Multi‐channel visual evoked potential as an ancillary tool to diagnose intraorbital optic nerve lesions

Multi‐channel visual evoked potential (MVEP) recording method was used to assist in diagnosing a 4‐month‐old Chinese Albino rabbit with an intraorbital mass. Subcutaneous MVEP of its both eyes were recorded simultaneously using 16 electrodes (4 × 4) multi‐channel array. Analysis of the cortical potential landscapes (CPL) showed that the conduction function of right eye was remarkably impaired in terms of decreased amplitudes and prolonged latencies. Specific side‐dominant distribution asymmetry of the decreased MVEP amplitudes indicated that the temporal side of the optic nerve (ON) was severely involved. Overall prolonged latencies of the CPL without side differences suggested that the functional impairment could have been caused by the mechanical compression exerted by an intraorbital mass. Surgical removal procedures confirmed that the mass was located temporally to the ON. Pathological examination provided a final diagnosis of a giant polycystic mucocele. Beyond its significance as a standard tool to assess functional changes of the visual pathway, MVEP recordings might assist locating intraorbital lesions that involve the ON by careful analysis of abnormal CPLs.     

Caudal epidural co-administration of methadone and morphine in horses: An evaluation of analgesic properties and effects on locomotor function,mentation and physical examination parameters

Caudal epidural analgesia is a well-established therapeutic modality for pain alleviation in horses. Additionally, epidural analgesia could potentially be a complementary diagnostic tool for confirmation of pain-related conditions in horses presenting with nonspecific signs of poor performance or rideability issues. To use the epidural as a diagnostic tool, the administered medications should provide efficient analgesia without accompanying adverse effects. Therefore, the objectives of the current study were to evaluate the analgesic properties and effects on locomotor function, mentation and physical examination parameters of caudal epidural co-administration of methadone and morphine in horses. Five mares received a caudal epidural injection of 0.1 mg/kg bwt methadone and 0.1 mg/kg bwt morphine diluted to a total volume of 4.4 mL/100 kg. Before and several times thereafter, horses were subjected to mechanical nociceptive threshold evaluation, physical examination, assessment of mentation and locomotor function examination. Horses were assigned ataxia scores (0–4) by a group of inexperienced raters (three senior-year veterinary students) and a group of experienced raters (two board-certified internal medicine specialists) that assessed the locomotor examinations either live or video-based. The epidural co-administration of methadone and morphine resulted in clinically relevant and statistically significant increases of horses’ tolerance to mechanical noxious stimuli at the coccygeal, perineal, sacral, lumbar and thoracic regions. Analgesia was evident after 4.4 h and lasted at least 5 h. Regional differences in the onset of analgesia reflected a cranial spread of the analgesic solution. No horses showed signs of gait disturbances; the overall median ataxia score was 0 at all times; and the average difference in scores between two randomly selected raters for a random horse at a random time point was 0.377 indicating high inter-rater agreement. There were no adverse changes of mentation and physical examination parameters. Observed side effects included signs of decreased frequency of defaecation, generalised sweating, and pruritus.     

保护草原 增强草原碳汇功能

在全球气候变暖对人类生存和发展产生严峻挑战的背景下,全球陆地生态系统碳循环成了世界各国科学家研究的热点。草原是我国最大的陆地生态系统,具有丰富的碳储量,草原生态系统碳收支对我国乃至世界陆地生态系统的碳平衡都具有非常重要的影响。为此,对国内外草地生态系统碳储量估算研究进展、我国草原的退化问题及草原生态系统固碳技术措施与潜力进行了简要概述,提出了加强草原保护、增强草原生态系统固碳能力的对策与建议。     

Formation of zinc protoporphyrin IX in Parma-like ham without nitrate or nitrite

Zinc protoporphyrin IX (ZPP) is a characteristic red pigment in meat products that are manufactured without the addition of a curing agent such as nitrate or nitrite. To examine the effects of impurities such as mineral components in sea salt on the formation of ZPP, we manufactured Parmatype dry-cured hams that were salted with refined salt or sea salt and examined the involvement of oxidation-reduction potential (ORP) in the formation of ZPP. The content of ZPP was increased drastically after 40 weeks. Microscopic observation showed strong fluorescence caused by ZPP muscle fiber after 40 weeks. Conversely, heme content varied considerably during processing. ORP increased during processing. However, there was no obvious difference between ham salted with refined salt and that salted with sea salt. Therefore, it was concluded that impurities in sea salt were not involved in the formation of ZPP.     

