83 research outputs found
Solving the subset-sum problem with a light-based device
We propose a special computational device which uses light rays for solving
the subset-sum problem. The device has a graph-like representation and the
light is traversing it by following the routes given by the connections between
nodes. The nodes are connected by arcs in a special way which lets us to
generate all possible subsets of the given set. To each arc we assign either a
number from the given set or a predefined constant. When the light is passing
through an arc it is delayed by the amount of time indicated by the number
placed in that arc. At the destination node we will check if there is a ray
whose total delay is equal to the target value of the subset sum problem (plus
some constants).Comment: 14 pages, 6 figures, Natural Computing, 200
Exact Cover with light
We suggest a new optical solution for solving the YES/NO version of the Exact
Cover problem by using the massive parallelism of light. The idea is to build
an optical device which can generate all possible solutions of the problem and
then to pick the correct one. In our case the device has a graph-like
representation and the light is traversing it by following the routes given by
the connections between nodes. The nodes are connected by arcs in a special way
which lets us to generate all possible covers (exact or not) of the given set.
For selecting the correct solution we assign to each item, from the set to be
covered, a special integer number. These numbers will actually represent delays
induced to light when it passes through arcs. The solution is represented as a
subray arriving at a certain moment in the destination node. This will tell us
if an exact cover does exist or not.Comment: 20 pages, 4 figures, New Generation Computing, accepted, 200
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1997 evaluation of tritium removal and mitigation technologies for Hanford Site wastewaters
This report contains results of a biennial assessment of tritium separation technology and tritium nitration techniques for control of tritium bearing wastewaters at the Hanford Site. Tritium in wastewaters at Hanford have resulted from plutonium production, fuel reprocessing, and waste handling operations since 1944. this assessment was conducted in response to the Hanford Federal Facility Agreement and Consent Order
Loss-of-function of triacylglycerol lipases are associated with low flour rancidity in pearl millet [Pennisetum glaucum (L.) R. Br.]
Pearl millet is an important cereal crop of semi-arid regions since it is
highly nutritious and climate resilient. However, pearl millet is underutilized
commercially due to the rapid onset of hydrolytic rancidity of seed lipids
post-milling. We investigated the underlying biochemical and molecular
mechanisms of rancidity development in the flour from contrasting inbred
lines under accelerated aging conditions. The breakdown of storage lipids
(triacylglycerols; TAG) was accompanied by free fatty acid accumulation over
the time course for all lines. The high rancidity lines had the highest amount
of FFA by day 21, suggesting that TAG lipases may be the cause of rancidity.
Additionally, the high rancidity lines manifested substantial amounts of volatile
aldehyde compounds, which are characteristic products of lipid oxidation.
Lipases with expression in seed post-milling were sequenced from low and
high rancidity lines. Polymorphisms were identified in two TAG lipase genes
(PgTAGLip1 and PgTAGLip2) from the low rancidity line. Expression in a yeast
model system confirmed these mutants were non-functional. We provide
a direct mechanism to alleviate rancidity in pearl millet flour by identifying
mutations in key TAG lipase genes that are associated with low rancidity. These
genetic variations can be exploited through molecular breeding or precision
genome technologies to develop elite pearl millet cultivars with improved
flour shelf life
Effects of Nitrogen contamination in liquid Argon
A dedicated test of the effects of Nitrogen contamination in liquid Argon has
been performed at the INFN-Gran Sasso Laboratory (LNGS, Italy) within the WArP
R&D program. A detector has been designed and assembled for this specific task
and connected to a system for the injection of controlled amounts of gaseous
Nitrogen into the liquid Argon. Purpose of the test is to detect the reduction
of the Ar scintillation light emission as a function of the amount of the
Nitrogen contaminant injected in the Argon volume. A wide concentration range,
spanning from about 10^-1 ppm up to about 10^3 ppm, has been explored.
