Estimating recruitment dynamics and movement of rainbow trout (Oncorhynchus mykiss) in the Colorado River in Grand Canyon using an integrated assessment model

USGS Publications Warehouse

Korman, Josh; Martell, Steven J.D.; Walters, Carl J.; Makinster, Andrew S.; Coggins, Lewis G.; Yard, Michael D.; Persons, William R.

2012-01-01

We used an integrated assessment model to examine effects of flow from Glen Canyon Dam, Arizona, USA, on recruitment of nonnative rainbow trout (Oncorhynchus mykiss) in the Colorado River and to estimate downstream migration from Glen Canyon to Marble Canyon, a reach used by endangered native fish. Over a 20-year period, recruitment of rainbow trout in Glen Canyon increased with the annual flow volume and when hourly flow variation was reduced and after two of three controlled floods. The model predicted that approximately 16 000 trout·year–1 emigrated to Marble Canyon and that the majority of trout in this reach originate from Glen Canyon. For most models that were examined, over 70% of the variation in emigration rates was explained by variation in recruitment in Glen Canyon, suggesting that flow from the dam controls in large part the extent of potential negative interactions between rainbow trout and native fish. Controlled floods and steadier flows, which were originally aimed at partially restoring conditions before the dam (greater native fish abundance and larger sand bars), appear to have been more beneficial to nonnative rainbow trout than to native fish.

Coexistence in streams: Do source-sink dynamics allow salamanders to persist with fish predators?

USGS Publications Warehouse

Sepulveda, A.J.; Lowe, W.H.

2011-01-01

Theory suggests that source-sink dynamics can allow coexistence of intraguild predators and prey, but empirical evidence for this coexistence mechanism is limited. We used capture-mark-recapture, genetic methods, and stable isotopes to test whether source-sink dynamics promote coexistence between stream fishes, the intraguild predator, and stream salamanders (Dicamptodon aterrimus), the intraguild prey. Salamander populations from upstream reaches without fish were predicted to maintain or supplement sink populations in downstream reaches with fish. We found instead that downstream reaches with fish were not sinks even though fish consumed salamander larvae-apparent survival, recruitment, and population growth rate did not differ between upstream and downstream reaches. There was also no difference between upstream and downstream reaches in net emigration. We did find that D. aterrimus moved frequently along streams, but believe that this is a response to seasonal habitat changes rather than intraguild predation. Our study provides empirical evidence that local-scale mechanisms are more important than dispersal dynamics to coexistence of streams salamanders and fish. More broadly, it shows the value of empirical data on dispersal and gene flow for distinguishing between local and spatial mechanisms of coexistence. ?? 2011 Springer-Verlag.

Effectiveness of an integrated hatchery program: Can genetic-based performance differences between hatchery and wild Chinook salmon be avoided?

USGS Publications Warehouse

Hayes, Michael C.; Reisenbichler, Reginald R.; Rubin, Stephen P.; Drake, Deanne C.; Stenberg, Karl D.; Young, Sewall F.

2013-01-01

Performance of wild (W) and hatchery (H) spring Chinook salmon (Oncorhynchus tshawytscha) was evaluated for a sixth generation hatchery program. Management techniques to minimize genetic divergence from the wild stock included regular use of wild broodstock and volitional releases of juveniles. Performance of HH, WW, and HW (hatchery female spawned with wild male) crosses was compared in hatchery and stream environments. The WW juveniles emigrated from the hatchery at two to three times the rate of HH fish in the fall (HW intermediate) and 35% more HH than WW adults returned (27% more HW than WW adults). Performance in the stream did not differ statistically between HH and WW fish, but outmigrants (38% WW, 30% HW, and 32% HH fish) during the first 39 days of the 16-month sampling period composed 74% of total outmigrants. Differences among hatchery-reared crosses were partially due to additive genetic effects, were consistent with domestication (increased fitness for the hatchery population in the hatchery program), and suggested that selection against fall emigration from the hatchery was a possible mechanism of domestication.

Dam operations affect route-specific passage and survival of juvenile Chinook salmon at a main-stem diversion dam

USGS Publications Warehouse

Perry, Russell W.; Kock, Tobias J.; Couter, Ian I; Garrison, Thomas M; Hubble, Joel D; Child, David B

2016-01-01

Diversion dams can negatively affect emigrating juvenile salmon populations because fish must pass through the impounded river created by the dam, negotiate a passage route at the dam and then emigrate through a riverine reach that has been affected by reduced river discharge. To quantify the effects of a main-stem diversion dam on juvenile Chinook salmon in the Yakima River, Washington, USA, we used radio telemetry to understand how dam operations and river discharge in the 18-km reach downstream of the dam affected route-specific passage and survival. We found evidence of direct mortality associated with dam passage and indirect mortality associated with migration through the reach below the dam. Survival of fish passing over a surface spill gate (the west gate) was positively related to river discharge, and survival was similar for fish released below the dam, suggesting that passage via this route caused little additional mortality. However, survival of fish that passed under a sub-surface spill gate (the east gate) was considerably lower than survival of fish released downstream of the dam, with the difference in survival decreasing as river discharge increased. The probability of fish passing the dam via three available routes was strongly influenced by dam operations, with passage through the juvenile fish bypass and the east gate increasing with discharge through those routes. By simulating daily passage and route-specific survival, we show that variation in total survival is driven by river discharge and moderated by the proportion of fish passing through low-survival or high-survival passage routes.

Theoretical life history responses of juvenile Oncorhynchus mykiss to changes in food availability using a dynamic state-dependent approach

USGS Publications Warehouse

Romine, Jason G.; Benjamin, Joseph R.; Perry, Russell W.; Casal, Lynne; Connolly, Patrick J.; Sauter, Sally S.

2013-01-01

Marine subsidies can play an important role in the growth, survival, and migratory behavior of rearing juvenile salmonids. Availability of high-energy, marine-derived food sources during critical decision windows may influence the timing of emigration or the decision to forego emigration completely and remain in the freshwater environment. Increasing growth and growth rate during these decision windows may result in an altered juvenile population structure, which will ultimately affect the adult population age-structure. We used a state dependent model to understand how the juvenile Oncorhynchus mykiss population structure may respond to increased availability of salmon eggs in their diet during critical decision windows. Our models predicted an increase in smolt production until coho salmon eggs comprised more than 50 percent of juvenile O. mykiss diet at the peak of the spawning run. At higher-than intermediate levels of egg consumption, smolt production decreased owing to increasing numbers of fish adopting a resident life-history strategy. Additionally, greater growth rates decreased the number of age-3 smolts and increased the number of age-2 smolts. Increased growth rates with higher egg consumption also decreased the age at which fish adopted the resident pathway. Our models suggest that the introduction of a high-energy food source during critical periods of the year could be sufficient to increase smolt production.

[Passport registers: their limits and possibilities for the study of emigration].

PubMed

Baganha, M I

1996-08-01

"There are two main nominal sources of data on Portuguese emigration during the nineteenth and early twentieth centuries: the Rois de Confessados or Rois de Desobriga and the Livros de Registos de Passaportes.... The major question regarding passport registers concerns the level of clandestine emigration. Thus a comparison with U.S. ship lists reveals two different pictures of Portuguese emigration [with regard to] sex ratio, occupations and age distribution. Data obtained point at a larger generalization: sources containing data on legal emigration only do not reflect ¿true' emigration in countries with important clandestine streams." (EXCERPT)

Juvenile salmonid use of freshwater emergent wetlands in the floodplain and its implications for conservation management

USGS Publications Warehouse

Henning, Julie A.; Gresswell, Robert E.; Fleming, Ian A.

2006-01-01

A recent trend of enhancing freshwater emergent wetlands for waterfowl and other wildlife has raised concern about the effects of such measures on juvenile salmonids. We undertook this study to quantify the degree and extent of juvenile Pacific salmon Oncorhynchus spp. utilization of enhanced and unenhanced emergent wetlands within the floodplain of the lower Chehalis River, Washington, and to determine the fate of the salmon using them. Enhanced emergent wetlands contained water control structures that provided an outlet for fish emigration and a longer hydroperiod for rearing than unenhanced wetlands. Age-0 and age-1 coho salmon O. kisutch were the most common salmonid at all sites, enhanced wetlands having significantly higher age-1 abundance than unenhanced wetlands that were a similar distance from the main-stem river. Yearling coho salmon benefited from rearing in two enhanced wetland habitats, where their specific growth rate and minimum estimates of survival (1.43%/d by weight and 30%; 1.37%/d and 57%) were comparable to those in other side-channel rearing studies. Dissolved oxygen concentrations decreased in emergent wetlands throughout the season and approached the limits lethal to juvenile salmon by May or June each year. Emigration patterns suggested that age-0 and age-1 coho salmon emigrated as habitat conditions declined. This observation was further supported by the results of an experimental release of coho salmon. Survival of fish utilizing emergent wetlands was dependent on movement to the river before water quality decreased or stranding occurred from wetland desiccation. Thus, our results suggest that enhancing freshwater wetlands via water control structures can benefit juvenile salmonids, at least in the short term, by providing conditions for greater growth, survival, and emigration.

The role of emergent wetlands as potential rearing habitats for juvenile salmonids

USGS Publications Warehouse

Henning, Julie A.; Gresswell, Robert E.; Flemming, Ian A.

2006-01-01

A recent trend of enhancing freshwater emergent wetlands for waterfowl and other wildlife has raised concern about the effects of such measures on juvenile salmonids. We undertook this study to quantify the degree and extent of juvenile Pacific salmon Oncorhynchus spp. utilization of enhanced and unenhanced emergent wetlands within the floodplain of the lower Chehalis River, Washington, and to determine the fate of the salmon using them. Enhanced emergent wetlands contained water control structures that provided an outlet for fish emigration and a longer hydroperiod for rearing than unenhanced wetlands. Age-0 and age-1 coho salmon O. kisutch were the most common salmonid at all sites, enhanced wetlands having significantly higher age-1 abundance than unenhanced wetlands that were a similar distance from the main-stem river. Yearling coho salmon benefited from rearing in two enhanced wetland habitats, where their specific growth rate and minimum estimates of survival (1.43%/d by weight and 30%; 1.37%/d and 57%) were comparable to those in other side-channel rearing studies. Dissolved oxygen concentrations decreased in emergent wetlands throughout the season and approached the limits lethal to juvenile salmon by May or June each year. Emigration patterns suggested that age-0 and age-1 coho salmon emigrated as habitat conditions declined. This observation was further supported by the results of an experimental release of coho salmon. Survival of fish utilizing emergent wetlands was dependent on movement to the river before water quality decreased or stranding occurred from wetland desiccation. Thus, our results suggest that enhancing freshwater wetlands via water control structures can benefit juvenile salmonids, at least in the short term, by providing conditions for greater growth, survival, and emigration.

Ecological correlates of fish movement in a network of Virginia streams

USGS Publications Warehouse

Albanese, B.; Angermeier, P.L.; Dorai-Raj, S.

2004-01-01

Identifying factors that influence fish movement is a key step in predicting how populations respond to environmental change. Using mark-recapture (four species) and trap capture (eight species) data, we examined relationships between three attributes of movement and 15 ecological variables. The probability of emigrating from a reach was positively related to intermittency (one species) and body size (one species) and negatively related to distance from the mainstem creek (two species) and habitat complexity (one species). The number of fish moving upstream through traps was positively related to increases in flow (five species), day length (three species), and water temperature (two species); the number moving through downstream traps was positively associated with increases in flow (three species). Distance moved was greater for fish moving through unsuitable reaches (one species). Floods have a pervasive effect on fish movement, and human activities that affect flows will have widespread implications. The importance of other factors varies interspecifically, which may translate into variation in persistence and colonization rates. For example, species that exhibit reach fidelity in complex habitats may increase movement if habitats are homogenized. These species may suffer population declines because of the cost of increased movement and may ultimately be replaced by ecological generalists.

Behavioral thermoregulation by juvenile spring and fall chinook salmon, Oncorhynchus tshawytscha, during smoltification

USGS Publications Warehouse

Sauter, S.T.; Crawshaw, L.I.; Maule, A.G.

2001-01-01

Fall chinook salmon evolved to emigrate during the summer months. The shift in the temperature preference we observed in smolting fall chinook but not spring chinook salmon may reflect a phylogenetic adaptation to summer emigration by (1) providing directional orientation as fall chinook salmon move into the marine environment, (2) maintaining optimal gill function during emigration and seawater entry, and/or (3) resetting thermoregulatory set-points to support physiological homeostasis once smolted fish enter the marine environment. Phylogenetically determined temperature adaptations and responses to thermal stress may not protect fall chinook salmon from the recent higher summer water temperatures, altered annual thermal regimes, and degraded cold water refugia that result from hydropower regulation of the Columbia and Snake rivers. The long-term survival of fall chinook salmon will likely require restoration of normal annual thermographs and rigorous changes in land use practices to protect critical thermal refugia and control maximum summer water temperatures in reservoirs.

Predation of juvenile salmonids by smallmouth bass and northern squawfish in the Columbia River near Richland, Washington

USGS Publications Warehouse

Tabor, Roger A.; Shively, Rip S.; Poe, Thomas P.

1993-01-01

The importance of juvenile salmonids in the diet of smallmouth bass Micropterus dolomieu and northern squawfish Ptychocheilus oregonensis was examined at a 6-km stretch of the Columbia River. Piscivorous fish were sampled with electrofishing gear on 4 d (May 2–3 and June 20–21, 1990) during emigration of juvenile anadromous salmonids. Sixty-two smallmouth bass and 69 northern squawfish were collected for diet analysis. Juvenile salmonids made up 59% of smallmouth bass diet by weight and were present in 65% of the stomachs of smallmouth bass. By a meal turnover method, smallmouth bass were estimated to consume from 1.4 (May 2–3) to 1.0 (June 20–21) salmonids per predator daily. Crayfish were the dominant prey item (41.4% by weight) of northern squawfish, but juvenile salmonids (28.8%) were also important. Northern squawfish consumed from 0.55 (May 2–3) to 0.34 (June 20–21) salmonids per predator daily. Smallmouth bass and northern squawfish consumed mostly subyearling Chinook salmon Oncorhynchus tshawytscha, which may have been wild Chinook salmon that emigrated downstream from the Hanford reach. Predation rates on salmonids by smallmouth bass are apparently high during spring and early summer because subyearling Chinook salmon are abundant and of suitable forage size and their habitat overlaps with that of smallmouth bass.

Opinions of medical students at the University of Cape Town on emigration, conscription and compulsory community service.

PubMed

Wynchank, D R; Granier, S K

1991-05-04

A study was conducted to determine emigration intentions of medical students at the University of Cape Town. Students from 1st to 5th year complete a self-administered questionnaire. A response rate of 86% was achieved. Over half the students (54%) were considering emigration. The most frequently selected motivating factors were moral dissatisfaction with the present government and career opportunities abroad. Men who were eligible for military conscription rated this factor as an important deterrent to remaining in South Africa, and 81% stated objections to national service. However, 71% would be less likely to emigrate were an alternative national service (ANS) instituted. Should a compulsory community service be implemented, 41% of those eligible would be more inclined to emigrate. Recommendations include the implementation of ANS; a re-evaluation of the compulsory community service proposal; and further investigation of emigration trends and of ways to curb emigration. Suggestions offered are a reappraisal of both selection criteria and medical education; and the provision of incentives for doctors to work in rural areas.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hepler, K.R.; Hansen, P.A.; Bernard, D.R.

Five emigrating populations of Dolly Varden and cutthroat trout were intercepted in 1989-1991 during seaward migration to Prince William Sound following the Exxon Valdez oil spill; two into the spill area, three into non-spill areas. Study populations were comprised of tagged adults and subadults. Survival rates were estimated with log-linear models of capture histories of tagged fish. We used a two-stage simulation based on bootstrapping and Monte Carlo techniques to compare average survival rates in study populations that were and were not associated with spilled oil. Growth and survival rates were significantly lower in study populations associated with spilled oil.more » Results are consistent with the occurrence of a deleterious impact on growth and survival of emigrating species, although unable to be confirmed as results emanated from observation, not experiment.« less

Entrainment of Juvenile and Adult American Shad at a Pumped Storage Facility

DOE PAGES

Mathur, Dilip; Heisey, Paul G.; Royer, Doug D.; ...

2017-12-13

The American Shad Alosa sapidissima has been targeted for restoration to the upper Susquehanna River, and entrainment losses at hydroelectric facilities on the river, including the Muddy Run Pumped Storage Facility, are of concern for the potential growth of the American Shad population. Based on the integration of pumping volume, time of entrainment, and literature–reported diel emigration of juvenile American Shad, the entrainment rate (N = 145; 53 exposed to pumping) was estimated at 3.5%. The entrainment rate for adults (N = 507) was estimated at 0.3–3.9%. Using multistate mark–recapture models, the estimated entrainment probabilities (Ψ) of radio–tagged juveniles weremore » higher during periods of extended pumping (>1 h; Ψ = 0.093; 95% confidence interval [CI] = 0.054–0.156) than at periods of no pumping or short–duration pumping (<1 h; Ψ < 0.0001; 95% CI = 0.0–0.001); the high extended pumping occurred between 2300 and 0600 hours. Entrainment probabilities for adults were low (Ψ < 0.02); the highest probability occurred for fish detected downstream of the intake during the peak portion of the run (Ψ = 0.015; 95% CI = 0.004–0.047). Entrainment probability for most adult fish did not differ from zero. The low values of Ψ for both life stages were attributed to (1) the deep location of the intake (intake ceiling >11.7 m below the water surface), (2) the surface orientation of American Shad (upper 3.1 m), (3) the low overlap between high–volume pumping and peak emigration/migration times, (4) the pumping volume relative to prevailing river flows, and (5) the prolonged, robust swimming speed of American Shad, particularly that of adults (>2.2 m/s), which exceeded the intake velocity (0.2–0.9 m/s). Entrainment of juveniles increased with co–occurrence of low incoming river flows, high pumping volume, and peak emigration times. Furthermore, quantification of migratory species’ entrainment at pumped storage facilities requires integration of diel migration/emigration times with the frequency, timing, and duration of pumping volume.« less

Range and movement of resident holdover and hatchery brown trout tagged with radio transmitters in the Farmington River, Connecticut

USGS Publications Warehouse

Popoff, N.D.; Neumann, Robert M.

2005-01-01

The 5.8-km West Branch Farmington River Trout Management Area (TMA) is one of Connecticut's premier catch-and-release fisheries for brown trout Salmo trutta. However, little is known about the behavior of brown trout in this system and to what extent brown trout emigrate from the TMA. The objectives of this study were to determine the movement, range, and emigration of resident holdover and newly stocked brown trout tagged with radio transmitters in the TMA. Transmitters were implanted into 22 first-year (mean total length = 314 mm) and 25 second-year (mean total length = 432 mm) holdover brown trout. Twenty catchable-size (mean total length = 290 mm) brown trout were also implanted with transmitters and released into the TMA. The mean range (distance between the extreme upstream and downstream locations) was greater for second-year holdover brown trout than for first-year holdover brown trout, and it was greater in fall than in winter. The movement (distance moved between successive locations) of holdover brown trout was greater in fall than in winter. Movement of first-year holdover brown trout was significantly related to discharge, water temperature, and the number of days between successive locations. Newly stocked brown trout exhibited the two largest ranges (5.3 and 4.7 km). The range of newly stocked brown trout was not different between seasons, but movement was greater in spring than in summer. Through 16 weeks poststocking, there was no discernable difference in the percentage of stocked brown trout dispersing in a predominantly upstream or downstream direction. Mean dispersal distances from the stocking location were 0.5 and 0.9 km at 2 and 12 weeks poststocking, respectively. Movement of newly stocked brown trout was positively related to discharge and negatively related to water temperature. A known 6% (4 of 67) of the tagged brown trout emigrated from the TMA, but up to 21% (14 of 67) of tagged fish could have left the study area if all missing fish were emigrants. ?? Copyright by the American Fisheries Society 2005.

Entrainment of Juvenile and Adult American Shad at a Pumped Storage Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathur, Dilip; Heisey, Paul G.; Royer, Doug D.

The American Shad Alosa sapidissima has been targeted for restoration to the upper Susquehanna River, and entrainment losses at hydroelectric facilities on the river, including the Muddy Run Pumped Storage Facility, are of concern for the potential growth of the American Shad population. Based on the integration of pumping volume, time of entrainment, and literature–reported diel emigration of juvenile American Shad, the entrainment rate (N = 145; 53 exposed to pumping) was estimated at 3.5%. The entrainment rate for adults (N = 507) was estimated at 0.3–3.9%. Using multistate mark–recapture models, the estimated entrainment probabilities (Ψ) of radio–tagged juveniles weremore » higher during periods of extended pumping (>1 h; Ψ = 0.093; 95% confidence interval [CI] = 0.054–0.156) than at periods of no pumping or short–duration pumping (<1 h; Ψ < 0.0001; 95% CI = 0.0–0.001); the high extended pumping occurred between 2300 and 0600 hours. Entrainment probabilities for adults were low (Ψ < 0.02); the highest probability occurred for fish detected downstream of the intake during the peak portion of the run (Ψ = 0.015; 95% CI = 0.004–0.047). Entrainment probability for most adult fish did not differ from zero. The low values of Ψ for both life stages were attributed to (1) the deep location of the intake (intake ceiling >11.7 m below the water surface), (2) the surface orientation of American Shad (upper 3.1 m), (3) the low overlap between high–volume pumping and peak emigration/migration times, (4) the pumping volume relative to prevailing river flows, and (5) the prolonged, robust swimming speed of American Shad, particularly that of adults (>2.2 m/s), which exceeded the intake velocity (0.2–0.9 m/s). Entrainment of juveniles increased with co–occurrence of low incoming river flows, high pumping volume, and peak emigration times. Furthermore, quantification of migratory species’ entrainment at pumped storage facilities requires integration of diel migration/emigration times with the frequency, timing, and duration of pumping volume.« less

Emigration from China in Comparative Perspective*

PubMed Central

Lu, Yao; Liang, Zai; Chunyu, Miao David

2014-01-01

Comparative research on international migration has increasingly focused on immigrant integration rather than the process of emigration. By investigating the different streams of Chinese migration to the United States and Europe, as well as the different stages of Chinese migration to the U.S., this study examines the way in which both receiving and sending contexts combine to shape the process of emigration. Using data from a 2002–2003 survey of emigration from China’s Fujian Province, we demonstrate that under restrictive exit and entry policies and high barriers to migration (i.e., clandestine migration from Fuzhou to the U.S.), resources such as migrant social capital, political capital (cadre resources), and human capital all play a crucial role in the emigration process. However, the roles of these resources in the migration process are limited when migration barriers are sufficiently low and when local governments adopt proactive policies promoting emigration (i.e., legal migration from Mingxi to Europe). Comparisons over time suggest that the importance of migrant social capital, political capital, and human capital has strongly persisted for Fuzhou-US emigration, as a result of tightening exit and entry policies. Despite these marked differences between Fuzhou and Mingxi emigration, the results also point to two general processes that are highly consistent across settings and over time—the cumulative causation of migration and the advantage conferred by traditional positional power (cadre status). PMID:26146414

Physicists' Forced Migrations under Hitler

NASA Astrophysics Data System (ADS)

Beyerchen, Alan

2011-03-01

When the Nazis came to power in early 1933 they initiated formal and informal measures that forced Jews and political opponents from public institutions such as universities. Some physicists retired and others went into industry, but most emigrated. International communication and contact made emigration a viable option despite the desperate economic times in the Great Depression. Another wave of emigrations followed the annexation of Austria in 1938. Individual cases as well as general patterns of migration and adaptation to new environments will be examined in this presentation. One important result of the forced migrations was that many of the physicists expelled under Hitler played important roles in strengthening physics elsewhere, often on the Allied side in World War II.

