Multiscale control of vegetation patterns: the case of Doñana (SW Spain)

The early studies about the plant ecology of Doñana carried out at a small scale showed that the main process controlling vegetation composition of the stabilized dunes was soil water availability. However, the extrapolation of this model to larger spatial scales failed to explain observed vegetation patterns. In this work, the vegetation patterns and the processes causing them are studied at a larger scale. Data of topography, soil pH, electrical conductivity, and available iron allowed to distinguish three large geomorphologic zones on the stabilized dunes of the Doñana Biological Reserve which correspond to different dune building episodes. Different dune episodes showed differences in both water table depth and dynamics, which are due to groundwater flow systems of different scale. It is further manifested by differences in shrub composition. The results show that geomorphology controls the vegetation pattern at different scales mediated through water availability. Differences in water availability are due to the connection to groundwater flow systems of contrasted scale. On a small scale (10−10² m), along dune slopes, there is a gradient from dune ridges to slacks, from xerophyte to hygrophyte vegetation types. On a mesoscale (10²−10³ m), there are several dune episodes with variable topographic altitude, dominated by different types of xerophytes. On a regional scale (>10³ m), the discharges of the regional aquifer produce strong environmental and biotic stresses resulting in a mixed community.     

分根交替渗透胁迫与脱落酸对玉米根系生长和蒸腾效率的影响

用Hoagland溶液培养玉米幼苗, 研究分根交替胁迫对玉米根系生长和叶片蒸腾效率的影响, 实验证明： 当一半根系处于高水势, 另一半根系处于低水势, 并在一定时间间隔内交替, 4～5天后受胁迫一半根系能够形成大量侧根使根总量和总长度超过未受胁迫的对照, 当1/2根受胁迫时, 这部分根系内源ABA含量明显增加, 与气孔导度     

Effects of haul distance and stocking density on young suckling calves transported in Japan

We conducted applicability evaluation of recommendations of the European Union (EU) and the Royal Society for Prevention of Cruelty to Animals (RSPCA) for suckling calves. Nineteen calves (14 Holstein aged 11–26 days and five cross‐bred aged 13–45 days) were divided into six groups. Three groups were allocated into the stocking densities of 0.25, 0.35, 0.45 m²/head and were weekly transported 50, 100, 150 km in this order. Another three groups were allocated and transported in reverse order. Observation was conducted during and after transportation. Blood sampling was performed before and after transportation. The occurrences of lying and turning round on the truck were significantly associated with stocking density (P < 0.05), but not with haul distance. Scratching was observed only in one calf. Incidence of watery feces was not associated with both factors. There were significant effects of haul distance on the concentrations of plasma cortisol and noradrenaline, and serum aspartate aminotranserase (AST) and IgM (P < 0.05). These concentrations, except cortisol, were higher after transportation at 150 km compared to the pre‐transportation value (AST and IgM P < 0.05; noradrenaline P < 0.10). Results suggest that haul distances greater than 100 km should not be recommended even for suckling calves transported in Japan.     

Split luciferase complementation assay to detect regulated protein-protein interactions in rice protoplasts in a large-scale format

Background

The rice interactome, in which a network of protein-protein interactions has been elucidated in rice, is a useful resource to identify functional modules of rice signal transduction pathways. Protein-protein interactions occur in cells in two ways, constitutive and regulative. While a yeast-based high-throughput method has been widely used to identify the constitutive interactions, a method to detect the regulated interactions is rarely developed for a large-scale analysis.

Results

A split luciferase complementation assay was applied to detect the regulated interactions in rice. A transformation method of rice protoplasts in a 96-well plate was first established for a large-scale analysis. In addition, an antibody that specifically recognizes a carboxyl-terminal fragment of Renilla luciferase was newly developed. A pair of antibodies that recognize amino- and carboxyl- terminal fragments of Renilla luciferase, respectively, was then used to monitor quality and quantity of interacting recombinant-proteins accumulated in the cells. For a proof-of-concept, the method was applied to detect the gibberellin-dependent interaction between GIBBERELLIN INSENSITIVE DWARF1 and SLENDER RICE 1.

