cssi/SciSciGPT-SciSciNet huggingface dataset:
Intra-session reliability of local dynamic stability of walking

While local dynamic stability measures have been successfully used to characterize walking stability, they require long continuous walking data, which may be difficult to obtain from a clinical population. We investigated the amount of walking data necessary to obtain reliable measures of local dynamic stability. Twenty healthy adults walked on a motorized treadmill at their self-selected speed for three trials of 5 min each. Trunk motion was used to construct a 12-dimensional state space comprised of the linear and angular positions and velocities. Mean divergence of locally perturbed trajectories was calculated as a measure of local dynamic stability using the first 1-5 min of data from each trial. Exponential divergence rates were quantified. Divergence was also parameterized using a double-exponential function. Intra-class correlation coefficients ICC(2,1) were calculated for each divergence measure for each trial length. ICC(2, 1) values increased with trial length, and reached 0.5-0.9. Good reliability was obtained for short-term measures for trial lengths of 2 and 3 min, but 5 min was not adequate to estimate the long-term coefficients based on a single trial.
Nutritional cirrhosis in rhesus monkeys: Electron microscopy and histochemistry

Abstract A choline-deficient low protein diet was fed to twelve Rhesus monkeys for two years. Eight of the animals died, most of them during the latter part of the first year. Mortality among males was higher than in females. Three of the four surviving animals developed fatty metamorphosis followed by cirrhosis. Eight sequential liver biopsies from each of these animals were studied. Control specimens showed paracrystalline mitochondrial inclusions in the hepatocytes and cytoplasmic crystalloids in the endothelial cells of the hepatic sinusoids and portal vessels. The significance of both structures remains unknown. Striking cytoplasmic vacuoles, possibly produced by anoxia during surgical liver biopsy, were observed in some specimens. The hepatocytes of the animals on the experimental diet, in addition to fatty change, showed mitochondria with bizarre shapes, circular cristae or increased electron opacity. Focal cytoplasmic degradation and Golgi dilatation were prominent. Microvilli developed along the intercellular spaces and became more prominent in the space of Disse. Basement membranes which were rarely continuous could be seen between hepatocytes and sinusoidal lining cells. In Disse spaces and intercellular spaces microfibrils and increased collagen fibers developed. In the later biopsies septa were formed which contained a higher proportion of typical collagen to microfibrils than the fibrillar material in the Disse spaces. The hepatocytes in the cirrhotic nodules stained more strongly for glycogen and were more active in nearly all histochemical enzyme reactions than the hepatocytes in non-nodular areas. This suggests that the nodules differed metabolically from the rest of the parenchyma.
One at a time

Review of abstracts presented at the 2004 Annual Meeting of the American Society for Reproductive Medicine clearly demonstrate that good prognosis patients should be given the option of a single embryo transfer.
Stress and microstructure of nanocrystalline FeXN (X = Ta, Si, and Al) thin films

Abstract Magnetic domain structures in thin-film heads are influenced by magnetoelastic anisotropy which is proportional to the film stress. In this study we have undertaken systematic measurements of thin film stress in the as-deposited state for sputtered FeXN (X = Ta, Si, and Al) thin films as a function of Ta, Si, Al, and N content. All as-deposited films exhibited the α-Fe structure with a (1 1 0) growth texture. It was found that pure Fe exhibits a tensile stress and this stress becomes more compressive as the amounts of Ta, Si, Al, and N in the films are increased. These stresses appear to be a cumulative effect of the amounts of Ta, Si, Al, and N added to the pure Fe. It was also found that N decreases the biaxial modulus of FeN and Fe-10TaN thin films.
Scheduling interfering job sets on parallel machines

Abstract We consider bicriteria scheduling on identical parallel machines in a nontraditional context: jobs belong to two disjoint sets, and each set has a different criterion to be minimized. The jobs are all available at time zero and have to be scheduled (non-preemptively) on m parallel machines. The goal is to generate the set of all non-dominated solutions, so the decision maker can evaluate the tradeoffs and choose the schedule to be implemented. We consider the case where, for one of the two sets, the criterion to be minimized is makespan while for the other the total completion time needs to be minimized. Given that the problem is NP-hard, we propose an iterative SPT–LPT–SPT heuristic and a bicriteria genetic algorithm for the problem. Both approaches are designed to exploit the problem structure and generate a set of non-dominated solutions. In the genetic algorithm we use a special encoding scheme and also a unique strategy – based on the properties of a non-dominated solution – to ensure that all parts of the non-dominated front are explored. The heuristic and the genetic algorithm are compared with a time-indexed integer programming formulation for small and large instances. Results indicate that the both the heuristic and the genetic algorithm provide high solution quality and are computationally efficient. The heuristics proposed also have the potential to be generalized for the problem of interfering job sets involving other bicriteria pairs.
Exodus Revisited: The Politics and Experience of Rural Loss in Central Brazil

