to the late Tertiary Rio Grande Rift and may be a precursor of Basin and Range structure in the area. The late Tertiary fault pattern in the area indicates that earlier volcano-tectonic structures had important effects on the pattern of late Tertiary Basin and Range structures. Locally, late Tertiary faults were inherited from and duplicate the position of earlier subsidence faults or the synclinal moat. Elsewhere, the north-trending regional fault pattern was considerably modified by structural and litho-logic inhomogeneities of volcano-tectonic origin, particularly the Sierra de las Uvas dome and its buried intrusive masses.
Calibration of an analyzing magnet using an α-source and heavy-ion beams

Abstract A simple method is described for absolutely calibrating an analyzing magnet system at a heavy-ion accelerator facility.
Protein structural change at the cytoplasmic surface as the cause of cooperativity in the bacteriorhodopsin photocycle

The effects of excitation light intensity on the kinetics of the bacteriorhodopsin photocycle were investigated. The earlier reported intensity-dependent changes at 410 and 570 nm are explained by parallel increases in two of the rate constants, for proton transfers to D96 from the Schiff base and from the cytoplasmic surface, without changes in the others, as the photoexcited fraction is increased. Thus, it appears that the pKa of D96 is raised by a cooperative effect within the purple membrane. This interpretation of the wild-type kinetics was confirmed by results with several mutant proteins, where the rates are well separated in time and a model-dependent analysis is unnecessary. Based on earlier results that demonstrated a structural change of the protein after deprotonation of the Schiff base that increases the area of the cytoplasmic surface, and the effects of high hydrostatic pressure and lowered water activity on the photocycle steps in question, we suggest that the pKa of D96 is raised by a lateral pressure that develops when other bacteriorhodopsin molecules are photoexcited within the two-dimensional lattice of the purple membrane. Expulsion of no more than a few water molecules bound near D96 by this pressure would account for the calculated increase of 0.6 units in the pKa.
Case history: Averison therapy for fire setting by a deteriorated schizophrenic

This report concerns a chronic, deteriorated schizophrenic patient whose persistent fire-setting behavior presented a major management problem. His verbal communications were generally incoherent. The fire-setting behavior was successfully eliminated by an aversive technique in which electric shocks were made contingent on setting fire to paper with a match. There has been no recurrence in nearly four years.
Rational inlet design for a portable atmospheric pressure ionization–mass spectrometer (API–MS)

Abstract Equations are derived that describe the gas-dynamic flow through three types of high pressure inlets into a vacuum system: (1) a sonic orifice inlet, (2) a sonic capillary inlet and (3) a pulsed sonic capillary inlet. These equations can be used for rational inlet design for portable atmospheric pressure ionization–mass spectrometers (API–MS) taking into account the optimum operating pressure of the mass filter and the pumping characteristics of the system.
Inhibition of lymphocyte mitogenesis by an arachidonic acid hydroperoxide

Incubation of murine spleen cells with the oxidation product of soybean lipoxidase-treated arachidonic acid results in profound inhibition of induction of proliferation and maturation of these cells. The active entity was shown to be the 15-hydroperoxide of arachidonic acid (15-HPAA). Inhibition of the enzymes of the cyclo-oxygenase pathway fails to disturb this effect, indicating that 15-HPAA is not a substrate for this series of enzymes. 15-HPAA produced in this manner interfered with RNA synthesis, DNA synthesis, and blastogenesis, while failing to exert cytotoxic effects on the cells themselves. A variety of lymphocyte subpopulations, distinguished by their responsiveness to a diverse group of mitogens, were all equally inhibited by the addition of 15-HPAA to culture. Addition of this agent even as late as 24 h after initiation of culture resulted in profound inhibition of the proliferative and differentiative responses of splenic B cells to bacterial lipopolysaccharide (LPS). Exposure of cells to 15-HPAA for 10-30 min was adequate to initiate inhibition, an event that exhibited marked temperature dependence. The effects of pre-incubation with 15-HPAA could not be reversed in its absence in recovery periods of up to 6 h prior to addition of LPS. The implications of these data with reference to cellular activation mechanisms are discussed.
13C nuclear magnetic resonance observations on the interaction between p-amidinophenylpyruvic acid and trypsin

