cssi/SciSciGPT-SciSciNet huggingface dataset:
PROBING THE “30 μm” FEATURE: LESSONS FROM EXTREME CARBON STARS

Some carbon-rich evolved stars exhibit a very prominent spectral feature at {approx}{sup 3}0 {mu}m''. The C-rich nature of these objects suggests that the carrier is a sulfide, carbide, or other substance apt to form in a reducing environment. However, the carrier of this spectral feature remains disputed, with magnesium sulfide (MgS) as the most favored candidate. In order to investigate the carrier of the {sup 3}0 {mu}m'' feature further, we have taken a dual approach, studying both laboratory and observational data. In order to obtain a homogeneous sample, we studied the {sup 3}0 {mu}m'' feature observed in the spectra of galactic extreme carbon stars that exhibit the 11 {mu}m SiC absorption feature. Thus, we avoid potential differences in the target objects that could contribute to the observed differences in the shape, position, and strength of the {sup 3}0 {mu}m'' feature. In addition, we analyzed the shape and position of the {sup 3}0 {mu}m'' features for a range of sulfide minerals for which laboratory data exist. Our study of observed astronomical features shows a range of shapes and positions for the {sup 3}0 {mu}m'' feature despite similarities in the source objects. The nature of our sample argues against grain processing ormore » temperature differences due to hardening of the stellar radiation field with evolution. While there are very few correlations between spectral parameters for our sample, the peak positions of the {approx}11 {mu}m absorption and 30 {mu}m emission features do correlate, and these peak positions correlate with the modeled optical depth. These correlations suggest that the carriers of the observable spectral features are closely related to one another and to the density/pressure in the dust formation zone. Furthermore, we suggest that the blue-broadening of the 11 {mu}m feature cannot be attributed to SiS{sub 2} based on existing laboratory spectra, but further lab work is needed to investigate the effect of increasing oxidation.« less
OXYGEN ACTIVATION CATALYZED BY METHANE MONOOXYGENASE HYDROXYLASE COMPONENT: PROTON DELIVERY DURING THE O-O BOND CLEAVAGE STEPS

The effects of solvent pH and deuteration on the transient kinetics of the key intermediates of the dioxygen activation process catalyzed by the soluble form of methane monooxygenase (MMO) isolated from Methylosinus trichosporium OB3b have been studied. MMO consists of hydroxylase (MMOH), reductase, and “B” (MMOB) components. MMOH contains a carboxylate- and oxygen-bridged binuclear iron cluster that catalyzes O2 activation and insertion chemistry. The diferrous MMOH−MMOB complex reacts with O2 to form a diferrous intermediate compound O (O) and subsequently a diferric intermediate compound P (P), presumed to be a peroxy adduct. The O decay reaction was found to be pH-independent within error at 4 °C (kobs= 22 ± 2 s-1 at pH 7.7; kobs= 26 ± 2 s-1 at pH 7.0). In contrast, the P formation rate was found to decrease sharply with increasing pH to near zero at pH 8.6; the observed rate constants fit to a single deprotonation event with a pKa = 7.6 and a maximal formation rate at 4 °C of kP = 9.1 ± 0.9 s-1 achie...
Consumer sensory evaluations of aging effects on beef quality.

ABSTRACT: The most important sensory attribute affecting consumer acceptability is tenderness, which is a complex trait. Aging is the practice of holding meat at low temperatures to improve tenderness. In order to assess consumer quality attributes, cattle were selected to represent a range of quality grades from Utility to Prime. Steaks from these cattle were aged in vacuum bags for 0, 7, or 14 d, cut, and cooked on open hearth grills to 70 °C. Sensory evaluation was completed by consumers (n= 522). Warner–Bratzler (WB) shear and various physical characteristics were also determined. Shear values decreased with aging time and tenderness increased. Consumers perceived the majority of change in tenderness occurred during the first 7 d of aging while change in WB shear was similar during the first 7 d and the second 7 d of aging. Aging had no effect (P > 0.05) on juiciness, flavor, pH, lipid content, or water content of steaks.
Falling down and falling out: management and outcome analysis.

Background: This study compares young (< 65 years old) and elderly (≥ 65 years old) patients who fall secondary to syncope and seeks to determine whether syncope workups are being appropriately performed and whether they contribute new information that results in a change in management. Methods: A retrospective review of patients who fell and were admitted to a Level I trauma center was performed. Data included mechanism of injury, comorbidities, and severity scores in addition to details regarding a syncope workup in patients who had unclear reasons for falling. Outcome variables were mortality, intensive care unit and hospital lengths of stay, and whether each test resulted in a change in management. Results: The data set included 387 patients. Elderly patients who fell (n = 157) had significantly higher Injury Severity Scores and mortality, lower Glasgow Coma Scale scores, and longer intensive care unit and hospital lengths of stay than the younger cohort (n = 230). When a fall occurred secondary to syncope, however, there was no difference in injury severity or outcome. Patients who fell secondary to syncope (n = 61) had zero to six of the recommended tests ordered. Nineteen tests in the young group and 79 tests in the elderly patients had abnormal results. Overall, 37.8% of patients had specific interventions performed because of the abnormal test results Conclusion: Syncope workups were erratically performed in both young and older groups. These workups frequently resulted in abnormal findings that required intervention. Protocols are currently being developed at our institution to ensure complete assessment of trauma patients who fall for unknown reasons.
Marine microbial community dynamics and their ecological interpretation

