cssi/SciSciGPT-SciSciNet huggingface dataset:
Arsenic toxicokinetic modeling and risk analysis: Progress, needs and applications

Arsenic (As) poses unique challenges in PBTK model development and risk analysis applications. Arsenic metabolism is complex, adequate information to attribute specific metabolites to particular adverse effects in humans is sparse, and measurement of relevant metabolites in biological media can be difficult. Multiple As PBTK models have been published and used or adapted for use in various exposure and risk analysis applications. These applications illustrate the broad utility of PBTK models for exposure and dose-response analysis, particularly for arsenic where multi-pathway, multi-route exposures and multiple toxic effects are of concern. Arsenic PBTK models have been used together with exposure reconstruction and dose-response functions to estimate risk of specific adverse health effects due to drinking water exposure and consumption of specific foodstuffs (e.g. rice, seafood), as well as to derive safe exposure levels and develop consumption advisories. Future refinements to arsenic PBTK models can enhance the confidence in such analyses. Improved estimates for methylation biotransformation parameters based on in vitro to in vivo extrapolation (IVIVE) methods and estimation of interindividual variability in key model parameters for specific toxicologically relevant metabolites are two important areas for consideration.
Between containment and rollback: the United States and the Cold War in Germany: Christian Ostermann, (Stanford: Stanford University Press, 2021), xix + 392 pp.

The three victors of the Second World War – the United States, Britain, and the Soviet Union – began redrawing the political, geographical, and demographic map of Europe at the 1944 summit meeting ...
Geometric Approximation Algorithms

Exact algorithms for dealing with geometric objects are complicated, hard to implement in practice, and slow. Over the last 20 years a theory of geometric approximation algorithms has emerged. These algorithms tend to be simple, fast, and more robust than their exact counterparts. This book is the first to cover geometric approximation algorithms in detail. In addition, more traditional computational geometry techniques that are widely used in developing such algorithms, like sampling, linear programming, etc., are also surveyed. Other topics covered include approximate nearest-neighbor search, shape approximation, coresets, dimension reduction, and embeddings. The topics covered are relatively independent and are supplemented by exercises. Close to 200 color figures are included in the text to illustrate proofs and ideas.
Abstract T P116: Impact of Serum Nutritional Status on Physical Function in African American and Caucasian Stroke Survivors

Difficulties with speech and cognition may interfere with obtaining accurate dietary records to assess dietary quality in those chronically disabled by stroke. Several serum biomarkers commonly found on general comprehensive chemistry panels (e.g. albumin, hemoglobin, uric acid, and lipids) may provide a surrogate clinical indication of nutritional risk when dietary recall is not valid. Thus, the purpose of this study was to determine whether serum nutritional markers differ by race and relate to physical function in stroke. Further, we sought to compare serum profiles in chronic stroke survivors with a representative sample of U.S. Adults (NHANESIII). Fasting serum samples were collected for analysis of lipids, hemoglobin, uric acid, and albumin in 145 African American (AA) and 111 Caucasian (C) stroke survivors (age: 60±1 years [mean±SEM]; BMI: 28 kg/m2). VO2max (N=159), six-minute walk (N=134), 30 foot timed walk (N=161), and isokinetic hamstring strength (N=91) tests were performed in subsets of stroke survivors. VO2max was “very poor” in 96% of stroke survivors and mean walking speed was 40% below recommendations for maintenance of functional independence. Lipids were less favorable in C than AA women stroke survivors (40% higher triglycerides (TG) and 11% lower HDL cholesterol; Ps<0.05). In contrast, serum albumin was 6% lower in AA than C women (P<0.05). Uric acid was ~10% lower in C than AA stroke survivors (P<0.05). These racial differences were similar to that observed in the reference sample, but HDL cholesterol, albumin, and hemoglobin generally were lower (Ps<0.05) in stroke. Lipids were more favorable (~20% lower total cholesterol and ~25% lower TG; Ps<0.01) in stroke, likely due to a high prevalence of lipid lowering medication usage (64%). Uric acid was related to six-minute walk time (r=0.16) and hamstring strength (r=0.20) in stroke survivors (Ps<0.05), suggesting that low uric acid qualifies as a marker worth monitoring in the context of predicting stroke-related functional decline. Although nutritional risk varies according to race in stroke, the racial differences appear similar to a representative U.S. non-stroke sample. Regardless of race, serum nutritional risk does appear elevated in stroke compared to the general population.
Chapter 22 Restless legs syndrome and periodic limb movements in sleep

Publisher Summary This chapter discusses restless legs syndrome (RLS) and periodic limb movements in sleep. Sleep disturbance is the main complaint that brings RLS patients in for treatment, but sleep disturbance is not necessary for the diagnosis of RLS. The leg discomfort and periodic leg movements in wakefulness in RLS may cause difficulty in initiating and maintaining sleep. Patients may experience daytime drowsiness because of the insomnia. The periodic limb movements in sleep usually do not cause conscious awareness of sleep disturbance in the patient, but spousal sleep disruption because of such leg kicks is common. The neurological examination is normal in the idiopathic and familial forms of the disorder. Cases associated with peripheral neuropathy and radiculopathy are also seen. There is an increased frequency of RLS in cases of renal failure and RLS may be temporarily exacerbated during pregnancy. Iron deficiency makes the symptoms of RLS worse and every patient should be screened for deficiency of the iron-binding protein, ferritin.
A linear method for deviation detection in large databases

