Differences In Migration Patterns Research Articles

An Endogenous Basis for Differential Migration in the Dark-Eyed Junco

Male and female Dark-eyed Juncos, Junco hyemalis hyemalis, partially segregate along a latitudinal gradient in North America during winter. The sex ratio favors males in the north and females in the south. The sexes differ, not only in their midwinter distribution, but also in the timing of fall migration, with females passing through stopover sites earlier than males. To investigate the basis for these differences in migration patterns, several measures of migratory behavior, including the date of onset and the duration of migratory activity (Zugunruhe), were compared in captive adult male and female juncos. When held under the same photoperiod and given free access to food, females initiated fall Zugunruhe twelve days earlier than males and continued to be active after the males stopped. This resulted in females showing, on average, 21 more days of migratory activity. There was no difference between the sexes in the proportion of nights during the migration period spent exhibiting migratory activity or in the average amount of activity per bird for the season. Females briefly showed higher migratory activity in early September. Both sexes exhibited a significant increase in body fat at the onset of migratory activity but there was no significant difference between the two groups at any time during the sampling period. Although differences in social status, physiological constraints, and/or importance of early arrival have been proposed as both past and current factors influencing differential migration in many species, these data illustrate sufficient endogenous sex-related differences that can result in differential migration in Dark-eyed Juncos.

Vegetation and Climate Change in Eastern North America Since the Last Glacial Maximum

Response surfaces describing the empirical dependence of surface pollen percentages of 13 taxa on three standard climatic variables (mean July temperature, mean January temperature, and mean annual precipitation) in eastern North America were used to infer past climates from palynological data. Inferred climates at 3000—yr intervals from 18 000 years ago to the present, based on six taxa (spruce, birch, northern pines, oak, southern pines, and prairie forbs), were used to generate time series of simulated isopoll maps for these taxa and seven others (hickory, fir, beech, hemlock, elm, alder, and sedge). The simulations captured the essential features of the observed isopoll maps for both sets of taxa, including differences in migration patterns during the past 10 000 yr that have previously been attributed to differential migration lag. These results establish that the continental—scale vegetation patterns have responded to continuous changes in climate from the last glacial maximum to the present, with lags ≤ 1500 yr. The inferred climatic changes include seasonality changes consistent with orbitally controlled changes in insolation, and shifts in temperature and moisture gradients that are consistent with modelled climatic interactions of the insolation changes with the shrinking Laurentide ice sheet. These results pose new ecological questions about the processes by which vegetated landscapes approach dynamic equilibrium with their changing environment.

Optimal fat loads and long‐distance flights by migrating Knots Calidris canutus, Sanderlings C. alba and Turnstones Arenaria interpres

Arctic waders often build up large fat loads and complete their migratory journeys by a few long‐distance flights between traditional staging sites. Optimal fat loads and choices of staging sites differ depending on whether the birds are adapted to minimize energy or time spent on migration. In the latter case, we predict that the birds will depart for the next staging site when the instantaneous speed of migration expected after arrival at the next site, exceeds the corresponding speed at the departure site. The instantaneous migration speed is a function of the rate of fat deposition and the current fat load. As a consequence of this, overloading (birds deposit larger fat loads than needed merely for covering the flight distance to the next destination) and by‐passing of possible, but low‐quality staging sites, are expected under specific conditions in time‐selected migration.Estimates of fat deposition rates and departure fat loads were obtained by captures of Knots Calidris canutus, Sanderlings C. alba and Turnstones Arenaria interpres in W. Iceland during spring migration. Further fat deposition data referring to spring migration of these species were compiled from the literature. Fat deposition rates at different sites, as measured by the daily gain in mass relative to lean body‐mass, range between 1.0 and 3.6%/day, and departure fuel loads (in % of lean body‐mass) between 27 and 73%.Comparison with flight range estimates suggests that overloading may be a regular phenomenon during spring migration of Knots, Sanderlings and Turnstones. Furthermore, fat deposition rates at different staging sites, and the general difference in migration patterns between spring and autumn, indicate that by‐passing of possible staging sites may well occur. Hence, it cannot be excluded that the waders' migratory habits primarily serve to maximize the overall speed of migration.

