cssi/SciSciGPT-SciSciNet huggingface dataset:
Relations between fine motor skill and parental report of attention in young children with neurofibromatosis type 1

Neurofibromatosis type 1 (NF1) is one of the most common genetic disorders presenting in approximately 1 in 3,500 live births. NF1 is a highly variable condition with a large number of complications. A common complication is neuropsychological problems, including developmental delays and learning difficulties that affect as many as 60% of patients. Research has suggested that school-aged children with NF1 often have poorer fine motor skills and are at greater risk for attention difficulties than the general population. Thirty-eight children with NF1 and 23 unaffected children between the ages of 4 and 6 years, who are enrolled in a study of early development in NF1, were included in the present study. Varying levels of fine motor functioning were examined (simple to complex fine motor tasks). For children with NF1, significant difficulties were demonstrated on lab-based mid-level and complex fine motor tasks, even after controlling for nonverbal reasoning abilities, but not on simple fine motor tasks. Parental report also indicated difficulties in everyday adaptive fine motor functioning. No significant correlations were found between complex fine motor ability and attention difficulties. This study provides much needed descriptive data on the early emergence of fine motor difficulties and attention difficulties in young children with NF1.
Descriptive Classification of Traumatic Injuries to the Teeth and Supporting Structures

A summary of descriptively classifying traumatic injuries to the teeth and supporting structures was described. It is based on a description of the tooth structures involved, direction or level of crown or root fracture, the type and direction of displacement, and the effect on supporting structures.
A NOVEL PCR ASSAY FOR LISTERIA WELSHIMERI TARGETING TRANSCRIPTIONAL REGULATOR GENE LWE1801

Transcriptional regulator genes encode a group of specialized molecules that play essential roles in microbial responses to changing external conditions. These genes have been shown to possess species or group specificity and are useful as detection targets for diagnostic application. The present study examined transcriptional regulator genes from a nonpathogenic species Listeria welshimeri that often causes difficulty in the laboratory diagnosis of Listeria monocytogenes-related foodborne disease. The comparison of transcriptional regulator gene sequences from L. welshimeri Special Listeria Culture Collection 5334 genome with other microbial genes at GenBank led to the identification of lwe1801. The application of polymerase chain reaction (PCR) primers derived from lwe1801 enabled the amplification of a specific band of 510 bp from the DNA of L. welshimeri only and not from that of other Listeria and common bacterial species. Given its unique presence in L. welshimeri, the transcriptional regulator gene lwe1801 constitutes a novel molecular marker for species-specific confirmation of this bacterium. PRACTICAL APPLICATIONS The Listeria species are closely related bacteria demonstrating significant morphologic, biochemical and ecologic resemblances. The ability to accurately distinguish nonpathogenic Listeria species, such as Listeria welshimeri, from pathogenic Listeria monocytogenes in a timely manner is critical for the control of human listeriosis. The use of polymerase chain reaction (PCR) primers from the transcriptional regulator gene lwe1801 offers a rapid, specific and sensitive means to identify L. welshimeri. Further analysis of the lwe1801 and its translated protein will reveal new insights on the molecular regulation of L. welshimeri survival and adaptation to its niche environment.
Meteorological research contemplated for an expedition to north Greenland

Meteorological studies in Greenland are certain of leading to interesting results of both practical and theoretical value. These values arise in part from the fact that Greenland is unique in the Northern Hemisphere, having a great cap of inland-ice which covers all but a narrow border of land about its margin. Professor Hobbs in his theory of the glacial anticyclone has considered this continental glacier to be overlain by a persistent system of descending air-currents, making Greenland the wind-pole of the Northern Hemisphere and, at the same time, accounting for the accumulation and distribution of snow which maintains the great ice-cap. Others who oppose or would greatly modify this theory have suggested that any such high-pressure system over a continental glacier must be ephemeral and of little significance in either wide-spread general wind-circulation or in the maintenance of the icecap. They consider that marginal low-pressure disturbances migrate onto the glacier, penetrating far inland and carrying great amounts of moisture which are there precipitated, thus accounting for the snow-supply which maintains the ice-cap, and emphasizing the weakness of any anticyclonic circulation.
Graffiti and film school culture: displaying alienation

Graffiti created by students in “film school” are examined as an organizational document from a cultural and critical‐cultural perspective. The graffiti serve as a critical discourse that reflects and creates meanings related to the sectional interests of film students. In so doing, graffiti create and reflect an ideology that is positioned against the ideology of other sectional interests, both organizational and industrial. The study reviews a variety of themes related to film students’ alienation and the discourse that counters the sources of that alienation. Themes include editing as a disliked and avoided activity, isolation, lack of artistic control, and career filters. The humorous communicative style of graffiti creates tension among cultural meanings that mediates between alienation and liberation.
Thermoregulatory behavior of the triggerfish Balistes fuscus in an electronic shuttlebox