Abstract The formation of an enzyme-inhibitor adduct between bovine trypsin and [2- 13 C] p -amidinophenylpyruvic acid has been investigated by 13 C NMR spectroscopy. The observation of a resonance at 100.8 ppm demonstrates that the hemiketal formed between the hydroxyl of serine-195 and the 2- 13 C carbon of p -amidinophenylpyruvic acid is sp 3 hybridized with no significant deviation from tetrahedral geometry. It is shown that stabilization of the hemiketal oxyanion if it occurs is less effective than in chloromethylketone inhibitor complexes. The tetrahedral adduct is stable from pH 3 to 8. The mechanisms of breakdown of the tetrahedral adduct at pH extremes are discussed.
Decision-theoretic perspective on racial mistrust

The work by Stanley et al. (1) reported these results. First, most respondents had pro-white scores on the implicit association test (IAT). Second, the target person's race did not affect ratings of trustworthiness (study 1) or investment decisions (study 2). Third, IAT scores predicted trust-related responses over participants.
An international trade model to capture linkages among supply-constrained economies

Abstract The development of a country's domestic and international markets depends on its own actions as much as on those of its trading partners. The study of market linkages is thus vital for policy making. Borrowing from the conceptual framework of Leontief's input-output analysis and from the national accounts equation, this paper presents a new model to calculate multilateral trade multipliers while minimizing data requirements. The novelty of the approach consists in the column-wise (supply-oriented) normalization of trade as opposed to the row-wise (demand-oriented) normalization that prevails in the literature. The explanatory power of the model has been successfully tested on data that refer to 1973–1974. Divergence from reality inevitably reflects the great fluidity that characterized trade during that period. Although most successful when applied to trade among supply-oriented economies (such as those of socialist or developing countries), at present empirical tests have been run only for a handful of OECD and OPEC countries.
Submarine hydrothermal vents and associated gradient environments as sites for the origin and evolution of life

Submarine hydrothermal vents are the only comtemporary geological environment which may be called truly primeval; they continue to be a major source of gases and dissolved elements to the modern ocean as they were to the Archean ocean. Then, as now, they encompassed a multiplicity of physical and chemical gradients as a direct result of interactions between extensive hydrothermal activity in the Earth's crust and the overlying oceanic and atmospheric environments. We have proposed that these gradients provided the necessary multiple pathways for the abiotic synthesis of chemical compounds, origin and evolution of ‘precells’ and ‘precell’ communities and, ultimately, the evolution of free-living organisms. This hypothesis is consistent with the tectonic, paleontological, and degassing history of the earth and with the use of thermal energy sources in the laboratory to synthesize amino acids and complex organic compounds. In this paper, we expand upon the geophysical, chemical, and possible microbiological analogies between contemporary and Archean hydrothermal systems and suggest several hypotheses, related to our model for the origin and evolution of life at Archean vents, which can be tested in present-day hydrothermal systems.
Collaborative Research in Sociology: Trends and Contributing Factors

To what extent do sociologists collaborate? Has this changed over time? What factors contribute to research collaboration among sociologists? To answer these questions, we examine trends in collaboration over a 70 year period and empirically test a variety of explanations for the increase in collaboration that we find. We analyze data collected from a stratified random sample of articles in two leading sociology journals between 1935 and 2005 (n = 1274). Most of our analyses are descriptive and display trends over time. However, we pool the data across all years and estimate logistic regression models to assess the relative contribution of various factors. We find that the importance of geographical location has been waning since the 1950s, although the growth in cross-place collaborations stagnated between 1980 and 2005. We find that quantitative research is more likely to be collaborative, as are projects requiring data collection, though this may change because the collaboration rate among secondary data users is increasing at a faster rate. We find no significant gender differences in rates of collaboration, although male sole-authorship remains the most common form of publication. We also find the institutional prestige of coauthors is typically higher than that of sole-authors. Our results elucidate the extent of collaboration in sociology and reveal how several factors have contributed to this major shift in work organization.
GHB Free Acid: II. Isolation and Spectroscopic Characterization for Forensic Analysis

