4-H Ewe and Lamb Project

June, 1956."University of Missouri College of Agriculture and the United States Department of Agriculture Cooperating"--Page [8].Title from caption

Global Vitamin C Status and Prevalence of Deficiency: A Cause for Concern?

Vitamin C is an essential nutrient that must be obtained through the diet in adequate amounts to prevent hypovitaminosis C, deficiency and its consequences—including the potentially fatal deficiency disease scurvy. Global vitamin C status and prevalence of deficiency has not previously been reported, despite vitamin C’s pleiotropic roles in both non-communicable and communicable disease. This review highlights the global literature on vitamin C status and the prevalence of hypovitaminosis C and deficiency. Related dietary intake is reported if assessed in the studies. Overall, the review illustrates the shortage of high quality epidemiological studies of vitamin C status in many countries, particularly low- and middle-income countries. The available evidence indicates that vitamin C hypovitaminosis and deficiency is common in low- and middle-income countries and not uncommon in high income settings. Further epidemiological studies are required to confirm these findings, to fully assess the extent of global vitamin C insufficiency, and to understand associations with a range of disease processes. Our findings suggest a need for interventions to prevent deficiency in a range of at risk groups and regions of the world

Factors Affecting Vitamin C Status and Prevalence of Deficiency: A Global Health Perspective

A recent review of global vitamin C status has indicated a high prevalence of deficiency, particularly in low- and middle-income countries, as well as in specific subgroups within high-income countries. Here, we provide a narrative review of potential factors influencing vitamin C status globally. The in vivo status of vitamin C is primarily affected by dietary intake and supplement use, with those who supplement having a higher mean status and a lower prevalence of deficiency. Dietary intake can be influenced by cultural aspects such as traditional cooking practices and staple foods, with many staple foods, such as grains, contributing negligible vitamin C to the diet. Environmental factors can also affect vitamin C intake and status; these include geographic region, season, and climate, as well as pollution, the latter partly due to enhanced oxidative stress. Demographic factors such as sex, age, and race are known to affect vitamin C status, as do socioeconomic factors such as deprivation, education and social class, and institutionalization. Various health aspects can affect vitamin C status; these include body weight, pregnancy and lactation, genetic variants, smoking, and disease states, including severe infections as well as various noncommunicable diseases such as cardiovascular disease and cancer. Some of these factors have changed over time; therefore, we also explore if vitamin C status has shown temporal changes. Overall, there are numerous factors that can affect vitamin C status to different extents in various regions of the world. Many of these factors are not taken into consideration during the setting of global dietary intake recommendations for vitamin

Light-driven reductive transformations by Shewanellaceae

The use of finite fossil reserves within the energy and petrochemicals industries has harmful environmental impacts due to the release of CO2 into the Earth’s atmosphere. Consequently, new technologies that harness renewable forms of energy, such as solar energy, are required for the sustainable production of valuable chemicals including fuels. Taking inspiration from plants and photosynthetic micro-organisms, artificial systems are being developed for solar-chemicals production by combining light-harvesting photosensitisers, such as molecular dyes and semiconducting nanoparticles, with electrocatalysts such as purified enzymes and whole-cell bacteria. In particular, whole-cell bacteria have emerged as effective electrocatalysts because they provide opportunities to develop self-regenerating systems that can facilitate multiple chemical transformations. The work presented in this thesis aimed to develop a cell-based approach to solar-chemicals production where a single micro-organism can act as a multi-faceted electrocatalyst without the requirement for costly and time-consuming enzyme purification. The approach was developed with the non-photosynthetic bacterium Shewanella oneidensis MR-1, a model micro-organism for extracellular electron transfer. The system uses methyl viologen as an electron shuttle to transfer photo-energised electrons from water-compatible photosensitisers to bacterial enzymes for H2-evolution and the reduction of fumarate, pyruvate and CO2 to succinate, lactate and formate, respectively. Preliminary experiments were also carried out to investigate the possibility of using new-generation carbon dot photosensitisers for light-driven H2-evolution in the absence of an exogenous electron shuttle. The work was performed in a step-wise manner involving an assessment of the determinants of each system using a range of analytical techniques and the findings form a basis for sustainable cell-based photocatalysis with other species of bacteria or genetically-modified Shewanella strains

