cssi/SciSciGPT-SciSciNet huggingface dataset:
Investigation of mechanisms underlying transient T2 normalization in longitudinal studies of ischemic stroke.

Purpose To determine if the phenomenon of transient normalization of T2 relaxation in the subacute stage of ischemic stroke is associated with either magnetic susceptibility effects secondary to hemorrhage or changes in tissue water content. Materials and Methods We utilized a rat model of transient, focal, cerebral ischemia. The possibility of hemorrhage was evaluated with T2*-weighted (T2*W) imaging and histology. Changes in water content were assessed by brain wet-to-dry weight. Results Susceptibility effects were not evident in T2*W images, and neither red blood cells nor unchelated Fe(III) was found in hematoxylin and eosin (H-E)– or Prussian Blue–stained sections, respectively. However, between the peak of T2 contrast and the point of transient T2 normalization, water content consistently decreased by an average of 3%. Conclusion Transient T2 normalization is associated with normalization of water content and can occur without evidence of hemorrhage. J. Magn. Reson. Imaging 2002;15:130–136. © 2002 Wiley-Liss, Inc.
Heat Shock and Genetic Activation of HSF-1 Enhance Immunity to Bacteria

The relationship between fever and microbial infections has been known for a number of years, as well as several key mediators involved in its elicitation. However, the mechanisms by which fever confers protection to infected hosts are less clear. The nematode Caenorhabditis elegans, which has been extensively used in recent years to study microbial infections and innate immune responses, has recently been used to study the effect of increased temperature in immunity. Upon heat shock exposure, nematodes become more resistant to Pseudomonas aeruginosa and the enhanced resistance to the pathogen requires heat shock transcription factor 1 (HSF-1) and a system of small and 90 kDa heat shock proteins (HSPs). Experiments using additional Gram negative and Gram positive pathogens show that HSF-1 is part of a multipathogen defense pathway. In addition, C. elegans innate immunity can be activated enhancing HSF-1 activity by directly overexpressing HSF-1 or by overexpressing DAF-16, which is a forkhead transcription factor that acts upstream HSF-1 in aging and immunity. Blocking the inhibitory signal of the DAF-2 insulin like receptor, which acts upstream DAF-16, also results in an enhanced HSF-1 dependent immunity. In addition, mutations that affect DAF-21, C. elegans homologue of Hsp90 which forms an inhibitory complex with HSF-1, appear to boost immunity by activating the HSF-1 pathway. The role of the HSF-1 pathway in innate immunity and immunosenescence is discussed.
Liquid chromatographic method for the determination of nicotine in pharmaceutical formulations

A simple high-performance liquid chromatography method was developed and validated for the analysis of nicotine in various pharmaceutical formulations. This method required a simple liquid-liquid extraction procedure prior to liquid chromatography analysis. The chromatographic separation was achieved on a reversed-phase C18 column with ultraviolet detection at 260 nm. This isocratic system was operated at ambient temperature and required 10 min of chromatographic time. The mobile phase consisted of methanol-citrate phosphate buffer (15:85, v/v) at a flow-rate of 0.7 ml/min. Standard curves were linear over the concentration range 1.0–51 μg/ml. Within-day and day-to-day relative standard deviations ranged from 1.3 to 4.4% and from 2.4 to 4.2%, respectively.
Five rules for scheduling 12-hour night shifts.

Do you find that your nurses aren't well educated on managing fatigue when working the night shift and all too frequently come to work without adequate rest? In some instances, this is due to poor sleep habits. In other cases, it's due to poor scheduling that leaves nurses with not enough ho
Niacin: A powerful adjunct to other lipid-lowering drugs in reducing plaque progression and acute coronary events

Recent clinical trial data have demonstrated the benefits of utilizing niacin therapy in the management of dyslipidemia. In the Familial Atherosclerosis Treatment Study and the HDL Atherosclerosis Treatment Study (HATS), niacin combination therapy with a statin or resin resulted in significant reduction in cardiovascular events. The angiographic benefits in the HATS trial appear to be related to the change in large, high-density lipoprotein particle concentration, which is a prominent effect of niacin treatment. Recent evaluation in diabetic populations also has demonstrated a reduction in clinical events. Changes in hemoglobin Alc levels with niacin appear to be clinically insignificant and, therefore, the relative underutilization of niacin in diabetic patients is probably not warranted based on the most recent data.
Adolescent romantic couples influence on substance use in young adulthood.

Adolescent peer group affiliations are amongthe strongest and most consistent predictors of the initiation and maintenance of substance use (Petraitis, Flay, & Miller, 1995;Bauman E Fergusson, Swain, Nicola, H (2) not examined whether these associations depend on type of substance used; and (3) not evaluated potential interpersonal covariates such as relationship seriousness. Exploration of each of these areas is important for prevention research and will expand our understanding of how adolescent romantic relationships affect substance use behavior across development.
Cobalt–Carbon Eutectic Fixed Point for Contact Thermometry

