cssi/SciSciGPT-SciSciNet huggingface dataset:
Geologic setting of the Snake Pit Hydrothermal Site: an active vent field on the Mid-Atlantic Ridge

TheSnake Pit Hydrothermal Site lies on the axis of the Mid-Atlantic Ridge at 23°22′ N latitude, about 30 km south of the Kane Transform Intersection. Active ‘black smoker’ vents and a surrounding field of hydrothermal sediment occur at the crest of a laterally extensive neovolcanic ridge. It is one of the first active hydrothermal vent fields to be found on a slow-spreading ridge axis and despite significant differences in its geologic setting from those of the East Pacific Rise, has many similarities to its fast-spreading counterparts. Although preliminary reports have documented many interesting aspects of these vents and their surroundings, new data collected from the manned submersible ALVIN and the deep-towed ANGUS camera system define the regional tectonic setting as well as the local geologic environment of this fascinating area. The Snake Pit vents are located on a local peak of a volcanic constructional ridge at a depth of 3450 m, 700–800 m deeper than vents known from the East Pacific Rise, Galapagos, or Juan de Fuca spreading centers. The vent field is at least 600 m long and up to 200 m wide and is covered by a thick blanket of greenish to yellow-orange hydrothermal sediment. Both active and extinct vents are perched along the crests of steep-sided sulfide mounds that reach heights of over 40 m. High-temperature (350° C) fluids are vented from black smoker chimneys and low-temperature (226° C) fluids seep from sulphide domes and subordinate anhydrite constructions. Water temperatures, flow rates, fluid chemistries, and mineralization are strikingly similar to vents of faster spreading ridge crests; however, a somewhat distinct fauna inhabit the area.
Effect of Monomer Structure on Curing Behavior, CO2 Solubility, and Gas Permeability of Ionic Liquid-Based Epoxy-Amine Resins and Ion-Gels

New imidazolium- and pyrrolidinium-based bis(epoxide)-functionalized ionic liquid (IL) monomers were synthesized and reacted with multifunctional amine monomers to produce cross-linked, epoxy–amine poly(ionic liquid) (PIL) resins and PIL/IL ion-gel membranes. The length and chemical nature (i.e., alkyl versus ether) between the imidazolium group and epoxide groups were studied to determine their effects on CO2 affinity. The CO2 uptake (millimoles per gram) of the epoxy–amine resins (between 0.1 and 1 mmol/g) was found to depend predominately on the epoxide-to-amine ratio and the bis(epoxide) IL molecular weight. The effect of using a primary versus a secondary amine-containing multifunctional monomer was also assessed for the resin synthesis. Secondary amines can increase CO2 permeability but also increase the time required for bis(epoxide) conversion. When either the epoxide or amine monomer structure is changed, the CO2 solubility and permeability of the resulting PIL resins and ion-gel membranes can be...
Low-loss GaAs/GaAlAs strip-loaded waveguides with high coupling efficiency to single-mode fibres

We report measurements of low-loss MOVPE-grown GaAlAs/GaAs strip-loaded waveguides with high coupling efficiency to single-mode fibres. A propagation loss of 2 dB/cm and a coupling efficiency of 70% has been achieved for a p+-i-n+-structure waveguide. A propagation loss of 0.7 dB/cm and a coupling efficiency of 61% has also been achieved for an n¯-i-n¯-structure waveguide.
Constant false alarm rate target detection in clutter: a neural processing algorithm

A serious degradation in detection probability of conventional Constant False Alarm Rate (CFAR) processors used in the automatic detection of radar targets results from a reduction in the number of available reference cells. Several factors such as any constraints on the radar system used (in terms of resolution and sampling time), presence of interfering targets and nonstationary clutter may contribute to the reduction in the number of reference cells. This paper presents a novel neural network-based CFAR detection scheme (referred to as NN- CFAR scheme) that offers robust performance in the face of loss of reference cells. This scheme employs a multilayer feedforward neural network trained by error backpropagation approach using the optimal detector as the teacher. The excellent pattern classification capabilities of trained neural networks are exploited in this application to effectively counter performance degradations due to reduced reference window sizes. In particular it is demonstrated that a neural network implementation of the CFAR detection scheme provides an efficient approach for accommodating more input parameters without increasing design complexity for countering the information loss due to reduced reference window size. Precise quantitative performance evaluation of the NN-CFAR scheme are conducted in a variety of situations that include both homogeneous and nonhomogeneous clutter backgrounds and the target detection performance is compared with that of the traditional CA-CFAR scheme to highlight the benefits.
Genes, environments, development and asthma: a reappraisal

Significant advances have been made in our understanding of the role of genetic variation in determining complex human phenotypes such as asthma. It is now well established that there is no single "gene for asthma", in the way that the cystic fibrosis transmembrane receptor is the "gene for cystic fibrosis". It is also clear that among all genetic variants eventually found to be associated with asthma, only a few will be replicated, and in the same direction, in the majority of well-performed studies. Current evidence suggests that most asthma-related polymorphisms determine risk for the disease in a context-dependent manner, i.e. they interact with environmental factors, with polymorphisms in other genes and with the specific developmental phase of the disease in which the association is tested. Elucidating these complex interactions will allow us to understand better the heterogeneity of the disease and thus to develop therapeutic tools tailored to the specific form of the disease in each patient.
“No more cigar store indians”: Ethnographic and historical representationby andof the Waccamaw-Siouan peoples and their socioeconomic, legal, and political consequences

