985 research outputs found
Dissolution of Calcite in the Twilight Zone: Bacterial Control of Dissolution of Sinking Planktonic Carbonates Is Unlikely
We investigated the ability of bacterial communities to colonize and dissolve two biogenic carbonates (Foraminifera and oyster shells). Bacterial carbonate dissolution in the upper water column is postulated to be driven by metabolic activity of bacteria directly colonising carbonate surfaces and the subsequent development of acidic microenvironments. We employed a combination of microsensor measurements, scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and image analysis and molecular documentation of colonising bacteria to monitor microbial processes and document changes in shell surface topography. Bacterial communities rapidly colonised shell surfaces, forming dense biofilms with extracellular polymeric substance (EPS) deposits. Despite this, we found no evidence of bacterially mediated carbonate dissolution. Dissolution was not indicated by Ca2+ microprofiles, nor was changes in shell surface structure related to the presence of colonizing bacteria. Given the short time (days) settling carbonate material is actually in the twilight zone (500–1000 m), it is highly unlikely that microbial metabolic activity on directly colonised shells plays a significant role in dissolving settling carbonates in the shallow ocean
Implementation of a closed-loop structural control system using wireless sensor networks
Wireless sensor networks have rapidly matured in recent years to offer data acquisition capabilities on par with those of traditional tethered data acquisition systems. Entire structural monitoring systems assembled from wireless sensors have proven to be low cost, easy to install, and accurate. However, the functionality of wireless sensors can be further extended to include actuation capabilities. Wireless sensors capable of actuating a structure could serve as building blocks of future generations of structural control systems. In this study, a wireless sensor prototype capable of data acquisition, computational analysis and actuation is proposed for use in a real-time structural control system. The performance of a wireless control system is illustrated using a full-scale structure controlled by a semi-active magnetorheological (MR) damper and a network of wireless sensors. One wireless sensor designated as a controller automates the task of collecting state data, calculating control forces, and issuing commands to the MR damper, all in real time. Additional wireless sensors are installed to measure the acceleration and velocity response of each system degree of freedom. Base motion is applied to the structure to simulate seismic excitations while the wireless control system mitigates inter-storey drift response of the structure. An optimal linear quadratic regulation solution is formulated for embedment within the computational cores of the wireless sensors. Copyright © 2007 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/60230/1/214_ftp.pd
Alkyl substituted poly(p-phenylene vinylene)s by ring opening metathesis polymerisation
The ring opening metathesis polymerisation (ROMP) of three n-octyl substituted [2.2]paracyclophane-1,9-dienes, initiated by Grubbs ruthenium carbene complexes is reported.</p
Retrieving Aerosol in a Cloudy Environment: Aerosol Availability as a Function of Spatial and Temporal Resolution
The challenge of using satellite observations to retrieve aerosol properties in a cloudy environment is to prevent contamination of the aerosol signal from clouds, while maintaining sufficient aerosol product yield to satisfy specific applications. We investigate aerosol retrieval availability at different instrument pixel resolutions, using the standard MODIS aerosol cloud mask applied to MODIS data and a new GOES-R cloud mask applied to GOES data for a domain covering North America and surrounding oceans. Aerosol availability is not the same as the cloud free fraction and takes into account the technqiues used in the MODIS algorithm to avoid clouds, reduce noise and maintain sufficient numbers of aerosol retrievals. The inherent spatial resolution of each instrument, 0.5x0.5 km for MODIS and 1x1 km for GOES, is systematically degraded to 1x1 km, 2x2 km, 4x4 km and 8x8 km resolutions and then analyzed as to how that degradation would affect the availability of an aerosol retrieval, assuming an aerosol product resolution at 8x8 km. The results show that as pixel size increases, availability decreases until at 8x8 km 70% to 85% of the retrievals available at 0.5 km have been lost. The diurnal pattern of aerosol retrieval availability examined for one day in the summer suggests that coarse resolution sensors (i.e., 4x4 km or 8x8 km) may be able to retrieve aerosol early in the morning that would otherwise be missed at the time of current polar orbiting satellites, but not the diurnal aerosol properties due to cloud cover developed during the day. In contrast finer resolution sensors (i.e., 1x1 km or 2x2 km) have much better opportunity to retrieve aerosols in the partly cloudy scenes and better chance of returning the diurnal aerosol properties. Large differences in the results of the two cloud masks designed for MODIS aerosol and GOES cloud products strongly reinforce that cloud masks must be developed with specific purposes in mind and that a generic cloud mask applied to an independent aerosol retrieval will likely fail