Two Co–C eutectic fixed points were constructed for thermocouple calibration. The eutectic fixed points were measured with a Pt/Pd thermocouple calibrated at the freezing temperatures of Sn, Zn, Al, Ag, and Au. A temperature of (1323.99 ± 0.52) °C (k = 2) was determined via this method. The cell design allowed filling to be accomplished in a single step. Each cell was held above 1300 °C for at least 42 h and was subjected to at least 20 melt/freeze cycles with no mechanical failure occurring.
Surface Emitting Sources For Optical Waveguides

The basic design principles of radiation emitting diodes are discussed. Theoretical and experimental values of radiant power, radiant intensity, and radiance of GaAs and GaAlAs infrared surface emitting sources are reviewed. A comparison of various device geometries shows that small-area, high-radiance, etched-well emitters are the optimum design for coupling to individual optical fibers but that high-radiant-intensity shaped emitters are the optimum design for coupling to larger diameter fiber bundles. Improved linearity can be achieved with GaAlAs planar emitters incorporating a buried-junction structure to minimize non-radiative surface recombination.© (1975) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The coelomycetous genera Chaetomella and Pilidium represent a newly discovered lineage of inoperculate discomycetes

The coelomycetous genera Chaetomella and Pilidium were determined to be closely related to each other, yet are recognized as distinct genera based on both morphological observations and rDNA sequence analyses. Analyses of the SSU and LSU of the nuclear ribosomal RNA genes suggest that Chaetomella and Pilidium along with Sphaerographium tenuirostrum and Synchaetomella lunatospora constitute a distinct lineage within the ascomycetes that is allied with the Leotiomycetes. Chaetomella and Pilidium both produce black pycnidia generally opening by a raphe, acropleurogenous conidiogenous cells, and non-septate, hyaline, usually fusiform to falcate, rarely ellipsoid, conidia. Pycnidia of Pilidium are smooth while those of Chaetomella have setae of various types. A Hainesia sporodochial synanamorph was observed in cultures of C. oblonga and C. raphigera similar to H. lythri, the synanamorph of P. concavum. Specimens of C. oblonga, type species of Chaetomella, C. acutiseta, C. circinoseta, C. raphigera, Pilidium acerinum, type species of Pilidium, and P. concavum were examined. Diagnoses and illustrations are provided for these species along with a key to the accepted species in both genera.
Tungsten pentacarbonyl complexes of cis- and trans-1,2-dimethyldiazene and 1,2-dimethylhydrazine. Preferential oxidation of the coordinated hydrazine to the cis-diazene complex.

Abstract The complexes W(CO)5L (L=CH3NHNHCH3, c-CH3N=NCH3, t-CH3N=NCH3) and [W(CO)5]2 (t-CH3N=NCH3) have been obtained from the reaction of W(CO)5THF with the corresponding ligand. Each W(CO)5 group is coordinated to the lone pair of one of the nitrogen atoms of the ligand. W(CO)5 (c-CH3N=NCH3) undergoes coordination site exchange between the two nitrogen atoms with a coalescence temperature of 40 + 2°C and ΔG† = 16.0 + 0.1 kcal/mole in the NMR spectrum. Infrared, visible, and NMR spectra are interpreted and comparisons drawn with other Group VIB carbonyl complexes of diazenes. The role of alkyl group size in determining the types of complexes formed by cis and trans acyclic diazenes and the properties of these complexes is discussed. Activated MnO2 was found to preferentially oxidize CH3NHNHCH3 to c-CH3N=NCH3 at -50°C, offering a convenient large scale synthesis of this molecule. The hydrazine complex W(CO)5 (CH3NHNHCH3) is similarly oxidized in high yield to about a 5:1 mixture of W(CO)5 (c-CH3N=NCH3) and W(CO)5 (t-CH3N=NCH35) and is the better synthetic route to these complexes. W(CO)5 (c-CH3N=NCH3) tautomerizes readily to a complex of formaldehyde methylhydrazone W(CO)5 (H2C=NNHCH3), which is believed to be coordinated through the imino nitrogen.
Biosecurity and bovine respiratory disease.

Respiratory disease problems represent a major area of concern for allphases of cattle production. All types and all ages of cattle are susceptibleto respiratory problems, and in some production settings, respiratory dis-ease is the single most important cause of livestock morbidity and mortality.In recent national surveys, respiratory disease is reported to account for24.5% of preweaned dairy heifer calf deaths, and it is the leading cause ofdeath in weaned heifer calves, accounting for 44.8% of calf death losses[54]. In adult dairy cows, respiratory disease is less important than mastitis,lameness, metabolic diseases, and reproductive disorders as a cause of mor-bidity, but it still aﬀects 2.5% of adult dairy cattle on a yearly basis, and9.6% of dairy cow deaths are attributed to respiratory disease [54]. In pre-weaned beef calves over 3 weeks of age, respiratory problems represent21% of health problems, occurring in approximately 0.8% of all calves[52]. Respiratory disease accounts for 16.3% of total beef calf death loss and6.0% of total breeding cattle death loss on cow–calf operations [52]. Ship-ping fever was recently reported to occur in 14.4% of feedlot cattle, and thisrespiratory problem was more than 4 times more prevalent than the nextleading cause of morbidity, which was acute interstitial pneumonia [56].Annual death loss estimates due to respiratory disease for all cattle andcalves in the United States exceed 1.2 million animals, with an estimatedtotal economic loss greater than $478 million [53].These morbidity and mortality estimates underscore the tremendousimportance of respiratory disease to cattle producers. Considerable eﬀortover many years has been focused on improving our understanding of thisproblem. Despite improvements in our understanding of pathogenesis, char-acteristics of causative agents, vaccine technology, and means of prevention
Ideology and Inconsistency: The “Cross-Pressured” Nigerian Worker

