cssi/SciSciGPT-SciSciNet huggingface dataset:
Squamous-cell cancer of the skin in patients given PUVA and ciclosporin: nested cohort crossover study

Summary Background Immunosuppressive treatments have been associated with an increased risk of skin cancer, especially in patients who have had organ transplants. We aimed to assess the risk of skin cancer in patients taking the ciclosporin who had been exposed to psoralen and ultraviolet-A light (PUVA) and other treatments for severe psoriasis. Methods We did a nested cohort crossover study of 28 participants in the PUVA follow-up study who were on ciclosporin to compare the frequency of squamous-cell carcinoma before and after first use of ciclosporin. We also analysed the entire PUVA study cohort (1380) to assess the relation between use of this drug and frequency of squamous-cell carcinoma. Findings In the 5 years before first use, six of 28 (21%) ciclosporin users developed a total of 20 squamous cell cancers. After ciclosporin use (average follow-up 6 years), 13 (46%) developed a total of 169 squamous-cell carcinomas. In the nested cohort, after adjustment for amount of exposure to PUVA and methotrexate, incidence of tumours was seven times higher after first ciclosporin use than in the previous 5 years (incidence rate ratio 6·9 [95% Cl 4·3–11]). Multivariate analysis of the entire cohort showed that risk of squamous-cell carcinoma after any use of ciclosporin is close to that recorded for at least 200 PUVA treatments (3·1 [2·6–3·7] and 2·8 [2·6–3·2], respectively). Interpretation The risk of squamous cell cancer of the skin is increased by ciclosporin in patients with psoriasis who have been exposed to PUVA. Such risks should be balanced against the effectiveness of the drug and possible newer immunosuppressive agents.
Molybdenum cofactor deficiency in a patient previously characterized as deficient in sulfite oxidase

The metabolic status of a patient previously characterized as deficient in sulfite oxidase was reexamined applying new methodology which has been developed to distinguish between a defect specific to the sulfite oxidase protein and sulfite oxidase deficiency which arises as a result of molybdenum cofactor deficiency. Urothione, the metabolic degradation product of the molybdenum cofactor, was undetectable in urine samples from the patient. Analysis of molybdenum cofactor levels in fibroblasts by monitoring reconstitution of apo nitrate reductase in extracts of the Neurospora crassa mutant nit-1 revealed that cells from the patient were severely depleted. Quantitation of urinary oxypurines showed that hypoxanthine and xanthine were highly elevated while uric acid remained in the normal range. These results were interpreted to indicate a severe but incomplete deficiency of the molybdenum cofactor. The presence of very low levels of active cofactor, supporting the synthesis of low levels of active sulfite oxidase and xanthine dehydrogenase, could explain the metabolic patterns of sulfur and purine products and the relatively mild clinical symptoms in this individual.
Copper Concentrations in Channel Catfish Ictalurus punctatus Ponds Treated with Copper Sulfate

Copper sulfate (CuSO45H2O) is used to reduce the abundance of blue-green algae and combat off-flavor in channel catfish culture. Copper sulfate usually is applied at a concentration of one-one hundredth of the total alkalinity. A study was performed at the Auburn University Fisheries Research Unit to determine the duration of elevated copper (Cu) concentration following copper sulfate applications. Two alkalinity treatments, 20-40 mg/L and 110-130 mg/L (as CaCO3), were examined. Copper sulfate was applied biweekly for 14 wk at 03 mg/L for the low alkalinity treatment and 1.2 mg/L for the high alkalinity treatment. Total copper concentrations in pond waters declined to the background level by 48-h post treatment. In addition, total copper concentrations were determined in waters of 38 catfish production ponds located in west central Alabama. The mean and standard deviation were 0.0092 ± 0.0087 mg Cu/L. Copper quickly precipitates from the water or is absorbed by sediments following copper sulfate treatment. Although concentrations of copper in pond waters increase immediately following copper sulfate treatment, they rapidly decrease and seldom exceed the United States Environmental Protection Agency's National Recommended Water Quality Criteria for Priority Toxic Pollutants of 0.013-mg Cu/L. Findings of this study suggest that copper sulfate treatment will not contaminate effluent from catfish ponds because of the short time that applied copper remains in the water column. Furthermore, the most frequent applications of copper sulfate occur in late summer months when rainfall is minimal and pond overflow is rare.
S2. Therapeutic strategies based on overcoming immune resistance mechanisms within the melanoma tumour microenvironment

Meeting abstracts Two major categories of melanoma metastases have been observed based on gene expression profiling and confirmatory assays. One subgroup of patients has an inflamed phenotype that includes expression of chemokines, T cell markers, and other immunoregulatory factors. In contrast,
Extraintestinal non-Hodgkin's lymphoma presenting as obstructive jaundice in a patient with Crohn's disease

We report the case of a 58-yr-old woman, previously diagnosed with Crohn's disease of the duodenum, who presented with jaundice and an epigastric mass. Diagnostic studies revealed an extraintestinal non-Hodgkin's lymphoma located near the head of the pancreas and causing obstructive jaundice. A review of the literature indicates the rarity of this association. We discuss the etiology, pathogenesis, and management of extraintestinal lymphomas in patients with Crohn's disease.
A simulation of sulfur wet deposition and its dependence on the inflow of sulfur species to storms

