cssi/SciSciGPT-SciSciNet huggingface dataset:
Unifying theory for stability of continuous, discontinuous, and discrete-time dynamical systems

We show that if the hypotheses for the classical Lyapunov stability results for continuous dynamical systems (Zubov, 1964; Hahn, 1967) (continuous-time dynamical systems whose motions are continuous with respect to time) are satisfied, then the hypotheses of the corresponding stability results for discontinuous dynamical systems (continuous-time dynamical systems whose motions are not necessarily continuous with respect to time, abbreviated DDS), reported by Ye et al. (1998), are also satisfied. We then embed discrete-time dynamical systems into a class of DDS with equivalent stability properties and we show that when the hypotheses of the classical Lyapunov stability results for discrete-time dynamical systems are satisfied, then the hypotheses of the corresponding stability results for DDS are also satisfied. This shows that the stability results for DDS given by Ye et al. (1998) are less conservative than corresponding classical Lyapunov stability results for continuous dynamical systems and discrete-time dynamical systems. This is demonstrated further by means of two specific examples. The results summarized above, establish a unifying stability theory for continuous dynamical systems, discrete-time dynamical systems and discontinuous dynamical systems
Environmental Impact of Yucca Mountain Repository in the Case of Canister Failure

Mathematical models and a computation code have been developed for total release of transuranic (TRU) and fission product radionuclides from waste packages in the Yucca Mountain Repository (YMR) in...
The correlated evolution of antipredator defences and brain size in mammals

Mammals that possess elaborate antipredator defences such as body armour, spines and quills are usually well protected, intermediate in size, primarily insectivorous and live in simple open environments. The benefits of such defences seem clear and may relax selection on maintaining cognitive abilities that aid in vigilance and predator recognition, and their bearers may accrue extensive production and maintenance costs. Here, in this comparative phylogenetic analysis of measurements of encephalization quotient and morphological defence scores of 647 mammal species representing nearly every order, we found that as lineages evolve stronger defences, they suffer a correlated reduction in encephalization. The only exceptions were those that live in trees-a complex three-dimensional world probably requiring greater cognitive abilities. At the proximate level, because brain tissue is extremely energetically expensive to build, mammals may be trading off spending more on elaborate defences and saving by building less powerful brains. At the ultimate level, having greater defences may also reduce the need for advanced cognitive abilities for constant assessment of environmental predation risk, especially in simple open environments.
A Practical Gram-Scale Synthesis of Acrylohydroxamic Acid

Acrylohydroxamic acid, which is a useful monomer for the preparation of polymeric materials, has been prepared in a straightforward, two-step synthesis from readily available starting materials. The key steps are coupling of acrylic acid with O-tetrahydropyranylhydroxyl amine to provide protection of the hydroxylamine functionality, followed by acid cleavage of the protecting group.
Postrhinoplasty fibrotic syndrome

Over the years there have been numerous anecdotal reports of nasal tip enlargement and loss of tip definition post rhinoplasty. Subsequent revisionary procedures not only failed to reduce the tip size but aggravated the problem causing an even larger and less defined nasal tip. The final result was often worse than the preop condition and uncorrectable. Six patients who demonstrated an aggravation of the postop result with subsequent revisionary or secondary surgeries were evaluated to find common causes or circumstances. All patients had 1) worsening of nasal tip result with subsequent procedures, e. g., nasal tip enlargement and/or loss of tip definition with subsequent procedures 2) exhibited substantial postop edema at one or more surgeries and 3) extensive subcutaneous fibrous tissue noted at revisionary procedures. The nasal scenario described is referred to as postrhinoplasty fibrotic syndrome. It is recommended that if revision surgery is necessary by a surgeon, the scale of the surgery should be smaller than that of the primary operation. If yet another revision is necessary that surgery should be of an even smaller scale than the prior surgery. Augmentation rather than reduction rhinoplasty is clearly a better approach. With the surgical philosophy of smaller and/or less surgery with each revision (should it be necessary) the irreversible condition of postrhinoplasty fibrotic syndrome should be avoidable.
Understanding and Breaking Scaling Relations in Single-Site Catalysis: Methane to Methanol Conversion by FeIV═O

Computational high-throughput screening is an essential tool for catalyst design, limited primarily by the efficiency with which accurate predictions can be made. In bulk heterogeneous catalysis, linear free energy relationships (LFERs) have been extensively developed to relate elementary step activation energies, and thus overall catalytic activity, back to the adsorption energies of key intermediates, dramatically reducing the computational cost of screening. The applicability of these LFERs to single-site catalysts remains unclear, owing to the directional, covalent metal–ligand bonds and the broader chemical space of accessible ligand scaffolds. Through a computational screen of nearly 500 model Fe(II) complexes for CH4 hydroxylation, we observe that (1) tuning ligand field strength yields LFERs by comparably shifting energetics of the metal 3d levels that govern the stability of different intermediates and (2) distortion of the metal coordination geometry breaks these LFERs by increasing the splittin...
A Self-Consistent, Semiclassical Electrothermal Modeling Framework for Mott Devices