Measurements have been done with electrons in the energy range of minimum
ionizing particles (gamma-conversion from radioactive sources). Source spectra
at different Nitrogen contaminations are analyzed, showing sensitive reduction
of the scintillation yield at increasing concentrations. The rate constant of
the light quenching process induced by Nitrogen in liquid Ar has been found to
be k(N2)=0.11 micros^-1 ppm^-1. Direct PMT signals acquisition at high time
resolution by fast Waveform recording allowed to extract with high precision
the main characteristics of the scintillation light emission in pure and
contaminated LAr. In particular, the decreasing behavior in lifetime and
relative amplitude of the slow component is found to be appreciable from O(1
ppm) of Nitrogen concentrations
What do individuals with schizophrenia need to increase their well-being
The aim of this qualitative study was to deepen the knowledge of how individuals with schizophrenia themselves describe what they need in order to increase their well-being in everyday life. Seven patients were interviewed. An open explorative approach was applied and grounded theory was used for the analysis resulting in five categories illustrating how patients with schizophrenia handle their struggle for a normal life. The patients stressed first the importance of receiving information about the disease: for themselves, for society, and for their families. Taking part in social contacts such as attending meeting places and receiving home visits were identified as important as well as having meaningful employment. They also pointed out the importance of taking part in secure professional relationships. Mainly they expressed the need for continuity in the relationships and the wish to be heard and seen by the professionals. Finally, interviewees addressed the need for support for sustaining independent living through practical housekeeping and financial help. To conclude, the participants in the present study described their need for help as mainly linked to activities in their overall life situation rather than just their psychosis
Incident acute coronary syndromes in chronic dialysis patients in the United States11The opinions are solely those of the authors and do not represent an endorsement by the Department of Defense or the National Institutes of Health. This is a U.S. Government work. There are no restrictions on its use.
Incident acute coronary syndromes in chronic dialysis patients in the United States.BackgroundPatients on dialysis have a disproportionately high rate of cardiovascular disease (CVD). However, the incidence and risk factors for incident acute coronary syndromes (ACS) have not been previously assessed in dialysis patients.MethodsWe analyzed the United States Renal Data System (USRDS) Dialysis Morbidity and Mortality Study (DMMS) Wave II in a historical cohort study of ACS. Data from 3374 patients who started dialysis in 1996 with valid follow-up times were available for analysis, censored at the time of renal transplantation and followed until March 2000. Cox regression analysis was used to model factors associated with time to first hospitalization for ACS (ICD9 code 410.x or 411.x) adjusted for comorbidities, demographic factors, baseline laboratory values, blood pressures and cholesterol levels, type of vascular access, dialysis adequacy, and cardioprotective medications (angiotensin-converting enzyme inhibitors, calcium channel blockers, HMG-CoA reductase inhibitors (statins), beta blockers, and aspirin). Follow-up was 2.19 ± 1.14 years.ResultsThe incidence of ACS was 29/1000 person-years. Factors associated with ACS were older age, the extreme high and low ranges of serum cholesterol level, history of coronary heart disease (CHD), male gender, and diabetes. No cardioprotective medications including statins had a significant association with ACS in this study. However, medications known to reduce mortality after ACS were used in less than 50% of patients with known CHD at the start of the study, and statins were used in less than 10% of patients with CHD.ConclusionsDialysis patients had similar risk factors for ACS compared to the general population. Cardioprotective medications were not associated with a significant benefit, possibly due to their striking underutilization in this at-risk population
Positive symptoms associate with cortical thinning in the superior temporal gyrus via the ENIGMA-Schizophrenia consortium