We describe the problem of finding deviations in large data bases. Normally, explicit information outside the data, like integrity constraints or predefined patterns, is used for deviation detection. In contrast, we approach the problem from the inside of the data, using the implicit redundancy of the data. We give a formal description of the problem and present a linear algorithm for detecting deviations. Our solution simulates a mechanism familiar to human beings: after seeing a series of similar data, an element disturbing the series is considered an exception. We also present experimental results from the application of this algorithm on real-life datasets showing its effectiveness.
Iron Enzymes in Iron Deficiency. V. Succinic Dehydrogenase in Rat Liver, Kidney and Heart

Manometric determinations of the enzyme succinic dehydrogenase have been carried out on liver, heart and kidneys of iron-deficient and control rats. Even after prolonged, moderately severe iron deficiency, no decrease in enzyme activity of liver homogenates could be demonstrated. However, enzyme depletion could be demonstrated to have occurred in the hearts and kidneys of iron-deficient animals.
A real-time control, management and information transport architecture for broadband networks

A unified framework of an architecture for broadband networks is outlined. The network architecture is based on three fundamental principles: the separation principle, the layering principle and the principle of asynchronous resource management. Based on these three principles the network objects are organized into an integrated reference model (IRM). The IRM consists of the traffic control, the management and information transport architecture. These architectures run on different time scales. Their main requirement is to guarantee quality of service as negotiated at call set up. The traffic control model employed consists of a statistical and a dynamic database and a set of distributed algorithms that interact by writing and reading onto these databases. They are part of a network database capable of supporting monitoring, control, configuration and fault management tasks. The design of the network database is exemplified by modeling one of the fundamental building blocks of the future gigabit architecture. >
Scene segmentation of natural images using texture measures and back-propagation

Knowledge of the three-dimensional world is essential for many guidance and navigation applications. A sequence of images from an electro-optical sensor can be processed using optical flow algorithms to provide a sparse set of ranges as a function of azimuth and elevation. A natural way to enhance the range map is by interpolation. However, this should be undertaken with care since interpolation assumes continuity of range. The range is continuous in certain parts of the image and can jump at object boundaries. In such situations, the ability to detect homogeneous object regions by scene segmentation can be used to determine regions in the range map that can be enhanced by interpolation. The use of scalar features derived from the spatial gray-level dependence matrix for texture segmentation is explored. Thresholding of histograms of scalar texture features is done for several images to select scalar features which result in a meaningful segmentation of the images. Next, the selected scalar features are used with a neural net to automate the segmentation procedure. Back-propagation is used to train the feed forward neural network. The generalization of the network approach to subsequent images in the sequence is examined. It is shown that the use of multiple scalar features as input to the neural network result in a superior segmentation when compared with a single scalar feature. It is also shown that the scalar features, which are not useful individually, result in a good segmentation when used together. The methodology is applied to both indoor and outdoor images.
Inverse Problem on the Entire Line and Some Connected Questions of Spectral Theory

In this paper we consider several separate questions for one-dimensional-Schrodinger operators on the entire line. The paper consists of an Introduction, seven short Sections and three Appendices. Each of these Sections and Appendices is almost independent.
Abstract 3393: Nuclear receptor Nurr1 mediates cell proliferation and is involved in a p53-microRNA-34 regulatory network

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Nuclear receptor (NR) subfamily 4 member 2 (NR4A2), also known as Nurr1, has been shown to have oncogenic properties, in which it can mediate cell transformation, migration and drug resistance. However, the manner in which Nurr1 mediates these cancer-promoting features is not completely understood, but research implicates p53 as a potential intermediary. In this study, we show that Nurr1 enhances the proliferative rate of colorectal cancer cells. This increase in cell growth is accompanied by an upregulation of cyclin D3, a putative target gene of Nurr1. To understand how Nurr1 itself is regulated, we performed a reporter screen to identify microRNA regulators of Nurr1's 3’UTR. We identified miR-34c as a putative regulator of Nurr1 and this direct regulation was confirmed through site-directed mutagenesis of the predicted seed region. We next determined if p53 activation could affect Nurr1 expression through transcriptional activation of miR-34. Using Nutlin-3a to activate p53, we found that Nurr1 expression decreased in a dose response manner. Lastly, we sought to determine if Nurr1 could attenuate p53 activation. We found that overexpression of Nurr1 in colorectal cancer cells caused an attenuation of p53 transactivation of target genes following Nutlin-3a treatment. Our results suggest that a p53-miR-34-Nurr1 regulatory network exists, which would allow p53 to maintain Nurr1 in a suppressed state through miR-34-mediated regulation and prevent tumorigenesis. In cases of p53 mutation or Nurr1 overexpression, this network would be compromised, allowing Nurr1 to enhance tumorigenesis or drug resistance. Citation Format: Jordan A. Beard, Justin L. Hills, Alexa Tenga, Apana A. Takwi, Taosheng Chen. Nuclear receptor Nurr1 mediates cell proliferation and is involved in a p53-microRNA-34 regulatory network. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3393. doi:10.1158/1538-7445.AM2014-3393
Metal and plastic suture anchors for rotator cuff repair

