cssi/SciSciGPT-SciSciNet huggingface dataset:
Comprehensive Functional Analysis of Mycobacterium tuberculosis Toxin-Antitoxin Systems: Implications for Pathogenesis, Stress Responses, and Evolution

Toxin-antitoxin (TA) systems, stress-responsive genetic elements ubiquitous in microbial genomes, are unusually abundant in the major human pathogen Mycobacterium tuberculosis. Why M. tuberculosis has so many TA systems and what role they play in the unique biology of the pathogen is unknown. To address these questions, we have taken a comprehensive approach to identify and functionally characterize all the TA systems encoded in the M. tuberculosis genome. Here we show that 88 putative TA system candidates are present in M. tuberculosis, considerably more than previously thought. Comparative genomic analysis revealed that the vast majority of these systems are conserved in the M. tuberculosis complex (MTBC), but largely absent from other mycobacteria, including close relatives of M. tuberculosis. We found that many of the M. tuberculosis TA systems are located within discernable genomic islands and were thus likely acquired recently via horizontal gene transfer. We discovered a novel TA system located in the core genome that is conserved across the genus, suggesting that it may fulfill a role common to all mycobacteria. By expressing each of the putative TA systems in M. smegmatis, we demonstrate that 30 encode a functional toxin and its cognate antitoxin. We show that the toxins of the largest family of TA systems, VapBC, act by inhibiting translation via mRNA cleavage. Expression profiling demonstrated that four systems are specifically activated during stresses likely encountered in vivo, including hypoxia and phagocytosis by macrophages. The expansion and maintenance of TA genes in the MTBC, coupled with the finding that a subset is transcriptionally activated by stress, suggests that TA systems are important for M. tuberculosis pathogenesis.
An evaluation of pre- and postoperative nonsteroidal antiinflammatory drugs in patients undergoing knee arthroscopy. A prospective, randomized, double-blinded study.

The potential benefits of a nonsteroidal antiinflamma tory drug to 67 patients undergoing knee arthroscopy were evaluated in a prospective, randomized, placebo- controlled, double-blinded study. Group A received the drug (diclofenac, 75 mg twice daily) for 3 to 5 days before and for 7 days after surgery. Group B received a placebo preoperatively and the drug postoperatively. Group C received a placebo at both times. Codeine was available postoperatively for all patients if needed. Outcomes reported by the subjects included pain, crutch use, and return to activities. Outcomes assessed by physicians included knee effusion, range of motion, and gait. Knee flexion and extension strengths were measured isokinetically pre- and postoperatively.Pain scores on the 1 st postoperative day were higher in Group C than in Group A. Pain scores at all other time points were not significantly different in the three treatment groups. Groups A and B required less co deine during the first 72 hours after surgery than Group C...
The kinetics of sickle blood viscosity changes following rapid deoxygenation and reoxygenation.

Abstract A technique is described in which alterations in sickle blood viscosity can be measured following rapid oxygenation or deoxygenation. The results for two SS blood samples and one SC sample indicate that no measurable rheological changes occur for 21 to 33 sec after partial deoxygenation. Viscosity changes following reoxygenation were too rapid to be accurately measured with this technique. Possible evidence that oxygen exchange may be impaired in sickle cells is also presented. The results suggest that sickle cell crisis may be initiated when the sickling delay time, following exposure to low oxygen tension, becomes shorter than the time required for most cells to return to the lungs, rather than the time needed to traverse a systemic capillary.
Recognizing the potential for violence in the ICU.

Violence in health care institutions, specifically critical care units, throughout the country is increasing at an alarming rate. This problem is not confined to the urban areas but also encompasses rural regions. This article assists the nurse in identifying the potential for violence by patients, family, or visitors while they are in the critical care unit. The author describes strategies that have been successful in controlling violence in the ICU and suggests steps nurse educators and managers can take to reduce the risk of violence in their units. The article is followed by Education STATPack material that can be used by current subscribers for an inservice. Language: en
Too Close for Comfort: Real-Time Science Teaching Reflections via Digital Video Editing

This study examined the use of digital video editing as the main venue for fostering reflection. The impact of digital video editing technology on preservice teachers' beliefs included shifts in (a) reflections regarding children's thinking, (b) planning and instruction informed by reflection, and (c) notions of teaching expertise and requisite knowledge. Results were based on an instructional approach emphasizing the exploration of preservice teachers' own planning and teaching as they edited their own video accounts. These findings contrast typical video usage in teacher preparation in which teachers reflect upon the practice of others. Implications for teacher education programs and future research are discussed.
Human Placental 17β-Estradiol Dehydrogenase. VI. Substrate Specificity of the Diphosphopyridine Nucleotide (Triphosphopyridine Nucleotide)-Linked Enzyme1

The substrate specificity of pure D(T)PN-linked 17β-estradiol dehydrogenase of human placenta was examined and shown to differ in several aspects from the results previously obtained with less pure preparations. The enzyme, in addition to having an absolute stereospecificity for the 17β-hydroxy group, appears also to have an absolute requirement for an aromatic ring A. Three non-aromatic steroids (testosterone, 19-nortestosterone and 20α-hydroxypregn- 4-en-3-one) previously reported to be substrates for 17β-estradiol dehydrogenase were not oxidized by the pure enzyme with either DPN or TPN as cofactors. Diethylstilbestrol, estriol, 17α-estradiol and 17β-hydroxy-4,4,17α-trimethyl- 3-oxoandrost-5-ene-2α-nitrile are weak inhibitors of 17β-estradiol dehydrogenase. (Endocrinology 88: 1165, 1971)
Analysis of craniofacial asymmetry by multiplane cephalometry.