Recent advances in studying the dynamics of marine microbial communities have shown that the composition of these communities follows predictable patterns and involves complex network interactions, which shed light on the underlying processes regulating these globally important organisms. Such 'holistic' (or organism- and system-based) studies of these communities complement popular reductionist, often culture-based, approaches for understanding organism function one gene or protein at a time. In this Review, we summarize our current understanding of marine microbial community dynamics at various scales, from hours to decades. We also explain how the data illustrate community resilience and seasonality, and reveal interactions among microorganisms.
Changes in soil respiration across a chronosequence of tallgrass prairie reconstructions

Abstract Close relationships among climatic factors and soil respiration (Rs) are commonly reported. However, variation in Rs across the landscape is compounded by site-specific differences that impede the development of spatially explicit models. Among factors that influence Rs, the effect of ecosystem age is poorly documented. We hypothesized that Rs increases with grassland age and tested this hypothesis in a chronosequence of tallgrass prairie reconstructions in central Iowa, U.S.A. We also assessed changes in root biomass, root ingrowth, aboveground net primary productivity (ANPP), and the strength of soil temperature and moisture in predicting Rs. We found a significant increase in total growing season Rs with prairie age (R2 = 0.79), ranging from 714 g C m−2 in the youngest reconstruction (age 4) to 939 g C m−2 in the oldest prairie (age 12). Soil temperature was a strong predictor of intra-seasonal Rs among prairies (R2 = 0.78–0.87) but mean growing season soil temperature and moisture did not relate to total Rs. The increase in Rs with age was positively correlated with root biomass (r = 0.80) and ANPP (r = 0.87) but not with root ingrowth. Our findings suggest that growing season Rs increases with tallgrass prairie age, root biomass, and ANPP during young grassland development.
Engineered Chimeric Streptavidin Tetramers as Novel Tools for Bioseparations and Drug Delivery

We report the construction of chimeric streptavidin tetramers that are composed of subunits of both wild-type (WT) streptavidin and genetically-engineered streptavidin variants designed for enhanced bioseparation and drug delivery performance. Subunit mixing is accomplished by guanidine thiocyanateinduced denaturation of an equimolar mixture of WT streptavidin and the respective site-directed mutant, followed by renaturation and reassociation of mixed tetramers. In the first example, we demonstrate the mixing of WT subunits with an Asn49Cys (N49C) mutant. The WT/n49C tetramers can be used for site-specific and stoichiometric attachment of therapeutics/imaging agents or targeting proteins through the genetically-engineered thiol while retaining unhindered access to biotin-binding at the WT subunits. Second, we demonstrate that the His127Cys mutation (H127C) results in a streptavidin mutant that forms a disulfide-linked dimer under non-reducing conditions. Mixing of H127C and WT streptavidin subunits results in chimeric tetramers where both the stoichiometry (WT:H127C::1:1) and subunit architecture is controlled by the unique disulfide bridge engineered into H127C. In the third example, WT subunits were mixed with the subunits of a site-directed mutant, Trp120Ala (W120A), which displays a biotin dissociation constant that is enhanced by more than 10(4) compared to WT streptavidin. The W120 biotin-binding affinity is sufficiently high (Ka approximately equal to 10(7) M-1) to immobilize the mutant on a biotinagarose affinity chromatography column, but the engineered off-rate allows for facile elution with excess biotin at physiological pH, whereas WT streptavidin is irreversibly immobilized on the column. We demonstrate that the purified WT/W120A chimeric tetramers combine the advantages of both subunits, allowing for irreversible immobilization of biotinylated targets at the WT subunit, while retaining the reversible separation capabilities of the W120A subunits via biotin-agarose affinity chromatography.
Removal of waxes from sunflower seed oil by miscella refining and winterization

Miscella refining and winterization produced a sunflower seed salad oil that did not cloud on refrigeration for 7 days. Refining reduced phospholipid content, and this facilitated wax removal during winterization.
Synthesis, characterization, and reactivity of a d2, Mo(IV) complex supported by a new OCO-trianionic pincer ligand.

The new terphenyl pincer precursor 3,3‘ ‘-di-tert-butyl-1,1‘:3‘,1‘ ‘-terphenyl-2,2‘ ‘-diol (1) is examined for its ability to support early transition metals as a trianionic ligand. Metalation proceeds smoothly at −35 °C with Mo(NMe2)4 to provide the Mo(IV), d2 amido−amine complex [3,3‘ ‘-di-tert-butyl-2,2‘ ‘-di(hydroxy-κO)-1,1‘:3‘,1‘ ‘-terphenyl-2‘-yl-κC2‘](N-methylmethanaminato)bis(N-methylmethanamine)molybdenum(IV), abbreviated as [tBuOCO]Mo(NMe2)(NHMe2)2, (2).
On equivalent reformulations for absolute value equations

