cssi/SciSciGPT-SciSciNet huggingface dataset:
Purine sensing by riboswitches

Structured mRNA elements called riboswitches control gene expression by binding to small metabolites. Over a dozen riboswitch classes have been characterized that target a broad range of molecules and vary widely in size and secondary structure. Four of the known riboswitch classes recognize purines or modified purines. Three of these classes are closely related in conserved sequence and secondary structure, but members of these classes selectively recognize guanine, adenine or 2'-deoxyguanosine. Members of the fourth riboswitch class adopt a distinct structure to form a selective binding pocket for the guanine analogue preQ(1) (7-aminomethyl-7-deazaguanine). All four classes of purine-sensing riboswitches are most likely to recognize their respective metabolites by utilizing a riboswitch residue to make a canonical Watson-Crick base-pair with the ligand. This review will provide a summary of the purine-sensing riboswitches, as well as discuss the complex functions and applications of these RNAs.
Epithelioid cell strains derived from rabbit peripheral blood.

SummaryMononuclear leukocytes obtained from rabbits by cardiac puncture, and purified of erythrocytes by gravity sedimentation in a gelatin solution and of platelets and polymorphonuclear leukocytes by filtration through nylon columns, gave rise to cell strains when cultured for 2 weeks. During serial passage, the emergent strains retained a diploid number of chromosomes and displayed a morphology ranging from the fusiform to the epithelioid. Similar cell strains were also initiated by culture of cells obtained by needle biopsy simulating cardiac puncture in the thoracic region. Contrariwise, cell populations could not be established from blood drawn from the exposed femoral artery. These observations cast doubt on previous reports which suggest that stable tissue culture cell populations were derived from cells of the blood. The use of aspiration material from the chest provides a simple and reproducible method of initiating primary cell strains from rabbits.
Experimental studies of the MIT 3.3-GHz relativistic klystron amplifier

We report experiments on a 3.3 GHz relativistic klystron amplifier. The MIT RKA has a compact and flexible design. The central component of this experiment is a novel compact input cavity in which an explosive emission electron gun is embedded. The electron gun generates a 5 kA, 350 kV annular electron beam with 1.9 cm radius and 2 mm thickness. The beam is confined by a 10 - 17 kG solenoidal magnetic field produced by a superconducting magnet. Up to 5% of beam current modulation has been observed. Magnetic and electric probes placed along the drift tube are used to study beam bunching. Theoretical calculations and MAGIC simulations show good agreement with experimental results.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Composition Differences at Surfaces Detected by Adsorption and Desorption of Radiotracers

A novel method for the detection of composition differences on solid surfaces is based on differences in the adsorption and subsequent partial desorption of a radiotracer by heterogeneities of the surface.
Relationship Violence Prevention Education in Schools: What's Working, What's Getting in the Way, and What are Some Future Directions

Abstract This article summarizes five K-12 school-based dating violence prevention curricula/programs that have gone through some form of evaluation and peer review. These programs were selected as a result of a broad and comprehensive review of the relationship violence literature that has been published in the past decade. Program objectives, components, outcomes, and evaluation procedures are compared and discussed. The programs that were reviewed were generally found to be not very effective at preventing relationship violence in the short term, and less effective in the long term, suggesting the need for more program depth, length, and a systematic, longitudinal process for collecting and analyzing data. Reasons for a lack of overall effectiveness in addition to suggestions for future programs and evaluations are discussed.
That Was a Good Story! Preliminary Construction of the Perceived Story Quality Index

The objective of this research was to develop a preliminary Perceived Story Quality Index to assess laypersons' views of story quality. Research to date has not employed a standard measure of perceived quality, nor reported whether different lay-raters judge stories similarly. The study involved systematically generating core dimensions of perceived story quality and addressing whether (a) lay-raters of different ages and genders evaluate story quality consistently and (b) multiple dimensions of story quality form a general factor (i.e., an index). Sixteen lay-raters judged 129 autobiographical and fictional stories. Analyses show that young and older men and women lay-raters judged story quality consistently (i.e., share an implicit theory) and that quality ratings form a unitary factor. This structure holds for both types of stories and is maintained across age and gender. The discussion focuses on the scope and limitations of the developed preliminary Perceived Story Quality Index.
Uniqueness of an Equilibrium in Infinite-Horizon Economies Subject to Taxes and Externalities

Abstract This paper verifies the uniqueness of an equilibrium for a class of stochastic infinite-horizon economies with capital that are subject to distortionary taxes or externalities. The proof develops the property of concavity for a nonlinear monotone operator whose fixed points correspond to equilibria. As the underlying monotone operator has been useful for establishing the existence of an equilibrium, and for computing an equilibrium, this approach also brings under one roof the study of existence, uniqueness, and approximation of an equilibrium in distorted economies. Journal of Economic Literature Classification Numbers: C60, H20.
Checklist of Diatoms from the Laurentian Great Lakes. II