A reference standard for gamma-hydroxybutyric acid (GHB) free acid is not commercially available, making its analysis in forensic exhibits more difficult. GHB free acid is typically encountered in aqueous solution and in the presence of the lactone, gamma-butyrolactone (GBL), presenting difficulty in Fourier transform infrared (FT-IR) analysis. The strong infrared (IR) absorptivity of the GBL carbonyl band, the shifting of the GBL carbonyl band in aqueous solutions, and the position of the O-H bend for water can mask the main carbonyl band for GHB free acid. Model solutions of beta-hydroxybutyric acid (BHB) and GBL were studied in order to further understand the masking of the GHB free acid carbonyl band in FT-IR analysis. The use of second derivative FT-IR spectroscopy was shown to provide resolution of the free acid carbonyl band, and a presumptive test for GHB free acid was developed and applied. An extension of this work included preparing, for use as a standard reference material, small amounts (< or = 10 mg) of GHB free acid. Preparation was based on the instantaneous reaction of GHB's sodium salt with a stoichiometric amount of hydrochloric acid in aqueous solution, and subsequent isolation of the free acid in neat liquid form. Both FT-IR and proton nuclear magnetic resonance spectra of the neat reference material were obtained and used to verify its identity. The isolation of GHB free acid from actual forensic exhibits is also presented, with identity confirmation using FT-IR.
Endothelial cells mediate the regeneration of hematopoietic stem cells

Recent studies suggest that endothelial cells are a critical component of the normal hematopoietic microenvironment. Therefore, we sought to determine whether primary endothelial cells have the capacity to repair damaged hematopoietic stem cells. Highly purified populations of primary CD31(+) microvascular endothelial cells isolated from the brain or lung did not express the pan hematopoietic marker CD45, most hematopoietic lineage markers, or the progenitor marker c-kit and did not give rise to hematopoietic cells in vitro or in vivo. Remarkably, the transplantation of small numbers of these microvascular endothelial cells consistently restored hematopoiesis following bone marrow lethal doses of irradiation. Analysis of the peripheral blood of rescued recipients demonstrated that both short-term and long-term multilineage hematopoietic reconstitution was exclusively of host origin. Secondary transplantation studies revealed that microvascular endothelial cell-mediated hematopoietic regeneration also occurs at the level of the hematopoietic stem cell. These findings suggest a potential therapeutic role for microvascular endothelial cells in the self-renewal and repair of adult hematopoietic stem cells.
Inflammatory bowel disease in pregnancy.

The term inflammatory bowel disease (IBD) refers to ulcerative colitis and Crohn's disease, two chronic conditions of unknown cause. Whereas the incidence of ulcerative colitis has remained stable, the incidence of Crohn's disease has increased during the past few decades. The consequence of this trend is a growing population of women in their childbearing years with concerns about the effects of IBD on fertility and pregnancy. Important issues concerning a woman with IBD who is pregnant or contemplating pregnancy include inheritance of IBD in the offspring, fertility, the effect of pregnancy on IBD, and, conversely, the effect of IBD on the pregnancy, as well as the safety of drugs on the developing fetus and nursing newborn. A male partner afflicted with IBD also raises concerns regarding fertility and potential teratogenicity of prescribed medications. This article reviews these issues with a focus on recent studies and developments.
Race Bending: "Mixed" Youth Practicing Strategic Racialization in California.

As more U.S. youth claim "mixed" heritages, some adults are proposing to erase race words altogether from the nation's inequality analysis. Yet such proposals, as detailed ethnography shows, ignore the complex realities of continuing racialized practice. At an urban California high school in the 1990s, "mixed" youth strategically employed simple "race" categories to describe themselves and inequality orders, even as they regularly challenged these very labels' accuracy. In so "bending" race categories, these youth modeled a practical and theoretical strategy crucial for dealing thoughtfully with race in 21st century America.
Comparison of available gum-elastic bougies.

Abstract Introduction The purpose of this study was to compare 4 different gum-elastic bougies (GEBs) for differences in success rate, speed of intubation, and device preference. Methods This was a randomized study of 4 different GEBs (Sunmed, Portex, Greenfield, and Eschmann) used by emergency medicine (EM) and anesthesiology residents and attending physicians on a simulated difficult airway model. Success, time to intubation, and personal preference were recorded for each participant. Data were compared with analysis of variance, χ2 and t tests, and 95% confidence intervals (95% CIs) where appropriate. P Results Twenty-one participants from EM (16 residents, 5 faculty) and 13 from anesthesia (9 residents, 4 faculty) were entered into the study. Overall success rates were 88% for Sunmed, 68% for Portex, 88% for Greenfield, and 79% for Eschmann. Participants were significantly more likely to be successful when using either the Sunmed or the Greenfield GEB compared with the Portex GEB (relative risk [RR] = 1.3, 95% CI = 1.0-15.6). Success rate by specialty was significantly different with 60 (71%) of 84 for EM physicians and 50 (96%) of 52 for anesthesiologists. Speed of intubation was a mean ± SD of 22.5 ± 9.7 seconds, with no significant difference by GEB or specialty. Participants were significantly more likely to prefer the Sunmed over the Greenfield (P = .001, RR = 6.9, 95% CI = 1.5-24.8) and the Eschmann over the Greenfield (P = .003, RR = 6.1, 95% CI = 1.6-63.0). Conclusion Emergency medicine physicians had better success rates using the Sunmed and Greenfield GEBs but low preference for the Greenfield GEB.
Honeycomb networks: Topological properties and communication algorithms