Mott materials have been investigated since late 1950s for their remarkably abrupt insulator to metal transition (IMT) in response to changes in temperature, strain, or electrical stimulus. Interest in these materials has been revived by recent demonstration of nanosecond-scale switching along with reproducible and fully reversible transitions in VO2-based thin film devices. These phenomena make VO2-based Mott insulator devices technologically relevant for various applications, such as memory selectors, logic switches, and building blocks for neuromorphic computing. Several groups have provisionally attributed the IMT switching to Joule heating. However, an electrothermal device simulation framework that self-consistently reproduces IMT phase transition, and in addition, explaining a variety of electrical/optical phenomena associated with IMT is still lacking. In this paper, we develop a self-consistent electrothermal device simulation framework which captures these key experimental attributes of IMT using VO2 as a model material. This framework will enable predictive modeling as well as provide insight on switching mechanisms and design of novel Mott insulator devices.
Adaptation Planning to Mitigate Coastal-Road Pavement Damage from Groundwater Rise Caused by Sea-Level Rise

Sea level in coastal New England is projected to rise 3.9–6.6 ft (1.2–2.0 m) by the year 2100. Many climate-change vulnerability and adaptation studies have investigated surface-water flooding from...
Quasi-static Polycrystalline Uniaxial Stress Experiments

In the range of strain rates from 1 sec−1 to the highest diffraction grating measured value of 70,000 sec−1, inertial contributions are sufficiently important so that the non-linear wave propagation effects of Chapter II must be considered. Strain rates of 1 sec−1 and below are in the domain of quasi-static, uniaxial stress experiments where this inertial contribution is negligible. For these experiments one need only establish that a uniform distribution of stress and finite strain is maintained with only the axial principal stress being non-zero. As will be shown below from the study of over 250 polycrystalline quasi-static, uniaxial stress experiments in nineteen crystalline elements and two binary combinations, the dynamic generalization of Eq. (2.20) is still applicable. As long as strain is increasing at the finite amplitude wave front in dynamic experiments, the integral value of the large deformation mode index r has been found to be stable until the maximum strain is reached. In quasi-static experiments, on the other hand, transitions from one parabolic large deformation mode to another are found to occur as the strain increases.
Causes, Effects, and Side Effects: Choosing Between the Better and the Best

Through the history of Western thought, philosophers and physicians have explored the nature of causation and the general relation that obatains between effects and causes. They have sought to discover causal relationships and even causal laws. Physicians have, however, not conducted themselves as pure scientists. They have, instead, attended to causes through a grid of value judgments embedded in particular practices of curing and caring. As has been argued in comparisons of law and medicine, these non-epistemic goals direc the language of causation in applied disciplines [4].
Matching in R

The statistical package R is used to construct several matched samples from one data set. The focus is on the mechanics of using R, not on the design of observational studies. The process is made tangible by describing it in detail, closely inspecting intermediate results; however, essentially, three steps are involved, (i) creating a distance matrix, (ii) adding a propensity score caliper to the distance matrix, and (iii) finding an optimal match. One appendix contains a short introduction to R. A second appendix contains short R functions used to create distance matrices used in matching.
Selecting High Tech Production Machines: A Guide for Entrepreneurs and Small Manufacturing Businesses

This study presents a set of practical criteria and guidelines for small manufacturing business entrepreneurs who are looking for starting or growing a business through the addition of multifunctional computer numerical controlled (CNC) technology. Even though adopting this advanced technology can be costly in terms of initial investment and training, recently-developed equipment may have a positive long-term effect by simplifying production methods or providing the means to accomplish tasks that were once considered impractical. The multifunctional CNC machines are capable of meeting several production goals including faster processing, minimizing non-value added times, concurrent processing of multiple parts and flexibility in processing high mix of products. This technology has become increasingly sophisticated and expensive capital equipment. This study entails a framework of technology selection and discussion of critical selection criteria such as product design features, impact of material type on processing power requirement and production goals. Technical and cost data from several suppliers as well as practical examples are provided to assist small manufacturing business entrepreneurs in selection of this multifunctional technology.
Biophysical Spandrels form a Hot-Spot for Kosmotropic Mutations in Bacteriophage Thermal Adaptation.

Temperature plays a dominating role in protein structure and function, and life has evolved myriad strategies to adapt proteins to environmental thermal stress. Cellular systems can utilize kosmotropic osmolytes, the products of complex biochemical pathways, to act as chemical chaperones. These extrinsic molecules, e.g., trehalose, alter local water structure to modulate the strength of the hydrophobic effect and increase protein stability. In contrast, simpler genetic systems must rely on intrinsic mutation to affect protein stability. In naturally occurring microvirid bacteriophages of the subfamily Bullavirinae, capsid stability is randomly distributed across the phylogeny, suggesting it is not phylogenetically linked and could be altered through adaptive mutation. We hypothesized that these phages could utilize an adaptive mechanism that mimics the stabilizing effects of the kosmotrope trehalose through mutation. Kinetic stability of wild-type ID8, a relative of ΦX174, displays a saturable response to trehalose. Thermal adaptation mutations in ID8 improve capsid stability and reduce responsiveness to trehalose suggesting the mutations move stability closer to the kosmotropic saturation point, mimicking the kosmotropic effect of trehalose. These mutations localize to and modulate the hydrophobicity of a cavern formation at the interface of phage coat and spike proteins—an evolutionary spandrel. Across a series of genetically distinct phages, responsiveness to trehalose correlates positively with cavern hydrophobicity suggesting that the level of hydrophobicity of the cavern may provide a biophysical gating mechanism constraining or permitting adaptation in a lineage-specific manner. Our results demonstrate that a single mutation can exploit pre-existing, non-adaptive structural features to mimic the adaptive effects of complex biochemical pathways.
Pilot Study of Skin Cancer Risk Reduction Behaviors, Cancer Communication, and Skin Cancer Beliefs in Hispanics

