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51.
Chemical Characterization of Rain and Fog Water in the Cervenohorske Sedlo (Hruby Jesenik Mountains, Czech Republic) 总被引:1,自引:0,他引:1
Field study at the Cervenohorske sedlo (1,013 m a.s.l.) (Hruby Jesenik Mountains, the Czech Republic, Central Europe) during 1999–2002 has been conducted in order to analyse the chemistry of rain/snow water using bulk and throughfall collector and fog/cloud water using modified passive Grunow collector. Fog water input to coniferous forest (Picea abies) was quantified using canopy balance method. For all samples pH, and the concentrations of $ {\text{NH}}^{{\text{ + }}}_{{\text{4}}} $ , Ca2+, K+, Mg2+, Na+, Cl?, $ {\text{NO}}^{{\text{ - }}}_{{\text{3}}} $ , and $ {\text{SO}}^{{{\text{2 - }}}}_{{\text{4}}} $ were measured. The volume-weighted mean pH value varied from 4.92 to 5.43 in open bulk precipitation, from 4.30 to 4.71 in throughfall and from 4.66 to 5.23 in fog water. The fog droplets generally contain higher ion concentrations than rainwater. The related enrichment factors lie between 1.1 and 10.7 for the relevant species. The fog samples exhibit higher concentrations of $ {\text{NO}}^{{\text{ - }}}_{{\text{3}}} $ and $ {\text{NH}}^{{\text{ + }}}_{{\text{4}}} $ as compared to the bulk samples during 2000–2002. $ {\text{NO}}^{{\text{ - }}}_{{\text{3}}} $ are 5.7–10.7 times more concentrated in fog water and $ {\text{NH}}^{{\text{ + }}}_{{\text{4}}} $ are 3.4–7.2 times more concentrated in fog water. These differences may result from the height and characteristics of formation of the droplets. Based on canopy balance method, the annual fog water inputs were estimated to be 22 and 19% of rain and snow annual amounts in 1999 and 2000, respectively. For $ {\text{NO}}^{{\text{ - }}}_{{\text{3}}} $ , $ {\text{NH}}^{{\text{ + }}}_{{\text{4}}} $ , and $ {\text{SO}}^{{{\text{2 - }}}}_{{\text{4}}} $ , the contribution of fog deposition in total (bulk + fog) deposition is estimated as 54, 47, and 42%, respectively. 相似文献
52.
Glyphosate was recently evaluated for its potential to interact with the estrogen, androgen and thyroid (EAT) hormone pathways, including steroidogenesis, under the United States Environmental Protection Agency's (USEPA) Endocrine Disruptor Screening Program (EDSP), then by Germany, the rapporteur Member State who led the European Annex 1 renewal for glyphosate, and then by the European Food Protection Agency (EFSA) also as part of the Annex 1 renewal for glyphosate. Under the EDSP, 11 Tier 1 assays were run following the USEPA's validated 890‐series test guidelines and included five in vitro and six in vivo assays to evaluate the EAT pathways. Steroidogenesis was evaluated as part of the estrogen and androgen pathways. An up‐to‐date critical review has been conducted that considered results from the EDSP Tier 1 battery, guideline regulatory studies and an in‐depth analysis of the literature studies that informed an endocrine assessment. A strength of this evaluation was that it included data across multiple levels of biological organization, and mammalian and nonmammalian test systems. There was strong agreement across the in vitro and in vivo Tier 1 battery, guideline studies and relevant literature studies, demonstrating that glyphosate does not interact with EAT pathways including steroidogenesis. Based on an analysis of the comprehensive toxicology database for glyphosate and the literature, this review has concluded that glyphosate does not have endocrine‐disrupting properties through estrogen, androgen, thyroid and steroidogenic modes of action. © 2020 Society of Chemical Industry 相似文献
53.
Forterre F Konar M Tomek A Doherr M Howard J Spreng D Vandevelde M Jaggy A 《Journal of the American Veterinary Medical Association》2008,232(4):559-563
OBJECTIVE: To evaluate the accuracy of neurologic examination versus magnetic resonance imaging (MRI) in localization of cervical disk herniation and evaluate the usefulness of withdrawal reflex testing in dogs. DESIGN: Retrospective case series. ANIMALS: 35 client-owned dogs with a single-level cervical disk herniation as determined via MRI. PROCEDURES: 1 of 2 board-certified neurologists performed a complete neurologic examination in each dog. Clinical signs of a cervical lesion included evidence of neck pain and tetraparesis. The withdrawal reflex was used for neuroanatomic localization (C1-C5 or C6-T2). Agreement between results of neurologic and MRI examinations was determined. RESULTS: Agreement between neurologic and MRI diagnoses was 65.8%. In 11 dogs in which the lesion was clinically localized to the C6-T2 segment on the basis of a decreased withdrawal reflex in the forelimbs, MRI revealed an isolated C1-C5 disk lesion. In 1 dog, in which the lesion was suspected to be at the C1-C5 level, MRI revealed a C6-T2 lesion. Cranial cervical lesions were significantly associated with an incorrect neurologic diagnosis regarding site of the lesion. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that the withdrawal reflex in dogs with cervical disk herniation is not reliable for determining the affected site and that a decreased withdrawal reflex does not always indicate a lesion from C6 to T2. 相似文献
54.
