cssi/SciSciGPT-SciSciNet huggingface dataset:
Antibiotic prophylaxis in anterior skull-base surgery: a survey of the North American Skull Base Society.

BACKGROUND There is a paucity of data evaluating antibiotic use in anterior skull-base surgery (ASBS). The goal of this study was to determine antibiotic prescribing patterns and factors that influence antibiotic use in ASBS. METHODS An online-based survey was distributed to the membership of the North American Skull Base Society in 2018. Outcomes included practitioner preference regarding intraoperative and postoperative antibiotic use, practice location and environment, surgeon experience, and patient factors influencing antibiotic use. RESULTS There were 208 respondents (25.6% response rate) of which 182 (87.5%) performed ASBS; 60.4% were in academic institutions. Respondents were neurosurgeons (59.3%) or otolaryngologists (40.7%), and 75.3% were fellowship-trained in ASBS. Most surgeons (95.0%) gave intraoperative antibiotics. Academic surgeons were 4 times more likely to prescribe intraoperative antibiotics than private practitioners (odds ratio [OR] 3.98; 95% confidence interval [CI], 1.53 to 10.36; p = 0.005). Among surgeons who did not routinely prescribe intraoperative antibiotics, regression analysis indicated that the presence of actively infected sinuses, transplantation, diabetes, human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS), and pulmonary disease influenced decision-making (p < 0.03). Postoperative antibiotics were prescribed by 73.6% of respondents. European surgeons were 3 times less likely to prescribe postoperative antibiotics (OR 0.34; 95% CI, 0.15 to 0.80; p = 0.01). Regression modeling indicated that HIV/AIDS, cystic fibrosis, diabetes, transplantation, and pulmonary disease, as well as the use of absorbable packing influenced the decision to use postoperative antibiotics (p < 0.003). CONCLUSION This study demonstrates the significant variation in intra- and postoperative antibiotic use among surgeons performing ASBS. Prospective randomized studies are necessary to establish evidence-based practice guidelines for perioperative antibiotic use in ASBS.
Inappropriate noise detection in Tendril family pacing leads.

INTRODUCTION Noise oversensing encountered in patients with Abbott Tendril leads in our hospital triggered an internal investigation. METHODS We retrospectively analyzed patients with a Tendril lead model 1688, 1788, 1888, and 2088. Most leads were connected to Abbott generators. To exclude a primary generator issue as the cause of noise oversensing, we enrolled a cohort of patients in whom Medtronic CapSureFix leads model 4076 and 5076 were prospectively connected to similar Abbott generators. RESULTS A total of 1063 Tendril leads were implanted in 869 patients. Noise was encountered in 66 leads (6.2%) during a follow-up of 3.9 years. Most affected leads had normal impedance and only a few of these patients were symptomatic. Reprogramming was attempted in 44 of 66 (67%), and reduced oversensing in 34 of 44 (77%) of these patients. Seventeen malfunctioning leads (1.5%) were replaced, including 16 of 66 (24%) of those with noise. Of the four leads with noise extracted and returned to the manufacturer, lead to device abrasion was identified in two and inner insulation breach in one. None of the 145 Medtronic CapSureFix leads connected to Abbott generators had noise during a follow-up of 3.6 years. CONCLUSION Noise oversensing was relatively common in Tendril leads, but was not detected in Medtronic leads despite connecting to Abbott generators. Although the majority of the affected leads did not show abnormal impedance, outer or inner insulation breach was identified in three of the four returned leads. As patients with affected leads are generally asymptomatic, most of them can be managed conservatively.
Neuromuscular blocking agents and skeletal muscle relaxants

Abstract Neuromuscular blocking agents and skeletal muscle relaxants are commonly used medications in the critically ill patient population. Like all medications, these come with adverse effects that must be evaluated and taken into consideration when choosing a particular medication. Adverse effects are directly related to their mechanism of action on the central nervous system and skeletal muscle, but can also extend to multiple other organ systems such as respiratory system, cardiovascular system, gastrointestinal system, and renal system. The following literature is an update from previous volumes of Side Effects of Drug Annual that describes adverse effects with neuromuscular blockers and skeletal muscle relaxants.
Ion-doped hydroxyapatite: An impasse or the road to follow?

Abstract Doping hydroxyapatite (HAp) with foreign ions has been increasing in popularity as a chemical approach to augment the existing and impart new properties to it. However, it is uncertain whether this approach can elicit properties strong enough to make HAp competitive for commercial applications in biomedicine and elsewhere. In particular, material properties, such as grain size, morphology, surface charge, porosity, topology and others may prove to be more effective in controlling properties of HAp than the dopant choice and concentration. This study tackles this question through a meta-analysis of the dependence of selected materials properties on dopant concentrations reported across the literature, showing that doping is a convenient way of controlling some, but not all properties in HAp and should be implemented ideally in combination with other structural and compositional factors of influence. This meta-analysis is coupled to a bibliographic analysis of the evolution of trends in terms of the type, frequency and concurrency of dopants in HAp, covering the entire Periodic Table, all 72 elements incorporated into HAp so far and the 1990 – 2019 period split into successive lustra. The study demonstrates a continuously ascending trend in popularity of certain elements, such as Sr, Ce and Se, and a continuously declining trend of others in the past two decades, including F, Y, I, Ti and most lanthanides. For the fourth period transition metals a trend of constancy was observed and for yet other elements, including Ag and Mg, a period of ascent was succeeded by a steady decline, the onset of which coincided in the case of Ag with the peak in the airing of the concerns over its cytotoxicity by the scientific community. Reasons for these trends with respect to most elements are explained and connected with trends governing broader realms of materials science. It is shown that the choice of ions as dopants in HAp is largely driven by broader trends in materials science, rendering the doped HAp a mirror to view these existing and past trends in. Theoretically, by following the historic progression of these trends, a gaze in this mirror could assist in extrapolation of future trends, which normally come at the cost extinguishing some of the existing ones. This immersion in more general developments in materials science opened the path toward drawing connections between the bibliographically assessed geopolitical trends in doped HAp and in broader aspects of the scientific community, including the growing gap between the rich and the poor pervading it. The analysis reported here is conceptually novel and could be applied to numerous other materials.
Real-time weed-crop classification and localisation technique for robotic weed control in lettuce

Robotic weed control for vegetables is necessary to increase crop productivity, avoid intensive hand weeding as labour shortages in developed countries such as United States has led to a surge in food production costs. However, development of a reliable, intelligent robotic system for weed control in real-time for vegetables still remains a challenging task. The main issue arises while distinguishing crops from weeds in real-time. In this paper, a novel technique to crop signalling to distinguish crops from in-row weeds in complex natural scenarios, such as high weed densities commonly found on organic farms, in real-time using machine vision is presented. Crop signalling is a simple and low-cost technique in which a signalling compound is produced by or applied to the crop and where the signalling compound is machine readable and helps to create visual features that uniquely distinguish the crops from weeds. The crop and weed mapping algorithm presented here were specially designed and developed for a vision-based weeding robot equipped with a micro-jet herbicide-spraying system for weed control in a lettuce field. The proposed technique involves weed/crop mapping and decision making. Experimental results show that the crop detection accuracy was 99.75%, and 98.11% of sprayable weeds were detected. The proposed technique is highly accurate, reliable and more robust than other sensor-based techniques presented in the literature.
Progress and issues in second-order analysis of hippocampal replay

Patterns of neural activity that occur spontaneously during sharp-wave ripple (SWR) events in the hippocampus are thought to play an important role in memory formation, consolidation and retrieval. Typical studies examining the content of SWRs seek to determine whether the identity and/or temporal order of cell firing is different from chance. Such 'first-order' analyses are focused on a single time point and template (map), and have been used to show, for instance, the existence of preplay. The major methodological challenge in first-order analyses is the construction and interpretation of different chance distributions. By contrast, 'second-order' analyses involve a comparison of SWR content between different time points, and/or between different templates. Typical second-order questions include tests of experience-dependence (replay) that compare SWR content before and after experience, and comparisons or replay between different arms of a maze. Such questions entail additional methodological challenges that can lead to biases in results and associated interpretations. We provide an inventory of analysis challenges for second-order questions about SWR content, and suggest ways of preventing, identifying and addressing possible analysis biases. Given evolving interest in understanding SWR content in more complex experimental scenarios and across different time scales, we expect these issues to become increasingly pervasive. This article is part of the Theo Murphy meeting issue 'Memory reactivation: replaying events past, present and future'.
Linear spectral statistics of eigenvectors of anisotropic sample covariance matrices

Consider sample covariance matrices of the form $Q:=\Sigma^{1/2} X X^* \Sigma^{1/2}$, where $X=(x_{ij})$ is an $n\times N$ random matrix whose entries are independent random variables with mean zero and variance $N^{-1}$, and $\Sigma$ is a deterministic positive-definite matrix. We study the limiting behavior of the eigenvectors of $Q$ through the so-called eigenvector empirical spectral distribution (VESD) $F_{\mathbf u}$, which is an alternate form of empirical spectral distribution with weights given by $|\mathbf u^\top \xi_k|^2$, where $\mathbf u$ is any deterministic unit vector and $\xi_k$ are the eigenvectors of $Q$. We prove a functional central limit theorem for the linear spectral statistics of $F_{\mathbf u}$, indexed by functions with H{o}lder continuous derivatives. We show that the linear spectral statistics converge to universal Gaussian processes both on global scales of order 1, and on local scales that are much smaller than 1 and much larger than the typical eigenvalues spacing $N^{-1}$. Moreover, we give explicit expressions for the means and covariance functions of the Gaussian processes, where the exact dependence on $\Sigma$ and $\mathbf u$ allows for more flexibility in the applications of VESD in statistical estimations of sample covariance matrices.
Reasons for and experience in obtaining pharmacist prescribed contraception

Abstract Objective To describe reasons for and experiences with obtaining contraception from pharmacists. Study design Cross-sectional survey. Results Our sample included 426 women presenting for hormonal contraception (n = 150 pharmacist prescribers). The most common reasons women chose to obtain their contraception from a pharmacist were because no appointment was required (25%) or their prescription had lapsed (24%). Women receiving contraception from pharmacists were highly satisfied (95.3% vs 100.0%; p = 0.007). Women recalled similar side-effects counseling points regardless of prescriber type (p = 0.30). Conclusion Women chose to obtain contraceptive care at the pharmacy because it was timely and convenient.
Least Squares Monte Carlo and Approximate Linear Programming with an Energy Real Option Application

