cssi/SciSciGPT-SciSciNet huggingface dataset:
Rapid nitrous oxide cycling in the suboxic ocean

Nitrous oxide (N2O) is a powerful greenhouse gas and a major cause of stratospheric ozone depletion, yet its sources and sinks remain poorly quantified in the oceans. We used isotope tracers to directly measure N2O reduction rates in the eastern tropical North Pacific. Because of incomplete denitrification, N2O cycling rates are an order of magnitude higher than predicted by current models in suboxic regions, and the spatial distribution suggests strong dependence on both organic carbon and dissolved oxygen concentrations. Furthermore, N2O turnover is 20 times higher than the net atmospheric efflux. The rapid rate of this cycling coupled to an expected expansion of suboxic ocean waters implies future increases in N2O emissions.
Evaluation of proficiency survey results for serum immunoglobulins following the introduction of a new international reference material for human serum proteins

A new international reference material for 14 human serum proteins was certified by the Bureau Communitaire de Reference, Brussels, Belgium, in 1992 and released as CRM 470 (1). The same material was released in the United States by the College of American Pathologists (CAP) in 1993 as the Reference Preparation for Proteins in Human Serum, or RPPHS (2)(3). The large interlaboratory variance of values obtained on national quality control samples before 1990 was one of the major reasons for the preparation and introduction of this new material (3)(4)(5). We undertook the present study to determine what effect, if any, the introduction of RPPHS has had on results of the CAP surveys for the major immunoglobulins IgG, IgA, and IgM. The overwhelming majority of clinical assays in the US are performed by immunonephelometry, utilizing the Beckman or …
Molecular characterization of the t(3;9) associated with immortalization in the MCF10A cell line

The t(3;9)(p14;p21) in the MCF10A human mammary gland epithelial cell line was the single cytogenetic event that accompanied the transition from primary culture to immortalized cell line, suggesting that it is related to the development of the immortalization phenotype. To study the molecular consequences of the breakpoints in this rearrangement, we used a combination of fluorescence in situ hybridization (FISH) and array comparative genomic hybridization (CGH). The 3p14 translocation breakpoint occurs within BAC RP11-795e22, which accommodates only the TAFA1 gene, a novel cysteine-rich secreted protein thought to be involved in cytokine signaling. TAFA1 is expressed in normal breast tissue, not in MCF10A, and shows differential expression in a range of breast cancer cell lines. The 9p translocation breakpoint results in a deletion of approximately 4 megabases on the derivative chromosome 9, which includes the CDKN2A (p16) gene. Array CGH and FISH analysis demonstrated that BAC 149i22, which contains the CDKN2A/B genes, is also deleted specifically on the apparently normal copy of chromosome 9, making MCF10A null for the p16/p15 genes. The exact extent of gains and losses of chromosome regions resulting from rearrangements involving chromosomes 1q, 5q, and 8q have also been characterized using the BAC arrays.
YOUTH IN THE LABOR MARKET: EMPLOYMENT PATTERNS AND CAREER GOALS IN WATTS AND EAST LOS ANGELES

Paul Bullock is presently a Research Economist with the Institute of Industrial Relations at the University of California (L os Angeles). He has previously been affiliated with the Wage Stabilization Board of Los Angeles as a Wage Analyst, and has taugh at Occidental College and El Camino College, both in L os Angeles. He has served as a consultant for many of the commissions, most notably the McCone Commission in 1965 and the Kerner Commission in 1967. He is the author of numerous books and articles, among the former Equal Opportunity in Employment (1960, UCLA), and Hard-Core Unemployment and Poverty in Los Angeles, coauthored with Fred H. Schmidt and Robert Singleton (1965, Government Printing Office). He is at present at work on a biography of Jerry Voorhis, former Congressman and Cooperative League Director, and on a study of minority youth in the labormarket.
Phase coexistence in random copolymers

We study the phase coexistence in random copolymer systems. In the framework of the one-loop approximation it is shown that the phase transition between liquidlike and lamellar phases in the symmetric random copolymers occurs through the two-phase region. We derive an analytic expression describing the volume fractions of the coexisting phases in this region. To illustrate the phase behavior of the random copolymers, the phase diagram of a polydisperse A–B multiblock copolymer melt is calculated.
Mathematical Approach to the Prediction of Scientific Discovery

In the field of symbolic logic at least, fundamental discoveries seem to follow patterns, suggesting that future discoveries may in some sense be predictable.
A systems biology analysis for the whole genome sequencing data

The next generation sequencing technology has enabled the understanding of the whole genome of an organism at a greater coverage and reduced cost. In this study, we provide a systems biology approach to understand the functional relevance of the single nucleotide variants identified by the whole genome sequencing studies. This approach also includes a methodology for the identification of conserved modules among the family members. Our study contributes towards the much needed downstream functional analysis of the variant data, especially for the low frequency and novel variants, and provides a framework for the analysis of multiple genomes to derive relations between variants and diseases.
Biosynthesis of thyroid hormone: Basic and clinical aspects☆