Characterization of Seminoma-Derived Placental-Like Alkaline Phosphatase

Characteristics of placental-like alkaline phosphatase (PLAP-like enzyme) in seminoma was studied. By use of lectin affinity chromatography, PLAP-like enzyme in seminoma revealed extra sugar chains compared to placental alkaline phosphatase (PLAP), indicating heterogeneity of the carbohydrate moiety. However, the glycosylation patterns were found to be essentially similar between seminoma and normal testis. On isoelectric focusing, differences in migration patterns were revealed between seminoma-derived and normal testis-derived PLAP-like enzyme as well as between PLAP-like enzyme and PLAP. The differences in charge were mainly due to differences in sialylation of the molecules. The complex pattern of PLAP-like enzyme from seminoma on isoelectric focusing was not altered by neuraminidase treatment, indicating a considerable charge heterogeneity within the population of the enzyme molecules from the tumor.

Enzymatic heterogeneity of seminomas

Heterogeneity of placental-like alkaline phosphatase (PLAP-like enzyme) in seminoma was studied. PLAP-like enzyme from seminoma tissues was separated into three areas with different proportions between tumors, while PLAP and PLAP-like enzymes in normal testes were separated into two areas on the basis of hydrophobicity. By use of lectin affinity chromatography, PLAP-like enzyme in seminoma revealed extra sugar chains compared to PLAP, indicating heterogeneity of the carbohydrate moiety. However, the glycosylation patterns were found to be essentially similar between seminoma and normal testis. On isoelectric focusing, differences in migration patterns of PLAP-like enzyme were revealed between seminoma and normal testis as well as between PLAP-like enzyme and PLAP. The differences in charge were mainly due to differences in sialylation of the molecules. The complex pattern on isoelectric focusing was not altered by neuraminidase treatment, indicating a considerable charge heterogeneity within the population of PLAP-like enzyme molecules from seminoma.

T-Cell Receptor γδ Bearing Cells in Normal Human Skin

T-cell antigen receptors (TCR) are divided into common alpha beta and less common gamma delta types. In the murine skin, TCR gamma delta+ cells have been reported to form the great majority of epidermal T lymphocytes. We have examined the relative contribution of TCR alpha beta+ and TCR gamma delta+ cells to the T-cell population in normal human skin. Serial sections of freshly frozen skin specimens were acetone fixed, incubated with anti-CD3, beta F1 (anti-TCR alpha beta), anti-TCR gamma delta-1 and anti-TCR delta 1 (anti-TCR gamma delta) monoclonal antibodies (MoAb), and stained with a highly sensitive method. Over 90% of the T cells of normal human skin are localized around the postcapillary venules of the dermis, while less than 5% are present within the epidermis. In papillary dermis, TCR gamma delta+ cells formed on average 7% (anti-TCR gamma delta-1) or 9% (anti-TCR delta 1) of the total number of CD3+ cells, while TCR alpha beta+ cells constituted up to 80%. In epidermis, these percentages were 18% and 29% for TCR gamma delta+ cells, and up to 60% for TCR alpha beta+ cells. It is concluded that there is no preferential immigration or in situ expansion of TCR gamma delta+ T cells in normal human skin, because the relative percentages found for the TCR alpha beta+ and TCR gamma delta+ populations in skin are comparable to those found in lymphoid organs and peripheral blood. However, the percentage of TCR gamma delta+ cells in epidermis seemed on average higher than in papillary dermis. Therefore, there may still be a difference in migration patterns of TCR gamma delta+ v TCR alpha beta+ cells, but this does not result in their preferential localization in human epidermis. The hypothesis that TCR gamma delta+ T cells have a specialized function in immunosurveillance of epithelia may thus not be valid for human epidermis.

