cssi/SciSciGPT-SciSciNet huggingface dataset:
THE ROLE OF PHOSPHORUS AVAILABILITY IN THE RESPONSE OF SOIL NITROGEN CYCLING, UNDERSTORY VEGETATION AND ARBUSCULAR MYCORRHIZAL INOCULUM POTENTIAL TO ELEVATED NITROGEN INPUTS

The impacts of increased nitrogen (N) inputs into temperate ecosystems via atmospheric nitrogen deposition on nitrogen cycling and nitrogen retention have been described in a variety of ecosystem types. The role of secondary nutrients such as phosphorus (P) in ecosystem responses to increased N inputs is less well-understood. N and P availability are likely to interact to influence ecosystem productivity and N cycling rates, and this interaction would be expected to vary as N inputs increase. Furthermore, N and P inputs may affect plant-mycorrhizal associations and the ability of arbuscular mycorrhizae (AM) to colonize roots. We added nitrogen (97 kg ha-1 yr-1) and phosphorus (30 kg ha-1 yr-1) to an oak-maple forest in southwestern Virginia (U.S.A.) from 1994 through 1996. Inorganic nitrogen concentrations, net nitrogen mineralization, net nitrification rates and arbuscular mycorrhizal inoculum potential (MIP) were assessed during the growing season in 1996. Responses of the understory vegetation and soil N cycling to N addition suggested that the ecosystem was strongly N-limited. Nitrogen cycling rates were not affected by P inputs, though P addition increased P availability and decreased MIP. It was hypothesized that P availability may have more significant influences on N cycling and the plant-mycorrhizal association in ecosystems showing stronger symptoms of nitrogen saturation. Results suggest that the use of P fertilization would be effective in alleviating P-deficiency in vegetation receiving elevated atmospheric N deposition, but perhaps at the cost of benefits that associations with arbuscular mycorrhizae provide.
Electron FLASH Delivery at Treatment Room Isocenter for Efficient Reversible Conversion of a Clinical LINAC.

Purpose In this study, procedures were developed to achieve efficient reversible conversion of a clinical linear accelerator (LINAC) and deliver ultrahigh-dose-rate (UHDR) electron or conventional beams to the treatment room isocenter for FLASH radiation therapy. Methods and Materials The LINAC was converted to deliver UHDR beam within 20 minutes by retracting the x-ray target from the beam's path, positioning the carousel on an empty port, and selecting 10 MV photon beam energy in the treatment console. Dose rate surface and depth dose profiles were measured in solid water phantom at different field sizes with Gafchromic film and an optically stimulated luminescent dosimeter (OSLD). A pulse controller counted the pulses via scattered radiation signal and gated the delivery for a preset pulse count. A fast photomultiplier tube–based Cherenkov detector measured the per pulse beam output at a 2-ns sampling rate. After conversion back to clinical mode, conventional beam output, flatness, symmetry, field size, and energy were measured for all clinically commissioned energies. Results The surface average dose rates at the isocenter for 1-cm diameter and 1.5-in diameter circular fields and for a jaws-wide-open field were 238 ± 5 Gy/s, 262 ± 5 Gy/s, and 290 ± 5 Gy/s, respectively. The radial symmetry of the beams was within 2.4%, 0.5%, and 0.2%, respectively. The doses from simultaneous irradiation of film and OSLD were within 1%. The photomultiplier tube showed the LINAC required ramp up time in the first 4 to 6 pulses before the output stabilized, after which its stability was within 3%. Conclusions At the isocenter of the treatment room, 10 MeV UHDR beams were achieved. The beam output was reproducible but requires further investigation of the ramp up time, equivalent to ∼1 Gy, requiring dose monitoring. The UHDR beam can irradiate both small and large subjects to investigate potential FLASH radiobiological effects in minimally modified clinical settings, and the dose rate can be further increased by reducing the source-to-surface distance.
A clinical review of the t:slim X2 insulin pump

Insulin pumps are commonly used for intensive insulin therapy to treat type 1 diabetes in adults and youth. Insulin pump technologies have advanced dramatically in the last several years to integrate with continuous glucose monitors (CGM) and incorporate control algorithms. These control algorithms automate some insulin delivery in response to the glucose information received from the CGM to reduce the occurrence of hypoglycemia and hyperglycemia and improve overall glycemic control. The t:slim X2 insulin pump system became commercially available in 2016. It is an innovative insulin pump technology that can be updated remotely by the user to install new software onto the pump device as new technologies become available. Currently, the t:slim X2 pairs with the Dexcom G6 CGM and there are two advanced software options available: Basal-IQ, which is a predictive low glucose suspend (PLGS) technology, and Control-IQ, which is a Hybrid Closed Loop (HCL) technology. This paper will describe the different types of advanced insulin pump technologies, review how the t:slim X2 insulin pump works, and summarize the clinical studies leading to FDA approval and commercialization of the Basal-IQ and Control-IQ technologies.
Population demographics in geographic proximity to hospitals with robotic platforms do not correlate with disparities in access to robotic surgery.

