Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900  Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{GW}(f)<1.0(f/1300  Hz)^{3} for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

p47phox and reactive oxygen species production modulate expression of microRNA-451 in macrophages

The production of microRNAs (miRNA) is influenced by various stimuli, including environmental stresses. We hypothesized that reactive oxygen species (ROS)-associated stress could regulate macrophage miRNA synthesis. miRNAs undergo unique steps of maturation processing through either one of two pathways of cytoplasmic processing. Unlike the canonical pathway, the regulation of alternative cytoplasmic processing of miRNA has not been fully elucidated yet. We cultured bone marrow derived macrophages (BMDM) from wild type (WT) and p47(phox-/-) mice and profiled miRNA expression using microarrays. We analyzed 375 miRNAs including four endogenous controls to normalize the data. At resting state, p47(phox-/-) BMDM has the markedly reduced expression of miR-451 compared to WT BMDM, without other significant differences. Unlike majority of miRNAs, miR-451 goes through the unique alternative processing pathway, in which Ago2 plays a key role. In spite of significant reduction of mature miR-451, however, its precursor form, pre-mir-451, was similar in both BMDMs, suggesting that the processing of pre-mir-451 is impaired in p47(phox-/-) BMDM. Moreover, p47(phox-/-) BMDM expressed significantly reduced level of Ago2. In contrast, Ago2 mRNA levels were similar in WT and p47(phox-/-) BMDM, suggesting a post-transcriptional defect of Ago2 production in p47(phox-/-) macrophages, which resulted in impaired processing of pre-miR-451. In order to examine the functional significance of miR-451 in macrophages, we cultured BMDMs from miR-451 knock-out mice. Of interest, miR-451-deficient BMDM exhibited reduced ROS generation upon zymosan stimulation, compared to WT BMDM. Our studies suggest functional crosstalk between ROS and miR-451 in the regulation of macrophage oxidant stress.

Gamma-tocotrienol attenuates high-fat diet-induced obesity and insulin resistance by inhibiting adipose inflammation and M1 macrophage recruitment

BACKGROUND AND OBJECTIVE

We have previously demonstrated that gamma tocotrienol (γT3) potently inhibits adipocyte hyperplasia in human adipose-derived stem cells (hASCs). In this study, our objective was to investigate the γT3 effects on early-onset obesity, inflammation and insulin resistance in vivo.

METHODS

Young C57BL/6J mice were fed a high-fat (HF) diet supplemented with 0.05% γT3 for 4 weeks. The concentrations of γT3 in plasma and adipose tissue were measured using high-performance liquid chromatography. Effects of γT3 on body weight gain, adipose volume, plasma levels of fasting glucose, insulin (enzyme-linked immunosorbent assay (ELISA)), proinflammatory cytokines (mouse cytokine array), insulin signaling (western blotting) and gene expression (quantitative real-time PCR, qPCR) in the liver and adipose tissue were examined. Influences of γT3 on [3H]-2-deoxyglucose uptake and lipopolysaccharide (LPS)-mediated NFκB signaling (western blotting) were assessed in hASCs. Effects of γT3 on macrophage M1/M2 activation were investigated using qPCR in mouse bone marrow-derived macrophages.

RESULTS

After a 4-week treatment, γT3 accumulated in adipose tissue and reduced HF diet-induced weight gain in epididymal fat, mesenteric fat and the liver. Compared with HF diet-fed mice, HF+γT3-fed mice were associated with (1) decreased plasma levels of fasting glucose, insulin and proinflammatory cytokines, (2) improved glucose tolerance and (3) enhanced insulin signaling in adipose tissue. There were substantial decreases in macrophage specific markers, and monocyte chemoattractant protein-1, indicating that γT3 reduced the recruitment of adipose tissue macrophages (ATMs). In addition, γT3 treatment in human adipocytes resulted in (1) activation of insulin-stimulated glucose uptake and (2) a significant suppression of MAP kinase and NFκB activation. In parallel, γT3 treatment led to a reduction of LPS-mediated M1 macrophage polarization.