Study of the representation and images of identity among the Waccamaw-Siouan, a small group of Native Americans residing in eastern North Carolina. The Waccamaw actively struggle to gain authority over representation of their identity, often in direct contradiction to hegemonic scholarly, as well as popular, imaging of them. This struggle over the construction of their historical and contemporary identity has very real and important consequences for them - economic, legal, political, and social. Yet, the validity of their representations is challenged both by scholarly discourse and the legal system.
Factors Influencing the Onset and Progression of Diabetic Retinopathy in Subjects with Insulin-dependent Diabetes Mellitus

Background: The etiology of diabetic retinopathy is poorly understood. In the current study, factors associated with the onset and the progression or regression of retinopathy are evaluated. Methods: Two hundred seventy-seven subjects with insulin-dependent (type I) diabetes mellitus (IDDM) were evaluated longitudinally for retinal changes over a mean of 2.7 years. The multistate Markov model was used to analyze the influences of the duration of diabetes, a family history of hypertension, age, sex, cigarette smoking, systolic blood pressure, diastolic blood pressure, cholesterol levels, and longitudinal glycohemoglobin (GHb) values on the development and the progression or regression of retinopathy. Results: Univariate analysis confirmed that four factors were significantly associated with the etiology and the progression or regression of diabetic retinopathy: age, duration of diabetes, mean longitudinal GHb levels (all at P P Conclusions: The onset of diabetic retinopathy is associated with the duration of diabetes, mean longitudinal GHb levels, smoking, and diastolic blood pressure. A longer duration of diabetes, higher GHb values, and higher diastolic blood pressure levels are associated with an increased risk of progression and a decreased chance of regression of diabetic retinopathy.
A novel DNA/protein complex interacts with the insulin-like growth factor binding protein-1 (IGFBP-1) insulin response sequence and is required for maximal effects of insulin and glucocorticoids on promoter function

Glucocorticoids stimulate and insulin inhibits hepatic production of IGFBP-1 at the level of gene transcription. We previously identified contiguous insulin and glucocorticoid response sequences in the proximal rat IGFBP-1 promoter. This insulin response sequence (IRS) is palindromic (CAAAACAAACTTATTTTG) and each half resembles an IRS in the phosphoenolpyruvate carboxykinase (PEPCK) gene. We have reported that both the IGFBP-1 and PEPCK IRSs bind hepatocyte nuclear factor-3 (HNF-3) proteins [1]. We now report that IRSs from the IGFBP-1 and PEPCK, as well as an IRS which also binds HNF-3 in the rat tyrosine aminotransferase (TAT) gene, also interact with another DNA/protein complex in gel shift studies. Further, methylation interferences studies, gel shift and transient transfection studies with site-specific mutations identified a single base in the first half of the IRS that is critical both for interactions with proteins in this complex, and for maximal effects of insulin and glucocorticoids, on promoter function. Of note, a 250-fold excess of an oligo containing a C/EBP binding site (but not other AT-rich sequences) inhibits the formation of this complex in gel shift assays. Nevertheless, interactions with this C/EBP site are negligible at lower titers (< or = 100-fold excess), and antibodies against known C/EBP proteins do not react with this complex. Similarly, preincubation with CHOP, a truncated member of the C/EBP family which contains a beta-leucine zipper domain, does not prevent or alter the mobility of this novel DNA/protein complex, indicating that components of this complex do not form heterodimers with beta-ZIP proteins. We conclude that HNF-3 proteins and this novel C/EBP-related DNA/protein complex may play an important role in mediating interactions between glucocorticoids and insulin in the regulation of IGFBP-1 and perhaps multiple hepatic genes.
Artifacts in aberration-corrected ADF-STEM imaging.

Abstract The introduction of an experimental black level may introduce unintended artifactual details into high-resolution annular dark field scanning transmission electron microscopy (ADF-STEM) lattice images. This article presents the multislice simulation results of such possible situations. Three simulated scanning transmission electron microscopy (STEM) probes of sizes 0.8, 1.2 and 2.0 A are scanned on the surface of a 〈 1 10〉 oriented Si/Ge crystal. The simulation results suggest that high-frequency artifact peaks will appear in the power spectra when an artificial black level clips the lowest (background) signal. The lowest signal in an ADF-STEM image decreases as the incident probe shrinks in size. Therefore, care must be taken when interpreting the resolution limit of the microscope from images taken with nonzero black level setting, especially in case of sub-A microscope. The simulation result is compared with an experimental image and they agree with each other. The analysis suggests that aberration corrected STEM provide sensitive low level detail.
Cardiovascular Disease Risk in Young People with Type 1 Diabetes

Cardiovascular disease (CVD) is the most frequent cause of death in people with type 1 diabetes (T1D), despite modern advances in glycemic control and CVD risk factor modification. CVD risk identification is essential in this high-risk population, yet remains poorly understood. This review discusses the risk factors for CVD in young people with T1D, including hyperglycemia, traditional CVD risk factors (dyslipidemia, smoking, physical activity, hypertension), as well as novel risk factors such as insulin resistance, inflammation, and hypoglycemia. We present evidence that adverse changes in cardiovascular function, arterial compliance, and atherosclerosis are present even during adolescence in people with T1D, highlighting the need for earlier intervention. The methods for investigating cardiovascular risk are discussed and reviewed. Finally, we discuss the observational studies and clinical trials which have thus far attempted to elucidate the best targets for early intervention in order to reduce the burden of CVD in people with T1D.
Use of soil and water protection practices among farmers in three midwest watersheds.