Disparities in access to robotic surgery have been shown on the local, regional, and national level. This study aims to see if the location of hospitals with robotic platforms (HWR) correlates with population trends to explain the disparity in access to robotic surgery. Hospitals with da Vinci surgical systems were identified by compiling data from the publicly available da Vinci surgeon locator website. Demographic, and economic data were compiled. Multivariate logistic regression and place-based analysis were used to determine population characteristics associated with geographic proximity to HWR. The United States has 1971 HWR (5.93 hospitals with robots per 1 million people). The states with the most HWR are Texas (203), California (175), and Florida (162). Multivariate logistic regression analysis of Texas counties determined population (OR 1.97, 95% CI 1.40–3.38) education level (OR 1.64, 95% CI 1.07–3.21), and urban designation (OR 1.15, 95% CI 1.05–1.31) remained significantly associated with HWR. When applied to a national level, population remained associated with higher numbers of HWR (R = 0.945), however level of education and urbanization were not. Based on this study of population-level data, disparities in access to robotic surgery seen in prior literature cannot be explained exclusively by sociodemographic factors related to the geographic proximity of HWR. This suggests other biases are involved in the lack of robotic procedures performed among minority and underprivileged populations.
Leptomeningeal disease in pancreas ductal adenocarcinoma: A manifestation of longevity.

Abstract Background /Objectives: Pancreatic adenocarcinoma (PDAC) metastatic to the leptomeninges is a rare and lethal event. Leptomeningeal disease (LMD) research is limited in PDAC, and insights into clinical descriptors, possible disease predictors, and treatment strategies is necessitated. Methods Memorial Sloan Kettering databases were queried with Institutional Review Board approval to identify patients with LMD and PDAC treated between January 2000 and June 2020. Medical record review was used to abstract clinical, genomic, pathologic, and radiographic data. Overall survival was calculated from date of PDAC diagnosis to date of death. Previously published literature on LMD from PDAC was reviewed. Results Four patients with LMD from PDAC were identified, two males and two females. Age at diagnosis ranged from 57 to 68 years. All four patients had predominant lung metastasis and a relatively low burden of intra-abdominal disease. Somatic testing indicated alterations typical of PDAC and no PDAC defining pathogenic germline mutations were identified. An extended clinical course prior to LMD diagnosis was observed in all patients, ranging from 16 to 148 months. Upon diagnosis of LMD, three patients elected for supportive care and one patient received a limited course of craniospinal radiation. The median survival following diagnosis of LMD was 1.6 months (range 0.5–2.8 months). Conclusions LMD from PDAC is a rare occurrence that may be more frequent in patients with lung metastasis and/or a more indolent clinical course. Following diagnosis of LMD, prognosis is poor, and survival is short. New treatment strategies for this manifestation of PDAC are needed.
Impact of the new heart allocation policy on patients with restrictive, hypertrophic, or congenital cardiomyopathies.

Background Patients with restrictive or hypertrophic cardiomyopathy (RCM/HCM) and congenital heart disease (CHD) do not derive clinical benefit from inotropes and mechanical circulatory support. Concerns were expressed that the new heart allocation system implemented in October 2018 would disadvantage these patients. This paper aimed to examine the impact of the new adult heart allocation system on transplantation and outcomes among patients with RCM/HCM/CHD. Methods We identified adult patients with RCM/HCM/CHD in the United Network for Organ Sharing (UNOS) database who were listed for or received a cardiac transplant from April 2017-June 2020. The cohort was separated into those listed before and after allocation system changes. Demographics and recipient characteristics, donor characteristics, waitlist survival, and post-transplantation outcomes were analyzed. Results The number of patients listed for RCM/HCM/CHD increased after the allocation system change from 429 to 517. Prior to the change, the majority RCM/HCM/CHD patients were Status 1A at time of transplantation; afterwards, most were Status 2. Wait times decreased significantly for all: RCM (41 days vs 27 days; P<0.05), HCM (55 days vs 38 days; P<0.05), CHD (81 days vs 49 days; P<0.05). Distance traveled increased for all: RCM (76 mi. vs 261 mi, P<0.001), HCM (88 mi. vs 231 mi. P<0.001), CHD (114 mi vs 199 mi, P<0.05). Rates of transplantation were higher for RCM and CHD (P<0.01), whereas post-transplant survival remained unchanged. Conclusions The new allocation system has had a positive impact on time to transplantation of patients with RCM, HCM, and CHD without negatively influencing survival.
Explaining Missing Data in Graphs: A Constraint-based Approach

This paper introduces a constraint-based approach to clarify missing values in graphs. Our method capitalizes on a set Σ of graph data constraints. An explanation is a sequence of operational enforcement of Σ towards the recovery of interested yet missing data (e.g., attribute values, edges). We show that constraint-based approach helps us to understand not only why a value is missing, but also how to recover the missing value. We study Σ-explanation problem, which is to compute the optimal explanations with guarantees on the informativeness and conciseness. We show the problem is in $\Delta _2^P$ for established graph data constraints such as graph keys and graph association rules. We develop an efficient bidirectional algorithm to compute optimal explanations, without enforcing Σ on the entire graph. We also show our algorithm can be easily extended to support graph refinement within limited time, and to explain missing answers. Using real-world graphs, we experimentally verify the effectiveness and efficiency of our algorithms.
Time for an Update? A Look at Current Guidelines for Venous Thromboembolism Prophylaxis After Hip and Knee Arthroplasty and Hip Fracture