After the nationwide general strike of June 1964, workers in Nigeria gained unprecedented political prominence. The timing of the strike had much to do with this, for only five months hence the Federal elections of December 1964 were to be held and Nigerian politicians became keenly aware of the labor movement. Two kinds of politicians began to compete for the labor vote. On the one hand, there were politically oriented labor leaders who wanted to take the opportunity of the strike and of the elections to form a Nigerian Labor party. They made their appeals to the class-consciousness and self-interest of Nigerian workers defined as workers, not as members of this or that ethnic group. On the other hand there were the politicians of the major political parties who made their appeals to the ethnic loyalties of the workers.2 Thus between June and December 1964, and for some months after, workers were crosspressured between their labor and their ethnic loyalties.3 Working against the effect of the
Activity-Dependent Expression of Lmx1b Regulates Specification of Serotonergic Neurons Modulating Swimming Behavior

Summary Genetic programs, environmental factors, and electrical activity interact to drive the maturation of the brain. Although the cascade of transcription factors that leads to specification of the serotonergic phenotype has been well characterized, its interactions with electrical activity are not known. Here we show that spontaneous calcium spike activity in the hindbrain of developing Xenopus laevis larvae modulates the specification of serotonergic neurons via regulation of expression of the Lmx1b transcription factor. Activity acts downstream of Nkx2.2 but upstream of Lmx1b, leading to regulation of the serotonergic phenotype. Using global manipulation of activity and targeted alteration of Lmx1b expression, we also demonstrate that changes in the number of serotonergic neurons change larval swimming behavior. The results link activity-dependent regulation of a transcription factor to transmitter specification and altered behavior.
Computation of exterior potential fields by infinite substructuring

Abstract A numerical method is presented to evaluate approximate solutions of elliptic partial differential equations outside an arbitrary convex region. The exterior region is conceived as an infinite assembly of geometrically similar finite element cells. A complete set of spatially discretized shape functions is derived for the entire unbounded exterior within which Laplace's equation is required to be satisfied. These functions with the characteristic of outward decay are evaluated by solving a quadratic eigenproblem. The coefficient matrices therein are furnished by the finite element system matrix (which relates the resulting nodal fluxes to the corresponding field strengths) of a typical cell. Elements of that matrix are viewed in the light of the virtual work principle. The energy terms associated with any pair of those basic functions form a convergent geometrical series over a sequence of similarly shaped elements with increasing characteristic dimensions. The exact infinite sum of the virtual work quantities yields the elements of the boundary matrix for the unbounded region. This enables one to carry out the proposed infinite substructuring scheme over the entire infinite collection of those cells. Finally, an expression to estimate the exterior field at an arbitrary point is also presented. The present study has applications to elastostatic, hydrodynamic, electro- and magneto-static protentials in two and three dimensions.
Structure and sequence of the human α-l-iduronidase gene

In humans, a deficiency of the lysosomal hydrolase alpha-L-iduronidase (IDUA;EC 3.2.1.76) results in the lysosomal storage of the glycosaminoglycans heparan sulfate and dermatan sulfate, thereby causing the lysosomal storage disorder mucopolysaccharidosis type I. The gene for IDUA is split into 14 exons spanning approximately 19 kb. We report the sequence of two non-contiguous segments of the IDUA gene, one 1.8-kb segment containing exons 1 and 2 and surrounding sequences and a second segment of 4.5 kb containing the last 12 exons. The potential promoter for IDUA has only GC box type consensus sequences consistent with a housekeeping promoter and is bounded by an Alu repeat sequence. The first two exons of IDUA are separated by an intron of 566 bp, then there is a large intron of approximately 13 kb, and the last 12 exons are clustered within 4.5 kb. No consensus polyadenylation signal was found in the 3' untranslated region, although two variant polyadenylation signals are proposed.
Increase in plasma turbidity as a result of cerebral stimulation.

THE milky opalescent appearance of plasma associated with lipaemia is related to the size and number of fat-laden particles. Resolution of these particles and prompt clearing of the turbidity of plasma during absorptive lipaemia follow the intravenous administration of heparin1. The present report shows that the reverse phenomenon, an increase in plasma turbidity, can be readily produced by electrical stimulation of certain deep structures of the brain.
OROPHARYNGEAE DYSPHAGIAS IN THE DOG: A CINEFLUOROGRAPHIC ANALYSIS OF EXPERIMENTALLY INDUCED AND SPONTANEOUSLY OCCURRING SWALLOWING DISORDERS

