cssi/SciSciGPT-SciSciNet huggingface dataset:
Localized correlation treatment using natural bond orbitals

Abstract We present studies using natural bond orbitals (NBOs) as a starting point for a localized electron correlation treatment, as these kind of localized orbitals lead to CCSD results which show significant transferability and exponential decay patterns in the T 2 amplitudes. The NBO CCSD approach combines the advantages of both the HF CCSD formulation (less amplitudes, orthogonal orbitals) and the AO-based CCSD strategy (fast decay of amplitudes and integrals).
Psychosocial variables, quality of life, and religious beliefs in ESRD patients treated with hemodialysis

Abstract Background: Religious and spiritual aspects of quality of life (QOL) have not been fully assessed in patients with end-stage renal disease (ESRD) treated with hemodialysis (HD), but psychosocial factors are associated with patient survival. Methods: To investigate interrelationships between religious beliefs and psychosocial and medical factors, we studied 53 HD patients. Psychosocial and medical variables included perception of importance of faith (spirituality), attendance at religious services (religious involvement), the Beck Depression Inventory, Illness Effects Questionnaire, Multidimensional Scale of Perceived Social Support, McGill QOL Questionnaire scores, Karnofsky scores, dialysis dose, and predialysis hemoglobin and albumin levels. Results: Eighty-seven percent of participants were African-American. Men had higher depression scores, perceived lower social support, and had higher religious involvement scores than women. No other parameters differed between sexes. Perception of spirituality and religiosity did not correlate with age, Karnofsky score, dialysis dose, or hemoglobin or albumin level. Greater perception of spirituality and religiosity correlated with increased perception of social support and QOL and less negative perception of illness effects and depression. A one-question global QOL measure correlated with depression, life satisfaction, perception of burden of illness, social support, and satisfaction with nephrologist scores, but not with age or Karnofsky score. Conclusion: Religious beliefs are related to perception of depression, illness effects, social support, and QOL independently of medical aspects of illness. Religious beliefs may act as coping mechanisms for patients with ESRD. The relationship between religious beliefs and clinical outcomes should be investigated further in patients with ESRD. Am J Kidney Dis 40:1013-1022. © 2002 by the National Kidney Foundation, Inc.
In Brief: Fractures in Brief: Calcaneal Fractures

Calcaneal fractures are the most common tarsal fractures. Intraarticular calcaneus fractures frequently are caused by axial load, eg, from a fall or motor vehicle accident. Accordingly, these fractures can be bilateral and not infrequently are seen with other fractures (plafond, tibial plateau, hip, and spine) caused by proximal transmission of the same load.
Enzymatic hydrolysis of T-2 toxin for the quantitative determination of total T-2 and HT-2 toxins in cereals

The selective enzymatic deacetylation of T-2 toxin to give HT-2 toxin has been investigated in aqueous crude extracts of different cereals and exploited to develop an analytical method for the determination of the sum of T-2 and HT-2 toxins. The method has been validated for the analysis of total T-2 and HT-2 toxins in maize, wheat, and oats, showing recoveries from 72 to 97% for maize, from 67 to 84% for wheat, and from 61% to 87% for oats, at spiking levels of 20–400 μg/kg, with relative standard deviation lower than 10%. Liquid chromatography-tandem mass spectrometry was used for quantitative toxin determination. The potential biological role of this enzymatic conversion and its perspectives for application in the development of antibody-based analytical techniques are discussed.
Molecular weight and charge heterogeneity of Thy-1 glycoprotein in different populations of T-cells

Molecular weight and charge microheterogeneity of Thy-1 glycoprotein expressed on different T-cell populations were compared by two-dimensional gel electrophoresis and endoglycosidase treatment. Thy-1 was immunoprecipitated from detergent lysates of radioiodinated T-cells of spleens, lymph nodes, Peyer's patches, peripheral blood, IL-2-cultured thymocytes and peanut agglutinin (PNA) separated thymocytes. In general, thymocytes and IL-2-cultured thymocytes expressed the highest levels of Thy-1 with a large Mr and charge variation. The Thy-1 of these cells was basic and contained low levels of sialic acid. On the other hand, peripheral T-lymphocytes exhibited a restricted Mr and more limited charge heterogeneity with higher amounts of sialic acid. The Thy-1 glycoprotein of mature, low Thy-1 PNA- thymocytes had Mr and charge heterogeneity identical to peripheral T-lymphocytes. The Mr and charge variation of immature PNA+ thymocytes was essentially identical to that of whole thymocytes. The molecular source of Mr heterogeneity in thymocyte Thy-1 and restricted Mr in lymph node Thy-1 was studied by analysis with endoglycosidase-H (Endo-H) and Endo-D. The results of Endo-H digestion showed that most of the Thy-1 polypeptides from both thymocyte and lymph node contained one high-mannose type oligosaccharide which was relatively small and not heterogeneous with respect to Mr. The complex-type oligosaccharides (Endo-D-sensitive) were larger and were responsible for the broad Mr-heterogeneity found in thymocyte Thy-1. Both thymocyte and lymph node Thy-1 generally appear to contain three N-linked oligosaccharides (one high-mannose and two complex) and sequential hydrolysis with Endo-H and Endo-D resulted in an unglycosylated polypeptide with an Mr of approx. 12,500.
TTGs and adakites: Are they both slab melts?