Venous thromboembolism is a well-established complication of total hip and knee arthroplasty and hip fracture surgery. Clinical practice guidelines have been proposed to help clinicians provide prophylaxis against this risk. However, most guidelines reference data that are becoming outdated because of new advances in perioperative protocols. Recent data would suggest that aspirin may be appropriate for most patients after total hip and knee replacement and a more potent chemoprophylaxis for higher risk patients. Low-molecular-weight heparin remains the recommended choice after hip fracture surgery, although there is a paucity of recent literature in this patient population. There are randomized trials currently underway in the arthroplasty population that may guide clinicians in the appropriate choice of chemoprophylaxis. These studies should inform updates to the current clinical practice guidelines.
Microarray analysis of small cell lung cancer reveals altered apoptotic imbalance and distinct expression signatures of MYC family gene amplification

877 DNA copy number alterations (CNAs), as amplifications of oncogenes and deletions of tumor suppressor genes, frequently contribute to the development and progression of lung cancer. To identify novel such alterations in small cell lung cancer (SCLC), we performed array-based comparative genomic hybridization (aCGH) on a set of 24 SCLC cell lines using cDNA microarrays representing ∼22,000 human genes (providing an average mapping resolution of MYC (8q24), MYCN (2p24) and MYCL1 (1p34). Other highly-localized DNA amplifications suggested candidate oncogenes not previously identified as amplified in SCLC, including the anti-apoptotic genes TNFRSF4 (1p36), DAD1 (14q11), BCL2L1 (20q11) and BCL2L2 (14q11). Likewise, newly-discovered PCR-validated homozygous deletions suggested candidate tumor suppressor genes (TSGs), including the pro-apoptotic genes MAPK10 (4q21) and TNFRSF6 (10q23). To characterize the effect of DNA amplification on gene expression patterns, we performed expression profiling using the same microarray platform. Among our findings, we identified sets of genes whose expression correlated with amplification of the MYC family oncogenes, MYC , MYCN and MYCL1 , with surprisingly little overlap among gene sets. MYC and MYCN amplification were associated with increased and decreased expression of known MYC up-regulated and down-regulated targets, respectively, while MYCL1 amplification was associated only with the latter. In summary, our findings support a role for altered apoptotic balance in the pathogenesis of SCLC, and suggest the possibility that MYC oncoproteins might effect transformation through distinct sets of targets, in particular highlighting the importance of transcriptional repression.
Sticky DNA: effect of the polypurine.polypyrimidine sequence.

The polypurine.polypyrimidine sequence requirements for the formation of sticky DNA were evaluated in Escherichia coli plasmid systems to determine the potential occurrence of this conformation throughout biological systems. A mirror repeat, dinucleotide tract of (GA.TC)(37), which is ubiquitous in eukaryotes, formed sticky DNA, but shorter sequences of 10 or 20 repeats were inert. (GGA.TCC)(n) inserts (where n = 126, 159, and 222 bp) also formed sticky DNA. As shown previously, the control sequence (GAA.TTC)(150) (450 bp) readily adopted the X-shaped sticky structure; however, this structure has never been found for the nonpathogenic (GAAGGA.TCCTTC)(65) of the same approximate length (390 bp). A sequence that is replete with polypurine.polypyrimidine tracts that can form triplexes and slipped structures but lacks long repeating motifs (the 2.5-kbp intron 21 sequence from the polycystic kidney disease gene 1) was also inert. Interestingly, tracts of (GAA.TTC)(n) (where n = 176 or 80) readily formed sticky DNA with (GAAGGA.TCCTTC)(65) cloned into the same plasmid when the pair of inserts was in the direct, but not in the indirect (inverted), orientation. The stabilities of the triple base (Watson-Crick and Hoogsteen) interactions in the DNA/DNA associated triplex region of the sticky conformations account for these observations. Our results have significant chemical and biological implications for the structure and function of this unusual DNA conformation in Friedreich's ataxia.
Immigration and its Effects on U.S. Labor Markets

Through the years, labor economists have been studying the effects of immigrants within different labor markets. This paper attempts to shed light on some of the issues surrounding America's sudden change in heart. Do immigrants suppress the wages of native born workers and increase the income disparity? Do they lead to higher unemployment and labor market crowding? And finally, is there room for improvement, or will immigrants prove to be a drain on America's resources and economic well-being? This article is available in The Park Place Economist: http://digitalcommons.iwu.edu/parkplace/vol7/iss1/15 Immigration and its Effects on U.S.
Nanoscale memristive radiofrequency switches

Radiofrequency switches based on micro-electromechanical systems or phase-change materials are large and require high voltages. Here, the authors demonstrate a nanoscale radiofrequency switch based on a memristive device with actuation voltages as low as 0.4 V and a typical cutoff frequency of 35 THz.
Norms in Branching Space-Times