Ten blue triggerfish,Balistes fuscus, were tested individually for 3 days each in Ichthyotron electronic shuttleboxes to measure their thermoregulatory behavior. The modal thermal preferendum, a species-specific measure of temperature preference which is independent of prior thermal acclimation, was 25 °C. The triggerfish voluntarily occupied a 16–27 °C range of temperature, out of a potentially available range of 0–50 °C. There was no significant difference in preferred temperature between night and day, indicating lack of a thermoregulatory rhythm in this species. The preferred temperature range of this tropical marine reef species is similar to that of cool temperate freshwater and marine fishes; many warm temperate species prefer higher temperatures.
The action of thrombin on peptide p-nitroanilide substrates: Hydrolysis of Tos-Gly-Pro-Arg-pNA and D-Phe-Pip-Arg-pNA by human α and γ and bovine α and β-thrombins

Human and bovine alpha-thrombins (greater than 90% alpha form) with high fibrinogen clotting activities (approximately 3,000 U.S. units/mg protein) exhibit similar Michaelis menten kinetics with the p-nitroanilide tripeptide substrates Tos-Gly-Pro-arg-pNA (Chromozym-TH) and D-Phe-Pip-Arg-pNA (S-2238). The kinetic parameters at I = 0.11 M, 25 degrees C, pH 7.8 are: (Km = 4.18 +/- 0.22 and 3.61 +/- 0.15 microM; kcat = 127 +/- 8 and 100 +/- 1 s-1) for Chromozym TH and (Km = 1.33 +/- 0.07 and 1.50 +/- 0.10 microM; kcat = 91.4 +/- 1.8 and 98.0 +/- 0.5 s-1) for S-2238 for the human and bovine enzymes, respectively. Unlike the native enzyme forms, their "non-clotting" terminal degradative forms, human gamma-thrombin (approximately 5 units/mg) and bovine beta-thrombin (approximately 200 units/mg), give increased values for these parameters (km = 14.3 +/- 2.4 and 14.4 +/- 2.2 microM; kcat = 160 +/- 9 and 124 +/- 6 s-1) for Chromozym-TH; and (Km = 2.50 +/- 0.36 and 2.99 +/- 0.33 microM; kcat = 106 +/- 3 and 106 +/- 3 s-1) for S-2238. Based on these parameters, 50% degradation of human or bovine alpha-thrombins can be calculated to produce relatively small errors in the kinetic measurement of total thrombin concentrations (maximally 9% and 7% for Chromozym-TH; 7% and 3% for S-2238, respectively) if the kinetic parameters for all alpha forms are erroneously used and assays are at 150 microM substrate. This is in contrast to the large errors inherent in clotting activity measurements on thrombin mixtures. Incorporation of 1 mg/ml of polyethylene glycol 6,000 into assay solutions eliminates systematic errors otherwise caused by thrombin adsorption to surfaces and enables thrombin to be accurately assayed at concentrations less than 0.1 nM or 0.01 clotting unit/ml of alpha-thrombin.
Preconditioned iterative methods on sparse subspaces

Abstract When some rows of the system matrix and a preconditioner coincide, preconditioned iterations can be reduced to a sparse subspace. Taking advantage of this property can lead to considerable memory and computational savings. This is particularly useful with the GMRES method. We consider the iterative solution of a discretized partial differential equation on this sparse subspace. With a domain decomposition method and a fictitious domain method the subspace corresponds a small neighborhood of an interface. As numerical examples we solve the Helmholtz equation using a fictitious domain method and an elliptic equation with a jump in the diffusion coefficient using a separable preconditioner.
Mothers and fathers of children with Down syndrome: parental stress and involvement in childcare.

Abstract Parental stress was examined in socioeconomically matched samples of mothers and fathers of children with Down syndrome and typically developing children. Parents of children with Down syn...
Drug Therapy for Obesity in the Elderly

The prevalence of obesity is increasing rapidly in the US and other developed countries. Even though the percentage of older individuals is increasing worldwide, obesity has only recently become a recognised problem in this population. Obesity occurs when energy intake chronically exceeds energy expenditure. Moreover, advancing age is associated with an inability to couple energy intake with energy expenditure. Obesity contributes to many adverse health outcomes, including non-insulin-dependent (type II) diabetes mellitus, as well as to an increase in both cardiovascular and all-cause mortality. Only recently has the medical community begun to accept obesity as a disease with a multifactorial pathogenesis that requires systematic lifestyle changes and pharmacological treatment. Several groups of drugs are available for the pharmacotherapy of obesity; anorectic medications (e.g. fenfluramine, dexfenfluramine); substances affecting energy expenditure and body composition [e.g. chromium (chromium picolinate), ephedrine, anabolic steroids, beta 3-adrenoceptor agonists]; and drugs affecting the absorption of nutrients (e.g. orlistat). To date, few drugs have produced and sustained a significant bodyweight loss. However, some drugs induce a significant short term reduction in bodyweight compared with placebo. Moreover, there is a paucity of information regarding the effectiveness of these drugs in the treatment of obesity in the elderly. Furthermore, it is even debated whether obesity should be treated with drug intervention in the elderly. Clinicians prescribing medications for obesity treatment in the elderly need to carefully consider the benefit: risk ratio, given the high prevalence of polypharmacy in elderly patients. Furthermore, physiological changes that occur with aging may affect the pharmacokinetics of administered drugs and need to be taken into consideration.
Characteristics of skylight at the zenith during twilight as indicators of atmospheric turbidity. 2: Intensity and color ratio

