cssi/SciSciGPT-SciSciNet huggingface dataset:
Rapid Recovery of Damaged Ecosystems

Background Recent reports on the state of the global environment provide evidence that humankind is inflicting great damage to the very ecosystems that support human livelihoods. The reports further predict that ecosystems will take centuries to recover from damages if they recover at all. Accordingly, there is despair that we are passing on a legacy of irreparable damage to future generations which is entirely inconsistent with principles of sustainability. Methodology/Principal Findings We tested the prediction of irreparable harm using a synthesis of recovery times compiled from 240 independent studies reported in the scientific literature. We provide startling evidence that most ecosystems globally can, given human will, recover from very major perturbations on timescales of decades to half-centuries. Significance/Conclusions Accordingly, we find much hope that humankind can transition to more sustainable use of ecosystems.
Unmasking of fetal determinants on adult bone marrow cells.

The phasing-out of an SV40 cross-reactive fetal antigen in the developing hamster fetus after day 10 occurs concomitantly with an increase of bound sialic acid in membrane, microsomal and soluble cell fractions1. A masking phenomenon is suggested by the fact that the antigen can be uncovered on older fetal tissue by trypsinisation2. Similarly, a murine oncofetal antigen under study in our laboratory is optimally expressed on the haematopoietic stem cells of the fetal liver at the 15th day of gestation3, just before the onset of haematopoiesis and collagen production in the spleen4. The expression of this antigen on human leukaemic blast cells has, furthermore, been correlated with low levels of sialic acid on the surface of these tumour cells5. As fetal determinants can be expressed on adult bone marrow in disease states not involving malignant transformation6, it is of interest to know whether production of this oncofetal antigen is repressed, or whether the determinants are in cryptic form at the plasma membrane due to some masking phenomenon. The investigation described here demonstrates that determinants which cross-react immunologically with fetal liver tissue can be enzymatically unmasked on normal adult murine haematopoietic stem-cell surfaces. This finding suggests that the expression of these oncofetal antigens on malignant cells does not depend on de novo production of the antigens, and that these determinants may play some part in normal differentiation control mechanisms.
Towards Transactional Data Management over the Cloud

We propose a consistency model for a data store in the Cloud and develop a framework towards the goal of deploying Database as a Service over the Cloud. This includes consistency across the data partitions and consistency of any replicas that exist across different nodes in the system. We target applications which need stronger consistency guarantees than the applications currently supported by the data stores on the Cloud. We propose a cost-effective algorithm that ensures distributed consistency of data without really compromising on availability for fully replicated data. This paper describes a design in progress, presents the consistency and recovery algorithms for relational data, highlights the guarantees provided by the system and presents future research challenges. We believe that the current notions of consistency for databases might not be applicable over the Cloud and a new formulation of the consistency concept may be needed keeping in mind the application classes that need to be supported.
The Prevention of Reading Difficulties

Abstract The purpose of this article is to provide practical advice about methods to prevent reading failure that is grounded in the new knowledge we have acquired about reading and learning to read over the past 2 decades. Recent research on reading is used to establish a set of facts about reading and reading growth that is relevant to establishing instructional objectives and methods for the prevention of reading difficulties. Within the context of our current understanding of the reasons many children find it difficult to learn to read, the article also identifies the instructional conditions that need to be in place to prevent the development of reading difficulties in all but a very small proportion of children. The article concludes with a discussion of issues and procedures for the early identification of children who are likely to experience difficulties learning to read.
Endogenous nitric oxide regulates right coronary blood flow during acute pulmonary hypertension in conscious dogs.

This study investigated the role of nitric oxide (NO) in the control of right coronary (RC) blood flow at rest and during acute pulmonary hypertension. Experiments were performed in seven chronically instrumented, conscious dogs. NO synthesis was inhibited by systemic administration of Nω-nitro-L-arginine (LNA, 35 mg/kg). Inflation of a balloon in the main pulmonary artery raised right ventricular (RV) peak systolic pressure from 34 ± 2 to 47 ± 3 mmHg before LNA and from 37 ± 2 to 47 ± 3 mmHg after LNA, but did not affect mean systemic arterial pressure. RV O2 consumption (MVO2) increased from 4.4 ± 0.7 to 6.1 ± 0.7 ml/min/100 g. 82 % of the elevated RV MVO2 was provided by RC blood flow, which increased from 46 ± 7 to 61 ± 8 ml/min/100 g. After LNA, resting RV MVO2 and RC flow fell. RC venous PO2 fell, but RV lactate uptake was not altered. During pulmonary hypertension, the increase in RC blood flow was blunted by LNA, so that only 66 % of the elevated RV MVO2 was supplied by increased RC flow. Analysis of O2 supply variables as functions of RV MVO2 further demonstrated a significant role of NO in regulating RC flow at rest and during moderate pulmonary hypertension. Conclusions NO is required for the RC hyperemic response to acute pulmonary hypertension as well as for normal resting RC blood flow. After blockade of NO synthesis, RV O2 supply at rest and during pulmonary hypertension was sustained by increased RV O2 extraction.
Large deviation probabilities for order statistics