Cinefluorography and videofluorography were used to record and analyze functional swallowing deficits of 12 dogs with spontaneously occurring oropharyngeal dysphagias and six experimental dogs with selected neurectomies. Ten of the 12 dogs had dysphagias affecting the cricopharyngeal stage of the oropharyngeal phase of swallowing. Two dogs had mixed oropharyngeal dysphagias. Clinical signs of cricopharyngeal dysphagia could not be differentiated from those of dysphagias due to pharyngeal or mixed oropharyngeal deficits. Signs of cricopharyngeal dysphagia consisted of: 1) repeated attempts to swallow; 2) excessive head movement; 3) dropping food from the mouth after unsuccessful swallowing attempts; 4) reingestion of dropped food. Nine of these dogs had cinefluorographic evidence of asynchrony between the normal pharyngeal contraction and relaxation, and subsequent cricopharyngeal relaxation and contraction. Only one dog demonstrated a consistent cricopharyngeal non-opening (achalasia). Seven of the dogs responded dramatically to cricopharyngeal myotomy. Two dogs with mixed oropharyngeal dysphagias had poor contractility of the pharyngeal muscles in addition to cricopharyngeal dysphagia. Clinical and cinefluorographic evaluation following cricopharyngeal myotomy of one dog verified exacerbation of functional deficits due to the iatrogenic cricopharyngeal chalasia. Esophagopharyngeal reflux accentuated the contrast medium retention in the pharynx and laryngotracheal aspiration. The need was stressed for careful differentiation between cricopharyngeal dysphagia and dysphagias involving the pharyngeal stage. Four experimental dogs with selective bilateral neurectomies of branches of the glossopharyngeal (IX) and vagus (X) nerves were evaluated clinically and cinefluorographically in an attempt to identify the pathogenesis of cricopharyngeal dysphagia. The variable results in the four dogs and the observed recovery in two dogs suggested that peripheral motor nerve deficits are not a major cause of cricopharyngeal dysphagia. Glossopharyngeal neurectomy in two dogs induced a profound functional disorder involving the pharyngeal and cricopharyngeal stages and the esophageal phase of swallowing. This would support a new hypothesis that the glossopharyngeal nerve is sensory to the esophagus as well as the pharynx, and may play a major role in disorders of the pharynx, upper esophageal sphincter, and esophagus, including congenital or acquired megaesophagus.
Rhythm in Mother-Infant Interactions

Rhythmic behavior and the association of vocal rhythmic behavior with language development were studied in a sample of 30 mother-infant dyads. Dyads were observed in 2 contexts (1 involved sharing pictures and the other sharing musical toys)when infants were 18 and 24 months of age. Vocal rhythmic behavior was seen in both contexts, and in both contexts mothers matched their infant's vocal rhythmic behavior at greater than chance rates. Greater matching tended to be associated with higher language scores whereas, counter to prediction, higher rates of maternal vocal rhythmic behavior tended to be associated with lower language scores. At 24 months of age, mother-daughter dyads showed more matching than mother-son dyads. These results suggest that differences in maternal production of vocal rhythmic behavior may foster different language learning strategies.
Utilizing hydrogen bonds and halogen–halogen interactions in the design of uranyl hybrid materials

Reactions of the uranyl cation (UO22+) with 4-halopyridinium ions (X = Cl, Br, I) in high halide media (X′ = Cl, Br) have produced six novel compounds, the structures of which have been determined by single crystal X-ray diffraction (XRD). The compounds can be divided into two categories based on the different modes of hydrogen bonding and halogen–halogen interactions present in the crystal structures, with one group showing approximately Type I halogen–halogen interactions and the second showing Type II. Presented is a discussion of the relative strengths of the interactions as a function of halogen size.
Problems encountered by early endoscopists

FIGURE 1. Bozzini’s very special candle holder. should enable us to appreciate our beginnings and evolution to present-day practice. Endoscopy began in 1804 when Bozzini invented an instrument which he called the lichtleiter for inspecting the urethra.’ It consisted of a candle holder in a box and a hollow tube for viewing (Fig. 1). The Medical Faculty of Vienna condemned it on the grounds of insufficient illumination, and there are no reports of the instrument being used on a human. Fortunately for us this instrument, with only 1 candlepower, illuminated the way for further interest and advancement. In 1853, Desormeaux presented his endoscope to the French Academy of Medicine in Paris. The instrument, composed of a viewing tube with a light source at right angles to it, was the first workable cystoscope (Fig. 2). A candle was first used as illumination, but this soon gave way to alcohol, petroleum, and finally camphor with petroleum to increase the light from the flame. Due to the proximity of the light source to the patient, there were several incidents of burns both to
Effects of Rearing Temperature on Growth, Body Form, and Hematology of Fall Chinook Fingerlings

(1971). Effects of Rearing Temperature on Growth, Body Form, and Hematology of Fall Chinook Fingerlings. The Progressive Fish-Culturist: Vol. 33, No. 1, pp. 20-26.
Phenomenological electronic energy bands in graphite intercalation compounds

Abstract The electronic energy bands near the Fermi level for both donor and acceptor graphite intercalation compounds are modelled using a kz-axis zone folded form of the SWMcC bands for pristine graphite. The effect of intercalation is included through terms for the intercalant and for the interaction between intercalant and graphite layers. Graphitic π-bands appropriate to both donor and acceptor compounds are presented.
Ca2+Na+ exchanger and Na+, K+ 2Cl− cotransporter in lens fiber plasma membrane vesicles