Least Squares Monte Carlo and Approximate Linear Programming with an Energy Real Option Application
Testing Relationships Between Racial-Ethnic Identity, Racial-Ethnic Discrimination, and Substance Misuse Among Black and Latinx Older Adults in a Nationally Representative Sample:

Older adults (aged 55+) comprise a rapidly growing population both in number and racial-ethnic diversity. In recent years, substance misuse prevalence among older adults has increased and is expect...
Prospective Associations between Attitudes toward Sweet Foods, Sugar Consumption, and Cravings for Alcohol and Sweets in Early Recovery from Alcohol Use Disorders.

Sweet liking (heightened preference for highly sweet solutions) is linked to Alcohol Use Disorder (AUD) and relapse, as well as attitudes toward sweet foods – use of sugar to cope with negative aff...
Van der Waals material integrated nanophotonics

Atomically thin van der Waals (vdW) materials have generated strong interest in the community due to its unusual physical properties and possibility of creating high-performance devices. However, the ultrathin nature of these materials limits the achievable light-matter interaction. One promising way to increase such interaction is via nanophotonic confinement of light. In fact, researchers have demonstrated various nanophotonic devices using such vdW materials, including optically pumped lasing, second harmonic generation, cavity enhanced electroluminescence, and exciton-polaritons. In this talk, I will explore the possibility of going to quantum optical regime using this material system integrated with nanophotonic resonators. I will discuss the role of exciton-phonon interaction in the cavity photoluminescence spectrum and present a quantum optical model of the coupled system in presence of the phonons. I will then report the observation of the exciton-polaritons using TMDs.
“Fight for Your Land”: Southern High School Activism and the Struggle for Youth Autonomy During and After the Second World War

This chapter examines the politics of southern high school student activism and the historically Black high school during and after the Second World War. As an institution designed to protect and prepare youth, the Black high school was the most important state institution in the lives of youth during and after the Second World War. By the 1940s, Black high schools, in concert with the NAACP and the Southern Negro Youth Congress (SNYC), built upon the foundations of a youth movement established a generation before the war. Students, teachers, and civil rights organizers transformed high school youth and the institutions they attended into critical sites that presaged the activism and politics of a burgeoning freedom struggle that defined the 1950s and 1960s.
Nanomechanical Characterization of the Carbonated Wollastonite System

This paper focuses on the nano-mechanical characterization of carbonated calcium silicate mineral (wollastonite (CaSiO3)) using nanoindentation technique. While exposed to carbon dioxide (CO2), the calcium component of wollastonite undergoes carbonation reaction which results in formation of two main products: calcium carbonate (CaCO3) and silica (SiO2). The mechanical properties of these partially reacted wollastonite systems were evaluated using the nanoindentation technique from which the reduced elastic modulus (Er) of silicate phase found to be around 38 GPa. For calcium carbonate phase this value was around 60 GPa.
When We Motated off the Face of the Earth

THE SUMMER OF THE YEAR we motated off the earth, my husband's bicycle was broken. He took this pretty well, considering?not six months before?he was almost strangled into silence by his own nerves, shot to pieces and aimless. He was not a person driven to grab whatever gusto he could get (especially if this bothered the neighbors), to win friends, or to influence anyone, really. For no good reason he didn't fit on this planet. He couldn't make himself fit in. He could no longer say what his dreams were?or what they had been. Did you ever dream you could fly? The day we motated off the face of the earth was like that. In dreams (or was this real?) I have pushed off from the bottom of the ocean and floated up through the quilted buoyant blue, feet like wings on the pedals, powering me?us?forward. Two spokes and a piece of flange had broken off the rear axle of my hus band's bicycle and there we were, on the far side of Wyoming, the closest bike dealer three hundred miles away. Ahead of me my husband's sweaty, hunkered-down back (the color of wet wood with tiny freckles on each shoulder) had pulled my bicycle in its draft, a pull stronger than I could explain. On the east side of the Wind River Range a hawk shrieked from somewhere over the ridge. A herd of antelope like chess pieces grazed below the rocks fifty yards from the highway. Going uphill, of course, you must do your own work. There's not much draft at that slow a pace. His rear wheel wobbles, though with our spoke wrench we have trued it as best we can. We've released the rear brake so the wobbly tire doesn't rub. We have repacked the bulk of his load onto my bike: tools, tent, extra water. Still, he does not feel safe. Once over the top and descending, his big back blocks the wind and pulls me along like music. From the mountains to the prairies to the oceans white with foam, I'm a steamroller, baby, I'm gonna roll all over you, this land is your land, they call the wind Mariah. The wind sears our eyes inside our sunglasses; tears dry on our cheeks. Naturally my husband must apply his brakes.
The use of detrital mineral cooling ages to evaluate steady state assumptions in active orogens: An example from the central Nepalese Himalaya