Data were collected from 1011 farmers in three Midwestern watersheds (Ohio, Iowa, and Minnesota) to assess factors that influence the use of conservation production systems at the farm level. The "vested interests" perspective used to guide the investigation was derived from elements of social learning and social exchange theories. Respondents were asked to indicate their frequency of use for 18 agricultural production practices that could be adopted on Midwestern farms at the time of the study. Responses to the 18 items were summed to form a composite variable, termed "conservation production index," for use as the dependent variable in multivariate analysis. Eleven independent variables were identified from the theory as likely predictors of conservation adoption, including respondents' perceptions about production costs, output and risks, and perceived importance of access to subsidies, technical assistance, and informational/educational programs. Regression analysis was used to assess the performance of the independent variables in explaining variance in the conservation production index. Explained variance in the three regression models ranged from 2% in the Minnesota watershed to 19% in the Ohio watershed. The researchers concluded that the model had limited utility in predicting adoption of conservation production systems within the three study watersheds. Findings are discussed in the context of conservation programs within the three areas.
Expression of nicotinic acetylcholine receptor subtypes in brain and retina.

Neuronal nicotinic acetylcholine receptors (AChRs) are composed of two types of subunits: ACh-binding (termed alpha 2, alpha 3, alpha 4 ...) and structural (termed beta 2, beta 3, beta 4 ...). AChR subtypes composed of combinations of subunits of these two types encoded by several related genes are expressed in different parts of the nervous system, where they presumably serve different functional roles. Here we identify the ACh-binding subunit of the most prominent chicken brain AChR subtype by N-terminal amino acid sequence and show that it corresponds to the alpha 4 gene. Previously we identified the structural subunit for this AChR subtype from chicken brain as beta 2 by N-terminal amino acid sequence. Thus, this identifies both genes which encode subunits of the major nicotinic AChR subtype in avian brains. By immunoprecipitation, immunohistochemistry, and northern blot analysis we show that alpha 3 (or a very closely related sequence) is expressed at low levels in the brain and relatively high levels in the retina, while alpha 4 is expressed at high levels in the brain and lower levels in the retina. This differential expression indicates that alpha 3-containing 'ganglionic-type' AChRs may be an important AChR subtype in avian retina.
Oxidative coupling of methane over unsupported and alumina-supported samaria catalysts

Abstract Being the shortest unsaturated hydrocarbon, ethylene is a valuable feedstock gas for synthesizing longer chain hydrocarbon products. Using the oxidative coupling of methane to produce ethylene and ethane (C2 products) has been studied extensively over the past few decades. In this work, samaria nanoparticles (NPs) and alumina-supported samaria catalysts were prepared using different methods (water/toluene reverse microemulsion, metal-oleate high temperature decomposition, and incipient-wetness impregnation followed by calcination) and various types of alumina supports (high and low surface area nanoparticle alumina [n-Al2O3(+), n-Al2O3(−)] and a porous gamma alumina support [p-Al2O3]). The highest product yields were obtained over Sm2O3 NPs synthesized using the metal-oleate high temperature decomposition and a nitrate precursor. Using a chloride precursor in the preparation of the Sm2O3 NPs resulted in less active and selective catalysts, and should be avoided. While the C2 selectivities were lower over the Sm2O3/Al2O3 catalysts, the yield per gram of Sm2O3 were higher compared with the Sm2O3 NPs. The best supported catalyst was the Sm2O3/n-Al2O3(−) prepared using incipient wetness impregnation of a nitrate precursor, since this leads to the smallest Sm2O3 particles as well as the largest coverage of the acidic Al2O3 support. XRD analysis revealed that high-temperature calcinations form SmAlO3 on the Al2O3-supported catalysts. While this reduced the near surface Sm2O3 concentration, it had beneficial effects as it also lowered the Al2O3 content. Therefore, Al2O3-supported Sm2O3 warrants further investigation, as surface modifications of the Al2O3 can reduce its acidity and lead to higher C2 selectivities in the oxidative coupling of methane over these catalysts.
Adventures in molecular electronics: how to attach wires to molecules

Abstract Films of both methoxy-terminated alkanethiols and a molecular wire candidate on Au{1 1 1} substrates were exposed to a variety of transition and alkali earth metals (Al, Au, Ag, Ca, Cr, Fe, Cu, Mg, Ti). The results show that aggressively reacting metals, such as Ti, destroy the organic monolayer and metals of intermediate reactivity, e.g. Cu, react at the termini and also penetrate the monolayer and react with the substrate. The results of these investigations provide a basis by which future construction of molecular devices based on desired chemical reactivity may proceed.
Optimal design of cam-linkage mechanisms for dynamic-force characteristics