Survival of Seaward-Migrating PIT and Acoustic-Tagged Juvenile Chinook Salmon in the Snake and Columbia Rivers: An Evaluation of Length-Specific Tagging Effects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Richard S.; Oldenburg, Eric W.; Seaburg, Adam

Studies examining the survival of juvenile salmon as they emigrate to the ocean provide important information regarding the management of regulated river systems. Acoustic telemetry is a widely used tool for evaluating the behavior and survival of juvenile salmonids in the Columbia River basin. Thus, it is important to understand how the surgical tagging process and the presence of a transmitter affect survival so any biases can be accounted for or eliminated. This study evaluated the effects of fish length and tag type on the survival of yearling and subyearling Chinook salmon during their seaward migrations through the Snake andmore » Columbia rivers during 2006, 2007, and 2008. Fish were collected at Lower Granite Dam on the Snake River (river kilometer 695) and implanted with either only a passive integrated transponder (PIT) tag (PIT fish) or both a PIT tag and an acoustic transmitter (AT fish). Survival was estimated from release at Lower Granite Dam to multiple downstream locations (dams) using the Cormack–Jolly–Seber single release model, and analysis of variance was used to test for differences among length-classes and between tag types. No length-specific tag effect was detected between PIT and AT fish (i.e., length affected the survival of PIT fish in a manner similar to which it affected the survival of AT fish). Survival among the smallest length class (i.e., 80–89 mm) of both PIT and AT subyearling Chinook salmon was markedly low (i.e., 4%). Fish length was positively correlated with the survival of both PIT and AT fish. Significant differences in survival were detected between tag types; the survival of PIT fish was generally greater than that of AT fish. However, confounding variables warrant caution in making strong inferences regarding this factor. Further, results suggest that tag effects may be due to the process of surgically implanting the transmitter rather than the presence of the transmitter.« less

Use of PIT tag and underwater video recording in assessing estuarine fish movement in a high intertidal mangrove and salt marsh creek

NASA Astrophysics Data System (ADS)

Meynecke, Jan-Olaf; Poole, Geoffrey C.; Werry, Jonathan; Lee, Shing Yip

2008-08-01

We assessed movement patterns in relation to habitat availability (reflected by the extent of tidal flooding) for several commercially and recreationally important species in and out of a small mangrove creek within the subtropical Burrum River estuary (25°10'S 152°37'E) in Queensland, Australia. Movement patterns of Acanthopagrus australis, Pomadasys kaakan, Lutjanus russelli and Mugil cephalus were examined between December 2006 and April 2007 using a stationary passive integrated transponder (PIT) system adapted for saline environments (30-38 ppt) and underwater digital video cameras (DVCs). This is the second known application of a stationary PIT tag system to studying fish movement in estuarine environments. The transponder system was set in place for 104 days and recorded >5000 detections. Overall 'recapture' rate of tagged fish by the transponder system was >40%. We used PIT tags implanted in a total of 75 fish from a tidal creek connected to the main channel of the estuary. We also developed a high-resolution digital elevation (2.5 m cell size) model of the estuary derived from airborne light detection and ranging (LIDAR) and aerial imagery to estimate inundation dynamics within the tidal creek, and related the timing of inundation in various habitats to the timing of fish immigration to and emigration from the creek. Over 50% of all tagged fish were moving in and out of the creek at a threshold level when 50% of the mangrove forest became flooded. Individuals of all four species moved into and out of the tidal creek repeatedly at different times depending on species and size, indicating strong residential behaviour within the estuary. The main activity of fishes was at night time. Manual interpretation of video from >700 fish sightings at three different mangrove sites confirmed the findings of the stationary PIT system, that the function of shelter vs food in mangrove habitat may be size dependent. Our established techniques assess the spatial ecology of estuarine fish and provide important insights into fish habitat utilisation and site fidelity behaviour.

Of travertine and time: otolith chemistry and microstructure detect provenance and demography of endangered humpback chub in Grand Canyon, USA

USGS Publications Warehouse

Limburg, Karin E.; Hayden, Todd A.; Pine, William E.; Yard, Michael D.; Kozdon, Reinhard; Valley, John W.

2013-01-01

We developed a geochemical atlas of the Colorado River in Grand Canyon and in its tributary, the Little Colorado River, and used it to identify provenance and habitat use by Federally Endangered humpback chub, Gila cypha. Carbon stable isotope ratios (δ13C) discriminate best between the two rivers, but fine scale analysis in otoliths requires rare, expensive instrumentation. We therefore correlated other tracers (SrSr, Ba, and Se in ratio to Ca) to δ13C that are easier to quantify in otoliths with other microchemical techniques. Although the Little Colorado River’s water chemistry varies with major storm events, at base flow or near base flow (conditions occurring 84% of the time in our study) its chemistry differs sufficiently from the mainstem to discriminate one from the other. Additionally, when fish egress from the natal Little Colorado River to the mainstem, they encounter cold water which causes the otolith daily growth increments to decrease in size markedly. Combining otolith growth increment analysis and microchemistry permitted estimation of size and age at first egress; size at first birthday was also estimated. Emigrants < 1 year old averaged 51.2 ± 4.4 (SE) days and 35.5 ± 3.6 mm at egress; older fish that had recruited to the population averaged 100 ± 7.8 days old and 51.0 ± 2.2 mm at egress, suggesting that larger, older emigrants recruit better. Back-calculated size at age 1 was unimodal and large (78.2 ± 3.3 mm) in Little Colorado caught fish but was bimodally distributed in Colorado mainstem caught fish (49.9 ± 3.6 and 79 ± 4.9 mm) suggesting that humpback chub can also rear in the mainstem. The study demonstrates the coupled usage of the two rivers by this fish and highlights the need to consider both rivers when making management decisions for humpback chub recovery.

Of Travertine and Time: Otolith Chemistry and Microstructure Detect Provenance and Demography of Endangered Humpback Chub in Grand Canyon, USA

PubMed Central

Limburg, Karin E.; Hayden, Todd A.; Pine, William E.; Yard, Michael D.; Kozdon, Reinhard; Valley, John W.

2013-01-01

We developed a geochemical atlas of the Colorado River in Grand Canyon and in its tributary, the Little Colorado River, and used it to identify provenance and habitat use by Federally Endangered humpback chub, Gila cypha.  Carbon stable isotope ratios (δ13C) discriminate best between the two rivers, but fine scale analysis in otoliths requires rare, expensive instrumentation. We therefore correlated other tracers (SrSr, Ba, and Se in ratio to Ca) to δ13C that are easier to quantify in otoliths with other microchemical techniques. Although the Little Colorado River’s water chemistry varies with major storm events, at base flow or near base flow (conditions occurring 84% of the time in our study) its chemistry differs sufficiently from the mainstem to discriminate one from the other. Additionally, when fish egress from the natal Little Colorado River to the mainstem, they encounter cold water which causes the otolith daily growth increments to decrease in size markedly. Combining otolith growth increment analysis and microchemistry permitted estimation of size and age at first egress; size at first birthday was also estimated. Emigrants < 1 year old averaged 51.2 ± 4.4 (SE) days and 35.5 ± 3.6 mm at egress; older fish that had recruited to the population averaged 100 ± 7.8 days old and 51.0 ± 2.2 mm at egress, suggesting that larger, older emigrants recruit better. Back-calculated size at age 1 was unimodal and large (78.2 ± 3.3 mm) in Little Colorado caught fish but was bimodally distributed in Colorado mainstem caught fish (49.9 ± 3.6 and 79 ± 4.9 mm) suggesting that humpback chub can also rear in the mainstem. The study demonstrates the coupled usage of the two rivers by this fish and highlights the need to consider both rivers when making management decisions for humpback chub recovery. PMID:24358346

Instream cover and shade mediate avian predation on trout in semi-natural streams

USGS Publications Warehouse

Penaluna, Brooke E.; Dunham, Jason B.; Noakes, David L. G.

2015-01-01

Piscivory by birds can be significant, particularly on fish in small streams and during seasonal low flow when available cover from predators can be limited. Yet, how varying amounts of cover may change the extent of predation mortality from avian predators on fish is not clear. We evaluated size-selective survival of coastal cutthroat trout (Oncorhynchus clarkii clarkii) in replicated semi-natural stream sections. These sections provided high (0.01 m2 of cover per m2 of stream) or low (0.002 m2 of cover per m2 of stream) levels of instream cover available to trout and were closed to emigration. Each fish was individually tagged, allowing us to track retention of individuals during the course of the 36-day experiment, which we attributed to survival from predators, because fish had no other way to leave the streams. Although other avian predators may have been active in our system and not detected, the only predator observed was the belted kingfisher Megaceryle alcyon, which is known to prey heavily on fish. In both treatments, trout >20.4 cm were not preyed upon indicating an increased ability to prey upon on smaller individuals. Increased availability of cover improved survival of trout by 12% in high relative to low cover stream sections. Trout also survived better in stream sections with greater shade, a factor we could not control in our system. Collectively, these findings indicate that instream cover and shade from avian predators can play an important role in driving survival of fish in small streams or during periods of low flow.

Dispersal and selection mediate hybridization between a native and invasive species

USGS Publications Warehouse

Kovach, Ryan P.; Muhlfeld, Clint C.; Boyer, Matthew C.; Lowe, Winsor H.; Allendorf, Fred W.; Luikart, Gordon

2015-01-01

Hybridization between native and non-native species has serious biological consequences, but our understanding of how dispersal and selection interact to influence invasive hybridization is limited. Here, we document the spread of genetic introgression between a native (Oncorhynchus clarkii) and invasive (Oncorhynchus mykiss) trout, and identify the mechanisms influencing genetic admixture. In two populations inhabiting contrasting environments, non-native admixture increased rapidly from 1984 to 2007 and was driven by surprisingly consistent processes. Individual admixture was related to two phenotypic traits associated with fitness: size at spawning and age of juvenile emigration. Fish with higher non-native admixture were larger and tended to emigrate at a younger age—relationships that are expected to confer fitness advantages to hybrid individuals. However, strong selection against non-native admixture was evident across streams and cohorts (mean selection coefficient against genotypes with non-native alleles (s) ¼ 0.60; s.e. ¼ 0.10). Nevertheless, hybridization was promoted in both streams by the continuous immigration of individuals with high levels of non-native admixture from other hybrid source populations. Thus, antagonistic relationships between dispersal and selection are mediating invasive hybridization between these fish, emphasizing that data on dispersal and natural selection are needed to fully understand the dynamics of introgression between native and non-native species. .

Food and growth parameters of juvenile chinook in the central Columbia River

DOE Office of Scientific and Technical Information (OSTI.GOV)

Becker, C.D.

1994-10-01

Juvenile chinook, salmon (Oncorhynchus tshawytscha) in the Hanford area of the free-flowing central Columbia River, Washington consume almost entirely adult and larval stages of aquatic insects. The diet is dominated by midges (Diptera: Chironomidae). By numbers, adult midges provided 64 and 58% of the diet and larval midges 17 and 18% of the diet, in 1968 and 1969, respectively. The families Hydropsychidae (Trichoptera), Notonectidae (Hemiptera) and Hypogastruridae (Collembola) are of minor numerical importance with a combined utilization of 7% in 1968 and 15% in 1969. Distinctive features of food and feeding activity of juvenile chinook at Hanford are fourfold: (1)more » the fish utilize relatively few insect groups, predominantly Chironomidae; (2) they depend largely upon autochthonous river organisms; (3) they visually select living prey drifting, floating or swimming in the water; and (4) they are apparently habitat opportunists to a large extent. Analyses were made of variations in diet and numbers of insects consumed between six sampling stations distributed along a 38 km section of the river. Data are provided on feeding intensity, fish lengths, length-weight relationships, and coefficients of condition. Seasonal changes in river temperature and discharge, as well as variations in regulated flow levels are environmental features influencing feeding, growth, and emigration of fish in the Hanford environs.« less

Seasonal movement and habitat use by sub-adult bull trout in the upper Flathead River system, Montana

USGS Publications Warehouse

Muhlfeld, Clint C.; Marotz, Brian

2005-01-01

Despite the importance of large-scale habitat connectivity to the threatened bull trout Salvelinus confluentus, little is known about the life history characteristics and processes influencing natural dispersal of migratory populations. We used radiotelemetry to investigate the seasonal movements and habitat use by subadult bull trout (i.e., fish that emigrated from natal streams to the river system) tracked for varying durations from 1999 to 2002 in the upper Flathead River system in northwestern Montana. Telemetry data revealed migratory (N = 32 fish) and nonmigratory (N = 35 fish) behavior, indicating variable movement patterns in the subadult phase of bull trout life history. Most migrating subadults (84%) made rapid or incremental downriver movements (mean distance, 33 km; range, 6–129 km) to lower portions of the river system and to Flathead Lake during high spring flows and as temperatures declined in the fall and winter. Bull trout subadults used complex daytime habitat throughout the upper river system, including deep runs that contained unembedded boulder and cobble substrates, pools with large woody debris, and deep lake-influenced areas of the lower river system. Our results elucidate the importance of maintaining natural connections and a diversity of complex habitats over a large spatial scale to conserve the full expression of life history traits and processes influencing the natural dispersal of bull trout populations. Managers should seek to restore and enhance critical river corridor habitat and remove migration barriers, where possible, for recovery and management programs.

[Emigration and immigration in Italy. (1861-2011)].

PubMed

Pasini, Walter

2011-01-01

The creation of the Italian Kingdom was characterized by the mass emigration of Italian people, mainly peasants towards European and American destinations. Poverty, unemployment, diseases, like pellagra, malaria and tubercolosis forced millions of Italians to leave the Country. The phenomenon of emigration is usually divided in three periods: the mass emigration from 1976 to 1914, the second one between the two world wars, the third one from 1946 to 1976. In the last quarter of the 20th century the number of repatriations overcome expatriations and the number of immigrants from Albania, Romania, Senegal, Tunisia, China, Philippines grew up becoming more and more important. Italy was a country of emigrants, now is a country of immigrants. It is difficult to compare the work conditions of the Italian emigrants with the new immigrants. At the end of the 19th Century or in the first decades of the 20th Century there were no consideration for human rights, no legislations to protect workers. Immigration from North Africa and from all the low and middle income countries should be studied in all its aspects because it will characterize our future. In the new era of economical globalization, Universities should prepare the new medical doctors to extend their professional culture to a international dimension to be able to cope with the new challenges of our time.

Evaluation of stream flow effects on smolt survival in the Yakima River Basin, Washington, 2012-2014

USGS Publications Warehouse

Courter, Ian; Garrison, Tommy; Kock, Tobias J.; Perry, Russell W.

2015-01-01

The influence of stream flow on survival of emigrating juvenile (smolts) Pacific salmon Oncorhynchus spp. and steelhead trout O. mykiss is of key management interest. However, few studies have quantified flow effects on smolt migration survival, and available information does not indicate a consistent flow-survival relationship within the typical range of flows under management control. It is hypothesized that smolt migration and dam passage survival are positively correlated with stream flow because higher flows increase migration rates, potentially reducing exposure to predation, and reduce delays in reservoirs. However, available empirical data are somewhat equivocal concerning the influence of flow on smolt survival and the underlying mechanisms driving this relationship. Stream flow effects on survival of emigrating anadromous salmonids in the Yakima Basin have concerned water users and fisheries managers for over 20 years, and previous studies do not provide sufficient information at the resolution necessary to inform water operations, which typically occur on a small spatiotemporal scale. Using a series of controlled flow releases from 2012-2014, combined with radio telemetry, we quantified the relationship between flow and smolt survival from Roza Dam 208 km downstream to the Yakima River mouth, as well as for specific routes of passage at Roza Dam. A novel multistate mark-recapture model accounted for weekly variation in flow conditions experienced by radio-tagged fish. Groups of fish were captured and radio-tagged at Roza Dam and released at two locations, upstream at the Big Pines Campground (river kilometer [rkm] 211) and downstream in the Roza Dam tailrace (rkm 208). A total of 904 hatchery-origin yearling Chinook salmon O. tshawytscha were captured in the Roza Dam fish bypass, radio-tagged and released upstream of Roza Dam. Two hundred thirty seven fish were released in the tailrace of Roza Dam. Fish released in the tailrace of Roza Dam were tagged concurrently with fish released upstream of the dam using identical tagging methods. Tagging and release events were conducted to target a range of flow conditions indicative of flows observed during the typical migration period (March-May) for juvenile spring Chinook salmon in the Yakima River. Three, five and four separate upstream releases were conducted in 2012, 2013, and 2014 respectively, and at least 43 fish were released alive on each occasion. The release sample sizes in 2014 were much larger (~130) compared to previous years for the purpose of increasing precision of survival estimates across the range of flows tested. Migration movements of radio-tagged spring Chinook salmon smolts were monitored with an array of telemetry receiver stations (fixed sites) that extended 208 rkm downstream from the forebay of Roza Dam to the mouth of the Yakima River. Fixed monitoring sites included the forebay of Roza Dam (rkm 208), the tailrace of Roza Dam (rkm 207.9), the mouth of Wenas Creek (rkm 199.2), the mouth of the Naches River (two sites, rkm 189.4), Sunnyside Dam (two sites, rkm 169.1), Prosser Dam (rkm 77.2), and the mouth of the Yakima River (two sites, rkm2 3). This array segregated the study area into four discrete reaches in which survival of tagged fish was estimated. Aerial and underwater antennas were also used to monitor tagged fish at Roza Dam. Aerial antennas were located in the forebay, on the East gate, on the West gate, and in the tailrace of Roza Dam. Underwater antennas were located in the fish bypass, upstream of the East gate, and upstream of the West gate to collect route-specific passage data for tagged fish. Additional years of data collection and analysis could alter or improve our understanding of the influence of flow and other environmental factors on smolt survival in the Yakima River. Nevertheless, during 2012-2014, yearling hatchery Chinook salmon smolt emigration survival was significantly associated with stream flow in the

Dispersal and selection mediate hybridization between a native and invasive species.

PubMed

Kovach, Ryan P; Muhlfeld, Clint C; Boyer, Matthew C; Lowe, Winsor H; Allendorf, Fred W; Luikart, Gordon

2015-01-22

Hybridization between native and non-native species has serious biological consequences, but our understanding of how dispersal and selection interact to influence invasive hybridization is limited. Here, we document the spread of genetic introgression between a native (Oncorhynchus clarkii) and invasive (Oncorhynchus mykiss) trout, and identify the mechanisms influencing genetic admixture. In two populations inhabiting contrasting environments, non-native admixture increased rapidly from 1984 to 2007 and was driven by surprisingly consistent processes. Individual admixture was related to two phenotypic traits associated with fitness: size at spawning and age of juvenile emigration. Fish with higher non-native admixture were larger and tended to emigrate at a younger age--relationships that are expected to confer fitness advantages to hybrid individuals. However, strong selection against non-native admixture was evident across streams and cohorts (mean selection coefficient against genotypes with non-native alleles (s) = 0.60; s.e. = 0.10). Nevertheless, hybridization was promoted in both streams by the continuous immigration of individuals with high levels of non-native admixture from other hybrid source populations. Thus, antagonistic relationships between dispersal and selection are mediating invasive hybridization between these fish, emphasizing that data on dispersal and natural selection are needed to fully understand the dynamics of introgression between native and non-native species. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Private sector contributions and their effect on physician emigration in the developing world

PubMed Central

Ugarte-Gil, Cesar; Darko, Kwame

2013-01-01

Abstract The contribution made by the private sector to health care in a low- or middle-income country may affect levels of physician emigration from that country. The increasing importance of the private sector in health care in the developing world has resulted in newfound academic interest in that sector’s influences on many aspects of national health systems. The growth in physician emigration from the developing world has led to several attempts to identify both the factors that cause physicians to emigrate and the effects of physician emigration on primary care and population health in the countries that the physicians leave. When the relevant data on the emerging economies of Ghana, India and Peru were investigated, it appeared that the proportion of physicians participating in private health-care delivery, the percentage of health-care costs financed publicly and the amount of private health-care financing per capita were each inversely related to the level of physician expatriation. It therefore appears that private health-care delivery and financing may decrease physician emigration. There is clearly a need for similar research in other low- and middle-income countries, and for studies to see if, at the country level, temporal trends in the contribution made to health care by the private sector can be related to the corresponding trends in physician emigration. The ways in which private health care may be associated with access problems for the poor and therefore reduced equity also merit further investigation. The results should be of interest to policy-makers who aim to improve health systems worldwide. PMID:23476095

Private sector contributions and their effect on physician emigration in the developing world.

PubMed

Loh, Lawrence C; Ugarte-Gil, Cesar; Darko, Kwame

2013-03-01

The contribution made by the private sector to health care in a low- or middle-income country may affect levels of physician emigration from that country. The increasing importance of the private sector in health care in the developing world has resulted in newfound academic interest in that sector's influences on many aspects of national health systems. The growth in physician emigration from the developing world has led to several attempts to identify both the factors that cause physicians to emigrate and the effects of physician emigration on primary care and population health in the countries that the physicians leave. When the relevant data on the emerging economies of Ghana, India and Peru were investigated, it appeared that the proportion of physicians participating in private health-care delivery, the percentage of health-care costs financed publicly and the amount of private health-care financing per capita were each inversely related to the level of physician expatriation. It therefore appears that private health-care delivery and financing may decrease physician emigration. There is clearly a need for similar research in other low- and middle-income countries, and for studies to see if, at the country level, temporal trends in the contribution made to health care by the private sector can be related to the corresponding trends in physician emigration. The ways in which private health care may be associated with access problems for the poor and therefore reduced equity also merit further investigation. The results should be of interest to policy-makers who aim to improve health systems worldwide.