This is the second of two papers based on an extensive series of measurements of the intensity and polarization of light from the zenith sky during periods of twilight made at an altitude of 3400 m on the island of Hawaii. Part 1 dealt with the skylight polarization; part 2 is on the measured intensity and quantities derived from the intensity. The principal results are that (1) the polarization and intensity of light from the zenith during twilight are sensitive indicators of the existence of turbid layers in the stratosphere and upper troposphere, and (2) at least at Mauna Loa primary scattering of the sunlight incident on the upper atmosphere during twilight is strongly dominant over secondary or multiple scattering at wavelengths beyond ~0.60microm, whereas this is much less true at shorter wavelengths. It is suggested that the development and general use of a simple twilight polarimeter would greatly facilitate determinations of turbidity in the upper layers of the atmosphere.
Caregivers' observations and report of early symptoms of Alzheimer's disease

Caregivers of patients with Alzheimer's disease (AD) and other dementing illnesses are typically asked to recall details regarding the onset and course of specific symptoms. These reports are often essential for clinical diagnosis. We report caregivers' recalls of initial symptoms in family members diagnosed with AD. In addition, we determine whether caregivers' reports of specific symptoms are associated with certain caregiver/patient characteristics. In a sample of 76 caregivers of AD patients, the most frequent initial problems cited included memory, activities of daily living, disorientation, and personality change. Personality changes were reported as a first symptom significantly more often by spouses, younger caregivers, and caregivers of higher socioeconomic status. Caregivers of AD patients with longer duration of illness and higher age at onset were also more likely to report personality changes as a first symptom. The children of AD patients were more likely than spouses to report disorientatio...
Schwannoma with angiosarcoma. Report of a case and comparison with other types of nerve tumors with angiosarcoma

BACKGROUND Schwannoma with angiosarcomatous change is a rare tumor, the clinical characteristics of which have not been analyzed. METHODS A patient with schwannoma with angiosarcoma arising in the midneck and clinically mimicking a carotid body paraganglioma is described with a literature review of all previously reported cases and a comparison of their clinical features with those of schwannoma with conventional malignant transformation and cases of neurofibroma and malignant peripheral nerve sheath tumor (MPNST) with angiosarcoma. RESULTS There are four reported cases, including the present case. Schwannoma with angiosarcoma affects older adults, mainly men. Three tumors arose from the vagus nerve in the neck. Three of the four angiosarcomas were epithelioid in type. Treatment in all cases was surgical resection followed by radiation and chemotherapy in one case and by radiation alone in another. One patient died with residual local angiosarcoma 5 months after the diagnosis. The remaining three patients were alive and disease free at 27 months, 43 months, and 90 months, with distant metastasis (after 15 months) reported only in the patient described in this case report. CONCLUSIONS Schwannoma with angiosarcoma should be included in the differential diagnosis of presumed carotid body paragangliomas. Like angiosarcoma alone and schwannoma with conventional malignant transformation, but unlike cases of neurofibroma and MPNST with angiosarcoma, the patients are older adults, and there is a male prevalence. Schwannoma with angiosarcoma is capable of local spread with a fatal outcome and of distant metastasis, but follow-up strongly suggests that these patients have a better prognosis than patients with neurofibroma or MPNST with angiosarcoma. Recommended treatment is attempted complete surgical resection followed by radiation therapy and chemotherapy, if it can be tolerated by the patient. Cancer 2000;89:1577–85. © 2000 American Cancer Society.
Technological Innovations and Intervention Practices for Children With Cochlear Implants

This clinical forum has addressed many of the challenges associated with serving children who have cochlear implants. These include determining who may be a candidate for implantation; optimizing p...
Retardation of tree growth by injection of plant growth regulators

Previously topped American sycamore (Platanus occidentalis L.), cottonwood (Populus deltoides Bartr. ex Marsh), water oak (Quercus nigra L.), and bigleaf maple (Acer macrophyllum Pursh) trees were injected with aqueous solutions of maleic hydrazide or dikegulac-sodium in April-June, 1979 at various locations around the United States. Measurements made later in the autumn showed that dikegulac-sodium reduced sprout regrowth in all four species, whereas maleic hydrazide was only effective in controlling regrowth of American sycamore and cottonwood. The effects of dikegulac persisted through the second growing season. Significant variability was observed among treated trees and must be reduced in order to achieve consistent growth responses from an application of growth retardants.
Key parameters for modeling information diffusion in populations

Modeling and simulation can be an important tool in helping develop techniques to better communicate safety-critical information for disaster preparation and recovery. However, these tools are only moderately useful if they do not capture both the social component (how information diffuses in a population through communication between individuals) and the cognitive component (how individuals integrate information and change behavior). The objective of this paper is to lay the groundwork for more complex simulations by providing a summarization of some of the important phenomenon identified in the attitude change literature. We describe four processes that are important to capture: (1) the drive for consistency; (2) information distortion; (3) persuasion route; and (4) implicit/explicit attitudes. We describe the experiments that illustrated these phenomenon and the factors that influence them (cognitive load, attitude relationships, and the social network). Finally, we describe a conceptual model that captures some of these processes and can be used as a starting point.
Ab Initio Calculation of the Electronic Absorption of Functionalized Octahedral Silsesquioxanes via Time-Dependent Density Functional Theory with Range-Separated Hybrid Functionals

