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PubMed1996

The ethnic composition of migration in the former Soviet Union.

"This paper examines the impact of the disintegration of the Soviet Union on migration patterns within the newly independent states. Data on migration between Russia and the other 14 former Soviet republics are analyzed to reveal the magnitude and ethnic composition of migration after independence and to examine the assumption that Russians will tend to return to Russia, whereas members of other titular groups will emigrate to their respective newly independent states. The data suggest that nationalization not only pushes non-titular groups to emigrate from the former Soviet republics, but also pulls titular groups to immigrate to the newly independent states from Russia."

Culture↗
PubMed1992

[Demographic differences between nonnative groups: the impact of international migration].

The impact of international migration on the composition of the population of the Netherlands is examined. The authors conclude that "the non-native population shows a considerable variety from a demographic point of view. Differences in composition by age and sex can largely be attributed to differences in migration patterns. Both the size and the period of migration flows have had their influence, as well as the type of migration (labour migration, family reunification, etc.). Apart from the direct influence there are also indirect effects because of demographic events that took place after the migration, like births, marriages and deaths." (SUMMARY IN ENG)

Age Distribution↗
PubMed2005

For work and for school: internal migration of Canada's rural nurses.

Using data from the Registered Nurses Database and a recently conducted national survey, this study examined the internal migration patterns of Canadian-educated rural RNs. Inter-provincial migration rates, ranging from 11% to 27% depending on the database used, mask much wider variations in sub-provincial movement rates, which are particularly relevant when considering the provision of nursing services in rural and remote communities. Rural RNs are more likely to migrate if they are female, older, working in nursing stations, and living in remote communities. A majority of RNs whose migration is associated with going to school after their initial nursing education do not return to the jurisdiction where they were first registered. Targeted migration studies are needed to fully understand both the detailed patterns and the predictors of such movements in order to better assess recruitment and retention policies and to enhance our overall health human resources planning models.

Adult↗
PubMed2000

In ovo time-lapse analysis of chick hindbrain neural crest cell migration shows cell interactions during migration to the branchial arches.

Hindbrain neural crest cells were labeled with DiI and followed in ovo using a new approach for long-term time-lapse confocal microscopy. In ovo imaging allowed us to visualize neural crest cell migration 2-3 times longer than in whole embryo explant cultures, providing a more complete picture of the dynamics of cell migration from emergence at the dorsal midline to entry into the branchial arches. There were aspects of the in ovo neural crest cell migration patterning which were new and different. Surprisingly, there was contact between neural crest cell migration streams bound for different branchial arches. This cell-cell contact occurred in the region lateral to the otic vesicle, where neural crest cells within the distinct streams diverted from their migration pathways into the branchial arches and instead migrated around the otic vesicle to establish a contact between streams. Some individual neural crest cells did appear to cross between the streams, but there was no widespread mixing. Analysis of individual cell trajectories showed that neural crest cells emerge from all rhombomeres (r) and sort into distinct exiting streams adjacent to the even-numbered rhombomeres. Neural crest cell migration behaviors resembled the wide diversity seen in whole embryo chick explants, including chain-like cell arrangements; however, average in ovo cell speeds are as much as 70% faster. To test to what extent neural crest cells from adjoining rhombomeres mix along migration routes and within the branchial arches, separate groups of premigratory neural crest cells were labeled with DiI or DiD. Results showed that r6 and r7 neural crest cells migrated to the same spatial location within the fourth branchial arch. The diversity of migration behaviors suggests that no single mechanism guides in ovo hindbrain neural crest cell migration into the branchial arches. The cell-cell contact between migration streams and the co-localization of neural crest cells from adjoining rhombomeres within a single branchial arch support the notion that the pattern of hindbrain neural crest cell migration emerges dynamically with cell-cell communication playing an important guidance role.

Animals↗
PubMed1982

[Population structure of the forest Nentsi: demographic characteristics, marriage structure, migration and an analysis of mixing].