Snake River Sockeye Salmon Habitat and Limnological Research; 1999 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griswold, Robert G.; Taki, Doug; Lewis, Bert

2001-01-15

In March 1990, the Shoshone-Bannock Tribes petitioned the National Marine Fisheries Service (NMFS) to list the Snake River sockeye salmon (Oncorhynchus nerka) as endangered. As a result of that petition the Snake River sockeye salmon was officially listed as endangered in November 1991 under the Endangered Species Act (56 FR 58619). In 1991 the Snake River Sockeye Salmon Habitat and Limnological Research Program was implemented (Project Number 91-71, Intergovernmental Contract Number DE-BI79-91bp22548). This project is part of an interagency effort to prevent the extinction of the Redfish Lake stock of O. nerka. The Bonneville Power Administration (BPA) provides funding formore » this inter-agency recovery program through the Northwest Power Planning Council Fish and Wildlife Program (NPPCFWP). Collaborators in the recovery effort include the National Marine Fisheries Service (NMFS), the Idaho Department of Fish and Game (IDFG), the University of Idaho (UI), U.S. Forest Service (USFS), and the Shoshone-Bannock Tribe (SBT). This report summarizes activities conducted by Shoshone-Bannock Tribal Fisheries Department personnel during the 1999 calendar year. Project objectives include: (1) monitor over-winter survival and emigration of juvenile anadromous O. nerka stocked from the captive rearing program; (2) fertilize Pettit, and Alturas lakes, fertilization of Redfish Lake was suspended for this year; (3) conduct kokanee (nonanadromous O. nerka) population surveys; (4) monitor spawning kokanee escapement and estimate fry recruitment on Fishhook, Alturas Lake, and Stanley Lake creeks; (5) evaluate potential competition and predation interactions between stocked juvenile O. nerka and a variety of fish species in Redfish, Pettit, and Alturas lakes; (6) examine diet of emigrating O. nerka smolts; (7) monitor limnological parameters of Sawtooth Valley lakes to assess lake productivity.« less

Snake River Sockeye Salmon Habitat and Limnological Research; 2000 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohler, Andre E.; Griswold, Robert G.; Taki, Doug

2002-12-01

In March 1990, the Shoshone-Bannock Tribes petitioned the National Marine Fisheries Service (NMFS) to list the Snake River sockeye salmon (Oncorhynchus nerka) as endangered. As a result of that petition the Snake River sockeye salmon was officially listed as endangered in November 1991 under the Endangered Species Act (56 FR 58619). In 1991 the Snake River Sockeye Salmon Habitat and Limnological Research Program was implemented (Project Number 91-71, Intergovernmental Contract Number DE-BI79-91bp22548). This project is part of an interagency effort to prevent the extinction of the Redfish Lake stock of O. nerka. The Bonneville Power Administration (BPA) provides funding formore » this inter-agency recovery program through the Northwest Power Planning Council Fish and Wildlife Program (NPPCFWP). Collaborators in the recovery effort include the National Marine Fisheries Service (NMFS), the Idaho Department of Fish and Game (IDFG), the University of Idaho (UI), U.S. Forest Service (USFS), and the Shoshone-Bannock Tribe (SBT). This report summarizes activities conducted by Shoshone-Bannock Tribal Fisheries Department personnel during the 2000 calendar year. Project objectives include: (1) monitor over-winter survival and emigration of juvenile anadromous O. nerka stocked from the captive rearing program; (2) fertilize Pettit, and Alturas lakes, fertilization of Redfish Lake was suspended for this year; (3) conduct kokanee (nonanadromous O. nerka) population surveys; (4) monitor spawning kokanee escapement and estimate fry recruitment on Fishhook, Alturas Lake, and Stanley Lake creeks; (5) evaluate potential competition and predation interactions between stocked juvenile O. nerka and a variety of fish species in Redfish, Pettit, and Alturas lakes; (6) examine diet of emigrating O. nerka smolts; (7) monitor limnological parameters of Sawtooth Valley lakes to assess lake productivity.« less

A probabilistic approach to quantifying hydrologic thresholds regulating migration of adult Atlantic salmon into spawning streams

NASA Astrophysics Data System (ADS)

Lazzaro, G.; Soulsby, C.; Tetzlaff, D.; Botter, G.

2017-03-01

Atlantic salmon is an economically and ecologically important fish species, whose survival is dependent on successful spawning in headwater rivers. Streamflow dynamics often have a strong control on spawning because fish require sufficiently high discharges to move upriver and enter spawning streams. However, these streamflow effects are modulated by biological factors such as the number and the timing of returning fish in relation to the annual spawning window in the fall/winter. In this paper, we develop and apply a novel probabilistic approach to quantify these interactions using a parsimonious outflux-influx model linking the number of female salmon emigrating (i.e., outflux) and returning (i.e., influx) to a spawning stream in Scotland. The model explicitly accounts for the interannual variability of the hydrologic regime and the hydrological connectivity of spawning streams to main rivers. Model results are evaluated against a detailed long-term (40 years) hydroecological data set that includes annual fluxes of salmon, allowing us to explicitly assess the role of discharge variability. The satisfactory model results show quantitatively that hydrologic variability contributes to the observed dynamics of salmon returns, with a good correlation between the positive (negative) peaks in the immigration data set and the exceedance (nonexceedance) probability of a threshold flow (0.3 m3/s). Importantly, model performance deteriorates when the interannual variability of flow regime is disregarded. The analysis suggests that flow thresholds and hydrological connectivity for spawning return represent a quantifiable and predictable feature of salmon rivers, which may be helpful in decision making where flow regimes are altered by water abstractions.

Emigration from Nepal: some major issues.

PubMed

Singh, M L

1997-07-01

This study examined emigration from Nepal during 1952-91. Data were obtained from census records decennially. Records indicate that the volume of emigration amounted to about 2.39% of total population in 1952-53, and 3.58% in 1991. The level of emigration rose from 198,120 persons to 658,290. Emigrants are persons who were absent from their home for more than 6 months due to tourism, pilgrimage, business trips, studies, employment, or permanent migration. Most emigrants return home after several months or years. A recent survey finds that 14.1% returned after more than 5 years. The Nepal model of migration is different from conventional or Marxist models. For example, landlessness or near landlessness are not the primary reasons for migration. The recent emigration to Arab countries is driven by the desire for better income. Emigrants pay handsomely to go abroad for work (Rs. 85,000). Nepalese emigrate to Australia and the US for a better income and a better life. The proportion of female emigrants was 6.23% of total emigrants to Arab countries, and 16.2% to India. 31% of emigrants were females who emigrated to North America, and 29% emigrated to European countries. Emigrants to Arab countries were likely to return home. Emigrants to North America and Europe were likely to be permanent migrants. The author prefers Mellassoux's (1981) model that says that Nepal is losing manpower during their most productive years. Remittances do not offset the loss. Government costs are incurred for supporting education abroad, benefits in old age and for youth, and the spread of sexually transmitted diseases.

Effect of developmental stage of unfed fry on survival and growth of steelhead released in a stream and hatchery ponds (Study sites: Dworshak Hatchery and North Fork Palouse River; Stock: Dworshak hatchery; Year class: 1996): Chapter 6

USGS Publications Warehouse

Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Stenberg, Karl D.; Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Hayes, Michael C.

2012-01-01

We tested whether differences in developmental stage of unfed fry at release affected subsequent survival and growth of steelhead Oncorhynchus mykiss in a stream and hatchery ponds. Differences in development were created by artificially spawning hatchery steelhead from the Clearwater River, Idaho, and incubating their progeny at three different temperatures (means=10.9, 11.3, and 11.7°C). Time between fertilization and maximum alevin wet weight (MAWW) was predicted from incubation temperature using a model. MAWW is equivalent to the button - up fry stage of development. Developmental stages at release were “underdeveloped” (97.7% of model - predicted time to MAWW, mean weight=0.177 g, proportion yolk=0.087), “intermediate” (102.5%, 0.179 g, 0.044), and “overdeveloped” (107.9%, 0.156 g, 0.030). Neither survival nor growth in the hatchery to near the end of the standard one year rearing period differed among groups. In the stream, frequency of overdeveloped fish relative to the other two groups decreased fro m release in May to September, probably indicating lower survival for the overdeveloped fish during that interval since emigration of sub - yearlings is typically negligible. Length in September was less for overdeveloped than for intermediate fish and was in between for underdeveloped fish, suggesting that growth between May and September was less for overdeveloped fish than for intermediate fish. Although changes in relative frequency and size occurred among fry development groups from September to one ye ar later, those changes may have reflected differences in emigration rate during the interval rather than differential survival or growth. Our results show a cost to survival and growth in a stream, but not in a hatchery, from overdevelopment characterize d by loss of weight and yolk reserves relative to fry closer to MAWW at release. We didn’t find any cost from underdevelopment; however, our underdeveloped fry were closer to MAWW than the overdeveloped fry, and they may have been no farther from MAWW than the intermediate fry based on percentage of model - predicted time to MAWW at release. 

Esmeralda Energy Company, Final Scientific Technical Report, January 2008. Emigrant Slimhole Drilling Project, DOE GRED III

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deymonaz, John; Hulen, Jeffrey B.; Nash, Gregory D.

2008-01-22

The Emigrant Slimhole Drilling Project (ESDP) was a highly successful, phased resource evaluation program designed to evaluate the commercial geothermal potential of the eastern margin of the northern Fish Lake Valley pull-apart basin in west-central Nevada. The program involved three phases: (1) Resource evaluation; (2) Drilling and resource characterization; and (3) Resource testing and assessment. Efforts included detailed geologic mapping; 3-D modeling; compilation of a GIS database; and production of a conceptual geologic model followed by the successful drilling of the 2,938 foot deep 17-31 slimhole (core hole), which encountered commercial geothermal temperatures (327⁰ F) and exhibits an increasing, conductive,more » temperature gradient to total depth; completion of a short injection test; and compilation of a detailed geologic core log and revised geologic cross-sections. Results of the project greatly increased the understanding of the geologic model controlling the Emigrant geothermal resource. Information gained from the 17-31 core hole revealed the existence of commercial temperatures beneath the area in the Silver Peak Core Complex which is composed of formations that exhibit excellent reservoir characteristics. Knowledge gained from the ESDP may lead to the development of a new commercial geothermal field in Nevada. Completion of the 17-31 core hole also demonstrated the cost-effectiveness of deep core drilling as an exploration tool and the unequaled value of core in understanding the geology, mineralogy, evolutional history and structural aspects of a geothermal resource.« less

Fidelity and breeding probability related to population density and individual quality in black brent geese Branta bernicla nigricans

USGS Publications Warehouse

Sedinger, J.S.; Chelgren, N.D.; Ward, D.H.; Lindberg, M.S.

2008-01-01

1. Patterns of temporary emigration (associated with non-breeding) are important components of variation in individual quality. Permanent emigration from the natal area has important implications for both individual fitness and local population dynamics. 2. We estimated both permanent and temporary emigration of black brent geese (Branta bernicla nigricans Lawrence) from the Tutakoke River colony, using observations of marked brent geese on breeding and wintering areas, and recoveries of ringed individuals by hunters. We used the likelihood developed by Lindberg, Kendall, Hines & Anderson 2001 (Combining band recovery data and Pollock's robust design to model temporary and permanent emigration. Biometrics, 57, 273-281) to assess hypotheses and estimate parameters. 3. Temporary emigration (the converse of breeding) varied among age classes up to age 5, and differed between individuals that bred in the previous years vs. those that did not. Consistent with the hypothesis of variation in individual quality, individuals with a higher probability of breeding in one year also had a higher probability of breeding the next year. 4. Natal fidelity of females ranged from 0.70 ?? 0.07-0.96 ?? 0.18 and averaged 0.83. In contrast to Lindberg et al. (1998), we did not detect a relationship between fidelity and local population density. Natal fidelity was negatively correlated with first-year survival, suggesting that competition among individuals of the same age for breeding territories influenced dispersal. Once females nested at the Tutakoke River, colony breeding fidelity was 1.0. 5. Our analyses show substantial variation in individual quality associated with fitness, which other analyses suggest is strongly influenced by early environment. Our analyses also suggest substantial interchange among breeding colonies of brent geese, as first shown by Lindberg et al. (1998).

Estimating temporary emigration and breeding proportions using capture-recapture data with Pollock's robust design

USGS Publications Warehouse

Kendall, W.L.; Nichols, J.D.; Hines, J.E.

1997-01-01

Statistical inference for capture-recapture studies of open animal populations typically relies on the assumption that all emigration from the studied population is permanent. However, there are many instances in which this assumption is unlikely to be met. We define two general models for the process of temporary emigration, completely random and Markovian. We then consider effects of these two types of temporary emigration on Jolly-Seber (Seber 1982) estimators and on estimators arising from the full-likelihood approach of Kendall et al. (1995) to robust design data. Capture-recapture data arising from Pollock's (1982) robust design provide the basis for obtaining unbiased estimates of demographic parameters in the presence of temporary emigration and for estimating the probability of temporary emigration. We present a likelihood-based approach to dealing with temporary emigration that permits estimation under different models of temporary emigration and yields tests for completely random and Markovian emigration. In addition, we use the relationship between capture probability estimates based on closed and open models under completely random temporary emigration to derive three ad hoc estimators for the probability of temporary emigration, two of which should be especially useful in situations where capture probabilities are heterogeneous among individual animals. Ad hoc and full-likelihood estimators are illustrated for small mammal capture-recapture data sets. We believe that these models and estimators will be useful for testing hypotheses about the process of temporary emigration, for estimating demographic parameters in the presence of temporary emigration, and for estimating probabilities of temporary emigration. These latter estimates are frequently of ecological interest as indicators of animal movement and, in some sampling situations, as direct estimates of breeding probabilities and proportions.

Fish communities and the nursery role of the shallow inshore waters of a tropical bay in the gulf of Carpentaria, Australia

NASA Astrophysics Data System (ADS)

Blaber, S. J. M.; Brewer, D. T.; Salini, J. P.

The species composition of the fishes of the inshore zone between a tropical estuary and offshore trawling grounds were studied. The objectives were to investigate the affinities of the fishes with those of adjacent areas, to examine the influence of abiotic factors on species composition, and to assess the role and importance of the zone as a nursery area. The shallow (<5 m) inshore waters south of the Embley estuary were sampled in two wet, two dry and two pre-wet seasons between 1989 and 1993. A total of 7934 fish of 118 species were caught with gill nets (5741 individuals of 95 species) and beach seines (2193 individuals of 45 species). Forty-two of the species caught have not been reported in the adjacent offshore prawn or fish trawling grounds, 32 species have not been found in the nearby Embley estuary, and 15 species were caught only in the inshore zone. The dominant species caught by gill netting in the inshore zone were Scomberoides commersonianus (5.47 g m -1 h -1), Chanos chanos (3.67 g m -1 h -1) and Eleutheronema tetradactylum (3.57 g m -1 h -1). Overall, fish catch rates and biomasses were less than in the adjacent estuary and offshore waters, but greater than in tropical sea-grass localities. The number of species in the inshore zone (118) is less than in the Embley estuary (197), the clear inshore waters of Groote Eylandt in the western Gulf of Carpentaria (156) and in the offshore waters (237), but greater than in the Norman estuary (100). These differences are probably due to habitat diversity. Water turbidity, tidal range, wind and day versus night were the only abiotic factors that correlated with the relative abundances of some species. The inshore zone acts as a nursery for many species and is the first nursery ground for at least 11 species whose adults live mainly offshore. The overall juvenile component of the inshore fauna consists of fishes apparently restricted to the inshore habitat, larger juveniles that have emigrated from the estuary, and fish that occur in all three habitats. The inshore zone is not primarily or solely a transition zone between estuary and offshore. It is a habitat with characteristic juvenile and adult fish communities, but it supports some fish that move between offshore and estuarine habitats. It is also an important spawning area for some species as well as a foraging zone for a number of piscivores.

[The Dutch emigration pattern around 1840 in the European perspective].

PubMed

Stokvis Prd

1980-01-01

"In 1850 and 1860 the Netherlands ranked eighth among twelve North-Western European nations that contributed to the transatlantic migration. The Dutch emigration pattern reflecting the agrarian crisis of the 1840's resembled the one of Hanover and Westphalia, be it that like in Scandinavia the ecclesiastical situation played a more important part. Besides the motivating forces, conditions such as information, organization, public and official reactions, and transportation are reviewed." (SUMMARY IN ENG) excerpt

Patterns of fish use and piscivore abundance within a reconnected saltmarsh impoundment in the northern Indian River Lagoon, Florida

USGS Publications Warehouse

Stevens, Philip W.; Montague, C.L.; Sulak, K.J.

2006-01-01

Nearly all saltmarshes in east-central, Florida were impounded for mosquito control during the 1960s. The majority of these marshes have since been reconnected to the estuary by culverts, providing an opportunity to effectively measure exchange of aquatic organisms. A multi-gear approach was used monthly to simultaneously estimate fish standing stock (cast net), fish exchange with the estuary (culvert traps), and piscivore abundance (gill nets and bird counts) to document patterns of fish use in a reconnected saltmarsh impoundment. Changes in saltmarsh fish abundance, and exchange of fish with the estuary reflected the seasonal pattern of marsh flooding in the northern Indian River Lagoon system. During a 6-month period of marsh flooding, resident fish had continuous access to the marsh surface. Large piscivorous fish regularly entered the impoundment via creeks and ditches to prey upon small resident fish, and piscivorous birds aggregated following major fish movements to the marsh surface or to deep habitats. As water levels receded in winter, saltmarsh fish concentrated into deep habitats and emigration to the estuary ensued (200% greater biomass left the impoundment than entered). Fish abundance and community structure along the estuary shoreline (although fringed with marsh vegetation) were not analogous to marsh creeks and ditches. Perimeter ditches provided deep-water habitat for large estuarine predators, and shallow creeks served as an alternative habitat for resident fish when the marsh surface was dry. Use of the impoundment as nursery by transients was limited to Mugil cephalus Linnaeus, but large juvenile and adult piscivorous fish used the impoundment for feeding. In conclusion, the saltmarsh impoundment was a feeding site for piscivorous fish and birds, and functioned as a net exporter of forage fish to adjacent estuarine waters. ?? Springer 2006.

Restricted emigration, system inescapability, and defense of the status quo: system-justifying consequences of restricted exit opportunities.

PubMed

Laurin, Kristin; Shepherd, Steven; Kay, Aaron C

2010-08-01

The freedom to emigrate at will from a geographic location is an internationally recognized human right. However, this right is systematically violated by restrictive migration policies. In three experiments, we explored the psychological consequences of violating the right to mobility. Our results suggest that, ironically, restricted freedom of movement can lead to increased system justification (i.e., increased support of the status quo). In Study 1, we found that participants who read that their country was difficult to leave became stronger defenders of their system's legitimacy than before, even in domains unrelated to emigration policy (e.g., gender relations). In Study 2, we demonstrated that this increased system defense was the result of a motivated process. In Study 3, we broadened the scope of this psychological phenomenon by conceptually replicating it using a different system (participants' university) and measure of system defense. The importance of these two findings-the first experimental demonstration of the psychological consequences of restrictive emigration policies and the introduction of a novel psychological phenomenon-is discussed.

Connectivity of a large embayment and coastal fishery: spawning aggregations in one bay source local and broad-scale fishery replenishment.

PubMed

Hamer, P A; Acevedo, S; Jenkins, G P; Newman, A

2011-04-01

Ichthyoplankton sampling and otolith chemistry were used to determine the importance of transient spawning aggregations of snapper Chrysophrys auratus (Sparidae) in a large embayment, Port Phillip Bay (PPB), Australia, as a source of local and broad-scale fishery replenishment. Ichthyoplankton sampling across five spawning seasons within PPB, across the narrow entrance to the bay and in adjacent coastal waters, indicated that although spawning may occur in coastal waters, the spawning aggregations within the bay were the primary source of larval recruitment to the bay. Otolith chemical signatures previously characterized for 0+ year C. auratus of two cohorts (2000 and 2001) were used as the baseline signatures to quantify the contribution that fish derived from reproduction in PPB make to fishery replenishment. Sampling of these cohorts over a 5 year period at various widely dispersed fishery regions, combined with maximum likelihood analyses of the chemistry of the 0+ year otolith portions of these older fish, indicated that C. auratus of 1 to 3+ years of age displayed both local residency and broad-scale emigration from PPB to populate coastal waters and an adjacent bay (Western Port). While the PPB fishery was consistently dominated (>70%) by locally derived fish irrespective of cohort or age, the contribution of fish that had originated from PPB to distant populations increased with age. At 4 to 5+ years of age, when C. auratus mature and fully recruit to the fishery, populations of both cohorts across the entire central and western Victorian fishery, including two major embayments and c. 800 km of coastal waters, were dominated (>70%) by fish that had originated from the spawning aggregations and nursery habitat within PPB. Dependence of this broadly dispersed fishery on replenishment from heavily targeted spawning aggregations within one embayment has significant implications for management and monitoring programmes. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Effects of Chiloquin Dam on spawning distribution and larval emigration of Lost River, shortnose, and Klamath largescale suckers in the Williamson and Sprague Rivers, Oregon

USGS Publications Warehouse

Martin, Barbara A.; Hewitt, David A.; Ellsworth, Craig M.

2013-01-01

Chiloquin Dam was constructed in 1914 on the Sprague River near the town of Chiloquin, Oregon. The dam was identified as a barrier that potentially inhibited or prevented the upstream spawning migrations and other movements of endangered Lost River (Deltistes luxatusChasmistes brevirostris) suckers, as well as other fish species. In 2002, the Bureau of Reclamation led a working group that examined several alternatives to improve fish passage at Chiloquin Dam. Ultimately it was decided that dam removal was the best alternative and the dam was removed in the summer of 2008. The U.S. Geological Survey conducted a long-term study on the spawning ecology of Lost River, shortnose, and Klamath largescale suckers (Catostomus snyderi) in the Sprague and lower Williamson Rivers from 2004 to 2010. The objective of this study was to evaluate shifts in spawning distribution following the removal of Chiloquin Dam. Radio telemetry was used in conjunction with larval production data and detections of fish tagged with passive integrated transponders (PIT tags) to evaluate whether dam removal resulted in increased utilization of spawning habitat farther upstream in the Sprague River. Increased densities of drifting larvae were observed at a site in the lower Williamson River after the dam was removed, but no substantial changes occurred upstream of the former dam site. Adult spawning migrations primarily were influenced by water temperature and did not change with the removal of the dam. Emigration of larvae consistently occurred about 3-4 weeks after adults migrated into a section of river. Detections of PIT-tagged fish showed increases in the numbers of all three suckers that migrated upstream of the dam site following removal, but the increases for Lost River and shortnose suckers were relatively small compared to the total number of fish that made a spawning migration in a given season. Increases for Klamath largescale suckers were more substantial. Post-dam removal monitoring only included 2 years with below average river discharge during the spawning season; data from years with higher flows may provide a different perspective on the effects of dam removal on the spawning migrations of the two endangered sucker species.

Investment, population growth and GNP as determinants of US immigration.

PubMed

Kritz, M M

1998-09-01

Northern countries typically attract migrants from poorer countries because of the formers' high wage rates and demand for labor. In particular, the US receives large numbers of legal migrants from almost every country and region of the world. This paper explores the determinants of permanent emigration to the US during 1989-93 using data drawn from the US Immigration and Naturalization Service (INS) Annual Tapes for the period. The analysis is restricted to only legal migration from 150 countries, and specifically investigates whether emigration to the US during 1989-93 can be accounted for by demographic and economic conditions in sending countries, or by levels of US investment in sending countries. No support is found for claims that rapid population growth and US investment fuel US immigration; emigration is comparatively far lower from countries experiencing rapid population growth and not significantly correlated with US investment, while the US typically invests the most in the more developed countries which send relatively few migrants to the US. Geographic proximity is the most important correlate of migration, followed by the population size of sending countries, which is negatively related to emigration. Some evidence was found that emigration will decrease as countries develop. Who a country decides to admit and how many people are admitted depend mainly upon public policy and very little upon the economic and demographic conditions of sending countries.

Partitioning loss rates of early juvenile blue crabs from seagrass habitats into mortality and emigration

USGS Publications Warehouse

Etherington, L.L.; Eggleston, D.B.; Stockhausen, W.T.

