Impacto del COVID-19 en los medios de vida y en la seguridad alimentaria

French version available in IDRC Digital Library: L’impact de la COVID-19 sur les moyens de subsistance et la sécurité alimentaireEnglish version available in IDRC Digital Library: Impact of COVID-19 on livelihoods and food securit

Impact of COVID-19 on livelihoods and food security

French version available in IDRC Digital Library: L’impact de la COVID-19 sur les moyens de subsistance et la sécurité alimentaireSpanish version available in IDRC Digital Library: Impacto del COVID-19 en los medios de vida y en la seguridad alimentari

L’impact de la COVID-19 sur les moyens de subsistance et la sécurité alimentaire

English version available in IDRC Digital Library: Impact of COVID-19 on livelihoods and food securitySpanish version available in IDRC Digital Library: Impacto del COVID-19 en los medios de vida y en la seguridad alimentari

El impacto del Covid-19 en los medios de vida y en la seguridad alimentaria

Studies of livelihoods and food systems since the start of the global pandemic in 2020 have shown a consistent pattern: the primary risks to food and livelihood security are at the household level. Covid-19 is having a major impact on households’ production and access to quality, nutritious food, due to losses of income, combined with increasing food prices, and restrictions to movements of people, inputs and products. The studies included in this Research for Policy and Practice Report and supported by the Covid-19 Responses for Equity (CORE) Programme span several continents and are coordinated by leading research organisations with a detailed understanding of local food system dynamics and associated equity and livelihood issues in their regions: (1) the impact of the Covid-19 pandemic on livelihoods in sub-Saharan Africa; (2) supporting small and medium enterprises, food security, and evolving social protection mechanisms to deal with Covid-19 in Pakistan; and (3) impact of Covid-19 on family farming and food security in Latin America: evidence-based public policy responses.Les études sur les moyens de subsistance et les systèmes alimentaires depuis le début de la pandémie mondiale en 2020 ont montré un schéma constant : les principaux risques pour la sécurité alimentaire et les moyens de subsistance se situent au niveau des ménages. La COVID-19 a un impact important sur la production des ménages et sur l’accès à des aliments nutritifs et de qualité, en raison des pertes de revenus, combinées à l’augmentation des prix des denrées alimentaires, et des restrictions aux mouvements des personnes, des intrants et des produits. Les études comprises dans le Research for Policy and Practice Report et soutenues par le programme Covid-19 Responses for Equity (CORE) du CRDI s’étendent sur plusieurs continents et sont coordonnées par des organismes de recherche de premier plan ayant une compréhension détaillée de la dynamique des systèmes alimentaires locaux et des questions connexes d’équité et de moyens de subsistance dans leurs régions : (1) L’impact de la pandémie de COVID-19 sur les moyens de subsistance en Afrique subsaharienne ; (2) Soutien aux petites et moyennes entreprises, à la sécurité alimentaire et à l’évolution des mécanismes de protection sociale pour faire face à la COVID-19 au Pakistan ; (3) Impact de la COVID-19 sur l’agriculture familiale et la sécurité alimentaire en Amérique latine : interventions de politique publique fondées sur des données probantes.Los estudios de los medios de vida y los sistemas alimentarios desde el comienzo de la pandemia en 2020 han demostrado un patrón uniforme: los riesgos fundamentales para la seguridad alimentaria y los medios de vida se ubican en el ámbito doméstico. El Covid-19 está causando un enorme impacto en la producción y el acceso de los hogares a alimentos nutritivos de calidad debido a la pérdida de ingresos, junto con el aumento en los precios de los alimentos y las restricciones de movimiento de personas, insumos y productos. Los estudios incluidos en este Research for Policy and Practice Report y respaldados por el Programa Covid-19 Responses for Equity (CORE) del IDRC abarcan varios continentes. Además, se encuentran bajo la coordinación de organizaciones líderes en la investigación con un profundo conocimiento de la dinámica del sistema alimentario local y de temas relacionados con la igualdad y los medios de vida en sus regiones: (1) el impacto de la pandemia de Covid-19 en los medios de vida en la zona de África subsahariana; (2) el apoyo de las pequeñas y medianas empresas, la seguridad alimentaria y los cambiantes mecanismos de protección social para hacer frente al Covid-19 en Pakistán; (3) el impacto del Covid-19 en la agricultura familiar y la seguridad alimentaria en América Latina: respuestas fundamentadas de las políticas públicas.International Development Research Centr

The Transcription Factor Rfx3 Regulates β-Cell Differentiation, Function, and Glucokinase Expression