Chemical characterization and biologic properties of lipopolysaccharide from Bacteroides gingivalis strains W50, W83, and ATCC 33277.

The chemistry and selected biological activity of lipopolysaccharide (LPS) from Bacteroides gingivalis strains W50, W83, and ATCC 33277 were compared, as well as the role of this molecule as a mediator of selected inflammatory responses. Chemically, the LPSs consisted of 47-58% Lipid A, 5-10% carbohydrate, 0.05% 3-deoxy 2-octulosonic acid, 0.3% heptose, 3.8-5.2% hexosamine, and 2% phosphate. Rhamnose represented the dominant sugar (26-36%), with lesser amounts of glucose (18-34%), galactose (18-25%), mannose (9-12%), glucosamine (7-11%), and galactosamine (2-5%). The major fatty acids were: 13-methyl-tetradecanoate (42-45%), 3-OH-heptadecanoate (21-23%), hexadecanoate (16-19%), and 12-methyl-tetradecanoate (6-8%). SDS-PAGE and sodium deoxycholate-PAGE revealed the LPS to be a smooth chemotype. Differences in migration patterns between the virulent and avirulent strain LPSs also occurred. C3H/HeN macrophages (Mø) exposed to 1 microgram/ml of LPS released 3.2-4.2 ng of prostaglandin E (PGE)/ml of supernatant, representing 236-278% of control. Interleukin-1 (IL-1) activity in C3H/HeN and C3H/HeJ Mø exposed to 50 micrograms of LPS/ml was 382-724% and 270-300% of control, respectively; similar Mø exposed to 10 micrograms of LPS/ml released 1.6-2.0 ng and 0.3-0.5 ng of tumor necrosis factor (TNF)/ml of supernatant, respectively. Maximum TNF release in C3H/HeN Mø occurred in response to 50 micrograms of LPS/ml, and was sustained for up to 96 hours. These results suggest that LPS from the B. gingivalis strains stimulate cytokine production from Mø which, in turn, may play a role in orchestrating the inflammatory response for the development of periodontal diseases.

Settlers and Sojourners: The Case of Mexicans in the United States

This work attempts to contribute to our understanding of the process of settlement by undocumented Mexican immigrants. The behavior of single migrants (including individuals who migrated without spouse or children) is compared to that of migrants accompanied by spouse and/or children in relation to a number of factors, including the outcome of migration experiences, variation in household composition over time, attitudes concerning residence preferences, and labor market participation.The examination reveals observable differences in migration patterns and residence intentions. Single migrants are likely to be temporary workers in the U.S. labor market. They view their jobs as temporary and are likely to return to Mexico after a brief stay in the United States. They maintain strong social and economic relationships to their place of origin.In contrast, undocumented immigrants living with their families in the U.S. are likely to view their job as relatively secure and desire to continue residing in the Uni...

Aspects of Migration in an Advanced Industrial Society

This paper tests the hypothesis that 1935-80 U.S. migration patterns both within and between metropolitan and nonmetropolitan areas and regions and migrant/nonmigrant educational differences reflect regional changes in socioeconomic development and settlement patterns. Gross migration flows support the mobility transition hypothesis and the idea that developmental changes in metropolitanization structure the context of migration. Since the Great Depression, socioeconomic transformations of the periphery have reduced differences in migration patterns between the periphery and core regions. While migrants still have more education than nonmigrants, their differences vary systematically by regional socioeconomic development. Specifically, migrant/nonmigrant educational differences are (1) similar at origin and destination when both are at similar levels of socioeconomic development; (2) lower at the origin if the origin is higher in socioeconomic development; and (3) higher at the origin if the destination is higher in socioeconomic development.

Otosclerosis: A local manifestation of a generalized connective tissue disorder?