When the Ca(2+)-sensitive fluorescent probe, Fura-2, or the Na(+)-sensitive probe, SBFI, in their cell permeable forms or the Cl(-)-specific probe, SPQ, were incubated with plasma membrane vesicles prepared from dogfish and bovine lenses fibers, there was a selective accumulation of the ion-specific probes within the vesicles. The SBFI and Fura-2 fluorescent excitation ratios of 340 nm to 380 nm (em: 505 nm) in the presence of an outwardly-directed Na+ gradient across the vesicles membrane, indicate that the influx of Ca2+ is increased by 152.5% and 147.4% for dogfish and bovine vesicles, respectively. The Na+ influx into the vesicles is also enhanced by 154.1% for dogfish and 149.1% for bovine lens when an outwardly-directed Ca2+ was present. This stimulation is not affected when either 50 microM valinomycin, or 50 mM K+ is present. The activity of this bidirectional Ca2+/Na+ exchanger could be inhibited by 100 microM bepridil or 200 microM La3+. The entrance behaviour of Cl- as monitored by the SPQ fluorescent signal indicates that, the Cl- influx is Na(+)-dependent. The Cl- influx is stimulated 152.8% and 187.6% for dogfish and bovine lens, respectively, when an inwardly-directed Na+ gradient is present, and is further enhanced when a K+ gradient is also present. The stoichiometry of Na+ to Cl- entering the vesicles was 1:2. This Na+,K+ 2Cl- cotransporter is not affected by 20 microM valinomycin or 50 mM K+. However, the transporter is completely inhibited by 50 microM furosemide.(ABSTRACT TRUNCATED AT 250 WORDS)
The Role of Gastric Helicobacter and N‐methyl‐N′‐nitro‐ N‐nitrosoguanidine in Carcinogenesis of Mice

Background. The aim of this study was to determine whether gastric epithelial proliferation due to gastric Helicobacter infection in mice represents a preneoplastic lesion. Materials and Methods. Helicobacter heilmannii infected and uninfected mice were treated with 150 μg/ml N-methyl-N′-nitro-N-nitrosoguanidine in drinking water for either 20 or 38 weeks. Mice were killed 12 or 18 months after bacterial inoculation. Results. All infected mice developed lymphoplasmocytic gastritis and epithelial hyperplasia. Proliferative gastric lesions were characterised by nodular hypertrophy of the glandular mucosa, multifocal epithelial hyperplasia, and elevated BrdU labeling index. Intestinal metaplasia and true atrophy were not present but proliferative glands were poorly differentiated, lined by mucus-type epithelial cells with no parietal, chief or other specialized cell types. Neoplasms developed only in MNNG-treated mice. of the 180 treated mice the following neoplasms developed: 14 squamous cell carcinomas of mouth and forestomach; 37 hemangiosarcomas of the intestinal serosa; and 15 splenic lymphomas. No tumors were present in the glandular gastric mucosa, and infection did not affect tumor incidence. p53 overexpression occurred in 79% of hemangiosarcomas and 71% of squamous cell carcinomas but not in normal or proliferative gastric glandular mucosa. Conclusions. Gastric proliferative lesions in Helicobacter-infected mice are not preneoplastic, and the combination of an alkylating agent and non-neoplastic proliferation does not result in gastric carcinogenesis in mice.
Ab Initio Calculation of One‐Center Integrals of Semiempirical Theories of Valence

In order to highlight some of the apparent contradictions between semiempirical and ab initio theories of valence, a brief review of some facets of the two approaches is presented. The recently developed effective valence shell Hamiltonian, , is then briefly introduced to bridge the gap. Results of purely ab initio Hv calculations for atoms and simple molecules are mentioned. The ab initio one-center integrals are quantitatively much different from those of semiempirical theories. However, the exact contains extra terms, three- (or higher) electron interactions, which are totally absent in semiempirical theories. This paper shows that the nonclassical, three-electron terms are incorporated into semiempirical one- and two-electron integrals, and a parametrization scheme illustrating this is presented. As an example, the carbon system is chosen and the one-center carbon semiempirical integrals are calculated from the results of ab initio calculations for C and CH. This enables discussions of questions of the degree of transferability of semiempirical one-center integrals. The one-center one- and two-electron integrals obtained from ab initio calculations by including the effects of three-electron terms are found to be close to the traditional semiempirical values.
Recombination site selection by Tn3 resolvase: Topological tests of a tracking mechanism

Abstract In vitro recombination by Tn3 resolvase of plasmids containing two directly repeated recombination ( res ) sites generates two singly interlinked catenated rings. This simple product catenane structure was maintained over a wide range of substrate supercoil densities and in a reaction mixture in which phage λ. Int-mediated recombination generated its characteristic multiply interlinked forms. Using substrates containing four res sites, we found that resolvase recombined neighboring res sites with high preference. This position effect implies that resolvase searches systematically along the DNA for a partner site. Intervening res sites in the opposite orientation did not prevent translocation. We analyzed the geometric arrangement of the interlocked rings after multiple recombination events in a four-site substrate and the pattern of segregation of nonspecific reporter rings catenated to the standard substrate. The results of these novel topological tests imply that the translocating enzyme may not make continuous contact with the DNA.
Mating-induced ovarian recrudescence in the red-sided garter snake.

