Learning distance to subspace for the nearest subspace methods in high-dimensional data classification

The nearest subspace methods (NSM) are a category of classification methods widely applied to classify high-dimensional data. In this paper, we propose to improve the classification performance of NSM through learning tailored distance metrics from samples to class subspaces. The learned distance metric is termed as ‘learned distance to subspace’ (LD2S). Using LD2S in the classification rule of NSM can make the samples closer to their correct class subspaces while farther away from their wrong class subspaces. In this way, the classification task becomes easier and the classification performance of NSM can be improved. The superior classification performance of using LD2S for NSM is demonstrated on three real-world high-dimensional spectral datasets

Smoking affects gene expression in blood of patients with ischemic stroke.

ObjectiveThough cigarette smoking (CS) is a well-known risk factor for ischemic stroke (IS), there is no data on how CS affects the blood transcriptome in IS patients.MethodsWe recruited IS-current smokers (IS-SM), IS-never smokers (IS-NSM), control-smokers (C-SM), and control-never smokers (C-NSM). mRNA expression was assessed on HTA-2.0 microarrays and unique as well as commonly expressed genes identified for IS-SM versus IS-NSM and C-SM versus C-NSM.ResultsOne hundred and fifty-eight genes were differentially expressed in IS-SM versus IS-NSM; 100 genes were differentially expressed in C-SM versus C-NSM; and 10 genes were common to both IS-SM and C-SM (P < 0.01; |fold change| ≥ 1.2). Functional pathway analysis showed the 158 IS-SM-regulated genes were associated with T-cell receptor, cytokine-cytokine receptor, chemokine, adipocytokine, tight junction, Jak-STAT, ubiquitin-mediated proteolysis, and adherens junction signaling. IS-SM showed more altered genes and functional networks than C-SM.InterpretationWe propose some of the 10 genes that are elevated in both IS-SM and C-SM (GRP15, LRRN3, CLDND1, ICOS, GCNT4, VPS13A, DAP3, SNORA54, HIST1H1D, and SCARNA6) might contribute to increased risk of stroke in current smokers, and some genes expressed by blood leukocytes and platelets after stroke in smokers might contribute to worse stroke outcomes that occur in smokers

How do drying and rewetting events affect nutrient fluxes and bacteria dynamics in subtropical estuarine sediments?

Drying and rewetting occur frequently in coastal marsh sediments due to oscillations of rising and falling tides, and episodic droughts and floods. Similarly, drying events also occur within freshwater systems due to changing precipitation patterns. However, little is known about how these events affect biogeochemical processes in sediments. In this study we examined the effects of drying on the release of nutrients from sediments to overlying waters, together with associated bacterial dynamics. We incubated dried and rewetted salt marsh sediments collected from the Nueces River mouth at the Nueces Salt Marsh (NSM) and from a freshwater section of the Mission River (MR) in South Texas. During the incubations, we quantified the nutrients released and changes of bacterial abundance and community structure in slurries of wet and dry sediments under anoxic conditions. Our results showed that ammonium concentrations increased steadily for both NSM and MR dry treatment incubations, reaching a maximum of 203 and 51 μM respectively, as compared to only 124 and 2 μM in the wet treatments. Phosphate concentrations steadily increased throughout the incubation in the NSM dry treatment, but not in the wet treatment where concentrations remained below 5 μM. In contrast, we observed an opposite trend in the MR sediment with phosphate concentrations in the dry treatment remaining below those in the wet treatment throughout the incubation. The atomic C/N ratios for NSM and MR sediments ranged from 10 to 14 for both MR and NSM treatments, however they were significantly lower in the supernatants of the NSM dry treatment (12). Although both NSM and MR had higher ammonium releases in the dry treatments than the wet ones, patterns in phosphate release and C/N ratios of dissolved organic matter differed in these two sediments, likely resulting from the differences in salinity and grain size distribution. Bacteria that developed in the slurry of NSM dried sediment included Bacillus, Anaerobacillus, Haloplasma, and Vibrio; these species were perhaps involved in decomposing sedimentary organic matter, including lysates from biota killed by the drying. The MR sediment slurry developed a different microbial community, where Gemmobacter, Rhodobacter, and Mycoplasma were most notable in the dried treatment. Overall, this study demonstrates that drying and rewetting events can increase nutrient fluxes out of marsh sediments and affect bacterial communities, important in estuarine biogeochemical processes. Information on this topic is important in the context of the increasing frequency of extreme droughts and floods and rising sea levels associated with global change.Marine Scienc

Cosmic Neutron Star Merger Rate and Gravitational Waves constrained by the R Process Nucleosynthesis

