Distribution of S-Adenosylhomocysteine Hydrolase, S-Adenosylhomocysteine Nucleosidase, S-Ribosylhomocysteine Cleavage Enzyme and Homoserine Dehydratase in Various Species

Microorganisms, plants and the major organs from cold and warm blooded vertebrates ware assayed for the presence of S-adenosylhomocysteine hydrolase, S-adenosylhomocysteine nucleosidase, S-ribosylhomocysteine cleavage enzyme and homoserine dehydratase. S-Adenosylhomocysteine hydrolase was found in all yeasts and plants assayed and in the livers of all cold blooded vertebrates assayed except the Polyodon spathula (Paddlafish). Liver extracts from all warm blooded vertebrates except the Odocoileus hemionus (Mule deer), Odocoileus virginianus (Whitetail deer) and Homo sapiens (human) were also found to possess S-adenosylhomocysteine hydrolase. This enzyme was also found in the spleens of the Ictalurus punctatus (Channel cat), Perca flavescens (Yellow perch) and Bos (steer) and in the kidneys of the Ictiobus bubalus (Buffalohead), Ictalurus punctatus (Channel cat), Thamnophis sirtalis (Garter snake), Anas platyrhynchos (Rouen duck), Totanus flavipes (Lesser Yellowleg), Rattus rattus (white rat), Oryctolagus cuniculus (New Zealand white rabbit) and Canis familiaris (dog). There was no hydrolase activity found in brains or hearts of any of the vertebrates assayed. S-Adenosylhomocysteine hydrolase was also lacking in all bacteria assayed. S-Adenosylhonocysteiifie nucleosidase activity was not detectable in any yeasts, plants or vertebrate organs assayed. This enzyme was present in all bacteria assayed except Bacillus subtilis. S-Ribosylhomocysteine cleavage enzyme was lacking in all extracts assayed except Citrobacter freundii, Enterobacter aerogenes, Escherichia coli and Proteus vulgaris. Homoserine dehydratase was found in Bacillus subtilis, \u3eu\u3eBacillus cereus, Sarcina lutea and in all liver extracts except those of Ictiobus bubalus (Buffalohead), Galus galus (White Leghorn chicken), Pedioecetes phasianellus (Sharptail grouse), Cavia porcellus (Guinea pig), Oryctolagus cuniculus (New Zealand white rabbit) and Canis familiaris (dog). This enzyme was also found in brain extract of the Anas platyrhynchos (Rouen duck) and kidney extracts of Totanus flavipes (Lesser Yellowleg), Rattus rattus (white rat) and Odocoileus virginianus (Whitetail deer). Homoserine dehydratase was lacking in Gram negative bacteria, yeasts, plants and from hearts and spleens of all vertebrates assayed. Intravenous injections of S-adenosylhomocysteine into an anesthetized dog resulted in a rapid excretion of this compound in the urine with minimal retention by any organ assayed. As the liver and kidney had been found to contain S-adenosylhomoeysteine hydrolase these results suggested that this enzyme is inoperative against exogenous S-adenosylhomocysteine

THE MARKET FOR CITRUS HARVESTING LABOR

Labor and Human Capital,

Multiple cooperating manipulators: The case of kinematically redundant arms

Existing work concerning two or more manipulators simultaneously grasping and transferring a common load is continued and extended. Specifically considered is the case of one or more arms being kinematically redundant. Some existing results in the modeling and control of single redundant arms and multiple manipulators are reviewed. The cooperating situation is modeled in terms of a set of coordinates representing object motion and internal object squeezing. Nominal trajectories in these coordinates are produced via actuator load distribution algorithms introduced previously. A controller is developed to track these desired object trajectories while making use of the kinematic redundancy to additionally aid the cooperation and coordination of the system. It is shown how the existence of kinematic redundancy within the system may be used to enhance the degree of cooperation achievable