An updated diatom (Bacillariophyta) checklist for the Great Lakes is provided. The present checklist supplants the preliminary checklist published in The Journal for Great Lakes Research in 1978 and effectively represents a 20-year update. A series of procedures were used in this update which included: a reexamination of taxa reported in the 1978 list, additions of taxa reported from the Great Lakes during the past 20 years, and a revision of taxonomy, commensurate with systematic and nomenclatural changes which have occurred primarily during the past 8 years. 1488 diatom species or subordinate taxa are considered to be correct reports from the Great Lakes out of the 2188 diatom entities reported in the list. Of the 124 genera reported 105 are considered to be names in current use. The number of diatom species reported represents a 16.5% increase and the number of genera reported represents a 78% increase over those reported in the 1978 checklist. 13% of the species reported and 32% of the genera reported are due solely to nomenclatural changes. Results indicate that Great Lakes diatoms are a biodiverse component of the ecosystem, commensurate with the wide range of habitats found in the system. The present checklist indicates that most of the newly added species are primarily benthic or periphytic in nature and these represent largely understudied habitats. These results suggest that the present checklist may only represent approximately 70% or less of the extant diatom flora of the Great Lakes system.
Throughput versus routing overhead in large ad hoc networks

Consider a wireless ad hoc network with n nodes distributed uniformly on [0, 1]2. The transport capacity (TC) of such a wireless network scales like √n. To achieve this, each node should serve about √n distinct information flows. So the routing table of each node should be of the order √n bits. We show that if the size of the routing table is restricted to be of the order O(nH(δ)), the maximum achievable pernode TC is O(nR(δ)) when the source-destination distance is n-δ/2. We show that R(δ) = min {1/2, δ/2 + H(δ)} - 1 is the optimal tradeoff.
Tissue compression is not necessary for needle-localized lesion identification

Abstract Background Tissue compression to enhance lesion visibility on radiography of needle-localized breast biopsy specimens is widely used. We hypothesized that compression is not necessary for detection of lesions on specimen radiography. Methods Forty-nine consecutive patients underwent needle-localization biopsies of 59 mammographic targets. All specimens were radiographed without and with compression. The films were later independently reviewed and compared with preoperative mammograms by 2 surgeons and a breast-imaging radiologist. The primary end point was identification of mammographic targets in noncompressed specimen radiographs. Results Twenty-nine targets were masses, 36 contained calcifications, and 14 contained previously placed clips. All mammographically localized lesions were identified on noncompressed views. Overall concordance for the 2 images was 100% for all 3 reviewers and 98% among reviewers. Conclusions Tissue compression before specimen radiography is not routinely necessary for target lesion identification.
Apical membrane limits urea permeation across the rat inner medullary collecting duct.

Urea diffuses across the terminal inner medullary collecting duct (IMCD) via a facilitated transport pathway. To examine the mechanism of transcellular urea transport, membrane-apparent urea (Pme) and osmotic water (Pf) permeabilities of IMCD cells were measured by quantitative light microscopy in isolated IMCD-2 tubules perfused in the absence of vasopressin. Basolateral membrane Pf, determined by addition of raffinose to the bath, was 69 ,um/s. Basolateral membrane Pri, determined by substituting urea for raffinose without change in osmolality, was 14 X iO-5 cm/s. Bath phloretin inhibited basolateral P.,,m, by 85% without a significant effect on Pf. The basolateral reflection coefficient for urea, determined by addition of urea in the presence of phloretin, was 1.0. These results indicate that urea crosses the basolateral membrane by diffusion, and not by solvent drag. In perfused tubules, the rate of cell swelling following substitution of urea for mannitol was significantly greater with bath than lumen changes. After correcting for membrane surface area, the basolateral membrane was twofold more permeable than the apical membrane. Conclusions: (a) in the absence of vasopressin, urea permeation across the IMCD cell is limited by the apical membrane; (b) the basolateral membrane contains a phloretin-sensitive urea transporter, (c) transepithelial urea transport occurs by movement of urea through the IMCD cell. (J. Clin. Invest. 1990.
Premelting base pair opening probability and drug binding constant of a daunomycin-poly d(GCAT).poly d(ATGC) complex.

We calculate room temperature thermal fluctuational base pair opening probability of a daunomycin-poly d(GCAT).poly d(ATGC) complex. This system is constructed at an atomic level of detail based on x-ray analysis of a crystal structure. The base pair opening probabilities are calculated from a modified self-consistent phonon approach of anharmonic lattice dynamics theory. We find that daunomycin binding substantially enhances the thermal stability of one of the base pairs adjacent the drug because of strong hydrogen bonding between the drug and the base. The possible effect of this enhanced stability on the drug inhibition of DNA transcription and replication is discussed. We also calculate the probability of drug dissociation from the helix based on the selfconsistent calculation of the probability of the disruption of drug-base H-bonds and the unstacking probability of the drug. The calculations can be used to determine the equilibrium drug binding constant which is found to be in good agreement with observations on similar daunomycin-DNA systems.
Sensitivity of Fish ATPases to Polychlorinated Biphenyls

IN spite of widespread concern about the possible hazards of polychlorinated biphenyls (PCBs)1–11, little is known about the physiological action of these materials. We have therefore examined the effect of PCBs on the ATPase enzyme system, which is known to be sensitive to chemically similar compounds such as DDT12–18.
The hippocampus and caudomedial neostriatum show selective responsiveness to conspecific song in the female zebra finch.