Abstract Thyroid hormone formation requires the coincident presence of peroxidase, H2O2, iodide, and acceptor protein at one anatomic locus in the cell. The peroxidase enzyme appears to be a protoporphyrin IX containing heme protein, with binding sites for both iodide and tyrosine. It is probable that both iodide and tyrosine are oxidized to free radical forms which unite to form iodotyrosine. The peroxidase is also involved through an uncertain mechanism in iodotyrosine coupling and probably in oxidation of sulfhydryl bonds in thyroglobulin. H2O2 may be supplied by microsomal NADPH-cytochrome c reductase or NADH-cytochrome b5 reductase. Other possible intracellular H2O2 generating systems include monoamine oxidase and xanthine oxidase. The usual acceptor for iodide is thyroglobulin, which is currently believed to be iodinated within apical secretory vesicles at the cell border just prior to liberation into the colloid, or possibly after liberation into the colloid. Other soluble and insoluble proteins are also iodinated within the gland. The peroxidase is present in numerous cellular structures, but iodination activity occurs primarily, if not only, at the apical cell border. The controls of iodination are imperfectly known. Thyrotrophin modulation of iodide uptake, H2O2 generation, thyroglobulin synthesis, and peroxidase enzyme level obviously are the main regulations. Many of these actions are thought to involve mediation of adenyl cyclase and subsequent activation of intracellular phosphokinases. Antithyroid drugs of the thiocarbamide group are competitive inhibitors of iodination under some circumstances, but if much iodide is present, they react with the oxidized iodine intermediate and are irreversibly inactivated themselves. Clinical problems involving defective peroxidase function are among the most frequent hereditary defects of thyroid hormone formation. Recognized abnormalities include deficient peroxidase, abnormality in binding of the peroxidase apoprotein to its prosthetic group, and other less well-identified abnormalities in peroxidase structure and function. Peroxidase is typically elevated in thyroid tissue from patients with hyperthyroidism, sometimes deficient in cold thyroid nodules, and frequently diminished in tissue from patients with Hashimoto's thyroiditis.
Protective Capabilities of a Watersports Helmet for Boom-to-Head Impacts During Sailing

In sailing, the boom comes across the boat during tacks and jibes and has potential to impact a participant’s head and cause injury. To our knowledge, there are no sailing specific helmets on the market in the United States. To determine the effectiveness of a wakeboarding helmet to mitigate the risk of head injury, we measured the boom angular velocity on a 24-foot keel sailboat during controlled jibes. The boom motion was recreated in a laboratory setting and positioned to contact the occiput of the instrumented head of a Hybrid III 50th percentile male anthropometric testing device (ATD). Tests were conducted with an unhelmeted ATD and with an ATD wearing a wakeboarding helmet. Boom angular velocities and head accelerations for unhelmeted impacts were highly correlated (R2 = 0.996). The watersports helmet reduced head accelerations by 52 ± 4% when compared to accelerations from unhelmeted impacts.Copyright © 2010 by ASME
Discriminative stimulus properties of desipramine.

Abstract In an operant procedure of lever pressing on a FR10 schedule of food reinforcement, male hooded rats were trained to respond on a lever on one side of a food cup following a desipramine (10 mg/kg) injection and to respond on a lever on the other side following a saline injection. Sixty percent of the rats learned to reliably discriminate desipramine from saline. The rate of lever pressing at this dose of desipramine was 49% of the saline response rate. No tolerance to this depressant effect was observed after 20 injections. Subjects selected the appropriate desipramine lever 91, 29 and 18% of the time following 10, 2.5 and 0 (saline) mg/kg of desipramine. Imipramine and protryptyline each produced 50% selection of the desipramine lever at a dose of 40 mg/kg. Lower doses were less effective. d-Amphetamine produced 20 and 67% desipramine lever selection at 0.64 and 1.25 mg/kg respectively.
Electronic and structural properties of α-berlinite (AlPO4)

Abstract The electronic and structural properties of α-berlinite (AlPO4) are examined using ab initio pseudopotentials. The electronic band structure, the total and partial densities of states, and the pseudocharge valence density are presented. We find our total density of states to be in excellent agreement with X-ray photoemission spectroscopy and in good agreement with previous tight binding calculations. We also examine the charge density in order to investigate bond character.
Factors affecting the swelling during degassing of compacts containing uranium-aluminum intermetallics dispersed in aluminum

Abstract Above 500 °C the swelling of dispersions of UAl 3 in aluminum occurs in two stages. In the first, the swelling is gradual and believed to be due to adsorbed gases that are released from the surfaces of the aluminum and UAl 3 powder particles. After a varying “incubation time”, the second stage of swelling at a greatly increased rate begins. This incubation period increases with increasing UAl 3 particle size and decreasing temperature. The second stage is due to the transformation of the UAl 3 to UAl 4 through reaction with the aluminum matrix. The stability of UAl 3 containing either Si, Ge, Sn, or Zr was investigated. Silicon and germanium were the most effective stabilizers within the range of approximately 5 to 6 wt%. Tin was effective at approximately 1.5 wt%, but higher concentrations were detrimental. Zirconium was ineffective for concentrations up to approximately 6 wt%, but a 14 wt% alloy was stable.
Imaging of Receptors for Advanced Glycation End Products in Experimental Myocardial Ischemia and Reperfusion Injury

