Role of ABA in Arabidopsis Salt, Drought, and Desiccation Tolerance

The ability of plants to respond to environmental stimuli is essential to plant survival. Abscisic acid (ABA) is a phytohormone with roles at various stages of plant development. ABA also plays a major role in mediating physiological responses to environmental stresses such as salt, osmotic, and cold stress. Plant responses to environmental stress have been widely studied in the model plant Arabidopsis thaliana and ABA signaling mechanisms elucidated. In general, the adaptive responses of plants to various stress conditions can be either ABA-dependent or ABA-independent. Here we focus on the role of ABA in stress signaling and abiotic stress tolerance. We describe the intrinsic mechanisms that confer stress tolerance via ABA, as well as how ABA-regulated gene products play a role in salt and drought tolerance at different stages of the life cycle. In addition, the contribution of ABA to regulation of stomatal aperture and therefore desiccation tolerance will be discussed. Understanding ABA signaling mechanisms in abiotic stress provides avenues for improving plant performance

Ferruleless coupled-cavity traveling-wave tube cold-test characteristics simulated with micro-SOS

The three-dimensional, electromagnetic circuit analysis code, Micro-SOS, can be used to reduce expensive and time consuming experimental 'cold-testing' of traveling-wave tube (TWT) circuits. The frequency-phase dispersion and beam interaction impedance characteristics of a ferruleless coupled-cavity traveling-wave tube slow-wave circuit were simulated using the code. Computer results agree closely with experimental data. Variations in the cavity geometry dimensions of period length and gap-to-period ratio were modeled. These variations can be used in velocity taper designs to reduce the radiofrequency (RF) phase velocity in synchronism with the decelerating electron beam. Such circuit designs can result in enhanced TWT power and efficiency

Price Variation in Markets with Homogeneous Goods: The Case of Medigap

Nearly 30 percent of Americans age 65 and older supplement their Medicare health insurance through the Medigap private insurance market. We show that prices for Medigap policies vary widely, despite the fact that all plans are standardized, and even after controlling for firm heterogeneity. Economic theory suggests that heterogeneous consumer search costs can lead to a non-degenerate price distribution within a market for otherwise homogenous goods. Using a structural model of equilibrium search costs first posed by Carlson and McAfee (1983), we estimate average search costs to be $72. We argue that information problems arise from the complexity of the insurance product and lead individuals to rely on insurance agents who do not necessarily guide them to the lowest prices.

Energy, Carbon-emission and Financial Savings from Thermostat Control

Among the easiest approaches to energy, and cost, savings for most people is the adjustment of thermostats to save energy. Here we estimate savings of energy, carbon, and money in the United States of America (USA) that would result from adjusting thermostats in residential and commercial buildings by about half a degree Celsius downward during the heating season and upward during the cooling season. To obtain as small a unit as possible, and therefore the least likely to be noticeable by most people, we selected an adjustment of one degree Fahrenheit (0.56 degree Celsius) which is the gradation used almost exclusively on thermostats in the USA and is the smallest unit of temperature that has been used historically. Heating and/or cooling of interior building space for personal comfort is sometimes referred to as space conditioning, a term we will use for convenience throughout this work without consideration of humidity. Thermostat adjustment, as we use the term here, applies to thermostats that control the indoor temperature, and not to other thermostats such as those on water heaters. We track emissions of carbon only, rather than of carbon dioxide, because carbon atoms change atomic partners as they move through the carbon cycle, from atmosphere to biosphere or ocean and, on longer time scales, through the rock cycle. To convert a mass of carbon to an equivalent mass of carbon dioxide (thereby including the mass of the 2 oxygen atoms in each molecule) simply multiply by 3.67

Energy, Carbon-emission and Financial Savings from Thermostat Control

Among the easiest approaches to energy, and cost, savings for most people is the adjustment of thermostats to save energy. Here we estimate savings of energy, carbon, and money in the United States of America (USA) that would result from adjusting thermostats in residential and commercial buildings by about half a degree Celsius downward during the heating season and upward during the cooling season. To obtain as small a unit as possible, and therefore the least likely to be noticeable by most people, we selected an adjustment of one degree Fahrenheit (0.56 degree Celsius) which is the gradation used almost exclusively on thermostats in the USA and is the smallest unit of temperature that has been used historically. Heating and/or cooling of interior building space for personal comfort is sometimes referred to as space conditioning, a term we will use for convenience throughout this work without consideration of humidity. Thermostat adjustment, as we use the term here, applies to thermostats that control the indoor temperature, and not to other thermostats such as those on water heaters. We track emissions of carbon only, rather than of carbon dioxide, because carbon atoms change atomic partners as they move through the carbon cycle, from atmosphere to biosphere or ocean and, on longer time scales, through the rock cycle. To convert a mass of carbon to an equivalent mass of carbon dioxide (thereby including the mass of the 2 oxygen atoms in each molecule) simply multiply by 3.67

