cssi/SciSciGPT-SciSciNet huggingface dataset:
Changes in the soil C cycle at the arid-hyperarid transition in the Atacama Desert

[1] We examined soil organic C (OC) turnover and transport across the rainfall transition from a biotic, arid site to a largely abiotic, hyperarid site. With this transition, OC concentrations decrease, and C cycling slows precipitously, both in surface horizons and below ground. The concentration and isotopic character of soil OC across this transition reflect decreasing rates of inputs, decomposition, and downward transport. OC concentrations in the arid soil increase slightly with depth in the upper meter, but are generally low and variable (∼0.05%; total inventory of 1.82 kg m−2); OC-Δ14C values decrease from modern (+7‰) to very 14C-depleted (−966‰) with depth; and OC-δ13C values are variable (−23.7‰ to –14.1‰). Using a transport model, we show that these trends reflect relatively rapid cycling in the upper few centimeters, and spatially variable preservation of belowground OC from root inputs, possibly during a previous, wetter climate supporting higher soil OC concentrations. In the driest soil, the OC inventory is the lowest among the sites (0.19 kg m−2), and radiocarbon values are 14C-depleted (−365‰ to –696‰) but show no trend with depth, indicating belowground OC inputs and long OC residence times throughout the upper meter (104 y). A distinct depth trend in δ13C values and OC/ON values within the upper 40 cm at the driest site may reflect photochemical alteration of organic matter at the soil surface, combined with limited subsurface decomposition and downward transport. We argue that while root inputs are preserved at the wetter sites, C cycling in the most hyperarid soil occurs through infrequent, rapid dissolved transport of highly photodegraded organic matter during rare rain events, each followed by a pulse of decomposition and subsequent prolonged drought. These belowground inputs are likely a primary control on the character, activity, and depth distribution of small microbial populations. While the lack of water is the dominant control on C cycling, very low C/N ratios of organic matter suggest that when rainfall occurs, hyperarid soils are effectively C limited. The preservation of fossil root fragments in the sediment beneath the driest soil indicates that wetter climate conditions preceded formation of this soil, and that vadose zone microbial activity has been extremely limited for the past 2 My.
Failure of Pentamidine Isethionate to Provide Chemoprophylaxis against Pneumocystis carinii Infection in Rats

Latent Pneumocystis carinii infections were exacerbated in 54 adult male Sprague-Dawley rats by administration of alternating subcutaneous doses of hydrocortisone-21-phosphate and of cortisone acetate three times a week, plus 0.5% chlortetracycline in their drinking water, until death or the termination of the experiment at 120 days. Twenty-eight of the rats were also given pentamidine isethionate (4mg/kg) intramuscularly daily for 14 days. Pentamidine-treated animals that died within the 120 days of the experiment survived longer than control animals. At necropsy, however, every animal in both groups had P. carinii in the lungs. The intensity of the infection was the same in the pentamidine-treated and control groups. Pentamidine isethionate administered in this standard regimen does not exert a significant chemoprophylactic effect against proliferation of P. carinii in rats. The study provides little encouragement for use of pentamidine as a prophylactic agent against P. carinii in high-risk patients.
Stability of general relativistic gaseous masses and variational principles

The Einstein field equations for a self-gravitating fluid that obeys an equation of state of the formp=p(w),p the pressure andw the energy density may be derived from a variational principle. The perturbations of the metric tensor and the fluid dynamic variables satisfy equations which may be derived from a related variational principle, namely the principle associated with the “second variation problem.” It is shown that the variational principle given by Chandrasekhar from which a sufficient criterion may be obtained for deciding when a self gravitating spherical gaseous mass is unstable against spherically symmetric perturbations is that given by the “second variation problem”. It is further shown that this criterion is equivalent to requiring that the integral entering into the second variation be negative. The latter form of the criterion may be used in general situations.
Prepuberal Estrogen Treatment and Somatic Growth in Rats

Male and female rats receiving estradiol from weaning to early adulthood displayed a reduction in body weight gain and skeletal growth over the entire treatment period. At 76 days of age exogenous estrogen was discontinued and bilateral ovariectomies were performed on the females. The 17-week posthormone period was characterized by an accelerated rate of growth of both sexes; however, only the male rats had posthormone growth rates that indicated total compensation for the early depressant effects of estrogen. These results argue against recent proposals suggesting that mechanisms regulating the body weight and growth of rats are insensitive to estrogen until the onset of natural puberty. It is not clear from the present work what mechanism is responsible for the reduced growth. However, the similarities of the somatic growth effects of estradiol, as noted here, and the effects of undernutrition on young rats suggest that hypophagia may cause the depression of growth noted during estrogen treatment. (Endo...
Effect of selenium on methionine formation in vivo and in vitro.

