Train and test tightness of LP relaxations in structured prediction

This is the author accepted manuscript. The final version is available from Microtome Publishing via http://www.jmlr.org/proceedings/papers/v48/meshi16.htmlStructured prediction is used in areas such as computer vision and natural language processing to predict structured outputs such as segmentations or parse trees. In these settings, prediction is performed by MAP inference or, equivalently, by solving an integer linear program. Because of the complex scoring functions required to obtain accurate predictions, both learning and inference typically require the use of approximate solvers. We propose a theoretical explanation to the striking observation that approximations based on linear programming (LP) relaxations are often tight on real-world instances. In particular, we show that learning with LP relaxed inference encourages integrality of training instances, and that tightness generalizes from train to test data

FBA-SimVis: interactive visualization of constraint-based metabolic models

Summary: FBA-SimVis is a VANTED plug-in for the constraint-based analysis of metabolic models with special focus on the visual exploration of metabolic flux data resulting from model analysis. The program provides a user-friendly environment for model reconstruction, constraint-based model analysis, and interactive visualization of the simulation results. With the ability to quantitatively analyse metabolic fluxes in an interactive and visual manner, FBA-SimVis supports a comprehensive understanding of constraint-based metabolic flux models in both overview and detail

Evolution of seaward-dipping reflectors at the onset of oceanic crust formation at volcanic passive margins: Insights from the South Atlantic

Seaward-dipping reflectors (SDRs) have long been recognized as a ubiquitous feature of volcanic passive margins, yet their evolution is much debated, and even the subject of the nature of the underlying crust is contentious. This uncertainty significantly restricts our understanding of continental breakup and ocean basin–forming processes. Using high-fidelity reflection data from offshore Argentina, we observe that the crust containing the SDRs has similarities to oceanic crust, albeit with a larger proportion of extrusive volcanics, variably interbedded with sediments. Densities derived from gravity modeling are compatible with the presence of magmatic crust beneath the outer SDRs. When these SDR packages are restored to synemplacement geometry we observe that they thicken into the basin axis with a nonfaulted, diffuse termination, which we associate with dikes intruding into initially horizontal volcanics. Our model for SDR formation invokes progressive rotation of these horizontal volcanics by subsidence driven by isostasy in the center of the evolving SDR depocenter as continental lithosphere is replaced by more dense oceanic lithosphere. The entire system records the migration of >10-km-thick new magmatic crust away from a rapidly subsiding but subaerial incipient spreading center at rates typical of slow oceanic spreading processes. Our model for new magmatic crust can explain SDR formation on magma-rich margins globally, but the estimated crustal thickness requires elevated mantle temperatures for their formation

Thermal Exposure and Heat Illness Symptoms among Workers in Mara Gold Mine, Tanzania

Background: Working in a humid and hot environment creates challenges to occupational health and safety in tropical countries. Being in the region, Tanzania can experiences more than 30°C ambient temperature, which exposes miners to heat-related injury and illness. Objectives: This study was conducted to assess heat stress exposure and associated heat illness symptoms among gold mine workers in the Mara region. Methods: A cross-sectional study was conducted among 60 miners from four Similar Exposure Groups based on risk to extreme heat environment. The WBGT index was used to assess the heat load while the miners’ physiological condition explained the heat strain indicator. Data was analyzed using SPSS 20. Chi-square was used to differentiate proportion of miners with heat illness symptoms in different categories. Pearson correlation was used to determine association between environmental measures and change in physiological conditions of the miners. Independent 't'-test and ANOVA were used to assess differences between numerical data among groups. A 'p' < 0.05 at 95% confidence was considered to be statistically significant. Findings: The recorded average WBGT at the mining site was within the ACGIH TLV of 28.5°C, however, 78.4% of underground miners and 69.6% of open cut miners reported to have moderate heat illness. High body temperature and hot and dry skin were the most frequently reported heat illness symptoms. The mean core body temperatures of miners in open cut and underground were 38.4 ± 0.5°C and 37.3 ± 0.5°C respectively. Approximately 80% of miners in open cut indicated higher core body temperature above ISO 7933 threshold of 38.0°C for safety. The majority of workers under contract didn’t drink water prior to work shift commencement. Conclusions: The occupational setting at the mining area presents the potential exposure to a thermal condition that can contribute to heat illness symptoms. Effective strategies must be implemented to enhance workers’ safety

Materials for spintronics: electronic and transport properties of the zigzag graphene nanoribbon/hexagonal boron nitride heterostructures