Abstract A three-dimensional, multiplane cephalometric analysis is presented. This analysis permits visualization of skeletal midlines at selected depths of the craniofacial complex. When the midlines and associated anatomic structures are studied sequentially, the individual midlines may be combined conceptually into a warped midsagittal “plane.” This localizes craniofacial asymmetry in the posteroanterior and basilar views. The study of structures in various coronal and transverse planes makes it possible to measure and record the three-dimensional relationships of anatomic structures to one another. A case of hemicraniofacial microsomia in which this analysis was used is presented.
Primary Structures of Human Pituitary Growth Hormone and Sheep Pituitary Lactogenic Hormone Compared

The primary structures of human pituitary growth hormone and sheep pituitary lactogenic hormone have been compared with regard to similarities in their sequence. Three homologous segments in each molecule, comprising approximately 45 percent of either peptide chain, have been found. These two proteins have apparently evolved from a common ancestor molecule.
Consumption of introduced prey by native predators: Argentine ants and pit-building ant lions

When populations of native predators are subsidized by numerically dominant introduced species, the structure of food webs can be greatly altered. Surprisingly little is known, however, about the general factors that influence whether or not native predators consume introduced species. To learn more about this issue, we examined how native pit-building ant lions (Myrmeleon) are affected by Argentine ant (Linepithema humile) invasions in coastal southern California. Compared to areas without L. humile, invaded areas contained few native ant species and were deficient in medium-sized and large bodied native ants. Based on these differences, we predicted that Argentine ants would negatively affect ant lion larvae. Contrary to this expectation, observational surveys and laboratory growth rate experiments revealed that Myrmeleon were heavier, had longer mandibles, and grew more quickly when their main ant prey were Argentine ants rather than native ants. Moreover, a field transplant experiment indicated that growth rates and pupal weights were not statistically different for larval ant lions reared in invaded areas compared to those reared in uninvaded areas. Argentine ants were also highly susceptible to capture by larval Myrmeleon. The species-level traits that presumably make Argentine ant workers susceptible to capture by larval ant lions—small size and high activity levels—appear to be the same characteristics that make them unsuitable prey for vertebrate predators, such as horned lizards. These results underscore the difficulties in predicting whether or not numerically dominant introduced species serve as prey for native predators.
Effects of Modeling and Tempo Patterns as Practice Techniques on the Performance of High School Instrumentalists.

The purpose of this study was to examine the effect of modeling conditions and tempo patterns on the performance of high school instrumentalists. The independent variables of this study were (a) model versus no model and (b) steady increase of tempo versus performance speed tempo versus alternating (slower and faster) tempos. Subjects (N = 60) were high school wind instrumentalists from the American Midwest and South. Subjects sight-read an etude and then practiced the same etude six times using one of six practice conditions that combined the two independent variables. Subjects then performed a posttest on the same etude. Dependent measures were pretest-posttest gain score comparisons (as percentages) of correct pitches and rhythms as well as overall percentages of tempo gains. Results demonstrated the with-model condition to be superior to the no-model condition in rhythm percentage gain and tempo percentage gain. Tempo patterns had no significant effect on results.
Early RNA Folding Events During Assembly of the Signal Recognition Particle Monitored by Diffusion Single-Pair FRET

The Signal Recognition Particle (SRP) mediates the co-translational targeting of proteins destined for the secretory pathway. The particle recognizes a signal peptide as it emerges from the ribosome, temporarily halts translation and mediates docking of the SRP-ribosome-nascent chain complex to a membrane-bound SRP receptor. SRP consists of 7SL RNA and 6 SRP proteins. The ribonucleoprotein can be divided into two functional domains, the Alu domain and S domain. The last decade has yielded a significant amount of structural data on both of the SRP domains. However, dynamic information on the assembly and function of the SRP is lacking.Here we present a diffusion single-pair FRET study to directly monitor early RNA folding events during SRP assembly. We investigated the detailed folding behavior of the Alu and S domain three-way junctions under the influence of both salt and SRP proteins. The Alu domain folds completely upon addition of either Mg-ions or the SRP9/14 heterodimer. This behavior indicates autonomous folding of the Alu RNA, with SRP9/14 acting only as cofactor to stabilize the folded RNA structure. In contrast, the S domain RNA folds only in the presence of the SRP19 protein, thus representing an example of protein-assisted folding. Hence, our studies of SRP assembly have provided examples of two basic mechanisms of RNA folding. Future studies will probe later folding events and the overall SRP assembly process.
Worldwide Vertical Guidance of Aircraft Based on Modernized GPS and New Integrity Augmentations

