204 research outputs found
Patterson superposition system for the IBM 7074
A system is described which aids in resolving the N(N-1) peaks that appear on a PATTERSON MAP into the fundamental set of N vectors corresponding to the N atoms
Restoration of normal blood flow in atherosclerotic arteries promotes plaque stabilization
Blood flow is a key regulator of atherosclerosis. Disturbed blood flow promotes atherosclerotic plaque development, whereas normal blood flow protects against plaque development. We hypothesized that normal blood flow is also therapeutic, if it were able to be restored within atherosclerotic arteries. Apolipoprotein E-deficient (ApoE-/-) mice were initially instrumented with a blood flow-modifying cuff to induce plaque development and then five weeks later the cuffwas removed to allowrestoration of normal blood flow. Plaques in decuffed mice exhibited compositional changes that indicated increased stability compared to plaques in mice with the cuff maintained. The therapeutic benefit of decuffingwas comparable to atorvastatin and the combination had an additive effect. In addition, decuffing allowed restoration of lumen area, blood velocity, and wall shear stress to near baseline values, indicating restoration of normal blood flow. Our findings demonstrate that the mechanical effects of normal blood flow on atherosclerotic plaques promote stabilization
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Effect of iron limitation on the cadmium to phosphorus ratio of natural phytoplankton assemblages from the Southern Ocean
There is considerable interest in the biogeochemical cycling of cadmium (Cd) and phosphate (PO4) in surface waters, driven in part by the ongoing development of a paleonutrient proxy that utilizes Cd preserved in fossil planktonic foraminifera to determine past PO4 utilization efficiencies in ocean surface waters. The present article reports the results of a field study into the effects of Fe limitation on the Cd : P composition of natural assemblages of marine phytoplankton in the Antarctic Zone of the Pacific sector of the Southern Ocean. Iron enrichment to shipboard incubation bottles led to increases in community growth rate and final biomass. After 10.7 d of incubation, the climax community was dominated by large diatoms of the genus Fragillariopsis, Pseudonitzschia, and Nitzschia. Direct measurements of phytoplankton metal : P ratios from controlled shipboard experiments indicate that Cd : P, Co: P, and Zn : P ratios decreased from control values with increasing initial dissolved Fe concentrations in the incubation bottles, by factors of ~2–10 at highest Fe additions. We suggest that the effect of Fe limitation on resident diatoms is to decrease growth rate, leading to elevated cellular Cd content. The dissolved Cd : P ratio in iron-limited surface waters of the Southern Ocean may, therefore, respond to the supply of Fe to the resident phytoplankton community, which has implications for the developing paleonutrient proxy. We suggest that the biological uptake of Cd and P is independent of the dissolved Cd: PO4 ratio. As a consequence, the results argue against the use of empirical Rayleigh fractionation models or models with fixed phytoplankton uptake ratios to account for regional variability in surface water dissolved Cd : PO4
Aptamer-based multiplexed proteomic technology for biomarker discovery
Interrogation of the human proteome in a highly multiplexed and efficient manner remains a coveted and challenging goal in biology. We present a new aptamer-based proteomic technology for biomarker discovery capable of simultaneously measuring thousands of proteins from small sample volumes (15 [mu]L of serum or plasma). Our current assay allows us to measure ~800 proteins with very low limits of detection (1 pM average), 7 logs of overall dynamic range, and 5% average coefficient of variation. This technology is enabled by a new generation of aptamers that contain chemically modified nucleotides, which greatly expand the physicochemical diversity of the large randomized nucleic acid libraries from which the aptamers are selected. Proteins in complex matrices such as plasma are measured with a process that transforms a signature of protein concentrations into a corresponding DNA aptamer concentration signature, which is then quantified with a DNA microarray. In essence, our assay takes advantage of the dual nature of aptamers as both folded binding entities with defined shapes and unique sequences recognizable by specific hybridization probes. To demonstrate the utility of our proteomics biomarker discovery technology, we applied it to a clinical study of chronic kidney disease (CKD). We identified two well known CKD biomarkers as well as an additional 58 potential CKD biomarkers. These results demonstrate the potential utility of our technology to discover unique protein signatures characteristic of various disease states. More generally, we describe a versatile and powerful tool that allows large-scale comparison of proteome profiles among discrete populations. This unbiased and highly multiplexed search engine will enable the discovery of novel biomarkers in a manner that is unencumbered by our incomplete knowledge of biology, thereby helping to advance the next generation of evidence-based medicine
Development and preliminary validation of Brace Questionnaire (BrQ): a new instrument for measuring quality of life of brace treated scoliotics