[1] The distribution of detrital mineral cooling ages in modern sediments has been proposed as a proxy for long-term, catchment-averaged erosion rates in developing orogens. However, the applicability of this potentially valuable tool hinges on restrictive assumptions regarding a catchment's steady state thermal and topographic evolution. In this paper, we outline a method by which these assumptions can be tested through statistical comparisons of cooling age distributions for detrital minerals and the hypsometric curves for their source regions using cumulative synoptic probability density functions. Our approach is illustrated with new detrital muscovite 40Ar/39Ar dates from the Marsyandi River valley, in the central Nepalese Himalaya. One of three studied catchments (Nyadi Khola) showed the strong correlation of hypsometry and cooling ages expected for steady state conditions over the 11 to 2.5 Ma time frame. The pattern of mismatch between hypsometry and cooling age distribution in the other catchments suggests that spatially nonuniform and transient erosional processes may be responsible for departure from steady state. Cooling age distribution comparisons for samples collected from nearby localities, samples collected in different years, and different grain size fractions from the same sample were used to evaluate sampling fidelity over a range of spatial scales (200 to 2590 km2). We found that approximately 50 analyses from a single sediment sample adequately characterize the cooling age signal for tributary catchments with simple erosional histories. However, because of temporally and spatially transient erosion, a specific detrital sample is unlikely to adequately characterize the complex signal in trunk stream sediments that integrate information from several large tributaries.
Radiation from an Array of Longitudinal Fins of Triangular Profile

Radiation from an array of longitudinal fins of triangular profile is analyzed, including fin-to-fin and fin-to-base interactions. The effect of base cylinder radiation and the fin-base radiative interaction is found to be significant for fin width/tube radius ratios less than 8. Results presented may be used to optimize the design of a fin array with respect to weight.
Benefits of Alcoholics Anonymous Attendance

Abstract This study compared findings on the benefits associated with AA attendance across eleven clinical sites in Project MATCH. The largest benefit associated with AA attendance was increased abstinence, followed by reductions in alcohol-related consequences. The magnitude of these benefits did not differ between sites. A positive association was also found between AA attendance and increased purpose in life, but the size of this relationship was very small and was statistically significant only after controlling for measurement error. Several explanations are offered to reconcile findings in this study with earlier work concluding that: (1) treatment setting moderated subsequent AA benefit, and (2) AA attendance was associated with psychosocial improvement.
Fostering scientific argumentation by creating a need for students to attend to each other's claims and evidence

Scientific argumentation can provide students and teachers with opportunities to use evidence to make sense of the phenomena being studied and to engage in central practices of the scientific community. We posit that fostering the practice of argumentation requires transforming classroom interactions in order to create a need for students to attend to each other's claims and evidence. This paper examines the enactment of a 7th grade ecology unit created to generate this need and support these discussions. Our analyses of the student discussions show students moving beyond typical classroom interactions in order to understand the ways in which their claims differ and to evaluate one another's claims, in light of the evidence. Thus, we conclude that this approach of creating a need and supporting students as they attend to and critically evaluate one another's claims and evidence appears to be a promising strategy for fostering scientific argumentation.
Race, Employment Disadvantages, and Heavy Drinking: A Multilevel Model

AbstractWe intended to determine (1) whether stress from employment disadvantages led to increased frequency of heavy drinking and (2) whether race had a role in the relationship between such disadvantages and heavy drinking. Study data came from the National Longitudinal Survey of Youth, a prospective study that has followed a representative sample of youth since 1979. Our study employed data from 11 particular years, during which the survey included items measuring respondents’ heavy drinking. Our final sample numbered 10,171 respondents, which generated 75,394 person-waves for data analysis. Both of our hypotheses were supported by results from multilevel mixed-effects linear regression capturing the time-varying nature of three employment disadvantages and of the heavy-drinking outcome. Results show that more-frequent heavy drinking was associated with employment disadvantages, and that disadvantages’ effects on drinking were stronger for Blacks and Hispanics than for Whites. That worsening employment...
Mechanization, off-farm employment and agriculture.

Mechanization of agriculture has proceeded more rapidly in the Middle East and North Africa than in any of the other major areas of the developing world during the past 15 years (Binswanger 1986). Such technological change has been the response to both market forces and government policies. This paper focuses on the impact of labor market changes in inducing this form of change.
Patterns of gene flow and population genetic structure in the canyon treefrog, Hyla arenicolor (Cope).