CONCLUSION

Our results demonstrated that γT3 ameliorates HF diet-mediated obesity and insulin resistance by inhibiting systemic and adipose inflammation, as well as ATM recruitment.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Organic cleanliness of the Mars Science Laboratory sample transfer chain

One of the primary science goals of the Mars Science Laboratory (MSL) Rover, Curiosity, is the detection of organics in Mars rock and regolith. To achieve this, the Curiosity rover includes a robotic sampling system that acquires rock and regolith samples and delivers it to the Sample Analysis at Mars (SAM) instrument on board the rover. In order to provide confidence that any significant organics detection result was Martian and not terrestrial in origin, a requirement was levied on the flight system (i.e., all sources minus the SAM instrument) to impart no more than 36 parts per billion (ppb by weight) of total reduced carbon terrestrial contamination to any sample transferred to the SAM instrument. This very clean level was achieved by a combination of a rigorous contamination control program on the project, and then using the first collected samples for a "dilution cleaning" campaign of the sample chain prior to delivering a sample to the SAM instrument. Direct cleanliness assays of the sample-contacting and other Flight System surfaces during pre-launch processing were used as inputs to determine the number of dilution cleaning samples needed once on Mars, to enable delivery of suitably clean samples to the SAM experiment. Taking into account contaminant redistribution during launch thorough landing of the MSL on Mars, the amount of residue present on the sampling hardware prior to the time of first dilution cleaning sample acquisition was estimated to be 60 ng/cm(2) on exposed outer surfaces of the sampling hardware and 20 ng/cm(2) on internal sample contacting surfaces; residues consisting mainly of aliphatic hydrocarbons and esters. After three dilution cleaning samples, estimated in-sample contamination level for the first regolith sample delivered to the SAM instrument at the Gale Crater "Rocknest" site was bounded at ≤10 ppb total organic carbon. A Project decision to forego ejecting the dilution cleaning sample and instead transfer the first drill-acquired sample at the "John Klein" site to SAM resulted in an estimated level of terrestrial contamination of ≤430 ppb. The estimated terrestrial contamination for portions from the second drill-acquired sample, at Cumberland, was ≤69 ppb; the estimate for a future, third, drilled sample is ≤38 ppb. These levels are comparable in magnitude to the SAM instrument blanks at the nanomole level (as chlorohydrocarbon).

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

Short-duration hypothermia after ischemic stroke prevents delayed intracranial pressure rise

BACKGROUND

Intracranial pressure elevation, peaking three to seven post-stroke is well recognized following large strokes. Data following small-moderate stroke are limited. Therapeutic hypothermia improves outcome after cardiac arrest, is strongly neuroprotective in experimental stroke, and is under clinical trial in stroke. Hypothermia lowers elevated intracranial pressure; however, rebound intracranial pressure elevation and neurological deterioration may occur during rewarming.

HYPOTHESES

(1) Intracranial pressure increases 24 h after moderate and small strokes. (2) Short-duration hypothermia-rewarming, instituted before intracranial pressure elevation, prevents this 24 h intracranial pressure elevation.

METHODS

Long-Evans rats with two hour middle cerebral artery occlusion or outbred Wistar rats with three hour middle cerebral artery occlusion had intracranial pressure measured at baseline and 24 h. Wistars were randomized to 2·5 h hypothermia (32·5°C) or normothermia, commencing 1 h after stroke.

RESULTS

In Long-Evans rats (n = 5), intracranial pressure increased from 10·9 ± 4·6 mmHg at baseline to 32·4 ± 11·4 mmHg at 24 h, infarct volume was 84·3 ± 15·9 mm(3) . In normothermic Wistars (n = 10), intracranial pressure increased from 6·7 ± 2·3 mmHg to 31·6 ± 9·3 mmHg, infarct volume was 31·3 ± 18·4 mm(3) . In hypothermia-treated Wistars (n = 10), 24 h intracranial pressure did not increase (7·0 ± 2·8 mmHg, P < 0·001 vs. normothermia), and infarct volume was smaller (15·4 ± 11·8 mm(3) , P < 0·05).