The perception of song is vital to the reproductive success of both male and female songbirds. Several neural structures underlying this perception have been identified by examining expression of immediate early genes (IEGs) following the presentation of conspecific or heterospecific song. In the few avian species investigated, areas outside of the circuit for song production contain neurons that are active following song presentation, specifically the caudal hyperstriatum ventrale (cHV) and caudomedial neostriatum (NCM). While studied in detail in the male zebra finch, IEG responses in these neural substrates involved in song perception have not been quantified in females. Therefore, adult female zebra finches were presented with zebra finch song, nonzebra finch song, randomly generated tones, or silence for 30 min. One hour later they were sacrificed, and their brains removed, sectioned, and immunocytochemically processed for FOS expression. Animals exposed to zebra finch song had a significantly higher density of FOS-immunoreactive cells in the NCM than those presented with other songs, tones, or silence. Neuronal activation in the cHV was equivalent in birds that heard zebra finch and non-zebra finch song, expression that was higher than that observed in the groups that heard no song. Interestingly, the hippocampus (HP) and adjacent parahippocampal area (AHP) were activated in a manner comparable to the NCM. These results suggest a general role for the cHV in song perception and a more specific role for the NCM and HP/AHP in facilitating recognition of and responsiveness to species-specific song in female zebra finches.
Atmospheric photooxidation of alkylbenzenes-I. Carbonyl product analyses

Abstract Six alkylbenzenes—toluene, p -xylene, m -xylene, o -xylene, 1,3,5-trimethylbenzene and 1,2,4-trimethylbenzene—were selected to investigate the carbonyl products resulting from OH-initiated oxidation of aromatic compounds. Experiments were conducted in both indoor and outdoor smog chambers under simulated atmospheric conditions. Both batch samples and 30 min interval samples were taken in the outdoor smog chamber experiments using 1 ppmV alkylbenzene, 0.67 ppm NO x and sunlight as the light source. A wide variety of carbonyl products were detected and identified using gas chromatography/mass spectrometric (GC/MS) detection by their O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine (PFBHA) derivatives. Among the observed carbonyl products are aromatic aldehydes, quinones, di-unsaturated 1,6-dicarbonyls, unsaturated 1,4-dicarbonyls, saturated dicarbonyls, hydroxy dicarbonyls, glycolaldehyde, hydroxy acetone, and possibly triones and epoxy carbonyls. Quantification was achieved using 13 C 3 -acetone as a gas-phase internal standard. The numerous carbonyl products detected in itself partially explain previous difficulties in balancing the reacted carbon. They also provide additional insight into the oxidation mechanism for aromatic compounds, which will be discussed in this paper.
Management of brain metastases from breast cancer by combination chemotherapy.

Since most patients with brain metastases from breast cancer have disseminated disease elsewhere and a dismal prognosis when treated by whole brain irradiation alone, we investigated the use of systemic chemotherapy in 66 such patients. Fifty-two percent (34 of 66 patients) demonstrated an objective response to this therapy which was similar to the results obtained in patients treated for extracranial metastases. Eighteen patients who subsequently had recurrence of brain metastases were successfully retreated with secondary chemotherapy. The median duration of remission in 34 responders was ten months. The median survival, from the time of chemotherapy for brain metastases, was 13.1 months in 34 responders (range 5–74+) vs. 3.0 months in 32 non-responders (P < 0.001).
The "Internet of Things": What It Is and What It Means for Libraries

The "Internet of Things" is a popular buzzword but a poorly understood concept. In short, it refers to everyday objects that can sense the environment around them and communicate that data to other objects and services via the Internet. This column will briefly explain what the Internet of Things is and how it might be useful for libraries. It will also discuss some of the problems with and objections to this technology. A list of currently available Internet of Things examples is also included.
Bilayer Graphene System: Current-Induced Reliability Limit

We investigate the key reliability limiting factors of bilayer graphene (BLG) under current stressing by examining the breakdown characteristics of BLG with chemical-mechanical planarization copper contacts. It is observed that dc current-induced thermal annealing helps to reduce the BLG-to-Cu contact resistance. Breakdown occurs with two noticeably different failure modes depending on local stressing current level, while copper contact damage dominates in scaled structure. The measured linear dependence of breakdown current on graphene width/length aspect ratio suggests Joule heating as the primary breakdown mechanism.
Regional Differences in Emphysema Scores and BAL Glutathione Levels in HIV-Infected Individuals