The honeycomb mesh, based on hexagonal plane tessellation, is considered as a multiprocessor interconnection network. A honeycomb mesh network with n nodes has degree 3 and diameter /spl ap/1.63/spl radic/n-1, which is 25 percent smaller degree and 18.5 percent smaller diameter than the mesh-connected computer with approximately the same number of nodes. Vertex and edge symmetric honeycomb torus network is obtained by adding wraparound edges to the honeycomb mesh. The network cost, defined as the product of degree and diameter, is better for honeycomb networks than for the two other families based on square (mesh-connected computers and tori) and triangular (hexagonal meshes and tori) tessellations. A convenient addressing scheme for nodes is introduced which provides simple computation of shortest paths and the diameter. Simple and optimal (in the number of required communication steps) routing, broadcasting, and semigroup computation algorithms are developed. The average distance in honeycomb torus with n nodes is proved to be approximately 0.54/spl radic/n. In addition to honeycomb meshes bounded by a regular hexagon, we consider also honeycomb networks with rhombus and rectangle as the bounding polygons.
Impaired Learning and Motor Behavior in Heterozygous Pafah1b1 (Lis1) Mutant Mice

Heterozygous mutation or deletion of Pafah1b1 (LIS1) in humans is associated with syndromes with type 1 lissencephaly, a severe brain developmental disorder resulting from abnormal neuronal migration. We have created Lis1 heterozygous mutant mice by gene targeting. Heterozygous mutant mice are viable and fertile, but display global organizational brain defects as a result of impaired neuronal migration. To assess the functional impact of the mutation, Lis1 heterozygous mice and their wild-type littermates were evaluated on a wide variety of behavioral tests. Lis1 mutant mice displayed abnormal hindpaw clutching responses and were impaired on a rotarod test. Lis1 heterozygous mice were also impaired in the spatial learning version of the Morris water task. Impaired motor behavior and spatial learning and memory in Lis1 mutant mice indicates that impaired neuronal migration can have functional effects on complex behavioral responses. The behavioral findings also support the use of the Lis1 mutant mice as a model from human type 1 lissencephaly.
Breaking the Cycle of Pain In Diabetic Peripheral Neuropathy

An attitude of helplessness pervades both patients and health professionals when dealing with the problems of dia betic peripheral neuropathy. Those afflicted are often over whelmed by the pain and find themselves unable to fulfill the daily requirements of their diabetes regimen. The in consistencies in amounts and timing of meals, levels of ac tivity, and scheduling of insulin injections can result in hyperglycemia, a state that has been found to correlate strongly with the occurrence of nerve damage. Thus the pain perpetrates itself. For the health professional, having to confront this devastating pain without objective factors to assess and few scientific treatment measures to offer con tributes to a sense of inadequacy and ignorance. It is fre quently assumed that "nothing can be done." In reality, health professionals do have something to offer the person suffering from this condition. First, they can provide infor mation about the relationship between control and compli cations, and explain the nee...
Extracting spatial knowledge from the web

The content of the World-Wide Web is pervaded by information of a geographical or spatial nature, particularly location information such as addresses, postal codes, and telephone numbers. We present a system for extracting spatial knowledge from collections of Web pages gathered by Web-crawling programs. For each page determined to contain location information, we apply geocoding techniques to compute geographic coordinates, such as latitude-longitude pairs. Next, we augment the location information with keyword descriptors extracted from Web page contents. We then apply spatial data mining techniques on the augmented location information to derive spatial knowledge.
Endovascular repair of ruptured and symptomatic abdominal aortic aneurysms using a structured protocol in a community teaching hospital.