In this note we consider absolute value equations (AVE) of the type Ax+B|x|=c. We discuss unique solvability of AVE, and its relations with linear complementarity problem (LCP) and mixed integer programming.
Aspects of the rhetorical tradition‐I: The intellectual foundation

(1950). Aspects of the rhetorical tradition‐I: The intellectual foundation. Quarterly Journal of Speech: Vol. 36, No. 2, pp. 169-176.
The Islamization of knowledge: Philosophy, legitimation, and politics

(1996). The Islamization of knowledge: Philosophy, legitimation, and politics. Social Epistemology: Vol. 10, Islamic Social Epistemology, pp. 259-271.
Feeding the People, Feeding the Spirit: Revitalizing Northwest Coastal Indian Food

Review of Feeding the People, Feeding the Spirit: Revitalizing Northwest Coastal Indian Food . Elise Krohn and Valerie Segrest. 2010. Northwest Indian College, Bellingham, WA. Pp. x + 158, copiously illustrated, tables, bibliography.
Fragile X full mutations are more similar in siblings than in unrelated patients: further evidence for a familial factor in CGG repeat dynamics.

Purpose: We sought to compare patterns of full mutation repeat-length variability in the peripheral blood DNA of patients with fragile X syndrome to determine whether siblings possess mutation patterns more similar than those of unrelated patients. Methods: Mutation patterns were visualized by Southern blot analysis and captured digitally with a phosphor imager. Novel comparison strategies based on overlapping profile plots and calculation of weighted mean CGG repeat values were used to assess mutation pattern similarity. Results: Within the population that we analyzed of 56 patients with full mutation, mutation patterns were found to be more similar in siblings than in unrelated patients. Conclusion: These results indicate that repeat-length variability may be generated in a nonrandom manner and that familial factors influence this process.
The Use of Investigations in the Introductory Statistics Course

Abstract Reasons for including investigations in a first course in statistics are presented. Investigations create an environment of participation and give the student the opportunity to experience statistics in action. This participation highlights the interaction between science and statistics. Suggestions are made regarding the integration of investigations into a formal course environment. One investigation is presented in detail. Thirteen other investigations are outlined. Emphasis is placed on experiments that require minimal set-up time yet illustrate important statistical concepts.
Black Theology: A Survey of Its Past, Present, and Future

When considered as a whole, the genius of black theology involves an ability to shift and change, to reconceive itself in light of new understandings and alternate situations. From the initial work of figures such as James H. Cone and J. Deotis Roberts, through a second generation of thinkers such as Dwight Hopkins and James Evans, to more recent challenges offered by Eddie Glaude, Victor Anderson, and Anthony Pinn, black theology has given voice to the nature and meaning of religion within African-American communities. Mindful of this rich history, this article provides a survey of black theology's formation and structure – moving from its initial inception, through present developments and ongoing concerns.
A note on testing for switching regressions

Abstract This note shows that a well-known version of the switching regression model is not suitable for testing for parameter stability in a regression model because standard regularity conditions are not satisfied under the null hypothesis of parameter stability.
Distinctions between social support concepts, measures, and models

Le concept de support social doit etre abandonne au profit de concepts plus pertinents fondes sur les modeles de relations entre stress et detresse
Unilateral Absence of the Diaphragm in an Asymptomatic Adult

An asymptomatic 22-year-old man was evaluated for a persistent left lower lobe infiltrate. Barium enema and upper gastrointestinal series revealed colon and small bowel freely mobile in the left thorax. CT confirmed absence of the left hemidiaphragm. This is the first reported case of total absence of a hemidiaphragm in an adult, and extends the clinical spectrum of diaphragmatic defects. Unlike the more common partial diaphragmatic defects where strangulation of hernia contents may occur, the asymptomatic presentation of complete absence of the hemidiaphragm with the unimpeded movement of abdominal contents suggests that no treatment is necessary. (Chest 1988; 94:1301-03)
Speaking and writing: Distinct patterns of word choice

Abstract Natural conversations and popular television shows provide sufficient lexical diversity for children to develop novice levels of lexical expertise, but they are ill-suited for developing the higher levels of such expertise. In large part, this is due to distinct patterns of word choice in speaking and writing. Those patterns are revealed in a half-million word corpus, designed to represent all major language sources (print, television, and conversation). Each sample text is first compared against a common 10,000-type reference lexicon. This permits comparisons between texts from different language sources. The pattern of word choice in most printed texts is described by a simple linear equation, but conversations are fit by one or another cubic equation. Linear and S-curve texts differ in their relative use of the major articles, conjunctions, prepositions, pronouns, and most other function words, as well as the more common and rarer content words. The ranking of the 10 most common function words is uncorrelated in the two patterns. Consequently, conversations between college graduates more closely resemble a preschool child's speech to its parents than texts from newspapers. Implications of the linear and S-curved patterns for models of lexical acquisition are considered.
Two-and three-dimensional deterministic, L-system: An exploration of osmotic precipitation membranes