Patterns of gene flow and genetic structuring were examined in the canyon treefrog, Hyla arenicolor (Cope). Hierarchical analysis of genetic variation was performed on mitochondrial cytochrome b haplotypes from 323 individuals, representing 32 populations from previously described phylogeographic regions. Results from AMOVA revealed that 60.4–78.9% of the recovered genetic variation was the result of differences in the apportionment of genetic variation between subdivisions of the primary phylogeographic regions. In contrast, populations only contained between 13.9 and 30.1% of the observed haplotypic variation. Gene flow estimates based on calculations of ΦST revealed moderate levels of gene flow within phylogeographic regions, but there was no evidence of gene flow between these regions, suggesting that geographical boundaries were probably important in the formation of phylogeographic structure in H. arenicolor. Phylogeographic regions exhibited very different patterns of gene flow. One region showed evidence of recent colonization. Another region exhibited very limited gene flow. Moderate to high estimates of gene flow were obtained for populations from two distinct phylogeographic regions characterized by mesic and xeric environments. Isolation by distance was observed in both regions suggesting that these regions are in genetic equilibrium. Because gene flow is extremely unlikely between the populations in the xeric region, this result is interpreted as historical gene flow. These results indicate that isolation-by-distance effects may still be observed even when population genetic structure and gene flow are the result of historical association.
Mitochondrial DNA Haplogroups and Neurocognitive Impairment during HIV Infection

Background: Neurocognitive impairment (NCI) remains an important complication in persons infected with human immunodeficiency virus (HIV). Ancestry-related mitochondrial DNA (mtDNA) haplogroups have been associated with outcomes of HIV infection and combination antiretroviral therapy (CART), and with neurodegenerative diseases. We hypothesize that mtDNA haplogroups are associated with NCI in HIV-infected adults and performed a genetic association study in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) cohort. Methods: CHARTER is an observational study of ambulatory HIV-infected adults. Haplogroups were assigned using mtDNA sequence, and principal components were derived from ancestry-informative nuclear DNA variants. Outcomes were cross-sectional global deficit score (GDS) as a continuous measure, GDS impairment (GDS ≥ 0.50), and HIV-associated neurocognitive disorder (HAND) using international criteria. Multivariable models were adjusted for comorbidity status (incidental vs contributing), current CART, plasma HIV RNA, reading ability, and CD4 cell nadir. Results: Haplogroups were available from 1027 persons; median age 43 years, median CD4 nadir 178 cells/mm(3), 72% on CART, and 46% with HAND. The 102 (9.9%) persons of genetically determined admixed Hispanic ancestry had more impairment by GDS or HAND than persons of European or African ancestry (P < .001 for all). In multivariate models including persons of admixed Hispanic ancestry, those with haplogroup B had lower GDS (β = -0.34; P = .008) and less GDS impairment (odds ratio = 0.16; 95% confidence interval, .04, .63; P = .009) than other haplogroups. There were no significant haplogroup associations among persons of European or African ancestry. Conclusions: In these mostly CART-treated persons, mtDNA haplogroup B was associated with less NCI among persons of genetically determined Hispanic ancestry. mtDNA variation may represent an ancestry-specific factor influencing NCI in HIV-infected persons.
Protective and Memory Immunity to Histoplasma capsulatum in the Absence of IL-10

We determined whether the absence of IL-10 in mice influenced protective and memory immunity to Histoplasma capsulatum. IL-10(-/-) mice cleared primary and secondary infection more rapidly than wild-type controls. Administration of mAb to TNF-alpha or IFN-gamma, but not GM-CSF, abrogated protection in naive IL-10(-/-) mice; mAb to TNF-alpha, but not IFN-gamma or GM-CSF, subverted protective immunity in secondary histoplasmosis. The inflammatory cell composition in IL-10(-/-) mice was altered in those given mAb to IFN-gamma or TNF-alpha. More Gr-1(+) and Mac-3(+) cells were present in lungs of IL-10(-/-) mice given mAb to IFN-gamma, and treatment with mAb to TNF-alpha sharply reduced the number of CD8(+) cells in lungs of IL-10(-/-) mice. We ascertained whether the lack of IL-10 modulated memory T cell generation or the protective function of cells. The percentage of CD3(+), CD44(high), CD62(low), and IFN-gamma(+) cells in IL-10(-/-) mice was higher than that of wild-type at day 7 but not day 21 or 49 after immunization. Fewer splenocytes from immunized IL-10(-/-) mice were required to mediate protection upon adoptive transfer into infected TCR alphabeta(-/-) mice. Hence, deficiency of IL-10 confers a salutary effect on the course of histoplasmosis, and the beneficial effects of IL-10 deficiency require endogenous TNF-alpha and/or IFN-gamma. Memory cell generation was transiently increased in IL-10(-/-) mice, but the protective function conferred by cells from these mice following immunization is strikingly more vigorous than that of wild-type.
The letter-frequency effect and the generality of familiarity effects on perception.

A widely accepted perceptual principle is that familiar patterns are easier to recognize than are less familiar patterns. Previous letter-recognition studies are examined to determine whethermore frequent letters in English are easier to recognize than less frequent letters (the letterfrequency effect). Most studies required subjects to identify single letters, while some measured reaction time to compare two letters or name or classify a letter. The results, based on over 800, 000 observations from 58 studies that span nearly 100 years, showed that: (1) there is no letter-frequency effect in recognition studies in which subjects simply report letters, and (2) there is a letter-frequency effect in reaction time studies. The presence of la letter-frequency effect for reaction time studies is interpreted as demonstrating an effect of familiarity on a comparison stage and perhaps a response stage, but not on input coding. The absence of a letter-frequency effect for single-letter recognition studies is interpreted as limiting the generality of the effect of familiarity on perception and as limiting the generality of models that correctly predict frequency effects for words. Alternative explanations for the absence of a letter-frequency effect are discussed.
Corn inbreds differing in efficiency to zinc

