305 research outputs found
Contracting Agile Developments for Mission Critical Systems in the Public Sector
Although Agile is a well established software development paradigm, major concerns arise when it comes to contracting issues between a software consumer and a software producer. How to contractualize the Agile production of software, especially for security & mission critical organizations, which typically outsource software projects, has been a major concern since the beginning of the \u201cAgile Era.\u201d In literature, little has been done, from a foundational point of view regarding the formalization of such contracts. Indeed, when the development is outsourced, the management of the contractual life is non\u2013trivial. This happens because the interests of the two parties are typically not aligned. In these situations, software houses strive for the minimization of the effort, while the customer commonly expects high quality artifacts. This structural asymmetry can hardly be overcome with traditional \u201cWaterfall\u201d contracts. In this work, we propose a foundational approach to the Law & Economics of Agile contracts. Moreover, we explore the key elements of the Italian procurement law and outline a suitable solution to merge some basic legal constraints with Agile requirements. Finally, a case study is presented, describing how Agile contracting has been concretely implemented in the Italian Defense Acquisition Process. This work is intended to be a framework for Agile contracts for the Italian public sector of critical systems, according to the new contractual law (Codice degli Appalti)
Microbial activity in surficial sediments overlying acoustic wipeout zones at a Gulf of Mexico cold seep
Down core concentration gradients of dissolved methane and sulfate; isotope gradients of methane, dissolved inorganic carbon, and authigenic carbonate; and organic matter elemental ratios are incorporated into a vent evolution model to describe spatial and temporal variability of sedimentary microbial activity overlying acoustic wipeout zones at Mississippi Canyon (MC) 118, Gulf of Mexico. We tested the hypothesis that these zones indicate areas where sediments are exposed to elevated fluid flux and therefore should contain saturated methane concentrations and enhanced microbial activity from sulfate reduction (SR), anaerobic oxidation of methane (AOM), and methanogenesis (MP). Thirty surficial cores (between 22 and 460 cm deep) were collected from sediments overlying and outside the wipeout zones and analyzed for pore water and solid phase constituents. Outside the wipeout zones, sulfate and methane concentrations were similar to overlying-water values and did not vary with depth; indicating low microbial activity. Above the wipeouts, nine cores showed moderate activity with gently sloping sulfate and methane concentration gradients, methane concentrations <20 μM, and isotope depth gradients indicative of organic matter oxidation. In stark contrast to this moderate activity, four cores showed high microbial activity where sulfate concentrations were depleted by ∼50 cm below seafloor, maximum methane concentrations in the decompressed cores were above 4 mM, and down core profiles of δ13C-CH4 and δ13C-dissolved inorganic carbon (DIC) indicated distinct depth zones of SR, AOM, and MP. Bulk organic matter analysis suggested that the high activity was supported by an organic source that was enriched in carbon (C:N ∼15) and depleted in d15N and δ13C compared to other activity groups, possibly due to the influx of petroleum or chemosynthetically fixed carbon. Within high activity cores, the δ13C-DIC values were similar to the δ13C-CaCO3 values, a result expected for authigenic carbonate recently precipitated. However, these values were dissimilar in moderate activity cores, suggesting that microbial activity was higher in the past. This study provides evidence that the fluid flux at MC 118 varies over time and that the microbial activity responds to such variability. It also suggests that sediments overlying wipeout zones are not always saturated with respect to methane, which has implications for the formation and detection of gas hydrate
Hydrologic controls of methane dynamics in Karst subterranean estuaries
Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 32(12), (2019): 1759-1775, doi:10.1029/2018GB006026.Karst subterranean estuaries (KSEs) extend into carbonate platforms along 12% of all coastlines. A recent study has shown that microbial methane (CH4) consumption is an important component of the carbon cycle and food web dynamics within flooded caves that permeate KSEs. In this study, we obtained high‐resolution (~2.5‐day) temporal records of dissolved methane concentrations and its stable isotopic content (δ13C) to evaluate how regional meteorology and hydrology control methane dynamics in KSEs. Our records show that less methane was present in the anoxic fresh water during the wet season (4,361 ± 89 nM) than during the dry season (5,949 ± 132 nM), suggesting that the wet season hydrologic regime enhances mixing of methane and other constituents into the underlying brackish water. The δ13C of the methane (−38.1 ± 1.7‰) in the brackish water was consistently more 13C‐enriched than fresh water methane (−65.4 ± 0.4‰), implying