cssi/SciSciGPT-SciSciNet huggingface dataset:
Damage mechanisms in bithermal and thermomechanical fatigue of Haynes 188

Post failure fractographic and metallographic studies were conducted on Haynes 188 specimens fatigued under bithermal and thermomechanical loading conditions between 316 and 760 C. Bithermal fatigue specimens examined included those tested under high strain rate in-phase and out-phase, tensile creep in-phase, and compressive creep out-of-phase loading conditions. Specimens tested under in-phase and out-of-phase thermomechanical fatigue were also examined. The nature of failure mode (transgrandular versus intergranular), the topography of the fracture surface, and the roles of oxidation and metallurgical changes were studied for each type of bithermal and thermomechanical test.
Micromachined ultrasonic materials

Ultrasonic matching layers are necessary for efficient coupling between piezoelectric ceramics and either air or water. Current materials are formed by suspending particles in an epoxy matrix. A technique using silicon micromachining techniques and IC fabrication technology to build low-loss, high-purity, and controllable acoustic matching layers is proposed. The performance of micromachined matching layers was measured and compared with theory. With this technique it is possible to fabricate ultrasonic matching layers with impedances between 0.02 and 20 MRayls for operation at frequencies between 1 and 200 MHz. >
A Layered Wave Equation Model for Thermally Stratified Flow

Publisher Summary This chapter describes a layered wave equation model for thermally stratified flow. The dynamic behavior of stratified bodies of water is dramatically different from that of homogeneous bodies. It is well-known that large amplitude internal waves exist in lakes in temperate climates when thermal stratification develops in the summer months. This motion can induce substantial flows under the right wind conditions and hence, can play a significant role in the transport process in the main body of a lake. It can also induce exchange processes with the adjacent coves and bays. Internal waves have periods that are often orders of magnitude larger than the gravity waves based on the celerity of the same body under homogeneous conditions. The dynamic response of a thermally stratified body of water consists of the superposition of the homogeneous type waves, and the waves arising from stratification. As demonstrated, both waves are important to the solution and hence, the solution techniques must not mask or inadvertently filter out what might otherwise appear to be troublesome higher frequency components of the response.
Psychosocial characteristics of individuals with non-stage IV melanoma.

PURPOSE: Melanoma is the fastest growing solid tumor among men and women and accounts for 79% of skin cancer–related deaths. Research has identified that distress is frequently associated with a diagnosis of cancer and may slow treatment-seeking and recovery, increasing morbidity and even mortality through faster disease course. Given that the 5-year survival rates for individuals with melanoma are determined primarily by the depth and extent of spread, distress that interferes with seeking treatment has the potential to be life-threatening. PATIENTS AND METHODS: The current study was designed to identify levels of distress present in individuals seeking treatment at a large, Midwestern, multidisciplinary melanoma clinic. It also focused on determining the quality of life, level of anxiety, and coping strategies used by individuals with melanoma before treatment. Given that the course of treatment and outcome for patients with stage IV disease is vastly different from that of patients with stages I to III...
The Biochemistry and Molecular Regulation of Carbon Dioxide Metabolism in Cyanobacteria

Carbon dioxide is a greenhouse gas whose accumulation in the biosphere has been the cause for increasing concern. CO2 is also the source for virtually all organic carbon on Earth and its efficient assimilation is directly related to agricultural productivity. As organisms which often depend on the reduction and assimilation of CO2 as their prime source of carbon, cyanobacteria have become important tools for gaining an understanding of the biochemical and molecular mechanisms involved. These organisms take on added significance because the entire process, the catalysts employed and their structural genes, are to some extent quite similar to those of higher plants. Because of the relative ease in using molecular techniques and transferring genetic information in cyanobacteria, there are many advantages to these organisms as models for green plant CO2 metabolism. There are also differences that make cyanobacteria fascinating in their own right. Over the last few years, there has been a tremendous upsurge in interest in cyanobacterial CO2 fixation research. Important insights relative to the biochemistry of the process have emerged, fueled by the revolution in molecular biology. This chapter thus considers the current state of the field and reviews the many important contributions that have been made on this interesting and important area of cyanobacterial research.
Discrete Surface Signal Processing: The Polygon as the Surface Element