The hypothesis that otosclerosis is a local manifestation of a clinically and genetically heterogeneous group of generalized connective tissue disorders was tested by quantitative biochemical techniques. In contrast to previous studies, no significant differences were found in individual glycosaminoglycans excreted in urine of control subjects and patients with otosclerosis. Moreover, no significant differences were detected in the rate of synthesis and secretion of glycosaminoglycans and collagen in skin fibroblast cultures of patients and controls. Preliminary results obtained with more sensitive and specific methods suggest a possible error in collagen metabolism. Polyacrylamide gel electrophoresis revealed slight differences in migration patterns of several collagenous proteins between patients and control subjects. In addition, collagenase was significantly increased in three of five patients.

Migration of farmed adult Atlantic salmon with and without olfactory sense, released on the Norwegian coast

The dispersal and migration of farmed Atlantic salmon, Salmo salar, allowed to escape during the summer was studied. Three groups of 4–year–old fish of the River Imsa stock were released in coastal waters off south‐western Norway: one group, with functional olfactory organs, was released at a fish farm 4 km away from the R. Imsa; two other groups, one with transected olfactory nerves and the other with functional olfactory organs, were released in the sea 90 km from the R. Imsa. To compare them with the migration pattern of reared, large smolts of the Imsa stock, a group of 3 + smolts was released in the R. Imsa.Adults of salmon released as 3–year–old smolts homed with high precision to the R. Imsa. Four– year–olds released in the sea were recaptured in the fjord and in the coastal current, the majority north of the places of release. Immatures migrated to feeding areas in the North Atlantic. Matures seemed to enter rivers at random when ready to spawn. There was no difference in migration pattern between anosmics and controls. The olfactory sense was not mandatory for entering fresh water. The results indicate that the homing behaviour of Atlantic salmon is not a direct consequence of a single imprinting of the smolts, and that there is not a direct genetic link for return to a particular river. The present results support the sequential imprinting hypothesis proposed by Harden Jones (1968).

Ethnic Inequalities in Old Age: Some Comparisons Between Britain and the United States

Issues of ethnicity and aging are much discussed in the U.S.A., but have only recently begun to emerge in Britain. This paper sets out to review some of the main findings of the British research on the elderly of Asian and West Indian ethnic minorities and to compare these with American evidence on the position of the minority aged. Some of the difficulties in making valid comparisons are noted, particularly in view of the heterogeneity of ethnic groups, differences in migration patterns, social and welfare contexts and the paucity of evidence on ethnic minority aging in Britain. However, preliminary findings on income, health, satisfaction and social interaction do offer a basis for general, if not detailed, comparisons. Each of these aspects of social inequality is examined, using survey data from a study of minority ethnic groups in Birmingham, England. Inequalities in income and health are found to be marked, when old Asians and West Indians are compared with old white counterparts in the inner city; evidence on life satisfaction and social interaction is mixed, and the implications of these findings for the double jeopardy hypothesis are discussed.

