cssi/SciSciGPT-SciSciNet huggingface dataset:
Influence of percutaneous transluminal coronary rotational atherectomy with adjunctive percutaneous transluminal coronary angioplasty on coronary blood flow

Abstract The purpose of this study was to examine the influence of sequential percutaneous transluminal coronary rotational atherectomy (PTCRA) and coronary angioplasty on coronary blood flow and flow reserve in patients. Rotational coronary atherectomy restores lumen patency by partially ablating fibrocalcific plaque, releasing microparticulate debris into the distal coronary circulation. Adjunctive balloon angioplasty is usually performed to optimize the angiographic luminal dimensions. Serial alterations in coronary physiology have not been reported. Fourteen lesions in 13 patients were treated by sequential rotational atherectomy followed by adjunctive balloon angioplasty. Poststenotic baseline coronary blood flow velocity was measured by using a Doppler flow wire (FloWire, Cardiometrics, Inc., Mountain View, Calif.), and coronary blood flow was calculated by using the distal vessel cross-sectional area obtained by quantitative coronary angiography. Data were acquired at baseline and during hyperemia (12 to 18 μg of intracoronary adenosine), before and after PTCRA, and again after balloon angioplasty. The mean stenosis decreased from 76% ± 12% at baseline to 21% ± 11% at the completion of the procedure ( p p p p = not significant [NS] vs PTCRA) and increased to 143 ± 81 ml/min with hyperemia ( p = NS vs PTCRA). The poststenotic coronary flow reserve increased from an initial value of 1.1 ± 0.2 ml/min to 1.3 ± 0.3 ml/min after PTCRA ( p = NS vs baseline) and to 1.6 ± 0.3 ml/min after adjunctive balloon angioplasty ( p p = NS vs PTCRA). PTCRA significantly increased resting coronary blood flow. Adjunctive balloon angioplasty did not significantly augment resting or hyperemic coronary blood flow more than that achieved by rotational atherectomy alone. These data demonstrate that PTCRA alone improves baseline coronary blood flow with minimal additional physiologic change after adjunctive balloon angioplasty.
Interactions of the Native and Alien Faunas of New Zealand and the Problem of Fish Introductions

Abstract New Zealand possesses a small and unsaturated but peculiar indigenous freshwater fish fauna. In addition, a considerable variety of introduced species is now in competition with the native species and evidence suggests that this is causing depletion of the native fauna. It is considered that low saturation and high isolation of the New Zealand fauna has produced species with low competitive ability. The largely predatory introduced game fishes are of continental origin and their superior competitive ability is leading to competitive displacement of the native species.
SU‐FF‐T‐101: Characterizing Output for a Static TomoTherapy Field

Purpose: To determine in‐air and in‐phantom output factors for a static TomoTherapy beam. Method and Materials: Measurements and computer simulations of in‐air output ratios (Sc) and in‐phantom output factors (Scp) have been made for a static TomoTherapy beam. In‐air measurements were made at a depth of 10 cm in a commercial mini‐phantom for field widths ranging from 1.8 cm to 40 cm, for 2.5‐cm and 5.0‐cm jaw selections. Measurements were made at source‐chamber distances (SCDs) of 85 cm and 105 cm. In‐phantom measurements were made at a depth of 10 cm in a full size virtual water phantom for the same field sizes and at an SCD of 85 cm. Data were normalized to the values for the largest available field size (40 × 5 cm2). Both in‐air and in‐phantom measurements were compared with simulations made on the TomoTherapy planning system using simulated CT datasets of the full size and mini‐phantoms. Results: In general, measured and simulated data agreed within 2% for the output factors determined in this work. Measured and simulated Scps varied steeply (∼ 15%) for the field sizes investigated. In contrast, Scs showed little changes with field size or SCD, although the measured data demonstrated a slightly greater variation with field size than the simulated results. Results were consistent between data taken for different jaw selections, with the best agreement observed for the determined phantom scatter factors, Sp. Conclusion: The lack of a flattening filter in the TomoTherapy beam explains the small variation of Sc with field size and SCD. Thus, Scp is due primarily to phantom scatter, which should not vary greatly between TomoTherapy machines. The determination of output factors may be used in the verification of treatment planning doses, both for helical and static deliveries. Supported in part by a research agreement with TomoTherapy, Inc.
Electronic digital ratio equipment

The equipment provides an accurate method of multiplying a frequency by M/N, where M and N are integers and M ? N. Two batching counters are used to determine the output frequency in the long term and the equipment described restores the correct phase relationship. The equipment is transistorized and makes use of modern techniques for counting, gating and parallel addition and subtraction. A brief description is also given of a relay-operated decimal-to-binary converter which has been designed for the ratio equipment.
Orientation Dependence on Electro-Mechanical Coupling Behavior of 1-3 Piezoelectric Composites Under Compression