Smooth surfaces are approximated by polyhedral surfaces both for display, and for other computational purposes. This is probably the most common surface representation in computer graphics, because polygons are what the current generation of graphics hardware can display efficiently. In computer vision this representation has not been very popular for a long time, probably because it was not seen as very appropriate for object recognition and positioning applications. But it is now being used in more applications, particularly in the medical domain, where polyhedral surface approximations of unknown surfaces are routinely generated with iso-surface construction algorithms. We look at polyhedral surfaces as a generalization of digital images, where the polygon takes the place of the pixel. The polygon is the fundamental surface element. Digital images are functions defined at the nodes of a regular rectangular grid. Discrete surface signals are functions defined at the vertices of a polyhedral surface of arbitrary topology. Signal processing operations, and Fourier analysis in particular, are the fundamental tools of low level computer vision. The lack of regularity and self-similarity of arbitrary polyhedral surface meshes, as opposed to the regular rectangular grids of digital images, complicates the analysis and processing of digital surface signals. Nevertheless, in this paper we generalize Fourier analysis to discrete surface signals. As a first application of this theory we consider the problem of surface smoothing, which corresponds to low-pass filtering within this framework. As in the classical cases of one-dimensional signals, and of digital images, the analysis of discrete surface signals is reduced to matrix analysis, and matrix computation techniques are used to achieve fast discrete surface signal processing operations. We intend to continue along this line of research in the near future, extending higher level computer vision operations to arbitrary polyhedral surfaces.
glsA, a Volvox gene required for asymmetric division and germ cell specification, encodes a chaperone-like protein

The gls genes of Volvox are required for the asymmetric divisions that set apart cells of the germ and somatic lineages during embryogenesis. Here we used transposon tagging to clone glsA, and then showed that it is expressed maximally in asymmetrically dividing embryos, and that it encodes a 748-amino acid protein with two potential protein-binding domains. Site-directed mutagenesis of one of these, the J domain (by which Hsp40-class chaperones bind to and activate specific Hsp70 partners) abolishes the capacity of glsA to rescue mutants. Based on this and other considerations, including the fact that the GlsA protein is associated with the mitotic spindle, we discuss how it might function, in conjunction with an Hsp70-type partner, to shift the division plane in asymmetrically dividing cells.
Pathways of anaerobic organic matter decomposition in tundra soils from Barrow, Alaska

Arctic tundra soils store a large quantity of organic carbon that is susceptible to decomposition and release to the atmosphere as methane (CH4) and carbon dioxide (CO2) under a warming climate. Anaerobic processes that generate CH4 and CO2 remain unclear because previous studies have focused on aerobic decomposition pathways. To predict releases of CO2 and CH4 from tundra soils, it is necessary to identify pathways of soil organic matter decomposition under the anoxic conditions that are prevalent in Arctic ecosystems. Here molecular and spectroscopic techniques were used to monitor biological degradation of water-extractable organic carbon (WEOC) during anoxic incubation of tundra soils from a region of continuous permafrost in northern Alaska. Organic and mineral soils from the tundra active layer were incubated at –2, +4, or +8°C for up to 60 days to mimic the short-term thaw season. Results suggest that, under anoxic conditions, fermentation converted complex organic molecules into simple organic acids that were used in concomitant Fe-reduction and acetoclastic methanogenesis reactions. Nonaromatic compounds increased over time as WEOC increased. Organic acid metabolites initially accumulated in soils but were mostly depleted by day 60 because organic acids were consumed to produce Fe(II), CO2, and CH4. We conclude that fermentationmore » of nonprotected organic matter facilitates methanogenesis and Fe reduction reactions, and that the proportion of organic acids consumed by methanogenesis increases relative to Fe reduction with increasing temperature. As a result, the decomposition pathways observed in this study are important to consider in numerical modeling of greenhouse gas production in the Arctic.« less
Inner magnetospheric electron temperature and spacecraft potential estimated from concurrent Polar upper hybrid frequency and relative potential measurements

Direct measurement of low < 1 eV electron temperature is difficult to make in the Earth's inner magnetosphere for electron densities (Ne) < 3 × 102 cm−3. We compute these quantities by solving current balance equations in low-density regions. Concurrent measurements from the Polar spacecraft of the relative potential (VS − VP), between the spacecraft body and the electric field probe, and the electron density (Ne), derived from upper hybrid frequency (fUHR), were used in the current balance equations to solve for the electron temperature (Te), Vs, and Vp. Where VP is the probe potential and VS is the spacecraft potential relative to the nearby plasma. The assumption that the bulk plasma electrons are Maxwellian is used in the computations. Our data set covered 1.5 years of measurements when fUHR was detectable (L < 10). The following “averaged” Te versus L relation for 3 < L < 5 was obtained: Te = 0.58 + 0.49 (L − 3) eV. This expression is in reasonable agreement with extrapolations of ionospheric Te measurements by Akebono at lower altitudes. However, the solution is sensitive to the photoemission coefficients, substituting those of Scudder et al. (2000) with those of Escoubet et al. (1997), the Te curve shifted upward by ~1 eV. Also, the solution is sensitive to measurement error of VS − VP, applying a voltage shift of ±0.1 and ±0.2 V to VS − VP, the relative median error for our data set was computed to be 0.27 and 1.04, respectively. We believe that our Te values computed outside the plasmasphere are unrealistically low. We conclude that this method shows promise inside the plasmasphere but should be used with caution. We also quantified the Ne versus VS − VP relationship. The running median Ne versus VS − VP curve shows no significant variation over the 1.5 year period of the data set, suggesting that the photoemission coefficients did not change significantly over this time span. The Scudder et al. (2000) Ne model, based on only one Polar orbit, is in reasonable agreement (within a factor of 2) with our results.
Using abiotic variables to predict importance of sites for species representation

In systematic conservation planning, species distribution data for all sites in a planning area are used to prioritize each site in terms of the site's importance toward meeting the goal of species representation. But comprehensive species data are not available in most planning areas and would be expensive to acquire. As a shortcut, ecologists use surrogates, such as occurrences of birds or another well-surveyed taxon, or land types defined from remotely sensed data, in the hope that sites that represent the surrogates also represent biodiversity. Unfortunately, surrogates have not performed reliably. We propose a new type of surrogate, predicted importance, that can be developed from species data for a q% subset of sites. With species data from this subset of sites, importance can be modeled as a function of abiotic variables available at no charge for all terrestrial areas on Earth. Predicted importance can then be used as a surrogate to prioritize all sites. We tested this surrogate with 8 sets of species data. For each data set, we used a q% subset of sites to model importance as a function of abiotic variables, used the resulting function to predict importance for all sites, and evaluated the number of species in the sites with highest predicted importance. Sites with the highest predicted importance represented species efficiently for all data sets when q = 25% and for 7 of 8 data sets when q = 20%. Predicted importance requires less survey effort than direct selection for species representation and meets representation goals well compared with other surrogates currently in use. This less expensive surrogate may be useful in those areas of the world that need it most, namely tropical regions with the highest biodiversity, greatest biodiversity loss, most severe lack of inventory data, and poorly developed protected area networks.
On Being Supportive: The Emotional Consequences of Listening to Another's Distress

The present research explored supporters' feelings about giving emotional support to a person in distress. In a laboratory setting subjects talked with a confederate enacting a distressed role. The response of the confederate was manipulated, either `improvement' or `no improvement'. Responses of the subject were categorized as either supportive, i.e. primarily listening or providing encouragement, or `active', i.e. primarily problem solving. Subjects' affect, goal accomplishment and feelings of responsibility were assessed. Three factors were significantly related to an increase in the subject's anger and sadness: (1) when the confederate did not improve, (2) when the subject relied on `supportive' responses and (3) when subjects perceived that they had not accomplished their goal. In addition, the more responsible subjects felt for solving the problem the more negative affect they experienced after talking with a confederate who did not improve. Whether or not the confederate improved, subjects who reli...
Computed tomography findings in tuberculous mediastinitis

Tuberculous mediastinitis can be an elusive diagnosis. Computed tomography may be performed in patients before establishing this diagnosis, and one should consider this disease when mediastinal mass with infiltration of adjacent fat planes is noted. Five such cases are described.
Momentum diffusion of the quantum kicked rotor: Comparison of Bohmian and standard quantum mechanics

Abstract Momentum diffusion of the quantum kicked rotor is studied with both de Broglie–Bohm and standard approach to quantum mechanics. The Schrodinger equation is solved exactly for the case of quantum resonance and an analytical expression is given for the momentum diffusion. Numerical solutions for both resonance and nonresonance are obtained. We obtain agreement between the two approaches only when the quantum potential is included as part of the quantum kinetic energy.
Numerical Solutions of the Bethe-Salpeter Equation

After summarizing the application of the Rayleigh-Ritz and Schwinger variational principles to the unequal-mass ${\ensuremath{\varphi}}^{3}$ Bethe-Salpeter equation, we present, in graphical and tabular form, the solution of the bound-state problem. The dependence of the coupling-parameter eigenvalue on the exchange mass, external mass ratio, and binding energy is examined in detail for $s$ and $p$ ground states. Mixing of excited levels leading to complex solutions is briefly studied, and some Regge trajectories are also calculated. Scattering phase shifts for unequal-mass scattering have been calculated and representative examples are given. The fact that certain levels do not appear to contribute to Levinson's theorem is also examined. Finally, the foregoing methods are generalized to two-channel systems, and channel phase shifts and inelasticities are computed.
Lock-in of the vortex-induced vibrations of a long tensioned beam in shear flow

Abstract The occurrence of lock-in, defined as the local synchronization between the vortex shedding frequency and the cross-flow structural vibration frequency, is investigated in the case of a tensioned beam of length to diameter ratio 200, free to move in both the in-line and cross-flow directions, and immersed in a linear shear current. Direct numerical simulation is employed at three Reynolds numbers, from 110 to 1100, so as to include the transition to turbulence in the wake. The Reynolds number influences the response amplitudes, but in all cases we observed similar fluid–structure interaction mechanisms, resulting in high-wavenumber vortex-induced vibrations consisting of a mixture of standing and traveling wave patterns. Lock-in occurs in the high oncoming velocity region, over at least 30% of the cylinder length. In the case of multi-frequency response, at any given spanwise location lock-in is principally established at one of the excited vibration frequencies, usually the locally predominant one. The spanwise patterns of the force and added mass coefficients exhibit different behaviors within the lock-in versus the non-lock-in region. The spanwise zones where the flow provides energy to excite the structural vibrations are located mainly within the lock-in region, while the flow damps the structural vibrations in the non-lock-in region.
HYPERSENSITIVE TO RED AND BLUE 1 and its C‐terminal regulatory function control FLOWERING LOCUS T expression

Summary The red and far-red light-absorbing phytochromes and UV-A/blue light-absorbing cryptochromes regulate seedling de-etiolation and flowering responses. The signaling steps that mediate the photoreceptor regulation on key flowering genes remain largely unknown. We report that a previously identified photomorphogenic mutant, hypersensitive to red and blue 1 (hrb1), flowered late and showed attenuated expression of FLOWERING LOCUS T (FT) over both long days and short days. Transgenic plants that overexpress the full-length HRB1, or its C-terminal half, flowered early and accumulated more FT messages under short-day conditions. The transgenic plants also displayed hyposensitive de-etiolation phenotypes, and the expression of these phenotypes requires the action of PIF4. The double mutant of hrb1/cry2 showed a flowering phenotype and an FT expression pattern similar to hrb1 under long-day conditions, suggesting that HRB1 may function downstream of cry2 under long-day conditions. In contrast, hrb1/phyB-9 showed a flowering phenotype and an FT expression pattern similar to phyB-9 over both long days and short days, indicating a modulatory role of HRB1 in the flowering pathway mediated by phyB. Overexpression of HRB1 did not affect the expression of the central clock oscillators, TOC1 and CCA1. HRB1 therefore represents a signaling step that regulates FT expression downstream of red and blue light perception.
The International Criminal Court: A Pipe Dream to End Impunity?

The prospects of the emerging international criminal justice system, namely the International Criminal Court, serving as a catalyst to end impunity of those most responsible for crimes against humanity, war crimes, genocide, and massive violations of human rights, remains bleak given four underlying factors: the ideology of deterrence that undergirds the system, jurisdictional limitations, the backlash of its involvement in and issuance of arrest warrants during highly contentious conflicts. This article offers some insight into these issues and the obstacles they present to the success of the International Criminal Court in ending impunity and future cases of such criminality. We begin by discussing the International Criminal Court followed by the ideology of deterrence and issues associated with the Court’s jurisdiction. We then draw on two case examples, namely Uganda and Columbia, to discuss the challenges to involvement in ongoing conflicts and post-conflict situations.
Meeting in the margins: Effects of the teacher–student relationship on revision processes of EFL college students taking a composition course

Abstract Using a case study approach, we explored the role of the teacher–student relationship in how a teacher made written comments on students’ writing and in how students responded to these comments in revision. The focal participants were one non-native teacher of English and two of the students enrolled in her six-week composition course in a Korean university. Data sources included formal, informal, and text-based interviews, class observations, and writing samples with teacher written comments. Data analysis focused on the comments the teacher made on the students’ drafts and on how and why the students did or did not use her written comments. Findings showed that one student who had built a trusting relationship with his teacher faithfully used her written feedback in revision, thereby improving his drafts, whereas the other student who had difficulty trusting her did not respond to her feedback positively. Consequently, his drafts did not improve as much as those of other students. We argue that establishing a trusting relationship between teacher and students may be fundamental to the effective use of feedback in revision. Results encourage a re-envisionment of the cognitive process model of revision to add the role of the relationship between teacher and student.
Capacity-contingent nonlinear pricing by regulated firms

Second-best Pareto optimal pricing by a regulated firm subject to demand and capacity shocks is examined. Nonlinear price schedules for the firm's customers are obtained that are contingent on capacity realizations. The second-best Pareto optimal mechanism also is implemented by an allocation mechanism based on the consumer's choice of a minimum demand or firm power level. The optimal mechanism is implemented as well by a general form of priority pricing.
A support theorem for a Gaussian Radon transform in infinite dimensions

We prove that in infinite dimensions, if a bounded continuous function has zero Gaussian integral over all hyperplanes outside a closed bounded convex set then the function is zero outside this set. This is an infinite-dimensional form of the well-known Helgason support theorem for Radon transforms in finite dimensions.
Issues and Dilemmas in Conducting Research with Vulnerable Home Hospice Participants

Purpose: To describe issues and dilemmas related to nonparticipation, attrition, and needs for assistance in research with vulnerable home hospice participants. Design and Methods: Retrospective analysis, with descriptive statistics of the frequency of issues and dilemmas that occurred in a research study with a vulnerable population. Findings: From a group of 113 potential participants, 16 (14.1%) people who gave initial consent were unable to participate or were lost to the study (subset I) for the following reasons: unable to give informed consent, cognitive disturbance, and physical distress. Of the 97 participants who completed testing, 28 (28.8%) required assistance (subset II) because of poor vision, physical weakness, and other physical impairments. Conclusions: Loss of potential participants limited this study and hampered effect size. Research with home hospice patients required careful assessment for symptoms that precluded informed consent. Issues with cognition indicated need for a tool to assess mental acuity. Although several participants required assistance, those who completed testing expressed gratitude at being able to contribute information that they believed would benefit others.
Pathogenicity of conventional and debilitated Escherichia coli K12.