Abstract Numerical precipitation scavenging models are used to investigate the relationship between the inflow concentrations of sulfur species to precipitation systems and the resulting sulfur wet deposition. Simulations have been made for summer and winter seasons using concentration ranges of SO 2 , aerosol SO 4 2− , H 2 O 2 and O 3 appropriate for the eastern U.S. summer simulations use one-dimensional timedependent convective cloud and scavenging models; winter simulations use two-dimensional steady-state warm-frontal models. Sulfur scavenging mechanisms include nucleation scavenging of aerosol, aqueous reactions of H 2 O 2 , O 3 and HCHO with S(IV), and nonreactive S(IV) scavenging. Over the wide range of conditions that have been examined, the relation between sulfur inflow and sulfur wet deposition varies from nearly linear to strongly nonlinear. The degree of nonlinearity is most affected by aerosol SO 4 2− levels and relative levels of SO 2 vs H 2 O 2 . Higher aerosol SO 4 2− levels (as found in summer) produce a more linear relation. The greatest nonlinearity occurs when SO 2 exceeds H 2 O 2 . Winter simulations show more nonlinearity than summer simulations.
Regulation of Gene Expression in Magnocellular Neurons in Rat Supraoptic Nucleus during Sustained Hypoosmolality

Hypoosmolality produces a dramatic inhibition of vasopressin (VP) and oxytocin gene expression in the supraoptic nucleus (SON). This study examines the effect of sustained hypoosmolality on global gene expression in the oxytocin and VP magnocellular neurons of the hypothalamo-neurohypophysial system, to identify genes associated with the magnocellular neuron's adaptation to this physiological condition. Using laser microdissection of the SON, T7-based linear amplification of its RNA, and a 35,319-element cDNA microarray, we compare gene expression profiles between SONs in normoosmolar (control), 1-desamino-[8-D-arginine]-VP-treated normoosmolar, and hypoosmolar rats. We found 4959 genes with statistically significant differences in expression between normosmolar control and the hypoosmolar SONs, with 1564 of these differing in expression by more than 2-fold. These genes serve a wide variety of functions, and most were up-regulated in gene expression in hypoosmolar compared with control SONs. Of these, 90 were preferentially expressed in the SON, and 44 coded for transcription-related factors, of which 15 genes were down-regulated and 29 genes were up-regulated in the hypoosmolar rat SONs. None of these transcription-related factor genes significantly changed in expression after sustained 1-desamino-[8-D-arginine]-VP-treatment alone, indicating that these changes were associated with the hypoosmolar state and not due solely to a decreased activity in the SON. Quantitative in situ hybridization histochemistry was selectively used to confirm and extend these microarray observations. These results indicate that the hypoosmolar state is accompanied by a global, but selective, increase in expression of a wide variety of regulatory genes in the SON.
Effects of visual imagery on visual sensitivity and pupil diameter.

Sensitivity to a visual stimulus can be reduced by instructions to S to maintain a visual image (Segal, 1971). Imagery in turn may produce an increase in pupil diameter (Simpson & Paivio, 1966). It is possible that changes in pupil diameter might change sensitivity in the experimental conditions used by Segal, so that the decline in sensitivity produced by imagery might be a result of pupillary dilation in response to imagery. This possible explanation of the decline in sensitivity was tested in this experiment and rejected. Other possible peripheral explanations of the effect require further research, including possible changes in accommodation that might be induced by visual imagery.
Quantitative evaluation of amorphous selenium (a-Se) for region-of-interest (ROI) fluoroscopy

ROI imaging techniques can improve image quality and reduce radiation dose to patient and staff when the optimal combination of filter material and image receptor is used. An investigation was conducted to evaluate the effect of thickness of a-Se (0.5 mm and 1.0 mm) on image contrast, contrast to noise ratio (CNR), and figure of merit (FOM) with or without ROI filters (various thickness' of Gd and Cu) and to compare the results with the corresponding values obtained using a 0.4 mm thick cesium iodide (CsI) image receptor. Simulated x-ray spectra and published attenuation coefficients were used to calculate the x-ray transmission through a broad range of thickness' of various contrast materials for beams of 50 to 100 kVp. The results indicate that a-Se provides substantially better contrast compared to CsI for barium and iodinated contrast media for all cases, especially when the combination of Gd filter and the thinner a-Se is used. Moreover, during ROI procedures, the thicker a-Se generally increases image contrast, CNR, and FOM compared to CsI. Although, the thinner a-Se provides the highest image contrast for all cases, its combination with Cu results in lower CNR and FOM at higher kVp's compared to CsI.
Strengthening in Gold Nanopillars with Nanoscale Twins

The role of growth twin boundaries on the slip activity of gold nanopillars under uniaxial compression was investigated by molecular dynamics simulation. A new type of size-dependent strengthening was found in twinned gold nanopillars. Strengthening resulted from slip arrests in the form of Lomer−Cottrell locks at the intersection of partial dislocations and twin boundaries. The significance of such phenomenon was found to depend on the twin size. These findings could help engineers design tunable mechanical properties in nanowires by interfacial plasticity.
Effects of the Insect Growth Regulator Difluhenzuron on Non-Target Aquatic Populations in a Louisiana Intermediate Marsh