The effect of chronic selenosis on methionine and cystine content in liver of experimental animals was studied. The decrease in methionine in chronic selenosis was not associated with restricted food intake and sub sequent starvation. In in vitro experiments, using rat liver homogenate, sodium selenate and selenite inhibited transmethylation reactions of homocystine and homocysteine by betaine and choline. Selenite was a more active biological inhibitor than selenate. The significance of the results was discussed with reference to the detoxification mechanism in selenium poisoning in animals.
Mammoth: autonomic data processing framework for scientific state-transition applications

Scientific computing is becoming increasingly data-intensive, and more high-impact discoveries are relying on efficient processing of big scientific data. The popular MapReduce framework such as Hadoop offers an alternative to conventional solutions (e.g., MPI or OpenMP). However, they perform moderately when processing state-transition applications. There are three key challenges: (1) these applications generate the inflated intermediate data that may saturate the network; (2) they may cause substantial synchronization overheads if not managed well; (3) dynamically evolving scientific phenomena result in heterogeneous data distributions, causing significant computation skews. In this paper, we propose Mammoth, an autonomic parallel data processing framework for scientific state-transition applications. Mammoth features a MapReduce-style programming model that is familiar to users. To address the challenges mentioned, it is further enhanced with a series of optimizations that parallelize the computation automatically and efficiently. We evaluate Mammoth via a weather prediction application with real-world datasets. The experimental evaluation demonstrates that Mammoth is competitive with the MPI-based solution and at least 30% faster than the optimized Hadoop-based solution.
LMI control design for nonlinear vapor compression cycle systems

To effectively control vapor compression cycle (VCC) systems whose dynamics are highly nonlinear, it is necessary to develop plant models and control laws for different operating regions. This paper presents a first-principles modeling framework that captures four operation modes over the operating envelope to construct an invariant-order switched system. To synthesize a multi-input multi-output (MIMO) control system, the Linear Quadratic Regulator (LQR) technique is framed as a control optimization problem with Linear Matrix Inequality (LMI) constraints which can be simultaneously solved for the set of considered linear systems. Stability and performance characteristics of the controlled system are guaranteed using a common quadratic Lyapunov function. Simulation results in a case study show that the LMI-based controller can maintain system operation at optimal set-points with mode switching over a wide operating envelope.Copyright © 2012 by ASME
Priming effects of a reconciliation radio drama on historical perspective-taking in the aftermath of mass violence in Rwanda

Abstract A field experiment in Rwanda investigated the impact of a radio drama designed to increase perspective-taking with regard to the history of intergroup conflict. An audio-based priming technique was used to assess the causal impact of the radio drama. Rwandan participants ( N = 842) listened to an audio-delivered questionnaire recorded either in the voice of a main character of the radio drama (experimental priming condition) or an unknown actor (control condition). Participants primed with the radio drama reported higher levels of historical perspective-taking, engaged less in competitive victimhood, and expressed less mistrust toward the out-group. Overall, the findings suggest that fictional radio dramas can be used to address opposing historical narratives in the aftermath of violent conflict. Additionally, the study demonstrates the usefulness of a priming paradigm to assess causal influence of mass media interventions.
A numerical method for improving the reliability of knee translation measurement in skin marker-based motion analysis

In skin-marker based motion analysis, knee translation measurement is highly dependent on a pre-selected reference point (functional center) on each segment determined by the location of anatomical landmarks. However, the placement of skin markers on palpable anatomical landmarks (i.e., femoral epicondyles) has limited reproducibility. Thus, it produces large variances in knee translation measurement among different subjects, as well as across studies. In order improve the repeatability of knee translation measurement, in this study an optimization method was introduced, by which the femoral functional center was numerically determined. At that point the knee anteroposterior translation during the stance phase of walking was minimized. This new method was tested on 30 healthy subjects during walking in gait lab with motion capture system. Using this new method, the impact of skin marker position (at anatomical landmarks) on the knee translation measurement has been minimized. In addition, the ranges of anteroposterior knee translations during stance phase were significantly (p<0.001) smaller than those measured by conventional method which relies on a pre-selected functional center (11.1±3.5 mm vs. 19.9±5.5 mm). The results of anteroposterior translation using this new method were very close to a previously reported knee translation (12.4 mm) from dual fluoroscopic imaging technique. Moreover, this new method increased the reproducibility of knee translation measurement by 50%.
Nonsteroidal antiinflammatory drug use and risk of bladder cancer in the health professionals follow‐up study

Nonsteroidal antiinflammatory drugs (NSAIDs) use, particularly aspirin, may lower the risk of several cancers, including bladder. NSAIDs may reduce development of bladder tumors by decreasing inflammation, inhibiting cycloxygenase-2, inhibiting proliferation and inducing apoptosis of cancer cells. However, acetaminophen, a major metabolite of phenacetin, may be positively associated with bladder cancer risk. Results from case-control studies on NSAIDs and acetaminophen use and bladder cancer risk are inconsistent. We investigated the association between NSAID and acetaminophen use and bladder cancer risk in a large cohort of US males. Among 49,448 men in the Health Professionals Follow-Up Study, 607 bladder cancer cases were confirmed during 18 years of follow-up. Relative risks (RR) and 95% confidence intervals (CI) were calculated by Cox proportional hazards models. Multivariate RR were adjusted for age, current smoking status, pack years, geographic region and fluid intake. No significant associations were observed for regular aspirin (> or =2 tablets per week), (RR = 0.99, 95% CI 0.83-1.18), ibuprofen (RR = 1.11, 95% CI 0.81-1.54), acetaminophen (RR = 0.96, 95% CI 0.67-1.39) or total NSAID use (not including acetaminophen; RR = 1.01, 95% CI 0.85-1.20) and bladder cancer risk compared with nonuse. Consistent use (over 6 years) of aspirin, ibuprofen, acetaminophen and total NSAIDs, compared to nonuse, was not associated with bladder cancer risk. No association was observed between aspirin frequency and dose and bladder cancer risk. We observed no effect-modification by smoking, age or fluid intake. Our results suggest that regular NSAID or acetaminophen use has no substantial impact on bladder cancer risk among men.
Environmental Conditions Controlling Selenium Volatilization from a Wetland System

