Pilot-Scale Ozone Inactivation of Cryptosporidium and Other Microorganisms in Natural Water

A pilot-scale study was conducted to evaluate the inactivation by ozone against Cryptosporidium oocysts, Giardia cysts, poliovirus, and B. subtilis endospores spiked into Ohio River water. The indigenous Ohio River populations of total coliform bacteria, heterotrophic plate count bacteria and endospores of aerobic spore forming bacteria were also evaluated. Endospores were the only organisms found to be more resistant to ozone than Cryptosporidium oocysts. Endospores may serve as an indicator of microbial treatment efficiency. Cryptosporidium oocysts were more resistant than Giardia cysts or poliovirus. Although HPC bacteria were less resistant than Cryptosporidium oocysts, variability limits their usefulness as an indicator of treatment efficiency. Ozone inactivation data generated in a pilot-scale study employing natural surface waters were comparable to inactivation data derived from previously published bench-scale studies using laboratory waters. The ozone requirements for inactivation of Cryptosporidium oocysts may produce elevated levels of bromate and ozone byproducts.     

Registration of stereo and temporal images of the retina

The registration of retinal images is required to facilitate the study of the optic nerve head and the retina. The method we propose combines the use of mutual information as the similarity measure and simulated annealing as the search technique. It is robust toward large transformations between the images and significant changes in light intensity. By using a pyramid sampling approach combined with simulated reannealing we find that registration can be achieved to predetermined precision, subject to choice of interpolation and the constraint of time. The algorithm was tested on 49 pairs of stereo images and 48 pairs of temporal images with success.     

Response of two okra (Abelmoschus esculentus L. Moench) varieties to fertilizers: Yield and yield components as influenced by nitrogen and phosphorus application

The response of two okra (Abelmoschus esculentus L. Moench) varieties (White velvet and NHAE 47-4) to fertilization in northern Nigeria was examined using four rates of nitrogen (0, 25, 50 and 100 kg ha^–1) and three rates of phosphorus (0, 13 and 26 kg ha^–1). Nitrogen application significantly increased green pod yield, pod diameter, number of fruits per plant, number of seeds per pod and pod weight. Application of phosphorus also significantly increased green pod yield, pod number and number of seeds per pod. The two varieties responded to nitrogen application differentially with respect to green pod yield. For optimum green pod yield of White velvet 35 kg N ha^–1 is suggested while for variety NHAE 47-4, N fertilization can be increased to 70 kg ha^–1. There was no differential response of varieties to phosphorus fertilization for green pod yield; however, the application of 13 kg ha^–1 enhanced the performance of both varieties.     

Bis-Indole Alkaloids Isolated from the Sponge Spongosorites calcicola Disrupt Cell Membranes of MRSA

Antimicrobial resistance (AMR) is a global health challenge with methicillin resistant Staphylococcus aureus (MRSA), a leading cause of nosocomial infection. In the search for novel antibiotics, marine sponges have become model organisms as they produce diverse bioactive compounds. We investigated and compared the antibacterial potential of 3 bis-indole alkaloids—bromodeoxytopsentin, bromotopsentin and spongotine A—isolated from the Northeastern Atlantic sponge Spongosorites calcicola. Antimicrobial activity was determined by MIC and time-kill assays. The mechanism of action of bis-indoles was assessed using bacterial cytological profiling via fluorescence microscopy. Finally, we investigated the ability of bis-indole alkaloids to decrease the cytotoxicity of pathogens upon co-incubation with HeLa cells through the measurement of mammalian cell lysis. The bis-indoles were bactericidal to clinically relevant Gram-positive pathogens including MRSA and to the Gram-negative gastroenteric pathogen Vibrio parahaemolyticus. Furthermore, the alkaloids were synergistic in combination with conventional antibiotics. Antimicrobial activity of the bis-indole alkaloids was due to rapid disruption and permeabilization of the bacterial cell membrane. Significantly, the bis-indoles reduced pathogen cytotoxicity toward mammalian cells, indicating their ability to prevent bacterial virulence. In conclusion, sponge bis-indole alkaloids are membrane-permeabilizing agents that represent good antibiotic candidates because of their potency against Gram-positive and Gram-negative bacterial pathogens.     

Determination of teat dip germicidal activity using the excised teat model

Fifteen postmilking teat antiseptics were evaluated in seven trials using the excised teat model. All products were tested against Staphylococcus aureus Newbould 305 and Streptococcus agalactiae Cornell 48. Eight of nine iodophor products provided log reductions greater than 3 against Staph. aureus and Strep. agalactiae. A .045% iodophor product was ineffective. A .5% chlorhexidine product yielded a log reduction of 3.22 against Staph. aureus but only 2.92 against Strep. agalactiae. Two products containing fermented milk emulsified in detergent were tested upon receipt and after 1 yr storage. Fresh product provided log reductions greater than 3 against both pathogens. Storage for 1 yr resulted in minimal loss of germicidal activity. Three products containing 1, .5, and .2% dodecylaminoalkyl glycine provided log reductions greater than 3.5 against Staph. aureus and greater than 4 log reduction against Strep. agalactiae.     

Chemical and Enzymic Changes During the Fermentation of Bacteria-Free Soya Bean Tempe

Amounts of dry matter, ash, protein, free ammonia, crude lipid, glyceride–glycerol, free fatty acids, free glycerol, glucosamine, protease activity and lipase activity were monitored during the fermentation of bacteria-free tempe made with acidified soya bean cotyledons and Rhizopus oligosporus NRRL 2710 at 30°C. During the phase of mycelial growth (0–32 h) the total dry matter decreased by approximately 10% (w/w), accounted for by losses of crude lipid (3% of initial dry matter), protein/amino acids (0·5%), and unidentified compounds (6·5%). During the phase of mycelial senescence (60–180 h), decrease in dry matter (12% of initial dry matter) was due almost entirely to loss of crude lipid. Lipase activity and the production of free fatty acids occurred from the earliest stages of the fermentation. The production of only small amounts of free glycerol indicates that triglycerides were primarily hydrolysed to partial glycerides and free fatty acids. Protease activity and production of free ammonia were also detected at the earliest stages of the fermentation. During the phase of mycelial senescence, amounts of crude lipid and glycerol decreased in the absence of fungal growth, possibly due to the activity of enzymes released from senescent mycelium.     

Seasonal Patterns of Plant Flammability and Monoterpenoid Content in Juniperus ashei

The susceptibility of Juniperus communities to prescribed fires can vary greatly throughout the year. The objective of this project was to determine the relationship between the seasonal concentration and composition of volatile oils and plant flammability in two Ashe juniper (Juniperus ashei) populations. Total monoterpenoid concentration was significantly affected by season and by plant population. Mean monoterpenoid concentration of a population from each central Texas was 9.16 mg/g fresh weight of juniper needles while the mean concentration of a west central Texas population was 11.62 mg/g of fresh weight. Monoterpenoid concentrations were typically lowest during the summer and highest during the spring and winter in the western population, but there was no seasonal pattern in the eastern population. The eastern population of trees was slightly (4.8%) more flammable than the western population, and male trees were slightly (3.8%) more flammable than female trees. The concentration of limonene was positively related to plant flammability and could increase flammability by 30% over the range of cencentrations found in this species. Bornyl acetate was negatively related to flammability with each 1 mg/g increase in concentration resulting in a 2% decrease in flammability. Caloric energy content and percent leaf moisture were not significant factors in determining the percentage of the Ashe juniper plant actually burned. Secondary chemicals, usually considered as antiherbivore mechanisms, may also serve an important role in determining the likelihood of a plant being consumed by fire.