Abstract Although both high-Al TTG (tonalite–trondhjemite–granodiorite) and adakite show strongly fractionated REE and incompatible element patterns, TTGs have lower Sr, Mg, Ni, Cr, and Nb/Ta than most adakites. These compositional differences cannot be easily related by shallow fractional crystallization. While adakites are probably slab melts, TTGs may be produced by partial melting of hydrous mafic rocks in the lower crust in arc systems or in the Archean, perhaps in the root zones of oceanic plateaus. It is important to emphasize that geochemical data can be used to help constrain tectonic settings, but it cannot be used alone to reconstruct ancient tectonic settings. Depletion in heavy REE and low Nb/Ta ratios in high-Al TTGs require both garnet and low-Mg amphibole in the restite, whereas moderate to high Sr values allow little, if any, plagioclase in the restite. To meet these requirements requires melting in the hornblende eclogite stability field between 40- and 80-km deep and between 700 and 800 °C. Some high-Al TTGs produced at 2.7 Ga and perhaps again at about 1.9 Ga show unusually high La/Yb, Sr, Cr, and Ni. These TTGs may reflect catastrophic mantle overturn events at 2.7 and 1.9 Ga, during which a large number of mantle plumes bombarded the base of the lithosphere, producing thick oceanic plateaus that partially melted at depth.
Inequality in skill development on college campuses

Abstract While patterns of inequality in access and attainment in higher education are well documented, sociologists have left largely unexplored the question of disparities in skill development during college. Following a cohort of students across 23 four-year U.S. institutions from entry into college through their senior year, we examine inequalities in development of general collegiate skills. Findings indicate that despite unequal starting points, students from less educated families gain skills at the same rate as those from more educated families. African-American students, in contrast, enter college with lower levels of general collegiate skills than their white peers and gain less over time. A substantial portion, but not all, of the African-American/white gap in general collegiate skills is explained by academic preparation and selectivity of the institutions attended. Notably, African-American and white students experience similar benefits from being academically prepared and attending more selective institutions. These findings provide valuable insights for research and policy concerned with inequality in higher education.
NFIB Regulates Embryonic Development of Submandibular Glands

NFIB (nuclear factor I B) is a NFI transcription factor family member, which is essential for the development of a variety of organ systems. Salivary gland development occurs through several stages, including prebud, bud, pseudoglandular, canalicular, and terminal. Although many studies have been done to understand mouse submandibular gland (SMG) branching morphogenesis, little is known about SMG cell differentiation during the terminal stages. The goal of this study was to determine the role of NFIB during SMG development. We analyzed SMGs from wild-type and Nfib-deficient mice (Nfib (-/-)). At embryonic (E) day 18.5, SMGs from wild-type mice showed duct branching morphogenesis and differentiation of tubule ductal cells into tubule secretory cells. In contrast, SMGs from Nfib (-/-) mice at E18.5 failed to differentiate into tubule secretory cells while branching morphogenesis was unaffected. SMGs from wild-type mice at E16.5 displayed well-organized cuboidal inner terminal tubule cells. However, SMGs from Nfib (-/-) at E16.5 displayed disorganized inner terminal tubule cells. SMGs from wild-type mice at E18.5 became fully differentiated, as indicated by a high degree of apicobasal polarization (i.e., presence of apical ZO-1 and basolateral E-cadherin) and columnar shape. Furthermore, SMGs from wild-type mice at E18.5 expressed the protein SMGC, a marker for tubule secretory cells. However, SMGs from Nfib (-/-) mice at E18.5 showed apicobasal polarity, but they were disorganized and lost the ability to secrete SMGC. These findings indicate that the transcription factor NFIB is not required for branching morphogenesis but plays a key role in tubule cell differentiation during mouse SMG development.
Effects of Boron Stress on copper enzyme activity in tomato

Abstract Moderate B deficiency in plants has been reported to enhance Cu deficiency by keeping these plants in the vegetative growth stage. In this study, ascorbate oxidase activity was used as an index of the effect of B stress on Cu activity. When T3238FER (B‐inefficient) and Rutgers (B‐efficient) tomatoes (Lycopersicon esculentum Mill.) were grown in nutrient solutions at various B levels, B‐stressed plants had higher ascorbic acid oxidase activity than B‐sufficient plants. This activity was significantly higher in T3238FER than in Rutgers. Ascorbic acid oxidase activity may be directly or indirectly related to the role of B in plant growth and may be responsible for the more efficient use of B by Rutgers than by T3238FER tomato.
Closing the Achievement Gap: Examining the Role of Cognitive Developmental Level in Academic Achievement.