Purpose: Given rising rates of deadly melanoma skin cancer in Hispanics, the study objective was to examine skin cancer-related risk reduction behaviors and beliefs to dictate content for culturally targeted skin cancer prevention strategies for Hispanics. Methods/Data Source: An anonymous survey was administered to waiting room volunteers in a primary care facility in Albuquerque, New Mexico to assess skin cancer risk reduction behaviors, screening, cancer information seeking and communication, as well as skin cancer beliefs in Hispanics (n=48) and Non-Hispanic Whites (n=36). Results: We found lower levels of sun protection clothing use among Hispanics compared to Non-Hispanic Whites, but comparable use of sunscreen and shade-seeking among these groups. Hispanic ethnicity was the most important predictor of skin cancer misconceptions, with skin cancer information overload and misconceptions reported more often in Hispanics. Conclusions: This study demonstrates the need for culturally relevant information for ethnic minority populations such as Hispanics who have shown an increased risk of presenting with later stage, more aggressive melanoma skin cancer.
Icosahedral Ordering in Supercooled Liquids and Metallic Glasses

A metallic glass is a solid consisting of metallic atoms arranged in a random manner with no obvious long-range correlation in the atomic positions. While such random atomic arrangements are easy to achieve in materials with covalent bonding, until 1960 the solid state of all known metals and metallic alloys consisted of regular, periodic arrangements of the atoms. The first metallic glass was produced in 1960 by Duwez and co-workers [1] by rapidly cooling a molten alloy of gold and silicon. Metallic glasses have since then been created in large numbers of simple metal, transition metal, and metalloid systems by a variety of ingenious methods. “Splatcooling” techniques have been developed to achieve cooling rates of over a million degrees per second and have created a completely new metallurgical technology. The new metallic materials so produced have proved to be of considerable technological importance for their unique magnetic, mechanical, and corrosion-resistance properties [2].
Polycythemia Vera V. Enhanced Proliferation and Phosphorylation Due to Vanadate Are Diminished in Polycythemia Vera Erythroid Progenitor Cells: A Possible Defect of Phosphatase Activity in Polycythemia Vera

Erythropoietin (EP) and stem cell factor (SCF) are essential growth factors for erythroid progenitor cell proliferation and differentiation in serum-free culture. It has been previously shown that burst-forming units-erythroid and colony-forming units-erythroid from patients with polycythemia vera (PV) have enhanced sensitivity to EP and SCF compared with normal erythroid progenitors, but little is known about the mechanism for this difference. In the present investigation, the effect of EP and SCF on protein tyrosine phosphorylation in day-8 normal and PV erythroid colony-forming cells, which give rise to colonies of 2-49 hemoglobinized cells, was studied. EP rapidly induced tyrosine phosphorylation of the EP receptor, whereas the most prominent phosphorylated protein induced by SCF was identified as the SCF receptor. No additional phosphorylated proteins were evident when PV cells were compared with normal cells. Culture of normal erythroid progenitors with orthovanadate, an inhibitor of protein tyrosine phosphatases, resulted in an increased number of erythroid colonies and enhanced protein tyrosine phosphorylation. However, in contrast, little enhancement was evident with PV cells. These results indicate that, although vanadate may be acting in normal erythroid progenitors as a phosphatase inhibitor that potentiates the kinase activity induced by SCF and EP, this function is diminished in PV cells. Because erythropoiesis is regulated by a balance between protein tyrosine kinase activity and protein tyrosine phosphatase activity, PV patients may have an abnormal phosphatase activity allowing increased cell proliferation.
Postsurgical Recurrence of CSF-Venous Fistulas in Spontaneous Intracranial Hypotension

Spinal CSF-venous fistulas (CVF) were described in 2014 and are now recognized as an important etiology of spontaneous intracranial hypotension (SIH) 1-3. Surgical ligation is highly effective for treating CVFs4. Given the relatively recent discovery of this entity, long-term follow up on treated cases has not been available, however, surgery has generally been considered definitive treatment. We report four cases of SIH in which CVFs have recurred or developed de novo at a different spinal level following complete surgical ligation of the primary lesion. In all cases, the new CVF was not present on any pre-surgical imaging.
Nutritional Management of Hyperoxaluria