Recent advances in the ability to functionalize octahedral silsesquioxanes with different photoactive ligands, and thereby tune their optical properties, suggest that these molecules may serve as potential building blocks of light-harvesting, photovoltaic, and photonic devices. In this paper we report extensive ab initio calculations of the excitation energies underlying the absorption spectra of these systems. The calculations are based on density functional theory for the ground electronic state and time-dependent density functional theory for the excited electronic states. The ability of the commonly used B3LYP functional to reproduce the experimentally observed absorption excitation energies is compared to that of recently developed range-separated hybrid functionals. The importance of pairing the range-separated hybrid functionals with basis sets that include diffuse and polarization basis functions is demonstrated in the case of vinyl-functionalized silsesquioxanes. Absorptive excitation energies ar...
Induced hypertension improves regional blood flow and protects against infarction during focal ischemia: time course of changes in blood flow measured by laser Doppler imaging.

OBJECTIVE To characterize changes in regional blood flow (rCBF) during and after a period of arterial occlusion and determine the effect on rCBF and on the extent of infarction when the mean arterial blood pressure is increased during the period of occlusion. METHODS rCBF in the middle cerebral artery (MCA) territory of rabbits was monitored using laser Doppler perfusion imaging before, during, and after a 1- or 2-hour period of MCA occlusion, and the size of the infarction was assessed by 2,3,5-triphenyltetrazolamine chloride staining after 2 hours of reperfusion. Test animals, the mean arterial blood pressure of which was increased by 65 mm Hg with intravenous phenylephrine during the ischemia, were compared with control animals that remained normotensive. The laser Doppler perfusion imager (Lisca Developments Co., Linkoping, Sweden) scanned a 3-cm2 area of cortex with a resolution of 4 mm2 every 15 minutes. RESULTS MCA occlusion reduced rCBF to 71 +/- 2% of the control level (n = 24, P < 0.001). Hypertension (HTN) restored rCBF to 84 +/- 3% of the control level (n = 12, P < 0.01), but the HTN-induced improvement diminished with time, so that after 1 hour, there was no longer a significant difference between hypertensive and normotensive animals. HTN during the MCA occlusion caused a 97% reduction in infarct size (P < 0.05) in the animals subjected to 1 hour of occlusion but caused only a 45% reduction (P approximately 0.1) in the animals subjected to 2 hours of occlusion. CONCLUSION This study supports the use of HTN to minimize ischemic injury from short intervals of major intracranial vessel occlusion but fails to demonstrate protection when HTN is maintained during occlusions of more than 1 hour.
Beauty is in the soul of the beholder: psychological implications of beauty and African American women

The criteria for beauty in the United States are primarily based on Caucasian European American, middle-class standards. African American women tend to vary greatly from these criteria. Though very few studies have been conducted on the body image of Black women in the United States, historically, the physical images portrayed of African American women in the United States have not been positive. Mental health practitioners must understand how these negative images may affect the body image and self-esteem of African American women. Therapeutic and community interventions are discussed.
Strain-driven light-polarization switching in deep ultraviolet nitride emitters

Residual strain plays a critical role in determining the crystalline quality of nitride epitaxial layers and in modifying their band structure; this often leads to several interesting physical phenomena. It is found, for example, that compressive strain in Al${}_{x}$Ga${}_{1\ensuremath{-}x}$N layers grown on Al${}_{y}$Ga${}_{1\ensuremath{-}y}$N ($x$ $y$) templates results in an anticrossing of the valence bands at considerably much higher Al composition than expected. This happens even in the presence of large and negative crystal field splitting energy in the Al${}_{x}$Ga${}_{1\ensuremath{-}x}$N layers. A judicious magnitude of the compressive strain can support vertical light emission (out of the c-plane) from Al${}_{x}$Ga${}_{1\ensuremath{-}x}$N quantum wells up to $x$ \ensuremath{\approx} 0.80, which is desirable for the development of deep ultraviolet light-emitting diodes designed to operate at or below 250 nm with transverse electric polarization characteristics.
COSY with in-phase cross peaks☆

Abstract We have designed two pulse sequences that give rise to COSY-type spectra with in-phase multiplet structure. In these spectra, the cross peaks are absorptive and in-phase along both dimensions. Such 2D spectra are useful for quantitative measurements, such as measurement of the extent of H/D exchange in proteins and measurement of the concentrations of individual components in a series of mixtures. These spectra can also be used to emphasize cross peaks between weakly coupled protons.
Blunt notch strength of hybrid boron/glass/aluminum fiber metal laminates

