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Social exploitation of vitellogenin   总被引:13,自引:0,他引:13       下载免费PDF全文
Vitellogenin is a female-specific glucolipoprotein yolk precursor produced by all oviparous animals. Vitellogenin expression is under hormonal control, and the protein is generally synthesized directly before yolk deposition. In the honeybee (Apis mellifera), vitellogenin is not only synthesized by the reproductive queen, but also by the functionally sterile workers. In summer, the worker population consists of a hive bee group performing a multitude of tasks including nursing inside the nest, and a forager group specialized in collecting nectar, pollen, water, and propolis. Vitellogenin is synthesized in large quantities by hive bees. When hive bees develop into foragers, their juvenile hormone titers increase, and this causes cessation of their vitellogenin production. This inverse relationship between vitellogenin synthesis and juvenile hormone is opposite to the norm in insects, and the underlying proximate processes and life-history reasons are still not understood. Here we document an alternative use of vitellogenin by showing that it is a source for the proteinaceous royal jelly that is produced by the hive bees. Hive bees use the jelly to feed larvae, queen, workers, and drones. This finding suggests that the evolution of a brood-rearing worker class and a specialized forager class in an advanced eusocial insect society has been directed by an alternative utilization of yolk protein.  相似文献   
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Aims To discover whether the number of fatal alcohol peaks during festivities characterized by unrestrained drinking and relates to sales of alcoholic beverages. Design Time‐series and cross‐sectional. Data Fatal alcohol poisonings and retail alcohol sales in Finland in 1983–99. Findings Fatal alcohol poisonings were found to peak during weekends and in the May Day, Midsummer Day and Christmas celebrations. Regression analysis of quarterly series lead to a model showing that 1% increase in the sales of spirits increases the number of fatal alcohol poisonings by 0.4%. Conclusions At the population level, increases in the sales of spirits and periods of hard drinking seem to increase deaths from alcohol poisoning. The findings could be of use in efforts to decrease hard drinking.  相似文献   
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Objectives: Mechanical neck pain (MNP) is common in the athletic population. While symptoms may present at the cervical spine for patients complaining of MNP, thoracic spinal alignment or dysfunction may influence cervical positioning and overall cervical function. Clinicians often employ cervical high-velocity low-amplitude (HVLA) thrust manipulations to treat MNP, albeit with a small level of inherent risk. Mulligan Concept positional sustained natural apophyseal glides (SNAGs) directed at the cervicothoracic region are emerging to treat patients with cervical pain and dysfunction, as evidence supporting an interdependent relationship between the thoracic and cervical spine grows. The purpose of this a priori study was to evaluate outcome measures of patients classified with MNP treated with the Mulligan Concept Positional SNAGs. Methods: Ten consecutive young-adult patients, ages ranging from 15 to 18 years (mean = 16.5 ± 1.78), classified with MNP were treated utilizing Mulligan Concept Positional SNAGs. The Numeric Rating Scale (NRS), Patient-Specific Functional Scale (PSFS), Neck Disability Index (NDI), Disablement in the Physically Active (DPAS), and Fear-Avoidance Based Questionnaire-Physical Activity (FABQPA) were collected for inclusion criteria and to identify patient-reported pain and dysfunction. Results: Patients reported decreases in pain on the NRS [5.4 to .16, p = .001], increases in function on the PSFS [5.2 to 10, p = .001], and increases in cervical range of motion (CROM) [ext p = .003, flex p = .009, left rot p = .001, right rot p = .002] immediately post-treatment and between treatments. Discussion: Positional SNAGs directed at the cervicothoracic region may address a variety of patient reported symptoms for MNP, and the number of treatment sessions needed for symptom resolution may be closer to a single session rather than multiple treatments. Level of Evidence: 4.  相似文献   
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