The achievement gap in mathematics between African American and Caucasian students has been observed for several decades, though previous research has been unable to fully explain why the gap exists. Using a sample of 56 kindergarten and first grade students, this study examined the role that cognitive developmental level plays in the achievement gap. Results indicated that African American students scored significantly lower than the Caucasian students on a test of mathematical achievement. Furthermore, proportionally more African American students remained in the preoperational stage of development as compared to their same-age Caucasian peers. Finally, after controlling for cognitive developmental level, the achievement gap between the two groups became statistically indistinguishable, suggesting that cognitive developmental level mediates the relationship between ethnicity and mathematic achievement.
New scheme provides a first step toward geomagnetic storm prediction

Establishing a geomagnetic storm prediction scheme is like constructing a car, and the four disciplines of solar physics, solar wind physics, magnetospheric physics, and thermospheric (ionospheric) physics are like the car's parts. Unfortunately, in spite of much progress in the separate disciplines in the past, there has been little effort to integrate them. As constructing a car is different from improving its parts, considerable effort is needed to integrate solar physics, solar wind physics, magnetospheric physics, and thermospheric physics into a single discipline of geomagnetic storm prediction.
Diversifying Learning Opportunities: A Response to the Problems of Mass Education.

The large lecture section is often perceived as a homogeneous mass of students who can be taught satisfactorily by a single teaching method — usually lectures, textbooks, and objective exams. An attempt to improve the quality of teaching and learning was made by offering three distinct options to 695 students enrolled in two large classes: (1) conventional lecture/objective exam format; (2) small groups of five to eight students; (3) independent study. The students responded with 86% selecting the conventional method, 11% choosing small groups, and 3% deciding upon independent study. Students in the conventional classes tended to have high scores on Rotter's External Control Scale and high scores on personality need scales (Personality Research Form) for harm avoidance, order, social recognition, and succorence; they also tended to be less intellectually inclined and more vocationally oriented. The students in nonconventional options tended to have high personality need scores for cognitive structure, achievement, autonomy, and understanding.
Solid Lubricated Bearing Inter-Element Heat Transfer Mechanisms

Solid lubricated bearings suffer from the absence of a good heat transfer medium such as provided in conventional bearings by the lubricated oil. The frictional heat generated in localized areas in the bearing produces large temperature gradients, some of them periodic, which undoubtedly contribute to failure. A need exists for better knowledge of the internal heat transfer between bearing elements to aid in accurate computation of the element temperature distributions. In this paper, results are reported for a series of experiments made with actual bearings, both annular and pellet separator types, to explore the characteristics of the heat transfer occurring within the bearing operating in an air environment. Measured element temperatures reveal a strong propensity of the bearings to isolate themselves from the adjacent ambient air. Overall ring-to-ring conductances are evaluated from the measured temperatures and electrically imposed heat fluxes. The separate roles of convection and conduction are explored with tests on modified bearings and with a tentative model of the transient conduction at the ball-raceway contact.
N-Congruences of N-semigroups

Abstract By an N -semigroup we mean a commutative archimedean cancellative semigroup without idempotent. A congruence ϱ on an N -semigroup S is called an N -congruence on S if S/g9 is an N -semigroup. This paper discusses how to determine N -congruences on S in the two ways. There is a maximal N -congruence ϱ0 on S. S/ϱ0 is an irreducible N -semigroup. Every N -semigroup is isomorphic to a subdirect product of an irreducible N -semigroup and an abelian group.
Reducing over-reliance on task-guidance systems

Task-guidance systems are unsensored, computer-based systems that remind a user of the actions required to complete a task. These systems have various forms, including electronic procedures. Over-reliance, which has been documented as an issue with automation and decision-aiding systems, may also be a problem for task-guidance systems, despite their passive nature. This paper describes task-guidance systems and over-reliance on task-guidance systems as background, and then provides the results of a study into reducing this over-reliance on task guidance systems and thereby improving performance.
Characterization of leukotriene A4 and B4 bioysnthesis

Abstract We have studied LTA4 and LTB4 synthesis in a cell-free system from RBL-1 cells. All the enzymes leading to the formation of LTB4 from arachidonic acid are localized in the soluble fraction (100, 000 x g supernatant) of these cells. The formation of LTA4 and LTB4 is complete by 10 min. When we varied the arachidonic acid concentration from 1 to 300 μM, the synthesis of LTB4 leveled off at 30 μM and of LTA4 at 100 μM while 5-HETE had not reached a plateau at 300 μM. This enzyme system has the capacity to generate relatively large amounts of 5-HETE and LTA4 and only a relatively small amount of LTB4. Therefore, the rate limiting step is not the 5-lipoxygenase, the first step in the pathway, but the conversion of LTA4 to LTB4. This is in contrast to cyclooxygenase pathway where the first step is rate limiting. A second addition of arachidonic acid at submaximal concentration for LTA4 synthesis did not produce any additional LTA4 or LTB4. Further study of this phenomenon showed that the 5-lipoxygenase and LTA-synthase were inactivated with time by preincubation with arachidonic acid and that peroxy fatty acids seem to be the inactivating species.
A V log V algorithm for isomorphism of triconnected planar graphs

An algorithm for determining whether two triconnected planar graphs are isomorphic is presented. The asymptotic growth rate of the algorithm is bounded by a constant times |V| log |V| where |V| is the number of vertices in the graphs.
Myelinated nerve cell bodies in the dorsal horn of the monkey (Saimiri sciureus).

