cssi/SciSciGPT-SciSciNet huggingface dataset:
Model studies of the structures, reactivities, and reaction mechanisms of metalloenzymes

Electronic structure theory, which in recent years has been actively and effectively applied to the modeling of chemical reactions involving transition-metal complexes, is now also being applied to the modeling of biological processes involving metalloenzymes. In the first part of this paper, we review our recent electronic structure studies using relatively simple models of two metalloenzymes--methane monooxygenase and ribonucleotide reductase. In the second part of the paper, we review a new hybrid theoretical method we have developed for modeling the reactivities of large molecular systems. We describe the limitations of these models and indicate how they may be further improved to reliably model the reactivities of complicated metalloenzymes.
Protein dynamics during presynaptic-complex assembly on individual single-stranded DNA molecules

Homologous recombination is a conserved pathway for repairing double-stranded breaks, which are processed to yield single-stranded DNA overhangs that serve as platforms for presynaptic-complex assembly. Here we use single-molecule imaging to reveal the interplay between Saccharomyces cerevisiae RPA, Rad52 and Rad51 during presynaptic-complex assembly. We show that Rad52 binds RPA-ssDNA and suppresses RPA turnover, highlighting an unanticipated regulatory influence on protein dynamics. Rad51 binding extends the ssDNA, and Rad52-RPA clusters remain interspersed along the presynaptic complex. These clusters promote additional binding of RPA and Rad52. Our work illustrates the spatial and temporal progression of the association of RPA and Rad52 with the presynaptic complex and reveals a new RPA-Rad52-Rad51-ssDNA intermediate, with implications for how the activities of Rad52 and RPA are coordinated with Rad51 during the later stages of recombination.
If you feel it now you will think it later: The interactive effects of mood over time on brand extension evaluations†

While mood has been found to affect brand extension evaluations, the specific mechanisms by which it affects those evaluations remain largely untested. This study suggests that mood-induced differences in cognitive processing style (relational vs. item-specific elaboration) are possible explanations affecting brand extension evaluations. Results of two experiments showed that consumers in a positive (vs. negative) mood engaged in relational (vs. item-specific) elaboration and consequently evaluated brand extensions and brand extension fit more favorably than consumers in a negative mood. The effects were found immediately after exposure (Experiment 1) and after a one-week delay (Experiment 2). Theoretical and practical implications are discussed. © 2011 Wiley Periodicals, Inc.
Quantum circuit theory

Abstract The electronic Schroedinger Equation for devices which are small compared to the inelastic scattering length of electrons is solved by a transformation to an equivalent quantum circuit which is numerically tractable. The method is applied to dirty wires and reveals the existence of anomalously conductive states.
A result on rearrangements

Circular symmetry is defined for ordered sets ofn real numbers: (y)=(y1,...,yn). Letf(x) be non-decreasing and convex forx≧0 and let (y) be given except in arrangement. The Σi=1nf(|yi−yi+1|) (whereyn+1=y1) is minimal if (and under some additional assumptions only if) (y) is arranged in circular symmetrical order.
Thermodynamic properties of the mercury-uranium system

The mercury vapor pressure and e.m.f. data obtained in this investigation were combined with literature data to arrive at a consistent set of thermodynamic quantities for the mercury-uranium system. At 725 °C (998 K) the compound UHgx (x ≈ 1.0) decomposes to UHg2 and β-uranium. DTA data were employed to estimate the heat of reaction and to derive the free energy of formation of this compound. The free energy of formation (in joules) for the compounds in this system is given by the equations: ΔG°(UHg) = −27 585+ 19.94TT<942 KΔG°(UHg2) = −52 720 + 37.59T (548 – 853 K) ΔG°(UHg3) = −63 555 + 46.76T (433 – 684 K) ΔG°(UHg2) = −78 010 + 66.42T (388 – 683 K) Relations for the relative partial molal quantities for mercury and uranium in the various two-phase regions are derived. These data are reasonably consistent with the revised phase diagram.
Characterization of mitochondrial haplogroups in a large population-based sample from the United States

Mitochondrial DNA (mtDNA) haplogroups are valuable for investigations in forensic science, molecular anthropology, and human genetics. In this study, we developed a custom panel of 61 mtDNA markers for high-throughput classification of European, African, and Native American/Asian mitochondrial haplogroup lineages. Using these mtDNA markers, we constructed a mitochondrial haplogroup classification tree and classified 18,832 participants from the National Health and Nutrition Examination Surveys (NHANES). To our knowledge, this is the largest study to date characterizing mitochondrial haplogroups in a population-based sample from the United States, and the first study characterizing mitochondrial haplogroup distributions in self-identified Mexican Americans separately from Hispanic Americans of other descent. We observed clear differences in the distribution of maternal genetic ancestry consistent with proposed admixture models for these subpopulations, underscoring the genetic heterogeneity of the United States Hispanic population. The mitochondrial haplogroup distributions in the other self-identified racial/ethnic groups within NHANES were largely comparable to previous studies. Mitochondrial haplogroup classification was highly concordant with self-identified race/ethnicity (SIRE) in non-Hispanic whites (94.8 %), but was considerably lower in admixed populations including non-Hispanic blacks (88.3 %), Mexican Americans (81.8 %), and other Hispanics (61.6 %), suggesting SIRE does not accurately reflect maternal genetic ancestry, particularly in populations with greater proportions of admixture. Thus, it is important to consider inconsistencies between SIRE and genetic ancestry when performing genetic association studies. The mitochondrial haplogroup data that we have generated, coupled with the epidemiologic variables in NHANES, is a valuable resource for future studies investigating the contribution of mtDNA variation to human health and disease.
Synthesis and electrochemical characterization of [Ru(NCCH3)6]2+, tris(acetonitrile) tris(pyrazolyl)borate, and tris(acetonitrile) tris(pyrazolyl)methane ruthenium(II) complexes

