cssi/SciSciGPT-SciSciNet huggingface dataset:
Induction of tyrosine hydroxylase mRNA by nicotine in rat midbrain is inhibited by mifepristone

Repeated nicotine administration induces tyrosine hydroxylase (TH) mRNA in rat midbrain. In this study we investigate the mechanisms responsible for this response using two models of midbrain dopamine neurons, rat ventral midbrain slice explant cultures and mouse MN9D cells. In both models nicotine stimulates TH gene transcription rate in a dose-dependent manner. However, this stimulation is short-lived, lasting for 1 h, but less than 3 h, and is not sufficient to induce TH mRNA or TH protein. Nicotine elevates circulating glucocorticoids, which induce TH expression in some model systems. We tested the hypothesis that the effect of nicotine on midbrain TH mRNA is mediated by the glucocorticoid receptor. When rats are administered the glucocorticoid receptor antagonist mifepristone, the induction of TH mRNA by nicotine in both substantia nigra and ventral tegmentum is inhibited. Furthermore, the glucocorticoid receptor agonist dexamethasone stimulates TH gene transcription for sustained periods of time in both midbrain slices and MN9D cells, leading to induction of TH mRNA and TH protein. Our results are consistent with the hypothesis that nicotine induces TH mRNA in midbrain by elevating glucocorticoids, which then act on glucocorticoid receptors in dopamine neurons leading to transcriptional activation of the TH gene.
Isopiestic Technique: Measurement of Accurate Leaf Water Potentials

Sunflower leaf tissue of known potential was obtained by equilibrating an interveinal leaf sample, at constant temperature in air, with a potential determined by sucrose solutions. Equilibration occurred within 17 hours. Except for one determination, all measurements of the water potential of the equilibrated samples with an isopiestic technique were within 0.1 bar of the known potential of the tissue. This finding indicates that thermocouple psychrometers can measure accurate values of water potential when an isopiestic technique is used.
PPARδ as a therapeutic target in metabolic disease

PPARδ is the only member in the PPAR subfamily of nuclear receptors that is not a target of current drugs. Animal studies demonstrate PPARδ activation exerts many favorable effects, including reducing weight gain, increasing skeletal muscle metabolic rate and endurance, improving insulin sensitivity and cardiovascular function and suppressing atherogenic inflammation. These activities stem largely from the ability of PPARδ to control energy balance, reduce fat burden and protect against lipotoxicity caused by ectopic lipid deposition. Therefore, PPARδ represents a novel therapeutic target and the development of PPARδ agonists/modulators may be useful for treating the whole spectrum of metabolic syndrome.
Clinical Assessment of Drug-Induced Impairment of Sexual Function in Men

hthough there is an increasing awareness of the importance of induced sexual dysfunction in understanding noncompliance in hypertensive men, the fundamental nature of the dysfunctions produced, the ability to predict outcome before therapy, the selection of drugs, and the basal level of sexual function have not been thoroughly assessed in relation to psychosocial, neurologic, vascular, and endocrine parameters, particularly in men as they age. Treatment of hypertension with drugs into advanced age will be associated with a substantial incidence of impotence. The exact role of the agent must be elucidated. It is the responsibility of the therapist and the drug manufacturer to identify the incidence of untoward effects, their physiologic basis, and modes of prevention and of reversibility. Investigation of sexual dysfunction has been adversely affected because physicians are not well trained in pursuing the question of sexual performance. There also prevails the feeling that open discussion of sexual matters may induce a dysfunctional state. This no longer seems to be a tenable proposition, considering the strength of the sexual drive and the openness with which sexual matters are now discussed in our society. The need to treat hypertension creates an excellent experimental setting for investigation of the physiology of erection. A better understanding of the mechanisms may make it possible to reduce the risk of sexual dysfunction, improve compliance, and avoid more completely the complications of elevated blood pressure.
Lower extremity fractures in falls

Lower extremity fractures are very common in victims of falls. These fractures are usually associated with other bodily injuries and can lead to permanent disability if appropriate management is not provided. The aim of this study was to evaluate the incidence and outcomes of associated injuries in victims of falls with lower extremity fractures. This is a retrospective review (1995–2006) of all fall-related trauma patients evaluated at our Level I trauma center. Injuries were categorized as: isolated femur fractures (FF), isolated tibia fractures (TF), and both femur and tibia fractures (FTF). Data were analyzed for differences in patterns of injury, associated fractures and injuries, and mortality and morbidity according to age groups within patients with minor body injuries expressed by Abbreviated Injury Score (AIS) 25). A higher incidence of ISS > 25 was observed in patients with FF. Increased mortality was observed in the elderly group, especially in patients with an isolated femur fracture. Patients with a combination of femur and tibia fractures have a significantly higher risk of associated injuries compared to patients with either a femur or a tibia fracture. Elderly patients (≥65 years of age) have higher morbidity and mortality compared to younger patients after falls. Clinicians evaluating these patients should be aware of these injury patterns. Further studies assessing the impact of age and pattern of injury in patients following falls are warranted.
Duplications and Meiotic Behavior of the Chromosomes in Haploid Maize (Zea mays L.)