While observing electronmicroscopic preparations of laminae I–III of Rexed (1952), taken from the lumbosacral region of squirrel monkey spinal cord, several small neuronal cell bodies were found which were partially or completely encircled by compact myelin sheaths of varying thickness. Though found in all three laminae, the occurrence of these perikaryal sheaths was less frequent in the “inner zone” of lamina II where there were few myelinated fibers. Perikaryal profiles which were completely surrounded by myelin exhibited neither internal mesaxons nor external tongue processes and the origin of their myelin is obscure. In cases of partially enveloped cells the myelin was often clearly derived from extensions of myelin sheaths surrounding small-diameter axons. These overgrowths of myelin extended away from their axons at a pole near their internal mesaxon and spread out across the surface of neighboring nerve cells. In some cases the extensions were derived from the entire axonal sheath while in others only the external lamellae were included. The external tongue process, when observed, was located at the distal end of the axonal myelin extension. Overgrowths of axonal myelin which were unrelated to neuronal cell bodies were also found but these formations were less extensive.
Host Range and Development of Microplitis rufiventris (Hymenoptera: Braconidae) an Imported Parasitoid of Several Lepidopterous Pests

Microplitis rufiventris Kokujev (Hymenoptera: Braconidae) was imported from Cairo, Egypt, into the United States, where it developed successfully in the corn earworm, Heliothis zea (Boddie); the soybean looper, Pseudoplusia includens Walker; the beet armyworm, Spodoptera exigua Hubner; the fall armyworm, Spodoptera frugiperda (J. E. Smith); the cabbage looper, Trichoplusia ni Hubner; the black cutworm, Agrotis ipsilon (Hufnagel); and the tobacco budworm, Heliothis virescens (F.). Mean developmental time from oviposition to adult was 13.6–15.6 d at 28°C depending on host species. P. includens yielded the highest percentage of female progeny; however, H. zea and S. frugiperda were preferred hosts in laboratory tests utilizing these three hosts. The parasitoid successfully searched in field cages for H. zea, P. includens , and S. frugiperda feeding on soybeans. Incidence of parasitism reached 95% of S. frugiperda and H. zea in field cages.
Bioaccumulation of fossil fuel components during single-compound and complex-mixture exposures of Daphnia magna.

The authors conducted tests with the water flea (Daphnia magna) to compare the bioaccumulation of compounds presented alone with the bioaccumulation of these same compounds when they were presented within a complex coal liquid, water-soluble fraction. Phenol and aniline were used as representative compounds because they are highly soluble, moderately toxic, and common to many fossil fuel liquid products and corresponding wastes. The tests were primarily designed to aid in development of predictive models relating to the transport and fate of components from complex mixtures in aquatic biota.
The Pathogenesis of Functional Tricuspid Regurgitation

Functional tricuspid regurgitation (TR) is a common etiology of TR. Functional TR results from geometrical distortion of the normal spatial relationships of the tricuspid leaflets, annulus, chords, papillary muscles, and right ventricular (RV) walls. Functional TR results most commonly from left-sided heart disease, including mitral valve abnormalities and cardiomyopathy and RV dysfunction secondary to pulmonary disease (Cor pulmonale). The tricuspid annulus, which has a normal bimodal or saddle shape, becomes larger, flatter, and more circular with the development of functional TR. RV dilation can lead to papillary muscle displacement and tethering of the tricuspid leaflets, resulting in incomplete coaptation and development of functional TR.
Monoclonal Antibodies to Salmonella Typhimurium and Escherichia Coli Lipopolysaccharides

Monoclonal antibodies reacting to lipopolysaccharides (LPS) of Salmonella typhimurium and a slow-lactose-fermenting strain of Escherichia coli (0 serotype 81) were made by immunization of BALB/c mice with trichloroacetic acid-extracted LPS and fusion of lymphoid cells with Sp2/0-Agl4 cells. Fusion supernatants were screened by radioimmunoassay against phenol/water-extracted LPS. Some of the antibodies reacted with LPS from one bacterial species but not the other, suggesting that the antibodies are directed against the 0-specific side chains of the LPS. The fine specificity of one of the antibodies was studied by inhibition of radio-immunoassay by monosaccharides. Rhamnose and mannose inhibited best, followed by galactose and glucose, while the weakest inhibition was given by N-acetylglucosamine, which is not part of the S. typhimurium 0 antigen. Agglutination and immunofluorescence results suggest that the determinant is on the bacterial surface. Two other hybridomas were tested by Alf Lindberg and Stefan Svenson in an enzyme-linked immunosorbent assay against LPS and oligosaccharides. One antibody is directed against an α-galactose (1→2) mannose disaccharide, while the other appears to recognize factor 5 (2-acetyl-abequose).
Image alignment for multiple camera high dynamic range microscopy