Lindenmayer systems (L-systems) are parallel rewriting systems that have been used to describe the growth and development of biological, living systems; specifically, the branching characteristics or plants. Based on the presentation of initial, exploratative, three-dimensional deterministic L-system simulations and their comparison to experimental osmotic growth data it is argued that there is significant potential for L-systems to be used to model and simulate osmotic precipitation membranes. The fascinating experiments and experimental results obtained from the reproduction of Stephane Leduc's research in synthetic biology are reviewed. A three-dimensional deterministic L-system simulation of osmotic growth is presented. A discussion of the requirements for the migration of the simulation from the simple deterministic L-system to a table-driven, stochastic, L-system is proposed.
Movement and diving behavior of male California sea lion (Zalophus californianus) during anomalous oceanographic conditions of 2005 compared to those of 2004

[1] During the highly anomalous conditions in early 2005, characterized by increased water temperatures and decreased productivity, male California sea lions adopted previously undocumented foraging behaviors. We investigated the movement and spatially explicit foraging behavior of males using satellite-linked data loggers and compared foraging behavior and effort between 2003-2004 and 2004-2005. Males foraged almost exclusively over the continental shelf during short trips in 2003-2004, while during anomalous conditions in 2004-2005 they altered their foraging effort by spending more time at sea and venturing up to 450 km offshore. Foraging trips in 2004-2005 were more than twice the distance and three times the duration of trips during 2003-2004. Our data indicated that the effects of climatic shifts during 2005 extended beyond the physical oceanography and lower trophic levels, to an apex predator; providing insight into the plasticity of foraging behavior and movement patterns of sea lions as they respond to environmental perturbations.
Slow growth of isothermal lath martensite in an Fe21N4Mn alloy

Laths of martensite in an Fe21Ni4MMn alloy form isothermally below room temperature and grow very slowly. Some features of this growth have been observed. Observations were recorded on cine film and the growth characteristics were determined using a frame-by-frame analysis. The lengthening rate of laths formed at − 80°C has been measured to be about 2.53 × 10−3cm/s, which is 10−8 times slower than that of conventional plate martensite. The thickening rate of the laths was found to be about one-tenth the lengthening rate. Both the lengthening and thickening rates of the laths clearly correspond to “slow growing” martensite. To further understand the characteristics of isothermal lath formation, quantitative analysis of data obtained from the cine films was made. The growth activation energy at −80°C was calculated to be about 14,000 cal/mol. Although precise documentation is lacking, it is inferred that the slow growth rate may be associated with the movement of interfacial dislocations situated at the martensite/austenite interface.
Malic Enzyme Activity in Apple Fruit

THE capacity of apple fruit to decarboxylate malic acid oxidatively (the malate effect) is evident early in apple fruit ontogeny1, as well as in the stages characterized by the climacteric and post-climacteric phases of fruit respiration2. The stoichiometric characteristics of the malate decarboxylation reaction1 and the symmetrical distribution of carbon-14 in malic acid resulting from 14CO2 fixation in apple fruit3 suggested the malic enzyme may function in both reactions. This investigation was initiated to determine if malic enzyme is responsible for malate decarboxylation and carbon dioxide fixation into malic acid in apple fruit.
USING EXPERIMENTAL DESIGN TO OPTIMIZE THE STEREOLITHOGRAPHY PROCESS

Experimental design is an excellent method for characterizing and optimizing a process. Economical designs, such as those described in this article, are useful for gaining rapid knowledge of the effects of variables and their interactions, with a minimu..
Waiting for Sophia: 30 Years of Conceptualizing Wisdom in Empirical Psychology

In response to a proposed definition of wisdom that integrated sophia and phronesis, this article reviews the constructs of wisdom in the psychological literature in regard to their inclusion of both. The author found about one fourth of the 41 models examined to contain reference to aspects of sophia. He discusses elements of sophia in the global wisdom tradition, and makes the argument that two aspects of sophia must be included in a comprehensive definition of wisdom: (a) the perspective of the self-transcendent unity of being and (b) intuitive knowing of reality.
An Extensive Comparison of the Effect of Anthelmintic Classes on Diverse Nematodes

Soil-transmitted helminths are parasitic nematodes that inhabit the human intestine. These parasites, which include two hookworm species, Ancylostoma duodenale and Necator americanus, the whipworm Trichuris trichiura, and the large roundworm Ascaris lumbricoides, infect upwards of two billion people and are a major cause of disease burden in children and pregnant women. The challenge with treating these diseases is that poverty, safety, and inefficient public health policy have marginalized drug development and distribution to control infection in humans. Anthelmintics (anti-worm drugs) have historically been developed and tested for treatment of non-human parasitic nematodes that infect livestock and companion animals. Here we systematically compare the in vitro efficacy of all major anthelmintic classes currently used in human therapy (benzimidazoles, nicotinic acetylcholine receptor agonists, macrocyclic lactones, nitazoxanide) against species closely related to human parasitic nematodes-Ancylostoma ceylanicum, Trichuris muris, and Ascaris suum--- as well as a rodent parasitic nematode used in veterinary drug discovery, Heligmosomoides bakeri, and the free-living nematode Caenorhabditis elegans. Extensive in vitro data is complemented with single-dose in vivo data in three rodent models of parasitic diseases. We find that the effects of the drugs in vitro and in vivo can vary greatly among these nematode species, e.g., the efficacy of albendazole is strong on A. ceylanicum but weak on H. bakeri. Nonetheless, certain commonalities of the in vitro effects of the drugs can be seen, e.g., nitazoxanide consistently shows an all-or-nothing response. Our in vitro data suggest that further optimization of the clinical efficacy of some of these anthelmintics could be achieved by altering the treatment routine and/or dosing. Most importantly, our in vitro and in vivo data indicate that the hookworm A. ceylanicum is a particularly sensitive and useful model for anthelmintic studies and should be incorporated early on in drug screens for broad-spectrum human soil-transmitted helminth therapies.
A high-resolution thermometer for the range 0.75–1.0 K