THE development of ‘disabled’ strains of Escherichia coli for recombinant DNA work has so far concentrated on abolishing their ability to survive outside the test tube and to persist in the intestinal tract of man and animals. However, these changes make it impossible to test for any possible changes in pathogenicity in these strains caused by inserted foreign DNA by simple oral inoculation. Oral inoculation also does not provide any information on their relative pathogenicity if accidentally introduced by any other route. We have therefore investigated the ability of E. coli K12 DO-11 and of the ‘disabled’ E. coli χ1776 to colonise and kill susceptible mice when introduced by various parenteral routes. We show that at high concentrations both of these E. coli strains, which do not colonise the intestines of normal (non-germ-free) mice, can survive and prove lethal when injected intravenously, intraperitoneally or intracranially.
Recursive instrumental variable estimation simultaneous equations with autoregressive disturbances

Abstract A recursive instrumental variable algorithm is proposed for estimating the structural parameters of a simultaneous equation model with autoregressive error terms. The choice of the instruments is discussed in order to obtain asymptotically efficient estimation of the structural parameters.
Comments on “Wave CISK of Equatorial Waves and the Vertical Distribution of Cumulus Heating”

Comments on : Wave CISK of equatorial waves and the vertical distribution of cumulus heating.
Second-order modelling of particle dispersion in a turbulent flow

A set of second-order modelled equations for the motion of particles are presented. We consider the effects of the particle inertia and the crossing-trajectories effect on the particle dispersion. A simple case of a particle mixing layer in a decaying homogeneous turbulence for light and heavy particles is calculated. The results show that the crossing-trajectories effect on particle dispersion is very significant, while inertia only has a slight effect. This behaviour has been observed in experiments (Wells & Stock 1983) and is well predicted by an asymptotic analysis (Csanady, 1963). The calculation also shows that there is a significant difference between Favre-averaged particle velocity and conventional-averaged particle velocity in the low-particle-concentration region. All calculations are in good agreement with Wells & Stock's experimental data.
QUANTUM DOT COMPUTING GATES

Semiconductor quantum dots are a promising candidate for future quantum computer devices. Presently, there are three major proposals for designing quantum computing gates based on quantum dot technology: (i) electrons trapped in microcavity; (ii) spintronics; (iii) biexcitons. We survey these designs and show mathematically how, in principle, they will generate 1-bit rotation gates as well as 2-bit entanglement and, thus, provide a class of universal quantum gates. Some physical attributes and issues related to their limitations, decoherence and measurement are also discussed.
Preparation of poly(vinyl chloride-g-isobutylene) by BCl3

Poly(vinyl chloride-g-isobutylene) has been synthesized using mildly dehydrochlorinated (NaOH treated) PVC in conjunction with BCl3 coinitiator. Treatment of PVC with NaOH increases initial thermal dehydrochlorination rate and renders the polymer suitable for efficient grafting. Untreated PVC produces negligible grafting.
Horseradish Peroxidase Catalyzed Polymerization of Tyrosine Derivatives for Nanoscale Surface Patterning

Abstract Tyrosine and its derivatives can be polymerized by enzymatic catalysis with horseradish peroxidase (HRP). In the present study, tyrosine ethyl ester hydrochloride was nanopatterned on mercaptohexadecanoic acid (MHA) modified gold surfaces using dip‐pen nanolithography (DPN). Enzymatic polymerization was carried out on the well‐organized nanofeatures and confirmed by atomic force microscopy (AFM) phase images and electrostatic force microscopy (EFM) phase‐lag images. The results extend DPN to amino acid derivatives as biocompatible conducting circuitry with nanoscale features.
Testing the specificity between social anxiety disorder and drinking motives.

Abstract This study tested the specificity of the relationship between social anxiety disorder (SAD) and coping drinking motives (versus enhancement drinking motives and social drinking motives) within the context of a range of potentially confounding variables measured during adolescence (e.g., quantity and frequency of alcohol use, coping drinking motives) and substantively important variables assessed during young adulthood (e.g., other anxiety disorders and major depressive disorder ). A sample of high school sophomores and juniors ( n = 717) completed measures of substance use and risk factors during adolescence and were then prospectively followed-up in early- and middle-young adulthood, and psychiatric diagnoses and drinking motives (i.e., coping, enhancement, and social) were assessed each time. Findings indicated that SAD was specifically related to coping motives (measured during early-to-middle young adulthood) after controlling for the effects of a range of alcohol and mental health variables. In addition, adolescent variables predicted young adult drinking motives as did major depressive disorder and other anxiety disorders. These findings are discussed within a conceptual framework of the functional role (e.g., self-medication) that drinking motives, and especially coping drinking motives, may play in the etiology of alcohol problems and disorders. Implications for prevention and treatment interventions are discussed.
Stress responsiveness predicts individual variation in mate selectivity.

