31 research outputs found
Optimisation of Storage Conditions for ‘UC 157’ Asparagus
Asparagus (Asparagus officinalis L. cv. UC 157) was harvested in 3 seasons over 3 months and held at various temperatures, controlled atmospheres and relative humidities, and in dips, to optimise storage conditions. The optimum storage temperature was 1.5°C, and precooling needed to be applied with the shortest possible delay after harvest. However, asparagus became more sensitive to chilling and lost 3 of 4 weeks of storage life and 2 of 5 days of shelf life at 20°C as the season progressed. Increasing the relative humidity from recommended 94 to 100% reduced weight loss but not quality, and wetting of spears during cooling did not reduce quality provided butt rots were controlled by dipping asparagus butts in saturated calcium hypochlorite. Continuous storage of spears with their butt in aqueous solutions reduced quality due to rotting, splitting and bending, but controlled atmospheres of 8-15% CO/18-19% O extended storage life at 1.5°C by 1 week and shelf life at 20°C by 2 days
Long-Term Application of Biosolids on Apricot Production
The use and disposal of biosolids, or wastewater treatment sludge, as a fertilizer and soil amendment is becoming increasingly widespread. We evaluated the multiyear use of biosolids in apricot (Prunus armeniaca L.) production, grown on productive agricultural soils. Class A biosolids were initially applied annually at rates of 0, 1.9, 5.8, and 11.7 Mg · ha-1 (dry basis) to a 2-year-old apricot orchard on the USDAARS research site on the eastern side of the San Joaquin Valley, CA. These application rates provided estimated rates of 0 (control), 57, 170, and 340 kg total N · ha-1 yr-1, respectively. Compared to the control treatment, the applications of biosolids significantly increased soil salinity (electrical conductivity from 1:1 soil–water extract) and total concentrations of nutrients [e.g., calcium (Ca), magnesium (Mg), sulfur (S), phosphorus (P), zinc (Zn), and copper (Cu)] after 7 years but did not increase the concentrations of selected metals [cadmium (Cd), chromium (Cr), cobalt (Co), nickel (Ni), and lead (Pb)] between 0- and 60-cm soil depths. Mean concentrations of total nitrogen (N) and carbon (C) in soils (0- to 15-cm depth) ranged from a low of 1.3 g kg-1 to a high of 5.2 g · kg-1 and from 14.1 g · kg-1 to 45.7 g · kg-1 for the control and high biosolids treated soils, respectively
Reversible Reprogramming of Circulating Memory T Follicular Helper Cell Function during Chronic HIV Infection.
Despite the overwhelming benefits of antiretroviral therapy (ART) in curtailing viral load in HIV-infected individuals, ART does not fully restore cellular and humoral immunity. HIV-infected individuals under ART show reduced responses to vaccination and infections and are unable to mount an effective antiviral immune response upon ART cessation. Many factors contribute to these defects, including persistent inflammation, especially in lymphoid tissues, where T follicular helper (Tfh) cells instruct and help B cells launch an effective humoral immune response. In this study we investigated the phenotype and function of circulating memory Tfh cells as a surrogate of Tfh cells in lymph nodes and found significant impairment of this cell population in chronically HIV-infected individuals, leading to reduced B cell responses. We further show that these aberrant memory Tfh cells exhibit an IL-2-responsive gene signature and are more polarized toward a Th1 phenotype. Treatment of functional memory Tfh cells with IL-2 was able to recapitulate the detrimental reprogramming. Importantly, this defect was reversible, as interfering with the IL-2 signaling pathway helped reverse the abnormal differentiation and improved Ab responses. Thus, reversible reprogramming of memory Tfh cells in HIV-infected individuals could be used to enhance Ab responses. Altered microenvironmental conditions in lymphoid tissues leading to altered Tfh cell differentiation could provide one explanation for the poor responsiveness of HIV-infected individuals to new Ags. This explanation has important implications for the development of therapeutic interventions to enhance HIV- and vaccine-mediated Ab responses in patients under ART