Abstract Nonlinear programming techniques are applied to the optimum design of systems consisting of a four-bar linkage driven by a disk cam. Different prescribed output motions and torque loadings are considered, where the primary design objective is the minimization of input torque fluctuation under the assumed condition of constant input angular velocity of the cam. In addition, other design criteria, including maximum bearing forces, are examined. Design variables include the various cam and linkage dimensions, with constraints used to insure acceptable linkage size and cam profile characteristics. Constrained multidimensional optimizations are carried out utilizing a penalty function approach and performance trade offs are investigated. The effects on performance of the addition of a torsional spring are also investigated. It is shown that significant improvement in performance can be achieved through the use of an optimally designed spring and mechanism system. However, the optimization must be carried out in a combined fashion, considering geometric variables and spring variables simultaneously. Also, regions of multiple optima are found to exist for the minimization of torque fluctuation.
Successful Emergency Endovascular Treatment for Superior Vena Cava Injury

Superior vena cava (SVC) hemorrhage due to iatrogenic injury is an infrequent but important event. We report the case of a 56-year-old woman with a history of right pneumonectomy for lung cancer with iatrogenic SVC injury and hemorrhage. After unsuccessful attempts at suture repair of the defect, an endovascular approach using a stent graft succeeded in controlling hemorrhage while maintaining vessel patency. To our knowledge, this is the third report of SVC hemorrhage control using this technique, and it supports the experience of other authors that endovascular stenting is an effective means of treating emergent venous hemorrhage.
A report of a case: anesthetic management of a parturient with severe thrombotic stenosis of a mechanical aortic valve--an exercise in coordination of subspecialties.

The pregnant woman with valvular heart disease presents significant challenges to the obstetric, anesthesiology, and cardiology teams. Although successful outcomes for both mother and fetus are possible with coordinated medical care, the patient with a prosthetic valve who requires systemic anticoagulation provides a dilemma of insufficient anticoagulation leading to valve thrombosis versus the risks of maternal perinatal hemorrhage or fetal effects from oral or parenteral anticoagulants. This case report describes the peripartum management of a patient at 27 weeks' gestation with thrombus ona prosthetic aortic valve.
Comparisons of Two Statistical Models for Evaluating Boll Retention in Cotton

correlated and have different error variations; thus the mixed model with different error variance–covariance Boll number is one of the most important traits related to yield of structures may be used to improve the statistical testing properties at different fruiting sites would provide useful information On the other hand, a boll at a specific fruiting site for cotton breeding and cotton growth management. The presence or absence of aboll at each fruiting position canbe considered as binomi- on a plant is expressed as either present or absent, and ally distributed. In this study, 188 upland cotton recombinant inbred thus it can be considered as binomially distributed. Boll (RI) lines, two parental lines, and a control cultivar, Stoneville 474, retention varies among different fruiting sites. For exwere used. These lines were planted at Mississippi State, MS in 1999. ample,bollretentionatthefirstpositioninthemiddleof The data set was analyzed by the mixed linear model and logistic theplantisgenerallygreaterthanthatatotherpositions. regression model. The results showed that the boll retention for the Logistic regression analysis is often used to investigate first position was significantly different among nodes but expressed the relationship between a binary trait and a set of exsimilartotalnumbers fromthefirstpositionamongRI lines.Estimates planatory variables. Several books have discussed lofor boll retention were similar for both models; however, the logistic
Somatomedin Synthesis by a Subclone of Buffalo Rat Liver Cells: Characterization and Evidence for Immediate Secretion of de Novo Synthesized Hormone

Previous studies have reported that cultured Buffalo rat liver (BRL-3A) cells synthesize and release a soma-tomedin called multiplication-stimulating activity, a major component of which is rat insulin-like growth factor-II (rIGF-II). We have isolated a subclone of hepatocytes (BRL-3SC) from these cells, which release rIGF-II into serum-free medium at a similar but considerably more uniform rate than BRL-3A cells, and have described their morphology and defined some of the conditions regulating the rate of synthesis and secretion of rlGF-II. Time-course experiments indicate that after a 2-h lag, rlGF-II is released at a nearly constant rate of 70 μJ insulin-like activity/ml · 24 h for 5 days. These cells demonstrate considerable resistance to variations in environmental pH, with extremes of pH 6.8–8.0 in the initial culture medium causing a negligible effect on rIGF-II release. We found no evidence for the existence of an appreciable amount of intracellular rIGF-II, consistent with the lack of secretion g...
Asbestos-contaminated drinking water: its impact on household air.

