Comparison of comet 81P/Wild 2 dust with interplanetary dust from comets     

Ishii HA  Bradley JP  Dai ZR  Chi M  Kearsley AT  Burchell MJ  Browning ND  Molster F 《Science (New York, N.Y.)》2008,319(5862):447-450

The Stardust mission returned the first sample of a known outer solar system body, comet 81P/Wild 2, to Earth. The sample was expected to resemble chondritic porous interplanetary dust particles because many, and possibly all, such particles are derived from comets. Here, we report that the most abundant and most recognizable silicate materials in chondritic porous interplanetary dust particles appear to be absent from the returned sample, indicating that indigenous outer nebula material is probably rare in 81P/Wild 2. Instead, the sample resembles chondritic meteorites from the asteroid belt, composed mostly of inner solar nebula materials. This surprising finding emphasizes the petrogenetic continuum between comets and asteroids and elevates the astrophysical importance of stratospheric chondritic porous interplanetary dust particles as a precious source of the most cosmically primitive astromaterials.  相似文献   

The effect of harvest date and rate of nitrogen fertilization on the maturity,yield and chipping quality of potatoes     

G. W. Hope  D. C. MacKay  L. R. Townsend 《American Journal of Potato Research》1960,37(1):28-33

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Modelling the effects of forest landscape dynamics on focal species in Glen Affric, northern Scotland     

Hope  Joseph C.E.; Humphrey  Jonathan W.; Stone  Duncan 《Forestry》2006,79(3):293-302

Current conservation policies promote expansion of semi-naturalwoodland in order to offset effects of past loss and fragmentation.However, conflicts of interest may occur when such expansionwould be at the expense of open habitats considered to haveconservation value in their own right. Landscape modelling ispresented as a method that may prove useful in resolving complexland use issues such as this. An example is given of a modellingsystem that uses forest dynamics modelling, focal species andhabitat network analysis to address landscape change issuesin Glen Affric, a key area for biodiversity conservation innorthern Scotland. The results suggest that a dispersed patternof woodland expansion may offer the best chances of achievinga balance between woodland and open ground in a single catchment.However, there are high levels of uncertainty associated withboth model input data and some of the ecological assumptionswithin the modelling process. Landscape modelling is an emergingdiscipline, and further work is needed to enhance confidencein model outputs.  相似文献   

Specificity of four serologic assays for Mycobacterium avium ss paratuberculosis in llamas and alpacas: a single herd study.     

D S Miller  M T Collins  B B Smith  P R Anderson  J Kramsky  G Wilder  A Hope 《Journal of veterinary diagnostic investigation》2000,12(4):345-353

An investigation was conducted for Mycobacterium avium ss paratuberculosis infections in a research herd of llamas and alpacas. Herd culture-negative status was established over a 23-month period by screening any individuals with any signs compatible with paratuberculosis (n = 1), high serology values (n = 8), or other health and research related reasons (n = 24). There were no M. avium ss paratuberculosis isolates from radiometric cultures of multiple tissue and fecal samples from these individuals and no known sources of exposure. Paratuberculosis is uncommon in North American llamas and alpacas: only 5 cases were identified after an extensive search of the Veterinary Medical Data Base, diagnostic laboratory records, publication databases, and personal communications. Therefore, serum samples from llamas (n = 84) and alpacas (n = 16) in the culture-negative herd were used to obtain preliminary estimates of test specificity for 3 enzyme-linked immunoassays (ELISAs) and an agar gel immunodiffusion (AGID) assay kit for detecting serum antibodies to M. avium ss paratuberculosis in South American camelids. The ELISAs were modifications of established bovine assays for antibody detection. With provisional cutoffs, ELISA-A had 52 false positives (specificity 48%), ELISA-B had 8 false positives (specificity 92%), ELISA-C had two false positives (specificity 98%), and the AGID had 0 false positives (specificity 100%). The range of ELISA values for culture-positive llamas and alpacas (n = 10) from other herds overlapped the range of values for culture-negative llamas and alpacas. The accuracy of the ELISAs may be improved by using age- and sex-specific cutoffs because uninfected male llamas and alpacas that were older than 1 year had higher values for some tests. These tests can be used for either llamas or alpacas; the protein-G conjugate ELISA (ELISA-B) may be useful for multispecies applications. These assays are best used for rapid presumptive diagnoses of llamas and alpacas with diarrhea and weight loss and as a screening tool for herds known to be exposed to infection. All seropositive results should be confirmed with culture.  相似文献   

Toxicosis in horses after ingestion of hoary alyssum.   总被引：1，自引：0，他引：1  

R J Geor  R L Becker  E W Kanara  L R Hovda  W H Sweeney  T F Winter  J K Rorick  G R Ruth  E Hope  M J Murphy 《Journal of the American Veterinary Medical Association》1992,201(1):63-67