Objectives The aim of this study was to image expression of receptor for advanced glycation end products (RAGE) in a mouse model of myocardial reperfusion injury. Background RAGE and its ligands are implicated in the pathogenesis of ischemia/reperfusion injury and infarction. We hypothesized that RAGE-directed quantitative imaging of myocardial uptake of technetium-99m (99mTc)-anti-RAGE F(ab')2 in a mouse model of myocardial ischemic injury can detect RAGE expression and show quantitative differences between early (18 to 20 h) and later times (48 h) after reperfusion. Methods Twenty-five wild-type (WT) mice underwent left anterior descending coronary artery occlusion for 30 min. Mice were injected with 19.98 ± 1.78 MBq of 99mTc anti-RAGE F(ab')2 at 2 time points after reperfusion (at 18 to 20 h [n = 8] and at 48 h [n = 12]) and 5 h later with 6.14 ± 2.0 MBq of thallium-201 (201Tl). Five WT mice were injected with nonspecific F(ab')2 and 201Tl 18 to 20 h after reperfusion. Six WT mice underwent sham operation without coronary intervention. After injection with 201Tl, all mice immediately underwent dual isotope single-photon emission computed tomography/computed tomography. At completion of imaging, hearts were counted and sectioned. Results The uptake of 99mTc-anti-RAGE F(ab')2 in the ischemic zone from the scans as mean percentage injected dose was significantly greater at 18 to 20 h (5.7 ± 2.1 × 10−3%) as compared with at 48 h (1.4 ± 1.1 × 10−3%; p By immunohistochemical staining there was greater caspase-3 and RAGE staining at 18 to 20 h versus at 48 h (p = 0.04 and p = 0.01, respectively). On dual immunofluorescence, RAGE colocalized mainly with injured cardiomyocytes undergoing apoptosis. Conclusions RAGE expression in myocardial ischemic injury can be imaged in vivo using a novel 99mTc-anti-RAGE F(ab')2. RAGE plays a role in several cardiovascular diseases and is a potential target for clinical imaging.
Optical biosensors based on direct coupling of recognition, signal transduction, and amplification

Highly sensitive, specific and reagent-free optical signal transduction methods for detection of polyvalent proteins have been developed by directly coupling distance-dependent fluorescence self-quenching and/or resonant energy transfer to the protein receptor binding events. The ganglioside GM1 as recognition unit for cholera toxin (CT) was covalently labeled with fluorophores, and then incorporated into a biomimetic membrane surface. In the case using fluorescence self-quenching as a signal transduction mechanism, the fluorescence intensity drops significantly due to aggregation of the fluorophore-labeled GM1 on a biomimetic surface. By labeling GM1 with a fluorescence energy transfer pair, aggregation of the labeled-GM1 results in a decrease in donor and an increase in acceptor fluorescence, providing a unique signature for specific protein-receptor binding. The detection systems can reliably detect less than 0.05 nM CT with fast response (less than five minutes). This approach can easily be adapted to any biosensor scheme that relies on multiple receptors or coreceptors. The methods can also be applied to investigate the kinetics and thermodynamics of the multivalent interactions.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Uterine leiomyomata and decreased height: A common HMGA2 predisposition allele

Uterine leiomyomata (UL) are the most common female pelvic tumors and the primary indication for hysterectomy in the United States. We assessed genetic liability for UL by a known embryonic proliferation modulator, HMGA2, in 248 families ascertained through medical record-confirmed affected sister-pairs. Using a (TC)n repeat in the 5’ UTR and 17 SNPs spanning HMGA2, permutation based association tests identified a significant increase in transmission of a single TC repeat allele (TC227) with UL (allele-specific p = 0.00005, multiple testing corrected min-p = 0.0049). The hypothesis that TC227 is a pathogenic variant is supported by a trend towards higher HMGA2 expression in TC227 allele-positive compared to non-TC227 UL tissue as well as by absence of culpable exonic sequence variants. HMGA2 has also been suggested recently by three genome-wide SNP studies to influence human height variation, and our examination of the affected sister-pair families revealed a significant association of TC227 with decreased height (allele-specific p = 0.00033, multiple testing corrected min-p = 0.016). Diminished stature and elevated risk of UL development have both been correlated with an earlier age of menarche, which may be the biological mechanism for TC227 effects as a tendency of women with TC227 to have an earlier onset of menarche was identified in our study population. These results indicate HMGA2 has a role in two growth related phenotypes, UL predisposition and height, of which the former may affect future medical management decisions for many women.
Achievement goals and intrinsic motivation : their relation and their role in adaptive motivation

