cssi/SciSciGPT-SciSciNet huggingface dataset:
Treatment Options for Post-Prostatectomy Incontinence

AbstractIntroduction: Persistent urinary incontinence after radical prostatectomy is not uncommon and it results in negative consequences on quality of life. Multiple treatment options are available for men with post-prostatectomy incontinence. We reviewed the current state of available treatment options for men with post-prostatectomy incontinence.Methods: Select literature from 1970 until 2013 was reviewed. This literature along with the current state of the art of clinical practice and relevant American Urological Association guidelines were incorporated in preparing this study.Results: Treatment options for post-prostatectomy incontinence vary. They include pelvic floor muscle exercises, pharmacotherapy, urethral bulking agents, male slings, artificial urinary sphincters, and other novel and emerging procedures.Conclusions: Multiple treatment options exist for post-prostatectomy incontinence but most patients can be treated effectively. The degree and type of incontinence determine which options are a...
Usefulness of ST Depression in Ventricular Premature Complexes to Predict Myocardial Ischemia

Patients with coronary artery disease (CAD) frequently have ventricular premature complexes (VPCs) both at rest and during exercise. These ectopic beats may arise from almost any location in the ventricle and unless they are frequent enough to produce ventricular tachycardia, they are considered by most physicians to have little clinical significance. VPCs are more common (10% to 40%) in patients with CAD than in those without CAD. 1 The voltage and configuration of these ectopic beats vary a good deal and ST-segment depression in these complexes have not been correlated with the presence or absence of ischemia. We have recently noted, during treadmill stress testing, that the VPCs occurring at rest usually have minimal ST-segment deviations. As in subjects with left bundle branch block, the complexes in nonischemic subjects have ST deviation no .10% of the R-wave amplitude. There is evidence that when an acute myocardial infarction is suspected in a patient with left bundle branch block, significant ST deviation is indicative of an acute ischemic process. 2 An unpublished observational study performed in 2000 by Ronald H. Selvester, MD, at Long Beach Memorial Heart Institute suggests that nonischemic patients with left bundle branch block have ST deviation no .10% of the QRS amplitude. In these nonischemic subjects with left bundle branch block, he showed that plotting ST deviation (scaled at 10% of the peak QRS) against the peak QRS gave a 45° slope. All but 2 of 135 measurements fell within a 10% boundary on each side of the slope (Figure 1). We have noted that patients with significant CAD undergoing increased exercise appear to become more ischemic and the VPCs may have more ST-segment depression. Incorporating Selvester’s 10% rule, we hypothesize that ST depression of VPCs .10% of the R-wave amplitude may identify significant ischemia. If changes in the ST segment of VPCs were a consistent finding during ischemia, this would provide one more marker that would be useful when doing exercise testing. ••• Our stress testing computer printouts contain codes for exercise-induced VPCs as well as VPCs at rest. We searched the database, encompassing a 3-year period from 1997 to 1999, for all patients who had codes for VPCs at rest and during exercise. Patients who had a coronary angiogram within 6 months of the stress tests and no interventional procedures in the 6-month time period were also included. Patients who did not have exercise-induced stress (i.e., adenosine or dobutamine) were excluded.
Quantum theory of static shielding of an impurity charge by an electron gas plasma in a magnetic field

Abstract The detailed calculations of magnetic field effects on the static shielding of a point Coulomb impurity charge by a quantum plasma are presented here. The quantum plasma is described in terms of the random phase approximation (RPA) inverse dielectric function (1) in a manner that is valid for arbitrary magnetic field strength (to take account of Landau quantization) and arbitrary temperature (statistical regime). Magnetic field effects are found to occur only in conjunction with quantum modifications of the static shielding law, and they are accompanied by spatial anisotropy. This is manifest in both low- and high-wavenumber shielding phenomena. A low wavenumber evaluation results in a quantum analogue of the Debye-Thomas-Fermi shielding law which is characterized by a quantum-corrected anisotropic effective Debye length whose magnetic field dependence reflects the statistical regime under consideration. In the nondegenerate case magnetic field-quantum corrections and anisotropy enter through the parameter h ω c β . In the degenerate—DHVA case, the presence of DHVA oscillatory terms suggests that the anisotropic magnetic field-quantum corrections to the Debye-Thomas-Fermi shielding law could be useful in an experimental determination of ( gm m 0 ). In the quantum strong field limit magnetic field-quantum corrections and anisotropy in the effective Debye length occur through the parameter h ω c ζ alone. The evaluation of high wavenumber contributions to the static shielding law in the quantum strong field limit reveals an important change of character in the Friedel-Kohn (FK) “wiggle”. Specifically, the results show that the strong anisotropy induced by the magnetic field in this limit destroys the long-range character of the FK “wiggle”. Although anisotropic “wiggle” behavior is still discernable as an oscillatory function of 2pFrz, there is also an r -dependent factor which confines the “wiggle” within a decaying exponential envelope factor e −2p f ∥ r ∥ . Thus the FK “wiggle” is deprived of its long-range character in the quantum strong field limit. (rz is along the direction of the magnetic field, and r is transverse).
Energy bands, effective masses and g-factors of the lead salts and SnTe

