Monitoring distances travelled by horses using GPS tracking collars     

BA Hampson  JM Morton  PC Mills  MG Trotter  DW Lamb  CC Pollitt 《Australian veterinary journal》2010,88(5):176-181

Objective The aims of this work were to (1) develop a low-cost equine movement tracking collar based on readily available components, (2) conduct preliminary studies assessing the effects of both paddock size and internal fence design on the movements of domestic horses, with and without foals at foot, and (3) describe distances moved by mares and their foals. Additional monitoring of free-ranging feral horses was conducted to allow preliminary comparisons with the movement of confined domestic horses. Procedures A lightweight global positioning system (GPS) data logger modified from a personal/vehicle tracker and mounted on a collar was used to monitor the movement of domestic horses in a range of paddock sizes and internal fence designs for 6.5-day periods. Results In the paddocks used (0.8–16 ha), groups of domestic horses exhibited a logarithmic response in mean daily distance travelled as a function of increasing paddock size, tending asymptotically towards approximately 7.5 km/day. The distance moved by newborn foals was similar to their dams, with total distance travelled also dependent on paddock size. Without altering available paddock area, paddock design, with the exception of a spiral design, did not significantly affect mean daily distance travelled. Feral horses (17.9 km/day) travelled substantially greater mean daily distances than domestic horses (7.2 km/day in 16-ha paddock), even when allowing for larger paddock size. Conclusions Horses kept in stables or small yards and paddocks are quite sedentary in comparison with their feral relatives. For a given paddock area, most designs did not significantly affect mean daily distance travelled.  相似文献   

A 32-kD GTP-binding protein associated with the CD4-p56lck and CD8-p56lck T cell receptor complexes   总被引：10，自引：0，他引：10  

J C Telfer  C E Rudd 《Science (New York, N.Y.)》1991,254(5030):439-441

The guanosine triphosphate (GTP)-binding proteins include signal-transducing heterotrimeric G proteins (for example, Gs, Gi), smaller GTP-binding proteins that function in protein sorting, and the oncogenic protein p21ras. The T cell receptor complexes CD4-p56lck and CD8-p56lck were found to include a 32- to 33-kilodalton phosphoprotein (p32) that was recognized by an antiserum to a consensus GTP-binding region in G proteins. Immunoprecipitated CD4 and CD8 complexes bound GTP and hydrolyzed it to guanosine diphosphate (GDP). The p32 protein was covalently linked to [alpha-32P]GTP by ultraviolet photoaffinity labeling. These results demonstrate an interaction between T cell receptor complexes and an intracellular GTP-binding protein.  相似文献   

Quantum-confined stark effect in single CdSe nanocrystallite quantum dots     

SA Empedocles  MG Bawendi 《Science (New York, N.Y.)》1997,278(5346):2114-2117

The quantum-confined Stark effect in single cadmium selenide (CdSe) nanocrystallite quantum dots was studied. The electric field dependence of the single-dot spectrum is characterized by a highly polarizable excited state ( approximately 10(5) cubic angstroms, compared to typical molecular values of order 10 to 100 cubic angstroms), in the presence of randomly oriented local electric fields that change over time. These local fields result in spontaneous spectral diffusion and contribute to ensemble inhomogeneous broadening. Stark shifts of the lowest excited state more than two orders of magnitude larger than the linewidth were observed, suggesting the potential use of these dots in electro-optic modulation devices.  相似文献   

The Origin of the Great Bend of the Nile from SIR-C/X-SAR Imagery     

RJ Stern  MG Abdelsalam 《Science (New York, N.Y.)》1996,274(5293):1696-1698

The course of the Nile in northern Sudan follows a contorted path through Precambrian bedrock. Radar imagery shows that basement structures control the river's course in this region. Northward-flowing segments follow Precambrian fabrics, whereas east-west segments follow faults of much younger age. These faults may reflect recent uplift of the Nubian Swell and deflection of the river to the southwest to form the great bend of the Nile.  相似文献   

ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING A COMPOSITE COLLAGENOUS PROSTHESIS: A BIOMECHANICAL AND HISTOLOGIC STUDY IN RABBITS     

Dunn MG  Tria AJ  Kato YP  Bechler JR  Ochner RS  Zawadsky JP  Silver FH 《Veterinary surgery : VS》1993,22(1):56-56

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Nasal infection with Scedosporium apiospermum in a dog     

MG Coleman  MC Robson 《New Zealand veterinary journal》2013,61(1):81-83

CASE HISTORY: A 2-year-old female Siberian Husky was presented with a 6-month history of sneezing and mucous discharge from the right nostril.

CLINICAL FINDINGS: Reduced airflow through the right nostril was evident. Radiographs showed subtle loss of detail of turbinates within the right nasal chamber. Rhinoscopy revealed swollen and erythematous turbinates and a white mass within the caudal aspect of the right nasal cavity. Histopathologically, there was a heavy mixed inflammatory infiltrate in the submus- cosa of the right turbinate, and the presence of fungal hyphae and spores in the white mass. A heavy growth of Scedosporium apiospermum was cultured from the mass.

DIAGNOSIS: Chronic rhinitis of the right nasal cavity and infection with S. apiospermum.

CLINICAL RELEVANCE: This is the first reported case of S. apiospermum isolated from the nasal cavity of a dog in New Zealand. Fungal culture is necessary to differentiate this fungus from Aspergillus spp.  相似文献   

Pancreatic cyst in a cat     

MG Coleman  MC Robson  C Harvey 《New Zealand veterinary journal》2013,61(2):157-159

CASE HISTORY: A 5-year-old neutered male Cornish Rex cat was presented for evaluation with a history of vomiting over the previous 5 days.

CLINICAL FINDINGS: An abdominal mass was palpated, which was shown to be cystic by ultrasound examination. Exploratory surgery revealed this to be associated with the pancreas and it was duly resected. Histopathology was performed on the cystic mass.

DIAGNOSIS: Pancreatic cyst with associated chronic active infl ammation.

CLINICAL RELEVANCE: This is the first report of a true pancreatic cyst in a cat.  相似文献   

Pathogenesis of reproductive failure induced by Trypanosoma vivax in experimentally infected pregnant ewes     

Taciana MF Silva  Roberio G Olinda  Carla MF Rodrigues  Ant?nio CL Camara  Francisco C Lopes  Wesley AC Coelho  Múcio FB Ribeiro  Carlos IA Freitas  Marta MG Teixeira  Jael S Batista 《Veterinary research》2013,44(1):1

The present study was aimed at investigating the effect of experimental infection by Trypanosoma vivax in different stages of pregnancy, determining the pathogenesis of reproductive failure, and confirming transplacental transmission. We used 12 pregnant ewes distributed into four experimental groups: G1, was formed by three ewes infected with T. vivax in the first third of pregnancy (30 days); G2 comprised three infected ewes in the final third of pregnancy (100 days); G3 and G4 were composed of three non-infected ewes with the same gestational period, respectively. Each ewe of G1 and G2 was inoculated with 1.25 × 10⁵ tripomastigotes. Clinical examination, determination of parasitemia, serum biochemistry (albumin, total protein, glucose, cholesterol, and urea), packed cell volume (PCV), serum progesterone, and pathological examination were performed. Placenta, amniotic fluid, blood and tissues from the fetuses and stillbirths were submitted to PCR. Two ewes of G1 (Ewe 1 and 3) presented severe infection and died in the 34^th and 35^th days post-infection (dpi), respectively; but both fetuses were recovered during necropsy. In G2, Ewe 5 aborted two fetuses on the 130^th day (30 dpi) of pregnancy; and Ewe 6 aborted one fetus in the 140^th day (40 dpi) of gestation. Ewes 2 and 4 delivered two weak lambs that died five days after birth. Factors possibly involved with the reproductive failure included high parasitemia, fever, low PCV, body score, serum glucose, total protein, cholesterol, and progesterone. Hepatitis, pericarditis, and encephalitis were observed in the aborted fetuses. The presence of T. vivax DNA in the placenta, amniotic fluid, blood, and tissues from the fetuses confirms the transplacental transmission of the parasite. Histological lesion in the fetuses and placenta also suggest the involvement of the parasite in the etiopathogenesis of reproductive failure in ewes.  相似文献   

Media coverage of lethal control: A case study of kangaroo culling in the Australian Capital Territory     

Merryn McKinnon  Mizaan Ahmad  Meg Bongers  Rory Chevalier  Isabel Telfer  Clare Van Dorssen 《Human Dimensions of Wildlife》2018,23(1):90-99

Culling kangaroos, Australia’s most abundant marsupial, is a controversial practice in the Australian Capital Territory (ACT). The ACT government introduced a kangaroo management plan in response to the growing kangaroo population causing damage in grassland ecosystems. Although some groups (e.g., local government, some researchers) support implementation of this plan, critics claim it is inhumane and lacks concrete evidence. To examine media portrayal of this debate, this study conducted a content analysis of newspaper coverage between 2006 and 2016. Although ACT newspapers were impartial in their presentation of the debate, sources that previous studies found were typically considered trustworthy to speak on the scientific validity of the program were found to have conflicting messages and be less represented in the media. Thus, future research should explore if the messenger is more important than the message in determining influences on public perceptions about the use of lethal control.  相似文献   

Self-oriented regular arrays of carbon nanotubes and their field emission properties   总被引：4，自引：0，他引：4  

S Fan  MG Chapline  NR Franklin  TW Tombler  AM Cassell  H Dai 《Science (New York, N.Y.)》1999,283(5401):512-514

The synthesis of massive arrays of monodispersed carbon nanotubes that are self-oriented on patterned porous silicon and plain silicon substrates is reported. The approach involves chemical vapor deposition, catalytic particle size control by substrate design, nanotube positioning by patterning, and nanotube self-assembly for orientation. The mechanisms of nanotube growth and self-orientation are elucidated. The well-ordered nanotubes can be used as electron field emission arrays. Scaling up of the synthesis process should be entirely compatible with the existing semiconductor processes, and should allow the development of nanotube devices integrated into silicon technology.  相似文献