新生儿性别对产妇心理及生理的影响：附190例分析

了解新生儿性别对产妇心理及生理的影响。方法采用神经症筛选表及症状自评量表评定新生儿为男性的产妇８０例，新生儿为女性的产妇１１０例，并对比产后出血量、 复旧和乳汁分泌的差异。结果亲生儿为女性的产妇神经症选表及症状自评量得３分较高。     

母体效应对长白猪生长性状的影响

本文旨在研究母体效应对长白猪生长性状遗传参数和育种值估计的影响。以温氏长白种猪W51为研究对象,选取初生重、达到30 kg体重日龄和达到100 kg体重日龄3个与生长性能相关的数量性状,利用包含和不包含母体效应的2种数学模型进行遗传参数和育种值估计。结果表明使用包含母体效应的模型对生长性状的解释更加合理。当模型中不包含母体效应时,遗传力的估计值明显偏高,育种值估计偏离也较大。随着猪只日龄的增加,母体效应方差所占比重逐渐下降,而直接加性遗传方差的比重逐渐上升,说明母体效应对猪生长后期的影响在逐渐变小。在建立动物生长性状模型时,需要考虑母体效应对遗传参数和育种值估计的影响。     

Behavior and phylogeny: constriction in ancient and modern snakes

Comparative analyses of behavior have an underappreciated potential for revealing the role of ethoecological factors in the origins of higher taxa. Twenty-seven species (13 genera) in the advanced family Colubridae exhibited 19 patterns of coil application; one or two patterns were usually consistent within a genus. Forty-eight species (26 genera) in the primitive families Acrochordidae, Aniliidae, Boidae, and Xenopeltidae usually used a single pattern, despite differences in age, size, shape, habitat, and diet. This implies the shared retention of an action pattern used by their common ancestor no later than the early Paleocene. Constriction must have been used as a prey-killing tactic very early in the history of snakes and might have been a behavioral "key innovation" in the evolution of their unusual jaw mechanism.     

Tay-Sachs disease: prenatal diagnosis

Fifteen pregnant women with a 25 percent risk of delivering a child with Tay-Sachs disease were monitored by amniocentesis and hexosaminidase A assays of amniotic fluid, uncultured amniotic cells, and cultured amniotic cells. Tay-Sachs disease was diagnosed prenatally in six fetuses; the diagnosis was confirmed in one child after birth and in five fetuses after therapeutic abortion. Prenatal diagnosis indicated the absence of Tay-Sachs disease in nine other fetuses; this diagnosis was confirmed postnatally in six, three are still in utero.     

Hinged teeth in snakes: an adaptation for swallowing hard-bodied prey

Six genera of snakes, representing at least three lineages, possess teeth that fold backward against the jaws rather than being firmly ankylosed. This condition, effected by a connective tissue hinge at the base of each tooth, is associated with suites of cephalic modifications that enable the snakes to grasp and to swallow hard-bodied prey.     

Axial differences in the musculature of uropeltid snakes: the freight-train approach to burrowing

The shield-tailed snakes (family Uropeltidae) extend and widen the tunnels in which they live by alternately curving and straightening the anterior portion of their vertebral columns within the skin, a burrowing method that proves to be most effective for tunneling amid roots and rocks, as well as for producing tunnels wider than the trunk through unpredictably heterogeneous substrates. The muscles of the anterior portion of the uropeltid trunk are larger and thicker than those of the posterior and are further modified by the inclusion of large amounts of myoglobin, numerous mitochondria, and diverse other ultrastructural and enzymatic specializations, which presumably represent adaptations for sustained work loads. The very much thinner, serially homologous, but unmodified musculature of the posterior trunk occupies only a much smaller fraction of the cross-sectional area. This regional modification increases the effectiveness of the posterior body for storing viscera and developing embryos.     

Assessment of multiattribute preferences

Operational assumptions are made concerning the preferences of a decision maker. Functional forms of multiattribute utility functions that satisfy these assumptions are stated. These forms provide operational methods for assessing preferences over multiattribute consequences and have a wide range of practical application.     

耶利亚克的早年生活对其作品的影响

耶利亚克,作为2004年度的诺贝尔文学奖的得主,为读者创造了大量优秀的作品。她是一位具有强烈反叛精神的作家。激扬叛逆的独特艺术风格,对政治的热衷,为女权而呐喊使耶利亚克的作品别具一格。本文从作家耶利亚克早年生活着笔,谈到了其早年的种种变故对其思想的撞击,进而对她的文学之路及后来文学风格的形成所造成的不可忽视的影响。     

Auditory and vibratory responses in the midbrains of snakes

Airborne sound and substrate vibration each elicit electrical responses below the surface of the tectum in species of three families of snakes. Tones of 50 to 1000 hertz evoke responses independently of substrate vibration. Sensitivity to locally applied sound is present over much of the body surface. This sensitivity is attributed to the auditory nerve, because it is not altered by spinal section but is eliminated by destruction of the inner ear.     

Lesch-Nyhan mutation: prenatal detection with amniotic fluid cells

Cells cultured from the amniotic fluid of a 22-week fetus in a heterozygote for the X-linked Lesch-Nyhan mutation, which results in neurological and developmental disorders, lacked sex chromatin and were unable to incorporate hypoxanthine. The diagnosis of a mutant male was confirmed upon birth of enzyme-deficient, hyperuricemic twin boys whose amniotic membrane cells failed to incorporate hypoxanthine.     