In this article, the relation between research emerging from the goals approach to motivation and research emerging from the intrinsic motivation approach is examined. A review of relevant research suggests that factors promoting learning goals (emphasizing the development of competencies) are associated with enhanced intrinsic motivation, and that factors promoting performance goals (emphasizing the evaluation of competence) are associated with diminished intrinsic motivation. It is also suggested that important aspects of the goals approach are often incorporated into conceptions and measures of intrinsic motivation. Finally, a framework is presented in which adaptive motivation is described in terms of the coordination of achievement goals and intrinsic motivation.
Evaluation of a recently reported stable liebermann-burchard reagent and its use for the direct determination of serum total cholesterol

Abstract We have confirmed the reliability and the stability of a new Liebermann-Burchard reagent stabilized by adding anhydrous sodium sulfate. However, the reagent and sample must be mixed at Oo in order to obtain results which are in agreement with those of the A bell method which is generally recognized to be precise and accurate.
Load ratio, notch, and scale effects for bridged cracks in fibrous composites

Abstract This paper considers the problem of Mode I matrix cracks growing under either monotonic or cyclic loading in the presence of unidirectional, bridging fibers coupled to the matrix by friction. Scaling relations facilitate the presentation of exhaustive solutions for specimens of various shapes. Particularly simple results are found numerically for the ratio of the net to the applied crack tip intensity factor in monotonic loading or the ratio of their ranges in cyclic loading. Material properties that control how finite specimen size and applied stress level determine the relative strength of bridging are identified for monotonic and cyclic loading. Bending is shown to be important in edge notch specimens, even under uniform remote loading. Conditions are found for fracture surface contact during cyclic loading.
Laser temporal and spatial effects on ionization suppression

Ionization suppression can be defined as the decrease of photoinduced atomic ionization rates with an increased applied field intensity. The temporal and spatial intensity distribution of a focused laser pulse introduces difficulty in observing ionization suppression. An analysis of the effect of a temporally Gaussian laser pulse on ionization suppression from Rydberg levels is given. It is found that ionization suppression by the Gaussian pulse is still apparent, even though the low-intensity tails of the pulse produce moderate ionization. Further, the spatial effects are examined for a scheme whereby a narrow atomic beam is passed through the focus of a laser at which ionization is detected. Ionization suppression in the more intense region of the laser focus is predicted to be apparent above the background ionization from the relatively large region of low intensity surrounding the laser focus.
Demographic differences in how students navigate through MOOCs

The current generation of Massive Open Online Courses (MOOCs) attract a diverse student audience from all age groups and over 196 countries around the world. Researchers, educators, and the general public have recently become interested in how the learning experience in MOOCs differs from that in traditional courses. A major component of the learning experience is how students navigate through course content.This paper presents an empirical study of how students navigate through MOOCs, and is, to our knowledge, the first to investigate how navigation strategies differ by demographics such as age and country of origin. We performed data analysis on the activities of 140,546 students in four edX MOOCs and found that certificate earners skip on average 22% of the course content, that they frequently employ non-linear navigation by jumping backward to earlier lecture sequences, and that older students and those from countries with lower student-teacher ratios are more comprehensive and non-linear when navigating through the course.From these findings, we suggest design recommendations such as for MOOC platforms to develop more detailed forms of certification that incentivize students to deeply engage with the content rather than just doing the minimum necessary to earn a passing grade. Finally, to enable other researchers to reproduce and build upon our findings, we have made our data set and analysis scripts publicly available.
Improving DIC microscopy with polarization modulation

It is demonstrated experimentally, as well as analytically, that when the polarization of the light incident upon the first Nomarski–Wollaston prism in a differential interference contrast (DIC) light microscope is switched by 90°, image highlights are changed into shadows and vice versa. Using an inexpensive ferroelectric liquid-crystal modulator, which is easily installed in the microscope, this switching can be done at 30 frames s−1, synchronized to the camera. Subtraction of alternate digitized frames generates a stream of images in which contrast is doubled, compared with conventional video-enhanced DIC, while image defects and noise tend to cancel. Subtraction of alternate images is carried out efficiently by frame buffer operations and amounts to massively parallel synchronous detection. The new method eliminates the problems inherent in obtaining a separate background image, as required by current video-enhanced DIC practice, without loss of resolution.
Endocrine and molecular responses to surgical stress

