基于称量反馈的设施番茄灌溉系统的构建与应用

为提高设施番茄灌溉的精准性,该研究设计了一种基于称量反馈的灌溉系统,该系统包括称量反馈模块、多源信息采集传输模块、灌溉决策模块与水肥执行模块。称量反馈灌溉决策首先利用卫星定位模组获取灌溉地经纬度信息自动计算当天的日出时刻、日落时刻、日中时刻,结合椰糠条吸水特性与番茄植株日需水量变化规律,把1 d自动划分为4个不同的动态灌溉阶段;根据温室内温湿度信息及排液电导率（electrical conductivity,EC）值反馈的番茄植株根部信息,制定了一般模式灌溉肥液或洗盐模式灌溉清水（或低浓度营养液）。设计试验以基于辐射累积控制灌溉、定时灌溉作为对照,分别从栽培效果、灌溉效果、应用效益方面验证该灌溉系统的应用效果。结果显示使用该称量反馈灌溉系统比基于辐射累积控制灌溉系统灌溉量增加1.8%,用肥量减少7.3%,排液比降低7.9%,排液EC值降低9.3%;与定时灌溉方式相比灌溉量减少11.3%,用肥量减少20.0%,排液比降低17.9%,排液EC值降低4.9%。栽培效果显示,使用该称量反馈灌溉系统的椰糠条栽培番茄在茎粗、叶片叶绿素相对含量、糖度值、单穗质量和基于辐射累积的控制灌溉相比无显著性差异（P>0.05）,但株高增加4.8%;与定时灌溉相比在株高、茎粗、叶片叶绿素相对含量、糖度值、单穗质量均无显著性差异（P>0.05）。预计使用该称量反馈灌溉系统,园区15栋日光温室（1.22 hm²）相比基于辐射累积控制灌溉,应用效益月节约0.276万元,与定时灌溉方式相比,园区月节约2.247万元。该系统简化了番茄植株需水量的计算过程,实现了番茄栽培水分的精准感知与按需精量灌溉。     

The effects of cyclophosphamide and its uroprotective agents, mesna and hyperbaric oxygen, on urinary bladder motility in guinea pigs

The aim of this research was to observe the effects of cyclophosphamide and its uroprotective agents, mesna and hyperbaric oxygen (HBO), on the motility of urinary bladder muscle in guinea pigs. In the experimental groups, mesna and cyclophosphamide were intraperitoneally injected at a dose of 21.5 mg/kg and 68.1 mg/kg, respectively. For the combination of mesna and cyclophosphamide, one dose of mesna was injected 20 min before cyclophosphamide administration and three additional injections of mesna were repeated every three hours. A total of 8 HBO exposures were performed at 2.8 ATA for 90 min twice daily for another experimental group. In the HBO and cyclophosphamide combined group 5 HBO exposures were given prophylactically before cyclophosphamide. The combination of mesna, HBO and cyclophosphamide was administered by the same procedure. The contractions obtained in response to acetylcholine (ACh, 10(-4) M) in the control group were reduced using cyclophosphamide and HBO individually, but not by mesna. However, the contractions belonging to the various combinations of these three agents were not different from those seen in the control group. On the other hand, the combinations of cyclophosphamide, mesna and HBO showed higher responses to ACh than the groups in which cyclophosphamide and HBO were used individually, while the responses elicited by the cyclophosphamide and HBO combination were greater than those seen in the group treated with HBO only.     

