cssi/SciSciGPT-SciSciNet huggingface dataset:
Structure of cryptic λ prophages

When Escherichia coli cells lysogenic for bacteriophage lambda are induced with ultraviolet light, cells carrying cryptic lambda prophages are occasionally found among the apparently cured survivors. The lambda variant crypticogen (lambda crg) carries an insertion of the transposable element IS2, which increases the frequency of cryptic lysogens to about 50% of cured cells: 43 of these cryptic prophages have been characterized. They all contain substitutions that replace the early segment of the prophage genome (from the IS2 to near the cos site) with a duplicate copy of a large segment of the host chromosome. The right end of the substitution always results from recombination between the nin-QSR-cos region of the prophage and the homologous incomplete lambdoid prophage Qsr' at 12.5 minutes in the E. coli chromosome. The left end of the substitution is usually a crossover that recombines the IS2 element in the prophage with an E. coli IS2 at 8.5 minutes, near the lac gene, or with a second IS2 located counterclockwise from leu at 2 minutes, generating duplications of at least 200,000 bases. Five cryptic lysogens derived from cells lysogenic for a reference strain of lambda (which lacks the IS2 present in lambda crg) have been characterized. They contain substitutions whose right termini are generated by a crossover with the Qsr' prophage. The left termini of these substitutions are formed either by a crossover between the lambda exo gene and a short exo-homologous segment of Qsr' (2/5), or by a crossover between sequences to the left of attL and an unmapped distant region of the host chromosome (3/5). The large duplications carried by these cryptic lysogens are stable, unlike tandem duplications, and so may significantly influence the cell's evolutionary potential.
On the proof of correctness of "Yet another asynchronous distributed discrete event simulation algorithm (YADDES)"

The discipline of discrete event simulation may be utilized to model many physical systems such as digital hardware, queueing networks, telephone networks, simulated warfare, and banking transactions. Where the entities of a physical system execute independently and interact asynchronously, an asynchronous distributed event-driven simulation algorithm may enable the simulation of the system to execute on a parallel processor. This has the potential to significantly reduce the total simulation time. YADDES is the first algorithm that is characterized by: (1) acceptable performance, (2) freedom from deadlock, and (3) probably correct, for circuits where the interactions between the entities constitute a cyclic dependence. Given their complex, asynchronous nature, an important issue associated with all asynchronous distributed algorithms is their correctness, i.e., the generation of accurate output for given input stimulus, under all possible conditions. This paper presents a mathematical proof of correctness and reports the performance of YADDES on the Armstrong parallel processor at Brown University.
Oxidation of sulfur dioxide by oxygen and ozone in aqueous solution: A kinetic study with significance to atmospheric rate processes☆

Abstract The oxidation rates of SO2 by O2 and O3 have been studied in buffered aqueous solutions at pH between 4 and 12, temperatures between 5 and 25°C, oxygen partial pressures between 0.11 and 1.0 atm., and ozone partial pressures between 0.2 and 1.0 ppm. For the O2 reaction we observe oxidation rates of the form: d[SO 4 2− ] dt = {k 1 + k 2 [H + ] 1 2 + k3Po2[H+−1[SO2−3] with k1 = (4.8 ± 0.6) × 10−3s−1 k 2 = (8.9 ± 1.0) s −1 M − 1 2 k3 = (3.9 ± 0.6) × 10−12s−1 M atm−1, all at 298 K with a multiple correlation coefficient (R2) = 0.73. In acidic solutions this expression displays weak temperature dependence and zero-order O2 dependence. For the O3 reaction we observe oxidation rates of the form: d[SO 2− 4 ] dt = k 4 K HO 3 P O 3 [HSO − 3 ][H + ]−0.1±0.02 with K4 = (4.4 ±2.0) × 104M−0.9S−1KHO3 = 0.0123 M atm−1, both at 298 K, with R2 = 0.38. A simpler expression strictly proportional to bisulfite gives k5 = (1.6 ± 0.1) × 105Ms−1 with R2 = 0.33. We observe the O2 and O3 rate to be very nearly equal in neutral or weakly acidic solution. In clouds over the U.S. and Europe, with pH ⪝ 5 and O 3 ⪞ 50ppb , the O3 reaction should be important.
Forward current surge failure in semiconductor rectifiers

The application of semiconductor rectifiers to most practical circuits requires a knowledge of the device's ability to withstand the forward current surges encountered as a result of severe faults or high instantaneous overloads. In particular, an understanding of the nature of failure is desirable in order to properly protect the rectifier. Suitable fuses can then be chosen to obtain optimum utilization of the rectifier. Gutzwiller1 has developed fuse-selection techniques which are adequate for this purpose.
International perspectives on international leadership