Urine oxalate is derived both from the ingestion of foods that contain oxalate and its precursors (exogenous sources) and from biosynthesis (endogenous source). Oxalate biosynthesis occurs as an end-product of metabolism, by the degradation of dietary carbohydrates, ascorbate (vitamin C), and amino acids (hydroxyproline, phenylalanine, tryptophan). The relative contribution of exogenous and endogenous oxalate in urine varies greatly between individuals owing to metabolic, physiologic, and environmental factors. Patients with primary hyperoxaluria (there are three types) produce excessive oxalate due to enzyme deficiencies that would otherwise divert oxalate production to less toxic metabolites. Patients with altered gastrointestinal physiology (such as short bowel) or with inflammatory bowel disorders (such as Crohns or Celiac) absorb excessive oxalate from the gastrointestinal tract due to malabsorption and/or dysbiosis. Finally, patients with insufficient intakes of dietary factors that regulate oxalate absorption or its solubility in urine are at risk for higher urinary concentrations of oxalate and, thus, calcium oxalate stones. This chapter provides guidance on the management of high urine oxalate with dietary recommendations aimed at these challenges: controlling oxalate biosynthesis, controlling oxalate absorption, and controlling oxalate concentration in the gastrointestinal tract.
Encopresis and enuresis

Abstract The endpoint of the alimentary process involves elimination of urine and feces and these processes represent a common developmental milestone for children; however, failure to achieve appropriate elimination by the expected age is a common pediatric complaint. Specifically, enuresis (urine) and encopresis (feces) are estimated to occur in approximately 25% of 6-year old children. It has been noted by several authors that the prevalence is higher in boys than girls and that rates decrease as a function of age (Friman, 2008; Shepard & Cox, 2017). These disorders usually occur independently but can co-occur. There is a broad range of medical conditions that can cause encopresis and enuresis, but these causes are rare. They are real, however, and need to be ruled out prior to going forward with behavioral assessment and treatment. The vast majority of cases are functional and their comprehensive assessment readily yields functionally relevant variables that can either be modified or manipulated through behavioral intervention to bring about modifications in behavior related to elimination.
Metabolic status changes the interregulation of AMPK and CFTR (893.26)

A better understanding of CFTR Cl- channel regulation could suggest new therapies for cystic fibrosis (CF). We previously found that the α1 catalytic subunit of AMP-activated kinase (AMPK) binds to...
Investigating the applicability of biodynamic models to account for whole-body dynamics on automotive seats

Different occupant-seat models were explored for vibration comfort analyses of automotive seats. A nonlinear model of a seat cushion and its support mechanism was developed based on the measured static and dynamic characteristics. Subsequently, analyses and experiments were performed to examine the applicability of some selected linear occupant models.
The Object of Extension: Agricultural Education and Authentic Farmers in Pennsylvania

Cooperative extension, as an outreach mechanism of land grant universities in the USA, has long served the educational needs of rural and agricultural communities. The educational programming of extension, however, is generally divided into areas that reflect, reify and reinforce the gendered division of labour on farms in the USA. While it is well documented that extension inadequately serves women in providing knowledge about production practices in contemporary agriculture, the mechanisms by which women's access to knowledge is hindered are not well understood. Using Freire's ideas about authentic educational subjects we explore the social construction of authentic farming and educational programming in the cooperative extension system. Using interviews with extension educators at a large land grant university, this article describe how extension educators identify certain types of farmers and farming as authentic, while certain types of farms are seen as inauthentic. This belief feeds into the institutional discourse that the educational opportunities offered by extension are appropriate for all audiences of authentic farmers. We conclude by offering insights into how cooperative extension can reorient its programming toward the emerging cultural economies of agriculture in rural communities. For what is the object of Extension work? More bushels of corn? More bales of cotton? No, these are but means to an end. The end, the object of Extension work, is to aid the farmer and his family to improve living conditions on the farm, to provide a more satisfying rural life. (Clyde William Warburton, 1930. Director of Extension Work, United States Department of Agriculture).
Internet Connectivity Can Positively Influence Total Patient Experience

Abstract In a consumer-focused healthcare marketplace, the provision of in-suite Internet access to patients is among the boutique services hospitals can offer for product differentiation. A mechanism for influencing the total patient experience, Internet access can positively impact clinical outcomes indirectly, by enabling the patient to maintain contact with family and loved-ones and to exercise a level of control over personal and professional affairs, and directly by connecting the patient to relevant patient education materials. Among vehicles most commonly deployed for providing in-suite access, each offers advantages and disadvantages. However, implementation of wireless networks coupled with laptops-for-patients (LFP) lending programs may provide the most efficient and effective access solution. Such implementations also afford hospital libraries opportunities to exercise leadership.
The role of mania in the genesis of dangerous delusional misidentification

The delusional misidentification syndromes are characterized by a misidentification delusion of the self and/or others. Delusional misidentification syndromes frequently occur in psychotic disorders such as schizophrenia, psychotic disorder due to general medical condition, or psychotic disorder not otherwise specified. On rare occasions these syndromes may be associated with manic states secondary to bipolar disorder, schizoaffective disorder, or general medical conditions. The delusional misidentification syndromes may also be associated with verbal and physical aggression. In this article we present three cases of dangerous delusional misidentification associated with mania. We will discuss the role that mania may have in the genesis of dangerous delusional misidentification.
Abstract 204: The Adoption of Multiple Best Practices to Improve Out-of-Hospital Cardiac Arrest in Salt Lake City, Utah