At meiotic prophase of haploid maize, the number of microsporocytes forming 10 univalents or no bivalents, was found to be about 50 percent of the total 942 randomly selected cells. It was postulated that most of the duplicate factor inheritance, and perhaps also the triplicated and the quadruplicate factor inheritance in maize, are intrachromosomal.The frequent appearance of 10 univalents and the persistent chainconfigurations of the infrequently formed bivalents at diakinesis constitute a convincing evidence that modern maize is an alloploid with perhaps a basic chromosome number of five.The origin of spindle is discussed. The evidence that one or two strayed chromosomes were associated, at the centromeres, with an independent spindle at second meiotic metaphase, led to a conclusion that the spindle is of nuclear origin, probably in the centromeres of the chromosomes.
Polyelectrolyte/Nanosilicate Thin-Film Assemblies: Influence of pH on Growth, Mechanical Behavior, and Flammability

Thin composite films of branched polyethylenimine (BPEI) and Laponite clay platelets were prepared using layer-by-layer assembly. The film thickness was tailored by altering the pH of the aqueous mixtures used to deposit these films, resulting in growth that ranged from 0.5 to 5 nm/bilayer (BL). High-pH BPEI and low-pH clay produced the thickest films. The microstructure of tilted Laponite clay platelet stacks is observed with transmission electron microscopy when using unadjusted BPEI (pH 10.3) and pH 6 Laponite. This recipe resulted in a film with 83 wt % clay and a hardness of 0.5 GPa. In all films, the clay platelets are uniformly deposited and look analogous to a cobblestone path in atomic force microscopy surface images. Several 40-BL films, with thicknesses of 100 nm or more, exhibit reduced moduli ranging from 7 to 10 GPa and hardness of around 0.5 GPa, suggesting that these transparent films could be useful as hard coatings for plastic films. These thin coatings were also deposited onto cotton fa...
(Re)Constituting community through narrative argument: Eros and Philia in the big chill

This essay analyzes the way a specific narrative text—Lawrence Kasdan's 1983 feature film The Big Chill—confronts the relationship between communal norms and political possibilities. By inviting the audience to engage in a constant process of character and community identification and contrast, the film enacts a complex disjunctive narrative argument endorsing a specific form of communal affiliation (what Hannah Arendt refers to as philia) and rejecting its opposite (Arendt's sense of eros). In rejecting communities grounded in eros, the film also critiques what can be called “the politics of intimacy” and adumbrates an alternative “politics of friendship.” Additionally, the reading of the film illustrates the importance of narrative to communal constitution and political friendship.
An Introduction to Magnetic Resonance Imaging

The principles underlying nuclear magnetic resonance (NMR) are explained, and its use in image formation is described. The discussion also covers: multislice imaging; image resolution and contrast; effects of flow on images; hardware for magnetic resonance imaging; magnets; magnetic gradients; RF coil, transmitter, and receiver; computer system; and spectroscopy.
Approximations of the critical region for spearman’s rho with and without ties present

Exact tables for Spearman’s rho are available only for n ≤ 16 and no ties in the data. Some accurate methods of approximating the distribution with no ties present have been used to obtain approximate tables for larger values of n. Often ties are present in the data so these tables are no longer exact. Also sometimes the tables are not conveniently available to the user. In such situations an approximation that is both simple and accurate would be useful. Such an approximation is presented in this paper. Comparisons are made with other standard approximations for all cases where exact tables (no ties) are available, and for one case where exact tables were generated for a situation with ties. The results show the approximation presented here to be the most accurate of the approximations examined. Also it is simple enough to be readily understood by the average user of Spearman’s rho.
Development of a phantom-based methodology for the assessment of quantification performance in CT

The quantification of lung nodule volume from CT images provides valuable information for cancer diagnosis and staging. However, the usefulness of quantification depends on its precision. Direct assessment of the volume quantification precision involves multiple steps and can become intractable for a multiplicity of protocols. To assess quantification precision efficiently, we developed a prediction model, named the estimability index (e’). e’ provides a prediction of precision based on the characteristics of image noise and resolution, the nodule being quantified, and the segmentation software. It was further calibrated against empirical precision for 45 protocols of various reconstruction algorithms, slice thickness, and dose level. Results showed a strong correlation established between e’ and the empirical precision across all 45 protocols, demonstrating e’ as an effective surrogate of quantification precision. This study provides a useful framework for the optimization of CT protocols in terms of quantification precision. It also enables fast assessment of protocol compliance in terms of precision for biomarker quantification.
Mycotoxin Producing Potential of Fungi Associated with Dry Shrimps