The nonlinear electro-mechanical behavior of 1–3 piezoelectric composites with PZT5A1 fibers embedded in an epoxy matrix are studied under multi-axial mechanical loading. In order to evaluate the orientation effects of the polarization in PZT fibers to the overall performance of the ferroelectric composite system, the direction of the applied compressive loading is oriented by an angle of θ toward to the PZT fiber direction which is also the polarization direction. The non-linear responses in stress-strain and stress-electric displacement were measured at given loading angle θ. A two-level micromechanics theory based on irreversible thermodynamics and physics of domain switch is applied to compare with our experimental data. The theoretical results are found to be in good qualitative and quantitative agreement with our experimental data.Copyright © 2008 by ASME
Bisabolones and other constituents of Mikania shushunensis

Abstract Chemical investigation of the aerial parts of Mikania shushunensis furnished three new derivatives of cryptomerion as well as cryptomerion itself, a new thymol derivative, herniarin, 2,6-dimethoxyquinone, syringaldehyde and the corresponding alcohol.
Sensitivity analysis for project planning and scheduling under uncertain completions

Development of a sensitivity analysis (SA) procedure is a significant part of constructing robust solutions for a class of resource constrained planning and scheduling problems. The key uncertain parameters, the probabilities that projects will be terminated, occur in both the objective function and the left-hand side of the constraints. Estimates of the mean probability of failure for a task can be extracted from historical data; however, it is important to take into account the sensitivity of the proposed solution to variations in these estimates. Parameter studies show complex interactions between the objective function and the resource constraints. A method to study the behavior of the solution using branch and bound algorithms enhanced with logical programming is introduced.
A delineation of functional areas of competency considered important to consumer affairs professionals

Analysis of data collected from practicing consumer affairs professionals resulted in the delineation of functional areas of competency they consider important in performing their jobs. Important competency areas delineated through factor analysis include: general management and legal decisions; consumer project development and implementation; consumer relations and correspondence; research and communications; and consumer-oriented information. Areas of functional competency varied by type of organization, management level of the CAP, age, and sex.
Object class uncertainty induced snake with applications to medical image segmentation

Object segmentation is of paramount interest in many medical imaging applications. Among others, "snake"-an "active contour"-is a popular boundary-based segmentation framework where a spline is continuously deformed to lock onto an object boundary. The dynamics of a snake is governed by different internal and external forces. A major limitation of this framework has been the difficulty in using object-intensity driven features into snake dynamics which may prevent uncontrolled expansion/contraction once the snake leaks through a weak boundary region. In this paper, object-intensity force is effectively introduced into the snake-model using class uncertainty theory. Given a priori knowledge of object/background intensity distributions, class uncertainty yields object/background class of any location and establishes the confidence level of the classification. This confidence level has previously been demonstrated to be high inside the object/background regions and low near boundaries with intermediate intensities. This class uncertainty information adds an expanding (outward) force at locations pertaining to intensity-based object class and a squeezing (inward) force inside background regions. Consequently, the method possesses potential to resist an uncontrolled expansion of the snake (for an expanding type) into the background through a weak boundary while reducing the effect of this force near the boundary using the confidence information. The theory of object class uncertainty induced snake is developed and an implementation with efficient graphical interface is achieved. Preliminary results of application of the proposed snake approach on different images are presented and comparisons with conventional snake approaches are demonstrated.
Composition and evolution of the eucrite parent body - Evidence from rare earth elements

Quantitative modeling of the evolution of rare earth element (REE) abundances in the eucrites, which are plagioclase-pigeonite basalt achondrites, indicates that the main group of eucrites (e.g., Juvinas) might have been produced by approximately 10% equilibrium partial melting of a single type of source region with initial REE abundances which were chondritic relative and absolute. Since the age of the eucrites is about equal to that of the solar system, extensive chemical differentiation of the eucrite parent body prior to the formation of eucrites seems unlikely. If homogeneous accretion is assumed, the bulk composition of the eucrite parent body can be estimated; two estimates are provided, representing different hypotheses as to the ratio of metal to olivine in the parent body. Since a large number of differentiated olivine meteorites, which would represent material from the interior of the parent body, have not been detected, the eucrite parent body is thought to be intact. It is suggested that the asteroid 4 Vesta is the eucrite parent body.
Volume regulation and KCl cotransport in reticulocyte populations of sickle and normal red blood cells