We report on a new high-resolution thermometer (HRT) for use near the tricritical point in 3He-4He mixtures. It is based on an existing HRT design that uses a DC-SQUID to detect the magnetization of a paramagnetic sensing element.
Phase Diagram of Thermotropic Liquid Crystal Including Negative Pressure Region Generated in Metal Berthelot Tube

Phase diagrams including absolute negative pressure regions of thermotropic liquid crystals give useful information on science and technology. A phase diagram was depicted for ca. 40mg of a thermotropic liquid crystal in a pressure vs. temperature (P-T) plane by the Berthelot method using a metal tube. N-I phase transitions occurred even under-10MPa, and a polymorphism of the crystalline phase was observed.
Approximating reals by sums of rationals

Abstract We generalize Dirichlet's diophantine approximation theorem to approximating any real number α by a sum of two rational numbers a 1 q 1 + a 2 q 2 with denominators 1 ⩽ q 1 , q 2 ⩽ N . This turns out to be related to the congruence equation problem x y ≡ c ( mod q ) with 1 ⩽ x , y ⩽ q 1 / 2 + ϵ .
A Multiscale Model for the Modulation and Rectification of the ITCZ

AbstractThe authors introduce the modulation of the ITCZ equations (M-ITCZ), which describes the multiscale dynamics of the ITCZ on diurnal to monthly time scales in which mesoscale convectively coupled Rossby waves in the ITCZ are modulated by a large-scale gravity wave that is also generated by convection. Westward-propagating disturbances are observed to cause ITCZ breakup over the course of a few days, and the M-ITCZ meso-/planetary-scale coupled waves provide a mechanism for this interaction, thereby providing a framework to study the modulation and rectification of the Hadley circulation over long zonal length scales in the ITCZ.The authors consider examples of zonally symmetric heating profiles in the M-ITCZ system and generate a Hadley circulation consistent with the observed winds. Zonally localized heating creates a wind response throughout the tropics that is carried by a pair of zonally propagating gravity bores driving mean easterlies at the base and mean westerlies at the top of the troposph...
A backpropagation neural network for risk assessment

The authors investigate the credibility of the neural network approach as a viable tool in the field of developmental toxicity risk assessment. A three-layer artificial neural network (ANN) was trained using backpropagation. The topology of the network was decided based on a set of trials and errors. This network was trained to perform risk assessment on a set of toxicological data and give a decision like the decision given by experts. The assessment ability of the resulting network was compared with the statistical approach of discriminant analysis and the superiority of the neural network approach was established. >
Homeostatic proliferation of a Qa-1b-restricted T cell: a distinction between the ligands required for positive selection and for proliferation in lymphopenic hosts.

Naive T cells proliferate in response to self MHC molecules after transfer into lymphopenic hosts, a process that has been termed homeostatic proliferation (HP). Previous studies have demonstrated that HP is driven by low level signaling induced by interactions with the same MHC molecules responsible for positive selection in the thymus. Little is known about the homeostatic regulation of T cells specific for class Ib molecules, including Qa-1 and H2-M3, though it has been suggested that their capacity to undergo homeostatic expansion may be inherently limited. In this study, we demonstrate that naive 6C5 TCR transgenic T cells with specificity for Qa-1b have a capacity similar to conventional T cells to undergo HP after transfer into sublethally irradiated mice. Proliferation was largely dependent on the expression of β2-microglobulin, and experiments with congenic recipients expressing Qa-1a instead of Qa-1b demonstrated that HP is specifically driven by Qa-1b and not through cross-recognition of classical class I molecules. Thus, the same MHC molecule that mediates positive selection of 6C5 T cells is also required for HP. Homeostatic expansion, like positive selection, occurs in the absence of a Qa-1 determinant modifier, the dominant self-peptide bound to Qa-1 molecules. However, experiments with TAP−/− recipients demonstrate a clear distinction between the ligand requirements for thymic selection and HP. Positive selection of 6C5 T cells is dependent on TAP function, thus selection is presumably mediated by TAP-dependent peptides. By contrast, HP occurs in TAP−/− recipients, providing an example where the ligand requirements for HP are less stringent than for thymic selection.
Neisseria gonorrhoeae PilA Is an FtsY Homolog

