cssi/SciSciGPT-SciSciNet huggingface dataset:
Generalized Average Modeling of Dual Active Bridge DC–DC Converter

Full-order continuous-time average modeling and dynamic analysis of bidirectional dc-dc dual active bridge (DAB) converters are studied. The transformer current in DAB converter is purely ac, making continuous-time modeling difficult. The proposed full-order continuous-time average model uses the dc terms and first order terms of transformer current and capacitor voltage as state variables, resulting in a third-order model, if capacitor equivalent series resistance (ESR) is not considered, and a sixth-order model if ESR is considered. A control-to-output-voltage transfer function is derived for DAB converters. Experimental results confirm that the proposed model correctly predicts the small-signal frequency response and an even more accurate prediction can be obtained if capacitor ESR is taken into account.
CATECHOLAMINES IN NON-NEURAL CELLS OF THE CNS: A POSSIBILITY

Publisher Summary This chapter elaborates the catecholamines in non-neural cells of the CNS. The non-neural nature of some catecholamine-containing cells in the brain may contribute to the problems encountered in determining the physiological role of these compounds and to the controversy regarding dopamines role in gonadotrophin secretion. The small dopamine cells of the arcuate nucleus (AN) are at best atypical neurons in that they do not form synapses. That is, using either the standard gluteraldehyde-Os04 procedure or the ethanolic-phosphotungstic acid stain, no synaptic profiles were observed in median eminence either between axon and axon, or between axon and dendrite. The efferent cell processes of AN, appear to terminate adjacent to perivascular spaces. The situation in the AN can be contrasted with the substantia nigra-corpus striatum dopaminecontaining neurons which do form morphological synapses. There is the extreme resistance of AN dopamine to the depleting effect of 6-hydroxy-dopamine. In experiments involving chronic third ventricle cannulation in rats, high doses of 6-OHDA delivered directly into the third ventricle reduced hypothalamic norepinephrine levels to less than 10% of normal.
SmartGate: a smart push-pull approach to support role-based security in web gateways

Efficient and effective web gateways or proxy servers are important to control the access privileges of users and protect private networks that are connected to the Internet, thus providing a productive and safe web environment. Access control in the form of complex access rules based on users or user sets (groups) has been studied extensively. The objective of this work is to provide role-based (RB) security for web gateways utilizing Role-Based Access Control (RBAC). RB security reduces the administrative burden, provides fine grained access control and supports various constraints such as context-aware and temporal seamlessly.In this paper we elaborate on the problems, issues that need to be addressed, and our approach for providing RB security for web gateways by leveraging the flexibility and expressiveness of RBAC. Our approach enables the proxy server to act smarter, rather than just allow or deny access based on access rules, meanwhile preserving the principle of least privileges.
HEMODYNAMICS OF ENDOTOXIN SHOCK IN NEWBORN PUPPIES

Reports on neonatal hemodynamics in Endotoxin shock(ETX) are sparse. This study reports 58 newborn mongrel puppies, 260-800 grams in whom cardiac output(CO), mean arterial pressure(MAP), systemic vascular resistance(SVR), and minute work(MW), were measured q10 min. in controls (N=30) and 2 experimental groups receiving Ecoli(ETX) at a dosage of 1.5 mg/kg(group A=15), and 10 mg/kg(group B=13). RESULTS: MAP: fell below controls at 50 min. in group B, and at 70 min. in group A with parallel fall thereafter. CO: decreased immediately to 60% of control in both groups, and continued to decrease throughout the experiment, with gradual convergence of both groups at 120 min. SVR: rose to 200% in both groups A and B, and remained elevated throughout. MW: fell in both groups to 55% of control. SUMMARY: Newborn puppies respond to ETX with ↓ CO, ↓ MW, ↑ SVR, and late ↓ MAP, in contrast to adults subjects. Quantifications of interventions are now possible with this model.
The p75NTR tumor suppressor induces caspase-mediated apoptosis in bladder tumor cells

p75NTR was identified as a tumor and metastasis suppressor that functions in part via induction of apoptosis in tumor cells. To examine p75NTR-dependent apoptosis in tumor cells, we demonstrated that a dose-dependent increase in p75NTR expression was associated with a concomitant increase in the mitochondrial proapoptotic effector proteins Bad, Bax and Bik and a decrease in the mitochondrial prosurvival effector proteins phospho-Bad, Bcl-2 and Bcl-xL. Significantly, p75NTR-dependent induction of cytochrome c release from the mitochondria occurred during CHX potentiation of apoptosis. Furthermore, p75NTR expression largely suppressed expression of IAP-1 and induced cleavage of procaspase-9 and procaspase-7 but not of procaspases 2, 3, 6, 8 and 10. A specific peptide inhibitor of procaspase-9 cleavage also inhibited cleavage of procaspase-7, indicating that caspase-7 is downstream of caspase-9. As end points of apoptosis, we observed p75NTR-dependent annexin V binding to the plasma membrane, an indicator of early apoptotic events, and Hoechst staining of DNA nuclear fragmentation, an indicator of late apoptotic events, whereas control tumor cells that lack expression of the p75NTR protein did not exhibit either of these apoptotic markers. Together, these results delineate the mitochondria-mediated apoptotic pathway of the p75NTR tumor-suppressor gene product. © 2003 Wiley-Liss, Inc.
In-office unsedated transnasal balloon dilation of the esophagus and trachea.

