In situ observations of a high-pressure phase of H2O Ice

A previously unknown solid phase of H2O has been identified by its peculiar growth patterns, distinct pressure-temperature melting relations, and vibrational Raman spectra. Morphologies of ice crystals and their pressure-temperature melting relations were directly observed in a hydrothermal diamond-anvil cell for H2O bulk densities between 1203 and 1257 kilograms per cubic meter at temperatures between -10 degrees and 50 degreesC. Under these conditions, four different ice forms were observed to melt: two stable phases, ice V and ice VI, and two metastable phases, ice IV and the new ice phase. The Raman spectra and crystal morphology are consistent with a disordered anisotropic structure with some similarities to ice VI.     

Observations on the indirect transmission of virulent ovine footrot in sheep yards and its spread in sheep on unimproved pasture

SUMMARY: Virulent ovine footrot was transmitted accidentally to a group of 23 adult Merino sheep (flock B) after holding for 1 hour in sheep yards, which earlier the same day had contained another flock (flock A) with < 1% prevalence of sheep with footrot lesions. Sheep in flock B were rendered susceptible to virulent footrot by grazing 600 mm high unimproved pasture dominated by paspalum ( Paspalum dilatatum ) and kangaroo grass ( Themeda australis ) during warm, humid and wet weather. In addition to moisture, interdigital abrasions caused by the pasture might have predisposed the interdigital skin to infection with Dichelobacter nodosus .     

Detection of Clostridium botulinum types C and D toxin by ELISA

An ELISA to detect Clostridium botulinum type D toxin was developed using polyclonal antibodies to a semi-purified toxic complex of the neurotoxin. Sensitivity of the ELISA for detecting type C and type D toxin compared with mouse inoculation was 70% and specificity 96% on samples from animals with botulism diagnosed on clinical signs and herd history. However, both mouse inoculation and the ELISA failed to detect toxin in many animals with a presumptive diagnosis of botulism. Some cross-reaction was seen with Clostridium novyi type A, but not with other clostridial species. While the ELISA described here cannot replace mouse inoculation for the diagnosis of botulism, it is a useful additional test.     

Efficiency of a novel biodegradable pyrolysis liquid-amended mulch in weed control

Agrochemicals and plastics represent a burden on natural ecosystems and there is an urgent need to introduce alternative plant protection measures that have fewer negative impacts on the environment. Replacement of plastic mulches and synthetic pesticides with their biodegradable alternatives offers a way to decrease chemical residues. Pyrolysis liquids (PL) have been suggested as easily degradable and residue-free herbicides for agriculture. We tested the efficiency of PL (1%–10% of volume) containing peat mulch (PLM) in weed control under glasshouse and field conditions. We also estimated the length of the withdrawal period needed between PLM spreading and sowing/planting for crops and examined the light permeability and effects of PLM on soil temperature. In the glasshouse, the mulch amended with 5%–10% PL inhibited weed germination entirely. In the agricultural field, the number of weeds remained 44%–60% lower under PLM than under the control mulch. In a study performed in a city park, weed cover around the base of trees remained 64%–85% lower under PLM than without a mulch. However, a 7–21 d withdrawal period, depending on crop plant species, is needed to avoid injuring the crops. PLM inhibited sunlight effectively and the effects on soil heat sum across the growing season remained small. The weed-inhibiting effect of PLM is probably a result of both the PL compounds and the solid cover, formed by the sticky PL and peat fibres, which acts as a mechanical barrier. We conclude that the PLM is a promising alternative to plastic mulches.     

不同水分条件下施用稻草对土壤有机酸和有效磷的影响

稻草在分解过程中产生有机酸。高浓度的有机酸一方面对水稻生长产生毒害作用，另一方面，有机酸可通过酸溶、螯合和竞争吸附等机制活化土壤难溶态磷，提高磷的生物有效性。所以，研究稻草分解过程中有机酸和有效磷的动态变化，对于评价稻草还田在水稻营养中的作用，指导秸秆管理具有十分重要的意义。     

Diagnosis of hyperadrenocorticism in dogs: a survey of internists and dermatologists

OBJECTIVE: To determine testing protocols used by board-certified internists and dermatologists for diagnosis of hyperadrenocorticism (HAC) in dogs. DESIGN: Survey. STUDY POPULATION: Board-certified internists and dermatologists. PROCEDURE: A questionnaire was mailed to 501 specialists to gather information pertaining to diagnosis of HAC. RESULTS: 206 surveys were returned. Only 26% of respondents indicated they would screen a dog for HAC if the dog had only a few laboratory abnormalities consistent with HAC and no clinical signs consistent with the disease; 31% indicated they would not, and 43% indicated they would sometimes. Overall, 55% of respondents indicated they preferred to use the low-dose dexamethasone suppression test for routine screening of dogs suspected to have HAC. However, many respondents indicated they would use a different screening test than usual in particular circumstances. Sixty-eight percent of respondents indicated they would perform a second screening test for confirmation if results of an initial screening test were positive but there were few clinical or laboratory abnormalities consistent with HAC. Most respondents used some sort of test to differentiate pituitary-dependent HAC from HAC secondary to an adrenal tumor (AT), but no 1 test was clearly preferred. Ultrasonography was commonly used, whereas computed tomography and magnetic resonance imaging were not, even if available. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the low-dose dexamethasone suppression test is the test most commonly used to screen dogs for HAC but that other tests may be used in certain circumstances. A variety of tests were used to differentiate pituitary-dependent HAC from HAC secondary to an AT.     

Effects of dexamethasone infusion on the plasma cortisol response to cosyntropin (synthetic ACTH) injection in normal dogs

Graded dosages of cosyntropin (synthetic corticotropin) were injected into groups of normal dogs on consecutive days. On the first day, cosyntropin was administered alone and, on the second, dogs were infused with dexamethasone three hours before cosyntropin injection. Adrenocortical function was assessed by sequential measurement of plasma cortisol (hydrocortisone) concentration. While no response differences were noted to the various amounts of cosyntropin injected with or without dexamethasone pretreatment, the magnitude of adrenocortical response was significantly greater in dogs infused with dexamethasone. It is concluded that dexamethasone pretreatment renders the canine adrenal cortex more responsive to a subsequent injection of cosyntropin. The combined dexamethasone infusion-cosyntropin injection test produces consistent adrenocortical responses in normal dogs, and has potential value in evaluation of adrenopathic dogs.     

Functional and morphological studies on blood platelets in a thrombasthenic horse

A four-year-old Standardbred gelding presented with a 3.5 year history of intermittent epistaxis and spontaneous submucosal petechiae and ecchymoses in the nares and the mouth. Routine haematological and biochemical examinations were unremarkable. A thrombocytopathy was suspected when activated partial thromboplastin time, one stage prothrombin time, plasma fibrinogen and the platelet count were all normal. The patient's platelets failed to aggregate with serotonin, adenosine diphosphate, collagen (at 20 micrograms/ml) or the endoperoxide analogue U46619. Very high levels of collagen (100 micrograms/ml) did cause aggregation. The response to the calcium ionophore A23187 was reduced and although complete degranulation occurred the resulting aggregates were unstable. Thromboxane generation in response to collagen and ADP was inferred from the concentration of its stable metabolite thromboxane B2 and was reduced. A diagnosis of a thrombasthenia-like syndrome possibly equivalent to Type II Glanzmann's thrombasthenia in people was made.