Showing papers by "University of Georgia published in 1975"

Omnibus test contours for departures from normality based on √b1 and b2

Abstract: SUMMARY The test statistic X2(1bbl)+X2(b2), where X(1bl) and X(b2) are standardized normal equivalents to the sample skewness, Jbl, and kurtosis, b2, statistics, is considered in normal sampling. Using the Johnson system, Su and SB, as approximate normalizing distributions, contours in the (1bl, b2) plane of the test statistic are set up for sample sizes ranging from 20 to 1000.

The Reluctance to Transmit Bad News

Abstract: Publisher Summary This chapter focuses on pervasive bias on the part of communicators to encode (transmit) messages that are pleasant for the recipient and to avoid encoding those that are unpleasant (termed as the “MUM” effect). The hypothesized MUM effect appears to have considerable intuitive validity: “Of course people don't like to give others bad news!” Nevertheless, although anecdotal evidence is plentiful, the search of the empirical literature revealed no straightforward demonstration of, nor explicit attempt to demonstrate, the effect. The chapter attempts to define it more precisely and to demonstrate its existence unambiguously. An unambiguous demonstration of the MUM effect should not be linked with obvious extrinsic differential rewards associated with telling good or bad news, nor should news valence be dependent on the recipient's prior behavior. The chapter reviews evidence attesting to its generality, empirically examine a number of hypotheses generated to account for it, and some implications have been suggested.

The quenching of singlet oxygen by amino acids and proteins.

Abstract: — The physical quenching of singlet molecular oxygen (1Δg) by amino acids and proteins in D2O solution has been measured by their inhibition of the rate of singlet oxygen oxidation of the bilirubin anion. Steady-state singlet oxygen concentrations are produced by irradiating the oxygenated solution with the 1–06 μm output of a Nd-YAG laser, which absorbs directly in the electronic transition 1Δg+ 1v→3Σg-. The rate of quenching by most of the proteins studied is approximated by the sum of the quenching rates of their amino acids histidine, tryptophan and methionine, which implies that these amino acids in the protein structure are all about equally accessible to the singlet oxygen. The quenching constants differ from those obtained by the ruby-laser methylene-blue-photosensitized method of generating singlet oxygen, or from the results of steady-state methylene-blue-photosensitized oxidation, where singlet oxygen is assumed to be the main reactive species. The singlet oxygen quenching rates in D2O, pD 8, are (107? mol-1 s-1): alanine 0–2, methionine 3, tryptophan 9, histidine 17, carbonic anhydrase 85, lysozyme 150, superoxide dismutase 260, aposuperoxide dismutase 250.

Nitrogen fixation in a coral reef community.

Abstract: Algal reef flats at Enewetak Atoll, Marshall Islands, fix atmospheric nitrogen at rates comparable to those in managed agriculture. The dominant nitrogen fixer appears to be the blue-green alga Calothrix crustacea. Since this nutrient enrichment contributes to the high productivity of adjacent coral reefs and undoubtedly to atoll lagoons, it is recommended that the algal reef flats receive increased conservation priority.

Enewetak (Eniwetok) Atoll: Aspects of the nitrogen cycle on a coral reef1

Abstract: Changes in the concentrations of dissolved and particulate nitrogen in seawater crossing two interisland reef transects on Enewetak Atoll were measured. The upstream half of transect II consisted largely of algal pavement; the downstream half was visually dominated by corals. The other community, transect III, consisted of benthic algal covered pavement in its entirety, with only scattered small corals downstream. Both transects showed a significant net export of combined nitrogen, implying a large input of nitrogen into the reef system from a source other than the combined nitrogen in overlying waters. High rates of gaseous nitrogen fixation were found. There was a net uptake of nitrate by the community dominated by algae and a net export of nitrate from the transect dominated jointly by algae and corals. Although nitrification is of central importance in the marine nitrogen cycle, this coral-algal community at Enewetak appears to have been the first marine site at which this process has been measured directly.

Formation of methyl mercury by bacteria.

