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1.
Carbon storage in the soils on the Qinghai–Tibetan Plateau plays a very important role in the global carbon budget. In the 1990s, a policy of contracting collective grasslands to smaller units was implemented, resulting in a change from the traditional collective grassland management to two new management patterns: a multi‐household management pattern (MMP: grassland shared by several households without enclosures) and a single‐household management pattern (SMP: grassland enclosed and used by only one household). In 2016, 50 MMP and 54 SMP winter pastures on the Qinghai–Tibetan Plateau were sampled to assess the differences in soil organic carbon (SOC) between the two management patterns. Results showed that average SOC was significantly greater under MMP than under SMP, with an estimated 0.41 Mg C/ha/yr lost due to SMP following the new grassland contract. Based on the government's grassland policy, four grassland utilization scenarios were developed for both summer and winter pastures. We found that if the grassland were managed under SMP, likely C losses ranged between 0.31 × 107 and 6.15 × 107 Mg C/yr across the Qinghai–Tibetan Plateau relative to MMP, which more closely resembles pre‐1990s grassland management. Previous estimates of C losses have only considered land use change (with cover change) and ignored the impacts driven by land management pattern changes (without cover change). The new data suggest that C losses from the Qinghai–Tibetan Plateau are greater than previously estimated, and therefore that the grassland contract policy should be reviewed and SMP households should be encouraged to reunite into the MMP. These findings have potential implications for land management strategies not only on the Qinghai–Tibetan Plateau but also other grazing regions globally where such practices may exist.  相似文献   
2.
Each species is characterized by a specific set of chromosomes, which is described as the chromosome portrait or karyotype. In general, such a karyotype is the same for all individuals in the population. An exception to that rule has recently been found in the orchid Erycina pusilla, which has been reported to have two cytotypes with chromosome numbers of 2n = 10 and 2n = 12. Here, we examined the karyotypes of the two cytotypes and found differences in arm ratios and heterochromatin patterns as well as in the presence of satellite chromosomes and in the number and location of rDNA and telomeric repeat sites. These differences are extensive and would have required multiple chromosome rearrangements to generate the differences between the two karyotypes. We also found that F1 hybrids between the parents with the two different chromosome numbers resulted in sterile offspring, in accordance with our previous findings. The combination of hybrid sterility and extensively rearranged chromosomes supports the hypothesis that these two reported cytotypes are, in fact, two different species.  相似文献   
3.
A 6-year-old, mixed breed, intact male dog showed signs of left carpal joint swelling and weakness of the forelimbs one month before presentation. The symptoms gradually progressed to bilateral carpal and tarsal joint swelling and tetraparalysis. There were a number of radiographically identified lytic-proliferative bone lesions noted on the axial skeleton. Hypertrophic osteopathy of the metacarpi and all distal long bones was also evident. Because of the deteriorating quality of life and guarded prognosis, the patient was euthanized and a complete necropsy was performed. Renal cell carcinoma, with metastasis to the lung, thoracic vertebrae, ribs, and the right adrenal gland, was diagnosed. To our knowledge, renal cell carcinoma with bone metastases and hypertrophic osteopathy has not been reported in dogs.  相似文献   
4.
Surgical outcome and complications following evisceration and implantation of intraocular silicone prosthesis (ISP) in 20 canine eyes with end-stage glaucoma were analyzed, including clinical signs, complications, cosmetic appearance, and owners' responses. The mean postoperative follow-up time was 312 days. Major short-term surgical complications were central corneal ulceration (6/20) and infections (3/20), while long-term complication was keratoconjunctivitis sicca (KCS) (2/20). All patient owners (100%) showed satisfied with the surgical outcome and postoperative cosmetic effect including 85% of the owners gave an excellent or good rating of satisfaction. No more medication needed for long term control except the KCS cases. With careful case selection and post-operative care, evisceration with ISP implantation proves a good and safe surgical procedure with minimal complications for end stage glaucoma.  相似文献   
5.