Journey length and high temperatures: effects on rabbit welfare and meat quality

The transport of domestic animals by road can increase levels of stress and decrease meat quality, especially in unfavourable climates. The purpose of this study was to investigate the effect of journey duration and vertical position on the transport truck on some physiological indicators of stress and on instrumental meat quality parameters in commercial rabbits. In the summer months (June and July, 2003), 78 rabbits were subjected to either long (7 h) (LJ) or short (1 h) (SJ) journeys (3 replicates each, n = 6) between the farm and an abattoir in northern Spain. The position (top, middle, or bottom) occupied by the rabbits on the Multi-Floor cage Rolling Stand (MFRS) of the transport truck was recorded. Blood samples were collected at sticking and meat pH was measured at 24 h post-mortem (pH24). At 48 h post-mortem, samples of the M. longissimus dorsi were used to determine water-holding capacity (WHC) and instrumental tenderness using an INSTRON machine. The levels of corticosterone, glucose, lactate, and creatine kinase were slightly higher in LJ than in SJ samples, but the difference was not statistically significant (p < or = 0.10). Independent of journey length, rabbits in the middle and bottom of the MFRS showed higher levels (p < or = 0.05) of glucose and creatine kinase (middle), and corticosterone (bottom) than the rabbits located at the top floor. The pH 24 and WHC values of the SJ and LJ rabbits did not differ significantly. Journey length had a significant effect (p < or = 0.01) on meat tenderness. The meat from rabbits subjected to LJ had higher values of maximum stress and total toughness than did the SJ rabbits (p < or = 0.05). There were similar differences (p < or = 0.05) between LJ and SJ rabbits in their stress values of compression at 20% and 40% (measures of the tenderness of raw meat). In hot weather, the position on the transport truck appeared to have a greater effect on rabbit welfare than the duration of the journey.     

日粮添加镁、硒、铬对热应激肉仔鸡血清生化和血液流变学的影响

试验旨在研究热应激情况下镁、硒、铬联合添加对肉仔鸡血清生化指标和血液流变学的影响。选用240只1日龄AA肉公鸡,随机分为4个处理,每个处理6个重复。T1为常温对照组,T2、T3、T4为热应激组。T1、T2饲喂基础日粮,T3、T4在基础日粮中分别添加镁、硒、铬2000、1.5、1.5mg/kg和4000、3.0、3.0mg/kg。结果表明:T3、T4组热应激鸡只死亡率显著降低,血清TP、ALB、GLOB、HDL水平显著升高(P0.05),GLU、BUN、TC含量显著降低(P0.05)。同时,T3、T4组的GPT、CK酶活力及低切变率下的全血黏度均显著降低(P0.05)。试验表明,联合添加镁、硒、铬能有效改善热应激肉鸡的血液生化和血液流变学指标,减轻热应激对机体的损伤,从而降低鸡只死亡率。     

空肠弯曲菌耐药机制研究进展

空肠弯曲菌是一种全球关注的人兽共患病病原菌,由于滥用抗生素而造成其耐药性不断增强,成为公共卫生日益关注的问题.各类抗生素作用位点的基因突变是诱发空肠弯曲菌对各类临床常用的抗生素产生耐药的主要原因,同时细菌对药物的外排机制也在其对抗生素耐药过程中发挥了一定的作用.文章对空肠弯曲菌对各类临床常用抗生素的耐药机制做一综述.     

Partial characterization of phagocytic activity in neutrophils of the nine-banded armadillo Dasypus novemcinctus

Though the armadillo is important as a research model in leprosy studies, the activity of armadillo's neutrophils is an aspect of little research. The aim of this study was carried out to partially characterize the chemotaxis, endocytosis and bacteriocidal ability of the neutrophils found in the nine-banded armadillo (Dasypus novemcinctus). Results showed that the chemotactic activity of the neutrophils, evaluated by the movement of the neutrophils through a nitrocellulose membrane (5 microm) in response to a chemo-attractive substance, was greater towards the armadillo serum (5.16+/-1.35 migration index, p<0.05) than towards the formil methionyl leucil phenylalanine (fMLP, 1.43+/-0.18 migration index) or human serum (0.56+/-0.18 migration index). Regarding endocytic capacity of the neutrophils and the monocytes against Escherichia coli was evaluated by a flow cytometry and using opsonized and non-opsonized E. coli-FITC at the following incubation times: 5, 10, 20, 30 and 60 min. The largest percentage of endocytosis by the neutrophils was 92.32+/-0.12% with opsonized bacteria and 77.73+/-14.33% with non-opsonized bacteria at 10 min incubation time, while the largest percentage of endocytosis by monocytes was 89.94+/-1.40% with opsonized bacteria and 73.07+/-15.6% with non-opsonized bacteria at 20 min incubation time. Evaluation of the bacteriocidal capacity of neutrophils using the methyl-thiazol-tetrazolium salts (MTT) reduction color-measurement assay showed an 89.0+/-10% mortality rate of non-opsonized E. coli and 89.0+10% of opsonized E. coli. In conclusion, the armadillo neutrophils show a good phagocytosis and bacteriocidal activity; however, a deficiency in the migration towards the fMLP was observed. This deficiency could be a cause so that the armadillo neutrophils do not respond quickly to invading microorganism.     