Graduate Skills Assessment : Stage One Validity Study

The Graduate Skills Assessment (GSA) is a new test with complex aims and is in the first stages of development and application. Principally, the test aims to assess a set of valued and widely applicable generic skills that may be developed by the university experience and which are relevant to university achievement and graduate work. This publication reports on the validity of the first stage of the Graduate Skills Assessment test (GSA Stage One Validity Study), which covers the first two tests, Exit 2000 and Entry 2001. These tests involved the participation of 3663 students drawn from nine broad fields of study across 27 Australian universities. Details of these populations are given in the GSA Summary Reports (Hambur & Glickman, 2001, Hambur & Le, 2001). The study was commissioned by the Commonwealth Department of Education, Training and Youth Affairs

Vitamin C and COVID-19: should clinical trials be prioritised for low income settings and vitamin C-deficient populations?

Lette

The Emerging Role of Vitamin C in the Prevention and Treatment of COVID-19

Investigation into the role of vitamin C in the prevention and treatment of pneumonia and sepsis has been underway for many decades. This research has laid a strong foundation for translation of these findings into patients with severe coronavirus disease (COVID-19). Research has indicated that patients with pneumonia and sepsis have low vitamin C status and elevated oxidative stress. Administration of vitamin C to patients with pneumonia can decrease the severity and duration of the disease. Critically ill patients with sepsis require intravenous administration of gram amounts of the vitamin to normalize plasma levels, an intervention that some studies suggest reduces mortality. The vitamin has pleiotropic physiological functions, many of which are relevant to COVID-19. These include its antioxidant, anti-inflammatory, antithrombotic and immuno-modulatory functions. Preliminary observational studies indicate low vitamin C status in critically ill patients with COVID-19. There are currently a number of randomized controlled trials (RCTs) registered globally that are assessing intravenous vitamin C monotherapy in patients with COVID-19. Since hypovitaminosis C and deficiency are common in low–middle-income settings, and many of the risk factors for vitamin C deficiency overlap with COVID-19 risk factors, it is possible that trials carried out in populations with chronic hypovitaminosis C may show greater efficacy. This is particularly relevant for the global research effort since COVID-19 is disproportionately affecting low–middle-income countries and low-income groups globally. One small trial from China has finished early and the findings are currently under peer review. There was significantly decreased mortality in the more severely ill patients who received vitamin C intervention. The upcoming findings from the larger RCTs currently underway will provide more definitive evidence. Optimization of the intervention protocols in future trials, e.g., earlier and sustained administration, is warranted to potentially improve its efficacy. Due to the excellent safety profile, low cost, and potential for rapid upscaling of production, administration of vitamin C to patients with hypovitaminosis C and severe respiratory infections, e.g., COVID-19, appears warranted

Mid-Infrared Properties of Disk Averaged Observations of Earth with AIRS

We have investigated mid-infrared spectra of Earth obtained by the Atmospheric Infrared Sounder (AIRS) instrument on-board the AQUA spacecraft to explore the characteristics that may someday be observed in extrasolar terrestrial planets. We have used the AIRS infrared (R ~ 1200; 3.75-15.4 microns) spectra to construct directly-observed high-resolution spectra of the only known life bearing planet, Earth. The AIRS spectra are the first such spectra that span the seasons. We investigate the rotational and seasonal spectral variations that would arise due to varying cloud amount and viewing geometry and we explore what signatures may be observable in the mid-infrared by the next generation of telescopes capable of observing extrasolar terrestrial planets.Comment: 23 pages, 11 figure

Micronutrients and respiratory infections: the biological rationale and current state of clinical evaluation

A range of nutrients has been studied or proposed for use in preventing respiratory tract infections and reducing their severity. This article gives a narrative review of the existing literature, biological rationales and current state of clinical evaluation for micronutrient therapies. The importance of vitamin A, the B vitamins, vitamin C, vitamin D, eicosapentaenoic acid, vitamin E, selenium, zinc and a range of combination therapies are discussed, looking at their effects on reducing rates of infection, reducing severity of infection and improved recovery from infection. Further discussion regarding the level of evidence required for nutritional interventions is included