Abstract: Twenty-three Hg2+ resistant cultures were isolated from sediment of the Savannah River in Georgia; of these, 14 were gram-negative short rods belonging to the genera Escherichia and Enterobacter, six were gram-positive cocci (three Staphylococcus sp. and three Streptococcus sp.) and three were Bacillus sp. All the Escherichia, Enterobacter, and the Bacillus strain were more resistant to Hg2+ than the strains of staphylococci and streptococci. Adaptation using serial dilutions and concentration gradient agar plate techniques showed that it was possible to select a Hg2+-resistant strain from a parent culture identified as Enterobacter aerogenes. This culture resisted 1,200 μg of Hg2+ per ml of medium and produced methyl mercury from HgCl2, but was unable to convert Hg2+ to volatile elemental mercury (Hg0). Under constant aeration (i.e., submerged culture), slightly more methyl mercury was formed than in the absence of aeration. Production of methyl mercury was cyclic in nature and slightly decreased if DL-homocysteine was present in media, but increased with methyl-cobalamine. It is concluded that the bacterial production of methyl mercury may be a means of resistance and detoxification against mercurials in which inorganic Hg2+ is converted to organic form and secreted into the environment.

Microbial assimilation of hydrocarbons. I. The fine-structure of a hydrocarbon oxidizing Acinetobacter sp.

Abstract: 1. The fine-structure analysis of the hydrocarbon oxidizing microorganism, Acinetobacter sp., demonstrated a cytoplasmic modification resulting from growth on paraffinic and olefinic hydrocarbons. 2. Intracytoplasmic hydrocarbon inclusions were documented by electron microscopy with chemical identifications obtained by gas chromatography and X-ray diffraction. 3. These results demonstrate the ability of a micro-organism to accumulate hydrocarbon substrates intracellularly which, in turn, indicates transport across the cell membrane.

Negative ion properties of p‐benzoquinone: Electron affinity and compound states

Abstract: Bound and excited negative ion states of para‐benzoquinone (PBQ) are studied from experiments involving collisions of electrons and cesium beams with PBQ. The electron affinity of PBQ was measured to be 1.89+0.2−0.3 eV using the cesium collisional ionization technique. PBQ−(C6H4O−2) was the dominant negative ion observed following collisions of cesium beams with PBQ. Direct electron attachment to PBQ produced the fragment ions C5H4O−, C5H3O−, C4O2H−2, C2HO−, and C2H− as well as the parent C6H4O−2 ion. Our observations showed that the cross section for producing the metastable parent negative ion, C6H4O−2, peaks at 1.40±0.1 eV which is in disagreement with a previous value of 2.1 eV. Attachment of thermal electrons to PBQ at low pressure (<10−4 mm Hg) was not observed. Compound negative ion states were observed to peak at 0.70, 1.35, and 1.90 eV using the SF6 scavenger technique. The energies of these compound states agree qualitatively with the energies if the manifold of unfilled π* orbitals. The long‐li...

Presence of Cytochrome and Menaquinone in Clostridium formicoaceticum and Clostridium thermoaceticum

Abstract: Cytochrome b and menaquinone have been demonstrated in the homoacetate-fermenting Clostridium formicoaceticum and Clostridium thermoaceticum.

Food Partitioning in Net-spinning Trichoptera Larvae: Hydropsyche venularis, Cheumatopsyche etrona, and Macronema zebratum (Hydropsychidae)

Abstract: Larvae of 3 species of Hydropsychidae construct retreats and capture-nets on and under rocks downstream from a reservoir in northeastern Georgia. The capturenets of the 3 species have different mesh opening sizes: 134×249μ in Hydropsyche venularis Banks, 48×72μ in Cheumatopsyche etrona Ross and 5×40μ in Macronema zebratum Hagen. Hydropsyche venularis were found primarily on the tops of rocks whereas C. etrona and M. zebratum were located at the top, lower side and underneath rocks. Macronema zebratum larvae constructed retreats of 2 different designs, depending upon their location. Foregut analyses of the 3 species showed differences in both type and size of particles ingested. Size trends of food particles in the foregut closely paralleled sizes of capture-net mesh openings. Macronema zebratum larvae ingest much smaller particles (including nannoplankton) than the other 2 species, and Macronema foregut contents compared more closely in particle size to that of stream seston. Several strategies are involved in achieving partitioning of food resources, including: (1) variations in capture-net mesh size; (2) different microdistributional patterns with retreats designed for various current velocities; and (3) temporal variations in net construction.

