cssi/SciSciGPT-SciSciNet huggingface dataset:
MUTAGEN INDUCED VARIABILITY FOR OAT SEED WEIGHT IN SELECTED AND UNSELECTED POPULATIONS.

Abstract We used samples of random and selected oat seeds (for heavy weight) from thermal neutron-(TN) and ethyl methanesulfonate-(EMS) derived populations, to initiate a second cycle of mutagenesis with these same mutagens. Oat lines derived directly from the random and selected samples and from populations derived from new mutagen treatments were grown in a replicated field experiment and measured for 100-seed weight. The populations derived from the selected oat seeds had a mean genotypic variance component 41 per cent greater than that in the population derived from the random oat seeds. With a second mutagen treatment, the genotypic variance components were increased by 53 and 64 per cent in the random and selected materials, respectively. Recurrent treatment of selected and random samples with a mutagen reduced the mean 100-seed weight 0·02 and 0·01 g, respectively, both being nonsignificant values. The variant lines produced by the second mutagen treatment of either random or selected material were distributed to both heavier and lighter seed-weight classes. The expected gains from a second cycle of selection were greater than the actual gains in the first.
Metaproteomic Survey of Six Aquatic Habitats: Discovering the Identities of Microbial Populations Active in Biogeochemical Cycling

Our goal is to strengthen the foundations of metaproteomics as a microbial community analysis tool that links the functional identity of actively expressed gene products with host phylogeny. We used shotgun metaproteomics to survey waters in six disparate aquatic habitats (Cayuga Lake, NY; Oneida Lake, NY; Gulf of Maine; Chesapeake Bay, MD; Gulf of Mexico; and the South Pacific). Peptide pools prepared from filter-gathered microbial biomass, analyzed by nano-liquid chromatography–mass spectrometry (MS/MS) generating 9,693 ± 1,073 mass spectra identified 326 ± 107 bacterial proteins per sample. Distribution of proteobacterial (Alpha and Beta) and cyanobacterial (Prochlorococcus and Synechococcus spp.) protein hosts across all six samples was consistent with the previously published biogeography for these microorganisms. Marine samples were enriched in transport proteins (TRAP-type for dicarboxylates and ATP binding cassette (ABC)-type for amino acids and carbohydrates) compared with the freshwater samples. We were able to match in situ expression of many key proteins catalyzing C-, N-, and S-cycle processes with their bacterial hosts across all six habitats. Pelagibacter was identified as the host of ABC-type sugar-, organic polyanion-, and glycine betaine-transport proteins; this extends previously published studies of Pelagibacter's in situ biogeochemical role in marine C- and N-metabolism. Proteins matched to Ruegeria confirmed these organism's role in marine waters oxidizing both carbon monoxide and sulfide. By documenting both processes expressed in situ and the identity of host cells, metaproteomics tested several existing hypotheses about ecophysiological processes and provided fodder for new ones.
Kidney transplantation outcomes in African-, Hispanic- and Caucasian-Americans with lupus

African-American recipients of kidney transplants with lupus have high allograft failure risk. We studied their risk adjusting for: (1) socio-demographic factors: donor age, gender and race-ethnicity; recipient age, gender, education and insurance; donor–recipient race-ethnicity match; (2) immunologic factors: donor type, panel reactive antibodies, HLA mismatch, ABO blood type compatibility, pre-transplant dialysis, cytomegalovirus risk and delayed graft function (DGF); (3) rejection and recurrent lupus nephritis (RLN). Two thousand four hundred and six African-, 1132 Hispanic-, and 2878 Caucasian-Americans were followed for 12 years after transplantation. African- versus Hispanic- and Caucasian-Americans received more kidneys from deceased donors (71.6%, 57.3% and 55.1%) with higher two HLA loci mismatches for HLA-A (50%, 39.6% and 32.4%), HLA-B (52%, 42.8% and 35.6%) and HLA-DR (30%, 24.5% and 21.1%). They developed more DGF (19.5%, 13.6% and 13.4%). More African- versus Hispanic- and Caucasian-American...
Risk-Adapted Management of Thyroid Cancer

Objective: To describe a risk-adapted management paradigm for patients with differentiated thyroid cancer.Methods: A risk-stratification approach is described that combines the standard clinical factors available during the initial evaluation with response-to-therapy variables to predict risk of death from thyroid cancer, risk of recurrence, and risk of failing initial therapy. This classic oncologic approach views risk stratification as an active, ongoing process in which risks are adjusted on the basis of accumulated clinical data, rather than considered as a static initial assessment that does not change.Results: From a clinical standpoint, accurate real-time assessment of risk can be used to guide both the initial treatment recommendations (extent of thyroid surgical resection, role of radioiodine ablation, and degree of thyrotropin suppression) and the follow-up management paradigm (intensity of testing and modalities used to detect recurrent disease).Conclusion: By thinking like oncologists and indi...
Required attention for synthesized speech perception for two levels of linguistic redundancy

