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Biomedical subjects

Elizabeth Fisher

Publications and source records attributed to Elizabeth Fisher.

4 recordsLinked to original sources

Cooling lactating sows exposed to early summer heat wave alters circadian patterns of behavior and rhythms of respiration, rectal temperature, and saliva melatonin.

Heat stress (HS) exerts detrimental effects on animal production, with lactating sows being particularly vulnerable. Understanding the mechanisms involved in HS response could aid in developing effective strategies against the negative impacts on livestock. Recent genome wide association studies identified two core circadian clock genes as potential candidates in mediating HS response. The study aimed to investigate how cooling lactating sows under natural heat stress conditions impacted circadian patterns of respiration rate (RR), rectal temperature (RT), behavior, salivary melatonin and cortisol levels, and diurnal patterns of cytokines in saliva. Mixed parity lactating sows were assigned to one of two treatment groups: electronic cooling pad (C; n = 9) and heat-stressed (H; n = 9). The experiment spanned two 48 h periods of elevated ambient temperatures due to summer heat wave. In the first 48 h period, RR was recorded every 30 min, RT every 60 min, and behaviors (eating, standing, sitting, laying, sleeping, drinking, and nursing) every 5 min. In the second 48 h period, saliva samples were collected every 4 h. Cooling reduced RR and RT and altered circadian patterns (P < 0.05). Cooling did not affect amount of time engaged in any behavior over the 48 h period (P > 0.05), however, daily patterns of eating, standing and laying differed between the treatments (P < 0.05), with altered eating behavior related to RT increment in H sows (P < 0.05). Cooling increased and altered the circadian pattern of salivary melatonin (P < 0.05). Cooling also influenced the diurnal pattern of saliva cytokines. Cooling had no impact on saliva cortisol levels. In conclusion, cooling HS sows impacted circadian rhythms of physiology and behavior, supporting the need for further research to understand if circadian disruption underlies decreased production efficiency of HS animals.

Animals↗

Factors that predict health-related quality of life in patients with relapsing-remitting multiple sclerosis.

Health-Related Quality of Life (HRQoL) research is gaining acceptance in the field of multiple sclerosis (MS). Little is known about what precipitates quality of life change. It was hypothesized that physical aspects of quality of life decline with worsening objective disease measures and psychosocial aspects remain relatively stable regardless of change in objective measures. These assumptions are tested using data from a Phase 3 study of relapsing-remitting MS patients treated with interferon beta-1a and reassessed approximately eight years after study initiation. The Sickness Impact Profile (SIP) questionnaire is the generic quality of life measure used in this study. Three summary scores of the SIP (Physical, Psychosocial, and Total scores), Expanded Disability Status Scores, Multiple Sclerosis Functional Composite, and Brain Parenchymal Fraction were determined at baseline, year 2, and after an average of 8.1 years from study entry. SIP data collected during a clinic visit were available from 137 of the original 172 participants. All objective indicators worsened by follow-up. SIP Physical and Total scores significantly worsened from baseline to follow-up. SIP Psychosocial showed nonsignificant worsening. Regression analysis indicated that final measures of SIP Physical and Total scores were most strongly associated with change in objective measures and follow-up SIP Psychosocial was most strongly related to earlier scores on the same measure.

Adjuvants, Immunologic↗

Parameter space warping: shape-based correspondence between morphologically different objects.

This paper presents a novel and comprehensive method for the automated determination of correspondences between two morphologically different two-dimensional (2-D) or three-dimensional (3-D) objects. Correspondences are determined by warping parametric representations of the objects to be matched. The warp is guided by the minimization of a similarity criterion function that measures features related to structural correspondence, including Euclidian point-to-point distance and differences in normals and curvature. The method uses a continuous harmonic parameterization for both the object and the warp, which provides: 1) a high degree of computational efficiency; 2) robust extraction of differential features, not subject to discretization errors or noise amplification in differentiation; 3) direct formulation of constraints to avoid overlaps in the resulting correspondence set; and 4) a scale-space paradigm of object shape and warp. The new method does not search for individual landmarks, but operates with a complete, integrated representation of the object geometry. The method was tested on 2-D and 3-D objects with substantial shape differences. Results demonstrated substantial improvements of 2%-33% in correspondence accuracy and 15%-59% in correspondence quality compared with direct registration methods.

Algorithms↗