The role of arthroscopy in the treatment of rotator cuff tears continues to evolve and expand. The arthroscope offers several advantages to open techniques. It provides clear visualization of the glenohumeral joint, smaller incisions, no deltoid detachment, less soft-tissue dissection, less pain, and more rapid rehabilitation. The past few decades have seen explosive technological advances in the availability of arthroscopic implants, as well as improvement in equipment designs that have made arthroscopy an effective and efficient treatment tool. The development of suitable arthroscopic implants has been critical to the success of arthroscopic tissue repair. These various suture anchors are often used to reattach torn tissue back to bone in the shoulder. The past decade has seen a proliferation in the designs and types of suture anchors available, and this proliferation in implant availability often presents a confusing plethora of options. Each anchor has individual characteristics that influence the appropriateness of its usage including size, shape, composition, and holding strength. In light of the prodigious and voluminous anchor options, we attempt to concisely discuss the individual characteristics and provide quantitative data for the various metal and plastic suture anchors. We divide the anchors into 5 groups based on composition and morphology consisting of metal screw anchors, nonscrew metal anchors, minianchors, plastic suture anchors, and newer anchor designs that have not yet been tested in comparative biomechanical studies.
Cytokine signaling in the brain: putting a SOCS in it?

A new family of cytokine-inducible proteins, termed "suppressors of cytokine signaling" (SOCS), was discovered recently; these proteins function as negative regulators of signaling pathways involved in the cellular actions of many cytokines, growth factors, and hormones. Gene manipulation studies in mice point to the central importance of individual SOCS proteins in maintaining homeostasis by limiting cellular responses to specific cytokines or growth factors in a variety of different physiological systems. Cytokines modulate a wide variety of biological responses in the CNS, so members of the SOCS family might play crucial roles in regulating intracellular signaling by these effectors in both normal and disease states. Although to date studies of the neurobiology of the SOCS family have been limited, we know that many SOCS genes are constitutively expressed in the developing and adult brain, whereas the expression of others, particularly the SOCS1 and SOCS3 genes, can be highly regulated. Furthermore, roles for the SOCS are now evident in the modulation of neuroimmunoendocrine functions affected by a variety of cytokines, including leptin and members of the growth hormone and the interleukin-6/gp130 superfamilies. Overall, these findings point to the SOCS as likely crucial negative modulators in the temporal and spatial regulation and intensity of cytokine signaling and therefore actions in the CNS.
Convective assembly of linear gold nanoparticle arrays at the micron scale for surface enhanced Raman scattering

A convective assembly technique at the micron scale analogous to the writing action of a “pipette pen” has been developed for the linear assembly of gold nanoparticle strips with micron scale width and millimeter scale length for surface enhanced Raman scattering (SERS). The arrays with interparticle gaps smaller than 3 nm are hexagonally stacked in the vicinity of the pipette tip. Variable numbers of stacked layers and clean surfaces of the assembled nanoparticles are obtained by optimizing the velocity of the pipette tip. The SERS properties of the assembled nanoparticle arrays rely on their stacking number and surface cleanliness. Open image in new window
Public objections to environmental tobacco smoke.

Abstract Methods . A randomly selected sample of Californian adults was surveyed by telephone to assess their knowledge, attitudes, and behaviors with respect to tobacco use and its control. The questions asked of this sample were whether they had recently (in the past 12 months) asked someone not to smoke in certain situations and whether they would ever consider doing such a thing. Results . Results of the survey indicated that 59.1% of nonsmokers and 44.4% of smokers had asserted themselves within the past 12 months, while another 28.2 and 29.1% of the nonsmokers and smokers, respectively, indicated that they would consider asking someone not to smoke. Only 12.7% of the nonsmokers and 26.4% of the smokers indicated that they would not consider doing such a thing. Those more likely to object publicly to tobacco smoke are generally younger, are more educated, and have anti-tobacco attitudes related to either a specific health belief or social influence.
Food Stamp Participation is Associated with Fewer Meals Away From Home, Yet Higher Body Mass Index and Waist Circumference in a Nationally Representative Sample

Abstract Objective To examine associations between Food Stamp (FS) participation, meals away from home (MAFH), body mass index (BMI), and waist circumference (WC). Design Cross-sectional study. Setting Nationally representative. Participants Data from low-income, FS-eligible individuals (N = 945) ages 20-65 years, responding to the 2005-2006 National Health and Nutrition Examination Survey. Main Outcome Measure(s) MAFH per week, BMI, and WC. Analysis Multiple linear regression models were used to examine associations between FS participation and MAFH, BMI, and WC, adjusting for age, sex, race, and education level. Results Food Stamp authorization was associated with fewer MAFH ( P = .004). Among females, FS authorization was associated with higher BMI ( P = .04) and WC ( P = .04). Among females reporting amount of benefits in the prior month, more FS benefits received were associated with lower BMI ( P = .03) and WC ( P Conclusions and Implications Seemingly contradictory results regarding associations between FS authorization and FS benefits received in the previous month and BMI and WC should be explored further. Effective nutrition education and environmental change strategies are needed, particularly among female FS recipients.
Preliminary studies of grazing by Bittium varium on eelgrass periphyton

Abstract The grazing activities of Bittium varium Pfeiffer on periphyton colonizing live eelgrass ( Zostera marina L.) and artificial eelgrass (polypropylene ribbon) were investigated. Quantitative measurements of grazing impact on artificial substrates were determined by periphyton pigment extraction and dry weight differences between grazed and ungrazed blades. Significant differences occurred in phaeophytin and dry weight calculations, but chlorophyll a measurements were not significantly different. This suggests that senescent diatoms constituted the bulk of the periphyton weight and were selectively removed over more actively photosynthesizing diatoms. An examination of scanning electron micrographs further elucidated the impact of grazing by Bittium varium . Some micrographs revealed that B. varium removed primarily the upper layer of the periphyton crust on both artificial substrates and living Zostera marina . The diatom Cocconeis scutellum Ehrenb. which attaches firmly to living Z. marina blades was less commonly removed than Nitzchia or Amphora . Through its grazing activities, B. varium may maintain community dominance by tightly adhering diatoms such as C. scutellum . Evidence of the complete removal of periphyton exposing the Z. marina epithelium was revealed in other micrographs. The grazing activities of Bittium varium , which removes periphyton from seagrass blades, could have important implications for the distribution and abundance of Zostera marina in the Chesapeake Bay.
Architecture of an integrated computer-aided design system for optoelectronics

The architecture of an integrated CAD system to automate the design of optoelectronic systems is presented in this paper. Optoelectronic technology with free-space optical interconnects offers the potential to build high-performance computers. As this technology matures increased design complexity will mandate the use of CAD. CAD tools and specifications for the design process of optoelectronic systems are described. The proposed architecture extends existing CAD technologies to optoelectronics.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Effect in vivo of norepinephrine on the membrane resistance of brown fat cells.

La depolarisation de la membrane des cellules adipeuses brunes, produite par l'administration in vivo de noradrenaline, est aussi accompagnee d'une augmentation de la permeabilite mesuree par une augmentation de la resistance membranaire.
Bayesian analysis and the accumulation of evidence in crime and justice intervention studies

In recent years a great deal of attention has turned to the need for policy-relevant research in criminology. Methodologically, attention has been trained on the use of randomized experimental designs and cumulative systematic reviews of evidence to accomplish this goal. Our work here reviews and demonstrates the utility of the Bayesian analytic framework, in the context of crime prevention and justice treatment studies, as a means of furthering the goals of research synthesis and creation of policy-relevant scientific statements. Evidence from various fields is used as a foundation for the discussion, and an empirical example illustrates how this approach might be useful in practical criminological research. It is concluded that Bayesian analysis offers a useful complement to existing approaches and warrants further inclusion in the ongoing discussion about how best to assess program effectiveness, synthesize evidence, and report findings from crime and justice evaluations in a way that is relevant to policy makers and practitioners.
On the feasibility of quantitative analysis of atmospheric OH by titration

A method is proposed for quantitative analysis of atmospheric OH using a titration technique. The method uses a mixture of two gases: the titrant gas which is destroyed predominantly by reaction with OH on a time scale of a few days or less; and the dispersant gas which is inert essentially and is used to determine the dispersion rate of the mixture once it is released into the atmosphere. The rate of change of the ratio of the concentrations of the titrant and dispersant gases can be related to the local OH concentration. Measurements of this ratio are made for an hour or so after release of the mixture. A hypothetical example is given which utilizes a mixture of two halocarbons measured using a gas chromatograph with an electron-capture detector.
The Prime Spectrum of Commutative Differential Algebras

For a commutative differential algebra A, if p1 and p2 are prime ideals with p1 ⊂ p2, p1 ≠ p2, and D(p1) not contained in p2, then there exists a prime ideal p3 ⊂ p2, with p3 ⊄ p1 and p1 ⊄ p3 and {x/Dkx ∈ p1 for all k ≥ 0} ⊂ p3. This yields an alternative proof that there is no non-trivial derivation on Ck([0,1]) and gives a generalized existence theorem for polarized prime ideals of C∞([0,1], C).
Pulse-capture circuit for microcomputer data acquisition.