In the female red-sided garter snake (Thamnophis sirtalis parietalis) mating initiates a neuroendocrine reflex that has both a short-term (within hours) effect on circulating estrogen concentrations and a long-term (6–7 weeks) effect on ovarian development. The perception of mating appears at least facultative, if not obligatory, for the initiation and maintenance of vitellogenesis and hence successful reproduction.
Ultrahigh-resolution imaging of biological systems based on standing-wave total internal reflection microscopy

Light microscopy is widely used in biomedical research. Its power derives from the ability to study living biological systems on the microscopic scale. Since its inception over three centuries ago, there has been little improvement in the lateral resolution of optical microscopy. Today, electron microscopy is one of the few methods capable of imaging on length scales below 100nm. Although electron microscopy is a powerful high resolution imaging technique, it is restricted to study fixed specimens. Clearly, there is a need for developing an in vivo optical technique with significantly improved lateral resolution. We have recently developed a new technique, Standing Wave Total Internal Reflection Microscopy (SW-TIRM), that can reach a resolution of about 50 nm. However, the theoretical basis for resolution enhancement in standing-wave total internal reflection microscopy has not been completely examined. SW- TIRM technique relies on the formation of an excitation field containing super-diffraction limited spatial frequency components. While the fluorescence generated at the object planes contains high frequency information of the object distribution, this information is lost at the image plane where detection optics act as a low pass filter. From the perspectives of point spread function engineering, one can show that if this excitation field is translatable experimentally, the high frequency information can be extracted from a set of images where the excitation fields have different displacement vectors. We have developed algorithms for this task that combine this image set to generate a composite image with an effective point spread function that is equal to the product of the excitation field and the Fraunhofer point spread function.
Collagenase-1 and collagen in epidermal repair

An invariable feature of wounded skin, whether a normally healing or chronic lesion, is the expression of collagenase-1 by migrating basal keratinocytes. Collagenase-1 is a member of the matrix metalloproteinase family of enzymes and is the principal human enzyme which cleaves native fibrillar collagen. Following injury, basal keratinocytes move from the basement membrane and interact with new connective tissue proteins in the dermis and wound bed. Contact with native type I collagen, the most abundant protein in the dermis, induces expression of collagenase-1. This metalloproteinase cleaves collagen, thereby altering its structure and, hence, the affinity to which cells bind it. Thus, collagenase-1 serves a beneficial role in wound healing by facilitating the movement of keratinocytes over the collagen-rich dermis during reepithelialization.
Phase separation properties of several aqueous alkyldimethylphosphine oxide/phospholipid mixtures and their potential use for protein purification

Abstract The phase separation properties of several aqueous alkyldimethylphosphine oxide/phospholipid mixtures were investigated. The addition of synthetic phospholipids with acyl residues ranging from 12 to 18 carbon atoms, a soybean phospholipid extract, and a red blood cell ghost extract lowered the temperature of phase separation below that of the surfactant alone. The high relative viscosity of the top layer suggests that asymmetric mixed micelles exist, whereas the relative viscosity of the bottom layer approached the value of 2.5 expected for spherical particles. The relative concentration of lipid in the top layer decreased with increasing molecular weight for the synthetic lecithins. The addition of 0.1 M univalent salts was investigated and no dependence of the cloud point on cation size was observed. However, a set of potassium halides exhibited a trend which followed the Hofmeister series. Finally, the composition of the top and bottom layers was investigated at 38, 42, 48 and 55°C for one DodDPO/DMPC mixture, and the solute was observed to be progressively concentrated in a smaller volume as the temperature was increased for each of five initial concentrations ranging from 12 to 53.6 mg/ml.
Evidence for complete translational and reflectional invariance in visual object priming.

The magnitude of priming on naming reaction times and on the error rates, resulting from the perception of a briefly presented picture of an object approximately 7 min before the primed object, was found to be independent of whether the primed object was originally viewed in the same hemifield, left—right or upper—lower, or in the same left—right orientation. Performance for same-name, different-examplar images was worse than for identical images, indicating that not only was there priming from block one to block two, but that some of the priming was visual, rather than purely verbal or conceptual. These results provide evidence for complete translational and reflectional invariance in the representation of objects for purposes of visual recognition. Explicit recognition memory for position and orientation was above chance, suggesting that the representation of objects for recognition is independent of the representations of the location and left—right orientation of objects in space.
A New Thermionic Instrument

A new form of vacuum tube voltmeter that has certain merits not possessed by existing instruments is described by this paper. Advantage is taken of the properties of a bridge circuit, one of whose arms is the plate-filament impedance of a common three-element pliotron to permit the building of very sturdy instruments of unusual sensitivity and dependability.
Accretive Operators and Markov Decision Processes

The dynamic programming functional equation for an abstract, continuous parameter, Markov decision process is shown to involve an operator which is m-accretive, thus giving rise to a nonlinear semigroup, called the Bellman semigroup. A class of controls is specified for which the maximum expected reward over a finite planning horizon is given by this semigroup. This theory is applied to controlled jump, diffusion, and storage processes.
Alternate reality games: a realistic approach to gaming on campus?

