Search

Mycotic keratitis, an important ophthalmologic problem, especially in outdoor workers in the tropics, is frequently caused by filamentous fungi such as species of Fusarium, Aspergillus and Curvularia, and by yeast-like fungi such as Candida. A rapid, presumptive diagnosis can be made by recognition of certain typical clinical features and by direct microscopic detection of fungi in corneal scrapings stained by various methods. The diagnosis is confirmed by culture. In difficult cases, microbiological studies on corneal biopsies or histopathological studies on tissue sections may need to be performed. The use of fluorescein-conjugated lectins and similar diagnostic tools is aimed at providing rapid, species-specific detection of fungi in corneal tissue. Antifungal therapy must be instituted as soon as the diagnosis is made. While keratitis due to Aspergillus, Candida and dematiaceous fungi can be successfully treated by many of the currently available polyenes and azoles, the treatment of Fusarium keratitis still frequently requires the use of pimaricin or econazole. Treatment by the oral and parenteral routes may prove useful in severe mycotic keratitis. Surgery may need to be performed on cases unresponsive to medical therapy or where serious complications are likely to occur. The pathogenesis of mycotic keratitis appears to involve agent factors, such as invasiveness and toxigenicity, and host factors, such as trauma and intrinsic defects in resistance. Areas for future research include the development of rapid, species-specific diagnostic aids, of broad-spectrum antifungal compounds active by various routes, and of therapeutic modalities which act on the fungus and on molecules involved in the pathogenesis of the condition.

Lasiodiplodia theobromae, a recognized plant pathogen, was isolated in culture from a case of human mycotic keratitis. Chemotherapy with a variety of azoles was unsuccessful and the lesion was removed surgically. Electron microscopy of thin sections of the excised corneal tissue revealed several examples of intrahyphal hyphae, a unique process described previously in in vitro cultures of various zoopathogenic fungi. We believe this to be the first report of the presence of intrahyphal hyphae in parasitized animal or human tissue. The demonstration of this process in vivo is thought to be consistent with the hypothesis that intrahyphal hyphae might represent an attempt by the invading fungus to survive in an otherwise unfavourable environment.

To get a better understanding of the possible role of proteases in the pathogenesis of fungal keratitis, the extracellular proteases of a clinical isolate of Aspergillus flavus , from a severe case of kerititis, were identified and partially characterized. This strain, designated CU226/88, was grown with a variety of substrates as nitrogen sources, under conditions that would be expected to derepress the production of extracellular proteases. When grown on minimal medium with milk protein as a nitrogen source, the fungus appeared to produce primarily a metalloprotease, which has a zinc cofactor. When grown with insoluble collagen or elastin as a nitrogen source, a serine protease and cysteine protease, as well as the metalloprotease, are produced. Strain CU226/88 can grow with collagen, but not elastin, as the sole source of carbon as well as nitrogen. It is possible that the collagenase activity is a mediator of the severe corneal destruction caused by this isolate.

In Georgia, horticulture is now the number two commodity in the state. The labor needs of the industry is increasing, however, enrollment in horticulture classes at UGA has been dropping. Most entry-level employees joining horticulture firms are completely without training or understanding of the industry, the type of work or the basic skills necessary to be functional. If horticulture was taught, it was by persons with Vo-Ag training in small engines, or animal husbandry etc. Students reported teachers had very little enthusiasm for the subject, no school facilities and that the school principle/administration had no vision for, or understanding of, horticulture. We are addressing this situation through an innovative partnership between Georgia High Schools, The Georgia Department of Education, and the University of Georgia. We can reverse the trend by training new and existing high school teachers by providing them a standardized floriculture curriculum and comprehensive training in greenhouse management, classroom teaching methods, industry awareness and a provide a long-term link to UGA. Our objective is to increase the number of students who are trained, motivated and willing to work in the field of horticulture as entry level workers. To do this we set about to standardize the course curriculum statewide, certify the high-school, faculty and administration for commitment and program continuity, Set up a model training greenhouse system at UGA, and conduct new teacher training at UGA through ALEC, and conduct postcertification training for teachers at UGA during the summer to upgrade skills, enthusiasm. The venture, including a model greenhouse at UGA, has been funded for over $100,000. The program currently has 218 Schools, 64 w/labs and greenhouses, 215 teachers and 25,049 students participating.

