Organic farming provides reliable environmental benefits but increases variability in crop yields: a global meta-analysis

To promote food security and sustainability, ecologically intensive farming systems should reliably produce adequate yields of high-quality food, enhance the environment, be profitable, and promote social wellbeing. Yet, while many studies address the mean effects of ecologically intensive farming systems on sustainability metrics, few have considered variability. This represents a knowledge gap because producers depend on reliable provisioning of yields, profits, and environmental services to enhance the sustainability of their production systems over time. Further, stable crop yields are necessary to ensure reliable access to nutritious foods. Here we address this by conducting a global meta-analysis to assess the average magnitude and variability of seven sustainability metrics in organic compared to conventional systems. Specifically, we explored the effects of these systems on (i) biotic abundance, (ii) biotic richness, (iii) soil organic carbon, (iv) soil carbon stocks, (v) crop yield, (vi) total production costs, and (vii) profitability. Organic farms promoted biotic abundance, biotic richness, soil carbon, and profitability, but conventional farms produced higher yields. Compared to conventional farms, organic farms had lower variability in abundance and richness but greater yield variability. Organic farms thus provided a “win-win” (high means and low variability) for environmental sustainability, while conventional farms provided a “win-win” for production by promoting high crop yields with low variability. Despite lower yields, and greater yield variability, organic systems had similar costs to conventional systems and were more profitable due to organic premiums. Our results suggest certification guidelines for organic farms successfully promote reliable environmental benefits, but greater reliance on ecological processes may reduce predictability of crop production

Identifying Farming Strategies Associated With Achieving Global Agricultural Sustainability

Sustainable agroecosystems provide adequate food while supporting environmental and human wellbeing and are a key part of the United Nations Sustainable Development Goals (SDGs). Some strategies to promote sustainability include reducing inputs, substituting conventional crops with genetically modified (GM) alternatives, and using organic production. Here, we leveraged global databases covering 121 countries to determine which farming strategies—the amount of inputs per area (fertilizers, pesticides, and irrigation), GM crops, and percent agriculture in organic production—are most correlated with 12 sustainability metrics recognized by the United Nations Food and Agriculture Organization. Using quantile regression, we found that countries with higher Human Development Indices (HDI) (including education, income, and lifespan), higher-income equality, lower food insecurity, and higher cereal yields had the most organic production and inputs. However, input-intensive strategies were associated with greater agricultural greenhouse gas emissions. In contrast, countries with more GM crops were last on track to meeting the SDG of reduced inequalities. Using a longitudinal analysis spanning 2004–2018, we found that countries were generally decreasing inputs and increasing their share of agriculture in organic production. Also, in disentangling correlation vs. causation, we hypothesize that a country's development is more likely to drive changes in agricultural strategies than vice versa. Altogether, our correlative analyses suggest that countries with greater progress toward the SDGs of no poverty, zero hunger, good health and wellbeing, quality education, decent work, economic growth, and reduced inequalities had the highest production of organic agriculture and, to a lesser extent, intensive use of inputs

Organic Farming Provides Reliable Environmental Benefits but Increases Variability in Crop Yields: A Global Meta-Analysis

To promote food security and sustainability, ecologically intensive farming systems should reliably produce adequate yields of high-quality food, enhance the environment, be profitable, and promote social wellbeing. Yet, while many studies address the mean effects of ecologically intensive farming systems on sustainability metrics, few have considered variability. This represents a knowledge gap because producers depend on reliable provisioning of yields, profits, and environmental services to enhance the sustainability of their production systems over time. Further, stable crop yields are necessary to ensure reliable access to nutritious foods. Here we address this by conducting a global meta-analysis to assess the average magnitude and variability of seven sustainability metrics in organic compared to conventional systems. Specifically, we explored the effects of these systems on (i) biotic abundance, (ii) biotic richness, (iii) soil organic carbon, (iv) soil carbon stocks, (v) crop yield, (vi) total production costs, and (vii) profitability. Organic farms promoted biotic abundance, biotic richness, soil carbon, and profitability, but conventional farms produced higher yields. Compared to conventional farms, organic farms had lower variability in abundance and richness but greater yield variability. Organic farms thus provided a “win-win” (high means and low variability) for environmental sustainability, while conventional farms provided a “win-win” for production by promoting high crop yields with low variability. Despite lower yields, and greater yield variability, organic systems had similar costs to conventional systems and were more profitable due to organic premiums. Our results suggest certification guidelines for organic farms successfully promote reliable environmental benefits, but greater reliance on ecological processes may reduce predictability of crop production