A study was conducted in a Louisiana coastal marsh to determine the ecological impact of the insect growth regulator diflubenzuron on populations of non-target aquatic organisms. Six applications of diflubenzuron (28 mg AI/ha) over an 18-mo period caused statistically significant differences in the population density of aquatic organisms when treated and untreated populations were compared. Populations of 5 taxa (nymphs of Trichocorixa louisianae Jaczewski and Buenoa spp., Coenagrionidae naiad spp., Berosus infuscatus LeConte adults, and Hyalella azteca (Saussure)) were significantly (P 0.05) difference when the treated and untreated populations were compared.
Social Support and Suicidal Ideation in Older Adults Using Home Healthcare Services

Objective The objective of this study was to examine the associations between objective and subjective social support and suicidal ideation in older adults receiving home healthcare services. Method Participants were randomly selected from a sample of older adults newly starting skilled nursing care from a certified home health agency in Westchester County, NY. Research interviewers assessed 522 older adults aged 65 years and older who were receiving home care services. Subjective and objective components of social support were assessed using measures of social network, social interaction patterns, instrumental support, and perceptions of social support. Suicidal ideation was assessed using items from the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition and the Hamilton Depression Rating Scale. Results In bivariate analyses, neither objectively determined size of social network nor instrumental support was associated with suicidal ideation. However, lower social interaction patterns and lower perceived social support were significantly related to suicidal ideation. After adjusting for potential confounders, only lower perceived support remained significantly associated with suicidal ideation. In post hoc analyses of the perceptions of social support scale items, satisfaction with one's relationships and feeling useful to family and friends were significantly associated with a lower likelihood of suicidal ideation in the final multivariate logistic regression model controlling for possible confounding variables. Conclusions Subjective social support is a potentially modifiable risk factor for suicide in later life. Findings suggest that the perception of social support is an important construct to examine in future longitudinal studies examining risk and protective factors for suicidal ideation and behaviors in older adults.
A stochastic model for the AIDS epidemic involving several risk populations

In this paper I develop a stochastic model for the AIDS epidemic involving several risk populations. The probability generating function (PGF) of the latent persons, infective persons and AIDS cases is derived. By using this PGF, it is shown that the expected values, the variances and the covariances of the latent persons, infective persons and AIDS cases satisfy some ordinary differential equations. These equations have been solved numerically to assess effects of various factors on the AIDS epidemic.
Ecological Partitioning of Cercopithecus campbelli , C. petaurista , and C. diana in the Taï Forest

I determined the degree of ecological partitioning among 3 species of guenons (Cercopithecus campbelli, C. petaurista, and C. diana) in the Tai Forest, Cote d’Ivoire and used the partitioning data to understand competitive relationships among them. Over a 13-mo period, I measured ecological partitioning in terms of food and canopy stratum use for 2 habituated groups of each guenon species and also collected data on food availability. I found that the study species diverged primarily in food items consumed and vertical strata occupied. Cercopithecus petaurista ate much more foliage than the other species did and used mostly the middle strata (5–20 m). Cercopithecus diana ate primarily fruit and used mostly the upper strata (>20 m). Cercopithecus campbelli ate mostly fruit together with large amounts of animal matter and primarily occupied the ground and low strata (<5 m). Of the specific pairs, the diets of Cercopithecus campbelli/C. diana overlapped the most overall and decreased during the season of low fruit availability. Cercopithecus campbelli and C. diana age/sex classes also overlapped more than the age/sex classes of other species pairs. The results suggest that the potential for competition was more intense for Cercopithecus campbelli/C.diana relations than it is for other species pairs. I compare my results from Tai with those from other primate and guenon communities and demonstrate that dietary overlaps and seasonal dietary divergence are lower in Tai than in most other guenon communities.
Fundamental Optical Absorption in Magnesium Oxide

The optical absorption and reflectivity of single crystals of MgO and the optical absorption of thin films of MgO, both supported by a LiF substrate and unsupported, have been measured in the energy range from 6 ev to 13.5 ev. Absorption peaks due to impurities were observed at 6.0 ev, 6.3 ev, and 6.9 ev. The room-temperature fundamental absorption and reflectivity spectra are interpreted in terms of an exciton peak at 7.6 ev with a probable second peak at 8.8 ev. Some evidence is present for additional exciton structure on the low-energy side of the first peak. The width of the forbidden energy band in MgO is estimated to be about 8.7 ev. The effects of temperature and internal strains on the absorption spectra are discussed.
Treatment of warfarin-related intracranial hemorrhage: a comparison of prothrombin complex concentrate and recombinant activated factor VII.