Among 114 fungi isolated from 20 dry shrimp samples, 27 isolates were capable of producing mycotoxins. Aspergillus and Penicillium were-the-predominant fungi. Two of 3 Aspergillus flavus could produce aflatoxin B1 and G1 on yeast extract sucrose medium and on surface sterilized dry shrimps. For other toxigenic species, toxicity was found mostly in the chloroform extracts of cultures. Visibly mouldy dry shrimps had significantly higher moisture content than the non-mouldy ones. Most of the fungi were isolated from mouldy samples.
Clinical Analysis of Steep Central Islands After Excimer Laser Photorefractive Keratectomy

Purpose: To examine topographic irregularities known as steep central islands that may occur after excimer laser refractive surgery and affect visual acuity. Methods: We reviewed the computed corneal topographic maps of 35 eyes that had undergone excimer laser photorefractive keratectomy with an excimer laser for compound myopic astigmatism or anisometropic myopia. Steep central islands were defined as areas of steepening of at least 3 diopters and 1.5 mm in diameter. A classification system was developed based on the presence of steep central islands during the postoperative period as follows: class 0, absent; class 1, present at 1 week; class 2, present at 1 month; class 3, present at 3 months. Results: Steep central islands were seen in 25 eyes (71%) at 1 week, 18 eyes (51%) at 1 month, seven eyes (20%) at 3 months, and four eyes (11%) at 6 months. After surgery without nitrogen gas blowing, 16 of 25 patients had class 2 or 3 steep central islands compared with two of 10 eyes when gas blowing was used. Loss of best spectacle-corrected visual acuity of 2 Snellen lines or more was seen in eight of 18 eyes with class 2 or 3 steep central islands at 1 month and three of 18 eyes at 3 months. A similar loss occurred in one of 17 eyes with class 0 or 1 steep central islands at 1 month and none of 17 eyes at 3 months. In all eyes with only class 2 steep central islands, loss of at least 1 Snellen line of best spectacle-corrected visual acuity at 1 month was associated with visual restoration at 3 months when the island was no longer present. Conclusion: Loss of best spectacle-corrected visual acuity is associated with steep central island formation, and may prolong visual rehabilitation after excimer laser photorefractive keratectomy.
Childhood overweight and obesity in Qatar: A literature review

Childhood obesity and overweight have reached epidemic proportions in both developed as well as some developing countries including Qatar. This paper is a literature review of studies published in the last 10 years in the area of childhood overweight and obesity in the state of Qatar. A high gross domestic product in Qatar has led to a high socio economic status among the Qatari population and the adoption western lifestyles that promote childhood overweight and obesity. Risk factors for overweight and obesity include poor dietary habits, lack of physical activity, sedentary lifestyles and socio-cultural practices. The prevalence of childhood overweight and obesity in Qatar was found to be comparable to other GCC countries. The state of Qatar is called upon to prioritize this public health issue and implement interventions to combat the problem.
The Dynamics of Nucleation in Stochastic Cahn–Morral Systems

Cahn-Morral systems serve as models for several phase separation phenomena in multicomponent alloys. In this paper we study the dynamical aspects of nucleation in a stochastic version of these models using numerical simulations, concentrating on ternary, i.e., three-component, alloys on two- dimensional square domains. We perform numerical studies and give a statistical classification for the distribution of droplet types as the component structure of the alloy is varied. We relate these statistics to the low-energy equilibria of the deterministic equation.
On the effect of location inaccuracy on geographic face routing in wireless networks

Geographic routing protocols [1], [5], [6]) are very( attractive choices for routing in wireless networks for several reasons. First, such protocols incur low route discovery overhead relative to flooding-based approaches, and hence conserve energy and bandwidth. Second, these protocols are stateless in the sense that nodes need not maintain per-destination nformation, and only neighbor locationi information is needed to route packets. In mobile networks with frequent topology changes, geographic routing can find new routes quickly by using only local topology information. For these reasons, geographic routing is expected to become the protocol of choice for many applications in wireless networks, for example in sensor networks it is proposed for data-centric storage [7] and distributed indexing [2]. Hence, it is quite crucial to develop a detailed understanding of the behavior of geographic routing for various practical settings and to evaluate its performance and (more importantly) its correctness in those settings. Most geographic routing protocols use greedy forwarding as its basic mode of operation, where the next forwarding hop is chosen to minimize the distance to the destination. Greedy forwarding, however, fails in the presence of
The subunit structure of Daphnia pulex hemoglobin

Abstract 1. 1. The extracellular hemoglobin of Daphnia pulex has an apparent molecular weight of 430,000–470,000 by gel chromatography and an S 20, w = 16.9 at pH 7.0. 2. 2. Purified hemoglobin contains one heme per 18,000–20,000 g protein. The polypeptide chains are heterogeneous with mol. wts between 31,000–37,000. Some high mol. wt ( M r = 53,000–86,000) material is also present. 3. 3. The hemoglobin dissociates at pH 10.5 in EDTA into 3S material which can be digested with subtilisin into 16,000 mol wt heme-containing polypeptide chains. 4. 4. The amino acid composition of the intact hemoglobin is identical to that of the heme-containing fragments generated by proteolytic digestion of the 3S material. 5. 5. These results are consistent with the hypothesis that D. pulex hemoglobin is composed of subunits containig two heme groups per 35,000 mol. wt polypeptide chain.
Variability in soman toxicity in the rat: Correlation with biochemical and behavioral measures☆

