177 research outputs found

    Aging of polymers of intrinsic microporosity studied by sorption and permeation

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    Polymers of intrinsic microporosity (PIMs)1 seem to be effective materials for gas and vapor separations.2 However, gas separation efficiency of PIMs can be strongly influenced by the material aging process connected with the changes of PIMs inner structure.3 With respect to potential industrial applications, the investigation of such changes and their effect on gas and vapor transport is necessary. In this work, we present a detailed study of i) CO2 sorption in PIM-1 via momentary measurements during four years and ii) methanol permeation in PIM-11 and EA-TB-PIM2 via continuous and momentary experiments. Sorption experiments were performed gravimetrically using a self-developed apparatus equipped with McBain’s spiral balances. In this case, PIM-1 membranes were pre-treated (soaking in ethanol with consequent drying at different temperatures) in order to study the influence of temperature on PIM-1 aging. Methanol permeation experiments were performed using a differential flow permeameter with H2 and He as carrier gases. Permeation experiment were performed with PIM-1 and PIM-EA-TB methanol treated membranes. CO2 sorption measurements revealed that, assuming the validity of the solution-diffusion model, the decrease of permeability during aging can be attributed directly to the decrease of diffusivity, whereas solubility is time independent in the studied period of four years. Although higher preparation temperature led to the initial drop of diffusivity, this process stabilized separation performance of PIMs over time (Figure 1). MeOH permeation experiments confirmed previous findings from CO2 tests, that the permeability decrease during the aging is a diffusivity controlled process. Moreover, it was found that the momentary permeation data can be mathematically transferred to continuous data, which are more relevant for applications but more difficult to measure. The nature of aging process was studied by infrared spectroscopy. We have found that aging of PIMs does not influence their chemical structure and; therefore, they undergo only the so called physical-aging. Please click Additional Files below to see the full abstract

    Data for decision-making for sustainable food systems transformation in the Eastern Cape of South Africa: what is needed?

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    Transforming global food systems to promote food and nutritional security can help alleviate both poverty and ill-health, and support sustainable development. Such transformations need to be tailored and sensitive to the vulnerabilities and needs of marginalized communities yet are hindered by knowledge gaps. In particular, the food and nutrition security needs of the most vulnerable are often poorly understood, as are the policy frameworks and resource requirements associated with meeting their needs. To aid the development of frameworks to address these gaps, we review the current state of indicators relating to food systems for the improvement of food and nutrition security at the national and sub-national levels in South Africa. We identify gaps in the decision-making data in South Africa, including absence of food and nutrition security indicators. Integration of the South African Multidimensional Poverty Index and Food System Dashboard indicators could help address this, especially if applied at a sub-national level. Participatory food system mapping could also link data collection with system-level interactions and feedback loops to inform sub-national stakeholders in achieving food and nutritional security

    Food mapping approaches for understanding food system transformations in rapid-growth city regions in the Global South

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    The world’s food systems are rapidly changing due to socioeconomic, environmental, and demographic changes, globalization, and urbanization. Urban regions connect urban food consumption with rural food production and are associated with rapid dietary transitions in developing counties. Despite urbanization being a key driver of city-regional and global food system transformations, city-regional food systems (particularly in developing countries) are under-researched. Although the importance of dynamic urban and peri-urban food systems has led to new frameworks and approaches for mapping food flows within urban regions, our study highlights both opportunities and limitations to food mapping in high-growth city regions in the Global South. We review existing approaches to food mapping using three contrasting city-regional food systems as case studies, namely, Bahir Dar (Ethiopia), Hanoi (Vietnam), and Cali (Colombia), and identify priorities for future progress. These include temporal dimensions of food access; nutritional outcomes of food flows; economic, cultural, and ethnic factors affecting consumer behavior; and how consumption of healthier foods could be enabled by decision-making throughout food supply chains. In addition, the roles of food loss and waste could also be more specifically considered. We conclude that providing a more comprehensive and nutrition sensitive understanding of city-regional food systems can guide evidence-based interventions and activities to enable transitions to healthier, equitable, and more sustainable urban food systems