Objective Warfarin-related intracranial hemorrhage (ICH) is a devastating complication of warfarin therapy. Several studies have demonstrated successful correction of the international normalized ratio (INR) using prothrombin complex concentrate (PCC) or recombinant activated factor VII (rFVIIa). To our knowledge, no study has directly compared these agents for treatment of warfarin-related ICH. Methods We retrospectively reviewed the charts of 15 patients who received rFVIIa and 9 who received PCC for treatment of warfarin-related ICH over a 2-year period. The primary objective was to compare the efficacy of rFVIIa and PCC in correcting the INR to 1.3 or less. Baseline INR was compared to INR obtained within 1, 3, 6, 12, and 24 hours after rFVIIa or PCC administration. Results Six patients in the rFVIIa group and five in the PCC group had a follow-up INR within 1 hour of agent administration. In the rFVIIa group, the mean INR decreased from 6.1 to 1.1 and from 2.3 to 1.48 in the PCC group. At 6 hours, all rFVIIa patients and six (67%) PCC patients had at least one subsequent INR, with 93% and 50% correcting to an INR of 1.3 or less. Mean dose for all patients included was 53.4 ± 17.5 μg/kg and 27.8 ± 15.4 units/kg for rFVIIa and PCC, respectively. Conclusion Correction of the INR is more reliably obtained with rFVIIa when compared to PCC. Larger, prospective studies comparing these therapies for warfarin-related ICH are needed.
The role of rationalization in consumer decision processes: A revisionist approach to consumer behavior

Consumer behavior theory, as it has largely evolved from economics with its rigid adherence to marginal utility theory, suggests that consumers are highly rational and that they basically strive to maximize utility or satisfaction by the careful rationing of resources. In this paper, the typical assumptions in consumer decision process models are reviewed and analyzed, the empirical evidence supporting the models of the rational consumer is challenged, the concept of rationalization is developed and the existential support for the concept is examined, the role and significance of alternative ego state on consumer decision processes are explained and finally, the rudiments of a revisionist approach to consumer behavior are advanced.
A comparison of dedicated 1.0 T extremity MRI vs large-bore 1.5 T MRI for semiquantitative whole organ assessment of osteoarthritis: the MOST study

Summary Objective To date semiquantitative whole-organ scoring of knee osteoarthritis (OA) relies on 1.5 Tesla (T) Magnetic resonance imaging (MRI) systems. Less costly 1.0T extremity systems have been introduced that offer superior patient comfort, but may have limitations concerning field-of-view and image quality. The aim of this study was to compare semi-quantitative (SQ) scoring on a 1.0T system using 1.5T MRI as the standard of reference. Methods The Multicenter Osteoarthritis Study (MOST) is a longitudinal study of individuals who have or are at high risk for knee OA. A sample of 53 knees was selected in which MRI was performed on a 1.0T extremity system as well as on a 1.5T scanner applying a comparable sequence protocol. MRIs were read according to the Whole Organ Magnetic Resonance Imaging Score (WORMS) score. Agreement was determined using weighted kappa statistics. Sensitivity, specificity and accuracy were assessed using the 1.5T readings as the reference standard. In addition the number of non-readable features was assessed. Results Agreement (w-kappa) for seven main WORMS features (cartilage, bone marrow lesions (BMLs), osteophytes, meniscal damage and extrusion, synovitis, effusion) ranged between 0.54 (synovitis) and 0.75 (cartilage). Sensitivity ranged between 68.1% (meniscal damage) and 88.1% (effusion). Specificity ranged between 63.6% (effusion) and 96.4% (BMLs). Although the overall rate of non-readable features was very low, it was higher for the 1.0T system (1.9% vs 0.2%). Conclusions Semiquantitative whole organ scoring can be performed using a 1.0T peripheral scanner with a moderate to high degree of agreement and accuracy compared to SQ assessment using a 1.5T whole body scanner. Our results are comparable to the published inter- and intra observer exercises obtained from 1.5T systems. Sensitivity to change of longitudinal scoring was not evaluated in this cross-sectional design and should be investigated in future validation studies.
Mechanistic, mutational, and structural evaluation of a taxus phenylalanine aminomutase.

The structure of a phenylalanine aminomutase (TcPAM) from Taxus canadensis has been determined at 2.4 A resolution. The active site of the TcPAM contains the signature 4-methylidene-1H-imidazol-5(4H)-one prosthesis, observed in all catalysts of the class I lyase-like family. This catalyst isomerizes (S)-α-phenylalanine to the (R)-β-isomer by exchange of the NH2/H pair. The stereochemistry of the TcPAM reaction product is opposite of the (S)-β-tyrosine made by the mechanistically related tyrosine aminomutase (SgTAM) from Streptomyces globisporus. Since TcPAM and SgTAM share similar tertiary- and quaternary-structures and have several highly conserved aliphatic residues positioned analogously in their active sites for substrate recognition, the divergent product stereochemistries of these catalysts likely cannot be explained by differences in active site architecture. The active site of the TcPAM structure also is in complex with (E)-cinnamate; the latter functions as both a substrate and an intermediate. T...
The determinants of lifespan in the nematode Caenorhabditis elegans: a short primer.

