Natural killer cells as an initial defense against pathogens.

Natural killer (NK) cells serve as a crucial first line of defense against tumors and a diverse range of pathogens. Recognition of infection by NK cells is accomplished by the activation of receptors on the NK cell surface, which initiate NK cell effector functions. Many of the receptors and ligands involved in NK cell antimicrobial activity have been identified, and we are beginning to appreciate how they function during infection. In addition, NK cells are activated by cytokines (e.g. interleukin 12 and type I interferons), which are products of activated macrophages and dendritic cells. In response to these activating stimuli, NK cells secrete cytokines and chemokines and lyse target cells. Recent studies have focused on the mechanisms by which NK cells recognize and respond to viruses, parasites and bacteria, and on the unique role of NK cells in innate immunity to infection

An Integrated Drought Index (IDI) Incorporating Physical and Social Aspects

The purpose of this research was to determine significant bio-physical (physical and environmental) and social variables that can be integrated into a drought index to predict areas susceptible to drought. Severe drought events are capable of causing millions of dollars in damage. The 1988 drought caused the United States approximately $40 billion in damage. Drought forecasting, modeling, and detection have, therefore, become imperative to understand the social, economic and environmental impacts of droughts, and also to explore how these impacts play a role in the occurrence of a drought. A number of drought indices widely used in the U.S. rely on physical and meteorological factors to describe and predict drought conditions. Though social factors, especially, urbanization seem to contribute to the occurrence and severity of a drought they are rarely used in drought prediction and monitoring. In this research, the following research questions were answered to aid with drought prediction by incorporating physical and social variables: (1) Which physical parameters are significant in drought forecasting? (2) Can a social variable be used as a predictor for drought? If so, what impact does it have on drought severity

'Unlicensed' natural killer cells dominate the response to cytomegalovirus infection.

Natural killer (NK) cells expressing inhibitory receptors that bind to self major histocompatibility complex (MHC) class I are 'licensed', or rendered functionally more responsive to stimulation, whereas 'unlicensed' NK cells lacking receptors for self MHC class I are hyporesponsive. Here we show that contrary to the licensing hypothesis, unlicensed NK cells were the main mediators of NK cell-mediated control of mouse cytomegalovirus infection in vivo. Depletion of unlicensed NK cells impaired control of viral titers, but depletion of licensed NK cells did not. The transfer of unlicensed NK cells was more protective than was the transfer of licensed NK cells. Signaling by the tyrosine phosphatase SHP-1 limited the proliferation of licensed NK cells but not that of unlicensed NK cells during infection. Thus, unlicensed NK cells are critical for protection against viral infection

Increasing Low-income Residents’ Access to Fresh Produce through a Local Mobile Pantry

Seeds that Feed (STF) is a mobile food pantry located in Fayetteville, Arkansas. STF receives produce from local farmers to distribute to residents in low-income housing sites throughout Northwest Arkansas. According to Feeding America, food insecurity affected 14.3% Washington County, Arkansas’ population in 2016. The purpose of this study was to determine if STF’s model is an effective way to increase individuals’ access to fresh fruits and vegetables and increase their potential to meet the United States Department of Agriculture’s Food Patterns (USDA-FP) for to fruit and vegetable consumption. Twenty-three participants from three sites completed the study. A survey was used to collect basic demographics and dietary patterns. Record was taken of what foods each participant received on the survey day including plans for preparation and to whom it would be served. All anonymous responses were statistically analyzed using Excel. The results indicated that the likelihood to meet the USDA-FP for overall fruit and vegetable intake increased significantly after receiving approximately one cup of fruit and 1 ½ cups of vegetables from STF. A positive correlation was found between the number of times participants received produce from STF and participant’s total fruit intake and total intake of the “red/orange” and “other” vegetable subgroups. Therefore, STF’s model appears to be an effective method to increase access to fresh produce. Future research could utilize STF’s model to assess the potential for other supplemental nutrition programs to help low-income residents meet the USDA-FP and reduce food insecurity via mobile pantry

