cssi/SciSciGPT-SciSciNet huggingface dataset:
Hypospadias Risk from Maternal Residential Exposure to Heavy Metal Hazardous Air Pollutants.

Objective: Investigate whether residential prenatal exposure to heavy metal hazardous air pollutants (HMHAPs) is associated with an increased risk of hypospadias. Methods: Data on non-syndromic hypospadias cases (n = 8981) and control patients delivered in Texas were obtained from the Texas Birth Defects Registry and matched 1:10 by birth year. Average exposure concentrations of HMHAPs were obtained from the 2005 U.S. Environmental Protection Agency National-Scale Air Toxics Assessment and categorized into quintiles. Odds ratios and 95% confidence intervals were estimated. STROBE reporting guidelines were followed. Results: We observed associations between hypospadias and prenatal HMHAP exposure. Manganese demonstrated significant increased risk of hypospadias at the medium, medium-high and high exposure quintiles; lead in the medium-high and high exposure quintiles. Cadmium, mercury and nickel demonstrated a significant inverted “U-shaped” association for exposures with significant associations in the medium and medium-high quintiles but not in the medium-low and high quintiles. Arsenic and chromium demonstrated a significant bivalent association for risk of hypospadias in a lower quintile as well as a higher quintile with non-significant intermediate quintiles. Conclusions: Using data from one of the world’s largest active surveillance birth defects registries, we identified significant associations between hypospadias and HMHAP exposures. These results should be used in counseling for maternal demographic risk factors as well as avoidance of heavy metals and their sources.
Balancing the Roles of a Junior Faculty Member: Perspectives from Athletic Training and Physical Therapy

Context The role of a faculty member in higher education includes engaging in the 3 facets of research, service, and teaching. Allied health faculty members face additional responsibilities such as...
Echolocation in a Nocturnal Primate

Recently it has been noted that Gursky's spectral tarsier emits ultrasonic calls. Because high-frequency sounds are capable of travelling only short distances, their function is limited by the distance the sound can be discerned. One possible function for these short-distance, high-frequency sounds is that they might be used by the tarsiers to navigate throughout their environment. I conducted this study at Tangkoko Nature Reserve in Sulawesi, Indonesia, from May to August 2017. Using the focal follows, I recorded the start of each locomotor activity to the nearest second. I also simultaneously recorded all ultrasonic vocalisations that the focal individual emitted using a Wildlife Acoustics Ultrasonic Song Meter BAT3. Approximately 42% of the ultrasonic calls that I recorded during this study were given within 1 s prior to engaging in locomotor activity. The tarsiers gave statistically more ultrasonic calls during locomotion than during other behaviours (rest, forage and social). Four types of ultrasonic calls were given while locomoting: whistles, doubles, trills and frequency-modulated calls. Of these, the trill and the frequency-modulated call were only given during locomotion, and trills were only given prior to leaping. These results preliminarily suggest that the tarsiers do use ultrasonic calls for navigation. Studying echolocation in organisms closely related to bats is critical for understanding the evolution of echolocation.
Apoptosis contributes to the cytotoxicity induced by amodiaquine and its major metabolite N-desethylamodiaquine in hepatic cells

Amodiaquine (ADQ), an antimalarial drug used in endemic areas, has been reported to be associated with liver toxicity; however, the mechanism underlying its hepatoxicity remains unclear. In this study, we examined the cytotoxicity of ADQ and its major metabolite N-desethylamodiaquine (NADQ) and the effect of cytochrome P450 (CYP)-mediated metabolism on ADQ-induced cytotoxicity. After a 48-h treatment, ADQ and NADQ caused cytotoxicity and induced apoptosis in HepG2 cells; NADQ was slightly more toxic than ADQ. ADQ treatment decreased the levels of anti-apoptotic Bcl-2 family proteins, which was accompanied by an increase in the levels of pro-apoptotic Bcl-2 family proteins, indicating that ADQ-induced apoptosis was mediated by the Bcl-2 family. NADQ treatment markedly increased the phosphorylation of JNK, extracellular signal-regulated kinase (ERK1/2), and p38, indicating that NADQ-induced apoptosis was mediated by MAPK signaling pathways. Metabolic studies using microsomes obtained from HepG2 cell lines overexpressing human CYPs demonstrated that CYP1A1, 2C8, and 3A4 were the major enzymes that metabolized ADQ to NADQ and that CYP1A2, 1B1, 2C19, and 3A5 also metabolized ADQ, but to a lesser extent. The cytotoxicity of ADQ was increased in CYP2C8 and 3A4 overexpressing HepG2 cells compared to HepG2/CYP vector cells, confirming that NADQ was more toxic than ADQ. Moreover, treatment of CYP2C8 and 3A4 overexpressing HepG2 cells with ADQ increased the phosphorylation of JNK, ERK1/2, and p38, but not the expression of Bcl-2 family proteins. Our findings indicate that ADQ and its major metabolite NADQ induce apoptosis, which is mediated by members of the Bcl-2 family and the activation of MAPK signaling pathways, respectively.
Colony Breeding Structure of Reticulitermes (Isoptera: Rhinotermitidae) in Northwest Arkansas