Bumblebees (Bombus spp.) are important pollinators of mostly self-sterile rabbiteye blueberry (Vaccinium ashei Reade). Annual bee colonies start from solitary overwintered queens who emerge in near-synchrony with rabbiteye blueberry bloom. Although colony populations may reach several hundred individuals by midsummer, in early spring most Bombus visiting rabbiteye blueberry are queens reared the previous season. Thus, practices that encourage production of queens in summer may increase populations of blueberry pollinators the next spring. In south Georgia, midsummer shortages of nectar-yielding plants may nutritionally limit queen production, and cultured bee forages may help overcome this deficiency. Candidate plants must not compete with the crop for pollinators, and they must be attractive to bees, easy to grow, vigorous, and non-invasive. In 3 years of trials, the following plants have shown promise as supplemental bumblebee forages in south Georgia: Althea (Hibiscus syriacus), abelia (Abelia ×grandifolia), vitex (Vitex agnuscastus), red clover (Trifolium pratense perenne), Mexican heather (Cuphea hyssopifolia), monkey grass (Liriope muscari), summer sweet (Clethra alnifolia), and giant sunflower (Helianthus giganteus).

The first ion implanted optical waveguide in the nonlinear material KTP is reported. The refractive index profiles are characterised for both nx and nz, and the loss is examined after an annealing. The index changes (∼0% in the electronic interaction region and ∼4% decrease in the nuclear stopping region) show that a typical barrier waveguide is formed in the implanted KTP. The tuning wavelength ranges for type 2 zero mode phase matching SHG in ion implanted waveguides as a function of guide widths are calculated for different propagating angles.

A chip set for high-speed radix-2 fast Fourier transform (FFT) applications up to 512 points is described. The chip set comprises a (16+16)/spl times/(12+12)-bit complex number multiplier, and a 16-bit butterfly chip for data reordering, twiddle factor generation, and butterfly arithmetic. The chips have been implemented using a standard cell design methodology on a 2-/spl mu/m bulk CMOS process. Three chips implement a complex FFT butterfly with a throughput of 10 MHz, and are cascadable up to 512 points. The chips feature an offline self-testing capability.

Hydrogen diffusion into evaporated amorphous silicon leads to changes of the electronic properties which makes the films a useful material for electronic devices. This diffusion which has been so far realized using a hf hydrogen plasma is hardly controlled and has experimental limitations. It is shown here that hydrogen diffusion into amorphous silicon occurs when one uses a dc hydrogen plasma and produces the same changes as observed after hf treatments. Hydrogen diffusion from a dc plasma is much easier to control than the hf one and offers several other advantages.

X-ray observations have shown that early-type galaxies contain a hot interstellar medium. This implies that the galaxies have a) a low supernova rate; b) high total gravitational binding masses and c) continuous star formation. Much of the gas in isolated galaxies is probably due to stellar mass-loss. The details of its behaviour are complex.

Summary Measurements of the net photosynthesis and dark respiration rates of excised twigs from Betula pubescens Ehrh. subsp. odorata (Bechst.) Warburg and B. pendula Roth, at different light intensities were made using infra-red gas analysis. B. pubescens appears to possess leaves which on the basis of physiological responses can be described as sun and shade leaves. In the more open canopy of B. pendula differences between leaf types are less pronounced. The presence of sun and shade leaves is suggested as a means whereby the net assimilation rate of the shrubby growth form of B. pubescens can be increased. This type of mechanism becomes increasingly important at high altitudes and latitudes.

The disease-free, postresection, 2 year survival rate of patients with T1 N0 non-small cell lung cancer surgically/pathologically staged by the Lung Cancer Study Group is about 82%. This study of the rate of cancer recurrence and histopathologic types is based on 572 eligible patients who submitted to complete resection of T1 N0 lung cancer and rigorous, systematic mediastinal lymph node sampling. The initial pathologic interpretation and staging were reviewed by pathologists of the Lung Cancer Study Group Pathology Reference Center to assure uniformity. Review was completed for 82% of patients included in this report. Postoperative cancer recurrence was observed in 107 of the 572 eligible patients. Histopathologic classification was squamous carcinoma (226 patients) or nonsquamous, non-small cell carcinoma (346 patients). Cancer recurrences are more frequent and recurrence rates are higher in the patients with nonsquamous cancer. There is a greater probability of first recurrence in the brain in the nonsquamous carcinoma group. This study substantiates the observation that lung cancer recurrences are histopathologically dependent in the T1 N0 subgroup of Stage I non-small cell lung cancer, with higher rates occurring among patients with nonsquamous carcinoma.

More than 1700 samples of Salvinia molesta Mitchell were collected from sites distributed from close to the equator in Papua New Guinea to 33°S in Australia. Nitrogen content ranged from 0.62 to 4.0% dry weight, phosphorus from 0.03 to 1.07% and potassium from 0.31 to 5.32%. Tops contained more concentrated N and P than roots, while K was more concentrated in roots. Concentrations of N and P were significantly correlated. Rainfall, followed by runoff, resulted in peaks of N, P and K in plants in one lake, but the sequence could not be demonstrated at other sites. At sites experiencing marked seasonal changes in temperature, N and P contents were inversely correlated with temperature, probably due to greater growth and utilisation of nutrients in summer. Damage caused by the biological control agent Cyrtobagous salviniae Calder and Sands decreased K content, while N and P contents were increased in some cases, but not in others. Thick mats of S. molesta in Papua New Guinea contained less concentrated N and P than thin mats, but this was not necessarily the case in the Australian sites. The reasons for these differences, and the likely effects on biological control agents, are discussed. Urea and superphosphate were found to increase N and P concentrations in the plant by amounts useful for experimental purposes and for aiding establishment of biological control agents. An equation related N concentration to the amount of urea applied and background N content of the plant. Concentrations of N, P and K decreased with age. Levels of N and P dropped most quickly as buds opened, then dropped slowly until the onset of senescence caused another rapid decline. The implications of these changes for insects feeding on S. molesta are discussed.

