cssi/SciSciGPT-SciSciNet huggingface dataset:
Micro-Porous PLLA Scaffolds for Orthopedic Surgical Fixation Devices

Anterior cruciate ligament (ACL) reconstructive surgery is a major health concern world-wide because of a large aging population and increased occurrence of sport-related injuries. Tissue engineering is a rapidly growing interdisciplinary field that offers a promising new approach for ACL repair. The aim of this project is to explore novel “smart” surgical fixation devices that not only secure a graft in place without strength failure, but also incorporate and release bioactive materials, intended to promote bone tissue growth. In order to facilitate bioactive reagent release, biopolymeric scaffolds with continuous micro-porous structure were developed. The morphology of the porous structures in the poly-L-lactic acid (PLLA) matrix reflects the differential influence of the concentration of sacrificial material (PS-polystyrene), phase separation levels of the immiscible polymers (PLLA and PS), and melt-blending conditions (Fig. 1) [1]. During removal of the sacrificial material, the chemical solvent might introduce some chemical reactant into the scaffolds. In order to assess the feasibility of using the micro-porous structures for medical applications, 7F2 osteoblasts were cultured on these scaffolds for 7 days. The attachment and proliferation of 7F2 cells on all scaffolds were assessed by fluorescent nuclear staining with Hoechst 33258 and phalloidin. The morphology of 7F2 osteoblasts on solid PLLA and PLLA/HA with 40% porous structure scaffolds till the 7 days pos-seeding was observed under confocal microscopy (Fig. 2A and B). The results showed that removal of the sacrificial material does not influence cell growth and the composites are biocompatible. Besides in vitro cytotoxicity test, in vivo test of all the micro-porous structural scaffolds was performed through rat subcutaneous surgery. Histological analysis (H&E staining) of the porous PLLA/HA with 40% pores retrieved from rat subcutaneous tissue 4 weeks postimplantation show that cells start to grow inside the porous scaffold (Fig. 3A). The morphology of surrounding extracellular matrix (ECM) growing on the scaffolds was observed under SEM. Figure 3B shows soft tissue attached onto PLLA/HA porous scaffold after 1 month post implantation time point, which indicates the good biocompatibility of the scaffolds. Based on these data we predict that these scaffolds will be suitable for inducing and sustaining bone tissue regeneration, and will be feasible for ACL repair.Copyright © 2010 by ASME
Optimization of Coupling Ratio and Kinematics of an Underactuated Robot Leg for Passive Terrain Adaptability

This paper investigates how the passive adaptability of an underactuated robot leg to uneven terrain is affected by variations in design parameters. In particular, the ratio between the joint torques, the ratio between the link lengths, and the initial joint rest angles are varied to determine configurations that allow for maximum terrain roughness adaptability while minimizing the transmission of disturbance forces to the body. The results show that a proximal/distal joint torque coupling ratio of 1.58, proximal/distal leg length ratio of 0.5, and an initial proximal joint angle of −49 degrees maximize the terrain variability over which the robot can remain stable by exerting a near-constant vertical reaction force while minimizing lateral force and moment disturbances. In addition, the spring stiffness ratio allows for a tradeoff to be made between the different performance metrics.Copyright © 2012 by ASME
Insights from the structure of a smallpox virus topoisomerase-DNA transition state mimic

Poxviruses encode their own type IB topoisomerases (TopIBs), which release superhelical tension generated by replication and transcription of their genomes. To investigate the reaction catalyzed by viral TopIBs, we have determined the structure of a variola virus topoisomerase-DNA complex trapped as a vanadate transition state mimic. The structure reveals how the viral TopIB enzymes are likely to position the DNA duplex for ligation following relaxation of supercoils and identifies the sources of friction observed in single-molecule experiments that argue against free rotation. The structure also identifies a conformational change in the leaving group sugar that must occur prior to cleavage and reveals a mechanism for promoting ligation following relaxation of supercoils that involves an Asp-minor groove interaction. Overall, the new structural data support a common catalytic mechanism for the TopIB superfamily but indicate distinct methods for controlling duplex rotation in the small versus large enzyme subfamilies.
Probability distribution of the project payback period using the equivalent cash flow decomposition

For stochastic cash flows, probabilistic approaches to determine a complete distribution of payback period are very limited. The payback analysis based on the net present value (NPV) has several advantages. For annual cash flows, however, the NPV-based method does not provide a complete payback distribution. This article proposes a new technique, the equivalent cash flow decomposition (ECFD), which converts an annual cash flow into an equivalent subannual cash flow at a desired level of precision. The ECFD technique can be used in conjunction with any probabilistic cash flow technique. This article demonstrates that the ECFD technique overcomes the discontinuity limitation of the conventional NPV-based payback period method and generates a complete distribution of the payback period of annual cash flows. Examples indicate that the proposed method is robust with the accuracy comparable to Monte Carlo simulation.
Reductive decomposition of calcium sulfate with carbon monoxide: reaction mechanism