Termites, as social insects, have a complicated life cycle in which the colony breeding structure, that is the number of and origin of reproductives in a colony, can vary in relation to age and environmental factors. In this study, we used genetic methods to characterize the breeding structure of three species of Reticulitermes from three sites in northwest Arkansas and compared two habitats: undeveloped, forested sites and developed, agricultural sites. We found 57.1% of R. flavipes (Kollar) in northwest Arkansas (n = 28) were simple families, 39.3% were extended families and 3.6% were mixed families. Similarly, for R. hageni Banks (n = 23), we found 58.3% simple families, 33.3% extended families, and 8.3% mixed families. All of the R. virginicus (Banks) samples (n = 5) were simple families. For R. flavipes and R. hageni , the percentage of extended families is intermediate to southeastern and northern USA populations, corresponding to the intermediate seasonality and climate in Arkansas. The level of inbreeding in Arkansas, estimated via F IT , was relatively high and similar to northern populations of Reticulitermes . There were significantly more extended family colonies at the developed site compared to the two undeveloped sites which contained more simple family colonies. This difference may occur as a strategy to cope with sparse resources in urban environments or as a consequence of different abiotic factors.
α-Synuclein perturbs in vivo neural activity following seeding in the olfactory bulb

Parkinson9s disease (PD) neuropathology is characterized by intraneuronal protein aggregates composed of misfolded α-Synuclein (α-Syn), as well as degeneration of substantia nigra dopamine neurons. Deficits in olfactory perception and aggregation of α-Syn in the olfactory bulb (OB) are observed during early stages of PD, and have been associated with the PD prodrome, before onset of the classic motor deficits. α-Syn fibrils injected into the OB of mice cause progressive propagation of α-Syn pathology throughout the olfactory system and are coupled to olfactory perceptual deficits. We hypothesized that accumulation of pathogenic α-Syn in the OB impairs neural activity in the olfactory system. To address this, we monitored spontaneous and odor-evoked local field potential dynamics in awake wild type mice simultaneously in the OB and piriform cortex (PCX) one, two, and three months following injection of pathogenic preformed α-Syn fibrils in the OB. We detected α-Syn pathology in both the OB and PCX. We also observed that the presence of α-Syn pathology, triggered by α-Syn fibril injection, influenced certain oscillatory spectral bands in these regions. These changes in neural activity occurred with region specificity, and in some cases transiently relative to the number of months that had elapsed after injection. Together, we provide evidence that α-Syn pathology in the olfactory system impacts in vivo neural activity and provides initial insights into its network-level effects.
Higher line speed in young chicken slaughter establishments does not predict increased Salmonella contamination risks.

Abstract Do faster slaughter line speeds for young chickens increase risk of Salmonella contamination? We analyze data collected in 2018–2019 from 97 slaughter establishments processing young chickens to examine the extent to which differences in slaughter line speeds across establishments operating under the same inspection system explain observed differences in their microbial quality, specifically frequencies of positive Salmonella samples. A variety of off-the-shelf statistical and machine learning techniques applied to the data to identify and visualize correlations and potential causal relationships among variables showed that the presence of Salmonella or other indicators of process control, such as noncompliance records for regulations associated with process control and food safety, are not significantly increased in establishments with higher line speeds (e.g., above 140 birds per min) compared with establishments with lower line speeds when establishments are operating under the conditions present in this study. This included some establishments operating under specific criteria to obtain a waiver for line speed. A null hypothesis advanced over 30 yr ago by the National Research Council that increased line speeds result in a product that is not contaminated more often than before line speeds were increased, appears to be fully consistent with these recent data.
HMDA, Housing Segregation, and Racial Disparities in Mortgage Lending

Housing segregation and discrimination remain tenacious problems in America. This Article first explores the passage of the Home Mortgage Disclosure Act (HMDA) of 1975 and its 1989 amendments in order to clarify their objectives and requirements for providing data to the public that potentially may be used to combat redlining and lending discrimination in the nation's housing market. Given this background, this Article then relies on HMDA data to investigate the following question: Are racial minorities in America's largest metropolitan statistical areas (MSAs) more likely to receive government-insured mortgages rather than conventional mortgages if they reside in more segregated metropolitan areas?The analysis indicates that housing segregation has a significant negative effect on African Americans' ability to receive conventional mortgages, thereby distinguishing them from Asians, Hispanics, and whites. If African Americans are unlikely to receive conventional mortgages in more segregated areas, this suggests that in the future, highly segregated MSAs are likely to remain segregated along black-white lines and that African Americans will continue to be the mast segregated racial group in the country. Based on this analysis, the Article concludes that HMDA should be amended to require additional data from commercial banks in order to determine the extent to which lending discrimination is occurring and thus perpetuating-and possibly even increasing-housing segregation in the United States. At minimum this data should include such basic information as applicants' total financial assets, credit scores and history, number of dependents, value of the property to be purchased, and size of down payments required Banks routinely collect this data during the mortgage application process, so it should be relatively easy to include in their lending disclosure forms.
The Selective Perception Of Managers Revisited

Results of a systematic replication of studies by Dearborn and Simon and by Walsh suggest that differences in their conclusions resulted from differences in their experimental procedures. Managers ...
The combined use of thoracic and abdominal aortic stent grafts for endovascular repair of wide neck abdominal aortic aneurysms in high risk patients.