The idea of norms presupposes agency, and agency presupposes an indeterministic causal order (so that "ought" does not imply "is"). So much can be modeled in "branching time with agents and choices" (BTAC). The seriously ontological independence of agentive choices, however, requires, as a necessary condition, a causal order permitting space-like separation of those choices in a sense definable in "branching space-times with agents and choices" (BSTAC).Let us idealize an agent, when restricted to a single space-time, as a kind of spatio-temporal "worm" in the familiar way, representing the life of the agent in that space-time. Then a representation of "the agent," since it must include representation of seriously objective choices, must look like a tree with two kinds of branching. In both kinds of branching, there is a single past-pointing worm-like representation of the past-life of the agent up to the branching, and an entire assemblage of distinct worm-like representations of the possible future-life of the agent subsequent to the branching, one for each history in which the life of the agent continues. The first kind of branching occurs at choice-points for the agent. According to BSTAC, such branching will involve a last point of agent's-choice-not-yet-made (say, a last point of deliberation), but no first point of agent's-choice-has-beenmade in any possible future-life of the agent. In the second kind of branching, the agent is passive, having two or more possible future-lives due to space-like-related choices by other agents, or by metaphorical "choices" by some space-like-related element of Nature. In this case, BSTAC says that there will be no last point of the past-life of the agent, but instead a first point for each of the agent's possible future-lives.
Friction Factors for Flow in Sand-Bed Channels

A new predictor is developed for friction factors of flows in sand-bed channels. A dimensional analysis is pursued to obtain the form of the quantities entering the relation between the geometry of the bed features, the flow properties, and the equivalent shear stress due to the form-drag of the ripples, dunes, etc. Theoretical considerations of the bed stability lead to expressions for the length and height of the bed features in terms of the properties of the bed sediment and flow. These are introduced into the expression yielded by the dimensional analysis, and the resulting frictional relation is quantified with field and laboratory data. The graphical relation of Lovera and Kennedy is used to obtain the flat-bed friction factor. The predictor is evaluated using field data not included in preparation of the graphical relation between the bed-form friction factor, Froude number, and relative roughness. The depth-discharge relations predicted are found to be in good agreement with the measured data.
Djurleite, digenite, and chalcocite: Intergrowths and transformations

Intergrowths between djurleite (approximately Cu1.94S) and digenite (approximately Cu1.8S) and between djurleite and chalcocite (Cu2S) and the transformation between djurleite (dj) and chalcocite (cc) were studied using high-resolution transmission electron microscopy. Pseudohexagonal twins are common in djurleite; crystal blocks are rotated relative to each other around [100], the normal of the close-packed layers, by multiples of 60-degrees. Djurleite and digenite (dg) bands are intergrown, with (111)dg parallel to (100)dj, thereby creating a cubic-hexagonal alternation in the sequence of close-packed layers. The typical orientational relationship between coexisting djurleite and chalcocite is where [001]cc is parallel to [100]dj and [010]cc is parallel to one of the [010] or [012] directions of djurleite. If both djurleite and chalcocite occur in a sample, chalcocite easily converts to djurleite under the electron beam through the rearrangement of Cu atoms. A similar electrochemical transformation probably takes place in Cu2S-CdS solar cells and is the reason for the instability of chalcocite in such devices.
The making of TPC-DS

For the last decade, the research community and the industry have used TPC-D and its successor TPC-H to evaluate performance of decision support technology. Recognizing a paradigm shift in the industry the Transaction Processing Performance Council has developed a new Decision Support benchmark, TPC-DS, expected to be released this year. From an ease of benchmarking perspective it is similar to past benchmarks. However, it adjusts for new technology and new approaches the industry has embarked on in recent years. This paper describes the main characteristics of TPC-DS, explains why some of the key decisions were made and which performance aspects of decision support system it measures.
Re-Engaging Cross-Reactive Memory B Cells: The Influenza Puzzle

The emergence of a novel influenza A virus strain into humans poses a continuous public health threat. Vaccination is the most effective means of protection against influenza. The generation of memory B cells and long-lived plasma cells that can maintain protective levels of influenza-specific antibodies for protracted periods of time is the foundation for the success of such vaccines. Influenza vaccines elicit an antibody response that is primarily targeting viral surface glycoproteins. However, frequent amino acid mutations within the immunodominant epitopes allow the virus to efficiently escape neutralization by pre-existing antibodies and consequently cause annual epidemics and occasional pandemics. Recently, monoclonal antibodies (mAbs) that target subdominant influenza epitopes have been extensively characterized. These epitopes are immunogenic, can mediate virus neutralization, and most importantly are conserved among different influenza strains. It remains puzzling, however, that despite being repeatedly exposed to such conserved domains of influenza hemagglutinin (HA) either in the form of vaccination or natural infection, most humans do not develop immunological memory that can provide broad protection against emerging virus strains. Here we will discuss the conditions that may be required for engaging such cross-reactive memory B cells in the immune response to influenza infection and vaccination in humans.
Feature-based design: Four hypotheses for future CAD systems