Asbestos contamination in excess of 10 billion fibers per liter was detected in a community's drinking water. To assess the possibility of waterborne asbestos becoming airborne, air samples were collected from impacted houses receiving contaminated water from three control houses. Collected within each house were three samples on 0.6-μm-pore Nuclepore filters and three samples on 0.8-μm-pore Millipore filters. In addition, bulk samples of suspect material and water samples were collected. Mean waterborne asbestos concentrations were 24 million fibers per liter (MFL) in the impacted houses versus only 1.1 MFL in the control houses. Transmission electron microscopy revealed that airborne asbestos concentrations were highest in impacted houses, with airborne asbestos concentrations positively correlated with waterborne concentrations. For fiber and mass measurements on both filter types, airborne asbestos concentrations were significantly higher in the impacted houses: mean concentrations in impacted houses were 0.12 fibers/cm3 and 1.7 ng/m3 on Nuclepore filters and 0.053 fibers/cm3 and 2.3 ng/m3 on Millipore filters versus only 0.037 fibers/cm3 and 0.31 ng/m3 on Nuclepore filters and 0.0077 fibers/cm3 and 0.14 ng/m3 on Millipore filters from control houses. Also detected in the air samples from impacted houses were clusters of chrysotile, often with several hundreds of fibers. When estimates of these individual fibers were added to the total fiber count, the difference between the impacted and control houses became even greater. The increased concentrations in impacted houses were due primarily to short (
Dimensions of everyday eating and drinking episodes

This study sought to gain conceptual understanding of the situational nature of eating and drinking by analyzing 7 consecutive, qualitative 24-h recalls of foods and beverages consumed from 42 US adults who worked in non-managerial, non-professional positions. Participants were purposively recruited to vary in age, gender, occupation, and household composition. For each recall, participants described foods and beverages consumed, location, people present, thoughts and feelings, and activities occurring at that time. Analysis of verbatim transcripts of interviews identified 1448 eating and drinking episodes. Constant comparative analysis of participants' descriptions for episodes resulted in a conceptual framework that characterizes eating and drinking episodes as holistic and as having eight interconnected dimensions (food and drink, time, location, activities, social setting, mental processes, physical condition, recurrence). Each dimension has multiple features that can be used to describe the episodes. In recalling episodes, participants used conventional labels (e.g. "dinner") as well as modified-conventional labels (e.g. "birthday dinner") and uniquely constructed labels (e.g. "unwind time"). Labels provided insights into the dimensions of the episodes. Results suggest approaches for researchers and practitioners who seek to understand how people manage everyday eating at a time when traditional meal patterns are changing.
A comparison of the PVCILO calculated stabilization energies of the DA complexes of N-phenylmaleimide and 4-phenyl-1,2,4-triazoline-3,5-dione with methyl vinyl ether

A PVCILO method has been used to compare the stabilization energies of the electron donor electron acceptor complexes between methyl vinyl ether as donor and the enophiles, 4-phenyl 1-1,2,4-triazoline-3,5-dione (1) and N-phenylmaleimide (2), respectively, as acceptor. A stabilization energry difference in favor of the more reactive 1 was obtained, which is being interpreted as an explanation for the enhanced rate of reaction of 1 vs 2, often by factors >104.
Probing viruses with mass spectrometry

Mass spectrometry offers a new perspective on the solution and gas-phase properties of viruses. Its broad application to local and global viral structure provides unique insights into many biological processes, including viral–antibody binding, protein–protein interactions and protein dynamics. Mass measuring viral proteins is now routine and since viruses are typically well characterized, in that the capsid proteins and DNA (or RNA) sequences are known, identifying a virus based on the mass of the protein and enzymatic digestion fragments is relatively straightforward. Using mass spectrometry, this paper describes the identification of viral protein post-translational modifications such as myristoylation, phosphorylation and disulfide bridging. Furthermore, complementary data obtained with mass spectrometry and x-ray crystallography demonstrate that viruses are highly dynamic particles whose viral capsid’s mobility could, until recently, be inferred only from inherently static spectroscopic methods. Lastly, mass spectrometry has been applied on a global scale via the mass measurement of entire intact viruses. Given the general utility of mass spectrometry, its continuing development should further its application to viral dynamics, structure, function and identification. © 1998 John Wiley & Sons, Ltd.
Fusing ultra-wideband radar and lidar for small UGV navigation in all-weather conditions

Autonomous small UGVs have the potential to greatly increase force multiplication capabilities for infantry units. In order for these UGVs to be useful on the battlefield, they must be able to operate under all-weather conditions. For the Daredevil Project, we have explored the use of ultra-wideband (UWB) radar, LIDAR, and stereo vision for all-weather navigation capabilities. UWB radar provides the capability to see through rain, snow, smoke, and fog. LIDAR and stereo vision provide greater accuracy and resolution in clear weather but has difficulty with precipitation and obscurants. We investigate the ways in which the sensor data from UWB radar, LIDAR, and stereo vision can be combined to provide improved performance over the use of a single sensor modality. Our research includes both traditional sensor fusion, where data from multiple sensors is combined in a single representation, and behavior-based sensor fusion, where the data from one sensor is used to activate and deactivate behaviors using other sensor modalities. We use traditional sensor fusion to combine LIDAR and stereo vision for improved obstacle avoidance in clear air, and we use behavior-based sensor fusion to select between radar-based and LIDAR/vision-based obstacle avoidance based on current environmental conditions.
Donor iliac vein interposition during liver transplantation in a patient with a migrated transjugular intrahepatic portosystemic shunt.