BACKGROUND: The quality of life among children with idiopathic scoliosis during their adolescence has been reported to be affected by the brace itself. However, a controversy exists whether brace treated scoliotics experience a poor quality of life, thus there is a need for the development of a brace-oriented instrument, as the now-existing questionnaires that are commonly used, such as the SRS -22, take into consideration the effects of both the conservative and the surgical treatment on quality of life of scoliotic children. The aim of the present study is to assess the validity and reliability of Brace Questionnaire (BrQ), a new instrument for measuring quality of life of scoliotic adolescents who are treated conservatively with a brace. MATERIAL-METHOD: Methodology of development involved literature review, patient and health care professionals' in-depth interviews and content validity analysis on patients. A validation study was performed on 28 brace treated scoliotic children aged between 9 and 18 years old. BrQ was assessed for the following psychometric properties: item convergent validity, floor and ceiling effects, internal consistency reliability, clinical validity and responsiveness to change. RESULTS: BrQ is self administrated and developmentally appropriate for ages 9 to 18 years old and is consisted of 34 Likert-scale items associated with eight domains: general health perception, physical functioning, emotional functioning, self esteem and aesthetics, vitality, school activity, bodily pain and social functioning of scoliotic children treated conservatively with a brace. The subscales of these eight dimensions can be combined to produce a total score. Higher scores mean a better quality of life. An item convergent validity ≥ 0.40 was satisfied by all items in the present study. A satisfactory internal consistency reliability for the BrQ was recorded (Cronbach's alpha coefficient was 0.82). There were no floor or ceiling effects. The correlation between BrQ overall scores and mild and moderate scoliosis was statistically significant (p < 0.001), revealing high clinical validity. An increase in effect sizes for the patient with improved scoliotic curves indicates that the BrQ is responsive to change in health status. CONCLUSION: BrQ is reliable, valid and responsive to change in adolescents with IS who are treated conservatively with a brace
Biogeochemical cycling of dissolved zinc along the GEOTRACES South Atlantic transect GA10 at 40°S
The biogeochemical cycle of zinc (Zn) in the South Atlantic, at 40°S, was investigated as part of the UK
GEOTRACES program. To date there is little understanding of the supply of Zn, an essential requirement for
phytoplankton growth, to this highly productive region. Vertical Zn profiles displayed nutrient-like distributions
with distinct gradients associated with the watermasses present. Surface Zn concentrations are among the lowest
reported for theworld’s oceans (<50 pM). A strong Zn-Si linear relationshipwas observed (Zn (nM)= 0.065 Si (μM),
r2=0.97, n = 460). Our results suggest that the use of a global Zn-Si relationship would lead to an underestimation
of dissolved Zn in deeper waters of the South Atlantic. By utilizing Si* and a new tracer Zn* our data indicate that
the preferential removal of Zn in the Southern Ocean prevented a direct return path for dissolved Zn to the surface
waters of the South Atlantic at 40°S and potentially the thermocline waters of the South Atlantic subtropical gyre.
The importance of Zn for phytoplankton growth was evaluated using the Zn-soluble reactive phosphorus (SRP)
relationship. We hypothesize that the low Zn concentrations in the South Atlantic may select for phytoplankton
cells with a lower Zn requirement. In addition, a much deeper kink at ~ 500m in the Zn:SRP ratio was observed
compared to other oceanic regions
The experience of brace treatment in children/adolescents with scoliosis
BACKGROUND: Idiopathic scoliosis is a chronic illness with several different braces used for its treatment. Brace treatment during childhood/adolescence can produce stress. There are studies supporting that it can decrease body-image perception while other studies support that it has no such effect. The purpose of this study was to explore the experience of brace treatment in children/adolescents with scoliosis. The aim was to investigate which feelings are created by the bracing experience in children/adolescents with scoliosis and what are the children/adolescents' with scoliosis opinions of the support provided to them by health-care professionals and by their families. METHODS: We conducted interviews with the help of a semi-structured interview guide in order to address the topic of the experience of brace treatment. A convenient sample of twelve children and adolescents with scoliosis was selected from patients attending follow-up appointments at the Outpatient Scoliosis Clinics of two Greek hospitals. The data was analysed using the method of content analysis. RESULTS: Patients in the sample were 10–16 years old and they were mainly females (71%). Almost all of the participants reported having to deal with stress, denial, fear, anger, and shame. They were satisfied with the information they received regarding their condition and therapy. However, the information was not accompanied by support from the health care professionals. They reported that they were receiving support mainly from their families, friends, and classmates. CONCLUSION: The present study is contributing to the development of a better understanding of significant issues related to the experience of bracing therapy. It is clear that scoliosis children/adolescents have to be provided with support during the long period of bracing. It is apparent that those children/adolescents have unmet needs for care and health professionals and policy makers should try to find a way to address those needs
Alongshore variability of the California Current System from Central to Baja California in winter and spring 2003, physical, chemical and biological properties