The inhibition of cholinesterase (ChE) activity in the central nervous system of the rat by the potent organophosphorus compound soman was examined. At soman doses greater than 55 micrograms/kg s.c. (0.5 LD50), there were: (1) dose-related inhibition of ChE activity in brain regions; (2) variability in the degree of ChE inhibition at each soman dose in each brain region; and (3) variability in the severity of signs of intoxication at each dose. These data suggest that measurements of ChE should be made directly or predicted individually in each animal for which the effects of soman are assessed. At the estimated ED50 soman dose for signs of intoxication (66 micrograms/kg s.c.), the remaining ChE activity in brain correlated poorly with ChE activity in plasma and red blood cells (R = 0.14-0.20), moderately with behavioral scores based on overt signs of intoxication (R = 0.63-0.94), and well with spinal cord ChE activity (R = 0.93-0.98). Finally, ChE activity in the thoracic and lumbosacral regions of spinal cord were not affected by headfocused microwave inactivation of brain enzymes, demonstrating that ChE activity in these regions of the cord can be used to predict the level of ChE inhibition in brain when direct measurement in brain is unfeasible.
Informational DNA Synthesis Distinguished from That of Nuclear DNA by Inhibitors of DNA Synthesis

With inhibitors of DNA synthesis used in the presence of ethidium bromide, it has been possible to distinguish between synthesis of informational DNA (I-DNA) and that of nuclear DNA. Hydroxyurea depresses I-DNA synthesis preferentially but does not affect DNA transport between cell compartments. 5-Fluorodeoxyuridine and cytosine arabinoside reduce synthesis of I-DNA to a much lesser degree than that of nuclear DNA.
Mini-Fizeau Interferometer for Curvature Sensing in the NIST Geometry Measuring Machine

We describe the design of a miniature Fizeau interferometer, which is intended to be an accurate curvature sensor for the NIST Geometry Measuring Machine (GEMM), which is used to measure aspheric and free form surfaces.
Inclusion and exclusion approximations of copolymer solids applied to calculation of solid-liquid transitions

A model of copolymer solids hypothesizing inclusion of the comonomer units in the crystalline domain is applied to calculation of solid−liquid transitions. Such an inclusion model is compared to an exclusion model hypothesizing exclusion of the comonomer units from the crystalline domain. Both models are used with the copolymer SAFT equation of state1 to represent the solid−liquid transition temperatures of polyethylene and poly(ethylene-co-octene-1) in propane, isooctane, and a mixture of isooctane + ethylene. The inclusion model is found to be more predictive and to have a correct high polymer-concentration limit, which is the melting temperature of pure polymer. Furthermore, the inclusion parameters, the fold energy and the energy penalty, are found to be solvent- and composition-independent, while the exclusion parameter, the crystallizability, is found to be both solvent- and composition-dependent.
Preservers of Maximally Entangled States

Abstract The linear structure of the real space spanned by maximally entangled states is investigated, and used to completely characterize those linear maps preserving the set of maximally entangled states on M m ⊗ M m , where M m denotes the space of m × m complex matrices. Aside from a degenerate rank one map, such preservers are generated by a change of orthonormal basis in each tensor factor, interchanging the two tensor factors, and the transpose operator.
Leisure Satisfaction and Quality of Life in China, Japan, and South Korea: A Comparative Study Using AsiaBarometer 2006

Leisure satisfaction is positively associated with quality of life (QOL), more specifically, subjective QOL, which is often expressed as happiness. Compared to industrial nations in North America and Europe, however, significantly less is known about Asian nations. The purpose of this study is to examine the understudied areas of China, Japan and South Korea, all of which share cultural values and practices (e.g., Confucianism). Internationally representative 2006 AsiaBarometer data from Mainland China (n = 2,000), Japan (n = 1,003) and South Korea (n = 1,023) are employed to examine the concept of QOL, and the association between leisure satisfaction and QOL in these specific Asian populations. Results of confirmatory factor analysis demonstrate the validity of the QOL concept based on a series of satisfaction measures (i.e., leisure, income, health, family, spirituality, and friendship). Subsequently, generalized ordinal logistic regression was used to model QOL as a function of leisure satisfaction and covariates. Results show that leisure satisfaction is independently positively associated with QOL only in South Korea, although other satisfaction measures including income, health and spiritual satisfactions are consistently significant in all three nations. These findings may be useful for developing locally-sensitive policies and services to improve/maintain QOL in each nation. Possible explanations about the diverse relationships between leisure satisfaction and QOL are discussed in view of the different stage of societal development, common Confucian values, as well as each nation’s unique characteristics.
The discovery of the top quark