Introduction Treatment of abdominal aortic aneurysms (AAA) with large (28 mm to 34 mm) and wide diameter (> 35 mm) necks remains a challenge in patients who are high-risk candidates for open repair. While several case reports describe the use of a thoracic stent graft in conjunction with a traditional modular bifurcated stent graft, most patients do not have the aortic length to accommodate such a configuration. We present our experience utilizing a distal unibody bifurcated aortic stent graft (Endologix, Irvine, CA) in conjunction with a proximal thoracic aortic stent graft (Medtronic, Minneapolis, MN) to treat wide-necked non-ruptured AAAs in patients who were otherwise poor candidates for open or fenestrated repair. Methods A single center retrospective review of patients treated with a combination of a distal unibody bifurcated aortic stent graft and a proximal thoracic aortic stent graft extension from 2013 to 2019 was performed. Demographics, perioperative details and long-term outcomes were collected and summarized. Standard statistical methods were utilized. Results We identified 7 patients who underwent this procedure during the study interval. Of these, all 7 (100%) were male with an average age of 69.1 ± 5.1 years. Average Charlson Comorbidity Index was 5.0. Average pre-operative maximum aortic and neck diameters were 57.9 mm (± 5.8) and 37.4 mm (± 4.5) respectively. All patients underwent repair with a distal 28 mm diameter unibody bifurcated aortic stent graft and proximal extension with a thoracic aortic stent graft that ranged from 40 to 46 mm in diameter. Technical success was achieved in all 7 patients. There were no perioperative mortalities or aorta-related deaths. Follow up was a mean of 1.98 years with a mean survival of 4.75 years (± 0.86). One patient required an aneurysm-related intervention for a late type III endoleak. Conclusion The combined use of thoracic and abdominal aortic stent grafts is a safe and effective endovascular method to treat high-risk surgical candidates with wide-necked AAAs.
Neural bases of elements of syntax during speech production in patients with aphasia.

Abstract The ability to string together words into a structured arrangement capable of conveying nuanced information is key to speech production. The assessment of the neural bases for structuring sentences has been challenged by the need of experts to delineate the aberrant morphosyntactic structures in aphasic speech. Most studies have relied on focused tasks with limited ecological validity. We characterized syntactic complexity during connected speech produced by patients with chronic post-stroke aphasia. We automated this process by employing Natural Language Processing (NLP). We conducted voxel-based and connectome-based lesion-symptom mapping to identify brain regions crucially associated with sentence production and syntactic complexity. Posterior-inferior aspects of left frontal and parietal lobes, as well as white matter tracts connecting these areas, were essential for syntactic complexity, particularly the posterior inferior frontal gyrus. These findings suggest that sentence structuring during word production depends on the integrity of Broca’s area and the dorsal stream of language processing.
The Classification of Finite Simple Groups: Groups of Characteristic 2 Type

The book provides an outline and modern overview of the classification of the finite simple groups. It primarily covers the "even case", where the main groups arising are Lie-type (matrix) groups over a field of characteristic 2. The book thus completes a project begun by Daniel Gorenstein's 1983 book, which outlined the classification of groups of "noncharacteristic 2 type". However, this book provides much more. Chapter 0 is a modern overview of the logical structure of the entire classification. Chapter 1 is a concise but complete outline of the "odd case" with updated references, while Chapter 2 sets the stage for the remainder of the book with a similar outline of the "even case". The remaining six chapters describe in detail the fundamental results whose union completes the proof of the classification theorem. Several important subsidiary results are also discussed. In addition, there is a comprehensive listing of the large number of papers referenced from the literature. Appendices provide a brief but valuable modern introduction to many key ideas and techniques of the proof. Some improved arguments are developed, along with indications of new approaches to the entire classification--such as the second and third generation projects--although there is no attempt to cover them comprehensively. The work should appeal to a broad range of mathematicians--from those who just want an overview of the main ideas of the classification, to those who want a reader's guide to help navigate some of the major papers, and to those who may wish to improve the existing proofs.
Heteropatriarchy Kills: Challenging Gender Violence in a Prison Nation

