三疣梭子蟹(Portunus trituberculatus)体重遗传力的估计

应用数量遗传学原理和全同胞组内相关法估计了三疣梭子蟹80日龄和120日龄体重的遗传力。实验中的400只亲蟹均来自人工养殖的选育群体。通过群体间杂交,构建了37个全同胞家系包括13个半同胞家系,分别测定了80日龄和120日龄时大约30个个体的体重。利用SPSS软件的一般线性模型(GL.M)过程,计算表型变量的方差组分,估计体重性状的遗传力。结果表明,三疣梭子蟹80日龄和120日龄体重的遗传力估计值分别在0.42—0.64和0.25—0.39之间。雌性遗传方差组分均显著大于雄性遗传方差组分,说明雌性遗传方差组分存在显著的母性效应。经过t检验,父系半同胞、母系半同胞方差组分估计的遗传力均未达到显著水平,全同胞方差组分估计的遗传力达到极显著水平。因此可以认为基于全同胞方差组分估计的遗传力是对三疣梭子蟹两个发育阶段狭义遗传力的无偏估计值,估计值分别为0.53和0.35。说明三疣梭子蟹体重属于中度遗传力,对其选择育种具有较大的潜力。     

Critical visceral methods and methodologies: Debate title: Better than text? Critical reflections on the practices of visceral methodologies in human geography

Researchers interested in visceral or bodily methods and methodologies should be prepared to fully engage with the politics of research as well as the social and political context of their studies. Longer-term, intentional, applied, and collaborative projects may be particularly relevant. Finally, visceral methods could be particularly apt for advancing biosocial science and inquiries into body-environment relations.     

体应变最大熵谱分析在江苏及邻区中强震的预报应用

最大熵谱分析方法具有分辨率高、灵敏度和稳定性好等优点。把它引用到应力应变学科中 ,为该学科在地震预报中开辟一条新路 ,也是对最大熵谱分析方法应用的推广。选用了徐州台、溧阳台近年来的体应变观测资料 ,着重研究了南黄海 6.1级地震、苍山 5 .2级地震和射阳4.6级地震。研究结果表明 ,地震前的短临阶段体应变谱结构第一主频均有不同程度的衰减或增强 ,这种变化反映了地震前兆信息 ,因而可用于地震的短临预报     

Complex Rays and Wave Packets for Decaying Signals in Inhomogeneous,Anisotropic and Anelastic Media

Diffraction and anelasticity problems involving decaying, evanescent or inhomogeneous waves can be studied and modelled using the notion of complex rays. The wavefront or eikonal equation for such waves is in general complex and leads to rays in complex position-slowness space. Initial conditions must be specified in that domain: for example, even for a wave originating in a perfectly elastic region, the ray to a real receiver in a neighbouring anelastic region generally departs from a complex point on the initial-values surface. Complex ray theory is the formal extension of the usual Hamilton equations to complex domains. Liouville's phase-space-incompressibility theorem and Fermat's stationary-time principle are formally unchanged. However, an infinity of paths exists between two fixed points in complex space all of which give the same final slowness, travel time, amplitude, etc. This does not contradict the fact that for a given receiver position there is a unique point on the initial-values surface from which this infinite complex ray family emanates. In perfectly elastic media complex rays are associated with, for example, evanescent waves in the shadow of a caustic. More generally, caustics in anelastic media may lie just outside the real coordinate subspace and one must trace complex rays around the complex caustic in order to obtain accurate waveforms nearby or the turning waves at greater distances into the lit region. The complex extension of the Maslov method for computing such waveforms is described. It uses the complex extension of the Legendre transformation and the extra freedom of complex rays makes pseudocaustics avoidable. There is no need to introduce a Maslov/KMAH index to account for caustics in the geometrical ray approximation, the complex amplitude being generally continuous. Other singular ray problems, such as the strong coupling around acoustic axes in anisotropic media, may also be addressed using complex rays. Complex rays are insightful and practical for simple models (e.g. homogeneous layers). For more complicated numerical work, though, it would be desirable to confine attention to real position coordinates. Furthermore, anelasticity implies dispersion so that complex rays are generally frequency dependent. The concept of group velocity as the velocity of a spatial or temporal maximum of a narrow-band wave packet does lead to real ray/Hamilton equations. However, envelope-maximum tracking does not itself yield enough information to compute synthetic seismograms. For anelasticity which is weak in certain precise senses, one can set up a theory of real, dispersive wave-packet tracking suitable for synthetic seismogram calculations in linearly visco-elastic media. The seismologically-accepiable constant-Q rheology of Liu et al. (1976), for example, satisfies the requirements of this wave-packet theory, which is adapted from electromagnetics and presented as a reasonable physical and mathematical basis for ray modelling in inhomogeneous, anisotropic, anelastic media. Dispersion means that one may need to do more work than for elastic media. However, one can envisage perturbation analyses based on the ray theory presented here, as well as extensions like Maslov's which are based on the Hamiltonian properties.     