Quand CaSO 4 est traite avec un melange de CO, CO 2 , SO 2 et N 2 a 1150°C dans un equipement d'analyse thermogravimetrique, differentes etapes de reaction sont identifiees et la distribution des produits finaux depend du potentiel reducteur (P CO /P CO2 2) des gaz. A de faibles potentiels (≤10), CaSO 4 2) des gaz. A de faibles potentiels (≤10), CaSO 4 est converti completement en CaO. A des potentiels moderes (par exemple 0,20), CuSO 4 est rapidement converti en CaO, qui est converti plus lentement en CaS
Spontaneous Variability of Ventricular Ectopic Activity in Patients with Sustained Ventricular Tachycardia and in Survivors of Cardiac Arrest

Background: Spontaneous variability of ventricular arrhythmia has been described in patients with chronic stable ventricular arrhythmias and in patients with chronic heart failure. However, no data are available on spontaneous variability in patients with sustained ventricular tachyarrhythmias. Thus, the present study was designed to prospectively determine the extent of spontaneous variability of ventricular arrhythmia in patients with sustained ventricular tachyarrhythmias and in survivors of cardiac arrest. Methods: Ventricular arrhythmia variability was determined in 470 patients (413 men, 57 women), age (mean ± SD) 64.6 ± 9.5 years with documented ventricular tachycardia (VT), cardiac arrest, or syncope who were prospectively enrolled in a randomized trial of the comparison of electrophysiological testing with Holter monitoring to predict antiarrhythmic drug efficacy. Coronary artery disease was present in 398 (85%) patients, and the mean left ventricular ejection fraction was 0.32 ± 0.13. They underwent two 24-hour ambulatory recordings separated by 1 day. Spontaneous variability was determined for total premature ventricular complexes (PVCs), pairs, and VT events. Results: Arithmetic mean of hourly total PVCs on day 1 was 315 ± 425. The 95% confidence limit of spontaneous reduction in total PVC count was 71%. Corresponding values for pairs, VT events of 3–15 beats, 0.32 and 76% for those with an ejection fraction ltm 0.32 (P = 0.024). Patients who presented with unmonitored syncope showed less spontaneous variability than either patients with documented, sustained VT or cardiac arrest. Conclusions: Marked spontaneous variability of ventricular arrhythmias is observed in patients with sustained ventricular tachyarrhythmias. Variability is affected by the degree of left ventricular dysfunction. The lowest variability was observed in patients presenting with unmonitored syncope. Thus, large changes in arrhythmia frequency must be observed in this population, as in others, to be ascribed to drug effect.
Outcomes and stability in patients with anterior open bite and long anterior face height treated with temporary anchorage devices and a maxillary intrusion splint

Introduction Temporary skeletal anchorage devices now offer the possibility of closing anterior open bites and decreasing anterior face height by intruding maxillary posterior teeth, but data for treatment outcomes are lacking. This article presents outcomes and posttreatment changes for consecutive patients treated with a standardized technique. Methods The sample included 33 consecutive patients who had intrusion of maxillary posterior teeth with a maxillary occlusal splint and nickel-titanium coil springs to temporary anchorage devices in the zygomatic buttress area, buccal and apical to the maxillary molars. Of this group, 30 had adequate cephalograms available for the period of treatment, 27 had cephalograms including 1-year posttreatment, and 25 had cephalograms from 2 years or longer. Results During splint therapy, the mean molar intrusion was 2.3 mm. The mean decrease in anterior face height was 1.6 mm, less than expected because of a 0.6-mm mean eruption of the mandibular molars. During the postintrusion orthodontics, the mean change in maxillary molar position was a 0.2-mm extrusion, and there was a mean 0.5-mm increase in face height. Positive overbite was maintained in all patients, with a slight elongation ( Conclusions Intrusion of the maxillary posterior teeth can give satisfactory correction of moderately severe anterior open bites, but 0.5 to 1.5 mm of reeruption of these teeth is likely to occur. Controlling the vertical position of the mandibular molars so that they do not erupt as the maxillary teeth are intruded is important in obtaining a decrease in face height.
Interface characterization of fiber-reinforced Ni3Al matrix composites

The interfacial reaction characteristics of SCS-6, Sigma, and B4C/B fibers with nickel aluminide (Ni3Al) matrix have been investigated between 780°C to 980°C for times ranging from 1 to 100 hours. The microstructure and elemental compositions across the reaction zone have been analyzed quantitatively using microscopy and electron probe microanalyses, respectively. The results show that Ni3Al reacts extensively with SCS-6, Sigma, and B4C/B fibers to form complex reaction products, and Ni is the dominant diffusing species controlling the extent of reaction. In the SiC/Ni3Al composite, the C-rich layer on the SiC surface can slow down but cannot stop the inward diffusion of Ni into SiC fiber. When the C-rich layer is depleted, a rapid increase in reaction zone thickness occurs. Diffusion barrier coating on the fibers is required to minimize the interfacial reactions.
160) Hypersensitivity to cutaneous thermal nociceptive stimuli in myofascial pain and fibromyalgia syndromes