Background. Transjugular intrahepatic portosystemic shunts (TIPS) are sometimes used to reduce the risk of variceal bleeding or treat intractable ascites before orthotopic liver transplantation (OLT). TIPS usually do not make OLT more difficult, but rarely, malposition of TIPS can significantly complicate OLT. Methods and Results. The following report describes a patient in whom an initially well-placed Wallstent migrated to the confluence of the splenic and superior mesenteric veins. During liver transplantation, the portal vein containing the Wallstent was completely resected, and the portal vein was reconstructed with donor iliac vein. After sewing the iliac vein onto the portal remnant, the liver transplant was completed under portosystemic bypass. The patient had an uneventful recovery. Conclusions. Wallstents can migrate within the portal vein. An interposition graft of donor vein allows full resection of the portal vein containing a migrated stent and facilitates portosystemic bypass and portal anastomosis.
Muscarinic m4 receptor activation by some atypical antipsychotic drugs

To clarify the findings that clozapine is both a muscarinic receptor agonist and antagonist, we examined the effects of neuroleptics on forskolin-stimulated cAMP accumulation in Chinese hamster ovary cells expressing human muscarinic m4 receptors (CHO-hm4) and in rat striatum. With CHO-hm4 cells, clozapine induced a concentration-dependent and atropine-sensitive inhibition on cAMP formation, with EC50 = 60 nM and Emax = 74% of carbachol maximum. Other atypical neuroleptics, fluperlapine, tenilapine and olanzapine, were similar but less potent, while risperidone, rilapine, quetiapine (ICI 204,636), sertindole, and ziprasidone had almost no effect. Typical neuroleptics, haloperidol, chlorpromazine, fluphenazine, thiothixene, thioridazine, and molindone, showed either no effect or an atropine-resistant inhibition of cAMP formation. However, in rat striatal tissues, clozapine, up to 10 microM, did not show a significant inhibition of cAMP formation, probably due to a relatively low abundance of muscarinic m4 receptors and the presence of multiple types of muscarinic and other receptors, with which clozapine interacts. Nevertheless, muscarinic m4 receptor agonism, to some extent, may be a relevant mechanism for the therapeutic efficacy and side effects of clozapine and some atypical neuroleptics.
Design of a 3-DOF Compliant Parallel Mechanism for Displacement Amplification

Prevalent general design methods and applications of compliant displacement amplifiers are focused on 1-DOF units composed into serial structures, which are limited by their output motions, stiffness, heat balance, repeatability and resonant frequencies. To improve the output properties of compliant displacement amplifiers, a monolithic structure is presented in the form of a compliant parallel mechanism. In the proposed moving structure, the compliant mechanism of the displacement amplifier is designed with 3-DOF to generate uniformly magnified output properties in all directions. High first resonant frequencies and amplification ratios are achieved in a compact size compared to existing compliant displacement amplifiers. The related kinematics, amplification ratios and resonant frequencies of the amplifier are analytically modeled, and the results are simulated by finite-element analysis. The proposed design is employable for micro/nano positioning stages operating within a prismatic output workspace.Copyright © 2013 by ASME
Overexpression of violaxanthin de-epoxidase: properties of C-terminal deletions on activity and pH-dependent lipid binding

Violaxanthin de-epoxidase (VDE) is localized in the thylakoid lumen and catalyzes the de-epoxidation of violaxanthin to form antheraxanthin and zeaxanthin. VDE is predicted to be a lipocalin protein with a central barrel structure flanked by a cysteine-rich N-terminal domain and a glutamate-rich C-terminal domain. A full-length Arabidopsis thaliana (L.) Heynh. VDE and deletion mutants of the N- and C-terminal regions were expressed in Escherichia coli and tobacco (Nicotiana tabacum L. cv. Xanthi) plants. High expression of VDE in E. coli was achieved after adding the argU gene that encodes the E. coli arginine AGA tRNA. However, the specific activity of VDE expressed in E. coli was low, possibly due to incorrect folding. Removal of just 4 amino acids from the N-terminal region abolished all VDE activity whereas 71 C-terminal amino acids could be removed without affecting activity. The difficulties with expression in E. coli were overcome by expressing the Arabidopsis VDE in tobacco. The transformed tobacco exhibited a 13- to 19-fold increase in VDE specific activity, indicating correct protein folding. These plants also demonstrated an increase in the initial rate of non-photochemical quenching consistent with an increased initial rate of de-epoxidation. Deletion mutations of the C-terminal region suggest that this region is important for binding of VDE to the thylakoid membrane. Accordingly, in vitro lipid-micelle binding experiments identified a region of 12 amino acids that is potentially part of a membrane-binding domain. The transformed tobacco plants are the first reported example of plants with an increased level of VDE activity.
Hypertension and the Kidney: Perspectives on the Relationship of Kidney Disease and Cardiovascular Disease

Background and objectives: The kidney is important not only in the genesis of blood pressure elevation, but declining renal function is also important for predicting cardiovascular risk. The primacy of the kidney in causing essential hypertension was a topic of debate until the proof-of-principle experiment was performed, which demonstrated remission of essential hypertension in six African-American hypertensives with ESRD after they received successful kidney transplants from normotensive donors. The resolution of hypertension and hypokalemia in a patient with Liddle9s syndrome and ESRD after subsequent successful renal transplantation also demonstrated the primacy of the kidney in a monogenic form of hypertension related to sodium epithelial channel dysfunction. Design, setting, participants, & measurements: A review of the available evidence linking cardiovascular disease with chronic kidney disease. Results: The cause for the inverse continuous relationship between kidney function and cardiovascular events in patients with native kidney disease and kidney transplant recipients is unknown but may be related to traditional and nontraditional cardiovascular risk factors. This is an important clinical concern and requires close attention to cardiovascular risk reduction measures. Conclusions: Increased cardiovascular disease in patients with chronic kidney disease is an important clinical concern. Improved biomeasures of cardiovascular risk and response to therapy are needed.
Living organ donation. Shifting responsibility.