Asymptotic representations are found for the large deviation probabilities that the nα-th order statistic exceeds δ, where δ>α. The probabilities are first expressed in terms of the empirical distribution function, and then the 1960 theorem of Bahadur and Ranga Rao is applied. The result is then shown to be more precise than a logarithmic statement in a 1969 paper of Sievers dealing with the asymptotic relative efficiency of the sample median test.
The state of the science in the meta-analysis of single-case experimental designs

The articles in the previous, special issue of Evidence-Based Communication Assessment and Intervention provided an excellent review of the meta-analysis of single-case designs. This article weaves commentary about those articles into a larger narrative about two major lines of attack on this problem: the use of parametric approaches like regression and multilevel modeling, and the development of parametric and nonparametric effect-size estimators. On each of these two topics, we describe an agenda of research topics that need to be addressed; and we also introduce a new effect-size estimator that may prove to be comparable to the usual standardized mean difference statistics (d) widely used in between-groups analysis. The article ends with observations about ways in which developments in the meta-analysis of single-case designs may have far wider implications than previously appreciated. Source of funding: U.S. Department of Education, Institute of Education Science, Grant # H324U050001-06
The association between muscle strengthening activities and red blood cell distribution width among a national sample of U.S. adults.

Abstract Red blood cell distribution width (RDW) is a novel biomarker indicative of cardiovascular disease. However, little research has examined the association of muscle strengthening activities (MSA) on RDW. Objective Examine the association between MSA and RDW among a national sample of U.S. adults. Methods Data from the 2003–2006 (n = 8257) National Health and Nutrition Examination Survey were used. Multivariable linear and logistic regression analyses were used to examine the association between MSA with RDW. Participants self-reported their extent of MSA (e.g., lifting weights, push-ups, and sit-ups) and RDW was assessed from a blood sample. Results Independent of demographics, aerobic-based physical activity and established cardiovascular disease risk factors, for every 1 MSA session per day increase, the odds of having an elevated RDW (≥ 14.1%) reduced by 34% (p Conclusion Engagement in MSA is inversely associated with RDW. Although speculative, these findings suggest that changes in RDW may be one potential mechanism through which MSA may influence cardiovascular disease.
Lifetime psychiatric symptoms in persons with schizophrenia who died by suicide compared to other means of death

The focus of this report is to compare the psychiatric symptomatology of individuals with schizophrenia who have died by suicide to those who have died by other means of death. This study includes individuals with a diagnosis of schizophrenia whose families donated their brain tissue to the Maryland Brain Collection between September 1989 and August 1998. The psychological autopsy method was used to assess the deceased individual's demographic and clinical characteristics, psychiatric symptoms and history of suicidal thoughts and attempts. Ninety-seven individuals with schizophrenia were identified for this study. Fifteen had committed suicide, while the remaining 82 died from other causes. Thoughts of suicide and previous suicide attempts were more frequent among the group that died from suicide (93% compared to 26%) (p < 0.0001). Suicide victims had a higher rate of depressive symptoms and were twice as likely to have a depressed mood. The incidence of thoughts of dying was 60% compared to 20% in those who did not commit suicide (p = 0.002). Loss of interest was reported to occur in 20% in the suicide group compared to 4% in the group of individuals that died from other causes (p = 0.05). Victims of suicide also had higher rates of positive symptoms throughout their lifetime including thought control, flight of ideas, and loose associations. Suicide is one of the leading cause of premature death in individuals with schizophrenia and identification of risk factors is of great importance. Individuals who die by suicide experience higher rates of depressive symptoms, suicidal thoughts and positive symptoms during their life.
Immunomodulatory effects of transfusion

HE administration of blood and its components can be life-saving, particularly during resuscitation in trauma patients when blood loss can be severe enough to result in cellular hypoxia.1 Also, during other critical illness such as systemic inflammatory response syndrome, especially if the patient is septic with significant acute lung injury, blood is administered to augment oxygen delivery to avoid cellular hypoxia and lactate production. 2 Even though there are risks following blood transfusions, the benefits seem to be insurmountable 3 (Table 1). Despite this, the risks of infection, especially from human immunodeficiency virus, have taken center stage even in the lay press. Thus, the immunologic effects of transfusion have not gained the attention deserved. Nonetheless, certain disciplines--hematology, critical care medicine, oncology, surgery, and particularly transplantation-have appreciated the immunologic potential from its use. This article will discuss the basics of immunology, concentrating on the immunologic consequences of transfusions, the clinical and animal studies affecting tumor recurrence, and infection.
High temperature cuprate-like superconductivity

Abstract The percolative (quasi-one-dimensional) topological network model shows that high-transition-temperature superconductivity (HTSC) in non-cuprate ceramics quantitatively obeys the same Pauling–Phillips phenomenology as that found in ionic cuprates, not only in bulk, but even for nanometer-sized interfaces and clusters. The new covalent LaFeAsO 1− x F x superfamily provides the latest and most spectacular example of the success of the topological network approach. Several recent cuprate experiments have confirmed many specific features of the 20-year old zigzag percolative all-atom (coarse-grained) model based on dopant-centered electron–phonon interactions that decisively distinguish it from far more popular continuum models based on CuO 2 planes only.
Inhibition of SIRT1 reactivates silenced cancer genes without loss of promoter DNA hypermethylation.