The internal differences among people who have been referred to as peasants, and the long history of labour market participation by rural people in Latin America, suggest that rural exodus and urbanization must be treated as complex processes that have varied widely across time and space. Rural exodus continues to be a compelling metaphor for the contradictions of modernization today in Latin America. This article looks at the process and meaning of expulsion from the land in a prosperous agricultural region of central Brazil where almost all people today live in cities and towns. Intensive interviews with former rural dwellers, and rural union documentation of a number of cases of tenant expulsion by landowners, help situate the experience of rural exodus within two major commodity systems: free range cattle ranching and cotton production. In the first, a more traditional local system, tenant farmers known as agregados were eased off the land over a generation. Their loss occurred in a context of paternalism and negotiation which shielded many of them from the potentially devestating impact of landlessness. Workers in cotton production were first dislodged from other poorer regions in Brazil before being taken by labour brokers to the region of study. As day labourers with few local social ties, these people had a harder time in their move to town. It is important to recognize the political and economic relationships of working people to the land to understand why, in a region such as this, neither group of workers has insisted on returning to it. Resident cattle workers and cotton workers held no claims to land ownership. In addition, their long-established dependence on town life have made them reluctant to seek returning to the land.
The M1 and M2 isozymes of pyruvate kinase are the products of the same gene

Abstract The M1 and M2 isozymes of pyruvate kinase from several mammalian species were compared in their reactivity toward monoclonal anti-pyruvate kinase antibodies and by one and two-dimensional peptide mapping. Inter-species differences between the M2 isozymes were always accompanied by similar interspecies differences in the M1 isozymes, supporting the conclusion that these two isozymes are the products of the same gene.
Plasma Indicator Dispersion in Arteries of the Human Leg

Indicator-dilution curves were recorded from the femoral and dorsalis pedis arteries of five normal men after injections of indocyanine green into the superior vena cava or thoracic aorta. By considering the femoral curves as inputs to a mathematically linear system and the dorsalis pedis curves as outputs, transfer functions (the distribution of transit times) for the arterial segment between these sites were obtained in terms of a four-parameter model, the lagged normal density curve, over a sixfold range of flow rates. The parameters of the spread (dispersion) of 57 transfer functions were proportional to the mean transit time. The mean difference between transit time and appearance time was 0.30 t; the square root of the variances was 0.18 t. These linear relationships suggest that flow rate has no significant influence on dispersion and that, since no transition from laminar to turbulent flow was apparent, arterial flow characteristics were not significantly changed over a wide range of flow rates. The secondary implication is that the rate of spatial longitudinal spreading of indicator with distance traveled is primarily a function of the geometry of the arterial system, not of the rate of flow, and, therefore, that the spatial distribution at any instant is a function of this rate and of the distance traveled through the system.
Effect Of Neutron Irradiation On Laser Diode Properties

The effects of neutron irradiation on several properties of both single and multiple stripe laser diodes have been examined. Prior to fast neutron irradiation, total light output as a function of laser current, threshold current, near field pattern, far field pattern, and laser output wavelength spectra were measured at roan torperature. These measurements were then repeated at intermittent neutron fluence levels. It was observed that the threshold current increased with neutron fluence for all devices examined. In contrast, neutron irradiation had only an indirect effect on the remainder of the laser diode properties in that the higher currents required for operation after irradiation caused variations in these properties.
Comparison of the incorporation of oleate and ricinoleate into phosphatidylcholines and acylglycerols in soybean microsomes.

The incorporations of oleate (endogenous) and ricinoleate (nonendogenous) into phosphatidylcholine (PC) and acylglycerol (AG) in immature soybean microsomes were compared. [ 14 C]Oleate and [ 14 C]-ricinoleate were incubated individually with soybean microsomal preparations for up to 4 h, and molecular species of PC and AG incorporated were identified and quantified by HPLC. The activities of acyl CoA:lysoPC acyltransferase and phospholipase A 2 are in general not affected by the fatty acid (FA) chain at the sn-1 position. However, comparison between oleate and ricinoleate revealed that different FA incorporated at sn-2 of PC showed some different selection of the molecular species of lysoPC. The incorporation of [ 14 C]ricinoleate into triacylglycerols (TAG) was slightly better than that of [ 14 C]oleate and indicated that soybean was capable of incorporating ricinoleate into TAG when ricinoleate can be produced endogenously in a transgenic soybean. The incorporation of FA into TAG in soybean microsomes was much slower than that in castor microsomes.
Hispanic Americans: comparative considerations and the educational problems of children.