persistent methane oxidation in the cave. Using a hydrologically based mass balance model, we calculate that methane consumption in the KSE was 21–28 mg CH4·m−2·year−1 during the 6‐month dry period, which equates to ~1.4 t of methane consumed within the 102‐ to 138‐km2 catchment basin for the cave. Unless wet season methane consumption is much greater, the magnitude of methane oxidized within KSEs is not likely to affect the global methane budget. However, our estimates constrain the contribution of a critical resource for this widely distributed subterranean ecosystem.Funding for T. M. I. and D. B. was provided by TAMU‐CONACYT (project 2015‐049). D. B. was supported by the Research‐in‐Residence program (NSF award 1137336, Inter‐university Training in Continental‐scale Ecology), the Boost Fellowship (Texas A&M University at Galveston), and the Postdoctoral Scholar Program by Woods Hole Oceanographic Institution and U.S. Geological Survey. We thank Jacob Pohlman and István Brankovits for assistance with field expeditions. Special thanks to the late Bil Phillips (Speleotech) for the support and expertise provided us during field operations. We also thank Pete van Hengstum for productive discussions and guidance during the development of the manuscript. Michael Casso and Adrian Green helped with laboratory analyses. The manuscript was greatly improved by helpful comments from an anonymus reviewer, Jeff Chanton, and Meagan Gonneea. This work is contribution number UMCES 5541. Any use of trade names is for descriptive purposes and does not imply endorsement by the U.S. Government. The authors declare no competing financial interests. Archival data are available through the USGS ScienceBase‐Catalog at https://doi.org/10.5066/P9U0KRVM
Focused Fluid Flow along the Nootka Fault Zone and Continental slope, Explorer‐Juan de Fuca Plate Boundary
Key Points:
- Fluid flow is focused along Nootka Fault traces resulting in shallow bright spots
- Two seafloor mounds are the result of basaltic intrusions in the Nootka Fault zone
- Gas hydrates occur at the Nootka Slope and are imaged seismically as bottom-
simulating reflectors suggesting a regional heat-flow of ~80 mW/m2 along the slope
Abstract
Geophysical and geochemical data indicate there is abundant fluid expulsion in the Nootka fault zone (NFZ) between the Juan de Fuca and Explorer plates and the Nootka continental slope. Here we combine observations from > 20 years of investigations to demonstrate the nature of fluid‐flow along the NFZ, which is the seismically most active region off Vancouver Island. Seismicity reaching down to the upper mantle is linked to near‐seafloor manifestation of fluid flow through a network of faults. Along the two main fault traces, seismic reflection data imaged bright spots 100 – 300 m below seafloor that lie above changes in basement topography. The bright spots are conformable to sediment layering, show opposite‐to‐seafloor reflection polarity, and are associated with frequency‐reduction and velocity push‐down indicating the presence of gas in the sediments. Two seafloor mounds ~15 km seaward of the Nootka slope are underlain by deep, non‐conformable high amplitude reflective zones. Measurements in the water column above one mound revealed a plume of warm water, and bottom‐video observations imaged hydrothermal vent system biota. Pore fluids from a core at this mound contain predominately microbial methane (C1) with a high proportion of ethane (C2) yielding C1/C2 ratios < 500 indicating a possible slight contribution from a deep source. We infer the reflective zones beneath the two mounds are basaltic intrusions that create hydrothermal circulation within the overlying sediments. Across the Nootka continental slope, gas hydrate related bottom‐simulating reflectors are widespread and occur at depths indicating heat‐flow values of 80 – 90 mW/m2
Cellulose acetate phthalate, a common pharmaceutical excipient, inactivates HIV-1 and blocks the coreceptor binding site on the virus envelope glycoprotein gp120
BACKGROUND: Cellulose acetate phthalate (CAP), a pharmaceutical excipient used for enteric film coating of capsules and tablets, was shown to inhibit infection by the human immunodeficiency virus type 1 (HIV-1) and several herpesviruses. CAP formulations inactivated HIV-1, herpesvirus types 1 (HSV-1) and 2 (HSV-2) and the major nonviral sexually transmitted disease (STD) pathogens and were effective in animal models for vaginal infection by HSV-2 and simian immunodeficiency virus. METHODS: Enzyme-linked immunoassays and flow cytometry were used to demonstrate CAP binding to HIV-1 and to define the binding site on the virus envelope. RESULTS: 1) CAP binds to HIV-1 virus particles and to the envelope glycoprotein gp120; 2) this leads to blockade of the gp120 V3 loop and other gp120 sites resulting in diminished reactivity with HIV-1 coreceptors CXCR4 and CCR5; 3) CAP binding to HIV-1 virions impairs their infectivity; 4) these findings apply to both HIV-1 IIIB, an X4 virus, and HIV-1 BaL, an R5 virus. CONCLUSIONS: These results provide support for consideration of CAP as a topical microbicide of choice for prevention of STDs, including HIV-1 infection
The acute-to-chronic workload ratio:An inaccurate scaling index for an unnecessary normalisation process?