PURPOSE OF REVIEW Since the advent of ultrathin flexible endoscopes with working channels office-based esophagoscopy and tracheobronchoscopy have been undertaken frequently by otolaryngologists. As a natural extension of these diagnostic procedures, more office-based esophageal and tracheal therapeutic procedures are being undertaken. RECENT FINDINGS Esophageal and tracheal balloon dilation can be performed in the unsedated patient using a transnasal approach. These transnasal techniques have not been described in the recent literature. Esophageal balloon dilation is a well-accepted technique for gastrointestinal endoscopists, and recent literature has focused on indications (such as cricopharyngeal dysfunction) and the development of removable stents for prevention of restenosis. Pulmonary balloon dilation is likewise well accepted, with recent literature focusing on the timing of intervention and the incidence of tracheobronchial laceration. SUMMARY Office-based esophageal and tracheal balloon dilations in unsedated patients are newly described techniques made possible with thin-caliber transnasal endoscopes.
Electron Diffraction and High‐Resolution Electron Microscopy of Mineral Structures

This book is a well-written English translation of the original 1981 Russian edition, Strukturnoye issledovaniye mineralov metodami mikrodifraktsii i elechtronnoi mikroskopii vysokogo razresheniya. The 1987 English version has been extensively updated and includes references up to 1986. The book is essentially a text on the theoretical and experimental aspects of transmission electron microscopy and has chapters on the reciprocal lattice, electron diffraction (both kinematic and dynamic), and high-resolution electron microscopy. Electron diffraction is emphasized, especially its use for structure analysis of poorly crystalline and fine-grained phases not readily determined by the more exact X ray diffraction method. Two methods of electron diffraction are discussed: selected area electron diffraction (SAED) and oblique-texture electron diffraction (OTED); the latter technique is rarely used in the west and is never discussed in western electron microscopy texts. A SAED pattern is formed by isolating a small micrometer-size area with an aperture and obtaining single-crystal patterns from the diffracted beams. By tilting the sample and obtaining many patterns, a complete picture of the reciprocal lattice can be taken. An OTED pattern is formed when the incident electron beam passes through an inclined preparation consisting of a great number of thin platy crystals lying normal to the texture axis (axis normal to the support grid). To form an OTED pattern, the plates must all lie on a common face, such as a basal plane in phyllosilicates. Upon tilting the plates, an elliptical powder diffraction pattern is formed. Intensities measured from these patterns are used for a structural analysis of the platy minerals.
Limits of 3D dipole localization and orientation estimation for single-molecule imaging: towards Green’s tensor engineering

The 3D orientation and location of individual molecules is an important marker for the local environment and the state of a molecule. Therefore dipole localization and orientation estimation is important for biological sensing and imaging. Precise dipole localization is also critical for superresolution imaging. We propose and analyze wide field microscope configurations to simultaneously measure these parameters for multiple fixed dipole emitters. Examination of the images of radiating dipoles reveals how information transfer and precise detection can be improved. We use an information theoretic analysis to quantify the performance limits of position and orientation estimation through comparison of the Cramer-Rao lower bounds in a photon limited environment. We show that bi-focal and double-helix polarization-sensitive systems are attractive candidates for simultaneously estimating the 3D dipole location and orientation.
Changing Social Work Students' Attitudes toward Substance Abusers through the Use of an Abstinence Assignment: A Pilot Study.

ABSTRACT Per se, increased knowledge about substance abuse has not been effective in altering social workers' negative attitudes towards substance abusers or their failure to recognize or address substance abuse problems among clients. In this paper, we describe an experiential abstinence assignment integrated with the content of an elective substance abuse course. This abstinence assignment served as a simulation of what clients in treatment for substance abuse experience. At the end of the course, most students reported they gained new personal insight and understanding on addictions and developed more empathy for addicts as a result of the abstinence experience. More rigorous research is recommended to assess the impact of this abstinence assignment on social workers' willingness to serve and awareness of clients who abuse substances.
N,N-DIMETHYLSPHINGOSINE INHIBITION OF SPHINGOSINE KINASE AND SPHINGOSINE 1-PHOSPHATE ACTIVITY IN HUMAN PLATELETS

Potential sphingosine (Sph) metabolites include phosphorylated, N-acylated, and N-methylated derivatives. Phosphorylated Sph, i.e., sphingosine 1-phosphate (Sph-1-P), may act as an autocrine stimulator of blood platelets, as it is abundantly stored in platelets and released extracellularly and its exogenous addition induces platelet activation. In this study, we evaluated Sph-1-P formation and its effects in human platelets in the presence of other Sph metabolites. On addition of [3H]Sph to intact platelets, the label was rapidly converted to Sph-1-P. This conversion into [3H]Sph-1-P was inhibited by N,N-dimethylsphingosine (DMS) in a dose-dependent manner, but not by other structurally related Sph derivatives, including ceramide. The inhibition of Sph-1-P formation by DMS was reproduced using a cell-free system (Sph kinase obtained from platelet cytosolic fractions) and much stronger than that by dl-threo-dihydrosphingosine, which had been considered to be the strongest inhibitor of Sph kinase. Administr...
The pitfalls of cross-cultural research

