Changes in water relations of Eucalyptus nitens nursery stock during and after lifting and transplanting

Field symptoms of transplanting shock in Eucalyptus nitens open rooted (1/2 + 1/2) transplants suggest water stress. To identify stages in the development of symptoms, changes in water relations were monitored from undisturbed seedlings growing in a commercial nursery through lifting, transplanting into pots and re-establishment of normal water relations. Hydraulic resistance measured as leaf specific resistivity increased with each step in the transplanting process. Resistivity after lifting was double that measured on undisturbed plants in the nursery and subsequently doubled with each of the two successive stages, root trimming and planting out. Resistivity fell after the initial rise, returning to the values recorded in the nursery in two stages. An initial rapid decrease, which was not accompanied by any measurable root growth, was followed by a seven day period without a change in resistivity before a further gradual decrease as root volume increased with new root growth.All water relations measurements were taken on trees which had not suffered any permanent leaf damage as a result of transplanting. For a small group of trees which did suffer damage there was a significant relationship between root volume at planting and the retained healthy leaf area. Before shoot growth had recommenced the final ratio of turgid leaf area to initial root volume was comparable with plants immediately after lifting and before trimming. The results are discussed in terms of the changes in predawn leaf water potential, leaf water potential and the leaf damage or defoliation symptoms occuring in plantations.     

个体差异对西沙群岛海域鸢乌贼角质颚外部形态变化的影响

角质颚结构稳定、信息量大,是研究头足类渔业生物学的重要材料。根据2017年5—8月我国灯光罩网渔船在中国南海西沙群岛海域采集的860尾鸢乌贼样本,研究了个体差异对鸢乌贼角质颚外部形态变化的影响。结果显示,上头盖长(UHL)、上脊突长(UCL)、上喙宽(URW)、上侧壁长(ULWL)、下头盖长(LHL)、下脊突长(LCL)、下喙长(LRL)和下侧壁长(LLWL)可作为外形特征因子描述鸢乌贼角质颚的外形变化。方差分析(ANOVA)和最小显著性差异法(LSD)结果显示,主要外形特征因子在不同性别、不同胴长组和不同性成熟度间均存在显著性差异,但主要外形特征因子与脊突长(CL)的比值基本稳定。研究表明,在个体生长过程中,角质颚各区的比例基本稳定,胴长121～150 mm和性腺成熟度Ⅲ期可能是鸢乌贼角质颚外形生长的拐点。     

头足类角质颚的研究进展

随着世界传统经济渔业资源的衰退,头足类资源的开发和利用得到各国的普遍重视,对其资源状况、生物学等方面的研究得到不断地开展。角质颚是头足类的主要捕食器官和硬质组织之一,具有结构稳定、耐腐蚀、储存信息良好等特点,可作为分类和生物学研究等的重要材料。本文根据国内外学者对其研究的成果,系统描述了角质颚的形态特征,对其在头足类生物学和分类地位、资源量估算、捕食动物的食性分析等方面的应用研究做了综述。分析认为,尽管角质颚在头足类研究中已取得一定的进展,但其在年龄鉴定和资源评估等方面还面临着一些问题,需要在以后的研究过程中加以解决。     

3D打印光敏树脂假喙治疗鹦鹉断喙

对3例上喙不同程度缺损导致采食困难的鹦鹉进行治疗,通过整体方案的制定,采用对标本3D扫描、实际断端测量和软陶翻模的方法采集数据,再经Geomagic Design X修整和编辑后,获得鹦鹉上喙建模数据,进行3D打印光敏树脂假喙。3例病例均采用对接法拼接进行手术安装,术后1周内均恢复采食饮水行为,无副作用,假喙牢固。对接法安装的3D打印的鹦鹉假喙,为鹦鹉断喙病例提供了一种新型、有效的治疗方案。     

茎柔鱼角质颚的机械强度特性

茎柔鱼角质颚不仅表面存在色素沉积的梯度变化,从喙部到翼部黑色素逐渐变浅,其机械性能也存在显著的梯度变化,喙部具有很高的机械强度,从喙部到翼部机械强度逐渐变小,韧性逐渐增大。测定无水以及水合状态下茎柔鱼角质颚不同部位(喙部、侧壁、翼部)的机械强度(杨氏模量),以及主要化学成分、内部分子交联结构,并利用电子扫锚显微镜观察了其不同部位表面和断面上的物理结构,探究茎柔鱼角质颚机械强度梯度变化的主要原因。研究显示:无水茎柔鱼角质颚具有很高的杨氏模量,模量从喙部到翼部差异不显著(P0.01);而水合的角质颚杨氏模量明显减小,模量从喙部到翼部呈现显著梯度变化(P0.01)。茎柔鱼角质颚主要含有蛋白质、儿茶酚、壳聚糖和水,其机械强度随蛋白质、儿茶酚含量增加而增大,机械强度同时与内部分子交联反应形成的多巴-多交联多聚体以及与其表面和断面上物理结构有关,茎柔鱼喙部断面层状结构十分显著,生物体中分层越明显,其机械强度越大。     

夏伐桑树不同疏芽时间对秋叶产量的影响

通过不同疏芽时间对秋叶产量影响的初步试验表明:在其它桑园管理措施一致的前提下,新稍条长80%达到5～10 cm疏芽,能极显著提高芽条生长量及秋叶产量.     

Effects of beak trimming on the performance,beak length,behavior, and carcass traits of a local broiler breed reared in battery cages

This study investigated the effects of beak trimming on a local broiler breed. A total of 648 one‐day‐old birds were randomly allocated into three treatments: no trimming (NBT), infrared beak trimming (IRBT), and hot‐blade beak trimming (HBBT). The performance, beak length, behavior, carcass traits, organ percentages, and meat quality were inspected. The body weight (BW) from 7 to 35 days in the IRBT group was significantly lower than that in the NBT group, and the BW from 7 to 49 days was lower than that in the HBBT group (p < .05). Compared with untrimmed birds, birds in the IRBT group had lower average daily feed intake (ADFI) from 15 to 21 days, and higher heart percentage and L* value in the breast muscle. The upper beak length at 28 and 49 days of age were longest in untrimmed birds, intermediate in birds in the HBBT group, and shortest in the IRBT groups (p <.05). No evidence was found that HBBT caused changes in performance, behavior, carcass traits, organ percentages, and meat quality except for lower change in spleen percentage. Taken together, IRBT had more influence at inhibiting early BW, ADFI, and upper beak length than HBBT in the local broiler breed.     

Farriery for the foal: A review part 1: Basic trimming

The extensive nature of this topic warrants this review paper to be divided into two parts: ‘Routine basic trimming in foals’ and ‘Therapeutic farriery in foals’. Hoof care in the first few months of life is serious business and should never be taken lightly. Good farriery is vital for the development of the hoof capsule and the conformation of the limb. Management of the feet and limbs during the juvenile period will often dictate the success of the foal as a sales yearling or mature sound athlete. Overall hoof care of a foal is often a joint venture between the veterinarian and the farrier. Part 1 of this paper will outline the concept of a footcare programme, examination of the foal's feet and limbs along with what constitutes good basic farriery to properly apply the trim. It will also emphasise the importance of maintaining a good veterinarian-farrier relationship - the farrier being responsible for basic trimming with veterinary oversight when necessary, and if orthopaedic disorders develop, the farrier will have significant input with therapeutic farriery.