Traditional paper-based visual analogue scale (VAS) measures used in clinical trials may not sufficiently capture the experience of pain in fibromyalgia (FM). More frequent, real-time, home-based assessments are possible with electronic pain diaries (e-diaries). This study directly compared the performance of e-diaries and paper-based assessments of pain intensity over a 3-month period in the context of a large randomized clinical trial of milnacipran, a potential treatment for FM. FM patients (n 881) were randomized to placebo (n 294), 100 (n 264), or 200 mg/day (n 260) of milnacipran. Pain ratings were collected monthly during clinic visits using traditional paper measures (10-cm VAS) as average pain over the last week or over the previous 24 hours. Daily e-diary monitoring captured pain assessments at semi-random prompts 3-5 times daily; a morning recall of average pain for the previous 24 hours; and average pain over the last week (collected once per week). Paperbased methods produced consistently higher baseline values than did e-diaries; but all 5 measures showed greater agreement at 3-months. Baseline correlations ranged between r 0.60–0.94; whereas 3-month correlations ranged more narrowly r 0.85-0.98. Effect sizes (Cohen’s d) for change in pain at 3 months relative to baseline were calculated comparing each treatment arm to placebo. For milnacipran 100 mg/day, all 5 methods produced comparable effect sizes. For milnacipran 200 mg/day, each of the e-diary methods demonstrated larger effect sizes compared to the paper-based methods. Given the larger effect sizes, e-diary methods appeared to be more sensitive for detecting change over time than paper methods. Enhanced e-diary sensitivity is likely due to decreased dependence upon long recall intervals, denser data collection, and the ability to capture data in patients’ home environment. These data found no superiority of paper over e-diaries, and some advantage of e-diary methodology in terms of sensitivity. Supported by Forest Laboratories and Cypress Bioscience. (162) Pain modulation in IBS and MPS patients: Deficiency of Diffuse Noxious Inhibitory Controls
Skewness and asymmetry of distributions

The ‘skewness’ of a distribution, a poorly-defined term, is conventionally deemed to be invariant under linear transformations. A comparison is made of three criteria of it: the sign of odd central moments; the several relationships of the mean, the median and the mode; and asymmetry proper which is the set of ratios of the probability densities of all pairs of points equidistant above and below some arbitrary point, usually the principal mode. Some useful general relationships are discussed. The skeness of convolutions is briefly discussed. A class of distributions is identified for which the skewness of the minimum ofk competing processes is independent ofk. It has importance in the parametric study of survivorship.
A Note on the Definition of the Economic Region of the Production Function

S EAGRAVES AND PASOUR (hereafter S-P) offer a strong argument for accepting a cost-oriented definition of the "uneconomic regions" of the production function in the theory of the firm [3]. We hope in this note to make a few amendments to the S-P argument and, in so doing, to cast further doubt on the usefulness of the traditional "stages of production" notion as a pedagogical device. To illustrate the problems with conventional definitions of "economic region," S-P have employed a homogeneous production function. They also, implicitly at least, assumed the "fixed factor" to be perfectly divisible.1 We shall argue that: 1. In the case of a two-input production function, when one input is fixed and indivisible, the firm facing constant input and product prices will choose not to produce if output price falls below average variable costs. The reason for this is not that the marginal physical productivity of the "fixed input" is zero at the output corresponding to minimum average variable costs (this is true, however, for linear and homogeneous production functions), but rather that if the firm produces when product price is less than average variable costs, it will earn a negative quasi-rent. For some functions, the marginal physical productivity of the "fixed factor" may be negative at the minimum average variable cost output. The firm may wish to employ fewer units of that factor but is unable to do so because of its indivisible nature. Thus, production where the marginal physical productivity of an input is negative need not imply "uneconomic" production. 2. In the case of a two-input production
Effect of low-intensity warfarin anticoagulation on level of activity of the hemostatic system in patients with atrial fibrillation. BAATAF Investigators.

The Boston Area Anticoagulation Trial for Atrial Fibrillation (BAATAF) demonstrated that low-intensity warfarin anticoagulation can, with safety, sharply reduce the rate of stroke in patients with nonvalvular atrial fibrillation. The beneficial effect of warfarin was presumably related to a decrease in clot formation in the cardiac atria and subsequent embolization. To assess the effect of warfarin therapy on in vivo clotting in patients in the BAATAF, we measured the plasma level of prothrombin activation fragment F1+2. One sample was obtained from 125 patients from the BAATAF; 62 were taking warfarin and 63 were not taking warfarin (control group). The warfarin group had a 71% lower mean F1+2 level than the control group (mean F1+2 of 1.57 nmol/L in the control group compared with a mean of 0.46 nmol/L in the warfarin group; P .1). We conclude that prothrombin activation was significantly suppressed in vivo by warfarin but not aspirin among patients in the BAATAF. These findings correlate with the marked reduction in ischemic stroke noted among patients in the warfarin treatment group observed in the BAATAF.
Development of new methods for phalangeal fracture fixation.