Background Open abdominal aortic aneurysm (AAA) repair has gradually been replaced by endovascular aneurysm repair (EVAR). The primary objective of this study is to establish baseline mortality data and compare our institutional mortality rates for ruptured AAA patients with published rates from institutions using similar approaches. Methods This study is a retrospective review of 49 patients treated using a structured ruptured AAA (rAAA) protocol in a community teaching hospital. Variables examined include demographics, repair type, device used, presenting systolic blood pressure, presenting glomerular filtration rate, initial hematocrit, transfusions required, and development of postoperative abdominal compartment syndrome. Results Forty-nine patients were treated using the rAAA protocol and 48 underwent repair. The 30-day mortality for rAAA and symptomatic AAA (sAAA) was 36.4% (12/33) and 20.0% (3/15), respectively, with a mean mortality of 31.2% (15/48). Mortality for rAAA treated by EVAR was 32.0% (8/25). Mortality for rAAA in the open repair group was 33% (2/6). Conversion from EVAR to open procedure (3/48) or 6% resulted in 100% mortality (P = 0.266). The development of abdominal compartment syndrome was an absolute predictor of death as mortality was 100% (P Conclusions The management and endovascular repair of sAAA or rAAA can be improved at the community hospital level by the implementation of standardized protocols. Blood transfusions and development of postoperative abdominal compartment syndrome significantly increase mortality. Individual institutional knowledge of results is critical to effective process improvement and optimal patient outcomes.
Clustered disturbances lead to bias in large-scale estimates based on forest sample plots

Assessments from field plots steer much of our current understanding of global change impacts on forest ecosystem structure and function. Recent widespread observations of net carbon accumulation in field plots have suggested that terrestrial ecosystems may be a carbon sink, possibly resulting from climate change and/or CO(2) fertilization. We hypothesize that field plots may inadequately sample inherently rare mortality events, leading to bias when plot level measurements are scaled up to larger domains. In this study, we constructed a simple computer simulation model of forest dynamics to investigate the effects of disturbance patterns on landscape-scale carbon balance estimates. The model was constructed to be a balanced biosphere at the landscape-scale with a uniform spatial pattern of forest growth rates. Disturbance gap-size distributions across the landscape were modelled with a power-law distribution. Small and frequent disturbances result in a well-mixed heterogeneous forest where even small sample plots represented domain-wide behaviour. However, with disturbances dominated by large and rare events, sample plots as large as 50 ha displayed significant bias towards growth. We suggest that the accuracy of domain level estimates of carbon balance from sample plots are highly sensitive to the distribution of disturbance events across the landscape, and to the number, size and distribution of field plots that comprise the estimate. Assumptions that small clusters of field plots may be representative of domain-wide conditions should only be made very cautiously, and warrant further investigation for verification.
Latent Variable Bayesian Models for Promoting Sparsity

Many practical methods for finding maximally sparse coefficient expansions involve solving a regression problem using a particular class of concave penalty functions. From a Bayesian perspective, this process is equivalent to maximum a posteriori (MAP) estimation using a sparsity-inducing prior distribution (Type I estimation). Using variational techniques, this distribution can always be conveniently expressed as a maximization over scaled Gaussian distributions modulated by a set of latent variables. Alternative Bayesian algorithms, which operate in latent variable space leveraging this variational representation, lead to sparse estimators reflecting posterior information beyond the mode (Type II estimation). Currently, it is unclear how the underlying cost functions of Type I and Type II relate, nor what relevant theoretical properties exist, especially with regard to Type II. Herein a common set of auxiliary functions is used to conveniently express both Type I and Type II cost functions in either coefficient or latent variable space facilitating direct comparisons. In coefficient space, the analysis reveals that Type II is exactly equivalent to performing standard MAP estimation using a particular class of dictionary- and noise-dependent, nonfactorial coefficient priors. One prior (at least) from this class maintains several desirable advantages over all possible Type I methods and utilizes a novel, nonconvex approximation to the l0 norm with most, and in certain quantifiable conditions all, local minima smoothed away. Importantly, the global minimum is always left unaltered unlike standard l1-norm relaxations. This ensures that any appropriate descent method is guaranteed to locate the maximally sparse solution.
The role of computer models in the Grasshopper Integrated Pest Management Project