Limb regeneration: induction in the newborn opossum

The marsupial Didelphys virginiana (the North American opossumn) is uniquely suited for studies of mammalian limb replacement. By transplanting nervous tissute to the limb, regeneration has been successfully induced in this mammal.     

Xeroderma pigmentosum: a rapid sensitive method for prenatal diagnosis

When normal human cells, capable of repairing ultraviolet-induced lesions in their DNA, are incubated in the thymidine analog 5-bromodeoxyuridine after ultraviolet irradiation, the analog is incorporated into the repaired regions. When such repaired cells are subsequently irradiated with 313-nanometer radiation and placed in alkali, breaks appear in the DNA at sites of incorporation of 5bromodeoxyuridine, inducing a dramatic downward shift in the sedimentation constant of the DNA. Cells from patients with the disease xeroderma pigmentosum, which causes sensitivity to ultraviolet, are incapable or only minimally capable of repair; such cells incorporate little 5-bromodeoxyuridine into their DNA under these conditions and, upon 313-nanometer irradiation and sedimentation in alkali, exhibit only minor shifts in DNA sedimentation constants. When fibroblasts developed from biopsies of normal skin and of skin from patients with xeroderma pigmentosum, as well as cells cultured from midtrimester amniotic fluid, were assayed in this fashion unequivocal differences between normal and xeroderma pigmentosum cells were shown. Xeroderma pigmentosum heterozygotes are clearly distinguishable from homozygous mutants, and results are available 12 hours after irradiation.     

Paths out of poverty: International experience

The global community has committed, as the first priority of the Sustainable Development Goals(SDGs), to end poverty in all its forms everywhere. While the decline of global poverty continues, progress has slowed and remains uneven through different parts of the world. To ensure that no one is left behind in China and beyond, research will be critical to inform paths out of poverty. In this regard, it is valuable to take stock of international experiences and the various pathways out of poverty with a focus on agriculture. Africa's agricultural growth has been largely driven by land expansion and poverty reduction has been the slowest among all regions. South Asia agriculture has been led by diversification of smallholder agriculture and its poverty reduction impact has been large, but its future poverty reduction is limited by rural–urban migration and lack of formal jobs in urban centers. Social protection programs have been used by many Latin American countries as the region is more urbanized than any other developing regions. China's agricultural and economic success was driven by agriculture-led reforms and rural development. These changes brought significantly higher incomes among rural residents, which accounted for highest initial levels of poverty and hunger, and in increased availability of food at affordable prices. Investments in nutrition, health, education, clean water, and good sanitation also complemented progress. The foremost lesson is that smallholder-led agriculture growth in land scarce countries often have the largest impact on poverty reduction. Secondly, nonfarm employment and rural–urban migration must follow once agricultural productivity has reached a certain level. However, premature exiting from agriculture can do more harm. Thirdly, even before large scale poverty reduction through sectoral and regional development is exhausted, social safety nets must be established to cover those who have not benefited from growth and development. Productive social safety nets have proven to be cost-effective in many countries. Urban poverty should also be part of the protection scheme when large proportion of rural population moves to cities.     

浙江重点蛇类资源数量与生态分布研究

采用系统抽样技术和样带法,对浙江12个重点蛇种的数量和生态分布进行了研究.初步查清了这12个蛇种在其分布区范围的种群出现密度和种群资源量,分别为:赤链蛇,2.97条/km2,60.47×104条;王锦蛇,4.57条/km2,93.05×104条;玉斑锦蛇,0.39条/km2,7.94×104条;黑眉锦蛇,0.83条/km2,33.80×104条;赤峰锦蛇,5.09条/km2,0.36×104条;灰鼠蛇,1.04条/km2,21.17×104条;滑鼠蛇,0.74条/km2,15.07×104条;乌梢蛇,4.08条/km2,83.07×104条;银环蛇,1.35条/km2,41.23×104条;眼镜蛇,2.80条/km2,57.01×104条;五步蛇,1.40条/km2,27.96×104条;蝮蛇,4.37条/km2,63.10×104条.生态分布的统计研究表明:在小地形类型上,下坡和山谷地带蛇类数量最多,主要为王锦蛇、灰鼠蛇、滑鼠蛇、乌梢蛇、眼镜蛇和五步蛇;平地上次之,主要是赤链蛇、蝮蛇和银环蛇;黑眉锦蛇和玉斑锦蛇在平地与下坡及山谷地带分布数量不相上下.在小生境类型上,以灌草丛上蛇类最多,主要是眼镜蛇、滑鼠蛇、五步蛇和黑眉锦蛇;农田和旱地次之,主要为赤链蛇、灰鼠蛇和银环蛇;再是园地和乔木林,玉斑锦蛇主要在园地,五步蛇集中分布在灌草丛和乔木林;乌梢蛇和王锦蛇在上述生境均有分布,在灌草丛上稍占优势;蝮蛇则多见于农田、旱地、园地和灌草丛.文末,提出了如何保护好浙江蛇类资源的对策和建议.