The potassium chloride co-transporter (KCC) is a member of the electroneutral cation chloride family of cotransporters found in multiple tissues that are involved in transepithelial ion transport and regulation of intracellular ion content and cell volume. We have shown previously that three of the four KCC genes - KCC1, KCC3, and KCC4 - are expressed in red blood cells (RBC) (Exp. Hem. 33:624, 2005). Functionally, the KCC mediates volume reduction of reticulocytes that establishes the higher cellular hemoglobin concentration (CHC) of mature RBC. KCC activity is higher in reticulocytes and diminishes with age. KCC activity in RBC containing sickle hemoglobin (SS RBC) is elevated compared to normal (AA RBC) in part due to reticulocytosis in SS blood. However, we have demonstrated that SS reticulocytes have abnormal regulation of KCC activity leading to increased CHC upon activation of KCC compared to AA reticulocytes (Blood 104:2954, 2004; Blood 109:1734, 2007). These findings implicate KCC as a factor in the dehydration of SS RBC, which leads to elevated Hb S concentration and enhances Hb S polymerization and hemolysis. Because KCC activity correlates with cell age, standard flux measurements on blood samples with different numbers of reticulocytes or young non-reticulocytes are not comparable. The Advia automated cell counter measures cell volume (MCV) and cellular hemoglobin concentration (CHC) in reticulocytes, an age-defined population of cells, and thus circumvents the problem of variable reticulocyte counts among SS and AA blood samples. In this study, reticulocyte CHC measurements on fresh blood demonstrated a clear difference between AA and SS cells, reflecting in vivo dehydration of SS reticulocytes, although there was significant inter-individual variation, and the CHC distributions of the two groups overlapped. After KCC activation in vitro by cell swelling using the nystatin method, the initial changes in reticulocyte MCV and CHC with time were used to estimate flux rates mediated by KCC, assuming that changes were associated with isotonic KCl movements. After 20-30min a final steady state MCV/CHC (set point) was achieved and maintained, reflecting inactivation of the transporter. CHC set points were 26.5-29g/dl in SS reticulocytes compared to 25-26.5g/dl in AA reticulocytes, reflecting abnormal regulation in SS cells. These results were reproducible in the same individual over time. KCC flux derived from CHC ranged from 5 to 10.3mmolK/kgHb/min in SS reticulocytes, compared to 2.9-7.2mmolK/kgHb/min in AA reticulocytes. Such measures of KCC activity in red cell populations controlled for cell age will facilitate further studies correlating KCC activity with phenotypic or genetic variability in sickle cell disease.
Phytobilin biosynthesis: cloning and expression of a gene encoding soluble ferredoxin‐dependent heme oxygenase from Synechocystis sp. PCC 6803

The phytobilin chromophores of phycobiliproteins and phytochromes are biosynthesized from heme in a pathway that begins with the opening of the tetrapyrrole macrocycle of protoheme to form biliverdin IX alpha, in a reaction catalyzed by heme oxygenase. A gene containing an open reading frame with a predicted polypeptide that has a sequence similar to that of a conserved region of animal microsomal heme oxygenases was identified in the published genomic sequence of Synechocystis sp. PCC 6803. This gene, named ho1, was cloned and expressed in Escherichia coli under the control of the lacZ promoter. Cells expressing the gene became green colored due to the accumulation of biliverdin IX alpha. The size of the expressed protein was equal to the predicted size of the Synechocystis gene product, named HO1. Heme oxygenase activity was assayed in incubations containing extract of transformed E. coli cells. Incubations containing extract of induced cells, but not those containing extract of uninduced cells, had ferredoxin-dependent heme oxygenase activity. With mesoheme as the substrate, the reaction product was identified as mesobiliverdin IX alpha by spectrophotometry and reverse-phase HPLC. Heme oxygenase activity was not sedimented by centrifugation at 100, 000 g. Expression of HO1 increased several-fold during incubation of the cells for 72 h in iron-deficient medium.
Simulation of Folding of a Small Alpha-helical Protein in Atomistic Detail using Worldwide- distributed Computing

By employing thousands of PCs and new worldwide-distributed comput- ing techniques, we have simulated in atomistic detail the folding of a fast- folding 36-residue a-helical protein from the villin headpiece. The total simulated time exceeds 300 ms, orders of magnitude more than previous simulations of a molecule of this size. Starting from an extended state, we obtained an ensemble of folded structures, which is on average 1.7 A ˚ and 1.9 Aaway from the native state in C a distance-based root-mean- square deviation (dRMS) and C b dRMS sense, respectively. The folding mechanism of villin is most consistent with the hydrophobic collapse view of folding: the molecule collapses non-specifically very quickly (, 20 ns), which greatly reduces the size of the conformational space that needs to be explored in search of the native state. The conformational search in the collapsed state appears to be rate-limited by the formation of the aromatic core: in a significant fraction of our simulations, the C-terminal phenylalanine residue packs improperly with the rest of the hydrophobic core. We suggest that the breaking of this interaction may be the rate-determining step in the course of folding. On the basis of our simulations we estimate the folding rate of villin to be approximately 5 ms. By analyzing the average features of the folded ensemble obtained by simulation, we see that the mean folded structure is more similar to the native fold than any individual folded structure. This finding high- lights the need for simulating ensembles of molecules and averaging the results in an experiment-like fashion if meaningful comparison between simulation and experiment is to be attempted. Moreover, our results demonstrate that (1) the computational methodology exists to simulate the multi-microsecond regime using distributed computing and (2) that potential sets used to describe interatomic interactions may be sufficiently accurate to reach the folded state, at least for small proteins. We conclude with a comparison between our results and current protein-folding theory. q 2002 Elsevier Science Ltd. All rights reserved
Mapping three invasive weeds using airborne hyperspectral imagery

