200 research outputs found

    Addressing food security, WASH and climate vulnerability: the WaterAid-CARE partnership in Timor-Leste

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    The small tropical country of Timor-Leste is in a period of social, political and environmental change. Its predominantly rural population is coping with aberrations in historical rainfall patterns and seasonal cycles, affecting communities’ ability to manage food and water security throughout the year. In 2012 CARE and WaterAid successfully applied for funding under the Australian Government’s Community Based Climate Change Action Grant. The objective of the joint project is to increase the adaptive capacity of women and men in vulnerable households living in Liquiça District with the goal of increasing resilience to the unavoidable impacts of climate change. The partnership has generated many interesting lessons, particularly around taking a catchment scale view and an integrated approach to managing water and food security. This paper will highlight selected lessons from the partnership, including addressing competing demands for water and mitigating conflict between its productive and domestic uses

    Multiple roles of the replication initiation protein Cdtl during helicase loading in S. cerevisiae

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    Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2011.Cataloged from PDF version of thesis.Includes bibliographical references.The faithful transmission of genetic information is critical for the events of cell division and propagation. In eukaryotic cells, chromosomal replication is carefully coordinated with the cell cycle to ensure that the entire genome is replicated exactly once prior to cell division. Underpinning this coordination is the tightly regulated loading and activation of the eukaryotic replicative DNA helicase, the hetero-hexameric Mcm2-7 complex. As cells enter G1 phase of the cell cycle, all potential sites of replication initiation are selected by the loading of inactive Mcm2-7 double hexamers. The anti-parallel orientation of the Mcm2-7 hexamers within the double hexamer is proposed to be critical to establish bidirectional sister replisomes upon helicase activation in S phase. Although the proteins involved in helicase loading are known, the mechanism that drives Mcm2-7 double-hexamer formation and loading is unclear. The replication initiation protein Cdtl is essential for loading Mcm2-7 onto origin DNA, but its functions during the loading event are unclear. Through analysis of Cdtl mutations, I identified regions of Cdtl that are essential for Mcm2-7 helicase binding, origin recruitment, and activation. I found that multiple Cdtl molecules are recruited to the origin during the helicase-loading process, and disrupting of the assembly of the multi-Cdtl intermediate prevents Mcm2-7 loading. Finally, I demonstrated that the Nterminal domain of Cdtl, although dispensable for stable helicase loading, is required for subsequent helicase activation and replication initiation. These findings reveal that Cdtl performs multiple functions during helicase loading and influences the competence of loaded Mcm2-7 to subsequently become activated. This work provides insight into the process of Mcm2-7 double-hexamer loading and supports a model in which Cdtl initiates Mcm2-7 double-hexamer formation early in the helicase-loading process.by Thomas J. Takara.Ph.D

    Generalization of the Second Law for a Nonequilibrium Initial State

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    We generalize the second law of thermodynamics in its maximum work formulation for a nonequilibrium initial distribution. It is found that in an isothermal process, the Boltzmann relative entropy (H-function) is not just a Lyapunov function but also tells us the maximum work that may be gained from a nonequilibrium initial state. The generalized second law also gives a fundamental relation between work and information. It is valid even for a small Hamiltonian system not in contact with a heat reservoir but with an effective temperature determined by the isentropic condition. Our relation can be tested in the Szilard engine, which will be realized in the laboratory

    Modeling of extreme freshwater outflow from the north-eastern Japanese river basins to western Pacific Ocean

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    This study demonstrates the importance of accurate extreme discharge input in hydrological and oceanographic combined modeling by introducing two extreme typhoon events. We investigated the effects of extreme freshwater outflow events from river mouths on sea surface salinity distribution (SSS) in the coastal zone of the north-eastern Japan. Previous studies have used observed discharge at the river mouth, as well as seasonally averaged inter-annual, annual, monthly or daily simulated data. Here, we reproduced the hourly peak discharge during two typhoon events for a targeted set of nine rivers and compared their impact on SSS in the coastal zone based on observed, climatological and simulated freshwater outflows in conjunction with verification of the results using satellite remote-sensing data. We created a set of hourly simulated freshwater outflow data from nine first-class Japanese river basins flowing to the western Pacific Ocean for the two targeted typhoon events (Chataan and Roke) and used it with the integrated hydrological (CDRMV3.1.1) and oceanographic (JCOPE-T) model, to compare the case using climatological mean monthly discharges as freshwater input from rivers with the case using our hydrological model simulated discharges. By using the CDRMV model optimized with the SCE-UA method, we successfully reproduced hindcasts for peak discharges of extreme typhoon events at the river mouths and could consider multiple river basin locations. Modeled SSS results were verified by comparison with Chlorophyll-a distribution, observed by satellite remote sensing. The projection of SSS in the coastal zone became more realistic than without including extreme freshwater outflow. These results suggest that our hydrological models with optimized model parameters calibrated to the Typhoon Roke and Chataan cases can be successfully used to predict runoff values from other extreme precipitation events with similar physical characteristics. Proper simulation of extreme typhoon events provides more realistic coastal SSS and may allow a different scenario analysis with various precipitation inputs for developing a nowcasting analysis in the future