This report is a third one in a series of works devoted to the genetic structure (biodemographic studies) of the Forest Nentsy. The main parameters of the population studied were as follows: the total number in seven subpopulations amounting to 1734 persons, the sex ratio 0.93, percentage of children in the group of 0 to 15 years old--39,1%, reproductive and effective sizes--29,5% and 22,0%, respectively, the mean number and variance of offspring per mating, when reproduction is completed being 2,7 (5,2). It has been shown that kin and territorial subdivision of the population contributes to the formation of conjugal pairs and migration pattern. Within-kin matings make 0,041, whereas, according to the panmixia hypothesis, this value would be 0,243. The average index of isolation for particular subpopulation is 62,7%. An exchange of migrants occurs between adjacent groups. Migration stream to the different subpopulations varies in volume and ethnic composition. Analysis of the admixture based on the pedigree isoname method has shown that the proportion of the Forest Nentsy gene contribution to their own population is 74,4%. Data on subpopulation size, patterns of matings, migration and admixture may serve as a basis to account for intrapopulation heterogeneity.

Adolescent↗
PubMed1992

Alcohol dose and low density lipoprotein heterogeneity in squirrel monkeys (Saimiri sciureus).

The present study was designed to determine whether normolipidemic male squirrel monkeys (Saimiri sciureus) exhibit low density lipoprotein (LDL) heterogeneity similar to that observed in humans and if present, whether LDL subfractions are altered by consumption of low vs. high dose ethanol (EtOH). Primates were divided into three groups designated control, low, and high EtOH and fed isocaloric liquid diets containing 0%, 12% and 24% of calories as EtOH, respectively, for 6 months. The 12% EtOH caloric level resulted in a modest, non-significant increase in high density lipoprotein (HDL) cholesterol and no change in LDL cholesterol or plasma apolipoprotein B (apo B), while the 24% dose produced significant elevations in plasma, LDL and HDL cholesterol and apo B. Using a single-spin density gradient ultracentrifugation procedure developed for humans, three distinct LDL subclasses designated LDL1a (d = 1.031 g/ml), LDL1b (d = 1.038 g/ml) and LDL 2 (d = 1.046 g/ml) were isolated from all three treatment groups. Monkey LDL subfractions were nearly identical to very light, light and heavy LDL subspecies isolated from human plasma in terms of their: (1) isopycnic densities following ultracentrifugation; (2) co-migration as single bands with beta-electrophoretic mobility in cellulose acetate and agarose electrophoretic gels; (3) size-dependent migration pattern in polyacrylamide gradient electrophoretic gels; (4) co-migration as a single band corresponding to apo B-100, following SDS polyacrylamide gel electrophoresis; and (5) decrease in total cholesterol/protein ratios with increasing LDL subclass density. Although there were no treatment differences in LDL particle size, within each treatment group, mean particle size for each LDL subfraction was significantly different from every other subfraction. Low (12%) dose alcohol had no effect on LDL subfraction mass relative to controls while high alcohol consumption resulted in marked increases in all lipid (except triglyceride) and protein of the larger, buoyant LDL subspecies (LDL1a and LDL1b). Moreover, the best correlation between plasma apo B and LDL subfraction total mass was demonstrated with LDL1b (r = 0.735). Since neither the lipid nor the protein concentration of the small, dense, purportedly more atherogenic, LDL2 changed with the 24% EtOH dose, we propose that the LDL subfraction alterations associated with high alcohol intake in squirrel monkeys (increased LDL1a, increased LDL1b, LDL2 no effect) may represent a compensatory response to modulate the overall atherogenic lipoprotein profile associated with elevations in total LDL cholesterol and plasma apolipoprotein B.

Animals↗
PubMed2004

Twist functions in vertebral column formation in medaka, Oryzias latipes.