Fever, limb edema, and laminitis were observed in horses 18 to 36 hours after they consumed hoary alyssum (Berteroa incana) under field and experimental conditions. Clinical signs were not observed in all horses that had ingested the plant. Diagnosis in the field cases was limited to observation of clinical signs and evidence of plant ingestion in hay or on pasture. In most cases, clinical remission was observed 2 to 4 days after empirical treatment, removal of the plant source, or both.  相似文献   

Size and shape of the lateral intercellular spaces in a living epithelium   总被引：7，自引：0，他引：7  

K R Spring  A Hope 《Science (New York, N.Y.)》1978,200(4337):54-58

The lateral intercellular spaces of Necturus gallbladder epithelium were seen and measured while the living tissue was perfused in a new chamber. The compliance of the lateral cell membranes was calculated from the measured pressure-volume characteristics of the lateral intercellular spaces.  相似文献   

Masking of two in vitro immunological assays for Mycobacterium bovis (BCG) in calves acutely infected with non-cytopathic bovine viral diarrhoea virus.     

B Charleston  J C Hope  B V Carr  C J Howard 《The Veterinary record》2001,149(16):481-484

Acute infection of calves, previously vaccinated with bacille Calmette-Guerin (BCG), with non-cytopathic viral diarrhoea virus (BVDV) resulted in the temporary suppression of two in vitro assays used to monitor Mycobacterium bovis infection. Lymphocyte proliferation and interferon-gamma production by whole blood cultures containing purified protein derivatives prepared from Mycobacterium avium (PPD-A) and M bovis (PPD-B) were markedly suppressed. The implication is that acute infections of cattle with non-cytopathic BVDV may temporarily compromise diagnostic tests for M. bovis infections and result in a failure to identify cattle with tuberculosis.  相似文献   

Low prevalence of iron-deficiency anaemia among Inuit preschool children: Nunavut Inuit Child Health Survey, 2007-2008     

Pacey A  Weiler H  Egeland GM 《Public health nutrition》2011,14(8):1415-1423

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Cytotoxicity and cytokine production by bovine alveolar macrophages challenged with wild type and leukotoxin-deficient Mannheimia haemolytica     

Kuldeep Singh  Anthony W. Confer  Jayne C. Hope  Theresa Rizzi  John H. Wyckoff III  Hsin-Yi Weng  Jerry W. Ritchey 《Veterinary journal (London, England : 1997)》2011,188(2):221-227

The aim of this study was to investigate the use of ultrasound (US) guidance to perform sciatic and saphenous nerve blocks in dogs. Five dogs were sedated with medetomidine and butorphanol. A high-resolution US transducer was used to locate the nerves, guide placement of the needle and visualise the perineural injection of lidocaine 2%. Electrostimulation was used to confirm correct placement prior to the sciatic block. Nerve functions were evaluated over a 3 h period following administration of atipamezole. Successful identification of the nerves and the quality of the blocks were recorded. Location of the nerves, complete sensory block of the saphenous nerve, and partial to complete sensory and motor blocks of the sciatic nerve were achieved in all dogs. The resultant US guidance is potentially valuable for blocking the sciatic and saphenous nerves in dogs, although further work will be required to ensure a complete block of the sciatic nerve.  相似文献   

Size-fractionated fish hydrolysate as feed ingredient for rainbow trout (Oncorhynchus mykiss) fed high plant protein diets. II: Flesh quality, absorption, retention and fillet levels of taurine and anserine     

Anders Aksnes  Britt Hope  Sissel Albrektsen 《Aquaculture (Amsterdam, Netherlands)》2006,261(1):318-326

In the work to find replacement for fish meal in feed for fish, the inclusion of plant protein sources at high dietary level is an important issue. The present experiment was carried out to reveal how different feed ingredients affected the eating quality of the grown up fish with focus on nitrogen compounds as amino acids, taurine and anserine. Six experimental diets were fed to rainbow trout in triplicates for 90 d. All diets were composed to be equal in protein, lipid, energy and lysine. Three levels of a mixture of plant sources (full fat soy, extracted soy, soy protein concentrate, corn gluten) constituting 57.2%, 73.9% and 90.6% of total dietary protein were used. A small amount of fish meal was added in 5 diets constituting 9.4% of total protein. A fish hydrolysate that was high in free amino acids, taurine and anserine was tested at 16% and 32% dietary inclusion of total protein. Two other diets contained the same level of protein from the same hydrolysate that was ultra filtrated to remove low molecular weight compounds. Digestibility of taurine and anserine was found to be close to 99% for all groups, except for the group containing high level of plant sources. The levels of taurine in whole trout and fillets decreased during the feed experiment, but were about the same for all groups at the end of the feeding experiment and independent of dietary levels. The level of anserine in fish and fillets was equal from start to end of the experiment and independent of dietary inclusion. Taurine and anserine therefore seem to be homeostatic regulated in trout and independent on dietary levels. Amino acid content in fish and fillet was also equal for all groups and independent of protein sources used in the diets. The chemical composition showed higher lipid and dry matter levels in fish and fillet in fish that grew the fastest. In conclusion, plant protein sources may be included in diets for trout at high levels without affecting the eating quality as evaluated by amino acids, taurine and anserine levels.  相似文献