The pilA gene of Neisseria gonorrhoeae was initially identified in a screen for transcriptional regulators of pilE, the expression locus for pilin, the major structural component of gonococcal pili. The predicted protein sequence for PilA has significant homology to two GTPases of the mammalian signal recognition particle (SRP), SRP54 and SRalpha. Homologs of SRP54 and SRalpha were subsequently identified in bacteria (Ffh and FtsY, respectively) and appear to form an SRP-like apparatus in prokaryotes. Of the two proteins, PilA is the most similar to FtsY (47% identical and 67% similar at the amino acid level). Like FtsY, PilA is essential for viability and hydrolyzes GTP. The similarities between PilA and the bacterial FtsY led us to ask whether PilA might function as the gonococcal FtsY. In this work, we show that overproduction of PilA in Escherichia coli leads to an accumulation of pre-beta-lactamase, similar to previous observations with other bacterial SRP components. Low-level expression of pilA in an ftsY conditional mutant can complement the ftsY mutation and restore normal growth to this strain under nonpermissive conditions. In addition, purified PilA can replace FtsY in an in vitro translocation assay using purified E. coli SRP components. A PilA mutant that is severely affected in its GTPase activity cannot replace FtsY in vivo or in vitro. However, overexpression of the GTPase mutant leads to the accumulation of pre-beta-lactamase, suggesting that the mutant protein may interact with the SRP apparatus to affect protein maturation. Taken together, these results show that the gonococcal PilA is an FtsY homolog and that the GTPase activity is necessary for its function.
The Calculation of Physiological Parameters Using Sequential Angiographic Images

We have developed a rule-based, expert system for the analysis of digital angiographic images. The standard method of analyzing the sequence of images from an injection of contrast material ignores the information contained in the time sequence. This results in significant errors in the calculation of percent stenosis -particularly in vessels sloped with respect to the image plane. We have aimed at using the complete time sequence to improve the accuracy of detection and quantification of stenosis in arteries.
Tumor Genetic Screening Programs: A Call to Action

that although 39% of patients had at least one potentially actionable alteration, only 11% of these patients (4% of patients overall) were subsequentlyenrolledontoagenomicallymatchedstudy.Theactionablegenomicalterationsthatmostcommonlypromptedenrolledtoa genotype-matched trial were mutations in PIK3CA (41%), BRAF (28%), EGFR (8%), KRAS (5%), and ERBB2 (5%). Interestingly, patientswithanactionablealterationwereonlymarginallymorelikelyto enrollontoaclinicaltrial(eithermatchedorunmatched)whencompared with patients without an actionable alteration (28.4% v24.4%). This prospective tumor profiling effort was conducted at a large cancer center with an extensive clinical trial portfolio. Therefore, we are forced to consider whether the 4% enrollment rate to a genotypematched study may be the upper limit of what can expected from similarprofilingeffortsinadiversepatientpopulation.Itisimportant
A magnetic sensor utilizing an avalanching semiconductor device

A new semiconductor device for sensing uniaxial magnetic fields has been realized. The device is basically a dual-collector open-base lateral bipolar transistor operating in the avalanche region, and is referred to as a Magnetic Avalanche Transistor. It exhibits high magnetic transduction sensitivity compared to traditional Hall-effect and conventional nonlinear magnetoresistive devices. Several hundred experimental devices have been designed, fabricated, and tested over the past two years. Many structural and some process parameters were varied. The magnetic sensitivity of a typical device was found to be proportional to substrate resistivity. A sensitivity of 30 volts per tesla was measured for devices which used 5-ohm-cm p-type substrates. The output signal measured between collectors is differential and responds linearly with field magnitude and polarity. A typical signal-to-noise ratio is 20 000 per tesla. The bandwidth is known to extend well beyond 5 MHz. The sensitive area is calculated to be on the order of 5 µm2. This communication describes the basic structure, fabrication, and characteristics for the magnetic avalanche transistor.
After Writing Culture: Epistemology and Praxis in Contemporary Anthropology

After Writing Culture: Epistemology and Praxis in Contemporary Anthropology. ALLISON JAMES. JENNY HOCKEY. and ANDREW DAWSON. eds. London: Routledge, 1997. + 273 pp., contributors, figures, notes, references, indexes.
Biofilms and chronic otitis media: an initial exploration into the role of biofilms in the pathogenesis of chronic otitis media.

Abstract Purpose The aim of the study was to compare the extent of biofilm infection in percentage of mucosal surface area of adenoids removed from children with otitis media with effusion (OME) vs those with recurrent acute otitis media (RAOM) and obstructive sleep apnea (OSA). Materials and methods Comparative microanatomical investigation of adenoid mucosa using scanning electron microscopy obtained from 30 children with OME, RAOM, and OSA was used in this study. Seventeen males and 13 females ranging in age from 9 months to 10 years were included in this study. Percentage of biofilm surface area involvement was the main measure. Results Adenoids removed from patients with OME had moderately dense mature biofilms covering the mucosal surface with a mean of 27.7% of their mucosal surface covered with mature biofilms. These results were distinct from results obtained from patients diagnosed with RAOM and OSA with means of 97.6% and 0.10% of their mucosal surfaces covered with mature biofilms, respectively. These differences were statistically significant at P Conclusions Adenoids removed from patients with OME were characterized by distinctly different percentage of biofilm mucosal surface area coverage, with significantly more biofilm presence than OSA patients but significantly less biofilm presence than RAOM patients. Although previous investigations have supported a dominant role of nasopharyngeal biofilms in RAOM pathogenesis, these results suggest nasopharyngeal biofilms may play a different role in the pathogenesis of OME and that this clinical entity may be more multifactorial in nature.
Herbivores on a dominant understory shrub increase local plant diversity in rain forest communities