BACKGROUND: Survival from out-of-hospital cardiac arrest has remained unchanged over the last 30 years in the United States, with the exception of survival in a few high-performance EMS systems. We hypothesized that the implementation of several best practices from such EMS systems would result in improved survival in our community. METHODS: In September 2011, the Salt Lake City Fire Department (SLCFD) implemented a 2010 AHA-based protocol for reducing hands-off time and improving CPR quality, including use of CPR-filtering technology to reduce pauses for rhythm analysis, real-time CPR feedback, intra-arrest chilled saline, team resuscitation based on a pit crew model, impedance threshold device CPR, and post-incident audit and feedback of all cardiac arrests by the medical director. Outcomes were collected from each receiving hospital, and Cerebral Performance Category (CPC) was used to estimate neurologic outcome. A CPC 1 or 2 was considered neurologically-intact. We evaluated performance prior to and f...
Second-Generation Drug-Eluting Stents and the Continuous Need for Rapidly Available Real-World Data⁎

Drug-eluting stents (DES), by markedly reducing the need for repeat target vessel revascularization (TVR) compared with bare-metal stents (BMS), have been so rapidly and widely employed that use continues to far outpace data regarding indications and outcomes. After the initial success of first-
Enhanced near- and far-field Faraday rotation with a monolayer array of core-shell nanoparticles

We study Faraday rotation by magnetized core-shell nanoparticles. We theoretically show enhanced polarization rotation in the near-zone and several-fold increase of the Faraday effect in the far-zone for a periodic array of nanoparticles.
Results of Goeckerman Treatment for Psoriasis in Children: A 21‐Year Retrospective Review

Goeckerman treatment has been used for the management of widespread psoriasis in children for several decades at Mayo Clinic. We aimed to review our institutional experience with the effectiveness of Goeckerman treatment for psoriasis in children. We retrospectively reviewed the records of pediatric patients who underwent Goeckerman treatment over a 21-year period (1983-2003). The main outcome measure was improvement in psoriasis. During the study period, 65 children received Goeckerman treatment for predominantly widespread, recalcitrant psoriasis. The mean age was 11.6 years (range, 3 mos to 18 yrs), and the female-to-male ratio was 2:1. Psoriasis improved in all patients: 55 patients (85%) had >80% clearance of their psoriasis. The only adverse effect was folliculitis, occurring in 27 patients (42%). Mean duration of follow-up was 2.6 years (range, 17 days-18.2 yrs); average duration of remission was 2.6 years (range, 2 mos-12.79 yrs). Goeckerman treatment is an effective treatment for widespread psoriasis in children.
mkpkg: A software packaging tool

mkpkg is a tool that helps software publishers create installation packages. Given software that is ready for distribution, mkpkg helps the publisher develop a description of the software package, including manifests, dependencies, and post-install customizations. mkpkg automates many of the painstaking tasks required of the publisher, such as determining the complete package manifest and dependencies of the executables on shared libraries. Using mkpkg ,a publisher can generate software packages for complex software such as TeX with only a few minutes effort. mkpkg has been implemented on HP-UX using Tcl/Tk and provides both graphical and command line interfaces. It builds product-level packages for Software Distributor (SD-UX).
BACK TO BASICS: TWO ISSUE AREAS FOR THE FUTURE URBAN POLITICS AGENDA

This essay argues for the importance of two areas of inquiry in the future agenda of urban politics: urban infrastructure and urban policing. Both topical areas have deep roots in the field. However, this essay argues that we know less than we should about how varied institutional arrangements used to produce and manage urban infrastructure might help account for quality and equity problems of urban infrastructure. This essay also argues that urban politics research on local policing has diminished relative to contributions from other disciplines and the interdisciplinary criminal justice field, resulting in important substantive gaps and biases in topical coverage because the distinctive voice of political science is much too muted. The kinds of police-related research themes or topics that need additional work from an urban politics perspective are outlined.
Tolerance and cross-tolerance to central nervous system depressants after chronic pentobarbital or chronic methaqualone administration

This study reports on tolerance and cross-tolerance to the rotarod (RR)-disrupting effects of various central nervous system (CNS) depressants. Female rats trained on the RR were fed ground chow containing pentobarbital (PB, 2.0 mg/g chow) or methaqualone (MQ, 1.0 mg/g chow) and were injected twice daily (PB) or daily MQ) with 30 mg/kg IP for 6 days. Control rats received ground chow and saline injections. On day 7 the subjects were tested with various doses of PB, MQ, diazepam (DZ), or ethanol (ET) for disruption of RR performance over the time-course of the drug effect (up to 12 hours). Control animals demonstrated a dose-dependent duration of impairment for all 4 agents. Both groups receiving chronic drug showed a prominent decrease in duration of RR impairment after PB, a less marked decrease after MQ, and even less of a decrease after DZ. However, neither chronic drug group showed an appreciable tolerance to the RR disruption of ET, relative to the control group. Based on the time of 50% recovery (RR performance recovering to 90 seconds or more), both chronic treatments resulted in a significant shift of the dose-response curves for PB, MQ and DZ to the right. Therefore, the degree of tolerance and cross-tolerance in rats chronically treated with PB or MQ was dramatic for PB and MQ, was significant for DZ, but was not demonstrable for ET.
Why Don't More Young People Go to College?

