Epidemiological and clinical investigations into big liver and spleen disease of broiler breeder hens

SUMMARY The epidemiological and clinical features of big liver and spleen disease (BLS) in flocks on two broiler breeder farms were investigated by serology and gross pathology. The most common necropsy findings on farm 1 were splenomegaly and hepatomegaly, with kidney enlargement in some birds. In one flock (farm 1), a decline in egg production began at 40 weeks of age and lasted for 9 weeks. Seroconversion to BLS antigen was first detected at 45 weeks (3.1% of birds) and increased to 72% at 50 weeks, which coincided with clinical recovery in the flock. Antigen was detected before antibody at 44 weeks and persisted at low incidence (<15%). Farm egg production statistics and serology indicated that the disease affected all flocks on the farm. In three of eight flocks, seroconversion was detected in birds before peak production. The birds in the remaining sheds did not seroconvert or become sick until after peak production. On the second farm, sampling began within a flock already experiencing BLS. Clinical signs and pathology were similar to those seen in flocks on farm 1. However, the lesions that were seen in the pancreas in 15% of birds have not been reported previously. BLS antibody was detected in 78%, and circulating antigen in 14%, of sick birds.     

Reproductive and Metabolic Responses of Early‐lactating Dairy Cows Fed Different Dietary Protein Sources

Optimal reproduction is very closely tied with optimal nutrition, and early‐lactation diets in cows are critical to successful reproduction and monitoring is important. To evaluate the effects of different dietary protein sources on metabolic parameters and reproductive activity, a total of 36 Italian Friesian early‐lactating dairy cows were assigned for 16 weeks to three dietary treatments as follow: the control diet contained soya bean meal (SBM) as the main protein source, whereas the experimental diets contained faba bean (FB) or pea seeds (PS) as alternative protein sources. Diets were formulated to be isocaloric and isonitrogenous. Cow blood samples were collected, and plasma were analysed for metabolites, biological enzymes, β‐hydroxybutyrate (BHBA) and non‐esterified fatty acids (NEFA). Feeding alternative protein sources had no effects on most metabolic blood profile, except for blood cholesterol, triglycerides and urea. Results from reproductive parameters indicated that cows fed FB diet had a lower insemination index, but a shorter calving to conception period and an improved conception rate and artificial insemination outcome, when compared to cows fed SBM or PS diets. It can be concluded that replacing conventional dietary SBM with alternative protein sources, especially FB, resulted in improved reproductive performances and metabolic parameters in early‐lactating dairy cows.     

The antiplasmodial activity of spermine alkaloids isolated from Albizia gummifera

In the present study the methanolic extract of Albizia gummifera was fractionated into various fractions. These fractions were tested against choroquine sensitive (NF54) and resistant (ENT30) strains of Plasmodium falciparum. All other fractions apart from the alkaloidal fraction showed low activity with IC 50 above 3 microg/ml. The alkaloidal fraction exhibited strong activity against NF54 and ENT30 with IC 50 of 0.16+/-0.05 and 0.99+/-0.06 microg/ml, respectively. Five known spermine alkaloids were isolated from the alkaloidal fraction. These alkaloids exhibited activities against NF54 and ENT30 with IC 50 ranging from 0.09+/-0.02 to 0.91+/-0.10 microg/ml. Four of the alkaloids were further evaluated for in vivo activity against rodent malaria parasite Plasmodium berghei. The alkaloids showed percentage chemosuppression of parasitaemia in mice ranging from 43 to 72%. The use of the extracts A. gummifera for treatment of malaria in traditional medicine seems to have a scientific basis.     

Methods of detection of Chlamydia psittaci in domesticated and wild birds

OBJECTIVE: To study the occurrence of Chlamydia psittaci in domesticated and wild birds and compare the sensitivity of molecular detection with cell culture isolation. DESIGN: Study of cell culture isolation and PCR detection of C psittaci in avian samples. PROCEDURE: Samples were obtained from 485 birds. Domesticated birds were selected at random from pet shops, private aviaries and zoos, while wild birds were captured locally, sampled, and immediately released. Swabs were collected from choanal slit, conjunctiva and cloaca of each bird and pooled. Samples were divided into equal portions for use in PCR dot-blot and cell culture detection. PCR and dot-blot detection was based on the ompB gene. RESULTS: Prevalence of infection varied markedly between flocks of captive birds. It was highest where there were frequent changes in the flock members or where there were many birds confined in small areas. C psittaci was not detected in wild birds or water birds. The sensitivity of cell culture compared to PCR dot-blot detection was 68%. All samples positive by cell culture were also positive by PCR. CONCLUSIONS: PCR-dot blot detection of C psittaci in birds appears to be more sensitive than cell culture isolation in this study. C psittaci infection of birds may occur in clinically normal captive birds.     

Electrical conductivity in the precambrian lithosphere of western canada

The subcrustal lithosphere underlying the southern Archean Churchill Province (ACP) in western Canada is at least one order of magnitude more electrically conductive than the lithosphere beneath adjacent Paleoproterozoic crust. The measured electrical properties of the lithosphere underlying most of the Paleoproterozoic crust can be explained by the conductivity of olivine. Mantle xenolith and geological mapping evidence indicate that the lithosphere beneath the southern ACP was substantially modified as a result of being trapped between two nearly synchronous Paleoproterozoic subduction zones. Tectonically induced metasomatism thus may have enhanced the subcrustal lithosphere conductivity of the southern ACP.     

Antagonistic effect of soil rhizosphere microorganisms on Bipolaris sorokiniana,the causal agent of wheat seedling blight

The biocontrol efficiency of Epicoccum purpurascens, Gliocladium roseum, three strains of Bacillus subtilis, and Pseudomonas fluorescens, isolated from the rhizosphere of wheat plants, was assessed in relation to seedling blight caused by Bipolaris sorokiniana. An in vitro study of the potential antagonist was performed using the dual culture technique and by ‘sowing’ wheat seeds pelleted with the saprophytes in plates with water agar?+?the pathogen. In vivo assays were carried out in the greenhouse and in the field with pelleted seeds sown in artificially infested soil. Both the number of living plants and the number of plants with necrosis on the leaves and the base of the stems and roots were assessed 15 days after sowing. Under greenhouse conditions, B. subtilis 3 and G. roseum reduced the level of infection of Buck Pucará and Trigomax 100 cultivars, respectively. In the field, biocontrol of the disease was not achieved.     

Self-Assembly of Mesoscale Objects into Ordered Two-Dimensional Arrays

Regular arrays of topologically complex, millimeter-scale objects were prepared by self-assembly, with the shapes of the assembling objects and the wettability of their surfaces determining the structure of the arrays. The system was composed of solid objects floating at the interface between perfluorodecalin and water and interacting by lateral capillary forces; patterning of the wettability of the surfaces of the objects directs these forces. Self-assembly results from minimization of the interfacial free energy of the liquid-liquid interface. Calculations suggest that this strategy for self-assembly can be applied to objects on a micrometer scale.     

The utility of screening diagnostic tests in identifying associative immune-mediated haemolytic anaemia in dogs

The study aimed to (1) define the proportion of dogs with immune-mediated haemolytic anaemia (IMHA) that have associative and non-associative disease and (2) evaluate the utility of screening diagnostic tests in identifying potential triggers of associative IMHA. Medical records of 78 dogs diagnosed with IMHA at a specialist hospital in Sydney from July 2008 to August 2017 were reviewed. The original diagnosis was revised according to published guidelines (Garden et al., 2019) as either diagnostic, supportive or suspicious for IMHA. Associative IMHA was confirmed if immunosuppressive therapy was discontinued within six weeks of effective treatment of a potential trigger. Associative IMHA was considered possible when a potential trigger was identified but its significance could not be confirmed. Associative IMHA was confirmed (3) or suspected (7) in 10 dogs (13%, confidence interval [CI] 7.1%–22%), with 68 cases presumed to be non-associative. Associative IMHA was present in 3/29 (10.3%) of dogs with criteria diagnostic for IMHA, 4/42 (9.5%) of dogs with criteria supportive for IMHA and 3/7 (42.9%) of dogs with criteria suspicious for IMHA. Abdominal ultrasound was performed in 68 dogs and identified possible triggers in five (7.3%, CI 3.2% to 16%). Thoracic radiographs were performed in 70 dogs but did not identify any potential triggers (0%, CI 0% to 5.2%). Urine culture was performed in 22 dogs and was positive in three (14%, CI 4.7% to 33.3%). Routine screening tests, particularly thoracic radiographs, have a low yield in identifying potential triggers of associative IMHA, but are more likely to be useful in dogs fulfilling less stringent diagnostic criteria of IMHA.     

Triterpenes of Albizia versicolor and Albizia schimperana stem barks

Several triterpenes were isolated from stem barks of Albizia versicolor and A. schimperana. Spectral data of acacic acid lactone (1) are presented.     

Hierarchically ordered oxides

Porous silica, niobia, and titania with three-dimensional structures patterned over multiple length scales were prepared by combining micromolding, polystyrene sphere templating, and cooperative assembly of inorganic sol-gel species with amphiphilic triblock copolymers. The resulting materials show hierarchical ordering over several discrete and tunable length scales ranging from 10 nanometers to several micrometers. The respective ordered structures can be independently modified by choosing different mold patterns, latex spheres, and block copolymers. The examples presented demonstrate the compositional and structural diversities that are possible with this simple approach.