In the 2020 time frame, the Global Positioning System (GPS) will be fully modernized, and other satellite navigation systems will be operational. With an additional layer of fault detection, these systems will provide vertical guidance worldwide. This capability will be born of three important technologies. First and foremost, avionics will receive signals on two frequencies: L1/E1 and L5/E5a. This frequency diversity will do much to obviate the impact of ionospheric storms that troubles aviation use of GPS today. Secondly, a multiplicity of data broadcasts will be available to convey integrity information from the ground to the airborne users. These will include the navigation satellites themselves, geostationary satellites, and possibly terrestrial transmitters. However, the most important change will be the most subtle. The fault monitoring burden will be split between the aircraft and the supporting ground systems in a new way relative to the fault-detection techniques used in 2008. This new integrity allocation and the associated architectures are the subject of this paper.
A new solution to an old problem

Although a personal god of mixed moral character is logically possible, no personal god that has been represented as less than wholly good has gained more than a strictly local appeal. The Judaeo-Christian god is no exception. The god is represented as merciful, kind, longsuffering, forgiving, loving - in a word, wholly good. Of course, representing a god as wholly good is one thing; providing a convincing defence of his goodness is quite another. Indeed, many would contend that of all the defences provided within the Judaeo-Christian system, the defence of the goodness of God is the least convincing.
Elastic stability of a simply supported plate under linearly variable compressive stresses.

It should be pointed out that, in this analysis, only the linear one-parameter group was employed. However, a similar analysis by a spiral group, defined in Hansen, has led to the same result; that is, the form of the body force has limited the number of similarity solutions. Thus, it appears that the boundary condition of an isothermal wall must be used if a similarity transformation is to be found for simultaneous heat and mass transfer in free convection.
Must the Advance of Science Advance Global Inequality

One long cited rationale for doing and funding Western modern sciences has been that such research advances social welfare in egalitarian ways. Yet the long service of these sciences to militarism, nationalisms, profit–maximizing, and the desire for social control would seem to provide compelling evidence, at least in the contemporary era, against the happy relation imagined in this rationale. This essay reviews the older utopian and dystopian responses to the title question, and examines their assumptions about the nature of science which no longer are empirically or theoretically justifiable. It then identifies themes in recent empirical and theoretical work which point the way to a more realistic understanding of the kind of philosophy of science necessary to contribute to sciences in the service of social justice. Philosophies of science, like the sciences on which they reflect, always participate in larger social discourses.
Guided ion beam and theoretical study of the reactions of Os+ with H2, D2, and HD.

Reactions of the third-row transition metal cation Os+ with H2, D2, and HD to form OsH+ (OsD+) were studied using a guided ion beam tandem mass spectrometer. A flow tube ion source produces Os+ in its 6D (6s15d6) electronic ground state level. Corresponding state-specific reaction cross sections are obtained. The kinetic energy dependences of the cross sections for the endothermic formation of OsH+ and OsD+ are analyzed to give a 0 K bond dissociation energy of D0(Os+–H) = 2.45 ± 0.10 eV. Quantum chemical calculations are performed here at several levels of theory, with B3LYP approaches generally overestimating the experimental bond energy whereas results obtained using BHLYP and CCSD(T), coupled-cluster with single, double, and perturbative triple excitations, levels show good agreement. Theory also provides the electronic structures of these species and the potential energy surfaces for reaction. Results from the reactions with HD provide insight into the reaction mechanism and indicate that Os+ reacts ...
Spectral and directional thermal radiation characteristics of selective sufaces for solar collectors

Abstract Surface systems suitable for collectors of solar heat energy are examined. Spectral radiation characteristics of metallic substrates coated with semiconductor and antireflection layers are considered. Directional spectral reflectances of several surface coatings are presented and evaluated. Commercial chemical dip treatments of copper and steel are shown to give selective characteristics desirable for low temperature collectors such as solar water heaters.
The reproducibility of ethnic differences in the proportional awake–sleep blood pressure decline among women