Abstract Corn (Zea mays L.) inbreds H84 (Zn efficient) and A635 (Zn inefficient) were grown in solution culture with moderate (contaminants only) and high (10‐4 M) levels of Zn and with 3 different phosphorus levels. Each of these treatments were with and without 10‐4 M chelating agent EDTA. The upper shoots of the plants tended to have lower Zn concentrations in the Zn inefficient inbred than in the Zn efficient inbred, particularly at the low level of Zn application. This was independent of the P levels. In roots the opposite was observed at the low level of Zn application but at the high level of Zn the inefficient inbred had sometimes more and sometimes less than the Zn efficient inbred partly depending upon P level. The high Zn level was mildly toxic to both inbreds at the low P level and an Fe interaction was involved (induced Fe deficiency). The effect of P in increasing and decreasing Zn concentrations was not consistent. EDTA tended to decrease Zn uptake and, at the low P level, caused a much gre...
Super-Resolution Imaging of IgE Receptor Clustering Initiated by Structurally-Defined Ligands in Rbl Mast Cells

Cross-linking of IgE bound to its receptor, FceRI, by multivalent ligands initiates a transmembrane signaling cascade that activates allergic and inflammatory responses in mast cells. Super-resolution fluorescence localization microscopy is an effective tool for quantitative nanoscale imaging of the distribution and ligand-induced redistribution of FceRI. We use structurally-defined trivalent ligands specific for anti-dinitrophenyl (DNP) IgE, for which the ligand size and valency is precisely controlled, to cross-link IgE-FceRI. These ligands are based on a Y-shaped double-stranded DNA scaffold with DNP groups conjugated to each of the three 5’ ends. The distance between DNP groups is fixed by the length of single-stranded oligonucleotides annealed to form the Y-shaped structure. As described previously for these Yn-DNP3 ligands, (Sil et al., 2007, ACS Chem Biol) some (but not other) cell signaling pathways depend on inter-DNP distances, ranging from 5 – 15 nm, which constrain the proximity of ligand-bound IgE-receptors. We are investigating the organization and dynamics of ligand-induced IgE-receptor clustering to gain new information about interactions of cross-linked IgE-receptors within the membrane that accompany or limit transmembrane signaling. We image fixed and live cells and compare Yn-DNP3 ligands with the heterogeneous ligand, DNP20-BSA. IgE is labeled with a photo-switchable probe and IgE-receptor clustering is quantified in super-resolution images with spatial correlation functions. In living cells, we record single-receptor trajectories, and receptor mobility is monitored in real time through analysis of populations of tracks. Both DNP20-BSA and Y16-DNP3 cause a sharp decrease in mobility upon ligand addition, but produce IgE-receptor clusters that appear distinctive in size and density. Y16-DNP3–stimulated changes occur on a shorter time scale when matched for DNP concentration with DNP20-BSA. Continuing work with Yn-DNP3 ligands will probe clustering-dependent IgE-receptor association with membrane structures and downstream signaling partners.
Decomposition of alkene adducts of thianthrene cation radical in nitrile solvents. Formation of alkyl-2-oxazolines and a new class of four-component products: 5-[(1-alkoxyalkylidene)ammonio]alkylthianthrenium diperchlorates.

The monoadducts (4a−d) of thianthrene cation radical perchlorate (1a) and isobutene, 2-methylbutene, 2-methyl-2-butene, and 2-methylpentene decompose spontaneously in acetonitrile (MeCN) solution, with the formation of thianthrene (Th). Decomposition of 4a (1,2-(5,10-thianthreniumdiyl)-2-methylpropane diperchlorate) and 4a‘, the corresponding dihexafluorophosphate, was studied in depth and extensively with 1H and 13C NMR spectroscopy. Decomposition of 4a was found to involve the solvent itself as well as water in the solvent, remaining from incomplete drying, and gave, apart from Th, successively, the perchlorate salts of 2,4,4-trimethyl-2-oxazoline (6) and 2-amino-2-methylpropyl acetate (7). These salts, 6-HClO4 and 7-HClO4, respectively, were prepared and used in understanding the reactions of 4a as well as the relationships among 6, 7, and 2-(acetylamino)-2-methyl propanol (8) in acidified MeCN solution. Decompositions of 4a−d in MeCN and other nitriles (RCN) containing an added alcohol (R‘OH) led to n...
Paleoclimatic Variation and Brain Expansion during Human Evolution

One of the major adaptations during the evolution of Homo sapiens was an increase in brain size. Here we present evidence that a significant and substantial proportion of variation in brain size may be related to changes in temperature. Based on a sample of 109 fossilized hominid skulls, we found that cranial capacities were highly correlated with paleoclimatic changes in temperature, as indexed by oxygen isotope data and sea-surface temperature. Indeed, as much as 52% of the variance in the cranial capacity of these skulls could be accounted for by temperature variation at 100 ka intervals. As an index of more short-term seasonal fluctuations in temperature, we examined the latitude of the sites from which the crania originated. More than 22% of the variance in cranial capacity of these skulls could be accounted for by variation in equatorial distance.
Flight spectral response of the ACIS instrument