    Climate-related migration and the climate-security-migration nexus in the Central American Dry Corridor

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    The Central American Dry Corridor (CADC) is among the most climate-vulnerable regions worldwide. Climate change, commonly referred to as a “threat multiplier” of pre-existing socioeconomic issues, already undermines rural livelihoods by reducing agricultural yields and income opportunities. This paper provides a review of climate-related migration in the CADC region while identifying the specific pathways by which climate change manifests itself as a threat multiplier to migration. Different forms of human mobility (seasonal/temporal/permanent and internal/international migration) are increasingly attempted as adaptation strategies by affected households to diversify incomes and offset climate impacts. Preferred intra-regional migrant destinations tend to be less climate-vulnerable and also less violent. Notably, climate change is not isolated from socioeconomic and political migration drivers. Erosion of rural livelihoods reduces the costs of engaging in illicit coping strategies (e.g., illegal crop production) and simultaneously favours rapid urbanisation, which is linked to (forced) gang recruitment, primarily affecting the youth. These processes contribute to extraordinarily high violence levels, which are a major push factor for migration on their own, ultimately challenging state authority. Moreover, as outmigration from the region is projected to increase, the observed securitisation of borders, particularly along the USA-Mexico border and the Mexico-Guatemala border, while unfit to limit migration attempts, make migration more desperate and dangerous, allowing organised crime to step in and exploit migration as an economic undertaking. Thus, for the CADC, the depoliticised and simplistic narrative of migration serving as adaptation must be questioned. Policy coherence and state capacity for addressing climate-security-migration nexus challenges are critical needs

    Genome-wide association studies of grain yield and quality traits under optimum and low-nitrogen stress in tropical maize (Zea mays L.)

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    Soils in sub-Saharan Africa are nitrogen deficient due to low fertilizer use and inadequate soil fertility management practices. This has resulted in a significant yield gap for the major staple crop maize, which is undermining nutritional security and livelihood sustainability across the region. Dissecting the genetic basis of grain protein, starch and oil content under nitrogen-starved soils can increase our understanding of the governing genetic systems and improve the efficacy of future breeding schemes. An association mapping panel of 410 inbred lines and four bi-parental populations were evaluated in field trials in Kenya and South Africa under optimum and low nitrogen conditions and genotyped with 259,798 SNP markers. Genetic correlations demonstrated that these populations may be utilized to select higher performing lines under low nitrogen stress. Furthermore, genotypic, environmental and GxE variations in nitrogen-starved soils were found to be significant for oil content. Broad sense heritabilities ranged from moderate (0.18) to high (0.86). Under low nitrogen stress, GWAS identified 42 SNPs linked to grain quality traits. These significant SNPs were associated with 51 putative candidate genes. Linkage mapping identified multiple QTLs for the grain quality traits. Under low nitrogen conditions, average prediction accuracies across the studied genotypes were higher for oil content (0.78) and lower for grain yield (0.08). Our findings indicate that grain quality traits are polygenic and that using genomic selection in maize breeding can improve genetic gain. Furthermore, the identified genomic regions and SNP markers can be utilized for selection to improve maize grain quality traits

    Implementation of the Climate-Smart village approach

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    Climate change is affecting global population and agriculture. Through climate-smart agriculture practices in climate-smart villages, it promotes adaptation, builds resilience to climatic stresses and ensures food security. This research thesis aims to support the planning and decision-making processes to promote and scale out climate-smart agriculture among smallholder farmers in Colombia. The research thesis analyzed the data from a Gender-sensitive Smart Household Monitoring instrument to assess climate-smart agriculture performance and outcomes in Cauca climate-smart village. Data was analyzed through different indicators tracked at household level disaggregated by gender and examines the Climate-smart agriculture adoption and dis-adoption trends and related factors (financial, technical/operational and social) that enable its implementation. The study found that climate-smart practices related to water and ensure food security during the year are the most preferred. This study highlights the importance of climate informatics services to promote a higher adaptation to climate change. Furthermore, this study give a recommendation to improve the surveys to future monitoring instruments to address correctly smallholder farmers and practitioners to scale out climate-smart agriculture

