Dynamical study of the hyperextended scalar-tensor theory in the empty Bianchi type I model

The dynamics of the hyperextended scalar-tensor theory in the empty Bianchi type I model is investigated. We describe a method giving the sign of the first and second derivatives of the metric functions whatever the coupling function. Hence, we can predict if a theory gives birth to expanding, contracting, bouncing or inflationary cosmology. The dynamics of a string inspired theory without antisymetric field strength is analysed. Some exact solutions are found.Comment: 18 pages, 3 figure

Notes on Euclidean Wilson loops and Riemann Theta functions

The AdS/CFT correspondence relates Wilson loops in N=4 SYM theory to minimal area surfaces in AdS5 space. In this paper we consider the case of Euclidean flat Wilson loops which are related to minimal area surfaces in Euclidean AdS3 space. Using known mathematical results for such minimal area surfaces we describe an infinite parameter family of analytic solutions for closed Wilson loops. The solutions are given in terms of Riemann theta functions and the validity of the equations of motion is proven based on the trisecant identity. The world-sheet has the topology of a disk and the renormalized area is written as a finite, one-dimensional contour integral over the world-sheet boundary. An example is discussed in detail with plots of the corresponding surfaces. Further, for each Wilson loops we explicitly construct a one parameter family of deformations that preserve the area. The parameter is the so called spectral parameter. Finally, for genus three we find a map between these Wilson loops and closed curves inside the Riemann surface.Comment: 35 pages, 7 figures, pdflatex. V2: References added. Typos corrected. Some points clarifie

The influence of sarcoplasmic reticulum Ca2+ concentration on Ca2+ sparks and spontaneous transient outward currents in single smooth muscle cells

Localized, transient elevations in cytosolic Ca2+, known as Ca2+ sparks, caused by Ca2+ release from sarcoplasmic reticulum, are thought to trigger the opening of large conductance Ca2+-activated potassium channels in the plasma membrane resulting in spontaneous transient outward currents (STOCs) in smooth muscle cells. But the precise relationships between Ca2+ concentration within the sarcoplasmic reticulum and a Ca2+ spark and that between a Ca2+ spark and a STOC are not well defined or fully understood. To address these problems, we have employed two approaches using single patch-clamped smooth muscle cells freshly dissociated from toad stomach: a high speed, wide-field imaging system to simultaneously record Ca2+ sparks and STOCs, and a method to simultaneously measure free global Ca2+ concentration in the sarcoplasmic reticulum ([Ca2+]SR) and in the cytosol ([Ca2+]CYTO) along with STOCs. At a holding potential of 0 mV, cells displayed Ca2+ sparks and STOCs. Ca2+ sparks were associated with STOCs; the onset of the sparks coincided with the upstroke of STOCs, and both had approximately the same decay time. The mean increase in [Ca2+]CYTO at the time and location of the spark peak was approximately 100 nM above a resting concentration of approximately 100 nM. The frequency and amplitude of spontaneous Ca2+ sparks recorded at -80 mV were unchanged for a period of 10 min after removal of extracellular Ca2+ (nominally Ca2+-free solution with 50 microM EGTA), indicating that Ca2+ influx is not necessary for Ca2+sparks. A brief pulse of caffeine (20 mM) elicited a rapid decrease in [Ca2+]SR in association with a surge in [Ca2+]CYTO and a fusion of STOCs, followed by a fast restoration of [Ca2+]CYTO and a gradual recovery of [Ca2+]SR and STOCs. The return of global [Ca2+]CYTO to rest was an order of magnitude faster than the refilling of the sarcoplasmic reticulum with Ca2+. After the global [Ca2+]CYTO was fully restored, recovery of STOC frequency and amplitude were correlated with the level of [Ca2+]SR, even though the time for refilling varied greatly. STOC frequency did not recover substantially until the [Ca2+]SR was restored to 60% or more of resting levels. At [Ca2+]SR levels above 80% of rest, there was a steep relationship between [Ca2+]SR and STOC frequency. In contrast, the relationship between [Ca2+]SR and STOC amplitude was linear. The relationship between [Ca2+]SR and the frequency and amplitude was the same for Ca2+ sparks as it was for STOCs. The results of this study suggest that the regulation of [Ca2+]SR might provide one mechanism whereby agents could govern Ca2+ sparks and STOCs. The relationship between Ca2+ sparks and STOCs also implies a close association between a sarcoplasmic reticulum Ca2+ release site and the Ca2+-activated potassium channels responsible for a STOC