A growing body of evidence indicates that African Americans (AA), on average, have a smaller proportional decline in blood pressure (BP) from waking to sleep than European Americans (EA), but this difference is largely based on correlational data from a single assessment day. The persistence of this difference over repeated sampling is not well established. The purpose of this study was to evaluate whether ethnic differences in the awake-sleep BP decline between AA and EA persisted over three monthly assessments. The subjects were 47 AA (age = 39.7 +/- 8.7) and 92 EA (age = 37.4 +/- 9.2) normotensive women. Subjects had 24-h ambulatory BP monitoring done on midweek workdays at 1-month intervals for three consecutive months. The proportional decline in BP was calculated as follows: (average awake - average sleep)/average sleep. The persistence of ethnic differences was evaluated using repeated-measures ANCOVA and by examining Bland-Altman plots. The ANCOVA results revealed that overall, the proportional decline of AA women was less than that of EA women for both SBP (P < 0.038) and DBP (P < 0.083), consistent with previous research, and that there were also no significant ethnic differences by monthly assessment. Bland-Altman plots revealed that overall and by ethnicity, the proportional decline in BP among individual subjects over the 3 months was also reproducible. These results suggest that the ethnic difference in awake-sleep BP between AA and EA women persists over time and that the awake-sleep decline in BP among individuals, whether AA or EA, is also reproducible.
Of Athenians and Spartans: Profiles of freedom and enlightenment in the leadership styles of criminal justice academic administrators: An essay

Abstract This essay examines the dubious relationship between the quality of criminal justice education and the kind of treatment faculty members and students receive from their academic administrators. It is based on three premises: criminal justice colleges and departments should be held to higher rational and moral standards not because they are qualitatively different from other liberal arts departments, but because they teach justice; if the virtues of criminal justice are worth teaching, then criminal justice faculty members and students should be treated in a manner consistent with these virtues; and treating criminal justice faculty members and students unfairly, disrespectfully, or irresponsibly makes them unable or disinterested in endorsing the noble nature of criminal justice. This article categorizes academic administrators as either Athenians or Spartans. The former are best suited intellectually and temperamentally to administer because they possess a talent for reasoning and act in good faith. The latter are unsuited because, regardless of how well they mask it, they practice domination, deception, favoritism, and indignity. This essay is a theoretical discourse based on the contiguity of modalities, experiences, and impressions generally shared by criminal justice educators and graduate students. Its logic is Humeian and its method is broadly ethnographic.
Biosynthesis of glycosaminoglycans in the developing retina.

Abstract The glycosaminoglycans of neural retinas from 5-, 7-, 10-, and 14-day chick embryos were labeled in culture with [3H]glucosamine and 35SO4, extracted, and isolated by gel filtration. The incorporation of label per retina into glycosaminoglycans increased with embryonic age, but that per cell and per unit weight of uronic acid decreased. Specific enzyme methods coupled with gel filtration and paper chromatography demonstrated that [3H]glucosamine incorporation into chondroitin sulfate increased between 5 and 14 days from 7 to 34% of the total incorporation into glycosaminoglycans. During this period, incorporation into chondroitin-4-sulfate increased relative to that into chondroitin-6-sulfate. Between 5 and 10 days, incorporation into heparan sulfate showed a relative decline from 89 to 61%. Incorporation into hyaluronic acid always represented less than 2% of the total. A twofold greater increase in galactosamine concentration than in glucosamine concentration in the glycosaminoglycan fraction between 7 and 14 days supports the conclusion that chondroitin sulfate was the most rapidly accumulating glycosaminoglycan. ECTEOLA-cellulose chromatography revealed a heterogeneity in the size and/or net charge of chondroitin sulfate and heparan sulfate. We conclude that incorporation of exogenous precursors into glycosaminoglycans in the chick retina decreases relative to cell number as differentiation progresses from a period of high mitotic activity to one of tissue specialization, and that it is accompanied by a net accumulation of glycosaminoglycan and a change in the pattern of its synthesis.
Participatory Research Mapping of Indigenous Lands in Darién, Panama

This article describes a participatory research mapping (PRM) project to document the subsistence lands used by the indigenous populations of the Darien Province, eastern Panama. The region is the historic territory of the Kuna, Embera, and Wounaan peoples, with a biosphere reserve, two indigenous comarca homelands, and one of the most active colonization fronts in Central America. Having fought for recognition of their land rights in the face of encroaching outsiders, indigenous leaders were well aware of the power and importance of cartographic information. Indeed, the Darien was the most inaccurately mapped province in the country, and indigenous leaders embraced the idea of a mapping project to document their expanding settlements and natural resources. Community representatives were trained to complete land-use assessments using questionnaires and sketch maps. They worked with a team of specialists, including the author, to transform this information into standard cartographic and demographic results. The project's simple design brought outstanding results, including the first large-scale mapping of indigenous lands in this little-known region. The methodology shows how indigenous peoples can work with researchers in data collection and interpretation to transform their cognitive knowledge into standard forms, producing excellent scientific and applied results while enhancing their ability to manage their own lands.
On Augmenting Community Economic Performance by New or Continuing Irrigation Developments

Having been asked to present a paper at this meeting on the above topic reflects the continuing existence of an unresolved issue among agricultural economists: the nature and extent of regional development impacts of irrigation developments. We do not want to foster the expectation that our paper will resolve this problem. Instead, we shall attempt to sort out some of the major policy issues involved, classify relevant empirical studies on this subject, and make some suggestions for research approaches in this area. The concern for this issue is old and relates
Statistical analysis of large on-chip power grid networks by variational reduction scheme

