538 research outputs found
Immigrant gender convergence in education and on the labor market
Immigration tends to have a mitigating effect on the socioeconomic gender gap among immigrants. To explain this finding, we propose a gender convergence hypothesis that states that migration to a modern ‘open’ society offers women the opportunity to improve their position relative to that of men. In such a society, there are (almost) equal chances to participate in education and paid labor. The equalizing effect will be larger if the immigrants come from less developed regions, since women then have more room to improve their position. However, there may also be countervailing cultural powers within the immigrant group. The gender convergence hypothesis proposed here is tested for immigrants in the Netherlands. Using survey data, we investigate the educational and labor market position of Turkish, Moroccan, Surinamese, and Antillean males and females. We find convergent trends, particularly among Moroccan immigrants who come from less developed regions in their country of origin and who meet less cultural in-group barriers than, for example, Turkish immigrants.
A single-electron inverter
A single-electron inverter was fabricated that switches from a high output to
a low output when a fraction of an electron is added to the input. For the
proper operation of the inverter, the two single-electron transistors that make
up the inverter must exhibit voltage gain. Voltage gain was achieved by
fabricating a combination of parallel-plate gate capacitors and small tunnel
junctions in a two-layer circuit. Voltage gain of 2.6 was attained at 25 mK and
remained larger than one for temperatures up to 140 mK. The temperature
dependence of the gain agrees with the orthodox theory of single-electron
tunneling.Comment: 3 pages, 4 figures (1 color), to be published in Appl. Phys. Let
THE TABON, PHILIPPINE MEGAPODE, Megapodius cumingii, AS DESCRIBED IN HISTORICAL SOURCES
Abstract not availabl
THE BEHAVIOUR OF THE MOLLUCAN MEGAPODE, EULIPOA WALLACEI CAVES:MEGAPODIDAE) IN NESTING GROUNDS
The moluccan -megapode, Eulipoa wallacei is the only hole digging megapode in the island of Haruku. The birds lay eggs in a communal nesting ground exposed to the heat of the sun. The eggs collected between 1987 and 1995 showed an increase in number. The factors influencing the increase in number were not fully known, but it seems the social economic activities of the local peoples influenced the intensity of searching the eggs. There were also differences in number of eggs collected in wet and dry season.The birds lay eggs at the depth of 60-90 CIII in soil, the average eggs length 78.1 mm, average width 48.9 mm. The average soil temperature 27° - 35°C. The eggs in the incubation boxes resulted in 92.7% hatchlings, average incubation time 74.2 days, and the hatchlings found on the soil surface have an average weight of 57 gr. The behaviour of the bird in detail is indicated
Negative differential resistance due to single-electron switching
We present the multilevel fabrication and measurement of a Coulomb-blockade
device displaying tunable negative differential resistance (NDR). Applications
for devices displaying NDR include amplification, logic, and memory circuits.
Our device consists of two Al/AlO islands that are strongly coupled
by an overlap capacitor. Our measurements agree excellently with a model based
on the orthodox theory of single-electron transport.Comment: 3 pages, 3 figures; submitted to AP
Immigrant gender convergence in education and on the labor market
Immigration tends to have a mitigating effect on the socioeconomic gender gap among immigrants. To explain this finding, we propose a gender convergence hypothesis that states that migration to a modern ‘open’ society offers women the opportunity to improve their position relative to that of men. In such a society, there are (almost) equal chances to participate in education and paid labor. The equalizing effect will be larger if the immigrants come from less developed regions, since women then have more room to improve their position. However, there may also be countervailing cultural powers within the immigrant group. The gender convergence hypothesis proposed here is tested for immigrants in the Netherlands. Using survey data, we investigate the educational and labor market position of Turkish, Moroccan, Surinamese, and Antillean males and females. We find convergent trends, particularly among Moroccan immigrants who come from less developed regions in their country of origin and who meet less cultural in-group barriers than, for example, Turkish immigrants
HI and Galaxy Formation in Loose Groups
Models of hierarchical galaxy formation predict that large numbers of
low-mass, dark matter halos remain around galaxies today. These models predict
an order of magnitude more halos than observed stellar satellites in the Local
Group. One possible solution to this discrepancy is that the high-velocity
clouds (HVCs) around the Milky Way may be associated with the excess dark
matter halos and be the gaseous remnants of the galaxy formation process. If
this is the case, then analogs to the HVCs should be visible in other groups.