Effects of remifentanil on monophasic action potential and transmural dispersion of repolarization in rabbit myocardium

AIM: To study the effect of remifentanil on monophasic action potential and transmural dispersion of repolarization (TDR) in the 3-layer myocardium of isolated rabbit hearts. METHODS: Adult rabbits (n=18, 2.0 ~ 2.5 kg) were used to isolate the hearts for preparing Langendorff perfusion model. The hearts were randomly divided into 3 groups after perfusion with K-H solution for 15 min: the perfusion in control group (C group) continued for 60 min; the hearts in remifentanil group (R group) were perfused with 12 μg/L remifentanil K-H solution for 60 min; the hearts in remifentanil+aminophylline group (RA group) were given 60-min perfusion of 12 μg/L K-H remifentanil+30 mg/L aminophylline. The HR and 3 layers of myocardial monophasic action potential (MAP) in the left ventricular anterior wall were recorded at time points after balanced infusion for 15 min (T₀), and continued perfusion for 15 min (T₁), 30 min (T₂) and 60 min (T₃). The monophasic action potential duration of repolarization at 90% (MAPD₉₀) and the transmural dispersion of repolarization (TDR) were calculated. The early afterdepolarization, delay afterdepolarization and arrhythmia were also observed. RESULTS: In R group, slower HR and prolonger MAPD₉₀ and TDR at T₁~T₃ were observed as compared with those at T₀ (P<0.05). R group showed slower HR and longer MAPD₉₀ and TDR than C group and RA group (P<0.05). CONCLUSION: Remifentanil slows the HR, extends the MAPD₉₀ and increases the TDR, thus being prone to induce reentry. Aminophylline makes HR faster and MAPD₉₀ shorter, thereby reducing the TDR.     

中国城镇化过程中村庄土地整理潜力估算

该文在理论分析的基础上，创建了一个定量的数学模型来估算村庄土地整理净增加的潜力。估算结果表明，全国平均整理系数2010年为1.42～2.42、2030年为2.27～3.27，分别可净增加耕地面积173.81～296.58万hm²、279.10～401.86万hm²。通过对不同时间和不同生态区的整理系数比较，村庄土地整理潜力具有明显的时空分布规律。在时序上，随着社会经济的发展和城镇化水平的提高，我国农村人口会逐渐减少，整理潜力逐渐增大；在空间上，东部和中部村庄土地     

中南地区节水农业建设的战略思考

本文在阐述了中南地区发展节水农业的战略地位和重要性的基础上，分析了中南地区的自然和社会经济条件、农业用水的供需矛盾和节水潜力．以及节水农业建设存在的问题，从思想认识，规划协调、投入，技术研究、种植结构调整、农产品质量诸方面．提出发展节水农业是中南地区农业可持续发展的战略举措。     

不同工艺对牛粪堆沤肥过程气体排放的影响

堆沤肥是中国畜禽粪便处理利用的最主要方式。为探究不同堆沤肥方式对温室气体和氨气排放规律和温室效应,在北京市密云区开展了为期71d的堆沤肥试验,以牛粪和玉米秸秆为原料,分析了静态堆沤 (T1)、堆沤+翻抛 (T2)、堆沤+覆膜 (T3)、翻抛+覆膜 (T4)等4种方式对堆沤肥过程中腐熟度、温室气体和氨气等指标的影响。结果表明,4个处理的种子发芽指数分别达到131.33%、134.49%、108.76%和136.24%,均满足堆肥产品的腐熟度要求（≥70%）。翻抛有利于CO₂、N₂O和NH₃的排放,而覆膜抑制了N₂O的生成,T2处理的增温潜势最高,T3处理的增温潜势最低,较对照组T1处理减排20.14%。因此,T3处理在能够保证堆肥产品的腐熟度要求的前提下,还可有效减少增温潜势。该研究可为中小养殖场户堆沤肥的工艺优化实践提供技术指导。     

Effects of drought on chlorophyll fluorescence in potato (Solanum tuberosum L.). I. Plant water status and the kinetics of chlorophyll fluorescence

Summary The slow kinetics of chlorophyll fluorescence were examined in seven potato genotypes grown either fully irrigated or droughted from the time of plant emergence. Constant and variable fluorescence (F _o andF _v respectively) declined with time in plants from both irrigated and droughted treatments, but the decline was greater in droughted than irrigated plants. However, the yield of variable fluorescence (F _v/(F _o+F _v)) was unaffected by the drought treatment. The main effect of drought was upon the quenching of variable fluorescence. Both the half life of the decay of variable fluorescence (q_1/2) and the secondary maximum (M) were significantly greater in the droughted plants than in those from the irrigated treatment. Significant differences between genotypes were found forF _v/(F _o+F _v),M andq _1/2. Genotype-by-treatment interactions were non-significant for all the variables examined. Changes in chlorophyll fluorescence transients were not closely related to changes in leaf water potential.     

Critical period for grain number establishment of near isogenic lines of two- and six-rowed barley

In barley no studies have attempted to pinpoint the critical period for grain number determination, and it is frequently stated that the critical period is similar to that of wheat. However, there are important differences between the species and among barley genotypes (i.e. two- and six-rowed types) suggesting that this assumption requires testing. The objectives of this paper were (i) to determine the critical period for grain number determination in two- and six-rowed barleys, and (ii) to identify which yield components were more sensitive to changes in incident radiation during that period.

Two field experiments were conducted using two pairs of near isogenic lines differing only in the spike type. Shading was imposed at different periods throughout the crop cycle (from 60 days before heading to 15 days after) to reduce incident solar radiation approximately 70%.

The critical period for grain number determination tended to be slightly earlier in two- (ca. between 40 and 10 days before heading) than in six-rowed barleys (ca. between 30 days before heading until that stage). In terms of the external phenology, the beginning of the critical period for setting grains was 10 days after the beginning of stem elongation, and 10 days before flag leaf appearance in two- and six-rowed lines, respectively. Changes in the number of grains per unit area were correlated with crop growth rate during the critical period for yield determination.