Natural selenium volatilization from Benton Lake, MT, a wetland system containing moderate levels of selenium, was studied in water−sediment, water−sediment with a flood ing−drying cycle, and plant−water−sediment microcosms. Results showed that selenium volatilization occurred from water, sediment, and wetland plants. Sediment and plants were the major producers of volatile selenium from the system. The rate of selenium volatiliza tion from algae and high-selenium sediment was much higher than that from watermilfoil and low-selenium sediment. The rate was also controlled by various environmental factors. Higher temperature, higher air flow, flooding−drying and the decomposition of wetland plants greatly increased the removal rates of selenium through selenium volatilization. Our results suggest that natural selenium volatilization can be an important process removing selenium from wetland systems.
Androgen Receptor Gene Polyglutamine Length is Associated With Testicular Histology in Infertile Patients

ABSTRACTPurpose: Androgens and a functioning androgen receptor are required for normal spermatogenesis. The androgen receptor gene (AR) has a repetitive DNA sequence in exon 1 that encodes a polyglutamine tract. Within the normal polymorphic range this (CAG)n tract length is inversely related to the transcriptional activity of the androgen receptor. In a prospective analysis we determined the association of AR (CAG)n tract length with testicular histology in infertile males.Materials and Methods: Blood DNA from 70 severely infertile patients without obstruction who were undergoing testicular biopsy was amplified by polymerase chain reaction targeting the AR (CAG)n tract. A total of 37, 15 and 18 men presented with the Sertoli-cell-only syndrome, maturation arrest and hypospermatogenesis, respectively. Blood DNA from 55 fertile men served as the control. Polymerase chain reaction amplified DNA was direct sequenced using a genetic analyzer.Results: Median CAG repeat length was 22 (range 17 to 33) in inferti...
A larval brush-footed butterfly (Lepidoptera: Nymphalidae) in Dominican amber, with a summary of fossil Nymphalidae

The first fossil member of the family Nymphalidae (Lepidoptera) in Dominican amber and the first fossil nymphalid caterpillar is placed near the genus Smyrna of the tribe Coloburini (Nymphalinae) on the basis of the morphology, position and arrangement of its spines. The larva is regarded as prototypic ancestor near the Pycina-Vanessa lineage and its closest descendants probably occur in Central and South America, thus illustrating yet another case of disjunct distribution in the Dominican amber fauna. This represents the second family of butterflies reported from Dominican amber (previously only the Riodinidae). A summary of the confirmed cases of fossil Nymphalidae is presented.
Head to head polymers. XXIX: A new synthetic route to poly (1,1-dimethylpropane)

Poly(1,1-dimethylpropane) was synthesized by Wurtz coupling polymerization. The polymer was of moderate molecular weight, about 50% crystalline, had a melting temperature of 87°C and a glass transition temperature of −17°C. The polymer was essentially the same material as that obtained by cationic hydride transfer polymerization of 3-methylbutene-1 at very low temperatures, or by cationic ring opening polymerization of 1,1-dimethylcyclopropane. Poly(1,1-dimethylpropane) obtained by the Wurtz reaction was obtained in only low yield; a substantial part of the total reaction product was 1,1-dimethylcyclopropane. Poly(1,1-dimethylpropan) wurde mittels der Wurtzschen Reaktion synthetisiert. Das erhaltene Polymer hat nur masige relative Molekulmasse, ist zu etwa 50% kristallin und hat eine Schmelztemperatur von 87°C sowie eine Glasubergangstemperatur von −17°C. Das Polymer ist im wesentlichen das gleiche Material, das durch kationische Hydrid-transfer-Polymerisation von 3-Methyl-buten-1 bei niedrigen Temperaturen oder durch kationische Ringoffnungs-polymerisation von 1,1-Dimethylcyclopropan erhalten wird. Poly(1,1-dimethylpropan) wurde nach der Wurtzschen Synthese nur in niedriger Ausbeute erhalten; ein wesentlicher Teil des Reaktionsproduktes war 1,1-Dimethylcyclopropan.
VLSI Processing, Radiation, and Hardening

Process-induced radiation damage to silicon dioxide films is expected to be commonplace for VLSI circuit fabrication. This might be expected to be most serious for the production of radiation-hardened VLSI. In this paper, the oxide damage due to ion processing is reviewed and the radiation levels associated with advanced lithographic techniques are estimated. Implications for radiation-hardened VLSI circuits are considered.
From mission planning to flight control of unmanned aerial vehicles: Strategies and implementation tools