Poster.-- American Society of Limnology and Oceanography and the Oceanography Society, Honolulu, Hawaii (USA), 15-20 febrero 2004Sixteen stations along the continental slope of western North America were occupied in February 18-27 and May 22-31, 2003, and form a meridional section from Monterey Bay, California (37º N, 122º W) to Cabo San Lucas, Mexico (23º N, 110º W). Our purpose was to compare trends in California Current (CC), Inshore Countercurrent (ICC) and California Undercurrent (CUC) properties with latitude, and between winter and spring conditions. In winter, coastal upwelling was near zero and the along-transect dynamic height was high and flat, allowing the ICC to advect tropical properties northward. In spring, coastal upwelling had commenced and surface flow along the transect presumably became equatorward. As a consequence of these dynamics, in winter the thermocline was deeper, SST was higher, macronutrients, chlorophyll and primary production were low along the entire transect, with most properties lacking strong latitudinal trends. In spring, the thermocline, macronutrients, chlorophyll and primary production rose along the entire section but most dramatically in the north where upwelling was stronger. Prochlorophytes and other small open-ocean phytoplankton were more abundant in winter along the entire transect and to the south in spring, whereas diatoms, a characteristic coastal group of phytoplankton, were more abundant in spring and in the north. Surface iron was higher in the north in winter, but lower there in spring, presumably reflecting drawdown by diatoms. These results are detailed in the figure captionsWe would like to express our gratitude to the David and Lucile Packard Foundation for funding this workN
Biogeochemical iron budgets of the Southern Ocean south of Australia : decoupling of iron and nutrient cycles in the subantarctic zone by the summertime supply
Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 23 (2009): GB4034, doi:10.1029/2009GB003500.Climate change is projected to significantly alter the delivery (stratification, boundary currents, aridification of landmasses, glacial melt) of iron to the Southern Ocean. We report the most comprehensive suite of biogeochemical iron budgets to date for three contrasting sites in subantarctic and polar frontal waters south of Australia. Distinct regional environments were responsible for differences in the mode and strength of iron supply mechanisms, with higher iron stocks and fluxes observed in surface northern subantarctic waters, where atmospheric iron fluxes were greater. Subsurface waters southeast of Tasmania were also enriched with particulate iron, manganese and aluminum, indicative of a strong advective source from shelf sediments. Subantarctic phytoplankton blooms are thus driven by both seasonal iron supply from southward advection of subtropical waters and by wind-blown dust deposition, resulting in a strong decoupling of iron and nutrient cycles. We discuss the broader global significance our iron budgets for other ocean regions sensitive to climate-driven changes in iron supply.T.W. was supported by a BDI grant from CNRS and Région PACA, by CNRS PICS project 3604, and by the “Soutien à la mer” CSOA CNRS-INSU. P.W.B. was supported by the New Zealand FRST Coasts and Oceans OBI. This research was supported by the Australian Government Cooperative Research Centres Programme through the Antarctic Climate and Ecosystems CRC (ACE CRC) and Australian Antarctic Science project 2720
Trait determinants of impulsive behavior: a comprehensive analysis of 188 rats
Impulsivity is a naturally occurring behavior that, when accentuated, can be found in a variety of neuropsychiatric disorders. The expression of trait impulsivity has been shown to change with a variety of factors, such as age and sex, but the existing literature does not reflect widespread consensus regarding the influence of modulating effects. We designed the present study to investigate, in a cohort of significant size (188 rats), the impact of four specific parameters, namely sex, age, strain and phase of estrous cycle, using the variable delay-to-signal (VDS) task. This cohort included (i) control animals from previous experiments; (ii) animals specifically raised for this study; and (iii) animals previously used for breeding purposes. Aging was associated with a general decrease in action impulsivity and an increase in delay tolerance. Females generally performed more impulsive actions than males but no differences were observed regarding delay intolerance. In terms of estrous cycle, no differences in impulsive behavior were observed and regarding strain, Wistar Han animals were, in general, more impulsive than Sprague-Dawley. In addition to further confirming, in a substantial study cohort, the decrease in impulsivity with age, we have demonstrated that both the strain and sex influences modulate different aspects of impulsive behavior manifestations.FEDER funds, through the Competitiveness Factors Operational Programme (COMPETE) and the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement as well as national funds, through the Foundation for Science and Technology (FCT) [projects POCI-01–0145-FEDER-007038, NORTE-01-0145-FEDER-000013, NORTE-01-0145-FEDER-000023 and PTDC/NEU-SCC/5301/2014]. Researchers were supported by FCT [grant numbers SFRH/BD/52291/2013 to ME and PD/BD/114117/2015 to MRG via Inter-University Doctoral Programme in Ageing and Chronic Disease, PhDOC; PDE/BDE/113601/2015 to PSM via PhD Program in Health Sciences (Applied) and Phd-iHES; SFRH/BD/109111/2015 to AMC; SFRH/BD/51061/2010 to MMC; SFRH/SINTD/60126/2009 to AM; SFRH/BD/98675/2013 to BC; IF/00883/2013 to AJR; IF/00111/2013 to AJS; SFRH/BPD/80118/2011 to HLA]info:eu-repo/semantics/publishedVersio
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