The notch strength of high modulus hybrid fiber/metal laminates (FMLs) was investigated. The composite layers used in this material, which contain both boron fibers and S2-glass fibers, were adhesively bonded to 2024-T3 aluminum sheets and consolidated using an autoclave process. The results of tensile tests clearly showed that high modulus FMLs with a good ductility can be achieved by mingling of boron and glass fibers. The effects of notch sizes and constituents on the failure behavior were determined. The experiments showed that the notched hybrid FMLs exhibited excellent strength retaining characteristics even with the presence of large notches. Microscopy, X-ray radiography and chemical removal technique were used to examine the fracture characteristics of hybrid FMLs. A finite element analysis (FEA) model was established to analyze the notch behavior of hybrid FMLs. Experimental results of the blunt-notch strength are in good agreement with the stresses calculated by computational modeling of hybrid FMLs.
The Liver: An Integral Part of the Enteric Mucosal Immune System

The inclusion of the liver and biliary tract as an integral part of the enteric mucosal immune defense has come about in the past 5 years as a result of experimental studies in laboratory animals. The importance of secretory IgA and IgA immune complexes in the generation of an immune response and their participation in the immune exclusion of potentially pathogenic molecules and organisms are areas of active investigation. The transport of IgA and IgA immune complexes by the liver from serum to bile may provide another means of immune-mediated host defense against enteric pathogens.
Social Capital, Household Welfare and Poverty in Burkina Faso

This paper investigates empirically the importance of social capital, in the form of local associations and networks, for the welfare of rural households in Burkina Faso. It draws on a unique database combining standard information on household welfare with multidimensional measures of social capital. The analysis finds that higher levels of social capital are associated with higher household per capita expenditures and better access to credit. The distribution of social capital was found to be more equal than that of other assets. Poor households and those who own little land obtain a higher return from social capital than other households. Copyright 2002, Oxford University Press.
Liquidus temperature model for Hanford high-level waste glasses with high concentrations of zirconia

A study was conducted on glasses based on a simulated transuranic waste with high concentrations of ZrO{sub 2} and Bi{sub 2}O{sub 3} to determine the compositional dependence of primary crystalline phases and liquidus temperature (T{sub L}). Starting from a baseline composition, glasses were formulated by changing mass fractions of Al{sub 2}O{sub 3}, B{sub 2}O{sub 3}, Bi{sub 2}O{sub 3}, CeO{sub 2}, Li{sub 2}O, Na{sub 2}O, P{sub 2}O{sub 5}, SiO{sub 2}, and ZrO{sub 2}, one at a time, while keeping the remaining components in the same relative proportions as in the baseline glass. Liquidus temperature was measured by heat treating glass samples for 24 h in a uniform temperature furnace. The primary crystalline phase in the baseline glass and the majority of the glasses was zircon (ZrSiO{sub 4}). A change in the concentration of certain components (Al{sub 2}O{sub 3}, ZrO{sub 2}, Li{sub 2}O, B{sub 2}O{sub 3}, and SiO{sub 2}) changed the primary phase to baddeleyite (ZrO{sub 2}), while cerium oxide (CeO{sub 2}) precipitated from glasses with more than 3 wt% CeO{sub 2}. Zircon T{sub L} was strongly increased by Al{sub 2}O{sub 3}, ZrO{sub 2} and CeO{sub 2}, and slightly by P{sub 2}O{sub 5} and SiO{sub 2}; decreased strongly by Li{sub 2}O andmore » Na{sub 2}O and moderately by B{sub 2}O{sub 3}. A first-order model was constructed for T{sub L} as a function of composition for zircon primary crystalline phase glass.« less
Response to Johnson: Controversy remains: regulation of pH gradient across the thylakoid membrane

In our review [1] we addressed the mechanisms with which the chloroplast achieves the flexibility needed for both energy conversion and photoprotection under rapidly changing environmental conditions. Giles Johnson brings up two interesting points. First, he suggests that because linear electron flow (LEF) translocates fewer protons to the lumen than are needed to sustain the ATP:NADPH output balance needed for the Calvin–Benson cycle, this process should not produce a net proton motive force (pmf).
Three-dimensional nuclear magnetic resonance microimaging of trabecular bone.

The conventional approach to measuring structural parameters in trabecular bone rests on stereology from optical images, derived from sections of embedded bone. In order to provide data that are statistically representative of a sufficiently large volume, multiple sections need to be analyzed in each of the three orthogonal planes. In this work, an alternative technique is presented which is based on three-dimensional (3D) volumetric proton nuclear magnetic resonance (NMR) microimaging. The method presented provides images from 9 x 9 x 4 mm 3 volumes of defatted bone specimens in 15-20 minutes scan time at isotropic resolution corresponding to (78 μm) 3 voxel size. Surface-rendered images of bovine and human trabecular bone are shown and an algorithm was developed and implemented for determining the orientation and magnitude of the principal axes of the mean intercept length tensor. (J Bone Miner Res 1995 ;10 :1452-1461)
A Penalty Function Procedure for Sensitivity Analysis of Concave Programs

Given a concave program, consider its optimal objective value as a function of the right-hand side. The behavior of this optimal response function reflects the sensitivity of the objective value to changes in the right-hand side. A scheme involving the optimization of a penalty function is developed for determining the value and gradient of the optimal response function at points within a region of interest. This scheme is then applied to a simple example to illustrate its potential usefulness.
Local properties at interfaces in nanodielectrics: An ab initio computational study