Study objectives: Evidence exists that HIV-seropositive individuals may be at increased risk for the development of precocious pulmonary emphysema. HIV infection is also associated with antioxidant deficiency in both the serum and lungs, and it is therefore possible that increased oxidant stress may contribute to parenchymal lung injury occurring in the setting of HIV. We sought to determine the regional distribution of emphysema and regional distribution of glutathione (GSH) concentrations among HIV-seropositive subjects with emphysema. Design: Cross-sectional evaluation of a prospective, longitudinal study. Setting: University teaching hospital. Subjects/measurements: HIV-seropositive subjects without AIDS-related pulmonary complications participating in a descriptive study of lung biology in HIV-seropositive individuals. Emphysema scoring and evaluation of emphysema lobar distribution was performed among 40 subjects with emphysema. Eleven subjects underwent BAL of the right middle lobe (RML) and right upper lobe (RUL) with measurement of epithelial lining fluid (ELF) GSH in each lobe. Results: We found that the mean emphysema scores were much higher in the upper lobes compared to the rest of the lung. Mean GSH levels were significantly greater in the RUL compared to the RML. The regional differences were present in both smokers and nonsmokers. Conclusions: We conclude that in the setting of HIV, emphysema is more prominent and lung GSH concentrations are higher in the upper lobes. We hypothesize that the increased GSH may represent a compensatory response to increased oxidant stress in the upper lobes. (CHEST 2004; 126:1439–1442)
A bovine herpesvirus type 1 mutant virus with truncated glycoprotein E cytoplasmic tail has defective anterograde neuronal transport in rabbit dorsal root ganglia primary neuronal cultures in a microfluidic chamber system.

Bovine herpesvirus type 1 (BHV-1) is an important component of the bovine respiratory disease complex (BRDC) in cattle. Following primary intranasal and ocular infection of cattle, BHV-1 establishes lifelong latent infection in trigeminal ganglia (TG). Upon reactivation from latency, the virus is transported from neuronal cell bodies in the TG to projected nerve endings in nose and cornea of latently infected cattle where the virus shedding occurs. This property of BHV-1 plays a significant role in the pathogenesis of BRDC and maintenance of BHV-1 in the cattle population. Recently, we have reported that a glycoprotein E (gE) cytoplasmic tail-truncated BHV-1 (BHV-1 gEAm453) did not reactivate from latency and was not shed in the nasal and ocular secretions of calves and rabbits. Here we describe the methods to establish rabbit primary dorsal root ganglia (DRG) neuron cultures in a microfluidic chamber system and to characterizein vitro anterograde and retrograde axonal transport properties of BHV-1 gE-deleted and BHV-1 cytoplasmic tail-truncated gEAm453 mutant viruses relative to BHV-1 gEAm453-rescued/ wild-type viruses. The results clearly demonstrated that whereas the BHV-1 gE-deleted, BHV-1 gEAm453, and BHV-1 gEAm453-rescued/wild-type viruses were transported equally efficiently in the retrograde direction, only the BHV-1 gEAm453-rescued/wild-type virus was transported anterogradely. Therefore, we have concluded that sequences within the BHV-1 gE cytoplasmic tail are essential for anterograde axonal transport and that primary rabbit DRG neuronal cultures in the microfluidic chambers are suitable for BHV-1 neuronal transport studies.
A family of ROP proteins that suppresses actin dynamics, and is essential for polarized growth and cell adhesion.

ABSTRACT In plants, the ROP family of small GTPases has been implicated in the polarized growth of tip-growing cells, such as root hairs and pollen tubes; however, most of the data derive from overexpressing ROP genes or constitutively active and dominant-negative isoforms, whereas confirmation by using loss-of-function studies has generally been lacking. Here, in the model moss Physcomitrella patens , we study ROP signaling during tip growth by using a loss-of-function approach based on RNA interference (RNAi) to silence the entire moss ROP family. We find that plants with reduced expression of ROP genes, in addition to failing to initiate tip growth, have perturbed cell wall staining, reduced cell adhesion and have increased actin-filament dynamics. Although plants subjected to RNAi against the ROP family also have reduced microtubule dynamics, this reduction is not specific to loss of ROP genes, as it occurs when actin function is compromised chemically or genetically. Our data suggest that ROP proteins polarize the actin cytoskeleton by suppressing actin-filament dynamics, leading to an increase in actin filaments at the site of polarized secretion.
Implementation Intentions Increase Parent–Teacher Communication Among Latinos

This research tested an implementation intentions intervention to increase parent–teacher communication among Latino parents of young children. Parents (n = 57) were randomly assigned to form implementation intentions or simply goal intentions to communicate with their child's teacher. They completed measures of communication and goal intentions immediately prior to the manipulation and after the manipulation for 6 consecutive weeks. Implementation intentions increased parent–teacher communication among parents with higher initial (premanipulation) goal intentions but not among those with lower initial goal intentions. The findings support existing work on the conditions for implementation intentions to work, and address an important aspect of Latino children's educational success.
Nuclear mechanics: lamin webs and pathological blebs.