Features are meaningful abstractions of geometry that engineers use to reason about components, products, and processes. For design activity, features are design primitives, serve as the basis for product representations, and can incorporate information relevant to life-cycle activities such as manufacturing. Research on feature-based design has matured to the point that results are being incorporated into commercial CAD systems. The intent of this paper is to look forward. Hence, this paper does not play the role of a standard survey, which necessarily only reviews the past. Nevertheless, an appropriate historical context is provided as a basis for these particular futuristic projections. Applications of feature-based design and technologies of feature representations are reviewed, then open research issues are identified and put in the context of past and current work. Features are prominent as catalysts for computer-based design tools, but the vision presented expands upon this basis, delving beyond features. For that future design environment, four hypotheses are proposed as research challenges: two on the existence of fundamental subfeature elements and relationships for features, one that presents a new definition of design features, and one that argues for the successful development of concurrent engineering languages. Evidence for these hypotheses is provided from recent research results and from speculation about the future of feature-based design.
Surgical tool attributes from monocular video

HD Video from the (monocular or binocular) endoscopic camera provides a rich real-time sensing channel from surgical site to the surgeon console in various Minimally Invasive Surgery (MIS) procedures. However, a real-time frame- work for video understanding would be critical for tapping into the rich information-content provided by the non-invasive and well-established digital endoscopic video-streaming modality. While contemporary research focuses on enhancing aspects such as tool-tracking within the challenging visual scenes, we consider the associated problem of using that rich (but often compromised) streaming visual data to discover the underlying semantic attributes of the tools. Directly analyzing the surgical videos to extract more realistic attributes online can aid in the decision-making and feedback aspects. We propose a novel probabilistic attribute labelling framework with Bayesian filtering to identify associated se- mantics (open/closed, stained with blood etc.) to ultimately give semantic feedback to the surgeon. Our robust video- understanding framework overcomes many of the challenges (tissue deformations, image specularities, clutter, tool-occlusion due to blood and/or organs) under realistic in-vivo surgi- cal conditions. Specifically, this manuscript performs rigorous experimental analysis of the resulting method with varying parameters and different visual features on a data-corpus consisting of real surgical procedures performed on patients with da Vinci Surgical System (9).
Urinary arsenic species, toenail arsenic, and arsenic intake estimates in a Michigan population with low levels of arsenic in drinking water.

Urinary arsenic species, toenail arsenic, and arsenic intake estimates in a Michigan population with low levels of arsenic in drinking water
Effect of wnt-1 and related proteins on gap junctional communication in Xenopus embryos

The proto-oncogene wnt-1 (previously referred to as int-1) is thought to be important in embryonic pattern formation although its mechanisms of action are unknown. Premature and increased expression of the Wnt-1 protein, achieved by injection of synthetic wnt-1 RNA into fertilized Xenopus eggs, enhanced gap junctional communication between ventral cells of the developing embryo. This result is consistent with the hypothesis that Wnt proteins activate a receptor-mediated signal transduction pathway and that gap junctional communication can be a target of this pathway. The effects of two Wnt-1-related proteins on gap junctional communication were also investigated: overexpression of Xwnt-8 increased gap junctional coupling in a manner similar to Wnt-1, whereas Xwnt-5A did not. These findings are consistent with the existence of multiple receptors for Wnt proteins.
Separable potential calculations on the 12+ neutron-deuteron system

Abstract Various rank-three separable potentials containing tensor forces and repulsion have been used to calculate phase shifts and mixing parameters over a range of energies above and below breakup in the J π = 1 2 + neutron-deuteron system. The calculated phase shifts agree well with the phase-shift analysis of van Oers and Seagrave, although the calculated phase shifts display a somewhat different energy dependence. Calculated quantities are sensitive to the deuteron percent D-state but are relatively insensitive to the shape of the form factors used once repulsion has been included.
Periodicity and unbordered segments of words

Abstract A nonempty word β is said to be a border of a word α if and only if α = λβ = βρ for some nonempty words λ and ρ. For an arbitrary (possibly infinite) sequence α the expression # α denotes the (possibly infinite) supremum of the set of all |β| for β an unbordered finite segment of α.
Development and evaluation of iodinated tracers targeting amyloid plaques for SPECT imaging.

Successful development of iodinated ligands for various neurotransmitter receptors prompted us to explore the feasability of having iodinated ligands to target amyloid plaques of Alzheimer’s disease. Several potential iodinated tracers based on various chemical backbone structures have been successfully prepared and evaluated toward this purpose. High binding affinities for Aβ aggregates were consistently observed for those ligands. However, the desirable in vivo properties were generally missing in the majority of those iodinated ligands. Only ligands with the promising in vitro and in vivo characteristics such as IMPY will likely warrant their success to be potential imaging agents mapping amyloid plaques in living human brain.
Al/Ti contacts to sb-doped p-type ZnO

Sb-doped p-type ZnO film was grown on Si (100) substrate by molecular-beam epitaxy. Al/Ti metal was evaporated on the ZnO film to form contacts. As-deposited contacts were Schottky with a barrier height of 0.8 eV. Ohmic conduction was achieved after thermal annealing. The different combinations of Ohmic and Schottky contacts on Sb-doped ZnO layer led to metal-semiconductor-metal (MSM), Schottky, and photoconductive devices. Ohmic contacts on Sb-doped p-type ZnO and backside of n-type Si substrate formed a heterojunction diode. MSM, Schottky, and photoconductor devices exhibited typical electrical characteristics, however, inverted rectification was observed for heterojunction diodes. All devices exhibited ultraviolet (UV) photoresponse. Secondary ion mass spectroscopy measurements were performed on the Ohmic and Schottky contacts on Sb-doped ZnO film to trace the metal profiles before and after annealing. Mechanisms of the formation of Schottky and Ohmic contacts to Sb-doped p-type ZnO and their device op...
Dynamics of nonspherical capsules in shear flow.