Presence of bacteria and bacteriophages in full-scale trickling filters and an aerated constructed wetland

Aerated Constructed Wetlands are a state-of-the-art design that provides a different physical and chemical environment (compared to traditional passive wetland designs) for the wastewater treatment processes and, thus, may have different pathogen removal characteristics. In order to establish the fate of bacterial and viral indicators, a field study was carried out at a Sewage Treatment Works (STW) in the UK (serving 20,000 pe). The STW consists of primary and secondary sedimentation tanks and trickling filters (TF) as the biological stage. A large (1,160 m2) pilot aerated Vertical Flow Constructed Wetland (AVFCW) was constructed at the STW as tertiary stage receiving ¼ of the total flow rate, i.e., 1250 m3/day. Effluent quality of the AVFCW complied with national and international standards for environmental discharge and reuse. For the first time, two sets of bacterial (Faecal coliforms, E.coli and intestinal enterococci) and viral indicators (Somatic coliphages, F-RNA specific bacteriophages and human-specific B. fragilis GB124 phages) were simultaneously investigated in an AVFCW and TF. High elimination rates were detected (up to 3.7 and 2.2 log reduction for bacteria indicators and phages, respectively) and strong correlations between the two sets were found. The superior efficiency of the aerated Constructed Wetlands in microbiological contamination removal compared to passive wetland systems was established for the first time, which may have implications for process selection for wastewater reuse. This field study therefore provides new evidence on the fate of bacteriophages and a first indication of their potential use for performance evaluation in TF and aerated Constructed Wetlands. It also demonstrates that the combination of TF with aerated constructed wetlands could be a novel and effective treatment scheme for new STW or for the upgrade of existing STW

Low levels of Caspase-3 predict favourable response to 5FU-based chemotherapy in advanced colorectal cancer: Caspase-3 inhibition as a therapeutic approach.

Colorectal cancer (CRC) is one of the most common cancers in the Western world. 5-Fluorouracil (5FU)-based chemotherapy (CT) remains the mainstay treatment of CRC in the advanced setting, and activates executioner caspases in target cells. Executioner caspases are key proteins involved in cell disassembly during apoptosis. Activation of executioner caspases also has a role in tissue regeneration and repopulation by stimulating signal transduction and cell proliferation in neighbouring, non-apoptotic cells as reported recently. Tissue microarrays (TMAs) consisting of tumour tissue from 93 stage II and III colon cancer patients were analysed by immunohistochemistry. Surprisingly, patients with low levels of active Caspase-3 had an increased disease-free survival time. This was particularly pronounced in patients who received 5FU-based adjuvant CT. In line with this observation, lower serum levels of active Caspase-3 were found in patients with metastasised CRC who revealed stable disease or tumour regression compared with those with disease progression. The role of Caspase-3 in treatment responses was explored further in primary human tumour explant cultures from fresh patient tumour tissue. Exposure of explant cultures to 5FU-based CT increased the percentage of cells positive for active Caspase-3 and Terminal Deoxynucleotidyl Transferase dUTP Nick end Labelling (TUNEL), but also the expression of regeneration and proliferation markers β-Catenin and Ki-67, as well as cyclooxygenase-2 (COX-2). Of note, selective inhibition of Caspase-3 with Ac-DNLD-CHO, a selective, reversible inhibitor of Caspase-3, significantly reduced the expression of proliferation markers as well as COX-2. Inhibition of COX-2 with aspirin or celecoxib did not affect Caspase-3 levels but also reduced Ki-67 and β-Catenin levels, suggesting that Caspase-3 acted via COX-2 to stimulate cell proliferation and tissue regeneration. This indicates that low levels of active Caspase-3 may represent a new predictor of CT responsiveness, and inhibition of Caspase-3, or antagonising downstream effectors of Caspase-3 paracrine signalling, such as COX-2 may improve patient outcomes following CT in advanced CRC