Aspects to T-cell phenotype during infection with HIV, CMV and Hepatitis C virus

This work concerns itself with understanding the organisation of cellular immune responses to three major human pathogens - HIV, CMV and Hepatitis C (HCV). Each was studied to form three projects, each undertaken with a different approach - arrived at independently - and largely owing their origins to opportunity and circumstance as much as design. Each project led to exploration of a particular aspect of T-cell phenotype (that is the expression of particular molecular markers on T-cells) and its’ broader biological significance. I found that T-cell phenotype was strongly linked to the magnitude of T-cell responses (CMV) and the ability of T-cells to control infection (HIV). Finally I explored the significance of expression of a molecule known as CD161 on the surface of HCV specific CD8+ T-cells, indicating a phenotype of T-cell that may not follow the ‘normal rules’ applicable to T-cells in general

Aspects to T-cell phenotype during infection with HIV, CMV and Hepatitis C virus

This work concerns itself with understanding the organisation of cellular immune responses to three major human pathogens - HIV, CMV and Hepatitis C (HCV). Each was studied to form three projects, each undertaken with a different approach - arrived at independently - and largely owing their origins to opportunity and circumstance as much as design. Each project led to exploration of a particular aspect of T-cell phenotype (that is the expression of particular molecular markers on T-cells) and its’ broader biological significance. I found that T-cell phenotype was strongly linked to the magnitude of T-cell responses (CMV) and the ability of T-cells to control infection (HIV). Finally I explored the significance of expression of a molecule known as CD161 on the surface of HCV specific CD8+ T-cells, indicating a phenotype of T-cell that may not follow the ‘normal rules’ applicable to T-cells in general.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Burkholderia pseudomallei infection, or melioidosis, and nephrotic syndrome.

In summary, we present a case of melioidosis that amply demonstrates its ability to cause severe illness, often in patients with pre-existing renal problems, and its propensity to cause further severe derangement in renal function. Usually this is in the form of oliguric acute renal failure presumably caused, in the main, by acute tubular necrosis. However, the case we present indicates that, in common with certain other specific infectious diseases, nephrotic syndrome may be a significant (albeit rare) complication of infection with B. pseudomallei. We postulate that immune-complex mediated renal injury may occur in melioidosis

Human Immunodeficiency Virus Type 1 (HIV-1)-Specific CD8+ TEMRA Cells in Early Infection Are Linked to Control of HIV-1 Viremia and Predict the Subsequent Viral Load Set Point▿

CD8+ T cells are believed to play an important role in the control of human immunodeficiency virus type 1 (HIV-1) infection. However, despite intensive efforts, it has not been possible to consistently link the overall magnitude of the CD8+ T-cell response with control of HIV-1. Here, we have investigated the association of different CD8+ memory T-cell subsets responding to HIV-1 in early infection with future control of HIV-1 viremia. Our results demonstrate that both a larger proportion and an absolute number of HIV-1-specific CD8+ CCR7− CD45RA+ effector memory T cells (TEMRA cells) were associated with a lower future viral load set point. In contrast, a larger absolute number of HIV-1-specific CD8+ CCR7− CD45RA− effector memory T cells (TEM) was not related to the viral load set point. Overall, the findings suggest that CD8+ TEMRA cells have superior antiviral activity and indicate that both qualitative and quantitative aspects of the CD8+ T-cell response need to be considered when defining the characteristics of protective immunity to HIV-1

Large scale analysis of pediatric antiviral CD8+ T cell populations reveals sustained, functional and mature responses

Abstract Background Cellular immunity plays a crucial role in cytomegalovirus (CMV) infection and substantial populations of CMV-specific T cells accumulate throughout life. However, although CMV infection occurs during childhood, relatively little is know about the typical quantity and quality of T cell responses in pediatric populations. Methods One thousand and thirty-six people (Male/Female = 594/442, Age: 0–19 yr.; 959 subjects, 20–29 yr.; 77 subjects) were examined for HLA typing. All of 1036 subjects were tested for HLA-A2 antigen. Of 1036 subjects, 887 were also tested for HLA-A23, 24 antigens. In addition, 50 elderly people (Male/Female = 11/39, Age: 60–92 yr.) were also tested for HLA-A2 antigen. We analyzed the CD8+ T cell responses to CMV, comparing these to responses in children and young. The frequencies, phenotype and function CD8+ T cells for two imunodominant epitopes from pp65 were measured. Results We observed consistently high frequency and phenotypically "mature" (CD27 low, CD28 low, CD45RA+) CMV-specific CD8+ T cell responses in children, including those studied in the first year of life. These CD8+ T cells retained functionality across all age groups, and showed evidence of memory "inflation" only in later adult life. Conclusion CMV consistently elicits a very strong CD8+ T cell response in infants and large pools of CMV specific CD8+ T cells are maintained throughout childhood. The presence of CMV may considerably mould the CD8+ T cell compartment over time, but the relative frequencies of CMV-specific cells do not show the evidence of a population-level increase during childhood and adulthood. This contrast with the marked expansion ("inflation") of such CD8+ T cells in older adults. This study indicates that large scale analysis of peptide specific T cell responses in infants is readily possible. The robust nature of the responses observed suggests vaccine strategies aimed at priming and boosting CD8+ T cells against major pathogens (including HIV, malaria and CMV itself) could be successful in this age-group.</p