Despite intensive research on perceived overqualification, empirical evidence on overqualified employees' job search behavior remains relatively insufficient. Notably, no studies have explored the possible link between perceived overqualification and internal job searching behaviors. In the present study, we consider whether—and more importantly when—employees with high perception of overqualification search for internal and external job opportunities. Applying the ability–motivation–opportunity (AMO) framework, we propose and test a model that specifies how motivation and opportunity to move or stay activate differential effects in overqualifiers' job searching process. Results from two studies surveying employees in Taiwan (Study 1: N = 268; Study 2: N = 210) show that overqualifiers displayed greater intentions to leave the current job and, in turn, engaged in more external job search behaviors; this relation was strongest for those whose perceived ease of movement and proactive personality increased or person–organization (PO) fit decreased. Furthermore, overqualifiers displayed greater intentions to leave the current job and also increased their internal job search behaviors; this relation was strongest for those whose perceived ease of movement and PO fit increased. A series of supplemental analyses also lends support to our theorizing. 相似文献
Arthropod communities in pear are conceptualized as hierarchically organized systems in which several levels of organization
or subsystems can be recognized between the population level and the community as a whole. An individual pear tree is taken
to be the community habitat with arthropod subcommunities developing on leaf, fruit, and wood subcommunity habitats. Each
subcommunity is composed of trophically organized systems of populations. Each system of populations is comprised of a functional
group or guild of phytophagous arthropods that use the habitat primarily for feeding but also for overwintering or egg deposition,
and associated groups of specialized predators, parasitoids, and hyperparasitoids. Several species move from one subcommunity
to another during the course of community development and thus integrate community subsystems.
Community development or change in organization through time is conceptualized as being jointly determined by the development
of the habitat and the organization of the species pool. The influence of habitat development on community development within
a species pool is emphasized in this research. Seasonal habitat development is expressed as change in the kinds and biomasses
of developmental states of wood, leaf, and fruit subcommunity habitats. These changes are accompanied by changes in the kinds,
biomasses, and distributions of associated community subsystems. 相似文献
In this report we have summarized our experience with the prenatal diagnosis of β-thalassemia in 1000 pregnancies followed at least until 12 months after birth. In the majority of these cases, the thalassemia lesion was the nonsense mutation at the codon corresponding to amino acid 39, which produces the hematological phenotype of β-thalassemia. Fetal blood sampling was carried out by placental aspiration, by which a sufficient amount of fetal blood for analysis was obtained in the majority of cases (99 per cent). The fetal mortality associated with fetal blood sampling was 6·3 per cent. Those placental samples contaminated by maternal cells were successfully purified by Ørskov lysis. Fetal blood was analysed by globin chain synthesis on CM–52 columns, which gave reliable results. Two misdiagnoses (0·2 per cent) have been made of which one was due to a non-globin protein co-migrating with the β-chains while the other resulted from a misclassification of the type of thalassemia segregating in the family. 相似文献
Markedly decreased fetal activity (akinesia/hypokinesia) is usually readily apparent to experienced mothers, and frequently this concern leads to attempts at prenatal diagnosis. We report prenatal diagnosis of two fetuses with congenital contractures, markedly decreased fetal movement, and microcephaly due to severe holoprosencephaly. Such familial recurrence to phenotypically normal parents suggests a newly recognized autosomal recessive or X-linked syndrome that is readily detectable by prenatal ultrasonography. 相似文献
Meckel–Gruber syndrome is a rare autosomal recessive disorder often resulting in neonatal death within a few hours of life. The condition is usually diagnosed ultrasonographically in the second trimester and earlier diagnosis has been mainly confined to high recurrence risk pregnancies. We describe the earliest non-invasive diagnosis of this condition at 12+2 weeks' gestation in a patient with no previous history using transabdominal ultrasound. Pregnancy termination was declined. Subsequent development of anhydramnios in the mid-trimester resulted in poor fetal visualization. We propose that first-trimester diagnosis of this condition is not only possible but preferable, as normal liquor volume facilitates visualization of fetal anatomy. 相似文献
We report a case of Pallister-Killian syndrome initially diagnosed prenatally as tetrasomy 21. A 33-year-old primiparous woman was noted at 24 weeks' gestation to have moderate polyhydramnios. Ultrasonography showed diminished fetal stomach filling, hydronephrosis, and prominence of the cisterna magna. Cytogenetic analysis of cultured amniocytes was initially interpreted as mosaic tetrasomy 21: 46,XX/47,XX,+i(21q). The patient was then referred to our centre for genetic counselling. At 34 weeks' gestation, a dysmorphic infant was delivered and died within 30 min. Physical features were consistent with the Pallister-Killian syndrome. Renal, gastrointestinal, and central nervous system anomalies were found at post-mortem examination. Analysis of peripheral lymphocytes revealed 5 per cent of cells with a marker chromosome, while 92 per cent of cultured fibroblasts had this same marker. Fluorescent in situ hybridization (FISH) using an alpha-satellite probe for chromosomes 13 and 21 failed to hybridize to the marker, while a chromosome 12 centromeric probe unequivocally identified it as an i(12p). Use of FISH can provide rapid, specific prenatal diagnosis of ambiguous marker chromosomes and improve prenatal counselling. 相似文献
Recent attention has focused on genetic compatibility as an adaptive function for why females engage in extrapair mating.