CONCLUSIONS

We saw major intracranial pressure elevation 24 h after stroke in two rat strains, even after small strokes. Short-duration hypothermia prevented the intracranial pressure rise, an effect sustained for at least 18 h after rewarming. The findings have potentially important implications for design of future clinical trials.

Dengue fever mimicking acute appendicitis: A case report

INTRODUCTION

Dengue fever is an acute viral disease, which usually presents as a mild febrile illness. Patients with severe disease present with dengue haemorrhagic fever or dengue toxic shock syndrome. Rarely, it presents with abdominal symptoms mimicking acute appendicitis. We present a case of a male patient presenting with right iliac fossa pain and suspected acute appendicitis that was later diagnosed with dengue fever following a negative appendicectomy.

PRESENTATION OF CASE

A 13-year old male patient presented with fever, localized right-sided abdominal pain and vomiting. Abdominal ultrasound was not helpful and appendicectomy was performed due to worsening abdominal signs and an elevated temperature. A normal appendix with enlarged mesenteric nodes was found at surgery. Complete blood count showed thrombocytopenia with leucopenia. Dengue fever was now suspected and confirmed by IgM enzyme-linked immunosorbent assay against dengue virus.

DISCUSSION

This unusual presentation of dengue fever mimicking acute appendicitis should be suspected during viral outbreaks and in patients with atypical symptoms and cytopenias on blood evaluation in order to prevent unnecessary surgery.

CONCLUSION

This case highlights the occurrence of abdominal symptoms and complications that may accompany dengue fever. Early recognition of dengue fever mimicking acute appendicitis will avoid non-therapeutic operation and the diagnosis may be aided by blood investigations indicating a leucopenia, which is uncommon in patients with suppurative acute appendicitis.

A systematic approach to the development of novel therapeutics for lung cancer using genomic analyses

Molecularly targeted drugs for cancer therapy represent a therapeutic advance, but the proportion of patients who receive clinical benefit is still very limited. We present here the rationale and initial results of our program to define molecules involved in lung carcinogenesis with the goal of identifying new therapeutic targets and/or predictive biomarkers for drug response. We have used gene expression analysis of 120 lung cancers followed by RNA interference, tumor-tissue microarray analysis, and functional analyses to systematically distinguish potential target molecules specifically expressed in cancer cells. Through this approach, we have identified oncoproteins that provide the starting point for the development of therapeutic antibodies, dominant negative peptides, small-molecule inhibitors, and therapeutic cancer vaccines. We believe that the approach we describe should result in new molecularly targeted therapies with minimal risk of adverse events.

Resveratrol prevents renal lipotoxicity and inhibits mesangial cell glucotoxicity in a manner dependent on the AMPK-SIRT1-PGC1α axis in db/db mice

AIMS/HYPOTHESIS

Many of the effects of resveratrol are consistent with the activation of AMP-activated protein kinase (AMPK), silent information regulator T1 (SIRT1) and peroxisome proliferator-activated receptor (PPAR)γ co-activator 1α (PGC-1α), which play key roles in the regulation of lipid and glucose homeostasis, and in the control of oxidative stress. We investigated whether resveratrol has protective effects on the kidney in type 2 diabetes.

METHODS

Four groups of male C57BLKS/J db/m and db/db mice were used in this study. Resveratrol was administered via gavage to diabetic and non-diabetic mice, starting at 8 weeks of age, for 12 weeks.