Transparent, easily-maintained, amenable to genetic manipulation, and living for only a few weeks, the nematode Caenorhabditis elegans is a leading animal model for the study of the determinants of...
Inviscid Interactions Between Wake Vortices and Shear Layers

Aircraft trailing vortices can be influenced significantly by atmospheric conditions such as crosswind, turbulence, and stratification. According to the NASA 1994 and 1995 field measurement program in Memphis, Tennessee, the descending aircraft wake vortices could stall or be deflected at the top of low-level temperature inversions that usually produce pronounced shear zones. Numerical simulations of vortex/shear interactions with ground effects have been performed by several groups. Burnham used a series of evenly spaced line vortices at a particular altitude to model the ground shear layer of the cross- wind. He found that the wind shear was swept up around the downwind vortex and caused the downwind vortex to move upward, and claimed that the effect was actually produced by the vertical gradient in the wind shear rather than by the wind shear directly, because uniformly distributed wind-shear vortices would have no effect on the trailing vortex vertical motion. Recently, Proctor et al. numerically tested the effects of narrow shear zones on the behavior of the vortex pair, motivated by the observation of the Memphis field data. The shear-layer sensitivity tests indicated that the downwind vortex was more sensitive and deflected to a higher altitude than its upwind counterpart. The downstream vortex contained vorticity of opposite sign to that of the shear. There was no detectable preference for the downwind vortex (or upwind vortex) to weaken (or strengthen) at a greater rate.
Distorted learning from unusual medical anecdotes.

Summary Doctors are encouraged to look upon each patient as a learning experience (Wyngaarden, 1979). Caseoriented learning begins in the clinical years of medical school and continues throughout the professional career of the doctor. Clinical cases, or anecdotes, have the potential of producing accurate, relevant and meaningful learning for the clinician even though they are uncontrolled in a scientific sense. However, unusual or atypical cases can also result in erroneous learning which can negatively affect patient care. The purpose of this article is to identify difficulties in this form of subjective learning which can lead to suboptimal doctor practice patterns. Six actual clinical cases are briefly described to illustrate how inaccurate learning distorted subsequent clinical problem-solving by doctors. Suggestions are then made for ameliorating this difficulty.
Comparison of the peptide structural requirements for high affinity interaction with bombesin receptors

Recently it has been established that both a gastrin-releasing peptide (GRP)-preferring bombesin receptor and a neuromedin B-preferring bombesin receptor mediate the mammalian actions of bombesin-related peptides. Because many tissues used for studies of the structure-activity relationship of these peptides possess both receptor subtypes and none possess only the neuromedin B-preferring subtype, there is minimal information on the peptide structural features determining receptor selectivity and it is unknown whether the determinants of agonism at both bombesin receptor subtypes are similar. In the present study we have used native cells either possessing only one bombesin receptor subtype or stably transfected with one subtype to study in detail the peptide structural requirements for interacting and activating each receptor subtype. For the naturally occurring agonists, at the GRP-preferring bombesin receptor the relative affinities were litorin = ranatensin = bombesin > GRP >> neuromedin B, phyllolitorin and at the neuromedin B-preferring bombesin receptor were litorin = neuromedin B = ranatensin > bombesin, phyllolitorin >> GRP. For the GRP-preferring bombesin receptor the heptapeptide and for the neuromedin B-preferring bombesin receptor the octapeptide was the minimal carboxyl fragment interacting with the receptor/or causing biologic activity, and the nonapeptide and full decapeptide, respectively, were the minimal required for full affinity. Making neuromedin B more bombesin- or GRP-like by replacing amino acids in position 3, 6, and 9 demonstrated that position 3 was the most important, followed by position 9 for receptor subtype selectivity. A conformationally restricted GRP analogue, [D-Cys6,D-Ala11,Cys14]bombesin-(6-14) had a significantly higher affinity for GRP-preferring bombesin receptor than NMB receptor. These results demonstrate that: (1) the structure-function relations for the two mammalian bombesin receptors have important differences; (2) suggest that the active conformation of neuromedin B must differ markedly from the beta-sheet model proposed for GRP; and (3) suggest that one important function of the NH2 terminus of GRP and neuromedin B is determining receptor subtype selectivity.
Purification and Properties of an Acid Phosphoprotein Phosphatase from Lactating Bovine Mammary Gland with Activity Toward Phosphotyrosine

Abstract An acid phosphatase has been partially purified from lactating bovine mammary gland. Properties of this enzyme were compared with those of a well-characterized phosphoprotein phosphatase from bovine spleen. The two enzymes were similar in their activation by sulfhydryl reagents and inhibition by metal chelating agents. Both enzymes rapidly hydrolyze ATP and aromatic phosphates and are relatively inactive toward alkyl phosphates; both are tartrate-resistant phosphatases. The mammary enzyme has a low Michaelis constant for α s 1 -casein (42μ M ), and thus, like the spleen enzyme, appears to be a phosphoprotein phosphatase. Finally, the spleen and mammary enzymes displayed reactivity toward phosphotyrosine, a model substrate for phosphotyrosyl protein phosphatase. Thus, the phosphatases from spleen and mammary gland are quite similar in reactivity and could possibly be similar in function.
Inhibition of ferricyanide reduction in chloroplast particles by anaerobicity

Abstract The reduction of ferricyanide by spinach and pea chloroplast particles was the same under aerobic or anaerobic conditions. The rate of ferricyanide reduction by these particles uncoupled by ammonium chloride or carboxycyanide p-trifluoromethoxyhydrazone, or Chlamydomonas reinhardi or Euglena gracilis particles uncoupled by sonic oscillation, was inhibited by anaerobic conditions. This inhibition by anaerobicity may explain the cessation of the photolysis of water as measured by H2 production in reconstituted preparations consisting of chloroplast particles, ferredoxin and fully active hydrogenase.
Resistance of hippocampal synaptic transmission to hypoxia in carbonic anhydrase II-deficient mice