2003-01-01

Determining how post-settlement processes modify patterns of settlement is vital in understanding the spatial and temporal patterns of recruitment variability of species with open populations. Generally, either single components of post-settlement loss (mortality or emigration) are examined at a time, or else the total loss is examined without discrimination of mortality and emigration components. The role of mortality in the loss of early juvenile blue crabs, Callinectes sapidus, has been addressed in a few studies; however, the relative contribution of emigration has received little attention. We conducted mark-recapture experiments to examine the relative contribution of mortality and emigration to total loss rates of early juvenile blue crabs from seagrass habitats. Loss was partitioned into emigration and mortality components using a modified version of Jackson's (1939) square-within-a-square method. The field experiments assessed the effects of two size classes of early instars (J1-J2, J3-J5), two densities of juveniles (low: 16 m-2, high: 64 m-2), and time of day (day, night) on loss rates. In general, total loss rates of experimental juveniles and colonization rates by unmarked juveniles were extremely high (range = 10-57 crabs m-2/6 h and 17-51 crabs m-2/6 h, for loss and colonization, respectively). Total loss rates were higher at night than during the day, suggesting that juveniles (or potentially their predators) exhibit increased nocturnal activity. While colonization rates did not differ by time of day, J3-J5 juveniles demonstrated higher rates of colonization than J1-J2 crabs. Overall, there was high variability in both mortality and emigration, particularly for emigration. Average probabilities of mortality across all treatment combinations ranged from 0.25-0.67/6 h, while probabilities of emigration ranged from 0.29-0.72/6 h. Although mean mortality rates were greater than emigration rates in most treatments, the proportion of experimental trials in which crab loss from seagrass due to mortality was greater than losses due to emigration was not significantly different from 50%. Thus, mortality and emigration appear to contribute equally to juvenile loss in seagrass habitats. The difference in magnitude (absolute amount of loss) between mean emigration and mean mortality varied between size classes, such that differences between emigration and mortality were relatively small for J1-J2 crabs, but much larger for J3-J5 crabs. Further, mortality rates were density-dependent for J3-J5 juvenile stages but not for J1-J2 crabs, whereas emigration was inversely density-dependent among J3-J5 stages but not for J1-J2 instars. The co-dependency of mortality and emigration suggests that the loss term (emigration or mortality) which has the relatively stronger contribution to total loss may dictate the patterns of loss under different conditions. For older juveniles (J3-J5), emigration may only have a large impact on juvenile loss where densities are low, since the contribution of mortality appears to be much greater than emigration at high densities. The size-specific pattern of density-dependent mortality supports the notion of an ontogenetic habitat shift by early juvenile blue crabs from seagrass to unvegetated habitats, since larger individuals may experience increased mortality at high densities within seagrass beds. Qualitative comparisons between this study and a concurrent study of planktonic emigration of J1-J5 blue crabs (Blackmon and Eggleston, 2001) suggests that benthic emigration among J1-J2 blue crabs was greater than planktonic emigration; for J3-J5 stages benthic and planktonic emigration were nearly equal. This study demonstrates the potentially large role of emigration in recruitment processes and patterns of early juvenile blue crabs, and illustrates how juvenile size, juvenile density, and time of day can affect mortality and emigration rates as well as total loss and colonization. The components of po

A seascape approach to investigating fish spillover across a marine protected area boundary in Hawai'i

USGS Publications Warehouse

Stamoulis, Kostantinos A.; Friedlander, Alan M.

2013-01-01

Marine protected areas (MPAs) can benefit fisheries through export of pelagic eggs and larvae and the net emigration of adults and juveniles (spillover). Spillover was investigated for a marine protected area on the north shore of Oahu, Hawai‘i utilizing a seascape approach. This study incorporated habitat variables and underwater visual surveys of fishes and benthos measured at two distinct scales (125 m2 and 1000 m2) inside and outside the protected area at varying distance from the boundary. The relationship between fish biomass from fine-scale surveys and key habitat variables was found to account for a large portion of the variability for both resource (targeted) fish species (15%) and non-resource fish (28%). The remaining variation in resource fish biomass was significantly correlated with distance from the MPA boundary showing a decreasing gradient from inside to outside (r2 = 0.46, p = 0.001), indicating fish spillover at a local scale (p = 0.45). The evidence of spillover based on the fine-scale surveys was corroborated by results from broad-scale surveys, which also showed a significant relationship (r2 = 0.19, p < 0.01) between resource fish biomass and distance from the MPA boundary. In addition, observed spatial distribution of fishing effort was consistent with predictions that fishers respond to biomass gradients across protected area boundaries. Fish spillover can help mitigate costs associated with the establishment of marine protected areas in terms of lost fishing area and therefore have a positive effect on the attitudes of fishers toward marine reserves and marine protected areas.

Radiological Diagnoses in the Context of Emigration: Infectious diseases.

PubMed

Stojkovic, Marija; Müller, Jan; Junghanss, Thomas; Weber, Tim Frederik

2018-02-01

 Globalization and emigration impact on the spectrum of diseases challenging health care systems. Medical practitioners have to particularly prepare for infectious diseases.  The database of a health care center specialized on tropical medicine was screened for patients with history of migration and one of the following diagnoses: Cystic echinococcosis, tuberculosis, schistosomiasis, visceral leishmaniosis, and neurocysticercosis. Representative casuistics were prepared from select case histories. Radiological pertinent knowledge was compiled based on literature search.  A small selection of frequently imported infectious diseases covers a considerable fraction of health care problems associated with migration. For cystic echinococcosis, schistosomiasis, and neurocysticercosis imaging is the most relevant diagnostic procedure defining also disease stages. Tuberculosis and visceral leishmaniosis are important differentials for malignant diseases.  Imaging plays a meaningful role in diagnosis, treatment stratification, and follow-up of imported infectious diseases. Radiological skills concerning these diseases are important for providing health care for patients in context of migration.   · Imaging plays a meaningful role in multidisciplinary care for imported infectious diseases.. · A small selection covers a considerable fraction of infectious diseases expected in context of migration.. · Stojkovic M, Müller J, Junghanss T et al. Radiological Diagnoses in the Context of Emigration: Infectious diseases. Fortschr Röntgenstr 2018; 190: 121 - 133. © Georg Thieme Verlag KG Stuttgart · New York.

Psychoanalysis and the Emigration of Central and Eastern European Intellectuals.

PubMed

Erős, Ferenc

2016-12-01

One of the most important phenomena in the intellectual history of the 20th century was the exodus of the European mind, the emigration of persons, ideas, techniques, and institutions in the vast areas of social, human, and natural sciences, as well as in literature and the visual arts. Among these exiled intellectuals, psychoanalysts formed a special group. This paper examines the major lines of the emigration of psychoanalysts from the countries of issue to the countries of reception. It focuses, in particular on Hungarian analysts and analytic candidates who left their country of birth in two waves, first after the failure of revolutions in 1918/19 for Berlin, and then after 1938, to escape the Nazis. The paper comments on the existential situation of émigré psychoanalysts in light of Hannah Arendt's writings on refugees.

Emigration dynamics in Bangladesh.

PubMed

Mahmood, R A

1995-01-01

This study of emigration dynamics opens by noting that emigration is one of the most dynamic economic and social elements in Bangladesh. The history of emigration from Bangladesh is sketched, and the level and trend of emigration is described for various destinations (especially the UK, the Middle East and North Africa, and Japan) and in terms of the socioeconomic background of migrants, channels of migration, occupations, the potential level of emigration, and applications for US Visas. The next section of the report presents the economic and demographic setting in terms of the gross national and domestic products, quality of life, the size and distribution of the population, the labor force, literacy, unemployment and underemployment, urbanization, internal migration, poverty, and income distribution. The discussion then centers on the sociopolitical setting and such factors as unmet basic human needs, the demand for expatriate workers, and emigration policy. It is concluded that the desperate economic situation in Bangladesh has combined with the demand for expatriate workers and the development of institutions to facilitate emigration. The result is increasing interest in emigration, which is fueled by mass communication highlighting the differences between the quality of life in Bangladesh and abroad.

Spatially explicit dynamic N-mixture models

USGS Publications Warehouse

Zhao, Qing; Royle, Andy; Boomer, G. Scott

2017-01-01

Knowledge of demographic parameters such as survival, reproduction, emigration, and immigration is essential to understand metapopulation dynamics. Traditionally the estimation of these demographic parameters requires intensive data from marked animals. The development of dynamic N-mixture models makes it possible to estimate demographic parameters from count data of unmarked animals, but the original dynamic N-mixture model does not distinguish emigration and immigration from survival and reproduction, limiting its ability to explain important metapopulation processes such as movement among local populations. In this study we developed a spatially explicit dynamic N-mixture model that estimates survival, reproduction, emigration, local population size, and detection probability from count data under the assumption that movement only occurs among adjacent habitat patches. Simulation studies showed that the inference of our model depends on detection probability, local population size, and the implementation of robust sampling design. Our model provides reliable estimates of survival, reproduction, and emigration when detection probability is high, regardless of local population size or the type of sampling design. When detection probability is low, however, our model only provides reliable estimates of survival, reproduction, and emigration when local population size is moderate to high and robust sampling design is used. A sensitivity analysis showed that our model is robust against the violation of the assumption that movement only occurs among adjacent habitat patches, suggesting wide applications of this model. Our model can be used to improve our understanding of metapopulation dynamics based on count data that are relatively easy to collect in many systems.

[Pakistan: emigration in the Gulf and its effects on the home economy].

PubMed

Imdad, N

1985-01-01

Pakistani emigration since the early 1970s has been primarily directed toward the oil-rich Gulf states. Over 2 million Pakistanis, 10% of the adult male workforce, now live outside their home country, 3/4 of them in the Gulf states. The emigration has shortterm advantages for Pakistan, which has a high unemployment rate and few other exports. 2 government bureaus and over 300 recruiting agencies encourage Pakistani emigration to the Gulf, and because of the foreign exchange earnings generated, such emigration has become an important concern of the government. Emigration has a long history in Pakistan as part of the migratory movements of the Indian subcontinent in general. Emigration in the 1960s was prompted by mechanization of agriculture and disturbances of traditional agrarian labor arrangements brought on by the Green Revolution. Concentrations of lands among the successful middle-sized producers led to a rural proletariat and exodus towards the cities, where possibilities of employment were scarce. Regions of declining income around the new capital of Islamabad were the 1st to take advantage of new employment opportunities in the Gulf states. Pakistani migration to the Gulf countries is temporary for individual workers, who stay an average of 3-6 years, but the effect is of chain migration as returning workers are replaced by other family members. Workers are not accompanied by family members and have almost no contact with the local Arab populations. They send most of their earnings to their families in Pakistan. 3/4 are under 30 years old, most are of rural origin, and the majority are from the northern provinces. Although 70% are married, only 4% of migrants, the most highly qualified, are accompanied by their families. About 41% are unskilled workers and 42.6% are semiskilled or skilled manual workers. In 1981, the average annual salary repatriated by a Pakistani working in the Gulf was $3000. The Pakistani government has not defined a migration policy but has established rules and procedures to curtail clandestine departures. Most migrants use the services of licensed private employment agencies and very few use public channels. Because the migration is relatively new and few studies have been done, it is difficult to evaluate its effects on the local economy. 1 result is a severe local shortage of labor, especially in construction and transportation, which has promoted inflation and particularly affected the most impoverished classes. Remissions are now the most important source of Pakistan's foreign exchange earnings, but are not being invested in economic, industrial, or agricultural development, which has remained stagnant while 55% of the national budget is directed to defense. Most migrant earnings are invested in housing, marriages and dowries, and luxury imported consumer goods. In the current state of Pakistan's economy, migration is the sole means of socioeconomic advancement for the vast majority, but the future of the movement is uncertain.

Work Element B: 157. Sampling in Fish-Bearing Reaches [Variation in Productivity in Headwater Reaches of the Wenatchee Subbasin], Final Report for PNW Research Station.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polivka, Karl; Bennett, Rita L.

2009-03-31

We studied variation in productivity in headwater reaches of the Wenatchee subbasin for multiple field seasons with the objective that we could develop methods for monitoring headwater stream conditions at the subcatchment and stream levels, assign a landscape-scale context via the effects of geoclimatic parameters on biological productivity (macroinvertebrates and fish) and use this information to identify how variability in productivity measured in fishless headwaters is transmitted to fish communities in downstream habitats. In 2008, we addressed this final objective. In collaboration with the University of Alaska Fairbanks we found some broad differences in the production of aquatic macroinvertebrates andmore » in fish abundance across categories that combine the effects of climate and management intensity within the subbasin (ecoregions). From a monitoring standpoint, production of benthic macroinvertebrates was not a good predictor of drifting macroinvertebrates and therefore might be a poor predictor of food resources available to fish. Indeed, there is occasionally a correlation between drifting macroinvertebrate abundance and fish abundance which suggests that headwater-derived resources are important. However, fish in the headwaters appeared to be strongly food-limited and there was no evidence that fishless headwaters provided a consistent subsidy to fish in reaches downstream. Fish abundance and population dynamics in first order headwaters may be linked with similar metrics further down the watershed. The relative strength of local dynamics and inputs into productivity may be constrained or augmented by large-scale biogeoclimatic control. Headwater streams are nested within watersheds, which are in turn nested within ecological subregions; thus, we hypothesized that local effects would not necessarily be mutually exclusive from large-scale influence. To test this we examined the density of primarily salmonid fishes at several spatial and temporal scales within a major sub-basin of the Columbia River and associations of density with ecoregion and individuals drainages within the sub-basin. We further examined habitat metrics that show positive associations with fish abundance to see if these relationships varied at larger spatial scales. We examined the extent to which headwater fish density and temporal variation in density were correlated between the headwaters and the main tributaries of the sub-basin, and the influence of ecoregion influence on density differences, particularly at wider temporal scales. Finally, we examined demographic parameters such as growth and emigration to determine whether density-dependence differs among ecoregions or whether responses were more strongly influenced by the demography of the local fish population.« less

On the use of secondary capture-recapture samples to estimate temporary emigration and breeding proportions

USGS Publications Warehouse

Kendall, W.L.; Nichols, J.D.; North, P.M.; Nichols, J.D.

1995-01-01

The use of the Cormack- Jolly-Seber model under a standard sampling scheme of one sample per time period, when the Jolly-Seber assumption that all emigration is permanent does not hold, leads to the confounding of temporary emigration probabilities with capture probabilities. This biases the estimates of capture probability when temporary emigration is a completely random process, and both capture and survival probabilities when there is a temporary trap response in temporary emigration, or it is Markovian. The use of secondary capture samples over a shorter interval within each period, during which the population is assumed to be closed (Pollock's robust design), provides a second source of information on capture probabilities. This solves the confounding problem, and thus temporary emigration probabilities can be estimated. This process can be accomplished in an ad hoc fashion for completely random temporary emigration and to some extent in the temporary trap response case, but modelling the complete sampling process provides more flexibility and permits direct estimation of variances. For the case of Markovian temporary emigration, a full likelihood is required.

Distribution and movement of bull trout in the upper Jarbidge River watershed, Nevada

USGS Publications Warehouse

Allen, M. Brady; Connolly, Patrick J.; Mesa, Matthew G.; Charrier, Jodi; Dixon, Chris

2010-01-01

In 2006 and 2007, we surveyed the occurrence of bull trout (Salvelinus confluentus), the relative distributions of bull trout and redband trout (Oncorhynchus mykiss), and stream habitat conditions in the East and West Forks of the Jarbidge River in northeastern Nevada and southern Idaho. We installed passive integrated transponder (PIT) tag interrogation systems at strategic locations within the watershed, and PIT-tagged bull trout were monitored to evaluate individual fish growth, movement, and the connectivity of bull trout between streams. Robust bull trout populations were found in the upper portions of the East Fork Jarbidge River, the West Fork Jarbidge River, and in the Pine, Jack, Dave, and Fall Creeks. Small numbers of bull trout also were found in Slide and Cougar Creeks. Bull trout were numerically dominant in the upper portions of the East Fork Jarbidge River, and in Fall, Dave, Jack, and Pine Creeks, whereas redband trout were numerically dominant throughout the rest of the watershed. The relative abundance of bull trout was notably higher at altitudes above 2,100 m. This study was successful in documenting bull trout population connectivity within the West Fork Jarbidge River, particularly between West Fork Jarbidge River and Pine Creek. Downstream movement of bull trout to the confluence of the East Fork and West Fork Jarbidge River both from Jack Creek (rkm 16.6) in the West Fork Jarbidge River and from Dave Creek (rkm 7.5) in the East Fork Jarbidge River was detected. Although bull trout exhibited some downstream movement during the spring and summer, much of their emigration occurred in the autumn, concurrent with decreasing water temperatures and slightly increasing flows. The bull trout that emigrated were mostly age-2 or older, but some age-1 fish also emigrated. Upstream movement by bull trout was detected less than downstream movement. The overall mean annual growth rate of bull trout in the East Fork and West Fork Jarbidge River was 36 mm. This growth rate is within the range reported in other river systems and is indicative of good habitat conditions. Mark-recapture methods were used to estimate a population of 147 age-1 or older bull trout in the reach of Jack Creek upstream of Jenny Creek.

[The use of personal sources for the study of emigration from Galicia: present state and perspectives].

PubMed

Vazquez Gonzalez, A

1996-08-01

"Spanish sources for the study of emigration are sparse and fragmentary.... Mortgage documents for the payment of ocean transportation enable us to appreciate the spreading action of shipping agents; official listings of draft dodgers reveal that in general the River Plate was a favorite destination, rather than Cuba or Brazil. People from Galicia emigrated from rural origins to urban destinations in America; the analysis of place of birth of emigrants residing in A Coruna at the time of emigration show that there was also, in some cases, a first stage of rural-urban migration within Galicia. The general picture of emigration from Galicia is built [up] through the combination of the existing sources in Spain." (EXCERPT)

Atlantic salmon brood stock management and breeding handbook

USGS Publications Warehouse

Kincaid, Harold L.; Stanley, Jon G.

1989-01-01

Anadromus runs of Atlantic salmon have been restored to the Connecticut, Merrimack, Pawcatuck, Penobscot, and St. Croix rivers in New England by the stocking of more than 8 million smolts since 1948. Fish-breeding methods have been developed that minimize inbreeding and domestication and enhance natural selection. Methods are available to advance the maturation of brood stock, control the sex of production lots and store gametes. Current hatchery practices emphasize the use of sea-run brood stock trapped upon return to the rivers and a limited number of captive brood stock and rejuvenated kelts. Fish are allowed to mature naturally, after which they are spawned and incubated artificially. Generally, 1-year smolts are produced, and excess fish are stocked as fry in headwater streams. Smolts are stocked during periods of rising water in spring. Self-release pools are planned that enable smolts to choose the emigration time. Culturists keep good records that permit evaluation of the performance of strains and the effects of breeding practices. As Atlantic salmon populations expand, culturists must use sound breeding methods that enhance biotic potential while maintaining genetic diversity and protecting unique gene pools.

Fatty-acid profiles of white muscle and liver in stream-maturing steelhead trout Oncorhynchus mykiss from early migration to kelt emigration

USGS Publications Warehouse

Penney, Zachary L.; Moffitt, Christine M.

2015-01-01

The profiles of specific fatty acids (FA) in white muscle and liver of fasting steelhead troutOncorhynchus mykiss were evaluated at three periods during their prespawning migration and at kelt emigration in the Snake–Columbia River of Washington, Oregon and Idaho, to improve the understanding of energy change. Twenty-seven FAs were identified; depletion of 10 of these was positively correlated in liver and white muscle of prespawning O. mykiss. To observe relative changes in FA content more accurately over sampling intervals, the lipid fraction of tissues was used to normalize the quantity of individual FA to an equivalent tissue wet mass. Saturated and monounsaturated FAs were depleted between upstream migration in September and kelt emigration in June, whereas polyunsaturated FAs were more conserved. Liver was depleted of FAs more rapidly than muscle. Three FAs were detected across all sampling intervals: 16:0, 18:1 and 22:6n3, which are probably structurally important to membranes. When structurally important FAs of O. mykiss are depleted to provide energy, physiological performance and survival may be affected.

[Preventive health control of U. S. emigrants at the beginning of 20th century on the example of hotel "Emigrants" in Rijeka].

PubMed

Rotim Malvić, Jasna

2015-01-01

Rijeka inscribed herself on the list of great European emigration ports like Hamburg, Bremen, Liverpool in the end of the year 1903 when a ship of the British Cunard Line established a travel line from Rijeka to New York. Up to the year 1914, 317639 passengers - emigrants travelled to America from the port of Rijeka. The large flow of people caused problems for the city, for that reason, already in 1906 did the Hungarian ministry of home affairs started the construction of a grandiose building intended for the emigrants. When it was opened in 1908 it was named Hotel Emigrants and had a capacity of 2500 guests. The name Hotel was given to him because of the highest construction and sanitary standards applied during his construction, but also because of comfort provided for the emigrants, large bright dormitories, living rooms, one big and spacious terrace and a number of smaller ones indicated more to a touristic hotel than to a house for emigrants. Health surveillance of emigrants was performed by Dr. David Friedman, Dr. Arturo Jellouscheg and Dr. Emil Tauffer. They were in charge in front of the Maritime Gubernia in Rijeka, the U.S. consulate in Rijeka and the Adria Maritime Society. Although the city authorities and the Hungarian authorities boasted of the hotel and the rigid medical control over immigrants which was done there, American authorities have still often returned some emigrants, at the expense of the company, after inspection at Ellis Island revealing that before landing some individuals are sick.

Brain drain or links to the world: views on emigrants from Singapore.

PubMed

Yap, M T

1994-01-01

"This article will present a general picture of emigration and emigrants from Singapore, with specific references to Australia where the data permit. The first section presents some flow data on the magnitudes of emigration from Singapore.... It is necessary to place this outflow against the background of the constraints imposed by the country's small size. This is discussed in the second section, together with the economic policies and strategies adopted to overcome these constraints. The third section documents the public debate on emigration and the responses to the 'problem.' This is followed in the last section by a prognosis for the future, particularly with regard to the implications for Australia. The article ends with a discussion of the relationship between emigration and nation building, using Singapore as a case study." excerpt

The role of local populations within a landscape context: Defining and classifying sources and sinks

USGS Publications Warehouse

Runge, J.P.; Runge, M.C.; Nichols, J.D.

2006-01-01

The interaction of local populations has been the focus of an increasing number of studies in the past 30 years. The study of source-sink dynamics has especially generated much interest. Many of the criteria used to distinguish sources and sinks incorporate the process of apparent survival (i.e., the combined probability of true survival and site fidelity) but not emigration. These criteria implicitly treat emigration as mortality, thus biasing the classification of sources and sinks in a manner that could lead to flawed habitat management. Some of the same criteria require rather restrictive assumptions about population equilibrium that, when violated, can also generate misleading inference. Here, we expand on a criterion (denoted ?contribution? or Cr) that incorporates successful emigration in differentiating sources and sinks and that makes no restrictive assumptions about dispersal or equilibrium processes in populations of interest. The metric Cr is rooted in the theory of matrix population models, yet it also contains clearly specified parameters that have been estimated in previous empirical research. We suggest that estimates of emigration are important for delineating sources and sinks and, more generally, for evaluating how local populations interact to generate overall system dynamics. This suggestion has direct implications for issues such as species conservation and habitat management.

Improving decision speed, accuracy and group cohesion through early information gathering in house-hunting ants.