Chronology of Migration by American Coots in Oklahoma

American coots (Fulica americana) were studied on large reservoirs in north-central Oklahoma in 1979-82 to determine chronologies of migrations by ageand sex class. Coots began migrating into Oklahoma in mid-September, numbers peaked in early to mid-October, and few birds were seen after 1 November. Some late migrants appeared in mid-December. In spring, coots began migrating in late February, numbers peaked in mid-April, and the last birds were seen in mid-May. Generally, adult and juvenile males and juvenile female coots migrated simultaneously in autumn, but adult females completed migration by 1 November. A few juveniles and adult males migrated in December. Adult coots preceded yearlings in spring. Despite annual and between-lake differences in chronology of autumn migration, most coots migrated before waterfowl hunting seasons in Oklahoma. Coot hunting seasons in mid-latitude states should commence before the general waterfowl season where management goals are to increase hunter interest and the harvest of birds. J. WILDL. MANAGE. 49(1):241-246 Information on the chronology of movements by migratory game birds is essential to regulating harvest (Crissey 1965). Changes in regulations have provided hunters with greater harvest opportunities for waterfowl species migrating earlier than others (Martinson et al. 1966) or species not as vulnerable to shooting pressure (Crissey 1965). The chronology of migration of American coots has received little attention relative to harvest regulations and migration of different ageand sex classes, presumably because hunters have little interest in harvesting coots (Fredrickson et al. 1977:143, Gorenzel 1979:69). Nevertheless, annual harvest of coots averaged 1.17 million birds for 1964-76 (Martin 1979:33), and biologists believe the harvest can be increased (Fredrickson et al. 1977:138). Specific data on general and age-specific chronology of migration by coots are therefore necessary to determine potential changes in regulations to allow increased harvest of coots, the effects of such changes on different segments of coot populations, and the timing of habitat manipulations to attract migrating coots (Fredrickson and Taylor 1982). We determined chronology by age and sex of coots during autumn and spring migrations in Oklahoma to determine the overlap between coot migration chronology and waterfowl season dates and to elucidate patterns of differential migration by age and sex. We thank S. A. Martin, D. Martin, T. C. Tacha, M. E. Heitmeyer, D. P. Hector, D. Latham, P. Harjo, and others for field and laboratory assistance. Personnel of the Okla. Dep. of Wildl. Conserv. provided valuable logistical assistance. We also thank M. W. Weller, L. H. Fredrickson, W. P. Gorenzel, M. E. Heitmeyer, J. W. Lish, F. Schitoskey, and L. G. Talent for helpful comments on the manuscript. E. Waugh and D. Savage granted permission to use Sooner Lake and Lake Carl Blackwell as study areas, respectively. W. D. Warde provided statistical advice. This study was funded by the Accelerated Res. Program for Migratory Shore and Upland Game Birds, U.S. Fish and Wildl. Serv. Contract #14-16-0009-79-085; Oklahoma State Univ.; and the Oklahoma State Univ. Mus. of Nat. and Cult. Hist. The Okla. Coop. Wildl. Res. Unit is supported by the Okla. Dep. of Wildl. Conserv., Oklahoma State Univ., the U.S. Fish and Wildl. Serv., and The Wildl. Manage. Inst.

Microelectrophoretic study of radiation-induced DNA damages in individual mammalian cells

Mammalian cells were after irradiation suspended in melted agarose, and casted on microscope slides. The slides were after gelling at 0°C immersed in a neutral detergent solution which lysed the cells. A weak electric field (5 V/cm) was then applied over the gel for 5 minutes. The DNA in the gel was stained with the fluorescent dye acridine orange and gives a green emission in a microscope photometer. DNA had migrated towards the anode and this migration was more pronounced in irradiated than in control cells. The differences in migration pattern were quantitatively measured. The lower detection limit was below 0.5 Gy and a plateau in the dose-effect curve was reached at about 3 Gy. In repair experiments residual DNA damage could be observed after postirradiation incubation for 60 minutes. The advantages of the method is: no radioactive labelling and only a few number of cells is required.

Diurnal changes in the vertical distribution of phytoplankton in hypertrophic Lake Kasumigaura, Japan

The daily vertical migration of five species;Microcystis aeruginosa (Kutz.) Trevis,Anabaena spiroides Klebahn f.crassa (L.) Elenkin,Aphanizomenon flos-aquae (L.) Ralfs,Melosira granulata (E). Ralfs, andCoscinodiscus lacustris Grun. was studied using a close-interval water sampler on a calm summer day in Lake Kasumigaura. Many colonies ofMicrocystis were observed at the middle of the water column (approx. 1.5 m depth) in the afternoon, and at the surface in the early morning.Anabaena occurred mostly in the upper layer whileAphanizomenon tended to be uniformly distributed. The difference in migration patterns suggests thatMicrocystis is superior toAnabaena andAphanizomenon in obtaining both light and nutrients from this lake. Among diatoms,Melosira remained at the bottom of the water column throughout day and night, but Coscinodiscus was uniformly distributed.