We discuss the flight calibration of the spectral response of the Advanced CCD Imaging Spectrometer (ACIS) on-board the Chandra X-ray Observatory (CXO). The spectral resolution and sensitivity of the ACIS instrument have both been evolving over the course of the mission. The spectral resolution of the frontside-illuminated (FI) CCDs changed dramatically in the first month of the mission due to radiation damage. Since that time, the spectral resolution of the FI CCDs and the Backside-illuminated (BI) CCDs have evolved gradually with time. We demonstrate the efficacy of charge-transfer inefficiency (CTI) correction algorithms which recover some of the lost performance. The detection efficiency of the ACIS instrument has been declining throughout the mission, presumably due to a layer of contamination building up on the filter and/or CCDs. We present a characterization of the energy dependence of the excess absorption and demonstrate software which models the time dependence of the absorption from energies of 0.4 keV and up. The spectral redistribution function and the detection efficiency are well-characterized at energies from 1.5 to 8.0~keV primarily due to the existence of strong lines in the ACIS calibration source in that energy range. The calibration at energies below 1.5 keV is challenging because of the lack of strong lines in the calibration source and also because of the inherent non-linear dependence with energy of the CTI and the absorption by the contamination layer. We have been using data from celestial sources with relatively simple spectra to determine the quality of the calibration below 1.5 keV. We have used observations of 1E0102.2-7219 (the brightest supernova remnant in the SMC), PKS2155-304 (a bright blazar), and the pulsar PSR~0656+14 (nearby pulsar with a soft spectrum), since the spectra of these objects have been well-characterized by the gratings on the CXO. The analysis of these observations demonstrate that the CTI correction recovers a significant fraction of the spectral resolution of the FI CCDs and the models of the time-dependent absorption result in consistent measurements of the flux at low energies for data from a BI (S3) CCD.
Fragmentative and stereochemical isomerization probes for homolytic carbon to phosphorus bond scission catalyzed by bacterial carbon-phosphorus lyase

Three bacterial strains, Agrobacterium radiobacter, Klebsiella oxytoca, and Kluyvera ascorbata, isolated by enrichment culture for carbon to phosphorus bond cleavage ability, were analyzed for the mode of C-P bond fission. The cleavage of alkyl phosphonic acids to alkanes and inorganic phosphates proceeded both aerobically and anaerobically, and growth on trideuteromethylphosphonic acid yielded trideuteromethane as product. These data indicate that functionalization of the organic moiety does not precede carbon to phosphorus bond cleavage. As probes for radical intermediates, cyclopropylmethylphosphonic acid and cis-1,2-dideutero-1-propenylphosphonic acid were used in growth experiments and the gaseous hydrocarbon products were examined. With the cyclopropylmethylphosphonic acid probe, all three bacteria produced methylcyclopropane, but only K. oxytoca and K. ascorbata also generated the acyclic olefin I-butene, and then only in very low quantity (0.6 and 0.3% versus methylcyclopropane, respectively). With the propenylphosphonic acid probe, cis-1,Zdideuteropropene was formed with greater than 98% retention of configuration with each bacterial strain. Only for K. oxytoca was the alternate product, in this case trans-1,2dideuteropropene, clearly detected at 1.5%. Thus, C-P bond fission may yield radical intermediates that are trapped efficiently at the enzyme active site or, alternatively, homolysis of the C-P bond may occur as a minor reaction pathway.
The Arc Spectrum of Vanadium in the Violet

From new measurements between 2173A and 1848A, six new odd terms and 33 miscellaneous odd levels have been found. Almost all lines of intensity 10 and greater have thus been classified, but it has not been possible to fit them all into multiplets. Five of the new terms and one previously known term may form two triads and probably belong to the ${(3d)}^{3}4s\ifmmode\cdot\else\textperiodcentered\fi{}5p$ configuration.
CCN5 Expression in mammals. III. Early embryonic mouse development

CCN proteins play crucial roles in development, angiogenesis, cell motility, matrix turnover, proliferation, and other fundamental cell processes. Early embryonic lethality in CCN5 knockout and over-expressing mice led us to characterize CCN5 distribution in early development. Previous papers in this series showed that CCN5 is expressed widely in mice from E9.5 to adult; however, its distribution before E9.5 has not been studied. To fill this gap in our knowledge of CCN5 expression in mammals, RT-PCR was performed on preimplantation murine embryos: 1 cell, 2 cell, 4 cell, early morula, late morula, and blastocyst. CCN5 mRNA was not detected in 1, 2, or 4 cell embryos. It was first detected at the early morula stage and persisted to the preimplantation blastocyst stage. Immunohistochemical staining showed widespread CCN5 expression in post-implantation blastocysts (E4.5), E5.5, E6.5, and E7.5 stage embryos. Consistent with our previous study on E9.5 embryos, this expression was not limited to a particular germ layer or cell type. The widespread distribution of CCN5 in early embryos suggests a crucial role in development.
Heart Failure Patients with Lower Socioeconomic Status Generate Lower Charges