Quality of pharmaceutical care in hospitals.

Abstract: The objective of this study was to measure the quality of pharmaceutical services provided to hospital inpatients. Using Donabedian's model, normative standards from the Joint Commission on Accreditation of Hospitals and the American Society of Hospital Pharmacists were used to develop a personal interview schedule to access the structure and process components of pharmaceutical services. To determine the effect of bed size, rural vs. urban, and presence of a full- or part-time pharmacist on the quality of pharmaceutical services, three samples of short-term hospitals were drawn: a random sample of Mississippi hospitals with less than 100 beds; all Mississippi hospitals of 100 or more beds; and a sample of hospitals in Philadelphia, Pennsylvania. In each of the 112 hospitals a personal interview was conducted with either the chief pharmacist or the administrator responsible for the pharmaceutical service. The responses to the items were then tabulated and a structure and a process score were obtained for each hospital. The following conclusions can be made: (1) The quality of the "structural" components is positively related to the bed size and not to whether the hospital is located in a rural or urban setting; (2) the quality of the "process" components is related to both the bed size and the location of the hospital--hospitals having 100 or more beds or located in an urban area have a higher process quality than those having less than 100 beds or located in a rural area; and (3) hospitals employing a full-time pharmacist have a higher quality of care than those who do not.

Patterns of basidiomycete nutrient accumulation in conifer and deciduous forest litter

Abstract: Nutrient data were obtained for basidiomycete sporocarps, rhizomorphs and forest floor leaf litter samples collected from a white pine (Pinus strobus L.) watershed and from a mixed hardwood watershed at Coweeta Hydrologic Laboratory, N.C. Basidiocarps taken from the surface litter of both watersheds were fleshy representatives of Agaricaceae, Cantharellaceae or Clavariaceae. Forest floor basidiocarp samples (cap + stalk) from both watersheds had significantly greater concentrations of Cu, K, Na, P and Zn than the leaf litter from which they were removed. Bulked rhizomorph samples from both watersheds contained significantly more Ca, K, Na and Sr than forest floor leaf litter. Polyporaceae growing on hardwood branches concentrated Al, Mo, P and Zn.

Dematiaceous fungal keratitis. Clinical isolates and management.

Abstract: Clinical and laboratory features of 16 cases of keratitis that were caused by dematiaceous pigmented fungi are reported. Management, including the treatment of nine cases with Natamycin (Pimaricin), resulted in corneal healing in 14 cases, and therapeutic surgery in two cases.

Salmonella survival on pecans as influenced by processing and storage conditions.

Abstract: Survival of Salmonella senftenberg 775W, S. anatum, and S. typhimurium during exposure to currently practiced, as well as abusive, pecan processing and storage conditions was studied. Thermal treatments normally carried out during the processing of pecans are inadequate to consistently destory salmonellae in highly contaminated inshell nuts. Pecan nut packing tissue was toxic to salmonellae, thus affording some protection against high initial contamination and subsequent survival of the organisms. Examinations of inoculated inshell pecans stored at -18, -7, 5, and 21 C for up to 32 weeks revealed that the extent of survival was inversely correlated to the storage temperature. S. senftenberg 775W and S. anatum were not detectable on inshell nuts after 16 weeks of storage at 21 C. Little decrease in viable population of the three species was noted on inoculated pecan halves stored at -18, -7, and 5 C for 32 weeks. Due to organoleptic quality deterioration in pecan nutmeats at elevated temperatures, sterilization methods other than thermal treatment appear to be required for the elimination of viable salmonellae from pecan nuts.