One of the most critical challenges in today's CMOS VLSI design is the lack of predictability in chip performance at design stage. One of the process variabilities comes from the voltage drop variations in on-chip power distribution networks. In this paper, we present a novel analysis approach for computing voltage drops of large power grid networks under process variations. The new algorithm is very efficient and scalable for huge networks with a large number of variational variables. This approach, called variational extended truncated balanced realization (varETBR), is based on model order reduction techniques to reduce the circuit matrices before the variational simulation. It performs the parameterized reduction on the original system using variation-bearing subspaces. After the reduction, Monte Carlo based statistical simulation is performed on the reduced system and the statistical responses of the original system are obtained thereafter. varETBR calculates variational response Grammians by Monte Carlo based numerical integration considering both system and input source variations in generating the projection subspace. varETBR is very scalable for the number of variables and flexible for different variational distributions and ranges as demonstrated in experimental results. Experimental results, on a number of IBM benchmark circuits up to 1.6 million nodes, show that the varETBR can be 1900X faster than the Monte Carlo method and is much more scalable than one of the recently proposed approaches.
Treatment of Recurrent Corneal Erosion and Corneal Edema with Topical Osmotic Colloidal Solution

Ten patients with recurrent corneal erosion unresponsive to conventional therapy were treated with a topical colloidal solution to obtain epithelial dehydration and lubrication. Nine of the ten patients responded with improved vision and resolution of symptoms. All erosions healed and focal epithelial abnormalities were decreased or reversed. Similar treatment of ten patients with corneal edema due to endothelial decompensation did not significantly reduce symptoms or improve vision, but such a solution may have significant dehydrating effect when edema results solely from epithelial abnormalities. Pachometric studies of the cornea demonstrated no significant change in stromal thickness during therapy. Colloidal hyperosmotic solutions are well tolerated and appear effective in treating recurrent corneal erosion.
First Report of Leaf Spot Caused by Bipolaris spicifera on Switchgrass in the United States

Light-to-dark brown leaf spots and general chlorosis were observed on ‘Alamo’ switchgrass (Panicum virgatum L.) grown in ornamental plantings on the campus of the University of Tennessee in Knoxville in December 2007. Disease distribution was patchy, infecting ~10% of plants. Patches had mild to severely infected plants with stunting in areas of severe infection. Symptomatic leaf tissue was surface sterilized, air dried on sterile filter paper, and plated on 2% water agar amended with 10 mg/liter of rifampicin (Sigma-Aldrich, St. Louis, MO) and 10 μl/liter of 2.4 EC Danitol miticide (Valent Chemical, Walnut Creek, CA). Plates were incubated at 26°C in darkness for 5 days. A sporulating, dematiaceous mitosporic fungus was observed and transferred to potato dextrose agar (PDA). Conidiophores were single, light brown, multiseptate, mostly straight, polytretic, geniculate, and sympodial. Conidia were 17.5 × 12 (22) to 30 × 14 (12.5) μm, oval, light brown, and distoseptate, with one to three septa and a flatte...
The Paradox of Beta-Adrenergic Blockade in Hypertension

The effects of long-term treatment with propranolol, a beta-adrenergic blocking drug, were determined in 19 hypertensive patients (five with renal arterial disease, two with renal parenchymal disease, and 12 with essential hypertension) whose vascular disease was of mild to moderate severity. The drug reduced arterial pressure in 16 patients during 32 weeks of treatment (average); daily dose was 180 mg (average). No side effects required discontinuance of treatment. Orthostatic hypotension did not occur, an unusual finding for an antihypertensive drug which acts to inhibit autonomic neural function. In seven patients, hemodynamic studies, performed during treatment (after 10 months, average), confirmed reduction of arterial pressure and heart rate, and demonstrated associated diminution of cardiac output and increased peripheral resistance.
Is there a flexiglass ceiling? Flexible work arrangements and wages in the United States

Abstract Employment contracts that offer employees flexibility in their work schedules or locations are often touted as politically and economically viable solutions to contemporary employees' needs to balance work, leisure, and family. However, little is known about their career consequences or their impact on aggregate levels of gender inequality in labor market outcomes. This paper outlines possible sources of an association between flexible work and wages, then quantifies this association using data from the 2000 and 2001 Current Population Surveys (CPS). Results indicate that flexible-work employees earn wages that are at least equal to, and often higher than, their fixed-schedule and fixed-location counterparts. These wage premiums are greater in nonmanual occupations, but do not vary substantially by gender or parental status. The results contradict the notion of a “flexiglass ceiling” in wages, but also suggest that flexible work arrangements do little to reduce the gender gap in pay or the motherhood wage penalty.
Proximate composition and distribution of radioactive label in laboratory cultured Spartina alterniflora Loisel