T he substantive core of the book under review is a presentation of the results of an empirical study conducted jointly by Russian and American researchers in the late 1980s and early 1990s in Russia and the United States. The subject matter of the research project was a crossnational study of the "legal socialization" of Russian and American youth. "Legal socialization," says the author, "has been defined as the development of values, attitudes, and behaviors toward law. ''1 The study was conducted in two stages: during the initial stage (1987-1989) a total sample of 288 children and youths were surveyed, half from the United States and half from what was then Soviet Russia. The sample population comprised roughly equal numbers of delinquent and nondelinquent males and females. 2 The second stage (October-December 1992) focused on 425 Russian youths from five locations
An Ear-Core Interaction Regulates the Recruitment of the AP-3 Complex to Membranes

Abstract AP-3 is a heterotetrameric adaptor involved in the biogenesis of lysosome-related organelles. The function of AP-3 as an adaptor relies on its ability to bind to membranes in an Arf-dependent fashion and to recognize sorting signals in the cytosolic tails of the transmembrane cargo. Here, we report an interdomain interaction involving the ear domain of the δ subunit and the σ3 subunit of AP-3. This interaction interferes with the binding of AP-3 to Arf but not to dileucine-based sorting signals. As a consequence, the δ-ear inhibits the recruitment of AP-3 to membranes both in vitro and in vivo and impairs the sorting of lysosomal membrane proteins. These observations suggest a new regulatory mechanism for the recruitment of AP-3 to membranes involving δ-ear-σ3 interactions.
The Ear and Leaf-Stalk Contents of Corn Forage as Factors in Silage Evaluation

Summary And Conclusions Determinations of the dry-matter content and yields of the ear and leaf-stalk portions of corn forage at stages ranging from early-silage to advanced-silage condition were carried out during five successive seasons. High correlations were found between the percentage dry-matter content of the forage and the ear content of the forage. The data make it possible to estimate with a high degree of precision the ear content of corn forage or corn silage having a known dry-matter content. A procedure is presented for making this estimate and converting it into terms of farm commodities, namely, bushels of ears and pounds of hay equivalent, to which market prices may be applied.
Intensive Production of Guadalupe Bass

Abstract A study was conducted to determine if the threatened Guadalupe bass (Micropterus treculi) could adapt to fish hatchery production. Five hormone-injected fish (one female and four males) stocked in a 0.04-hectare spawning pond produced about 1,200 harvestable fingerlings. The fish were size-graded into three classes and stocked into indoor rectangular tanks. Fingerlings, 22-45 mm total length and 0.32-1.02 g, were trained to consume formulated feed in a simulated production environment. They received 1.0-1.5-mm-diameter semi-moist pellets at a rate greater than 48% of the stocked biomass per day throughout the 24-d training period. Training success for the three size classes was 96.4, 97.6, and 100.0%. Growth rates during and following training were similar to those of other Micropterus species. These results indicate that the Guadalupe bass will adapt to fish hatchery conditions and can be produced to supplement depleted native populations.
Finally, Polyubiquitinated PCNA Gets Recognized

Studies from Ciccia et al. (2012) and Yuan et al. (2012) in this issue of Molecular Cell, together with Weston et al. (2012), reveal that the translocase ZRANB3/AH2 can recognize K63-linked polyubiquitinated PCNA and plays an important role in restarting stalled replication forks.
Scaled-energy Floquet spectroscopy in a strong electric field: A semiquantal calculation of the recurrence spectrum

We consider a hydrogen atom in a strong static electric field with a weak parallel radio-frequency (rf) field. We compute the photoabsorption spectrum by calculating the spectrum of Floquet states, including their quasienergies and their oscillator strengths. Our calculation is based upon ``semiquantal'' formulas: we calculate the discrete spectrum of quasienergy states by using a quantum adiabatic approximation combined with semiclassical (Bohr-Sommerfeld) quantization rules. We express this spectrum in a manner consistent with the method of scaled-variable spectroscopy, and then calculate the Fourier transform. These calculated absorption spectra and recurrence spectra are in good agreement with experiments on Li atoms. Additional approximations show that the recurrence spectrum is approximately equal to the product of the recurrence spectrum in a static field times an envelope function. That envelope function is the Fourier transform of a cluster of sidebands surrounding a progenitor level in the rf field. The resulting formula agrees with the low-frequency limit of a formula obtained from a semiclassical treatment.
Prostaglandin endoperoxide synthetase-mediated metabolism of carcinogenic aromatic amines and their binding to DNA and protein.