Anomalies in the three-dimensional shape of the nucleus are associated with a number of genetic diseases. These shape distortions include lobulated structures, with localized bulges referred to as nuclear blebs. Blebbing can result from mutations in genes encoding lamin intermediate filaments that form the lamin cortex, a thin meshwork lining the nuclear envelope. However, the biophysical origins of nuclear blebs remain a mystery. A recent study by Funkhouser et al. provides a theoretical model in which the lamin cortex is modeled as a thin, inhomogeneous elastic shell. This model shows that partial segregation of different lamin sub-networks—each with distinct mechanical properties—can lead to shell morphologies similar to blebbed nuclei in living cells.
The Role of Self-Objectification in the Experience of Women with Eating Disorders

Objectification theory has linked self-objectification to negative emotional experiences and disordered eating behavior in cultures that sexually objectify the female body. This link has not been empirically tested in a clinical sample of women with eating disorders. In the present effort, 209 women in residential treatment for eating disorders completed self-report measures of self-objectification, body shame, media influence, and drive for thinness on admission to treatment. Results demonstrated that the internalization of appearance ideals from the media predicted self-objectification, whereas using the media as an informational source about appearance and feeling pressured to conform to media ideals did not. Self-objectification partially mediated the relationship between internalized appearance ideals and drive for thinness; internalized appearance ideals continued to be an independent predictor of variance. In accordance with objectification theory, body shame partially mediated the relationship between self-objectification and drive for thinness in women with eating disorders; self-objectification continued to be an independent predictor of variance. These results illustrate the importance of understanding and targeting the experience of self-objectification in women with eating disorders or women at risk for eating disorders.
TARP Performance in a Mobile World

Trust-aware routing protocol (TARP) has been proposed as a secure-trusted ad-hoc routing protocol. In TARP security is inherently built into the routing protocol where each node evaluates the trust level of its neighbors based on a set of attributes. In this paper, we study TARP performance using different mobility models. Three important mobility models are considered, namely, random waypoint, Manhattan grid and reference point group mobility (RPGM). The study shows the packet delivery ratio, network delay, routing overhead and the energy consumption versus mobility using the three different mobility models. The application of these models will enhance the realism of simulation to actual real life mobility in an urban or military setup scenario.
A Cholinergic Receptor Gene ( CHRM2 ) Affects Event-related Oscillations

We report genetic linkage and association findings which implicate the gene encoding the muscarinic acetylcholine receptor M2 (CHRM2) in the modulation of a scalp-recorded electrophysiological phenotype. The P3 (P300) response was evoked using a three-stimulus visual oddball paradigm and a phenotype that relates to the energy in the theta band (4–5 Hz) was analyzed. Studies have shown that similar electrophysiological measures represent cognitive correlates of attention, working memory, and response selection; a role has been suggested for the ascending cholinergic pathway in the same functions. The results of our genetic association tests, combined with knowledge regarding the presence of presynaptic cholinergic M2 autoreceptors in the basal forebrain, indicate that the cognitive processes required by the experiment may in part be mediated by inhibitory neural networks. These findings underscore the utility of electrophysiology and neurogenetics in the understanding of cognitive function and the study of brain-related disorders.
3-D Bayesian ultrasound breast image segmentation using the EM/MPM algorithm

In this paper, ultrasound breast image segmentation is improved by using the volumetric data available in neighboring slices. The new algorithm extends the EM/MPM framework to 3D by including pixels from neighboring frames in the Markov Random Field (MRF) clique. In addition, this paper describes a unique linear cost factor introduced in the optimization loop to compensate for the attenuation common to ultrasound images.
Yes, West, Brown and Enquist"s model of allometric scaling is both mathematically correct and biologically relevant

The WBE theory shows how the quarter-power scalings of metabolic rate and many other biological attributes have their origin in the fractal-like designs of resource distribution networks. These designs are based on three simple principles: (1) a space-filling network that branches hierarchically to supply all parts of the three-dimensional body; (2) body-size invariant terminal units, such as capillaries or leaf petioles; and (3) minimization of the energy and time required to distribute resources. The WBE model of the mammalian cardiovascular systems additionally shows quantitatively and realistically how the scalings of the structure and hydrodynamics solve the problem of distributing blood from a beating heart through elastic hierarchically branching arteries to body-size invariant capillaries. The model correctly predicts not only the scaling parameters and absolute values of many characteristics of mammalian cardiovascular systems that have been measured by biomedical researchers (see Table 1 in WBE), but also the values in the hypothetical numerical example proposed by K & K (see Table 1, below). By applying the fundamental principles listed above to other resource supply networks in different taxa of organisms, the WBE model explains the origin of the ubiquitous quarter-power scaling exponents that have puzzled biologists since the 1930s (e.g. Kleiber 1932; Peters 1983; McMahon & Bonner 1983; Calder 1984: Schmidt-Nielsen 1984).
DSont: DSpace to ontology transformation:

Semantic web facilitates the effective sharing and reuse of existing information. Institutional repositories (IRs) are built to organize and manage the intellectual output of an institute. They generally use relational databases for maintaining metadata of digital documents. The focus of this research is to share the information of an existing IR with other information systems for discovering common interests. To process the data in semantic context, a relational database needs to be transformed into an ontology. The existing relation to ontology transformation systems produces odd results if they are applied on an IR database because its schema is meta-schema. The proposed system first creates an intermediate database, having a normalized schema for the data model of an institute preserved in an IR database and then transforms it into an ontology. Finally semantic correspondence is established between entities of source and target ontologies in order to integrate them. The system has been implemented and...
Are wikis usable

Wikis are simple to use, asynchronous, Web-based collaborative hypertext authoring systems which are quickly gaining in popularity. In spite of much anecdotal evidence to the effect that wikis are usable by non technical experts, this has never been studied formally. In this paper, we studied the usability of a wiki through observation and problem-solving interaction with several children who used the tool to collaboratively author hypertext stories over several sessions. The children received a minimal amount of instruction, but were able to ask for help during their work sessions. Despite minimal instruction, 5 out of 6 teams were able to complete their story. Our data indicate that the major usability problems were related to hyperlink management. We report on this and other usability issues, and provide suggestions for improving the usability of wikis. Our analysis and conclusions also apply to hypertext authoring with non wiki-based tools.
A new finite-difference time-domain (FDTD) algorithm for efficient field computation in resonator narrow-band structures

It is pointed out that the finite-difference time-domain (FDTD) algorithm is a versatile method capable of solving a variety of problems from circuit component characterization to radiation analyses, but it exhibits slowness in convergence when employed for the study of resonant structures, because their transient responses often exhibit a ringing behavior for a long time. Here, an approach, called the FDTD-update algorithm, that can substantially improve the convergence properties of the FDTD method when used to compute the response of resonant type structures a single frequency at a time is described. The filtering behavior of the algorithm is demonstrated by considering the problem of coupling into a cavity. Application to other problems is illustrated by solving the microstrip patch antenna configuration, for which the update algorithm is shown to enhance the accuracy of the results. >
Prader-Willi Syndrome and Scoliosis

Of 37 patients with the Prader-Willi syndrome for whom spinal x-rays were available, 32 had a structural scoliosis of 10 degrees or greater. Kyphosis was also found to be more common in older persons with this syndrome, occurring in only one of 14 adolescents but in five of 10 adults. The scoliosis was analyzed in infantile, juvenile, adolescent and adult subgroups. The results suggest that the scoliosis is present from an early age and remains stable during childhood, but progresses in 15 to 20 per cent of cases during adolescence. Scoliosis in patients with Prader-Willi syndrome has many of the clinical characteristics encountered in idiopathic scoliosis. Because it is difficult to detect in these individuals, the authors recommended that baseline spinal X-rays be obtained in all such patients who have suspicious asymmetry of the spine, followed by regular clinical examination, especially during adolescence.
Thermodynamical treatment of nuclear surface energy

A thermodynamic treatment of nuclear surface energy which leads to an explicit expression for the surface tension is suggested. The theory is based on a comparison between the Gibbs model and a detailed thermodynamic treatment of the surface region.
Long-Term Assessment of the Effects of Transgenic Bt Cotton on the Abundance of Nontarget Arthropod Natural Enemies

Abstract A 6-yr field study assessed the long-term impact of Bt cotton producing the Cry1Ac δ-endotoxin on 22 taxa of foliar-dwelling arthropod natural enemies in Arizona. No chronic, long-term effects of Bt cotton were observed over multiple generations of nontarget taxa. Zero-2 taxa declined significantly in unsprayed Bt compared with non-Bt cotton each year. In contrast, positive control studies showed that insecticide applications for caterpillars and other pests in both non-Bt and Bt cotton had much greater negative effects on 10 taxa. Multivariate principal response curves supported the findings of univariate analyses for the entire natural enemy community, showing no effect of Bt cotton but large and long-lasting negative effects from the use of insecticides. Multi-year analyses provided greater statistical power and indicated significant reductions that averaged 19% in five arthropod predator taxa in unsprayed Bt compared with non-Bt cotton. Most of these reductions were likely associated with red...
Cross-validation of data in SAXS and cryo-EM

Cryo-Electron Microscopy (EM) and Small Angle X-ray Scattering (SAXS) are two different data acquisition modalities often used to glean information about the structure of large biomolecular complexes in their native states. A SAXS experiment is generally considered fast and easy but unveiling the structure at very low resolution, whereas a cryo-EM experiment needs more extensive preparation and post-acquisition computation to yield a 3D density map at higher resolution. In certain applications, one may need to verify if the data acquired in the SAXS and cryo-EM experiments correspond to the same structure (e.g., prior to reconstructing the 3D density map in EM). In this paper, a simple and fast method is proposed to verify the compatibility of the SAXS and EM experiments. The method is based on averaging the 2D correlation of EM images and the Abel transform of the SAXS data. The results are verified on simulations of conformational states of large biomolecular complexes.
Duplex Comb in the Chicken: A Multi-Allelic Trait