Abstract The ever-increasing awareness by businesses in every part of the world that distant organizations and distant events affect their own activities is driving new thinking about leadership just as it has affected all areas of business. Corporate-level leaders—chief executives and top-level management teams—find themselves challenged by a broad array of strategic alternatives for engaging in global competition. Leaders at all organization levels find themselves concerned with matters of multicultural relations and whether, what, and how cross-border learnings may be possible. Scholars working with international leadership find motivation for their research in these pressing problems. They grapple with questions of how far scientific social research can take us, and how the organization science ideas and methods developed in the United States and other technologically-advanced societies can be used elsewhere in the world. In this article, we deal with the kinds of efforts underway to deal with tensions between global consistency and local uniqueness in the nature and exercise of phenomena related to what social scientists have come to analyze under the label “leadership.” These tensions affect scholarly exchange no less than they affect multinational management. This article offers a context for this focus for both international leadership research, in general, and the work in this special issue, in particular.
Clinical Chorioamnionitis, Elevated Cytokines, and Brain Injury in Term Infants

Objectives. To determine the initial inflammatory cytokine response in term infants born to mothers with clinical chorioamnionitis and to assess whether the cytokine response is associated with birth depression, abnormal neurologic examination, and hypoxic-ischemic encephalopathy (HIE). Methods. Infants who were exposed to chorioamnionitis and admitted to the neonatal intensive care unit (n = 61) were studied prospectively. Cytokine concentrations were measured from umbilical cord blood and at 6 and 30 hours after birth. Control values (n = 50) were determined from cord blood of healthy term infants. Enzyme-linked immunosorbent assays were performed for interleukin (IL)-1β; IL-6; IL-8; regulated on activation, normal T-cell expressed and secreted (RANTES); macrophage inflammatory protein-1α; and tumor necrosis factor-α. Serial blinded neurologic examinations using a modified Dubowitz score were performed simultaneously at 6 and 30 hours. Results. Cord IL-6 (1071 ± 1517 vs 65 ± 46 pg/mL), IL-8 (2580 ± 9834 vs 66 ± 57 pg/mL), and RANTES (95 917 ± 16 518 vs 54 000 ± 14 306 pg/mL) concentrations only were higher in infants with chorioamnionitis versus control infants. IL-6 increased at 6 hours to 1451 ± 214 pg/mL, followed by a 5-fold decline at 30 hours in contrast to progressive decreases over time in IL-8 and RANTES. There was no relationship between cytokines and birth depression. Modified Dubowitz score correlated with IL-6 at 6 hours (r = 0.5). Infants with HIE/seizures (n = 5) had significantly higher cytokine concentrations at 6 hours versus infants without either (n = 56): IL-6 (3130 vs 1219 pg/mL), IL-8 (5433 vs 780 pg/mL), and RANTES (97 396 vs 46 914 pg/mL). Conclusions. There was a significant association between abnormalities in the neurologic examination and cytokine concentrations, with the highest cytokines concentrations observed in infants who developed HIE/seizures.
Spin-dependent resonant tunneling through semimetallic ErAs quantum wells in a magnetic field.

Resonant tunneling through semimetallic ErAs quantum wells embedded in GaAs structures with AlAs barriers was recently found to exhibit an intriguing behavior in magnetic fields: a peak splitting occurred only in fields perpendicular to the film while a second resonant channel opened for in-plane fields. The behavior is explained in terms of the valence-band states in ErAs in the vicinity of the \ensuremath{\Gamma} point, their exchange splitting induced by the localized Er 4f magnetic moments, and by a selection rule involving the total angular momentum component along the normal to the interface. \textcopyright{} 1996 The American Physical Society.
Further experience with staged ureterocolocolostomy urinary diversion.

Abstract Disenchantment with the long-term results with ureterosigmoidostomy and ileal loop urinary diversion led to increased use of the nonrefluxing colon conduit. In 1978, we reported our initial experience with 3 adult patients in whom such a diversion was initially performed followed by conversion with an end-to-side eoloeolostomy achieving a staged nonrefluxing ureterocolocolostomy. We believed that a staged procedure would allow decompression of the upper urinary tract away from the fecal stream, that one could confirm the adequacy of the nonrefluxing tunnels prior to exposure to the fecal stream, and that this might have a lower instance of electrolyte problems and pyelonephritis. Further follow-up on these original 3 patients as well as our experiences with two others, as reported here has somewhat tempered our initial enthusiasm.
A review of mathematica

The Mathematica computer system is reviewed from the perspective of its contributions to symbolic and algebraic computation, as well as its stated goals. Design and implementation issues are discussed.
Considerations for Transmission Line Design on MCMs using AC Coupled Interconnect with Buried Solder Bumps

AC coupled interconnect (ACCI) using buried solder bumps is a technology that provides a complete interconnect and packaging solution by integrating high-density, low inductance power and ground distribution with high-density, high-speed I/O. The mixture of solder bump technology and AC coupled I/O has the potential to improve yield during packaging and assembly since I/O channels are no longer dependent on the yield of a single solder bump. For the same reason, this technology has the potential to increase the long-term reliability of chip/carrier components of electronic systems used in harsh environments (e.g. extreme vibration, shock, and temperature variation). An important consideration in systems using this technology is how the electrical properties of transmission line are altered when it is routed beneath a die that is in close proximity (< 5 mum) to the surface of the substrate
Comparing Institutional and Policy Explanations for the Adoption of State Constitutional Amendments: The Case of Same-Sex Marriage