We need an analysis that furthers neither the conservative project of sequestering millions of men of color in accordance with the contemporary dictates of globalized capital and its prison industrial complex, nor the equally conservative project of abandoning poor women of color to a continuum of violence that extends from the sweatshops through the prisons, to shelters, and into bedrooms at home. How do we develop analyses and organizing strategies against violence against women that acknowledge the race of gender and the gender of race? 1 Professor of Law, University of California-Davis School of Law (King Hall). My thanks to Leigh Goodmark, Donna Coker, and James Ptacek for including me on a panel at the 2011 National Conference on Restorative Justice in Raleigh, North Dakota, and for the conversations, formal and informal, that ensued. Thank you to SpearIt, whose illuminating remarks on the cycle of destructive masculinity at the 2011 Access to Justice Conference at Washington University-St Louis shaped my thinking, and thank you to the organizers of that important conference, including Adrienne Davis, Annette Appell, and Karen Tokarz. Many thanks to Madhavi Sunder and my new colleagues at U.C. Davis, where I presented a version of this piece at a faculty workshop, and thanks to Randi W. Stebbins and Maria-Caterina LaBarbara, students at Berkeley Law, for their terrific research assistance. A larval version of this Article was first presented as the 2008 Dewey Lecture at the University of Minnesota Law School, and I thank then-Associate Dean Guy-Uriel Charles and the other kind people there who made that lecture possible. My profound thanks to the folks at GenerationFIVE, whose trainings schooled me profoundly on the intricate connections between embodied trauma and political movements, and who introduced me to the notion of transformative justice. Finally, thanks to my friends at UC Berkeley, including especially K.T. Albiston, Amy Kapczynski, Jeff Selbin, Sarah Song, and Charles Weisselberg, for their feedback and suggestions. Mary Louise Frampton deserves special recognition for her insights and her tireless efforts to connect the restorative justice movement to an anti-subordination practice in communities of color. 1. Angela Davis, Keynote Address to Color of Violence Conference, recorded in Charles Brown, The Color of Violence Against Women (Oct. 25, 2000), available at http://csf .colorado.edu/soc/m-fem/2000/msg01004.htm. Washington University Open Scholarship 14 Journal of Law & Policy [Vol. 37:13
Single-crystal neutron diffraction studies on Ni-based metal-pnictide superconductor BaNi2As2

We report the results of single-crystal neutron diffraction studies of the superconductor BaNi2As2. The experiments were performed on a tiny crystal of mass 0.8 mg at several temperatures between 20 and 200 K using the Single Crystal Diffractometer, SCD, at the Los Alamos Neutron Science Center. Above 130 K, BaNi2As2 crystallizes in the tetragonal ThCr2Si2 structure. Our neutron diffraction data corroborate a first-order structural transition around 130 K with a relatively large hysteresis of about 10 K, in agreement with observations from bulk studies. The anisotropic thermal displacement coefficients are enhanced along c-axis approaching the transition, and a splitting is observed for in-plane type reflections below the transition, which is evidence for a change in crystal structure.
How do you pay attention

How do we go about picking out one particular object from a number of related ones? Do we try to find the target by moving from one object to another in turn (attending the objects in ‘series’), or do we attempt to scan them all at once (attending in parallel)? This is a long-standing controversy, and the latest studies, using event-related potentials, come down on the side of serial processing.
An Isoform-Specific Myristylation Switch Targets Type II PKA Holoenzymes to Membranes.

Cyclic AMP-dependent protein kinase (PKA) is regulated in part by N-terminal myristylation of its catalytic (C) subunit. Structural information about the role of myristylation in membrane targeting of PKA has been limited. In mammalian cells there are four functionally non-redundant PKA regulatory subunits (RIα, RIβ, RIIα, and RIIβ). PKA is assembled as an inactive R2C2 holoenzyme in cells. To explore the role of N-myristylation in membrane targeting of PKA holoenzymes, we solved crystal structures of RIα:myrC and RIIβ2:myrC2, and showed that the N-terminal myristylation site in the myrC serves as a flexible "switch" that can potentially be mobilized for membrane anchoring of RII, but not RI, holoenzymes. Furthermore, we synthesized nanodiscs and showed by electron microscopy that membrane targeting through the myristic acid is specific for the RII holoenzyme. This membrane-anchoring myristylation switch is independent of A Kinase Anchoring Proteins (AKAPs) that target PKA to membranes by other mechanisms.
When supercolonies collide: territorial aggression in an invasive and unicolonial social insect.