Indirect effects of trophic interactions on biodiversity can be large and common, even in complex communities. Previous experiments with dominant understory Piper shrubs in a Costa Rican rain forest revealed that increases in herbivore densities on these shrubs caused widespread seedling mortality as a result of herbivores moving from Piper to seedlings of many different plant genera. We tested components of the Janzen-Connell hypothesis by conducting focused studies on the effects of specialist and generalist Piper herbivores on local seedling diversity. Whereas specialist herbivores are predicted to increase mortality to neighboring seedlings that are closely related to the source plant, true generalists moving from source plants may cause density-dependent mortality of many species, and possibly increase richness if new species replace abundant species that have been thinned by herbivores. Therefore, we hypothesized that seedling richness would be greater in understory control plots created in patches of Piper that had normal densities of generalist herbivores compared to plots from which we removed generalist herbivores manually from all Piper shrubs. After 15 months, generalist-herbivore-removal plots had >40% fewer seedlings, >40% fewer species, and 40% greater seedling evenness, on average, than control plots with generalist herbivores intact. Using a complementary approach in unmanipulated plots in four forests, we used path analysis to test for a positive association between seedling diversity and herbivore damage on Piper species. In unmanipulated plots, for both generalist and specialist herbivores, our data were significant fits to the causal model that Piper herbivores decrease evenness and increase plant species richness, corroborating the experimental results. Because herbivores changed how individuals were apportioned among the species and families present (lower evenness), one interpretation of these associations between herbivores on Piper shrubs and local seedling richness is that high seedling mortality in dominant families allowed the colonization or survival of less common species. If interspecific or apparent competition allowed for a relative increase in species richness, then the Janzen-Connell hypothesis may extend its predictions to generalist seedling predators. We speculate that apparent competition may explain some of the deviations from neutral model predictions, especially at small scales.
Characterization of Growth Defects in ZnTe Single Crystals

(111) wafers sliced from a boule of ZnTe grown by horizontal physical vapor transport (PVT) have been characterized using synchrotron white beam X-ray topography. The growth axis was about 6° off [311]. The presence of dislocation slip bands, subgrain structures and [111] axis 180° rotational twins were revealed. The slip bands were observed to break up the ordered dislocation cell structures comprising the subgrain boundaries. The initiation of slip at regions of stress concentration at the junctions of subgrain boundaries and twin boundaries was observed. The asymmetric distribution of slip bands either side of the twinned region of crystal suggests that twin boundaries can act as barriers for slip. Several types of detailed twin boundary configuration were determined from the topographs. Using a combination of white beam X-ray topography and Nomarski interference microscopy, the three dimensional shapes of the twin boundaries were determined. Approximate atomic structures at these boundaries are presented.
A commit protocol for checkpointing transactions

A commit protocol is described for checkpointing distributed transactions. Commit protocols are used by distributed transaction management systems to ensure that the multiple nodes participating in a distributed transaction will commit or abort together. This commit protocol is different from others in that a process executing on behalf of a transaction can be interrupted and restarted at some previous snapshot of its state (a checkpoint). The commit protocol guarantees that processes working on behalf of a distributed transaction will be consistent, which implies that the work performed by a restarted process between the time of the checkpoint and the time of the interruption will be undone automatically. The undoing includes any local state changes during that period of time, and any state changes in other processes due to communication with the restarted process in that period. The use of a commit protocol for recovery purposes allows normal execution to be resumed before recovery is completed. Recovery will be carried out in parallel, and the commit protocol guarantees that it is performed eventually. A novel approach of reusing portions of a transaction reduced lost work. >
Videoconferencing on the Internet

Videoconferences are becoming increasingly frequent on the Internet and are generating much research interest. Readily available software tools enable real-time audio and video channels as well as shared whiteboards that allow groups to collaborate on distributed group work more quickly and easily than ever. The paper considers how the Internet infrastructure is beginning to support videoconferencing applications in several ways. It particularly focuses on some of the problems experienced in the virtual classroom. >
Structure of GES-1 at atomic resolution: insights into the evolution of carbapenamase activity in the class A extended-spectrum beta-lactamases.