Invasive plant species present a serious problem to the natural environment and have adverse ecological and economic impacts on both terrestrial and aquatic ecosystems they invade. This article presents three case studies on the use of hyperspectral remote sensing for mapping invasive plant species in both terrestrial and aquatic environments. Methods and procedures for acquisition, processing and classification of airborne hyperspectral imagery as well as accuracy assessment are presented. Examples are excerpted and adapted from published work to illustrate how airborne hyperspectral imagery has been used to map two terrestrial weeds, Ashe juniper (Juniperus ashei Buchholz) and Broom snakeweed [Gutierrezia sarothrae (Pursh.) Britt. and Rusby], and one aquatic weed, waterhyacinth [Eichhornia crassipes (Mart.) Solms], in Texas. In addition to the standard classification methods used in the previous studies, a spectral unmixing technique, mixture tuned matched filtering (MTMF), was applied to the three study cases and the classification results are reported in this paper. A brief discussion is provided on the considerations of different types of remote sensing imagery for mapping invasive weeds.
Influence of solvent composition on the solubilities and solid-state properties of the sodium salts of some drugs

Abstract The solubilities of the sodium salts of some sulfonamides, barbiturates and hydantoins have been determined in mixtures of propylene glycol and water. In many cases, the solubilities of the salts in the mixed solvents were lower than those in water, however, several compounds exhibited enhanced solubilities in the mixed solvents. This unexpected increase in solubility was not related to the lipophilicity of the acidic forms of the drugs and occurred in at least one member of each group of compounds. Analysis of the solid phase which had been equilibrated with each solvent indicated the formation of crystal hydrates for most of the solutes, and in at least one instance, mixed solvates. These compounds could be categorized on the basis of their desolvation temperatures. Those compounds with low temperatures of desolvation had increased solubilities in propylene glycol-water mixtures while compounds with high desolvation temperatures had decreased solubilities in the mixed solvents. These data indicate that crystal hydrate formation plays a significant role in determining if a cosolvent can be used to enhance the solubilities of certain sodium salts.
An Experimental Study of Titanium Powder Reactivity in Gaseous Environments. Part I: Oxidation

Abstract A simultaneous thermogravimetric/differential thermal analyzer with a range from 20 to 1600°C was used to study the oxidation of Ti powder. The influences of powder morphology, initial oxygen and nitrogen content and the effects of heating rate and sample size were investigated. All the oxidation experiments terminated at the sample ignition point with an associated heating effect that induced sample melting. The ignition temperature for oxidation increased with higher initial oxygen content, and the nature of the ignition process changed: the transition from passivity to combustion via a regime of gradual oxidation collapsed, bypassing the initial oxidation process observed for powders with lower initial oxygen contents. Cracking of the protective oxide scale played an important part in this behavior. The complete history of the powder needs lo be known in order to characterize its reactivity: simple measurable powder characteristics like particle size, surface area and oxygen content alone, are...
A new HPLC method of hydrophobicity evaluation employing poly (butadiene)-coated alumina columns

The limitations of the existing methods and procedures of hydrophobicity evaluation by high-performance liquid chromatography are pointed out and a new approach is described allowing convenient, fast, and reproducible hydrophobicity quantitation for diverse basic, neutral, and acidic solutes of different chemical classes. The method is based on using poly(butadiene)-coated alumina developed by Schomburg and co-workers as the stationary phase which can be operated under wide range of eluent pH and which shows no tendency for specific interactions with solutes, typical for silica-based reversed-phase materials.
The Mannose-specific Bulb Lectin fromGalanthus nivalis(Snowdrop) Binds Mono- and Dimannosides at Distinct Sites. Structure Analysis of Refined Complexes at 2.3 Å and 3.0 Å Resolution

Galanthus nivalisagglutinin (GNA, a 50 kDa tetramer) is a mannose-specific lectin of the Amaryllidaceae family of bulb lectins. Crystal structures of GNA complexed with methyl-α-D-mannose (MeMan) and mannose-α1,3-D- mannose-α-OMe (MeMan-2) have been determined and analyzed in terms of internal structural symmetry and saccharide binding. The final model of the 2.29 A orthorhombic Δmethyl-α-Man complex refined with anR-factor of 0.167 (all data) includes 12 bound sugar ligands and 327 water molecules. The four independent subunits (A, B, C and D) of the 222 tetramer and the three four-stranded β-sheets (I,II and III) that constitute each subunit compare closely (r.m.sΔ=<1.0 A). The 12 bound methyl-α- Man molecules refined withB-factors <22 A2and occupancies in the range of 0.5 to 1.0. The highest occupied site is located in β-sheet I (site 1), where interactions from the dimer-related subunit contribute to complex stabilization. These subunit pairs (A-D and B-C) associate tightly with a buried surface area of 1738 A2and 33 interchain hydrogen bonds resulting from C-terminal strand exchange. In comparison, the A-B and C-D subunit pairs have narrow interfaces (476 A2) and no direct H-bond contacts. The 3.0 A structure of the cubic Man-α1,3-Man-OMe complex, determined by molecular replacement and refined with X-PLOR using NCS constraints and density modification methods, is less well ordered due to a high crystal solvent content (68%). Complexed disaccharide is responsible for the most crucial lattice contacts, which involve only one of the two independent subunits (A). The second subunit (C) shows a high degree of flexibility (Bav=41.7 A2). The complete disaccharide molecule is visible in both subunits at site 3, which is the only extended site. The ligand is oriented with its reducing end positioned in the specificity pocket. The non-reducing mannose is in contact through hydrogen bonding with a charged subsite (D37-K38) on the 2-fold-related subunit (A-B or C-D interfaces). Bound Man-α1,3-MeMan is also well defined in site 2 of subunit A, as a result of favorable lattice contacts, while only the mannose residue bound in the specificity pocket is visible at site 2 of subunit C and site 1 of both subunits. Together these results suggest that strong binding correlates with the presence of subsidiary contacts coming either from a dimer-related subunit or from lattice interactions. Site 1 is most specific for terminal non-reducing or reducing mannose, while site 3 is extended and complementary to α-1,3 linked mannose oligosaccharides.
Anaerobic treatment of PCP in fluidized-bed GAC bioreactors