PubMed

Stroeymeyt, Nathalie; Giurfa, Martin; Franks, Nigel R

2010-09-29

Successful collective decision-making depends on groups of animals being able to make accurate choices while maintaining group cohesion. However, increasing accuracy and/or cohesion usually decreases decision speed and vice-versa. Such trade-offs are widespread in animal decision-making and result in various decision-making strategies that emphasize either speed or accuracy, depending on the context. Speed-accuracy trade-offs have been the object of many theoretical investigations, but these studies did not consider the possible effects of previous experience and/or knowledge of individuals on such trade-offs. In this study, we investigated how previous knowledge of their environment may affect emigration speed, nest choice and colony cohesion in emigrations of the house-hunting ant Temnothorax albipennis, a collective decision-making process subject to a classical speed-accuracy trade-off. Colonies allowed to explore a high quality nest site for one week before they were forced to emigrate found that nest and accepted it faster than emigrating naïve colonies. This resulted in increased speed in single choice emigrations and higher colony cohesion in binary choice emigrations. Additionally, colonies allowed to explore both high and low quality nest sites for one week prior to emigration remained more cohesive, made more accurate decisions and emigrated faster than emigrating naïve colonies. These results show that colonies gather and store information about available nest sites while their nest is still intact, and later retrieve and use this information when they need to emigrate. This improves colony performance. Early gathering of information for later use is therefore an effective strategy allowing T. albipennis colonies to improve simultaneously all aspects of the decision-making process--i.e. speed, accuracy and cohesion--and partly circumvent the speed-accuracy trade-off classically observed during emigrations. These findings should be taken into account in future studies on speed-accuracy trade-offs.

Prey and predator emigration responses in the acarine system Tetranychus urticae-Phytoseiulus persimilis.

PubMed

Bernstein, C

1984-01-01

Some of the processes that influence the emigration of prey and predatory mites from bean plants were investigated experimentally. The emigration of the prey depends on the damage they cause to the plants and on predator density. The predator's emigration rate is a decreasing function of prey density, and does not change (or it slightly decreases) when prey and predator numbers are increased maintaining the same prey/predator ratio. The probability of emigration of the predators is independent of their own density when prey are absent and density dependent when prey density is kep constant. Forty three per cent of the variability in the predator's instantaneous rate of emigration in the different experiments is accounted for by a two parameter negative exponential function of capture rate (number of prey eaten per predator and per unit of time).

The health implications of deportation policy.

PubMed

Morris, Juliana E; Palazuelos, Daniel

2015-05-01

The United States detains and deports over 400,000 people annually. This large-scale effort has important consequences for the health of affected individuals and communities. A growing body of research suggests that deportation increases stress and mental illness, economic deprivation, and individual exposure to violence, while also contributing to destabilization and crime at the community level. The challenges to reintegration experienced by deportees are additional push factors that increase their desire to re-emigrate. Furthermore, the related destabilization of local communities also contributes to the push, not just for deportees, but for all affected people in the region. This phenomenon has important implications for the long-term effectiveness of current U.S. deportation policies, which may be contributing to destabilization in home countries and thus potentiating further unauthorized emigration to the U.S.

Orientation: Sensory basis; Proceedings of the Conference, New York, N.Y., February 8-10, 1971.

NASA Technical Reports Server (NTRS)

1971-01-01

Topics related to photoreceptors are considered, giving attention to visual pattern recognition and directional orientation in insects, the sensory basis of orientation in amphibians, and the aerial and underwater visual acuity in the California sea lion as a function of luminance. Other subjects explored are in the fields of phonoreceptors, chemoreception, vestibular receptors, and electrical and magnetic sensitivity. Questions of the development and evolution of orientation are also investigated, taking into account field studies of mass emigration and orientation in the spiny lobster and investigations concerning the jumping behavior in the Gobiid fish. Individual items are announced in this issue.

Movement patterns and study area boundaries: Influences on survival estimation in capture-mark-recapture studies

USGS Publications Warehouse

Horton, G.E.; Letcher, B.H.

2008-01-01

The inability to account for the availability of individuals in the study area during capture-mark-recapture (CMR) studies and the resultant confounding of parameter estimates can make correct interpretation of CMR model parameter estimates difficult. Although important advances based on the Cormack-Jolly-Seber (CJS) model have resulted in estimators of true survival that work by unconfounding either death or recapture probability from availability for capture in the study area, these methods rely on the researcher's ability to select a method that is correctly matched to emigration patterns in the population. If incorrect assumptions regarding site fidelity (non-movement) are made, it may be difficult or impossible as well as costly to change the study design once the incorrect assumption is discovered. Subtleties in characteristics of movement (e.g. life history-dependent emigration, nomads vs territory holders) can lead to mixtures in the probability of being available for capture among members of the same population. The result of these mixtures may be only a partial unconfounding of emigration from other CMR model parameters. Biologically-based differences in individual movement can combine with constraints on study design to further complicate the problem. Because of the intricacies of movement and its interaction with other parameters in CMR models, quantification of and solutions to these problems are needed. Based on our work with stream-dwelling populations of Atlantic salmon Salmo salar, we used a simulation approach to evaluate existing CMR models under various mixtures of movement probabilities. The Barker joint data model provided unbiased estimates of true survival under all conditions tested. The CJS and robust design models provided similarly unbiased estimates of true survival but only when emigration information could be incorporated directly into individual encounter histories. For the robust design model, Markovian emigration (future availability for capture depends on an individual's current location) was a difficult emigration pattern to detect unless survival and especially recapture probability were high. Additionally, when local movement was high relative to study area boundaries and movement became more diffuse (e.g. a random walk), local movement and permanent emigration were difficult to distinguish and had consequences for correctly interpreting the survival parameter being estimated (apparent survival vs true survival). ?? 2008 The Authors.

Lifecourse factors and likelihood of rural practice and emigration: a survey of Ghanaian medical students.

PubMed

Kotha, Sudha Rani; Johnson, Jennifer C; Galea, Sandro; Agyei-Baffour, Peter; Nakua, Emmanuel; Asabir, Kwesi; Kwansah, Janet; Gyakobo, Mawuli; Dzodzomenyo, Mawuli; Kruk, Margaret E

2012-01-01

Health worker shortages and maldistribution have important implications for the capacity of health systems. Ghana has one of the highest physician emigration rates in the world, and over 75% of those who remain work in Ghana's two largest cities. The aim of this study was to investigate the contribution of experiential factors across Ghanaian medical students' lifespans on intent to practice in a rural area and intent to emigrate. All fourth year medical students in Ghana were surveyed on demographics, rural and international experience, and future career plans. Key outcomes of interest were students' stated likelihood of practicing in a deprived rural area or emigrating after graduation. Lifecourse predictors of interest were parental socioeconomic status, gender, relationship status, rural and international living experience, and school of study. Bivariate and multivariate logistic regression were used to estimate associations between predictors and outcomes of interest. Of 310 eligible students, 307 (99%) participated in the survey. Of these, 228 were Ghanaian and the focus of this analysis. It was found that 131 (57.5%) were willing to work in a deprived area in Ghana and 148 (64.9%) had considered emigrating after graduation. In the multivariate regression models, willingness to work in a deprived area was predicted by male gender (OR: 2.31, 95%CI: 1.23-4.35), having lived in a rural area but never lived abroad (OR: 2.77, 95%CI: 1.08-7.13), and low parental professional and educational status (OR: 2.33, 95%CI: 1.23-4.43). Consideration of emigration was predicted by having lived abroad but never in a rural area (OR: 3.39, 95%CI: 1.15-9.97). A sub-set of 80 individuals (35%) reported that they were willing to work in a deprived area in Ghana but also considering emigration. These subjects were more likely to be male. Students with parents of a lower socioeconomic class, those with rural experience, and those without international experience are more likely to stay in Ghana and are also more likely to work in a deprived area after graduation. Selective admissions policies based on lifecourse factors combined with exposure to rural practice in medical school may have a role in increasing the number of rural physicians.

Demographic changes following mechanical removal of exotic brown trout in an Intermountain West (USA), high-elevation stream

USGS Publications Warehouse

Saunders, W. Carl; Budy, Phaedra E.; Thiede, Gary P.

2015-01-01

Exotic species present a great threat to native fish conservation; however, eradicating exotics is expensive and often impractical. Mechanical removal can be ineffective for eradication, but nonetheless may increase management effectiveness by identifying portions of a watershed that are strong sources of exotics. We used mechanical removal to understand processes driving exotic brown trout (Salmo trutta) populations in the Logan River, Utah. Our goals were to: (i) evaluate the demographic response of brown trout to mechanical removal, (ii) identify sources of brown trout recruitment at a watershed scale and (iii) evaluate whether mechanical removal can reduce brown trout densities. We removed brown trout from 2 km of the Logan River (4174 fish), and 5.6 km of Right Hand Fork (RHF, 15,245 fish), a low-elevation tributary, using single-pass electrofishing. We compared fish abundance and size distributions prior to, and after 2 years of mechanical removal. In the Logan River, immigration to the removal reach and high natural variability in fish abundances limited the response to mechanical removal. In contrast, mechanical removal in RHF resulted in a strong recruitment pulse, shifting the size distribution towards smaller fish. These results suggest that, before removal, density-dependent mortality or emigration of juvenile fish stabilised adult populations and may have provided a source of juveniles to the main stem. Overall, in sites demonstrating strong density-dependent population regulation, or near sources of exotics, short-term mechanical removal has limited effects on brown trout populations but may help identify factors governing populations and inform large-scale management of exotic species.

Global conservation outcomes depend on marine protected areas with five key features.

PubMed

Edgar, Graham J; Stuart-Smith, Rick D; Willis, Trevor J; Kininmonth, Stuart; Baker, Susan C; Banks, Stuart; Barrett, Neville S; Becerro, Mikel A; Bernard, Anthony T F; Berkhout, Just; Buxton, Colin D; Campbell, Stuart J; Cooper, Antonia T; Davey, Marlene; Edgar, Sophie C; Försterra, Günter; Galván, David E; Irigoyen, Alejo J; Kushner, David J; Moura, Rodrigo; Parnell, P Ed; Shears, Nick T; Soler, German; Strain, Elisabeth M A; Thomson, Russell J

2014-02-13

In line with global targets agreed under the Convention on Biological Diversity, the number of marine protected areas (MPAs) is increasing rapidly, yet socio-economic benefits generated by MPAs remain difficult to predict and under debate. MPAs often fail to reach their full potential as a consequence of factors such as illegal harvesting, regulations that legally allow detrimental harvesting, or emigration of animals outside boundaries because of continuous habitat or inadequate size of reserve. Here we show that the conservation benefits of 87 MPAs investigated worldwide increase exponentially with the accumulation of five key features: no take, well enforced, old (>10 years), large (>100 km(2)), and isolated by deep water or sand. Using effective MPAs with four or five key features as an unfished standard, comparisons of underwater survey data from effective MPAs with predictions based on survey data from fished coasts indicate that total fish biomass has declined about two-thirds from historical baselines as a result of fishing. Effective MPAs also had twice as many large (>250 mm total length) fish species per transect, five times more large fish biomass, and fourteen times more shark biomass than fished areas. Most (59%) of the MPAs studied had only one or two key features and were not ecologically distinguishable from fished sites. Our results show that global conservation targets based on area alone will not optimize protection of marine biodiversity. More emphasis is needed on better MPA design, durable management and compliance to ensure that MPAs achieve their desired conservation value.

Global conservation outcomes depend on marine protected areas with five key features

NASA Astrophysics Data System (ADS)

Edgar, Graham J.; Stuart-Smith, Rick D.; Willis, Trevor J.; Kininmonth, Stuart; Baker, Susan C.; Banks, Stuart; Barrett, Neville S.; Becerro, Mikel A.; Bernard, Anthony T. F.; Berkhout, Just; Buxton, Colin D.; Campbell, Stuart J.; Cooper, Antonia T.; Davey, Marlene; Edgar, Sophie C.; Försterra, Günter; Galván, David E.; Irigoyen, Alejo J.; Kushner, David J.; Moura, Rodrigo; Parnell, P. Ed; Shears, Nick T.; Soler, German; Strain, Elisabeth M. A.; Thomson, Russell J.

2014-02-01

In line with global targets agreed under the Convention on Biological Diversity, the number of marine protected areas (MPAs) is increasing rapidly, yet socio-economic benefits generated by MPAs remain difficult to predict and under debate. MPAs often fail to reach their full potential as a consequence of factors such as illegal harvesting, regulations that legally allow detrimental harvesting, or emigration of animals outside boundaries because of continuous habitat or inadequate size of reserve. Here we show that the conservation benefits of 87 MPAs investigated worldwide increase exponentially with the accumulation of five key features: no take, well enforced, old (>10 years), large (>100km2), and isolated by deep water or sand. Using effective MPAs with four or five key features as an unfished standard, comparisons of underwater survey data from effective MPAs with predictions based on survey data from fished coasts indicate that total fish biomass has declined about two-thirds from historical baselines as a result of fishing. Effective MPAs also had twice as many large (>250mm total length) fish species per transect, five times more large fish biomass, and fourteen times more shark biomass than fished areas. Most (59%) of the MPAs studied had only one or two key features and were not ecologically distinguishable from fished sites. Our results show that global conservation targets based on area alone will not optimize protection of marine biodiversity. More emphasis is needed on better MPA design, durable management and compliance to ensure that MPAs achieve their desired conservation value.

Steelhead Supplementation Studies; Steelhead Supplementation in Idaho Rivers, Annual Report 2002.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byrne, Alan

The Steelhead Supplementation Study (SSS) has two broad objectives: (1) investigate the feasibility of supplementing depressed wild and natural steelhead populations using hatchery populations, and (2) describe the basic life history and genetic characteristics of wild and natural steelhead populations in the Salmon and Clearwater Basins. Idaho Department of Fish and Game (IDFG) personnel stocked adult steelhead from Sawtooth Fish Hatchery into Frenchman and Beaver creeks and estimated the number of age-1 parr produced from the outplants since 1993. On May 2, 2002, both Beaver and Frenchman creeks were stocked with hatchery adult steelhead. A SSS crew snorkeled the creeksmore » in August 2002 to estimate the abundance of age-1 parr from brood year (BY) 2001. I estimated that the yield of age-1 parr per female stocked in 2001 was 7.3 and 6.7 in Beaver and Frenchman creeks, respectively. SSS crews stocked Dworshak hatchery stock fingerlings and smolts from 1993 to 1999 in the Red River drainage to assess which life stage produces more progeny when the adults return to spawn. In 2002, Clearwater Fish Hatchery personnel operated the Red River weir to trap adults that returned from these stockings. Twelve PIT-tagged adults from the smolt releases and one PIT-tagged adult from fingerling releases were detected during their migration up the mainstem Columbia and Snake rivers, but none from either group were caught at the weir. The primary focus of the study has been monitoring and collecting life history information from wild steelhead populations. An adult weir has been operated annually since 1992 in Fish Creek, a tributary of the Lochsa River. The weir was damaged by a rain-on-snow event in April 2002 and although the weir remained intact, some adults were able to swim undetected through the weir. Despite damage to the weir, trap tenders captured 167 adult steelhead, the most fish since 1993. The maximum likelihood estimate of adult steelhead escapement was 242. A screw trap has been operated annually in Fish Creek since 1994 to estimate the number of emigrating parr and smolts. I estimated that 18,687 juvenile steelhead emigrated from Fish Creek in 2002, the lowest number of migrants since 1998. SSS crews snorkeled three streams in the Selway River drainage and 10 streams in the Lochsa River drainage to estimate juvenile steelhead densities. The densities of age-1 steelhead parr declined in all streams compared to the densities observed in 2001. The age-1 densities in Fish Creek and Gedney Creek were the lowest observed since this project began monitoring those populations in 1994. The SSS crews and other cooperators tagged more than 12,000 juvenile steelhead with passive integrated transponder (PIT) tags in 2002. In 2002, technicians mounted and aged steelhead scales that were collected from 1998 to 2001. A consensus was reached among technicians for age of steelhead juveniles from Fish Creek. Scales that were collected in other streams were aged by at least one reader; however, before a final age is assigned to these fish, the age needs to be verified by another reader and any age differences among readers resolved. Dr. Jennifer Nielsen, at the U.S. Geological Survey Alaska Biological Science Center, Anchorage continued the microsatellite analysis of the steelhead tissue samples that were collected from Idaho streams in 2000. Two thousand eighteen samples from 40 populations were analyzed. The analysis of the remaining 39 populations is continuing.« less

Gone for good? An online survey of emigrant health professionals using Facebook as a recruitment tool.

PubMed

McAleese, Sara; Clyne, Barbara; Matthews, Anne; Brugha, Ruairí; Humphries, Niamh

2016-06-30

Health professionals, particularly doctors, nurses and midwives, are in high demand worldwide. Therefore, it is important to assess the future plans and likelihood of return of emigrating health professionals. Nevertheless, health professionals are, by definition, a difficult population to track/survey. This exploratory study reports on the migration intentions of a sample of doctors, nurses and midwives who had emigrated from Ireland, a high-income country which has experienced particularly high outward and inward migration of health professionals since the year 2000. Health professionals who had emigrated from Ireland were identified via snowball sampling through Facebook and invited to complete a short online survey composed of closed and open response questions. A total of 388 health professionals (307 doctors, 73 nurses and 8 midwives) who had previously worked in Ireland completed the survey. While over half had originally intended to spend less than 5 years in their destination country at the time of emigration, these intentions changed over time, with the desire to remain abroad on a permanent basis increasing from 10 to 34 % of doctor respondents. Only a quarter of doctors and a half of nurses and midwives intended to return to practice in Ireland in the future. The longer health professionals remain abroad, the less likely they are to return to their home countries. Countries should focus on the implementation of retention strategies if the 'carousel' of brain drain is to be interrupted. This would allow source countries to benefit from their investments in training health professionals, rather than relying on international recruitment to meet health system staffing needs. Improved data collection systems are also needed to track the migratory patterns and changing intentions of health professionals. Meanwhile, social networking platforms offer alternative methods of filling this information gap.

High Emigration Propensity and Low Mortality on Transfer Drives Female-Biased Dispersal of Pyriglena leucoptera in Fragmented Landscapes

PubMed Central

Awade, Marcelo; Candia-Gallardo, Carlos; Cornelius, Cintia; Metzger, Jean Paul

2017-01-01

Dispersal is a biological process performed in three stages: emigration, transfer and immigration. Intra-specific variation on dispersal behavior, such as sex-bias, is very common in nature, particularly in birds and mammals. However, dispersal is difficult to measure in the field and many hypotheses concerning the causes of sex-biased dispersal remain without empirical confirmation. An important limitation of most empirical studies is that inferences about sex-biased dispersal are based only on emigration proneness or immigration success data. Thus, we still do not know whether sex-biased immigration in fragmented landscapes occurs during emigration, transfer or in both stages. We conducted translocation and radiotracking experiments to assess i) whether inter-patch dispersal movements of a rainforest bird (Pyriglena leucoptera) is sex-biased and ii) how dispersal stages and the perceptual range of the individuals are integrated to generate dispersal patterns. Our results showed that inter-patch dispersal is sex-biased at all stages for P. leucoptera, as females not only exhibit a higher emigration propensity but are subjected to a lower risk of predation when moving through the matrix. Moreover, our data support a perceptual range of 80 m and our results showed that dispersal success decreases considerably when inter-patch distances exceeds this perceptual range. In this case, birds have a higher probability of travelling over longer routes and, as a consequence, the risk of predation increases, specially for males. Overall, results supported that assuming dispersal as a single-stage process to describe dispersal behavior may be misleading. In this way, our study advanced our understanding of processes and patterns related to inter-patch dispersal of neotropical forest birds, shedding light on potential implications for population dynamics and for the management of fragmented landscapes. PMID:28107517

Testing Ødegaard's selective migration hypothesis: a longitudinal cohort study of risk factors for non-affective psychotic disorders among prospective emigrants.

PubMed

van der Ven, E; Dalman, C; Wicks, S; Allebeck, P; Magnusson, C; van Os, J; Selten, J P

2015-03-01

The selection hypothesis posits that the increased rates of psychosis observed among migrants are due to selective migration of people who are predisposed to develop the disorder. To test this hypothesis, we examined whether risk factors for psychosis are more prevalent among future emigrants. A cohort of 49,321 Swedish military conscripts was assessed at age 18 years on cannabis use, IQ, psychiatric diagnosis, social adjustment, history of trauma and urbanicity of place of upbringing. Through data linkage we examined whether these exposures predicted emigration out of Sweden. We also calculated the emigrants' hypothetical relative risk compared with non-emigrants for developing a non-affective psychotic disorder. Low IQ [odds ratio (OR) 0.5, 95% confidence interval (95% CI) 0.3-0.9] and 'poor social adjustment' (OR 0.4, 95% CI 0.2-0.8) were significantly less prevalent among prospective emigrants, whereas a history of urban upbringing (OR 2.3, 95% CI 1.4-3.7) was significantly more common. Apart from a non-significant increase in cannabis use among emigrants (OR 1.6, 95% CI 0.8-3.1), there were no major group differences in any other risk factors. Compared to non-emigrants, hypothetical relative risks for developing non-affective psychotic disorder were 0.7 (95% CI 0.4-1.2) and 0.8 (95% CI 0.7-1.0), respectively, for emigrants narrowly and broadly defined. This study adds to an increasing body of evidence opposing the selection hypothesis.

'Emigration is a matter of self-preservation. The working conditions . . . are killing us slowly': qualitative insights into health professional emigration from Ireland.

PubMed

Humphries, Niamh; McAleese, Sara; Matthews, Anne; Brugha, Ruairi

2015-05-16

Achieving a sustainable health workforce involves training and retaining sufficient staff to deliver health services. The Irish health workforce is characterised by a high level of emigration of Irish-trained staff and a heavy reliance on internationally trained staff. This paper presents qualitative findings from a mixed-method study of doctors, nurses and midwives who have recently emigrated from Ireland. Using Facebook, this study elicited 556 (388 completed) responses to an exploratory mixed-method online survey in July 2014. Respondents provided rich responses to two free-text questions, one on health worker return (N = 343) and another on health professional emigration (N = 209) from the source country (Ireland). Respondents emigrated because of difficult working conditions in the Irish health system (long working hours, uncertain career progression), which compared poorly with conditions in the destination country. Respondents' experiences in the destination country vindicated the decision to emigrate and complicated the decision to return. Their return to Ireland was contingent upon significant reform of the Irish health system and an improvement in working conditions, expressed, for example, as: 'It's not about the money, it's about respect . . . we love working in medicine, but we love our families and health more' (RD283). This paper highlights that doctors, nurses and midwives are emigrating from Ireland in search of better working conditions, clear career progression pathways and a better practice environment. The question for the source country is whether it can retain and attract back emigrant doctors, nurses and midwives by matching their expectations.

Visual Navigation during Colony Emigration by the Ant Temnothorax rugatulus

PubMed Central

Bowens, Sean R.; Glatt, Daniel P.; Pratt, Stephen C.