Conclusions

A method to detect regulated protein-protein interactions was developed towards establishment of the rice interactome.     

Maternal dietary linoleic acid supplementation promotes muscle fibre type transformation in suckling piglets

As meat quality is basically dependent on muscle fibre characteristics, it is important to know how muscle fibres are regulated and transformed. This study aimed to investigate the effect of maternal dietary supplementation on muscle fibre types using 3% saturated fatty acid (palmitic acid, PA) or 3% unsaturated fatty acid (linoleic acid, LA) from 80 days of gestation to the weaning of offspring (25 days post‐natal). The results indicated that higher mRNA levels of MyHCI type genes were found in the soleus muscles of piglets that suckled from LA‐supplemented sows than from PA‐supplemented sows. In addition, LA treatment increased the gene expression of the type I muscle fibre marker troponin I (p < 0.01), suggesting that LA promoted muscle fibre type transformation to type I fibres. Moreover, PGC‐1α (p < 0.01) and MEF2c (p < 0.05) mRNA levels were higher in the piglets from the LA treatment group than in those from the PA treatment group. Furthermore, LA supplementation also significantly increased AMP‐activated protein kinase (AMPK) mRNA levels (p < 0.05), which is an upstream regulator of PGC‐1α. Collectively, these findings demonstrated that maternal dietary LA supplementation promoted muscle fibre transformation to type I fibre and that this process may be mediated through an AMPK‐dependent pathway.     

Luteinizing hormone and growth hormone secretion in early lactating Spanish beef cows

The episodic release of luteinizing hormone (LH) and growth hormones (GH) was studied in three suckling regimens and two breeds of Spanish suckled cows. Parda de Montaña (PA) cows (n = 21) were assigned to once‐daily, twice‐daily or ad libitum (ADLIB) suckling. Pirenaica (PI) cows (n = 7) were used to evaluate the breed effect in twice‐daily suckling. Coccygeal blood samples were collected twice weekly during lactation to determine the interval from calving to first ovulation through peripheral progesterone. On day 32 ± 3 post‐partum, jugular blood samples were drawn at 15 min intervals during 8 h to analyse circulating LH and GH. The interval to first ovulation was greater in PA cows suckling ADLIB than in restricted suckling treatment (RESTR1), whereas in RESTR2 it did not differ from the other two treatments. There were no differences between PA and PI cows in the interval to first ovulation. RESTR1 cows showed a tendency to have shorter LH peak widths than ADLIB cows. PA cows showed a tendency to have longer LH peak widths than their PI counterparts. There were no differences across treatments or breeds in any of the GH measures of secretion. The LH release was more affected by breed than by suckling frequency, whereas that of GH was not influenced by any of these parameters. The variables that best allowed discrimination between ADLIB and restricted nursing systems were the interval to post‐partum first ovulation, LH peak number and the mean GH concentration.     

Irrigation and nitrogen scheduling as a requirement for optimising wheat yield and quality in Haryana, India