Medaka twist, a basic helix-loop-helix (bHLH) transcription factor, is expressed in the sclerotome during embryogenesis. We previously established a line of twist-EGFP transgenic medaka, whose EGFP expression is regulated by the twist promoter; therefore, we could observe the behavior of sclerotomal cells in vivo. In the transgenic medaka embryos, EGFP-positive sclerotomal cells migrated dorsally around the notochord and the neural tube, where at a later stage the vertebral column would be formed. This finding strongly suggests that twist-expressing sclerotomal cells participate in vertebral column formation in medaka. To clarify the function of twist gene in the sclerotome, we performed knockdown analysis of twist by using two kinds of morpholino antisense oligonucleotides targeted against twist (MO1 and MO2). Both the MO1 and MO2 morphants exhibited absence of neural arches, which are bilaterally paired, dorsomedially oriented bones on the dorsal aspect of the centrum. In addition, MO2, which blocks translation of only endogenous twist mRNA in the twist-EGFP transgenic medaka, did not affect the migration pattern of EGFP-positive cells, revealing that the migration of sclerotome-derived cells were normal in the absence of twist gene function. These results demonstrate that medaka twist functions in vertebral column formation by regulating the sclerotomal cell differentiation.

Amino Acid Sequence↗
PubMed2005

Type I interferon dependence of plasmacytoid dendritic cell activation and migration.

Differential expression of Toll-like receptor (TLR) by conventional dendritic cells (cDCs) and plasmacytoid DC (pDCs) has been suggested to influence the type of immune response induced by microbial pathogens. In this study we show that, in vivo, cDCs and pDCs are equally activated by TLR4, -7, and -9 ligands. Type I interferon (IFN) was important for pDC activation in vivo in response to all three TLR ligands, whereas cDCs required type I IFN signaling only for TLR9- and partially for TLR7-mediated activation. Although TLR ligands induced in situ migration of spleen cDC into the T cell area, spleen pDCs formed clusters in the marginal zone and in the outer T cell area 6 h after injection of TLR9 and TLR7 ligands, respectively. In vivo treatment with TLR9 ligands decreased pDC ability to migrate ex vivo in response to IFN-induced CXCR3 ligands and increased their response to CCR7 ligands. Unlike cDCs, the migration pattern of pDCs required type I IFN for induction of CXCR3 ligands and responsiveness to CCR7 ligands. These data demonstrate that mouse pDCs differ from cDCs in the in vivo response to TLR ligands, in terms of pattern and type I IFN requirement for activation and migration.

Animals↗
PubMed1976

New temperate bacteriophage for Bacillus subtilis, rho 11.

A new temperate bacteriophage, rho11, isolated by J. Hoch, has been characterized. This new phage is very similar to the temperate phage phi3T in size (380 nm), host range, homoimmunity, DNA buoyant density (1.694 g/ml), antigenicity, and molecular weight (around 6.0 X 10(7)) as determined in gels. Like phi3T, rho11 converts thymine auxotrophs to prototrophy at high frequency (250 out of 250 tested). Phage rho11 differs from phi3T in plaque morphology and in the endonuclease R-EcoRI digest pattern. Sixteen of the 20 rho11 DNA fragments have migration patterns corresponding to those of the 21 fragments of phi3T. The close similarities yet clear differences between these phages suggest that the two phages have a common ancestor.

Bacillus subtilis↗
PubMed1975

Trends in return migration to the South.

The rate of return migration to the South rose by nearly 19 percent between the late 1950's and the late 1960's and was an important factor in changing the South's overall migration pattern. But an increase in the rate of return migration was somewhat less important in changing Southern migration than (1) a decline in the rate of out-migration of native Southerners and (2) an increase in the rate at which non-Southern-born persons move to the South. The probability of former migrants returning to the South was over four times greater for whites than for blacks in the 1955-1960 period and three and one-fourth times greater in the 1965-1970 period. Since 1970 the rate of return migration has apparently continued to rise at a faster rate for blacks, but the black rate of return migration is still below the white rate.

Adolescent↗
PubMed1990

Genetic variation at the immunoglobulin allotype loci in Creoles of Trinidad.