Integrating physical and economic data into experimental water accounts for the United States: Lessons and opportunities

Water management increasingly involves tradeoffs, making its accounting highly relevant in our interconnected world. Physical and economic data about water in many nations are becoming more widely integrated through application of the System of Environmental-Economic Accounts for Water (SEEA-Water), which enables the tracking of linkages between water and the economy. We present the first national and subnational SEEA-Water accounts for the United States. We compile accounts for water: (1) physical supply and use, (2) productivity, (3) quality, and (4) emissions for roughly the years 2000 to 2015. Total U.S. water use declined by 22% from 2000 to 2015, falling in 44 states though groundwater use increased in 21 states. Water-use reductions, combined with economic growth, led to increases in water productivity for the overall national economy (65%), mining (99%), and agriculture (68%). Surface-water quality trends were most evident at regional levels, and differed by waterquality constituent and region. This work provides (1) a baseline of recent historical water resource trends and their value in the U.S., and (2) a roadmap for the completion of future accounts for water, a critical ecosystem service. Our work also aids in the interpretation of ecosystem accounts in the context of long-term water resources trends.This work was conducted as a part of the “Accounting for U.S. Ecosystem Services at National and Subnational Scales” working group supported by the National Socio-Environmental Synthesis Center (SESYNC) under funding received from the National Science Foundation (grant DBI-1052875) and the U.S. Geological Survey (USGS) John Wesley Powell Center for Analysis and Synthesis (grant GX16EW00ECSV00). We thank members of the working group for constructive discussions of the scope and content of U.S. water accounts and reviews of this manuscript. We thank the following individuals for assistance with data access and interpretation: Cheryl Dieter, Carey Johnston, John Lovelace, Molly Maupin, Gary Rowe, and Lori Sprague. Support for Bagstad and Ancona’s time was provided by the USGS Land Change Science Program

Climatic, Ecophysiological, and Phenological Controls on Plant Ecohydrological Strategies in Seasonally Dry Ecosystems

Large areas in the tropics and at mid-latitudes experience pronounced seasonality and inter-annual variability in rainfall and hence water availability. Despite the importance of these seasonally dry ecosystems (SDEs) for the global carbon cycling and in providing ecosystem services, a unifying ecohydrological framework to interpret the effects of climatic variability on SDEs is still lacking. A synthesis of existing data about plant functional adaptations in SDEs, covering some 400 species, shows that leaf phenological variations, rather than physiological traits, provide the dominant control on plant-water-carbon interactions. Motivated by this result, the combined implications of leaf phenology and climatic variability on plant water use strategies are here explored with a minimalist model of the coupled soil water and plant carbon balances. The analyses are extended to five locations with different hydroclimatic forcing, spanning seasonally dry tropical climates (without temperature seasonality) and Mediterranean climates (exhibiting out of phase seasonal patterns of rainfall and temperature). The most beneficial leaf phenology in terms of carbon uptake depends on the climatic regime: evergreen species are favoured by short dry seasons or access to persistent water stores, whereas high inter-annual variability of rainy season duration favours the coexistence of multiple drought-deciduous phenological strategies. We conclude that drought-deciduousness may provide a competitive advantage in face of predicted declines in rainfall totals, while reduced seasonality and access to deep water stores may favour evergreen species. This article has been contributed to by US Government employees and their work is in the public domain in the USA

Murray Valley encephalitis virus surveillance and control initiatives in Australia.