Abstract Successful adaptation to stress is a prerequisite for the survival of all organisms living in an environment in which noxious stimuli are constantly present. Higher organisms, including human beings, have developed complex mechanisms to tolerate the myriad of insults that occur to cellular constituents and organ systems after trauma with its resultant blood loss and tissue injury. Surgical stress can be conceptualized in this context, and it is therefore not surprising that human beings have developed an array of integrated stress-response axes that work in concert to return the host to a sustainable homeostatic plateau. The most important aspects of these axes are depicted in Figure 24. Surgical stress activates the higher cortical center of the brain and the spinal and baroreceptor reflexes that stimulate the hypothalamus to secrete CRH. CRH stimulates the release of ACTH from the pituitary gland, which causes the release of glucocorticoids from the adrenal cortex. Simultaneously, in a parallel fashion, surgical stress activates the sympathetic system to release catecholamines. Glucocorticoids and catecholamines are the major effectors of stress adaptation and interact at multiple levels in a synergistic fashion. They bind to specific receptors that are present in virtually every organ, although the number and affinity of a given tissue's receptor vary dramatically for individual ligands. Receptor occupancy results in short-term and long-term effects that ultimately improve the host's prospects of tolerating the stressful event. The short-term effects result in rapid actions, such as cardiovascular and metabolic responses that benefit the host in a “fight or flight” reaction. The long-term effects generally occur through alterations in gene transcription that prepare the host for, or adapt the host to, repetitive or chronic stress. Changes in the phosphorylation state of intracellular proteins are a common mode of action for both the short-term and long-term responses. These stress-responsive proteins have an enormous functional capacity: they alter enzymatic pathways, modulate hormone levels, and act as transcription factors to modify the expression of stress-responsive genes. During the last decade considerable progress has been made in explaining the complex signal transduction pathways mediating these responses. The importance of the HSPs in the host response to acute stress and their intimate association with activation of the HPA axis and sympathetic nervous system have recently been appreciated. The HSPs are likely to be induced early during organ rejection or ischemia and thus serve as diagnostic indicators. They are also known to be induced in chronic autoimmune disease states and may prove to be useful for prognostic evaluations. Finally, the ability to modulate their actions (e.g., in healing wounds) may have therapeutic benefits.
Sex-specific neuroanatomical correlates of fear expression in prefrontal-amygdala circuits.

Abstract Background The neural projections from the infralimbic region of the prefrontal cortex to the amygdala are important for the maintenance of conditioned fear extinction. Neurons in this pathway exhibit a unique pattern of structural plasticity that is sex-dependent, but the relationship between the morphologic characteristics of these neurons and successful extinction in male and female subjects is unknown. Methods Using classic cued fear conditioning and an extinction paradigm in large cohorts of male and female rats, we identified subpopulations of both sexes that exhibited high (HF) or low (LF) levels of freezing on an extinction retrieval test, representing failed or successful extinction maintenance, respectively. We combined retrograde tracing with fluorescent intracellular microinjections to perform three-dimensional reconstructions of infralimbic neurons that project to the basolateral amygdala in these groups. Results The HF and LF male rats exhibited neuroanatomical distinctions that were not observed in HF or LF female rats. A retrospective analysis of behavior during fear conditioning and extinction revealed that despite no overall sex differences in freezing behavior, HF and LF phenotypes emerged in male rats during extinction and in female rats during fear conditioning, which does not involve infralimbic–basolateral amygdala neurons. Conclusions Our results suggest that the neural processes underlying successful or failed extinction maintenance may be sex-specific. These findings are relevant not only to future basic research on sex differences in fear conditioning and extinction but also to exposure-based clinical therapies, which are similar in premise to fear extinction and which are primarily used to treat disorders that are more common in women than in men.
Elemental online coal analysis using pulsed neutrons

A neutron generator-based on-line coal analysis system has been developed, capable of measuring the major and minor chemical elements contained in coal. The system utilizes nuclear reactions produced from fast and thermal neutrons, as well as from neutron activation of isotopes with half- lives of seconds or minutes. Characteristic gamma rays detected with BGO (bismuth germanate) detectors are used for the identification of the various chemical elements. A key feature of the analyzer is its ability to analyze automatically three distinct gamma-ray spectra, and produce the elemental content of coal as it moves through a coal chute. A prototype analyzer has been built, able to analyze several tons/hour of coal. The main features of the analyzer are self-calibration independent of the coal seam, better accuracy in the determination of elements such as carbon, oxygen, and sodium, and diminished radiation risk.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Insulin-like Growth Factors and Cancer

The insulin-like growth factor (IGF) family of peptides, binding proteins, and receptors are important for normal human growth and development and are involved in the specialized functions of most physiologic systems. Most members of the IGF system are expressed by different cancer cells and may play an important role in the propagation of these malignancies. New therapies aimed at modulating various components of the IGF system could affect the progression and metastasis of cancer.
Remarks on bang-bang control in a Hilbert space

The control of a linear system, whose performance index is the sum of a linear term and a quadratic term, is considered. A necessary and sufficient condition is given for the optimal control to be bang-bang, and this is used to extend and clarify the results of Refs. 1–2. As an illustration, an application to an elliptic boundary-value problem is given.
Observation of Extended Boundary Layers in the Permeative Flow of a Smectic-A Liquid Crystal around an Obstacle

Experimental evidence is presented which supports the prediction of de Gennes of anomalous extended boundary layers accompanying the permeative steady-state flow of a single-domain smectic-$A$ around an obstacle.
Teaching Robots New Actions through Natural Language Instructions

Robots often have limited knowledge and need to continuously acquire new knowledge and skills in order to collaborate with its human partners. To address this issue, this paper describes an approach which allows human partners to teach a robot (i.e., a robotic arm) new high-level actions through natural language instructions. In particular, built upon the traditional planning framework, we propose a representation of high-level actions that only consists of the desired goal states rather than step-by-step operations (although these operations may be specified by the human in their instructions). Our empirical results have shown that, given this representation, the robot can reply on automated planning and immediately apply the newly learned action knowledge to perform actions under novel situations.
Potential Conflicts of Interest Generated by the Use of Non-Heart-Beating Cadavers