INTERACTIONS OF HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS WITH TOBACCO TREATED STREPTOCOCCUS MUTANS

poster abstractStreptococcus mutans and tobacco are risk factors for atherosclerosis. The objective of this study was to determine the ability that a spaP isogenic defective mutant of S. mutans UA 159 has on binding to Human Umbilical Vein Endothelial Cells (HUVEC) when treated with tobacco products and what second messenger signals are involved. The study was conducted to examine the effects that various concentrations of cigarette smoke condensate (CSC)- and nicotine have on S. mutans cell cytotoxicity and expression of cytokines and growth factors from HUVECs. S. mutans was grown at 37°C and planktonic and biofilm cells were separated from the culture supernatant. The supernatant was discarded the cells were washed, sterilized with formaldehyde and washed again to remove the formaldehyde. The concentrations of the various S. mutans cells were standardized to the same concentration (absorbance of 0.50 ± 0.01) by spectroscopy at a wavelength of 600 nm. The lowest non-toxic levels of the sterilized bacterial cells were used to treat HUVECs for 72 hours and cytotoxicity was determined by lactate dehydrogenase (LDH) assays. The cytokine/growth factor expression will be determined by antibody protein arrays. The results are expected to indicate an increase in cytotoxicity with increasing cell concentrations, along with increased pro-inflammatory cytokine/growth factors expression by the HUVECs treated with tobacco treated S. mutans compared to S. mutans that was not treated with tobacco products. Second messenger signaling pathways will be analyzed with ERK and JNK inhibitors and specific antibodies to ERK and phospho-JNK. Immunoblots using HUVECs will be done to determine expression of ERK/JNK. A better understanding of the detrimental effects that tobacco has on the underlining causes of atherosclerosis can advance the quest of controlling the disease

Homeostatic Control of Memory Cell Progenitors in the Natural Killer Cell Lineage

SummaryRecent studies have demonstrated that natural killer (NK) cells are able to undergo clonal expansion and contraction and to generate self-renewing memory cells after infection with mouse cytomegalovirus (MCMV). It is unclear whether all or only certain subsets preferentially contribute to the generation of memory NK cells. Here, we show that memory NK cells predominantly arise from killer cell lectin-like receptor G1 (KLRG1)-negative NK cell progenitors, whereas KLRG1-positive NK cells have limited capacity for expansion during infection with MCMV. Unexpectedly, the frequency of KLRG1-positive NK cells is significantly affected by the presence of T cells in the host and potentially by the host microbiota. Our findings demonstrate that excessive availability of interleukin (IL)-15 may erode the pool of memory progenitors, resulting in the decreased efficiency of memory generation in the NK cell lineage

Concept for a power system controller for large space electrical power systems

The development of technology for a fail-operatonal power system controller (PSC) utilizing microprocessor technology for managing the distribution and power processor subsystems of a large multi-kW space electrical power system is discussed. The specific functions which must be performed by the PSC, the best microprocessor available to do the job, and the feasibility, cost savings, and applications of a PSC were determined. A limited function breadboard version of a PSC was developed to demonstrate the concept and potential cost savings

Increasing Profitability of Small Scale Orchard Producers through Optimizing Replacement Rate: The Case Study of Ghana

This study sets out to empirically estimate the optimum annual replacement rate and age of cocoa trees in order to maximize the net present value of four common cocoa production systems. The study examines the costs and returns of four common cocoa production systems in Ghana associated with changes in cocoa prices, fertilizer prices, inflation rates, and labor prices. While this study focuses on cocoa, the methodology is applicable to any perennial crop. This study uses empirical yield curves and cost of production data from Ghana to determine when and what percentage of a cocoa orchard should be replaced annually to maximize net present value of revenues over time. Successive versions of the model are solved to determine how input and output price changes affect optimal replacement rates and replacement ages. Producers in both high- and low-income countries are reluctant to cull still productive assets, such as trees that are diminishing in yield over time. The Excel based model developed in this study could provide extension personnel with a simple yet powerful tool to illustrate to producers the benefits of systematic tree replacement. This study provides strong evidence of the benefits of replacing trees at the optimal time and rate.Cocoa, Replacement Rate, Net Present Value (NPV), Production Economics, Q01, Q15, Q32,