2013-01-01

Many ants rely on both visual cues and self-generated chemical signals for navigation, but their relative importance varies across species and context. We evaluated the roles of both modalities during colony emigration by Temnothorax rugatulus. Colonies were induced to move from an old nest in the center of an arena to a new nest at the arena edge. In the midst of the emigration the arena floor was rotated 60°around the old nest entrance, thus displacing any substrate-bound odor cues while leaving visual cues unchanged. This manipulation had no effect on orientation, suggesting little influence of substrate cues on navigation. When this rotation was accompanied by the blocking of most visual cues, the ants became highly disoriented, suggesting that they did not fall back on substrate cues even when deprived of visual information. Finally, when the substrate was left in place but the visual surround was rotated, the ants' subsequent headings were strongly rotated in the same direction, showing a clear role for visual navigation. Combined with earlier studies, these results suggest that chemical signals deposited by Temnothorax ants serve more for marking of familiar territory than for orientation. The ants instead navigate visually, showing the importance of this modality even for species with small eyes and coarse visual acuity. PMID:23671713

Solving the Puzzle of Metastasis: The Evolution of Cell Migration in Neoplasms

PubMed Central

Chen, Jun; Sprouffske, Kathleen; Huang, Qihong; Maley, Carlo C.

2011-01-01

Background Metastasis represents one of the most clinically important transitions in neoplastic progression. The evolution of metastasis is a puzzle because a metastatic clone is at a disadvantage in competition for space and resources with non-metastatic clones in the primary tumor. Metastatic clones waste some of their reproductive potential on emigrating cells with little chance of establishing metastases. We suggest that resource heterogeneity within primary tumors selects for cell migration, and that cell emigration is a by-product of that selection. Methods and Findings We developed an agent-based model to simulate the evolution of neoplastic cell migration. We simulated the essential dynamics of neoangiogenesis and blood vessel occlusion that lead to resource heterogeneity in neoplasms. We observed the probability and speed of cell migration that evolves with changes in parameters that control the degree of spatial and temporal resource heterogeneity. Across a broad range of realistic parameter values, increasing degrees of spatial and temporal heterogeneity select for the evolution of increased cell migration and emigration. Conclusions We showed that variability in resources within a neoplasm (e.g. oxygen and nutrients provided by angiogenesis) is sufficient to select for cells with high motility. These cells are also more likely to emigrate from the tumor, which is the first step in metastasis and the key to the puzzle of metastasis. Thus, we have identified a novel potential solution to the puzzle of metastasis. PMID:21556134

Estimation of temporary emigration in male toads

USGS Publications Warehouse

Muths, E.; Scherer, R. D.; Corn, P.S.; Lambert, B.A.

2006-01-01

Male boreal toads (Bufo boreas) are thought to return to the breeding site every year but, if absent in a particular year, will be more likely to return the following year. Using Pollock's robust design we estimated temporary emigration (the probability a male toad is absent from a breeding site in a given year) at three locations in Colorado, USA: two in Rocky Mountain National Park and one in Chaffee County. We present data that suggest that not all male toads return to the breeding site every year. Our analyses indicate that temporary emigration varies by site and time (for example, from 1992 to 1998, the probability of temporary emigration ranged from 10% to 29% and from 3% to 95% at Lost Lake and Kettle Tarn, respectively). Although the results provide weak evidence that males are more likely to return after a year's hiatus, a general pattern of state-dependent temporary emigration was not supported. We also hypothesized relationships between temporary emigration and a number of weather variables. While some competitive models included weather covariates, imprecise and variable estimates of the effects of these covariates precluded fully defining their impact on temporary emigration. ?? 2006 by the Ecological Society of America.

Emigration and welfare in an economy with foreign capital.

PubMed

Djajic, S

1998-08-01

Discussion of the brain drain problem in the 1970s sparked considerable theoretical research upon the effects of emigration. In many cases, it has been determined that emigration reduces the level of welfare of the remaining residents in the source country, regardless of whether or not human capital is exported. In an economy producing traded and non-traded goods. Rivera-Batiz demonstrated that the level of welfare of the remaining residents declines as a consequence of emigration or at most remains unchanged. This paper generalizes the Rivera-Batiz model in another direction to examine the effects of emigration upon the welfare of remaining residents when foreign capital is employed in the economy. In contrast to other earlier studies, it is found that emigration improves the welfare of remaining residents if both they and the migrants have identical preferences and factor endowments. The author also compares the welfare implications of remittance flows back to the source country when they are used to finance consumption and when they are used to finance capital accumulation.

Combining genetic, isotopic, and field data to better describe the influence of dams and diversions on Burbot Movement in the Wind River Drainage, Wyoming

USGS Publications Warehouse

Hooley-Underwood, Zachary; Mandeville, Elizabeth G.; Gerrity, Paul C.; Deromedi, J. W.; Johnson, Kevin; Walters, Annika W.

2018-01-01

Dams and water diversions fragment habitat, entrain fish, and alter fish movement. Many Burbot Lota lota populations are declining, with dams and water diversions thought to be a major threat. We used multiple methods to identify Burbot movement patterns and assess entrainment into an irrigation system in the Wind River, Wyoming. We assessed seasonal movement of Burbot with a mark–recapture (PIT tagging) study, natal origins of entrained fish with otolith microchemistry, and historic movement with genotyping by sequencing. We found limited evidence of entrainment in irrigation waters across all approaches. The mark–recapture study indicated that out‐migration from potential source populations could be influenced by flow regime but was generally low. Otolith and genomic results suggested the presence of a self‐sustaining population within the irrigation network. We conclude that emigration from natural tributary populations is not the current source of the majority of Burbot found in irrigation waters. Instead, reservoir and irrigation canal construction has created novel habitat in which Burbot have established a population. Using a multi‐scale approach increased our inferential abilities and mechanistic understanding of movement patterns between natural and managed systems.

Life history of the striped newt at a north-central Florida breeding pond

USGS Publications Warehouse

Johnson, S.A.

2002-01-01

I studied the life history of Striped Newts (Notophthalmus perstriatus) at a breeding pond in north-central Florida. Newts were captured in pitfall traps at a drift-fence as they migrated into and out of the pond basin. During the 2-year study, I recorded 10,290 captures (8,127 individuals) of newts at the drift-fence. Newts were active during each month of the study, but there were four peak activity periods, each of which included immigration and emigration events. Immigration events were almost exclusively comprised of adults, whereas emigration events were comprised of adults and recently transformed larvae. I documented 5,296 recently transformed, immature larvae (efts) and 435 recently transformed mature larvae (paedomorphs) during four distinct periods of emigration. Efts matured in the uplands before returning to the pond to breed. In the uplands, male efts (n = 16) grew 0.0183 mm/day on average, whereas average female (n = 24) growth was 0.0167 mm/day. Immigrating adults of both sexes were significantly smaller than emigrating adults. Emigrating efts were smallest, followed by emigrating paedomorphs, immigrating adults, then emigrating adults. The overall adult sex ratio was 1:1.25 (m:f). Sex ratio of emigrating paedomorphs was highly skewed towards females, with one male for every 4.43 females. Newts tended to move during wetter periods, and captures were significantly correlated with rainfall, but rainfall was a poor predictor of the magnitude of newt movements.

Coastal nurseries and their importance for conservation of sea kraits.

PubMed

Bonnet, Xavier; Brischoux, François; Bonnet, Christophe; Plichon, Patrice; Fauvel, Thomas

2014-01-01

Destruction and pollution of coral reefs threaten these marine biodiversity hot stops which shelter more than two thirds of sea snake species. Notably, in many coral reef ecosystems of the Western Pacific Ocean, large populations of sea kraits (amphibious sea snakes) have drastically declined during the past three decades. Protecting remaining healthy populations is thus essential. In New Caledonia, coral reefs shelter numerous sea krait colonies spread throughout an immense lagoon (24,000 km2). Sea kraits feed on coral fish but lay their eggs on land. However, ecological information on reproduction and juveniles is extremely fragmentary, precluding protection of key habitats for reproduction. Our 10 years mark recapture study on Yellow sea kraits (L. saintgironsi >8,700 individuals marked) revealed that most neonates aggregate in highly localized coastal sites, where they feed and grow during several months before dispersal. Hundreds of females emigrate seasonally from remote populations (>50 km away) to lay their eggs in these coastal nurseries, and then return home. Protecting these nurseries is a priority to maintain recruitment rate, and to retain sea krait populations in the future.

Coastal Nurseries and Their Importance for Conservation of Sea Kraits

PubMed Central

Bonnet, Xavier; Brischoux, François; Bonnet, Christophe; Plichon, Patrice; Fauvel, Thomas

2014-01-01

Destruction and pollution of coral reefs threaten these marine biodiversity hot stops which shelter more than two thirds of sea snake species. Notably, in many coral reef ecosystems of the Western Pacific Ocean, large populations of sea kraits (amphibious sea snakes) have drastically declined during the past three decades. Protecting remaining healthy populations is thus essential. In New Caledonia, coral reefs shelter numerous sea krait colonies spread throughout an immense lagoon (24,000 km2). Sea kraits feed on coral fish but lay their eggs on land. However, ecological information on reproduction and juveniles is extremely fragmentary, precluding protection of key habitats for reproduction. Our 10 years mark recapture study on Yellow sea kraits (L. saintgironsi >8,700 individuals marked) revealed that most neonates aggregate in highly localized coastal sites, where they feed and grow during several months before dispersal. Hundreds of females emigrate seasonally from remote populations (>50 km away) to lay their eggs in these coastal nurseries, and then return home. Protecting these nurseries is a priority to maintain recruitment rate, and to retain sea krait populations in the future. PMID:24670985

Applying Organizational Commitment and Human Capital Theories to Emigration Research

ERIC Educational Resources Information Center

Verkhohlyad, Olga; McLean, Gary N.

2012-01-01

Purpose: This study aims to bring some additional insight into the issue of emigration by establishing a relationship between emigration and psychic return of citizens to their human capital investment in the country. Design/methodology/approach: The article adopts a quantitative research strategy. It applies organizational commitment and human…

Space, authority and the female emigrant afloat.

PubMed

Gothard, J

1999-01-01

In the latter half of the nineteenth century, all emigrants travelling out to the Australian colonies experienced a range of measures designed for their protection. As well as physical protection, the future roles of single emigrant women, as paid domestic labour or, ultimately, as unpaid wives and mothers, required that the care accorded to them also took on social and moral concerns. This paper discusses the shipboard structures, particularly spatial arrangements, that were designed both to protect emigrant women in transit to the colonies and to protect the colonial investment.

An emigration versus a globalization perspective of the Lebanese physician workforce: a qualitative study

PubMed Central

2012-01-01

Background Lebanon is witnessing an increased emigration of physicians. The objective of this study was to understand the perceptions of Lebanese policymakers of this emigration, and elicit their proposals for future policies and strategies to deal with this emigration. Methods We conducted semi-structured individual interviews with the deans of Lebanon’s seven medical schools, the presidents of the two physicians professional associations, and governmental officials. We analyzed the results qualitatively. Results Participants differed in the assessment of the extent and gravity of emigration. Lebanon has a surplus of physicians, driven largely by the over-production of graduates by a growing number of medical schools. Participants cited advantages and disadvantages of the emigration on the personal, financial, medical education system, healthcare system, and national levels. Proposed strategies included limiting the number of students entering medical schools, creating job opportunities for graduating students, and implementing quality standards. Most participants acknowledged the globalization of the Lebanese physician workforce, including exchanges with the Gulf region, exchanges with developed countries, and the involvement of North American medical education institutions in the region. Conclusion Many Lebanese policy makers, particularly deans of medical schools, perceive the emigration of the physician workforce as an opportunity in the context of the globalization of the profession. PMID:22646478

An emigration versus a globalization perspective of the Lebanese physician workforce: a qualitative study.

PubMed

Akl, Elie A; Maroun, Nancy; Rahbany, Aline; Hagopian, Amy

2012-05-30

Lebanon is witnessing an increased emigration of physicians. The objective of this study was to understand the perceptions of Lebanese policymakers of this emigration, and elicit their proposals for future policies and strategies to deal with this emigration. We conducted semi-structured individual interviews with the deans of Lebanon's seven medical schools, the presidents of the two physicians professional associations, and governmental officials. We analyzed the results qualitatively. Participants differed in the assessment of the extent and gravity of emigration. Lebanon has a surplus of physicians, driven largely by the over-production of graduates by a growing number of medical schools. Participants cited advantages and disadvantages of the emigration on the personal, financial, medical education system, healthcare system, and national levels. Proposed strategies included limiting the number of students entering medical schools, creating job opportunities for graduating students, and implementing quality standards. Most participants acknowledged the globalization of the Lebanese physician workforce, including exchanges with the Gulf region, exchanges with developed countries, and the involvement of North American medical education institutions in the region. Many Lebanese policy makers, particularly deans of medical schools, perceive the emigration of the physician workforce as an opportunity in the context of the globalization of the profession.

Tributary use by imperiled Flannelmouth and Bluehead Suckers in the upper Colorado River Basin

USGS Publications Warehouse

Fraser, Gregory S.; Winkelman, Dana L.; Bestgen, Kevin R.; Thompson, Kevin G.

2017-01-01

Habitat alterations and establishment of nonnative fishes have reduced the distributions of Flannelmouth Sucker Catostomus latipinnis and Bluehead Sucker C. discobolus to less than 50% of their historical ranges in the Colorado River basin. Tributaries are sometimes less altered than main-stem habitat in the basin and may be important to support various life history processes, but their role in the maintenance of Flannelmouth Sucker and Bluehead Sucker populations is poorly understood. Using mark–recapture techniques, we show tributaries are important habitat for native suckers in the upper Colorado River basin and report three main findings. First, both Flannelmouth and Bluehead suckers likely respond to a thermal cue that initiates spawning movement patterns. Suckers moved into Coal Creek from the White River beginning in mid-May of 2012 and 2013 to spawn. The majority of sucker spawning movements occurred when water temperatures in White River exceeded 11–14°C and those in Coal Creek were 2.5–4°C warmer, while flows varied between years. Second, based on PIT tag detection arrays, 13–45% of suckers showed spawning site fidelity. Sampling only with fyke nets would have resulted in the conclusion that site fidelity by native suckers was only 1–17%, because nets were less efficient at detecting marked fish. Third, most suckers of both species emigrated from Coal Creek within 48 h after being captured while suckers that were detected only via arrays remained resident for 10–12 d. The posthandling flight response we observed was not anticipated and to our knowledge has not been previously reported for these species. Remote PIT tag antenna arrays allowed for a stronger inference regarding movement and tributary use by these species than what could be achieved using just fyke nets. Tributaries are an important part of Flannelmouth Sucker and Bluehead Sucker life history and thus important to conservation strategies for these species.

Growth characteristics and Otolith analysis on Age-0 American Shad

USGS Publications Warehouse

Sauter, Sally T.; Wetzel, Lisa A.

2011-01-01

Otolith microstructure analysis provides useful information on the growth history of fish (Campana and Jones 1992, Bang and Gronkjaer 2005). Microstructure analysis can be used to construct the size-at-age growth trajectory of fish, determine daily growth rates, and estimate hatch date and other ecologically important life history events (Campana and Jones 1992, Tonkin et al. 2008). This kind of information can be incorporated into bioenergetics modeling, providing necessary data for estimating prey consumption, and guiding the development of empirically-based modeling scenarios for hypothesis testing. For example, age-0 American shad co-occur with emigrating juvenile fall Chinook salmon originating from Hanford Reach and the Snake River in the lower Columbia River reservoirs during the summer and early fall. The diet of age-0 American shad appears to overlap with that of juvenile fall Chinook salmon (Chapter 1, this report), but juvenile fall Chinook salmon are also known to feed on age-0 American shad in the reservoirs (USGS unpublished data). Abundant, energy-dense age-0 American shad may provide juvenile fall Chinook salmon opportunities for rapid growth during the time period when large numbers of age-0 American shad are available. Otolith analysis of hatch dates and the growth curve of age-0 American shad could be used to identify when eggs, larvae, and juveniles of specific size classes are temporally available as food for fall Chinook salmon in the lower Columbia River reservoirs. This kind of temporally and spatially explicit life history information is important to include in bioenergetics modeling scenarios. Quantitative estimates of prey consumption could be used with spatially-explicit estimates of prey abundance to construct a quantitative assessment of the age-0 American shad impact on a reservoir food web.

Fritz Goro on Tape: An Emigre Photojournalist's Professional Biography.

ERIC Educational Resources Information Center

Smith, C. Zoe

Emigres associated with Black Star Picture Agency and "Life" shared much in common: most were well-educated European Jews who became journalists after being involved in other professions and most had worked for German magazines and had emigrated to the United States to pursue their careers while escaping the Nazis. After being trained on…

75 FR 79016 - Notice of Availability of the Final Environmental Impact Statement for the Newmont Mining...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-17

... Newmont Mining Corporation Emigrant Project Plan of Operation, Nevada AGENCY: Bureau of Land Management... Mining Corporation Emigrant Project Plan of Operations and by this notice is announcing its availability...: Copies of the EIS for the Newmont Mining Corporation Emigrant Project Plan of Operation are available for...

Teachers on the Move: International Migration of School Teachers from India

ERIC Educational Resources Information Center

Sharma, Rashmi

2013-01-01

Emigration of qualified teachers from developing countries is a double loss for the source countries, not only leading to emigration of high-skill labour but also affecting their future developmental base when these countries are already struggling to meet the millennium development goals (MDGs) in education. This article discusses emigration of…

Inbreeding avoidance, patch isolation and matrix permeability influence dispersal and settlement choices by male agile antechinus in a fragmented landscape.

PubMed

Banks, Sam C; Lindenmayer, David B

2014-03-01

Animal dispersal is highly non-random and has important implications for the dynamics of populations in fragmented habitat. We identified interpatch dispersal events from genetic tagging, parentage analyses and assignment tests and modelled the factors associated with apparent emigration and post-dispersal settlement choices by individual male agile antechinus (Antechinus agilis, a marsupial carnivore of south-east Australian forests). Emigration decisions were best modelled with on data patch isolation and inbreeding risk. The choice of dispersal destination by males was influenced by inbreeding risk, female abundance, patch size, patch quality and matrix permeability (variation in land cover). Males were less likely to settle in patches without highly unrelated females. Our findings highlight the importance of individual-level dispersal data for understanding how multiple processes drive non-randomness in dispersal in modified landscapes. Fragmented landscapes present novel environmental, demographic and genetic contexts in which dispersal decisions are made, so the major factors affecting dispersal decisions in fragmented habitat may differ considerably from unfragmented landscapes. We show that the spatial scale of genetic neighbourhoods can be large in fragmented habitat, such that dispersing males can potentially settle in the presence of genetically similar females after moving considerable distances, thereby necessitating both a choice to emigrate and a choice of where to settle to avoid inbreeding. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Ecology of fall-migrating ducks in central Illinois: A radar perspective

NASA Astrophysics Data System (ADS)

O'Neal, Benjamin J.

Research from the last two decades has elucidated the importance of migration in the annual cycle of ducks, but many aspects of migration ecology remain poorly understood due to the difficulty of investigating movements that occur over large spatial scales, at substantial heights and at night. Weather surveillance radar (WSR) offers a unique tool for observing movements of birds aloft, but until now has been used primarily to address questions only relevant to broad taxonomic groups. Using thermal infrared imaging, portable radar, and natural history, I ground-truthed WSR echoes originating from a complex of wetlands in the central Illinois River valley to develop a technique for identifying and enumerating ducks as they emigrated from this important stopover area. With this technique, I quantified duck emigrations during 7 falls (1996, 1997, 2003, and 2005-2008). I used WSR-derived estimates of annual turnover in combination with aerial inventory estimates of duck use to estimate the average amount of time ducks spent at my study site during fall (stopover duration). The mean stopover duration estimate of 11 days (SD = 4 days) was much shorter than a historical estimate (28 days) that has been use for regional waterfowl conservation planning. I also regressed average annual stopover duration estimates against an index of annual foraging habitat quality and found a strong, positive relationship (r2 = 0.71), suggesting ducks assessed local habitat conditions and adjusted time spent at the site. Weather influences the timing of migration in many avian taxa, but this relationship is poorly understood for ducks. An evaluation of competing models including 15 years of data indicated following winds aloft, no precipitation, less cloud cover, decreasing temperatures, increasing barometric pressure and date best predicted emigration (R2 = 0.52). Based on this model, the odds of a duck emigration occurring when winds were following and precipitation was absent were 13.2 to 1.0 (95% CI 7.8--22.4). Finally, the notion that ducks rely on leading-lines of rivers for visual orientation during flight is a dominant paradigm in waterfowl science. I examined departure tracks of emigration events from my study site during 1995--2009 and found ducks had a significant SSE directional preference (152°; P < 0.05), which differed significantly in all years from the course of the Illinois River (220°; P ≤ 0.001). This pattern was markedly different than the river-oriented route described for ducks departing this site in the mid-20th century. Thus, leading lines appear to have been unimportant for orientation in the majority of duck emigration events from the major stopover area examined here.

Breeding pond selection and movement patterns by eastern spadefoot toads (Scaphiopus holbrookii) in relation to weather and edaphic conditions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cathryn H. Greenberg; George W. Tanner

2004-08-31

Cathryn H. Greenberg and George W. Tanner. 2004. Breeding pond selection and movement patterns by eastern spadefoot toads (Scaphiopus holbrookii) in relation to weather and edaphic conditions. J. Herp. 38(4):569-577. Abstract: Eastern Spadefoot Toads (Scaphiopus holbrookii) require fish-free, isolated, ephemeral ponds for breeding but otherwise inhabit the surrounding uplands, commonly xeric longleaf pine (Pinus palustris) wiregrass (Aristida beyrichiana). Hence both pond and upland conditions can potentially affect their breeding biology, and population persistence. Hardwood invasion due to fire suppression in sandhills could alter upland and pond suitability by higher hardwood density and increased transpiration. In this paper we explore breedingmore » and neonatal emigration movements in relation to weather, hydrological conditions of ponds, and surrounding upland matrices. We use 9 years of data from continuous monitoring with drift fences and pitfall traps at 8 ephemeral ponds in 2 upland matrices: regularly-burned, savanna-like sandhills (n = 4), and hardwood-invaded sandhills (n = 4). Neither adult nor neonate captures differed between ponds within the 2 upland matrices, suggesting that they are tolerant of upland heterogeneity created by fire frequency. Explosive breeding occurred during 9 periods and in all seasons; adults were captured rarely otherwise. At a landscape-level rainfall, maximum change in barometric pressure, and an interaction between those 2 variables were significant predictors of explosive breeding. At a pond-level, rainfall, change in pond depth during the month prior to breeding, and days since a pond was last dry were significant predictors of adult captures. Transformation date, rather than weather, was associated with neonatal emigrations, which usually were complete within a week. Movement by first-captured adults and neonates was directional, but adult emigrations were apparently not always toward their origin. Our results suggest that Spadefoot Toads are highly adapted to breeding conditions and upland habitat heterogeneity created by weather patterns and fire frequency in Florida sandhills.« less

Development and the Urban and Rural Geography of Mexican Emigration to the United States

ERIC Educational Resources Information Center

Hamilton, Erin R.; Villarreal, Andres

2011-01-01

Past research on international migration from Mexico to the United States uses geographically-limited data and analyzes emigrant-sending communities in isolation. Theories supported by this research may not explain urban emigration, and this research does not consider connections between rural and urban Mexico. In this study we use national data…

Different forms, reasons and motivations for return migration of persons who voluntarily decide to return to their countries of origin.