Genotype and Phenotypic Characteristics of Persons with Cardiac Amyloidosis from the Multinational Transthyretin Amyloidosis Outcomes Survey (THAOS) Registry Kumar Dharmarajan, Say Salomon, Stephen Helmke, Sergio Tereyua, Claudio Rapezzi, Rodney Falk, Mathew S. Maurer; Clinical Cardiovascular Research Lab for the Elderly, Columbia University, New York; Harvard Vanguard Medical Associates, Boston; University of Bologna, Bologna, Italy
Summary of the First NUVA Conference Space Astronomy: the UV Window to the Universe

In this summary of the conference Space Astronomy: the UV Window to the Universe, held in El Escorial, Spain, May 28 to June 1, 2007, I identify the important scientific questions posed by the speakers and the corresponding discoveries that future ultraviolet space instruments should enable. The science objectives described by the various speakers naturally fall into groups according to the needed instrumental requirements: wavelength coverage, spectral resolution, sensitivity, rapid access to targets, monitoring, and signal/noise. Although most of the science objectives presented during the conference require UV spectra in the 1,170–3,200 A range, there are important science objectives that require spectra in the 912–1,170 A range and at shorter wavelengths. I identify the limitations of present instruments for meeting these requirements. To avoid the upcoming UV dark age, important work must be done to properly build the World Space Observatory (WSO) and to plan future space missions.
Mass scales in two-step symmetry breakings in grand unified theories

Abstract It is shown that in SU(N>5), two-step symmetry breaking patterns can give rise to an intermediate mass scale anywhere between MW and the grand unification mass MG. It isalso shown that in the two-step breaking of SO(N), the intermediate mass scale is equal to MG and MG of SO(N) can be arbitrarily large.
Kinetic and chemical mechanisms of homocitrate synthase from Thermus thermophilus

The homocitrate synthase from Thermus thermophilus (TtHCS) is a metal-activated enzyme with either Mg2+ or Mn2+ capable of serving as the divalent cation. The enzyme exhibits a sequential kinetic mechanism. The mechanism is steady state ordered with α-ketoglutarate (α-Kg) binding prior to acetyl-CoA (AcCoA) with Mn2+, whereas it is steady state random with Mg2+, suggesting a difference in the competence of the E·Mn·α-Kg·AcCoA and E·Mg·α-Kg·AcCoA complexes. The mechanism is supported by product and dead-end inhibition studies. The primary isotope effect obtained with deuterioacetylCoA (AcCoA-d3) in the presence of Mg2+ is unity (value 1.0) at low concentrations of AcCoA, whereas it is 2 at high concentrations of AcCoA. Data suggest the presence of a slow conformational change induced by binding of AcCoA that accompanies deprotonation of the methyl group of AcCoA. The solvent kinetic deuterium isotope effect is also unity at low AcCoA, but is 1.7 at high AcCoA, consistent with the proposed slow conformational change. The maximum rate is pH independent with either Mg2+ or Mn2+ as the divalent metal ion, whereas V/Kα-Kg (with Mn2+) decreases at low and high pH giving pK values of about 6.5 and 8.0. Lysine is a competitive inhibitor that binds to the active site of TtHCS, and shares some of the same binding determinants as α-Kg. Lysine binding exhibits negative cooperativity, indicating cross-talk between the two monomers of the TtHCS dimer. Data are discussed in terms of the overall mechanism of TtHCS.
THE INACTIVATION OF BACTERIOPHAGE BY MERCURY BICHLORIDE; THE REACTIVATION OF BICHLORIDE-INACTIVATED PHAGE.

1. The inactivation of antistaphylococcus bacteriophage suspended in infusion broth at pH 7.6 and 22°C. by HgCl2 proceeds according to the equation dP/dt = k [HgCl2] [Po – Pi] over the range studied. 2. This inactivation can be reversed by precipitation of Hg++ with H2S. In the present experiments the inactivation was carried out until only some 5 per cent of the initial phage remained active. After reactivation the [P] had increased to 100 per cent of the initial [P].
Quantification in tail-recursive function definitions

We investigate the logical issues behind axiomatizing equations that contain both recursive calls and quantifiers in ACL2. We identify a class of such equations, named extended tail-recursive equations, that can be uniformly introduced in the logic. We point out some potential benefits of this axiomatization, and discuss the logical impediments behind introducing more general quantified formulas.
A theory of interregional tax competition

A general equilibrium model is constructed to study tax competition, where local governments compete for capital by holding down property tax rates and public expenditure levels. An exact definition of tax competition is provided, and both the existence and nonexistence of tax competition are shown to be theoretically possible. It is argued, however, that tax competition must occur under empirically reasonable conditions. Inefficiency in public production is also explicitly modeled. The amount of capital used to produce a given level of public service output is shown to be greater than that which is required to minimize costs evaluated at the prices facing private firms.
Cardiac lymph and lymphatics in normal and infarcted myocardium

Abstract Cardiac lymphangiography was applied to 29 normal dogs (ND) and 14 dogs following acute coronary occlusions. In five of the ND, lymph collected from infarcted dogs was selectively injected into the coronary artery prior to the lymphangiogram. In ND, the lymphatic density (LD) was 6.6% ventricular area (VA). Acute coronary occlusion induced a change in the LD. The infarcted zone registered a decrease in LD (3.6% of VA p