Abstract Tris(acetonitrile) tris(pyrazolyl)borato- and tris(pyrazolyl)methano ruthenium(II) complexes would make good synthons in ruthenium chemistry for synthesis of catalysts and DNA binding drugs. However, these complexes are not widely used as starting materials due to the long reaction times and multiple synthetic steps required or the lack of their successful synthesis. We have developed a new synthesis for the ruthenium(II) acetonitrile complex [Ru(NCCH3)6]2+ with noncoordinating BF4− or OTf (OTf = trifluoromethanesulfonate) counterions. Using this [Ru(NCCH3)6]2+ complex, the previously reported tris(acetonitrile) tris(pyrazolyl)borato ruthenium(II) complexes [TpRRu(NCCH3)3]+ (TpR = tris(pyrazolyl)borate; R = H, Me) and the unreported tris(acetonitrile) tris(pyrazolyl)borato ruthenium(II) complex (R = Ph) have been synthesized using an improved synthetic pathway that reduces the number of required steps by up to six and the average synthesis times by up to 45 h. Novel tris(acetonitrile) tris(pyrazolyl)methano ruthenium(II) complexes of the formula [TpmRRu(NCCH3)3]2+ (TpmR = tris(pyrazolyl)methane; R = Me, Ph) have also been synthesized in one step in 12 h using this method. Cyclic voltammetry studies of the synthesized complexes show that Ru2+/3+ redox potentials generally increase with increasing steric bulk of the TpR or TpmR ligand. The ability to sterically tune Ru2+/3+ redox potentials may be used to promote catalysis development and in the development of ruthenium-based drugs.
Support effects in dispersed metal catalysts

Abstract Impregnated nickel and nickel/cerium catalysts, supported by silica and magnesium silicate, have been characterized by transmission electron microscopy (TEM), nitrogen and hydrogen sorption, photoelectron spectroscopy and mercury porosimetry. Methanation turnover numbers have been determined in order to assess catalyst activity. Nickel particle size data, obtained by TEM and hydrogen chemisorption, and photoelectron spectroscopy, indicate a higher degree of metal-support interaction in the magnesium silicate supported catalysts compared to the silica supported catalysts. Turnover numbers are generally 30 to 40 times smaller in the magnesium silicate catalysts, indicating that the higher degree of metal-support interaction in these systems correlates with lower catalyst activity.
An Assessment of the Current State of Cybercrime Scholarship

Computers and the Internet have become a vital part of modern life across the world, affecting communications, finance, and governance. At the same time, technology has created unparalleled opportunities for crime and deviance on- and off-line. Criminological research has expanded its focus over the last two decades to address the various forms of technology-enabled crime and the applicability of traditional theories to account for offending. There is, however, a need for careful consideration of the state of the field in order to identify issues requiring further study and analysis. This study examines the current literature on virtually all forms of cybercrime and the theoretical frameworks used to address these issues. In turn, we hope to give direction to refine our understanding of criminological theory and social policies to combat these offenses.
Measures of working memory, sequence learning, and speech recognition in the elderly.

This study describes the measurement of 2 cognitive functions, working-memory capacity and sequence learning, in 2 groups of listeners: young adults with normal hearing and elderly adults with impa...
Phosphorylation affects voltage gating of the delayed rectifier K+ channel by electrostatic interactions

The delayed rectifier K+ channel of the squid axon undergoes a series of modifications in its kinetic and conductive parameters when it is phosphorylated as the result of shifts in its voltage-dependent parameters. These effects can be interpreted as due to electrostatic interaction between the voltage sensor of the channel and the transferred phosphate from ATP. Using different concentrations of intracellular Mg2+, we determined the density of surface charges seen by the K+ channel voltage sensor before and after phosphorylation. Values for the surface charge density in the cytoplasmic side of the membrane were between 1/350 and 1/250 e-/A2 in the absence of ATP and between 1/160 and 1/155 e-/A2 under phosphorylating conditions. Incorporation of a surface potential into a kinetic model for the delayed rectifier channel can predict quantitatively phosphorylation-like changes in K+ currents. These results provide evidence for the importance of electrostatic interactions as one of the mechanisms by which phosphorylation modulates the behavior of voltage-dependent channels.
ANALYSIS OF RESPONSE COVARIATION AMONG MULTIPLE TOPOGRAPHIES OF FOOD REFUSAL