Some species of ants possess an unusual form of social organization in which aggression among nests is absent. This type of social organization, called unicoloniality, has been studied in only a handful of species and its evolutionary origins remain unclear. To date, no study has examined behavioural and genetic patterns at points of contact between the massive supercolonies that characterize unicoloniality. Since interactions at territory boundaries influence the costs of aggression and the likelihood of gene flow, such data may illuminate how supercolonies are formed and maintained. Here we provide field data on intraspecific territoriality for a widespread and invasive unicolonial social insect, the Argentine ant (Linepithema humile). We observed abrupt and well-defined behavioural boundaries at 16 contact zones between three different pairs of supercolonies. We visited nine of these zones weekly during a six-month period and observed consistent and intense intercolony aggression that resulted in variable, but often large, levels of worker mortality. Microsatellite variation along six transects across territory borders showed that FST values were lower within supercolonies (0.08 ± 0.01 (mean ± SE)) than between supercolonies (0.29 ± 0.01) and that this disparity was especially strong right at territory borders, despite direct and prolonged contact between the supercolonies. Matrix correspondence tests confirmed that levels of aggression and genetic differentiation were significantly correlated, but no relationship existed between geographic distance and either intraspecific aggression or genetic differentiation. Patterns of FST variation indicated high levels of gene flow within supercolonies, but little to no gene flow between them. Overall, these findings are inconsistent with a model of relaxed ecological constraints leading to colony fusion and suggest that environmentally derived cues are not the prime determined of nestmate recognition in field populations of Argentine ants.
EFFECT OF CANNING AND STORAGE ON THE PHENOLIC COMPOSITION OF PEANUTS

ABSTRACT Increased commercialization of boiled peanuts packaged in cans has made it necessary to investigate the effect of canning on the phytochemical composition of this product. Retorting (canning) remains a core processing technology for the extension of shelf life of foods. This study evaluates the effect of canning and storage on the phenolic composition of peanuts. Peanuts canned in 5% brine, retorted and stored for 4 weeks were analyzed for phenolic composition. A total of nine compounds (trans-resveratrol and three conjugates, caffeic acid, luteolin, genistein, quercetin and catechin) were identified in both raw and canned kernels. Quercetin and catechin were not in quantifiable amounts in canned peanut kernels. Concentrations of trans-resveratrol declined initially and stabilized after 2 weeks of storage. The presence of resveratrol in the brine indicates leaching from peanut kernels. Although canning has been shown to be detrimental to certain nutrients, canned peanuts still retained some bioactive polyphenols with antioxidant activity. PRACTICAL APPLICATIONS Retorting and canning of foods still remain important unit processes in food preservation technology as canned products have a longer shelf life compared to other packaged products. This is mainly due to it durability, portability and minimal susceptibility to contamination. While different foods contain various classes of bioactive compounds that have diverse physicochemical properties, it is necessary to investigate the effect of thermal processing on their bioactive constituents. There are several processing methods for peanuts such as roasting (dry- and oil-roasted), boiling and retorting. Of these methods, retorting in cans is the best way to extend the shelf life of boiled peanuts. Previous studies have looked at the effect of roasting and boiling on the phytochemical composition of processed peanuts. This study aims at understanding how retorting affect these bioactive compounds in peanuts.
Modeling Roughness of Rock Discontinuity Surfaces: A Signal Analysis Approach

Barton’s (1973) model for estimating the peak shear strength of rock discontinuity surfaces includes an input variable, called joint roughness coefficient (JRC). Using this model, Barton and Choubey (1977) empirically determined the JRC values of a large number of discontinuities and designated a set of ten roughness profiles (Fig. 1) that represents the JRC range of 0–20. These ten profiles continue to function as a practical tool for visually matching and assigning corresponding JRC values to discontinuity surfaces. A growing number of studies designed to quantify the profile matching process show that the JRC values of the original ten profiles correlate reasonably well with a variety of mathematical expressions of roughness (Tse and Cruden 1979; Yu and Vayssade 1991; Tatone and Grasselli 2010; Jang et al. 2014). On the other hand, a close inspection of these profiles reveals inconsistent transitions in the nature of roughness of subsequent profiles, often displaying sudden changes in the characteristics of the most prominent morphological features. This raises several important questions: (1) why do these ten profiles perform in the given order? (2) to what extent do slight and/or local changes along a profile influence its shear strength (and therefore JRC)? and (3) will the same degree of correlation and/or confidence interval hold for any subset of discontinuity profiles other than the original ten? These questions can be explored by physical experiments and numerical simulations, or by decoding the constituent structure of roughness profiles with signal analysis. This technical note is designed to shed light on these questions using the latter approach, and to pave the way for development of a physically based roughness quantification method that is consistent (in expressing morphology and assigning ranking), explicit (in its procedures and assumptions) and comprehensive (in equally efficient representation for all possible roughness patterns).
Enrichment of 210Pb and 210Po in the sea-surface microlayer

Chemical fractionation at the air–sea interface is frequently suggested1–5 as a possible mechanism contributing to the enrichment of a number of trace metals in the marine atmosphere6,7. The origin of the long-lived radon daughters (210Pb, 210Bi and 210Po) in the atmosphere is of special interest because of their use in the estimation of tropospheric aerosol residence times8. It has been proposed9 that injection of a fractionated marine component by bubbles bursting at the sea surface might be responsible for the occurrence of anomalously high atmospheric 210Po/210Pb ratios in Antarctica10 and Hawaii11. Here we report the first measurements of 210Pb (t1/2 = 22.3 yr) and 210Po (t1/2 = 138 d) in the sea-surface microlayer. These measurements were made to determine whether or not a significant flux of these radionuclides from the sea surface to the atmosphere could occur. We also introduce a method for treating chemical data that we believe may be useful in determining the origin of the trace-metal enrichments often observed1,2 in the microlayer.
Cytokine and immunosuppressive therapies of type 1 diabetes mellitus