The arachidonic acid-dependent metabolism of the carcinogens, 2-naphthylamine, 4-aminobiphenyl, 2-aminofluorene, benzidine, and N-methyl-4-aminoazobenzene was mediated by a prostaglandin endoperoxide synthetase preparation. Phenacetin, a suspected carcinogen, was not a substrate but its deacetylated metabolite, p-phenetidine, was rapidly oxidized. For each arylamine, extensive metabolism (14–81%) was observed, resulting in high levels of products bound covalently to protein. A low level of binding to added DNA was also detected for each substrate, except p-phenetidine and N-methyl-4-aminoazobenzene. Chromatography of the ethyl acetate-extractable metabolites indicated that the major products were N-oxidized and/or C-oxidized derivatives.
Some observations on the behaviour of the Recent brachiopod Megerlina pisum under laboratory conditions

Tank experiments with the terebratuloid Megerlina pisum indicate that food is obtained by filtration of sea-water drawn into the shell at the sides and exhaled anteriorly. Under laboratory conditions feeding periods of up to 12 hours were interspersed with resting periods of about equal duration. During the feeding periods the valves were maintained at full gape except for brief interruptions by complete or partial closures. Complete closures lasted several minutes whereas partial closures occurred about half as frequently and lasted only 1 or 2 seconds. Most of these closures did not involve the expulsion of faecal pellets. During the resting periods the valves remained closed for several hours at a time and this condition occasionally continued for 10 hours or more. Apparently a very low respiratory rate operates during these resting periods.
On solving the critical-core neutronics problem

Abstract This is a discussion about solving the nuclear reactor-core neutronics problem for the critical state. Methods are described that have evolved for routine application in the assessment of core performance. Of prime interest are the conditions associated with the critical state, and supporting methods development is challenged to solve these problems. Special procedures have been found to be necessary to generate reliable information at a reasonable computation cost. Techniques that have proven useful are discussed, as well as the difficulties that have been experienced in applying multidimensional diffusion theory.
Reaction-driven instabilities in down-flow packed beds

Flow maldistributions and corresponding hot spots may cause adverse effects in the operation of down-flow packed-bed reactors. To avoid these phenomena it is necessary to know when and how they occur. In this work, a three-dimensional model that considers the effects of fluid flow, mass transfer by diffusion, heat transfer by conduction and reactant consumption by an exothermic irreversible first-order reaction is used to analyse an adiabatic packed-bed reactor with down-flow. It is shown that the one-dimensional uniform down-flow can become unstable to three-dimensional stationary and time-dependent perturbations, giving rise to non-uniform flow fields that lead to fixed as well as moving hot spots. The boundary of the region of the operating conditions at which these instabilities occur is determined as a function of the various physicochemical parameters that characterize the packed-bed reactor.
Comparison of the systemic and pulmonary inflammatory response to endotoxin of neutropenic and non-neutropenic rats.

Background Neutrophil infiltration commonly occurs in acute lung injury and may be partly responsible for the inflammatory response. However, acute lung injury still occurs in the neutropenic host. The objectives of this study are to determine if inflammation and acute lung injury are worse in neutropenic versus the normal host after endotoxemia.
Benign osseous and articular abnormalities of the pelvis: a review of CT imaging findings

Computed tomography (CT) has become the standard of care for evaluation and follow-up for a wide range of abdominal and pelvic pathology. Many incidental osseous and articular abnormalities of the pelvis are detected on these studies, most of which have a benign etiology. However, most of these studies are interpreted by nonmusculoskeletal radiologists, who may not be familiar with the CT appearances of these benign musculoskeletal abnormalities. Uncertainty often leads to mischaracterization or unnecessary follow-up, resulting in increased health care costs and patient anxiety. This article reviews the CT appearance of the benign musculoskeletal entities that occur in pelvis.
Temozolomide in malignant gliomas: current use and future targets

Temozolomide (TMZ) is an oral alkylating agent that is regarded as a tolerable and effective drug. When combined with radiotherapy in patients with newly diagnosed glioblastoma, survival is significantly prolonged. This finding has led to widespread use of TMZ for patients with this disease. We summarize developing concerns regarding the use of TMZ, imaging of malignant gliomas, and the pharmacology of TMZ—mechanism of action, scheduling and strategies for overcoming resistance.
Segregation and Black and Hispanic Group Outcomes Policing in Large Cities

This research uses Black and Hispanic employment on large-city police forces to explore the relative efficacy of two competing hypotheses on the potential effect of residential segregation on minority-group outcomes. The latent-need hypothesis postulates that Blacks and Hispanics would fare better in more segregated communities because Black and Hispanic personnel are needed to police “their” own neighborhoods. Alternatively, the discrimination hypothesis contends that, ceteris paribus, the extent of residential segregation is an indicator of community-level intolerance and expects that more segregated communities would present Blacks and Hispanics with fewer opportunities in policing. The analysis indicates that the discrimination imperative is germane for Blacks. However, residential segregation is of no significant consequence for Hispanics.
Segregation of electro- and mechanoreceptive inputs to the elasmobranch medulla.

Summary The anterior lateral line nerve of the thornback ray consists of fibers that innervate head electroreceptive ampullary organs and mechanoreceptive neuromasts. As the anterior lateral line nerve enters the medulla it divides into dorsal and ventral roots. Single unit responses of dorsal root fibers to electric field and mechanical stimuli indicate that the dorsal root consists only of ampullary fibers, whereas the ventral root consists only of mechanoreceptive fibers. The dorsal and ventral roots of the anterior lateral line nerve terminate in the dorsal and medial octavolateralis nuclei respectively, indicating that the dorsal nucleus is the primary electroreceptive nucleus of the elasmobranch medulla and the medial nucleus is the mechanoreceptive nucleus. Averaged evoked potential responses to electric field stimuli could be recorded from the dorsal but not the medial nucleus, further evidence that the dorsal nucleus is the electroreceptive nucleus. A second evoked response to electric field stimuli was elicited from the lateral reticular nucleus, suggesting that the reticular formation may be a secondary target of efferents of the dorsal octavolateralis nucleus. A dorsal octavo-lateralis nucleus exists not only in elasmobranchs, but also in agnathan, chondrostean, dipnoan, and crossopterygian fishes, suggesting that all of these taxa are also electroreceptive.
Effect of edeine on aminoacyl-tRNA binding to ribosomes and its relationship to ribosomal binding sites.