Abstract Surgical intervention is warranted in the fixation of finger fractures only if it results in high mechanical stability. This allows early motion and avoids loss of range of motion and stiffness often associated with immobilization. To facilitate the rational design of finger fracture fixation devices an analytical and experimental program is presented to establish appropriate design criteria. The analytical scheme uses composite beam theory treating the device and bone as components of a system contributing to the strength and rigidity of fixation. The experimental program uses the pig metacarpal as an animal model for the proximal phalanx. K-wire fixation and intramedullary fixation with a polylactic acid polymer (PLA)-carbon fiber composite device are considered. Fixation rigidity is found to be limited by device slippage and device-bone hardness mismatch. However, both techniques are shown to be capable of sustaining the bending moments expected in normal pinch hand function. A method of fixation using four 0.712-mm ( 28 1000 - in. ) wires is shown to increase the maximum bending moment by 170% and bending rigidity by 300% over the conventional two crossed K-wire method. Its maximum bending moment capability provides a safety factor of 2.01 over expected tip pinch moments. A method using a 3.5-mm square cross-section PLA-carbon intramedullary (IM) device is shown to increase the maximum bending moment by 240% and bending rigidity by 297% over the two-wire method with a maximum bending moment safety factor of 2.53.
Characterization of a chimeric foot-and-mouth disease virus bearing a bovine rhinitis B virus leader proteinase

Bovine rhinitis B virus (BRBV) shares many motifs and sequence similarities with foot-and-mouth disease virus (FMDV). This study examined if the BRBV leader proteinase (L(pro) ) could functionally replace that of FMDV. A mutant A24LBRV3DYR FMDV engineered with the BRBV L(pro) and an antigenic marker in the 3D polymerase exhibited growth properties and eIF4G cleavage similar to parental A24WT virus. The A24LBRV3DYR type I interferon activity in infected bovine cells resembled that of A24LL virus that lacks L(pro), but this effect was less pronounced for A24LBRV3DYR infected porcine cells. In vivo studies showed that the A24LBRV3DYR virus was attenuated in cattle, and exhibited low virulence in pigs exposed by direct contact. The mutant virus induced protective immunity in cattle against challenge with parental A24WT. These results provide evidence that L(pro) of different Aphthoviruses are not fully functionally interchangeable and have roles that may depend on the nature of the infected host.
Optical and Thermal Analysis for Immersed Cooling of Photovoltaic Cells in a Highly Concentrated Beam

Concentrated solar radiation can be utilized to generate electrical power from photovoltaic cells, but it increases the photovoltaic cell temperature. This can lead to a degradation of the cell efficiency and too high of a temperature can damage the cell integrity. This is particularly important in dish and tower systems where a maximum uniform flux may be difficult to achieve. While a variety of approaches have been used to the keep the cells cool, most are based upon removal of heat from the back (opposite to the incident flux) of the cell. This paper reports on an immersion cooling technique for the cells, where a coolant is circulated over the complete cell including the front surface. An analysis is given where the cells are placed in a cylindrical glass tube where a liquid is circulated. The impacts of the various thermal processes that result from this approach are described here. A comparison is made to limited experimental data.Copyright © 2011 by ASME
Cult/Brainwashing Cases and Freedom of Religion

" C u l t cases" have attracted considerable attention from the legal profession, scholars in several disciplines, the media, and the general public in recent years, as different types of legal action have been initiated involving new religions--popularly called cults--as parties. Hundreds of "cult cases" have been filed in courts around the country, concerning issues as varied as solicitation ordinances, tax status of such groups, zoning regulations, and violations of labor laws. Several "cult cases" have reached the United States Supreme Court. 1 A specific "cult'" case which deserves special attention might be caUed the "cult/brainwashing'" case. This involves tases which allege that a person has been "brainwashed" into joining a group and participating in activities in which the person otherwise would not join, except for the alleged brainwashing and subsequent "mind control." Such allegations have been made as part of a defense for false imprisonment claims in civil cases (of for criminal charges of kidnapping) sometimes made against parents of participants or their agents, the deprogrammers. 2 Brainwashing allegations are sometimes a part of conser-
Activation of the right fronto-temporal cortex during maternal facial recognition in young infants.

Background/aim: Within the first days of life infants can already recognize their mother. This ability is based on several sensory mechanisms and increases during the first year of life, having its most crucial phase between 6 and 9 months when cortical circuits develop. The underlying cortical structures that are involved in this process are still unknown. Herein we report how the prefrontal cortices of healthy 6- to 9-month-old infants react to the sight of their mother's faces compared to that of an unknown female face. Methods: Concentrations of oxygenated haemoglobin [HbO2] and deoxygenated haemoglobin [HHb] were measured using near infrared spectroscopy (NIRS) in both fronto-temporal and occipital areas on the right side during the exposure to maternal and unfamiliar faces. Results: The infants exhibited a distinct and significantly higher activation-related haemodynamic response in the right fronto-temporal cortex following exposure to the image of their mother's face, [HbO2] (0.75 μmol/L, p < 0.001), as compared to that of an unknown face (0.25 μmol/L, p < 0.001). Conclusion: Event-related haemodynamic changes, suggesting cortical activation, in response to the sight of human faces were detected in 6- to 9-month old children. The right fronto-temporal cortex appears to be involved in face recognition processes at this age.
Wilder Penfield, Pío del Río-Hortega, and the discovery of oligodendroglia.