Even though the gap between prospects for high school and college graduates has remained wide, young people are not rushing to attend college. Indeed, many economists believe widespread college education is the main avenue to future economic growth. These two analysts find that the pay-off of college does not accrue to all as is widely thought. And they propose that we channel policies to make college more financially worthwhile.
Evaluation of on-site wastewater system Escherichia coli contributions to shallow groundwater in coastal North Carolina

The study goal was to determine if on-site wastewater systems (OSWWS) installed in coastal areas were effective at reducing indicator bacteria densities before discharge to groundwater. Groundwater Escherichia coli ( E. coli ) densities and groundwater levels adjacent to 16 OSWWS in three different soil groups (sand, sandy loam, and sandy clay loam) were monitored and compared to background groundwater conditions on four occasions between March 2007 and February 2008 in coastal North Carolina. Groundwater beneath OSWWS had significantly ( p ≤0.05) lower densities of E. coli than septic tank effluent, but significantly higher densities of E. coli than background conditions for each soil type. Twenty three percent of all groundwater samples near OSWWS had E. coli densities that exceeded the EPA freshwater contact standards (single sample 235 cfu/100 mL) for surface waters. Groundwater E. coli densities near OSWWS were highest during shallow water table periods. The results indicate that increasing the required vertical separation distance from drainfield trenches to seasonal high water table could improve shallow groundwater quality.
Airborne fungi associated with ornamental plant propagation in greenhouses

The objective was to determine potential exposure to airborne fungi in greenhouses and to characterize the temporal patterns of airborne fungi in relation to environmental conditions. We analyzed air samples collected in two greenhouses. Results showed that the top 5 fungi in greenhouse 1 were Trichoderma, hyphal fragments, Aspergillus/Penicil- lium-like, Cladosporium, and Botrytis in a descend- ing order. Those in greenhouse 2 were Aspergillus/ Penicillium-like, Cladosporium, Botrytis, yeast-like, and hyphal fragments. Maximum concentrations of Trichoderma and total spores in greenhouse 1 were 36,426 and 49,729 spores/m 3 , respectively. Maxi- mum concentrations of Aspergillus/Penicillium and total spores in greenhouse 2 were 46,961 and 71,037 spores/m 3 , respectively. Airborne fungal populations fluctuated dramatically within 2 h during work hours, tenfold for Aspergillus/Penicillium, 66-fold for Trich- oderma, and sevenfold for total spores. QPCR detected Trichoderma harzianum ranging from 7 to 3,500 conidia E/m 3 . Aspergillus/Penicillium and Botrytis showed diurnal patterns, but not Tricho- derma. Aspergillus/Penicillium and Cladosporium were positively correlated with temperature, relative humidity, dew point, heat index, and light and negatively with air movement and air pressure. Botrytis and Trichoderma were not correlated with the environmental factors. Greenhouse workers were potentially exposed up to 71,037 spores/m 3 of air-
Luminescent properties of graded cadmium sulfoselenide electrodes prepared from cadmium sulfide substrates

Inhomogeneous samples of n-type CdSxSe1−x(0.2 ≲ x <1) were prepared by vapor-phase diffusion of SE into a single-crystal n-CdS substrate. Characterization of the samples by Auger electron spectroscopy (AES)/Ar ion sputter etching indicates that Se substitutes for S in the lattice to produce a graded region where x monotonically increases with depth from − 0.2 at the surface to unity over a distance of ~ 1 μm. Photoluminescence (PL) and electroluminescence (EL) of these CdS/Se samples are dominated by edge emission characteristic of the near-surface CdSxSe1−x compositions ( ~ 650–700 nm). The narrowness of the spectra compared to spectra reported for CdSe/S graded solids prepared by diffusion of S into n-CdSe is rationalized in terms of the electronic structures of the two compounds. A previously established linear correlation between emission maxima and composition in homogeneous CdSxSe1−x samples provides a spatial probe of electron—hole pair recombination in the inhomogeneous material: Regions from which PL and EL originate can be inferred from their spectral distribution in combination with the AES/depth profile data. The CdS/Se samples can be used as photoanodes of photoelectrochemical cells (PEC's) employing aqueous (poly)sulfide electrolyte. PL quenching accompanying the passage of photocurrent indicates that the effective electric field (EEF) in the solid at ~ 0.3 V vs. SCE extends ~ 0.1–0.2 μm into the solid. By etching away the graded layer from one face of the CdS/Se crystal, PL can be excited and viewed through the exposed CdS face and yields a similar value for the EEF thickness; photoaction spectra support the PL data in identifying the near-surface portion of the graded zone as principally responsible for photocurrent. Both CdS/Se and CdSe/S electrodes lend themselves to the construction of display devices by spatially-controlled etching: by appropriate masking and etching techniques, patterned, multi-colored emitting electrodes can be fabricated. For the CdS/Se samples, PEC etching can be exploited to control etching depth with excitation wavelength
Prediction of viscosity of refrigerants and refrigerant mixtures