The class III histone deactylase (HDAC), SIRT1, has cancer relevance because it regulates lifespan in multiple organisms, down-regulates p53 function through deacetylation, and is linked to polycomb gene silencing in Drosophila. However, it has not been reported to mediate heterochromatin formation or heritable silencing for endogenous mammalian genes. Herein, we show that SIRT1 localizes to promoters of several aberrantly silenced tumor suppressor genes (TSGs) in which 5′ CpG islands are densely hypermethylated, but not to these same promoters in cell lines in which the promoters are not hypermethylated and the genes are expressed. Heretofore, only type I and II HDACs, through deactylation of lysines 9 and 14 of histone H3 (H3-K9 and H3-K14, respectively), had been tied to the above TSG silencing. However, inhibition of these enzymes alone fails to re-activate the genes unless DNA methylation is first inhibited. In contrast, inhibition of SIRT1 by pharmacologic, dominant negative, and siRNA (small interfering RNA)–mediated inhibition in breast and colon cancer cells causes increased H4-K16 and H3-K9 acetylation at endogenous promoters and gene re-expression despite full retention of promoter DNA hypermethylation. Furthermore, SIRT1 inhibition affects key phenotypic aspects of cancer cells. We thus have identified a new component of epigenetic TSG silencing that may potentially link some epigenetic changes associated with aging with those found in cancer, and provide new directions for therapeutically targeting these important genes for re-expression.
Genetic control of estrogen action in the rat: mapping of QTLs that impact pituitary lactotroph hyperplasia in a BN x ACI intercross.

Estrogens are important regulators of growth and development and contribute to the etiology of several types of cancer. Different inbred rat strains exhibit marked, cell-type-specific differences in responsiveness to estrogens as well as differences in susceptibility to estrogen-induced tumorigenesis. Regulation of pituitary lactotroph homeostasis is one estrogen-regulated response that differs dramatically between different inbred rat strains. In this article we demonstrate that the growth response of the anterior pituitary gland of female ACI rats to 17β-estradiol (E2) markedly exceeds that of identically treated female Brown Norway (BN) rats. We further demonstrate that pituitary mass, a surrogate indicator of absolute lactotroph number, behaves as a quantitative trait in E2-treated F2 progeny generated in a genetic cross originating with BN females and ACI males. Composite interval mapping analyses of the (BN×ACI)F2 population revealed quantitative trait loci (QTLs) that exert significant effects on E2-induced pituitary growth on rat chromosome 4 (RNO4) (Ept5) and RNO7 (Ept7). Continuous treatment with E2 rapidly induces mammary cancer in female ACI rats but not BN rats, and QTLs that impact susceptibility to E2-induced mammary cancer in the (BN×ACI)F2 population described here have been mapped to RNO3 (Emca5), RNO4 (Emca6), RNO5 (Emca8), RNO6 (Emca7), and RNO7 (Emca4). Ept5 and Emca6 map to distinct regions of RNO4. However, Ept7 and Emca4 map to the same region of RNO7. No correlation between pituitary mass and mammary cancer number at necropsy was observed within the (BN×ACI)F2 population. This observation, together with the QTL mapping data, indicate that with the exception of the Ept7/Emca4 locus on RNO7, the genetic determinants of E2-induced pituitary growth differ from the genetic determinants of susceptibility to E2-induced mammary cancer.
The Elusive Arts of Reflexivity in the ‘Sciences’ of International Relations

There are a number of highly laudable aspects of Patrick Jackson’s broadened discussion of scientific inquiry in the field of International Relations, among them the attention he gives to feminist ...
Effect of strain rate and temperature on mechanical properties and fracture mode of high strength precipitation hardened ferritic steels

The effect of strain rate on the flow stress of a low carbon high strength ferritic steel that contains nanometer size Cu–Ni–Al precipitates is found to be much less than that of HSLA 65 that does not have such precipitates. This result is in agreement with the theory that such precipitates locally lower the Peierls stress for screw dislocations in body-centered cubic iron. The fracture mode in the steel is ductile over the wide ranges of strain rate and temperature investigated.
Univariate Blending Functions and Alternatives

This paper develops the exponential function as an alternative to the classical Hermite basis. Other alternatives such as a Hermite-type basis produced from B-splines are also discussed. These alternatives allow the user greater flexibility in creating free-form curves and surfaces. The cardinal bases permit the introduction of intuitive and tractable control parameters. Arc length and surface area as well as derivative data are placed under user control. Changes in these parameters have only a local effect on the curve or surface. These bases are constructed in such a way as to allow interchanges between different sets of bases. This yields even greater flexibility.
Translation of Near-Infrared Fluorescence Imaging Technologies: Emerging Clinical Applications