Plastic Pitfall Trap

Abstract: An easily constructed pitfall trap was made by burying a plastic cup at ground level, inserting a smaller plastic cup to capture specimens, and covering the cups with a conical coffee cup liner which had the bottom removed to form a funnel. A solution of water, ethylene glycol, formalin, and detergent was added to the inner container to kill and preserve captured specimens. A variety of animals were captured.

Population estimates for uca pugnax (smith, 1870) on the duplin estuary marsh, georgia, u.s.a. (decapoda brachyura, ocypodidae)

Abstract: model, several additional compartments have been considered. The Uca spp. populations may represent a bio-energetically significant group of macro-inverte brates in the salt marsh ecosystem. Standing stock data from Uca pugnax popula tions (the most widely distributed and most abundant species of the genus) coupled with transfer rates between U. pugnax and other compartments, provide a new pathway for quantification. Standing stock data for the crabs are presented herein. Efforts already underway (by SFS) are focusing on potential net energy transfer rates between fiddler crabs and other compartments of the mathematical model. Once necessary flux rates and standing stock have been incorporated into the model, we can more accurately assess the importance of fiddler crab populations in the energy flow of the salt marsh. Three species of fiddler crabs, U. pugnax (Smith, 1870), U. pugilator Bosc, 1801, U. minax (Le Conte, 1855), are among the most conspicuous macro-faunal consumers of the Georgia salt marsh. These detritus feeders (Marples, 1966) may play a large role in the energy flow of the marsh, based solely on their abundance. Teal (1958) divided the marsh habitat into seven types; creek bank, tall Spartina edge marsh, medium S par tina levee marsh, short Spartina low marsh, short Spar tina high marsh, Salicornia and Distichlis marsh, and funcus marsh and estimated adult crabs from each habitat except the funcus marsh. Fiddler crabs were found in all of these areas; however, each species occupied characteristic zones. Teal (1962) also published estimates of Uca spp. populations (excluding the young, <0.2 g wet weight) on creek bank, levee, short Spartina and Salicornia-Distichlis marshes. These populations were sampled by placing metal rings (30 cm high) on the marsh at high tide and removing organisms within the ring at low tide. Crabs were separated, counted and weighed. Rings of 0.20 m2 were used for adults

The Realm of Ichnology, its Strengths and Limitations

Abstract: Ichnology is the study of all manner of gouges, scrapes, and traces made by living or ancient organisms At first glance, these oddities might seem to offer little encouragement for serious study But many looks later, a surprisingly sophisticated body of information begins to emerge, most of it unavailable from any other source Fossils that once were dismissed simply as “indirect evidence of ancient life” or “secondary sedimentary structures” now are proving to be invaluable in interpreting many forms of ancient life and the associated sedimentological and environmental conditions

Modification of a selenium toxicity in chicks by dietary silver and copper

Abstract: Studies were conducted to determine the effects of high levels of dietary silver nitrate and copper sulfate on the response of chicks to toxic levels of dietary selenium Adding 5 ppm or more selenium to a basal stock diet significantly reduced growth rate, and 40 ppm or higher significantly increased mortality during the 2-week experiments Dietary silver or copper (1,000 ppm) counteracted the growth depression and prevented mortality at the higher levels of selenium Hepatic selenium reached a maximum in chicks fed the basal diet with 10 ppm dietary selenium Hepatic selenium of chicks fed silver was less than that of the control chicks when diets containing 10 ppm or less selenium were fed Adding copper to the diet resulted in considerable accumulation of selenium in the liver, which was evident even at the lower levels of added selenium Results of an experiment to determine the effects of dietary silver and copper on the distribution of /sup 75/Se administered either orally or intramuscularly showed that silver interfered with absorption of selenium The results of these experiments suggest that silver modified selenium toxicity both by interfering with selenium absorption and by causing the accumulation of a nondeleterious selenium compound in themore » tissues Copper modifies selenium toxicity primarily by causing the accumulation of a nondeleterious compound in the tissues« less