Sirtuins对雌性动物生殖的影响研究进展

沉默信息调节因子（silence information regulator,Sirtuins）为烟酰胺腺嘌呤二核苷酸依赖性组蛋白去乙酰化酶,可与组蛋白和多种转录因子结合,在调控卵巢储备、卵泡发育、卵母细胞成熟、颗粒细胞功能与胚胎发育等多个生理过程中发挥着重要功能。本文综述了Sirtuins对雌性动物生殖的影响,以期为Sirtuins深入研究提供依据。     

黄华属植物叶表皮特征及其生物学意义

在光学显微镜下观察披针叶黄华复合体、高山黄华复合体及黄华属其它种的叶表皮特征。结果表明,表皮细胞形状、垂周壁式样及气孔器类型具有重要的分类学意义。表皮细胞形状为多边型和不规则型,垂周壁式样为平直或具波纹。黄华属植物除新疆黄华,之字枝黄华,东亚黄华,柔毛黄华上表皮无气孔外,其余的上下表皮均具气孔,气孔器类型多为不规则型,只有紫花黄华为不等细胞型,有些无规则型中稍混有不等细胞型。笔者认为气孔器类型对划分属内种上等级具有一定价值。对披针叶黄华复合体、高山黄华复合体和黄华属不同种间气孔指数方差分析结果表明,气孔指数在居群水平及不同种间变化差异极显著,气孔大小及气孔指数主要受环境因子的控制。     

平山湖温性荒漠草地草畜平衡现状及发展措施

2008年通过对张掖市平山湖蒙古族乡草地、农牧业生产经营情况的入户调查,全乡有天然草地8.67万hm^2,可利用草地6.38万hm^2。草地理论载畜量为2.03万羊单位,实际存栏6.843万羊单位,超载4.813万羊单位,达237%。由于草地严重超载过牧,造成温性荒漠草地退化加剧,裸露草地数量增加,水土流失严重,草原生态环境日益恶化,使当地农牧民生产、生活受到严重的影响。必须通过调整优化畜群结构,使饲养牲畜公母比例由1∶1.4提高到1∶2.5-3.0,改变传统的全放牧饲养方式,加快畜群周转,达到草畜平衡,实现草地畜牧业可持续发展。     

日粮能量水平对牦牛生产性能、肉品质和瘤胃菌群的影响

为了探讨冷季能量补饲对牦牛生产性能、肉品质和瘤胃菌群的影响。本研究选取30头((269.75±35.46) kg)2岁大通公牦牛,随机分为3组,每组10头,分别饲喂低、中、高3个综合净能水平(5.51 MJ·kg^-1,6.22 MJ·kg^-1,6.94 MJ·kg^-1)日粮,经15 d预饲期和90 d正试期后屠宰,测定牦牛生长性能、屠宰性能、肉品质、瘤胃发酵参数瘤胃微生物区系。结果表明：高能量组牦牛试验末重、干物质采食量、宰前活重、胴体重、屠宰率和眼肌面积显著高于中、低能量组(P<0.05),瘤胃异丁酸、丁酸、异戊酸和戊酸含量显著高于中、低能量组(P<0.05);高能量组牦牛肉色L^*值显著低于中、低能量组(P<0.05);高能量组牦牛瘤胃细菌Chao1和ACE指数显著低于中、低能量组,普雷沃菌属(Prevotella)相对丰度显著高于中、低能量组,理研菌科RC9菌属相对丰度显著低于中、低能量组(P<0.05)。综上,冷季饲喂高能量(6.94 MJ·kg^-1