Association of Smooth Muscle Myosin and its Carboxyl Isoforms with Actin Isoforms in Aorta Smooth Muscle

The contraction mechanism of smooth muscle is not fully understood. The primary interaction that leads to the formation of tension, the myosin-actin crossbridge, has been studied extensively. However, even this aspect of the contraction has proven not to be as simple as it might seem. There are several isoforms of smooth muscle myosin and actin, and the differences in the activities of these isoforms and their interactions during the contractile process are largely unknown. The studies to be discussed are directed at the determination of the interaction of these isoforms during the contraction of rat aortic smooth muscle. Chapter II describes the association of smooth muscle myosin with two of the actin isoforms found in smooth muscle, α-actin and β-actin, using a novel method of fluorescence resonance energy transfer (FRET) to examine this association in both the A7r5 cell model and in intact tissue. We show that the contractile apparatus undergoes significant remodeling during contraction and that the interaction of myosin with α-actin and β-actin is different at the various time points of contraction. In Chapter III, we describe more detailed experiments examining the two different myosin tail isoforms, SM1 and SM2. The results of these studies confirm our findings of remodeling of the cytoskeleton and the contractile apparatus during contraction and show that α-actin and β-actin interact differently with these myosin isoforms. The results provide the first direct evidence of contractile remodeling in smooth muscle and suggest that complex changes in actin-myosin interaction may be important in the contraction of this muscle type

Studies of Autumn calving suckler cows, bulls at pasture and winter grazing

End of project reportMost beef and dairy cows are spring calving leading to distinct seasonality of supply. Calving a proportion of the beef herd in the autumn would lead to a more uniform annual supply of cattle for slaughter and potentially increase the proportion of grazed grass in the diet of the suckler progeny. Autumn calving sucklers also facilitate the use of AI, which should enhance the product quality. This project aimed to address the technical aspects of autumn calving sucklers, which differ from those of spring calvers. The currently available international energy models were evaluated for autumn calving lactating suckler cows using the type of cow typically found in Irish suckler herds (Experiment 1). The winter accommodation of the suckler cow and calf unit and its impact on cow reproductive performance was evaluated (Experiment 2). The final part of the project evolved into component studies to determine the effect of supplementary feed on the performance of grazing bulls (Experiment 3), and the consequences of weanling cattle grazing pasture in winter as an alternative to housing them in winter (Experiments 4 to 7)

EVALUATING USE OF OUTLOOK INFORMATION IN GRAIN SORGHUM STORAGE DECISIONS

This study examines grain sorghum storage decisions in the Texas Coastal Bend region. Decisions involving use and non-use of outlook information are compared using stochastic dominance criteria. Results indicate outlook information is of value to most classes of decision-makers. The value of outlook information, however, is contingent upon producers' risk preferences. The methodology presented could be used to evaluate a more extensive set of marketing strategies for grain sorghum as well as for other crops.Crop Production/Industries,

Cloning, purification and characterization of the 6-phospho-3-hexulose isomerase YckF from Bacillus subtilis

The enzyme 6-phospho-3-hexulose isomerase (YckF) from Bacillus subtilis has been prepared and crystallized in a form suitable for X-ray crystallographic analysis. Crystals were grown by the hanging-drop method at 291 K using polyethylene glycol 2000 monomethylether as precipitant. They diffract beyond 1.7 A using an in-house Cu Kalpha source and belong to either space group P6(5)22 or P6(1)22, with unit-cell parameters a = b = 72.4, c = 241.2 A, and have two molecules of YckF in the asymmetric unit

Utilizing the principles and implications of the base stock model to improve supply chain performance

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science; and, Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1998.Includes bibliographical references (leaf 44).by Brian E. Black.M.S

Environmental controls on the production of calcium carbonate by earthworms

Lumbricus terrestris earthworms produce calcium carbonate (CaCO3) granules with unknown physiological function. To investigate carbon sequestration potential, the influence of temperature and CO2 concentration ([CO2]) on CaCO3 production was investigated using three soils, five temperatures (3-20 C) and four atmospheric [CO2] (439-3793 ppm). Granule production rates differed between soils, but could not be related to any soil characteristics measured. Production rates increased with temperature, probably because of higher metabolic rate, and with soil CO2 concentration. Implications for carbon sequestration are discussed. CaCO3 production in earthworms is probably related to pH regulation of blood and tissue fluid in the high CO2 environment of the soil

Eva Q. Black

Eva Black, Class of 1930, makes a speech at a Los Angeles alumni meeting, reflecting on how knowledge learned from higher education can be applied later on in life to make better decisions

Modeling and Simulation of a Long-Wave Infrared Polarimetric Sensor for Space Object Detection and Characterization

Long-Wave Infrared (LWIR, wavelength \u3e 8 um) polarimetric measurements can be used to characterize space objects. A simulation of a sensor for collection of LWIR polarimetric signatures of space objects has been assembled using two software packages: MATLAB, and FRED. A statistical approach developed for unresolved visible light polarimetric observations of GEO satellites has been adapted for unresolved LWIR polarimetric observations of LEO satellites, showing both that well-known objects can be recognized and anomalies--for example, a major change in shape due to the presence in the scene of another object--can be detected. Though the satellites are effectively point sources, the aggregate polarization values across many measurements can be used to differentiate objects of different shape and material composition