Cet article decrit un circuit interessant pour l'acquisition informatique de signaux analogues ou la magnitude du voltage est le seul parametre necessaire a l'analyse des donnees. Son avantage est qu'il necessite un materiel informatique peu onereux pour la memorisation et l'affichage des donnees
Assessing students' preparedness towards sustainability in US and European undergraduate agricultural curricula

This work focused on the evaluation of undergraduate curricula in agriculture for a selected group of institutions from Louisiana and Texas in the US, and France and Italy. The primary research objective was pursued through the measurement of knowledge acquisition in sustainable agriculture principles of undergraduate students as they were approaching the completion of their curriculum. Quantitative data were collected through the administration of a test to eight samples (n = 20) of senior students from each university participating in the study. An analysis of frequencies for every test question indicated the strengths but also the weaknesses that still exist in the agricultural curricula when students' academic achievement was measured. Every institution acknowledged the emerging sustainable agriculture paradigm in brochures, catalogs and web sites. There is a need for ameliorating agricultural curricula as the long-term productivity of farms is threatened by market policies uncontrollable by single producers and by the manipulation of resources that frequently accelerate environmental degradation. Therefore, we show opportunities for the strengthening of study programs to incorporate sustainable agriculture principles in undergraduate curricula.
FIRST-ORDER ECONOMIZING: IRRIGATION TECHNOLOGY ADOPTION AND THE FARM

Expected future water shortages and emerging environmental concerns place microirrigation near the forefront of technological alternatives for the agricultural sector. Drip irrigation—under favorable soil, biological, climatic, organizational, and economic conditions—is economically preferred to traditional flood, furrow, and even sprinkler technologies. However, superior management is required to produce the incremental yield increases necessary for acceptable returns on this investment. Other incremental benefits from adopting drip technology are realized through complementarities between the technology, other inputs, and the firm's marketing strategy.
Preparation and characterization of molecular weight fractions of guar galactomannans using acid and enzymatic hydrolysis

Abstract A procedure is described for the preparation of large amounts of guar galactomannan by acid hydrolysis that yields samples of various molecular weights (MW) with uniform polydispersity. This contrasts with preparation by enzymatic degradation that yields samples with a marked increase in polydispersity and a much broader molecular weight distribution (MWD). Acid hydrolyzed guar samples had a Mark–Houwink–Sakurada (MHS) relationship of [η]=3.04×10−4 Mw0.747 dl/g and a characteristic ratio of 11.87 as determined by gel permeation chromatography (GPC) and dilute solution viscometry. The Huggins coefficient for degraded guars is much smaller (∼0.4) than that of the native guar (∼0.79), suggesting a weakening of intermolecular association in guar prepared by acid hydrolysis.
Netrin-4 induces lymphangiogenesis in vivo.

Netrin-4, a laminin-related secreted protein is an axon guidance cue recently shown essential outside of the nervous system, regulating mammary and lung morphogenesis as well as blood vascular development. Here, we show that Netrin-4, at physiologic doses, induces proliferation, migration, adhesion, tube formation and survival of human lymphatic endothelial cells in vitro comparable to well-characterized lymphangiogenic factors fibroblast growth factor-2 (FGF-2), hepatocyte growth factor (HGF), vascular endothelial growth factor-A (VEGF-A), and vascular endothelial growth factor-C (VEGF-C). Netrin-4 stimulates phosphorylation of intracellular signaling components Akt, Erk and S6, and their specific inhibition antagonizes Netrin-4–induced proliferation. Although Netrin receptors Unc5B and neogenin, are expressed by human lymphatic endothelial cells, suppression of either or both does not suppress Netrin-4–promoted in vitro effects. In vivo, Netrin-4 induces growth of lymphatic and blood vessels in the skin of transgenic mice and in breast tumors. Its overexpression in human and mouse mammary carcinoma cancer cells leads to enhanced metastasis. Finally, Netrin-4 stimulates in vitro and in vivo lymphatic permeability by activating small GTPases and Src family kinases/FAK, and down-regulating tight junction proteins. Together, these data provide evidence that Netrin-4 is a lymphangiogenic factor contributing to tumor dissemination and represents a potential target to inhibit metastasis formation.
Monogyny and Polygyny in the Fire Ant, Solenopsis invicta

In a survey for multiple-queen colonies of the fire ant, Solenopsis invicta Buren, 15 colonies were found in Mississippi, but none could be found in Georgia. The 15 contained 476 dealated females (3–63 per colony) of which 87% were shown, partly by direct observation but chiefly by means of oviposition tests, to be functional egg-layers. Dissection of 133 of these females showed that 96% had mature oocytes in their ovarioles and 90% were inseminated. All the queens of the 15 polygynous colonies were less physogastric than queens of monogynous colonies, and individually they laid far fewer eggs, but collectively they produced a significantly greater number of eggs per colony. The significance of polygyny in the North American populations of S. invicta is briefly discussed.
Low-fluence laser excitation processes

Experimental results show that low-fluence UV laser irradiation induces non-thermal photosputtering from surfaces. The photophysical process is the result of surface electronic excitation and energy pooling at particular sites. We present data which show the preferential removal of arsenic from arsenic doped silicon and the role of plasmon excitation in the species desorption from thin metallic films. The observed phenomena has application in nanofabrication technology.
Crystal structure of muconolactone isomerase at 3.3 A resolution.