Abstract Spartina alterniflora Loisel was grown hydroponically in a 14 CO 2 atmosphere of constant specific activity. Plant material from this experiment (50–126 μCi·g C −1 ) closely approximated the specific activity of the [ 14 C]BaCO 3 used to produce the 14 CO 2 atmosphere. In contrast, the specific activity of material grown previously in the same culture apparatus, but in an organically enriched substrate using transplants, only achieved up to 17% (13–24 μCi·g C −1 ) of the specific activity of [ 14 C]BaCO 3 used for that experiment. Hydroponically grown seedlings had a lower percentage of cell wall constituents in the leaves and, with the exception of the green leaves, had a lower lignin content than transplants grown in organically enriched soil. Hydroponic growth increased and improved the consistency of the specific activity of the labeled product but altered the structural composition relative to transplants and plants from natural Spartina marshes.
Euclidean Geometry and Minkowskian Chronometry

The term “Minkowskian Chronometry” is used here for the study of the structure of space-time appropriate to Einstein’s special relativity. This term suggests a parallel with Euclidean geometry. Originally, geometry was an empirical science which dealt with measuring of distances on earth. The Greeks transformed this science into a beautiful mathematical discipline. Chronometry is the science of the measurement of time intervals. Einstein’s first paper was a critical study of time measurements. It was Minkowski, however, who made a geometrical discipline out of Einstein’s chronometry. More recently, Synge ([2], [3]) has been an able advocate of the geometrical point of view in relativity.
Rap1, a small GTP-binding protein is upregulated during arrest of proliferation in human keratinocytes.

Rap1 is a small GTP-binding protein (SMG) that exists in two 95% homologous isoforms, rap1A and rap1B. The functions of the rap1 proteins are not well understood. In this report we examined expression and function of rap1 in primary (HOKs) and immortalized (IHOKs) human oral keratinocytes under different growth conditions. In HOKs, rap1 increased with passage number, suggesting a role in differentiation and arrest of proliferation. Similarly, when inhibition of proliferation and differentiation were induced in HOKs by 1.2 mM CaCl2, both rap1 and involucrin increased with increasing concentrations of CaCl2. However, when similar experiments were done with IHOKs, which continue to proliferate in the presence of 1.2 mM CaCl2, the increase in involucrin expression was similar to HOKs but there was no substantial increase in rap1, suggesting that increased expression of rap1 is linked to inhibition of proliferation rather than differentiation of keratinocytes. Upon transfection of immortalized keratinocytes with rapGAP, which inactivates both isoforms of endogenous active rap1, enhanced proliferation was observed. Thus, we conclude that rap1 inhibits proliferation in keratinocytes.
Purification and characterization of wheat α-gliadin synthesized in the yeast, Saccharomyces cerevisiae

Abstract The development of efficient methods for production and purification of plant seed storage proteins in heterologous microbial hosts would facilitate structure-function studies of these proteins. This report describes such methods applied to the production and isolation of wheat α-gliadin, a prolamine-type seed storage protein, from Saccharomyces cerevisiae . Beginning with the vector, growth conditions, and extraction methods of Neill et al. [Gene 55 (1987) 303–317], we implemented several improvements to increase the yields of α-gliadin per volume of yeast cell culture. The CYC1::Gli-A2 -Y transcriptional fusion vector, pAY31 (Neill et al., 1987), was modified by replacing the ARS1 region of replication with that of the 2 μ plasmid of yeast. We formulated a new medium, a derivative of synthetic defined (SD) medium supplemented with several nitrogen sources, that allows both selection for maintenance of plasmids and growth to high cell densities. Stationary phase cultures of cells bearing the modified expression vector, and grown in this medium with glycerol and lactate as carbon sources, contain significantly higher levels of α-gliadin than log-phase cultures grown in SD glucose. Sonication in 80% ethanol selectively and efficiently extracts the α-gliadin from cell pellets of small- or large-scale cultures, allowing the purification of several hundred μg of the wheat protein per liter injust a few high-yield steps. The α-gliadin isolated from yeast elutes at the same position in HPLC as the A-gliadin fraction purified from wheat flour. N-terminal amino acid (aa) sequencing reveals that the signal peptide is removed from the gliadin precursor in yeast cells. About two-thirds of the molecules have the same N terminus as A-gliadin made in wheat endosperm cells. The remaining third of the α-gliadin is apparently cleaved at a similar processing site three aa closer to the N terminus of the prepeptide.
Effect of K2SO4 and CaSO4 Dihydrate Solutions on Crystallization and Strength of Gypsum

Crystal formations obtained from evaporating clear filtrates of dental stone mixed with various solutions were examined with an optical and scanning electron microscope. It was found that when K2SO4 was present in any concentration, a spherulitic structure dissimilar to that of CaSO4 2H2O and K2SO4 was dominant. It is concluded that syngenite (a complex compound of CaS04 and K2SO4) forms at the center of the nuclei of crystallization and is responsible for spherulitic formation. The use of K2SO4 solution and saturated CaSO 4 solution was also found to improve the strength both at one and 24 h.
A canine model of paired graft thrombosis