This paper presents an overview of the diversity in character among the various Hispanic-American subgroups. The author compares the following subgroups historically and demographically: Mexican-Americans Cuban-Americans Mainland Puerto-Ricans and "other" Hispanics. As a group Hispanic-Americans lag far behind the majority population in any array of standard educational measurements. 40% of Hispanic-American students leave school before 10th grade. Children of "immigrant" minorities such as Chinese Japanese and South and Central Americans tend to do better in school than "caste-like" minorities such as Black Americans Mainland Puerto-Ricans and Mexican-Americans in the US. The author discusses several models which explain why Mexican and Puerto-Rican Americans fail in American schools at such high rates: 1) culture of poverty 2) the various schools emphasizing "discontinuity" between the minority Hispanic and the majority culture and 3) the psychosocial approach. Features which differentiate immigrants from caste-like minorities include 1) caste-like minorities were incorporated into the society against their will whereas historically immigrant minorities choose more or less freely to leave their country to enter a new social order; and 2) immigrants may anticipate or fantasize that in the future they will return home to enjoy the fruits of their hard work in the foreign land. 2 factors alleviate the longterm effects of the hardships and discrimination immigrants face: 1) the levels of discrimination became less evident as accents disappeared and names were Anglicized; immigrants develop a dual frame of reference enabling them to evaluate their current reality against the reality of life back home; and 3) hard work in the new land will at the very least benefit the children in the future. Factors which veto the Mexican immigrant case as a heurstically "paradiomatic" immigrant minority include: 1) many Mexicans still resent the loss of 1/3 or Mexicos territories to Anglo colonists 2) Americans still treat Mexican immigrants as a "case-like" minority despite the fact that they are immigrants and 3) many of the "immigrants" lack official immigrant status.
Electron Paramagnetic Resonance in Frozen and Dried Biological Materials

Kent and Mallard1 and Truby and Goldzieher2 have recently indicated that free radicals formed in organic omaterial are artefacts, apparently resulting from lyophilization. Our findings are not in agreement with this concept. We believe that lyophilization of living biological materials, of and by itself, produces few if any free radicals. Our investigations indicate that the electron paramagnetic resonance signals observed by others3–5 were the result of a reaction between oxygen and an unidentified component in dried specimens which formed free radicals during the interval between lyophilization and observation in the electron paramagnetic resonance spectrometer.
A Rab GTPase Is Required for Homotypic Assembly of the Endoplasmic Reticulum

To define the requirements for the homotypic fusion of mammalian endoplasmic reticulum (ER) membranes, we have developed a quantitative in vitro enzyme-linked immunosorbent assay. This assay measures the formation of IgG (H2L2) following the fusion of ER microsomes containing either the heavy or light chain subunits. Guanine nucleotide dissociation inhibitor (GDI), a protein that extracts Rab GTPases in the GDP-bound form from membranes, potently inhibits fusion. Inhibition was not observed using GDI mutants defective in Rab binding. Kinetic analysis of the inhibitory effects of GDI revealed that Rab activation is required immediately preceding or coincident with fusion and that this step is preceded by a priming event requiring a member of the AAA ATPase family. Our results suggest that homotypic fusion of ER membranes requires Rab and that Rab activation is a transient event necessary for the formation of a fusion pore leading to the mixing of luminal contents of ER microsomes.
Metal-catalyzed phosphodiester cleavage: secondary 18O isotope effects as an indicator of mechanism.

Information about the transition states of metal-catalyzed hydrolysis reactions of model phosphate compounds has been obtained through determination of isotope effects (IEs) on the hydrolysis reactions. Metal complexation has been found to significantly alter the transition state of the reaction from the alkaline hydrolysis reaction, and the transition state is quite dependent on the particular metal ion used. For the diester, ethyl p-nitrophenyl phosphate, the nonbridge 18O effect for the hydrolysis reactions catalyzed by Co(III) 1,5,9-triazacyclononane and Eu(III) were 1.0006 and 1.0016, respectively, indicative of a slightly associative transition state and little net change in bonding to the nonbridge oxygen. The reaction catalyzed by Zn(II) 1,4,7,10-tetraazacyclododecane had an 18O nonbridge IE of 1.0108, showing the reaction differs significantly from the reaction of the noncomplexed diester and resembles the reactions of triesters. Reaction with Co(III) 1,4,7,10-tetraazacyclododecane showed an inve...
Lithium effects on active and passive avoidance behavior in the rat

Lithium chloride reduced the rate of acquisition of a passive-avoidance response and decreased the rats' reaction to the shock delivery. Acquisition of an active-avoidance response was unimpaired by lithium, although lithium-administered rats responded predominantly to the cue stimulus, making significantly fewer precue avoidance responses than did controls. Lithium's efficacy in the treatment of manic disorders may, therefore, be the result of a decrease in the individual's reactivity to low-intensity stimulation.
Plasma diagnostics using high-resolution spectroscopic techniques*†

Density-sensitive line intensity ratios measurable in high-resolution spectra are discussed for high-temperature plasmas (1.5–1300 eV). By working along isoelectronic sequences, it is possible to find density-sensitive ratios over a wide range of electron densities (1012 to ∼1021 cm−3). This range includes the density of a number of laboratory plasmas of current interest. We also discuss the temperature sensitivity of some of the line ratios for ions formed in the colder plasmas with temperatures of 1.5–15 eV. We present a table of forbidden lines obtained from Skylab spectra of the solar corona. Lines of this type should be detectable in certain laboratory spectra. Their long wavelengths make these lines particularly suitable for measuring the ion temperature or nonthermal motions. Finally, we show the feasibility of detecting megagauss magnetic fields in high-temperature plasmas, from profiles of selected spectral lines.
Pointing accuracy of a dual-spin satellite due to torsional appendage vibrations