OBJECTIVE To describe the contribution of Wilder Penfield to the early characterization of glial cells in collaboration with Pio Del Rio-Hortega and Santiago Ramon y Cajal during his study in La Residencia des Estudiantes, Laboratorio de Histopatologia in Madrid in 1924. METHODS Comprehensive review of the English and Spanish-language literature pertinent to the history of Wilder Penfield (1891-1976), his associations with Pio Del Rio-Hortega (1882-1945) and Santiago Ramon y Cajal (1852-1934), and his articles describing glial cells. RESULTS Penfield went to Spain in the spring of 1924 to work with Rio-Hortega and Cajal, which resulted in a fruitful 5 months of study. During this trip, he published several articles, including a landmark report in which he completed the characterization of the "third element" of Cajal (non-astrocyte glial cells) and its relationship to classical neuroglia. The article was accepted for publication in Brain, the leading British neurology journal of the time. CONCLUSION Today, Wilder Penfield is much better known for his seminal explorations of the cortical basis of higher function, his contributions to epilepsy surgery, and as the founder of the Montreal Neurological Institute than for his original work with Sherrington in England or Rio-Hortega and Cajal in Spain. While working with Rio-Hortega, his report on oligodendroglia was critical to advancing the characterization of this important class of glial cells.
Molecular diagnostics complementing morphology in superficial mesenchymal tumors

Molecular techniques are increasingly important in the practice of surgical pathology. In soft tissue tumors, there are a number of tumors with recurring cytogenetic abnormalities. Knowledge of these abnormalities has furthered our understanding of these tumors and has also allowed development of molecular techniques to aid in the diagnosis. This review will focus on mesenchymal tumors with specific cytogenetic abnormalities that may present as a superficial tumor of the dermis or subcutis.
Sparse reconstruction for radar

Imaging is not itself a system goal, but is rather a means to support inference tasks. For data processing with linearized signal models, we seek to report all high-probability interpretations of the data and to report confidence labels in the form of posterior probabilities. A low-complexity recursive procedure is presented for Bayesian estimation in linear regression models. A Gaussian mixture is chosen as the prior on the unknown parameter vector. The algorithm returns both a set of high posterior probability mixing parameters and an approximate minimum mean squared error (MMSE) estimate of the parameter vector. Emphasis is given to the case of a sparse parameter vector. Numerical simulations demonstrate estimation performance and illustrate the distinctions between MMSE estimation and maximum a posteriori probability (MAP) model selection. The proposed tree-search algorithm provides exact ratios of posterior probabilities for a set of high probability solutions to the sparse reconstruction problem. These relative probabilities serve to reveal potential ambiguity among multiple candidate solutions that are ambiguous due to low signal-to-noise ratio and/or significant correlation among columns in the super-resolving regressor matrix.
Thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) following treatment with deoxycoformycin in a patient with cutaneous T-cell lymphoma (Sezary syndrome): A case report.

We present a case of a patient who developed all manifestations of thrombotic thrombocytopenic purpura-hemolytic uremic syndrome (TTP-HUS) acutely following treatment of cutaneous T-cell lymphoma (CTCL, Sezary syndrome) with deoxycoformycin (pentostatin). Symptoms and signs included severe thrombocytopenia and microangiopathic hemolytic anemia; hallucinations, confusion and disorientation; oliguric acute renal failure requiring hemodialysis; and fever. No other etiology for these symptoms and signs was present. Complete recovery followed treatment for one month with plasma exchange and glucocorticoids. During the succeeding 20 months she has remained well and her CTCL remains stable on no further treatment. This case and two previously published cases suggest that acute and severe TTP-HUS may be a dose-dependent toxicity of deoxycoformycin (pentostatin).
Synergistic association between alcohol intake and body mass index with serum alanine and aspartate aminotransferase levels in older adults: the Rancho Bernardo Study

Background Body-mass-index (BMI) and alcohol consumption predict elevated serum alanine (ALT) and aspartate (AST) aminotransferase levels in young adults. It is unclear if alcohol intake and BMI and their joint association have a differential effect on ALT and AST levels in older adults.
The Need to Revisit VTE Quality Measures

Objectives To prospectively determine the incidence of venous thromboembolism (VTE) following major head and neck surgery. At the midpoint of enrollment, an interim analysis was performed to determine if it was ethical to continue this study as an observational study without routine anticoagulation. Design Prospective, observational cohort study. Setting Academic surgical center. Patients The interim analysis comprised 47 subjects.
Effect of Material Magnesium Sulfate Exposure on Hypoxia-Induced Glutamate Release in the Intact Preterm Fetal Sheep Cerebral Cortex

Effect of Material Magnesium Sulfate Exposure on Hypoxia-Induced Glutamate Release in the Intact Preterm Fetal Sheep Cerebral Cortex
Periodic effects in catalysis: The relation between trends in catalytic activity and calculated electronic structure of transition-metal sulfides