Abstract A fluidized-bed granular activated carbon (GAC) bioreactor was evaluated for anaerobically treating wastewater containing pentachlorophenol (PCP). PCP removal efficiencies of greater than 99.9% were achieved at PCP loadings as high as 4 g/kg of GAC per day and influent PCP concentrations as high as 1333 mg/litre. In addition to PCP, ethanol was fed to the bioreactors as the primary substrate. The chemical oxygen demand (COD) loading to the reactor was increased several times as high as 63 g/kg of GAC per day using reactor empty bed contact times as low as 9.3 h in order to exhaust the adsorptive capacity of the GAC for PCP, thus allowing for the development of a PCP-degrading biofilm on the carbon. A major proportion of the influent COD, ranging from 70 to 90%, was converted to methane, which constituted more than 85% of the product gas stream. Due to incomplete mineralization, nearly all PCP was stoichiometrically converted to 3- and 4-chlorophenols. Low levels of 2,4,6- and 3,4,5-trichlorophenols, 2,4- and 3,4-dichlorophenols and phenol were observed in the reactor. The primary biotransformation product of PCP, 4-chlorophenol, inhibited the methanogenic culture at concentrations as low as 116 mg/litre. Toxicity was minimized by controlling the influent PCP concentration, the primary source of the inhibitory products.
Novel tastes elevate c-fos expression in the central amygdala and insular cortex: implication for taste aversion learning.

Taste novelty strongly modulates the speed and strength of taste aversion conditioning. To identify molecular signals responsive to novel tastes, immunostaining for c-fos protein (Fos-like immunoreactivity [FLI]) was used to mark neurons that responded differentially to taste novelty. Novel saccharin induced larger increases in FLI than familiar saccharin. This pattern was seen in central amygdala and insular cortex, but not in basolateral amygdala, parabrachial nucleus, or nucleus of the solitary tract. Other parameters known to influence aversion learning were tested for effects on FLI. Manipulations known to reduce the strength of learning blunted the FLI response, supporting the idea that FLI marks neural pathways critical to taste processing during acquisition, and that c-fos expression is a key transcriptional event underlying this plasticity.
Computer-Related Assistive Technology: Satisfaction and Experiences among Users with Disabilities

Many people with disabilities use assistive technology devices (ATDs) for computer access. The specific focus of this exploratory study was (a) to assess the experiences, opinions, and satisfaction levels of 24 individuals with disabilities using computer-related ATDs; (b) to investigate their awareness of health risk factors related to computer usage; and (c) to examine the psychosocial impact of computer-related ATDs on users. Data were collected via telephone interviews with 24 individuals with physical disabilities who had experience using one or more ATDs. The Quebec User Evaluation with Assistive Technology instrument was used to evaluate users' satisfaction with ATDs in a number of dimensions, including their physical attributes. The Psychosocial Impact of Assistive Devices Scale measured the psychosocial impact (i.e., independence, competence, and adequacy) of an ATD on users. Additional questions were posed to gather information about user's opinions and experiences. Training appeared to be an im...
Electrokinetically Pumped Liquid Propellant Microthrusters for Orbital Station Keeping

For most orbital maneuvers, small satellites in the sub-10 kg range require thrusters capable of spanning the micro-Newton to milli-Newton force range. At this scale, electrokinetic (EK) pumping offers precise metering of monergolic or hypergolic liquid propellants under purely electrical control at pressures and flow rates well-suited to microthruster applications. We have demonstrated direct and indirect EK pumping for delivery of anhydrous hydrazine and hydrogen peroxide monopropellants, respectively, into capillary-based microthrusters with integrated in-line catalyst beds. Catalytic decomposition generates gases which accelerate through a plasma-formed converging-diverging nozzle, producing thrust. Specific impulses up to 190 s have been shown for hydrazine in non-optimized nozzles.
Determination of Permethrin in Environmental Waters by Gas Chromatography-Selected Ion Monitoring-Mass Spectroscopy Using Ion Counting Detection