Distribution of radiolabelled lymph cells in lymph nodes and the migratory properties of blood lymphocytes in sheep.

The results found in this study supported the concept of lymphocyte populations with preferential migratory pathways. Preferential localization of lymphocytes in lymph nodes could not explain the non-random lymphocyte migration patterns observed in sheep. The migration of lymphocytes isolated from the blood was similar to that of lymphocytes in the efferent lymph of a subcutaneous lymph node, but was different from the migration of lymphocytes isolated from efferent intestinal lymph. The subcutaneous lymph node did not need to be selective for lymphocytes which entered from blood. However, there must be a selective entry of a population of lymphocytes with preference for migrating through mesenteric lymph nodes into efferent intestinal lymph in order to observe the differential lymphocyte migration patterns exhibited by the lymphocytes in the efferent intestinal lymph of sheep.

Population migration and growth in agricultural production.

The relationship between rural-urban migration and agricultural labor resources in the USSR is analyzed. Regional differences in migration patterns and in the size of the working-age population are described. The effectiveness of various methods of recruiting manpower to areas experiencing labor shortages is considered.

Social and family patterns on the colonial Louisiana frontier

As the pendulum of historical scholarship swings toward the close of another century, momentum has propelled it toward the re‐establishment of a traditional relationship severed by professional historians at the turn of the last century. History and genealogy were inseparable until early 20th‐century humanists elevated the serious pursuit of history from the armchair to the university chair. In the generations since, a chasm of disdain has separated “real” history from so‐called family history in which untrained amateurs dabble with abandon. Yet the family is the heart of society. To study a people's history without understanding the family structure from which it evolved is to confront a robot and pretend that one feels a pulse. Tardily, professional history is shifting from the “subjects' of broad national interest” to a study of society in microcosm, that is, the family, at the same time that academically oriented genealogists are upgrading their standards to prove that family history can be a legitimate field of scholarly inquiry. This reunion of history and genealogy has produced outstanding re‐evaluations of society; but in the United States the emphasis to date has been on Anglo‐American culture. This article provides pioneer exploration of the nation's Latin heritage and finds significant differences in patterns of migration and settlement, marriage and morality. Such a study of French and Spanish borderlands in America upsets traditional, stereotyped conceptions of mobility, fertility, and family structure in colonial America.

Interregional migration in Indonesia as a reflection of social and regional inequalities.

According to the population census of 1971 less than 5% of the Indonesian population was enumerated outside its province of birth. Therefore interregional migration might be considered a relatively unimportant phenomenon in a quantitative-demographic sense. This fact fits Zelinskys mobility transition theory which states a close relationship between the type and degree of phase agrarian frontier migration and rural-urban migration are predominant. Presently both types occur in Indonesia on a relatively modest scale and already have attracted growing attention. The less conspicuous interregional migration has only been studied at a macro-level since the nineteen sixties i.e. since new census and survey data became available. Most of these studies are of a quantitative-descriptive character and thus are weak from the analytical point of view. Recent migration theories however based on both the push-pull and the centre-periphery approach (Amin 1974) might offer an attractive analytical framework for these studies. The main reason to study interregional migration in Indonesia therefore is the assumption that this type of migration reflects the historically evolved social and economic inequalities between the various regions or provinces through regional differences in migration patterns. (excerpt)

Differential Net Migration Patterns in the SMSA's of the Southern United States, 1950–1960*

International MigrationVolume 6, Issue 1-2 p. 22-32 Differential Net Migration Patterns in the SMSA's of the Southern United States, 1950–1960* T. W. Rogers, T. W. RogersSearch for more papers by this author T. W. Rogers, T. W. RogersSearch for more papers by this author First published: January‐April 1968 https://doi.org/10.1111/j.1468-2435.1968.tb01048.xCitations: 2 * SMSA = Standard Metropolitan Statistical Area. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume6, Issue1-2January‐April 1968Pages 22-32 RelatedInformation