This paper deals with the attitude motion of a dual-spin satellite with a finite sized rigid body attached to the end of a flexible beam. The equations of motion are derived using Lagrange's equations and are solved using the perturbation technique known as the Krylov-Bogoliubov-Mitropolsky method. The special case of torsional flexibility is presented in its entirety. The relationships between the satellite, beam and tip mass parameters, and pointing accuracy of the satellite are examined. KBM method instead of generalized averaging since the equa- tions of motion obtained for the satellite are not in periodic standard form. By deriving an approximate analytical solution of the non- linear equations of motion, the work of this paper allows examination of the effects of system parameters on the motion of the spacecraft in question. Although resonances are easily obtained from a simple examination of the fundamental fre- quencies of the problem, this work allows the examination of behavior away from resonance. This provides the opportunity to look for local minima of the perturbation from rigid-body behavior as a function of the system parameters and hence allows for a more optimally designed spacecraft. In addition, control of the spacecraft could be more efficiently imple- mented if a general idea of the form of the motion is available. With numerically computed results, it is not possible to exam- ine the effects of individual parameters without many repeated evaluations of the motion. The approach in this paper provides full-field parametric relationships for the examination of all system parameters. Also of note is the fact that the effects of finite size tip masses are investigated. Rotary inertia of the tip mass intro- duces a set of equations of motion for the tip mass that are coupled to the equations of motion for the system through the dynamics of the elastic beam. Very little has been done con- cerning analytical examination of such a tip mass. These re- sults will provide a new tool for the design and control of spacecraft of this type, as well as introducing the KBM ap- proach to the body of literature relating to this topic.
THE DISAPPEARANCE OF PHOSPHATASE FROM THE HYDRONEPHROTIC KIDNEY.

"Alkaline" phosphatase disappears or only remains in small amounts in the rabbit and rat kidney after periods of hydronephrosis of 2 to 5 days or more, following complete obstruction of the ureter. By the use of the Gomori-Takamatsu technique it has been possible to distinguish normally functioning from non-functioning cells, when by ordinary histologic stains the cells are indistinguishable.
Retrace prevention in multi-curve graphs

Abstract A method is presented to prevent over-exposure of microfilm caused by retracing the parts of a figure where multiple curves merge. The method by-passes hardware vector generation by a mapping of the points to be used into a display data structure which eliminates redundant points. When all curves for a particular graph have been mapped, the display data is transmitted to the graphics device which is treated as if it were a point plotter. The method should also be applicable to pen and ink plotters and storage CRT's.
Immunity to Rotavirus in T Cell Deficient Mice

Abstract Rotavirus infection was studied in adult nude mice (BALB/c background), αβ or γδ and αβ/γδ T cell receptor (TCR) knockout (−/−) mice (C57BL/6 and C57BL/6×129 backgrounds), and SCID mice (C57BL/6 background). The γδ TCR −/− mice cleared infection just like control mice. All of the nude mice, αβ, and αβ/γδ TCR −/− mice cleared primary rotavirus infection, with a short delay, compared to immunocompetent control mice and developed a rotavirus-specific intestinal IgA measured by ELISA. Elispot analysis with spleen and lamina propia cells showed that the virus-specific intestinal IgA response in immunocompetent C57BL/6 mice was similar to the γδ TCR −/− mice and 7- to 60-fold higher than in the αβ TCR −/− and αβ/γδ TCR −/− mice. Likewise, the response of nude +/− mice was 20 times greater than that of nude −/− littermates. While the intestinal IgA antibodies of C57BL/6 mice, γδ TCR −/− mice, and nude +/− mice recognized insect cells infected with recombinant baculovirus expressing rotavirus VP6 and VP4 proteins, those of the αβ TCR −/−, αβ/γδ TCR −/−, and nude −/− mice recognized only VP6. Immunocompetent C57BL/6 mice depleted of CD4 + T cell developed similar levels of rotavirus-specific intestinal IgA as the αβ TCR −/− mice, suggesting that this T cell-independent IgA response is present in normal mice. In contrast to previously published results with BALB/c SCID and RAG 2 −/− (C57BL/6×129 background) mice, all of which become chronically infected with murine rotavirus, 40% of the C57BL/6 SCID mice cleared primary rotavirus infection. These results suggest that both a T cell-independent antibody response and innate mechanisms can contribute to immunity to murine rotavirus and show that γδ T cells are not necessary for efficient clearance of primary rotavirus infection in mice.
Evaluation of the stability and analysis of halogenated furanones in disinfected drinking waters

Abstract A refined method for the sub-nanomolar analysis of 13 halogenated furanones in chlorinated drinking water is proposed which uses liquid–liquid extraction, methylation where necessary, gas chromatographic separation, and either micro-electron capture or ion trap mass spectrometric detection. Liquid–liquid extraction with methyl tert-butyl ether was demonstrated to be effective for recovery of halogenated furanones. Confirmation of the halogenated furanones identity and reduction of natural organic matter interference were achieved by ion trap tandem mass spectrometry. Compound stabilities and procedural efficiencies were evaluated to permit optimization of the method for reasonable sample volumes and a 1000:1 pre-concentration factor that would permit feasible sample collection in the field. Both chlorinated and brominated analogues of MX (3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone) were included in a suite of compounds targeted in a national occurrence study of disinfection by-products.
The rich and the irradiated

Uranium Frenzy: Boom and Bust on the Colorado Plateau. by Raye C. Ringholz W.W. Norton: 1989. Pp.310. $18.95. To be published in Britain in June, £13.95.
Chaos in the classical relativistic mechanics of a damped Duffing-like driven system

Abstract We study classically the problem of two relativistic particles with an invariant Duffing-like potential which reduces to the usual Duffing form in the nonrelativistic limit. We demonstrate, by means of computer calculations, the onset of chaos and the existence of a strange attractor and a limiting hyperbolic motion in the presence of driving forces and dissipation. The chaotic behavior of the position variable is reflected in chaos in the time of occurrence of the corresponding events. Thus, spacetime may be chaotic.
Parameter estimation of generalized backscatter models using entropy maximization

ABSTRACT                                                         Keywords: !                 1. INTRODUCTION "     #!$%        &              '  !$      $  (            #$)% !$   "           *$     #)+%      )+                          13 "           46 )             )  )   )         &                         
Cerebrovasculature-mediated Neuronal Cell Death

: The presence of significant vascular disease in patients with Alzheimer's disease (AD) and the recognition of the ApoE genotype as a risk factor for both coronary disease and AD support an association between AD and vascular disease. It is our hypothesis that brain microvessels contribute to the pathogenesis of AD by producing soluble factors that injure or kill neurons. In this study we report that AD microvessels produce factors that are noxious to neurons and that these vessels can evoke neuronal cell death in vitro. In these experiments, microvessels are isolated from the cerebral cortices of AD patients and nondemented elderly and young controls. Microvessels isolated from AD brains produce high levels of a known neurotoxin nitric oxide, compared to vessels from aged-matched controls. In addition, we demonstrate a direct neurotoxic effect of AD microvessels when co-cultured with primary rat cerebral cortical neurons. In contrast, vessels from elderly non-demented donors are less lethal, and brain vessels from younger donors are not neurotoxic. Similarly, AD vessels exhibit a dose-dependent toxicity in co-culture with the human neurons. Finally, treatment of AD microvessels with the protein synthesis inhibitor cycloheximide reduces AD vessel neurotoxicity, suggesting that the neurotoxic factor is a protein. These findings suggest that the cerebral microvasculature is a source of factors that can injure neurons and implicate a novel mechanism of vascular-mediated neuronal cell death in AD.
Purification and properties of rat uterine procollagenase

Abstract A procollagenase from monolayer cultures of postpartum rat uterine cells has been purified. The crucial step in the purification is the binding of the procollagenase from crude, fetal bovine serum-containing culture medium to heparin-Sepharose, followed by elution with extremely low concentrations (5–10 n m ) of dextran sulfate. Resultant eluates contain 8–10% procollagenase. Purification is completed by ion-exchange chromatography on DEAE-Sepharose, gel filtration on AcA-44, and chromatography on blue-Sepharose. Rat uterine procollagenase appears as a protein doublet of Mr ~ 58,000, as indicated by two polyacrylamide gel electrophoresis systems, by AcA-44 chromatography, and by equilibrium sedimentation ultracentrifugal analysis. The proenzyme forms are converted by trypsin to an active enzyme doublet of Mr ~ 48,000. Small amounts of active enzyme, which are often generated during the purification, are electrophoretically indistinguishable from trypsin-activated collagenase. Active collagenase can be separated from the zymogen forms by DEAE-Sepharose chromatography. The two forms of the proenzyme doublet can be partially separated by gel filtration on AcA-44 and preliminary analysis indicates each has equal collagenolytic activity. The amino acid analysis of rat uterine collagenase reveals it to be markedly different from two other vertebrate collagenases whose composition is known. The uterine proenzyme is unusually rich in glycine and in the hydroxy amino acids and is considerably more acidic than the human skin fibroblast collagenase, consistent with the different ionexchange behavior of the two molecules. The specific activity of rat uterine collagenase at 37 °C is approximately 3000 μg collagen/min/mg, using native reconstituted guinea pig skin type I collagen fibrils as substrate. The enzyme cleaves denatured collagen, but fails to attack a variety of noncollagen proteins.
Effects of the Kelvin-Helmholtz surface instability on supersonic jets

An exact numerical calculation is provided for of linear growth and phase velocity of Kelvin-Helmholtz unstable wave modes on a supersonic jet of cylindrical cross section. An expression for the maximally unstable wavenumber of each wave mode is found. Provided a sharp velocity discontinuity exists all wave modes are unstable. A combination of rapid jet expansion and velocity shear across a jet can effectively stabilize all wave modes. The more likely case of slow jet expansion and of velocity shear at the jet surface allows wave modes with maximally unstable wavelength longer than or on the order of the jet radius to grow. The relative energy in different wave modes and effect on the jet is investigated. Energy input into a jet resulting from surface instability is discussed. Previously announced in STAR as N83-17379
Examination of Icing Induced Loss of Control and Its Mitigations

Factors external to the aircraft are often a significant causal factor in loss of control (LOC) accidents. In today s aviation world, very few accidents stem from a single cause and typically have a number of causal factors that culminate in a LOC accident. Very often the "trigger" that initiates an accident sequence is an external environment factor. In a recent NASA statistical analysis of LOC accidents, aircraft icing was shown to be the most common external environmental LOC causal factor for scheduled operations. When investigating LOC accident or incidents aircraft icing causal factors can be categorized into groups of 1) in-flight encounter with super-cooled liquid water clouds, 2) take-off with ice contamination, or 3) in-flight encounter with high concentrations of ice crystals. As with other flight hazards, icing induced LOC accidents can be prevented through avoidance, detection, and recovery mitigations. For icing hazards, avoidance can take the form of avoiding flight into icing conditions or avoiding the hazard of icing by making the aircraft tolerant to icing conditions. Icing detection mitigations can take the form of detecting icing conditions or detecting early performance degradation caused by icing. Recovery from icing induced LOC requires flight crew or automated systems capable of accounting for reduced aircraft performance and degraded control authority during the recovery maneuvers. In this report we review the icing induced LOC accident mitigations defined in a recent LOC study and for each mitigation describe a research topic required to enable or strengthen the mitigation. Many of these research topics are already included in ongoing or planned NASA icing research activities or are being addressed by members of the icing research community. These research activities are described and the status of the ongoing or planned research to address the technology needs is discussed
The Male Nursing Student as a Token

The purpose of this research was to test the applicability of Kanter's theory of tokenism to male nursing students. Kanter's theory states that numerical underrepresentation, not cultural factors, causes tokens to experience greater performance pressure, social isolation, and role entrapment. Subjects were 322 male and female nursing students from two similar midwestern nursing schools. Subjects completed instruments measuring social isolation, upward communication distortion, performance pressure, and communication apprehension. This research did not find support for Kanter's claims. Possible explanations for the findings include sex status differences and the nurturing character of the nursing profession.
Price variation and volume dynamics of securitized timberlands

Abstract An increasing amount of timberlands have been securitized and made available to investors in the form of Master Limited Partnerships (MLPs) or Real Estate Investment Trusts (REITs). In this study, Generalized Autoregressive Conditional Heteroscedasticity (GARCH) and extreme value models were utilized to examine price variation and volume dynamics of six firms that have specialized in timberland investment. Total standing shares and average daily turnover rates for the MLPs were smaller than those for the timber REITs. Both the GARCH and extreme value models revealed a positive return–volume relation, which provided a strong empirical support for the mixture-of-distribution hypothesis. During extreme market movements, the MLPs had stronger and more stable return–volume relations than the timber REITs. Asymmetric return–volume relation was identified for the MLPs, while the relation was fairly symmetric for the timber REITs.
Elimination of n-butylated hydroxytoluene methylation during fatty acid analysis by gas chromatography

An improved method for fatty acids analysis with optimum recovery of highly polyunsaturated fatty acids methyl esters in biological systems is presented. The method is based on transesterification of phospholipid and triacylglycerols to fatty acid methyl esters using a commercially available reagent, Methyl-Prep II. Without proper precautions, as much as 50% of n-butylated hydroxytoluene (BHT) added to prevent oxidation of polyunsaturated fatty acids, could be methylated during the transesterification step. Methylated BHT elutes close to 14:0 (myristic acid) and no longer functions as an antioxidant, but the modified conditions virtually eliminate the methylation of BHT. Sample extraction and methylation was completed in 30 min at room temperature. A chelator (diethylenetriamine-pentaacetic acid; DTPA) is also added to prevent peroxidation of metal catalyzed free radical chain reactions. The standard deviations of the major fatty acids from multiple human plasma samples prepared on different days were less than 5%. The recovery of arachidonic acid, 20:4, from plasma was improved using the new method, and the recovery for docosahexaenoic acid, 22:6, spiked to human plasma was found to be 99%.
The interaction between price and long-run variables in a multinational brand market

Abstract This study examined how long-run variables and pricing decisions interacted to affect market shares of multinational brands. By applying a brand market share model, the study focused on how price sensitivity was affected by long-run variables such as product quality, advertising expenditure, and country names, within the U.S. subcompact car market. This study generated three major findings: (1) the advertising effect on price sensitivity was positively related to competitive reactivity, (2) only the reliability factor reduced price sensitivity, whereas other less important product dimensions (such as performance and size factors) worked differently, and (3) country image reduced price elasticity for premium pricing. Important managerial implications for pricing decisions were discussed in relation to the interaction with the long-term variables.
BEAM PROFILE OF THE FLASHLAMP PUMPED PULSED DYE LASER : SUPPORT FOR OVERLAP OF EXPOSURE SPOTS