Evidence for pair production of a new particle consistent with the standard-model top quark has been reported recently by groups studying proton-antiproton collisions at 1.8 TeV center-of-mass energy at the Fermi National Accelerator Laboratory. This paper both reviews the history of the search for the top quark in electron-positron and proton-antiproton collisions and reports on a number of precise electroweak measurements and the value of the top-quark mass that can be extracted from them. Within the context of the standard model, the authors review the theoretical predictions for top-quark production and the dominant backgrounds. They describe the collider and the detectors that were used to measure the pair-production process and the data from which the existence of the top quark is evinced. Finally, they suggest possible measurements that could be made in the future with more data, measurements that would confirm the nature of this particle, the details of its production in hadron collisions, and its decay properties. {copyright} {ital 1997} {ital The American Physical Society}
Sustainability, sustainable development and forest resources

SUMMARY There are competing views on sustainability which mainly stem from differences in assumptions upon which each of these views is based. Perhaps the most debated assumption is the extent to which manufactured capital and natural capital are substitutes. Neo-Malthusians, the Club of Rome, and other Stationary-State theorists fill the ranks of the legion of pessimistic economists who fear any negative changes in the total stock of natural capital. Diametrically opposed to these doomsayers stands Solow (1986) and other optimistically inclined neoclassical economists who look favourably on the ‘Backstop Technology Theory’ of resource use. Falling inconspicuously between the polar extremes, there is a third group of theorists who incorporate certain aspects of each of the other two groups in addition to employing the principles embodied by Hartwick's Rule. The term sustainable development (SD) is also subject to considerable debate. This paper examines various concepts of sustainability and SD. Policy ma...
The effect of periodic boundary conditions on homogeneous nucleation observed in computer simulations

Abstract The sudden rapid crystallization observed after a variable induction time in molecular dynamics simulations of the supercooled Lennard-Jones liquid is an artifact of periodic boundary conditions and is not related to formation of a critical nucleus.
A TECHNIQUE FOR RECOVERING THE VERTICAL NUMBER DENSITY PROFILE OF ATMOSPHERIC GASES FROM PLANETARY OCCULTATION DATA

Abstract The occultation technique of determining the properties of the atmosphere using absorption spectroscopy is examined. The intensity of a star, in certain atmospheric absorption bands, is monitored by a satellite tracking the star during occultation by the Earth's atmosphere. The intensity data in certain wavelength intervals, where absorption is attributed to a single species, are related to the tangential column number density of the absorbing species through Beer's law. The equation for the tangential column number density is the Abel integral equation which is inverted to obtain the number density profile of the absorbing species at the occultation tangent ray point. Two numerical schemes for inverting the Abel integral equation for signals of low intensity with statistical noise superimposed are presented; one for determining the number density profile of atmospheric species that decrease exponentially with height, and the second for determining the profile of constituents having a more complex vertical structure, such as ozone. The accuracy of retrieving the number density distribution from planetary occultation data is examined. A theoretical analysis of the errors in determining the number density from occultation data of very low signal intensity is also presented. The errors in retrieving the number density profile are related to the intensity of the source, the number of data points per scan, and the degree of data smoothing required before inversion. As a specific example, calculations are made of the errors in retrieving the molecular oxygen and ozone number density profiles from occultation intensity data in the Schumann-Runge continuum of molecular oxygen at 1450 A and the Hartley continuum of ozone at 2450 A.
Determination of the 41F and 51F lifetimes of HeI

Abstract Measurements of the decay rates of cascade components of emission from the 31D and 41D states of atomic helium are used to determine the previously unmeasured lifetimes of the 41F and 51F states of Hel. The measured values are 67 ± 10 and 140 ± 14 ns for the 41F and 51F states, respectively.
Using permutations instead of student's t distribution for p-values in paired-difference algorithm comparisons

The paired-difference t-test is commonly used in the machine learning community to determine whether one learning algorithm is better than another on a given learning task. This paper suggests the use of the permutation test instead because it calculates the exact p-value instead of an estimate. The permutation test is also distribution free and the time complexity is trivial for the commonly used 10-fold cross-validation paired-difference test. Results of experiments on real-world problems suggest it is not uncommon to see the t-test estimate deviate up to 30-50% from the exact p-value.
Performance analysis of future event sets

The linked list and indexed list future event sets are investigated. The interaction hold model and the Jackson network model are the underlying stochastic models considered. For the interaction hold model and for the (doubly) linked list, we find, for example, the mean number of key comparisons performed in order to find a record's insertion point into the list; this is useful when deciding whether to scan from the head or the tail of the list. The distribution of the relative position of the to-be-inserted record is also obtained; for indexed lists, this is helpful when deciding the number of sublists and position(s) of the middle pointer(s). The Jackson network model has a realistic event logic, but events are restricted to be exponentially distributed. Because the stationary probabilities can be computed for this model, it is then possible to evaluate and compare the (steady-state) performance of certain future event sets (e.g. linked lists scanned from the head or the tail).
Archival HTTP redirection retrieval policies