Wheat in Haryana (NW India) is grown as a winter crop in an annual sequence with rice, cotton, pearl millet or cluster bean as the main monsoon crops. Higher wheat yields in Haryana are associated with the use of modern varieties, increase in fertiliser use, improved irrigation practice and conservation tillage, and the recommendation to farmers for N fertiliser rates and timing and irrigation practice have an emphasis on optimising yield and input efficiencies. In India the importance to consumers of product quality does exist and, although the market place presently does not actively reward farmers for better quality wheat, the need for creating suitable and targeted marketing opportunities is now recognised. This paper examines aspects of input efficiencies and focuses on combinations of N-fertiliser and irrigation input in wheat crops grown with these four rotations (rice-wheat, cotton-wheat, pearl millet-wheat and cluster bean-wheat). Management practices that optimise grain production as well targeting grain that achieves best chapatti (Indian flat bread) quality are evaluated within a split-plot experiment where 4 irrigation schedule treatments were split with nitrogen management treatments involving a 2-way or 3-way split of N fertiliser. With the rice-wheat system, there were no differences between different split timings of N with grain yield, however with the 3 other wheat systems the 3 way split of N-fertiliser application, with N applied equally at N-fertiliser applied at seeding, early tillering and first node stage, always gave the highest yield. With all 4 rotations the highest protein level was achieved (range 11.8-12.5%) with this 3-way N application split. Grain yield increased in a step-wise manner as additional irrigation was implemented with all rotations and the highest protein outcomes were achieved with the least irrigations. The apparent recovery of N fertiliser applied was similar and highest with the 3-way split, and the 2-way split that did not include a basal N fertiliser application. Different rates of N fertiliser were included in separate experiments using the 3-way split of N application, and with the rice-wheat rotation the GreenSeeker instrument was used to establish the rate for the third application of N. The application of extra N-fertiliser with the non rice-wheat rotations produced no additional grain yield with an increase in the N-fertiliser input beyond 150 kg N ha⁻¹, although protein and N-content increased incrementally. Grain hardness and chapatti score trended higher with increases in N-fertiliser input but the increases were relatively small. The use of the GreenSeeker instrument with the rice-wheat rotation resulted in N saving of 21-25 kg N ha⁻¹ with similar grain yield, protein and grain hardness to that provided by using the recommended 150 kg N ha⁻¹. Where the GreenSeeker was used the apparent recovery was 70-75% compared with 60% with the wheat receiving the recommended 150 kg N ha⁻¹, suggesting farmers are likely to be over-fertilising their wheat crop. The best yields obtained in these experiments were about 5.5-6.0 t ha⁻¹ and these yields are consistent with a decade-long attainable yield identified for wheat in rice-wheat rotation for Haryana. If farmers can achieve market recognition for chapatti quality, and with the use of appropriate varieties, then farmers can assume that the best practice outlined here for optimising grain yield with integrated nutrient and soil management will be the same practice that optimises chapatti quality.     

低聚半乳糖对脂多糖刺激哺乳仔猪盲肠微生物区系、肠道炎症和屏障功能的影响

本试验旨在研究低聚半乳糖(GOS)对脂多糖(LPS)刺激的哺乳仔猪盲肠微生物区系、肠道炎症和屏障功能的影响。选取18头初始体重[(1.57±0.05)kg]相近的新生哺乳仔猪,随机分为对照组、LPS刺激组和GOS添加组,每组6头。GOS添加组的仔猪每天灌喂1 g/kg BW的GOS溶液,对照组和LPS刺激组的仔猪灌喂等量无菌生理盐水。第14天,LPS刺激组和GOS添加组的仔猪腹腔注射80μg/kg BW的LPS溶液,对照组的仔猪腹腔注射等量无菌生理盐水。所有仔猪在腹腔注射LPS溶液或无菌生理盐水2 h后屠宰取样。结果表明:1)与LPS刺激组相比,GOS添加组的Shannon指数有升高的趋势(P=0.051);在门水平上,GOS添加组盲肠食糜中厚壁菌门(Firmicutes)的相对丰度显著提高(P<0.05);在属水平上,GOS添加组盲肠食糜中粪杆菌真核菌群([Eubacterium]_coprostanoligenes_group)、考拉杆菌属(Phascolarctobacterium)、普氏菌属2(Prevotella_2)、毛螺菌科NK4A136群(Lachnospiraceae_NK4A136_group)和粪杆菌属(Faecalibacterium)的相对丰度显著或极显著提高(P<0.05或P<0.01)。2)与LPS刺激组相比,GOS添加组仔猪盲肠食糜中乙酸、丙酸、丁酸和总短链脂肪酸含量显著或极显著提高(P<0.05或P<0.01),盲肠食糜pH显著降低(P<0.05)。3)与LPS刺激组相比,GOS添加组盲肠黏膜中白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)含量显著降低(P<0.05)。4)与LPS刺激组相比,GOS添加组盲肠黏膜中闭合蛋白-1(claudin-1)的蛋白表达水平显著提高(P<0.05),闭合小环蛋白-1(ZO-1)的蛋白表达水平有提高的趋势(P=0.075)。由此可见,早期GOS干预可以调节LPS刺激的哺乳仔猪的盲肠菌群结构,提高盲肠食糜中短链脂肪酸含量,并可以缓解LPS造成的肠道炎症反应和维持肠道屏障功能。     