The literature on state constitutional amendments remains undeveloped despite recent activity in the area of same-sex marriage policy. Previous studies have assumed that the adoption of state constitutional amendments is governed by routine policy considerations, but there are strong theoretical reasons for expecting attributes of state institutions also to affect adoption. In this study, I compare institutional and policy explanations for the enactment of state constitutional amendments prohibiting same-sex marriage. Although I expect routine policy considerations to affect the adoption of amendments, I also expect adoption to be influenced by attributes of state institutions, in particular, the capacity of state high courts to produce decisions favoring marriage equality. Using event history analysis, I find that the initial consideration of amendments is driven by policy considerations but that adoption is also guided by institutional considerations, such as the professionalization of state high courts.
Regional Research on Poultry in the United States

(1968). Regional Research on Poultry in the United States. World's Poultry Science Journal: Vol. 24, No. 3, pp. 231-240.
The Effects of Withholding Water on the Body Temperature of Poults

Abstract IT might be stated that water is the most critical of the essential nutrients. Yet relatively little has been published as to its requirements by the turkey poult or of the effects of its withdrawal for extended periods of time. The fact that poults do require water has been taken for granted by turkey raisers for years yet stated in the literature by only a few researchers. Morehouse (1949) has reported weekly water consumption data for Broad Breasted Bronze poults for their first 26 weeks. That care must be exercised when attempting to change from one type of poult waterer to an unfamiliar one is suggested and demonstrated by Marsden et al. (1965). Ataxia and convulsions accompanied by high mortality resulted after their poults were allowed free access to drinking water after a deprivation period of approximately 48 hours. Bierer et al. (1965) have determined the survival time of 5-week-old …
Gender Differences in Clinical Evaluation and Triage in Coronary Artery Disease

Background Women undergo evaluation and treatment for cardiac diseases less frequently than men with similar symptoms. The purpose of this study was to determine what differences exist in clinical evaluation and treatment between men and women presenting with coronary heart disease that may indicate a gender bias. Methods A single hospital retrospective review of patients admitted with the diagnosis of cardiac ischemic syndrome, undergoing stress testing, coronary arteriography, percutaneous interventional procedure, or coronary bypass surgery was performed, including an evaluation by gender of the demographic, clinical, and angiographic parameters of 1 year of patients undergoing hospital admission, evaluation, or revascularization therapy for coronary heart disease in a single university hospital. Results Women admitted to the coronary care unit with a coronary diagnosis were less likely to undergo coronary arteriography than men. Women having a positive stress test result were as likely to undergo coronary arteriography as men with similar findings. Women undergoing coronary arteriography were as likely as men to undergo percutaneous transluminal coronary angioplasty, but less likely to undergo coronary artery bypass surgery. Conclusions A gender-based selection bias exists in choosing patients to undergo coronary arteriography and coronary artery bypass grafting.
Effects of Therapeutic Doses of Albuterol on β2-Adrenergic Receptor Density and Metabolic Changes

β2-Agonist drugs at inhaled supratherapeutic doses or when given orally or parenterally alter peripheral lymphocyte β2-adrenoceptor density (βAR) and have demonstrable metabolic effects. However, it is not known whether these changes occur at therapeutic inhaled doses. We therefore studied the effects of therapeutic doses of inhaled albuterol in five asthmatic subjects (mean age 23.0 ±2.4 years) and six normal subjects (mean age 28.3 ± 3.3 years). Subjects were studied in a randomized, double-blind protocol in which each subject received either inhaled albuterol (270 μg four times daily) for 2 weeks followed by placebo or vice versa in two sequential 2-week periods separated by a 2-week washout period. In the asthmatics, baseline FEV1 increased significantly (p < 0.05) after 2 weeks of inhaled albuterol treatment compared to the initial visit and after 2 weeks of placebo (mean FEV1: 3.2 L ± 0.7 L, 2.9 L ± 0.5 L, and 3.0 L ± 0.7 L, respectively). Baseline peripheral lymphocyte βAR was not significantly dif...
Use of indomethacin to reverse neonatal hypotension

Treatment with indomethacin elevated systemic arterial pressure and pulmonary vascular resistance in hypotensive newborn goats. Indomethacin may be of value in restoration of systemic arterial pressure in stress-induced hypotension.
Age and Velopharyngeal Function During Speech Production

This investigation was designed to determine if velopharyngeal function during speech production, as reflected in measures of nasal air flow, differs with age in adults. Eighty subjects were studied, 40 women and 40 men, representing four age groups (20–30, 40–50, 60–70, and 80+ years). Results showed no age-related differences in nasal air flow. Sex-related differences in flow were found on productions of nasal consonants only. These findings do not support the suggestion of Hutchinson, Robinson, and Nerbonne (1978) that velopharyngeal function deteriorates with age.
Seidel's legacy and the existence of complex equiangular Parseval frames