Technical developments in near-infrared fluorescence (NIRF) imaging and tomography have enabled recent translation into investigational human studies. Noninvasive imaging of the lymphatic vasculature for diagnosis and assessment of function has been uniquely accomplished with NIR using indocyanine green (ICG), a nonspecific dye that has comparatively poor fluorescent properties compared to emerging dyes. Adjunct use of NIRF-ICG for (a) intraoperative sentinel lymph node mapping for cancer staging, (b) video-angiography during surgery, and (c) discrimination of malignant from benign breast lesions detected by mammography and ultrasongraphy also evidences the clinical utility of NIRF. Future NIRF imaging agents that consist of bright fluorescent dyes conjugated to disease-targeting moieties promise molecular imaging and image-guided surgery. In this review, emerging NIRF imaging is described within the context of nuclear imaging technologies that remain the "gold standard" of molecular imaging.
Phase I Dose-Escalation Trial of Checkpoint Kinase 1 Inhibitor MK-8776 As Monotherapy and in Combination With Gemcitabine in Patients With Advanced Solid Tumors

Purpose We determined the safety, pharmacokinetics, pharmacodynamics, and recommended phase II dose of MK-8776 (SCH 900776), a potent, selective checkpoint kinase 1 (Chk1) inhibitor, as monotherapy and in combination with gemcitabine in a first-in-human phase I clinical trial in patients with advanced solid tumor malignancies. Patients and Methods Forty-three patients were treated by intravenous infusion with MK-8776 at seven dose levels ranging from 10 to 150 mg/m2 as monotherapy and then in combination with gemcitabine 800 mg/m2 (part A, n = 26) or gemcitabine 1,000 mg/m2 (part B, n = 17). Forty percent of patients had three or more prior treatment regimens, and one third of patients had previously received gemcitabine. Results As monotherapy, MK-8776 was well tolerated, with QTc prolongation (19%), nausea (16%), fatigue (14%), and constipation (14%) as the most frequent adverse effects. Combination therapy demonstrated a higher frequency of adverse effects, predominantly fatigue (63%), nausea (44%), de...
The influence of precursor structure on the development of porosity in polymer-derived SiC

Polymer-based routes to ceramic oxides take advantage of precursor chemistry and structure to produce materials with a range of pore sizes. Polymer precursor routes to non-oxide ceramics offer products with superior thermal and chemical stability in many cases. Polymethylsilane (PMS), a versatile cross linked SiC precursor, [(MeHSi){sub x}(MeSi){sub y}], was synthesized using published procedures to yield fluid precursors with a low (20--40%) degree of cross linking. Unique, highly cross linked (60--70%), solid polymers were produced under reaction conditions which carefully conserve the volatile monomer. These two polymers were converted to SiC to determine the relative importance of the various contributions to porosity, and to assess the role of precursor structure on porosity development in non-oxides. Initial results indicate that precursor structure has little effect on porosity. The development of the porosity appears to be dominated by high temperature thermochemistry and/or microstructural changes.
Error Probability Bounds and Approximations for DS Spread-Spectrum Communication Systems with Mutiple Tone or Multiple Access Interference

Upper and lower bounds on the average probability of error of direct sequence (DS) spread-spectrum communication systems operating in the presence of either multiple tone or multiple access interference are presented. The bounds are quite tight and can be used without the restriction that the peak level of the interference be less than the desired signal level. A simple method for evaluating approximations to the bounds for multiple access systems, in which the peak interference does indeed exceed the desired signal level, is presented as well. The tightness of both the bounds and the approximations are illustrated with numerical results.
Haplotyping and mapping a large cluster of downy mildew resistance gene candidates in sunflower using multilocus intron fragment length polymorphisms.

Summary Downy mildew (Plasmopara halstedii (Farl.) Berlese et de Toni) is a serious foliar pathogen of cultivated sunflower (Helianthus annuus L.). Genetic resistance is conditioned by several linked downy mildew resistance gene specificities in the HaRGC1 cluster of TIR-NBS-LRR resistance gene candidates (RGCs) on linkage group 8. The complexity and diversity of the HaRGC1 cluster was assessed by multilocus intron fragment length polymorphism (IFLP) genotyping using a single pair of primers flanking a hypervariable intron located between the TIR and NBS domains. Two to 23 bands were amplified per germplasm accession. The size of the included intron ranged from 89 to 858 nucleotides. Forty-eight unique markers were distinguished among 24 elite inbred lines, six partially isogenic inbred lines, nine open-pollinated populations, four Native American land races, and 20 wild H. annuus populations. Nine haplotypes (based on 24 RGCs) were identified among elite inbred lines and were correlated with known downy mildew resistance specificities. Sixteen out of 39 RGCs identified in wild H. annuus populations were not observed in elite germplasm. Five partially isogenic downy mildew resistant lines developed from wild H. annuus and H. praecox donors carried eight RGCs not found in other elite inbred lines. Twenty-four HaRGC1 loci were mapped to a 2–4 cM segment of linkage group 8. The multilocus IFLP marker and duplicated, hypervariable microsatellite markers tightly linked to the HaRGC1 cluster are powerful tools for distinguishing downy mildew resistance gene specificities and identifying and introgressing new downy mildew resistance gene specificities from wild sunflowers.
Retinoids in lung development.