Living donors have been with us since the birth of renal transplantation. 1 They have served us well, often providing the recipient the best hope for a successful outcome. Yet, as Singer 2 recently emphasized, after more than 30 years, the use of living kidney donors as a means of alleviating the severe organ shortage remains controversial. Most controversial is the use of unconventional living donors (ie, those who are genetically unrelated to the recipient and those who are at added risk). 3 Furthermore, a few prominent transplant physicians have even questioned the continued acceptance of traditional living-related kidney donors. 4,5 It seems timely to review some of the issues involved as living donors have recently been called on to provide other organs as well. 6 I emphasize that the following discussion is directed only toward altruistic adults and should not be extrapolated to paid donors; the latter group raises
Incorporation of intravenously injected [2-14C]acetate into tissue lipids of hamsters during the last hour of 3-, 6-, and 24-hour periods of hypothermia

Abstract The in vivo incorporation of total lipid 14 C from [2- 14 C]acetate is decreased in kidney, liver, and small intestine tissue from 3-, 6-, and 24-hr hypothermic hamsters compared to tissues from normothermic animals. The length of time in hypothermia affects hamster tissues differently; thus, 14 C activity: decreases with time in kidney; increases with time in liver; and increases at 3 and 6 hr but decreases from 6 to 24 hr of hypothermia in small intestine. Tissues from hypothermic hamsters incorporated a greater percentage of [2- 14 C] acetate into free sterols and diglycerides and a smaller percentage into phospholipid than did corresponding tissues from normothermic hamsters. The percentage of total fatty acid 14 C activity found as polyunsaturated fatty acid 14 C activity increases in hypothermic kidney, liver, and small intestine with a decrease in the percentage of 14 C activity measured in the saturated fatty acids. Esterification of fatty acid was inhibited in all tissues taken from hypothermic hamsters.
Thermoelectric effects and magnetic field amplification in magnetogasdynamic turbulence

It will be shown that thermoelectric effects amplify magnetic fields in compressible magnetogasdynamic turbulence (though not nearly as much as occurs across a curved reently bowshock). The importance of this result lies in the recognition that thermoelectric effects (in addition to kinetic effects) provide a real mechanism for the amplification of magnetic field strength (and total energy dissipation through ohmic losses) in a compressible, turbulent plasma.
Logistics of building a laser practice for the treatment of hypertrophic burn scars.

Introduction Although lasers can improve burn scars, such treatment has not been adopted universally, due to operational challenges starting a practice and the perception that such a program is not financially viable. We report the logistics of building a laser practice for the treatment of hypertrophic burn scars. Methods We analyzed the clinical, operational, and financial components of our laser practice, focusing on treatment of hypertrophic burn scars, using pulsed dye laser, fractional CO2 laser, and intense pulsed light. Cases were performed in an operating room, with anesthesia, after preauthorization. We examined professional charges and collections, case time, variable and indirect expenses, and breakeven volumes. Results Our practice grew as follows: 2008, 1 case; 2009, 44 cases; 2010, 169 cases; and 2011, 415 cases. Overall collection rate was 32.1%. Expenses incurred by the provider, per 8-hour session, included laser rental/lease ($2375), personnel salaries ($1900), and physician overhead ($808), for a total cost of $5083. Mean charge was $1642 per case; mean collection was $527 per case. Median case time (procedure plus turnover) was 40 minutes. In this model, breakeven volume is 9.7 cases per day; breakeven time is 49.7 minutes. Provider profit margin for 10 cases per day, or 83% capacity utilization, is $187 per day (income - expenses = $5270 - $5083). Conclusions Despite high costs associated with starting and operating a laser practice for the treatment of hypertrophic burn scars, a sustainable enterprise can be achieved when the provider has accrued enough volume to batch cases over an entire day. Critical to achieving breakeven is preauthorization, controlling overhead, and efficient throughput.
Comparative subcellular distribution of aldehyde dehydrogenase in rat, mouse and rabbit liver