Abstract This paper reviews aspects of unmanned aerial vehicle (UAV) autonomy as suggested by the Autonomous Control Logic chart of the U.S. DoD UAV autonomy roadmap; levels of vehicle autonomy addressed through intelligent control practices and a hierarchical/intelligent control architecture are presented for UAVs. Basic modules of the control hierarchy and their enabling technologies are reviewed; of special interest, from an intelligent control perspective, are the middle and high echelons of the hierarchy. Here, mission planning, trajectory generation and vehicle navigation routines are proposed for the highest level. At the middle level, the control role is portrayed by mode transitioning, envelope protection, real-time adaptation and fault detection/control reconfiguration algorithms which are intended to safeguard the UAV's integrity in the event of component failures, extreme operating conditions or external disturbances. The UAV thus exhibits attributes of robustness and operational reliability assuring a satisfactory degree of autonomy. The control technologies are demonstrated through flight testing results.
Accessing 3D memory information by means of nonlinear absorption

A novel method for accessing information from two-photon 3D volume memory devices is presented. We have used the decrease in laser intensity induced by two-photon absorption as the means for reading 3D information. The ratio of the initial laser intensity to the intensity after two-photon absorption is increased drastically by passing both beams through a second and fourth harmonic crystal. This means eliminates the need for focusing and collecting lenses and the disadvantages associated with the fluorescence method of reading information.
Structure and function of the hamster corpus luteum during the estrous cycle

Luteal cell structure and function were studied by electron microscopy in conjunction with measurement of progesterone production by corpora lutea which were isolated and incubated in vitro on successive days of the four-day hamster estrous cycle. Granulosal cells were primarily responsible for the formation of the corpus luteum. Agranular endoplasmic reticulum and lipid droplets developed during luteinization of granulosal cells on the first post-ovulation day (day 1). Luteal cell hypertrophy on day 2 resulted from dilation of tubular agranular endoplasmic reticulum and swelling of mitochondria with tubular cristae. Plasma progesterone levels on the first two days of the cycle appeared to be correlated with luteal activity as corpora lutea were demonstrated to synthesize progesterone during this interval. Luteolysis occurred on day 3 with a reduction in luteal cell size accompanied by condensation of the agranular endoplasmic reticulum, regressive changes in the mitochondria, and a marked drop in luteal progesterone synthetic activity. On day 4, extensive phagocytic activity and luteal cell autolysis indicated an advanced involutional state. The short but functional luteal phase in the cyclic hamster does not appear to involve the production of 20α-hydroxy-pregn-4-en-3-one as occurs in the rat. This progestin was not detectable in plasma or luteal tissue before or after incubation at any time during the cycle. Possible mechanisms regulating luteal cell development and regression during the estrous cycle are discussed.
Cooperative receding horizon control for multi-target interception in uncertain environments

In this paper, the problem of cooperative dynamic vehicle routing for tracking a set of moving objects with unknown trajectories and dynamics is investigated. The notion of “meeting a target” is defined to describe the tasks and a cooperative receding horizon controller is designed to address the problem. The design is based on the prediction of the future positions of targets with limited information, and a reward allocation strategy for accomplishing the defined tasks. A target tracking scenario is considered, where a sequence of targets arrive in the mission space. It is shown that the number of targets which are not met by any vehicle will remain sufficiently small in time, if the arrival of the targets is sufficiently sufficiently infrequent.
Symmetric Stretching Vibrations of Two-Coordinate Oxygen Bridges as a Cause for Negative Thermal Expansion in ZrVxP2−xO7andAW2O8(A=Zr, Hf) at High Temperature

Abstract To examine the origin of negative thermal expansion in oxides ZrV x P 2− x O 7 ( x =0–2) and A W 2 O 8 ( A =Zr, Hf), ab initio self-consistent-field molecular orbital calculations were carried out for a model compound (HO) 3 P–O–P(OH) 2+ 3 . Our study suggests that symmetric stretching vibrations of two-coordinate oxygen bridges are strongly coupled with their bending vibrations and are more important for negative thermal expansion at high temperature. The oxygen bridges accomodate a large stretching of the A –O ( A =Zr, Hf) and M –O ( M =P,V) bonds at high temperature by decreasing the bond angles of the oxygen bridges. When the bond angles increase, the bonds are shortened due to the π-type orbital interactions associated with the oxygen lone pair orbitals.
Isotope effect in the Hubbard model with local phonons

The isotope effect (IE) in the two-dimensional Hubbard model with Holstein phonons is studied using the dynamical cluster approximation with quantum Monte Carlo. At small electron-phonon (EP) coupling the IE is negligible. For larger EP coupling there is a large and positive IE on the superconducting temperature that decreases with increasing doping. A significant IE also appears in the low-energy density of states, kinetic energy, and charge excitation spectrum. A negligible IE is found in the pseudogap and antiferromagnetic (AF) properties at small doping, whereas the AF susceptibility at intermediate doping increases with decreasing phonon frequency ${\ensuremath{\omega}}_{0}$. This IE stems from increased polaronic effects with decreasing ${\ensuremath{\omega}}_{0}$. A larger IE at smaller doping occurs due to stronger polaronic effects determined by the interplay of the EP interaction with stronger AF correlations. The IE of the Hubbard-Holstein model exhibits many similarities with the IE measured in cuprate superconductors.
A brief survey of the effects of potential antimetabolites and enzymes on the development of giant silkmoths