The "retinoid revolution" has had considerable impact on research activity in the field of lung development. Postnatal lungs are very sensitive to dietary retinol (R) deprivation. The trachea and the bronchopulmonary tree in R-deficient animals show a striking change in morphology. The columnar epithelium undergoes keratinizing metaplasia, which is reversed when R is supplied. The fetal lung develops postnatally to become one of the most complex organs, characterized by 40 different cell types. The fetal lungs can accumulate retinyl esters. Before birth an unknown signal causes the lowering of these esters, which may be the source of retinoic acid (RA). The administration of glucocorticoids speeds up this process, which in turn is followed by acceleration of lung maturation, ending postnatally. It is not clear what role, if any, the cellular retinoid binding proteins play in this phenomenon. Fetal lung branching leading to the development of the alveolar tree is accelerated by RA, and so is the expression...
Two major dust storms, one Mars year apart: Comparison from Viking data

The Viking Mars Landers have been on the Mars surface for over two Mars years. During the first year two major, probably global, dust storms occurred. The first was unusually early compared to most previous earth-based observations. A major storm occurred during the second year, almost precisely one year after the first storm of the first year. Meteorological data show roughly similar atmospheric behavior for the two early storms. Of particular note is the increase in amplitude of pressure oscillations (probably of baroclinic origin) and concurrent increases in wind speed during the build-up phase of all three storms. The generation of these waves appears to be a natural consequence of seasonal effects not associated with the dust storms. It is suggested that baroclinic waves, should they exist in the Southern Hemisphere during the time of dust storm generation, could be an important factor in the growth and development of the dust storms.
Analysis of rainfall and fine aerosol data using clustered trajectory analysis for National Park sites in the Western US

We calculated daily back-trajectories using the NOAA-HYSPLIT model to analyze 7 years of precipitation and PM2.5 data from three National Park sites in the Western US. Using a k-means clustering algorithm, the trajectories were segregated into six main transport patterns. At each site, we calculated trajectory clusters for 1, 5, and 10 days to represent short, medium and long-range flow patterns. Most clusters show marked seasonality. Faster flow patterns are more prevalent in winter, and slower/stagnant patterns are more prevalent in summer. The analyses between the 1, 5, and 10-day clusters revealed that the clusters of different duration show very different predictive power for rainfall and PM2.5. We found that the 1-day clusters are a better predictor for precipitation and PM2.5 concentrations, followed by the 5-day clusters. The 10-day clusters did a poorer job of differentiating precipitation and PM2.5. This is because the 10-day clusters show the greatest variability during the first day or two of transport.
Nitrogen Transformations Following Tropical Forest Felling and Burning on a Volcanic Soil

We measured nitrogen transformations and loss following forest clearing in a relatively fertile tropical forest site. Nitrogen mineralization, nitrification, and amounts of ammonium and nitrate increased substantially in surface soils during the 6 mo following burning, then returned to background levels. The nitrogen content of microbial biomass declined to half its original value 6 mo after clearing and remained low in the cleared sites. Plant uptake of nitrogen was substantial on cleared plots (50 g/m2), but it accounted for only 18% of 15N label added to field plots. Microbial immobilization of 15N was small relative to that in a cleared temperate site, and measurements of denitrification potentials suggested that relatively little mineralized nitrogen was lost to the atmosphere. Substantial amounts of nitrogen (40-70 g/m2) were retained as exchangeably bound nitrate deep in the soils of a cleared plot on which revegetation was prevented; this process accounted for 12% of the 15N label added to field plots.
Endocrine Manifestations of Stimulatory G Protein α-Subunit Mutations and the Role of Genomic Imprinting

The heterotrimeric G protein Gs couples hormone receptors (as well as other receptors) to the effector enzyme adenylyl cyclase and is therefore required for hormone-stimulated intracellular cAMP generation. Receptors activate Gs by promoting exchange of GTP for GDP on the Gs α-subunit (Gsα) while an intrinsic GTPase activity of Gsα that hydrolyzes bound GTP to GDP leads to deactivation. Mutations of specific Gsα residues (Arg201 or Gln227) that are critical for the GTPase reaction lead to constitutive activation of Gs-coupled signaling pathways, and such somatic mutations are found in endocrine tumors, fibrous dysplasia of bone, and the McCune-Albright syndrome. Conversely, heterozygous loss-of-function mutations may lead to Albright hereditary osteodystrophy (AHO), a disease characterized by short stature, obesity, brachydactyly, sc ossifications, and mental deficits. Similar mutations are also associated with progressive osseous heteroplasia. Interestingly, paternal transmission of GNAS1 mutations leads...
Science Teacher Retention in Today's Urban Schools: A Study of Success and Failure.