The non-heart-beating cadaver donor procurement process might come in conflict with the organ sharing system by diverting organs from potential recipients. It might also have a negative effect on public attitudes about transplantation. The process could start society down a slippery slope leading to extending donor criteria. Some of these scenarios are merely theoretical, but the procedure should be monitored to avoid such problems.
Time Course of Release in vivo of PGE2, PGF2α, 6-Keto-PGF1α, and TxB2 into the Brain Extracellular Space after 15 Min of Complete Global Ischemia in the Presence and Absence of Cyclooxygenase Inhibition

The time-dependent release of prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), thromboxane (Tx) B2, and 6-keto-PGF1 alpha (6-keto) from brain was measured before, during, and after a 15-min interval of total ischemia (four-vessel occlusion) in halothane-anesthetized cats using the technique of cerebroventricular perfusion. Resting levels of PGE2, PGF2 alpha, 6-keto, and Tx were: 253 +/- 75, 953 +/- 300, 650 +/- 200, and 550 +/- 170 pg/ml, respectively. During the 15-min ischemia, all prostanoids rose significantly, yet the highest levels were not observed until the first 15-60 min of the reflow at which time levels of PGE2, PGF2 alpha, 6-keto, and Tx, as compared with the preischemic baseline, rose approximately 8, 3.4, 3, and 55-fold, respectively. Significantly, although all prostanoids showed increases relative to baseline, the ratios of PGF2 alpha/6-keto and PGE2/6-keto remained stable throughout the experiment in both groups of animals. In contrast, the Tx/6-keto ratio rose from approximately 1 to approximately 30 during the 60 min after reflow in untreated cats. Treatment with zomepirac sodium (5 mg/kg, i.v.), a cyclooxygenase inhibitor, resulted in highly significant reductions in the levels of all prostanoids during the preischemic period. In zomepirac sodium-treated animals, there were also highly significant reductions in the prostanoid response to ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
Ethical challenges with hemodialysis patients who lack decision-making capacity: behavioral issues, surrogate decision-makers, and end-of-life situations

Hemodialysis (HD) is routinely offered to patients with end-stage renal disease in the United States who are ineligible for other renal replacement modalities. The frequency of HD among the US population is greater than all other countries, except Taiwan and Japan. In US, patients are often dialyzed irrespective of age, comorbidities, prognosis, or decision-making capacity. Determination of when patients can no longer dialyze is variable and can be dialysis-center specific. Determinants may be related to progressive comorbidities and frailty, mobility or access issues, patient self-determination, or an inability to tolerate the treatment safely for any number of reasons (e.g., hypotension, behavioral issues). Behavioral issues may impact the safety of not only patients themselves, but also those around them. In this article the authors present the case of an elderly patient on HD with progressive cognitive impairment and combative behavior placing him and others at risk of physical harm. The authors discuss the medical, ethical, legal, and psychosocial challenges to care of such patients who lack decision-making capacity with a focus on variable approaches by regions and culture. This manuscript provides recommendations and highlights resources to assist nephrologists, dialysis personnel, ethics consultants, and palliative medicine teams in managing such patients to resolve conflict.
Angiographic evaluation of saphenous vein bypass grafts: Artifactual “occlusion” caused by dual sources of flow

Angiography after coronary bypass surgery has engendered conflicting reports regarding the effect of grafting on proximal lesions. Analysis of a series of postoperative arteriographic injections demonstrates that routine studies may produce artifactual "occlusion" caused by altered or competitive flow relations. High pressure contrast injection can reveal persistent stenotic lumens at sites of apparent complete occlusion. Thus, angiographic technical factors and not surgical sequelae may be responsible for the disparate reports on this subject.
Products of the reactions of the dry and aqueous electron with hydrated DNA: hydrogen and 5,6-dihydropyrimidines

Abstract Molecular products resulting from the reaction of radiation-produced dry and aqueous electrons with DNA hydrated between 2.5 and 367 waters per nucleotide (Γ) are quantified in this work. Specifically, the yields of the 5,6-dihydropyrimidines (formed from the reaction of electrons with thymine and cytosine) and molecular hydrogen (H2) (formed in the reaction of intra-spur electrons) have been studied. We find the yields for the 5,6-dihydropyrimidines are highest (41–108 nmol/J) and the yields of hydrogen lowest (14–18 nmol/J) at low hydrations (Γ Γ = 32 . This result would suggest that the H2 produced in the irradiated hydrated DNA is derived mainly from intra-spur reactions in bulk water. However, an analysis of the H2 G-values calculated based on the dry mass of DNA (i.e., an analysis of the contribution of the water alone to the H2 yields) suggests that H2 produced in irradiated hydrated DNA is derived not only from intra-spur reactions in bulk water (44–45 nmol/J) but also from DNA (61 nmol/J). This is an interesting finding that suggests fully hydrated DNA (Γ>33) forms H2 in competition with dihydropyrimidines.
On adaptive timers for improved RPL operation in low-power and lossy sensor networks