Abstract The basis for periodic effects in the catalytic activity of transition-metal sulfides is not understood. In this paper the results of SCF Xα calculations on cluster models of transition-metal sulfides are used to identify electronic factors related to catalytic activity. Calculated quantities are combined to form an activity parameter which shows a direct correlation between electronic structure and catalytic activity of the sulfides.
On the optimal kinematic design of spherical and spatial mechanisms

The optimal kinematic design of spherical and spatial mechanisms for dexterity and workspace volume is addressed. The concept of dexterity used is based on the distortion measure of harmonic mappings which is defined in a natural, coordinate-invariant way. The author analyzes the performance of robotic wrists with respect to these kinematic criteria, and determines the optimal link lengths for a simple two-link, 3R spatial open chain. In addition, he compares the kinematic dexterity of three redundant 7R open chains. >
Low-cost terrain relative navigation for long-range AUVs

Recent development of underwater Terrain Relative Navigation (TRN) provides an enabling capability for low-cost navigation on underwater vehicles. High performance TRN systems have been demonstrated using both high-accuracy inertial navigation systems (INS) and high-quality sonars such as multibeam echo sounders. Moving to systems with lower-cost sensor equipment would enable a broader range of TRN applications. This paper considers the performance trade-offs in moving to sonars as low-cost as altimeters, as well as in moving to lower-accuracy inertial systems. The effects of translational and orientation uncertainty on the TRN estimate are explored, and the results of these studies are validated through field trials on the Monterey Bay Aquarium Research Institute (MBARI) Dorado Autonomous Underwater Vehicle (AUV). The field trials demonstrate success on both DVL and altimeter-based TRN configurations.
Effects of Fertilization Distance on Male Gain Curves in A Free-Spawning Marine Invertebrate: A Combined Empirical and Theoretical Approach

Male gain curves describe the relationship between allocation to sperm production and male reproductive success and are central to models of sex allocation in hermaphrodites. Sperm competition is expected to result in more linear gains and select for increased allocation. We hypothesized that high sperm production in passively mating systems may also be the result of selection to enhance the ability to fertilize distant ova. Consequently, we explored the effect of distance on male gain curves in a free-spawning colonial ascidian. The performance of focal males that varied in sperm production was assayed at three distances via microsatellite markers. An advection-diffusion model was used to estimate sperm concentration gradients, to predict male reproductive gain integrated across multiple downstream females, and explore effects of hydrodynamic conditions. As distance increased, male reproductive success decreased and empirical gain curves became increasingly linear. Our model predicted that the expected net gain curve is relatively insensitive to variation in flow regime and will saturate much more slowly than if only a single, nearby distance is considered. Thus, high levels of sperm production may enhance fitness both in competitive situations and with increasing fertilization distance, highlighting the need to consider distance effects when evaluating gain curves.
RADIATION SENSITIVITY OF HAEMOPHILUS INFLUENZAE: A COMPOSITE RESPONSE.

The survival of ultraviolet (UV)-irradiated cultures of Haemophilus influenzae Rd is determined by at least two responses: (i) excision-repair ability and (ii) UV-induced cell lysis. An UV-resistant mutant, BC200, has the same capabilities as the wild type, Rd, for excising dimers but does not exhibit lysis. Lytic response is dose-dependent. Relative to the wild type, a lower dose of UV causes lysis of a UV-sensitive mutant, BC100, which is incapable of excising thymine dimers. A lytic protein is present in cultures undergoing lysis. Synthesis of this protein is initiated 45 to 60 min after irradiation. Lysis appears to be due to derepression of a defective prophage which codes for an endolysin-like lytic enzyme.
Large Magnetoresistance Effects in Self-Doped La0.936Mn0.982O3Single Crystals

The authors report here for the first time colossal magnetoresistance effects ({approximately}77% MR at 5 T) in bulk single crystals of self-doped La{sub 0.936}Mn{sub 0.982}O{sub 3} prepared by fused-salt electrolysis. The crystals form with rhombohedral symmetry and show a high degree of perfection by electron backscatter diffraction. The maximum in the MR% was observed in the vicinity of {approximately}250 K where the crystals undergo a sharp insulator-to-metal as well as a paramagnetic-to-ferromagnetic transition.
Bovine Oocyte Cytoplasm Supports Development of Embryos Produced by Nuclear Transfer of Somatic Cell Nuclei from Various Mammalian Species

The transfer of nuclei from one cell to another provides a powerful tool for studying the interactions between the cytoplasm of one cell and the nucleus of another. This study was designed to examine the ability of the bovine metaphase oocyte cytoplasm to support mitotic cell cycles under the direction of differentiated somatic cell nuclei of various mammalian species. Skin fibroblast cells from cows, sheep, pigs, monkeys, and rats were used as sources of donor nuclei. Nuclear transfer units produced by fusion of enucleated bovine oocytes and individual fibroblasts from all species examined underwent transition to interphase accompanied by nuclear swelling, further progression through the cell cycle, and completion of the first mitosis. Regardless of the species of donor fibroblasts used, some cleaving units progressed further and developed to advanced stages, as evidenced by continuation of cell proliferation and formation of a blastocoele cavity at the time appropriate for the donor fibroblast species. Although no pregnancies have been carried to term after transfer of embryos into surrogate animals, these observations suggest that mechanisms regulating early embryonic development may be conserved among mammalian species and that bovine oocyte cytoplasm can support the introduced differentiated nucleus regardless of chromosome number, species, or age of the donor fibroblast.
The aging human orbitofrontal cortex: Decreasing polyunsaturated fatty acid composition and associated increases in lipogenic gene expression and stearoyl-CoA desaturase activity