The sera of a sample of 204 Creoles from Trinidad were tested for the presence of polymorphic gene complexes occurring on immunoglobulin light- and heavy-chain molecules including the allotypic markers IGKC 1, IGHA2 1 and 2, IGHG1 A, X, F, and Z, and IGHG3 G, G5, B0, B1, B3, B4, B5, C3, C5, S, and T. Nine IGHG (GM) haplotypes occur in polymorphic frequencies (greater than .01) in this population, including known African, Asian, Caucasian, and Amerindian marker haplotypes. Significant differences (P less than .01) were found in the frequency distributions of three IGHG (GM) haplotypes and the frequency of IGKC*1 in these data and data from Creole populations of Belize and St. Vincent. The Creoles of Trinidad and St. Vincent are more similar in IGHG (GM) haplotype distributions than are Trinidad and Belize populations. Previous testing has revealed no significant differences between St. Vincent and Belize Creoles at the Ig allotypic loci. Analysis of migration patterns in the Caribbean suggests that different rates of Asian migration have maintained regional diversity at these loci, while continuous gene flow from the eastern Caribbean to Trinidad has had a relative homogenizing effect on the gene pools of this area.

Chi-Square Distribution↗
PubMed1998

Analysis of a polymorphism in the tuberous sclerosis (TSC2) gene does not predispose to schizophrenia.

The tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by the development of malformations in various organs including the brain. A polymorphism in the TSC2 gene has been found to be increased in gangliogliomas, a lesion which is associated with disturbed neuro-glial cell migration pattern. Since these pathomorphological changes are compatible with disturbed neuronal migration in schizophrenic brains, we investigated this polymorphism in 130 families with a schizophrenic index patient. A 222-bp fragment of genomic DNA containing the TSC2 variant was analyzed by SSCP. The analysis revealed that there is no association with schizophrenia.

Adult↗
PubMed2004

Migration of saline solutions in variably saturated porous media.

Migration of concentrated NaNO3 solutions in homogeneous packs of pre-wetted silica sands was investigated using a light transmission system. Solutions of 5 molal NaNO3 were found to migrate downward 24-62% faster than pure water, in an unstable, fingered manner. This behavior was attributed primarily to a surface tension induced, non-zero apparent contact angle between the imbibing and the resident fluids. For saline solutions of similar surface tension to that of pure water (achieved by the addition of 2% methanol), the migration rates and plume shapes were comparable to that of water, demonstrating that density was not the primary source of the observed differences in migration patterns. At depths where resident saturation increased above residual, the migration process appeared to occur via film flow with slight changes in saturation (<4%), rather than in a series of abrupt jumps, as observed at shallower depths. A method for contact angle scaling was used to illustrate the effects of non-zero contact angles on capillary pressure-saturation curves.

Filtration↗
PubMed1998

Poor people on the move: county-to-county migration and the spatial concentration of poverty.

"Poverty rates in high-poverty and low-poverty rural [U.S.] counties, and, thus, the spatial concentration of poverty, are affected by poverty-specific differences in in-migration and out-migration patterns. These patterns are investigated using 1985-90 county-to-county migration data from the decennial census. Effects on poverty rates of four migration flows (in- and out-migration of poor, in- and out-migration of nonpoor) are quantified, and their impacts on spatial concentration of poverty are assessed. The effect of selected county characteristics on the migration of the poor and nonpoor in nonmetro counties [is] estimated."

Americas↗
PubMed1994

Epithelial migration in mastoid cavities.

The epithelial migration in 18 dry ears with a cavity after surgery was studied by the ink-dot method and compared with the epithelial migration in 15 normal ears. A qualitatively normal centrifugal migration pattern was observed in all cavity ears. Considerable variation in migration speed was observed within the same cavity ear, thus a comparison with the migration speed in normal ears was impossible. No definite relationship was apparent between migration speed and the self-cleansing ability of the ear, which primarily appeared to be a function of the macroscopic appearance of the cavity (i.e. the presence of pockets or ridges). We conclude that epithelial migration is as important in maintaining the self-cleansing function and non-infected state in cavity ears as it is in normal ears.

Adult↗
PubMed1990

Importance of rotavirus and adenovirus types 40 and 41 in acute gastroenteritis in Korean children.