The subcellular distribution of hepatic aldehyde dehydrogenase (ALDH) activity was determined in Buffalo, Fischer 344, Long-Evans, Sprague-Dawley, Wistar and Purdue/Wistar rats. These subcellular distributions were compared to the distribution of mouse and rabbit liver ALDH. For the six rat strains, at millimolar propionaldehyde concentrations, NAD-dependent ALDH activity was associated primarily with mitochondria (51%) and microsomes (30%). At millimolar acetaldehyde concentrations, NAD-dependent ALDH was primarily mitochondrial (up to 80%). Less than 1% of total NAD-dependent aldehyde dehydrogenase was found in the cytosol. The highly inbred Purdue/Wistar line possessed significantly less acetaldehyde-NAD ALDH activity as well as less total NADP-dependent ALDH activity than the other strains. In CD-1 mouse liver, millimolar Km, NAD-dependent ALDH activity was found in mitochondria (60%), microsomes (23%) and cytosol (5%). In rabbit liver, millimolar Km, NAD-dependent ALDH was also distributed among mitochondria (36%), microsomes (19%) and cytosol (28%). At micromolar substrate concentrations, mitochondria possessed the majority of rat, mouse and rabbit liver ALDH activity. In all three species, NADP-dependent ALDH activity was found predominantly in the microsomal fraction (up to 65%). The cytosol possessed little NADP-dependent ALDH in any species. We conclude that there are significant species differences in the subcellular distribution of aldehyde dehydrogenase between rat, mouse and rabbit liver. In all three species, mitochondria and microsomes possessed the majority of hepatic aldehyde dehydrogenase activity. However, the cytosol of mouse and rabbit liver also made a significant contribution to total ALDH activity. For the six rat strains examined, liver cytosol possessed little or no ALDH activity.
Reaction-time variability, periodicities in reaction-time distributions, and the EEG gating-signal hypothesis.

Abstract Variability in a person's reaction time (RT) was investigated in relation to a model which hypothesized that the speed of information processing is a function of two factors, namely, the time characteristics of a cortical gating signal, and the recovery period of the events activated by the gating signals. A total of 280 RTs were obtained from each of six young adult subjects while electroencephalograms (EEGs) were simultaneously recorded. Half of the trials were performed under conditions which yielded short, low variability RTs while the other 140 trials were obtained under conditions which produced longer, highly variable RTs. Distributions of RTs from the two conditions were examined in relation to distributions of EEG half waves — which were assumed to define the period of the cortical gating signal — taken from the interval between stimulus and response. Findings were consistent with the model under investigation, namely : (1) the two different conditions produced periodicities or multiple peaks in the RT distributions; (2) the magnitude of the time intervals between consecutive peaks in the subjects' RT distributions was correlated with the duration of the most frequently occurring half waves in their EEGs; and (3) inter-subject differences in variability of the RT distributions were associated with differences in variability of the EEG distributions.
Dynamics of the exponential integrate-and-fire model with slow currents and adaptation

In order to properly capture spike-frequency adaptation with a simplified point-neuron model, we study approximations of Hodgkin-Huxley (HH) models including slow currents by exponential integrate-and-fire (EIF) models that incorporate the same types of currents. We optimize the parameters of the EIF models under the external drive consisting of AMPA-type conductance pulses using the current-voltage curves and the van Rossum metric to best capture the subthreshold membrane potential, firing rate, and jump size of the slow current at the neuron's spike times. Our numerical simulations demonstrate that, in addition to these quantities, the approximate EIF-type models faithfully reproduce bifurcation properties of the HH neurons with slow currents, which include spike-frequency adaptation, phase-response curves, critical exponents at the transition between a finite and infinite number of spikes with increasing constant external drive, and bifurcation diagrams of interspike intervals in time-periodically forced models. Dynamics of networks of HH neurons with slow currents can also be approximated by corresponding EIF-type networks, with the approximation being at least statistically accurate over a broad range of Poisson rates of the external drive. For the form of external drive resembling realistic, AMPA-like synaptic conductance response to incoming action potentials, the EIF model affords great savings of computation time as compared with the corresponding HH-type model. Our work shows that the EIF model with additional slow currents is well suited for use in large-scale, point-neuron models in which spike-frequency adaptation is important.
Drug treatments to restore vascular function and diabesity

Over the last decades, an escalating rate of type 2 diabetes has paralleled an epidemic rise in the prevalence of obesity. Both diabetes and obesity confer an increased risk of cardiovascular comorbidities, including hypertension, coronary artery disease and stroke. Vascular dysfunction, represented by impaired endothelial release of vasodilator substances or defective smooth muscle vasodilator reactivity, is the early stage of the process leading to atherosclerosis and a common finding in patients with diabesity. It is understandable, therefore, that effective treatments for diabesity should restore vascular function to prevent the development of cardiovascular disease. Recent evidence from clinical studies supports the efficacy of incretin-based antidiabetic therapies for vascular protection. Thus, glucose control with either DDP-4 inhibitor or GLP-1 receptor therapies seems associated with favorable effects on vascular function in diabetes and the metabolic syndrome. Another mechanism to counter excess plasma glucose and reduce body weight in these patients may rely on drug therapies targeting gut hormones, as suggested by the efficacy of bariatric surgery to produce both sustained weight loss and high diabetes remission rates. Also, as knowledge of the multifaceted vascular actions of adipokines and their dysregulation in patients with diabesity increases, these substances become attractive targets for treatments aimed at cardiovascular prevention. The increasing coexistence of diabetes and obesity presents complex treatment challenges owing to the elevated risk of developing cardiovascular complications. Hence, therapeutic strategies integrating glycemic control, weight loss and vascular protection are of the greatest importance to successfully counteract the health and economic burden posed by diabesity.