75 research outputs found

    Production Networks Linkages, Innovation Processes and Social Management Technologies. A Methodological Approach Applied to the Volkswagen case in Argentina

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    The purpose of this paper -as a part of a wider research project - is to analyze the concept of production network from a methodological and theoretical viewpoint based on a three-plane perspective. These dimensions are the linkages among agents, the innovation activities, and the social management technology, including work process organization and the social agreement generation model in force. It is an experimentally methodological approach that tries to go from a theoretical conceptualization of the phenomenon to its empirical evaluation. The questions guiding this research are as follows: What are the variables and dimensions to be observed in the analysis of a group of interconnected firms in order to define a production network? Is it a unique definition or, on the contrary, does it involve a range of alternatives? What are the externalities generated by the agents who belong to one network? What is the relationship between the network’s firms’ technological behavior and their organizational counterpart? How are learning processes in the business firms linked to their own training systems? Has the social management technology some differential role in the learning process and in the development of skills? How do knowledge transmission processes manifest themselves within the “network”? What indicators are useful for the empirical identification of the different means of manifestation of the network according to the theoretical viewpoint adopted? How can those indicators be articulated in order to elaborate typologies intended for the identification of “hybrid” models? How can a complex indicator be built in order to show the different levels of circulation of intangible assets, development of learning processes and work process organization? In the first section, the conceptualization of the production “network” used in this paper is discussed. In the second section, most relevant variables and indicators are presented in order to feature the business firms and the network in terms of: a) type, quantity and quality of tangible and intangible exchanges among the agents; b) innovative capacity and learning; c) social management technology. Then we elaborate a typology of networks based on the consideration of the previous parameters. Lastly, in the fourth section, we discuss how the three dimensions interact in the case of Volkswagen and his forty main local suppliers.Innovation, production process, case study

    Effects of Genetic Traits on Nonlint Trash and Nep Content of Cotton, Gossypium Hirsutum L.

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    Gin induced lint quality problems (neps, short fiber content, seed-coat fragments and reductions in lint turnout) need the consideration of the entire cotton production system. Genetic traits could help reduce seed-cotton trash and/or improve cleanability at the gin. Twelve near-isolines involving four leaf shapes (okra, semi-okra, super-okra and normal), two bract types (frego and normal), two leaf-pubescence levels (semi-smoothness and hairy) and certain trait combinations were grown during 1985, 1986, and 1987 at three locations in Louisiana (Alexandria, Bossier City, and St. Joseph), and harvested with a spindle-picker. Seedcotton samples were ginned on a cut-down version of a commercial gin under a controlled environment, constant feeding rates, and with zero, one, and two lint cleaners. An inclined sieve inside the trash chamber of the Shirley Analyzer allowed the separation of motes and leafy material. Nep content was determined by the U.S.D.A. method. The use of the inclined sieve inside the Shirley Analyzer helped clarify the behavior of the traits by separating the leafy material and motes components in the non-lint visible fraction. Semi-smooth isolines (t\sb3) were associated with reduced number of motes at the wagon (22% reduction compared with the normal pubescent counterpart) and with improved seed-cotton small-leaf cleanability (+12%). In addition to decreasing the small-leaf percentage in the feeder apron by 20%, super-okra leaf shape reduced the number of motes (15%); both traits (semi-smoothness and super-okra) ended with the same level of leafy material and grade index after one lint cleaner as did the check after two lint cleaners. The open-canopy and frego bract cottons had more small-leaf wagon trash than the check (21 and 12%, respectively), but the differences disappeared at the gin stand. Frego bract isolines had lower levels of leafy material in the lint than their normal bract counterparts at any level of lint cleaning. None of the traits affected the number of neps at zero, one, or two stages of lint cleaning; micronaire and fiber length had the highest direct effects on the nep counts according to the path analysis, but did not explain the majority of the variability found in the data