Abstract Using the pseudopotential scheme of Lin and Kleinman we have calculated the energy bands of PbTe, PbSe and PbS so as to obtain direct band gaps, effective masses and g -factors in very good agreement with experiment. Fitting the direct gap (the only piece of experimental data available) we have extrapolated the pseudopotential parameters to SnTe and obtained energy bands, effective masses and g -factors. Unlike other first principles and pseudopotential calculations we find the SnTe effective masses at the ( 1 2 1 2 1 2 ) point in the Brillouin Zone to be positive, i.e. the band extrema occur exactly at rather than just near the ( 1 2 1 2 1 2 ) point.
Nd Isotopic Studies: Some new perspectives on Earth structure and evolution

Geochronology is generally regarded as a branch of geochemistry that focuses on the determination of the ages of rocks. Although the reliable determination of ages of rocks is no trivial task, the above definition of geochronology is overly restrictive because the long-lived radioactive nuclides that can reveal the age of rocks can also yield a unique type of information about the internal structure of planets and the processes by which that structure is formed. In the case of the earth and the terrestrial planets, the internal structure can be described grossly by the division into core, mantle, crust, and an atmosphere-hydrosphere system where present. The present state of the earth (moon, Mars, etc.) can be studied by a number of methods, including photogeologic, petrologic, and chemical characterization of crustal rocks, and geophysical studies of the interior through the use of seismicity, gravity, heat flow, and other methods. But when and how this structure formed cannot generally be ascertained by those methods except by inference from theoretical models. The time dimension is uniquely accessible through the study of variations in the natural abundances of radioactive elements and their decay products, i.e., through geochronology. By using information about the geochemical properties of the elements, coupled with the measured isotopic variations, the nature of planetary differentiation processes and the associated time scales can be inferred. Such information is critical for linking what is known about the present structure of the earth to models of its evolution over the past 4.5 billion years. There is, however, an important restriction to the applicability of isotopic measurements, and that is that only if the geochemical properties of the particular elements are well understood can isotope abundance variations caused by radioactive decay be translated into information on planetary evolution.
The concept of disorder as a foundation for the DSM's theory-neutral nosology: response to Follette and Houts, Part 2.

Abstract Follette and Houts [Follette, W. C., Houts, A. C. (1996). Models of scientific progress and the role of theory in taxonomy development: a case study of the DSM. Journal of Consulting and Clinical Psychology, 64, 1120–1132] argue that ‘mental disorder’ and ‘function’ are value concepts that offer no scientific basis for the DSM's theory-neutral nosology or for distinguishing disorders from other behavioral problems. They also claim that the DSM presupposes a biological theory of etiology, thus is not really theory-neutral. They recommend replacing the DSM by theory-laden diagnostic manuals. I argue: (1) DSM criteria do not imply a biological model of disorder, (2) ‘mental disorder’ and ‘function’ have scientific content that allows one to distinguish disorder from nondisorder, (3) the evolutionary ‘harmful dysfunction’ analysis of disorder [Wakefield, J. C. (1992a). The concept of mental disorder: on the boundary between biological facts and social values. American Psychologist, 47, 373–388] coherently demarcates disorder from nondisorder, (4) the proposed behaviorist alternative to the DSM illustrated by the articles in Follette's special section [Follette, W. C. (Ed.) (1996a). Special section on the development of theoretically coherent alternatives to the DSM system. Journal of Consulting and Clinical Psychology, 64, 1117–1201] is incoherent because it does not distinguish disorder from nondisorder.
Age, working memory, figurative language type, and reading ability: influencing factors in African American adults' comprehension of figurative language.

This study investigated the cognitive and linguistic factors presumed to be associated with adult comprehension of figurative language, including age, working memory (WM), figurative language type, and reading comprehension (RC). Forty younger (M=22 years) and 40 older (M=63 years) healthy African American adults completed WM and reading tasks, and the 60-item forced-choice multiple-category (20 idioms, 20 metaphors, and 20 metonyms) Figurative Language Comprehension Test. After controlling for WM and RC, the older adults outperformed the younger adults on idioms and metonyms. Metaphor comprehension was comparable between the groups. Findings demonstrate that WM and RC underlie adults' comprehension of figurative language and should be considered when interpreting performance on tests assessing figurative language competence in this population.
The heat is on with TAC1.

Specific gene expression patterns must be tightly regulated for eukaryotic cells to acquire unique structural and functional features. A key step is transcriptional initiation, during which epigenetic activators are thought to facilitate the process by establishing and maintaining transcription-competent chromatin structures. Accumulating evidence shows that an epigenetic regulator can also control the next step — transcriptional elongation.
Awareness, Treatment and Control of Hypertension Among Filipino Immigrants

BACKGROUND Filipino Americans have high rates of hypertension, yet little research has examined hypertension awareness, treatment, and control in this group.
Total Parenteral Nutrition by a Nutrition Support Team: Improved Quality of Care