This study examined the effects of sequentially introducing treatment across multiple topographies of food refusal. Treatment with nonremoval of the spoon produced an increase in food acceptance and a decrease in disruption, but expulsion of food increased. When expulsion was treated, packing of food increased. Finally, when packing was treated, all refusal behaviors remained low, and acceptance continued to occur at high and stable levels.
A decision theory of clergy political behavior

Abstract Studies of clergy political behavior have used one of two empirical lenses to explain clergy actions—ideology and contextual influences. The first lens generally supposes that clergy behave according to their sincerely held preferences; the second takes personal ideology into account, but suggests that clergy are also subject to influence from the environment in which they serve. While both approaches have received adequate attention, there has been no attempt to develop a systematic decision theory outlining when and why clergy might elect to follow their ideological preferences in some cases, and respond to contextual influence in others. This research note proposes a decision theory based on work in the congressional behavior scholarship. It outlines the conditions under which clergy use their sincere preferences and reference group cues to determine their political behavior. It then tests these propositions using data from two national surveys of American clergy.
Economic Freedom and the Motivation to Engage in Entrepreneurial Action

Using institutional theory, the Heritage Foundation/Wall Street Journal 2003 Index of Economic Freedom, and the 2002 Global Entrepreneurship Monitor, we regress opportunity–motivated entrepreneuria...
Pathogenesis of Renal Injury in the Megabladder Mouse: A Genetic Model of Congenital Obstructive Nephropathy

Congenital obstructive nephropathy (CON) is the most common cause of chronic renal failure in children often leading to end-stage renal disease. The megabladder (mgb) mouse exhibits signs of urinary tract obstruction in utero resulting in the development of hydroureteronephrosis and progressive renal failure after birth. This study examined the development of progressive renal injury in homozygous mgb mice (mgb-/-). Renal ultrasound was used to stratify the disease state of mgb-/- mice, whereas surgical rescue was performed using vesicostomy. The progression of renal injury was characterized using a series of pathogenic markers including alpha smooth muscle isoactin (α-SMA), TGF-β1, connective tissue growth factor (CTGF), E-cadherin, F4/80, Wilm's tumor (WT)-1, and paired box gene (Pax) 2. This analysis indicated that mgb-/- mice are born with pathologic changes in kidney development that progressively worsen in direct correlation with the severity of hydronephrosis. The initiation and pattern of fibrotic development observed in mgb-/- kidneys appeared distinctive from previous animal models of obstruction. These observations suggest that the mgb mouse represents a unique small animal model for the study of CON.
Reconciling numerical and analytical results for the average persistent current in a mesoscopic ring

Abstract We propose scaling relationships for the disorder-averaged persistent current in mesoscopic normal-metal rings, as suggested by our analytical theory, and show how these allow one to resolve a discrepancy between recent numerical and analytical results for the average current.
Observations of jets in density stratified crossflows

Abstract The results are presented of a water tunnel study undertaken to determine the characteristics of a circular jet in a density stratified crossflow. Flow visualization indicates that the salient characteristics include a stable potential core of length L in the vicinity of the jet exit. The length of the stable potential core depends on the velocity ratio α = U J U ∞ and the non-dimensional frequency ND U ∞ . As α is increases the value of L increases; L also increases for increasing values of ND U ∞ . However, L decreases with increasing ND U ∞ for values of ND U ∞ > 0.03 . Knowledge of this variability is necessary for quantifying mixing rates. Further downwind, the jet trajectory evolves to a maximum height of rise zm, and subsequently relaxes to a lower equilibrium level, ze. Values of zm and ze are in agreement with the predictions of scaling arguments. Mean density measurements indicate rapid increase of dilution for small distances from the jet exit; however, for large distances predominantly horizontal mixing processes result in much slower increase of dilution with distance.
Statistical Standards and ISO, Part 4—Applications Related to the Implementation of Six Sigma

This is the fourth article in a series reviewing statistical standards published under the auspices of the International Organization for Standardization Technical Committee 69 on Applications of Statistical Methods.
Retransplantation for recurrent hepatitis C in the MELD era: Maximizing utility

Key Points 1 Retransplantation (re-LT) for hepatitis C virus (HCV) recurrence is controversial. Although re-LT accounts for 10% of all liver transplants (LTs), the number of patients requiring re-LT is expected to grow as primary LT recipients survive long enough to develop graft failure from recurrent disease. 2 Utility, as applied to the medical ethics of transplantation, refers to allocating organs to those individuals who will make the best use of them. The utility function (U) of liver transplantation is represented by the product of outcome (O = 1-year survival with LT) times emergency (E = 3-month mortality without LT), i.e., U = O × E. 3 For primary LT, maximal U is achieved by allocating organs at the highest model for end-stage liver disease (MELD) score (i.e., “sickest first”). No significant differences exist between HCV and non-HCV diagnoses. 4 For re-LT, maximal utility for HCV and non-HCV diagnoses are achieved at MELD scores of 21 and 24, respectively. Utility starts to decline at MELD scores above 28. 5 The current allocation system (MELD) fails to maximize utility with regard to re-LT. (Liver Transpl 2004;10:S59–S64.)
Geometric models of folding at Loch Monar, Scotland, using computer simulation