Seidel's combinatorial approach to the construction of real, symmetric matrices with unimodular entries and two eigenvalues has produced many equiangular Parseval frames for real Hilbert spaces. We follow Seidel's footsteps and develop a corresponding combinatorial characterization of complex Seidel matrices belonging to equiangular Parseval frames. We deduce necessary conditions for the existence of complex Seidel matrices containing pth roots of unity and having exactly two eigenvalues, under the assumption that p is prime. Explicitly examining the necessary conditions for p = 5, for example, rules out the existence of many such frames with a number of vectors less than 50. Nevertheless, there are examples, which we confirm by constructing p2 × p2 Seidel matrices containing pth roots of unity and having two eigenvalues. and thus the existence of the associated complex equiangular Parseval frames, for any p ≥ 2
Implicit learning of fifth- and sixth-order sequential probabilities.

Serial reaction time (SRT) task studies have established that people can implicitly learn sequential contingencies as complex as fourth-order probabilities. The present study examined people’s ability to learn fifth-order (Experiment 1) and sixth-order (Experiment 2) probabilities. Remarkably, people learned fifth- and sixth-order probabilities. This suggests that the implicit sequence learning mechanism can operate over a range of at least seven sequence elements.
A Catchment‐Based Hydrologic and Routing Modeling System with explicit river channels

In this paper, we present a macroscale hydrologic modeling system with an explicit representation of storage and movement of water in river channels and floodplains. The overall modeling system, called the Catchment-Based Hydrologic and Routing Modeling System (CHARMS), is composed of a land surface model and a river routing model that operate on a network of hydrologic catchments (or watersheds). The land surface model in CHARMS is based on the National Center for Atmospheric Research Community Land Model. The river routing model in CHARMS generates river discharge by transporting runoff generated by the catchment-based CLM through the river network. The routing model uses information on channel cross-section geometry, derived from the 90 m Shuttle Radar Topography Mission digital elevation model, to simulate river discharge and the associated flow depth and inundation width. CHARMS was implemented over the Wabash River basin in the central United States (drainage area 72282 km2), and simulated streamflow was validated using daily observations. Simulated flow depth and inundation extent generally followed seasonal variations in observed flooding and droughts. Limitations of some of the assumptions and scaling factors used in this study and the issues that need to be addressed for a continental- or global-scale implementation of CHARMS are discussed. This paper serves as the foundation for a catchment-based, global land surface modeling framework that could incorporate spatiotemporal variations in surface water bodies, as well as satellite measurements of these variations.
Investigation of metalorganic chemical vapor deposition grown CdTe/CdS solar cells

Abstract Polycrystalline CdTe films were grown on CdS/SnO 2 /glass substrates by metalorganic chemical vapor deposition (MOCVD) for solar cell applications. Cells fabricated on these films showed efficiency of 9.7% which is the highest efficiency reported so far for MOCVD grown CdTe solar cells. The bias-dependent spectral response of the 9.7% efficient cell showed an external quantum efficiency greater than 0.85 at zero bias but a significant wavelength-independent reduction in spectral response at higher voltages. The interface recombination model was used to calculate the interface collection function term to quantify the open-circuit voltage ( V oc ) and fill factor losses in the high efficiency cell. It was found that the interface recombination reduces the V oc and fill factor by 60 mV and 0.1 respectively. It was estimated that efficiency as high as 13.5% can be achieved by improving CdTe/CdS interface quality.
The Functional Role of Balinese Water Temples: A Response to Critics

In earlier publications we have proposed a model to explain the functional role of water temple networks in the agro-ecology of wet rice irrigation on the island of Bali. We argued that the key ecological effects of temple networks are best understood as emergent properties of a complex adaptive system. This argument implies that important aspects of the temple system are largely opaque from the perspective of conventional social science. We proposed that the Green Revolution created a real-world test of our model, by effectively removing the temple networks from their functional role in ecological management. The idea that water temple networks represent a hitherto-unknown kind of institution has been met with appropriate skepticism by other social scientists, who have run a fine-toothed comb through our evidence. Here we evaluate their critiques.
Model Based Testing Using Software Architecture

Software testing is an ultimate obstacle to the final release of software products. Software testing is also a leading cost factor in the overall construction of software products. On the one hand, model-based testing methods are new testing techniques aimed at increasing the reliability of software, and decreasing the cost by automatically generating a suite of test cases from a formal behavioral model of a system. On the other hand, the architectural specification of a system represents a gross structural and behavioral aspect of a system at the high level of abstraction. Formal architectural specifications of a system also have shown promises to detect faults during software back-end development. In this work, we discuss a hybrid testing method to generate test cases. Our proposed method combines the benefits of model-based testing with the benefits of software architecture in a unique way. A simple Client/Server system has been used to illustrate the practicality of our testing technique.
Laboratory investigation of polyethylene sheeting as a friction reducer in deep foundation