Effects of Population Density upon Channel Catfish in Enclosures

Channel catfish were held in 18-cubic-foot pens from June 1 to Sept. 9 at stocking rates of 2, 4, 8, 12, 18, and 24 fish per pen. Mean weight per fish on Sept. 9 showed an inverse relationship with population density. Condition factors increased in all pens throughout the study. Fish in pens with 2, 4, and 8 fish were in better condition than those in more crowded pens after July 15. Growth of fish in the pen with 2 fish was similar to that in the open pond. Growth of channel catfish was greater in 2 ft. of water than at 4 and 6 ft. Low dissolved oxygen at 6 ft. caused the death of channel catfish by July 1

AN ASSESSMENT OF APPLIED BIOLOGICAL SCIENCE INTERESTS OF SEVENTH GRADE STUDENTS!

Vocational education programs in high schools should be designed to prepare young people for their next pursuit after graduation. Students\u27 interests, needs, and employment opportunities should form the basis upon which decisions are made concerning what vocational courses to offer in the high school curriculum

Sexual Dimorphism and Intersexual Differences in Resource Allocations of a Dioecious Shrub, Lindera melissifolia (Walt.) Blume

Morphometric data were gathered to make intersexual comparisons on the morphology and reproductive resource allocation patterns of the rare, dioecious shrub, Lindera melissifolia. Females produced significantly fewer flowers and leaves than did males. No other significant differences could be detected in morphology. Female clones exhibit low area coverage and low stem density, which suggests higher costs of reproduction. If this is the case, the deficits produced in resource allocations directed toward sexual reproduction seem to result in increased mortality and/or reduced vegetative reproduction

Local Aerodynamic Heat Transfer and Boundary-Layer Transition on Roughened Sphere-Ellipsoid Bodies at Mach Number 3.0

A wind-tunnel investigation was made to determine heat-transfer distributions on three steel sphere-ellipsoid bodies with surface roughnesses of 5, 100, and 200 microinches. Tests were conducted in the Langley 9- by 6-foot thermal structures tunnel at a Mach number of 3.0, free-stream Reynolds numbers (based on model spherical diameter) of 4.25 x 10(exp 6) and 2.76 x l0(exp 6), and at a stagnation temperature of 650 F. Pressure distributions were obtained also on a fourth model. The results indicated that the combination of surface roughness and boundary-layer cooling tended to promote early transition and nullify the advantages attributable to the blunt shape of the model for reducing local temperatures. Good correlation between experimental heating rates and those calculated from laminar theory was achieved up to the start of boundary-layer transition. The correlation also was good with the values predicted by turbulent theory for surface stations downstream from the 45 deg. station

Effect of oil palm sustainability certification on deforestation and fire in Indonesia.

Many major corporations and countries have made commitments to purchase or produce only "sustainable" palm oil, a commodity responsible for substantial tropical forest loss. Sustainability certification is the tool most used to fulfill these procurement policies, and around 20% of global palm oil production was certified by the Roundtable on Sustainable Palm Oil (RSPO) in 2017. However, the effect of certification on deforestation in oil palm plantations remains unclear. Here, we use a comprehensive dataset of RSPO-certified and noncertified oil palm plantations (∼188,000 km2) in Indonesia, the leading producer of palm oil, as well as annual remotely sensed metrics of tree cover loss and fire occurrence, to evaluate the impact of certification on deforestation and fire from 2001 to 2015. While forest loss and fire continued after RSPO certification, certified palm oil was associated with reduced deforestation. Certification lowered deforestation by 33% from a counterfactual of 9.8 to 6.6% y-1 Nevertheless, most plantations contained little residual forest when they received certification. As a result, by 2015, certified areas held less than 1% of forests remaining within Indonesian oil palm plantations. Moreover, certification had no causal impact on forest loss in peatlands or active fire detection rates. Broader adoption of certification in forested regions, strict requirements to avoid all peat, and routine monitoring of clearly defined forest cover loss in certified and RSPO member-held plantations appear necessary if the RSPO is to yield conservation and climate benefits from reductions in tropical deforestation