Critical success index or F measure to validate the accuracy of administrative healthcare data identifying epilepsy in deceased adults in Scotland
Background: Methods to undertake diagnostic accuracy studies of administrative epilepsy data are challenged bylack of a way to reliably rank case-ascertainment algorithms in order of their accuracy. This is because it isdifficult to know how to prioritise positive predictive value (PPV) and sensitivity (Sens). Large numbers of truenegative (TN) instances frequently found in epilepsy studies make it difficult to discriminate algorithm accuracyon the basis of negative predictive value (NPV) and specificity (Spec) as these become inflated (usually >90%).This study demonstrates the complementary value of using weather forecasting or machine learning metricscritical success index (CSI) or F measure, respectively, as unitary metrics combining PPV and sensitivity. Wereanalyse data published in a diagnostic accuracy study of administrative epilepsy mortality data in Scotland.Method: CSI was calculated as 1/[(1/PPV) + (1/Sens) – 1]. F measure was calculated as 2.PPV.Sens/(PPV +Sens). CSI and F values range from 0 to 1, interpreted as 0 = inaccurate prediction and 1 = perfect accuracy. Thepublished algorithms were reanalysed using these and their accuracy re-ranked according to CSI in order to allowcomparison to the original rankings.Results: CSI scores were conservative (range 0.02–0.826), always less than or equal to the lower of the correspondingPPV (range 39–100%) and sensitivity (range 2–93%). F values were less conservative (range0.039–0.905), sometimes higher than either PPV or sensitivity, but were always higher than CSI. Low CSI and Fvalues occurred when there was a large difference between PPV and sensitivity, e.g. CSI was 0.02 and F was0.039 in an instance when PPV was 100% and sensitivity was 2%. Algorithms with both high PPV and sensitivityperformed best in terms of CSI and F measure, e.g. CSI was 0.826 and F was 0.905 in an instance when PPV was90% and sensitivity was 91%.Conclusion: CSI or F measure can combine PPV and sensitivity values into a convenient single metric that is easierto interpret and rank in terms of diagnostic accuracy than trying to rank diagnostic accuracy according to the twomeasures themselves. CSI or F prioritise instances where both PPV and sensitivity are high over instances wherethere are large differences between PPV and sensitivity (even if one of these is very high), allowing diagnosticaccuracy thresholds based on combined PPV and sensitivity to be determined. Therefore, CSI or F measures maybe helpful complementary metrics to report alongside PPV and sensitivity in diagnostic accuracy studies ofadministrative epilepsy data
Brief Amici Curiae of Intellectual Property Professors in Support of Petitioner, No. 18-600, Texas Advanced Optoelectronic Solutions, Inc. V. Renesas Electronics America, Inc.
To comply with the obligations of the Uruguay Round Agreements, particularly the Agreement on the Trade Related Aspects of Intellectual Property (TRIPS), Congress amended 35 U.S.C. § 271(a) to make it an act of infringement to “offer to sell” a patented invention within the United States. See Uruguay Round Agreements Act, Pub. L. No. 103-465, §§ 531-533, 108 Stat. 4809 (1994).
The Federal Circuit has interpreted this provision in a manner contrary to the presumption against the extraterritorial reach of United States laws. The Federal Circuit has held that location of the ultimate sale contemplated in the offer controls the locus of the act of infringement, not the location of the offer. Transocean Offshore Deepwater Drilling, Inc. v. Maersk Contractors USA, Inc., 617 F.3d 1296, 1309 (Fed. Cir. 2010) (holding that “the location of the contemplated sale controls whether there is an offer to sell within the United States.”). The Federal Circuit further clarified that an offer made in the United States to sell the invention abroad is not infringing. Halo Elecs., Inc. v. Pulse Elecs., Inc., 831 F.3d 1369, 1380 (Fed. Cir. 2016).