This paper investigates the problem of image alignment for multiple camera high dynamic range (HDR) imaging. HDR imaging combines information from images taken with different exposure settings. Combining information from multiple cameras requires an alignment process that is robust to the intensity differences in the images. HDR applications that use a limited number of component images require an alignment technique that is robust to large exposure differences. We evaluate the suitability for HDR alignment of three exposure-robust techniques. We conclude that image alignment based on matching feature descriptors extracted from radiant power images from calibrated cameras yields the most accurate and robust solution. We demonstrate the use of this alignment technique in a high dynamic range video microscope that enables live specimen imaging with a greater level of detail than can be captured with a single camera.
Engineered Model of the Intestine Suggests Active Transport of Lipid by Lymphatics

The lymphatic system has long been thought of as little more than a series of passive ducts as they serve to return fluid and proteins from interstitial spaces back to the blood, provide a route for immune cell trafficking, and transport dietary lipid from the intestine to the blood. Recent evidence has revealed that the lymphatics play an active role in lipid trafficking, and alterations in this function have been correlated with the presence of lymphatic diseases (Dixon, 2010). Here we describe the use of a two-cell, tissue engineered model to explore mechanisms of lipid transport across lymphatic endothelial cells (LEC). Previously this model was demonstrated to recapitulate essential features of the intestinal-lacteal interface with in the mammalian gut (Dixon et al., 2009). With our model we demonstrate, not only that lipid transport across the lymphatics is transcellular and ATP dependent, but also, this mechanism of transport utilizes the molecular motors dynein and kinesin.Copyright © 2011 by ASME
Sleep Stage Physiology, Mood, and Vigilance Responses to Total Sleep Deprivation in Healthy 80‐Year‐Olds and 20‐Year‐Olds

Little is known about sleep and the effects of total sleep loss in the 'old old' (i.e., 80-year-olds). We investigated sleep, mood, and performance responses to acute sleep deprivation in healthy 80-year-olds (n = 10) and 20-year-olds (n = 14). The protocol consisted of three nights of baseline sleep, one night of total sleep deprivation, and two nights of recovery sleep. Mood and vigilance were tested using visual analog scales and a Mackworth clock procedure in the morning and evening of each study day. Daytime sleepiness was measured by five naps on the days following the third and sixth nights. Old subjects had lower sleep efficiency and less delta sleep than young subjects. However, sleep continuity and delta sleep were enhanced in both groups on the first recovery night, indicating that sleep changes in old subjects are at least partially reversible by this procedure. Surprisingly, young subjects had shorter daytime sleep latencies than the old, suggesting a greater unmet sleep need in the former group. Mood and performance were disturbed by sleep loss in both groups, but to a greater extent among the young. This suggests that acute total sleep loss is a more disruptive procedure for the young than for the old.
Association of Physical Trauma With Risk of Herpes Zoster Among Medicare Beneficiaries in the United States

Risk factors for herpes zoster (HZ) are poorly defined. An age-matched, case-control study was conducted to assess the effect of physical trauma on HZ, using Medicare data. HZ cases were 3.4 times as likely as controls to have experienced trauma in the week before HZ onset, but the magnitude of the association between trauma and HZ declined over time. Cases who had cranial HZ were >25 times as likely as controls to have had cranial trauma in the week before HZ onset. Therefore, recent trauma can be a trigger for HZ.
Shyness, Sociability and Patterns of Everyday Affiliation:

The regulation of affiliation patterns in everyday life has important implications for subjective well-being. For instance, Cheek & Buss (1981) distinguished approach (sociability) motivation from avoidance tendencies (shyness) and found that individuals high in both traits experienced the most stilted and uncomfortable interaction in comparison to any other trait combination among dyad members. In the present field study, participants were free to self-regulate their social interaction in any way. Meaningful patterns of initiation of encounters, perceptions of the encounter and objective features of the encounter emerged. The pattern of findings suggests that further research on the self-regulation of affective life, through affiliation patterns, would be productive.
VISUAL FORM COMPLEXITY AND TV NEWS

An electronically estimated form complexity variable, static complexity, is analyzed throughout the course of a network TV newscast. No support is found for the hypothesis that audiences prefer an optimal level of static complexity, but there is support for the hypothesis that longitudinal analysis accounts for more variance than a cross-sectional approach. This study has implications for research in TV news that confines itself to content-based variables and assumes only a cross-sectional relationship between newscast material and audience responses. Both form variables and time should be considered along with content in the study of reactions to TV news.
Density functional theory model for calculating pore size distributions: pore structure of nanoporous catalysts

Using the example of nanoporous catalysts, we discuss the non-local density functional . theory NLDFT model applied to physical adsorption of nitrogen and argon. The model has been used for predicting adsorptionrdesorption isotherms in nanopores of different geome- . tries over a wide range of pore sizes 0.5)100 nm , and for calculating pore size distributions from adsorption isotherms based on given intermolecular fluid)fluid and fluid)solid poten- tials. The development of new nanoporous catalysts requires reliable characterization methods. We critically analyze different methods which are currently used for pore structure characterization in the range of nanometers. Calculations of the pore size distributions from nitrogen and argon adsorption isotherms are presented. Our primary method is based on the NLDFT model of adsorption on MCM-41, developed earlier. The results obtained with the NLDFT model are compared with other methods. It is shown, that the pore structure of nanoporous catalysts can be quite complex, and that Ar and N isotherms contain compli- 2 mentary information. The NLDFT model is recommended for evaluation of pore size distributions in nanoporous catalysts and other MCM-41 based materials. Q 1998 Elsevier Science B.V. All rights reserved.
Sensitivity of Multiband ZP-OFDM Ultra-Wide-Band and Receivers to Synchronization Errors