    Ethinylestradiol quantification in drinking water sources using a fluorescent paper based immunosensor

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    In this work we report a novel paper-based analytical device read-out via LED-induced fluorescence detection (FPAD) for the quantification of the emerging pollutant ethinylestradiol (EE2) in river water samples. The PAD was used as a reaction platform for a competitive enzyme immunoassay. For the PAD development, microzones of filter paper, printed by a wax printing method, were modified with amino-functionalized SBA-15 and subsequently, anti-EE2 specific antibodies were covalently immobilized. The determination of EE2 in water was carried out by adding a fixed concentration of EE2 conjugated with the enzyme horseradish peroxidase (HRP) to samples and standards. Then, the FPAD were added and incubated for 10 min. Finally, the detection was performed by the reaction of 10-acetyl-3,7-dihydroxyphenoxazine (ADHP) whose oxidation is catalyzed by HRP in the presence of H2O2, obtaining the highly fluorescent resorufin (R). Resorufin was detected by LED excitation at 550 nm, observing emission at 585 nm. The EE2 concentration in the samples was inversely proportional to the relative fluorescence obtained from the enzymatic reaction products. The FPAD assay showed a detection limit (LOD) of 0.05 ng L−1 and coefficients of variation (CV) below 4.5% within-assay and below 6.5% between-assay, respectively. The results obtained show the potential suitability of our FPAD for the selective and sensitive quantification of EE2 in river water samples. In addition, it has the PADs advantages of being disposable, easy to apply and inexpensive.Fil: Scala Benuzzi, MarĂ­a Luz. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - San Luis. Instituto de QuĂ­mica de San Luis. Universidad Nacional de San Luis. Facultad de QuĂ­mica, BioquĂ­mica y Farmacia. Instituto de QuĂ­mica de San Luis; ArgentinaFil: Takara, Eduardo Andres. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - San Luis. Instituto de QuĂ­mica de San Luis. Universidad Nacional de San Luis. Facultad de QuĂ­mica, BioquĂ­mica y Farmacia. Instituto de QuĂ­mica de San Luis; ArgentinaFil: Alderete, Mara. Universidad Nacional de San Martin. Instituto de Nanosistemas; ArgentinaFil: Soler Illia, Galo Juan de Avila Arturo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Universidad Nacional de San Martin. Instituto de Nanosistemas; ArgentinaFil: Schneider, Rudolf J.. Bundesanstalt fĂŒr Materialforschung und -prĂŒfung; AlemaniaFil: Raba, Julio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - San Luis. Instituto de QuĂ­mica de San Luis. Universidad Nacional de San Luis. Facultad de QuĂ­mica, BioquĂ­mica y Farmacia. Instituto de QuĂ­mica de San Luis; ArgentinaFil: Messina, GermĂĄn Alejandro. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - San Luis. Instituto de QuĂ­mica de San Luis. Universidad Nacional de San Luis. Facultad de QuĂ­mica, BioquĂ­mica y Farmacia. Instituto de QuĂ­mica de San Luis; Argentin

    In the absence of ATPase activity, pre-RC formation is blocked prior to MCM2-7 hexamer dimerization