It was hypothesized that additional contextual linguistic redundancy in the wording of synthesized speech cockpit warnings would result in less required attention for initial comprehension and subsequent recognition. Twelve airline pilots were repeatedly presented 16 unfamiliar warnings in two wording formats, key word and sentence; e.g., Fuel low, compared to The fuel pressure is low. Then they heard the same warnings embedded in weather broadcast at a warning‐to‐weather sound pressure level ratio of +3 dB. For both listening conditions the task was to read back the message and also estimate the passage of time during message comprehension or recognition. Peformance on time estimation had previously been found to correlate with hypothesized attention demands during manual tracking and aircraft simulator flying tasks. As expected in the present study, intelligibility was higher and response time shorter for the sentence format than for the key word format. For unfamiliar messages, the tendency to underestimate the passage of time was greater for the two word format than for the sentence format, implying that less attention was available for the time estimation task during comprehension of messages with less linguistic redundancy. By contrast, for familiar messages there was no significant difference in performance on the time estimation task for the two levels of linguistic redundancy. Possible reasons for the difference in attention requirements for comprehension compared to recognition will be discussed. [Work supported by NASA Grant NGL 05‐046‐002 to the San Jose State University Foundation.]
Consistent Covariance Matrix Estimation with Spatially Dependent Panel Data

Many panel data sets encountered in macroeconomics, international economics, regional science, and finance are characterized by cross-sectional or “spatial” dependence. Standard techniques that fail to account for this dependence will result in inconsistently estimated standard errors. In this paper we present conditions under which a simple extension of common nonparametric covariance matrix estimation techniques yields standard error estimates that are robust to very general forms of spatial and temporal dependence as the time dimension becomes large. We illustrate the relevance of this approach using Monte Carlo simulations and a number of empirical examples.
Automatic 3D model reconstruction based on novel pose estimation and integration techniques

Abstract An automatic three-dimensional (3D) model reconstruction technique is presented to acquire complete and closed 3D models of real objects. The technique is based on novel approaches to pose estimation and integration. Two different poses of an object are used because a single pose often hides some surfaces from a range sensor. A second pose is used to expose such surfaces to the sensor. Two partial 3D models are reconstructed for two different poses of the object using a multi-view 3D modeling technique. The two 3D models are then registered in two steps—coarse registration, and its refinement. Coarse registration is facilitated by a novel pose estimation technique, which estimates a rigid transformation between two models. The pose is estimated by matching a stable tangent plane (STP) of each pose-model with the base tangent plane, which is invariant for a vision system. We employ geometric constraints to find the STP. After registration refinement, two models are integrated to a complete 3D model based on voxel classification defined in multi-view integration. Texture mapping is done to obtain a photo-realistic reconstruction of the object. Reconstruction results and error analysis are presented for several real objects.
SOME PROPERTIES OF BOUND AND SOLUBLE DYNEIN FROM SEA URCHIN SPERM FLAGELLA

Axonemes were isolated from sperm of Colobocentrotus by a procedure involving two extractions with 1% Triton X-100 and washing The isolated axonemes contained 7 x 1015 g protein per µm of their length. Treatment of the axonemes with 0 5 M KCl for 30 min extracted 50–70% of the flagellar ATPase protein, dynein, and removed preferentially the outer arms from the doublet tubules. Almost all of the dynein (85–95%) could be extracted from the axonemes by dialysis at low ionic strength. In both cases the extracted dynein sedimented through sucrose gradients at 12–14S, and no 30S form was observed The enzymic properties of dynein changed when it was extracted from the axonemes into solution. Solubilization had a particularly marked effect on the KCl- and pH-dependence of the ATPase activity. The pH-dependence of soluble dynein was fairly simple with a single peak extending from about pH 6 to pH 10. The pH-dependence of bound dynein was more complex. In 0.1 M KCl, the bound activity appeared to peak at about pH 9, and dropped off rapidly with decreasing pH, reaching almost zero at pH 7; an additional peak at pH 10 0 resulted from the breakdown of the axonemal structure and solubilization of dynein that occurred at about this pH. A similar curve was obtained in the absence of KCl, except for the presence of a further large peak at pH 8 Measurement of the kinetic parameters of soluble dynein showed that both Km and Vmax increased with increasing concentrations of KCl up to 0.5 M When bound dynein was assayed under conditions that would induce motility in reactivated sperm (0 15 M KCl with Mg++ activation), it did not obey Michaelis-Menten kinetics, although it did when assayed under other conditions. The complex enzyme-kinetic behavior of bound dynein, and the differences between its enzymic properties and those of soluble dynein, may result from its interactions with tubulin and other axonemal proteins
Data sensing and analysis: Challenges for wearables

Wearables are a leading category in the Internet of Things. Compared with mainstream mobile phones, wearables target one order of magnitude form factor reduction, and offer the potential of providing ubiquitous, personalized services to end users. Aggressive reduction in size imposes serious limits on battery capacity. Wearables are equipped with a range of sensors, such as accelerometers and gyroscopes. Most economical sensors were developed for mobile phones, with energy consumptions more appropriate for phones than for ultra-compact wearables. This article describes the energy challenges for wearable sensing technologies, with a primary focus on the most widely used wearable sensors: MEMS-based inertial measurement units. Using sports and fitness wearables as the pilot application, we analyze the energy characteristics of MEMS IMU data sensing, analysis, and wireless communication. We then discuss the technologies needed to solve the power and energy consumptions challenges for wearables.
Isolation and Partial Characterization of the Major Seed Protein from Nicotiana tabacum, and Accumulation during Development

During the seed development of Nicotiana tabacum, appreciable accumulation of the soluble protein fraction started to occur at around the 6th day after anthesis and finally reached 12% on the basis of dry weight when seed maturation was accomplished. In the soluble fraction of mature seeds, four protein fractions were observed on analytical ultracentrifugation, and the protein having a sedimentation coefficient of 11.7S was the major one. The 11.7S protein was isolated and SDS-polyacrylamide gel electrophoresis indicated that the protein consisted of at least five subunits with molecular weights of 49,000, 31,000, 29,000, 21,000 and 19,000. The 11.7S protein was rich in glutamic acid or glutamine and arginine, and the presence of carbohydrate was confirmed.During development, all of the five subunits started to appear during the period between the 12th and 15th day after anthesis.
Fulminant and accelerated presentation of dermatomyositis in two previously healthy young adult males: a potential role for endotheliotropic viral infection.

Background: Dermatomyositis (DM) is a prototypic autoimmune syndrome, whereby immune-based microvascular injury is critical in the pathogenesis of skin lesions and the myopathy. Although not widely recognized or accepted as a pathogenetic trigger, endotheliotropic viral triggers including parvovirus B19 and cytomegalovirus have been linked to DM. At times, the clinical manifestations in DM can be fulminant with acute renal failure because of rhabdomyolysis, respiratory failure and gastrointestinal infarcts. Methods: Skin and lung tissues were processed for hematoxylin and eosin, immunohistochemical, immunofluorescent and reverse transcriptase in situ polymerase chain reaction studies. Case presentation: We present two cases of fatal DM in previously healthy immunocompetent males. One case had fatal catastrophic respiratory failure from diffuse alveolar damage; herpes simplex virus-2 RNA was uncovered in lung and skin biopsies during autopsy in the absence of classic cytopathic changes of herpes virus infection. The other case showed a Degos-like syndrome; parvovirus B19 RNA transcripts were found in cutaneous endothelium of affected skin. Conclusion: An accelerated clinical course can occur in the setting of DM in previously healthy patients. A viral-based etiology should be explored because antiviral therapy may define a critical and potentially lifesaving therapeutic endeavor.
Validity and reliability of the Berg Balance Scale for community-dwelling persons with lower limb amputation

Abstract Objective To evaluate the validity and reliability of the Berg Balance Scale (BBS) for use in people with lower-limb amputation. Design Cross-sectional study. Setting Research laboratory. Participants Individuals (N=30; age, 54±12y; 20 men) with unilateral transtibial (n=13), unilateral transfemoral (n=14), or bilateral (n=3) lower-limb amputation of dysvascular (n=7), traumatic (n=14), infectious (n=6), or congenital (n=3) origin. Interventions Not applicable. Main Outcome Measures BBS, 2-minute walk test, L test, Prosthesis Evaluation Questionnaire-Mobility Subscale, Activities-specific Balance Confidence Scale, and Frenchay Activities Index; self-reported descriptors were also collected, including frequency of prosthesis use, number of falls in 12 months before the visit, fear of falling, and daily mobility aid use. Results The BBS had high interrater reliability (intraclass correlation coefficient=.945) and internal consistency (α=.827). Relations between the BBS scores and those of other outcome measures were all statistically significant ( P ≤.001). Significant group differences in BBS scores were observed for fear of falling ( P =.008) and mobility aid use ( P P =.381). BBS items involving reaching forward, turning 360°, tandem standing, and standing on 1 leg had relatively greater frequencies of lower scores across participants. Conclusions The BBS appears to be a valid and reliable clinical instrument for assessing balance in individuals with lower-limb amputation, but it may not be able to discriminate between individuals with greater or lesser fall risk. Limitations in prosthetic motion and control may be responsible for the challenges experienced on items of lower performance. Future studies would be useful to assess the responsiveness of the BBS to interventions aimed at improving balance in individuals with lower-limb amputation.
Characterization of cooperative upconversion and energy transfer of Er3+ and Yb3+/Er3+ doped phosphate glasses

Cooperative upconversion and Yb3+-Er3+ energy transfer in newly developed phosphate glasses were studied in this paper. The cooperative upconversion coefficients of 4I13/2 level for different Er3+ concentrations were deduced from the pump intensity- dependent luminescence decay curves. Yb3+-Er3+ energy transfer efficiencies for different Yb3+ concentrations codoped with Er3+ (approximately 2 X 1020 ions/cm3) were estimated from the lifetime measurements of 2F5/2 level of Yb3+ ions. The small cooperative upconversion coefficients and high Yb3+-Er3+ energy transfer efficiencies indicate these newly developed Er3+ and Yb3+/Er3+ doped phosphate glasses are excellent for amplifier and laser applications.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Chondrocyte cells respond mechanically to compressive loads

Many studies have illustrated the effect of mechanical loading on articular cartilage and the corresponding changes in chondrocyte metabolism, yet the mechanism through which the cells respond to loading still is unclear. The purpose of this study was to evaluate the change in shape of chondrocytes under a statically applied uniaxial compressive load. Isolated chondrocytes from rat chondrosarcoma were embedded in 2% agarose gel. Strains of 5, 10, and 15% were applied, and images of the cell were recorded from initial loading to equilibrium (15 minutes). A finite-element model was used to model the experimental setup and to estimate the mechanical properties of the chondrocyte at equilibrium. The transient behavior of the composite in the experiment was analyzed with use of a standard linear viscoelastic model. We found that all cells decreased in cross-sectional area under each of the applied compressive strains. In the finite-element model, the elasticity of the chondrocyte was similar to that of the surrounding agarose gel (4.0 kPa) and had a Poisson's ratio of 0.4. Viscoelastic analysis showed that the chondrocytes contributed a significant viscoelastic component to the behavior of the composite in comparison with the agarose gel alone. If a decrease in cell volume proportional to the decrease in cross-sectional area is assumed, the decrease observed was greater than would be predicted by a passive cellular response due to an equivalent osmotic pressure. This indicates that the chondrocyte may be altering its intracellular composition by cellular processes in response to mechanical loading.
Fiber Optics Specifications

A spokesman for one of our leading optical manufacturers said, in 1963: "Fiber optics must find its place in industry within the next three years or revert to a fascinating but impractical curiosity, unobtainable for a competitive price. "
Isolation and structure of axinastatin 4 from the western indian ocean marine sponge Axinella cf. carteri

The Republic of the Comoros marine sponge Axinella cf. carteri has been found to contain a cell growth inhibitory (P388 lymphocytic leukemia cell line ED 50 0.057 μg/ml, and comparable activity against a series of human cancer cell lines) cyclo-heptapeptide named axinastatin 4 (3). The new peptide was obtained in 1.0 × 10 −6 % yield (6.1 mg) from 600 kg (wet wt) of the sponge. The structure of axinastatin 4 was deduced as cyclo-(Pro-Leu-Thr-Pro-Leu-Trp-Val) by a combination of high field (400 and 500 Mhz) 2D nmr ( 1 H- 1 H, 1 H- 13 C, HMBC and NOE) and high resolution mass spectral (principally by ms/ms) measurements and subsequent interpretations
Biocultural perspectives on stress in prehistoric, historical, and contemporary population research

Stress, a concept addressing the consequences of disruptive events on individuals and populations, can be a useful integrative idea. The stress process has much in common with its sister concept of adaptation. However, where adaptation focuses on “adaptive” or positive consequences, stress redresses an imbalance by focusing on the costs and limits of adaptation. In this paper we first review the interdisciplinary roots of the stress concept. While most stress research derives from research in environmental physiology, Selyean concepts of stress (involving increased catecholamine and corticosteroid output) have forced an expansion toward greater concern for perceptual and psychosocial stressors. What is largely missing from all traditions, however, is concern for sociopolitical processes which are not easily adapted to and consequently are persistent and pervasive causes of stress. Studies of stress in prehistoric, historical, and contemporary populations by biological anthropologists vary, in a complementary way, as to ability to delineate aspects of the stress process. Whereas the paleopathological methods of the prehistorian provide a suite of skeletal indicators of stress response, and the demographic measures of the historian provide a detailed analysis of consequence, a wide variety of techniques for examining all levels of the stress process are potentially available to those studying contemporary populations. In order to better utilize information from different levels of analysis one needs to focus on measures of stress, such as infant mortality, which are accessible at all levels. Biological anthropologists are in a unique position to elucidate the human condition if, via concepts such as stress, attention is paid to both human adaptive and political economic processes.
Rat ovarian insulin-like growth factor binding protein-4: a hormone-dependent granulosa cell-derived antigonadotropin.

TO assess the in vivo regulation of ovarian insulin-like growth factor binding protein-4 (IGFBP-4) mRNA expression by gonadotropins and estrogen. Whole ovarian RNA, obtained from two models of follicular development, was extracted and analyzed by Northern blotting. Immature rats were treated with pregnant mare serum gonadotropin (PMSC) followed 48 hours later with hCG, or alternatively were hypophyseciomized and treated with FSH and/or diethylstilbestrol (DES). Localization ojTGFBP-4 expression was assessed in the former study by in situ hybridization. Finally, the ability of human IGFBP-4 to antagonize FSH-stimulated progesterone accumulation was assessed in vitro. The ovarian content of IGFBP-4 transcripis increased threefold (P <.05) at 12 hours after PMSG but was near baseline at 24 and 48 hours. The abundance of IGFBP-4 mRNA increased (P <.05) again at 6 and 24 hours after hCG. The expression of IGFBP-4 was localized to granulosa cells of preantral (untreated) and small antral (12 hours after PMSG) follicles. No IGFBP-4 expression was noted in large (gonadotropin-primed) antral follicles. Hypophysectomy increased (P <.05) the ovarian content of IGFBP-4 mRNA by 1.5-fold, an effect further enhanced (1.8-fold; P <.05) by the provision of FSH and DES. In vitro studies revealed the ability of increasing concentrations (0.01-1 μg/mL) of recombinant human IGFBP-4 to inhibit the FSH-supported accumulation of progesterone. Increased expression after administration of PMSG, hCG, and FSH/DES suggests that IGFBP-4 is a dynamic and hormonally responsive component of the ovarian cycle. The lack of expression in preovulatory follicles and its antigonadotropic actions in vitro imply that the attenuated expression of IGFBP-4 may constitute a requirement for successful follicular maturation, (J Soc Gynecol Invest 1997;4:144–151) Copyright © 1991 by the Society for Gynecologic Investigation.
Astrophysics: A glimpse inside a magnetar.