In this article, the authors covered a number of issues that affect how researchers approach prevention of diabetes. The focus has been the use of cytokines and immunosuppressive therapies. The historical understanding of cytokine and immunosuppressive approaches, new developments in using these agents in humans, and the issues involved in designing diabetes prevention trials were reviewed. Although progress at times appears slow, the current research activities predict new developments in the next few years that may improve the understanding of the progression of diabetes and possible ways to intervene.
Anionic dispersion polymerization of styrene. I. Investigation of parameters for preparation of uniform micron-size polystyrene particles with narrow molecular weight distribution

Anionic dispersion polymerization in a hexane medium has been applied to the synthesis of monodisperse polystyrene particles in the size range of 1.41–6.16 μm, and having narrow molecular weight distributions Mw/Mn of 1.02–1.28. sec-Butyllithium was used as the initiator. Polystyrene-block-polybutadiene diblock copolymer containing 23% polystyrene block, (i.e., Stereon 730A) with a molecular weight of 147,000 g/mol and a polydispersity of 1.05, was found to be a suitable steric stabilizer for the preparation of micron-size polystyrene particles with narrow size distribution. Tetrahydrofuran (THF) was used as a promoter for obtaining narrow molecular weight distributions. However, this study revealed that the addition of small amounts of THF as promoter broadened the particle size distribution. High solids content polystyrene dispersions were also prepared without using any promoter by both batch and/or multi-addition monomer processes. © 1996 John Wiley & Sons, Inc.
On a difference equation arising in a learning-theory model

An analysis is presented of the equationf(x+a)−f(x)=e−x {f(x)−f(x−b)}. Herea andb denote arbitrary positive constants, and a solution is sought which satisfies the following conditions:f(−∞)=0,f(+∞)=1, 0≦f(x)≦1. Existence and uniqueness of solution are established, and then an analytical form of the solution is obtained by use of bilateral Laplace transform.
Multivariable Adaptive Computer Control by Identification Feedback

A multivariable adaptive control technique is presented which is aimed at the class of systems where the main control function is the following of a continuously varying desired output state with transients being of lesser importance. Adaptation is by identification feedback with the momentary control action being open loop.
Surface Complexation of Neptunium(V) with Goethite

Batch adsorption experiments in which neptunium bearing solutions were reacted with goethite (alpha-FeOOH) have been performed to study uptake mechanisms in sodium chloride and calcium-bearing sodium silicate solutions. This paper presents results identifying and quantifying the mechanisms by which neptunium is adsorbed as a function of pH and reaction time (aging). Also presented are results from tests in which neptunium is reacted with goethite in the presence of other cations (uranyl and calcium) that may compete with neptunium for sorption sites. The desorption of neptunium from goethite has been studied by resuspending the neptunium-loaded goethite samples in solutions containing no neptunium. Selected reacted sorbent samples were analyzed by x-ray absorption spectroscopy (XAS) to determine the oxidation state and molecular speciation of the adsorbed neptunium. Results have been used to establish the pH adsorption edge of neptunium on goethite in sodium chloride and calcium-bearing sodium silicate solutions. The results indicate that neptunium uptake on goethite reaches 95% at a pH of approximately 7 and begins to decrease at pH values greater than 8.5. Distribution coefficients for neptunium sorption range from less than 1000 (moles/kg)sorbed / (moles/kg)solution at pH less than 5.0 to greater than 10,000 (moles/kg)sorbed / (moles/kg)solution at pH greater than 7.0. Distribution coefficients as high as 100,000 (moles/kg)sorbed / (moles/kg)solution were recorded for the tests done in calcite equilibrated sodium silicate solutions. XAS results show that neptunium complexes with the goethite surface mainly as Np(V) (although Np(IV) is prevalent in some of the longer-duration sorption tests). The neptunium adsorbed to goethite shows Np-O bond length of approximately 1.8 angstroms which is representative of the Np-O axial bond in the neptunyl(V) complex. This neptunyl(V) ion is coordinated to 5 or 6 equatorial oxygens with Np-O bond lengths of 2.45 angstroms. The absence of a clearly recognizable Np-Fe interaction for the sodium chloride sorption tests suggests that neptunium in these solutions adsorbs as an outer-sphere complex. XAS results from the calcium-bearing sodium silicate sorption tests show evidence for a neptunyl(V) inner-sphere surface complex with a Np-Fe interaction at 3.5 angstroms. Desorption tests indicate that samples in which neptunium is bound as inner-sphere complexes show significant sorption hysteresis relative to samples in which neptunium is bound largely as outer-sphere complexes.
Sinusitis in children and adolescents with chronic or recurrent headache: a case-control study