Abstract We have developed a predictive corresponding states model for the viscosity of pure refrigerants and refrigerant mixtures. The model uses extended corresponding states with R134a (1,1,1,2-tetrafluoroethane) as the reference fluid. The model uses equilibrium shape factors and an equivalent substance reducing ratio (ESRR) for the viscosity which involves the molecular mass. The “mass” ESRR is found using viscosity data along the saturation boundary. We have fit these mass ESRR's to a general form involving reduced temperature and a structural factor. In addition, we have determined a set of universal coefficients for the mass ESRR that can be used to predict the viscosity of any halocarbon refrigerant given the critical parameters and the structural parameter. We give sample results comparing the model predictions with experimental data for pure fluids and a refrigerant mixture.
Initial Response of Butterflies to an Overstory Reduction and Slash Mulching Treatment of a Degraded Piñon‐Juniper Woodland

Overstory reduction and slash mulching (ORSM) has been shown to be an effective means for increasing herbaceous cover and diversity in degraded pinon (Pinus edulis) and juniper (Juniperus monosperma) woodlands of north-central New Mexico. Local fire history, tree age-class structure, and grazing records suggest that many areas now occupied by dense pinon-juniper woodlands were formerly more open, with grassy understories that supported well-developed soils and a fire regime. At Bandelier National Monument, studies are evaluating the use of ORSM treatments as a restoration management tool. In 1999 and 2001, we evaluated the effects of an ORSM treatment implemented in 1997 upon butterfly abundance and species richness between a pair of treated and control watersheds. Butterfly abundance and species richness were significantly greater on the treated watershed in both years, and these measures were correlated with significant increases in forb and grass cover in the treated watershed. Five of the 10 most common nectar and larval host plants had significantly greater cover in the treated watershed, including the legume Lotus wrightii. Our results suggest that the increased herbaceous cover resulting from an ORSM treatment of a single watershed induced a positive, initial response by butterflies. Using butterflies as indicators of site productivity and species richness, our results suggest ORSM is a promising technique for restoring biodiversity in degraded pinon-juniper woodlands.
Competing ion effect on chromium adsorption with fresh and starved subsurface bacterial consortium

The sorption of chromium (Cr+6) was investigated for 50 day starved and fresh cells in the presence of sulfate ion as a competing ion at three pH values (pH 6.0, 7.5 and 9.0). The chromium distribution in the subcellular components was also determined by conducting cell fractionation. Although a previous study showed that cells which had been starved for 50 days prior to being exposed to a chromium containing solution sorbed 10–15% more chromium than did fresh cells (Kong et al., 1992a), this study demonstrated that such cells did not sorb more chromium in the presence of sulfate ion.
The role of hydropedologic vegetation zones in greenhouse gas emissions for agricultural wetland landscapes

Abstract Net greenhouse gas (GHG) source strength for agricultural wetland ecosystems in the Prairie Pothole Region (PPR) is currently unknown. In particular, information is lacking to constrain spatial variability associated with GHG emissions (CH 4 , CO 2 , and N 2 O). GHG fluxes typically vary with edaphic, hydrologic, biologic, and climatic factors. In the PPR, characteristic wetland plant communities integrate hydropedologic factors and may explain some variability associated with trace gas fluxes at ecosystem and landscape scales. We addressed this question for replicate wetland basins located in central North Dakota stratified by hydropedologic vegetation zone on Jul 12 and Aug 3, 2003. Data were collected at the soil-atmosphere interface for six plant zones: deep marsh, shallow marsh, wet meadow, low prairie, pasture, and cropland. Controlling for soil moisture and temperature, CH 4 fluxes varied significantly with zone ( p 4 emissions were found near the water in the deep marsh (277,800 μg m − 2 d − 1 CH 4 ), which declined with distance from water to − 730 μg m − 2 d − 1 CH 4 in the pasture. Carbon dioxide fluxes also varied significantly with zone. Nitrous oxide variability was greater within zones than between zones, with no significant effects of zone, moisture, or temperature. Data were extrapolated for a 205.6 km 2 landscape using a previously developed synoptic classification for PPR plant communities. For this landscape, we found croplands contributed the greatest proportion to the net GHG source strength on Jul 12 (45,700 kg d − 1 GHG-C equivalents) while deep marsh zones contributed the greatest proportion on Aug 3 (26,145 kg d − 1 GHG-C equivalents). This was driven by a 30-fold reduction in cropland N 2 O–N emissions between dates. The overall landscape average for each date, weighted by zone, was 462.4 kg km − 2 d − 1 GHG-C equivalents on Jul 12 and 314.3 kg km − 2 d − 1 GHG-C equivalents on Aug 3. Results suggest GHG fluxes vary with hydropedologic soil zone, particularly for CH 4 , and provide initial estimates of net GHG emissions for heterogeneous agricultural wetland landscapes.
Blood pressure reductions with exercise and sodium restriction in postmenopausal women with elevated systolic pressure: role of arterial stiffness.