Allelism at the duplex comb locus was studied by means of crosses between the Sicilian Buttercup and La Fleche breeds of chickens and two single combed breeds. The horn V-shaped duplex comb of the La Fleche was shown to be inherited as an incomplete dominant when crossed with single comb birds, and it exhibited complete penetrance and a strong expression of duplex. The buttercup duplex comb of the Sicilian Buttercup in similar crosses was also shown to be inherited as an incompletely dominant trait, but with this type comb penetrance was reduced by 32% in females and its expression of duplex was greatly reduced when compared with the La Fleche. When the duplex comb types were crossed to each other, the V-shaped comb showed complete dominance over the buttercup comb. It is proposed that there are at least three alleles at the duplex locus: D (v-type) greater than Dc (buttercup type) greater than d+ (non-duplex type). The most dominant allele (Dv) causes both doubling of the comb and suppression of its tissue mass, while the less dominant allele (Dc) only causes doubling of the comb.
Proteins of Heart in Experimental Cardiac Hypertrophy in the Rat.

SummaryProtein fractions of hearts from rats in which cardiac hypertrophy was produced by exposure to elevated environmental temperature and reduced atmospheric pressure were studied. Increases occurred in all fractions but in a disproportionate manner. Largest increases were observed in the following fractions: (1) I5, due in part to an apparent increase in myoglobin, (2) in the contractile Fraction II β, due in part to appearance of a component not normally demonstrated, and (3) in the mitochondrial fraction. It is suggested that these changes represent an adaptation to work demands placed upon the heart under experimental conditions.
The production of migration inhibitory factor by nonimmune guinea pig lymphoid cells incubated with concanavalin A.

SummaryMigration inhibitory factor (MIF) is produced upon concanavalin A (Con A) stimulation of nonimmune lymphoid cells. This production is specific for the α-1, 4-arabinopyranoside affinity of the Con A as demonstrated by the inhibitory effect of methyl-α-D-mannoside. Con A-induced MIF synthesis is puromycin sensitive. Con A-induced MIF can be separated from Con A by column chromatography through Sephadex G-200. This mitogen-induced mediator seems to have approximately the same molecular weight as the antigen-induced MIF as measured by gel filtration. MIF can be produced by lymph node cells in the presence of serum supplemented media. Spleen cells do not require serum-supplemented media to produce Con A-induced MIF.
Climatic data-based analysis of boll weevil (Coleoptera: Curculionidae) overwintering survival and spring emergence

Analysis of data from a 15-yr study, composed of 97 boll weevil cohorts from overwintering habitats in the Rolling Plains of Texas, showed that overwintering survivorship and spring/summer emergence were influenced by the day of the year ( DOY ) when the weevils entered overwintering habitat ( DOY in), the amount of rainfall, and habitat temperatures experienced by the weevils during diapause. The earlier the date that weevils entered overwintering habitat or the greater the amount of rain occurring before emergence of the 1st weevil, the greater the positive degree-days (>6.1°C) required for weevils to emerge from overwintering habitat. There was no significant correlation between the timings of weevil emergence and the winter severity, measured in terms of negative degree-days(<0.0°C). Multiple least squares regression analyses describing the positive degree-days required for the weevils to start emergence ( DD start) and the time required for all weevils to emerge (duration of emergence) ( DD emerg) explained 88 and 77% of the variability in the data, respectively. With independent data, 75 and 36% of the variability were explained for DD start and DD emerg, respectively. Overwintering survival ranged from 0 to 50% in the 15-yr study. Survivorship was positively correlated with DOY in, and negatively correlated with NDD start and DD start. Multiple regression analysis with DOY in, negative degree-days, rainfall, positive degree-days, and their 1st order interactions explained 99% of the variability in overwintering survival. With independent data, 74% of the variability was explained by the survival function. A chi-square test for goodness-of-fit showed that 74% of the survival estimates did not differ significantly from their observed values. In contrast, when compared with independent data, 37% of the survival estimates did not differ significantly from their observed values. The spring/summer emergence pattern for the overwintering weevils was described by a sigmoid function that explained 95 and 92% of the variability for the verification data set and the independent data set, respectively. Boll weevil overwintering emergence patterns can be predicted with considerable accuracy, but greater knowledge of factors affecting boll weevil overwintering survival and the time to completion of emergence is required for these to be predicted accurately.
Studies of nondegenerate, quasi-phase-matched optical parametric amplification