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    The origin recognition complex (ORC) of Saccharomyces cerevisiae binds origin DNA and cooperates with Cdc6 and Cdt1 to load the replicative helicase MCM2–7 onto DNA. Helicase loading involves two MCM2–7 hexamers that assemble into a double hexamer around double-stranded DNA. This reaction requires ORC and Cdc6 ATPase activity, but it is unknown how these proteins control MCM2–7 double hexamer formation. We demonstrate that mutations in Cdc6 sensor-2 and Walker A motifs, which are predicted to affect ATP binding, influence the ORC–Cdc6 interaction and MCM2–7 recruitment. In contrast, a Cdc6 sensor-1 mutant affects MCM2–7 loading and Cdt1 release, similar as a Cdc6 Walker B ATPase mutant. Moreover, we show that Orc1 ATP hydrolysis is not involved in helicase loading or in releasing ORC from loaded MCM2–7. To determine whether Cdc6 regulates MCM2–7 double hexamer formation, we analysed complex assembly. We discovered that inhibition of Cdc6 ATPase restricts MCM2–7 association with origin DNA to a single hexamer, while active Cdc6 ATPase promotes recruitment of two MCM2–7 hexamer to origin DNA. Our findings illustrate how conserved Cdc6 AAA+ motifs modulate MCM2–7 recruitment, show that ATPase activity is required for MCM2–7 hexamer dimerization and demonstrate that MCM2–7 hexamers are recruited to origins in a consecutive process

    Quantitative Proteomic and Interaction Network Analysis of Cisplatin Resistance in HeLa Cells

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    Cisplatin along with other platinum based drugs are some of the most widely used chemotherapeutic agents. However drug resistance is a major problem for the successful chemotherapeutic treatment of cancer. Current evidence suggests that drug resistance is a multifactorial problem due to changes in the expression levels and activity of a wide number of proteins. A majority of the studies to date have quantified mRNA levels between drug resistant and drug sensitive cell lines. Unfortunately mRNA levels do not always correlate with protein expression levels due to post-transcriptional changes in protein abundance. Therefore global quantitative proteomics screens are needed to identify the protein targets that are differentially expressed in drug resistant cell lines. Here we employ a quantitative proteomics technique using stable isotope labeling with amino acids in cell culture (SILAC) coupled with mass spectrometry to quantify changes in protein levels between cisplatin resistant (HeLa/CDDP) and sensitive HeLa cells in an unbiased fashion. A total of 856 proteins were identified and quantified, with 374 displaying significantly altered expression levels between the cell lines. Expression level data was then integrated with a network of protein-protein interactions, and biological pathways to obtain a systems level view of proteome changes which occur with cisplatin resistance. Several of these proteins have been previously implicated in resistance towards platinum-based and other drugs, while many represent new potential markers or therapeutic targets

    A new portable monitor for measuring odorous compounds in oral, exhaled and nasal air

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    <p>Abstract</p> <p>Background</p> <p>The B/B Checker<sup>Âź</sup>, a new portable device for detecting odorous compounds in oral, exhaled, and nasal air, is now available. As a single unit, this device is capable of detecting several kinds of gases mixed with volatile sulfur compounds (VSC) in addition to other odorous gasses. The purpose of the present study was to evaluate the effectiveness of the B/B Checker<sup>Âź </sup>for detecting the malodor level of oral, exhaled, and nasal air.</p> <p>Methods</p> <p>A total of 30 healthy, non-smoking volunteers (16 males and 14 females) participated in this study. The malodor levels in oral, exhaled, and nasal air were measured using the B/B Checker<sup>Âź </sup>and by organoleptic test (OT) scores. The VSCs in each air were also measured by gas chromatography (GC). Associations among B/B Checker<sup>Âź </sup>measurements, OT scores and VSC levels were analyzed using Spearman correlation coefficients. In order to determine the appropriate B/B Checker<sup>Âź </sup>level for screening subjects with malodor, sensitivity and specificity were calculated using OT scores as an identifier for diagnosing oral malodor.</p> <p>Results</p> <p>In oral and nasal air, the total VSC levels measured by GC significantly correlated to that measured by the B/B Checker<sup>Âź</sup>. Significant correlation was observed between the results of OT scores and the B/B Checker<sup>Âź </sup>measurements in oral (r = 0.892, p < 0.001), exhaled (r = 0.748, p < 0.001) and nasal air (r = 0.534, p < 0.001). The correlation between the OT scores and VSC levels was significant only for oral air (r = 0.790, p < 0.001) and nasal air (r = 0.431, p = 0.002); not for exhaled air (r = 0.310, p = 0.096). When the screening level of the B/B Checker<sup>Âź </sup>was set to 50.0 for oral air, the sensitivity and specificity were 1.00 and 0.90, respectively. On the other hand, the screening level of the B/B Checker<sup>Âź </sup>was set to 60.0 for exhaled air, the sensitivity and specificity were 0.82 and 1.00, respectively.</p> <p>Conclusion</p> <p>The B/B Checker<sup>Âź </sup>is useful for objective evaluation of malodor in oral, exhaled and nasal air and for screening subjects with halitosis.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01139073">NCT01139073</a></p
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