Abstract A testing program was undertaken in which the effectiveness of polyethylene sheeting in mitigating downdrag in cohesionless soils was investigated using a direct shear apparatus and a rod shear test. A large number of concrete blocks were prepared in the laboratory and furnished with various arrangements of polyethylene sheets. These arrangements included samples with one or two sheets with fixed or free boundary conditions. The concrete-polyethylene-soil samples were tested in the laboratory under different temperatures and shearing rates. Based on the parameters used in this investigation, the obtained results demonstrated that the polyethylene sheets can be used as a friction reducer in piles. Using single layer of polyethylene sheeting reduced the skin friction by 62–67% depending on the soil type. The best arrangement was found in the two free 0·15 mm polyethylene sheets. This setup increased the effectiveness of the sheets to 77%. Lubricating the two sheet arrangement with mineral oil improved the effectiveness to 98%. Considering the effect of the shearing rate and the temperature on the behaviour of the lubricated sheets, a formula is suggested
Ultrasonic extraction of arsenic and selenium from rocks associated with mountaintop removal/valley fills coal mining: Estimation of bioaccessible concentrations.

Abstract Ultrasonic extraction (UE) was used to estimate the total bioaccessible fractions of arsenic and selenium released from rocks associated with mountaintop removal/valley fill coal mining. The combined readily bioaccessible amounts of arsenic and selenium in water soluble, exchangeable and NaOH fractions can be extracted from the solid phase within a 20 or 25 min application of 200 W cm−2 ultrasound energy in nanopure water for selenium and arsenic, respectively. Application of a two-way ANOVA predicted that there are no significant differences (p ⩽ 0.001, n = 12) in the extracted arsenic and selenium concentrations between the combined bioaccessible and ultrasonic extracts. The mechanisms for the UE of arsenic and selenium are thought to involve the formation of secondary minerals on the particle surfaces which eventually dissolve with continued sonication. This is supported by the presence of transient Si–O stretching and OH absorption and bending ATR-FTIR peaks at 795.33 cm−1, 696.61 cm−1 and 910.81 cm−1. The subsequent dissolution of secondary minerals is followed by the release of chemical species that include selenium and arsenic. Release rates decrease after the ultrasound energy elastic limit for the particles is reached. Selenium and arsenic are bound differently within the rock lattice because no selenium was detected in the acid soluble fraction and no arsenic was found in the exchangeable fraction. However, selenium was found in the exchangeable fraction and arsenic was found in the acid soluble fraction. The characterization of coal associated rocks is essential to the design of methodologies and procedures that can be used to control the release of arsenic and selenium from valley fills.
Distinct microRNA expression signatures are associated with melanoma subtypes and are regulated by HIF1A.

The complex genetic changes underlying metastatic melanoma need to be deciphered to develop new and effective therapeutics. Previously, genome-wide microarray analyses of human melanoma identified two reciprocal gene expression programs, including transcripts regulated by either transforming growth factor, beta 1 (TGFβ1) pathways or microphthalmia-associated transcription factor (MITF)/SRY-box containing gene 10 (SOX10) pathways. We extended this knowledge by discovering that melanoma cell lines with these two expression programs exhibit distinctive microRNA (miRNA) expression patterns. We also demonstrated that hypoxia-inducible factor 1 alpha (HIF1A) is increased in TGFβ1 pathway-expressing melanoma cells and that HIF1A upregulates miR-210, miR-218, miR-224, and miR-452. Reduced expression of these four miRNAs in TGFβ1 pathway-expressing melanoma cells arrests the cell cycle, while their overexpression in mouse melanoma cells increases the expression of the hypoxic response gene Bnip3. Taken together, these data suggest that HIF1A may regulate some of the gene expression and biological behavior of TGFβ1 pathway-expressing melanoma cells, in part via alterations in these four miRNAs.
Oscillatory Hall Effect, Magnetoresistance, and Magnetic Susceptibility of a Graphite Single Crystal

The Hall coefficient, magnetoresistance, and magnetic susceptibility of a graphite single crystal have been measured at liquid helium temperatures and in magnetic fields up to 25 kilogauss. All three phenomena are periodic functions of reciprocal field and exhibit the same period for like orientations of the crystal axes with respect to the magnetic field. The phases however are different. Where possible, experiment and theory have been compared.
Role of Thermal Contact Resistance in Pyrotechnic Ignition

This paper describes a pyrotechnic ignition model based on transient heat conduction from a heated bridgewire to a pyrotechnic that is placed in contact with it. The boundary condition used at the interface was a thermal contact conductance estimated at 31,200 W per sq m-K between the wire and the pyrotechnic. Ignition was assumed to occur when a 2.5-micron layer of pyrotechnic next to the bridgewire reached a critical ignition temperature. The times to ignition predicted by this model for constant current firings were in good agreement with experimentally observed times to fire at 3.5- and 5-ampere current levels and ambient temperatures from 144 K to 366 K.
Achievable Hierarchies In Voting Games