A novel canine model for reliably producing graft thrombosis is described. Two unilateral aortoiliac bypasses are performed while preserving the integrity of the native vascular tree. These grafts are briefly mechanically occluded at the time of the initial operation, and they remain occluded postoperatively because flow is preferentially directed through the larger-caliber, thrombo-resistant native circulation. Percutaneous temporary intra-arterial balloon occlusion of the native vessels redirects flow into the occluded graft segments, which can be used in experimental protocols. This new model for studying graft thrombosis requires only a single, simple operative procedure, and easily allows secondary percutaneous graft manipulation.
The relationship of social support to physically abused children's adjustment

Abstract Objective: This study had three main objectives: First, to assess physically abused children’s perceptions of teacher, peer, and family support; second, to determine whether the levels of perceived support differ according to the person’s social role; and third to assess which sources of social support show stronger associations with adjustment in a physically abused sample. Method: Perceived social support from teachers, families and peers was assessed in a sample of 37 physically abused children using a shortened version of the Survey of Children’s Social Support (Dubow & Ullman, 1989) . Child adjustment was indexed by child and parent reports of child depression, anxiety, and anger. Results: Analyses indicated that the children rated their families, peers, and teachers highly as sources of social support, with families being rated as the most important source. Hierarchical multiple regression analyses indicated that perceived peer support was significantly negatively related to children’s and parent’s reports of children’s depression and anxiety. Furthermore, perceived family support was significantly negatively associated with child reported depression. No significant relationships were found between perceived teacher support and symptomatology. Conclusions: Overall, the results suggest that peer and family support are particularly important for physically abused children’s psychological functioning, particularly for internalizing problems.
Observation of Electroluminescence and Photovoltaic Response in Ionic Junctions

Electronic devices primarily use electronic rather than ionic charge carriers. Using soft-contact lamination, we fabricated ionic junctions between two organic semiconductors with mobile anions and cations, respectively. Mobile ionic charge was successfully deployed to control the direction of electronic current flow in semiconductor devices. As a result, these devices showed electroluminescence under forward bias and a photovoltage upon illumination with visible light. Thus, ionic charge carriers can enhance the performance of existing electronic devices, as well as enable new functionalities.
Ovarian tumor expression is dependent on the functions of the somatic sex regulatory genes transformer-2 and doublesex.

Abstract The doublesex -dependent sex regulatory pathway in Drosophila controls major aspects of somatic sexual differentiation, but its expression is not required in the X / X germline. Nevertheless, mutations in doublesex and in the genes that directly regulate its expression, transformer and transformer-2 , disrupt early stages of oogenic differentiation to produce gonads containing immature germ cells. This indicates a critical, but uncharacterized, set of soma–germline interactions essential for oogenesis. In this paper, we examined the effects of mutations in transformer-2 on the expression and function of the germline-specific ovarian tumor gene. We demonstrated that in transformer-2 mutants, there was a marked reduction in the activity of the ovarian tumor promoter in the mutant germline. In addition, the phenotypic effects on the arrested germline could be partially suppressed by the simultaneous over-expression of both ovarian tumor and a second germline gene, Sex-lethal . This differs from transformer mutations, in which the over-expression of ovarian tumor alone is sufficient for a similar improvement in germline differentiation. In contrast to transformer-2 , doublesex activity was not required for ovarian tumor promoter activity and we found indirect evidence that the doublesex male-specific function might have a negative regulatory effect. These data indicate that the components of the genetic pathway regulating somatic sexual differentiation have specific and differential effects on germline gene activity.
Demographic Uncertainty and Welfare in a Life-cycle Model under Alternative Public Pension Systems

In this paper, I analyze consumption, aggregate savings,output and welfare implications of …ve dierent social security arragements whenever there is demographic uncertanity. Following Bohn(2002), I analyze the eect of an uncetain population growth in an extended version of a modi…ed Life-cycle model developed by Gertler(1999). Population growth dampens savings and output under all arrangements. Pay-as-you-go-De…ned Bene…t system appears to fare better than all other alternatives, falling short of the private annuity market with no pension system. But social security in general increases social welfare, with Fully Funded systems faring the best. Thus there appears to be a clear tradeobewteen growth and social welfare. The social security system also reduces the volatility of the economy.
Spectral encoding enhances visual flexibility of surgical endoscopes

Endoscope cameras play an important and growing role as a diagnostic and surgical tool. The endoscope camera is usually used to provide a view of the scene straight ahead of the instrument to the operator. As is common in many remotely operated systems, the limited field of view and the inability to pan the camera make it challenging to gain a situational awareness comparable to an operator with direct access to the scene. We present a spectral multiplexing technique for endoscopes that allows for overlay of the existing forward view with additional views at different angles to increase the effective field of view of the device. Our goal is to provide peripheral vision while minimally affecting the design and forward image quality of existing systems.
The Risk and Return from Factors