To examine the role of rotavirus (Rv) and adenovirus types 40 and 41 (Ad40/41) in Korean children with acute gastroenteritis, we evaluated 345 children with acute gastroenteritis and 90 children without acute gastroenteritis in Seoul, Korea, during a 29-month period. Stools were tested for group A Rv antigen and for Ad40/41 by using monoclonal antibody (MAb)-based assays. Rv was found in 68% of the ill children and 19% of the controls (P less than 0.001), whereas Ad40/41 was detected in 9% of the ill children and 2% of the controls (P less than 0.05). Also, 6% of the ill children and 0.01% of the controls excreted Rv and Ad40/41 simultaneously. Among the ill children, 96% of children with Rv and 94% of those with Ad40/41 were younger than 24 months. Although a peak of Rv infection was detected in early winter in both years of the study, there was no apparent seasonal trend with Ad40/41. Diarrhea with more than 10 stools per day, vomiting, or fever was most strongly associated with Rv shedding, whereas the first two manifestations were associated with coinfection of Rv and Ad40/41. To investigate the genetic and serotypic diversity of Rv strains, we tested 195 and 144 fecal Rv specimens isolated from the gastroenteritis cases, respectively, by polyacrylamide gel electrophoresis of the segmented RNA genome and by an enzyme-linked immunosorbent assay with serotype-specific MAbs. Of the 195 specimens, 154 yielded RNA patterns characteristic of group A Rv: 18% had short electrophoretic migration patterns, 81% had long patterns, and 1% had a mixture of short and long patterns. Of the 144 specimens, serotype specificity was determined in 51%: 89% were serotype 1, 10% were serotype 2, and 1% were serotype 3. Analysis of the specimens for which electropherotypes and serotypes were available indicated that a given RNA pattern corresponded to a particular serotype, except in one strain that showed short patterns but serotype 1. We suggest that Rv and Ad40/41 in stools be accepted critically as an important cause of diarrhea among young children in Korea.

Acute Disease↗
PubMed1998

Sensory development and its relation to habitat change in three species of sciaenids.

Visual and mechanosensory development of three sciaenid species was investigated to examine possible correlations between sensory morphology and patterns of habitat use. Although the three species have different migration patterns as early larvae, few differences in sensory morphology occurred between species until late in the larval period. Atlantic croaker, Micropogonias undulatus, were distinguished by enhancements of visual morphology (large eyes, abundant photoreceptors, and best summation of the three species). Croaker arrive inshore later in the larval period and, after settlement, appear to use deeper water habitats than do the other two species. Spotted seatrout, Cynoscion nebulosus, had the fewest enhancements of visual morphology but had more free neuromasts than the other two species late in the larval period. After settlement, seatrout are primarily associated with seagrass habitats. Red drum, Sciaenops ocellatus, did not have pronounced specialization of one sensory system, as did the other two species. For part of the larval period, neuromast numbers were higher in red drum than in the other two species. Later, enhancements of visual morphology did occur, but only eye and lens size were the same as those of Atlantic croaker. Red drum larvae appear to use a wider variety of habitats than do the other two species. In none of the species examined did sensory changes correlate with offshore to inshore movements, and only initial rod formation occurred prior to settlement. Distinct sensory changes did not occur concurrent with habitat changes, probably due to constructional and phylogenetic constraints. Rather, sensory differences are related to the environmental conditions in the predominant inshore habitat occupied by each species after settlement, when morphological limitations are less severe.

Animals↗
PubMed1989

Population migration and economic restructuring in the United States.

"This article demonstrates that sectoral employment shifts associated with the migration pattern changes of the 1970s are very different than those for the period 1955-60 to 1965-70. Changing competitiveness for jobs in manufacturing and other traditional basic sectors of the economy cannot account for the greatly accelerated levels of core-periphery net outflow that have been the dominant characteristic of interstate movement during the 1970s and 1980s. Instead, an interconnected set of activities that includes government, services, trade, and construction is associated with the broadscale shifts in the geographic pattern of the United States' population. The causal linkage from migration to employment change assumed heightened importance during the 1970s."

Americas↗