In this paper, we propose two adaptive algorithms to control Destination Advertisement Option (DAO) packet emissions in RPL non-storing mode: a centralized, or controlled by the DAG root, and a distributed. We propose new mechanisms to derive the most appropriate value for the DelayDAO Timer, a timer that determines how long a node should wait before transmitting its destination advertisement packet to the DAG root or collection point. We also propose similar mechanism for RPL-storing mode by implementing multiple destination aggregation in a single DAO packet. We show that instead of using a fixed universal timer to control DAO emissions, as recommended in the IETF standard, the use of an adaptive timer at each node allows the network to quickly adjust to topological changes. This is aimed at reducing congestion and packet drops, specially near the DAG root, which also impacts memory and buffer requirements, as well as data delivery delay. This is crucial for networks such as Urban LLNs or Smart Grid AMI networks, whose nodes have very limited resources with regards to energy and buffer space. We show how the proposed mechanisms outperform the default method in RPL with regards to these metrics.
Mice lacking connexin40 have cardiac conduction abnormalities characteristic of atrioventricular block and bundle branch block

Abstract Activation of cardiac muscle is mediated by the His–Purkinje system, a discrete pathway containing fast-conducting cells (Purkinje fibers) which coordinate the spread of excitation from the atrioventricular node (AV node) to ventricular myocardium [1]. Although pathologies of this specialized conduction system are common in humans, especially among the elderly [2], their molecular bases have not been defined. Gap junctions are present at appositions between Purkinje fibers and could provide a mechanism for propagating impulses between these cells [3]. Studies of the expression of connexins – the family of proteins from which gap junctions are formed – reveal that connexin40 (Cx40) is prominent in the conduction system [4]. In order to study the role of gap junction communication in cardiac conduction, we generated mice that lack Cx40. Using electrocardiographic analysis, we show that Cx40 null mice have cardiac conduction abnormalities characteristic of first-degree atrioventricular block with associated bundle branch block. Thus, gap junctions are essential for the rapid conduction of impulses in the His–Purkinje system.
Cognitive behavioral pain and anxiety interventions in Pediatric Oncology Centers and Bone Marrow Transplant Units

Although research conducted on the treatment of pain and anxiety in children has found a number of cognitive behavioral interventions to be effective, it is not known to what extent this research has been put into practice. The purpose of this project was to obtain information on the use of cognitive behavioral interventions to help children and families cope with the pain and anxiety experienced during lumbar punctures and bone marrow aspirations. In this descriptive study, 15 Pediatric Bone Marrow Transplant Units and 32 Pediatric Hematology/Oncology Centers from across the country were surveyed using a questionnaire developed to obtain information on the use and effectiveness of cognitive behavioral interventions and the availability of support services. This survey indicates that most centers use a number of cognitive behavioral interventions to help children cope with painful procedures. However, some interventions, such as providing information before procedures and positive reinforcement after procedures, are used more frequently than interventions, such as rhythmic breathing, distraction, and imagery, that require more time and training. A variety of support services were available, although psychological services were primarily available on an as needed basis and support groups were not usually offered on an ongoing basis. In general, nurses are the major providers of these interventions, with other professionals providing interventions specific to their training. Nurses need to continue to study appropriate ways to incorporate use of effective cognitive behavioral interventions into the routine care of children with cancer.
Small-molecule inhibitors of p21 as novel therapeutics for chemotherapy-resistant kidney cancer

“In the search for novel approaches for the treatment of resistant cancers, small molecules targeting the cyclin dependent kinase inhibitors have shown considerable promise”
Placental and other perinatal risk factors for chronic lung disease in very low birth weight infants

To clarify the relationship between chorioamnionitis and chronic lung disease (CLD) in very low birth weight (VLBW) infants, we performed a retrospective cohort study of all inborn patients between 1995-1997 with gestational age (GA) less than 32 wk, birth weight less than 1.5 kg, survival to 36 wk adjusted GA, and placentas submitted to pathology (n = 371). Racial distribution as defined by the mother was 40% white/60% nonwhite. Prevalence of CLD, defined as O(2) dependence at 36 wk adjusted GA, was 30%. In a preliminary analysis GA and birth weight for GA (standard deviations from the mean, Z-score), considered together, were inversely related to CLD. After adjustment for GA and Z-score, other risk factors for CLD were white race, acute respiratory distress, pulmonary air leak, patent ductus arteriosus, and septicemia. Two placental lesions were inversely related to CLD: histologic chorioamnionitis and acute atherosis (a placental indicator of preeclampsia). Following multivariate analysis, independent risk factors for CLD were GA (OR, 0.6; 95% CI = 0.5, 0.7), birthweight for GA (OR, 0.4; 95% CI = 0.3, 0.6), white race (OR, 1.9; 95% CI = 1.0, 3.3), patent ductus arteriosus (OR, 2.0; 95% CI = 1.0, 3.5), and pulmonary air leak (OR, 3.0; 95% CI = 1.3, 7.1). Acute atherosis was inversely related to CLD (OR, 0.2; 95% CI = 0.1, 0.8). Chorioamnionitis was stratified by subtype and again no association with CLD was seen in the population as a whole. Finally, chorioamnionitis of all subtypes tended to be increased in white infants and decreased in black infants with CLD. This dichotomy was not explained by differences in death rates, acute respiratory distress, intubation on d 2 of life, or total duration of assisted ventilation. We conclude that while chorioamnionitis was not a risk factor for CLD in our total population, racial differences in its relationship to CLD are worthy of further study.
Imaging the Impact of Single Oxygen Atoms on Superconducting Bi2+ySr2–yCaCu2O8+x