The structure of the class A extended-spectrum {beta}-lactamase GES-1 from Klebsiella pneumoniae has been determined to 1.1 Angstrom resolution. GES-1 has the characteristic active-site disulfide bond of the carbapenemase family of {beta}-lactamases and has a structure that is very similar to those of other known carbapenemases, including NMC-A, SME-1 and KPC-2. Most residues implicated in the catalytic mechanism of this class of enzyme are present in the GES-1 active site, including Ser70, which forms a covalent bond with the carbonyl C atom of the {beta}-lactam ring of the substrate during the formation of an acyl-enzyme intermediate, Glu166, which is implicated as both the acylation and deacylation base, and Lys73, which is also implicated as the acylation base. A water molecule crucial to catalysis is observed in an identical location as in other class A {beta}-lactamases, interacting with the side chains of Ser70 and Glu166. One important residue, Asn170, also normally a ligand for the hydrolytic water, is missing from the GES-1 active site. This residue is a glycine in GES-1 and the enzyme is unable to hydrolyze imipenem. This points to this residue as being critically important in the hydrolysis of this class of {beta}-lactam substrate. This is further supported more » by flexible-docking studies of imipenem with in silico-generated Gly170Asn and Gly170Ser mutant GES-1 enzymes designed to mimic the active sites of imipenem-hydrolyzing point mutants GES-2 and GES-5. « less
Analysis of branch prediction via data compression

Branch prediction is an important mechanism in modern microprocessor design. The focus of research in this area has been on designing new branch prediction schemes. In contrast, very few studies address the theoretical basis behind these prediction schemes. Knowing this theoretical basis helps us to evaluate how good a prediction scheme is and how much we can expect to improve its accuracy.In this paper, we apply techniques from data compression to establish a theoretical basis for branch prediction, and to illustrate alternatives for further improvement. To establish a theoretical basis, we first introduce a conceptual model to characterize each component in a branch prediction process. Then we show that current "two-level" or correlation based predictors are, in fact, simplifications of an optimal predictor in data compression, Prediction by Partial Matching (PPM).If the information provided to the predictor remains the same, it is unlikely that significant improvements can be expected (asymptotically) from two-level predictors, since PPM is optimal. However, there are a rich set of predictors available from data compression, several of which can still yield some improvement in cases where resources are limited. To illustrate this, we conduct trace-driven simulation running the Instruction Benchmark Suite and the SPEC CINT95 benchmarks. The results show that PPM can outperform a two-level predictor for modest sized branch target buffers.
Hepatic Microvascular Regulatory Mechanisms. II. Cholinergic Mechanisms

Several cholinergic agonists and their antagonists were administered topically at various concentrations (10−10 to 10−4 gm per ml) to the livers of anesthetized Sprague-Dawley rats. Changes in the microvasculature were measured for a period of 15 min using in vivo microscopic methods. The influence of cholinergic agonists on hepatic mast cells was determined by histochemical methods. Cholinergic agonists elicited constriction of portal venules, sinusoids, and terminal hepatic (central) venules accompanied within 5 to 20 sec by the adherence of platelets and leukocytes to the endothelial lining of these vessels. These responses were not observed in hepatic arterioles or hepatic (sublobular) venules. However, the responses drastically altered cellular flow through all segments of the microvasculature. The drugs were effective in the following ranking: bethanechol > pilocarpine > carbachol. Vascular responses were not antagonized by atropine; phentolamine modified the constrictor response of portal venules but of no other microvascular segment. These results suggest that the responses were not mediated by cholinergic (muscarinic) receptors and that the constriction of portal venules was caused by the chemical activation of a-adrenergic receptors. Histochemical methods revealed that pilocarpine and bethanechol also elicited a significant decrease in the number of visible mast cells suggestive of degranulation and the release of serotonin, histamine, and other polyanions (e.g., heparin) from these cells. Release occurred within the same period of time as the microvascular alterations (15 min). These data provide additional evidence that mast cell constituents and adrenergic mechanisms are involved in hepatic cholinergic mechanisms.
Almost-dominant Strategy Implementation

Though some economic environments provide allocation rules that are implementable in dominant strategies (strategy-proof), a signicant number of environments yield impossibility results. On the other hand, while there are quite general possibility results regarding implementation in Nash or Bayesian equilibrium, these equilibrium concepts make strong assumptions about the knowledge that players possess, or about the way they deal with uncertainty. As a compromise between these two notions, we propose a solution concept built on one premise: Players who do not have much to gain by manipulating an allocation rule will not bother to manipulate it. We search for ecient allocation rules for 2-agent exchange economies that never provide players with large gains from cheating. Though we show that such rules are very inequitable, we also show that some such rules are signicantly more flexible than those that satisfy the stronger condition of strategy-proofness.
Status Inconsistency and Drinking Patterns among Working Men and Women

Previous research suggests that status inconsistents constitute a social category that is vulnerable to embarrassments and disappointments, since individuals who are of high status on one dimension and low status on another tend to respond to themselves in terms of the higher status, while other people tend to respond to them in terms of the lower one. This article extends this research to patterns of alcohol consumption and finds that status and status inconsistency are significantly associated with frequency of consumption and quantity consumed per occasion among certain groups of drinkers.
Variable neural adaptive robust observer for uncertain systems

The design of variable neural adaptive robust observer is proposed for the state estimation of a class of uncertain systems. The proposed observer incorporates a variable-structure radial basis function (RBF) network to approximate unknown system dynamics. The RBF network can determine its structure on-line dynamically by adding or removing RBFs. The observer gain matrix is obtained by solving an optimization problem subject to linear matrix inequalities. The structure variation of the RBF network is taken into account in the stability analysis through the use of the piecewise quadratic Lyapunov function. The effectiveness of the proposed observer is illustrated with a simulation example.