Abstract Small-scale hand specimens were collected at Loch Monar, Scotland, one of the classic areas of fold interference patterns. From the analysis of these, the geometries of the F 1 and F 2 folds were derived. By computer simulation, the complex three-dimensional form of the fold interference shapes can then be reproduced very closely. F 2 fold shapes and motion directions derived from the small-scale structures, along with those derived from field observations of F 1 lineations deformed about F 2 folds, were then applied to an extrapolated pre-F 2 shape of the Loch Monar synform. This generated a map pattern strikingly similar to that mapped by Ramsay (1958). The geometric models provide useful information for mechanical hypotheses of the folding observed at Loch Monar. The simulation reveals an interesting problem that whereas many small-scale interference patterns reflect the map pattern of the major structure, there are exposures of interference patterns that do not. These are dome and basin (type 1) patterns found in an area where a major F 2 fold hinge crosses an F 1 fold hinge zone. By examining the deformed L 1 lineation patterns found in this area, along with the computed D 2 strain orientations and the field observations of F 2 fold geometries, we suggest that those patterns formed due to local variations in the displacement directions during the F 2 folding, perhaps due to the mechanical influence of relatively competent pegmatite veins on the small-scale F 2 folds. The very high D 2 strain has then amplified the dome and basin elements to very elongate cone and cylinder forms. This creates local type 1 patterns within a regional type 2 interference pattern structure.
A gustatory receptor paralogue controls rapid warmth avoidance in Drosophila

After previously discovering that the ion channel TRPA1 is used as an internal temperature sensor in Drosophila to control the slow response of flies to shallow thermal gradients, the authors show here that the rapid response of flies to steep warming gradients relies on a different protein, GR28B, providing the first example of a thermosensory role for a gustatory receptor. Flies use the TRPA1 ion channel as an internal temperature sensor to slowly adjust their response to shallow thermal gradients. Now Paul Garrity and colleagues show that the rapid response of flies exposed to steep warmth gradients does not require TRPA1, but instead relies on the gustatory receptor GR28B(D), acting in peripheral thermosensing cells. Gustatory receptors have been implicated in taste, olfaction and host-seeking by disease-vector insects, but have not previously been linked with thermosensation. Behavioural responses to temperature are critical for survival, and animals from insects to humans show strong preferences for specific temperatures1,2. Preferred temperature selection promotes avoidance of adverse thermal environments in the short term and maintenance of optimal body temperatures over the long term1,2, but its molecular and cellular basis is largely unknown. Recent studies have generated conflicting views of thermal preference in Drosophila, attributing importance to either internal3 or peripheral4 warmth sensors. Here we reconcile these views by showing that thermal preference is not a singular response, but involves multiple systems relevant in different contexts. We found previously that the transient receptor potential channel TRPA1 acts internally to control the slowly developing preference response of flies exposed to a shallow thermal gradient3. We now find that the rapid response of flies exposed to a steep warmth gradient does not require TRPA1; rather, the gustatory receptor GR28B(D) drives this behaviour through peripheral thermosensors. Gustatory receptors are a large gene family, widely studied in insect gustation and olfaction, and are implicated in host-seeking by insect disease vectors5,6,7, but have not previously been implicated in thermosensation. At the molecular level, GR28B(D) misexpression confers thermosensitivity upon diverse cell types, suggesting that it is a warmth sensor. These data reveal a new type of thermosensory molecule and uncover a functional distinction between peripheral and internal warmth sensors in this tiny ectotherm reminiscent of thermoregulatory systems in larger, endothermic animals2. The use of multiple, distinct molecules to respond to a given temperature, as observed here, may facilitate independent tuning of an animal’s distinct thermosensory responses.
Effect of exenatide on the pharmacokinetics of a combination oral contraceptive in healthy women: an open-label, randomised, crossover trial

Consistent with its effect on gastric emptying, exenatide, an injectable treatment for type 2 diabetes, may slow the absorption rate of concomitantly administered oral drugs resulting in a decrease in maximum concentration (Cmax). This study evaluated the drug interaction potential of exenatide when administered adjunctively with oral contraceptives, given their potential concomitant use. This trial evaluated the effect of exenatide co-administration on single- and multiple-dose pharmacokinetics of a combination oral contraceptive (ethinyl estradiol [EE] 30 μg, levonorgestrel [LV] 150 μg [Microgynon 30®]). Thirty-two healthy female subjects participated in an open-label, randomised, crossover trial with 3 treatment periods (oral contraceptive alone, 1 hour before exenatide, 30 minutes after exenatide). Subjects received a single dose of oral contraceptive on Day 8 of each period and QD doses on Days 10 through 28. During treatment periods of concomitant usage, exenatide was administered subcutaneously prior to morning and evening meals at 5 μg BID from Days 1 through 4 and at 10 μg BID from Days 5 through 22. Single- (Day 8) and multiple-dose (Day 22) pharmacokinetic profiles were assessed for each treatment period. Exenatide did not alter the bioavailability nor decrease daily trough concentrations for either oral contraceptive component. No substantive changes in oral contraceptive pharmacokinetics occurred when oral contraceptive was administered 1 hour before exenatide. Single-dose oral contraceptive administration 30 minutes after exenatide resulted in mean (90% CI) Cmax reductions of 46% (42-51%) and 41% (35-47%) for EE and LV, respectively. Repeated daily oral contraceptive administration 30 minutes after exenatide resulted in Cmax reductions of 45% (40-50%) and 27% (21-33%) for EE and LV, respectively. Peak oral contraceptive concentrations were delayed approximately 3 to 4 hours. Mild-to-moderate nausea and vomiting were the most common adverse events observed during the trial. The observed reduction in Cmax is likely of limited importance given the unaltered oral contraceptive bioavailability and trough concentrations; however, for oral medications that are dependent on threshold concentrations for efficacy, such as contraceptives and antibiotics, patients should be advised to take those drugs at least 1 hour before exenatide injection. ClinicalTrials.gov: NCT00254800 .
Comments on “coherence length and/or transfer width?”☆