Orbitofrontal cortex (OFC, Brodmann area 10) gray matter volume reductions and selective reductions in docosahexaenoic acid (DHA, 22:6n-3) are observed in adult patients with major depressive disorder (MDD). OFC gray matter volume also decreases with advancing age in healthy subjects. To examine if OFC gray matter DHA composition decreases during normal aging, we determined age-related changes in OFC gray matter fatty acid composition by gas chromatography in subjects aged 29-80 years (n=30). We additionally determined elongase (HELO1), delta-5 desaturase (FASD1), delta-6 desaturase (FASD2), peroxisomal (PEX19), and stearoyl-CoA desaturase (SCD) mRNA expression in the same tissues. Increasing age was associated with a progressive decline in polyunsaturated fatty acid (PUFA) composition, including DHA and arachidonic acid (AA, 20:4n-6), and transient, apparently compensatory, elevations in elongase and desaturase gene expression. The age-related reduction in PUFA composition was inversely correlated with SCD expression and activity resulting in elevations in monounsaturated fatty acid composition. These dynamic age-related changes in OFC gray matter fatty acid composition and biosynthetic gene expression may contribute to the progressive decline in OFC gray matter volume found with advancing age. The implications of age-related reductions in OFC PUFA composition for affective dysregulation in the elderly are discussed.
On downlink power allocation for multiuser variable‐bit‐rate video streaming

In this paper, we study the problem of power allocation for streaming multiple variable-bit-rate (VBR) videos in the downlink of a cellular network. We consider a deterministic model for VBR video traffic and finite playout buffer at the mobile users. The objective is to derive the optimal downlink power allocation for the VBR video sessions, such that the video data can be delivered in a timely fashion without causing playout buffer overflow and underflow. The formulated problem is a nonlinear nonconvex optimization problem. We analyze the convexity conditions for the formulated problem and propose a two-step greedy approach to solve the problem. We also develop a distributed algorithm based on the dual decomposition technique, which can be incorporated into the two-step solution procedure. The performance of the proposed algorithms is validated with simulations using VBR video traces under realistic scenarios. Copyright © 2012 John Wiley & Sons, Ltd.
Liver transplantation with monosegments.

Abstract Background: Shortage of size-matched pediatric donors led to the development of surgical techniques to reduce or split livers and thus increase the potential pool of donors. Despite this, neonatal transplantation remains a problem because of the small size of the recipients. Further reduction of the left lateral segment is possible to provide a single segment graft (segment III). We report our experience of transplanting 6 babies using this technique. Methods: Of 310 children transplanted in our center between October 1989 and March 1998, 6 patients, 2 male and 4 female, median age 37.5 days (range 5 to 92 days), median weight 3.45 kg (range 2.45 to 5.46 kg) were transplanted with a monosegment. The cause of liver failure was neonatal hemochromatosis in 4, retransplantation for hepatic artery thrombosis in 1, and hepatitis B in one. The donor liver was reduced or split to a left lateral segment. Segment II was then resected and discarded before transplantation. Results: Overall, graft and patient survival is 83.3%. Five patients are alive with good graft function at a mean follow-up of 30.4 months (range 8 to 82 months). One child who was transplanted for hepatic artery thrombosis died from sepsis and multiorgan failure 48 hrs after transplant. None of the survivors had vascular or biliary complications. Conclusions: Monosegment liver transplantation with segment III appears to be a satisfactory option for treating small babies with liver failure. (Surgery 1999;126:10-2.)
Phase-field method of phase transitions/domain structures in ferroelectric thin films: A review

This article briefly reviews recent applications of phase-field method to ferroelectric phase transitions and domain structures in thin films. It starts with a brief introduction to the thermodynamics of coupled electromechanical systems and the Landau description of ferroelectric transitions in homogeneous ferroelectric single crystals. The thermodynamic potentials of a homogeneous crystal under different mechanical boundary conditions are presented, including the thin-film boundary conditions. The phase-field approach to inhomogeneous systems containing domain structures is then outlined. It describes a domain structure using the spatial distribution of spontaneous polarization. The evolution of a domain structure towards equilibrium is driven by the reduction in the total-free energy of an inhomogeneous domain structure including the chemical driving force, domain wall energy, electrostatic energy as well as elastic energy. A number of examples are discussed, including phase transitions and domain stability in ferroelectric thin films and superlattices. It is demonstrated that using a set of independently measured thermodynamic parameters for the corresponding bulk single crystals, the phase-field approach is able to quantitatively predict not only the strain effect on phase transition temperatures but also the correct ferroelectric domain structures for a given strain and temperature.
THE DISK IMAGING SURVEY OF CHEMISTRY WITH SMA. I. TAURUS PROTOPLANETARY DISK DATA