RESULTS

The db/db mice treated with resveratrol had decreased albuminuria. Resveratrol ameliorated glomerular matrix expansion and inflammation. Resveratrol also lowered the NEFA and triacylglycerol content of the kidney, and this action was related to increases in the phosphorylation of AMPK and the activation of SIRT1-PGC-1α signalling and of the key downstream effectors, the PPARα-oestrogen-related receptor (ERR)-1α-sterol regulatory element-binding protein 1 (SREBP1). Furthermore, resveratrol decreased the activity of phosphatidylinositol-3 kinase (PI3K)-Akt phosphorylation and class O forkhead box (FOXO)3a phosphorylation, which resulted in a decrease in B cell leukaemia/lymphoma 2 (BCL-2)-associated X protein (BAX) and increases in BCL-2, superoxide dismutase (SOD)1 and SOD2 production. Consequently, resveratrol reversed the increase in renal apoptotic cells and oxidative stress, as reflected by renal 8-hydroxy-deoxyguanosine (8-OH-dG), urinary 8-OH-dG and isoprostane concentrations. Resveratrol prevented high-glucose-induced oxidative stress and apoptosis in cultured mesangial cells through the phosphorylation of AMPK and activation of SIRT1-PGC-1α signalling and the downstream effectors, PPARα-ERR-1α-SREBP1.

CONCLUSIONS/INTERPRETATION

The results suggest that resveratrol prevents diabetic nephropathy in db/db mice by the phosphorylation of AMPK and activation of SIRT1-PGC-1α signalling, which appear to prevent lipotoxicity-related apoptosis and oxidative stress in the kidney.

Changes of Reflex, Non-reflex and Torque Generation Properties of Spastic Ankle Plantar Flexors Induced by Intelligent Stretching

Spasticity, contracture, and muscle weakness are major sources of disability in stroke. Changes of torque-generating capacity as well as reflex and non-reflex properties of ankle plantar flexors induced by strenuous stretching in chronic hemiplegia were investigated. Twelve subjects with a unilateral stroke and 10 healthy controls underwent 30 minutes of strenuous intelligent stretching treatment. Reflex and non-reflex components of spastic hypertonia and force-generating capacity of ankle plantar flexors were investigated. Dorsiflexion (DF) range of motion (ROM) was increased (p=0.002) and passive stiffness and passive resistant torque of the spastic muscles were decreased (p=0.004 and 0.007, respectively), while reflex hyper-excitability diminished slightly but with no statistical significance. The maximal voluntary contraction (MVC) torque of the spastic ankle plantar flexors was increased after the forceful stretching treatment (p=0.041). In contrast, the stretching treatment of the healthy plantar flexors did not change any of the variables measured before and after stretching. The stroke subjects who gained more DF ROM or larger decrement of stiffness achieved greater increment of the peak torque generation after the stretching (r=0.597 with p=0.040 and r=-0.746 with p=0.005, respectively). These results suggest that the strenuous dynamic stretching could improve the force-generating capacity of spastic muscles as well as reduce the passive stiffness and increase ROM.

The mean intensity ofo activation than the number of activated voxels is a better index to reflect the levels of visuospatial performance

This study is to identify the more sensitive method to measure the brain activation by the visuospatial performance level by comparing two different methods of measuremtnt (i.e., a method calculating the number of activated voxels and the other, the mean intensity of activated voxels). Sixteen right-handed male college students (mean age 23.2 years) participated in this study and function brain images were scanned with a 3T MRI using the single-shot EPI method during visuospatial performance. There found no brain areas with correlation between the visuospatial performance level and number of activated voxels. However, there found a sifgnificant correlatgion between the visuospatial performance level and the mean intensity of selected activated voxels in the parietal, frontal, and other areas.f In conclusion, the method of meanintensity rather than the one of the number is considered as a better index.

What can be learned about the impact of diabetes on hospital admissions from routinely recorded data?

AIM

To determine whether inpatients with diabetes have different lengths of stay, day-case listing rates or emergency readmission rates compared with those without diabetes receiving similar treatment.

METHOD

English 2007-2008 Hospital Episode Statistics were analysed alone and after linkage to the 1.6 million people included in the 2007-2008 English National Diabetes Audit. Length of stay, day-case listing rates and emergency readmission rates were compared between those with and without diabetes by Health Resource Group chapter. Using univariate and multivariate statistics, the potential influences of age, sex, social deprivation, type and complexity of admission were considered.