Abstract A formula proposed to define the coherence length in molecular beam scattering from crystals is discussed.
Low-frequency energy deficit in electrolaryngeal speech.

The present exploratory project was undertaken (a) to determine the relative strength of low-frequency energy in the output of one widely used electronic artificial larynx (Servox) and (b) to asses...
Can This Really Be the End? Nation, Salvation, Commodification, Preservation

This essay begins with the close connections between messianism and superhero comics. In trying to understand how narrative functions, I take the classical epic as the master narrative and observe the ways in which the messianic tale and the comic book critique it. Looking at all three in relation to each other, we can see that death and embodiment are powerful items in the narrative toolkit, as part of a discourse of preservation in which narrative genres speak back and forth between cultural contexts.
The Great Recession, somatic symptomatology and alcohol use and abuse

While most research has examined the long-term effects of alcohol consumption on health, the current study examines how health status impacts on drinking behavior. Using data from a national study conducted between 2010 and 2011 to assess the impact of the recession on drinking behavior, this study examines how economic hardships linked to the recent economic recession affect physical health, and how physical health may in turn affect alcohol use. Structural equation models were used to test the predicted associations. The data demonstrate that many of the economic stressors linked to the recession are associated with increased somatic symptoms. Somatic symptoms are also associated with increased drinking for men, but not for women. These findings suggest that men may use alcohol to self medicate somatic symptomatology. The current findings are consistent with gender role-based explanations that account for gender disparities in the utilization of medical care.
Loss and Regeneration of Betacyanin Pigments During Processing of Red Beets

Samples of red beets were analyzed for betacyanin pigment losses during processing by high performance liquid chromatography. Total pigment loss was 41% after canning relative to the pigment content of fresh beets. Blanching to an internal temperature of 66°C caused a 23% loss while sterilization at 126°C for 10 min accounted for a loss of 22% of the pigment content of blanched beets. The betanin-isobetanin ratio changed with increasing heat treatment. The ratio for fresh, blanched and sterilized beets was 25:1, 9:1, and 2.5:1, respectively. Pigment regeneration after heating was observed in all samples, and was measured in beet juice and purified pigment solutions immediately and after appropriate intervals. Completion of pigment regeneration occurred within 10 hr in beet juice and 2 hr in purified pigment solutions.
The impact of the social context on resistance to persuasion : Effortful versus effortless responses to counter-attitudinal information

Abstract Past research has demonstrated that the presence of attitudinal diversity within a person’s social network increases his or her openness to attitude change. The current research explores whether this increased openness to attitude change is the result of relatively thoughtful or nonthoughtful processes. A nationally representative sample of US adults was exposed to a counter-attitudinal persuasive message that contained either strong or weak arguments. Attitudinal diversity within participants’ social networks was associated with greater argument quality differentiation: people embedded in networks that included a variety of views were more likely than those in attitudinally homogenous networks to carefully scrutinize attitude-relevant information, modifying their attitudes in response to strong but not weak arguments.
Status of aerial applications research in the Langley Vortex Research Facility and the Langley full-scale wind tunnel

Small scale models of agricultural airplanes were tested and numerical methods were utilized to study interactions between the airplane wake and the dispersed spray and granular materials. Methods were developed to measure and predict dispersal transport and wake characteristics and dispersal techniques to obtain interactions more favorable to wide, uniform deposition patterns and reduced drift. In the full scale wind tunnel, full scale agricultural airplanes and dispersal systems for both liquid and solid applications were evaluated to improve aircraft aerodynamics and dispersal systems efficiency. The program status in these two facilities is reported with emphasis on wake interactions and dispersal systems research.
Dynamics of neovascularization in normal tissue

Abstract Neovascularization of normal tissue was investigated by observing tissue grown in a transparent rabbit ear chamber. Stereological principles, applied to photomicrographs of the tissue, quantified vascular characteristics such as surface area, volume, and length per cubic millimeter of tissue. Mathematical models were developed to simulate growth of the microvasculature. The model developed here possesses, at least from a qualitative point of view, two important properties of observable growth kinetics: cell debris, mostly dead red blood cells and platelets, is required for the neovascularization to begin, and vessel density exhibits a maximum before reaching the steady-state value.
A reflection-absorption infrared study of carbon monoxide and nitric oxide adsorption on platinum (100)