When retrieving archived copies of web resources (mementos) from web archives, the original resource's URI-R is typically used as the lookup key in the web archive. This is straightforward until the resource on the live web issues a redirect: R ->R`. Then it is not clear if R or R` should be used as the lookup key to the web archive. In this paper, we report on a quantitative study to evaluate a set of policies to help the client discover the correct memento when faced with redirection. We studied the stability of 10,000 resources and found that 48% of the sample URIs tested were not stable, with respect to their status and redirection location. 27% of the resources were not perfectly reliable in terms of the number of mementos of successful responses over the total number of mementos, and 2% had a reliability score of less than 0.5. We tested two retrieval policies. The first policy covered the resources which currently issue redirects and successfully resolved 17 out of 77 URIs that did not have mementos of the original URI, but did of the resource that was being redirected to. The second policy covered archived copies with HTTP redirection and helped the client in 58% of the cases tested to discover the nearest memento to the requested datetime.
Sleep Disorders, Health, and Safety in Police Officers

Results Of the 4957 participants, 40.4% screened positive for at least 1 sleep disorder, most of whom had not been diagnosed previously. Of the total cohort, 1666 (33.6%) screened positive for obstructive sleep apnea, 281 (6.5%) for moderate to severe insomnia, 269 (5.4%) for shift work disorder (14.5% of those who worked the night shift). Of the 4608 participants who completed the sleepiness scale, 1312 (28.5%) reported excessive sleepiness. Of the total cohort, 1294 (26.1%) reported falling asleep while driving at least 1 time a month. Respondents who screened positive for obstructive sleep apnea or any sleep disorder had an increased prevalence of reported physical and mental health conditions, including diabetes, depression, and cardiovascular disease. An analysis of up to 2 years of monthly follow-up surveys showed that those respondents who screened positive for a sleep disorder vs those who did not had a higher rate of reporting that they had made a serious administrative error (17.9% vs 12.7%; adjusted odds ratio [OR], 1.43 [95% CI, 1.23-1.67]); of falling asleep while driving (14.4% vs 9.2%; adjusted OR, 1.51 [95% CI, 1.20-1.90]); of making an error or safety violation attributed to fatigue (23.7% vs 15.5%; adjusted OR, 1.63 [95% CI, 1.43-1.85]); and of exhibiting other adverse work-related outcomes including uncontrolled anger toward suspects (34.1% vs 28.5%; adjusted OR, 1.25 [95% CI, 1.09-1.43]), absenteeism (26.0% vs 20.9%; adjusted OR, 1.23 [95% CI, 1.08-1.40]), and falling asleep during meetings (14.1% vs 7.0%; adjusted OR, 1.95 [95% CI, 1.52-2.52]).
Analysis of a simplified hopping robot

This article offers some analytical results concerning sim plified models of Raibert's hopper. We represent the task of achieving a recurring hopping height for an actuated "ball" robot as a stability problem in a nonlinear discrete dynamical control system. We model the properties of Raibert's control scheme in a simplified fashion and argue that his strategy leads to closed-loop dynamics governed by a well-known class of functions, the unimodal maps. The rich mathematical literature on this subject greatly advances our ability to determine the presence of an essentially globally attracting fixed point-the formal ren dering of what we intuitively mean by a "correct" strat egy. The motivation for this work is the hope that it will facilitate the development of general design principles for "dynamically dexterous" robots.
Irradiation of Apple Cider: Impact on Flavor Quality

Serious outbreaks of illness in 1996 and 1999 linked to contamination of apple cider by E. coli O157:H7 have contributed to intense public concern regarding the safety of fresh apple cider. In response to this concern, the Food and Drug Administration (FDA) has proposed more stringent regulations on the production of apple cider including a requirement to reduce microbial contaminants by 5 logs (Terpstra, 1997). Currently, FDA requires a warning statement on all fruit and vegetable juice products that have not been pasteurized (FDA, 1998). The safety concerns associated with fresh apple cider have contributed to a need to evaluate new approaches to cider processing to provide a safe product without sacrificing quality (Terpstra, 1997).
The spectrum of cardiovascular disease in children with predialysis chronic kidney disease

Cardiovascular disease is the major cause of mortality in adults and children on chronic dialysis and in adults after kidney transplantation. Cardiovascular disease burden and cardiovascular mortality are high in adults with chronic kidney disease. The early development of cardiovascular disease risk factors, some of which are modifiable, largely explain this phenomenon. Limited data are available on the prevalence of chronic kidney disease in children, the prevalence of cardiovascular disease in children with chronic kidney disease, and the prevalence of cardiovascular disease risk factors in these patients. This article summarizes the current knowledge of the prevalence of cardiovascular disease and of cardiovascular disease risk factors in pediatric patients with predialysis chronic kidney disease. Long-term prospective studies are needed to determine the impact of early identification and treatment of cardiovascular disease and its risk factors on the natural history of cardiovascular disease in children with chronic kidney disease.
The kinematics of a midlatitude, continental mesoscale convective system and its mesoscale vortex