Abstract High charge carrier mobility in graphene at room temperature creates large potentials for the fabrication of electronic and spintronic devices For creating HEMT (high electron mobility transistor) devices based on ZGNR it is extremely important to study charge carriers mobility. It is necessary to understand and to be able to control the transport properties of electronic devices. Thus, in this work, the effects of the edge and substrate on the band gap, magnetism and transport properties of the charge carriers in 8-ZGNR/h-BN Band structure calculations were performed using the Quantum Espresso For both carrier types in the N-ZGNR/h-BN(0001) heterostructures a common picture is observed: increasing carrier mobility with the decrease of the number of dimers in nanoribbon. For electrons, the mobility increases from . It should also be noted that according to the PBEsol (PBE-D2) calculations the values of the carrier mobility in N-ZGNR/h-BN(0001) heterostructures appear to be 3.5% (7%) higher than in ZGNR without substrate. Thus, the influence of substrate and nanoribbon width on the low-energy spectrum of $\pi$-electrons, local magnetic moments of interface atoms, and the mobilities of charge carriers in N-ZGNR/h-BN(0001) (N = 2, 4, 6, 8) heterostructures have been studied using ab-initio plane-wave pseudopotential method within the DFT framework. Using two different approximations for total energy functional (PBEsol, PBE-D2) we have ascertained the effect of increase of charge carriers mobility by reduction of dimers&apos; number in nanoribbons. Our DFT study have shown that the mobilities of charge carriers in N-ZGNR/h-BN(0001) heterostructures were 5% higher than in suspended nanoribbons. Predicted high electro

Eosinophil and T Cell Markers Predict Functional Decline in COPD Patients

BACKGROUND. The major marker utilized to monitor COPD patients is forced expiratory volume in one second (FEV1). However, asingle measurement of FEV1 cannot reliably predict subsequent decline. Recent studies indicate that T lymphocytes and eosinophils are important determinants of disease stability in COPD. We therefore measured cytokine levels in the lung lavage fluid and plasma of COPD patients in order to determine if the levels of T cell or eosinophil related cytokines were predictive of the future course of the disease. METHODS. Baseline lung lavage and plasma samples were collected from COPD subjects with moderately severe airway obstruction and emphysematous changes on chest CT. The study participants were former smokers who had not had a disease exacerbation within the past six months or used steroids within the past two months. Those subjects who demonstrated stable disease over the following six months (ΔFEV1 % predicted = 4.7 ± 7.2; N = 34) were retrospectively compared with study participants who experienced a rapid decline in lung function (ΔFEV1 % predicted = -16.0 ± 6.0; N = 16) during the same time period and with normal controls (N = 11). Plasma and lung lavage cytokines were measured from clinical samples using the Luminex multiplex kit which enabled the simultaneous measurement of several T cell and eosinophil related cytokines. RESULTS AND DISCUSSION. Stable COPD participants had significantly higher plasma IL-2 levels compared to participants with rapidly progressive COPD (p = 0.04). In contrast, plasma eotaxin-1 levels were significantly lower in stable COPD subjects compared to normal controls (p < 0.03). In addition, lung lavage eotaxin-1 levels were significantly higher in rapidly progressive COPD participants compared to both normal controls (p < 0.02) and stable COPD participants (p < 0.05). CONCLUSION. These findings indicate that IL-2 and eotaxin-1 levels may be important markers of disease stability in advanced emphysema patients. Prospective studies will need to confirm whether measuring IL-2 or eotaxin-1 can identify patients at risk for rapid disease progression.National Heart, Lung, and Blood Institute (NO1-HR-96140, NO1-HR-96141-001, NO1-HR-96144, NO1-HR-96143; NO1-HR-96145; NO1-HR-96142, R01HL086936-03); The Flight Attendant Medical Research Institute; the Jo-Ann F. LeBuhn Center for Chest Diseas

Recognizing detachment-mode seafloor spreading in the deep geological past.

Large-offset oceanic detachment faults are a characteristic of slow- and ultraslow-spreading ridges, leading to the formation of oceanic core complexes (OCCs) that expose upper mantle and lower crustal rocks on the seafloor. The lithospheric extension accommodated by these structures is now recognized as a fundamentally distinct “detachment-mode” of seafloor spreading compared to classical magmatic accretion. Here we demonstrate a paleomagnetic methodology that allows unequivocal recognition of detachment-mode seafloor spreading in ancient ophiolites and apply this to a potential Jurassic detachment fault system in the Mirdita ophiolite (Albania). We show that footwall and hanging wall blocks either side of an inferred detachment have significantly different magnetizations that can only be explained by relative rotation during seafloor spreading. The style of rotation is shown to be identical to rolling hinge footwall rotation documented recently in OCCs in the Atlantic, confirming that detachment-mode spreading operated at least as far back as the Jurassic

Effect of roflumilast on inflammatory cells in the lungs of cigarette smoke-exposed mice