PubMed

Callea, S

1986-03-01

Although the 1973 oil crisis did not have the drastic effects on immigration which were originally feared, it did end a period of quasi-liberal immigration policy, establish intense and effective international cooperation on immigration, and arouse great interest in immigration studies and research. This paper analyzes the situations arising as a result of the petroleum shortage and focuses on the conditions relating to the return of emigrants to Southern European countries. This new research draws attention to the following fundamental aspects of the immigration problem: 1) the emigrant's return to his homeland cannot be considered a factor in development; it is a positive element in development only if the right socioeconomic conditions exist in the country of origin. 2) Concern for children's education is one of the most common reasons for return. 3) A large percentage of emigrants are satisfied with their work abroad. 4) An emigrant's return potential is wasted due to the slight use that is made of the resources he offers. 5) Returning workers most often want to set up an independent enterprise. 6) Savings are generally used to buy a house or farm. 7) Vocational level does not increase significantly between emigration and returning, though this increase becomes greater the longer the emigrant stays abroad. 8) The number of returning emigrants is too slight to bring about any change in the country of origin. 9) Incentives and subsidies to encourage return have not had a considerable impact on the decision to return. Callea recommends that officials of the country of origin posted abroad be assigned to counsel returning emigrants on finding employment, attending vocational development courses, obtaining housing, accruing interests and savings, and on the problems and perspectives of sociocultural reintegration.

Thymocyte emigration is mediated by active movement away from stroma-derived factors

PubMed Central

Poznansky, Mark C.; Olszak, Ivona T.; Evans, Richard H.; Wang, Zhengyu; Foxall, Russell B.; Olson, Douglas P.; Weibrecht, Kathryn; Luster, Andrew D.; Scadden, David T.

2002-01-01

T cells leave the thymus at a specific time during differentiation and do not return despite elaboration of known T cell chemoattractants by thymic stroma. We observed differentiation stage–restricted egress of thymocytes from an artificial thymus in which vascular structures or hemodynamics could not have been playing a role. Hypothesizing that active movement of cells away from a thymic product may be responsible, we demonstrated selective reduction in emigration from primary thymus by inhibitors of active movement down a concentration gradient (chemofugetaxis). Immature intrathymic precursors were insensitive to an emigration signal, whereas mature thymocytes and peripheral blood T cells were sensitive. Thymic stroma was noted to elaborate at least two proteins capable of inducing emigration, one of which was stromal cell–derived factor-1. Thymic emigration is mediated, at least in part, by specific fugetaxis-inducing factors to which only mature cells respond. PMID:11956248

The emigration of Germany's Jewish dermatologists in the period of National Socialism.

PubMed

Eppinger, S; Meurer, M; Scholz, A

2003-09-01

In the context of our investigation, we found information on 432 (76%) of the 569 Jewish dermatologists in Germany. There is evidence that 57 (10%) of the Jewish dermatologists were murdered in concentration camps, 61 (10.7%) died a natural death, 13 (2%) committed suicide, and 25 (4%) survived the Third Reich in Germany. After 1933, 276 (49%) Jewish dermatologists were able to leave Germany; the United States of America was the main destination and 107 (or 41%) emigrated there. A total of 34 (13%) Jewish dermatologists emigrated from Germany to Palestine and 16 to Latin America. Regarding emigration to other European countries, 20 of the Jewish dermatologists from Germany went to Great Britain (including Walter Freudenthal, 1893-1952, and Ernst Sklarz, 1894-1975), and 24 emigrated to other European countries, such as France (Rudolf Mayer, 1895-1962), Sweden (Carl Lennhoff, 1883-1963), and the Netherlands (Otto Schlein, 1895-1944).

Patterns of Spanish Emigration to the New World (1493-1580). Special Studies No. 34.

ERIC Educational Resources Information Center

Boyd-Bowman, Peter

The four periods discussed in this publication cover the patterns of Spanish emigration to the New World, mainly on the regional level and in terms of percentages. The effects of this emigration on the various Spanish American dialects are discussed. In the initial period (1493-1519), the largest single group, in every year and on all major…

Does the Attitude Toward Organ Donation Change as a Function of the Country Where People Emigrate? Study Between Uruguayan Emigrants to the United States and Spain.

PubMed

Ríos, A; López-Navas, A I; Sánchez, Á; Ayala, M A; Garrido, G; Sebastián, M J; Martinez-Alarcón, L; Ramis, G; Hernández, A M; Ramírez, P; Parrilla, P

2018-03-01

The Uruguayan population is sensitized toward transplantation. However, it has not been studied how this awareness can change when emigrating to different countries. To analyze the attitude toward cadaveric organ donation and living organ donation between the Uruguayan population residing in Florida (United States) and the Uruguayan population residing in Spain. Adults born in Uruguay and residing in Florida and Spain were screened. The questionnaire "PCID-DTO Ríos" (donation of cadaveric organs) and "PCID-DVR Ríos" (living renal donation) were used. Subjects were randomly selected according to age and gender stratification. Support from Latin-American immigration associations in Spain and Florida was needed. The survey was anonymized and self-administered. Verbal consent was obtained to collaborate in the study. Because the emigrant population to Spain is far larger than the emigrant population to the United States, a 2:1 proportional sampling was performed (n = 132). Sixty-seven percent of residents in Spain were in favor of organ donation at the time of death compared with 50% among residents in Florida (P = .082), and 100% of residents in Spain were in favor of living renal donation compared with 50% of those living in Florida (P < .001). The attitude toward donation is more favorable among Uruguayan emigrants to Spain than emigrants to the United States, especially in related kidney donation. Copyright © 2017 Elsevier Inc. All rights reserved.

Emigration-related attitudes of the final year medical students in Croatia: a cross-sectional study at the dawn of the EU accession

PubMed Central

Kolčić, Ivana; Čikeš, Mihaela; Boban, Kristina; Bućan, Jasna; Likić, Robert; Ćurić, Goran; Đogaš, Zoran; Polašek, Ozren

2014-01-01

Aim To investigate the emigration-related attitudes of final year medical students in Croatia at the dawn of the EU accession in 2013. Methods All final-year medical students at four Croatian medical schools (Zagreb, Rijeka, Split, and Osijek) were invited to participate in a cross-sectional survey on emigration attitudes. Results Among 260 respondents (response rate 61%), 90 students (35%) reported readiness for permanent emigration, expecting better quality of life (N = 22, 31%), better health care organization (N = 17, 24%), more professional challenges (N = 10, 14%), or simply to get a job (N = 8, 11%), while the least common expectation were greater earnings (N = 7, 10%). The most common target countries were Germany (N = 36, 40%), USA and Canada (N = 15, 17%), and UK (N = 10, 11%). In a multivariate analysis, readiness for permanent emigration was associated with an interest in undertaking a temporary training abroad (odds ratio [OR] 6.87; 95% confidence interval [CI] 2.83-16.72), while the belief that the preferred specialty could be obtained in Croatia appeared protective against emigration (OR 0.26; 95% CI 0.12-0.59). Conclusion Despite shortages of health care workers in Croatia, the percentage of students with emigration propensity was rather high. Prevalent negative perception of the Croatian health care and recent Croatian accession to the EU pose a threat of losing newly graduated physicians to EU countries. PMID:25358878

Reversed sex change by widowed males in polygynous and protogynous fishes: female removal experiments in the field.

PubMed

Kuwamura, Tetsuo; Suzuki, Shohei; Kadota, Tatsuru

2011-12-01

Sex change, either protogyny (female to male) or protandry (male to female), is well known among fishes, but evidence of bidirectional sex change or reversed sex change in natural populations is still very limited. This is the first report on female removal experiments for polygnous and protogynous fish species to induce reversed sex change in the widowed males in the field. We removed all of the females and juveniles from the territories of dominant males in the cleaner wrasse Labroides dimidiatus (Labridae) and the rusty angelfish Centropyge ferrugata (Pomacanthidae) on the coral reefs of Okinawa. In both species, if new females or juveniles did not immigrate into the territories of the widowed males, some of them emigrated to form male-male pairs. When a male-male pair formed, the smaller, subordinate partner began to perform female sexual behaviours (n = 4 in L. dimidiatus; n = 2 in C. ferrugata) and, finally, released eggs (n = 1, respectively). Thus, the reversed sex change occurred in the widowed males according to the change of their social status. These results suggest that such female removal experiments will contribute to the discovery of reversed sex change in the field also in other polygnous and protogynous species.

Reversed sex change by widowed males in polygynous and protogynous fishes: female removal experiments in the field

NASA Astrophysics Data System (ADS)

Kuwamura, Tetsuo; Suzuki, Shohei; Kadota, Tatsuru

2011-12-01

Sex change, either protogyny (female to male) or protandry (male to female), is well known among fishes, but evidence of bidirectional sex change or reversed sex change in natural populations is still very limited. This is the first report on female removal experiments for polygnous and protogynous fish species to induce reversed sex change in the widowed males in the field. We removed all of the females and juveniles from the territories of dominant males in the cleaner wrasse Labroides dimidiatus (Labridae) and the rusty angelfish Centropyge ferrugata (Pomacanthidae) on the coral reefs of Okinawa. In both species, if new females or juveniles did not immigrate into the territories of the widowed males, some of them emigrated to form male-male pairs. When a male-male pair formed, the smaller, subordinate partner began to perform female sexual behaviours ( n = 4 in L. dimidiatus; n = 2 in C. ferrugata) and, finally, released eggs ( n = 1, respectively). Thus, the reversed sex change occurred in the widowed males according to the change of their social status. These results suggest that such female removal experiments will contribute to the discovery of reversed sex change in the field also in other polygnous and protogynous species.

Scandinavian Emigration to Australia and New Zealand Project. Proceedings of a Symposium (Turku, Finland, February 17-19, 1982). Migration Studies C7.

ERIC Educational Resources Information Center

Koivukangas, Olavi, Ed.

These proceedings of a 1982 symposium on Scandinavian emigration in Australia include presentations on three general topics: field work conducted in Australia and New Zealand in 1980-82; research progress; and Australian immigration policy. The presentors and their papers are: (1) Hans Norman, "The Emigration to America from the Nordic…

Physician emigration from sub-Saharan Africa to the United States: analysis of the 2011 AMA physician masterfile.

PubMed

Tankwanchi, Akhenaten Benjamin Siankam; Ozden, Cağlar; Vermund, Sten H

2013-01-01

The large-scale emigration of physicians from sub-Saharan Africa (SSA) to high-income nations is a serious development concern. Our objective was to determine current emigration trends of SSA physicians found in the physician workforce of the United States. We analyzed physician data from the World Health Organization (WHO) Global Health Workforce Statistics along with graduation and residency data from the 2011 American Medical Association Physician Masterfile (AMA-PM) on physicians trained or born in SSA countries who currently practice in the US. We estimated emigration proportions, year of US entry, years of practice before emigration, and length of time in the US. According to the 2011 AMA-PM, 10,819 physicians were born or trained in 28 SSA countries. Sixty-eight percent (n = 7,370) were SSA-trained, 20% (n = 2,126) were US-trained, and 12% (n = 1,323) were trained outside both SSA and the US. We estimated active physicians (age ≤ 70 years) to represent 96% (n = 10,377) of the total. Migration trends among SSA-trained physicians increased from 2002 to 2011 for all but one principal source country; the exception was South Africa whose physician migration to the US decreased by 8% (-156). The increase in last-decade migration was >50% in Nigeria (+1,113) and Ghana (+243), >100% in Ethiopia (+274), and >200% (+244) in Sudan. Liberia was the most affected by migration to the US with 77% (n = 175) of its estimated physicians in the 2011 AMA-PM. On average, SSA-trained physicians have been in the US for 18 years. They practiced for 6.5 years before US entry, and nearly half emigrated during the implementation years (1984-1999) of the structural adjustment programs. Physician emigration from SSA to the US is increasing for most SSA source countries. Unless far-reaching policies are implemented by the US and SSA countries, the current emigration trends will persist, and the US will remain a leading destination for SSA physicians emigrating from the continent of greatest need. Please see later in the article for the Editors' Summary.

Physician Emigration from Sub-Saharan Africa to the United States: Analysis of the 2011 AMA Physician Masterfile

PubMed Central

Tankwanchi, Akhenaten Benjamin Siankam; Özden, Çağlar; Vermund, Sten H.

2013-01-01

Background The large-scale emigration of physicians from sub-Saharan Africa (SSA) to high-income nations is a serious development concern. Our objective was to determine current emigration trends of SSA physicians found in the physician workforce of the United States. Methods and Findings We analyzed physician data from the World Health Organization (WHO) Global Health Workforce Statistics along with graduation and residency data from the 2011 American Medical Association Physician Masterfile (AMA-PM) on physicians trained or born in SSA countries who currently practice in the US. We estimated emigration proportions, year of US entry, years of practice before emigration, and length of time in the US. According to the 2011 AMA-PM, 10,819 physicians were born or trained in 28 SSA countries. Sixty-eight percent (n = 7,370) were SSA-trained, 20% (n = 2,126) were US-trained, and 12% (n = 1,323) were trained outside both SSA and the US. We estimated active physicians (age ≤70 years) to represent 96% (n = 10,377) of the total. Migration trends among SSA-trained physicians increased from 2002 to 2011 for all but one principal source country; the exception was South Africa whose physician migration to the US decreased by 8% (−156). The increase in last-decade migration was >50% in Nigeria (+1,113) and Ghana (+243), >100% in Ethiopia (+274), and >200% (+244) in Sudan. Liberia was the most affected by migration to the US with 77% (n = 175) of its estimated physicians in the 2011 AMA-PM. On average, SSA-trained physicians have been in the US for 18 years. They practiced for 6.5 years before US entry, and nearly half emigrated during the implementation years (1984–1999) of the structural adjustment programs. Conclusion Physician emigration from SSA to the US is increasing for most SSA source countries. Unless far-reaching policies are implemented by the US and SSA countries, the current emigration trends will persist, and the US will remain a leading destination for SSA physicians emigrating from the continent of greatest need. Please see later in the article for the Editors' Summary PMID:24068894

Reducing bias in survival under non-random temporary emigration

USGS Publications Warehouse

Peñaloza, Claudia L.; Kendall, William L.; Langtimm, Catherine Ann

2014-01-01

Despite intensive monitoring, temporary emigration from the sampling area can induce bias severe enough for managers to discard life-history parameter estimates toward the terminus of the times series (terminal bias). Under random temporary emigration unbiased parameters can be estimated with CJS models. However, unmodeled Markovian temporary emigration causes bias in parameter estimates and an unobservable state is required to model this type of emigration. The robust design is most flexible when modeling temporary emigration, and partial solutions to mitigate bias have been identified, nonetheless there are conditions were terminal bias prevails. Long-lived species with high adult survival and highly variable non-random temporary emigration present terminal bias in survival estimates, despite being modeled with the robust design and suggested constraints. Because this bias is due to uncertainty about the fate of individuals that are undetected toward the end of the time series, solutions should involve using additional information on survival status or location of these individuals at that time. Using simulation, we evaluated the performance of models that jointly analyze robust design data and an additional source of ancillary data (predictive covariate on temporary emigration, telemetry, dead recovery, or auxiliary resightings) in reducing terminal bias in survival estimates. The auxiliary resighting and predictive covariate models reduced terminal bias the most. Additional telemetry data was effective at reducing terminal bias only when individuals were tracked for a minimum of two years. High adult survival of long-lived species made the joint model with recovery data ineffective at reducing terminal bias because of small-sample bias. The naïve constraint model (last and penultimate temporary emigration parameters made equal), was the least efficient, though still able to reduce terminal bias when compared to an unconstrained model. Joint analysis of several sources of data improved parameter estimates and reduced terminal bias. Efforts to incorporate or acquire such data should be considered by researchers and wildlife managers, especially in the years leading up to status assessments of species of interest. Simulation modeling is a very cost effective method to explore the potential impacts of using different sources of data to produce high quality demographic data to inform management.

Effect of tides, river flow, and gate operations on entrainment of juvenile salmon into the interior Sacramento–San Joaquin River Delta

USGS Publications Warehouse

Perry, Russell W.; Brandes, Patricia L.; Burau, Jon R.; Sandstrom, Philip T.; Skalski, John R.

2015-01-01

Juvenile Chinook Salmon Oncorhynchus tshawytscha emigrating from natal tributaries of the Sacramento River, California, must negotiate the Sacramento-San Joaquin River Delta (hereafter, the Delta), a complex network of natural and man-made channels linking the Sacramento River with San Francisco Bay. Fish that enter the interior and southern Delta—the region to the south of the Sacramento River where water pumping stations are located—survive at a lower rate than fish that use alternative migration routes. Consequently, total survival decreases as the fraction of the population entering the interior Delta increases, thus spurring management actions to reduce the proportion of fish that are entrained into the interior Delta. To better inform management actions, we modeled entrainment probability as a function of hydrodynamic variables. We fitted alternative entrainment models to telemetry data that identified when tagged fish in the Sacramento River entered two river channels leading to the interior Delta (Georgiana Slough and the gated Delta Cross Channel). We found that the probability of entrainment into the interior Delta through both channels depended strongly on the river flow and tidal stage at the time of fish arrival at the river junction. Fish that arrived during ebb tides had a low entrainment probability, whereas fish that arrived during flood tides (i.e., when the river's flow was reversed) had a high probability of entering the interior Delta. We coupled our entrainment model with a flow simulation model to evaluate the effect of nighttime closures of the Delta Cross Channel gates on the daily probability of fish entrainment into the interior Delta. Relative to 24-h gate closures, nighttime closures increased daily entrainment probability by 3 percentage points on average if fish arrived at the river junction uniformly throughout the day and by only 1.3 percentage points if 85% of fish arrived at night. We illustrate how our model can be used to evaluate the effects of alternative water management actions on fish entrainment into the interior Delta.

Reconsidering residency: Characterization and conservation implications of complex migratory patterns of shortnose sturgeon (Acispenser brevirostrum)

USGS Publications Warehouse

Dionne, Phillip E.; Zydlewski, Gayle B.; Kinnison, Michael T.; Zydlewski, Joseph D.; Wippelhauser, Gail S.

2013-01-01

Efforts to conserve endangered species usually involve attempts to define and manage threats at the appropriate scale of population processes. In some species that scale is localized; in others, dispersal and migration link demic units within larger metapopulations. Current conservation strategies for endangered shortnose sturgeon (Acipenser brevirostrum) assume the species is river resident, with little to no movement between rivers. However we have found that shortnose sturgeon travel more than 130 km through coastal waters between the largest rivers in Maine. Indeed, acoustic telemetry shows that shortnose sturgeon enter six out of the seven acoustically monitored rivers we have monitored, with over 70% of tagged individuals undertaking coastal migrations between river systems. Four migration patterns were identified for shortnose sturgeon inhabiting the Penobscot River, Maine: river resident (28%), spring coastal emigrant (24%), fall coastal emigrant (33%), and summer coastal emigrant (15%). No shortnose sturgeon classified as maturing female exhibited a resident pattern, indicating differential migration. Traditional river-specific assessment and management of shortnose sturgeon could be better characterized using a broader metapopulation scale, at least in the Gulf of Maine, that accounts for diverse migratory strategies and the importance of migratory corridors as critical habitat.

Characterization of Structural and Pigmentary Colors in Common Emigrant (Catopsilia Pomona) Butterfly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghate, Ekata; Kulkarni, G. R.; Bhoraskar, S. V.

2011-10-20

Study of structural colors in case of insects and butterflies is important for their biomimic and biophotonics applications. Structural color is the color which is produced by physical structures and their interaction with light while pigmentary color is produced by absorption of light by pigments. Common Emigrant butterfly is widely distributed in India. It is of moderate size with wing span of about 60-80 mm. The wings are broadly white with yellow or sulphur yellow coloration at places as well as few dark black patches. It belongs to family Pieridae. A study of structural color in case of Common Emigrantmore » butterfly has been carried out in the present work. The characterization of wing color was performed using absorption spectroscopy. Scanning electron microscopic study of the wings of Common Emigrant butterfly showed that three different types of scales are present on the wing surface dorsally. Diffracting structures are present in certain parts of the surfaces of the various scales. Bead like structures are embedded in the intricate structures of the scales. Absorption spectra revealed that a strong absorption peak is seen in the UV-range. Crystalline structure of beads was confirmed by the X-ray diffraction analysis.« less

The ability of individuals to assess population density influences the evolution of emigration propensity and dispersal distance.

PubMed

Poethke, Hans Joachim; Gros, Andreas; Hovestadt, Thomas

2011-08-07

We analyze the simultaneous evolution of emigration and settlement decisions for actively dispersing species differing in their ability to assess population density. Using an individual-based model we simulate dispersal as a multi-step (patch to patch) movement in a world consisting of habitat patches surrounded by a hostile matrix. Each such step is associated with the same mortality risk. Our simulations show that individuals following an informed strategy, where emigration (and settlement) probability depends on local population density, evolve a lower (natal) emigration propensity but disperse over significantly larger distances - i.e. postpone settlement longer - than individuals performing density-independent emigration. This holds especially when variation in environmental conditions is spatially correlated. Both effects can be traced to the informed individuals' ability to better exploit existing heterogeneity in reproductive chances. Yet, already moderate distance-dependent dispersal costs prevent the evolution of multi-step (long-distance) dispersal, irrespective of the dispersal strategy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Global Personality Norms: Multicultural, Multinational, and Managerial

ERIC Educational Resources Information Center

Oswald, Frederick L.

2008-01-01

The critical importance of understanding, selecting, and developing global management talent--management operating within internationally diverse interpersonal and situational contexts--has emerged from the increasing globalization of business and the concomitant high rates of immigration, emigration, and expatriation. With an awareness of this…

Waterfowl mortality factors

USGS Publications Warehouse

Nichols, J.D.; Beattie, Kirk H.

1989-01-01

The objectives of waterfowl management in North America involve population size and harvest. Any management action intended to influence population size must do so through one of four demographic variables: reproduction, mortality, immigration, and emigration. Mortality is especially important because hunting can be strongly influenced by management.

Food and History: Teaching Social History Through the Study of Cuisine Patterns

ERIC Educational Resources Information Center

Gordon, Bertram M.

1974-01-01

Some interesting relationships between food and history -- working women and convenience food, exploration and the importation of new vegetables, reliance on potatoes and Irish emigration -- are suggested to indicate the usefulness of exploring history through eating habits. (JH)

Thymic emigration revisited

PubMed Central

McCaughtry, Tom M.; Wilken, Matthew S.; Hogquist, Kristin A.

2007-01-01

Conventional αβ T cell precursors undergo positive selection in the thymic cortex. When this is successful, they migrate to the medulla and are exposed to tissue-specific antigens (TSA) for purposes of central tolerance, and they undergo maturation to become functionally responsive T cells. It is commonly understood that thymocytes spend up to 2 wk in the medulla undergoing these final maturation steps before emigrating to peripheral lymphoid tissues. In addition, emigration is thought to occur via a stochastic mechanism whereby some progenitors leave early and others leave late—a so-called “lucky dip” process. However, recent research has revealed that medullary thymocytes are a heterogeneous mix of naive αβ T cell precursors, memory T cells, natural killer T cells, and regulatory T cells. Given this, we revisited the question of how long it takes naive αβ T cell precursors to emigrate. We combined the following three approaches to study this question: BrdU labeling, intrathymic injection of a cellular tag, and RAG2p-GFP reporter mice. We established that, on average, naive αβ T cell precursors emigrate only 4–5 d after becoming single-positive (SP) thymocytes. Furthermore, emigration occurs via a strict “conveyor belt” mechanism, where the oldest thymocytes leave first. PMID:17908937

Migratory behavior of Chinook salmon microjacks reared in artificial and natural environments

USGS Publications Warehouse

Hayes, Michael C.; Rubin, Steve P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.