This study is based on data collected during 6 years (12 semesters) in the secondary science methods courses at an urban university in Southern California. The secondary science credential candidates were teaching on emergency permits or internship credentials in local urban secondary schools. They taught science during the day and pursued their teaching licenses in the late afternoons. Power relationships, urbanity, and critical pedagogy lenses were critical in analyzing the data. Multiple data sources, such as the credential candidates' written assignments, verbal communications, and field notes during classroom observations, were triangulated. Findings suggest that secondary science interns tend to thrive in schools where there is a perceived cohesive vision regarding science education and where efforts of all the stakeholders in the educational community (teachers, students, administration, community, including parents, district personnel, university instructors, and the science education research com...
The effect of inorganic nitrogen speciation on primary production in the San Francisco Estuary

Abstract We describe the results of a series of 96-h enclosure experiments conducted using water from stations in the northern San Francisco Estuary (SFE) along a gradient in ammonium (NH 4 ) and nitrate (NO 3 ) concentrations. Using dual-labeled 13 C/ 15 N tracers, we followed the timing and sequence of primary (carbon, C) production and phytoplankton nitrogen (N) use during experimental phytoplankton blooms. Our results show that diatoms consistently drive the phytoplankton blooms in the enclosures. By tracing both C and N uptake we provide clear evidence that high rates of C uptake are linked to phytoplankton NO 3 , and not NH 4 , use. Results from kinetics experiments demonstrated higher specific uptake rates (V MAx ) for NO 3 compared to NH 4 in the SFE. Finally, dissolved inorganic carbon and nutrient drawdown ratios in the enclosures from the chronically high NH 4 regions of the SFE were substantially lower than predicted from the Redfield ratio, suggesting suppressed C uptake, in relation to other elemental uptake. Our conceptual model of the DIN interactions that lead to higher primary production and phytoplankton blooms in the SFE suggests that higher rates of primary production that accompany phytoplankton NO 3 uptake are sufficient to outpace phytoplankton losses, leading to blooms, compared to the lower rates associated with NH 4 uptake (only 20% of that based upon NO 3 ). Historical changes in wastewater practices have increased the proportion of NH 4 to the DIN pool in the SFE leading to reduced access to NO 3 by phytoplankton. This may help to explain some of the reduced primary production and phytoplankton biomass observed there since the 1970s.
Localization of Surface Structures During Procaryotic Differentiation: Role of Cell Division in Caulobacter crescentus

Asymmetric cell division in Caulobacter crescentus produces two cell types, a stalked cell and a new swarmer cell, with characteristics surface structures. We have examined the role of the cell cycle in the differentiation of these two cells using the adsorption of bacteriophage oLC72, the assembly of the polar flagellum, and stalk formation as assays for changes in surface morphology. Previous studies of this aquatic bacterium [17, 25] have suggested that the replicating chromosome acts as a ‘clock’ in timing the formation of the flagellar filament at one pole of the new swarmer cell. The analysis of conditional cell cycle mutants presented here extends these results by showing that DNA synthesis is also required for adsorption of phage oLC72 and, more importantly, they also suggest that a late cell division step is involved in determining the spatial pattern in which the phage receptors and flagella are assembled. We propose that this cell division step is required for formation of ‘organizational’ centers which direct the assembly of surface structures at the new cell poles, and for the polarity reversal in assembly that accompanies swarmer cell to stalked cell development.
InfoTrac's SearchBank Databases: Business Information and More

Abstract Since early 1995, the University of Nevada, Reno (UNR) libraries have offered its user community a new and enhanced service through the InfoTrac SearchBank from Information Access Company (1AC). Available through the libraries' online catalog, this service offers useful features like remote access through the Internet, indexing and abstracting, fall-text access to 460 journal titles, as well as a powerful search engine. The service also provides access to a family of databases in areas such as, general reference, health, business and law information. The purpose of this article is to familiarize the business librarians and researchers with the business databases (General BusinessFile ASAP and Businesslndex Backfile) available through the InfoTrac SearchBank service.
Proper efficiency and the theory of vector maximization

Abstract : The concept of efficiency in problems with multiple criterion functions--sometimes under an alias such as 'admissibility' or 'Pareto optimality'--has long played an important role in economics, game theory, statistical decision theory, and in all optimal decision problems with noncomparable criteria. Here we propose a slightly restricted definition of efficiency that eliminates efficient points of a certain anomalous nature. This new definition, which we call proper efficiency, is related in spirit to the notion of 'proper' efficiency introduced by Kuhn and Tucker in their celebrated paper of 1950; but the present definition avoids certain drawbacks inherent in the earlier one. A comprehensive theory of vector maximization is constructed using the new definition, with and without various constraint qualification, convexity, and differentiability assumptions. The theory includes as a special case the standard theory of nonlinear programming.
BdlA, a Chemotaxis Regulator Essential for Biofilm Dispersion in Pseudomonas aeruginosa

Multiple environmental cues have been shown to trigger biofilm detachment, the transition from surface-attached, highly organized communities known as biofilms to the motile lifestyle. The goal of this study was to identify a gene product involved in sensing environmental cues that trigger biofilm dispersion in Pseudomonas aeruginosa. To do so, we focused on novel putative chemotaxis transducer proteins that could potentially be involved in environmental sensing. We identified a locus encoding such a protein that played a role in detachment, as indicated by the observation that an isogenic mutant biofilm could not disperse in response to a variety of environmental cues. The locus was termed bdlA for biofilm dispersion locus. The BdlA protein harbors an MCP (methyl-accepting chemotaxis protein) domain and two PAS (Per-Arnt-Sint) domains that have been shown to be essential for responding to environmental signals in other proteins. The dispersion-deficient phenotype of the bdlA mutant was confirmed by treatment with the biocide H(2)O(2) and by microscopic observations. The dispersion response was independent of motility. bdlA mutant biofilms were found to have increased adherent properties and increased intracellular levels of cyclic di-GMP (c-di-GMP). Our findings suggest that BdlA may be a link between sensing environmental cues, c-di-GMP levels, and detachment. Based on our findings, a possible involvement of BdlA in a signaling cascade resulting in biofilm dispersion is discussed.
A web server for performing electronic PCR

‘Electronic PCR’ (e-PCR) refers to a computational procedure that is used to search DNA sequences for sequence tagged sites (STSs), each of which is defined by a pair of primer sequences and an expected PCR product size. To gain speed, our implementation extracts short ‘words’ from the 3′ end of each primer and stores them in a sorted hash table that can be accessed efficiently during the search. One recent improvement is the use of overlapping discontinuous words to allow matches to be found despite the presence of a mismatch. Moreover, it is possible to allow gaps in the alignment between the primer and the sequence. The effect of these changes is to improve sensitivity without significantly affecting specificity. The new software provides a search mode using a query STS against a sequence database to augment the previously available mode using a query sequence against an STS database. Finally, e-PCR may now be used through a web service, with search results linked to other web resources such as the UniSTS database and the MapViewer genome browser. The e-PCR web server may be found at www.ncbi.nlm.nih.gov/sutils/e-pcr.
eMPI/eMPICH: embedding MPI

This paper discusses efforts toward providing embeddable versions of MPI for use in memory-constrained systems. Two design paradigms were followed: top-down, which removed certain functionality from a full MPI implementation, and bottom-up, which began with a six function MPI implementation and added functionality to create a sequence of embeddable libraries. A comparison between these two approaches is presented along with a discussion of more hardware-specific issues.
Phosphate supply explains variation in nucleic acid allocation but not C : P stoichiometry in the western North Atlantic

Marine microbial communities mediate many bio- geochemical transformations in the ocean. Consequently, processes such as primary production and carbon (C) export are linked to nutrient regeneration and are influenced by the resource demand and elemental composition of marine mi- crobial biomass. Laboratory studies have demonstrated that differential partitioning of element resources to various cel- lular components can directly influence overall cellular ele- mental ratios, especially with respect to growth machinery (i.e., ribosomal RNA) and phosphorus (P) allocation. To in- vestigate whether allocation to RNA is related to biomass P content and overall C : P biomass composition in the open ocean, we characterized patterns of P allocation and C : P elemental ratios along an environmental gradient of phos- phate supply in the North Atlantic subtropical gyre (NASG) from 35.67 N, 64.17 W to 22.676 N, 65.526 W. Because the NASG is characterized as a P-stressed ecosystem, we hypothesized that biochemical allocation would reflect sen- sitivity to bioavailable phosphate, such that greater phos- phate supply would result in increased allocation toward P- rich RNA for growth. We predicted these changes in allo- cation would also result in lower C : P ratios with increased phosphate supply. However, bulk C : P ratios were decou- pled from allocation to nucleic acids and did not appear to vary systematically across a phosphate supply gradient of 2.2-14.7 µmol m 2 d 1 . Overall, we found that C : P ratios ranged from 188 to 306 along the transect, and RNA repre- sented only 6-12 % of total particulate P, whereas DNA rep- resented 11-19 %. We did find that allocation to RNA was positively correlated with phosphate supply rate, suggesting a consistent physiological response in biochemical allocation to resource supply within the whole community. These re- sults suggest that community composition and/or nonnucleic acid P pools may influence ecosystem-scale variation in C : P stoichiometry more than nucleic acid allocation or P supply in diverse marine microbial communities.
R-Proxy Framework for In-DB Data-Parallel Analytics

R is a powerful programming environment for data analysis. However, when dealing with big data in R, a kind of main-memory based functional programming environment, the data movement and memory swapping become the major performance bottleneck. Therefore, executing a big-data-intensive R program could be many orders of magnitude less efficient than processing the SQL query directly inside the database for dealing with the same analytic task. Although there exists a number of “parallel-R” solutions, pushing R operations down to the parallel database layer, while retaining the natural R interface and the virtual R analytics flow, remains a very competitive alternative.
PP04.2 – 2598: The varicella-zoster virus vasculopathy: Case report