In this paper, we review the observations of HI clouds lacking stars around
other galaxies and in groups and present early results from our HI survey of
loose groups analogous to the Local Group and its implications for the nature
of HVCs and galaxy formation.Comment: 3 pages, 2 figures, to appear in PASA. Paper presented at workshop
`Structure and Dynamics in the Local Universe' 24-26 November, 2003, Sydney,
Australi
Psychological outcome and quality of life in children born with congenital diaphragmatic hernia
OBJECTIVE: To assess psychological and social functioning as well as health-related quality of life and its early determinants in children born with congenital diaphragmatic hernia (CDH). DESIGN: Cross-sectional follow-up study. SETTING: Outpatient clinic of a tertiary care hospital. PARTICIPANTS: Thirty-three CDH survivors aged 6-16 years. Main exposure: Patients who developed CDH associated respiratory distress within 24 hours after birth. MAIN OUTCOME MEASURE: Psychological and social functioning assessed with the Wechsler intelligence scale for children (WISC-R), Bourdon-Vos test, Beery Developmental Test of visual motor integration, Child Behaviour Checklist (CBCL) and Teacher Report Form (TRF). Health-related quality of life assessed with the Child Health Questionnaire (CHQ) and the Health Utilities Index (HUI). RESULTS: Normal mean total IQ (100.0 +/- 13.2) and normal visual-motor integration, but significantly lower results for sustained attention (Bourdon-Vos test (38.8 +/- 11.2 points)) were found. Learning difficulties were reported by 30% of the parents. Eight children had scores in the clinical range on the CBCL and/or TRF, indicating clinical significant behavioural problems. Except for the CHQ scale "General health", health status was not different from the reference population. No significant correlations between test results and severity of CDH were found, except an association of general health and physical functioning with length of hospital stay. CONCLUSION: CDH patients are at risk for relevant subtle cognitive and behavioural problems, probably not related to CDH severity. These may contribute to school failure and need for special educational services. Perception of general health is reduced when compared to the reference population indicating that CDH survivors and their parents believe their health is poor and likely to get wors
Effelsberg HI observations of compact high-velocity clouds
We have mapped 11 compact high-velocity clouds (CHVCs) in the 21-cm line
emission of neutral, atomic hydrogen, using the Effelsberg 100-m radio
telescope. The aim of our observations was to study the overall distribution of
the warm neutral medium of CHVCs with high sensitivity. The achieved baseline
rms of about 50 mK at the original 2.6 km/s velocity resolution allows us to
search for evidence of ram-pressure interaction with the ambient medium. In
addition, we have obtained spectra along an appropriate axis across each CHVC
with longer integration times and denser angular sampling. These deep slices
with a spectral baseline rms of about 25...35 mK allow us to determine the
column density profile in greater detail as well as the velocity and line width
gradient across each cloud. The most outstanding result of our observations is
the complexity of the HI column density distribution and the line profiles of
the investigated CHVCs. We have found only one cloud with a
spherically-symmetric appearance. Among the remaining clouds we observe
head-tail structures, bow-shock shapes, and objects with irregular shapes.
These complex morphologies in combination with the obtained physical parameters
suggest that ram-pressure interactions with an ambient medium may play a
significant role in shaping some of the CHVCs from our sample. These results
are consistent with a circumgalactic distribution of CHVCs with typical
distances of the order of 100 kpc. The pressure of the ambient medium might
also stabilise CHVCs in addition to their own gravitational potential.Comment: 18 pages, 11 figures, accepted for publication by Astronomy &
Astrophysic
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