We tested the genetic compatibility hypothesis in tree swallows (Tachycineta bicolor) over five breeding seasons using data from ten microsatellite loci. Tree swallows are socially monogamous passerines exhibiting
high levels of extrapair paternity. Overall, we found that 47% of offspring were the result of extrapair fertilizations, and
83% of females produced at least one extrapair offspring. Consistently for all years, extrapair offspring were more heterozygous
than their maternal half-siblings, which is in accordance with the genetic compatibility hypothesis. The difference was largely
caused by the high heterozygosity of extrapair offspring sired by unknown males, suggesting that females are engaging in extrapair
copulations with geographically distant males to increase the likelihood of being inseminated by a more compatible mate. Our
findings support the idea that postcopulatory mechanisms are important for females when assessing potential sires for their
offspring. 相似文献
Annual growth rings sampled from three free-standing trees (Platanus hybrida sp.), grew in the metropolitan area of Palermo (Italy) and covering a 118 years time span (1880–1998), have been studied for their 13C/12C carbon isotope ratios. It has been found that the 13C/12C tree ring record, during the study time interval, decreased of −3.6‰, from −26.4‰ in 1880 to −30‰ in 1998. Such a progressive depletion has been attributed to the addition of anthropogenic 13C depleted carbon dioxide to the local atmosphere. The observed 13C/12C decrease has been used to infer some possible pathways of atmospheric CO2 change in the study urban area. 相似文献
A case of early diagnosis at 13 weeks' gestational age of Meckel–Gruber syndrome by ultrasound is reported in a patient with a 25 percent recurrence risk. The usefulness of genetic counselling and aimed echographic examination is discussed. 相似文献
Objective: The objective of this study was to discuss the challenges in estimating bicycle helmet effectiveness from case–control studies of injured cyclists and to estimate helmet effectiveness from cases and available exposure data.
Methods: Data were extracted from studies of cyclists in Seattle; Victoria and New South Wales, Australia; and The Netherlands. Estimates of helmet use were used as exposure to compute relative risks for Seattle and Victorian data. Cycling distance data are routinely collected in The Netherlands; however, these data cannot be disaggregated by helmet use, which makes it unsuitable for estimating helmet effectiveness. Alternative controls were identified from larger cohorts for the Seattle and New South Wales cases.
Results: Estimates of helmet effectiveness were similar from odds ratios (ORs) using hospital controls or from relative risks (RRs) using helmet use estimates (Seattle: OR = 0.339, RR = 0.444; Victoria: OR = 0.500, RR = 0.353). Additionally, the odds ratios using hospital controls were similar when controls were taken from a larger cohort for head injury of any severity (Seattle: OR = 0.250, alt OR = 0.257; NSW: OR = 0.446, alt OR = 0.411) and for serious head injury (Seattle: OR = 0.135, alt OR = 0.139; NSW: OR = 0.335, alt OR = 0.308). Although relevant exposure data were unavailable for The Netherlands, the odds ratio for helmet effectiveness of those using racing, mountain, or hybrid bikes was similar to other estimates (OR = 0.371).
Conclusions: Despite potential weaknesses with case–control study designs, the best available evidence suggests that helmet use is an effective measure of reducing cycling head injury. 相似文献