OBJECTIVE: Pancreatic islets of perinatal mice lacking the transcription factor Rfx3 exhibit a marked reduction in insulin-producing beta-cells. The objective of this work was to unravel the cellular and molecular mechanisms underlying this deficiency. RESEARCH DESIGN AND METHODS: Immunofluorescence studies and quantitative RT-PCR experiments were used to study the emergence of insulin-positive cells, the expression of transcription factors implicated in the differentiation of beta-cells from endocrine progenitors, and the expression of mature beta-cell markers during development in Rfx3(-/-) and pancreas-specific Rfx3-knockout mice. RNA interference experiments were performed to document the consequences of downregulating Rfx3 expression in Min6 beta-cells. Quantitative chromatin immunoprecipitation (ChIP), ChIP sequencing, and bandshift experiments were used to identify Rfx3 target genes. RESULTS: Reduced development of insulin-positive cells in Rfx3(-/-) mice was not due to deficiencies in endocrine progenitors or beta-lineage specification, but reflected the accumulation of insulin-positive beta-cell precursors and defective beta-cells exhibiting reduced insulin, Glut-2, and Gck expression. Similar incompletely differentiated beta-cells developed in pancreas-specific Rfx3-deficient embryos. Defective beta-cells lacking Glut-2 and Gck expression dominate in Rfx3-deficent adults, leading to glucose intolerance. Attenuated Glut-2 and glucokinase expression, and impaired glucose-stimulated insulin secretion, were also induced by RNA interference-mediated inhibition of Rfx3 expression in Min6 cells. Finally, Rfx3 was found to bind in Min6 cells and human islets to two well-known regulatory sequences, Pal-1 and Pal-2, in the neuroendocrine promoter of the glucokinase gene. CONCLUSIONS: Our results show that Rfx3 is required for the differentiation and function of mature beta-cells and regulates the beta-cell promoter of the glucokinase gene

Changes in Natural Killer Cell Activation and Function during Primary HIV-1 Infection

Background: Recent reports suggest that Natural Killer (NK) cells may modulate pathogenesis of primary HIV-1 infection. However, HIV dysregulates NK-cell responses. We dissected this bi-directional relationship to understand how HIV impacts NK-cell responses during primary HIV-1 infection. Methodology/Principal Findings: Paired samples from 41 high-risk, initially HIV-uninfected CAPRISA004 participants were analysed prior to HIV acquisition, and during viraemic primary HIV-1 infection. At the time of sampling post-infection five women were seronegative, 11 women were serodiscordant, and 25 women were seropositive by HIV-1 rapid immunoassay. Flow cytometry was used to measure NK and T-cell activation, NK-cell receptor expression, cytotoxic and cytokine-secretory functions, and trafficking marker expression (CCR7, α$_4$β$_7$). Non-parametric statistical tests were used. Both NK cells and T-cells were significantly activated following HIV acquisition (p = 0.03 and p<0.0001, respectively), but correlation between NK-cell and T-cell activation was uncoupled following infection (pre-infection r = 0.68;p<0.0001; post-infection, during primary infection r = 0.074;p = 0.09). Nonetheless, during primary infection NK-cell and T-cell activation correlated with HIV viral load (r = 0.32'p = 0.04 and r = 0.35;p = 0.02, respectively). The frequency of Killer Immunoglobulin-like Receptor-expressing (KIR$_{pos}$) NK cells increased following HIV acquisition (p = 0.006), and KIR$_{pos}$ NK cells were less activated than KIR$_{neg}$ NK cells amongst individuals sampled while seronegative or serodiscordant (p = 0.001;p<0.0001 respectively). During HIV-1 infection, cytotoxic NK cell responses evaluated after IL-2 stimulation alone, or after co-culture with 721 cells, were impaired (p = 0.006 and p = 0.002, respectively). However, NK-cell IFN-y secretory function was not significantly altered. The frequency of CCR7+ NK cells was elevated during primary infection, particularly at early time-points (p<0.0001). Conclusions/Significance: Analyses of immune cells before and after HIV infection revealed an increase in both NK-cell activation and KIR expression, but reduced cytotoxicity during acute infection. The increase in frequency of NK cells able to traffic to lymph nodes following HIV infection suggests that these cells may play a role in events in secondary lymphoid tissue

Genome-Wide Comparative Gene Family Classification

Correct classification of genes into gene families is important for understanding gene function and evolution. Although gene families of many species have been resolved both computationally and experimentally with high accuracy, gene family classification in most newly sequenced genomes has not been done with the same high standard. This project has been designed to develop a strategy to effectively and accurately classify gene families across genomes. We first examine and compare the performance of computer programs developed for automated gene family classification. We demonstrate that some programs, including the hierarchical average-linkage clustering algorithm MC-UPGMA and the popular Markov clustering algorithm TRIBE-MCL, can reconstruct manual curation of gene families accurately. However, their performance is highly sensitive to parameter setting, i.e. different gene families require different program parameters for correct resolution. To circumvent the problem of parameterization, we have developed a comparative strategy for gene family classification. This strategy takes advantage of existing curated gene families of reference species to find suitable parameters for classifying genes in related genomes. To demonstrate the effectiveness of this novel strategy, we use TRIBE-MCL to classify chemosensory and ABC transporter gene families in C. elegans and its four sister species. We conclude that fully automated programs can establish biologically accurate gene families if parameterized accordingly. Comparative gene family classification finds optimal parameters automatically, thus allowing rapid insights into gene families of newly sequenced species

Promises of stem cell therapy for retinal degenerative diseases

With the development of stem cell technology, stem cell-based therapy for retinal degeneration has been proposed to restore the visual function. Many animal studies and some clinical trials have shown encouraging results of stem cell-based therapy in retinal degenerative diseases. While stem cell-based therapy is a promising strategy to replace damaged retinal cells and ultimately cure retinal degeneration, there are several important challenges which need to be overcome before stem cell technology can be applied widely in clinical settings. In this review, different types of donor cell origins used in retinal treatments, potential target cell types for therapy, methods of stem cell delivery to the eye, assessments of potential risks in stem cell therapy, as well as future developments of retinal stem cells therapy, will be discussed

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability