Experimental design and response surface analysis of pesticide trials

The search for combinations of pesticides or herbicides which have a synergistic effect is an important area of study and one which presents challenges for the statistician as well as for the experimenter. The aim is to find and to describe the interaction between a number of quantitative factors, and having done so to determine a combination which is economically optimal for a given level of control. The present paper discusses the role of a family of response functions called Inverse Polynomials to describe such phenomena. Examples are given of such functions and it is shown how it is possible to fit these functions to data and to plot the results on a routine basis. The importance of the experimental design for the estimation of such nonlinear regression models is investigated, and examples are given of experimental designs which are ‘optimal’ with respect to particular aims of the experimenter.     

屠宰绵羊卵巢卵母细胞的体外培养

为了使屠宰绵羊卵巢卵母细胞能够用于体外受精,本文着重探索了使卵巢卵母细胞体外培养成熟的方法和条件。实验结果表明,以TCM-199加10％FCS作为基本培养基,培养24～25小时,可以使绵羊卵巢卵母细胞培养成熟,其成熟率可达55.5％(435/784)。如果在培养液内添加hCG(0.02mg/ml)或LH(0.01mg/ml),并且尽可能保持卵丘细胞的完整,则可以使成熟率提高到76.9％(140/182)～82.9％(112/135)。     

A Comparison of Coulter ZBI and Fisher Autocytometer II Hematological Values in 28 Mammalian Species at the Metropolitan Toronto Zoo

One hundred and thirty-three blood samples from twenty-eight mammalian, nondomestic species were analyzed using both the Coulter ZBI and Fisher Autocytometer II. The WBC, RBC and Hb values for each species from both machines, were compared. The study indicated that for 27 species there was no significant difference (P > 0.05) between machines for the WBC. Twenty-one species showed no significant difference (P > 0.05) in the RBC results. Only one species exhibited a significant difference (P > 0.05) between machines in the hemoglobin value obtained.     

Melatonin content of the human pineal gland

Gas chromatography with electron capture detection was used to quantitate melatonin in single human pineal glands. The sensitivity of this melatonin assay is in the low picogram range. A 24-hour rhythm of pineal melatonin content was observed.     

Locally resonant sonic materials

We have fabricated sonic crystals, based on the idea of localized resonant structures, that exhibit spectral gaps with a lattice constant two orders of magnitude smaller than the relevant wavelength. Disordered composites made from such localized resonant structures behave as a material with effective negative elastic constants and a total wave reflector within certain tunable sonic frequency ranges. A 2-centimeter slab of this composite material is shown to break the conventional mass-density law of sound transmission by one or more orders of magnitude at 400 hertz.     

Clonal propagation of primate offspring by embryo splitting

Primates that are identical in both nuclear and cytoplasmic components have not been produced by current cloning strategies, yet such identicals represent the ideal model for investigations of human diseases. Here, genetically identical nonhuman embryos were produced as twin and larger sets by separation and reaggregation of blastomeres of cleavage-stage embryos. A total of 368 multiples were created by the splitting of 107 rhesus embryos with four pregnancies established after 13 embryo transfers (31% versus 53% in vitro fertilization controls). The birth of Tetra, a healthy female cloned from a quarter of an embryo, proves that this approach can result in live offspring.     

Discriminant and multiple regression analysis of anemia and opportunistic infection in Fell pony foals

Abstract: A condition resembling acquired immunodeficiency with anemia has been described in British Fell pony foals. The pathogenesis is unknown. The present study involved 322 foals of which 164 were of Fell breed and 12 were affected. Discriminant and multiple regression analyses were used to test the results of all clinical pathology parameters from these foals for statistical association with (1) breed origin and (2) presence of disease. Only hematocrit associated significantly with presence of disease. However, significant associations were found with Fell breed origin, including serum albumin concentration and lymphocyte count. The unexpected discovery of sporadic lymphocytosis in the breed indicates the value of this kind of analysis and may be evidence that Fell foal immunodeficiency is associated with retroviral infection.     

SPF鸡人工感染鸡败血霉形体后血液生物化学变化

用鸡败血霉形体（ＭＧ）国际标准强毒Ｒ株人工感染１５日龄ＳＰＦ鸡,在感染后１５ｄ采血作血液生物化学检验。结果：ＴＢｉｌ、ＧＯＴ、ＧＰＴ、ＡＬＰ、ＬＤｈ、ＣＯ２－ＣＰ、ＣＲＥ、ＢｕＮ、ＣＲＥ－Ｕ、无机磷、Ｍｇ＾２＋明显升高,而ＴＰ、ＡＬＢ、Ａ／Ｇ、Ｃｈｏ、Ｇｌｕ、Ｃａ＾２＋等明显下降,ＲＢＣ和Ｈｂ下降,ＷＢＣ上升,其中ＬＣ和嗜酸性白细胞明显上升。说明ＭＧ不仅造成呼吸系统障碍,也对肝功能和功能产生较大影     

Effects of partial liquid ventilation on acute lung injury in piglets

AIM: To observe the effect of partial liquid ventilation with perfluorocarbon on gas exchange, hemodynamics and lung histological change in the piglets with surfactant depletion-induced acute lung injury. METHODS: 12 piglets were treated by lung lavage to a partial pressure of oxygen in arterial blood (PaO₂) below 100 mmHg for one hour and randomly divided into gas ventilation group (control group) and partial liquid ventilation (PLV) group, in PLV group, piglets received PFC (FC3280) intratracheally at doses of 15 mL/kg. The parameters of gas exchange and hemodynamics were measured before lung lavage, after lung lavage when the acute lung injury (ALI) was established, and 1 hour, 2 hours after ALI. Animals underwent euthanasia at the end of the study, lung histologic analysis followed. RESULTS: Surfactant depletion by lung lavage induced a stable acute lung injury.Gas exchange increased markedly in the animals that underwent PLV, less hemodynamic damage was observed in PLV group compared with the animals in GV group. Lung histologic analysis demonstrated a less lung damage, including atelectasis, neutrophil excudation, intra-alveolar hemorrhage and interstitial edema in PLV group compared with control group. CONCLUSION: In piglets with surfactant depletion-induced acute lung injury, partial liquid ventilation with perfluorocarbon can improve the gas exchange with less adverse hemodynamic effect and less lung injury compared with conventional gas ventilation.