Abstract Mutant Car2 n /Car2 n mice deficient in carbonic anhydrase II (CA II; a major brain CA isozyme) suffer from systemic acidosis and are more resistant to experimental seizures than their normal littermates (+/+ or +/Car2 n ). The N -methyl-D-aspartate (NMDA) subtype of glutamate receptor has been shown to contribute to long-term potentiation (LTP) of synaptic transmission, hypoxic/ischemic neuronal injury and to be blocked by extracellular protons (acidosis). We compared the effects of hypoxia on synaptic transmission and LTP in field CA1 of hippocampal slices from CA II-deficient mice to their normal littermates. Slices were subjected to successive 5, 10 and 15 min-periods of hypoxia with 30 min-recoverry periods in between. Hippocampal slices from mutant, CA II-deficient mice, were more resistant to all periods of hypoxia tested than slices from normal littermates. In a separate set of mutant and normal slices, there were no differences in LTP of population spike amplitude. The relative resistance of CA II-deficient mice to hypoxia-induced damage may be a consequence of severe interstitial acidosis. The sustained influence of increased extracellular proton concentrations may change the characteristics of NMDA receptors resulting in an increased resistance of synaptic transmission in CA II-deficient mice to hypoxia compared to controls.
A hybrid mixture discriminant analysis-random forest computational model for the prediction of volume of distribution of drugs in human.

A computational approach is described that can predict the VDss of new compounds in humans, with an accuracy of within 2-fold of the actual value. A dataset of VD values for 384 drugs in humans was used to train a hybrid mixture discriminant analysis−random forest (MDA-RF) model using 31 computed descriptors. Descriptors included terms describing lipophilicity, ionization, molecular volume, and various molecular fragments. For a test set of 23 proprietary compounds not used in model construction, the geometric mean fold-error (GMFE) was 1.78-fold (±11.4%). The model was also tested using a leave-class out approach wherein subsets of drugs based on therapeutic class were removed from the training set of 384, the model was recast, and the VDss values for each of the subsets were predicted. GMFE values ranged from 1.46 to 2.94-fold, depending on the subset. Finally, for an additional set of 74 compounds, VDss predictions made using the computational model were compared to predictions made using previously de...
Multifunctional brushes made from carbon nanotubes.

Brushes are common tools for use in industry and our daily life, performing a variety of tasks such as cleaning, scraping, applying and electrical contacts. Typical materials for constructing brush bristles include animal hairs, synthetic polymer fibres and metal wires (see, for example, ref. 1). The performance of these bristles has been limited by the oxidation and degradation of metal wires, poor strength of natural hairs, and low thermal stability of synthetic fibres. Carbon nanotubes2,3, having a typical one-dimensional nanostructure, have excellent mechanical properties, such as high modulus and strength4,5,6, high elasticity and resilience7, thermal conductivity8 and large surface area (50–200 m2 g−1)9. Here we construct multifunctional, conductive brushes with carbon nanotube bristles grafted on fibre handles, and demonstrate their several unique tasks such as cleaning of nanoparticles from narrow spaces, coating of the inside of holes, selective chemical adsorption, and as movable electromechanical brush contacts and switches. The nanotube bristles can also be chemically functionalized for selective removal of heavy metal ions.
Persistent organic pollutants and policy.

Paul Webster's News of the Week article “For precarious populations, pollutants present new perils” (14 March, p. [1642][1]) testifies to the sometimes difficult relationship between scientific discovery and public policy. In the case of persistent organic pollutants (POPs), however, increases in our understanding of the production, transport, fate, and impact of these toxic chemicals have often led to meaningful changes in public policy in Canada, Europe, and the United States. Perhaps the most important development in this regard is the 2001 Stockholm Convention on Persistent Organic Pollutants. This global treaty places immediate, binding controls on 12 particularly pernicious POPs, often referred to as the “dirty dozen”; establishes scientifically based criteria for establishing controls on additional POPs; and mandates additional national and international research into POPs and their environmental and health impacts. Canada has long been a leading and influential advocate for international POPs science and policy. Its government should be encouraged to continue this leadership and to meet its research obligations under the Convention by continuing the important Arctic Science and the Northern Contaminants Program discussed in the article. In the United States and Europe, President Bush and other leaders should keep their promises to support full ratification and implementation of the Convention in their own countries and throughout the world. Science has shown us the problems. Policy-makers must now use that knowledge effectively. [1]: /lookup/doi/10.1126/science.299.5613.1642b
Motherhood and Earnings: Wage Variability by Major Occupational Category and Earnings Level

