Cerebellar abiotrophy in crossbred cattle

Cerebellar abiotrophy affected 9 of 74 calves sired by a Poll Hereford bull over 2 successive calving seasons. The disease was characterised by episodes of recumbency and ataxia, with hypermetria and wide base stance. Clinical signs commenced between birth and 8 months of age. Two calves which were affected first at 8 months of age recovered clinically 9 months later. Histological lesions were found in the cerebellar cortex of 7 calves and consisted of segmental degeneration and loss of Purkinje cells, and axonal swellings. The clinical signs and pathological findings were consistent with bovine familial convulsions and ataxia, which has not been described previously in Australia. The clinical signs were not attributable to the lesions observed in the cerebellum and an underlying electrophysiological abnormality is proposed. The aetiology of the condition is probably genetic and appears to have a multifactorial basis.     

The relationship between the prevalence of uterine lesions and the use of medroxyprogesterone acetate for canine population control

SUMMARY The prevalence of uterine disease was established during desexing of 175 bitches in the Torres Strait and Cape York, 42 of which had been treated with injectable medroxyprogesterone acetate (MPA) for oestrus postponement. The prevalence of uterine lesions was 45% for treated bitches, 5% for untreated bitches, and 14.9% for the sample population. A highly significant relationship (P<0.01) between MPA treatment and uterine lesions was established. A significant association (P<0.05) between age (>2 years old) and uterine lesions was found, most likely attributable to a significantly higher proportion (P<0.01) of MPA-treated bitches in the older population. There was no significant difference in the effect of MPA on the prevalence of uterine lesions between older and younger bitches. There was no effect of parity on the prevalence of uterine lesions.     

Assessment of Progesterone Concentration Using Enzymeimmunoassay, for Early Pregnancy Diagnosis in Sheep and Goats

The objective of this study was to determine a value of serum progesterone (P₄) concentration, assessed using an enzymeimmunoassay (EIA), for the early distinction between pregnant and non‐pregnant ewes and goats. Adult, non‐lactating ewes of Chios (n=53), Berrichon (n=30) and Sfakia (n=45) breeds were synchronized during the breeding season with progestagens and gonadotrophins and mated to fertile rams (Experiment I). Adult, lactating goats of Swiss breeds (Alpine and Saanen, n=104) and indigenous Greek breed (n=45) were synchronized during the transitional season with progestagens, PGF₂α and gonadotrophins. Cervical artificial insemination (AI) with fresh semen was applied once, 42–44 h after sponge removal (Experiment II). Jugular blood samples were collected on day 19 after sponge removal (ewes) or on day 21 after AI (goats) and serum P₄ concentration was determined by EIA. Progesterone concentrations ≥1.0, ≥1.5, ≥2.5 and ≥4.0 ng/ml were tested as indicative of pregnancy. Pregnancy diagnosis was verified on birth. In the case of sheep, using a discriminatory level of 2.5 ng/ml, overall accuracy of pregnancy diagnosis was 91.4% and predictive value of negative and positive diagnoses were 98.3 and 85.3%, respectively. In the case of goats, predictive value of negative diagnosis was 95.8 and 94.0% and predictive value of positive diagnosis 71.3 and 71.7%, for 1.5 and 2.5 ng/ml, respectively; overall accuracy was 79.2% using either level. The other discriminatory levels tested did not improve these results. A significant positive correlation was observed between P₄ concentration and the number of lambs or kids born, and further analysis indicated that this relationship is not a simple linear function. Based on the results of this study, P₄ concentrations of 2.5 ng/ml in the case of ewes and 1.5–2.5 ng/ml in the case of goats, determined with EIA, are proposed as discriminatory levels between pregnant and non‐pregnant animals, at an interval of one oestrous cycle after service.     

The Solar Acoustic Spectrum and Eigenmode Parameters

The Global Oscillation Network Group (GONG) project estimates the frequencies, amplitudes, and linewidths of more than 250,000 acoustic resonances of the sun from data sets lasting 36 days. The frequency resolution of a single data set is 0.321 microhertz. For frequencies averaged over the azimuthal order m, the median formal error is 0.044 microhertz, and the associated median fractional error is 1.6 x 10(-5). For a 3-year data set, the fractional error is expected to be 3 x 10(-6). The GONG m-averaged frequency measurements differ from other helioseismic data sets by 0.03 to 0.08 microhertz. The differences arise from a combination of systematic errors, random errors, and possible changes in solar structure.     