Abstract The adsorption of NO, CO, and NO/CO mixtures, onto Pt(100), is studied by RAIRS. CO and NO are found to adsorb into islands at 300 K, but the islands breakup upon heating to 400 K. Dosing with a mixture of NO and CO at temperatures below 325 K is found to produce a mixed NO/CO island. There is a shift in the CO peak and NO peak during mixed island formation which is attributed to a strong chemical interaction between the adsorbed NO and CO. This interaction is found to produce an increase in the desorption temperature of CO. Autocatalytic behavior is found to arise because of an enhanced reactivity when CO enters a mobile state. The autocatalytic behavior could be responsible for the “surface explosion” reported by Lesly and Schmidt.
Simple manipulation-resistant voting systems designed to elect Condorcet candidates and suitable for large-scale public elections

This article focuses on voting systems that (i) aim to select the Condorcet candidate in the common case where one exists and (ii) impede manipulation by exploiting voter knowledge of electorate preferences. The systems are relatively simple, both mathematically and for voter understanding, and are fully workable for large-scale elections. Their designated equilibrium strategies, under which voters vote sincerely, involve discerning the top one or two candidates in the preference ordering of the electorate. One set of systems uses its ballot to obtain voters’ preference rankings plus approval votes, and tallies the latter if no Condorcet winner exists. It offers solid advantages vis-a-vis instant-runoff voting, which uses a kindred ballot and has attracted recent reformers. Another set of systems uses only approval voting, which is examined from a new angle.
Principal components analysis of the atlas vertebra

Abstract Objective This project explored morphological asymmetry of the atlas by comparing multiple structural variables bilaterally using multivariate statistics. Methods Two hundred thirty-seven atlases were obtained from the Hamann-Todd Osteological Collection (Cleveland Museum of Natural History, Cleveland, Ohio). The following dimensions were bilaterally measured: anteroposterior length of the superior articular facet, width of the superior articular facet, length of the transverse process, width of the vertebral canal, anteroposterior diameter of the inferior facet, height of the lateral mass, transverse diameter of the inferior articular facet, width of the inferior lateral mass, slope of the inferior facet, convergence angle of the superior facet, circumference of the inferior articular facet, and circumference of the superior articular facet. Principal components analysis (varimax rotation) was used to determine sources of variation within the dataset. Multivariate analysis of variance and paired t tests were used to identify statistical differences between right and left sides for each variable. Results More than 99% of variance was accounted for across 11 eigenvectors, with most eigenvectors dominated by a single variable. Bilateral comparison of variables showed a significant difference between sides for the anteroposterior length of the superior facet, the width of the superior facet, the width of the vertebral canal, anteroposterior diameter of the inferior facet, and convergence angle of the superior facet (all significant at P Conclusion Based on statistical analysis of the atlantal variables, vertebral canal width and the morphology of the superior and inferior articular facets showed significant asymmetry. The role of these asymmetries related to the biomechanics of the C0 through C1 and encroachment on the spinal cord warrant further investigation.
Effect of methylene spacers on the spectral, electrochemical, and structural properties of bis(4,4'-disubstituted-2,2'-bipyridyl) ruthenium(II) dye analogues.

Two new ruthenium complexes, [Ru(L1OMe)2(NCS)2] and [Ru(L2OMe)2(NCS)2] (where L1OMe = 2,2′-bipyridine-4,4′-di(methyl ethanoate) and L2OMe = 2,2′-bipyridine-4,4′-di(methyl propionate)), have been synthesized and characterized using spectroscopic and electrochemical techniques. The [Ru(L2OMe)2(NCS)2] complex has also been characterized by X-ray diffraction studies and reveals a distorted octahedral coordination geometry about the ruthenium center. Cyclic voltammetry studies of both complexes exhibit quasi-reversible Ru(II/III) couples and a number of ligand reduction events. The complex with one methylene spacer between the bipyridyl ligand and the methyl ester functional group, [Ru(L1OMe)2(NCS)2], was particularly unstable under reducing conditions. The properties of these complexes are compared with the ethyl ester analogue of the N3 photosensitizer [Ru(L0OEt)2(NCS)2].
Herpes simplex virus 2 ICP34.5 confers neurovirulence by regulating the type I interferon response

The γ34.5 gene of herpes simplex virus (HSV) 2 encodes ICP34.5, which enhances HSV-2 neurovirulence by an unknown mechanism. We found that an HSV-2 γ34.5-null mutant (γ34.5(-/-)) replicated less robustly than its rescue virus (γ34.5R) in wild-type mouse embryo fibroblasts (MEFs), and in cells primed with IFNβ. Increased eIF2α phosphorylation correlated with γ34.5(-/-) attenuation. However, γ34.5(-/-) achieved titers equivalent to γ34.5R in MEFs lacking the type I IFN receptor (IFNα/βR(-/-)) or lacking protein kinase R. γ34.5(-/-) also replicated poorly in the vaginal mucosa of wild-type mice, caused little genital inflammation, and spread to the nervous system at lower levels compared to γ34.5R. In IFNα/βR(-/-) mice, however, γ34.5(-/-) regained the capacity to replicate and cause disease equivalent to γ34.5R after intravaginal infection or direct inoculation into the central nervous system. Thus, the capacity of HSV-2 ICP34.5 to interdict the type I IFN response in vivo largely determines its neurovirulence.
Molecular tension sensors report forces generated by single integrin molecules in living cells