Prior research has indicated that women with children earn less than their childless counterparts. In addition, recent research has found that the motherhood wage penalty may be most severe for low-income earners. Using panel data from the National Longitudinal Survey of Youth (1979), we test two hypotheses. First, are there occupational differences in the motherhood wage penalty? Second, are there occupational differences in the relative wage penalty experienced by low and high wage mothers? Our results indicated that mothers in sales occupations are penalized at a significantly higher rate than mothers in non-sales occupations, while mothers in blue-collar occupations were penalized the least. Furthermore, the wage cost of motherhood was greatest amongst the highest earners in sales occupations.
Weight Change in Pediatric TennCare Recipients Referred to a Commercial Weight Loss Program

Abstract Background The epidemic of overweight and obesity in the United States is not limited to adults but also affects children and adolescents. Low-income children are disparately affected because they have an elevated risk for developing obesity. Effective interventions are urgently needed to prevent and treat obesity in children. In 2006, Tennessee Medicaid (TennCare) and Weight Watchers formed the TennCare Weight Watchers Partnership Program, which allowed pediatric recipients to attend Weight Watchers with no out-of-pocket cost. Methods This study is a nonconcurrent prospective analysis of administrative data from the TennCare Weight Watchers Partnership Program. It examined the weight change of TennCare beneficiaries between the ages of 10 and 17 who participated in the program from January 2006 to January 2009 and compared the weight change to the recommendations of the Expert Committee Recommendations Regarding the Prevention, Assessment, and Treatment of Childhood and Adolescent Overweight and Obesity. Results Fifty-three percent of participants either met or exceeded the recommendations of the panel on childhood obesity at the end of their involvement in the program. Participants who attended the program for more than 12 weeks and those who attended 10 or more meetings had a 5% decrease in their body mass index z score. Conclusions The TennCare Weight Watchers Partnership Program was successful in helping a majority of children and adolescents who participated to meet or exceed the Expert Committee's recommendations. This type of partnership can give children in low-income families the opportunity to participate in a structured program with a good chance of success.
Adaptive Position and Attitude-Tracking Controller for Satellite Proximity Operations Using Dual Quaternions

This paper proposes a nonlinear adaptive position and attitude-tracking controller for satellite proximity operations between a target and a chaser satellite. The controller requires no information about the mass and inertia matrix of the chaser satellite and takes into account the gravitational acceleration, the gravity-gradient torque, the perturbing acceleration due to Earth’s oblateness, and constant (but otherwise unknown) disturbance forces and torques. Sufficient conditions to identify the mass and inertia matrix of the chaser satellite are also given. The controller is shown to ensure almost global asymptotical stability of the translational and rotational position and velocity tracking errors. Unit dual quaternions are used to simultaneously represent the absolute and relative attitude and position of the target and chaser satellites. The analogies between quaternions and dual quaternions are explored in the development of the controller.
Soft constraints in identification of distributed parameters

In this article, we introduce an idea of using soft constraint to improve effectiveness of existing optimization methods for identifying unknown parameter zones for distributed parameter identification problems. The constraint is put on the projected size of each parameter zone. But the constraint is only softly imposed due to uncertainty consideration. Two identification procedures based on such a constrained optimization idea are described. Results on three examples are presented to illustrate the advantages of this new approach.
Mass Transport Properties of Co(polyether)polyurethane Membranes II: Permeability and Sorption Characteristics

Abstract A series of co(polyether)polyurethane polymers containing polyethylene glycol 600, 1000, or 1540 was synthesized, purified by reprecipitation, and cast into clear, tough, flexible membranes using the solution method. Hydration and membrane swelling increased with increasing polyethylene glycol molecular weight. Paroxypropione, 5‐nitrosalicylic acid, sulfaguanidine, and phenylbutazone were used as penetrants at a 1 m M donor concentration. Transport rates through the 1540 and 1000 copolymer membranes were in decreasing order: paroxypropione > 5‐nitrosalicylic acid > sulfaguanidine > phenylbutazone; however, through the 600 copolymer membrane the rates were paroxypropione 5‐nitrosalicylic acid ˜ sulfaguanidine. Phenylbutazone did not penetrate during the experiment. Good agreement was obtained between apparent diffusion coefficients calculated by both the time lag and nonsteady‐state methods. Boundary layer effects were examined by variations in stirring speeds. Evidence that diffusion may occur primarily through the aqueous region of the hydrated membranes is presented.
Reversal of Global CD4+ Subset Dysfunction Is Associated with Spontaneous Clinical Resolution of Pulmonary Sarcoidosis

Sarcoidosis pathogenesis is characterized by peripheral anergy and an exaggerated, pulmonary CD4 + Th1 response. In this study, we demonstrate that CD4 + anergic responses to polyclonal TCR stimulation are present peripherally and within the lungs of sarcoid patients. Consistent with prior observations, spontaneous release of IL-2 was noted in sarcoidosis bronchoalveolar lavage CD4 + T cells. However, in contrast to spontaneous hyperactive responses reported previously, the cells displayed anergic responses to polyclonal TCR stimulation. The anergic responses correlated with diminished expression of the Src kinase Lck, protein kinase C-θ, and NF-κB, key mediators of IL-2 transcription. Although T regulatory (Treg) cells were increased in sarcoid patients, Treg depletion from the CD4 + T cell population of sarcoidosis patients did not rescue IL-2 and IFN-γ production, whereas restoration of the IL-2 signaling cascade, via protein kinase C-θ overexpression, did. Furthermore, sarcoidosis Treg cells displayed poor suppressive capacity indicating that T cell dysfunction was a global CD4 + manifestation. Analyses of patients with spontaneous clinical resolution revealed that restoration of CD4 + Th1 and Treg cell function was associated with resolution. Conversely, disease progression exhibited decreased Th1 cytokine secretion and proliferative capacity, and reduced Lck expression. These findings implicate normalized CD4 + T cell function as a potential therapeutic target for sarcoidosis resolution.
Factors influencing partners' involvement in women's contraceptive services.