RESULTS

Of all inpatient spells in Hospital Episode Statistics, 6.2% have diabetes coded at discharge. Substantial under-recording of diabetes has been identified-a further 3% of inpatient spells involve people with diabetes. Inpatients with recorded diabetes stay in hospital for 100% longer on average, are 50% less likely to be treated as day cases and are almost 100% more likely to be readmitted as an emergency. The adverse impact of diabetes on length of stay was similar to that for chronic obstructive pulmonary disease. Most of this adverse effect was in patients coded with diabetes in Hospital Episode Statistics. Multivariate statistical analysis showed that diabetes is independently associated with increased length of stay. The effect differed up to threefold between hospitals.

CONCLUSIONS

Diabetes has an independent adverse effect on key aspects of hospital inpatient stays. If the lowest levels of adverse impact on inpatients with diabetes were more common, substantial cost savings and improved experience of care would be realized.

Haloperidol and clozapine block formation of autophagolysosomes in rat primary neurons

Early intervention and maintenance treatment for schizophrenia patients may prolong the duration of exposure to antipsychotic agents; however, there have been few studies on the neurotoxicity of these agents. Here, we investigated the effects of antipsychotics on cell viability and autophagy in rat primary neurons. Cultured cortical neurons obtained from rat embryos were treated with various concentrations of haloperidol and clozapine, and the neuronal toxicity was assessed by measuring lactate dehydrogenase (LDH) activity and 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. Autophagosomes were quantitated by measuring the level of microtubule-associated protein 1A/1B-light chain 3 (LC3-II) by Western blot and immunofluorescence staining. Autophagic flux was assayed using bafilomycin A1 and GFP-mCherry-LC3 transfection. Haloperidol and clozapine decreased the viability of neurons in vitro in a concentration- and time-dependent manner. We also observed increased accumulation of autophagosomes after antipsychotic treatment. Using bafilomycin A1 and GFP-mCherry-LC3 transfection, we discovered that haloperidol and clozapine inhibited autophagosome turnover resulting in a dysfunctional autophagic process, including impaired lysosomal fusion. Together, these results suggest that haloperidol and clozapine negatively affect neuronal viability, possibly by blocking autophagolysosome formation.

Underdiagnosis of hypertension using electronic health records

BACKGROUND

Hypertension is highly prevalent and contributes to cardiovascular morbidity and mortality. Appropriate identification of hypertension is fundamental for its management. The rates of appropriate hypertension diagnosis in outpatient settings using an electronic health record (EHR) have not been well studied. We sought to identify prevalent and incident hypertension cases in a large outpatient healthcare system, examine the diagnosis rates of prevalent and incident hypertension, and identify clinical and demographic factors associated with appropriate hypertension diagnosis.

METHODS

We analyzed a 3-year, cross-sectional sample of 251,590 patients aged ≥18 years using patient EHRs. Underlying hypertension was defined as two or more abnormal blood pressure (ABP) readings ≥140/90 mm Hg and/or pharmaceutical treatment. Appropriate hypertension diagnosis was defined by the reporting of ICD-9 codes (401.0-401.9). Factors associated with hypertension diagnosis were assessed through multivariate analyses of patient clinical and demographic characteristics.

RESULTS

The prevalence of hypertension was 28.7%, and the diagnosis rate was 62.9%. The incidence of hypertension was 13.3%, with a diagnosis rate of 19.9%. Predictors of diagnosis for prevalent hypertension included older age, Asian, African American, higher body mass index (BMI), and increased number of ABP readings. Predictors for incident hypertension diagnosis were similar. In patients with two or more ABP readings, hypertension diagnosis was associated with significantly higher medication treatment rates (92.6% vs. 15.8%, P < 0.0001).

CONCLUSIONS

Outpatient EHR diagnosis rates are suboptimal, yet EHR diagnosis of hypertension is strongly associated with treatment. Targeted efforts to improve diagnosis should be a priority.