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41.
1. The selection of an oviposition site by a phytophagous insect can depend on many factors, including the risk of predation. Many species avoid predators by laying eggs where enemies searching host plants are unlikely to find them. 2. Females of the Peruvian butterfly, Oleria onega Hewitson (Lepidoptera: Nymphalidae: Danainae: Ithomiini) lay most of their eggs (76 ± 9%) off the host plant, Solanum mite Ruiz & Pav. These off‐host eggs may be laid up to 0.5 m from the nearest host‐plant individual, on twigs or leaf litter, as well as on living plants of species unsuitable for larval food. 3. Disappearance of eggs on and off the host plant was recorded by transferring eggs laid in captivity to known locations in the wild and recording rates of disappearance before the larvae emerged. After 2 days, eggs on the host were significantly more likely to have disappeared compared to eggs laid elsewhere. 4. We conclude that a high risk of predation is a likely trigger that caused O. onega to evolve a behaviour of laying eggs off its host plant. 相似文献
42.
The reporting of child sexual abuse (CSA) and physician-patient sexual
relationships (PPSR) are currently the focus of professional, legal and media
attention in several countries. This paper briefly reviews mental health policies
on these issues and reports on a WPA survey of them. While the WPA Madrid
Declaration permits breaching confidentiality for mandatory reporting of CSA
and clearly prohibits PPSR, it is not known how or to what extent these policies
are implemented in WPA Member Societies’ countries. It is also not known
whether policies or laws exist on these topics nationally or to what extent
psychiatrists and the public are aware of them. Representatives of WPA Member
Societies were e-mailed a survey about issues pertaining to CSA and PPSR.
Fifty-one percent of 109 countries replied. All reporting countries had laws
or policies regarding the reporting of CSA, but this was often voluntary (63%)
and without protection for reporting psychiatrists either by law (29%) or
by Member Societies (27%). A substantial number of psychiatric leaders did
not know the law (27%) or their Society’s policy (11%) on these matters.
With respect to PPSR, some reporting countries lacked laws or policies about
PPSR with current (17%) or past (56%) patients. Fewer than half of responding
representatives believed that their Society’s members or the public
were well informed about the laws and policies pertaining to CSA or PPSR.
There is clearly a wide range of laws, policies and practices about CSA and
PPSR in WPA Member Societies’ countries. There is a need in some countries
for laws or supplemental policies to facilitate the protection of vulnerable
child and adult patients through clear, mandatory reporting policies for CSA
and PPSR. Mechanisms to protect and support reporting psychiatrists should
also be developed where they do not already exist. There is also a need in
some countries to develop strategies to improve the education of psychiatrists,
trainees, and the public on these issues. 相似文献
43.
WILLIAM A. GAHL BRIAN POTTERF DONNA DURHAM-PIERRE MURRAY H. BRILLIANT VINCENT J. HEARING 《Pigment cell & melanoma research》1995,8(5):229-233
Tyrosine is the endogenous substrate for melanin production within melanosomes, but the method of tyrosine transport into the melanosome has not been investigated. In the mouse, melanogenesis is disrupted by mutations in the p gene resulting in the pink-eyed dilution phenotype; it has been suggested that the p gene codes for a tyrosine transport protein. We determined that normal (melan-a) melanosome-rich granular fractions take up 10 μm [3H]tyrosine at 21.1 ± 6.1 (SEM, standard error of the mean) pmol/min/mg protein (N=7) compared with 21.3 ± 5.8 SEM pmol/min/mg protein (N=5) for pink-eyed dilution, whose plasma membrane tyrosine transport was also normal (Km 89 μM; Vmax 302 pmol/min/mg cell protein). We also demonstrated that pink-eyed dilution melanosomes are immature by virtue of their low density, high hexosaminidase activity, and lack of pigment. These data indicate that a tyrosine transport system exists in the melanosomal membrane and that the p gene does not encode a tyrosine transporter of critical importance. 相似文献
44.
DONNA CASSIDY-HANLEY HELEN R. SMITH PETER J. BRUNS 《The Journal of eukaryotic microbiology》1995,42(5):510-515
ABSTRACT. We have developed a simple, efficient procedure for the long term freezing of Tetrahymena thermophila in liquid nitrogen. This technique yields excellent recovery of viable cells with all strains tested and does not require the use of a controlled rate low temperature freezer. To optimize the freezing technique, we have examined the effects of varying a number of parameters, including the physiological state of the cells prior to freezing, the time of exposure to cryoprotectant, and the rate of freezing and thawing. the frequency of viable cell recovery following freezing using this technique has been tested for a variety of different cell lines. 相似文献