Abstract 1. The antibiotic edeine, an oligopeptide produced by Bacillus brevis, possesses a Mg2+ concentration-dependent inhibitory activity with respect to messenger-directed aminoacyl-tRNA binding. 2. At low Mg2+ concentrations (3–5 mM) edeine inhibits both the enzymatic and non-enzymatic binding to the A and P sites. 3. At 10–15 mM Mg2+ concentration edeine inhibits specifically binding to the P site. Residual aminoacyl-tRNA bound in the presence of an excess of edeine is puromycin insensitive. 4. Edeine does not interfere with the reaction catalyzed by peptidyl transferase. 5. Edeine is capable of removing an aminoacyl-tRNA prebound to a trinucleotide codon. However, an aminoacyl-tRNA prebound to a hexa- or polynucleotide messenger is resistant to the antibiotic.
Analysis of heat-flux calorimeter signals

Abstract General results on the operation of heat-flux calorimeters are obtained from a hereditary integral formulation of the calorimeter response. The behaviors of heat-flux calorimeters at long time intervals after a thermal event are examined using final value theorems of Laplace transforms. Experimental confirmation of the resulting predictions suggests an analytic procedure for desmearing or inverting calorimeter signals without the need for specific models or computer numerical techniques. Particular solutions are obtained for instantaneous heat and heat flow corresponding to an apparatus function of interest in the practice of heat-flux calorimetry.
George Herbert Mead on Intelligent Social Reconstruction

Many thinkers have discussed the possibility of intelligent social reconstruction; but few have examined the nature of such reconstruction as closely as did George Herbert Mead. This paper explores Mead's analysis through his understanding of human nature and intelligence, his discussion of value conflicts and the possibility of their resolution by means of the community, and his recognition of the need for popular commitment as a necessary condition for any wide-spread success. While pointing to certain problems with his position, this paper concludes that there is a basic soundness to Mead's approach.
Organic matter mineralization with the reduction of ferric iron: A review

Abstract A review of the literature indicates that numerous microorganisms can reduce ferric iron during the metabolism of organic matter. In most cases, the reduction of ferric iron appears to be enzymatically catalyzed and, in some instances, may be coupled to an electron transport chain that could generate ATP. However, the physiology and biochemistry of ferric iron reduction are poorly understood. In pure culture, ferric iron‐reducing organisms metabolize fermentable substrates, such as glucose, primarily to typical fermentation products, and transfer only a minor portion of the electron equivalents in the fermentable substrates to ferric iron. However, fermentation products, especially hydrogen and acetate, may be important electron donors for ferric iron reduction in natural environments. The ability of some organisms to couple the oxidation of fermentation products to the reduction of ferric iron means that it is possible for a food chain of iron‐reducing organisms to completely mineralize nonrecal...
Effects of the Liquid Polarity and the Wall Slip on the Heat and Mass Transport Characteristics of the Micro-Scale Evaporating Transition Film

Abstract A mathematical model is developed to describe the micro-/nano-scale fluid flow and heat/mass transfer phenomena in an evaporating extended meniscus, focusing on the transition film region under non-isothermal interfacial conditions. The model incorporates polarity contributions to the working fluid field, a slip boundary condition on the solid wall, and thermocapillary stresses at the liquid–vapor interface. Two different disjoining pressure models, one polar and one non-polar, are considered for water as the working fluid so that the effect of polar interactions between the working fluid and solid surface can be exclusively examined on heat and mass transfer from the thin film. The polar effect is examined for the thin film established in a 20-μm diameter capillary pore. The effect of the slip boundary condition is separately examined for the thin film developed in a two-dimensional 20-μm slotted pore. The analytical results show that for a polar liquid, the transition region of the evaporating meniscus is longer than that of a non-polar liquid. In addition, the strong polar attraction with the solid wall acts to lower the evaporative heat transfer flux. The slip boundary condition, on the other hand, increases evaporative heat and mass flux and lowers the liquid pressure gradients and viscous drag at the wall. The slip effect shows a more pronounced enhancement as superheat increases. Another thing to note is that the slip effect of elongating the transition region can counteract the thermocapillary action of reducing the region and a potential delay of thermocapillary driven instability onset may be anticipated.
The effect of preparation temperature on some properties of a temperature-sensitive hydrogel