Abstract Traces of permethrin in wastewater have been quantitated by GC-SIM-MS using direct ion counting detection. Under the recommended conditions, the detection limit for permethrin is 50picograms with a signal-to-noise ratio of 6:l. This level of detection permits the determination of about 0.05 ppb permethrin in raw wastewater samples which have been concentrated and cleaned up by column chromatography. The method has been found sensitive and specific for permethrin in the presence of a variety of co-eluting substances. Details of the equipment and data system are described. The method has general utility.
Functional motor unit failure precedes neuromuscular degeneration in canine motor neuron disease

Hereditary canine spinal muscular atrophy (HCSMA) features rapidly progressive muscle weakness that affects muscles in an apparent proximal-to-distal gradient. In the medial gastrocnemius (MG) muscle of homozygous HCSMA animals, motor unit tetanic failure is apparent before the appearance of muscle weakness and appears to be presynaptic in origin. We determined whether structural changes in neuromuscular junctions or muscle fibers were apparent at times when tetanic failure is prevalent. We were surprised to observe that, at ages when motor unit tetanic failure is common, the structure of neuromuscular junctions and the appearance of muscle fibers in the MG muscle were indistinguishable from those of symptom-free animals. In contrast, in more proximal muscles, many neuromuscular junctions were disassembled, with some postsynaptic specializations only partially occupied by motor nerve terminals, and muscle fiber atrophy and degeneration were also apparent. These observations suggest that the motor unit tetanic failure observed in the MG muscle in homozygous animals is not due to synaptic degeneration or to pathological processes that affect muscle fibers directly. Together with previous physiological analyses, our results suggest that motor unit failure is due to failure of neuromuscular synaptic transmission that precedes nerve or muscle degeneration.
Pdx-1 and Ptf1a concurrently determine fate specification of pancreatic multipotent progenitor cells

The pancreas is derived from a pool of multipotent progenitor cells (MPCs) that co-express Pdx-1 and Ptf1a. To more precisely define how the individual and combined loss of Pdx-1 and Ptf1a affects pancreatic MPC specification and differentiation we derived and studied mice bearing a novel Ptf1aYFP allele. While the expression of Pdx-1 and Ptf1a in pancreatic MPCs coincides between E9.5 and 12.5 the developmental phenotypes of Pdx-1 null and Pdx-1; Ptf1a double null mice are indistinguishable, and an early pancreatic bud is formed in both cases. This finding indicates that Pdx-1 is required in the foregut endoderm prior to Ptf1a for pancreatic MPC specification. We also found that Ptf1a is neither required for specification of Ngn3-positive endocrine progenitors nor differentiation of mature β-cells. In the absence of Pdx-1 Ngn3-positive cells were not observed after E9.5. Thus, in contrast to the deletion of Ptf1a, the loss of Pdx-1 precludes the sustained Ngn3-based derivation of endocrine progenitors from pancreatic MPCs. Taken together, these studies indicate that Pdx-1 and Ptf1a have distinct but interdependent functions during pancreatic MPC specification.
Integrating elements of Frank Lloyd Wright's architectural and decorative designs in a liberal arts mathematics class

Frank Lloyd Wright's architectural designs have many aspects that can be creatively integrated in a mathematics class. In this article, the author describes examples from the study of symmetry, graph theory and function theory. Designs from the Froebel kindergarten system are used to illustrate the rules of symmetry. Graph theory is used to model floor plans and to illustrate the uniqueness of Wright's designs. The theory of shape grammars is discussed as a function approach to modelling Wright's residential prairie designs.
DOME: a diverse outdoor mobile testbed

A series of complex dependencies conspire to make it difficult to model mobile networks, including mobility, channel and radio characteristics, and power consumption. To address these challenges, we have designed and built a testbed for large-scale mobile experimentation, called the Diverse Outdoor Mobile Environment. DOME consists of computer-equipped buses, battery-powered nomadic nodes, organic WiFi APs, and a municipal WiFi mesh network. While the construction of a testbed such as DOME presents a significant engineering challenge, this paper describes a concrete set of scientific results derived from this experience. We argue that a broad range of mobility experiments could be performed in a testbed which provides the properties of temporal, technological, and spatial diversity. We demonstrate these properties in our testbed through analysis of data collected from DOME over a period of four years. Finally, we use DOME to provide insight into several open problems in mobile systems research.
Flow-injection atomic spectrometry: A new analytical technique