In January and February 2010, a project team at the University of North Carolina at Chapel Hill ran the University's first alternate reality game (ARG) designed for learning. This paper describes the design of the ARG and offers suggestions for creating, marketing, and running an educational ARG.
The patch microstructure in concrete : Evidence that it exists and is not a backscatter SEM artifact

Abstract Many mortars and concretes have been shown by backscatter SEM to contain dense local patches of cement paste exhibiting few detectable pores adjacent to local patches that are highly porous. It has recently been alleged that the dense patches are artifacts induced in backscatter SEM examination in areas insufficiently impregnated with resin. In the present paper we present evidence that these allegations are incorrect. Fully resin-impregnated specimen surfaces show dense and porous patches, as do completely resin-free areas of specimen surfaces. Secondary electron examination in the resin-free areas shows that the porous patches clearly exhibit the rim brightness effects characteristic of empty pores, but the dense patches do not. The boundaries between dense and porous areas may or may not be sharp, and may vary in sharpness even in the same locality. The alleged “artifact” attributed to backscatter SEM is also readily observed in optical microscope thin section examination. Dense and porous patches are also seen in micro-CT examination, which involves no resin and indeed no specimen preparation at all. The patchy structure in hardened concrete appears to originate in corresponding areas of dense and open assemblages of cement grains in fresh concrete.
The digital computer and power system short-circuit calculations

Precalculation of short-circuit currents is necessary in order to provide effective protection of power systems against possible short circuits. A method for determining these currents by means of a digital computer is described. Among its advantages are speed, accuracy, and the ability to be operated without highly trained professional personnel.
Role of pain catastrophizing during pain processing in a cohort of patients with chronic and severe arthritic knee pain.

Abstract We examined the relationship between catastrophizing and a 3-stage model of pain processing, consisting of pain sensation intensity (stage 1), pain unpleasantness (stage 2), and suffering (stage 3). We studied 310 patients with chronic and severe osteoarthritic knee pain (68.7% female) using 4 competing structural equation models. A strong relationship was found between the suffering construct and its indicators. Of the 4 theoretically plausible models, we found a model with 3 specific pathways of pain sensation leading to the final stage of pain-related suffering. A unique contribution of this study is the integration of catastrophizing into the 3 pain stages. In this model, catastrophizing mediates the relationship between pain-related unpleasantness and suffering, as well as the relationship between sensation and suffering through unpleasantness. Psychological intervention targeting catastrophizing could provide reduction of pain-related suffering that adds to the benefits of therapies directed toward the primary sensory and immediate unpleasant dimensions of pain. These results emphasize the benefit of integrating knowledge of the psychological and neural mechanisms of pain.
Catalysis of the reduction of acetylene at poly-3-methylthiophene electrodes

Abstract Widespread interest has been evoked in recent years in conducting polymers due to their possibilities in the areas of battery/fuel cell research and electroanalysis. This study is part of a long-term effort to explore the potential applications of poly-3-methylthiophene (P3MT) electrodes, deposited both on noble metal electrodes and on active metals such as nickel, copper, iron and stainless steel, molybdenum (these are designated here as M/P3MT electrodes). Reported here are the results for the reduction of acetylene at M/P3MT electrodes, where M=Pt, glassy carbon, glassy carbon and Mo. We have found that it is possible to shift the product ratio for the reduction toward ethylene (as opposed to ethane) to a varying extent in these electrodes, especially when molybdenum is incorporated into the P3MT film.
Time window expansion for HDX analysis of an intrinsically disordered protein.

Application of typical HDX methods to examine intrinsically disordered proteins (IDP), proteins that are natively unstructured and highly dynamic at physiological pH, is limited because of the rapid exchange of unprotected amide hydrogens with solvent. The exchange rates of these fast exchanging amides are usually faster than the shortest time scale (10 s) employed in typical automated HDX-MS experiments. Considering the functional importance of IDPs and their association with many diseases, it is valuable to develop methods that allow the study of solution dynamics of these proteins as well as the ability to probe the interaction of IDPs with their wide range of binding partners. Here, we report the application of time window expansion to the millisecond range by altering the on-exchange pH of the HDX experiment to study a well-characterized IDP; the activation domain of the nuclear receptor coactivator, peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α). This method enabled mapping the regions of PGC-1α that are stabilized upon binding the ligand binding domain (LBD) of the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ). We further demonstrate the method’s applicability to other binding partners of the IDP PGC-1α and pave the way for characterizing many other biologically important ID proteins.
A model for simulation of the climate and hydrology of the Great Lakes basin

[1] The Coupled Hydrosphere-Atmosphere Research Model (CHARM) was developed by coupling the Regional Atmospheric Modeling System (RAMS) to models of the land hydrology of the Great Lakes basin and of the evaporation and thermodynamics of the Great Lakes. It is intended for running coupled atmosphere-surface climate scenarios for the Great Lakes basin, to gain a perspective that has been missed by running hydrologic models in off-line mode, driven by the output of global general circulation models. This paper presents validation of this model using historical atmospheric data to drive the regional embedded CHARM model. The current version of CHARM simulates the near-surface air temperature in the region quite well, with some positive bias during the winter and negative bias during the summer. Biases in the temperature averaged over 1 month and over the portion of the domain that is not directly forced by observations are less than or approximately 2 K. The annual precipitation has a positive bias of 6.6% and does well at placing the lake-effect precipitation areas, but may have too strong a west-east gradient. Simulation of annually averaged runoff meets well with expectations, but additional empirical fitting may be required to replicate the seasonal cycle. Aspects of the model that remain troublesome are the tendency for unrealistically low pressure at mean sea level and for persistent heavy low stratus clouds.
Excluded-Volume Effect on Dipole Moments of Polymer Chains