First-principles computational methodologies are presented to study the impact of surfaces and interfaces on the dielectric and electronic properties of emerging technologically important systems over length scales of the order of inter-atomic distances. The variation of dielectric constant across Si-SiO2, Si-HfO2 and SiO2-polymer interfaces has been correlated to interfacial chemical bonding environments, using the theory of the local dielectric permittivity. The local electronic structure variation across Si-HfO2 and SiO2-polymer interfaces, including band bending, band offsets and the creation of interfacial trap states have been investigated using a layer-decomposed density of states analysis. These computational methods form the groundwork for a more thorough analysis of the impact of surfaces, interfaces, and atomic level defects on dielectric and electronic properties of a wide variety of nano-structured systems.
Fatty acids modulate protein kinase C activation in porcine vascular smooth muscle cells independently of their effect on de novo diacylglycerol synthesis.

Aims/hypothesis. Diabetes-induced activation of protein kinase C has been associated with the development of vascular complications. Elevated de novo diacylglycerol synthesis has been postulated to underlie this protein kinase C activation. Diabetes also increases the circulating concentrations of non-esterified fatty acids, which are immediate precursors of diacylglycerol through the de novo pathway. We hypothesized that increased fatty acids contribute to de novo diacylglycerol synthesis and activation of protein kinase C in vascular cells. Methods. Primary cultures of porcine carotid smooth muscle cells were exposed to fatty acids, bound to albumin in physiologic ratios. Diacylglycerol and triacylglycerol were measured in extracts of these cells. Protein kinase C activation was measured as membrane translocation with isoform-specific antibodies. Results. Saturated fatty acids caused considerable accumulation of diacylglycerol through de novo synthesis. Unsaturated fatty acids increased triacylglycerol, but not diacylglycerol. Platelet-derived growth factor activated the α, ɛ and ζ protein kinase C isoforms. Activation of the α and ζ isoforms was amplified by oleate pretreatment but inhibited by palmitate. In the absence of growth factor stimulation, neither palmitate nor oleate had any effect on the membrane/cytosol distribution of any protein kinase C isoform. Conclusion/interpretation. Saturated fatty acids elicited de novo diacylglycerol synthesis in vascular smooth muscle cells without activating protein kinase C. Effects of fatty acids on protein kinase C activation by platelet-derived growth factor did not correlate with the effects on de novo diacylglycerol synthesis. These results indicate that de novo diacylglycerol synthesis is, by itself, insufficient to activate protein kinase C. [Diabetologia (2000) 43: 1136–1143]
Surgical Management of Achilles Tendon Overuse Injuries: A Long-term Follow-up Study

We studied 79 cases of surgically treated Achilles tendon overuse injuries in 66 patients. Fifty-three (80%) of these patients were competitive or serious recreational runners operated on between 1978 and 1991. There were 49 men and 17 women with a mean age of 33 years (range, 17 to 59). The cases were divided into surgical subgroups based on their site of primary symptoms and abnormalities: paratenonitis (23), tendinosis (partial rupture or degeneration) (15), retrocalcaneal bursitis (24), insertional tendinitis (7), and combined abnormalities (10). Followup included a comprehensive patient questionnaire and office examination. There were 79% satisfactory (51% excellent, 28% good) and 21% unsatisfactory (17% fair, 4% poor) results. The percentages of satisfactory results in the paratenonitis group (87%) were best and those in the tendinosis group were the worst (67%). Satisfactory results were obtained in 75% of the patients with retrocalcaneal bursitis and 86% with insertional tendinitis. Seven of the 45 cases with longer than 5-year followup with initially satisfactory results deteriorated with time and required reoperation (16%). Of these, 4 were in the tendinosis group, 2 had retrocalcaneal bursitis, and 1 had paratenonitis. One of the 34 patients followed less than 5 years required reoperation.
A Graph Algebra for Scalable Visual Analytics

Visual analytics (VA), which combines analytical techniques with advanced visualization features, is fast becoming a standard tool for extracting information from graph data. Researchers have developed many tools for this purpose, suggesting a need for formal methods to guide these tools' creation. Increased data demands on computing requires redesigning VA tools to consider performance and reliability in the context of analysis of exascale datasets. Furthermore, visual analysts need a way to document their analyses for reuse and results justification. A VA graph framework encapsulated in a graph algebra helps address these needs. Its atomic operators include selection and aggregation. The framework employs a visual operator and supports dynamic attributes of data to enable scalable visual exploration of data.
Helping, manipulation, and magic