Living cells are exquisitely responsive to mechanical cues, yet how cells produce and detect mechanical force remains poorly understood due to a lack of methods that visualize cell-generated forces at the molecular scale. Here we describe Forster resonance energy transfer (FRET)-based molecular tension sensors that allow us to directly visualize cell-generated forces with single-molecule sensitivity. We apply these sensors to determine the distribution of forces generated by individual integrins, a class of cell adhesion molecules with prominent roles throughout cell and developmental biology. We observe strikingly complex distributions of tensions within individual focal adhesions. FRET values measured for single probe molecules suggest that relatively modest tensions at the molecular level are sufficient to drive robust cellular adhesion.
Complex biological models: Their construction and effective use

Abstract The need for complex models in biology, and reasons such as esthetics and tradition for resistance to their use, are discussed. Examples considered are an existing cardiac metabolism model, and a possible comprehensive and complex diabetes model, with their associated problems. Characteristic problems of complex modeling include how complex a model should be, combination and interaction of models from different sources, the kind of underlying information involved, and the usual problems of model credibility. Specific problems of biological modeling include: effective interaction with experimenters to secure timely solution of currently important problems, (e.g., by experimental design), and effective interaction within the community of biological modelers.
On the gauge transformations admitted by the equations of defect dynamics

Abstract This paper deals with gauge invariance applied to dislocations and disclinations in the field theory formulation given by Kossecka and de Wit[1,2]. The gauge transformations of the strain, linear velocity, bend-twist, and rotational velocity that leave the dislocation and disclination densities and currents invariant are obtained explicitly, and the equations of balance of linear momentum are shown to lead to a natural gauge condition. These transformations are generated by a vector field that depends upon position and time and two vector fields that depend on time alone. The latter two fields are shown to realize superimposed rigid body motions as part of the generalized gauge transformation structure of the theory. Representation of the space and time generating vector in terms of a gradient plus the curl of another vector is shown to lead to several useful decompositions.
Autologous blood patch for persistent air leak in children

Abstract Purpose Persistent air leak (PAL) is associated with increased morbidity. Standard treatment of PAL includes chemical or mechanical pleurodesis. Long-term impact of these interventions is not known in the pediatric population. Autologous blood patch (ABP) offers a novel treatment option. We report our experience with autologous blood patch to successfully treat PAL in eight children. Methods Children with PAL were treated with ABP. A fresh whole blood sample was obtained from each patient and injected via their pre-existing chest tube. Volume of blood injected, time to cessation of air leak, time to chest tube removal, outcomes and complications were reviewed. Results Eight children aged 2 months to 18 years underwent ABP. Three children had immediate seal of air leak, while two patients sealed after 1 and 2 days. Three patients required a second ABP, after which they had immediate seal of air leak. Chest tubes were removed within 2–3 days in 7 cases. One child developed an asymptomatic pneumothorax and required 8 days for radiographic resolution. Conclusion ABP appears to be a safe and effective treatment option for PAL in children. ABP offers an inexpensive, easy to perform technique and avoids use of toxic chemicals for pleurodesis in pediatric patients.
Comparison of Cylinder Data and Code Calculations for Homogeneous Explosives

Vergleich der Zylindertest-Daten mit den Rechen-Codes fur homogene Explosivstoffe Daten aus dem Kupferzylindertest von homogenen Explosivstoffen wurden gesammelt und verglichen mit den Relativ-Volumina nahe 2, 4 und 7. Die Detonationsenergien, proportional zum Quadrat der Zylinderwandgeschwindigkeit, wurden bezogen auf hochverdichtetes PETN. Diese Energien werden verglichen mit JWL-Werten, die abgeleitet wurden aus dem Hydrocode und aus den drei Codes fur das Chemische Gleichgewicht: Tiger BKWR, Tiger JCZ3 und CHEQ. Die Werte des BKWR sind durchweg hoch, konnen aber korrigiert werden durch Eichung mit PETN. JCZ3 liefert die besten allumfassenden Energiewerte der 3 Modelle, obwohl diese durchweg hoch sind bei v, = 2. Die gesamte Detonationsenergie beim JWL-Code liegt nahe der gemessenen Werte. Alles in allem ist die Qualitat beim Fitten der thermochemischen Codes auf die aus den Zylinderwerten abgeleiteten Detonationsenergien schlecht und ein renormalisierter Code is dringend notwendig.
On the relation between undetected errors and the error detection criteria of a Reed-Solomon decoder correcting errors and erasures