Three-dimensional numerical simulations using a front-tracking method are presented on the dynamics of oblate shape capsules in linear shear flow by considering a broad range of viscosity contrast (ratio of internal-to-external fluid viscosity), shear rate (or capillary number), and aspect ratio. We focus specifically on the coupling between the shape deformation and orientation dynamics of capsules, and show how this coupling influences the transition from the tank-treading to tumbling motion. At low capillary numbers, three distinct modes of motion are identified: a swinging or oscillatory (OS) mode at a low viscosity contrast in which the inclination angle $\ensuremath{\theta}(t)$ oscillates but always remains positive; a vacillating-breathing (VB) mode at a moderate viscosity contrast in which $\ensuremath{\theta}(t)$ periodically becomes positive and negative, but a full tumbling does not occur; and a pure tumbling mode (TU) at a higher viscosity contrast. At higher capillary numbers, three types of transient motions occur, in addition to the OS and TU modes, during which the capsule switches from one mode to the other as (i) VB to OS, (ii) TU to VB to OS, and (iii) TU to VB. Phase diagrams showing various regimes of capsule dynamics are presented. For all modes of motion (OS, VB, and TU), a large-amplitude oscillation in capsule shape and a strong coupling between the shape deformation and orientation dynamics are observed. It is shown that the coupling between the shape deformation and orientation is the strongest in the VB mode, and hence at a moderate viscosity contrast, for which the amplitude of shape deformation reaches its maximum. The numerical results are compared with the theories of Keller and Skalak, and Skotheim and Secomb. Significant departures from the two theories are discussed and related to the strong coupling between the shape deformation, inclination, and transition dynamics.
Profit potential as a martingale process

Abstract The hypothesis of systematic shortfall from profit potential is rejected by applying a theoretical definition of potential to data from the Markstrat environment. Profit potential is defined as the NPV of the net marketing contribution resulting from realization of the optimal market share. Firms are found to be equally likely to exceed potential or to fail to reach it. This pattern is modeled by a martingale process. Factors that impact achievement of profit potential are explored.
Structural Evolution of the Southwestern Tobacco Root Mountains, Montana

In the Sheridan district, southwestern Tobacco Root Mountains, Montana, Precambrian metasediments and metavolcanics are complexly folded and refolded. The exposed metamorphic bedrock is divided into the following major mappable units: quartzo-feldspathic gneiss, amphibolite-hornblende gneiss, anthophyllite-garnet gneiss, intermediate gneiss, and marble. Mapping delineates a series of slightly overturned, isoclinal antiforms and synforms which plunge N. 10° W., 24° NW. The nose of an earlier recumbent fold is also preserved. Primarily, all folding occurred during two major deformational episodes; an early episode of recumbent folding around northeast axes and a second, intense period of refolding around nearly north-trending axes that produced the dominant isoclinal folds. During the second folding phase, the nose of a recumbent fold became detached, flowed to the east, and was refolded. The degree of metamorphism produced during recumbent folding is unclear. Progressive regional metamorphism of Barrovian type occurred during the second folding episode and produced mineral assemblages indicative of the amphibolite and granulite facies. Petrofabric evidence substantiates inferences based on regional analysis. Calcite, dolomite, and quartz petrofabrics also reveal a third, less intense phase of folding which was related to the second phase, but which occurred around a distinct axis. Joint systems within the Sheridan district are a result of both Precambrian and Laramide deformations. Dominant, nearly vertical, joint planes with average trends of N. 75° W., N. 45° W., N. 2° E., and N. 65° E. are thought to be Precambrian in origin on the basis of close agreement with theoretical trends. Dominant fracture systems probably controlled the intrusion of the Tobacco Root batholith and the orientations of the Noble and other post metamorphic faults, all of which are associated with the Laramide orogeny.
The crystal structure of wheat germ agglutinin at 2-2 A resolution.

The crystal structure of the dimeric lectin wheat germ agglutinin is described in terms of the three-dimensional folding pattern of the protomer polypeptide chain at a nominal resolution of 2·2 A. The structure was derived from an electron density map phased using the multiple isomorphous replacement method. The wheat germ agglutinin dimers (dimensions 40 A×40 A×70 A) consist of two closely associated protomers of 164 amino acid residues each, which are centered about the crystallographic 2-fold axes. Each protomer is an assembly of four structurally homologous and spatially distinct domains here denoted as A, B, C and D. Each domain contains 41 residues folded in an irregular fashion with very little ordered secondary structure, but with four disulfide bonds in its interior. The four domains which are currently interpreted as constituting a protomer, make only limited contact with one another through long-range side chain interactions. In contrast to this, contact between domains of different protomers is extensive. The complementarity of this inter-promoter contact buries a large part of the protomer surface and is probably responsible for the stability of the dimer. Structural homology and partial sequence homology, involving all half-cystines and some glycines, suggest that the wheat germ agglutinin polypeptide chain evolved as a result of gene-quadruplication followed by divergent evolution. Low resolution analysis of a bound saccharide, 4-methyl umbelliferyl di- N -acetyl chitobiose, indicates one strongly occupied binding site in the crevice between domains C and D, and suggests a second minor binding site at the corresponding location in the crevice formed by domains A and B.
Factors Associated with Asthma Severity in Children: A Case–Control Study