Previous work by Diffo Lambo and Moulen [Theory and Decision 53, 313–325 (2002)] and Felsenthal and Machover [The Measurement of Voting Power, Edward Elgar Publishing Limited (1998)], shows that all swap preserving measures of voting power are ordinally equivalent on any swap robust simple voting game. Swap preserving measures include the Banzhaf, the Shapley–Shubik and other commonly used measures of a priori voting power. In this paper, we completely characterize the achievable hierarchies for any such measure on a swap robust simple voting game. Each possible hierarchy can be induced by a weighted voting game and we provide a constructive proof of this result. In particular, the strict hierarchy is always achievable as long as there are at least five players.
Interaction of lac repressor with inducer. Kinetic and equilibrium measurements

The rates of binding and dissociation of the inducer isopropyl-β, d -thiogalactoside to the lactose repressor protein of Escherichia coli were studied by monitoring changes in tryptophan fluorescence in a stopped-flow spectrometer. At pH 8·5 the association rate constant for inducer binding was found to be 1·7×104 m −1 s−1 and that for dissociation to be 0·53 s−1 in 1·0 m -Tris·HCl buffer. These kinetic measurements were made over a range of conditions, and a small but reproducible dependence on pH and ionic strength was observed. The presence of bound calf thymus DNA was found to affect only slightly the rats of inducer binding to the protein. The kinetically determined rate constants were used to calculate dissociation constants for the interaction between repressor and inducer. The calculated values were in agreement with those determined directly by equilibrium dialysis and ultraviolet spectral titration of repressor with inducer. It appears that repressor and inducer interact by a simple equilibrium process, the characteristics of which are similar whether repressor is free in solution or non-specifically bound to DNA.
A reliable iterative method for solving the time-dependent singular Emden-Fowler equations

Many problems of physical sciences and engineering are modelled by singular boundary value problems. In this paper, the variational iteration method (VIM) is used to study the time-dependent singular Emden-Fowler equations. This method overcomes the difficulties of singularity behavior. The VIM reveals quite a number of features over numerical methods that make it helpful for singular and nonsingular equations. The work is supported by analyzing few examples where the convergence of the results is observed.
The genetics of cell cycle checkpoints

Checkpoints help in the prevention of genetic damage by giving cells time to repair damaged structures before proceeding in the cell cycle. Genetic analyses in budding and fission yeast have identified a large number of cell cycle checkpoint genes. Several of these encode proteins related to components of other signal transduction pathways, including protein kinases, lipid kinases, and 14-3-3 proteins. In fission yeast, checkpoints play an important role in keeping cells from entering mitosis before they pass Start.
Thermoregulatory behaviour, diel activity and the relationship of spontaneous locomotor activity to temperature in the sea raven, Hemitripterus americanus (Gmelin)

Twelve sea ravens, Hemitripterus americanus, were tested individually for three day periods in electronic shuttleboxes to measure their preferred and avoided temperatures, diel activity pattern and relationship of activity to temperature. The fish avoided temperatures below 9°C or above 25°C, preferring temperatures with a central tendency of 15–17°C. The fish were primarily nocturnal, being more active at night than by day. Locomotor activity increased eightfold between 10 and 20°C, but exhibited an anomalous decrease between 14 and 18°C, corresponding to the preferred-temperature zone, characteristic of maximal summer temperatures in the natural habitat.
The nature of size scaling in the Ponzo and related illusions

The failure of previous investigators to obtain a Ponzo illusion when each test line is rotated 90 deg from its conventional placement has been interpreted as a refutation of constancy scaling theory. It was proposed that, instead, these results might be due to a failure of linear perspective to elicit foreshortening scaling, and vice versa, since the two types of perspective have different functions. This hypothesis was tested and confirmed.
Optical deflection and temporal characterization of an ultrafast laser-produced electron beam.

The interaction of a laser-produced electron beam with an ultraintense laser pulse in free space is studied. We show that the optical pulse with ${a}_{0}=0.5$ imparts momentum to the electron beam, causing it to deflect along the laser propagation direction. The observed 3-degree angular deflection is found to be independent of polarization and in good agreement with a theoretical model for the interaction of free electrons with a tightly focused Gaussian pulse, but only when longitudinal fields are taken into account. This technique is used to temporally characterize a subpicosecond laser-wakefield-driven electron bunch. Applications to electron-beam conditioning are also discussed.
Keck Interferometer nuller update

The Keck Interferometer combines the two 10 m Keck telescopes as a long baseline interferometer, funded by NASA, as a joint development among the Jet Propulsion Laboratory, the W. M. Keck Observatory, and the Michelson Science Center. Since 2004, it has offered an H- and K-band fringe visibility mode through the Keck TAC process. Recently this mode has been upgraded with the addition of a grism for higher spectral resolution. The 10 um nulling mode, for which first nulling data were collected in 2005, completed the bulk of its engineering development in 2007. At the end of 2007, three teams were chosen in response to a nuller key science call to perform a survey of nearby stars for exozodiacal dust. This key science observation program began in Feb. 2008. Under NSF funding, Keck Observatory is leading development of ASTRA, a project to add dual-star capability for high sensitivity observations and dual-star astrometry. We review recent activity at the Keck Interferometer, with an emphasis on the nuller development.
Radiation Effects in Zircon, Hafnon, and Thorite: Implications for Pu Disposal