The characteristics of recovery from total intravenous anesthesia (TIVA) with propofol and inhalation anesthesia with isoflurane was clinically compared in 149 client-owned dogs that anesthetized for surgical or diagnostic procedures. In all dogs, anesthesia was induced with an intravenous injection of propofol following premedication with acepromazine or diazepam. As a result, 58 dogs anesthetized with propofol-TIVA showed slower but smoother recovery than 91 dogs anesthetized with isoflurane anesthesia. The dogs stood at 34.5 +/- 19.3 and 27.7 +/- 17.2 min after propofol-TIVA and isoflurane anesthesia, respectively. Adverse effects, including hypersalivation, neurologic excitement (paddling, muscle tremor/twitching, opisthotonos) and vomiting/retching, were observed in similar infrequent incidences during the recovery from both anesthetic protocols. Propofol-TIVA is suggested to be an alternative anesthetic protocol for canine practice.  相似文献   
6.
OBJECTIVE: To investigate the effects of acupuncture on neural activity detected by use of manganese-enhanced functional magnetic resonance imaging (fMRI) and elucidate the relationship between somatic acupoint stimulation and brain activation. ANIMALS: 40 New Zealand White rabbits. PROCEDURE: Manganese-enhanced fMRI was performed in anesthetized rabbits manipulated with electroacupuncture (EA) on Zusanli (ST-36) and Yanglingquan (GB-34) acupoints. Image acquisition was performed on a 1.5T superconductive clinical scanner with a circular polarized extremity coil. T1-weighted images were acquired sequentially as follows: baseline, after mannitol injection, after manganese infusion, and 5 and 20 minutes after initiation of EA. RESULTS: Changes in focal neural activity were detected by use of manganese-enhanced fMRI. Stimulation on Zusanli (ST-36) for 5 minutes resulted in activation of the hippocampus, whereas stimulation on Yanglingquan (GB-34) resulted in activation of the hypothalamus, insula, and motor cortex. Activation became less specific after 20 minutes of EA. Furthermore, stimulation on ipsilateral acupoints led to bilateral brain activation. CONCLUSIONS AND CLINICAL RELEVANCE: Each acupoint has a corresponding cerebral linkage, and stimulation on these points resulted in time-dependent neural activation. Understanding the linkage between peripheral acupoint stimulation and central neural pathways may provide a useful guide for clinical applications of acupuncture.  相似文献   
7.
The efficacy of Mycoplasma hyopneumoniae oral vaccine was investigated in microsphere dosage form. A co-spray drying process was used to apply an encapsulating material, Eudragit L30 D-55, to microspheres containing Mycoplasma hyopneumoniae antigens. The microspheres were generally effective (>93%) with protein release at pH 7.4, but almost none were released at pH 1.2, for 3 hr in an in vitro dissolution test. An SPF-swine model was used to evaluate the effectiveness of the microspheres as an oral vaccine, and the related immune responses. The serum's systemic IgG against M. hyopneumoniae was evoked by ELISA analysis, after a 2nd immunization of all pigs. The vaccinated groups' mean lesion score was significantly lower after the Mycoplasma hyopneumoniae challenge than that of the nonvaccinated/challenged groups (P<0.05). This study strongly suggests that the oral microspheres vaccine prepared by a co-spray drying method can provide effective protection against M. hyopneumoniae infection in pigs.  相似文献   
8.
Oral-vaccine microspheres based on formalin-inactivated Actinobacillus pleuropneumoniae serotype 1 (AP-1) antigens and enteric-coated polymers were prepared using a co-spray drying process. We evaluated using this for a peroral vaccine. We measured specific-antibody titers and protection from challenge in mouse and pig models. In mice (24 per group), a subcutaneous aluminum-adjuvant vaccine or oral vaccination with three doses of AQ6-AP microspheres provided similar protection against intranasal challenge with 5 x 10(8) colony-formation units (cfu) of AP-1 bacterial culture broth. Two weeks after four oral vaccinations with 600 mg of AQ6-AP microsphere acetate solution (containing formalin-inactivated AP-1 antigens of 1.0 x 10(10) cfu bacterial broth), pigs (9 per group) were challenged intranasally with 1 ml of AP-1 bacterial culture broth (5 x 10(9) cfu). The clinical signs, percentage of pig survival ratio, lung lesion areas, and microscopic examinations indicated that the oral AQ6-AP vaccine provided more protection than vaccinating pigs intramuscularly with AP-1 aluminum vaccine.  相似文献   
9.