Abstract More than 150 common purines, pyrimidines, purine and pyrimidine derivatives, and vitamin analogues were analysed for effects on insect growth and development. Compounds were injected into diapausing pupae of Samia cynthia and into pupae of Callosamia promethea just prior to the initiation of adult development. Most compounds were ineffective (e.g. uracil, 8-azaxanthine) or toxic (e.g. 6-methyl uracil, hypoxanthine). However, two classes of compounds had striking morphogenetic effects: the methyl xanthines (caffeine, theophylline, and theobromine) and barbituric acid and some of its analogues. The methyl xanthines prevented initiation of adult development but were not toxic to pupae, many of which lived more than 2 months after injection. These compounds specifically attacked the insect's central nervous system, causing extensive degenerative changes in the brain and segmental ganglia. They prevented adult development by damaging neurosecretory mechanisms within the brain. Barbituric acid and certain of its analogues (e.g. 5-amino uracil, 4,6-dihydroxy-pyrimidine, 1,3-dimethyl uracil, 6-methyl thiouracil) caused striking changes in the epidermis of developing adults but seemed to have little effect on the rest of the insect. The adults that emerged were almost devoid of scales, and the scales that did form were small and misshapen. Several proteases, esterases, and nucleases were also assayed for effects on development. Ribonuclease proved especially interesting, because in sublethal doses it caused abnormalities of the epidermis strikingly similar to those produced by barbituric acid. These results, and other evidence, suggest that both barbituric acid and ribonuclease interfere with the RNA metabolism of epidermal cells.
Characterization of micropacked alkyl-bonded silica columns for gas chromatographic analyses of light hydrocarbons in planetary atmospheres

Abstract Micropacked columns of different types of chemically bonded n-octyl- and n-octadecyl stationary phases were prepared and evaluated for the separation of light hydrocarbons under isothermal conditions. Column selectivities and efficiencies varied with surface coverage and the functionality of the silanizing agents. As might be expected, solute retentions are higher on the C18 phases than on the C8 phases due to the increased effective interactive surface between the solute and the stationary phase. Among the phases examined, the polymeric n-octadecyl packings gave the highest plate number and better retention characteristics for the test solutes. The H versus u plots obtained revealed the applicability of the columns for fast analysis at low linear carrier-gas velocities and correspondingly low volumetric flow-rates without any substantial loss in efficiency. Within the temperature range investigated, thermal-stability experiments indicate that the polymeric n-octadecyl phase can be used at temperatures up to 250°C with little or no column bleed.
Hominin Obstetrics and the Evolution of Constraints

Birth is significantly more complicated and dangerous in modern humans than in other great apes. This disparity is often hypothesized to be the result of evolutionary constraints on obstetric dimensions related to bipedalism and/or thermoregulation in later hominins. Previous attempts to test such hypotheses have used biomechanical methods and results have been mixed. But evolutionary constraints, restrictions or limitations on the course or outcome of evolution, are the result of an interaction between selective pressures and genetic constraints—the latter revealed in patterns of integration. Integration between traits can result in directional or stabilizing selection on one trait leading to correlated responses in other traits, which can bias and constrain evolutionary trajectories. Therefore, trait evolution may be constrained for reasons separate from those that can be estimated using biomechanical models, and to study evolutionary constraints it is necessary to understand the role genetic constraints play in morphological change. The results presented here show that genetic constraints can significantly reduce the evolutionary potential of the birth canal to evolve in humans, apes, and likely earlier hominins, but also point to an overall reduction in the level of constraints during hominin evolution. These findings suggest that divergent selection pressures for obstetric requirements and other pelvic functions in hominins reduced levels of genetic constraint on birth canal evolution, likely lowering the amount of time needed for evolutionary change, and permitting morphological evolution along a trajectory that might have previously been difficult or impossible to traverse.
Surface analysis of organic materials with TOF-SIMS

Abstract The application of TOF-SIMS to the study of organic materials, primarily polymers, is reviewed. A description of instrumentation is given along with the types of ions formed in the SIMS process. Metastable ions are formed in reasonable abundance for fluoropolymers. The fragmentation mechanisms for large polymers are discussed with particular emphasis on their importance for interpretation of polymer derived spectra. Two other major topics covered are quantitative analysis and use of derivatizing reagents.
Endourologic therapy of bladder calculi in simultaneous kidney-pancreas transplant recipients

Objectives. To identify the incidence and the success of endourologic therapy for symptomatic bladder-related calculi in simultaneous kidney-pancreas (SPK) transplant patients with bladder drainage. Methods. A retrospective review of 300 SPK transplant patients with bladder drainage, treated at the University of Wisconsin, Madison from December 1985 to November 1995, is presented. A 3% incidence of bladder calculi was identified. All patients underwent cystolitholapaxy using electrohydraulic lithotripsy and endoscopic suture removal. Follow-up ranged from 15 to 86 months. Results. A 100% stone-free rate was achieved after cystolitholapaxy and endoscopic suture removal. Two patients (22%) developed postprocedural urinary tract infections. No pancreaticoduodenocystotomy leaks or further complications were identified. Conclusions. SPK transplant patients with nonabsorbable sutures used for the duodenocystotomy anastomosis are at an increased risk for bladder calculi. Cystolitholapaxy with electrohydraulic lithotripsy is a safe and effective treatment for these suture-related stones.
Strategy and History: The Soviet Approach to Military History and Its Implications for Military Strategy