The authors present a unique, scale-discriminating study of the environment-relative circulations within a mesoscale convective system (MCS) and mesoscale convective vortex (MCV). The MCS, a leading convective line and trailing stratiform region that became asymmetric, passed through the National Oceanic and Atmospheric Administration (NOAA) Profiler Network (NPN) in Kansas and Oklahoma on 1 August 1996. The MCV appeared in the MCS’s stratiform region just prior to the system’s mature stage and grew to a depth of over 12 km as the MCS dissipated. The MCV did not apparently survive to the next day. A spatial bandpass filter was used to divide observed wind into a component that was predominantly synoptic background wind and a component that was predominantly a mesoscale perturbation on that background wind. A mesoscale updraft, mesoscale downdraft, and divergent outflows in the lower and upper troposphere were evident after the synoptic background wind was removed, so these four circulations were internal and fundamental to the MCS. The mesoscale perturbation in wind in the middle troposphere extended farther behind the MCS than ahead of it, consistent with analytic studies and numerical simulations of gravity waves generated by heat sources characteristic of MCSs with leading convective lines and trailing stratiform regions. Deepening of the MCV appeared to be reflected in the vertical wind shear at the vortex’s center: as the MCV strengthened, the mesoscale shear through its lower part decreased, perhaps as wind became more vortical at increasing altitudes. Mesoscale and synoptic vertical shears were of similar magnitude, so an average of environmental soundings outside an MCS probably does not accurately represent the shear that affects an MCV. This suggests the need to reevaluate how the kinematical settings of MCVs are diagnosed.
Grounded object individuation by a humanoid robot

This paper proposes a theoretical model that enables a robot to partition its unlabeled sensorimotor experience with different objects into discrete clusters, each corresponding to a specific object. To solve this object individuation problem, the robot was trained to detect whether two perceptual stimuli were produced by the same object or by two different objects. The model was tested using a large-scale experiment in which a humanoid robot explored 100 different objects by performing a variety of exploratory behaviors on them and detecting the resulting sensory feedback from several sensory modalities. The results show that with a small amount of prior training, the robot's model was able to successfully individuate the objects with a high degree of accuracy.
A Novel Approach to Quantifying Designer’s Mental Stress in the Conceptual Design Process

The objective of the present thesis is to quantify designer's mental stress during the conceptual design process, in which designers usually describe the design problem and design solutions using natural language, combined with sketches. In the process of solving a design problem, the design problem itself will evolve according to the design solutions generated at each step of the design. The design problem together with its solutions at each step is called a design state. Quantifying the designer's mental stress would assist in understanding the designer's creative and innovative design process, through which a design methodology can be optimized. In the present thesis, a cognitive experiment is used to study the quantification of the designer's mental stress. Subjects were invited to design a new litter-disposal system in a passenger compartment located in the trains of NS (Dutch Railways). In quantifying the designer's mental stress, the recorded design protocol data is firstly segmented into design states, each of which is then encoded into a Recursive Object Model diagram through linguistic analysis. The number of objects and relationships included in an ROM diagram is then used to quantify the designer's mental stress. The validation through the cognitive experiment shows that ROM is an effective encoding scheme. The analysis presented in this research shows that the designer's mental stress changes in a dynamic, nonlinear, and spiral manner along with the time.
PESTICIDES AND AMPHIBIANS: THE IMPORTANCE OF COMMUNITY CONTEXT

The widespread application of pesticides has attracted the attention of ecol- ogists as we struggle to understand the impacts of these chemicals on natural communities. While we have a large number of laboratory-based, single-species studies of pesticides, such studies can only examine direct effects. However, in natural communities, species can experience both direct and indirect effects. We conducted an outdoor mesocosm experiment on aquatic communities containing three tadpole species (Hyla versicolor, Bufo americanus, and Rana pipiens), zooplankton, and algae. We then manipulated a factorial combination of predators (no predators; newts, Notophthalmus viridescens; and larval beetles, Dytiscus sp.) and pesticides (no pesticides, the insecticide malathion, and the herbicide Roundup). We found that Roundup (1.3 mg of active ingredient/L) had substantial direct negative effects on the tadpoles, reducing total tadpole survival and biomass by 40%. However, Roundup had no indirect effects on the amphibian community via predator survival or algal abundance. Malathion (0.3 mg/L) had few direct effects on the tadpoles. Malathion caused no indirect effects with one of the predators (red-spotted newts) but caused substantial positive effects on amphibians (a five-fold increase in total tadpole survival and biomass) due to the sensitivity of the predatory beetles to the insecticide. Thus, while high concen- trations of malathion can directly kill larval anurans, more ecologically relevant concen- trations can have large positive effects in mesocosms by removing predatory insects. These results make it clear that pesticides can have both direct and indirect effects in natural communities and that these effects critically depend upon the composition of the community.
Comparison of Outcrop and Subsurface Sandstone Permeability Distribution, Lower Cretaceous Fall River Formation, South Dakota and Wyoming