Mechanisms for monitoring Murray Valley encephalitis (MVE) virus activity include surveillance of human cases, surveillance for activity in sentinel animals, monitoring of mosquito vectors and monitoring of weather conditions. The monitoring of human cases is only one possible trigger for public health action and the additional surveillance systems are used in concert to signal the risk of human disease, often before the appearance of human cases. Mosquito vector surveillance includes mosquito trapping for speciation and enumeration of mosquitoes to monitor population sizes and relative composition. Virus isolation from mosquitoes can also be undertaken. Monitoring of weather conditions and vector surveillance determines whether there is a potential for MVE activity to occur. Virus isolation from trapped mosquitoes is necessary to define whether MVE is actually present, but is difficult to deliver in a timely fashion in some jurisdictions. Monitoring of sentinel animals indicates whether MVE transmission to vertebrates is actually occurring. Meteorological surveillance can assist in the prediction of potential MVE virus activity by signalling conditions that have been associated with outbreaks of Murray Valley encephalitis in humans in the past. Predictive models of MVE virus activity for south-eastern Australia have been developed, but due to the infrequency of outbreaks, are yet to be demonstrated as useful for the forecasting of major outbreaks. Surveillance mechanisms vary across the jurisdictions. Surveillance of human disease occurs in all States and Territories by reporting of cases to health authorities. Sentinel flocks of chickens are maintained in 4 jurisdictions (Western Australia, the Northern Territory, Victoria and New South Wales) with collaborations between Western Australia and the Northern Territory. Mosquito monitoring complements the surveillance of sentinel animals in these jurisdictions. In addition, other mosquito monitoring programs exist in other States (including South Australia and Queensland). Public health control measures may include advice to the general public and mosquito management programs to reduce the numbers of both mosquito larvae and adult vectors. Strategic plans for public health action in the event of MVE virus activity are currently developed or being developed in New South Wales, the Northern Territory, South Australia, Western Australia and Victoria. A southern tri-State agreement exists between health departments of New South Wales, Victoria and South Australia and the Commonwealth Department of Health and Aged Care. All partners have agreed to co-operate and provide assistance in predicting and combatting outbreaks of mosquito-borne disease in south-eastern Australia. The newly formed National Arbovirus Advisory Committee is a working party providing advice to the Communicable Diseases Network Australia on arbovirus surveillance and control. Recommendations for further enhancement of national surveillance for Murray Valley encephalitis are described

Remote real-time monitoring of subsurface landfill gas migration

The cost of monitoring greenhouse gas emissions from landfill sites is of major concern for regulatory authorities. The current monitoring procedure is recognised as labour intensive, requiring agency inspectors to physically travel to perimeter borehole wells in rough terrain and manually measure gas concentration levels with expensive hand-held instrumentation. In this article we present a cost-effective and efficient system for remotely monitoring landfill subsurface migration of methane and carbon dioxide concentration levels. Based purely on an autonomous sensing architecture, the proposed sensing platform was capable of performing complex analytical measurements in situ and successfully communicating the data remotely to a cloud database. A web tool was developed to present the sensed data to relevant stakeholders. We report our experiences in deploying such an approach in the field over a period of approximately 16 months. Copyright 2011 by the authors; licensee MDPI, Basel, Switzerland

Coordinated Regulation of Intestinal Functions in C. elegans by LIN-35/Rb and SLR-2

LIN-35 is the sole C. elegans representative of the pocket protein family, which includes the mammalian Retinoblastoma protein pRb and its paralogs p107 and p130. In addition to having a well-established and central role in cell cycle regulation, pocket proteins have been increasingly implicated in the control of critical and diverse developmental and cellular processes. To gain a greater understanding of the roles of pocket proteins during development, we have characterized a synthetic genetic interaction between lin-35 and slr-2, which we show encodes a C2H2-type Zn-finger protein. Whereas animals harboring single mutations in lin-35 or slr-2 are viable and fertile, lin-35; slr-2 double mutants arrest uniformly in early larval development without obvious morphological defects. Using a combination of approaches including transcriptome profiling, mosaic analysis, starvation assays, and expression analysis, we demonstrate that both LIN-35 and SLR-2 act in the intestine to regulate the expression of many genes required for normal nutrient utilization. These findings represent a novel role for pRb family members in the maintenance of organ function. Our studies also shed light on the mechanistic basis of genetic redundancy among transcriptional regulators and suggest that synthetic interactions may result from the synergistic misregulation of one or more common targets