    Carbon dioxide and water vapor exchange in a warm temperate grassland

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    Grasslands cover about 40% of the ice-free global terrestrial surface, but their contribution to local and regional water and carbon fluxes and sensitivity to climatic perturbations such as drought remains uncertain. Here, we assess the direction and magnitude of net ecosystem carbon exchange (NEE) and its components, ecosystem carbon assimilation ( A c ) and ecosystem respiration ( R E ), in a southeastern United States grassland ecosystem subject to periodic drought and harvest using a combination of eddy-covariance measurements and model calculations. We modeled A c and evapotranspiration (ET) using a big-leaf canopy scheme in conjunction with ecophysiological and radiative transfer principles, and applied the model to assess the sensitivity of NEE and ET to soil moisture dynamics and rapid excursions in leaf area index (LAI) following grass harvesting. Model results closely match eddy-covariance flux estimations on daily, and longer, time steps. Both model calculations and eddy-covariance estimates suggest that the grassland became a net source of carbon to the atmosphere immediately following the harvest, but a rapid recovery in LAI maintained a marginal carbon sink during summer. However, when integrated over the year, this grassland ecosystem was a net C source (97 g C m −2 a −1 ) due to a minor imbalance between large A c (−1,202 g C m −2 a −1 ) and R E (1,299 g C m −2 a −1 ) fluxes. Mild drought conditions during the measurement period resulted in many instances of low soil moisture ( θ <0.2 m 3 m −3 ), which influenced A c and thereby NEE by decreasing stomatal conductance. For this experiment, low θ had minor impact on R E . Thus, stomatal limitations to A c were the primary reason that this grassland was a net C source. In the absence of soil moisture limitations, model calculations suggest a net C sink of −65 g C m −2 a −1 assuming the LAI dynamics and physiological properties are unaltered. These results, and the results of other studies, suggest that perturbations to the hydrologic cycle are key determinants of C cycling in grassland ecosystems.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47701/1/442_2003_Article_1388.pd

    WHF IASC Roadmap on Chagas Disease

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    Background: Chagas Disease is a neglected tropical disease caused by the protozoan Trypanosoma cruzi, with some of the most serious manifestations affecting the cardiovascular system. It is a chronic, stigmatizing condition, closely associated with poverty and affecting close to 6 million people globally. Although historically the disease was limited to endemic areas of Latin America recent years have seen an increasing global spread. In addition to the morbidity and mortality associated with the disease, the social and economic burdens on individuals and society are substantial. Often called the ‘silent killer’, Chagas disease is characterized by a long, asymptomatic phase in affected individuals. Approximately 30% then go on develop chronic Chagas cardiomyopathy and other serious cardiac complications such as stroke, rhythm disturbances and severe heart failure. Methods: In a collaboration of the World Hearth Federation (WHF) and the Inter-American Society of Cardiology (IASC) a writing group consisting of 20 diverse experts on Chagas disease (CD) was convened. The group provided up to date expert knowledge based on their area of expertise. An extensive review of the literature describing obstacles to diagnosis and treatment of CD along with proposed solutions was conducted. A survey was sent to all WHF Members and, using snowball sampling to widen the consultation, to a variety of health care professionals working in the CD global health community. The results were analyzed, open comments were reviewed and consolidated, and the findings were incorporated into this document, thus ensuring a consensus representation. Results: The WHF IASC Roadmap on Chagas Disease offers a comprehensive summary of current knowledge on prevention, diagnosis and management of the disease. In providing an analysis of ‘roadblocks’ in access to comprehensive care for Chagas disease patients, the document serves as a framework from which strategies for implementation such as national plans can be formulated. Several dimensions are considered in the analysis: healthcare system capabilities, governance, financing, community awareness and advocacy. Conclusion: The WHF IASC Roadmap proposes strategies and evidence-based solutions for healthcare professionals, health authorities and governments to help overcome the barriers to comprehensive care for Chagas disease patients. This roadmap describes an ideal patient care pathway, and explores the roadblocks along the way, offering potential solutions based on available research and examples in practice. It represents a call to action to decision-makers and health care professionals to step up efforts to eradicate Chagas disease

    Detecting forest response to droughts with global observations of vegetation water content