    Community-level impacts of climate-smart agriculture interventions on food security and dietary diversity in climate-smart villages in Myanmar

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    Based on survey responses, the study examined how pathways of Climate Smart Agriculture (CSA) practices, tailored to different contexts of Myanmar’s four agroecological regions, contributed to observed changes in health and livelihoods. Livelihood resilience may rely on diversification, including climate smart fruit trees; livestock; and off‐farm incomes, as risk aversion strategies for the rural poor. Analysis of knowledge, attitudes and practices (KAP) findings indicate that current nutrition education interventions in Myanmar CSVs are inadequate, and will need further improvement for better health and nutrition outcomes.Consultative Group of International Agricultural Research Centers—Climate Change, Agriculture; Food Security Program (CGIAR‐CCAFS

    Ambulatory management of primary spontaneous pneumothorax: an open-label, randomised controlled trial

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    BACKGROUND: Primary spontaneous pneumothorax occurs in otherwise healthy young patients. Optimal management is not defined and often results in prolonged hospitalisation. Data on efficacy of ambulatory options are poor. We aimed to describe the duration of hospitalisation and safety of ambulatory management compared with standard care. METHODS: In this open-label, randomised controlled trial, adults (aged 16-55 years) with symptomatic primary spontaneous pneumothorax were recruited from 24 UK hospitals during a period of 3 years. Patients were randomly assigned (1:1) to treatment with either an ambulatory device or standard guideline-based management (aspiration, standard chest tube insertion, or both). The primary outcome was total length of hospital stay including re-admission up to 30 days after randomisation. Patients with available data were included in the primary analysis and all assigned patients were included in the safety analysis. The trial was prospectively registered with the International Standard Randomised Clinical Trials Number, ISRCTN79151659. FINDINGS: Of 776 patients screened between July, 2015, and March, 2019, 236 (30%) were randomly assigned to ambulatory care (n=117) and standard care (n=119). At day 30, the median hospitalisation was significantly shorter in the 114 patients with available data who received ambulatory treatment (0 days [IQR 0-3]) than in the 113 with available data who received standard care (4 days [IQR 0-8]; p<0·0001; median difference 2 days [95% CI 1-3]). 110 (47%) of 236 patients had adverse events, including 64 (55%) of 117 patients in the ambulatory care arm and 46 (39%) of 119 in the standard care arm. All 14 serious adverse events occurred in patients who received ambulatory care, eight (57%) of which were related to the intervention, including an enlarging pneumothorax, asymptomatic pulmonary oedema, and the device malfunctioning, leaking, or dislodging. INTERPRETATION: Ambulatory management of primary spontaneous pneumothorax significantly reduced the duration of hospitalisation including re-admissions in the first 30 days, but at the expense of increased adverse events. This data suggests that primary spontaneous pneumothorax can be managed for outpatients, using ambulatory devices in those who require intervention. FUNDING: UK National Institute for Health Research

    BET Bromodomain Inhibition as a Therapeutic Strategy to Target c-Myc

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    SummaryMYC contributes to the pathogenesis of a majority of human cancers, yet strategies to modulate the function of the c-Myc oncoprotein do not exist. Toward this objective, we have targeted MYC transcription by interfering with chromatin-dependent signal transduction to RNA polymerase, specifically by inhibiting the acetyl-lysine recognition domains (bromodomains) of putative coactivator proteins implicated in transcriptional initiation and elongation. Using a selective small-molecule bromodomain inhibitor, JQ1, we identify BET bromodomain proteins as regulatory factors for c-Myc. BET inhibition by JQ1 downregulates MYC transcription, followed by genome-wide downregulation of Myc-dependent target genes. In experimental models of multiple myeloma, a Myc-dependent hematologic malignancy, JQ1 produces a potent antiproliferative effect associated with cell-cycle arrest and cellular senescence. Efficacy of JQ1 in three murine models of multiple myeloma establishes the therapeutic rationale for BET bromodomain inhibition in this disease and other malignancies characterized by pathologic activation of c-Myc.PaperFlic
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