Most of the studies that have examined the effect of nutrition support teams (NST) on the quality of total parenteral nutrition (TPN) have found reductions in the frequency of metabolic and central venous catheter related complications. Previous studies have not examined the patterns of nutrient delivery (eg, calories and protein) when TPN is provided either by a primary physician or by a NST. We compared the quality of TPN care provided by our NST or by primary physicians utilizing nonspecialized hospital personnel and resources. As expected, catheter complications were significantly less frequent in NST patients. Assessment of nutritional status and nutrient requirements as well as nitrogen balance were performed and documented significantly more often in NST patients. In addition, nutritional goals for calories and protein were achieved and positive nitrogen balance documented more often in NST patients.The need to consult the NST physician to utilize the NST was not well received by primary attending ...
Stresses in a radially constructed rotating cylinder

Abstract The dynamic radial stress distribution in a circular hollow cylinder, bonded to a rigid core at its inner surface and prevented from outward displacement by a smooth rigid cylindrical wall, due to a rotational motion with a variable angular velocity, is analyzed. The stress as a function of radial distance and time is determined. A sample calculation shows that the stress changes from tension at the inner surface to compression at the outer surface, as would be expected. The variation of stress vs radial distance is plotted for several instants of time. Also, the stress vs time for various radial positions is plotted.
Estimating an equivalent wall-thickness of a cerebral aneurysm through surface parameterization and a non-linear spring system

Cerebral aneurysms are an enlargement of a brain blood-vessel due to a weakened wall and can pose significant health risks. Computational simulations have been thus utilized to help doctors in the understanding of cerebral aneurysms. In order to provide more accurate patient-specific simulations, not only does geometry for the fluid domain need to be created from medical image data, but more accurate wall-models need to be generated as well. However, the wall-thickness and material properties are very difficult to obtain experimentally, and thus most computational simulations, except for a few we have seen in the recent years, are performed using walls with uniform thickness and constant material properties. To provide a more accurate computational model for the weakened wall-structure, this paper presents a novel estimation of an equivalent cerebral aneurysm wall-thickness by deforming a healthy vessel onto an aneurysm through surface parameterization and a non-linear spring system. The resulting wall-model is thinnest over the dome of the aneurysm, and for the patient-specific models used has an average thickness of 75µm. Fluid–structure interaction simulations of three patient-specific cerebral aneurysms are carried out. Compared with using a uniform wall-thickness, using the equivalent wall-thickness gives a more accurate prediction of the rupture site. Copyright © 2010 John Wiley & Sons, Ltd.
Reaction of a peptide with polyvinylpyrrolidone in the solid state

Abstract During stability studies at high temperature (70°C) and low relative humidity (∼0%), the recovery of an asparagine containing hexapeptide (VYPNGA) and its known deamidation products from solid polyvinylpyrrolidone (PVP) matrices was incomplete. To determine the causes of this mass loss, formulations were prepared by lyophilizing solutions containing PVP, glycerol, and the Asn‐hexapeptide in pH 7.5 phosphate buffer, followed by storage at 70°C and 0% relative humidity. Asn‐hexapeptide loss was mono‐exponential and reached a plateau at about 30% remaining. Total recovery of the peptide and its known deamidation products was ∼30% of peptide load. Size exclusion chromatography with fluorescence detection indicated the formation of a PVP–peptide adduct that was stable in the presence of 6 M guanidine hydrochloride. Similar stability studies using N ‐acetyl phenylalanine, phenylalanine ethyl ester, and N ‐acetyl tyrosine ethyl ester demonstrated that the reaction involves the peptide N‐terminus. The adduct was disrupted in the presence of carboxypeptidase‐A, suggesting the formation of an amide bond between the peptide and PVP. 15 N solid‐state nuclear magnetic resonance spectroscopy using 15 N‐labeled valine as a model of the peptide N‐terminus showed different populations of 15 N, suggesting that noncovalent peptide–polymer interactions precede amide bond formation.
On the Impossibility of Nonzero Reversal Potentials of Passive Pores Separating Symmetric Solutions: Comment on Haemophilus influenzae Outer Membrane Protein P5 Is Associated with Inorganic Polyphosphate and Polyhydroxybutyrate

In their recent article, Zakharian and Reusch (1xHaemophilus influenzae outer membrane protein P5 is associated with inorganic polyphosphate and polyhydroxybutyrate. Zakharian, E. and Reusch, R.N. Biophys. J. 2007; 92: 588–593Abstract | Full Text | Full Text PDF | PubMed | Scopus (18)See all References(1) “unpredictably” measure a nonzero reversal potential when reconstituting NTHi P5 channels into a lipid bilayer separating identical solutions. They then attempt to explain this “unexpected asymmetry” by invoking an asymmetric association of polyanions with this passive pore. Although such an association may influence NTHi P5's selectivity, it cannot be responsible for generating a nonzero reversal potential across a membrane separating symmetric solutions. Any potential arising from a surface charge generates an asymmetry in the distribution of ions near the membrane that in turn creates a transmembrane potential of equal magnitude and opposite sign. The measured reversal potential, which represents the voltage difference between the bath electrodes on the two sides of the membrane, will therefore always be zero in symmetric solutions at equilibrium (2xElectrostatic interactions in membranes and proteins. Honig, B.H., Hubbell, W.L., and Flewelling, R.F. Annu. Rev. Biophys. Biophys. Chem. 1986; 15: 163–193Crossref | PubMedSee all References(2).But a much more potent argument can be made—one that does not rely on the subtleties of electrostatic theory of surface charges—for why this observation cannot be correct: it violates the second law of thermodynamics. By connecting the system described by Zakharian and Reusch to an external device, one could construct a perpetual motion machine of the second kind, in which thermal energy is converted to work without any change in the universe (3.xPhysical principles and formalisms of electrical excitability. Finkelstein, A. and Mauro, A. See all References, 4.xThermodynamics. Fermi, E. See all References). This impossibility explains why the authors would not have previously read about such an effect in any other passive pore similarly reconstituted, which in turn probably accounts for their description of their result as unexpected and unpredictable. Indeed, this odd finding should have been a clarion call to both the authors and reviewers to search for a source of systematic error in the experimental setup rather than for the “molecular basis” of the finding.
Genistein Inhibits Cardiac L-Type Ca2+ Channel Activity by a Tyrosine Kinase-Independent Mechanism

It has been suggested that protein tyrosine kinase (PTK) activity can directly regulate cardiac L-type Ca2+ channels. This conclusion is based to a large extent on the observation that the PTK inhibitor genistein can inhibit the cardiac L-type Ca2+current. The purpose of the present study was to determine whether the ability of genistein to inhibit cardiac L-type Ca2+ channel activity is due to inhibition of PTK activity. Genistein significantly reduced the magnitude of the L-type Ca2+ current in guinea pig ventricular myocytes recorded using the whole-cell patch-clamp technique. However, this effect was associated with extracellular, not intracellular, application of the drug. Peroxovanadate (PVN), a potent protein tyrosine phosphatase inhibitor, had no effect on the basal Ca2+ current. PVN was also ineffective in preventing the inhibitory effect of genistein. Internal perfusion of cells with a pipette solution containing ATPγS was used to prevent reversibility of phosphorylation-dependent processes. This treatment did not alter the inhibitory effect of genistein, although it did result in irreversible protein kinase A-dependent regulation of the Ca2+ current. Bath application of lavendustin A, a PTK inhibitor that is structurally unrelated to genistein, did not affect the Ca2+ current amplitude. The inhibitory effect of genistein was also associated with a hyperpolarizing shift in the voltage dependence of Ca2+ channel inactivation. These results are consistent with the conclusion that the cardiac L-type Ca2+ current is not directly regulated by PTK activity and that the inhibitory effect of genistein is due to direct non-catalytic blockade of the channels.
A finite element algorithm for elliptical equations over unstructured domains on a data parallel computer

In the past, most finite element algorithms on data-parallel computers have been limited to structured problem domains. Here, we consider methods to generalize the finite element method on data-parallel architectures to unstructured domains. A nodal assembly algorithm is described which effectively allows for both the generation of the sparse interaction matrix (coefficient matrix) and its solution via a preconditioned conjugate-gradient type routine utilizing several polynomial preconditioners on the Connection Machine 200 (CM-200). Jacobi preconditioning along with Neumann series and least-squares polynomial preconditioners are presented and implemented are presented and implemented. Only the Jacobi preconditioner produces an improvement in the convergence time for the problems examined. Several irregular interprocessor communication protocols available on the CM-200 are investigated in the solution portion of the algorithm, yielding differing performance characteristics. For one such protocol, sustained performance of over two-hundred MFlops/s, is demonstrated for a test problem on a 512 processing element CM-200 in slicewise mode. The results are discussed and conclusions are drawn concerning this finite element algorithm.
Purification of nitrophenylvaleric acid reaction mixtures by counter-current chromatography

Abstract Failure of purification of nitrated phenylvaleric acid reaction mixtures by conventional recrystallization and column chromatographic methods using silica gel, led to a trial of counter-current chromatography. Poor solubility of the nitration products precluded the use for aqueous systems and let to the examination of systems using ethylene glycol or formamide as the stationary phase, with chloroform and other solvents as mobile phases. Prospective solvent pairs were first screened by a micropartitioning method and then by counter-current chromatography in an analytical micro counter-current chromatograph. Partition coefficients derived from these methods facilitated optimization of the solvent system and scale-up to a preparative counter-current chromatography range. Using the system chloroform-ethylene glycol, crude product was readily purified and then identified as 5-(2,4-dinitrophenyl)valeric acid. Purification using a 292-ml column provided high resolution and required 6 h. Purification with lower resolution on a 56-ml column required 2 h.
Uncoupling of oxidative phosphorylation in rat liver mitochondria by chloroethanols