55.
Pasnik DJ Vemulapalli R Smith SA Schurig GG 《Veterinary immunology and immunopathology》2003,95(1-2):43-52
A recombinant vaccine was constructed for piscine mycobacteriosis utilizing a Brucella abortus strain RB51 vector expressing a mammalian Mycobacterium sp. 85A antigen. Juvenile striped bass were inoculated with the resulting construct at doses equivalent to 10(6), 10(7), 10(8), 10(9), and 10(10) colony-forming units/fish. Blood and tissue samples from these fish demonstrated significant specific humoral and cell-mediated immune responses towards the 85A antigen in a dose-dependent manner. However, survival studies determined that inoculated fish failed to demonstrate cross-protective responses after live Mycobacterium marinum challenge 70 days post-inoculation. 相似文献
56.
Jaime Viscasillas Christopher J Seymour David C Brodbelt 《Veterinary anaesthesia and analgesia》2013,40(2):212-219
Objective To compare the success by inexperienced anaesthetists of using a modified infraorbital approach to the maxillary nerve with the traditional percutaneous approach. Study design Prospective, randomized, blinded controlled study. Animals Heads from 37 euthanized Beagle and Beagle cross dogs. Methods Four anaesthetists were recruited to perform two different approaches to block the maxillary nerve of the cadavers. The infraorbital (I) approach advanced an intravenous catheter along the infraorbital canal. Earlier measurements from scans of similar heads were used to assess suitable catheter size. The percutaneous (P) approach introduced a needle percutaneously just below the ventral border of the zygomatic arch. The side of the head where the technique was to be performed was randomized. A total volume of 0.5 mL methylene blue was injected in each approach. After completion of injections, head dissections were performed by an investigator unaware of the approach used and staining of the maxillary and pterygopalatine nerves was evaluated. Chi squared analysis examined the relationship between the methods (p < 0.05). Complications related to the techniques, such as intravascular/intraneural injection and location of the dye, were evaluated macroscopically. Results Maxillary nerve staining >6 mm was found in 64.9% (I) versus 21.6% (P) attempts; staining <6 mm was found in 27% (I) versus 21.6% (P); and no nerve staining 8.1% (I) versus 56.8% (M). Pterygopalatine nerve staining was found in 70% (I) versus 21% (P). The infraorbital approach demonstrated significantly higher maxillary and pterygopalatine nerve staining compared to the percutaneous approach (p = 0.001 for both nerves). No evidence of intravascular/intraneural injections was found. Conclusion and clinical relevance The infraorbital approach was more successful than the percutaneous approach when performed by inexperienced anaesthetists. No macroscopic complications were observed. 相似文献
57.
Berman DM Karhadkar SS Hallahan AR Pritchard JI Eberhart CG Watkins DN Chen JK Cooper MK Taipale J Olson JM Beachy PA 《Science (New York, N.Y.)》2002,297(5586):1559-1561
Constitutive Hedgehog (Hh) pathway activity is associated with initiation of neoplasia, but its role in the continued growth of established tumors is unclear. Here, we investigate the therapeutic efficacy of the Hh pathway antagonist cyclopamine in preclinical models of medulloblastoma, the most common malignant brain tumor in children. Cyclopamine treatment of murine medulloblastoma cells blocked proliferation in vitro and induced changes in gene expression consistent with initiation of neuronal differentiation and loss of neuronal stem cell-like character. This compound also caused regression of murine tumor allografts in vivo and induced rapid death of cells from freshly resected human medulloblastomas, but not from other brain tumors, thus establishing a specific role for Hh pathway activity in medulloblastoma growth. 相似文献
58.
59.
Femtosecond time-resolved Faraday rotation spectroscopy reveals the instantaneous transfer of spin coherence through conjugated molecular bridges spanning quantum dots of different size over a broad range of temperature. The room-temperature spin-transfer efficiency is approximately 20%, showing that conjugated molecules can be used not only as interconnections for the hierarchical assembly of functional networks but also as efficient spin channels. The results suggest that this class of structures may be useful as two-spin quantum devices operating at ambient temperatures and may offer promising opportunities for future versatile molecule-based spintronic technologies. 相似文献
60.
David Jenkins 《Biological conservation》1981,20(2):123-132
Habitats for inclusion within otter havens are illustrated from a case-history study on the middle part of the Aberdeenshire River Dee. The environment is divided into breeding and rearing areas and places for non-breeding otters. One good location for a haven incorporating all three habitats includes 12–13 km of river and two nearly lochs. In this area, part of the river bank is inaccessible, and there are secluded islands and deep woods. Havens should include tiny tributaries leading to shelter where otters are likely to have their young. An otter haven in mid-Deeside planned to incorporate all these habitats may be regarded as a model for conservation that could be followed in other similar environments elsewhere. 相似文献