High Daily Stress Research Articles

The Role of Maternal Stress and Family Functioning in Maternal Distress and Mother-Reported and Child-Reported Psychological Adjustment of Nonreferred Children

Sought to replicate with nonreferred children findings regarding the psychological adjustment of children with chronic illness and their mothers. Two questions were addressed. In the absence of the strains of chronic childhood illness: (a) Is maternal distress related to maternal perceptions of daily stress and family functioning? (b) Is child-reported and/or mother-reported child adjustment related to maternal stress and distress? Maternal distress was related to maternal perceptions of high daily stress but not to family functioning. Maternal reports of their children's behavior problems and symptoms were related to maternal perceptions of high daily stress and low family supportiveness. Children's self-reported symptoms were also related to maternal perceptions of high daily stress.

The Effects of Psychological Stress on Electromyographic Activity and Negative Affect in Ambulatory Tension‐Type Headache Patients

Fourteen female dental hygiene students (seven with episodic tension-type headache and seven who rarely or never experienced headache) wore an ambulatory electromyographic recorder and completed hourly subjective ratings of pain and negative affective states for six days while they carried out their normal daily activities. Three of the days were designated as high stress days by virtue of the fact that the students were required to take a major course examination or undergo a clinical evaluation on that day. The remaining three days were designated as low stress days by virtue of the fact that no unusual demands were made on the students, and they simply attended lectures as usual. All students showed significantly greater levels of electromyographic activity on the high stress days compared to the low stress days, but there was not a statistically significant difference between the headache and control groups. Headache group subjects reported significantly higher levels of pain compared to the control group, but their pain ratings did not differ between high and low stress days. Subjective ratings of negative affective states (anxiety, anger, sadness, and frustration) were significantly greater on high stress days compared to low stress days. Headache group subjects also exhibited a tendency to report higher levels of negative affective states than did control group subjects, but only in the case of frustration was the .05 level of statistical significance achieved.

Illness representations and matching labels with symptoms.

Three studies are reported that show that health-relevant information (e.g., blood pressure [BP] or symptoms) initiates an active cognitive search process that results in the construction of an illness representation. Study 1 showed that informing subjects that their BP was elevated affected two attributes of illness representation: identity (label and symptoms), and time line or expected chronology of the health threat. Subjects given a high-BP reading reported symptoms commonly associated with high BP, especially if they attributed the high-BP reading to stress. Study 2 showed that the active search process uses causal information (a third attribute of representations) to give meaning to symptoms. Specifically, subjects used environmental cues to interpret whether familiar, unfamiliar, and ambiguous symptoms were due to illness or to stress. In Study 3 we showed that the constructive process, initiated by a high-BP reading, is directed by prior beliefs about the time line for developing high BP and by the presence of external cues about the stressfulness of the subject's daily life. Subjects who believed BP was labile and that they were under high daily stress or who believed BP was stable and that they were under low daily stress reported more symptoms. The significance of these findings for understanding how people process diagnostic labels and symptom information involved in the construction of illness representations is discussed.

Phenotype and drought tolerance in wheat

An extensive root system is associated with drought resistance in wheat and selection for high yield under moisture stress conditions does select for larger root system. While breeders have occasionally selected consciously, or unconsciously, for extensive rooting, a systematic breeding program for a desirable root system will contribute to higher yields under moisture stress. Early rapid growth builds up a reserve that will carry the plant through severe drought and contribute to yield even when that plant is not particularly resistant to desiccation. During high stress days Pitic 62 continues to photosynthesize and produce more root. It maintains a higher assimilation rate and utilizes the available soil moisture more efficiently than other varieties tested. The genetics of characters associated with drought are complex. To breed for a combination of attributes requires the use of: (a) a few carefully studied parents; (b) large population to permit the combination of many favorable genes; and (c) yield testing from early generation (F 3 if practical) onward to homogeneity.

Photosynthesis Under Field Conditions. XI. Soil‐Plant‐Water Relations During Drought Stress in Corn1

AbstractThe variation of leaf water potential at different heights in a corn crop canopy (Zea mays) and with time during a period of increasing drought stress were examined along with soil moisture tension and evapotranspiration. These measurements plus growth measurements permitted an evaluation of the soil‐plant‐water transport system and its effects on plant growth during drought.On clear summer days the upper leaves of the corn crop had higher water potentials with a bimodal tendency in contrast to the lower leaves which had lower and almost constant water potentials.On high stress days the magnitude of the maximum afternoon leaf water potential increased by an amount equal to the increase in soil moisture tension. On days of comparable evaporative demand, the gradient of water potential from the upper leaves to the soil increased regularly with an increase in soil moisture tension in the root zone.Since total transpiration was not bimodal even though upper leaves exhibited bimodal variations of water potential, it is concluded that if midday stomatal closure of the upper leaves occurred, it apparently was ineffectual or compensating transpiration must have been carried on by lower leaves.A 2‐week drought period was examined in detail. Computation of the “effective conductance” of liquid water in the plant was compared with the moisture conductivity of the soil. This permitted a calculation of the “effective root length” where the gradient of water potential from plant to soil was assumed to represent the gradient from the root surface to the ambient untapped soil moisture. This calculated length was small by comparison to those calculated by Slatyer (1957), but the computational error is large.Transpiration was not detectably changed by the decrease in effective plant conductance and soil conductivity, so it is. concluded that the plant was still able to keep pace by maintaining sufficient potential gradient to transport the needed amount of water. The growth processes, however, were slowed down with increasing leaf water potential and decreasing turgor of the tissues. This slowdown was evident even at the relatively low soil moisture tension of less than one bar and a leaf water potential of less than 3.5 bars.