Louise A. Frey, MS, is Professor and Director of Continuing Education, School of Social Work, Boston Univer sity, Boston, Massachusetts, and Asso ciate Director of the Mental Health Continuing Education Consortium, Belmont. Golda M. Edinburg, MSW, is Director, Social Work Department, McLean Hospital, Belmont, Massa chusetts. A reexamination of the concept of disparate and unequal roles to the par "helping" is in order at a time when ties in helping transactions. Through manipulation, modification, and proan examination of these myths, better gramming are popular techniques in understanding of social work's an therapy, education, and training; when cient cultural origins may be possible, major psychic and behavioral change This could result in greater awareness is expected as the result of specialized of the elements of magic, "witchdoc experiences such as muscle relaxation, toring," and manipulation that are in screaming, and group vilification; herent in "helping." Efforts could then when the individual's emotions are exbe directed toward minimizing the in ploited by entrepreneurs promising fluence of superstition and irrational various benefits from their particular ity from the past. This is not an easy brand of experience; and when social task, for no one can escape the in workers are trying new techniques, usfluence of a cultural belief system. In ing new terms and acronyms, and subdeed, there is evidence that magical scribing to new schools of thought, beliefs and irrational faith are neces The wish to improve practice by sary for any healing to take place, broadening knowledge and considerSome of the dimensions of this di ing new ideas is laudable because it lemma will be examined by placing the forces a reevaluation of dearly held profession in its cultural context as a tenets and methods. There is a danger, healing myth and ritual, however, that new modes of helping Frank analyzes contemporary psy will be accepted uncritically, just bechotherapeutic intervention as a cul cause they appear to be similar to sotural myth which supports the belief cial work practice. Practitioners may that people have the ability to cope modify deliberately or drift away unwith life's stresses.2 He identifies the wittingly from the traditions of social therapeutic process as having four work values and methods. basic elements. The first is the special In this article the authors reaffirm kind of relationship between a patient tradition by examining the concept of and help-giver.
The Relationship Between Pubertal Timing and Delinquent Behavior in Maltreated Male and Female Adolescents

This study examined the relationship between pubertal timing and delinquent behavior across two time points in a sample of 303 maltreated and 151 comparison adolescents aged between 9 and 13 years at enrollment. The first aim was to examine the relationship between pubertal timing and delinquency for the total sample and then to test for gender differences using multiple group models. The second aim was to examine the interaction effect of pubertal timing and maltreatment on delinquency as well as gender differences for this interaction effect. Results showed that earlier pubertal timing was related to higher delinquency and this relationship was not significantly different for males and females. Maltreatment did not moderate the relationship between pubertal timing and delinquency for the total sample; however, there was evidence of a three-way interaction. These findings highlighted the need to examine contextual factors that may affect the amplification and direction of these relationships.
Structurating Activity Theory: An Integrative Approach to Policy Knowledge

This article presents a theoretical framework for investigating the communicative construction of policy knowledge. Research regarding public policy and organizational knowledge demonstrates the importance of these areas for organizational communication scholars. In light of this research, structurating activity theory is offered as an integration of structuration theory and cultural-historical activity theory (CHAT). Four theoretical constructs are discussed: (a) structuration through activity, (b) mediation of social activity, (c) contradictions as generative mechanisms, and (d) intersections of activity systems. Six propositions offer the explanatory significance of each construct, and then the theory is applied to a case study of the construction of special education policy knowledge. Additional applications of structurating activity theory are proposed and suggestions for future research directions are offered.
Atomistic Simulations of Damage Evolution in Silicon

We have studied the damage annealing process using kinetic lattice Monte Carlo (KLMC) and molecular dynamics (MD) with initial damage distribution from Monte Carlo ion implant simulations. MD calculations find a long range interstitial vacancy interaction, as also seen in previous tight-binding molecular dynamics (TBMD) simulations.1 The influence of the long range interaction as well as the initial spatial correlations present in the implant damage are then analyzed with KLMC in the form of corrections to the +1 model. We find that both long range interactions and the initial spatial correlations are significant at low doses, while the effects disappear at high doses.
Structurally ferroelectric SrMgF4. Erratum

In the paper by Abrahams (2002) Acta Cryst. (2002), B58, 34–37 two errors were printed. First, in the abstract the Curie temperature was incorrectly given as ∼1450 K. The correct value is ∼450 K. The second error occurs in section (a) of p. 36. The polar displacement expression is currently given as Δzl ≃ 1 A. The correct expression should be Δzi ≃ 1 A.
Pattern formation during vasculogenesis

Vasculogenesis, the assembly of the first vascular network, is an intriguing developmental process that yields the first functional organ system of the embryo. In addition to being a fundamental part of embryonic development, vasculogenic processes also have medical importance. To explain the organizational principles behind vascular patterning, we must understand how morphogenesis of tissue level structures can be controlled through cell behavior patterns that, in turn, are determined by biochemical signal transduction processes. Mathematical analyses and computer simulations can help conceptualize how to bridge organizational levels and thus help in evaluating hypotheses regarding the formation of vascular networks. Here, we discuss the ideas that have been proposed to explain the formation of the first vascular pattern: cell motility guided by extracellular matrix alignment (contact guidance), chemotaxis guided by paracrine and autocrine morphogens, and sprouting guided by cell-cell contacts.
The Resolution of d'Alembert's Paradox and Thermodynamic Admissibility