Chloroethanols are toxic chemicals used in industry and also formed as a result of the metabolism of several widely used halogenated hydrocarbons. The effect of 2-chloroethanol (CE), 2,2-dichloroethanol (DCE) and 2,2,2-trichloroethanol (TCE) on rat liver mitochondrial respiration was studied. Rat liver mitochondria were isolated in a medium consisting of 250 mM sucrose, 10mM Tris-HCl and 1 mM EDTA (pH 7.4). Mitochondrial respiration was determined with an oxygen electrode at 30 degrees C and the polarographic buffer consisted of 250 mM mannitol, 10 mM KCl, 10 mM K2HPO4, 5 mM MgCl2, 0.2 mM EDTA and 10 mM Tris-HCl (pH 7.4). With succinate as the respiratory substrate and using chloroethanols (150 mM), CE stimulated respiration by 28.2 +/- 6.5% and DCE by 202.7 +/- 8.2% while TCE inhibited mitochondrial respiration (greater than 95%). The effect of change in the concentration of chloroethanols on mitochondrial respiration was also studied. CE showed maximum stimulation at 600 mM (97.6%), DCE at 150 mM (202.6%) and TCE at 30 mM (313.6%). Respiratory stimulation was independent of mitochondrial protein concentration. Chloroethanols (optimal concentrations for respiratory stimulation with succinate) inhibited mitochondrial respiration when glutamate-malate was used as the respiratory substrate. Estimation of adenosine triphosphate (ATP) showed that chloroethanols inhibited the synthesis of ATP. These results indicate that chloroethanols stimulate mitochondrial respiration by uncoupling oxidative phosphorylation and that the uncoupling potency is proportional to the extent of chlorination at the beta-position of haloethanol.
Phase transitions in vertebrate and invertebrate photoreceptor membranes.

Phase transitions in the photoreceptor membranes of the vertebrate frog (Rana catesbiana) and the invertebrate squid (Loligo pealii) have been detected by differential scanning calorimetry in ethylene glycol. Both the intact membranes and the extracted lipids exhibit relatively sharp endothermic transitions, the frog centering at −28°C and the squid centering at −31°C. The transition for the lipids is observed to be slightly larger in absolute heat content and shifted somewhat downward in temperatures for the two membranes differ also, the frog membranes thermally denaturing at 58°C and the squid membranes denaturing at 74°C. Both denaturations occur identically in buffer, glycol or glycerol.
Altered regulation of cardiac muscle contraction by troponin T mutations that cause familial hypertrophic cardiomyopathy.

To study the effect of troponin (Tn) T mutations that cause familial hypertrophic cardiomyopathy (FHC) on cardiac muscle contraction, wild-type, and the following recombinant human cardiac TnT mutants were cloned and expressed: I79N, R92Q, F110I, E163K, R278C, and intron 16(G1 → A) (In16). These TnT FHC mutants were reconstituted into skinned cardiac muscle preparations and characterized for their effect on maximal steady state force activation, inhibition, and the Ca2+ sensitivity of force development. Troponin complexes containing these mutants were tested for their ability to regulate actin-tropomyosin(Tm)-activated myosin-ATPase activity. TnT(R278C) and TnT(F110I) reconstituted preparations demonstrated dramatically increased Ca2+sensitivity of force development, while those with TnT(R92Q) and TnT(I79N) showed a moderate increase. The deletion mutant, TnT(In16), significantly decreased both the activation and the inhibition of force, and substantially decreased the activation and the inhibition of actin-Tm-activated myosin-ATPase activity. ATPase activation was also impaired by TnT(F110I), while its inhibition was reduced by TnT(R278C). The TnT(E163K) mutation had the smallest effect on the Ca2+sensitivity of force; however, it produced an elevated activation of the ATPase activity in reconstituted thin filaments. These observed changes in the Ca2+ regulation of force development caused by these mutations would likely cause altered contractility and contribute to the development of FHC.
Teaching, Learning, and Collaborating in the Cloud: Applications of Cloud Computing for Educators in Post-Secondary Institutions:

“Cloud computing” refers to the use of computing resources on the Internet instead of on individual personal computers. The field is expanding and has significant potential value for educators. Thi...
Actin Sliding Velocities are Influenced by Actin - Myosin Attachment Kinetics

Unloaded muscle shortening velocities (V) are widely thought to be limited by actin-myosin detachment kinetics (Ton); however, recent studies indicate that actin-myosin attachment kinetics (katt) significantly influence V. To test the hypothesis that V varies with katt, we use stopped flow fluorescence spectrometry to study effectors of katt and in vitro motility assays to correlate observed effects on katt with changes in V. Here we consider the combined effects of sucrose and potassium chloride, KCl. We show that sucrose specifically inhibits the rate of actin-myosin binding, katt, and the effects of sucrose on katt correlate with its effects on V. Moreover, the addition of KCl enhances the effects of sucrose on katt, with the combined effects of KCl and sucrose on katt mirroring their effects on V, suggesting that the ionic strength-dependence of katt contributes to the ionic strength-dependence of V. We are investigating mechanisms by which both KCl and sucrose influence katt, and we have developed a collective force model that accounts for the observed influence of both katt and Ton on V. Our data and model imply that factors that decrease katt such as regulatory proteins, certain disease related mutations, and inhibitors such as blebbistatin can slow V through kinetic rather than recruitment or sequestration mechanisms.
Monitoring Thermal Fatigue Damage In Nuclear Power Plant Materials Using Acoustic Emission