Synthetic ZrSiO4, HfSiO4, and ThSiO4 single-crystal specimens were irradiated by 800 keV Kr+ ions, and the microstructural evolution was observed in-situ in a transmission electron microscope. All three compounds were found to become amorphous up to temperatures in excess of 600°C. Using a new model, the activation energies for annealing were found to be in the range of 3.1 to 3.6 eV for these compounds. At temperatures above 600°C, the orthosilicates were observed to decompose into the component oxides (e.g., tetragonal ZrO2 + amorphous SiO2 in the case of zircon). A single-crystal zircon specimen was also irradiated with a pulsed picosecond Nd:YAG laser operated at 355 nm, and the resulting microstructure was investigated by optical absorption, SEM, AFM, and TEM techniques.
TRUSS: a reliable, scalable server architecture

Traditional techniques that mainframes use to increase reliability -special hardware or custom software - are incompatible with commodity server requirements. The Total Reliability Using Scalable Servers (TRUSS) architecture, developed at Carnegie Mellon, aims to bring reliability to commodity servers. TRUSS features a distributed shared-memory (DSM) multiprocessor that incorporates computation and memory storage redundancy to detect and recover from any single point of transient or permanent failure. Because its underlying DSM architecture presents the familiar shared-memory programming model, TRUSS requires no changes to existing applications and only minor modifications to the operating system to support error recovery.
Future of multiprocessors: Heterogeneous Chip Multiprocessors

As computer applications are becoming complex, large and versatile; the advent of Chip multiprocessor is ubiquitous. There are numerous researches going on about the core architectures within the chip. Heterogeneous Chip Multiprocessor (CMP) is leading the innovation. Heterogeneous CMP is composed of cores of varying performance, and complexity. It gives better area to performance ratio, high throughput, and higher speed up and mitigates Amdahl's bottleneck to some extent. There are three major issues to Heterogeneous CMP- scheduling applications to different cores, configuration of cores, and Amdahl's law utilization. This paper discusses recent researches of these three issues in details and finally, some recommendations are drawn from the study.
ECOLOGICAL AND EVOLUTIONARY ASPECTS OF LEARNING IN PHYTOPHAGOUS INSECTS

To date, learning has been demonstrated in six orders of insects with phytophagous habits. Most examples of learning in these orders have come to light relatively recently [all but a few since the last review of learning in the Annual Review of Entomology 17 years ago (3)], and many more will surely be uncovered. Still, the study of learning in other insects such as the social Hymenoptera remains far more advanced than in phytophagous insects. In this review, work on learning in phytophagous insects is placed into the broader perspective of learning in a variety of insects including bees and parasitic wasps. Although historically the study of learning in phytophagous insects has emphasized the acquisition of host resources for feeding and oviposition, we believe that, as in bees and wasps, learning impinges on almost every aspect of the natural history of a phytophagous insect. Following discussion of the definition of learning, the natural history of learning, and the host stimuli involved in learning, we review the ecological significance of learning with respect to both the traditional categories erected by behaviorists and the more recent concept of programed learning developed by ethologists. Finally, we evaluate critically hypotheses about the evolution of learning and suggest approaches for future research.
Delayed Traumatic Pseudoaneurysm of a Jejunal Artery A Case Report

The authors report a rare case of giant delayed traumatic pseudoaneurysm of a jejunal branch of the superior mesenteric artery secondary to abdominal trauma. A forty-seven- year-old patient presented with a painless, enlarging epigastric mass eleven years after a stab wound to the abdomen. A giant post-traumatic pseudoaneurysm of a jejunal artery was diagnosed by computed tomography, confirmed by ultrasound and angiography, and successfully treated surgically. This case demonstrates the importance of computed tomography in diagnosis of abdominal pseudoaneurysm in patients with previous abdominal trauma.
Dress Matters Change and Continuity in the Dress Practices of Bosnian Muslim Refugee Women

Dress serves as a discursive daily practice of gender, and this article explains the dress practices of Bosnian Muslim refugee women living in Vermont. These dress practices tend toward elaborate, carefully cultivated styles for hair, makeup, and dress. Based on participant observation, in-depth interviews, and secondary historical sources, the authors seek to explain the meanings and practice of these dress practices. They argue that gendered dress practices reflect agentic processes that are situated within the flow of time and are rooted in relational processes that occur at the macrostructural level of history and nation and at the micro world of social interaction and lived experience.
Historical and Contextual Correlates of Parallel Services for Elders in African American Communities

Employing ethnographic and historical research methods, this article examines the organization and delivery of parallel services (locally generated alternatives to formal, externally controlled services) for older residents in four of the all-Black towns of Oklahoma. These towns are rural, social-ecological enclaves that generally have remained totally African American since they were established in the late 1800s and early 1900s. Elders, even impaired older people, are prominent agents in the production of alternative services, and the organization of parallel services can be directly related to historical and contextual characteristics of the communities. The results demonstrate the value of taking into account community history and context, as well as the mix of parallel services, when developing formal services for minority communities.
Reciprocity explains food sharing in humans and other primates independent of kin selection and tolerated scrounging: a phylogenetic meta-analysis.