This correspondence analyzes the sensitivity of multiband zero-padding (ZP) orthogonal-frequency-division multiplexing (OFDM)-based ultra-wide-band receivers to carrier and sampling clock errors. Analytical expressions and numerical results for the power of intercarrier interference (ICI) and signal-to-interference-and-noise ratio (SINR) induced by imperfect carrier frequency and phase synchronization are presented and corroborated via computer simulations. It is found that the multiband zero-padding OFDM-based ultra-wide-band receivers are quite sensitive to carrier frequency errors but robust to sampling clock errors and small carrier phase offset errors
Semi-Adiabatic Model of the Deep Stratification and Meridional Overturning

AbstractAn analytical model of the Atlantic deep stratification and meridional overturning circulation is presented that illustrates the dynamic coupling between the Southern Ocean and the midlatitude gyres. The model, expressed here in terms of the two-and-a-half-layer framework, predicts the stratification and meridional transport as a function of the mechanical and thermodynamic forcing at the sea surface. The approach is based on the classical elements of large-scale circulation theory—ideal thermocline, inertial western boundary currents, and eddy-controlled Antarctic Circumpolar Current (ACC) models—which are combined to produce a consistent three-dimensional view of the global overturning. The analytical tractability is achieved by assuming and subsequently verifying that the pattern of circulation in the model is largely controlled by adiabatic processes: the time-mean and eddy-induced isopycnal advection of buoyancy. The mean stratification of the lower thermocline is determined by the surface fo...
Threshold for improvement in insulin sensitivity with adolescent weight loss.

Objectives To assess the association of weight loss and insulin sensitivity, glucose tolerance, and metabolic syndrome (MS) in obese adolescents following weight loss treatment, and to determine the threshold amount of weight loss required to observe improvements in these measures. Study design A randomized, controlled behavioral weight loss trial was conducted with 113 obese adolescents. Changes in fasting insulin, homeostasis model assessment of insulin resistance, whole body insulin sensitivity index (WBISI), body mass index (BMI), and MS criteria were assessed at baseline and at month 4. Results There was significant improvement in all measures of insulin sensitivity at month 4. Mean fasting insulin dropped from 22.3 to 16.6 μU/mL ( P P = .001) and WBISI increased significantly from 2.87 to 3.98 ( P P = .03) and was the optimal threshold. Fewer individuals met criteria for MS after weight loss ( P = .0038), although there were no significant changes in the individual features of the syndrome. Conclusions In this trial, weight loss at month 4 was associated with improved insulin sensitivity in obese adolescents. An approximate decrease in BMI of 8% was the threshold level at which insulin sensitivity improved. As more weight loss programs are designed for obese adolescents, it will be important to have reasonable weight loss goals that will yield improvements in metabolic and cardiovascular disease risk factors.
Dairy Cattle Housing with Emphasis on Economics, Sanitation, Health, and Production

Summary Modern dairy cattle management requires adequate equipment and economical housing designed to produce high-quality milk, meet health requirements of cows, combined with convenience and efficiency of the operator. Annual dairy building costs represent approximately 10% of dairy costs. Under high-level management, structural features (stanchion vs. loose-housing) do not appear to be related to quality of the milk. Bedding materials and alternatives such as rubber mats, slatted floors, liquid manure handling, moving debris with water, and individual stalls for dairy cattle in loose-housing systems are all examples of recent managerial changes in housing philosophies. A lowered incidence of udder (serious mastitis cases) and limb (stiffness or lameness, foot rot, injured knees and hocks) disorders was found under loose-housing conditions. A number of studies indicate both a decrease and an increase in milk production associated with stanchion barn management. One factor sometimes overlooked in loose-housing arrangements is the possible advantage of a more highly organized labor-saving milking system, utilizing a milking parlor.
MOLECULAR STUDIES OF EVOLUTION: A SOURCE OF NOVEL STATISTICAL PROBLEMS*

Abstract The recently opened and rapidly developing field of evolution research, conducted on the level of molecules, is a novel source of interesting statistical and probabilistic problems. The biological studies are concerned with macromolecules which, in organisms as diverse as Man, Monkey, Carp, Whale and Yeast, perform similar functions and have similar structures. The apparently inconsequential differences among such homologous macromolecules, their sites and their frequencies, are at the base of current efforts to establish lineages linking the species studied to a common ancestor. The nature of statistical problems originating from such biological studies is illustrated on two tentative stochastic models of “inconsequential” substitutions in the macromolecules.
An application of the LFP survival model to smoking cessation data