Chemistry plays an important role in the structure and evolution of protoplanetary disks, with implications for the composition of comets and planets. This is the first of a series of papers based on data from DISCS, a Submillimeter Array survey of the chemical composition of protoplanetary disks. The six Taurus sources in the program (DM Tau, AA Tau, LkCa 15, GM Aur, CQ Tau, and MWC 480) range in stellar spectral type from M1 to A4 and offer an opportunity to test the effects of stellar luminosity on the disk chemistry. The disks were observed in 10 different lines at {approx}3'' resolution and an rms of {approx}100 mJy beam{sup -1} at {approx}0.5 km s{sup -1}. The four brightest lines are CO 2-1, HCO{sup +} 3-2, CN 2{sub 33/4/2} - 1{sub 22/3/1}, and HCN 3-2, and these are detected toward all sources (except for HCN toward CQ Tau). The weaker lines of CN 2{sub 22}-1{sub 11}, DCO{sup +} 3-2, N{sub 2}H{sup +} 3-2, H{sub 2}CO 3{sub 03}-2{sub 02}, and 4{sub 14}-3{sub 13} are detected toward two to three disks each, and DCN 3-2 only toward LkCa 15. CH{sub 3}OH 4{sub 21}-3{sub 1} {sub 2} and c-C{sub 3}H{sub 2} are not detected.more » There is no obvious difference between the T Tauri and Herbig Ae sources with regard to CN and HCN intensities. In contrast, DCO{sup +}, DCN, N{sub 2}H{sup +}, and H{sub 2}CO are detected only toward the T Tauri stars, suggesting that the disks around Herbig Ae stars lack cold regions for long enough timescales to allow for efficient deuterium chemistry, CO freeze-out, and grain chemistry.« less
THYROID FUNCTION, IODINE NUTRITION AND FETAL BRAIN DEVELOPMENT

SUMMARY The clinical effects of congenital hypothyroidism on brain function have been well documented and the need for early diagnosis and treatment established. This is now possible through neonatal screening. Improved results may be expected but there is evidence of prenatal effects. More evidence of the effects of fetal hypothyroidism on brain development is required in order to determine the need for antenatal diagnosis. Experimental studies indicate significant effects of hypothyroidism on fetal brain development in the monkey and the sheep during the third trimester. In the rat, significant effects, particularly on the cerebellum, can be shown in the first 3 weeks postnatally, a period corresponding to the third trimester of the human pregnancy. Retardation of cerebellar nerve cell migration, differentiation, growth and arborization have all been demonstrated, together with persistence of the external granular zone and DNA polymerase activity. Such effects provide an explanation for the common occurrence of ataxia and nystagmus in congenital hypothyroidism. Severe iodine deficiency with an intake less than 20 μg per day and high goitre prevalence in endemic goitre areas is associated with the condition of endemic cretinism characterised in its fully developed form by mental deficiency, deaf mutism, spastic diplegia and squint with absence of clinical hypothyroidism. This condition does not respond to replacement therapy with thyroid hormones. Correction of the iodine deficiency prior to pregnancy will prevent the condition, but correction of the iodine deficiency in the latter half of pregnancy will not. This indicates the necessity of iodine for fetal brain development in man. Experimental studies in the guinea pig and sheep indicate an effect of severe iodine deficiency on brain growth early in pregnancy at the time of neuroblast multiplication. Such an early effect could provide an explanation for the irreversibility of the effects of severe iodine deficiency on brain development in man. The role of maternal and fetal hypothyroidism and iodine deficiency itself in these effects has still to be defined. It may be concluded that the relation
Negotiating Solidarity: Indra Sinha’s Animal’s People and the ‘NGO-ization’ of Postcolonial Narrative

AbstractThis essay examines the relationship between transnational non-governmental organizations (NGOs) and postcolonial disasters as represented in literature. After the 1990s expansion of humanitarian organizations, a wide array of NGO-related literature emerges, including depictions of aid workers in fiction as well as humanitarian-authored narratives. While these texts contain a capacity for self-critique typically lacking in transnational NGO campaign materials, they remain mired in a ‘bureaucratic imagination’, sequestered from supposed beneficiaries. Alongside this literary development is an increasing pressure on postcolonial fiction to align with narrowly defined NGO missions, or what might be called an ‘NGO-ization of postcolonial narrative’. This essay interprets Indra Sinha’s Animal’s People as a vociferous refutation of such humanitarian pressure. Sinha stages the interaction between subaltern survivor and humanitarian benefactor not in terms of heroic salvation or radical rejection but as a...
Application of supervisory control methods to uncertain multiple contact mechanical systems

Estimation of contact state is important to any multi-point interaction that involves frictional stick/slip phenomena. In particular, when there are more kinematic constraints than there are degrees of freedom, some contact interfaces must slip, leading to the need for contact state estimation. Fortunately, supervisory control techniques from adaptive control can he applied to this problem with relatively little modification. We discuss this approach in terms of a distributed manipulation experiment developed to explore overconstrained manipulation. In this context, we show in a simulated model that on-line contact state estimation dramatically improves performance over methods that estimate contact states off-line.