The ability to identify which factors best capture systematic return covariation is central to applications of multifactor pricing models. This paper uses a common data set to evaluate the performance of various proposed factors in capturing return comovements. Factors associated with the market, size, past return, book-to-market and dividend yield help explain return comovement on an out-of-sample basis (although they are not necessarily associated with large premiums in average returns). Except for the default premium and the term premium, macroeconomic factors perform poorly. We document regularities in the behavior of the more important factors, and confirm their influence in the Japanese and U.K. markets as well.
Depression Symptoms Associated with Cannabis Dependence in an Adolescent American Indian Community Sample

Background Depression and substance use disorders, including cannabis dependence, arise during adolescence, are frequently co-morbid, and represent major health burdens in the general U.S. population. Yet little is known about the association of depression symptoms with cannabis and other substance use and use disorders in Native American adolescents.
The chemical component dictionary: complete descriptions of constituent molecules in experimentally determined 3D macromolecules in the Protein Data Bank

Summary: The Chemical Component Dictionary (CCD) is a chemical reference data resource that describes all residue and small molecule components found in Protein Data Bank (PDB) entries. The CCD contains detailed chemical descriptions for standard and modified amino acids/nucleotides, small molecule ligands and solvent molecules. Each chemical definition includes descriptions of chemical properties such as stereochemical assignments, chemical descriptors, systematic chemical names and idealized coordinates. The content, preparation, validation and distribution of this CCD chemical reference dataset are described. Availability and implementation: The CCD is updated regularly in conjunction with the scheduled weekly release of new PDB structure data. The CCD and amino acid variant reference datasets are hosted in the public PDB ftp repository at ftp://ftp.wwpdb.org/pub/pdb/data/monomers/components.cif.gz, ftp://ftp.wwpdb.org/pub/pdb/data/monomers/aa-variants-v1.cif.gz, and its mirror sites, and can be accessed from http://wwpdb.org. Contact: ude.sregtur.bscr@tsewj. Supplementary information: Supplementary data are available at Bioinformatics online.
An analog VLSI model of muscle sarcomeres

We have developed analog VLSI circuits to model the behavior demonstrated by biological sarcomeres, the force generating components of muscle tissue. The circuits are based upon the mathematical description of crossbridge populations developed by A.F. Huxley. We have implemented the sarcomere circuit using a standard 1.2 /spl mu/ process, and have demonstrated transient and steady-state behaviors experimentally.
Catalytic antibodies to HIV: Physiological role and potential clinical utility

Immunoglobulins (Igs) in uninfected humans recognize residues 421–433 located in the B cell superantigenic site (SAg) of the HIV envelope protein gp120 and catalyze its hydrolysis by a serine protease-like mechanism. The catalytic activity is encoded by germline Ig variable (V) region genes, and is expressed at robust levels by IgMs and IgAs but poorly by IgGs. Mucosal IgAs are highly catalytic and neutralize HIV, suggesting that they constitute a first line of defense against HIV. Lupus patients produce the Igs at enhanced levels. Homology of the 421–433 region with an endogenous retroviral sequence and a bacterial protein may provide clues about the antigen driving anti-SAg synthesis in lupus patients and uninfected subjects. The potency and breadth of HIV neutralization revives hopes of clinical application of catalytic anti-421–433 Igs as immunotherapeutic and topical microbicide reagents. Adaptive improvement of anti-SAg catalytic Igs in HIV infected subjects is not customary. Further study of the properties of the naturally occurring anti-SAg catalytic Igs should provide valuable guidance in designing a prophylactic vaccine that amplifies protective catalytic immunity to HIV.
Ontogeny of body size variation in African apes.

Size variation in African apes (Gorilla gorilla [gorilla], Pan paniscus [pygmy chimpanzee], and Pan troglodytes [“common” chimpanzee]) is substantial, both within and between species. We investigate the possible evolutionary significance of this variation through an analysis of the ontogeny of size variation in this group. In addition, we highlight possible areas of future endocrinological research, and evaluate recently proposed alternative models that attempt to account for ontogenetic variation in apes. The present study shows that intergeneric variation in size is largely a consequence of differences among species in the rate of body weight growth. Interspecific size variation in Pan is a product of both rate and duration differences in growth. The ontogenetic bases of sexual dimorphism vary in this group. Dimorphism is largely a result of sex differences in the duration of body weight growth in gorillas and pygmy chimpanzees, but results from differences in the rate of growth in common chimpanzees. Ontogenetic analyses largely confirm earlier interpretations, but with better data and methods. The great degree of ontogenetic variation within and among these species, especially in the timing and magnitude of “pubertal” growth spurts, implies that studies of endocrine growth control in African apes could be a productive line of future research. We also suggest that ontogenetic variation can be understood with respect to ecological risks. Growth rates seem to be negatively correlated with ecological risk in African apes, suggesting links between ontogenetic patterns and social and ecological variables. High growth rates in gorillas compared to Pan are most consistent with this model. Variation between chimpanzees and pygmy chimpanzees (especially females) also seem to fit predictions of this model. © 1996 Wiley-Liss, Inc.