Abstract Much of the recent research in analytical atomic spectrometry has been concerned with problems of a practical nature. In particular, the inaccuracies arising from a variety of matrix effects and the limitations of sample introduction systems have provided a considerable driving force for recent developments in the various techniques. The philosophy of attempting to eliminate, or compensate for, interferences by procedures implemented at the atomization stage has had success for electrothermal atomization atomic absorption spectrometry but has proved of limited utility for other techniques. Despite considerable efforts, solid-sample introduction is still best done by procedures whose intitial stage is dissolution. There is a steady growth in the flow-injection atomic spectrometric literature and a survey of the ca. 50 publications in 1990 shows that much of the interest is now centered on coupling preconcentration and matrix removal procedures with atomic spectrometry, although there is still work concerned with the basic characteristics of flow injection introduction, such as the reduction in sample loading, on-line dilution for calibration purposes and the ability to handle small sample volumes, being published. The role of the flow-injection valve as an interface between flow systems is highlighted. This interface allows independent optimization of the various flow systems coupled in this fashion. Several possible applications of recirculating closed-loop manifolds are described. These include the serial dilution of a stock standard for calibration purposes and to establish a working detection limit. This is illustrated by the dilution of a 2.45 mg l −1 solution of magnesium by a factor of 2.20 per injection. This procedure established a detection limit for the instrument involved of between 4.2 and 5.2 ng ml −1 . The on-line acid leaching of calcium from charcoal is shown to be sufficiently precise for the basis of a rapid screening procedure and the determination of copper in matrices containing up to 50 g l −1 silver is made possible by the on-line precipitation of the matrix as the chloride in a circulating loop containing a filter column of nylon fibres. The additional possibilities afforded by these designs of manifold and the great variety of manifolds described in the literature suggest that flow-injection atomic spectrometry may be emerging as an analytical methodology analogous to the variety of procedures encompassed by terms such as liquid chromatography in the vocabulary of the analytical methodology for molecular species.
Prokinetics in Gastroparesis

Prokinetic agents are medications that enhance coordinated gastrointestinal motility and transit of content in the gastrointestinal tract, mainly by amplifying and coordinating the gastrointestinal muscular contractions. In addition to dietary therapy, prokinetic therapy should be considered as a means to improve gastric emptying and symptoms of gastroparesis, balancing benefits and risks of treatment. In the United States, metoclopramide remains the first-line prokinetic therapy, because it is the only approved medication for gastroparesis. Newer agents are being developed for the management of gastroparesis. This article provides detailed information about prokinetic agents for the treatment of gastroparesis.
Nutrient Export in Stormflow following Forest Harvesting and Site-Preparation in East Texas

Etude de l'impact de l'exploitation forestiere sur la qualite des eaux d'orage se deversant dans neuf bassins de l'est du Texas. Quantification des teneurs de base en nutriment dans les forets non exploitees, determination des changements de concentration dans les eaux d'orage et des pertes en nutriment apres exploitation de la foret
On the origin of primer for glycogen synthesis

Abstract Glycogen and starch may be synthesized on a protein backbone, with the protein forming an integral part of the macromolecular product.
Transient analytical temperature distributions in cylindrical packed beds volumetrically heated by radiogenic decay energy

Abstract Analytical solutions are presented for the problem of the transient distribution of fluid and solid phase temperatures in a packed, porous, cylindrical particle bed with constant thermophysical properties. The packed particle bed is volumetrically heated by radiogenic decay energy from fission products. Flowing through the particle bed by forced convection is a single-phase fluid, either subcooled liquid or superheated vapor. The dynamic response of the packed bed is for low Reynolds numbers. In this case the transient will develop through the packed bed slowly enough for interphase heat transfer to keep the fluid and solid phase temperatures from having large differences. The two-dimensional, time-dependent Modified Dispersion-Concentric Model (D-C model) is used in the analysis of this problem. The D-C model energy equations are solved using Green's function. The mathematical solution characteristics for the transient fluid and solid phase temperature distributions are presented for three different volumetric heat generation terms: two-dimensional, time-dependent; simplified two-dimensional, time-dependent; and two-dimensional, time-independent. Using the two time-dependent volumetric heat generation terms, a comparison is presented for the transient fluid and solid phase temperatures and the radioactive decay heat power coming from the fission products in the particles.
Solution grown Ga1−xAlxAs superlattice structures

Abstract An improved apparatus which employs a solution growth method called isothermal solution mixing (ISM) has been developed for the preparation of one-dimensional superlattice structures of Ga1−xAlxAs. Growth by this method occurs when two saturated solutions having different compositions are isothermally mixed together in the presence of a GaAs substrate. Structures have been made which exhibit a one-dimensional periodic variation in composition with a period of 1000 A and 20 periods thick.
Finite Element Modeling of Cell Traction

Cell traction forces generated via the actomyosin interaction within the cell play a critical role in many biological and pathological processes including angiogenesis, wound healing, embryogenesis, metastasis, tumor invasion, and inflammation. In the case of tumor invasion, several studies have reported a correlation between cellular traction and invasion potential; however, these results are inconsistent. In their study, Kraning-Rush et al. reported a positive correlation between cellular traction as measured by total force and metastasis potential. On the other hand, Koch et al. reported a negative correlation between tumor cell invasion and cellular traction as measured by strain energy. We hypothesized that this ambiguity could be a result of overlooked effects of other parameters on measured cellular traction. Using finite element modeling of cell traction, we explored the effect of multiple morphological and mechanical parameters on the measured cellular traction using both strain energy and cellular traction forces as the model outputs. Our results demonstrate a clear dependence of strain energy on substrate stiffness, cell polarity, and contact area, whereas, total force was independent of any of the tested parameters. In addition, our results predict the ability of cells to alter the apparent stiffness of their environment by changing their focal adhesion size.
Arbitration and the incentive to bargain: The role of expectations and costs