Papaya ringspot virus (PRSV) HA 5-1, a nitrous acid-induced mild mutant of severe strain HA, widely applied for control of PRSV by cross-protection, was used to study the genetic basis of attenuation. Using infectious clones, a series of recombinants was generated between HA 5-1 and HA and their infectivity was analyzed on the systemic host papaya and the local lesion host Chenopodium quinoa. The recombinants that contained mutations in P1 and HC-Pro genes caused attenuated infection on papaya without conspicuous symptoms, similar to HA 5-1. The recombination and sequence analyses strongly implicated two amino acid changes in the C-terminal region of P1 and two in HC-Pro of HA 5-1 involved in the attenuated infection on papaya. The recombinants that infected C. quinoa plants without local lesions contained the same mutations in the C-terminal region of HC-Pro for attenuated infection on papaya. We conclude that both P1 and HC-Pro bear important pathogenicity determinants for the infection on the systemic host papaya and that the mutations in HC-Pro affecting pathogenicity on papaya are also responsible for the inability to induce hypersensitive reaction on C. quinoa.  相似文献   
10.
Chu FH  Yeh SD 《Phytopathology》1998,88(4):351-358
ABSTRACT Double-stranded genomic RNAs (dsRNAs) extracted from Chenopodium quinoa infected with watermelon silver mottle virus (WSMV) were similar to those of tomato spotted wilt virus (TSWV, serogroup I) and impatiens necrotic spot virus (INSV, serogroup III), except that the S dsRNA of WSMV is 0.75 and 0.6 kbp longer than those of TSWV and INSV, respectively. The complete nucleotide sequence of the genomic M RNA of WSMV was determined from cDNA clones generated from separated M dsRNA. The M RNA is 4,880 nucleotides in length with two open reading frames (ORFs) in an ambisense organization. The M RNA-encoded nonstructural (NSm) ORF located on the viral strand encodes a protein of 312 amino acids (35 kDa), and the G1/G2 ORF located on the viral complementary strand encodes a protein of 1,121 amino acids (127.6 kDa). The RNA probe corresponding to the NSm or G1/G2 ORF of WSMV failed to hybridize with the M dsRNAs of TSWV and INSV. Comparison of M and S RNAs of WSMV, TSWV, INSV, and peanut bud necrosis virus (PBNV, serogroup IV) revealed a consensus sequence of eight nucleotides of 5'-AGAGCAAU...-3' at their 5' ends and 5'-...AUUGCUCU-3' at their 3' ends. The low overall nucleotide identities (56.4 to 56.9%) of the M RNA and the low amino acid identities of the NSm and G1/G2 proteins (30.5 to 40.9%) with those of TSWV and INSV indicate that WSMV belongs to the Tospovirus genus but is phylogenetically distinct from viruses in serogroups I and III. The M RNA of WSMV shares a nucleotide identity of 79.6% with that of PBNV, and the two viruses share 83.4 and 88.7% amino acid identities for their NSm and G1/G2 proteins, respectively. It is concluded that they are two related but distinct species of serogroup IV. In addition to the viral or viral complementary full-length M RNA, two putative RNA messages for the NSm gene and the G1/G2 gene, 1.0 and 3.4 kb, respectively, were detected from the total RNA extracted from WSMV-infected tissue of Nicotiana benthamiana. The 1.0- and 3.4-kb RNAs were also detected in the viral RNAs extracted from purified nucleocapsids, suggesting that the putative messages of the M RNA of WSMV can also be encapsidated by the nucleocapsid protein.  相似文献   
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