Objectives Varicella zoster virus (VZV) is a common childhood infection. Reactivation may cause various neurological complications, including infection of cerebral arteries, resulting in vascular remodeling and stroke. We are presenting an unusual pediatric case of VZV vasculopathy. Case report A six years old boy, with no history of immunologic or neurologic disorder, was admitted to our hospital due to two episodes of diplopia and gait unsteadiness. No history of severe headaches was noted. He had chickenpox 20 months earlier and no history of zoster rash. Physical examination revealed only mild torticollis. Ophthalmological examination was unremarkable. On magnetic resonance imaging (MRI) multiple T2/FLAIR hyperintensities were seen, most pronounced was in the ventral part of the right thalamus, and an old ischemic lesion in the left postcentral cortex, suggesting ischemic lesions of different ages. MR angiography was unremarkable. Cerebrospinal fluid (CSF) pleocytosis was present and it tested positive for VZV DNA; specific anti-VZV antibodies were not detected. Thrombophilia screening revealed he was homozygous for methylenetetrahydrofolate (MTHFR) gene mutation. Fourteen day treatment with intravenous acyclovir was applied. After three months the follow-up MRI showed two old lacunar ischemic lesions and multiple T2/FLAIR hyperintensities at the same locations, new lesions were not found. Symptoms have not reoccurred. Conclusion Our patient had an atypical clinical presentation of multifocal, probably small artery vasculopathy and subsequent ischemic strokes presumably after VZV reactivation wihout the preceding rash.
The Stability of Veins Under Torsion

Twisted veins are observed throughout the body and are often associated with health risks such as hypertension and diabetes mellitus [1]. Recently, it has been shown that veins will buckle and become tortuous when lumen pressure exceeds a critical value [2]. However, veins also undergo twist deformations in vivo due to body movement, vein grafting, and microanastomosis procedures which may lead to reduced patency, kinking, and thrombus formation [3, 4]. In spite of this, little data is available regarding the stability of veins when subject to twist deformations. Therefore, it is of clinical interest to investigate the mechanical stability of veins under torsion.© 2012 ASME
Oscillographing Commutation

To the designer of electric equipment, even these few curves indicate clearly the entire problem of commutation. The effect of variation in the adjustment of the commutating pole and of mutual inductance upon the rate of change of current is shown. The difficulty of getting the several coils in a slot to commutate equally is revealed. The need for brushes to absorb the residual voltages under the best of conditions is suggested. Commutation theory is proved to be correct, and a better understanding of commutation is promoted. Beyond this point, what use can be made of the oscillograph in extending the range of commutation? At this time we cannot answer this question. It is like asking whether the microscope is of any use as an instrument after having employed it on but one specimen. If we consider as specimens each type of armature coil, pitching, and arrangement, and if we consider the oscilloscope as a microscope for the examination of each, this device could be the tool to assist the designer to select the ones that are better and, what is more to tell why they are better. In this manner, it ultimately may point the way to extension of the commutation range of d-c apparatus.
Characterization of a Polyvalent Conjugate of Bacteroides fragilis by Fluorescent Antibody Staining

A polyvalent conjugate (fluorescein-isothiocyanate-labeled antibody reagent) prepared for Bacteroides fragilis contained conjugates prepared against three strains of B. fragilis . This conjugate stained 93% of the 111 B.fragilis test strains; the other 7% of B.fragilis stained at certain times but not others. The conjugate was specific for B. fragilis , 91 strains of anaerobes other than B. fragilis and aerobes failed to give a positive fluorescence. The advantage of this conjugate is that it provides a quicker and less expensive identification of B. fragilis than the use of pre-reduced biochemical media and gas chromatography.
Assisted Reproductive Technology and Early Intervention Program Enrollment

OBJECTIVES: We examined the prevalence of Early Intervention (EI) enrollment in Massachusetts comparing singleton children conceived via assisted reproductive technology (ART), children born to mothers with indicators of subfertility but no ART (Subfertile), and children born to mothers who had no indicators of subfertility and conceived naturally (Fertile). We assessed the natural direct effect (NDE), the natural indirect effect (NIE) through preterm birth, and the total effect of ART and subfertility on EI enrollment. METHODS: We examined maternal and infant characteristics among singleton ART (n = 6447), Subfertile (n = 5515), and Fertile (n = 306 343) groups and characteristics associated with EI enrollment includingpreterm birth using χ2 statistics (α = 0.05). We estimated the NDE and NIE of the ART–EI enrollment relationship by fitting a model for enrollment, conditional on ART, preterm and the ART-preterm delivery interaction, and covariates. Similar analyses were conducted by using Subfertile as the exposure. RESULTS: The NDE indicated that the odds of EI enrollment were 27% higher among the ART group (odds ratioNDE = 1.27; 95% confidence interval (CI): 1.19 1.36) and 20% higher among the Subfertilegroup (odds ratioNDE = 1.20; 95% CI: 1.12 1.29) compared with the Fertile group, even if the rate of preterm birth is held constant. CONCLUSIONS: Singleton children conceived through ART and children of subfertile mothers both have elevated risks of EI enrollment. These findings have implications for clinical providers as they counsel women about child health outcomes associated with ART or subfertility.