Hundreds of neutron stars have exhibited 'glitches' in their spin-down rates — an indication of ultra-dense superfluids in their interiors. Now one highly magnetized star has shown a surprising glitch in the 'wrong' direction. See Letter p.591 Hundreds of glitches observed in the emission of radio pulsars and magnetars — strongly magnetic neutron stars emitting X- and γ-rays — have involved a sudden spin-up, or increase in the surface angular velocity. Glitches are thought to arise when angular momentum is transferred between the solid outer crust and the superfluid component of the inner crust. This paper reports the first observation of an 'anti-glitch', a sudden spin-down event, in the magnetar 1E 2259+586. The event coincided with an X-ray flare and X-ray bursts similar to those seen during some previous magnetar spin-up glitches, suggesting an origin in the stellar interior rather than the magnetosphere. Current models of neutron star spin-down do not predict such behaviour.
The primacy of narcissism.

Arguments are presented in support of Freud's position that narcissism developmentally precedes object love. Narcissism in mature human relationships can be exemplified by the case of being in love.
The effects of aqueous bicarbonate and calcium ions on uranium biosorption by Arthrobacter G975 strain

Uranium (VI) biosorption was investigated using carbonate-free and carbonate amended synthetic groundwater (SGW) under conditions relevant to Ca-rich carbonate-bearing subsurface environments. SGW was amended with bicarbonate concentrations ranging between 0.5 and 5 mM and a G975 Arthrobacter oxydans strain, a soil bacterium previously isolated from Hanford Site soil. Selected treatments were amended with 5 mM of calcium to evaluate its effect on U(VI) biosorption. The study confirmed that Arthrobacter sp. G975 can effectively remove soluble U(VI) ions from aqueous solution. The Langmuir, Linear, and Freundlich isotherms were fitted to the experimental data. Based on a higher correlation coefficient, the data was better fit by the Langmuir model. The presence of calcium and bicarbonate ions in SGW affects the sorption behavior of U(VI) due to the formation of highly soluble and stable uranyl-carbonate and calcium uranyl carbonate complexes that reduce adsorption of U(VI). Increasing aqueous bicarbonate concentrations exponentially reduced the U(VI) microbial adsorption compared to values obtained in carbonate-free solutions. The differences in U(VI) uptake generated by calcium additions in bicarbonate-free solutions were small enough to conclude that calcium was not a governing factor in biosorption. Results suggest that in the presence of bicarbonate and calcium, the damage to bacterial cells caused by U(VI) toxicity was reduced, yielding similar values for TOC degradation and cell density compared to U(VI)-free controls.
Method of linear combination of structural motifs for surface and step energy calculations: Application to GaAs(001)

First-principles calculations of the atomic structure and formation energies of semiconductor surfaces and surface steps are often complicated by the existence of complex structural patterns. We suggest here a simpler, algebraic (not differential) approach that is based on two observations distilled from previous first-principles calculations. First, a relatively large collection of equilibrium structures of surfaces and bulk point defects can be built from a limited number of recurring local ``structural motifs,'' including for GaAs tetrahedrally bonded Ga and As and miscoordinated atoms such as threefold-coordinated pyramidal As. Second, the structure is such that band-gap levels are emptied, resulting in charged miscoordinated atoms. These charges compensate each other. We thus express the total energy of a given surface as a sum of the energies of the motifs, and an electrostatic term representing the Madelung energy of point charges. The motif energies are derived by fitting them to a set of pseudopotential total-energy calculations for flat GaAs(001) surfaces and for point defects in bulk GaAs. This set of parameters is shown to suffice to reproduce the energies of other (001) surfaces, calculated using the same pseudopotential approach. Application of the ``linear combination of structural motif'' (LCSM) method to flat GaAs(001) surfaces reveals the following: (i) The observed h(2\ifmmode\times\else\texttimes\fi{}3) surface may be a disordered c(8\ifmmode\times\else\texttimes\fi{}6) surface. (ii) The observed (2\ifmmode\times\else\texttimes\fi{}6) surface is a metastable surface, only 0.03 eV/(1\ifmmode\times\else\texttimes\fi{}1) higher than the \ensuremath{\alpha}(2\ifmmode\times\else\texttimes\fi{}4) surface having the same surface coverage. (iii) We confirm the recent suggestion by Hashizume et al. that the observed \ensuremath{\gamma}(2\ifmmode\times\else\texttimes\fi{}4) phase of the (2\ifmmode\times\else\texttimes\fi{}4) surface is a mixture of the \ensuremath{\beta}2(2\ifmmode\times\else\texttimes\fi{}4) and c(4\ifmmode\times\else\texttimes\fi{}4) surfaces. In particular, we examined an 8\ifmmode\times\else\texttimes\fi{}7 surface structure which has a lower energy than the earlier proposed \ensuremath{\gamma}(2\ifmmode\times\else\texttimes\fi{}4) structure. Application of the LCSM method to prototype steps on the GaAs(001)-(2\ifmmode\times\else\texttimes\fi{}4) surface is illustrated, comparing the LCSM results directly to pseudopotential results. \textcopyright{} 1996 The American Physical Society.
Enhancing the Activity of a Protein by Stereospecific Unfolding CONFORMATIONAL LIFE CYCLE OF INSULIN AND ITS EVOLUTIONARY ORIGINS