This study examines, within the context of a model developed recently by Farber and Katz, the role of expectations, uncertainty, and costs on the incentive to bargain. It is shown that experience with a compulsory arbitration process can best be viewed as creating opposing effects on the frequency of use. While decreased uncertainty will reduce incentives to bargain, the convergence of expectations can work either to increase or decrease arbitration usage over time. Empirical evidence, while suggestive, is found to be too limited to draw strong conclusions on the relative magnitude of these effects. In addition, the paper incorporates arbitration costs into the bargaining model, and the effects of costs on arbitration usage and on the outcomes of negotiated settlements are examined. Available evidence on the magnitude of direct arbitration costs is then summarized. Because these costs are often low and provide little incentive to bargain, the authors suggest a policy approach for levying costs on the parties.
Endoscopic Perforator Ligation for Venous Stasis Disease: Value of Intraoperative Ultrasound Guidance

Videoscopic perforator ligation (VPL) is emerging as a safe and viable alternative to open techniques. Complete ligation of all perforators is crucial to reversal of venous stasis consequences. A review of the authors' experience with 19 VPLs revealed six missed perforators when completeness was evaluated by intraoperative duplex scanning. Two were paratibial, three were in the distal part of the compartment, and one was outside the compartment. Three were ligated videoscopically and three by direct subfascial ligation. Nonhealed ulcers proved to have retained perforators requiring direct ulcer excision and perforator ligation. The authors conclude that intraoperative duplex scanning allows more thorough perforator ligation and eliminates retained perforator problems.
Complement activation by synthetic vascular prostheses

Abstract Morphologic evaluation of synthetic grafts (both seeded and unseeded) harvested within 2 weeks of implantation has revealed heavy infiltration with polymorphonuclear leukocytes (PMNs). Since complement-activated PMNs are known to damage endothelial cells, we hypothesized that complement activation might prove a barrier to optimal endothelial cell seeding of prosthetic grafts. To determine whether synthetic vascular prostheses activate complement and whether the type of graft material influences the degree of activation, we assayed the plasma of 10 healthy donors for complement activity following incubation with short segments of knitted Dacron and polytetrafluoroethylene (PTFE) graft material. C5a generation was measured by radioimmunoassay and granulocyte aggregometry. Standard hemolytic assays were used to determine depletion of functional classical pathway (CH 50 and C4) alternative pathway (APH 50 ) activity. Results indicated substantial complement activation by Dacron and virtually none by PTFE. Activation by Dacron appeared to occur via both complement pathways. Such complement "reactivity" may have important implications for the performance of prosthetic materials as small-caliber vascular grafts, whether seeded with endothelial cells or not. (J VASC SURG 1984;1:829-838.)
Redescription of Placobdella papillifera Verrill, 1872 (Hirudinida: Glossiphoniidae)

ABSTRACT The identification and taxonomy of Placobdella papillifera (Verrill, 1872) Moore, 1952 have been blurred by its varieties and have been compounded by the apparent lack of type material. Leeches collected from May 2008 through August 2012 from West River, New Haven, New Haven County, Connecticut, the type locality of Clepsine papillifera Verrill, 1872, were consistant with P. papillifera (Verrill, 1872) Moore 1952 as described by Verrill (1872). The acquisition of these specimens from the type locality facilitated redescription of P. papillifera. A neotype is designated to stabilize the concept of P. papillifera. Placobdella papillifera appears to exhibit relatively low host specificity, having been documented on Chrysemys picta, Chelydra serpentina, Sternotherus odoratus and Homo sapiens in this study. Molecular comparison of CO-I sequence data from P. papillifera revealed differences of 15% from Placobdella ornata, 16% from P. rugosa, 18% from P. ali, 17% from P. multilineata and 14% from P. par...
Outpatient parenteral antibiotic therapy in different countries

Abstract Home and outpatient parenteral antibiotic therapy offers potential cost savings as well as improved quality of care in many countries. This form of therapy has been successful in countries with adequate resources for health care, but the potential benefits in other countries should also be considered. Parenteral therapy can be provided by a visiting nurse, at an infusion center, or through self-administration models, depending upon patient need, resources available, and the experience of the medical team. There are, however, a number of factors to consider in establishing or developing an outpatient infusion therapy program. A dedicated team of health care workers with knowledge of parenteral therapy and with access to medications and devices for vascular access and infusion is essential. Other considerations include the local geography, home environment, knowledge of medicine, and cultural attitudes. Financial and political problems are often limiting factors. The concepts involved in managed care continue to expand outpatient and home therapy in the United States and will likely bring change to other countries as well.
Hybrid Techniques for Inelastic Dynamic Problems

Hybrid computation programming techniques are used to study the dynamic behavior of certain inelastic systems and its dynamic responses due to earthquake excitations. The methods of solution are examined in detail. Sources of error and cost comparison with digital computation results are presented. Computed results confirms the conclusions obtained from theoretical predication. It has been found that P-Δ\N effect parameters have significant influence on the dynamic behavior of inelastic systems. These parameters, which are in dimensionless forms, are related to the masses, the lateral stiffnesses, and the height of each story of the structure.