Abstract Background Involving women's partners in family planning services may be one avenue by which rates of unplanned pregnancies can be reduced. Study Design In 2009, we surveyed a nationally representative sample of 2113 women aged 18–49 years receiving services from Title X family planning clinics in the United States about their contraceptive use and their current partner, including partners' past involvement in seeking and obtaining contraceptive services. Results More than half of the women in the sample (56%) indicated that their partners were at least partially involved in their contraceptive services. In the multivariable analysis, race/ethnicity, union status and relationship satisfaction were all significant predictors of partner involvement in contraceptive services. Women reporting that their partners interfere with their birth control were nearly twice as likely as women without interfering partners to report those partners being involved in their contraceptive services. Contraceptive use at last sex was not associated with partner involvement in contraceptive services in either bivariable or multivariable analyses. Conclusion In designing future couple-focused programs, clinics may need to focus on the interpersonal dynamics of couple-based decision-making and behaviors and tailor their programs given the characteristics of clients most likely to avail themselves of these services.
Functional defect of heat-inactivated human lymphocytes in mixed-lymphocyte culture.

Abstract Possible causes were examined for the inability of heat-inactivated lymphocytes to induce proliferative responses in mixed-lymphocyte cultures (MLC). Cells heated at 45 °C for 60 min lost >90% of their capacity to stimulate in primary (1 °c) or secondary (2 °c) MLC. This was not due to accelerated or delayed proliferation, nor to a simple quantitative loss of antigen since a 10-fold increase in stimulators or sequential addition of heated stimulators at 4-hr intervals was ineffective. Heated B lymphocytes had approximately 80% expression of HLA-DR and DQ antigens compared to unheated B cells when measured by flow cytometry using monoclonal antibodies detecting both monomorphic and polymorphic antigens. Contrary to some reports, there was no evidence of direct suppression or induction of suppression by heated stimulators or their supernatants. Reconstitution of 1 °c and 2 °c MLC with crude MLC supernatants or more purified interleukin 1 (Il-1) or interleukin 2 (Il-2) was unsuccessful. The results indicate the heatinduced defect occurs immediately and is not due to direct or indirect suppression, insufficient amounts of Il-1 or Il-2, nor loss of polymorphic Class II HLA determinants. Heat inactivation of stimulator function may result from failure to present an “immunogenic grid” or loss of accessory molecules required in lymphocyte interactions.
Low bit rate CELP using ternary excitation codebook

Code excited linear predictor coders hold promise to achieve high quality speech at low bit rates. We propose a ternary excitation based CELP coder with a new structure to achieve toll quality speech at 4 kbps. Speech quality is maintained by allocating more bits for the codebook index allowing for larger codebooks which provide better speech quality as quantization levels increase. To allocate more bits for the codebook index a backward adaptive 10-th order LPC predictor is used. Regular structure of the lattice codebook and convexity of error surface have been exploited to greatly improve the efficiency of the search algorithm. The storage requirement of the codebook is eliminated by transmitting the position of three weights used in generating the ternary codebook instead of the codebook index. Speech quality obtained using the new CELP structure is studied and results compared with the LBG and the Gaussian codebooks.
Enhancing the quality of teaching and learning: The U.S. experience

In the United States greater attention is being paid to learning that is more collaborative, actively engaged, and technologically enhanced.
The Renal Manifestations of Thyroid Disease

Thyroid hormones influence renal development, kidney structure, renal hemodynamics, GFR, the function of many transport systems along the nephron, and sodium and water homeostasis. These effects of thyroid hormone are in part due to direct renal actions and in part are mediated by cardiovascular and systemic hemodynamic effects that influence kidney function. As a consequence, both hypothyroidism and hyperthyroidism associate with clinically important alterations in kidney function and have relevance to its assessment. Disorders of thyroid function have also been linked to development of immune-mediated glomerular injury, and alterations in thyroid hormones and thyroid hormone testing occur in patients with kidney disease.
Difluprednate: changing the landscape of ocular pharmacology

Ophthalmic surgery has evolved substantially during the last 40 years to include minimally invasive procedures and premium intraocular lens implantation. Patients and physicians who invest in such advanced technology, materials and procedures expect equally advanced postoperative treatments. Ophthalmic pharmacology, however, has seen only modest gains during this same period. Difluprednate ophthalmic emulsion, a novel difluorinated prednisolone derivative, is the first strong ophthalmic steroid to be developed in the past 35 years and the first to be shown to reduce postoperative pain effectively, an attribute that may foster better compliance, result in fewer office visits and increase patient satisfaction. Other benefits include high potency, strong penetrability and a favorable safety profile; this suggests a wide spectrum of possible applications within ocular treatment.