仔猪喂奶系统设计与输送管道优化

针对当前仔猪喂奶自动化水平程度较低，劳动强度较大、饲喂效率低下这一问题，设计一种仔猪喂奶系统，开发以PLC控制器为核心的自动控制系统，实现仔猪喂奶过程中加水、控温、搅拌和饲喂等操作的自动化控制，并应用CFD数值模拟探究管径、管道材质、入口温度和管道流速对奶水输送管道压力分布及温度分布的影响，依据仿真结果确定了输送管路的基础参数值，即管道材质为PPR材质、管径为6分管（外径25 mm，壁厚2.8 mm）和管道流速为0.8 m/s。性能试验表明：仔猪配奶罐温度控制精度的平均相对误差为0.91%，温度变化幅度保持在±1℃；仔猪配奶罐温度控制稳定性试验的温度样本标准差为0.226 3℃，变异系数为0.499%；仔猪饲喂点的温度分布范围在36～45℃；仔猪喂奶器压力分布范围在28.36～53.20 kPa。研究结果表明，该仔猪喂奶系统可以正常实现供水、搅拌、加热、循环和排水等功能，各饲喂点的管道压力及温度分布均满足仔猪饲喂要求。     

甘草多糖对哺乳仔猪健康状况和血清抗氧化能力的影响

【目的】研究甘草多糖对哺乳仔猪健康状况和血清抗氧化能力的影响，为甘草多糖在仔猪饲粮中的应用提供参考。【方法】选择体质量相近的5日龄“杜×长×大”三元杂交仔猪180头，随机分成3个组，分别为对照组、1.0%甘草多糖组和2.5%甘草多糖组，每组8个重复，每重复7～8头仔猪。采取常规饲喂方法，对照组饲喂基础饲粮，1.0%甘草多糖组和2.5%甘草多糖组在基础饲料中分别添加质量分数2.5%和1.0%的甘草多糖，饲喂30 d，试验期末统计仔猪健康状况，观察其皮毛发育程度。试验结束后第2天，每重复随机选择1～2头仔猪，每组10头，空腹前腔静脉采全血10 mL/头，采集的血液分两管收集，其中一管血液抗凝用于血常规测定，另一管血液制备血清用于生化指标及抗氧化指标测定。【结果】与对照组相比，1.0%甘草多糖组仔猪的末质量和平均日增质量均显著升高（P＜0.05）；2.5%甘草多糖组仔猪的末质量和平均日增质量虽有升高，但与对照组差异不显著。与对照组相比，1.0%甘草多糖组和2.5%甘草多糖组仔猪的平均日采食量和料重比均显著升高（P＜0.05），但其死亡率显著降低。与对照组相比，1.0%甘草多糖组仔猪皮毛发育状况评为5分的比例显著升高，评为1分的比例显著降低。2.5%甘草多糖组仔猪血液中的白细胞数、红细胞数和血小板数最多，与对照组存在显著差异（P＜0.05）；1.0%甘草多糖组仔猪血液中的白细胞数、红细胞数和血小板数均高于对照组，但与对照组差异不显著。与对照组相比，1.0%甘草多糖组和2.5%甘草多糖组仔猪血清中甘油三酯、葡萄糖、总蛋白和总胆固醇含量均有提高，且其甘油三酯和葡萄糖含量与对照组差异显著（P＜0.05）。1.0%甘草多糖组仔猪血清中乳酸脱氢酶活性显著高于对照组（P＜0.05），2.5%甘草多糖组仔猪血清中谷胱甘肽过氧化酶活性显著高于对照组（P＜0.05），1.0%甘草多糖组仔猪血清中的MDA含量显著低于对照组（P＜0.05）。【结论】基础饲料中添加甘草多糖可以降低仔猪死亡率，改善皮毛发育，提高血糖水平，增强机体的抗氧化能力，进而提高仔猪的健康状况。甘草多糖添加量以1.0%为宜。