Abstract The crystal structure of muconolactone isomerase from Pseudomonas putida , a unique molecule with ten 96 amino acid subunits and 5-fold, and 2-fold symmetries, has been solved at 3.3 A resolution. The non-crystallographic symmetries were used to refine the initial single isomorphous replacement phases and produce an interpretable 10-fold averaged map. The backbone trace is complete and confirmed by the amino acid sequence fit. Each subunit is composed of a body with two α-helices and an antiparallel twisted β-sheet of four strands, and an extended arm. The helices and the sheet fold to form a two-layered structure with an enclosed hydrophobic core and a partially formed putative active site pocket. The C-terminal arm of another subunit related by a local dyad symmetry extends over the core to complete this pocket. The decameric protein is almost spherical, with the helices forming the external coat. There is a large hydrophilic cavity in the center with open ends along the 5-fold axis. Molecular interactions between subunits are extensive. Each subunit contacts four neighbors and loses nearly 40% of its solvent contact area on oligomerization.
Optimizing conditions and avoiding pitfalls for prolonged axonal tracing with carbocyanine dyes in fixed rat spinal cords

We have characterized a method of labeling of axons in the post-mortem spinal cord using a silastic disc holding pins coated with DiI and DiO at the rostral and caudal ends of the cord. We optimized the DiI and DiO tracing techniques under different conditions of fixative concentration (1% versus 4% paraformaldehyde, PF), at room temperature (RT) versus 37 degrees C for up to 24 weeks. Crystal coated pins embedded in a silastic disc provided a novel method of dye application. Confocal microscopy of longitudinal sections showed DiI and DiO labeled both the axonal membrane and myelin sheath. DiI diffused significantly longer distances than DiO. Both dyes migrated greater distances at 37 degrees C compared with RT. No significant difference of dye labeling was found between 1% and 4% PF fixation. After prolonged incubation there was evidence that dye diffused through the aqueous medium and produced circumferential labeling of the cord. Placing a wax seal around the labeling site prevented this non-contiguous labeling. Labeling of myelin sheaths at extended distances into the cord suggested that dye could migrate between cells with prolonged incubation periods. Our data suggested that higher temperature facilitated dye diffusion along the axons, and demonstrated that with caution DiI and DiO could be used as specific tracers in the same spinal cords.
Measurement of the Mechanical Properties of the Human Lung Tissue

The mechanical properties of human lung tissue were measured in a state of biaxial tension. The experimental data were fitted with a pseudo-elastic constitutive equation proposed earlier and the physical constants were identified.
Commonly used caspase inhibitors designed based on substrate specificity profiles lack selectivity.

Commonly used caspase inhibitors designed based on substrate specificity profiles lack selectivity
Dark recovery of UV-irradiated phage T1 III. Evidence for two modes of host cell repair from liquid- holding experiments ☆

Abstract The preceding paper 8 presented evidence that excision repair processes leading to maximal host-cell reactivation (HCR) occur only in a minor fraction of T1-infected cells, in which the repair events are strongly interdependent. The data suggested the existence of a second mode of excision repair, less efficient under usual plating conditions, but occuring in the majority or all of the phages. Work presented in this paper supports this notion. It indicates that the second mode of excision repair becomes maximally efficient when T1-infected cells are held in glucose-buffer at 37† for several hours prior to plating, thereby increasing the survival (“liquid holding recovery”). This is expressed by alteration of the upwardly concave survival curve into a convex curve with no change in the final slope. In particular, the second mode of excision repair has been studied by liquid- holding of the infected cells and subsequent plating in the presence of 2 mg/ml caffeine, which completely inhibits HCR on the plate. Our data show that in glucose-buffer (without or with chloramphenicol up to 400 μg/ml) excision repair proceeds through the caffeine-inhibitable step(s), resulting in repair events which occur equally in all complexes and affect lesions independently of one another. Such repair is completely absent if also the holding-buffer contains 2 mg/ml caffeine. In buffer containing only 0.2 mg/ml caffeine or in preirradiated host cells the rate of repair is considerably decreased, affecting—in contrast to non-liquid-holding conditions—all complexes and all lesions equally in a random fashion. No liquid-holding recovery is observed when UV-irradiated T1 is ν-gene-reactivated, i.e. repaired in excision-repair-deficient cells by superinfection with T4 ν + phage.
Natural convection above a line heat source: Higher-order effects and stability

Abstract The natural-convection plume above a horizontal line heat source is analyzed in terms of higher-order boundary-layer theory. A stability analysis of the resulting base flow is then performed by means of a systematic expansion for the disturbance field. Comparison of the theory with existing experimental results is found to be inconclusive.
Discrete Logarithms and Local Units

Let K be a number field and $\scr{O}\_{K}$ its ring of integers. Let l be a prime number and e a positive integer. We give a method to construct l$^{e}$th powers in $\scr{O}\_{K}$ using smooth algebraic integers. This method makes use of approximations of the l-adic logarithm to identify l$^{e}$th powers. One version we give is successful if the class number of K is not divisible by l and if the units in $\scr{O}\_{K}$ which are congruent to 1 modulo l$^{e+1}$ are l$^{e}$th powers. A second version only depends on Leopoldt's conjecture. We use the technique of constructing l$^{e}$th powers to find discrete logarithms in a finite field of prime order. Our method for computing discrete logarithms is closely modelled after Gordon's adaptation of the number field sieve to this problem. We conjecture that the expected running time of our algorithm is L$\_{p}$[1/3; (64/9)$^{1/3}$ + o(1)] for p $\rightarrow \infty $, where L$_{p}$[s;c] = exp (c (log q)$^{s}$ (log log q)$^{1-s}$). This is the same running time as is conjectured for the number field sieve factoring algorithm.
Paramagnetic Vanadium Silyl Complexes: Synthesis, Structure, and Reactivity