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    Droughts in a warming climate have become more common and more extreme, making understanding forest responses to water stress increasingly pressing. Analysis of water stress in trees has long focused on water potential in xylem and leaves, which influences stomatal closure and water flow through the soil-plant-atmosphere continuum. At the same time, changes of vegetation water content (VWC) are linked to a range of tree responses, including fluxes of water and carbon, mortality, flammability, and more. Unlike water potential, which requires demanding in situ measurements, VWC can be retrieved from remote sensing measurements, particularly at microwave frequencies using radar and radiometry. Here, we highlight key frontiers through which VWC has the potential to significantly increase our understanding of forest responses to water stress. To validate remote sensing observations of VWC at landscape scale and to better relate them to data assimilation model parameters, we introduce an ecosystem-scale analog of the pressure-volume curve, the non-linear relationship between average leaf or branch water potential and water content commonly used in plant hydraulics. The sources of variability in these ecosystem-scale pressure-volume curves and their relationship to forest response to water stress are discussed. We further show to what extent diel, seasonal, and decadal dynamics of VWC reflect variations in different processes relating the tree response to water stress. VWC can also be used for inferring belowground conditions-which are difficult to impossible to observe directly. Lastly, we discuss how a dedicated geostationary spaceborne observational system for VWC, when combined with existing datasets, can capture diel and seasonal water dynamics to advance the science and applications of global forest vulnerability to future droughts

    COVID-19: Implications for People with Chagas Disease.

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    As the global COVID-19 pandemic advances, it increasingly impacts those vulnerable populations who already bear a heavy burden of neglected tropical disease. Chagas disease (CD), a neglected parasitic infection, is of particular concern because of its potential to cause cardiac, gastrointestinal, and other complications which could increase susceptibility to COVID-19. The over one million people worldwide with chronic Chagas cardiomyopathy require special consideration because of COVID-19's potential impact on the heart, yet the pandemic also affects treatment provision to people with acute or chronic indeterminate CD. In this document, a follow-up to the WHF-IASC Roadmap on CD, we assess the implications of coinfection with SARS-CoV-2 and Trypanosoma cruzi, the etiological agent of CD. Based on the limited evidence available, we provide preliminary guidance for testing, treatment, and management of patients affected by both diseases, while highlighting emerging healthcare access challenges and future research needs

    Plant Antimicrobial Agents and Their Effects on Plant and Human Pathogens

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    To protect themselves, plants accumulate an armoury of antimicrobial secondary metabolites. Some metabolites represent constitutive chemical barriers to microbial attack (phytoanticipins) and others inducible antimicrobials (phytoalexins). They are extensively studied as promising plant and human disease-controlling agents. This review discusses the bioactivity of several phytoalexins and phytoanticipins defending plants against fungal and bacterial aggressors and those with antibacterial activities against pathogens affecting humans such as Pseudomonas aeruginosa and Staphylococcus aureus involved in respiratory infections of cystic fibrosis patients. The utility of plant products as “antibiotic potentiators” and “virulence attenuators” is also described as well as some biotechnological applications in phytoprotection

    Multi-Scale Motility Amplitude Associated with Suicidal Thoughts in Major Depression

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    Major depression occurs at high prevalence in the general population, often starts in juvenile years, recurs over a lifetime, and is strongly associated with disability and suicide. Searches for biological markers in depression may have been hindered by assuming that depression is a unitary and relatively homogeneous disorder, mainly of mood, rather than addressing particular, clinically crucial features or diagnostic subtypes. Many studies have implicated quantitative alterations of motility rhythms in depressed human subjects. Since a candidate feature of great public-health significance is the unusually high risk of suicidal behavior in depressive disorders, we studied correlations between a measure (vulnerability index [VI]) derived from multi-scale characteristics of daily-motility rhythms in depressed subjects (n = 36) monitored with noninvasive, wrist-worn, electronic actigraphs and their self-assessed level of suicidal thinking operationalized as a wish to die. Patient-subjects had a stable clinical diagnosis of bipolar-I, bipolar-II, or unipolar major depression (n = 12 of each type). VI was associated inversely with suicidal thinking (r =  –0.61 with all subjects and r =  –0.73 with bipolar disorder subjects; both p<0.0001) and distinguished patients with bipolar versus unipolar major depression with a sensitivity of 91.7% and a specificity of 79.2%. VI may be a useful biomarker of characteristic features of major depression, contribute to differentiating bipolar and unipolar depression, and help to detect risk of suicide. An objective biomarker of suicide-risk could be advantageous when patients are unwilling or unable to share suicidal thinking with clinicians
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