A central tenet of molecular biology holds that the function of a protein is mediated by its structure. An inactive ground-state conformation may nonetheless be enjoined by the interplay of competing biological constraints. A model is provided by insulin, well characterized at atomic resolution by x-ray crystallography. Here, we demonstrate that the activity of the hormone is enhanced by stereospecific unfolding of a conserved structural element. A bifunctional β-strand mediates both self-assembly (within β-cell storage vesicles) and receptor binding (in the bloodstream). This strand is anchored by an invariant side chain (PheB24); its substitution by Ala leads to an unstable but native-like analog of low activity. Substitution by d-Ala is equally destabilizing, and yet the protein diastereomer exhibits enhanced activity with segmental unfolding of the β-strand. Corresponding photoactivable derivatives (containing l- or d-para-azido-Phe) cross-link to the insulin receptor with higher d-specific efficiency. Aberrant exposure of hydrophobic surfaces in the analogs is associated with accelerated fibrillation, a form of aggregation-coupled misfolding associated with cellular toxicity. Conservation of PheB24, enforced by its dual role in native self-assembly and induced fit, thus highlights the implicit role of misfolding as an evolutionary constraint. Whereas classical crystal structures of insulin depict its storage form, signaling requires engagement of a detachable arm at an extended receptor interface. Because this active conformation resembles an amyloidogenic intermediate, we envisage that induced fit and self-assembly represent complementary molecular adaptations to potential proteotoxicity. The cryptic threat of misfolding poses a universal constraint in the evolution of polypeptide sequences.
Transesophageal echocardiography in fetal sheep. A monitoring tool for open and fetoscopic cardiac procedures.

Background: Cardiac procedures in exteriorized fetuses or assisted by fetoscopy require monitoring capabilities not attended by conventional maternal transabdominal echocardiography.
RETHINKING THE PAST AND ANTICIPATING THE FUTURE OF RELIGION AND SCIENCE

John Caiazza presents the current technoculture as the latest development in the ongoing conflict of science and religion that began with Tertullian in the third century. I argue that his presentation is historically inaccurate, because for most of Western history science and religion interacted with and cross-fertilized each other. Contrary to Caiazza's misleading presentation, Western thought did not follow the dichotomous model polemically posed by Tertullian. I take issue with Caiazza's portrayal of postmodernism and his claim that technology is the foundation of an inherently secularist culture. I conclude by highlighting certain ethical challenges engendered by the prevalence of new technologies and present the dialogue of science and religion as uniquely qualified to address these challenges.
Co‐translational protein targeting catalyzed by the Escherichia coli signal recognition particle and its receptor

The Ffh-4.5S ribonucleoprotein particle (RNP) and FtsY from Escherichia coli are homologous to essential components of the mammalian signal recognition particle (SRP) and SRP receptor, respectively. The ability of these E. coli components to function in a bona fide co-translational targeting pathway remains unclear. Here we demonstrate that the Ffh-4.5S RNP and FtsY can efficiently replace their mammalian counterparts in targeting nascent secretory proteins to microsomal membranes in vitro. Targeting in the heterologous system requires a hydrophobic signal sequence, utilizes GTP and, moreover, occurs co-translationally. Unlike mammalian SRP, however, the Ffh-4.5S RNP is unable to arrest translational elongation, which results in a narrow time window for the ribosome nascent chain to interact productively with the membrane-bound translocation machinery. The highly negatively charged N-terminal domain of FtsY, which is a conserved feature among prokaryotic SRP receptor homologs, is important for translocation and acts to localize the protein to the membrane. Our data illustrate the extreme functional conservation between prokaryotic and eukaryotic SRP and SRP receptors and suggest that the basic mechanism of co-translational protein targeting is conserved between bacteria and mammals.
The nature of qualitative comments in evaluating professionalism.