The aim of this study was to determine the frequency of misdiagnosis of sinus headache in migraine and other primary headache types in the children and adolescents with chronic or recurrent headaches. Children with chronic or recurrent headaches (n = 310) were prospectively evaluated. Data collection for each patient included history of previously diagnosed sinusitis due to headache, and additional sinusitis complaints (such as fever, cough, nasal discharge, postnasal discharge) at the time of sinusitis diagnosis, and improvement of the headache following treatment of sinusitis. If sinus radiographs existed they were recorded. The study included 214 patients with complete data. One hundred and sixteen (54.2%) patients have been diagnosed as sinusitis previously and 25% of them had at least one additional complaint, while 75% of them had none. Sinusitis treatment had no effect on the headaches in 60.3% of the patients. Sinus graphy had been performed in 52.8%, and 50.4% of them were normal. The prevalence of sinus headache concomitant with primary headache, and only sinus headache was detected in 7 and 1%, respectively, in our study. Approximately 40% of the patients with migraine and 60% of the patients with tension-type headache had been misdiagnosed as “sinus headache”. Children with chronic or recurrent headaches are frequently misdiagnosed as sinus headache and receive unnecessary sinusitis treatment and sinus graphy.
Isolating the effects of symbolic distance, and semantic congruity in comparative judgments: An additive-factors analysis

The time needed to compare two symbols increases as the cognitive distance between them on the relevant dimension increases (symbolic distance effect). Furthermore, when subjects are told to choose either the larger or the smaller of two stimuli, the response time is shorter if the instruction is congruent with the overall size of the stimuli (semantic congruity effect). Three experiments were conducted to determine the locus of these effects in terms of a sequence of processing stages. The developmental aspects of these effects were also evaluated, as the subjects were from kindergarten, first grade, third grade, fifth grade, and college. By varying the visual quality of the stimulus in each experiment, it was determined that the distance effect resides in a comparison stage, whereas the congruity effect is an encoding phenomenon. Both distance and congruity effects were present at all grade levels, but they decreased in magnitude as grade increased. The results were interpreted relative to recent models of comparative judgments.
Capital, corporate income taxes, and catastrophe insurance

Abstract We provide estimates of the equity capital needed and the resulting tax costs incurred when supplying catastrophe insurance/reinsurance using a partial equilibrium model that incorporates a specific loss distribution for US catastrophe losses. After consideration of insurer investment in tax-exempt securities, tax loss carry-back/forward provisions, and personal taxes, our results imply that the tax costs of equity finance alone have a substantial effect on the cost of supplying catastrophe reinsurance. These results help explain a variety of industry developments that reduce tax costs. Also, when coupled with non-tax costs of capital, these results help explain the limited scope of catastrophe insurance/reinsurance.
Copper-responsive magnetic resonance imaging contrast agents.

The design, synthesis, and evaluation of the Copper-Gad (CG) family, a new class of copper-activated magnetic resonance imaging (MRI) contrast agents, are presented. These indicators comprise a Gd3+−DO3A core coupled to various thioether-rich receptors for copper-induced relaxivity switching. In the absence of copper ions, inner-sphere water binding to the Gd3+ chelate is restricted, resulting in low longitudinal relaxivity values (r1 = 1.2−2.2 mM−1 s−1 measured at 60 MHz). Addition of Cu+ to CG2, CG3, CG4, and CG5 and either Cu+ or Cu2+ to CG6 triggers marked enhancements in relaxivity (r1 = 2.3−6.9 mM−1 s−1). CG2 and CG3 exhibit the greatest turn-on responses, going from r1 = 1.5 mM−1 s−1 in the absence of Cu+ to r1 = 6.9 mM−1 s−1 upon Cu+ binding (a 360% increase). The CG sensors are highly selective for Cu+ and/or Cu2+ over competing metal ions at cellular concentrations, including Zn2+ at 10-fold higher concentrations. 17O NMR dysprosium-induced shift and nuclear magnetic relaxation dispersion measur...
Inverse Grading Resulting from Coarse-sediment Transport Lag

Inverse grading in turbidites is conventionally ascribed to dispersive pressure caused by mutual collisions among grains within a traction carpet or grain flow. The shearing traction carpet is supposed to become stratified, with particle size increasing upward; "freezing" of this traction carpet yields an inversely graded layer. An alternative mechanism, proposed here, emerges from the fact that coarse sediment fractions are transported more slowly than fine fractions. In a turbidity current, a sufficiently heterogeneous mix of sediment sizes should undergo streamwise size segregation as the coarsest fractions lag behind. If deposition begins before the coarsest fraction that will reach a particular station has arrived, the lower part of the resulting deposit should be inversely graded. A similar mechanism may produce inversely graded intervals in pyroclastic flow deposits. Because the head of a turbidity current typically travels only about 0.83 as fast as flow velocity in the body a short distance behind the head, the coarsest grains able to keep up with the front of the flow are those having transport velocity V sed nearly equal 0.83 U body . If coarser size fractions are available, they will arrive later than the head, permitting the development of inverse grading. The proposed mechanism will not operate when the coarsest size fraction travels as fast as (or faster than) the head of the flow, or when onset of deposition is delayed until after the coarsest size fraction has arrived. Assuming a logarithmic velocity profile below the maximum-velocity streamline, transport velocity can be calculated for particular sizes of suspended sediment, and expressed as a fraction of flow velocity. An upper limit for flow strength (shear velocity) can then be derived from the fall velocity of the coarsest grains at the base of an inversely graded interval: u * <= 4 w init . Where deposition of an inversely graded turbidite began immediately after passage of the head of the current, u * nearly equal 4 w init .
Photocatalytic oxidation of ethylene by ammonium exchanged ETS-10 and AM-6