We use a limited failure population (LFP) model based on the Weibull distribution to model the times from initial abstinence to return to smoking for subjects enrolled in programmes to help them stop smoking. The model contains a third parameter that corresponds to the proportion of subjects who permanently abstain from smoking. The data are subject to both right and interval censoring. Furthermore, subjects receive treatment in groups, and individuals in the same group may provide correlated outcomes. Use of a maximum likelihood estimation procedure which assumes independent outcomes provides reasonable parameter estimates, but the corresponding standard errors tend to be too small, which results in tests with inflated type I error levels and confidence intervals that tend to be too narrow. We use a bootstrap procedure to obtain more reasonable values for the standard errors and to construct confidence intervals that more nearly achieve the stated coverage probabilities.
A new method for determining the long‐period component of the source time function of large earthquakes

Inversions of seismic body waves indicate that most large earthquakes involve spatial and temporal heterogeneity of the moment release, but seismic body waves usually lack sufficient bandwidth to constrain the long-period component of the radiation. Analysis of long-period surface waves and free oscillations can constrain the overall source duration and moment; however, most procedures assume simple trapezoidal or boxcar source-time histories, inconsistent with the body wave complexity. The authors find that source-time function complexity can affect long-period surface waves sufficiently to impact estimates of the source moment tensor, rupture duration and centroid depth. They present a procedure to objectively determine the long-period component of complex source-time functions in which they directly utilize results from body wave analysis. The method is applied to two great normal fault events of June 22, 1977 (Tonga, M{sub w} = 8.2) and August 19, 1977 (Indonesia, M{sub w} = 8.5). Standard long period analysis procedures underestimate the total slip duration in both cases. The overall source process times of both earthquakes are longer than 120 s.
Perception of Risk by Administrators and Home Health Aides

Increasing numbers of persons over 65, decreased length of hospital stay, and need for chronic (custodial) health care have placed a strain on home health care agencies. The second largest group of persons providing care is home health aides (HHAs), who perform in-home, nonskilled, technical procedures with little or no on-site supervision. They are generally high school graduates or hold GEDs. The purpose of this study was to compare home health care administrators' (HHCAs) and HHAs' perceptions of risk involved in home visiting. Given HHAs' educational preparation and limited supervision, they are basically on their own for work performed. Although agencies provide orientation sessions for new workers, periodic in-services often relate to tasks and competency testing and little attention directed toward protecting the self-specifically, strategies to decrease personal risk. In order to determine to what extent HHCAs and HHAs perceive risk, the Home Health Care Perception of Risk Questionnaire, a self-report measure, was administered to a national random sample of 93 HHCAs and 227 HHAs. Findings suggest that these groups differ in perception of risk and level of agency support in making home visits. Suggestions for meeting the needs of this HHA provider group are offered.
Assessing the Academic Medical Center as a Supportive Learning Community.

Academic medical centers are well-known for their emphasis on teaching, research and public service; however, like most large, bureaucratic organizations, they oftentimes suffer from an inability to learn as an organization. The role of the research administrator in the academic medical center has grown over time as the profession itself has become more important in the management of the research enterprise. The field of research administration within academic medical centers has grown to encompass a wide variety of responsibilities, including making sense of complicated rules, systems and processes in the administration of sponsored research, as well as managing the burden of regulatory compliance with applicable laws, contracts, institutional policies and sponsor guidelines. Keeping abreast of the complicated and fluctuating laws, guidelines, administrative processes and systems, and means of compliance is complicated even for the experienced research professional. This problem is compounded by struggles to foster the sharing of knowledge to new employees. Using an existing assessment tool, 121 research administrators at a large, private academic medical center were surveyed to define their perception of the academic medical center as a learning community (both collectively and by department type, gender and tenure) and to identify gaps in knowledge sharing, idea development, ability to learn from mistakes and reflective thinking.
Suppression of experimental autoimmune uveoretinitis by intraorchidic administration of S-antigen.

Experimental autoimmune uveoretinitis (EAU) induced by immunization of albino Lewis rats with a retinal soluble antigen (S-antigen) has been studied extensively by many workers. An intraorchidic injection of S-antigen 4 days prior to immunization of the animal with the antigen emulsified in adjuvant was found to prevent the onset of the disease. Orchiectomy in 24 hr after the intraorchidic injection did not abolish the effect of treatment. The systemic suppression induced by the orchidic treatment persisted at least for 3 weeks after treatment. In rats that received orchidic treatment, delayed-type hypersensitivity was markedly inhibited but anti-S-antigen antibody levels in the serum were as high as those in immunized rats without orchidic pretreat-ment. These results indicate that antigen challenge to the testis is a novel method to elicit systemic activation of the immunosuppressive mechanism.
Irreversible and Reversible Behavior of Spin Glasses: Broken Ergodicity

Over the past decade, a great deal of effort has gone into understanding the properties of spin glasses [1,2]. However, because these are rather unique systems which show simultaneously apparent phase transition as well as metastable or glassy behavior, progress has been slow. Though it was initially believed that spin glasses could be treated as if they had a true equilibrium phase transition, we now recognize that this cannot be the whole story. Recently, it has become clear that spin glasses are very complex systems, in which irreversible and time dependent effects play an important role. We now know that one must go beyond the regime of validity of equilibrium thermodynamics. In this paper, we will discuss the mountinq evidence, both experimental and theoretical, for why nonequilibrium approaches are essential in order to understand spin glasses.
Cell survival recovery kinetics in the KHT sarcoma following treatment with five alkylating agents and misonidazole.