The Grasshopper Integrated Pest Management Project (GHIPM) is a $15 million project initiated in 1986 to identify, develop, and implement rangeland grasshopper management tactics within the framework of Integrated Pest Management (IPM) in the Western United States. Computer simulation has been used to fulfill many original objectives for GHIPM. For example, models have been developed and/or used to simulate grasshopper population dynamics, forage growth and destruction, and ranch economics. These models also have been used to structure and deliver knowledge to land managers who make decisions about grasshopper control. In addition, another group of computer simulation studies were developed to probe at basic mechanisms and understanding of rangeland grasshopper ecology. For example, an object-oriented simulation is being developed that can represent any number of unique grasshopper cohorts for specific species, life stages, and disease status. Soil temperature and moisture are also being simulated to support a grasshopper egg hatch model. All of these research models were designed for basic science with a focus on improving management of rangeland grasshoppers.
Gender Research as Labor Activism: The Women's Bureau in the New Era

On June 5, 1920, Congress established the Women's Bureau, charging it to “formulate standards and policies which shall promote the welfare of wage-earning women, improve their working conditions, increase their efficiency, and advance their opportunities for profitable employment.” Support for the bureau was such that the House passed the bill by a vote of 255 to 10, and the Senate passed it without a recorded vote, though the Monthly Labor Review noted that “there was some opposition.” During a decade when policymakers celebrated the fruits of economic abundance garnered with only the lightest touch from the state, bureau leaders and investigators saw gender research as a form of labor activism that would advance the cause of all workers. The bureau provided a unique site for discourse and deliberation concerning labor standards that did not exist in any other branch of the federal government. No other organization in the federal government thought harder about how policies could be constructed to protect workers, irrespective of gender, from the continued harsh reality of employment in American industry. Along the way, advocates of protective legislation for women sought not only to protect the particular interests of women workers, but also to drive a wedge through a post-Adkins understanding of the “right to contract” and to expand the number of issues that should be seen as affected with a public interest.
Arabidopsis Fragile Fiber8, Which Encodes a Putative Glucuronyltransferase, Is Essential for Normal Secondary Wall Synthesis

Secondary walls in vessels and fibers of dicotyledonous plants are mainly composed of cellulose, xylan, and lignin. Although genes involved in biosynthesis of cellulose and lignin have been intensively studied, little is known about genes participating in xylan synthesis. We found that Arabidopsis thaliana fragile fiber8 (fra8) is defective in xylan synthesis. The fra8 mutation caused a dramatic reduction in fiber wall thickness and a decrease in stem strength. FRA8 was found to encode a member of glycosyltransferase family 47 and exhibits high sequence similarity to tobacco (Nicotiana plumbaginifolia) pectin glucuronyltransferase. FRA8 is expressed specifically in developing vessels and fiber cells, and FRA8 is targeted to Golgi. Comparative analyses of cell wall polysaccharide fractions from fra8 and wild-type stems showed that the xylan and cellulose contents are drastically reduced in fra8, whereas xyloglucan and pectin are elevated. Further structural analysis of cell walls revealed that although wild-type xylans contain both glucuronic acid and 4-O-methylglucuronic acid residues, xylans from fra8 retain only 4-O-methylglucuronic acid, indicating that the fra8 mutation results in a specific defect in the addition of glucuronic acid residues onto xylans. These findings suggest that FRA8 is a glucuronyltransferase involved in the biosynthesis of glucuronoxylan during secondary wall formation.
Functional Status and Social Contact Among Older Adults

This article tests whether functional status is associated with likelihood of social contact among older adults. Data come from the Second Longitudinal Study on Aging, a longitudinal nationally representative sample of 9,447 noninstitutionalized individuals aged 70 and over at baseline in 1995. Functional status is measured using an index of activities of daily living (ADL) and instrumental activities of daily living (IADL). Social contact is measured by asking respondents whether they had gotten together socially or talked on the phone with friends/neighbors or family in the past 2 weeks. Greater number of functional limitations is associated with a decreased likelihood of social contact at follow-up via the phone with friends (odd ratio [OR] = 0.94, p < .01) and family (OR = 0.96, p < .01), and a decreased likelihood of getting together with friends (OR = 0.93, p < .01) and family (OR = 0.97, p < .01). Results indicate that functional limitations have a broad impact on self-reported social contact among...