Abstract The physical and chemical characteristics of temperature-sensitive hydrogel, poly(N-isopropylacrylamide), were strongly dependent upon the preparation temperature and the kind of accelerator used for free radical polymerization. N, N,N′,N′-tetramethyl-ethylenediamine (TEMED) was a better accelerator for consistent gelation near room temperatures (17–24 °C) compared with sodium metabisulfite. Using TEMED, gelation time was 3.6 min at 18 °C, but decreased to 1.8 min at 23 °C. When the gel was prepared in a glass cylinder of 37 mm ID and 191 mm height at temperatures of 18 °C and below, it was completely transparent. The gel became more opaque starting from the core part of the gel cylinder, when prepared at higher temperatures. The gel became totally opaque at preparation temperatures of 23 °C and above. The transparent gel had better physical strength as determined by Instron, and higher transition temperature for volume change (lower critical solution temperature) as determined by differential scanning calorimetry. The transparent gel also had a better volume change capacity when the gel underwent temperature swings between 28 °C and 37 °C.
The Inversion Wind Pattern over West Antarctica

Abstract The surface windfield over the gently sloping interior ice fields of Antarctica is characterized by a high degree of persistence in terms of both direction and speed. The forcing of the surface wind is due primarily to the radiational cooling of the air adjacent to the sloping terrain. The representativeness of a simple diagnostic equation system in inferring the surface winds from a knowledge of terrain slope and temperature inversion structure is examined. Results suggest at least qualitatively accurate surface drainage patterns over the Antarctic continent are possible using this technique. A wintertime surface wind simulation for West Antarctica has been generated based on an accurate ice topography map. Close agreement is seen between the simulated surface windfield with field observations and sastrugi orientations. Implications of the simulation are discussed.
Ultrastructure of meiosis in Chlamydomonas reinhardtii

Ultrastructural details of meiosis in Chlamydomonas reinhardtii are presented. Zygotes undergo a resting stage prior to meiosis, during which a multi-layered zygote wall is deposited. Basal bodies reappear at interphase. Heterochromatin is not visible in the interphase nucleus. Leptotene is characterized by the appearance of axial cores and the condensation of chromonemata. By early zygotene, axial elements associated with the condensing chromatin associate with the nuclear envelope. Tubular elements appear in the perinuclear space adjacent to the associated chromosomes. Bivalents begin to associate with the nucleolus. By pachytene, typical synaptinemal complexes have formed. The synaptinemal complexes possess two lateral elements associated with the chromosomes and separated by a central space of about 130 nm. A central element may form midway between the lateral elements and be joined to them via transverse elements. Separated synaptinemal complexes appear in the cytoplasm by diplotene-diakinesis. At th...
Resting state cortical connectivity reflected in EEG coherence in individuals with autism

Background Theoretical conceptions of autism spectrum disorder (ASD) and experimental studies of cerebral blood flow suggest abnormalities in connections among distributed neural systems in ASD. Methods Functional connectivity was assessed with electroencephalographic coherence between pairs of electrodes in a high-density electrode array in narrow frequency bands among 18 adults with ASD and 18 control adults in an eyes closed resting state. Results In the θ (3–6 Hz) frequency range, locally elevated coherence was evident for the ASD group, especially within left hemisphere frontal and temporal regions. In the lower α range (8–10 Hz), globally reduced coherence was evident for the ASD group within frontal regions and between frontal and all other scalp regions. The ASD group exhibited significantly greater relative power between 3 and 6 Hz and 13–17 Hz and significantly less relative power between 9 and 10 Hz. Conclusions Robust patterns of over- and under-connectivity are apparent at distinct spatial and temporal scales in ASD subjects in the eyes closed resting state.
Emittance growth rates for displaced beams

We analyze emittance growth rates for beams initially displaced in focusing channels. If the focusing force is slightly nonlinear, there is a gradual transfer of the potential energy of beam displacement into kinetic energy associated with emittance growth. We present explicit results for the emittance growthdistance as a function of the nonlinearity of the channel. These results will have practical importance for designers of accelerators and transport systems when setting realistic tolerances for initial beam alignment. These tolerances will depend on the nonlinearity and the length of the system.
Targeted enhancement of cortical-hippocampal brain networks and associative memory

The influential notion that the hippocampus supports associative memory by interacting with functionally distinct and distributed brain regions has not been directly tested in humans. We therefore used targeted noninvasive electromagnetic stimulation to modulate human cortical-hippocampal networks and tested effects of this manipulation on memory. Multiple-session stimulation increased functional connectivity among distributed cortical-hippocampal network regions and concomitantly improved associative memory performance. These alterations involved localized long-term plasticity because increases were highly selective to the targeted brain regions, and enhancements of connectivity and associative memory persisted for ~24 hours after stimulation. Targeted cortical-hippocampal networks can thus be enhanced noninvasively, demonstrating their role in associative memory.
DOPA-decarboxylation in the striata of rats with unilateral substantia nigra lesions

The source and site of the DOPA decarboxylation to dopamine in Parkinson's disease (PD) and animal models of PD are controversial. Since most of aromatic L-amino acid decarboxylase (AADC) are lost along with the degenerating dopaminergic neurons, we addressed the possibility that other decarboxylases or a novel protein that is structurally different from AADC decarboxylate L-DOPA in the denervated striatum. Immunotitration of the extracts from the denervated striatum with AADC antibody showed that all activity can be attributed to AADC-immunoreactive protein. We then investigated if there are non-dopaminergic intrinsic striatal neurons that express AADC. No evidence of such neurons was noted by immunocytochemistry and in situ hybridization.
Controlled release of 2-heptanone using starch gel and polycaprolactone matrices and polymeric films†