Objective. To investigate factors associated with the severity of childhood asthma. Methods. We conducted a case–control study in a group of Brazilian children (2–12 years old) with diagnosis of asthma attending the pediatric pulmonology clinic of a teaching hospital. The study sample consisted of cases (children with persistent asthma) and controls (children with intermittent asthma). Data were collected through an interview with the child's parent or caretaker using a standard questionnaire. Association between asthma severity and studied variables was assessed by calculating odds ratios (OR) and 95% confidence interval (95% CI) through logistic regression test. Results. 171 children were included in this study, of which 104 (61%) had persistent asthma and 67 (39%) had intermittent asthma. Onset of the disease before 2 years of age, paternal educational level lower than 9 years, and low household income (≤1 minimum wage per month) were independent risk factors for persistent asthma, with adjusted OR (95...
Quantum probability model for spin

We present a realistic model in which spin measurements are represented by functions. By employing a simple amplitude density, we derive the usual spin distributions for the spin-1/2 case. Higher order spin measurements are represented by sums of spin-1/2 measurements. We treat the spin-1 and spin-3/2 cases explicitly and show that the model applies to spins of any order.
Stem cells, microenvironment mechanics, and growth factor activation.

Physicochemical features of a cell's microenvironment can exert important effects on cell behavior and include the effects of matrix elasticity on cell differentiation processes, but molecular mechanisms are largely mysterious. Here we highlight recent reports of a mechanical dependence to growth factor activation, with a particular focus on release of TGFβ (Transforming Growth Factor β) from its large latent complex via forced unfolding. We discuss these processes and pathways in the contexts of matrix adhesion and fluid shearing as they might relate to stem cell differentiation and other mechanisms in development, disease, and repair.
An M/M/1 retrial queue with unreliable server

We analyze an unreliable M/M/1 retrial queue with infinite-capacity orbit and normal queue. Retrial customers do not rejoin the normal queue but repeatedly attempt to access the server at i.i.d. intervals until it is found functioning and idle. We provide stability conditions as well as several stochastic decomposability results.
Temperature dependence of crosslinking processes in pyrolysing coals

Abstract Changes in the macromolecular structure of a lignite and a bituminous coal during rapid pyrolysis in the temperature range 300–1200 K are described. Solvent swelling techniques have clearly demonstrated that crosslinking occurs in lignites at somewhat lower pyrolysis temperatures than it does in bituminous coals. The onset of the crosslinking processes in bituminous coals coincides with the end of the tar formation period. In lignites, crosslinking occurs very early in the pyrolysis process, coinciding with low temperature release of CO2. The presence of natural moisture in the lignite appears to have a significant effect on pyrolysis chemistry, increasing the amount of crosslinking observed at any temperature.
Gender influences on sarcoplasmic reticulum Ca2+-handling in failing human myocardium.

Gender has recently been implicated as an important modulator of cardiovascular disease. However, it is not known how gender may specifically influence the Ca2+-handling deficits that characterize the depressed cardiac contractility of human heart failure. To elucidate the contributory role of gender to sarcoplasmic reticulum (SR) Ca2+ cycling alterations, the protein levels of SR Ca2+-ATPase (SERCA), phospholamban, and calsequestrin, as well as the site-specific phospholamban phosphorylation status, were quantified in a mixed gender population of failing (n=14) and donor (n=15) myocardia. The apparent affinity (EC50) and the maximal velocity (Vmax) of SR Ca2+-uptake were also determined to lend functional significance to any observed protein alterations. Phospholamban and calsequestrin levels were not altered; however, SERCA protein levels were significantly reduced in failing hearts. Additionally, phospholamban phosphorylation (serine-16 and threonine-17 sites) and myocardial cAMP content were both attenuated. The alterations in SR protein levels were also accompanied by a decreased V(max)and an increased EC50 (diminished apparent affinity) of SR Ca2+-uptake for Ca2+ in failing myocardia. Myocardial protein levels and Ca2+ uptake parameters were then analyzed with respect to gender, which revealed that the decreases in phosphorylated serine-16 were specific to male failing hearts, reflecting increases in the EC50 values of SR Ca2+-uptake for Ca2+, compared to donor males. These findings suggest that although decreased SERCA protein and phospholamban phosphorylation levels contribute to depressed SR Ca2+-uptake and left ventricular function in heart failure, the specific subcellular alterations which underlie these effects may not be uniform with respect to gender.
Transfer of Interferon Alfa Into Human Breast Milk

Originally assumed to be antiviral substances, the efficacy of interferons in a number of pathologies, including malignancies, multiple sclerosis, and other immune syndromes, is increasingly recognized. This study provides data on the transfer of interferon alfa (2B) into human milk of a patient receiving massive intravenous doses for the treatment of malignant melanoma. Following an intravenous dose of 30 million IU, the amount of interferon transferred into human milk was only slightly elevated (1551 IU/mL) when compared to control milk (1249 IU/mL). These data suggest that even following enormous doses, interferon is probably too large in molecular weight to transfer into human milk in clinically relevant amounts.
Serum Lp(a) level as a predictor of vein graft stenosis after coronary artery bypass surgery in patients.