Vanadium silyl complexes of the type Cp(dmpe)VSiHRR′ are formed by reaction of Cp(dmpe)VMe (1) with RR′SiH2 (2, R, R′ = Ph; 3, R = Mes, R′ = H) in benzene at room temperature with concomitant relea...
Helium Diffraction as a Probe of Surface Structure

The diffraction of He atoms from solid surfaces has been recently used to determine the electron distribution of electrons at surfaces. From this, the position of underlying atoms can usually be inferred. Recent developments which test the validity of the hard corrugated wall method to calculate diffraction intensities are discussed. Structural studies which have been carried out to date, on various surfaces with He beams, are tabulated.
Preservation of substrate crystal and enhancement of YBa2Cu3O7-x thin film growth using YSZ/Si3N4 as a buffer layer

Abstract Enhancement of high temperature superconducting YBa 2 Cu 3 O 7− x (YBCO) thin film growth on GaAs and preservation of the substrate crystal were succesfully realized using yttrium-stabilized ZrO 2 (YSZ)/Si 3 N 4 as a buffer layer. Highly c -axis oriented YBCO thin films with a zero resistance temperature as high as 85.5 K were obtained due to the use of a sub-top buffer of YSZ. The preservation of the GaAs surface at a temperature as high as 700°C in an oxygen-rich ambient, as revealed by photoreflectance measurement on the GaAs surface after removing YBCO, YSZ, and Si 3 N 4 layers, was realized owing to the use of a sub-bottom buffer of Si 3 N 4 . Material analysis using a combination of cross-sectional scanning electron microscopy and Auger electron spectroscopy depth profiling demonstrated quite weak interdiffusions among different regions. The electrical and structural properties of both the YBCO film and the GaAs substrate after YBCO thin film deposition are believed to be the best reported so far.
Laparoscopic instruments cause increased forearm fatigue: A subjective and objective comparison of open and laparoscopic techniques

SummaryBackground: Endoscopic surgery presents new ergonomic conditions for surgeons that may cause fatigue and decreased performance during prolonged laparoscopic procedures. This study uses a post-operative questionnaire and surface electromyography (EMG) to compare upper extremity discomfort and muscle contraction during real and simulated laparoscopic and open surgical tasks. Methods: We asked surgeons to rank upper extremity discomfort immediately following laparoscopic or open operations on a scale of 0–3. We also measured the surface EMG activity of the right upper forearm flexor and extensor compartment, Deltoid and Trapezius muscles in three surgeons during simulated surgical tasks. The maximum voluntary contraction (MVC) for each muscle was used to normalize the data between subjects. Statistical comparisons were carried out using paired t-tests and P lt; 0.05. Results: Surgeons reported a significant increase in moderate/severe discomfort of the dominant foream following laparoscopic operations...
Decrease in total aneurysm-related deaths in the era of endovascular aneurysm repair.

Objective With the expansion of elective abdominal aortic aneurysm (AAA) repair after the introduction of endovascular aneurysm repair (EVAR), there is a concern that even with a lower operative mortality there could be an increasing number of aneurysm-related deaths. To evaluate this, we looked at national trends in AAA repair volume as well as mortality rates after intact and ruptured AAA repair encompassing the introduction of EVAR. Methods Patients with intact or ruptured AAA undergoing open repair or EVAR and all those with a diagnosis of ruptured AAA were identified within the 1993 to 2005 Nationwide Inpatient Sample database using International Classification of Diseases, 9th Revision, diagnosis and procedure codes. The number of repairs, number of rupture diagnoses without repair, number of deaths, and associated mortality rates were measured for each year of the database. Outcomes (mean annual volumes) were compared from the pre-EVAR era (1993 to 1998) with the post-EVAR era (2001 to 2005). Results Since its introduction, EVAR increased steadily and accounted for 56% of repairs yet only 27% of the deaths for intact repairs in 2005. The mean annual number of intact repairs increased from 36,122 in the pre-EVAR era to 38,901 in the post-EVAR era, whereas the mean annual number of deaths related to intact AAA repair decreased from 1693 pre-EVAR to 1207 post-EVAR ( P P P = .31; EVAR, 1.3%). During the same time, the mean annual number of ruptured repairs decreased from 2804 to 1846, and deaths from ruptured AAA repairs decreased from 2804 to 1846 ( P P P P P Conclusion Since the introduction of EVAR, the annual number of deaths from intact and ruptured AAA has significantly decreased. This coincided with an increase in intact AAA repair after the introduction of EVAR and a decrease in ruptured AAA diagnosis and repair volume.
Trypanosoma cruz/‐induced decrease in the level of interferon‐7 receptor expression by resting and activated human blood lymphocytes