Varroa jacobsoni is a parasitic mite that is threatening the honeybee industry in many parts of the world. 2-Heptanone, a natural product made by honeybees at low concentrations, is effective at elevated concentrations in controlling mite populations in honeybee colonies, especially when released over a 42 day period. An extrusion process was used to encapsulate 14, 18, and 25% 2-heptanone in a polycaprolactone (PCL) matrix. Less than 18% of the 2-heptanone was encapsulated in the PCL matrix. The high vapor permeability of PCL to 2-heptanone resulted in a high flux rate and limited the usefulness of PCL as an encapsulation matrix for controlled-release devices. A starch gel containing three times its weight in 2-heptanone was prepared from starch-based microcellular foam (MCF). The gel had compressive, tensile, and flexural strength values in the range of 0.56 to 1.9 MPa. 2-Heptanone quickly evaporated from non-laminated gels. However, when the gel was laminated with different polymeric films, a wide range of flux rates was obtained. The T50 for gels laminated or coated with poly(vinyl alcohol) (PVAL, 99% hydrolyzed) and ethylene-vinyl alcohol copolymer (EVAL) was 72 and 1030 days, respectively. The most promising film was a starch/glycerol film that released 50% of the 2-heptanone (T50) in approximately 13 days. Copyright © 2007 John Wiley & Sons, Ltd.
Microbial populations in surface films and subsurface waters: Amino acid metabolism and growth

Sea surface microlayer (film) and subsurface microbial populations (biomass and activities) were studied in the Damariscotta (Maine) estuary in May and September, 1987. Dissolved free and combined amino acids (DFAA, DCAA), bacterial numbers, microbial ATP, bacterial and microbial DNA synthesis (via3H-thymidine and3H-adenine), and amino acid (3H-glutamic acid) metabolism were measured. DFAA and DCAA were typically enriched in the surface microlayers relative to surface waters, although utilization of glutamic acid was usually more rapid in subsurface waters, as was incorporation of thymidine. Bacteria represented 12 to 40% of the microbial biomass as determined by ATP, except during microalgal blooms in the microlayer. Bacteria were generally not enriched in the surface films, although ATP usually was enriched. Rain input appeared to deplete population densities but stimulated population activities. Two stations which contained similar microbial populations (as estimated by bacterial counts, chlorophylla and ATP) showed very different microbial activities, apparently due to the effects of a substantial rainstorm on one of the stations. The bacterially-dominated processes utilizing thymidine and glutamic acid were enhanced approx five-fold after the rain. Autotrophic carbon production increased approx two-fold, while total microbal community DNA synthesis (as estimated by adenine incorporation into DNA) increased nearly tenfold. The observations of this study indicate that surface microlayers in the temperate waters off the coast of Maine contain highly active heterotrophic and autotrophic populations. The microbial community responds rapidly to changes in nutrient and dissolved organic matter concentrations resulting from both seasonal and temporal effects, including rain and runoff.
Orall-2-Oxo-4-thiazolidine Reduces Bacterial Translocation after Radiation in the Fischer Rat

Abstract Glutathione (GSH) is important in protecting rapidly dividing intestinal cells against free radicals generated following radiation. l -2-Oxo-thiazolidine (OTZ) promotes GSH synthesis through increased cysteine delivery. We hypothesize that oral supplementation with OTZ will augment GSH levels and decrease the incidence of bacterial translocation after abdominal radiation, and these effects will be abrogated by treating with a blocker of GSH synthesis, buthionine sulfoximine (BSO). Fischer rats received by oral gavage either OTZ (OTZ/rad), OTZ plus BSO (OTZ/BSO/rad), or saline (sal/rad) 4 hr prior to and 18 hr after radiation. One group underwent saline gavage and no radiation (ctl/sal). On Day 4, animals were sacrificed and mesenteric lymph nodes (MLN) were cultured. Liver and jejunum were removed for GSH analysis by HPLC. Nonradiated, ctl/sal had higher levels of hepatic and jejunal GSH than ctl/rad (13.0 ± 1.2 vs 9.7 ± 1.5, 11.2 ± 1.0 vs 7.8 ± 2.5 μmol/g dry wt,P
A universal micro heating stage

There is described an electrically-heated, circular aluminum block which serves as stand and heating stage for many types of microchemical glass and porcelain ware. It is readily adaptable to automatic temperature control and is generally applicable in micro and semi-micro preparations and analyses.
Alcohol Studies and Science: Trapped in the Velvet Cage of Medical Research? An Editorial

Objective:This article offers the author’s assessment of the progress in research on alcohol related to alcohol misuse and alcohol use disorders.Method:The historical background of alcohol-problem research is reviewed in the context of defining problems for study and the pattern by which research is funded.Results:Progress in terms of cumulative research has been affected by the lack of central authority and the National Institutes of Health structure within which almost all funding for alcohol research in the United States has occurred. Problems are traced to the particular history and nature of alcohol-problem research, the continuing prominence of moral elements, and particular features of the treatment of alcohol use disorders.Conclusions:Although the scope of activity and production of publications in alcohol research has expanded greatly during the past 75 years, there is a potential shortfall in the cumulative research that has led to solutions to major problems associated with alcohol.
Recovery experiences and the source of aversive effects of electroconvulsive shock