Introduction We analysed written comments on clerkship evaluation forms to determine if they furthered our understanding of students' professional behaviour. Methods We transcribed all written comments related to professional behaviour for 1 medical school class in 4 major clerkships, then categorised the comments. Comments were coded into categories by two raters. They were also coded as positive, negative or equivocal. The 3 types of comments were each correlated with a Likert-type score for professionalism for each student in these same clerkships. Results Most comments covered initiative, working well with others, patient skills and working hard. Of the 1845 comments, 1721 were positive, 106 were negative and 18 were equivocal, neither wholly positive nor wholly negative. The total number of positive comments correlated with the students' numerical professionalism score (r = 0.29, P < 0.001); negative comments correlated negatively with the numerical professionalism score (r = −0.44, P < 0.001). Equivocal comments were significantly negative (r = −0.25, P = 0.002). Qualitative analysis revealed that equivocal comments were focused on maturity, initiative and teamwork. Conclusions Written comments contain unique indicators of students' professional behaviour and are largely positive in nature; negative comments stand out by their rarity and intensity. There is a set of negative comments masked by evaluators in language that appears neutral or even partly positive that statistically resemble negative comments and should be regarded as such by students who receive this type of comments. Evaluators should be encouraged and trained to express their qualitative views of students.
Water-Quality Effects of Tire Shreds Placed Above the Water Table: Five-Year Field Study

A field trial was constructed beneath a secondary state highway in North Yarmouth, Maine, to investigate the water-quality effects of tire shred fills placed above the groundwater table. Samples were collected in three 3-m2 geomembrane-lined basins located beneath the shoulder of the road. Two of the basins are overlaid by 0.61 m of tire shreds with a 75-mm maximum size topped by 0.72 to 1.37 m of granular soil. The third basin serves as a control and is overlaid by only 0.72 m of granular soil. Quarterly samples for inorganic constituents were taken from January 1994 through June 1999. In addition, samples were taken for volatile and semivolatile organic compounds on three dates. Filtered and unfiltered samples were analyzed for the following substances, which have a primary drinking water standard: barium, cadmium, chromium, lead, and selenium. There was no evidence that the presence of tire shreds altered the concentrations of these substances from their naturally occurring background levels. In additi...
Comparison of Genetic Distance Measures Using Human SNP Genotype Data

Quantification of the genetic distance between populations is instrumental in many genetic research initiatives, and a large number of formulas for this purpose have been proposed. However, selection of an appropriate measure for assessing genetic distance between real-world human populations that diverged as a result of mechanisms that are not fully known can be a challenging task. We compared results from nine widely used genetic distance measures to high-density whole-genome SNP genotype data obtained on individuals from 51 world populations. Using population trees and generalized analysis of molecular variance, we found that contradictory inferences could be drawn from analyses that used different distance measures. We determined the grouping of the distance measures in terms of similarity and consistency of their values using concordance, consistency, and Procrustes analyses. Overall, the Cavalli-Sforza and Edwards distance measure differed the most from the other measures. Wright's F(ST) for diploid data, the Latter and Reynolds distances, and Nei's minimum distance measures each yielded values that were most consistent with the other eight distance measures in terms of ordering populations based on genetic distance. The Cavalli-Sforza and Edwards distance and Nei's geometric distance were least consistent. Simulation studies showed that the Cavalli-Sforza and Edwards distance is relatively more sensitive in distinguishing genetically similar populations and that the Reynolds genetic distance provides the highest sensitivity for highly divergent populations. Finally, our study suggests that using the Cavalli-Sforza and Edwards distance may provide less power for studies concerning human migration history.
The myoglobin of primates X.

Abstract The amino acid sequences of skeletal muscle myoglobins from two old-world monkeys, Presbytis entellus and Erythrocebus patas , as well as one new-world monkey, Cebus apella were inferred by homology of the tryptic and peptic peptides with the known sequence of human myoglobin and by selective dansyl-Edman degradation. These new sequences were examined phylogenetically in conjunction with the 15 primate sequences already reported. It is clear that myoglobin evolution has been extremely conservative among cercopithecoid primates, so much so that the two surviving subfamilies cannot be distinguished using this protein.
Stt4 PI 4-kinase localizes to the plasma membrane and functions in the Pkc1-mediated MAP kinase cascade.

Abstract Production of the essential phospholipid PI4P at the Golgi by the Pik1 kinase is required for protein secretion, while a distinct pool of PI4P generated by the Stt4 kinase is critical for normal actin cytoskeleton organization. We identify a transmembrane protein that stabilizes Stt4 at the plasma membrane where it directs synthesis of PI4P, which is required for activation of the Rho1/Pkc1-mediated MAP kinase cascade. Inactivation of Stt4 or the PI4P 5-kinase Mss4 results in mislocalization of the Rho-GTPase GEF Rom2. Rom2 binds PI4,5P 2 through its PH domain and represents the first identified effector in the Stt4-Mss4 pathway. Based on these results, we propose that Stt4-Mss4 generates PI4,5P 2 at the plasma membrane, required to recruit/activate effector proteins such as Rom2.
One line decreases the visibility of a simultaneous identical distant second line

A top line decreased the visibility of a simultaneous, identical, distant bottom line. This context-produced decrease in visibility (DV) occurred when the bottom line was masked by flanking lines and hence was less visible than the top line. It continued when the top line was three times as far from the bottom line. It disappeared without the mask. There was a hint of an opposing context-produced increase in visibility (IV) when the lines were close together. The DV is not accounted for by numerous extant phenomena and theories. It means that the top line decreased the similarity in visibility between it and the bottom line, a contrast effect for visibility, rather than for a typical attribute. Contrast does not occur between two attributes that are perceptually equal. Therefore, the reason why two distant equally visible objects fail to result in a DV may be that their equal visibility precludes the occurrence of contrast. This DV-as-contrast theory is consistent with evidence that two groups (phenomenal wholes) are associated with both contrast and DVs, and thus also with evidence that one group is associated with both assimilation and IVs.
Autodetachment spectroscopy of vibrationally excited acetaldehyde enolate anion, CH2CHO-