Proactive aging management of nuclear power plant passive components requires technologies to enable monitoring and accurate quantification of material condition at early stages of degradation (i.e., pre-macrocrack). Acoustic emission (AE) is well-suited to continuous monitoring of component degradation and is proposed as a method to monitor degradation during accelerated thermal fatigue tests. A key consideration is the ability to separate degradation responses from external sources such as water spray induced during thermal fatigue testing. Water spray provides a significant background of acoustic signals, which can overwhelm AE signals caused by degradation. Analysis of AE signal frequency and energy is proposed in this work as a means for separating degradation signals from background sources. Encouraging results were obtained by applying both frequency and energy filters to preliminary data. The analysis of signals filtered using frequency and energy provides signatures exhibiting several characteristics that are consistent with degradation accumulation in materials. Future work is planned to enable verification of the efficacy of AE for thermal fatigue crack initiation detection. While the emphasis has been placed on the use of AE for crack initiation detection during accelerated aging tests, this work also has implications with respect to the use of AE as a primary tool for early degradation monitoring in nuclear power plant materials. The development of NDE tools for characterization of aging in materials can also benefit from the use of a technology such as AE which can continuously monitor and detect crack initiation during accelerated aging tests.
The effectiveness of adjustable gastric banding: a retrospective 6-year U.S. follow-up study.

Background This study aimed to assess the efficacy of laparoscopic adjustable gastric banding (LAGB) during a 6-year follow-up period.
Excretion of pipecolic acid by infants and by patients with hyperlysinemia.

Extract: Pipecolic acid has been found in urine from normal infants and from children with hyperlysinemia. The reaction of pipecolic acid with ninhydrin reagent, using separation procedures in automated ion-exchange systems for amino acid analysis, produced a color constant of low value (1.21 compared with 27.6 for leucine) that could be overlooked in routine analyses of physiological flusids. Pipecolic acid was present in the urine from: four premature infants (6–23 days old) 1.2–8.1 μg/mg creatinine; two of four term infants (3–5 days old) 1.3 and 2.1 μg/mg creatinine; and one of four infants (4–11 months old) 2.1 μ/mg. No pipecolic acid was found in the urines of four infants 14–30 months old. In patients with hyperlysinemia, the amounts of pipecolic acid excreated in the urine were: 3.1 μ/mg creatinine (4-year-old girl); 5.2 μ/mg creatinine (6-year-old boy); 6.2 μ/mg creatinine (9-year-old girl); and 4.8 μ/mg creatinine (12-year-old girl). Speculation: The low color yield of pipecolic acid, when separated by standard automated ion-exchange analysis methods, may account for past failures to detect small amounts of this substance in physiological fluids. Amounts of popecolic acid excreated by yound infants and by children with hyperlysinemia indicate that a degradation pathway for lysine, via pipevolic acid to α-aminoadipic acid, is operative in man.
Load-Balanced Parallel Streamline Generation on Large Scale Vector Fields

Because of the ever increasing size of output data from scientific simulations, supercomputers are increasingly relied upon to generate visualizations. One use of supercomputers is to generate field lines from large scale flow fields. When generating field lines in parallel, the vector field is generally decomposed into blocks, which are then assigned to processors. Since various regions of the vector field can have different flow complexity, processors will require varying amounts of computation time to trace their particles, causing load imbalance, and thus limiting the performance speedup. To achieve load-balanced streamline generation, we propose a workload-aware partitioning algorithm to decompose the vector field into partitions with near equal workloads. Since actual workloads are unknown beforehand, we propose a workload estimation algorithm to predict the workload in the local vector field. A graph-based representation of the vector field is employed to generate these estimates. Once the workloads have been estimated, our partitioning algorithm is hierarchically applied to distribute the workload to all partitions. We examine the performance of our workload estimation and workload-aware partitioning algorithm in several timings studies, which demonstrates that by employing these methods, better scalability can be achieved with little overhead.
Projected 21st-century changes to Arctic marine access

Climate models project continued Arctic sea ice reductions with nearly ice-free summer conditions by the mid-21st century. However, how such reductions will realistically enable marine access is not well understood, especially considering a range of climatic scenarios and ship types. We present 21st century projections of technical shipping acces- sibility for circumpolar and national scales, the international high seas, and three potential navigation routes. Projections of marine access are based on monthly and daily CCSM4 sea ice concentration and thickness simulations for 2011-2030, 2046-2065, and 2080-2099 under 4.5, 6.0, and 8.5 W/m 2 radiative forcing scenarios. Results suggest substantial areas of the Arctic will become newly accessible to Polar Class 3, Polar Class 6, and open-water vessels, rising from ~54 %, 36 %, and 23 %, respectively of the circumpolar International Maritime Organization Guidelines Boundary area in the late 20th century to ~95 %, 78 %, and 49 %, respectively by the late 21st century. Of the five Arctic Ocean coastal states, Russia experiences the greatest percentage access increases to its exclusive economic zone, followed by Greenland/Denmark, Norway, Canada and the U.S. Along the Northern Sea Route, July-October navigation season length averages ~120, 113, and 103 days for PC3, PC6, and OW vessels, respectively by late-century, with shorter seasons but substantial increases along the Northwest Passage and Trans-Polar Route. While Arctic navigation depends on other factors besides sea ice including economics, infrastructure, bathymetry, and weather, these projections are useful for strategic planning by governments, regulatory agencies, and the global maritime industry to assess spatial and temporal ranges of potential Arctic marine operations in the coming decades.
Hot-Wire CVD Amorphous Si Materials for Solar Cell Application