Manipulating Fibroblast Environment to Study Specific Gene Expression

We investigated a model system for cardiac fibrosis. Cardiac fibrosis is the thickening of the heart wall due to the inappropriate proliferation of cardiac fibroblasts and excess deposition of extracellular matrix in the cardiac muscle. To understand how the cells, respond to stress, we analyzed changes in gene expression. Our research imitated the stress conditions that the heart cells experience. We chose to analyze genes that have not previously been characterized under uniaxial, biaxial and stress-free environments to look at how gene expression varies under different conditions. We normalized all data to a validated housekeeping genes. This research will help people with various heart problems in repairing damaged tissue. We expect to increase the understanding of the cause of cardiac fibrosis and contribute to a solution. Our conclusions will compare gene expression during healthy conditions to damage repair conditions

Evaluation of the Effect of Vaccination Side on Subsequent Halter Breaking Side Preference in Cattle

The quality of animal-human interactions is important, as negative interactions may result in an animal being difficult to handle. Halter breaking is used as a means to make the process of moving and securing a calf easier, and theoretically should minimize stress for both the animal and handler. There are numerous ways that people can halter break a calf, for example tying up the cattle in barns for a defined period of time, touching the cattle for the first time using combs or using a “Talk and Touch” method. Anecdotal evidence shows with halter breaking that cattle have a side preference and it has been hypothesized that this side preference may be related to the side that vaccinations were given. Therefore, the goal of this study was to determine if a calf indicates a side approachability preference during halter breaking that is dependent on vaccination side. A total of 20 crossbred Angus/Simmental steers from Iowa State University’s (ISU) breeding herd were used. Steers were between 7 and 9 mo of age, averaging 272 kg BW. Steer was the experimental unit. A 2 (left or right neck side for vaccination) x 2 (left or right approach side) factorial arrangement of treatments was compared. One month after weaning, each steer had a nylon halter affixed to his head 2 d prior to the steer side preference test. Each handler was blind to vaccination side. Approach side for each steer had been randomly assigned prior to the beginning of the trial. Halter breaking methodology was conducted over five defined steps. Students were asked at the end of the 1-h period to conclude if the calf had a left, right, or no side preference. Data was analyzed using PROC GLIMMIX for the effects of vaccination side on subsequent halter breaking side preference. There was no difference observed between halter breaking side preference in relation to vaccination side (P \u3e 0.05). In conclusion, with this data set there was no halter breaking preference side related to vaccines given, indicating that the calves did not negatively associate humans with restraint and injections. This is helpful in understanding animal/human interactions as well as ability to approach an animal after vaccinations. This also implies that strategies such as the “Talk and Touch” method are useful in keeping calves calm and comfortable during halter breakin

UVSSA, UBP12, and RDO2/TFIIS Contribute to Arabidopsis UV Tolerance

Plant DNA is damaged by exposure to solar radiation, which includes ultraviolet (UV) rays. UV damaged DNA is repaired either by photolyases, using visible light energy, or by nucleotide excision repair (NER), also known as dark repair. NER consists of two subpathways: global genomic repair (GGR), which repairs untranscribed DNA throughout the genome, and transcription-coupled repair (TCR), which repairs transcribed DNA. In mammals, CSA, CSB, UVSSA, USP7, and TFIIS have been implicated in TCR. Arabidopsis homologs of CSA (AtCSA-1/2) and CSB (CHR8) have previously been shown to contribute to UV tolerance. Here we examine the role of Arabidopsis homologs of UVSSA, USP7 (UBP12/13), and TFIIS (RDO2) in UV tolerance. We find that loss of function alleles of UVSSA, UBP12, and RDO2 exhibit increased UV sensitivity in both seedlings and adults. UV sensitivity in atcsa-1, uvssa, and ubp12 mutants is specific to dark conditions, consistent with a role in NER. Interestingly, chr8 mutants exhibit UV sensitivity in both light and dark conditions, suggesting that the Arabidopsis CSB homolog may play a role in both NER and light repair. Overall our results indicate a conserved role for UVSSA, USP7 (UBP12), and TFIIS (RDO2) in TCR