The degree to which individual practitioners overlap exposure spots of the flashlamp pumped pulsed dye laser when treating large vascular lesions appears to be a matter of personal preference. There are few data to support one approach over another. We have measured the beam profile of this laser at two different energy fluences using a photodiode and a digitizing storage oscilloscope. Results show that for each energy fluence, the beam intensity decreases from the center to the outside rim of the beam. A plot of beam intensity versus the radius of the treatment field approaches a truncated normal distribution with a full width at half-maximum of 4.7-4.8 mm. These results help explain why clinical overlap of exposure spots can be safely undertaken and provide a rationale for recommendations concerning the degree of overlap needed to expedite treatment while still minimizing adverse reactions.
The percutaneous removal of difficult upper urinary tract calculi

Percutaneous nephrolithotomy has become an established procedure for urologic surgery. For the stone which is poorly accessible or of large volume, special approaches and techniques are essential for success. For example, exact anatomical conceptualization and pinpoint puncture are vital. These requirements are aided by retrograde hyperinflation with contrast medium and C-arm fluoroscopy. Sometimes multiple percutaneous nephrostomy tracts are required or the tract must be directed so that it courses transpleurally. Among the large number of instruments available for percutaneous nephrostomy, flexible endoscopy becomes increasingly important for the difficult stone. Intrarenal electrosurgery is also important. Finally, for ureteral stones, retrograde flushing with CO2 or saline through a percutaneous sheath may be useful. These additional approaches when judiciously applied can result in a stone-free status for virtually 100% of patients.
Robustness for large scale UAV autonomous operations

Unmanned aerial vehicles (UAVs) need multiple operators as of today. Because of limitations of human attention and sensory cueing the operators cannot use all of the data coming in through these sensors. Large scale autonomy would mean the following: fewer operators, larger areas of coverage, and more vehicles. Rigorous optimization of decision theory based approaches to handling this problem suffer from speed limits to real-time computations. Soft-computing methods based on heuristics (AI, reasoning, neural networks and fuzzy logic) are able to handle certain circumstances but cannot supply any guarantees of performance in unstructured environments. We provide solutions based on rigorous approaches, but avoid heavy real-time computation through off line processing. For mapped regions, we convert maps into traversability graphs using trapezoidal map/voronoi type algorithms. We then find the shortest permissible paths for different vehicles using Dijkstra's algorithm and then preening the allowable paths using constraints on individual vehicles. Out third step consists in determining the minimum time taken by a given vehicle over those paths. We insert margins of safety at each level of this hierarchy: buffer zones (size of buffer zone is a ten meters extended polygon around each building) around mapped structures to account for map errors; buffer zones around flight paths to account for position uncertainty of vehicles; performing 1-D optimal control within limits of the vehicles performance so that vehicles can slow down or speed up in response to unexpected events.
Clinical pearls in infectious diseases.

At the 2001 annual conference of the American College of Physicians, a new teaching format to aid physician learning, Clinical Pearls, was introduced. Clinical Pearls is designed with the 3 qualities of physician-learners in mind. First, we physicians enjoy learning from cases. Second, we like concise, practical points that we can use in our practice. Finally, we take pleasure in problem solving.
Use of pressure platform gait analysis in cats with and without bilateral onychectomy

Objective—To determine peak vertical force (PVF) and vertical impulse (VI) in cats that had or had not undergone bilateral forelimb onychectomy. Animals—26 healthy adult cats. Procedure—Onychectomized cats (n = 13) had undergone surgery more than 6 months prior to the study. The PVF and VI were collected from all limbs of each cat with a 2-m pressure platform walkway. Cats were allowed to walk at a comfortable velocity, and acceleration was restricted to ± 0.5 m/s2. Five valid trials were recorded for each cat with all trials collected in a single 1-hour session. All forces were normalized to and expressed as a percentage of the cat's body weight. Results—Gait data were successfully collected in all cats. No significant difference was found for PVF or VI between cats that had or had not had onychectomy. Limb loads were greater in forelimbs than hind limbs for all trials. Mean PVF and VI in the forelimbs of cats in the nononychectomy group were 56.41% and 18.85%, respectively. Mean PVF and VI in the hind l...
Dispersion relation calculation of the πNN form factor for one off-shell nucleon

Abstract We present a dispersion relation calculation of the πNN form factor in the kinematic region where one nucleon is off the mass shell and the pion is on its mass shell. The inclusion of πN inelasticity is shown to have a crucial effect on the results.
Targeted Therapeutic Agents for Colorectal Cancer