Abstract OBJECTIVES This study determined the relative efficacy of aerobic exercise (daily walking) and moderate dietary sodium restriction (sodium intake BACKGROUND Lifestyle behaviors are recommended for lowering blood pressure (BP) in adults with elevated baseline levels, but there is little information as to the relative efficacy of different interventions or the mechanisms underlying their potential beneficial effects. METHODS After baseline measurements and random assignment, 35 nonmedicated healthy postmenopausal women with SBP between 130 and 159 mm Hg completed three months of either aerobic (walking) exercise (n = 18; 62 ± 9 years, mean ± SD) or moderate dietary sodium restriction (SR) (n = 17; 65 ± 10 years, mean ± SD). RESULTS Body mass and composition, plasma volume, and fasting concentrations of metabolic coronary risk factors did not differ between the groups at baseline or change with intervention. Systolic BP and PP at rest decreased with both exercise and SR (p CONCLUSIONS Moderate SR lowers SBP and PP in postmenopausal women with elevated baseline levels more than does daily walking. The greater blood pressure reductions with SR may be mediated in part by a decrease in the stiffness of the large elastic arteries.
Effect of isotretinoin therapy on natural killer cell activity in patients with xeroderma pigmentosum.

Xeroderma pigmentosum (XP) is a rare autosomal recessive disorder characterized by sun sensitivity, defective DNA repair, markedly increased susceptibility to skin cancer, and a variety of immunological defects, including defective natural killer (NK) cell activity. Retinoid therapy has been demonstrated to protect effectively against the development of skin cancers in patients with XP, although its mechanism of action is unknown. We describe a series of eight XP patients, six of whom were given oral isotretinoin. The NK cell activity was not affected by low-dose isotretinoin, i.e. 0.5 mg/kg per day. However, higher doses of isotretinoin, e.g. 1.0 mg/kg per day, produced a significant decrease in NK cell function, at the same time as producing a reduction in the frequency of development of skin cancers. Retinoid therapy may have a skin cancer preventing effect by enhancing other immune effector mechanisms or via epithelial cell differentiation.
The Harvard open ocean model: calibration and application to dynamical process, forecasting, and data assimilation studies

Abstract The physical basis and numerical algorithm of the Harvard open ocean model is reviewed with emphasis on those details which are important to the application of the model. A summary of the validation and calibration of the model is presented focusing upon the studies which guide the selection of model parameters. A related analysis scheme for energy and vorticity is summarized and the use of this scheme demonstrated. The design and application of numerical simulations and some salient results of these studies are considered. An example of real data initialization is provided using the POLYMODE Mark II data set. Further examples of real data initialization, including altimeter data, demonstrate: (i) the capability of the model as a dynamical interpolation, nowcasting, and forecasting tool, and (ii) the power of the combined model-energy and vorticity analysis as a tool for the physical interpretation of real oceanic flow processes.
Effect of crystal defects on reverse I-V characteristics of 4H-SiC APDs

In this work, we investigated the effect of crystal defects on reverse I-V characteristics of avalanche photodiodes (APDs) using electron-beam induced current (EBIC) mode of SEM. Two types of SiC APD structures (I and II) were fabricated using 2 inch p-doped substrates with n-doped epilayers and 3 inch n-doped substrates with p- and n- epilayers. Areas of the formed diodes were approximately 1 mm2. The devices without any kind of electrically active 3-D structural defects demonstrated breakdown voltages close to theoretical values, ~500 V for the APD Type I and ~1200 V for Type II APD. Stability of Type I devices was tested by applying a short pulse of high voltage (~800 V). EBIC images, taken prior to and after the failure test, showed new defects in the dislocation free area, which, presumably, were caused by thermal breakdown.
Sucrose drinking reduces dorsal hypothalamic β-endorphin levels in spontaneously hypertensive rats but not in Wistar-Kyoto rats

Abstract The present study was performed to test whether drinking of a 10% sucrose solution would preferentially alter tissue content of β-endorphin in dorsal and ventral hypothalamic fragments from the spontaneously hypertensive rat (SHR), as opposed to the Wistar-Kyoto rat (WKY). Changes were correlated with cardiovascular function and circulating catecholamine levels to asses the role of hypothalamic β-endorphin, a putative mediator of sucrose-induced changes in cardiovascular sympathetic nervous tone. Male rats were trained to consume their total 24-h water intake in a single period between 0900–1100 h. Catheters were chronically implanted to sample blood and to record arterial blood pressure and heart rate. The experimental protocol consisted of a recording session, which included a 10-min drinking period wherein rats consumed 8 ml of either sucrose solution or deionized water. Rats were sacrificed and hypothalami removed for analysis of β-endorphin content. Comparable increases in blood pressure were noted in SHR and WKY during drinking of either sucrose or water. Drinking-induced tachycardia was blunted in SHR drinking sucrose. Plasma norepinephrine was increased only in sucrose-drinking SHR. Plasma glucose levels were elevated in both SHR and WKY following drinking of sucrose, but not water. β-Endorphin levels were reduced ( p