High-temperature cuprate superconductors display unexpected nanoscale inhomogeneity in essential properties such as pseudogap energy, Fermi surface, and even superconducting critical temperature. T...
Eolian landscape evolution and soil formation in the Chaco dune field, southern Colorado Plateau, New Mexico.

Abstract Eolian deposits of the Chaco dune field cover a broad expanse of the southeastern Colorado Plateau in New Mexico and comprise a large part of the late Quaternary sedimentary record in this region. The primary eolian landforms include sand sheets, parabolic and modified parabolic dunes, barchan-barchanoid dune complexes, and ridge dunes. Many of the eolian landforms in the Chaco dune field have remained stable over a sufficiently long time to permit soil development. Weakly to moderately developed calcic soils, which formed in eolian deposits of mid-Holocene and latest Pleistocene age, possess clay-enriched, weak argillic B horizons. These soils have been buried progressively by younger eolian sediments, forming regionally correlative bounding surfaces over the Chaco dune field and recording relict latest Pleistocene and middle Holocene eolian landscapes. Soil-geomorphic relations and radiocarbon-dated material within the eolian deposits have been useful in (1) delineating three regionally correlative soil-stratigraphic units and their associated landforms and (2) studying the types and rates of landscape evolution and climatic changes within this portion of the Colorado Plateau. The most significant period of eolian landform construction is inferred to have occurred during the latest Pleistocene glacial-to-interglacial climatic change, forming widespread sand sheets and modified parabolic dunes. Eolian deposition during the middle and late Holocene were dramatically influenced by the presence of previously developed latest Pleistocene to early Holocene (buried) soils which may have enhanced sand-sheet and parabolic-dune development due to the binding effect of the soils. Middle Holocene eolian deposition may be related primarily to neoglacial climatic changes which enhanced ground-surface moisture and promoted sand-sheet and parabolic-dune formation. The youngest period of wolian deposition occurred after 1.5 ka and resulted in the formation of the most diverse suite of eolian landforms and deposition of volumetrically more eolian sediments than the mid-Holocene event. In contrast to earlier interpretations, the classic mid-holocene or “altithermal event” apparently did not play a major role in the formation of eolian landscapes in the Chaco dune field.
Effects of multiple intracerebroventricular injections of [d-Pen2,d-Pen5]enkephalin and [d-Ala2,Glu4]deltorphin II on tolerance to their analgesic action and on brain δ-opioid receptors

Abstract Male Swiss–Webster mice were injected intracerebroventricularly (i.c.v.) with [ d -Pen 2 , d -Pen 5 ]enkephalin (DPDPE), a δ 1 -opioid receptor agonist (20 μg per mouse) twice a day for either 2 or 4 days. Vehicle injected mice served as controls. Treatment of mice with DPDPE for 2 or 4 days decreased its analgesic response by 44 and 76%, respectively in comparison to vehicle injected mice. Treatment of mice with DPDPE for 2 or 4 days decreased the receptor density ( B max ) of [ 3 H]DPDPE to bind to brain homogenates by 77 and 76%, respectively, in comparison to vehicle injected controls but the apparent dissociation constant ( K d ) values were not altered. The effects of i.c.v. injections of [ d -Ala 2 ,Glu 4 ]deltorphin II (deltorphin II), a δ 2 -opioid receptor agonist (20 μg per mouse) twice a day for either 2 or 4 days on its analgesic response as well as on brain receptors for [ 3 H]DPDPE were also determined. The analgesic response to deltorphin II decreased by 51 and 78%, respectively in mice treated with deltorphin II for 2 or 4 days, respectively. Two or four days treatment with deltorphin II decreased the B max of [ 3 H]DPDPE by 76 and 87%, respectively. The 2-day treatment also increased the K d value by 58%, but the 4-day treatment with deltorphin II had no effect on the K d of [ 3 H]DPDPE to bind to brain membranes. Thus, multiple injections of δ 1 - or δ 2 -opioid receptor agonists result in the development of tolerance to their analgesic action and the intensity of tolerance increases with the duration of treatment. Both δ 1 - and δ 2 -opioid receptor agonist, on chronic administration, result in the down-regulation of δ 1 -opioid receptors labeled with [ 3 H]DPDPE.
Direct Photon Production in High-Energy Collisions

The authors review the experimental evidence for the observation of single photons in hadronic reactions, summarize the phenomenology used in parametrizing the dynamics of the process, provide a survey of the current status of the experimental program, and discuss expectations from future investigations of direct-photon production at large transverse momenta.