Abstract The autodetachment spectrum of acetaldehyde enolate anion, CH2CHO−, is recorded near 14180 cm−1 using a coaxial laserion threshold photodetachment spectrometer. The spectrum repreents transitions from ν=1 in the ν3 CCO bending mode of CH2CHO− to ν=0 in the autodetaching dipole-bound state of the anion. The 32 rotationally resolved (0, 1) hot band transitions reported here were fit to Watson's A-reduced Hamiltonian in conjunction with the previously reported (0, 0) transitions. Rotational constants for ν3 ν=1 of the ground electronic state are determined to be A=2.782(2) cm−1, B=1.3619(4) cm−1, and C=0.3147(4) cm−1. The (O, 1) band origin is 14186.928(8) cm−1, which places ω0 for the ν3 mode at 525.82(1) cm−1.
CD28, Ox-40, LFA-1, and CD4 Modulation of Th1/Th2 Differentiation Is Directly Dependent on the Dose of Antigen

The involvement of specific accessory/costimulatory molecules in differentiation to Th1 and Th2 phenotypes is controversial. Reports suggest that molecules such as CD4, CD28, and Ox-40 support Th2 differentiation and suppress Th1 differentiation, whereas others such as LFA-1 support Th1 responses and suppress Th2 responses. We have previously defined an in vitro model of differentiation that is absolutely dependent on the initial dose and affinity of peptide presented to a naive CD4 cell. The dose and affinity of Ag regulate autocrine production of IL-2, IL-4, and IFN-gamma, which in turn govern differentiation to Th1 and Th2 phenotypes. We have used this system to confirm that CD4, CD28, and Ox-40 interactions can promote, and LFA-1 interactions can suppress, differentiation of cells secreting the Th2 cytokines IL-5 and IL-13. However, for CD4 and LFA-1, this is only seen over a certain range of peptide doses. In addition, CD28 and Ox-40 interactions also promote Th1 differentiation. In general, agonist Abs to accessory molecules shifted the response curves for IFN-gamma, IL-5, and IL-13 to lower doses, whereas antagonist reagents resulted in similar curves shifted toward the higher doses. We conclude that ligation of cell surface accessory receptors enables low doses of Ag to promote responses normally induced only by higher doses. Individual receptors do not intrinsically regulate one cytokine phenotype or another, suggesting that differentiation is controlled by the level of expression of multiple accessory molecule pairs integrated with the number and affinity of peptide/MHC complexes.
Position paper: nondeterminism is unavoidable, but data races are pure evil

Modern mainstream programming languages distinguish between "atomic" (or sometimes "volatile") variables, and ordinary data. Atomic accesses are treated as synchronization constructs, and support concurrent access with well-defined semantics. In contrast, concurrent accesses to ordinary data, if at least one access is an update, constitute a data race. Code with data races does not have well-defined semantics. Such code may fail completely when recompiled or run on a different operating system version. In C and C++ data races are equivalent to assignments to out-of-bounds array elements; any data race can result in arbitrary failures, including application crashes, hangs, and inexplicably and completely wrong answers.These language specifications, combined with implementation realities, make it unsafe to exploit "benign" data races to obtain performance, even if we are willing to tolerate approximate answers. Furthermore, even if we happen to get lucky, and code with data races happens to execute correctly with our current compiler, data races provide at best inconsequential performance advantages over atomics. In fact, there are interesting, and probably common, cases in which data races provide only a minor performance advantage, even over pervasive locking to avoid them, it at sufficiently large core counts. We demonstrate such a case.
Hierarchy under anarchy: informal empire and the East German state

Contemporary international politics embody a tension between formal equality and de facto inequality. States recognize each other as sovereign equals, yet the strong still push around the weak. Among the structures that reflect this tension are informal empires. The dominant assumptions in mainstream international relations theory, materialism and rationalism, privilege the formal equality of states in informal empires a priori: materialism by assuming that authority relations cannot exist between sovereign states; rationalism by assuming that states are sovereign over their own interests. A constructivist approach allows one to explore the hypothesis that transnational authority structures construct state identities and interests. An empirical analysis of the Soviet-East German relationship supports this hypothesis, which raises questions about the emerging study of international governance.
Evaluation in constitutional law: An application to the first amendment

This article argues that program evaluation data may be useful to the courts when they are deciding First Amendment constitutional law disputes. Specifically, we focus on how program evaluation data, quantitative and qualitative, may be dispositive in dealing with two types of First Amendment cases—pornography and commercial speech. The different evaluative approaches that are warranted with each type of case are compared and contrasted. The different possible legal routes that program evaluation data may take to influence the outcome of constitutional law disputes determines the empirical type of approach to be utilized. Where pornography cases lend themselves more to social science data being used in trials, cases of commercial speech are more likely to use data at the appellate level. Social scientists interested in conducting legally relevant research should structure their research accordingly.