Hydrogenated amorphous silicon (a-Si:H) thin films and their application to solar cells fabricated using the hot-wire chemical vapor deposition (HWCVD) or (CAT)-CVD will be reviewed. This review will focus on the comparison to the standard plasma enhance (PE) CVD in the terms of deposition technique, film properties, and solar cell performance. The advantages of using HWCVD for a-Si:H solar cell research as well as the criteria for industry's adaptation of this technique for mass production will be addressed.
Dry Farming in the Northern Great Plains: Years of Readjustment, 1920-1990

Grandiose plans for land retirement and expanded irrigation have been frequently proposed for the northern Great Plains, but they have not significantly affected agricultural practices in the region. Those major readjustments to farming methods that did occur in the region evolved out of local initiative in response to drought and depression during the 1920s. With some refinements but few amendments, procedures remain basically the same today. "In Dry Farming in the Northern Great Plains," Mary Hargreaves reviews the changes in agricultural technology and farm management through the 1920s, the introduction of federal programs as drought and depression recurred in the 1930s, and the realignment of concerns from drought to marketing instability during the recovery years that followed. Drought remains a perennial problem in the region, which in this study includes the eastern two-thirds of Montana and the western half of the Dakotas. But instability of marketing has been a greater concern, according to Hargreaves, and marketing, not environmental factors, occasioned the land retirement programs of the 1950s and 1980s. Despite the economy and practicability of dry farming, the national agricultural policy of acreage restrictions since the 1930s has promoted the use of costly inputs and enabled higher-cost producers to continue competitive operation. "Misconceptions and myths have too frequently entered into national land-use planning," Hargreaves writes. "There are still those who see the Plains as a 'Great American Desert'; still those who look to irrigation as the only basis for successful agriculture there; and still those who cherish the small diversified homestead operation as the agrarian dream, regardless of the environment." Dry farming has proved successful in the northern Great Plains, Hargreaves contends. That success is measured not only by production but also by limited erosion. On its record, dry-land agriculture should not now fall prey to "hyperbole, myth, or politics."
Visions of community and mobility: the community networking movement in the USA

Different visions of community and mobility may influence the ability of community computer network organizations to promote social change. Community networks successfully generate instrumental mobility, the literal movement of information across space, but have difficulty creating successful online spaces that promote communicative mobility, the metaphorical movement of people towards common understandings of a shared situation. Interviews with community networking activists explore the ways that community networks generate instrumental mobility online as well as barriers that community networks face in creating online spaces for communicative mobility. Ironically, given their technological focus, community networks have little difficulty generating communicative mobility in face-to-face situations. Differentiating between instrumental and communicative mobility allows this research to move beyond a simple discussion of the geography of the conduits of communication to consider the geography of communica...
Induction therapy in lung transplantation: a prospective, controlled clinical trial comparing OKT3, anti-thymocyte globulin, and daclizumab.

Abstract Background Because acute rejection is associated with inferior outcomes in lung transplantation, we have routinely employed OKT3, anti-thymocyte globulin (ATG), or daclizumab as adjuncts to reduce rejection. Method We performed a 4-year prospective, controlled clinical trial of these 3 therapies to determine differences in post-operative infection, rejection, survival, and bronchiolitis obliterans syndrome (BOS). Eighty-seven consecutive lung transplant patients received OKT3 ( n = 30), ATG ( n = 34), and daclizumab ( n = 23) as induction agents. The groups had similar demographics and immunosuppression protocols differing only in induction agents used. Results No differences were observed in immediate post-operative outcomes such as length of hospitalization, ICU stay, or time on ventilators. Twelve months post-transplant, OKT3 had more infections per patient than the other agents, a difference that only became significant 2 months post-operatively ( p = 0.009). The most common infection was bacterial and OKT3 had more bacterial infections than any other agent. Daclizumab had more patients remain infection free in the first year ( p = 0.02), having no fungal infections and a low rate of viral infections. No patient receiving daclizumab developed drug specific side-effects. Only those patients with episodes of acute rejection developed BOS. There were no significant differences in the freedom from acute rejection or BOS between the groups. The 2-year survival for the entire cohort was 68%, with no differences observed in patient survival. Conclusions This study again reveals the importance of acute rejection in the subsequent development of BOS. Although daclizumab offers a low risk of post-transplant infection and drug specific side-effects, no drug is superior in delaying rejection or BOS or in prolonging long-term survival.
Skeletal Muscle Signaling Pathway through the Dystrophin Glycoprotein Complex and Rac1

The dystrophin glycoprotein complex has been proposed to be involved in signal transduction. Here we have shown that laminin binding causes syntrophin to recruit Rac1 from the rabbit skeletal muscle. Laminin-Sepharose and syntrophin-Sepharose bind a protein complex containing Rac1 from the muscle membranes. The presence of heparin, which inhibits laminin interactions, prevents recruitment of Rac1. The dystrophin glycoprotein complex recruits Rac1 via syntrophin through a Grb2·Sos1 complex. A syntrophin antibody also prevents recruitment of Rac1, suggesting that the signaling complex requires syntrophin. PAK1 is in turn bound by Rac1. c-Jun NH2-terminal kinase-p46 is phosphorylated and activated only when laminin is present, and the p54 isoform is activated when laminin is depleted or binding is inhibited with heparin. In the presence of laminin, c-Jun is activated in both skeletal muscle microsomes and in C2C12 myoblasts, and proliferation increases in C2C12 myoblasts. We postulate that this pathway signals muscle homeostasis and hypertrophy.
Regression of pulmonary metastases from squamous cell carcinoma of the soft palate.