The treatment of colorectal cancer (CRC) has evolved substantially during the past decade with the advent of molecular targeted therapies. Inhibitors to the vascular endothelial growth factor and epidermal growth factor receptor (EGFR) pathways have been shown to enhance the efficacy of cytotoxic chemotherapy in patients with advanced CRC, and anti-EGFR antibodies demonstrate modest activity as monotherapeutic agents. These biologic agents have improved patient outcomes and survival and have been incorporated into routine clinical practice establishing a new standard of care. Molecular markers have recently been adopted into clinical practice with the finding that the KRAS oncogene is a predictive biomarker for anti-EGFR therapy, whereby the therapeutic benefit of anti-EGFR treatment is restricted to tumors with wild-type KRAS. The use of molecular targeted agents has fewer yet more specific toxicities compared with conventional cytotoxic drugs and enables a more personalized approach to cancer therapy. In contrast to the results for advanced CRC, targeted therapies have not shown a benefit in the adjuvant setting for patients with resected colon cancer. The goal of this review is to provide an update on the medical management of CRC, with a focus on the use of targeted therapy.
Oxygen precipitation in silicon

The behavior of oxygen in Czochralski grown silicon has been intensely studied in the last few years because of the beneficial and harmful effects that oxygen precipitates and oxygen precipitate-induced dislocation loops can have on the manufacture of electronic devices in silicon wafers. This paper will review four topics associated with the use of Czochralski silicon (1); the kinetics associated with nucleation and growth of oxygen precipitates in the bulk of the wafer; the creation of defect-free denuded zones at the front surface of wafers; the creation and annihilation of oxygen related donors; and the role of carbon impurities in oxygen precipitation.
Ordering in III/V Alloys

Simple calculations using the delta-lattice-parameter (DLP) model indicate that the enthalpy of mixing is invariably larger than or equal to zero for III/V alloys, and increases with increasing difference in lattice constant for the constituent binary compounds. In terms of the regular solution model this suggests the occurrence of miscibility gaps. Solid phase immiscibility has indeed been observed in a number of systems. Nevertheless, such alloys can be grown by OMVPE, including the highly metastable alloys GaPSb and InPSb. Initially surprising was the occurrence of ordered structures in these same alloys. The regular solution model apparently specifically excludes immiscibility and ordering in the same system. However, when the positive enthalpy of mixing is due to strain energy effects, as in III/V alloys, Hume-Rothery recognized very early that such phenomena should be anticipated. This was later confirmed by detailed first principles calculations. In fact, the tendency for ordering is anticipated to increase as the difference in tetrahedral radii of the elements sharing a common sublattice increases. Thus, it is somewhat surprising that ordering was first observed in the AlGaAs system where Al and Ga have nearly equal sizes. Ordered structures have now been observed in several III/V alloy systems including the ternary systems GaAsSb and GalnP and the quaternaries GalnAsP, GalnAsSb, and AlGalnP. In this paper, ordering in other alloy systems such as GaPSb and InAsSb will be described. Surprisingly, no strong correlation between atomic size difference and the degree of ordering has been observed. Another unexpected observation is that the preferred ordered structure for most ternaries involves ordering along the {111}directions. Both first principles total energy and simple strain energy calculations indicate that such ordered structures are only slightly more stable than the disordered solid solution. Other ordered structures, including L10, where ordering occurs along the {100} directions, are considerably more stable. Both phenomena must be explained in terms of the surface kinetic processes occurring during epitaxial growth. Such an explanation is supported by the importance of kinetic parameters such as growth rate, temperature, and substrate orientation in determining both the degree of order and the specific ordered structures observed.
Cryoprotectants and Extreme Freeze Tolerance in a Subarctic Population of the Wood Frog

Wood frogs (Rana sylvatica) exhibit marked geographic variation in freeze tolerance, with subarctic populations tolerating experimental freezing to temperatures at least 10-13 degrees Celsius below the lethal limits for conspecifics from more temperate locales. We determined how seasonal responses enhance the cryoprotectant system in these northern frogs, and also investigated their physiological responses to somatic freezing at extreme temperatures. Alaskan frogs collected in late summer had plasma urea levels near 10 μmol ml-1, but this level rose during preparation for winter to 85.5 ± 2.9 μmol ml-1 (mean ± SEM) in frogs that remained fully hydrated, and to 186.9 ± 12.4 μmol ml-1 in frogs held under a restricted moisture regime. An osmolality gap indicated that the plasma of winter-conditioned frogs contained an as yet unidentified osmolyte(s) that contributed about 75 mOsmol kg-1 to total osmotic pressure. Experimental freezing to –8°C, either directly or following three cycles of freezing/thawing between –4 and 0°C, or –16°C increased the liver’s synthesis of glucose and, to a lesser extent, urea. Concomitantly, organs shed up to one-half (skeletal muscle) or two-thirds (liver) of their water, with cryoprotectant in the remaining fluid reaching concentrations as high as 0.2 and 2.1 M, respectively. Freeze/thaw cycling, which was readily survived by winter-conditioned frogs, greatly increased hepatic glycogenolysis and delivery of glucose (but not urea) to skeletal muscle. We conclude that cryoprotectant accrual in anticipation of and in response to freezing have been greatly enhanced and contribute to extreme freeze tolerance in northern R. sylvatica.