中国对虾体液免疫实验方法的探讨

“以防为主”是目前国内外治疗虾病普遍采用的方法,其根本的问题是真正搞清虾体本身的免疫机制,尤其是对虾的体液免疫。在对中国对虾体液免疫研究中,笔者发现给虾服用增强免疫力的药饵(Astraga-     

关于鱼的生长方程的研究──Ⅰ.鱼的生长方程的修正

指出vonBertalanffy生长公式的局限性在于公式导出时所用假设“鱼的体重增加量同体重的2／3次方成比例，减少量同体重成比例”的根据不充分；其不足之处在于解方程时将变量l误为鱼的体长。本文作了更为一般的假设，即鱼的体重增加量同体重的P次方成比例；减少量同体重的q次方成比例。进而通过严格的数学推导，得出鱼的更为一般的生长方程w=w∞[1-e－k(s-s0)]r，使vonBertalanffy生长公式是该方程的特殊情形．     

南方鲇的鱼体能量密度及其预测模型

于1992年和1993年2－4月由嘉陵江收集的野生南方鲇雌、雄成鱼各20尾；1996年1－4月取得了不同摄食水平处理的幼鱼19尾，饥饿处理的幼鱼18尾，测定了这4个样本的鱼体能量密度及化学组成。结果表明，各样本能量密度均分别与干物质和脂肪含量呈显著的直线相关关系；幼鱼2个样本的能量密度与蛋白质含量的正相关关系也达到显著性，而雌、雄成鱼样本的能量密度分别与干物质（DM：％B．W．）的直线回归方程的协方差分析，可将雌雄成鱼群体的两个回归方程合并为公共的成鱼能量密度（EA：kJ/g）方程：EA＝1．67＋0．302DM；将不同营养状况幼鱼的两个回归方程合并为公共的幼鱼能量密度（D1：kJ／g）方程：EJ＝－2．26＋0．329DM。     

Emotional labour/body work: The caring labours of migrants in the UK’s National Health Service

The provision of care is an increasingly pressing issue in the Global North. With an ageing population and policies encouraging women into the labour market, there is a growing need for workers to undertake paid caring. This poses important and urgent questions about the social organisation of labour markets. Care work typically is low paid and undertaken in precarious, informal, or temporary situations. Many posts are filled by economic migrants, raising concerns about a care deficit in sending countries. In this paper we examine the ‘caring work’ undertaken by migrant workers in a West London Hospital. We employ a twofold characterisation of caring work. Like other bottom-end service sector work, this work is characterised by the face-to-face ‘emotional labour’. However, it also requires ‘body work’: close and often intimate physical contact between carers and those they care for. We argue that both of these aspects are important in understanding how caring work is constructed as poorly regarded and low paid. We show how these features play out in particular ways for migrant workers employed in such caring work.     

Allometry and body length of abelisauroid theropods: Pycnonemosaurus nevesi is the new king

Abelisauroid dinosaurs normally reached an average body length (BL) of 5–9 m, but there are controversies due to the incomplete or fragmentary nature of most specimens. For Ekrixinatosaurus, for example, BL was estimated as 10–11 m or 7–8 m; for Pycnonemosaurus it was proposed 7–8 m, however its preserved bones are larger than any other described abelisauroid. The lack of a consistent methodology complicates comparisons of estimated BL, so we reevaluated the estimative for the seven most complete specimens of abelisauroids and compared the values against 40 measurements from the skull, vertebrae and appendicular elements using bivariate equations. It allowed estimating the BL of other 30, less complete, specimens of abelisauroids and to evaluate the allometric scaling of the skeletal parts. Strong correlations (R² > 0.96) were obtained for all vertebrae and hindlimb measurements, as well as skull height, and length of skull roof, lacrimal–squamosal, scapulocoracoid and humerus; other skull and forelimb measurements present weak correlation due to extreme morphological transformations observed in Abelisauridae and were not adequate for BL estimation. Abelisauroids gradually increased in size during evolution: the mean BL was 3.3 ± 2.5 m for basal abelisauroids and Noasauridae, 5.4 ± 1.8 m for basal Brachyrostra and Majungasauridae, and 7.1 ± 2.1 m for Furileusaura. Despite this variation, diversity of BL on each geographic region and stratigraphic epoch was relatively constant (BL usually varied from 4 to 8 m). The smallest noasaurid and abelisaurid are, respectively, Velocisaurus (1.5 ± 0.1 m) and Genusaurus (3.6 ± 0.0 m). The largest abelisaurids is Pycnonemosaurus nevesi (8.9 ± 0.3 m) followed by Carnotaurus (7.8 ± 0.3 m), Abelisaurus (7.4 ± 0.7 m) and Ekrixinatosaurus (7.4 ± 0.8 m). Skull measurement scale negatively at a similar rate but the height scales almost isometrically and the skull roof length scales more negatively; this probably caused a bending on the skull that may explain the upward orientation of the snout in large taxa.