Fullerene pipes

Single-wall fullerene nanotubes were converted from nearly endless, highly tangled ropes into short, open-ended pipes that behave as individual macromolecules. Raw nanotube material was purified in large batches, and the ropes were cut into 100- to 300-nanometer lengths. The resulting pieces formed a stable colloidal suspension in water with the help of surfactants. These suspensions permit a variety of manipulations, such as sorting by length, derivatization, and tethering to gold surfaces.     

Mortality and F1 production of Rhyzopertha dominica (F.) on wheat treated with diatomaceous earth: impact of biological and environmental parameters on efficacy

A series of experiments were conducted in which label rate (0.3 g per kg of wheat) with diatomaceous earth (DE) formulation Protect-It. Exposure studies were carried out at two levels of relative humiditiy (40% and 55%), two levels of insect density (10 or 20 adults per vial), and three levels of exposure periods. Test insects were placed in vials containing 40 g of soft white winter wheat mixed with either 0 or 0.3 g Protect-It per kg of wheat. After relating exposure periods for both insect density and relative humidity levels, highest mortality was only 16%. Mortality, regardless of the dose rate applied (0 and 0.3 g) were not significantly increased as the exposure period increased. Regardless of relative humidity (r.h.) (40% and 55%r.h.), mortality in control were not significantly increased as the exposure period increased for the same insect density. However, significant differences among the three exposure periods in 10 adults’ density in 0.3 g DE application. Mortality was significantly increased in 10 adults’ density. In this case mortality of R. dominica adults increased with the increasing of the exposure intervals. As for 20 adults’ density, mortality in 0.3 g DE application was not significantly changed along with the exposure intervals. After insects were exposed for 1, 2, or 3 week, dead and live insects were removed, and the wheat in the vial were returned to relating humidity box and kept for 8 week until F₁ adults emerged. Then, the number of F₁ adult was counted. The mean numbers of F₁ adults on untreated wheat at all density and r.h. combinations, regardless of exposure periods were significantly higher than that of 0.3 g DE- treated wheat (Fig. 3). At each density and treatment, the mean number of F₁ adults at 55% r.h. were higher that that of 40%r.h. The comparison between adult densities at each r.h. and treatment showed that adult densities influenced the F₁ production of R. dominica and F₁ adults were always higher at 20 adults’ density. The mean number of F₁ adults at each density, regardless of treatment progressively increased as the exposure period increased. Fewer progeny were produced at 10 adults’ density compared to 20 adults’ density for same exposure periods. The highest reproduction occurred in 3 week of exposure period for both insect densities. Regardless of adult densities, the mean number of F₁ adults was significantly increased as the exposure period increased (Fig. 5) for both control and 0.3 g DE treatment. Reduction of F₁ adults at 0.3 g DE application compared to control were found to be 76.88, 74.78 and 67.63% for 1, 2 and 3 week of exposure period, respectively.     

Effect of Ram Age on Structural and Functional Competence of Frozen–Thawed Spermatozoa in Dairy Sheep

The objectives of this study were to investigate the influence of ram age on structural and functional competence of frozen–thawed spermatozoa and to test the hypothesis that increasing number of sperm bound to the zona pellucida in vitro was associated with decreasing in vivo fertility of frozen semen. Rams were allocated into two groups. Each group consisted of five rams aged either 1–2 years (young) or 4–5 years (mature). Three successive ejaculates were collected from each ram using an artificial vagina. Only ejaculates of ≥ 2.5 × 10⁹ sperm/ml and 80% sperm progressive motility were pooled per ram, diluted with Bioxcell^® medium and frozen in 0.25 ml straws. The end points of post‐thawing semen evaluation were computer‐assisted cell motility analysis, sperm capacitation (chlortetracycline assay), simultaneous assessment of plasma membrane integrity, mitochondrial membrane potential and condensation status of nucleus, per‐cell analysis of lipid peroxidation using C11‐BODIPY^581/591, sperm‐hemizona binding (HZB) ability and sperm fertility after laparoscopic insemination of ewes (n = 114) in the progestagen‐synchronized oestrus. The results showed that mature rams had significantly lower values of sperm hyperactivated motility and peroxidized sperm, higher percentages of live non‐capacitated sperm and sperm cells with intact plasma membrane, functional mitochondria and condensed chromatin, as well as, greater lambing rate and ewe prolificacy. Sperm HZB binding ability was higher (p < 0.05) for young than for mature rams. Significant correlations were found between number of spermatozoa bound to the zona pellucida and semen fertility (r = ?0.63 to ?0.71). In conclusion, mature rams have better semen quality and in vivo fertility than young rams. Cryocapacitation can be involved in decreasing ram semen fertility as evidenced by the high number of spermatozoa bound to the zona pellucida in vitro.