This paper makes an analysis based on tests, of the relation between the various error detection criteria used in the decoding of error-and-erasure correcting Reed-Solomon codes, and the undetected errors this decoder produces. A strong correlation is found to exist between the number of erasures /spl rho/ and the number of undetected errors: errata patterns with an even number of erasures cause a considerable larger number of undetected errors than patterns with an odd number of erasures. A suggestion how to improve the decoder probability of undetected error by discarding one erasure if /spl rho/ is even, and its effect on the degradation of the probability of correct decoding, is also discussed.
DRUNK DRIVING LEGISLATION AND TRAFFIC FATALITIES: NEW EVIDENCE ON BAC 08 LAWS

This article reexamines the effectiveness of blood alcohol content (BAC) laws in reducing traffic fatalities. Differences-in-differences estimators of U.S. state-level data with standard errors corrected for autocorrelation show no evidence that lowering the BAC limits to 0.08 g/dL reduced fatality rates, either in total or in crashes likely to be alcohol related, or in states that passed BAC 08 in laws either in advance of or in response to federal pressure. Other legislations, including administrative license revocation and primary seat belt laws, are found effective in reducing fatalities in all specifications. Endogeneity tests using event analyses confirm the differences-in-differences estimates. (JEL I18, K32)
Early Insulin Glycemic Control Combined With tPA Thrombolysis Reduces Acute Brain Tissue Damages In A Focal Embolic Stroke Model Of Diabetic Rats

Background and Purpose—Therapeutic effects of early insulin glycemic control for poststroke hyperglycemia in combination with tissue-type plasminogen activator (tPA) thrombolytic therapy have not yet been studied but are of great clinical interest. In this study, we tested the effects of insulin plus tPA combination in a model of focal embolic stroke in Type I diabetic rats. Methods—Streptozotocin was used to produce Type I diabetes in male Wistar rats for 6 weeks and then embolic focal strokes were induced. All rats were treated with insulin or saline at 1 hour followed by tPA or saline at 1.5 hour after stroke. Mortality, infarction, hemispheric swelling, hemorrhagic transformation, and perfusion defects were examined at 24 hours after stroke. Total plasma plasminogen activator inhibitor-1 antigen and activity levels were measured before stroke and 1.5, 3, and 6 hours after stroke by ELISA. Results—Early insulin glycemic control alone or tPA thrombolysis alone had no significant effects on ischemic infa...
High throughput screening of CO2-tolerating microalgae using GasPak bags

Microalgae are diverse in terms of their speciation and function. More than 35,000 algal strains have been described, and thousands of algal cultures are maintained in different culture collection centers. The ability of CO2 uptake by microalgae varies dramatically among algal species. It becomes challenging to select suitable algal candidates that can proliferate under high CO2 concentration from a large collection of algal cultures. Here, we described a high throughput screening method to rapidly identify high CO2 affinity microalgae. The system integrates a CO2 mixer, GasPak bags and microplates. Microalgae on the microplates will be cultivated in GasPak bags charged with different CO2 concentrations. Using this method, we identified 17 algal strains whose growth rates were not influenced when the concentration of CO2 was increased from 2 to 20% (v/v). Most CO2 tolerant strains identified in this study were closely related to the species Scenedesmus and Chlorococcum. One of Scenedesmus strains (E7A) has been successfully tested in in the scale up photo bioreactors (500 L) bubbled with flue gas which contains 10-12% CO2. Our high throughput CO2 testing system provides a rapid and reliable way for identifying microalgal candidate strains that can grow under high CO2 condition from a large pool of culture collection species. This high throughput system can also be modified for selecting algal strains that can tolerate other gases, such as NOx, SOx, or flue gas.
Effects of self-focusing on multiphoton absorption processes in polymer bis-paratoluene sulfonate (PTS)

Summary form only given. The spectral dispersion of multiphoton absorption (MPA) is important in nonlinear optics. For example, two-photon absorption (TPA) reveals the locations of even-symmetry excited states. Previous Z-scan experiments on poor optical quality crystals of bis-paratoluene sulfonate (PTS) have shown, at 1600 nm, the existence of strong four-photon absorption. We have recently developed new crystal growth and polymerization techniques to improve crystal quality substantially. Z-scan experiments have shown much larger MPA than previously and a dependence of the coefficients on a sample thickness. Here we report new measurements of the multi-photon absorption coefficients /spl alpha//sub 5/ and /spl alpha//sub 4/ where /spl Delta//spl alpha/=/spl alpha//sub 3/I/sup 2/+/spl alpha//sub 4/I/sup 3/ and interpret this thickness effect.
Structured flowcharts outperform pseudocode: an experimental comparison

The author discovered, while teaching a course on data structures, that his students overwhelmingly preferred structured flowcharts over pseudocode for comprehending the algorithms presented. He describes an experiment that he designed to find out if real differences in comprehension exist between structured flowcharts and pseudocode when used to describe conditional logic. He hypothesized that structured flowcharts (1) take less time to comprehend, (2) produce fewer errors in understanding, (3) give students more confidence in their understanding of an algorithm, (4) reduce the time spent answering questions about an algorithm, and (5) reduce the number of times students need to look at an algorithm. These hypotheses were tested on three algorithms of varying complexity. The results strongly indicate that structured flowcharts do indeed aid algorithm comprehension. A large difference was found even for the simplest algorithm. >