Prevalence of Cryptosporidium infection in goats in selected locations in three agroclimatic zones of Sri Lanka

The prevalence of Cryptosporidium oocysts in the faeces of 1020 goats in three age categories was examined during 1999 in selected locations of three agroclimatic zones of Sri Lanka. The oocysts were demonstrated using the Sheather's sucrose flotation method followed by staining with the modified Ziehl Neelsen technique. Cryptosporidium oocysts were detected in animals from all agroclimatic zones with the highest prevalence of infection in the dry zone (33.6%) compared with 24.7 and 21.7% in the intermediate zones and wet, respectively (P<0.001). Overall, Cryptosporidium oocyst counts were significantly higher in goats of <6 months and 7-12 months of age groups compared with goats of >12 months of age (P<0.001). Cryptosporidium oocysts were detected in 291/1020 (28.5%) animals, while 194/1020 animals (19%), 84/1020 animals (8.2%) and 13/1020 animals (1.3%) excreted low (1-1000 oocysts per gram of faeces), moderate (1000-5000 oocysts per gram of faeces) and high (>5000 oocysts per gram of faeces) counts, respectively. The mean Cryptosporidium count was 383 oocysts per gram of faeces. The majority of the infected goats were asymptomatic. These animals are likely to play an important role in the epidemiology of cryptosporidiosis in goat kids and humans.     

A High-Temperature Electrical Conduction Mechanism in the Lower Mantle Phase (Mg,Fe)1-xO

Measurements of electrical conductivity at high pressure and temperature were taken on the lower mantle phase magnesiowustite with varying Fe3+ content. Although previous measurements at atmospheric pressure suggest Fe2+-Fe3+ hopping (small polaron) as the dominant conductivity mechanism, the present experiments show a change in charge transport mechanism with temperature. The lower temperature measurements are consistent with small polaron conduction, but at higher temperatures, which are more applicable to the lower mantle, a large polaron mechanism is suggested. Because these mechanisms have different temperature and compositional dependencies, this transition has important implications for extrapolation to mantle conditions.     

Antioxidant properties of a radical-scavenging peptide purified from enzymatically prepared fish skin gelatin hydrolysate

Hoki (Johnius belengerii) skin gelatin was hydrolyzed with three commercial enzymes to identify radical-scavenging potencies of derived peptides. Peptides derived from tryptic hydrolysate exhibited the highest scavenging activities on superoxide, carbon-centered 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals assessed by ESR spectroscopy. Following consecutive chromatographic separations of tryptic hydroolysate, the peptide sequence His-Gly-Pro-Leu-Gly-Pro-Leu (797 Da) acted as a strong radical scavenger under studied conditions. Further, this peptide could act as an antioxidant against linoleic acid peroxidation and the activity was closer to the highly active synthetic antioxidant butylated hydroxytoluene (BHT). In addition, antioxidative enzyme levels in cultured human hepatoma cells were increased in the presence of this peptide and it was presumed to be the peptide involved in maintaining the redox balance in the cell environment. Present data indicate that free-radical-scavenging activities of hoki skin gelatin peptides substantially contribute to their antioxidant properties measured in different oxidative systems.     

Elaboration of a crude antigen ELISA for serodiagnosis of caprine neosporosis: validation of the test by detection of Neospora caninum-specific antibodies in goats from Sri Lanka

The protozoan parasite N. caninum is a major pathogen in cattle and dogs. However, clinical symptoms are occasionally described for other potential hosts. Natural abortion in goats due to N. caninum has been rarely reported and only little data is available on the seroprevalence of N. caninum in this species. In the present study, 486 goats from Sri Lanka were tested in a crude antigen ELISA for the presence of serum antibodies against N. caninum. Additionally, the sera were analysed by N. caninum-Western blot and indirect fluorescence antibody test (IFAT). In all three tests applied, only three sera (0.7%) were scored clearly positive for anti-N. caninum antibodies. The optimal correlation between ELISA, IFAT, and Western blot confirms the suitability of the ELISA for large-scale seroepidemiologic studies, not only in cattle but also in goats.     