As a result, the court has created an odd dichotomy: activity entirely outside of the United States can trigger liability for infringement of a United States patent, whereas activity within the United States does not. Such an approach is inconsistent with the presumption against extraterritoriality, particularly the two-step framework of RJR Nabisco, Inc. v. European Community, 136 S. Ct. 2090, 2101 (2016). This issue is of considerable importance, and this case is an excellent vehicle for assessing the appropriate territorial scope of § 271(a)
Role of ERO1-α–mediated stimulation of inositol 1,4,5-triphosphate receptor activity in endoplasmic reticulum stress–induced apoptosis
CHOP turns on ERO1-α to release calcium via IP3R and trigger cell death in response to ER stress
Frailty Confers High Mortality Risk across Different Populations:Evidence from an Overview of Systematic Reviews and Meta-Analyses
We performed an overview of systematic reviews and meta-analyses to summarize available data regarding the association between frailty and all-cause mortality. Medline, Embase, CINAHL, Web of Science, PsycINFO, and AMED (Allied and Complementary Medicine) databases were searched until February 2020 for meta-analyses examining the association between frailty and all-cause mortality. The AMSTAR2 checklist was used to evaluate methodological quality. Frailty exposure and the risk of all-cause mortality (hazard ratio [HR] or relative risk [RR]) were displayed in forest plots. We included 25 meta-analyses that pooled data from between 3 and 20 studies. The number of participants included in these meta-analyses ranged between 500,000. Overall, 56%, 32%, and 12% of studies were rated as of moderate, low, and critically low quality, respectively. Frailty was associated with increased risk of all-cause mortality in 24/24 studies where the HR/RRs ranged from 1.35 [95% confidence interval (CI) 1.05-1.74] (patients with diabetes) to 7.95 [95% CI 4.88-12.96] (hospitalized patients). The median HR/RR across different meta-analyses was 1.98 (interquartile range 1.65-2.67). Pre-frailty was associated with a significantly increased risk of all-cause mortality in 7/7 studies with the HR/RR ranging from 1.09 to 3.65 (median 1.51, IQR 1.38-1.73). These data suggest that interventions to prevent frailty and pre-frailty are needed
Bermuda grass latent virus in Australia: genome sequence, sequence variation, and new hosts
Bermuda grass latent virus (BGLV; genus Panicovirus) is identified for the first time in Australia and in only the second country after the USA. A full-length genome sequence was obtained, which has 97% nucleotide sequence identity to that of the species exemplar isolate. Surveys for BGLV, utilising a newly designed universal panicovirus RT-PCR assay for diagnosis, demonstrated widespread infection by this virus in a broad variety of Bermuda grass cultivars (Cynodon dactylon and C. dactylon × C. transvaalensis) grown in both New South Wales and Queensland. The virus was also detected in Rhodes grass (Chloris gayana) and Kikuyu grass (Cenchrus clandestinus), which are both important pasture grasses in subtropical Australia, and the latter is also grown as turf. Furthermore, the Rhodes grass plant, which had strong mosaic symptoms, was also infected with sugarcane mosaic virus, warranting further investigations as to whether synergistic interactions occur between these two viruses
Repeatability of baited remote underwater video station (BRUVS) results within and between seasons
Baited remote underwater video stations (BRUVS) are increasingly being used to evaluate and monitor reef communities. Many BRUVS studies compare multiple sites sampled at single time points that may differ from the sampling time of another site. As BRUVS use grows in its application to provide data relevant to sustainable management, marine protected area success, and overall reef health, understanding repeatability of sampling results is vital. We examined the repeatability of BRUVS results for the elasmobranch community both within and between seasons and years, and explored environmental factors affecting abundances at two sites in Indonesia. On 956 BRUVS, 1139 elasmobranchs (69% rays, 31% sharks) were observed. We found consistent results in species composition and abundances within a season and across years. However, elasmobranch abundances were significantly higher in the wet season. The elasmobranch community was significantly different between the two sites sampled, one site being more coastal and easily accessed by fishermen. Our results demonstrate that while BRUVS are a reliable and repeatable method for surveying elasmobranchs, care must be taken in the timing of sampling between different regions to ensure that any differences observed are due to inherent differences amongst sampling areas as opposed to seasonal dissimilarities
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