Abstract Steroid hormones, including glucocorticoids, mediate a variety of behavioral and physiological processes. Circulating hormone concentrations vary substantially within populations, and although hormone titers predict reproductive success in several species, little is known about how individual variation in circulating hormone concentrations is linked with most reproductive behaviors in free-living organisms. Mate choice is an important and often costly component of reproduction that also varies substantially within populations. We examined whether energetically costly mate selection behavior in female Galapagos marine iguanas ( Amblyrhynchus cristatus ) was associated with individual variation in the concentrations of hormones previously shown to differ between reproductive and non-reproductive females during the breeding season (corticosterone and testosterone). Stress-induced corticosterone levels – which are suppressed in female marine iguanas during reproduction – were individually repeatable throughout the seven-week breeding period. Mate selectivity was strongly predicted by individual variation in stress-induced corticosterone: reproductive females that secreted less corticosterone in response to a standardized stressor assessed more displaying males. Neither baseline corticosterone nor testosterone predicted variation in mate selectivity. Scaled body mass was not significantly associated with mate selectivity, but females that began the breeding period in lower body condition showed a trend towards being less selective about potential mates. These results provide the first evidence that individual variation in the corticosterone stress response is associated with how selective females are in their choice of a mate, an important contributor to fitness in many species. Future research is needed to determine the functional basis of this association, and whether transient acute increases in circulating corticosterone directly mediate mate choice behaviors.
A naturally occurring deletion mutant of figwort mosaic virus (caulimovirus) is generated by RNA splicing.

Abstract A naturally occurring deletion mutant is observed in plants infected with figwort mosaic virus (FMV), a caulimovirus. The encapsidated mutant genome is formed spontaneously in association with two different strains of FMV in four host plant species. The mutant also appears when cloned wild-type viral DNA is used as the inoculum. The deletion mutant alone is not infectious and it appears unable to replicate after its formation, even in the presence of wild-type virus. The gene for chloramphenicol acetyltransferase was inserted at different positions in the deletion mutant genome, and subsequent transient assays showed that gene expression of the mutant occurs despite the deletion. Sequence analyses of the mutant genome revealed a deletion of a 1237-bp segment encompassing a major portion of the coat protein gene and the 5′ end of the downstream reverse transcriptase gene. This deletion is associated with consensus signals for RNA splicing including the conserved 5′ and 3′ splice sites plus surrounding sequences, putative branch point(s) for lariat formation, and an extremely high adenosine content (41 %) of the removed fragment. This suggests that splicing of the FMV full-length transcript has occurred prior to reverse transcription and this accounts for the presence and accumulation of encapsidated DNAs with the same deletion.
The effect of X chromosome heterozygosity on the structure of the ribosomal genes in drosophila melanogaster

Sucrose gradient analysis of DNA isolated from detergent-pronase lysates of adult flies has been used to look for ribosomal genes not integrated into the DNA of the chromosome in genotypes containing various combinations of inversions having breakpoints in the proximal heterochromatin of the X chromosome. Unintegrated genes are found in females heterozygous for inversions which have one breakpoint between the nucleolus organizer and the centromere. Homozygotes and males do not have unintegrated genes. The results suggest that unintegrated ribosomal genes result from an interaction between homologues having different arrangements of the proximal heterochromatin. In addition, data from a series of stocks carrying duplications of the X heterochromatin provide independent evidence for the size of the DNA on our gradients.
Contamination analysis of TiO2 thin films deposited using ion assisted deposition

Abstract Elastic backscattering and recoil detection techniques have been used to analyze TiO2 films for possible contaminants introduced during O2+ ion assisted deposition. The principle impurities (H, C and W) together with the TiO2 film stoichiometry were monitored as a function of O2+ ion energy (60–500 eV), O2+ current density (0–180 μA cm 2 ) and the substrate temperature (50–250°C). The main findings were: (1) TiO2 film stoichiometry improved with increasing O2+ current except for the case of low temperature and high O2+ energy, (2) W levels were directly proportional to O2+ current, (3) C contamination increased at the higher temperatures and (4) the H levels were relatively insensitive to the deposition parameters. The last two findings indicate that the source of H and C contamination may have been residual gases in the vacuum chamber.
Iron-induced oligomerization of yeast frataxin homologue Yfh1 is dispensable in vivo.