Helping, i.e. behaviour increasing the fitness of others, can evolve when directed towards kin or reciprocating partners. These predictions have been tested in the context of food sharing both in human foragers and non-human primates. Here, we performed quantitative meta-analyses on 32 independent study populations to (i) test for overall effects of reciprocity on food sharing while controlling for alternative explanations, methodological biases, publication bias and phylogeny and (ii) compare the relative effects of reciprocity, kinship and tolerated scrounging, i.e. sharing owing to costs imposed by others. We found a significant overall weighted effect size for reciprocity of r = 0.20–0.48 for the most and least conservative measure, respectively. Effect sizes did not differ between humans and other primates, although there were species differences in in-kind reciprocity and trade. The relative effect of reciprocity in sharing was similar to those of kinship and tolerated scrounging. These results indicate a significant independent contribution of reciprocity to human and primate helping behaviour. Furthermore, similar effect sizes in humans and primates speak against cognitive constraints on reciprocity. This study is the first to use meta-analyses to quantify these effects on human helping and to directly compare humans and other primates.
Results from the 2009 data of the MEG experiment in the search for μ+→e+γ

The MEG experiment is the latest in a series of progressively more precise rare decay searches designed to exploit an observation of μ + → e + γ or lack thereof as a sensitive low energy probe of new physics. A first analysis of 43 days of data acquisition in 2009 results in an upper limit of B R ( μ + → e + γ ) 1.5 × 10 − 11 (90% CL).
The thermal stability of the polymorphs of hexanitrohexaazaisowurtzitane, Part I

Phase transitions in the α-, β-, γ-, and ϵ-polymorphs of 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIW) have been studied as a function of temperature. Described are the results of high temperature equilibrium solvation studies coupled with Fourier transform infrared spectroscopy (FTIR) for the identification of polymorphic conversion. These results are augmented by data in Part II from differential scanning calorimetry (DSC), differential thermal analysis/thermogravimetric analysis (DTA/TGA), and optical hot stage microscopy(6). The thermodynamic stability order of ϵ > γ > α-hydrate > β is shown, with the epsilon polymorph the most thermodynamically stable phase of HNTW at room temperature. The existence of multiple α-hydrate phases is shown to complicate the determination of the equilibrium P-T phase diagram of HNIW.
DCT Coefficient Prediction for JPEG Image Coding

The JPEG baseline algorithm follows a block-based coding approach and therefore, it does not explore source redundancy at the sub-block level. This note explores correlation between adjacent rows (or columns) at the block boundaries for predicting DCT coefficients of the first row/column of DCT blocks. Experimental results show that our prediction method reduces the average JPEG DC residual by about 75% for images compressed at the default quality level. The same for AC01/10 coefficients is about 30%. It reduces the final code bits by about 4.55% of the total image code for grey images. Our method can be implemented as a part of the JPEG codec without requiring any changes to its control structure or to its code stream syntax.
Stability of the palatal rugae as landmarks for analysis of dental casts in extraction and nonextraction cases

To determine whether the positions of the palatal rugae were affected by orthodontic therapy, pre- and posttreatment maxillary dental casts of 57 adult patients treated in the graduate orthodontic clinic at the University of North Carolina were evaluated. The orthodontic extraction group (n = 27) was composed of patients whose treatment included the extraction of two maxillary premolars. The remaining patients (n = 30) had been treated without extractions. Transverse changes observed over time were significantly different from zero only for the medial points of the first rugae in the nonextraction group and for the lateral points of the first rugae in the extraction group. None of the changes observed in the transverse measures were statistically different between the two groups. In the extraction group, there were significant anteroposterior changes in the right lateral points between the first and second rugae and between the second and third rugae, and in the right medial points between the second and third rugae. There were no statistically significant anteroposterior changes observed in the nonextraction group over time. When the two groups were compared, the average distance between the lateral first and second right rugae, and the average distance between the lateral second and third right rugae were significantly different. The medial and lateral points of the third rugae appear to be stable landmarks for the construction of anatomic reference pints in longitudinal cast analysis.
Parasite genotypes identify source populations of migratory fish more accurately than fish genotypes.

DNA-based assignment of individuals to their population of origin has many applications such as mixed-stock analysis, identifying individuals from protected populations, and elucidating migration patterns. However, low genetic differentiation among populations will cause misassignments. Thus, an alternative means of determining an individual's population of origin is needed in cases where there is little or no neutral differentiation among source populations. Here, we test the hypothesis that parasite genotypes can be used to identify the origins of hosts more accurately than host genotypes. Using microsatellite markers from steelhead trout and their trematode parasites, we show that the odds of correct assignment are four times greater with the parasite's genotypes than with the host's genotypes. Our analyses show that this result is simply explained by the greater genetic structure among populations of the trematode parasite. Recent studies on the comparative genetic structure of other host and parasite...