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ABSTRACT. In order to further investigate synapomorphic characters in the genus Sarcocystis , the small subunit ribosomal RNA gene sequences of Sarcocystis capracanis and Sarcocystis moulei were determined and used to infer the phylogenetic position of these two organisms within the cyst-forming coccidia. Phylogenies derived using distance, maximum parsimony and maximum likelihood methods demonstrated that S. capracanis groups with Sarcoystis tenella and Sarcocystis arieticanis as a clade that shares the characteristic of using canids as their definitive host. S. moulei was shown to group with Sarcocystis gigantea and Sarcocystis fusiformis as a clade that shares the characteristic of using felids as their definitive host.  相似文献   
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This study examined the transcultural robustness of a screening instrument for hypomania, the Hypomania Checklist-32, first revised version (HCL-32 R1). It was carried out in 2606 patients from twelve countries in five geographic regions (Northern, Southern and Eastern Europe, South America and East Asia). In addition, GAMIAN Europe contributed data from its members. Exploratory and confirmatory factor analyses were used to examine the transregional stability of the measurement properties of the HCL-32 R1, including the influence of sex and age as covariates. Across cultures, a two-factor structure was confirmed: the first factor (F1) reflected the more positive aspects of hypomania (being more active, elated, self-confident, and cogni-tively enhanced); the second factor (F2) reflected the more negative aspects (being irritable, impulsive, careless, more substance use). The measurement properties of the HCL-32 R1 were largely invariant across cultures. Only few items showed transcultural differences in their relation to hypomania as measured by the test. F2 was higher among men and in more severe manic syndromes; F1 was highest in North and East Europe and lowest in South America. The scores decreased slightly with age. The frequency of the 32 items showed remarkable similarities across geographic areas, with two excep-tions: South Europeans had lower symptom frequencies in general and East Europeans higher rates of substance use. These findings support the interna-tional applicability of the HCL-32 R1 as a screening instrument for hypomania.  相似文献   
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This paper deals with experimental designs used in conjoint analysis. The described approach permutes the structure of the underlying fractional experimental design to make different sets of combinations. The resulting experimental designs, suggested to be called Isomorphic Permuted Experimental Designs (IPED), are statistically equivalent to each other while combining diverse sets of the variables and levels into different designs. By facilitating distinctive individual designs (for each respondent), IPEDs reduce a bias caused by some possibly unusually strong performing combinations, and allow detection and estimation of interactions among variables, as well as identification of pattern-based segments emerging from individual models of utilities. This paper examines the theoretical foundation of the approach, formalizes the methodology for algorithmic implementation and shows a practical example of utilization.

PRACTICAL APPLICATIONS


Isomorphic Permuted Experimental Design (IPED) allows for overcoming multiple interlinked statistical problems that affect the traditional conjoint analysis approaches, thus leading to more reliable and targeted results in practice. IPED facilitates individual respondents' models based on unique designs, thus allowing for pattern-based segmentation. The approach also allows for the detection of any and all interactions between the elements (features) of the experiments, thus increasing the reliability of conjoint analysis results. It has been utilized in many practical applications, such as for message optimization, early stage new product development, advertising, package and website optimization.  相似文献   
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Recent studies of female insects indicate that reproductive activities, such as mating and oviposition, can impair immune ability. Using the two tropical damselfly species Argia anceps Garrison and Hetaerina americana (Fabricius), egg production and phenoloxidase (PO) activity, a key enzyme in insect immunity, are measured in mating, ovipositing and perching females in December and March. Perching females of both species have fewer eggs compared with mating and ovipositing females, which suggests that perching females are not engaged in reproduction. There is seasonal variation in egg number for the three categories in H. americana but not in A. anceps, which can be interpreted in terms of adaptive changes in egg production depending on female–male interactions in the former species but not in the latter species. There is no difference in PO activity among mating, ovipositing or perching females within either species, although measurements in December and March indicate distinct seasonal changes. Juvenile Hormone (JH) is known to reduce the effectiveness of the immune system by favouring the use of resources for reproduction. A possible role for JH is examined in H. americana, using the JH analogue methoprene to manipulate hormone activity, revealing that PO activity is reduced in methoprene‐treated H. americana females. Thus, although the results of the present study are indicative of possible hormone‐driven changes in PO, there is not necessarily a down‐regulation of immune function (as determined by PO activity) during mating or oviposition. The results complement some recent studies countering the idea that reproductive activities reduce the immune ability in insects.  相似文献   
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Oviparity, egg retention and ovoviviparity are known to occurin pulmonates, but the few reports of true viviparity are unconfirmed.Oviparity is defined as the release of eggs as soon as theyare fully formed; they usually contain a single celled, fertilizedovum. Egg retention involves holding eggs for variable periodof time; ovoviviparity involves release of live young. The numerousvariations on the theme of egg retention or ovoviviparity areshown diagrammatically in an attempt to clarify the literature.These latter modes of reproduction are one method of avoidingegg desiccation in some snails, or are a method of carryingan extra rood during winter hibernation. Physiological adaptationsaccompanying ovoviviparity are not understood (Received 28 April 1978; revised 27 March 1979;  相似文献   
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  总被引:3,自引:0,他引:3  
Aphid life cycles can encompass cyclical parthenogenesis, obligate parthenogenesis, obligate parthenogenesis with male production and an intermediate 'bet-hedging' strategy where an aphid genotype will over-winter by continuing to reproduce by parthenogenesis and by investment in sexually produced eggs. In this paper, we focus on aphid lineages that reproduce entirely parthenogenetically (asexual aphids), in contrast to those that have any sexual forms in the annual cycle. Using modern molecular techniques, aphid biologists have made many empirical observations showing that asexual lineages are widespread both geographically and temporally. Indeed, we are collectively beginning to gather data on the evolution and persistence of these lineages through time. Here we review aphid karyology and parthenogenesis, both essential for interpretation of the molecular and ecological evolution of aphid asexual lineages. We describe the growing list of studies that have identified aphid genotypes that are both temporally and geographically widespread. We then collate examples of molecular and chromosomal evolution in asexual aphids and review the literature pertaining to phenotypic evolution and ecological diversification of asexual aphid lineages. In addition, we briefly discuss the potential of bacterial endosymbionts and epigenetic effects to influence the evolution of asexual aphid lineages. Lastly we provide a list of aphid taxa believed to be obligately asexual. This will be a useful resource for those seeking parthenogenetic animals as study systems. In conclusion, we present guidelines for the use of the term clone in aphid biology and stress the need for well-designed and well-executed studies examining the potential of asexual aphid lineages for adaptive evolution.  © 2003 The Linnean Society of London. Biological Journal of the Linnean Society , 2003, 79 , 115–135.  相似文献   
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  总被引:1,自引:5,他引:1  
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  总被引:1,自引:0,他引:1  
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