Summary A substantial proportion of human peripheral blood mononuclear cells (PBMC) manifested a decreased capacity to express membrane interferon-γ receptors (IFN-γR) when co-cultured with Trypanosoma cruzi. Among the lymphocytes, B cells accounted for the bulk of this effect, evidenced by a marked drop in the proportion of CD19+ or CD20+ cells expressing IFN-γR. Decreased IFN-γR expression by B lymphocytes was seen as early as 3 h after co-culture with T. cruzi and persisted for at least 24 h. The parasite had no detectable effect on CD19, CD20 or DR antigen expression by B lymphocytes. Neither the proportion ofB cells expressing these markers nor the membrane density of these molecules varied significantly in the presence of T. cruzi. In PBMC cultures stimulated with Staphlyococcus aureus Cowan I (SACI), T. cruzi decreased the percentages of both IFN-γR+ and IFN-R +bnght (cells expressing above-normal levels of surface IFN-γR) B lymphocytes. Cell-free filtrates of T. cruzi suspensions reproduced the suppressive effects of living parasites on IFN-γR expression by B cells. When T. cruzi was present, the intracellular levels of IFN-γR molecules in resting or SACI-activated B lymphocytes, represented by fluorescence intensity, were well below control values, suggesting that decreased surface expression resulted from suppressed IFN-γR synthesis. Among T (CD3+) cells, 10–8% to 39–6% (7 donors) expressed surface IFN-γR and did so at a very low level. These percentages were also reduced by T. cruzi. If occurring in the host, downregulated expression of IFN-γR could curtail the utilization of IFN-γ, known to play a critical role in host defence against T. cruzi infection.
The managerial behaviour of families with preschool children

The purpose of this study is to examine the managerial behaviour of families with preschool children. Dummy variable regression analysis is used as an analysis of covariance procedure in order to ascertain how reported managerial behaviour scores of families with only younger children vary with regard to other family types. This study has resulted in two major findings. The first is that there is indication that managerial behaviour is more a function of family composition than socio-economic/demographic characteristics. The second finding is that families with only preschool children are more similar to families with only older children than to families with both younger and older children or families without children. The conclusion is that it is not just the presence of preschool children that makes a difference in managerial behaviour, but whether or not there are only preschool children in the family.
Arterial embolization for pelvic fractures after blunt trauma: are we all talk?

BACKGROUND: We hypothesized that arterial embolization for bleeding after pelvic fracture is used relatively infrequently. We sought to identify the true need for arterial embolization and define injury patterns associated with successful therapeutic angiographic embolization. METHODS: A retrospective review identified patients admitted to our urban, Level 1 trauma center with pelvic fractures from 2001 to 2009. Patients requiring pelvic arterial angiogram and embolization of pelvic bleeding were reviewed for pelvic fracture pattern and pelvic injury mechanism. RESULTS: There were 819 patients diagnosed with pelvic fractures, with only 31 patients (3.8%) undergoing diagnostic pelvic angiography. Of those, 18 patients (58.1%) had active bleeding requiring arterial embolization. Complex pelvic fracture patterns were common in patients undergoing angiogram. Patients undergoing pelvic angiography with an anteroposterior compression mechanism were more likely to have negative findings on angiogram. CONCLUSIONS: The actual need for angiography and therapeutic embolization is quite small in patients sustaining pelvic fracture. Although factors associated with the need for pelvic angiography frequently are debated, we may discuss angiography for pelvic fractures more often than it actually is performed.
Q and mantle creep

EXPERIMENTS on model materials show that the acoustic properties of the low velocity zone (LVZ) can arise from the formation of intergranular fluid or melt with no significant reduction in creep strength. Consequently, only very limited bounds on the asthenosphere can be inferred from seismic data.
Mechanical properties of polycarbonate–polysulfone and polycarbonate–polyetherimide blends

Abstract : This project is an attempt to produce a ballistic impact resistant transparent eye armor with improved scratch and chemical resistance over polycarbonate. The first stage of the project examines the thermal and mechanical properties of the polymers. Five, ten, and twenty percent by weight blends of polysulfone in polycarbonate and polyetherimide in polycarbonate were produced by melt blending using a counter-rotating twin screw extruder at 320C. The materials were injected molded into plaques 11.4 cm square by 3.2 mm and 1.6 mm thick. Mechanical analysis consisting of tensile, pendulum impact, and ballistic impact testing was conducted using the plaques or samples machined from the plaques. Dynamic mechanical testing was performed using bars machined from the 3/2 mm plaques to observe the low temperature loss peak and determine the activation energy of the loss mechanism. Differential scanning calorimetry was conducted to measure the glass transition temperatures of the material. The presence of two glass transition temperatures and lack of transparency have indicated that the blends are immiscible. Both sets of blends exhibit fair to good ballistic impact properties up to at least 20% polysulfone or polyetherimide. The tensile data of the blends show an increase in tensile strength over the same range.