<p>Abstract</p> <p>Background</p> <p>We reported that roflumilast, a phosphodiesterase 4 inhibitor, given orally at 5 mg/kg to mice prevented the development of emphysema in a chronic model of cigarette smoke exposure, while at 1 mg/kg was ineffective. Here we investigated the effects of roflumilast on the volume density (V_V) of the inflammatory cells present in the lungs after chronic cigarette smoke exposure.</p> <p>Methods</p> <p>Slides were obtained from blocks of the previous study and V_Vwas assessed immunohistochemically and by point counting using a grid with 48 points, a 20× objective and a computer screen for a final magnification of 580×. Neutrophils were marked with myeloperoxidase antibody, macrophages with Mac-3, dendritic cells with fascin, B-lymphocytes with B220, CD4+ T-cells with CD4+ antibody, and CD8+T-cells with CD8-α. The significance of the differences was calculated using one-way analysis of variance.</p> <p>Results</p> <p>Chronic smoke exposure increased neutrophil V_Vby 97%, macrophage by 107%, dendritic cell by 217%, B-lymphocyte by 436%, CD4+ by 524%, and CD8+ by 417%. The higher dose of roflumilast prevented the increase in neutrophil V_Vby 78%, macrophage by 82%, dendritic cell by 48%, B-lymphocyte by 100%, CD4+ by 98% and CD8+ V_Vby 88%. The lower dose of roflumilast did not prevent the increase in neutrophil, macrophage and B-cell V_Vbut prevented dendritic cells by 42%, CD4+ by 55%, and CD8+ by 91%.</p> <p>Conclusion</p> <p>These results indicate (<it>i</it>) chronic exposure to cigarette smoke in mice results in a significant recruitment into the lung of inflammatory cells of both the innate and adaptive immune system; (<it>ii</it>) roflumilast at the higher dose exerts a protective effect against the recruitment of all these cells and at the lower dose against the recruitment of dendritic cells and T-lymphocytes; (<it>iii</it>) these findings underline the role of innate immunity in the development of pulmonary emphysema and (<it>iiii</it>) support previous results indicating that the inflammatory cells of the adaptive immune system do not play a central role in the development of cigarette smoke induced emphysema in mice.</p

Differential Regulation of the Variations Induced by Environmental Richness in Adult Neurogenesis as a Function of Time: A Dual Birthdating Analysis

Adult hippocampal neurogenesis (AHN) augments after environmental enrichment (EE) and it has been related to some of the anxiolytic, antidepressant and neuroprotective effects of EE. Indeed, it has been suggested that EE specifically modulates hippocampal neurogenic cell populations over the course of time. Here we have used dual-birthdating to study two subpopulations of newborn neuron in mice (Mus musculus): those born at the beginning and at the end of enrichment. In this way, we demonstrate that while short-term cell survival is upregulated after an initial 1 week period of enrichment in 2 month old female mice, after long-term enrichment (2 months) neither cell proliferation nor the survival of the younger newly born cell populations are distinguishable from that observed in non-enriched control mice. In addition, we show that the survival of older newborn neurons alone (i.e. those born at the beginning of the enrichment) is higher than in controls, due to the significantly lower levels of cell death. Indeed, these parameters are rapidly adjusted to the sudden cessation of the EE conditions. These findings suggest both an early selective, long-lasting effect of EE on the neurons born in the initial stages of enrichment, and a quick response when the environment again becomes impoverished. Therefore, EE induces differential effects on distinct subpopulations of newborn neurons depending on the age of the immature cells and on the duration of the EE itself. The interaction of these two parameters constitutes a new, specific regulation of these neurogenic populations that might account for the long-term enrichment's behavioral effects

Effects of Enriched Physical and Social Environments on Motor Performance, Associative Learning, and Hippocampal Neurogenesis in Mice

We have studied the motor abilities and associative learning capabilities of adult mice placed in different enriched environments. Three-month-old animals were maintained for a month alone (AL), alone in a physically enriched environment (PHY), and, finally, in groups in the absence (SO) or presence (SOPHY) of an enriched environment. The animals' capabilities were subsequently checked in the rotarod test, and for classical and instrumental learning. The PHY and SOPHY groups presented better performances in the rotarod test and in the acquisition of the instrumental learning task. In contrast, no significant differences between groups were observed for classical eyeblink conditioning. The four groups presented similar increases in the strength of field EPSPs (fEPSPs) evoked at the hippocampal CA3-CA1 synapse across classical conditioning sessions, with no significant differences between groups. These trained animals were pulse-injected with bromodeoxyuridine (BrdU) to determine hippocampal neurogenesis. No significant differences were found in the number of NeuN/BrdU double-labeled neurons. We repeated the same BrdU study in one-month-old mice raised for an additional month in the above-mentioned four different environments. These animals were not submitted to rotarod or conditioned tests. Non-trained PHY and SOPHY groups presented more neurogenesis than the other two groups. Thus, neurogenesis seems to be related to physical enrichment at early ages, but not to learning acquisition in adult mice