(1990). Strategy and history: The soviet approach to military history and its implications for military strategy. The Journal of Soviet Military Studies: Vol. 3, No. 3, pp. 409-445.
Temporal variations of wall shear stress parameters in intracranial aneurysms—importance of patient-specific inflow waveforms for CFD calculations

To assess reliability of wall shear stress (WSS) calculations using computational fluid dynamics (CFD) dependent on inflow in internal carotid artery aneurysms (ICA). Six unruptured ICA aneurysms were studied. 3D computational meshes were created from 3D digital subtraction angiographic images (Axiom Artis dBA, Siemens Medical Solutions). Transient CFD simulations (Fluent, ANSYS Inc.) were performed for two inflow conditions: (1) idealized averaged waveform from normal subjects (ID) and (2) patient-specific waveform (PS) measured with 2D phase contrast magnetic resonance imaging. Stability of calculation was assessed by comparing mean WSS ( ), temporal wall shear stress magnitude variation (ΔWSS), and oscillatory shear index (OSI, a measure of variation in the WSS direction) on the aneurysmal wall for both conditions. For all cases, mean relative difference (PS−ID) of WSS ( ) was −15% (range −32% to 11%). Mean ΔWSS difference was −29.3% ( −100% to 67%). Mean OSI difference was 7.5% (−12% to 40%). Large variations in histograms of these parameters were noted. For accurate calculations of WSS parameters, patient-specific information on physiological flow may be necessary. Results obtained with averaged or idealized flow waveforms may have to be interpreted with caution.
Oxygen Levels Do Not Determine Radiation Survival of Breast Cancer Stem Cells

For more than a century oxygen has been known to be one of the most powerful radiosensitizers. However, despite decades of preclinical and clinical research aimed at overcoming tumor hypoxia, little clinical progress has been made so far. Ionizing radiation damages DNA through generation of free radicals. In the presence of oxygen these lesions are chemically modified, and thus harder to repair while hypoxia protects cells from radiation (Oxygen enhancement ratio (OER)). Breast cancer stem cells (BSCSs) are protected from radiation by high levels of free radical scavengers even in the presence of oxygen. This led us to hypothesize that BCSCs exhibit an OER of 1. Using four established breast cancer cell lines (MCF-7, T47D, MDA-MB-231, SUM159PT) and primary breast cancer samples, we determined the number of BCSCs using cancer stem cell markers (ALDH1, low proteasome activity), compared radiation clonogenic survival and mammosphere formation under normoxic and hypoxic conditions, and correlated these results to the expression levels of key members of the free radical scavenging systems. The number of BCSCs increased with increased aggressiveness of the cancer. This correlated with increased radioresistance (SF8Gy), and decreasing OERs. When cultured as mammospheres, breast cancer cell lines and primary samples were highly radioresistant and not further protected by hypoxia (OER∼1). We conclude that because BCSCs are protected from radiation through high expression levels of free radical scavengers, hypoxia does not lead to additional radioprotection of BCSCs.
Flow stress, strain rate, strain relationships in superplastic deformation

The superplastic deformation of materials has commonly been characterized by the strain rate sensitivity, m, determined from two-dimensional, flow stress against strain rate plots. For material in which flow stress varies with strain or because of microstructural changes due to time at a high temperature, superplastic deformation must be characterized with respect to a three dimensional plot in which strain or time is the third axis. Techniques for generating the necessary plots are indicated and a simple experimental method for determining the suitability of a given material to a particular forming operation is described.
The preparation of alpha-halo-beta, beta-difluorostyrenes

Abstract Halogenation of β,β-difluorostyrene gave excellent yields of PhCHXCF 2 X (X=Cl, Br). Li 2 CO 3 /DMF, NaOEt/EtOH, and KOBu/hexane promoted dehydrohalogenation of PhCHXCF 2 X (X=Cl, Br) gave reasonably good isolated yields of the titled olefins.
DYNAMICAL BEHAVIOR OF THE HIV-1 NUCLEOCAPSID PROTEIN