Quantification of permeability structure in outcrop reservoir analogs documents the distribution of flow units and barriers important for reservoir management and simulation. Differences in burial history and diagenesis of the outcrop analog and the subsurface reservoir must be quantified, however, before outcrop permeability data can be used to model subsurface strata appropriately. A case study of the Lower Cretaceous Fall River Formation shows that permeability differences between facies are accentuated by diagenesis, and permeability variation increases with the extent of burial diagenesis. The Fall River Formation, which is exposed in outcrop around the Black Hills uplift in Wyoming and South Dakota, USA, produces oil from fluvial and estuarine valley-fill sandstones in the adjacent Powder River Basin. Outcrop sandstones were buried to 2 km before being uplifted at the end of the Cretaceous, whereas reservoir sandstones remained at depths of 2-4 km throughout the Tertiary. The permeability of outcropping Fall River sandstones has a log-normal distribution. The main controls on permeability in outcrop sandstones are (1) ductile-grain content, (2) grain size, both properties being controlled by the energy of the depositional environment, and (3) hematite cement, an uplift-related diagenetic feature not present in the subsurface. Hematite was preferentially precipitated along zones of permeability contrast, including sequence boundaries, complicating the determination of changes in primary depositional permeability at important flow-unit boundaries. In contrast, the permeability of Fall River reservoir sandstones at a depth of 4 km has a bimodal distribution and is controlled by ductile-grain content, grain size, and quartz-cement volume. Quartz cementation and compaction due to ductile-grain deformation were more extensive in the estuarine facies, resulting in a greater permeability reduction during burial diagenesis than was observed in fluvial sandstones. Abundant stylolites developed in sandstones with clay partings or mud clasts, features that are common in estuarine sandstones. The stylolites acted as an internal source of silica. Sandstones near the stylolites typically have low permeability that probably resulted from above-average volumes of quartz cement. Diagenesis increased the coefficient of variation of permeability in all facies in the subsurface. This diagenetic overprint should be considered if outcrop permeability data are used to model a subsurface reservoir having a very different burial history.
Globally Optimal Linear Precoders for Finite Alphabet Signals Over Complex Vector Gaussian Channels

We study the design optimization of linear precoders for maximizing the mutual information between finite alphabet input and the corresponding output over complex-valued vector channels. This mutual information is a nonlinear and non-concave function of the precoder parameters, posing a major obstacle to precoder design optimization. Our work presents three main contributions: First, we prove that the mutual information is a concave function of a matrix which itself is a quadratic function of the precoder matrix. Second, we propose a parameterized iterative algorithm for finding optimal linear precoders to achieve the global maximum of the mutual information. The proposed iterative algorithm is numerically robust, computationally efficient, and globally convergent. Third, we demonstrate that maximizing the mutual information between a discrete constellation input and the corresponding output of a vector channel not only provides the highest practically achievable rate but also serves as an excellent criterion for minimizing the coded bit error rate. Our numerical examples show that the proposed algorithm achieves mutual information very close to the channel capacity for channel coding rate under 0.75, and also exhibits a large gain over existing linear precoding and/or power allocation algorithms. Moreover, our examples show that certain existing methods are susceptible to being trapped at locally optimal precoders.
Patient characteristics determining rHuEPO dose requirements

Suboptimal response to recombinant human erythropoietin (rHuEPO) is common in a substantial percentage of patients with chronic kidney disease. Consequently, a higher dose of rHuEPO is needed to attain target haematocrit (Hct) in such patients. Variables that affect rHuEPO dose requirements can be broadly divided into modifiable and immutable characteristics. To date, most of the scientific studies on rHuEPO hyporesponsiveness have focused on modifiable variables that affect rHuEPO response, such as iron status and dialysis adequacy, while exploration of immutable variables has received less attention. This review addresses the key immutable variables that have been suggested as potential determinants of rHuEPO dose requirement. Several investigators, on the basis of analysis of large patient databases, have suggested that diabetic individuals, women, and Black patients on haemodialysis (HD) require a higher dose of rHuEPO than their respective counterparts to attain target Hct. It is unclear whether the observed differences in achieved Hct are due to inherent biological differences in responsiveness to rHuEPO or failure of the investigators to account for modifiable variables that affect rHuEPO dose requirement. Protocol studies with specific a priori hypotheses have failed to confirm some of the findings from these large database analyses. Factors, such as nutritional status, pregnancy, duration of end-stage renal disease, and type of HD vascular access can all potentially modulate response to rHuEPO and should also be considered.
Kierkegaard on taking an outing to deer park

I offer an exegesis of a few pages of the Concluding Unscientific Postscript and explain how going to Deer Park religiously fits into the general structure of Kierkegaard's thought. Because desiring God requires passion, and passion requires energy, there is a limit to how long any individual person can maintain a continuous desire for God. Kierkegaard discusses how a person who is at that limit can maintain a less intense love of God as he allows himself to desire temporal things.