We have performed extensive numerical studies of quasi-phase-matched optical parametric amplification with the aim to improve its nondegenerate spectral bandwidth. Our multi-section fan-out design calculations indicate a 35-fold increase in spectral bandwidth.
Targeting miR-200c to Ameliorate Diabetes-Induced Endothelial Dysfunction

Endothelial dysfunction is one of the earliest manifestations of diabetes that can lead to numerous debilitating micro- and macrovascular complications (1,2). Identifying factors that mediate or augment endothelial dysfunction in diabetes can lead to the development of much-needed therapies that target early stages of various vascular complications and thereby prevent further progression. Chronic endothelial dysfunction includes impaired endothelium-dependent vasorelaxation (EDR), increased inflammation, and dysregulation of vascular remodeling (1–3). Inactivation or reduced bioavailability of gasotransmitter nitric oxide (NO), also known as EDR factor, is a key factor involved in the development of vascular diseases such as hypertension and atherosclerosis (1,4), which are accelerated under diabetic conditions. NO is produced by endothelial NO synthase (eNOS), and several studies have demonstrated increased oxidative stress, eNOS uncoupling, and reduced NO bioavailability under diabetic conditions (1–4). In addition to NO, endothelial cells (ECs) also produce several prostanoids with vasodilator and vasoconstrictor activities (5) mainly via the actions of the cyclooygenase enzymes COX-1 and COX-2. A fine balance between the levels of these prostanoids contributes to normal EDR. COX-2 produces both prostacyclin (PGI2), which reduces platelet aggregation, and prostaglandin E2 (PGE2), which can reduce EDR. In diabetes, high glucose (HG)-induced oxidative stress and reactive oxygen species (ROS) increase the expression of COX-2 and prostaglandin H2 (PGH2), a common precursor of prostaglandins. However, HG-induced ROS inhibit further metabolism of PGH2 into the vasodilator PGI2 via inhibition of PGI …
Testing of an improved design nitrogen heat pipe thermal intercept for current leads

With the increasing use of cryocoolers to cool superconducting magnets, attention is being focused on the problem of providing a thermally efficient intermediate heat sink for the current leads which also provides electrical isolation. The thermal intercept is a critical component for low heat leak HTS current leads because it significantly reduces the refrigeration requirement. Usually these two requirements are mutually exclusive for solid dielectric materials and one must accept a poorer thermal interface if electrical isolation is required. Further, the traditional methods of vapor cooled leads are not an option in a system cooled by a cryocooler because cryogens are usually absent. A novel method, developed at Los Alamos National Laboratory (LANL), utilizing gravity assisted heat pipes has been shown to circumvent this problem. We describe the fabrication and testing of a nitrogen-filled heat pipe for cooling of a current lead while providing electrical isolation. Previous efforts by our group at LANL had successfully produced a similar device but there were problems in creating and maintaining a reliable epoxy seal under the high pressure of the nitrogen gas and the stress of thermal cycling. A modified design and assembly method has helped but not completely solved the problem. Measurements of the thermal performance along with results from our heat pipe thermal model are presented. Peak heat transfer rates exceeding 150 watts were observed with good agreement with the thermal model. Testing of the electrical isolation between the heat pipe and the current lead was also performed and exceeded 1500 volts.
Osteoporosis as a pediaric disease : role of calcium and heredity

Osteoporosis is characterized by a reduction in bone mass. This reduction may be determined during growth or acquired in later life. Since osteoporosis is easier to prevent than to treat, the goal is therefore to identify individuals who might be at high risk. We suggest that the identification of those individuals should start in childhood and adolescence. Calcium intake and skeletal modelling/turnover are the most important determinants of calcium balance during this age period. Adequate calcium supply should contribute to peak bone mass and therefore prevention of osteoporosis later in life
The complexes in pregnancy

Abstract Seventeen patients during the third trimester of pregnancy with associated immune complex disease and/or immune complex state and their infants' cord blood were investigated for the presence of immune complexes. In comparing maternal levels of immune complex in normal third-trimester pregnancies to the study group, no statistical significant difference was noted. However, levels in cord blood were significantly lower (p
A two-stage approach to induction and intubation of two infants with Pierre Robin Sequence using a LMA Classic™ and Air-Q®: two cases report

The laryngeal mask airway (LMA) Classic™ and Air-Q® are supralaryngeal devices used for airway management in routine and difficult pediatric airways. We describe a novel two-stage technique of insertion of the LMA Classic™ awake prior to induction of anesthesia, to assure oxygenation and ventilation, and after induction removal and placement of the Air-Q® for intubation using the flexible fiberoptic bronchoscope. The LMA Classic's™ pliable design and relatively small size allow it to be easily placed in awake infants. In contrast, the Air-Q® is an excellent device for intubation because of its larger internal diameter and removable 9 mm adapter. Our goal was to reduce unpredictability and potentially increase the safety of induction of anesthesia and intubation in infants with Pierre Robin sequence. By using these devices in a two-stage approach we created a technique for consistent oxygenation, ventilation, and intubation in these infants.