The cosmic evolution of the neutron star merger (NSM) rate can be deduced from the observed cosmic star formation rate. This allows to estimate the rate expected in the horizon of the gravitational wave detectors advanced Virgo and ad LIGO and to compare those rates with independent predictions. In this context, the rapid neutron capture process, or r process, can be used as a constraint assuming NSM is the main astrophysical site for this nucleosynthetic process. We compute the early cosmic evolution of a typical r process element, Europium. Eu yields from NSM are taken from recent nucleosynthesis calculations. The same approach allows to compute the cosmic rate of Core Collapse SuperNovae (CCSN) and the associated evolution of Eu. We find that the bulk of Eu observations at high iron abundance can be rather well fitted by either CCSN or NSM scenarios. However, at lower metallicity, the early Eu cosmic evolution favors NSM as the main astrophysical site for the r process. A comparison between our calculations and spectroscopic observations at very low metallicities allows to constrain the coalescence timescale in the NSM scenario to about 0.1 to 0.2 Gyr. These values are in agreement with the coalescence timescales of some observed binary pulsars. Finally, the cosmic evolution of Eu is used to put constraints on the NSM rate, the merger rate in the horizon of the gravitational wave detectors advanced Virgo/ad LIGO, as well as the expected rate of electromagnetic counterparts to mergers (kilonovae) in large near-infrared surveys.Comment: accepted in MNRAS, 19 page

Systematic methods for knowledge acquisition and expert system development

Nine cooperating rule-based systems, collectively called AUTOCREW, were designed to automate functions and decisions associated with a combat aircraft's subsystem. The organization of tasks within each system is described; performance metrics were developed to evaluate the workload of each rule base, and to assess the cooperation between the rule-bases. Each AUTOCREW subsystem is composed of several expert systems that perform specific tasks. AUTOCREW's NAVIGATOR was analyzed in detail to understand the difficulties involved in designing the system and to identify tools and methodologies that ease development. The NAVIGATOR determines optimal navigation strategies from a set of available sensors. A Navigation Sensor Management (NSM) expert system was systematically designed from Kalman filter covariance data; four ground-based, a satellite-based, and two on-board INS-aiding sensors were modeled and simulated to aid an INS. The NSM Expert was developed using the Analysis of Variance (ANOVA) and the ID3 algorithm. Navigation strategy selection is based on an RSS position error decision metric, which is computed from the covariance data. Results show that the NSM Expert predicts position error correctly between 45 and 100 percent of the time for a specified navaid configuration and aircraft trajectory. The NSM Expert adapts to new situations, and provides reasonable estimates of hybrid performance. The systematic nature of the ANOVA/ID3 method makes it broadly applicable to expert system design when experimental or simulation data is available

A Review of Neurogenic Stunned Myocardium.

Neurologic stunned myocardium (NSM) is a phenomenon where neurologic events give rise to cardiac abnormalities. Neurologic events like stroke and seizures cause sympathetic storm and autonomic dysregulation that result in myocardial injury. The clinical presentation can involve troponin elevation, left ventricular dysfunction, and ECG changes. These findings are similar to Takotsubo cardiomyopathy and acute coronary syndrome. It is difficult to distinguish NSM from acute coronary syndrome based on clinical presentation alone. Because of this difficulty, a patient with NSM who is at high risk for coronary heart disease may undergo cardiac catheterization to rule out coronary artery disease. The objective of this review of literature is to enhance physician\u27s awareness of NSM and its features to help tailor management according to the patient\u27s clinical profile

Importance of perforating vessels in nipple-sparing mastectomy. an anatomical description

BACKGROUND: Nipple-sparing mastectomy (NSM), understood as an oncologically valid procedure, is relatively new, and is an evolution of traditional mastectomy, particularly in relation to breast-conserving surgery. The anterior perforating branches are responsible for the cutaneous vascularization of the breast skin, and their preservation is a fundamental step to avoid possible postoperative necrosis. Therefore, evaluating the potential complications of cancer-related reconstructive surgical procedures such as NSM, both the distance of the tumoral lesion from the skin and the surgical incision site should be carefully considered. The preferred site of incision corresponds to the inframammary fold or possibly the periareolar area. METHODS: We retrospectively reviewed 113 patients who underwent NSM from January 2005 to October 2012 to evaluate skin complications. The anatomical study was performed by magnetic resonance imaging of the breast. RESULTS: Only one of the 113 women who had undergone a NSM procedure had total necrosis (0.9%) and six patients had partial necrosis (5.8%) of the nipple-areola complex

Gene regulatory network subcircuit controlling a dynamic spatial pattern of signaling in the sea urchin embryo

We dissect the transcriptional regulatory relationships coordinating the dynamic expression patterns of two signaling genes, wnt8 and delta, which are central to specification of the sea urchin embryo endomesoderm. cis-Regulatory analysis shows that transcription of the gene encoding the Notch ligand Delta is activated by the widely expressed Runx transcription factor, but spatially restricted by HesC-mediated repression through a site in the delta 5′UTR. Spatial transcription of the hesC gene, however, is controlled by Blimp1 repression. Blimp1 thus represses the repressor of delta, thereby permitting its transcription. The blimp1 gene is itself linked into a feedback circuit that includes the wnt8 signaling ligand gene, and we showed earlier that this circuit generates an expanding torus of blimp1 and wnt8 expression. The finding that delta expression is also controlled at the cis-regulatory level by the blimp1-wnt8 torus-generating subcircuit now explains the progression of Notch signaling from the mesoderm to the endoderm of the developing embryo. Thus the specific cis-regulatory linkages of the gene regulatory network encode the coordinated spatial expression of Wnt and Notch signaling as they sweep outward across the vegetal plate of the embryo