Some while ago, in an attempt to improve communication between members in the Research Department, we published some comments in Aslib Proceedings on the terminology of the analysis of library systems. We were not in any way advocating a standard use of certain expressions, only trying to reach some mutual agreement on what we meant by the words we were actually using in our studies of various libraries, and offering the result in the hope that it might prove interesting or useful to others. One of the projects mentioned then, concerned with the use of bibliographic records in libraries, has progressed to a stage where some extension of our original comments can be made.

When I first joined Aslib I was asked how I felt about visiting different libraries and watching the people at work in them. The idea appealed to me, particularly as I had already found out how co‐operative librarians could be when working in a library myself, and beset by problems of re‐organization. Whatever the public image of librarians may be, the characteristics that have impressed me most are an absorbed interest in their work, and a willingness to talk about it. This helped me enormously, as my job has been to find out about their jobs. The librarians I have met through my work at Aslib have all been friendly and helpful, and interested enough in research to let me loose in their libraries in order to talk to their staff at some length about the various processes used.

A great deal of effort on the part of the members of Aslib Research Department during the past two years has gone into systems studies of various types of libraries. Because the work has involved a variety of techniques, for example O & M, market survey and analysis prior to mechanization, there have arisen, from time to time, difficulties in communication within the department with regard to the description of library/information systems. In particular, the meaning and use of words in ‘orthodox’ management terminology (if there is such a thing) are not always particularly relevant in the analysis of library systems, although the techniques themselves may be very useful. Lacking any standardized terminology, a group of co‐workers can at least attempt to isolate concepts and agree, amongst themselves, what words they are going to use to denote them.

The effect of five cement bases on the fracture strength of three amalgams was determined at 24 h after condensation. It was found that the type of base used was the most important factor in affecting the fracture strength of the amalgam, followed by the thickness of the base, and finally the type of amalgam that was used.

Formocresol and eugenol are the two nonspecific intracanal medicaments commonly used in endodontic practice. Both have high tissue irritation potential when used in conventional strength. Propylene glycol is an alcohol that is injectable and itself possesses significant antibacterial action. It is a popular vehicle and hence was used to modify the two drugs. Standard bacteriologic methods were employed to test the antibacterial action of these lower concentrations of the two drugs against four test organisms. The investigations indicate that formocresol at as low as 10 to 20 percent and eugenol at 75 percent are bactericidal in action and hence may be useful at these concentrations for clinical use. Evaluation of these lower concentrations is warranted for possible clinical use. Propylene glycol, which possesses antibacterial action and is remarkably innocuous to tissues, appears to be a suitable vehicle for dilution of formocresol and eugenol.

A chip set for high speed radix-2 FFT applications up to 512 points is described. The chip set comprises a (16+16)*(12+12) bit complex multiplier; and a 16 bit butterfly chip for data re-ordering, twiddle factor generation and butterfly arithmetic. The chips have been implemented using the Megacell design methodology on a 2 micron bulk CMOS process. Three chips implement a complex FFT butterfly with a throughput of 10MHz, and are cascadable up to 512 points. The chips feature an off-line self testing capability.

A twenty-four year old young man was discovered to have an enlarged left lobe of the liver with minimal symptoms and impaired liver function limited to delay in bromsulfalein excretion. Pathologically he had lobar cirrhosis with nodular hyperplasia (hamartoma) confined to and completely replacing the left lobe for which left hepatic lobectomy was performed. One and a half years after surgery the patient was in good health and without clinical evidence of involvement of the right lobe or of hepatic malfunction

L'influence de l'oxygene sur les proprietes electriques du CdS en couche mince a ete etudiee dans le systeme a ultravide ou les echantillons ont ete prepares par evaporation. L'entree d'oxygene entraine un accroissement de resistivite du a la fois a une diminution de la densite de porteurs libres et de leur mobilite. La decroissance de la densite d'electrons libres, associee a un piegeage en surface sur des niveaux accepteurs profonds lies a l'oxygene, est plus lente que dans les monocristaux de CdS car les barrieres de potentiel aux joints de grains limitent le courant d'electrons vers la surface. La decroissance de la mobilite est expliquee par une interaction entre l'oxygene et les barrieres de potentiel aux joints de grains. Il est demontre qu'une distribution inhomogene de niveaux donneurs existe au sein de chaque cristallite.