Abstract The HIV-1 nucleocapsid protein (NC) contains two CCHC-type zinc knuckle domains that are essential for genome recognition, packaging and infectivity. The solution structure of the protein has been determined independently by three groups. Although the structures of the individual zinc knuckle domains are similar, two of the studies indicated that the knuckles behave as independently folded, non-interacting domains connected by a flexible tether, whereas one study revealed the presence of interknuckle NOE cross-peaks, which were interpreted in terms of a more compact structure in which the knuckles are in close proximity. We have collected multidimensional NMR data for the recombinant, isotopically labeled HIV-1 NC protein, and confirmed the presence of weak interknuckle NOEs. However, the NOE data are not consistent with a single protein conformation. 15 N NMR relaxation studies reveal that the two zinc knuckle domains possess different effective rotational correlation times, indicating that the knuckles are not tumbling as a single globular domain. In addition, the 1 H NMR chemical shifts of isolated zinc knuckle peptides are very similar to those of the intact protein. The combined results indicate that the interknuckle interactions, which involve the close approach of the side-chains of Phe16 and Trp37, are transitory. The solution behavior of NC may be best considered as a rapid equilibrium between conformations with weakly interacting and non-interacting knuckle domains. This inherent conformational flexibility may be functionally important, enabling adaptive binding of NC to different recognition elements within the HIV-1 Ψ-RNA packaging signal.
Urban Service Providers' Perspectives on School Responses to Gay, Lesbian, and Questioning Students: An Exploratory Study

Perspectives regarding bullying of gay, lesbian, and questioning (GLQ) students were obtained from 16 school and community service providers in this exploratory study. Insights were gained regarding in-school responses to homophobic bullying threats beyond traditional punishments (e.g., suspension). Barriers to developing safe schools for GLQ students included passive school personnel, a conservative religious climate, victim blaming, and blindness to GLQ students. Facilitators to improving school climate and preventing GLQ bullying also were identified.
Molecular and Functional Analysis of the lepB Gene, Encoding a Type I Signal Peptidase from Rickettsia rickettsii and Rickettsia typhi

The type I signal peptidase lepB genes from Rickettsia rickettsii and Rickettsia typhi, the etiologic agents of Rocky Mountain spotted fever and murine typhus, respectively, were cloned and characterized. Sequence analysis of the cloned lepB genes from R. rickettsii and R. typhi shows open reading frames of 801 and 795 nucleotides, respectively. Alignment analysis of the deduced amino acid sequences reveals the presence of highly conserved motifs that are important for the catalytic activity of bacterial type I signal peptidase. Reverse transcription-PCR and Northern blot analysis demonstrated that the lepB gene of R. rickettsii is cotranscribed in a polycistronic message with the putative nuoF (encoding NADH dehydrogenase I chain F), secF (encoding protein export membrane protein), and rnc (encoding RNase III) genes in a secF-nuoF-lepB-rnc cluster. The cloned lepB genes from R. rickettsii and R. typhi have been demonstrated to possess signal peptidase I activity in Escherichia coli preprotein processing in vivo by complementation assay.
Haptic Perception with an Articulated, Sensate Robot Hand

In this paper we present a series of haptic exploratory procedures, or EPs, implemented for a multi-fingered, articulated, sensate robot hand. These EPs are designed to extract specific tactile and kinesthetic information from an object via their purposive invocation by an intelligent robotic system. Taken together, they form an active robotic touch perception system to be used both in extracting information about the environment for internal representation and in acquiring grasps for manipulation. The theory and structure of this robotic haptic system is based upon models of human haptic exploration and information processing. The haptic system presented utilizes an integrated robotic system consisting of a PUMA 560 robot arm, a JPL/Stanford robot hand, with joint torque sensing in the fingers, a wrist force/torque sensor, and a 256 element, spatially-resolved fingertip tactile array. We describe the EPs implemented for this system and provide experimental results which illustrate how they function and how the information which they extract may be used. In addition to the sensate hand and arm, the robot also contains structured-lighting vision and a Prolog-based reasoning system capable of grasp generation and object categorization. We present a set of simple tasks which show how both grasping and recognition may be enhanced by the addition of active touch perception.
The Changing Poetics of the Dissolve in Hollywood Film

Most films contain many shots knit together by several types of transitions, and by far the most prevalent is the cut. Over the last 70 years, fades and wipes have become increasingly rare. Dissolves have also diminished in frequency but, unlike the others, they remain an important part of the general visual narrative and have shown a small increase in contemporary film. We tracked the usage of dissolves in 150 films released from 1935 to 2005. We found: (a) that after a lull between 1970 and 1990, dissolves have become more numerous, although not nearly so common as during the studio era; (b) that shots surrounding single dissolves are fairly long compared to the median shot lengths of a given film, suggesting visual preparation for scene change before a dissolve, and a re-acceleration after; and (c) that after their nadir, dissolves have increasingly reappeared in clusters reflecting a rebirth of the Hollywood montage. We also discuss the functions and meanings of these montage sequences in the stream of a film’s narrative, with more contemporary films focusing on setups, altered mental states, and celebrations rather than older films’ focus on travel and time gaps of various sizes.
Ahnea , a new genus from New Zealand (Coleoptera: Staphylinidae: Pselaphinae), with description of a new species

Ahnea keejeongi Park and Carlton (Coleoptera: Staphylinidae: Pselaphinae), a new genus and new species of New Zealand endemic beetle belonging to the supertribe Faronitae is described. Six previously described species are included to this genus and four species are synonymised as follow: Sagola dissonans Broun, 1921 and S. planicula Broun, 1921 under Ahnea ventralis (Broun, 1912 ); S. carinata Broun, 1912 and S. lineiceps Broun, 1921 under Ahnea lineata (Broun, 1893 ). A key to species, habitus photographs, line drawings of diagnostic characters, and distribution maps are provided.
Hydrodynamics of Slurry Flow in Chemical Mechanical Polishing A Review