The hypothesis tested was that aversive effects associated with multiple administrations of electroconvulsive shock (ECS) are a function of the postECS recovery experience. One group of Ss was allowed to recover in the same compartment in which ECS was given, while a second group was allowed to recover in a dissimilar compartment. Avoidance of the shock compartment developed differentially in the two groups. The results supported the conclusion that part of the aversive effect developed as a function of the recovery experience.
Differential relationships of impulsivity or antisocial symptoms on P50, N100, or P200 auditory sensory gating in controls and antisocial personality disorder

Limited information is available on the relationship between antisocial personality disorder (ASPD) and early filtering, or gating, of information, even though this could contribute to the repeatedly reported impairment in ASPD of higher-order information processing. In order to investigate early filtering in ASPD, we compared electrophysiological measures of auditory sensory gating assessed by the paired-click paradigm in males with ASPD (n = 37) to healthy controls (n = 28). Stimulus encoding was measured by P50, N100, and P200 auditory evoked potentials; auditory sensory gating (ASG) was measured by a reduction in amplitude of evoked potentials following click repetition. Effects were studied of co-existing past alcohol or drug use disorders, ASPD symptom counts, and trait impulsivity. Controls and ASPD did not differ in P50, N100, or P200 amplitude or ASG. Past alcohol or drug use disorders had no effect. In controls, impulsivity related to improved P50 and P200 gating. In ASPD, P50 or N100 gating was impaired with more symptoms or increased impulsivity, respectively, suggesting impaired early filtering of irrelevant information. In controls the relationship between P50 and P200 gating and impulsivity was reversed, suggesting better gating with higher impulsivity scores. This could reflect different roles of ASG in behavioral regulation in controls versus ASPD.
TG-1: a marker for neuronal nuclei in Alzheimer's disease

Abstract TG-1 is a monoclonal antibody (mAb) raised against paired helical filaments purified from Alzheimer's Disease (AD) brain by immunoaffinity chromatography. By immunocytochemistry, TG-1 reveals abundant staining of neuronal nuclei in AD brain, but little or no staining in normal brain. TG-1 stained nuclei are observed in areas of AD brain with neurofibrillary pathology and in certain neurones that are not normally affected. Biochemical studies with TG-1 show antigens of 32–38 kDa in pellets and 50 kDa in supernatants from brain, with no obvious differences between normal and AD. TG-1 also recognizes an unusual structure, i.e., a ‘starburst’ in brain tissue from AD and elderly normals. Starbursts are not immunoreactive for the astrocytic marker, glial fibrillary acidic protein, and are not associated with amyloid. Widespread nuclear staining is observed with TG-1 in rat brain, and the immunoreactive antigens in purified nuclei are similar to those in human brain. Thus, TG-1 identifies neuronal nuclear antigens that are altered in AD, and provides a new avenue for studying pathogenic mechanisms in the disease.
Fine structure of hopping conductance fluctuations in finite-size semiconductors

The plateau paradox---the absence of flat regions from incoherent mesoscopic oscillations---is investigated. Random reproducible oscillations of the conductance G versus the gate voltage ${\mathit{V}}_{\mathit{g}}$ have been observed in the past few years in different field-effect structures in the strongly localized regime. The presence of plateaus should be a sign of the hopping nature of transport that is believed to be responsible for the existence of mesoscopic oscillations. The part p of the mesoscopic pattern that should be occupied by plateaus in one dimension is calculated analytically with the use of a traditional approach for hopping. The value p turns out to be parametrically small and decreases slowly with the sample length. To interpret the absence of plateaus in two-dimensional systems, two phenomena neglected in the traditional approach---Hubbard correlation between occupations of different sites and Coulomb interaction of electrons---are discussed. A mechanism for the suppression of Hubbard correlations in a disordered system is proposed. The influence of Coulomb effects on mesoscopic oscillations for the experiments of interest is shown to be sufficient to change dramatically the structure of a mesoscopic pattern.
Molecules with Perfect Cubic Symmetry as Nanobuilding Blocks for 3-D Assemblies. Elaboration of Octavinylsilsesquioxane. Unusual Luminescence Shifts May Indicate Extended Conjugation Involving the Silsesquioxane Core

The objectives of this work are to demonstrate facile routes to 3-D star materials with octa- and hexadecafunctionality to provide new nanoconstruction tools for the synthesis of new types of stars, dendrimers, and hyperbranched molecules or for the assembly of novel nanocomposites. A further objective is to identify novel properties inherent in the resulting new compounds. Octavinylsilsesquioxane (OVS, [VinylSiO1.5]8) with perfect 3-D or cubic symmetry is elaborated through metathesis with substituted styrenes to produce a series of RStyrenylOS compounds. The p-BrStyrenylOS compound is then further reacted with other sets of p-substituted styrenes via Heck coupling to produce a set of R′VinylStilbeneOS compounds. The R′ = NH2 compound is then reacted with 3,5-dibromo or dinitrobenzoyl chloride to produce hexadecafunctional 3-D stars. These synthetic methods provide perfect single core and then core−shell 3-D stars including in the third generation branch points such that these molecules can be used for t...