Abstract In order to determine the role of recovery of tumor cell survival in the enhanced tumor responses resulting from chemotherapeutic agent-sensitizer combinations, cell survival in KHT sarcomas as a function of time after treatment with the alkylating agents 1-(2-chloroethyl)-3-cyclohexyl-l-nitrosourea (CCNU), 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), cyclophosphamide (CYC), phenylalanine mustard (L-PAM) and 2-[3-(2-chloroethyl)-3-nitrosoureidol-D-glucopyranose (chlorozotozin; CLZ) either alone or in combination with the radiosensitizer misonidazole (MISO) was evaluated. Tumor-bearing mice were treated with single doses of CCNU, BCNU, CYC, L-PAM and CLZ, respectively. The doses, chosen to obtain approximately the same level of cell kill with each treatment, were administered either alone or in simultaneous combination with a 1.0 mg/g dose of MISO. Tumors were excised at 1, 2, 4, 8, 16 and 24 hr after drug injection. Clonogenic cell survival was assessed at these times using an in vivo to in vitro excision assay. The results showed that following treatment with each of the chemotherapeutic agents, tumor cell survival reached a minimum at ∼2–8 hr. Subsequently cell survival remained relatively constant for CYC, but increased with time by a factor of ∼10–100 for L-PAM, CCNU, BCNU and CLZ. The addition of MISO potentiated the cell killing effects of CYC, L-PAM, CCNU and BCNU, but not of CLZ. Also, in animals treated with certain of these chemotherapeutic agents plus the sensitizer, cell survival recovery was impaired. This effect was particularly marked when the nitrosourea CCNU was used in combination with MISO (i.e. 24 hr after treatment with CCNU plus MISO, tumor cell survival was a factor of ∼50 lower than observed in tumors of mice given only CCNU). These findings indicate that the enhancement of cell killing in the KHT sarcoma observed 24 hr after treatment with chemotherapeutic agent-MISO combinations may be at least in part the result of altered recovery in tumor cell survival.
Gradient descent learning of radial basis neural networks

This paper presents an axiomatic approach for building RBF neural networks and also proposes a supervised learning algorithm based on gradient descent for their training. This approach results in a broad variety of admissible RBF models, including those employing Gaussian radial basis functions. The form of the radial basis functions is determined by a generator function. A sensitivity analysis explains the failure of gradient descent learning on RBF networks with Gaussian radial basis functions, which are generated by an exponential generator function. The same analysis verifies that RBF networks generated by a linear generator function are much more suitable for gradient descent learning. Experiments involving such RBF networks indicate that the proposed gradient descent algorithm guarantees fast learning and very satisfactory generalization ability.
Coexistence of an ILPR i-Motif and a Partially Folded Structure with Comparable Mechanical Stability Revealed at the Single-Molecule Level

Investigation of i-motif is of high importance to fully understand the biological functions of G quadruplexes in the context of double-stranded DNA. Whereas single-molecule approaches have profiled G quadruplexes from a perspective unavailable by bulk techniques, there is a lack of similar literature on the i-motif in the cytosine (C)-rich region complementary to G quadruplex-forming sequences. Here, we have used laser tweezers to investigate the structures formed in 5′-(TGTCCCCACACCCC)2, a predominate variant in the insulin-linked polymorphic region (ILPR). We have observed two species with the change in contour length (ΔL) of 10.4 (±0.1) and 5.1 (±0.5) nm, respectively. Since ΔL of 10.4 nm is located within the expected range for an i-motif structure, we assign this species to the i-motif. The formation of the i-motif in the same sequence has been corroborated by bulk experiments such as Br2 footprinting, circular dichroism, and thermal denaturation. The assignment of the i-motif is further confirmed by...
The essentiality of nectar and arthropods in the diet of the Anna's hummingbird (Calypte anna)

Abstract 1. 1. Three adult male Anna's hummingbirds ( Calyptae anna ) were fed each of the following three diets over time: live fruit flies and a 22% sucrose in water solution (control diet), a 22% sucrose solution only, or live fruit flies and water only, and the birds' body mass changes and behavior were recorded. 2. 2. The hummingbirds were able to subsist for 10 days on the 22% sucrose solution with body mass loss but no obvious behavior changes. 3. 3. In the absence of the sucrose solution the hummingbirds made no attempt to catch fruit flies and became listless or torpid within a few hours. 4. 4. The results suggest that hummingbirds have a remarkable ability to survive with no protein in their diets as long as nectar is available.
Determinants of maximal exercise VO2 during single leg knee-extensor exercise in humans

Previously, a reduction in fractional inspired O2 (FIO2) during dynamic exercise of the human quadriceps muscles of one leg resulted in increased muscle blood flow (Q) and a fall in femoral venous ...
Practice-Based Interventions Addressing Concomitant Depression and Chronic Medical Conditions in the Primary Care Setting: A Systematic Review and Meta-Analysis

Background: Depression concomitant with chronic medical conditions is common and burdensome in primary care. Objective: To assess the effectiveness of practice-based interventions for improving dep...