Chemical mechanical polishing (CMP) is a process that is commonly used to planarize wafer surfaces during fabrication. Although the complex interactions between the wafer, pad, and slurry make the CMP process difficult to predict, it has been postulated that the motion of the slurry fluid at the wafer-pad interface has an important effect on the wafer surface wear distribution. This paper thus serves as a review of past studies of the hydrodynamics of slurry flow during chemical mechanical polishing. The reviewed studies include theoretical and numerical models as well as experimental measurements.
Probing the Structure of the S105 Hole

For most phages, holins control the timing of host lysis. During the morphogenesis period of the infection cycle, canonical holins accumulate harmlessly in the cytoplasmic membrane until they suddenly trigger to form lethal lesions called holes. The holes can be visualized by cryo-electron microscopy and tomography as micrometer-scale interruptions in the membrane. To explore the fine structure of the holes formed by the lambda holin, S105, a cysteine-scanning accessibility study was performed. A collection of S105 alleles encoding holins with a single Cys residue in different positions was developed and characterized for lytic function. Based on the ability of 4-acetamido-4′-((iodoacetyl) amino) stilbene-2,2′-disulfonic acid, disodium salt (IASD), to modify these Cys residues, one face of transmembrane domain 1 (TMD1) and TMD3 was judged to face the lumen of the S105 hole. In both cases, the lumen-accessible face was found to correspond to the more hydrophilic face of the two TMDs. Judging by the efficiency of IASD modification, it was concluded that the bulk of the S105 protein molecules were involved in facing the lumen. These results are consistent with a model in which the perimeters of the S105 holes are lined by the holin molecules present at the time of lysis. Moreover, the findings that TMD1 and TMD3 face the lumen, coupled with previous results showing TMD2-TMD2 contacts in the S105 dimer, support a model in which membrane depolarization drives the transition of S105 from homotypic to heterotypic oligomeric interactions.
Nocturnal awakenings and comorbid disorders in the American general population.

Abstract Objective Nocturnal awakenings are one of the most prevalent sleep disturbances in the general population. However, little is know about how its severity affects co-morbidity with mental disorders and organic diseases. Methods A representative sample consisting of 8937 non-institutionalized individuals aged 18 or over living in Texas, New York and California states were interviewed by telephone. The interviews included sleeping habits, health, sleep and mental disorders. Nocturnal awakenings were evaluated according to their frequency per week and per night, their duration and the motive(s) for the awakenings. Results A total of 35.5% of the sample reported awakening at least 3 nights per week: 23% of reported awakening at least one time every night; 4.5% 5 or 6 nights per week and 7.9% 3 or 4 nights per week. Nocturnal awakenings increased with age only among people with nightly awakenings and were more frequent among women than men only among those awakening every night. More than 90% of subjects reported this problem lasted for more than 6 months. About 40% of subjects with nocturnal awakenings also reported other insomnia symptoms. Generally speaking, organic diseases and psychiatric disorders were more frequent among subjects waking up at least 3 nights per week regardless the frequency of nocturnal awakenings. However, nightly nocturnal awakenings were associated with more frequent organic diseases, obesity and psychiatric disorders. Conclusions Nocturnal awakenings disrupt the sleep of about one third of the general population. Nocturnal awakenings are associated with a wide variety of organic diseases and psychiatric disorders that warrant appropriate treatment.
Project Performance and the Enabling Role of Information Technology: An Exploratory Study on the Role of Alignment

As firms focus on new product, process, and service innovations, improving the performance and productivity of projects that help deliver these innovations assumes greater importance. Information technology (IT) has been an enabler of manufacturing productivity improvement, but its effect on improving the productivity of innovation-intensive operational activities has been mixed. In this paper, we explore the pathways through which IT impacts project-level performance measured in terms of speed, quality, and cost. Specifically, in this exploratory study we seek to present a theory of how the fit between enabling IT and the core characteristics of the project impacts project performance. We test our research hypotheses empirically, using a relatively large, cross-sectional sample of project data. The central contribution is the development and testing of a research model to improve our understanding of the relationship between enabling IT-project alignment, project competencies, and project performance. In doing so, our study clarifies the role of information technologies in project management, providing insights into how to integrate IT into innovation-intensive operational activities for improving project execution competence and productivity.
BINARY MATRICES FOR MULTIPLEXED X-RAY IMAGING: CONSTANT-TIME AND CONSTANT-EXPOSURE MODELS

We study the optimization of binary matrix coding patterns for an imaging system consisting of multiple individually-controllable X-ray sources shining on a single detector in mixed noise. We develop a mathematical model for the noise in such a system and show that the noise is dependent on the properties of the matrix and on the average number of sources used for each code. We derive relations for two bases for comparing the performance of coding matrices: the basis of total imaging time (constant-time) and the basis of total X-ray exposure (constant-exposure). Simulation of a seven-source radiography system demonstrates that the noise model predicts performance in regions of nonuniform images. We conclude that the models developed provide a simple framework for analysis, discovery, and optimization of binary coding patterns used in multiplexed imaging systems