The d'Alembert paradox, annunciated in 1752, was established after it was shown that the result of a net zero drag, obtained by applying potential theory to the incompressible flow past a sphere, was in contradiction with experimental results which showed a positive drag. Interpreting the result as a flaw in the theory, resulted in the declaration of the paradox. Following d'Alembert, we assume a potential motion, and proceed to analyze the consequences of this assumption using the global principles of continuum mechanics. We show that if the fluid is inviscid, the potential motion is thermodynamically admissible, the drag is zero, and the motion can persist indefinitely. Although no conventional fluid is available to either falsify (or validate), this result experimentally, in principle, the theory could be tested by using a superfluid, such as liquid Helium. If the fluid is viscous, we show that the potential irrotational motion is thermodynamically inadmissible, it is in violation of the second law of thermodynamics, and hence such a motion cannot persist. Indeed, observations show that when a rigid body is impulsively set into motion, an irrotational motion may exist initially but does not persist. Any flow property which is derived from a thermodynamically inadmissible motion cannot be expected to be in agreement with experimental data. As an illustration we show that the drag, calculated from the viscous potential solution of the flow past a sphere, is zero. We submit that since the theory of continuum mechanics predicts that no agreement between results obtained from viscous potential theory and experimental data can be expected, there is no room for a paradox once a contradiction is in fact observed. In nature, or under experimental conditions, the nonpersistence of the thermodynamically inadmissible motion proceeds in a breakup of the irrotational motion which transforms into a rotational and obviously admissible motion. We show that by selecting boundary conditions, required in the solution of the differential equations of motion, such that they satisfy the Clausius–Duhem jump conditions inequality, the thermodynamic admissibility of the solution is a priori assured. We also show the vorticity distribution at the wall associated with the particular choice of boundary condition.
Adsorption of CO2 and N2 on synthesized NaY zeolite at high temperatures

NaY zeolite particles with a high surface area of 723 m2/g were synthesized by a hydrothermal method. Adsorption isotherms of pure gases CO2 and N2 on the synthesized NaY particles were measured at temperatures 303, 323, 348, 373, 398, 423, 448 and 473 K and pressures up to 100 kPa. It was found that the adsorption isotherm of CO2 on the synthesized zeolite is higher than that on other porous media reported in the literature. All measured adsorption isotherms of CO2 and N2 were fitted to adsorption models Sips, Toth, and UNILAN in the measured temperature/pressure range and Henry’s law adsorption equilibrium constants were obtained for all three adsorption models. The adsorption isotherms measured in this work suggest that the NaY zeolite may be capable of capturing CO2 from flue gas at high temperatures. In addition, isosteric heats of adsorption were calculated from these adsorption isotherms. It was found that temperature has little effect on N2 adsorption, while it presents marked decrease for CO2 with an increase of adsorbate loading, which suggests heterogeneous interactions between CO2 and the zeolite cavity.
Gas‐liquid‐fiber flow in a cocurrent bubble column

Effects of superficial gas velocity (Ul ≤ 10 cm/s), superficial liquid velocity (Ug ≤ 10 cm/s), and fiber mass fraction (0 ≤ C ≤ 2%) on gas holdup (ϵ) and flow regime transition are studied experimentally in well-mixed water-cellulose fiber suspensions in a cocurrent bubble column. Experimental results show that gas holdup decreases with increasing superficial liquid velocity when fiber mass fraction and superficial gas velocity are constant. Gas holdup is not significantly affected by fiber mass fraction in the range of C < 0.4%, but decreases with increasing fiber mass fraction in the range of 0.4% ≤ C ≤ 1.5%. The mechanisms behind the influences of superficial liquid velocity and fiber mass fraction on gas holdup in a gas-liquid-fiber bubble column are analyzed. The effects of gas distribution methods are also explained by comparison to previous results. The axial gas holdup distribution is shown to be a complex function of superficial gas and liquid velocities and fiber mass fraction. The drift-flux model is used to identify the flow regime transitions at different operating conditions. Three distinct flow regimes are observed when C ≤ 0.4%, but only two are identified when 0.6% ≤ C ≤ 1.5%. The superficial gas velocities at which the flow transitions from one regime to another are not significantly affected by Ul, and only slightly decrease with increasing C. © 2005 American Institute of Chemical Engineers AIChE J, 2005
Four Ecosystems, Four Questions

In the sandy savannas around the Great Lakes there lives a tiny butterfly called the Karner blue. It is a delicate beauty, but to see it you have to know where and when to look. The life of an adult is short – less than 2 weeks – and there aren’t as many as there used to be. In the past few decades the Karner blue population has dropped by 99%, and they are now found only in tiny remnants of their former range (Grundel et al. 1998). In part, the precipitous decline of this species is related to its feeding habits. The larvae of the Karner blue feed only on one plant, the wild lupine, and only in the northern portion of the wild lupine’s range. The butterfly is also preferential to grasslands with partial tree canopy, and this sensitivity to mixed sun and shade further limits its available habitat.
Palatalization/Velar Softening: What It Is and What It Tells Us about the Nature of Language

This study proposes an account both of the consonantal changes involved in palatalization/velar softening and of the fact that this change is encountered before front vowels. The change is a straightforward case of feature assimilation provided that segments/phonemes are viewed as complexes of features organized into the “bottle brush” model illustrated in example (4) and elsewhere in the text, and that the universal set of features includes, in addition to the familiar binary features, six unary features, which specify the designated articulator(s) for every segment (not only for consonants).