Objective: Based on the role of the superior temporal gyrus (STG) in auditory processing, language comprehension and self-monitoring, this study aimed to investigate the relationship between STG cortical thickness and positive symptom severity in schizophrenia. Method: This prospective meta-analysis includes data from 1987 individuals with schizophrenia collected at seventeen centres around the world that contribute to the ENIGMA Schizophrenia Working Group. STG thickness measures were extracted from T1-weighted brain scans using FreeSurfer. The study performed a meta-analysis of effect sizes across sites generated by a model predicting left or right STG thickness with a positive symptom severity score (harmonized SAPS or PANSS-positive scores), while controlling for age, sex and site. Secondary models investigated relationships between antipsychotic medication, duration of illness, overall illness severity, handedness and STG thickness. Results: Positive symptom severity was negatively related to STG thickness in both hemispheres (left: βstd = −0.052; P = 0.021; right: βstd = −0.073; P = 0.001) when statistically controlling for age, sex and site. This effect remained stable in models including duration of illness, antipsychotic medication or handedness. Conclusion: Our findings further underline the important role of the STG in hallmark symptoms in schizophrenia. These findings can assist in advancing insight into symptom-relevant pathophysiological mechanisms in schizophrenia
Widespread white matter microstructural differences in schizophrenia across 4322 individuals:Results from the ENIGMA Schizophrenia DTI Working Group
The regional distribution of white matter (WM) abnormalities in schizophrenia remains poorly understood, and reported disease effects on the brain vary widely between studies. In an effort to identify commonalities across studies, we perform what we believe is the first ever large-scale coordinated study of WM microstructural differences in schizophrenia. Our analysis consisted of 2359 healthy controls and 1963 schizophrenia patients from 29 independent international studies; we harmonized the processing and statistical analyses of diffusion tensor imaging (DTI) data across sites and meta-analyzed effects across studies. Significant reductions in fractional anisotropy (FA) in schizophrenia patients were widespread, and detected in 20 of 25 regions of interest within a WM skeleton representing all major WM fasciculi. Effect sizes varied by region, peaking at (d=0.42) for the entire WM skeleton, driven more by peripheral areas as opposed to the core WM where regions of interest were defined. The anterior corona radiata (d=0.40) and corpus callosum (d=0.39), specifically its body (d=0.39) and genu (d=0.37), showed greatest effects. Significant decreases, to lesser degrees, were observed in almost all regions analyzed. Larger effect sizes were observed for FA than diffusivity measures; significantly higher mean and radial diffusivity was observed for schizophrenia patients compared with controls. No significant effects of age at onset of schizophrenia or medication dosage were detected. As the largest coordinated analysis of WM differences in a psychiatric disorder to date, the present study provides a robust profile of widespread WM abnormalities in schizophrenia patients worldwide. Interactive three-dimensional visualization of the results is available at www.enigma-viewer.org.Molecular Psychiatry advance online publication, 17 October 2017; doi:10.1038/mp.2017.170
Cortical brain abnormalities in 4474 individuals with schizophrenia and 5098 control subjects via the enhancing neuro Imaging genetics through meta analysis (ENIGMA) Consortium
BACKGROUND: The profile of cortical neuroanatomical abnormalities in schizophrenia is not fully understood, despite hundreds of published structural brain imaging studies. This study presents the first meta-analysis of cortical thickness and surface area abnormalities in schizophrenia conducted by the ENIGMA (Enhancing Neuro Imaging Genetics through Meta Analysis) Schizophrenia Working Group.
METHODS: The study included data from 4474 individuals with schizophrenia (mean age, 32.3 years; range, 11-78 years; 66% male) and 5098 healthy volunteers (mean age, 32.8 years; range, 10-87 years; 53% male) assessed with standardized methods at 39 centers worldwide.
RESULTS: Compared with healthy volunteers, individuals with schizophrenia have widespread thinner cortex (left/right hemisphere: Cohen's d = -0.530/-0.516) and smaller surface area (left/right hemisphere: Cohen's d = -0.251/-0.254), with the largest effect sizes for both in frontal and temporal lobe regions. Regional group differences in cortical thickness remained significant when statistically controlling for global cortical thickness, suggesting regional specificity. In contrast, effects for cortical surface area appear global. Case-control, negative, cortical thickness effect sizes were two to three times larger in individuals receiving antipsychotic medication relative to unmedicated individuals. Negative correlations between age and bilateral temporal pole thickness were stronger in individuals with schizophrenia than in healthy volunteers. Regional cortical thickness showed significant negative correlations with normalized medication dose, symptom severity, and duration of illness and positive correlations with age at onset.
CONCLUSIONS: The findings indicate that the ENIGMA meta-analysis approach can achieve robust findings in clinical neuroscience studies; also, medication effects should be taken into account in future genetic association studies of cortical thickness in schizophrenia
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