Seroprevalence of Sarcosystis spp. in cattle and buffaloes from the wet and dry zones of Sri Lanka: a preliminary study

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of antibodies to Sarcosystis infection in cattle and buffaloes. Crude antigens derived from cystozoites of Sarcosystis cruzi and antibodies from the sera of naturally infected cattle and buffaloes were used. The assay was validated by determination of the specificity, sensitivity and negative and positive predictive values. Using ELISA, a sero-epidemiological survey for sarcosystosis was carried out in cattle (n = 215) and buffaloes (n = 123) from the wet and dry zones of Sri Lanka. The prevalence of infection in cattle was 69.3%. Prevalence of the infection collectively in both cattle and buffaloes in the dry zone was significantly higher (P < 0.001) than that in the wet zone. The number of sero-positive cattle and buffaloes in the dry zone was significantly higher than that in the wet zone (P < 0.05). Buffaloes in the dry and wet zones showed a greater prevalence of infection (P < 0.05) than cattle.     

Unitary control in quantum ensembles: maximizing signal intensity in coherent spectroscopy

Experiments in coherent magnetic resonance, microwave, and optical spectroscopy control quantum-mechanical ensembles by guiding them from initial states toward target states by unitary transformation. Often, the coherences detected as signals are represented by a non-Hermitian operator. Hence, spectroscopic experiments, such as those used in nuclear magnetic resonance, correspond to unitary transformations between operators that in general are not Hermitian. A gradient-based systematic procedure for optimizing these transformations is described that finds the largest projection of a transformed initial operator onto the target operator and, thus, the maximum spectroscopic signal. This method can also be used in applied mathematics and control theory.     

Ultrasonographic Examination of the Scrotal Content in the Rabbit

This study was performed to describe a practical technique for ultrasound examination of the scrotal content of the rabbit. The scrotal content of normal rabbits and those with induced lesions (i.e. needle biopsy of the testis and epididymal ligation) were viewed using a portable scanner connected to a 5 or 7.5 MHz real time, B-mode linear array transducer. The effect of frequency (5 and 7.5 MHz), pad material placed under the testicle (rubber, plastic and carton) and the presence of a water sack between the probe and organ were examined to optimize the technique. The best image quality was obtained using a 5-MHz probe when the testicle was fixed on a rubber pad and covered by a water sack. Testicular parenchyma was imaged as homogeneous and moderately echoic. Caput and cauda epididymis were identified as homogeneous and less echoic compared with the testis parenchyma. Variations in the testicular echotexture that occur secondarily to epididymal ligation and testis biopsy could be screened readily. In conclusion, real-time ultrasonography, performed as described in this study, may provide a valuable tool to screen scrotal contents and to identify certain pathological conditions that affect fertility in the rabbit.     

Seroprevalence of Toxoplasma gondii antibodies in captive elephants (Elephaus maximus maximus) in Sri Lanka

Serum samples collected during August 2003-June 2004 from 45 privately owned captive and 8 elephants from the Pinnawala Elephant Orphanage were tested for the presence of antibodies against Toxoplasma gondii using the direct modified agglutination test (MAT). Antibodies were found in sera of 14 of 45 (32%) privately owned elephants with titers of 1:25 in three, 1:50 in three, 1:100 in three, 1:200 in three, and 1:400 in three elephants. The elephants from Pinnawala Elephant Orphanage were seronegative. This is the first report of T. gondii seroprevalence in elephants in Sri Lanka.     

Analysis of potato microtuber proteins by sodium dodecylsulfate polyacrylamide gel electrophoresis

Summary Protein banding patterns of 119 lines (85 Japanese potato lines and introductions, 22 dihaploids, 1 wild source (Solanum bulbocastanum Dun.), 10 transformants and 1 somaclonal variant) were compared by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE). Microtubers formed in vitro were used as the source of plant materials. There were more than 15 bands in the 35–20 kDa molecular weight range and less than 10 bands in the 65–40 kDa range. The bands in the 65–40 kDa range which corresponded to the potato tuber storage protein patatin were focussed to about 40 kDa after heat treatment. The results indicate a distinct difference in the banding patterns among potato lines.