The excluded-volume effect on dipole moments of linear polymer chains is investigated by the perturbation method. Fixman’s formulation is followed here except for molecular models. In place of the multi-Gaussian-subchain model a more realistic model is adopted. The expansion factor αu for the dipole moment is found, up to the term in z3, to be αu2=1+(C1z+C2z2+C3z3+···)(‹r·u›02/‹r2›0‹u2›0) where r and u are the end-to-end and dipole-moment vectors, αu2=‹u2›/‹u2›0, the averages without and with the subscript 0 refer to those in the presence and in the absence of the excluded volume, and C’s and z are the familiar quantities in the similar expression for the end-to-end distance, αr2=1+C1z+C2z2+C3z3+···. This result strongly suggests αu2−1=(‹r·u›02/‹r2›0‹u2›0)(ατ2−1) An expression for ‹r·u›0 is given on the basis of the rotational-isomeric-state approximation for skeletal-bond rotations. From a structural symmetry consideration it is concluded that ‹r·u›0=0 and hence the excluded volume has no effect on dipole moments for polymers with no distinguishable direction along chain contours.
Board members' influence on the government‐nonprofit relationship

This study examines whether, how, and under what conditions nonprofit boards of directors influence the government and voluntary sector relationship. The survey responses of executive directors and board presidents in a randomly selected sample of 400 nonprofit organizations indicate that boards are not bystanders in the contracting relationship with government. Rather, many boards play multiple roles, simultaneously enhancing interdependence and maintaining the boundary between state government and nonprofits.
Importance of rearing-unit design and stocking density to the behavior, growth and metabolism of lake trout (Salvelinus namaycush)

Abstract Juvenile lake trout ( Salvelinus namaycush ) were held at different stocking densities (48 and 96 kg m −3 ) in rearing-units of different design (rectangular plug-flow, circular and cylindrical cross-flow) and the effects on behavior, growth and metabolism were examined. Ambient light levels and current velocities were measured in each of three tank sectors (upstream, middle and downstream) to determine their relative contributions to fish behavior and distribution. Rearing-unit design affected orientation to current, contact with surfaces, agonistic responses, turn rates and avoidance of or contact with other fish. Stocking density primarily affected contact with tank surfaces, avoidance and contact with other fish. Fish in circular tanks distributed themselves uniformly, whereas those in plug-flow tanks crowded upstream and those in cross-flow tanks congregated downstream. Stocking density affected fish distribution most in cross-flow and least in circular tanks. Ambient light, current velocity and total in situ aggression modified fish distribution at low stocking density, but at high density the effects of current velocity and total aggression were undetectable. Growth and food conversion were best in plug-flow, followed by cross-flow and then circular tanks. Net ammonia excretion and oxygen consumption were highest in circular tanks and lowest in cross-flow (NH 3 ) or cross-flow and plug-flow (O 2 ) tanks. Ammonia production was correlated with stocking density, but oxygen consumption was unrelated to density. Results demonstrate the interrelatedness of abiotic and biotic factors in fish culture and the ability to control fish behavior, growth and metabolism through the alteration of several physical and biological variables in the rearing unit.
The Oyster-drills on English Oyster-beds

THE occurrence of the American oyster-drill, Urosalpinx cinerea Say, on oyster beds in the River Blackwater, Essex, was recorded in NATURE (Aug. 18, 1928, P. 241), and has since been found to be present in great numbers on the shallower parts of these beds in summer-time. This pest, which was first confused with the rough tingle, Ocinebra erinacea (= Murex), has thus become acclimatised, like its congener, the American slipper-limpet, Crepidula fornicata, since its introduction from America, and unless care be taken may spread to other oyster-beds. There now occur in England three oyster-drills or tingles, which in the adult state bore holes through the shells of oysters—and other organisms—and devour the body of the prey through the hole made in the shell, namely:
A network that learns to recognize three-dimensional objects.

THE visual recognition of three-dimensional (3-D) objects on the basis of their shape poses at least two difficult problems. First, there is the problem of variable illumination, which can be addressed by working with relatively stable features such as intensity edges rather than the raw intensity images1,2. Second, there is the problem of the initially unknown pose of the object relative to the viewer. In one approach to this problem, a hypothesis is first made about the viewpoint, then the appearance of a model object from such a viewpoint is computed and compared with the actual image3–7. Such recognition schemes generally employ 3-D models of objects, but the automatic learning of 3-D models is itself a difficult problem8,9. To address this problem in computational vision, we have developed a scheme, based on the theory of approximation of multivariate functions, that learns from a small set of perspective views a function mapping any viewpoint to a standard view. A network equivalent to this scheme will thus 'recognize' the object on which it was trained from any viewpoint.