BACKGROUND: Problematic use of alcohol and other drugs (AOD) is highly prevalent among people living with the human immunodeficiency virus (PLWH), and untreated AOD use disorders have particularly detrimental effects on human immunodeficiency virus (HIV) outcomes. The Healthcare Effectiveness Data and Information Set (HEDIS) measures of treatment initiation and engagement are important benchmarks for access to AOD use disorder treatment. To inform improved patient care, we compared HEDIS measures of AOD use disorder treatment initiation and engagement and health care utilization among PLWH and patients without an HIV diagnosis.
METHODS: Patients with a new AOD use disorder diagnosis documented between October 1, 2014, and August 15, 2015, were identified using electronic health records (EHR) and insurance claims data from 7 health care systems in the United States. Demographic characteristics, clinical diagnoses, and health care utilization data were also obtained. AOD use disorder treatment initiation and engagement rates were calculated using HEDIS measure criteria. Factors associated with treatment initiation and engagement were examined using multivariable logistic regression models.
RESULTS: There were 469 PLWH (93% male) and 86,096 patients without an HIV diagnosis (60% male) in the study cohort. AOD use disorder treatment initiation was similar in PLWH and patients without an HIV diagnosis (10% vs. 11%, respectively). Among those who initiated treatment, few engaged in treatment in both groups (9% PLWH vs. 12% patients without an HIV diagnosis). In multivariable analysis, HIV status was not significantly associated with either AOD use disorder treatment initiation or engagement.
CONCLUSIONS: AOD use disorder treatment initiation and engagement rates were low in both PLWH and patients without an HIV diagnosis. Future studies need to focus on developing strategies to efficiently integrate AOD use disorder treatment with medical care for HIV
IGEMS : The Consortium on Interplay of Genes and Environment Across Multiple Studies - An Update
The Interplay of Genes and Environment across Multiple Studies (IGEMS) is a consortium of 18 twin studies from 5 different countries (Sweden, Denmark, Finland, United States, and Australia) established to explore the nature of gene-environment (GE) interplay in functioning across the adult lifespan. Fifteen of the studies are longitudinal, with follow-up as long as 59 years after baseline. The combined data from over 76,000 participants aged 14-103 at intake (including over 10,000 monozygotic and over 17,000 dizygotic twin pairs) support two primary research emphases: (1) investigation of models of GE interplay of early life adversity, and social factors at micro and macro environmental levels and with diverse outcomes, including mortality, physical functioning and psychological functioning; and (2) improved understanding of risk and protective factors for dementia by incorporating unmeasured and measured genetic factors with a wide range of exposures measured in young adulthood, midlife and later life.Peer reviewe
Implementing treat-to-target urate-lowering therapy during hospitalisations for gout flares.
OBJECTIVES: To evaluate a strategy designed to optimise care and increase uptake of urate-lowering therapy (ULT) during hospitalisations for gout flares. METHODS: We conducted a prospective cohort study to evaluate a strategy that combined optimal in-hospital gout management with a nurse-led, follow-up appointment, followed by handover to primary care. Outcomes, including ULT initiation, urate target attainment, and re-hospitalisation rates, were compared between patients hospitalised for flares in the 12 months post-implementation and a retrospective cohort of hospitalised patients from 12 months pre-implementation. RESULTS: 119 and 108 patients, respectively, were hospitalised for gout flares in the 12 months pre- and post-implementation. For patients with 6-month follow-up data available (n = 94 and n = 97, respectively), the proportion newly initiated on ULT increased from 49.2% pre-implementation to 92.3% post-implementation (age/sex-adjusted odds ratio (aOR) 11.5; 95% confidence interval (CI) 4.36-30.5; p < 0.001). After implementation, more patients achieved a serum urate ≤360 micromol/L within 6 months of discharge (10.6% pre-implementation vs. 26.8% post-implementation; aOR 3.04; 95% CI 1.36-6.78; p = 0.007). The proportion of patients re-hospitalised for flares was 14.9% pre-implementation vs. 9.3% post-implementation (aOR 0.53, 95% CI 0.22 to 1.32; p = 0.18). CONCLUSION: Over 90% of patients were initiated on ULT after implementing a strategy to optimise hospital gout care. Despite increased initiation of ULT during flares, recurrent hospitalisations were not more frequent following implementation. Significant relative improvements in urate target attainment were observed post-implementation; however, for the majority of hospitalised gout patients to achieve urate targets, closer primary-secondary care integration is still needed
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