A case of regression of pulmonary metastases from squamous cell carcinoma of the soft palate is presented. The lung nodules disappeared following a course of radiation therapy to the primary lesion. This appears to be the first reported case of such regression subsequent to irradiation of the primary lesion.
A new species of Ocotea (Lauraceae) from French Guiana

A new species ofOcotea,O. diffusa van der Werff, is described and illustrated based on recent collections from French Guiana and adjacent Brazil.
Core energy and peierls stress of edge dislocations on {110} and {001} slip planes in NaCl

Properties of straight edge dislocations on {110} and {001} slip planes are calculated by means of atomistic procedures. The energies of dislocation cores of radius 3b are 6.86 × 10—5and 7.43 ×10—5 erg/cm, respectively. Detailed investigations on convergence yield similar Coulomb interactions for both slip systems which leads to a correction of earlier assumptions. The calculated Peierls stresses of 75 and 90 MPa, respectively, fall between the experimental data of critical shear stresses. This finding might indicate that, in plastic deformation, dislocations do not move as ua whole bt by migrating in atomic steps. Mit atomistischen Verfahren werden Eigenschaften von geraden Stufenversetzungen auf {110} - und {001} -Gleitebenen berechnet. Es ergeben sich fur die Energie von 3b-Versetzungskernen, 686 ×10—5 bzw. 7,43 × 10—5 erg/cm. Wie eingehende Konvergenzuntersuchungen zeigen, mussen fruhere Vorstellungen uber die Coulomb-Wechselwirkung fur beide Gleitsysteme korrigiert werden. Die berechneten Peierls-Spannungen von 75 bzw. 90 MPa liegen zwischen den experimentellen Daten der kritischen Schubspannungen. Dieser Befund konnte darauf hinweisen, das bei plastischer Verformung Versetzungen sich nicht als Ganzes bewegen, sondern in atomaren Schritten fortschreiten.
Atomic packing in multicomponent aluminum-based metallic glasses

Abstract Three-dimensional atomic configurations have been established for Al-based multicomponent metallic glasses (MGs). This was achieved via computer simulations employing effective pair-potentials, which were derived from ab initio molecular dynamics simulation data using the inverse Monte Carlo (IMC) method. The ab initio and IMC structural models were validated using structure factors and extended X-ray absorption fine structures obtained from synchrotron X-ray experiments. The Al-based MGs are characterized by solute-centered quasi-equivalent clusters. These coordination polyhedra of different types and sizes intermix in the multicomponent alloy, resulting in improved glass-forming ability for the Al–La–Ni alloys when compared with binary Al–La and Al–Ni systems. Our survey of a large number of Al–solute systems using ab initio calculations demonstrates that the topological short-range order (cluster type, size and coordination number of the solute) correlates directly with the Al–solute bond length (or the effective atomic size ratio). The differences between our findings and previously proposed structural models are also discussed.
The Accuracy of Peizer Approximations to the Hypergeometric Distribution, with Comparisons to Some other Approximations

Abstract Results of an extensive empirical study of the accuracy of 12 normal and 3 binomial approximations to the hypergeometric distribution are presented in terms of maximum absolute error under various conditions on the variables. The most useful conditions employ the minimum cell in the given or complementary 2 × 2 table and the tail probability itself. Of the normal approximations, the best by far are of a heretofore unpublished type originated by Peizer. Especially detailed results on both absolute and relative errors are given for one Peizer approximation. Its absolute error is at most .0001, for example, if the minimum cell is at least 4.
Traffic Estimation and Capacity Assignment in Multimedia Distribution Networks with Guaranteed Quality of Service

This paper considers the provisioning of transmission line bandwidth on a private network with given traffic routing for the purpose of distribution of video-on-demand service with guaranteed end-to-end quality of service. We present an architecture for video-on-demand service delivery and model the assignment of bandwidth in the distribution network as a constrained, nonlinear optimization problem. To solve this optimization problem, we develop three new auction algorithm-based solution procedures. The optimization problem assumes that there is a functional relationship between the maximum acceptable end-to-end delay and the bandwidth requirement for the links in the distribution network. Absent reliable video traffic data models for MPEG-2 format, we sample a large number of DVD-recorded movies to form a basis for randomly generated aggregate traffic streams. The aggregate traffic streams are used in a simulation experiment to measure the maximum transmission buffer occupancy for each given traffic stream for different transmission rates. Based on this simulation experiment, we derive an empirical transmission line provisioning function that guarantees delivery of all video frames without frame loss within a maximum frame delay tolerance. To illustrate the effectiveness of the proposed solution procedure for the bandwidth assignment problem, we solve to near optimality 570 small problem instances under three demand structures and 100 large problem instances with uniformly distributed demand.