Abstract ETS-10 and AM-6 in the as-prepared and ammonium form have been characterized using Raman, X-ray powder diffraction, N 2 adsorption, energy dispersive X-ray (EDX) analysis, UV/vis spectroscopy, and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). Upon NH 4 + ion exchange, AM-6 shows the loss of the characteristic V–O–V stretch in the Raman spectrum similar to the effects observed for NH 4 + ion exchanged ETS-10. The UV/vis spectrum of NH 4 + ion exchanged AM-6 also shows similar changes to NH 4 + ion exchanged ETS-10, though the band gap in AM-6 is not red shifted as it is in ETS-10. Heating the NH 4 + exchanged AM-6 to form H-AM-6 changes the coordination environment of the vanadium from an octahedral coordination to a tetrahedral coordination, but does not cause the partial collapse of the AM-6 structure. The oxidation of ethylene under oxygen on as-synthesized AM-6 only produces partial oxidation products while the NH 4 + ion exchanged AM-6 was able to completely oxidize ethylene to CO 2 .
Exploring surface biophysical-climate sensitivity to tropical deforestation rates using a GCM: A feasibility study

AbstractDeforestation perturbs both biophysical and carbon feedbacks on climate. However, biophysical feedbacks operate at temporally immediate and spatially focused scales and thus may be sensitive to the rate of deforestation rather than just to total forest-cover loss. Explored here is a method for simulating annual tropical deforestation in the fully coupled Community Climate System Model, version 3.0 (CCSM3) with the Dynamic Global Vegetation Model (DGVM) for testing biosphere climate sensitivity to “preservation pathways.” Two deforestation curves were simulated—a 10% deforestation curve with a 10% preservation target (DFC10-PT10) versus a 1% deforestation curve with a 10% preservation target (DFC1-PT10). During active deforestation, albedo, net radiation, latent heat flux, and climate variables were compared for time dependence and sensitivity to tropical tree cover across the tropical band and the Amazon basin, central African, and Southeast Asian regions. The results demonstrated the feasibility ...
Airborne measurements of aerosol extinction in the lower and middle troposphere over Wyoming, USA

Abstract Particle size distributions, and scattering and absorption coefficients were measured over the Green River basin of Wyoming during the Southwest Wyoming Visibility Study (SWYVIS) in February and March 1996. Eleven flights were carried out, using the Wyoming King Air research aircraft. In the least polluted regions of the planetary boundary layer, particle number densities detected in the diameter range 0.13–3.0 μm were −3 . Aloft, in the stable air of the free troposphere, they were generally even lower, often falling to a few tens of particles per cm 3 . Analyses of bulk aerosol filter samples showed that organic carbonaceous material was the dominant chemical component, with sulfate and refractory species being the largest inorganic components. Combining the filter data with separately measured black carbon mass loading values allowed refractive indices for the aerosol to be calculated, so that PCASP measured size distributions could be revised. Characterizing size parameters were obtained by fitting particle populations to bimodal lognormal distributions. Particle size distributions were somewhat broader at higher altitudes so that larger particles made greater contributions to extinction. Optical closure was attempted by comparing scattering and total extinctions computed by Mie theory with the corresponding values derived from the observations. While the calculated and measured single scattering albedo average values were in reasonably good agreement, even though individual pairs of values sometimes differed significantly, computed scattering coefficients often exceeded those derived from the measurements, by an average of 60%. Reasons for this discrepancy are explored, including the possible modification of the size distribution by partial or total volatilization of particles within the nephelometer and its inlet.
Quasi-projection-operator calculation of inelastic resonances in He − and Li

Feshbach resonances of electrons incident of He and Li(+) are calculated below the 3(S-3) target threshold by means of the inelastic quasi-projection-operator technique of Temkin and Bhatia (1972). A configuration-interaction-type wave function is employed with up to 46 configurations. The calculations reveal, with reasonable accuracy, all presently observed Feshbach resonances. The method does not reveal shape resonances, but, for isoelectronic systems with greater nuclear charge, it is argued that shape resonance should become less important. This is already apparent in the case of Li, for which the known resonances are calculated and higher resonances, for which there are as yet no experimental data, are predicted.