The neurodegenerative disease Friedreich’s ataxia is caused by reduced levels of frataxin, a mitochondrial matrix protein. The in vivo role of frataxin is under debate. Frataxin, as well as its yeast homologue Yfh1, binds multiple iron atoms as an oligomer and has been proposed to function as a crucial iron-storage protein. We identified a mutant Yfh1 defective in iron-induced oligomerization. This mutant protein was able to replace functionally wild-type Yfh1, even when expressed at low levels, when mitochondrial iron levels were high and in mutant strains having deletions of genes that had synthetic growth defects with a YFH1 deletion. The ability of an oligomerization-deficient Yfh1 to function in vivo suggests that oligomerization, and thus oligomerization-induced iron storage, is not a critical function of Yfh1. Rather, the capacity of this oligomerization-deficient mutant to interact with the Isu protein suggests a more direct role of Yfh1 in iron–sulphur cluster biogenesis.
The effect of ACTH administration on aldosterone production in non salt-losing congenital adrenal hyperplasia.

ABSTRACT The effects of adrenocorticotropin stimulation (ACTH-gel, im for 3 days in a dose of either 20 IU/m2/every 12 hr or 20 IU/m2/ every 6 hr) on aldosterone secretion rate and plasma levels of cortisol and aldosterone were studied in seven patients with non salt-losing congenital adrenal hyperplasia (CAH) while on replacement steroid therapy and in ten normal individuals. All subjects were placed on a constant Na and K intake. When ACTH was given every 6 hr, there was a sustained increase of plasma cortisol in control subjects (mean ± sd on 3rd stimulation day: 48 ± 4 μg/100 ml), whereas the values of the patients were brought up to levels expected of normal, unstimulated individuals (mean ± sd on 3rd stimulation day: 13 ± 3 μg/100 ml). Elevation of plasma aldosterone occurred in both control subjects and patients, but the values of the patients remained significantly higher than those of the controls. By the third day of ACTH stimulation the mean (± sd) values of the patients were still elevated (47...
Fe(II) adsorption on hematite (0 0 0 1)

The surface structure of {alpha}-Fe{sub 2}O{sub 3}(0 0 0 1) was studied using crystal truncation rod (CTR) X-ray diffraction before and after reaction with aqueous Fe(II) at pH 5. The CTR results show the unreacted {alpha}-Fe{sub 2}O{sub 3}(0 0 0 1) surface consists of two chemically distinct structural domains: an O-layer terminated domain and a hydroxylated Fe-layer terminated domain. After exposing the {alpha}-Fe{sub 2}O{sub 3}(0 0 0 1) surface to aqueous Fe(II), the surface structure of both co-existing structural domains was modified due to adsorption of Fe at crystallographic lattice sites of the substrate, resulting in six-coordinated adsorbed Fe at the surface. The average Fe-O bond lengths of the adsorbed Fe are consistent with typical Fe(III)-O bond lengths (in octahedral coordination), providing evidence for the oxidation of Fe(II) to Fe(III) upon adsorption. These results highlight the important role of substrate surface structure in controlling Fe(II) adsorption. Furthermore, the molecular scale structural characterization of adsorbed Fe provides insight into the process of Fe(II) induced structural modification of hematite surfaces, which in turn aids in assessing the effective reactivity of hematite surfaces in Fe(II) rich environments.
A clarification of the φ mixing model

The authors review a deterministic model proposed for the analysis of two-way contingency tables that arise in counts of pairwise interactions. This model decomposes the table into the sum of two matrices with special forms: in one the contacts are distributed selectively, in the other they are distributed at random. We show that this model has several inherent problems. The decomposition is not unique, which compromises estimation and interpretation of the parameters; the deterministic framework provides no basis for estimation or hypothesis testing; and the assumption of decomposibility is supported by neither empirical evidence nor theoretical considerations. We show that generalized linear models provide a suitable alternative once the probability process is specified and the overparameterization is removed.
Properties of the ζ Aur-Type Binary System 22 Vul = QS Vul

The 22 Vul system is important for studying the winds and chromospheres of cool evolved stars because the G4 I component is rotating rapidly and probably faster than synchronously. We discuss the system's physical properties in the context of a wide range of constraints on them and propose values that may be marginally better than previous ones (see the end of § 3). We use Hα spectroscopy to assess the variability of the cool star's wind, and archival IUE observations to measure variation of density in the wind and rotation of the chromosphere. We argue that the terminal velocity of the wind must be at least as great as the edge velocity of Mg II and derive a new value of v∞ 208 ± 5 km s-1. Directly measured column densities for hydrogen (from Lyα), combined with column densities for metals, imply a β ~ 2.5 velocity law for the wind with a mass-loss rate of ~1.6 × 10-8 M⊙ yr-1, about 4 times the surface flux of 31 Cyg. Excitation temperatures and turbulent velocities in the inner 3R* of the wind are similar to those in other ζ Aur binaries. The apparent faster-than-synchronous rotation Griffin and coworkers found in the optical persists in IUE spectra out to at least 2.5R(G4 I). This implies that the wind is locked to the star through magnetic fields or that the material in the wind is viscous enough to maintain approximately solid-body rotation.
Structure of the Planetary Boundary Layer and Implications for its Modeling