Although the serum lipoprotein fraction Lp(a) has been associated with coronary artery atherosclerosis, its relationship to narrowing of saphenous vein grafts has not previously been elucidated. We therefore measured serum Lp(a) levels in 167 symptomatic patients undergoing cardiac catheterization who had had coronary artery bypass surgery 0.7 to 14.3 years earlier. Lp(a), total cholesterol, and total triglyceride levels were compared with the degree of saphenous vein graft stenosis to test for any association. Serum Lp(a) levels were significantly associated with the degree of stenosis of saphenous vein grafts (r = .24, p = .002). Mean Lp(a) levels (mg/dl) in the 135 patients with stenosis were almost double (32.0 +/- 32.7, mean +/- SD) those in the 32 patients with no graft stenosis (16.7 +/- 22.6; p = .002). Graft stenosis was not associated with previous myocardial infarction, hypertension, obesity, diabetes, or smoking. Serum cholesterol levels (mg/dl) were slightly higher in the stenosis group (251.3 +/- 69) than in the no-stenosis group (231.8 +/- 48.8), but the difference was of borderline significance (p = .06). A stepwise increase in mean Lp(a) was found in groups of patients with increasing vein graft stenosis. At a serum Lp(a) level of 31.6 mg/dl or above, 92% of the patients demonstrated vein graft stenosis. Thus, patients with elevated Lp(a) levels have an increased risk of developing saphenous vein graft stenosis after coronary bypass surgery.
Stents for uncommon malignant and benign esophageal indications (extrinsic compression, esophagorespiratory fistulas, and proximal esophageal obstruction)

Esophageal stents are approved for palliation of malignant esophageal disease. Stents are more commonly used for relief of dysphagia caused by esophageal cancer (intrinsic obstruction) located in the mid or distal esophagus. Less common indications for esophageal stent placement for malignant disease include extrinsic compression from intrathoracic masses and lymphadenopathy, esophagorespiratory fistulas, and high proximal esophageal obstruction. More recently, self-expandable stents have been placed for benign esophageal conditions, with indications similar to those for malignant disease; currently only a plastic stent has Food and Drug Administration approval for these indications. This review outlines the techniques and outcomes of esophageal stent placement for uncommon indications and/or difficult lesion location related to both malignant and benign esophageal diseases.
Transcriptional analysis of Schistosoma mansoni treated with praziquantel in vitro

Schistosomiasis is one of the foremost health problems in developing countries and has been estimated to account for the loss of up to 56 million annual disability-adjusted life years. Control of the disease relies almost exclusively on praziquantel (PZQ) but this drug does not kill juvenile worms during the early stages of infection or prevent post-treatment reinfection. As the use of PZQ continues to grow, there are fears that drug resistance may become problematic thus there is a need to develop a new generation of more broadly effective anti-schistosomal drugs, a task that will be made easier by having an understanding of why PZQ kills sexually mature worms but fails to kill juveniles. Here, we describe the exposure of mixed-sex juvenile and sexually mature male and female Schistosoma mansoni to 1 μg/mL PZQ in vitro and the use of microarrays to observe changes to the transcriptome associated with drug treatment. Although there was no significant difference in the total number of genes expressed by adult and juvenile schistosomes after treatment, juveniles differentially regulated a greater proportion of their genes. These included genes encoding multiple drug transporter as well as calcium regulatory, stress and apoptosis-related proteins. We propose that it is the greater transcriptomic flexibility of juvenile schistosomes that allows them to respond to and survive exposure to PZQ in vivo.
Biosynthesis of the coumarins IV. The formation of coumarin and herniarin in lavender

Abstract Evidence was found for the existence in Lavandula officinalis Chaix of 2-glucosyloxy-4-methoxy- cis -cinnamic acid 1 , which yields 7-methoxy showed that D -glucose, L -phenylalanine, and cinnamic acid are common precursors of coumarin and herniarin, but that o - and p -hydroxycinnamic acids are selectively converted to coumarin and herniarin, respectively. Data obtained were consistent with the occurrence of herniarin biosynthesis according to the partial sequence: Cinnamic acid→ p -coumaric acid→ p -methoxycinnamic acid→2-glucosyloxy-4-methoxy- trans -cinnamic acid→-2-glucosyloxy-4-methoxy- cis -cinnamic acid. Umbellic acid (2,4-dihydroxy- trans -cinnamic acid) and umbelliferone were utilized to a minor degree. An improved preparation of umbelliferone-2- 14 C, and syntheses of umbellic acid-carboxy- 14 C, p -methoxycinnamic acid-α- 14 C, 1 and 2-glucosyloxy-4-methoxy- trans -cinnamic acid-α- 14 C are described.