Abstract Through the innovative use of laboratory experiments, numerical simulations, and direct measurements, researchers have greatly extended our knowledge of planetary boundary layer (PBL) structure over the last 15 years. This paper reviews some recent findings as they bear on the modeling of both convective and stable PBLS. While recent reviews indicate that some PBL models used in air quality applications reflect little of our current understanding, there is also encouraging evidence that updating these models can be straightforward and rewarding. The time seems ripe for the development of a new generation of PBL models, and some issues involved in their optimum design are discussed.
On the causes of temperature change in inhomogeneous low-density astrophysical plasmas

The temperature changes that are possible in inhomogeneous low-density astrophysical plasmas were investigated for a variety of boundary distribution functions that occur in astrophysics, with emphasis placed on the spatial changes in temperature and their correlations with those of the density caused by time-independent, but spatially varying, conservative potentials. It is proven that decelerating forces produce equilibrium temperatures that are anticorrelated with densities, provided that the boundary condition is non-Maxwellian, and the proof is extended analytically for a generalized Lorentzian distribution, showing that they obey a polytrope relation with the value of gamma between 0 and l.
Acceptance of Surgery for Obesity by Academic Surgeons in North America

Background: Have surgeons in North America accepted operations for the treatment of severe obesity? This question was posed by organizers of the Ninth International Symposium on Obesity Surgery that met in Stockholm in September, 1995. Study design: In order to obtain opinions which might help to answer the question posed, a 1-page questionnaire was sent to 151 chairmen of academic departments of surgery in North America in December 1994 asking about the acceptance and use of surgical operations for the treatment of severe obesity. Results: Answers, received from 112 or 74%, indicated that operative treatment should be used (74%), was effective (77%) and safe (71%). However, only 65% of departments provided such operations. Operative treatment for obesity was available outside the department in 53%. The operations most frequently used were Rouxen-Y gastric bypass (RGB) and vertical banded gastroplasty (VBG). A single operation was offered by 44 departments and a choice of two or more operations in 30 departments. RGB and VBG were equally in use. Gastric banding was used as an alternative to VBG in six departments. Other operations were in use in six departments either alone (three) or as alternatives to RGB and VBG (three). Conclusions: It appears that surgical treatment of obesity is accepted and available in the majority of academic departments of surgery.
Statistical Treatment of Photon/Electron Counting: Extending the Linear Dynamic Range from the Dark Count Rate to Saturation

An experimentally simple photon counting method is demonstrated providing 7 orders of magnitude in linear dynamic range (LDR) for a single photomultiplier tube (PMT) detector. In conventional photon/electron counting methods, the linear range is dictated by the agreement between the binomially distributed measurement of counted events and the underlying Poisson distribution of photons/electrons. By explicitly considering the log-normal probability distribution in voltage transients as a function of the number of photons present and the Poisson distribution of photons, observed counts for a given threshold can be related to the mean number of photons well beyond the conventional limit. Analytical expressions are derived relating counts and photons that extend the linear range to an average of ∼11 photons arriving simultaneously with a single threshold. These expressions can be evaluated numerically for multiple thresholds extending the linear range to the saturation point of the PMT. The peak voltage distributions are experimentally shown to follow a Poisson weighted sum of log-normal distributions that can all be derived from the single photoelectron voltage peak-height distribution. The LDR that results from this method is compared to conventional single photon counting (SPC) and to signal averaging by analog to digital conversion (ADC).
Study of phenolic resins by PMR spectroscopy with arsenic trichloride as a solvent

The PMR spectra of several phenolic resins and model compounds related to these resins are reported. Arsenic trichloride as a PMR solvent for the resins is suggested. The PMR spectra of a resin which is linked in the ortho position only is compared to that of a resin where both ortho and para linkages occur. It is shown that the completely ortho-linked resin gives a phenolic OH signal which does not shift when HCl gas is added, while it does shift if the resin has both ortho and para linkages. This observation is explained by assigning a strong intramolecular hydrogen bond to the ortho-linked resin. The behavior of the phenolic OH signal when HCl is added can therefore be used to distinguish between ortho and ortho,para-linked resins. A semiquantitative approach to obtaining average molecular weights is also presented. By integrating the PMR signals of various structural units of the resin it is possible to estimate the relative number and therefore the total number of units of this type in a molecule. The total number is a measure of the molecular weight. Spectral assignments are given for the various types of structural units present in the resins.
Child abuse: clinical findings and management.

PURPOSE To provide an overview of the role of the nurse practitioner (NP) in identifying, reporting, and managing child abuse in primary care. DATA SOURCES Selected research, national guidelines, and the author's experience. CONCLUSIONS Child abuse is a complex phenomenon characterized by maladaptive behaviors between children and their parents. IMPLICATIONS FOR PRACTICE The role of the NP includes identification of families at risk, recognition of clinical findings of abuse, diagnosis of abuse, education for families identified at risk, and management of children diagnosed with abuse. The ultimate goal is the safe return of the child to a loving family.