2015-01-01

Emigration was evaluated for hatchery Chinook salmon (Oncorhynchus tshawytscha) microjacks (age-1 mature males) and immature parr (age-1 juveniles, both sexes) released from both a hatchery and a natural stream (fish released as fry). In the hatchery, volitional releases (∼14 to 15 months post-fertilization) to an adjacent river occurred during October–November. The hatchery release was monitored by using an experimental volitional release that diverted fish to a neighboring raceway. Fish captured during the experimental release (range 361–4,321 volitional migrants) were made up of microjacks and immature parr. Microjacks were found only in the migrant samples, averaged 18% (range 0–52%) of all migrants, and were rarely found in non-migrant samples. In comparison, immature parr were common in both the migrant and non-migrant samples. Microjacks were significantly longer (9%), heavier (36%), and had a greater condition factor (16%) than migrant immature parr (P<0.01). In addition, they differed significantly (P<0.01) from non-migrant immature parr; 10% longer, 44% heavier and 14% greater condition factor. In natural streams, microjacks were captured significantly earlier (P<0.01) than immature parr during the late-summer/fall migration and comprised 9–89% of all fish captured. Microjacks have the potential to contribute to natural spawning populations but can also represent a loss of productivity to hatchery programs or create negative effects by introducing non-native genes to wild populations and should be monitored by fishery managers.

Biological consequences of the coaster brook trout restoration stocking program in Lake Superior tributaries with Pictured Rocks National Lakeshore

USGS Publications Warehouse

Leonard, Jill B.K.; Stott, Wendylee; Loope, Delora M.; Kusnierz, Paul C.; Sreenivasan, Ashwin

2013-01-01

The coaster Brook Trout Salvelinus fontinalis is a Lake Superior ecotype representing intraspecific variation that has been impacted by habitat loss and overfishing. Hatchery strains of Brook Trout derived from populations in Lake Superior were stocked into streams within Pictured Rocks National Lakeshore, Michigan, as part of an effort to rehabilitate adfluvial coaster Brook Trout. Wild and hatchery Brook Trout from three streams (Mosquito River, Hurricane River, and Sevenmile Creek) were examined for movement behavior, size, physiology, and reproductive success. Behavior and size of the stocked fish were similar to those of wild fish, and less than 15% of the stocked, tagged Brook Trout emigrated from the river into which they were stocked. There was little evidence of successful reproduction by stocked Brook Trout. Similar to the results of other studies, our findings suggest that the stocking of nonlocal Brook Trout strains where a local population already exists results in limited natural reproduction and should be avoided, particularly if the mechanisms governing the ecotype of interest are poorly understood.

Salmon-mediated nutrient flux in selected streams of the Columbia River basin, USA

USGS Publications Warehouse

Kohler, Andre E.; Kusnierz, Paul C.; Copeland, Timothy; Venditti, David A.; Denny, Lytle; Gable, Josh; Lewis, Bert; Kinzer, Ryan; Barnett, Bruce; Wipfli, Mark S.

2013-01-01

Salmon provide an important resource subsidy and linkage between marine and land-based ecosystems. This flow of energy and nutrients is not uni-directional (i.e., upstream only); in addition to passive nutrient export via stream flow, juvenile emigrants actively export nutrients from freshwater environments. In some cases, nutrient export can exceed import. We evaluated nutrient fluxes in streams across central Idaho, USA using Chinook salmon (Oncorhynchus tshawytscha) adult escapement and juvenile production data from 1998 to 2008. We found in the majority of stream-years evaluated, adults imported more nutrients than progeny exported; however, in 3% of the years, juveniles exported more nutrients than their parents imported. On average, juvenile emigrants exported 22 ± 3% of the nitrogen and 30 ± 4% of the phosphorus their parents imported. This relationship was density dependent and nonlinear; during periods of low adult abundance juveniles were larger and exported up to 194% and 268% of parental nitrogen and phosphorus inputs, respectively. We highlight minimum escapement thresholds that appear to 1) maintain consistently positive net nutrient flux and 2) reduce the average proportional rate of export across study streams. Our results suggest a state-shift occurs when adult spawner abundance falls below a threshold to a point where the probability of juvenile nutrient exports exceeding adult imports becomes increasingly likely.

Emigration dynamics in South Asia, IOM / UNFPA workshop, 2-3 September 1996, IOM headquarters, Geneva, Switzerland.

PubMed

Appleyard, R

1996-01-01

This paper describes the six research monographs that were presented at the Emigration Dynamic Workshops in South Asia in September 1996. Research reports were presented by Associate Professor Nasra Shah on an overview of emigration dynamics, Dr. Godfrey Gunatilleke on the role of networks and community structures in migration from Sri Lanka, Dr. Raisul Awal Mahmood on illegal migration from Bangladesh to Singapore, Kuala Lumpur, Bangkok, and Delhi due to desperate poverty, Dr. Farooq-i-Azam on high and low labor-sending migration districts in Pakistan, Dr. Mahendra K. Premi on the impact of internal Indian migration on international migration, and Dr. P.R. Gopinathan Nair on emigration from Kerala, India, to the Middle East. Representatives of South Asian governments discussed the implications of the research findings. Pakistan's representative urged cooperation and joint strategies among labor-sending countries. He cautioned that income and remittance estimates were unstable and unrealistic for inclusion in economic development plans. The Indian representative noted that, although Indian emigration is low, it is highly visible in the press. He agreed with the suggestion for greater cooperation between sending countries. The Bangladesh representative stated that the country needed to locate new markets for Bangladeshi emigrants, to guarantee the rights of emigrant workers, and to prevent trafficking in illegal migrant workers. Three major topics were discussed in the workshop session on the implementation of programs based on research findings. Workshop participants recommended updated information on migration trends, updated information on labor markets in receiving countries, formal and regular policy dialogue between sending countries, and promotion of continuing research by the International Organization on Migration.

Coevolution of patch-type dependent emigration and patch-type dependent immigration.

PubMed

Weigang, Helene C

2017-08-07

The three phases of dispersal - emigration, transfer and immigration - are affecting each other and the former and latter decisions may depend on patch types. Despite the inevitable fact of the complexity of the dispersal process, patch-type dependencies of dispersal decisions modelled as emigration and immigration are usually missing in theoretical dispersal models. Here, I investigate the coevolution of patch-type dependent emigration and patch-type dependent immigration in an extended Hamilton-May model. The dispersing population inhabits a landscape structured into many patches of two types and disperses during a continuous-time season. The trait under consideration is a four dimensional vector consisting of two values for emigration probability from the patches and two values for immigration probability into the patches of each type. Using the adaptive dynamics approach I show that four qualitatively different dispersal strategies may evolve in different parameter regions, including a counterintuitive strategy, where patches of one type are fully dispersed from (emigration probability is one) but individuals nevertheless always immigrate into them during the dispersal season (immigration probability is one). I present examples of evolutionary branching in a wide parameter range, when the patches with high local death rate during the dispersal season guarantee a high expected disperser output. I find that two dispersal strategies can coexist after evolutionary branching: a strategy with full immigration only into the patches with high expected disperser output coexists with a strategy that immigrates into any patch. Stochastic simulations agree with the numerical predictions. Since evolutionary branching is also found when immigration evolves alone, the present study is adding coevolutionary constraints on the emigration traits and hence finds that the coevolution of a higher dimensional trait sometimes hinders evolutionary diversification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Changes over 50 years in fish fauna of a temperate coastal sea: Degradation of trophic structure and nursery function

NASA Astrophysics Data System (ADS)

van der Veer, Henk W.; Dapper, Rob; Henderson, Peter A.; Jung, A. Sarina; Philippart, Catharina J. M.; Witte, Johannes IJ.; Zuur, Alain F.

2015-03-01

The ongoing daily sampling programme of the fish fauna in the Dutch Wadden Sea using fixed gear was analysed for the years 1960-2011. Spring sampling caught immigrating fish from the coastal zone and autumn samples reflected emigration of young-of-the-year. In total 82 fish species were caught with no clear trend in biodiversity. In both spring and autumn total daily catch fluctuated and peaked in the late 1970s. From 1980 to the present catches of both pelagic and demersal species showed a 10-fold decrease in total biomass. Mean individual biomass decreased in spring between 1980 and the present from about 150 to 20 g wet weight. No trend was found in autumn mean individual biomass which fluctuated around 20 g wet weight. The trophic structure remained constant for both the demersal and benthopelagic fish fauna from 1980 to 2011, whilst the trophic position of pelagic fish in spring fell from about 3.9 to 3.1. Min/max auto-correlation factor analysis showed similar trends in spring and autumn species biomass time series: the first axis represented a decrease from the 1960s followed by stabilization from the mid-1990s. The second trend showed an increase with a maximum around 1980 followed by a steady decrease in spring and a decrease and stabilization from 2000 in autumn. It is argued that the most likely explanatory variables are a combination of external factors: increased water temperature, habitat destruction in the coastal zone (sand dredging and beach nourishment, fishing) and increased predation by top predators for the first trend, and large-scale hydrodynamic circulation for the second trend. We conclude that both the trophic structure of the coastal zone fauna and the nursery function of the Wadden Sea have been reduced since the 1980s. Our findings corroborate that ecological change in coastal ecosystems has not only occurred in the past but still continues.

The macrodynamics of international migration as a sociocultural diffusion process. Part A: theory.

PubMed

Diamantides, N D

1992-11-01

"This study formulates a model of the macrodynamics of international migration using a differential equation to capture the push-pull forces that propel it. The model's architecture rests on the functioning of information feedback between settled friends and family at the destination and potential emigrants at the origin." The author tests the model using data on Greek emigration to the United States since 1820 and on total emigration from Cyprus since 1946. excerpt

[Why would doctors from Debrecen go abroad? Results of a questionnaire].

PubMed

Szekanecz, Zoltán; Tóth, Zoltán; Hamar, Attila; Lánczi, Levente

2017-09-01

Numerous beliefs have arisen in relation to the emigration of doctors. First of all, in most cases emigration has been attributed to, almost exclusively, low salaries. There are a number of non-financial issues that could possibly be more easily addressed. In order to get closer to these issues, we sent out a 37-item questionnaire to doctors, who originally graduated from the University of Debrecen. Altogether 82 of them sent back the questionnaire. The mean age at the time of emigration was 32 years. The most popular destination was the United States, however, many colleagues left for the US to do research, as well as clinical practice. Among the European countries, the most popular ones were Sweden, Germany, United Kingdom, Switzerland and Norway. The five most popular clinical specialties were general practice, internal medicine, anesthesiology/intensive care, laboratory/pathology and surgery. With respect to the planned duration of working abroad, at the time of emigration one-fourth of our colleagues planned very short (<2 years) stay. When we asked them now, 38% plans much longer, even indefinite stay. The most common reasons of emigration were also assessed. The most common one was the lack of career track, followed by low salary, quality of life, family issues and adventurousness. Interestingly, burnout and "gratuities" were at the end of the list. A mean 1.3 million HUF per month would make our colleagues satisfied but they think that a mean 486.000 HUF would be realistic and would keep most doctors within the country. As far as university education is concerned, our colleagues agreed that the basic medical knowledge of Hungarian doctors is excellent, but their practical skills are much worse. Although returning to Hungary would be unrealistic by most colleagues, low salaries are definitely not the most important or exclusive reason for leaving the country. These issues are rather complex, there are numerous non-financial issues, which could be addressed much easier by expressing a positive attitude. Orv Hetil. 2017; 158(37): 1458-1468.

Partitioning Detectability Components in Populations Subject to Within-Season Temporary Emigration Using Binomial Mixture Models

PubMed Central

O’Donnell, Katherine M.; Thompson, Frank R.; Semlitsch, Raymond D.

2015-01-01

Detectability of individual animals is highly variable and nearly always < 1; imperfect detection must be accounted for to reliably estimate population sizes and trends. Hierarchical models can simultaneously estimate abundance and effective detection probability, but there are several different mechanisms that cause variation in detectability. Neglecting temporary emigration can lead to biased population estimates because availability and conditional detection probability are confounded. In this study, we extend previous hierarchical binomial mixture models to account for multiple sources of variation in detectability. The state process of the hierarchical model describes ecological mechanisms that generate spatial and temporal patterns in abundance, while the observation model accounts for the imperfect nature of counting individuals due to temporary emigration and false absences. We illustrate our model’s potential advantages, including the allowance of temporary emigration between sampling periods, with a case study of southern red-backed salamanders Plethodon serratus. We fit our model and a standard binomial mixture model to counts of terrestrial salamanders surveyed at 40 sites during 3–5 surveys each spring and fall 2010–2012. Our models generated similar parameter estimates to standard binomial mixture models. Aspect was the best predictor of salamander abundance in our case study; abundance increased as aspect became more northeasterly. Increased time-since-rainfall strongly decreased salamander surface activity (i.e. availability for sampling), while higher amounts of woody cover objects and rocks increased conditional detection probability (i.e. probability of capture, given an animal is exposed to sampling). By explicitly accounting for both components of detectability, we increased congruence between our statistical modeling and our ecological understanding of the system. We stress the importance of choosing survey locations and protocols that maximize species availability and conditional detection probability to increase population parameter estimate reliability. PMID:25775182

Social effects of labour migration: the Colombia experience.

PubMed

Cely Martinez, J N

1989-06-01

Colombia has traditionally been classified as a net exporter of manpower. However, the US's restrictions on immigration and the economic crisis in Venezuela, Colombia's sister republic, have affected both the volume and composition of emigration. It could be initially concluded that despite domestic difficulties and external problems, favorable economic prospects explain the present reduced outflow of immigrants. On the basis of a sample survey of applications taken during the last 2 years, 94% of arrivals were classified as professionals and technicians; the remainder were administrative workers. This achievement (which contrasts with high levels of unemployment among Colombian professionals) reflects new technological innovations. It appears that while Colombia exports engineers, it imports engineering. Opinion surveys conducted among employers, migrants, and educational authorities show that costs are not fully compensated by the migrant's improved standard of living in the country of destination, even if he has sent remittances to his country of origin. Investments in education and training yield no returns to the country if the recipient emigrates. The advantages of emigration, identified in the same surveys, include 1) reduction in internal pressure on the labor market, 2) improvement in the incomes of those who do not emigrate, and 3) resolution of economic problems for migrants. The Social Economics Plan implemented by the current government indirectly affects migratory processes by focusing on: 1) eradication of poverty; 2) the National Rehabilitation Plan, by which regional growth is stimulated in poor and economically precarious districts; and 3) the Integral Rural Development Plan which aims to eradicate poverty and improve production and commercialization in small-holding areas. The author concludes that the effects of migration on social structures must be examined in depth.

Terrestrial habitat selection and strong density-dependent mortality in recently metamorphosed amphibians.

PubMed

Patrick, David A; Harper, Elizabeth B; Hunter, Malcolm L; Calhoun, Aram J K

2008-09-01

To predict the effects of terrestrial habitat change on amphibian populations, we need to know how amphibians respond to habitat heterogeneity, and whether habitat choice remains consistent throughout the life-history cycle. We conducted four experiments to evaluate how the spatial distribution of juvenile wood frogs, Rana sylvatica (including both overall abundance and localized density), was influenced by habitat choice and habitat structure, and how this relationship changed with spatial scale and behavioral phase. The four experiments included (1) habitat manipulation on replicated 10-ha landscapes surrounding breeding pools; (2) short-term experiments with individual frogs emigrating through a manipulated landscape of 1 m wide hexagonal patches; and habitat manipulations in (3) small (4-m2); and (4) large (100-m2) enclosures with multiple individuals to compare behavior both during and following emigration. The spatial distribution of juvenile wood frogs following emigration resulted from differences in the scale at which juvenile amphibians responded to habitat heterogeneity during active vs. settled behavioral phases. During emigration, juvenile wood frogs responded to coarse-scale variation in habitat (selection between 2.2-ha forest treatments) but not to fine-scale variation. After settling, however, animals showed habitat selection at much smaller scales (2-4 m2). This resulted in high densities of animals in small patches of suitable habitat where they experienced rapid mortality. No evidence of density-dependent habitat selection was seen, with juveniles typically choosing to remain at extremely high densities in high-quality habitat, rather than occupying low-quality habitat. These experiments demonstrate how prediction of the terrestrial distribution of juvenile amphibians requires understanding of the complex behavioral responses to habitat heterogeneity. Understanding these patterns is important, given that human alterations to amphibian habitats may generate extremely high densities of animals, resulting in high density-dependent mortality.

Passive acoustic telemetry reveals highly variable home range and movement patterns among unicornfish within a marine reserve

NASA Astrophysics Data System (ADS)

Marshell, A.; Mills, J. S.; Rhodes, K. L.; McIlwain, J.

2011-09-01

Marine reserves are the primary management tool for Guam's reef fish fishery. While a build-up of fish biomass has occurred inside reserve boundaries, it is unknown whether reserve size matches the scale of movement of target species. Using passive acoustic telemetry, we quantified movement patterns and home range size of two heavily exploited unicornfish Naso unicornis and Naso lituratus. Fifteen fish ( N. unicornis: n = 7; N. lituratus: n = 4 male, n = 4 female) were fitted with internal acoustic tags and tracked continuously over four months within a remote acoustic receiver array located in a decade-old marine reserve. This approach provided robust estimates of unicornfish movement patterns and home range size. The mean home range of 3.2 ha for N. unicornis was almost ten times larger than that previously recorded from a three-week tracking study of the species in Hawaii. While N. lituratus were smaller in body size, their mean home range (6.8 ha) was over twice that of N. unicornis. Both species displayed strong site fidelity, particularly during nocturnal and crepuscular periods. Although there was some overlap, individual movement patterns and home range size were highly variable within species and between sexes. N. unicornis home range increased with body size, and only the three largest fish home ranges extended into the deeper outer reef slope beyond the shallow reef flat. Both Naso species favoured habitat dominated by corals. Some individuals made predictable daily crepuscular migrations between different locations or habitat types. There was no evidence of significant spillover from the marine reserve into adjacent fished areas. Strong site fidelity coupled with negligible spillover suggests that small-scale reserves, with natural habitat boundaries to emigration, are effective in protecting localized unicornfish populations.

Health professionals moving to... and from Portugal.

PubMed

Ribeiro, Joana Sousa; Conceição, Claudia; Pereira, Joel; Leone, Cláudia; Mendonça, Pedro; Temido, Marta; Vieira, Carlota Pacheco; Dussault, Gilles

2014-02-01

The mobility of health professionals in the European Union is a phenomenon which policy-makers must take into account to provide the conditions to adjust for demand and supply of health services. This paper presents the case of Portugal, a country which at the same time imports and exports health workers. Since the early 1990s Portugal became a destination country receiving foreign health care professionals. This situation is now changing with the current economic situation as fewer immigrants come and more Portuguese emigrate. Foreigners coming to Portugal do so in part for similar reasons that bring Portuguese to want to emigrate, mainly the search for better work conditions and professional development opportunities. The emigration of Portuguese health professionals is also stimulated by the difficulty for recently graduated nurses, dentists and diagnostic and therapeutic technicians to find employment, low salaries in the public and private sectors, heavy workloads, remuneration not related to performance and poor career prospects. The paradoxes described in this study illustrate the consequences of the absence of a policy for the health professions. Strategies based on evidence, and on an integrated information system that captures the dynamic evolution of the workforce in health are not only necessary but also a good investment. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Determinants of emigration and their impact on survival during dispersal in fox and jackal populations

PubMed Central

Kapota, Dror; Dolev, Amit; Bino, Gilad; Yosha, Dotan; Guter, Amichai; King, Roni; Saltz, David

2016-01-01

Animals disperse in response to poor resource conditions as a strategy of escaping harsh competition and stress, but may also disperse under good resource conditions, as these provide better chances of surviving dispersal and gaining fitness benefits such as avoiding kin competition and inbreeding. Individual traits should mediate the effect of resources, yielding a complex condition-dependent dispersal response. We investigated how experimental food reductions in a food-rich environment around poultry-growing villages interact with individual-traits (age, gender, body-mass) in two sympatric canids, red foxes and golden jackals, to jointly affect emigration propensity and survival during dispersal. Sub-adult foxes emigrated more frequently from the food-rich habitat than from the pristine, food-limited habitat, while adult foxes showed the opposite trend. During dispersal, adults exhibited lower survival while sub-adults did not experience additional mortality costs. Although fox mortality rates increased in response to food reduction, dispersal remained unchanged, while jackals showed strong dispersal response in two of the three repetitions. Jackal survival under food reduction was lowest for the dispersing individuals. While resources are an important dispersal determinant, different age classes and species experience the same resource environment differently and consequently have different motivations, yielding different dispersal responses and consequences. PMID:27050564

The Banyan tree: overseas migrants from South Asia.

PubMed

Tinker, H

1979-10-01

The number of Indian emigrants throughout the years has made little or no population difference to the country. With the population of India, Pakistan, and Bangladesh totalling about 700 million in the mid 1970s, emigration is almost irrelevant. In 3 small nations, Mauritius, Fiji, and Guyana, Indians form the majority of the population. Present demographic trends point to the same majority in Trinidad. Indians also are an important group in Malaya, Singapore, and Ceylon, where they are more than 10% of the overall population. In other countries Indians form a small, minority population without political power. Almost all the overseas communities preserved the essential of the Hindu, Muslim, or Sikh religions which they took with them. In the Caribbean the Indian, or East Indian, has discarded his mother tongue after 3 or more generations in isolation. In South Africa only very old emigrants still speak their native tongue. Indian communities abroad often separate into Hindu and Muslim communities. British society uses the term "multi-racial" to describe the pluralistic cultures in its colonies, but British culture is not multiracial. The term has meaning only when applied to an urban area such as Singapore. In Singapore a multilingual policy is applied in order to make the multiracial ideal a reality.

Effect of brook trout removal from a spawning stream on an adfluvial population of Lahontan cutthroat trout

USGS Publications Warehouse

Scoppettone, G. Gary; Rissler, Peter H.; Shea, Sean P.; Somer, William

2012-01-01

Independence Lake (Nevada and Sierra counties, California) harbors the only extant native population of Lahontan cutthroat trout Oncorhynchus clarkii henshawi in the Truckee River system and one of two extant adfluvial populations in the Lahontan basin. The persistence of this population has been precarious for more than 50 years, with spawning runs consisting of only 30–150 fish. It is assumed that this population was much larger prior to the introduction of nonnative brook trout Salvelinus fontinalis. Brook trout overlap with cutthroat trout in upper Independence Creek, where the cutthroat trout spawn and their resulting progeny emigrate to Independence Lake. In 2005, we began removing brook trout from upper Independence Creek using electrofishers and monitored the cutthroat trout population. Stomach analysis of captured brook trout revealed cutthroat trout fry, and cutthroat trout fry survival increased significantly from 4% to 12% with brook trout removal. Prior to brook trout removal, the only Lahontan cutthroat trout progeny emigrating to Independence Lake were fry; with brook trout removal, juveniles were found entering the lake. In 2010, 237 potential spawners passed a prefabricated weir upstream of Independence Lake. Although the results of this study suggest that brook trout removal from upper Independence Creek has had a positive influence on the population dynamics of Independence Lake Lahontan cutthroat trout, additional years of removal are needed to assess the ultimate effect this action will have upon the cutthroat trout population.

[The effects of manpower emigration on income distribution and consumption models in the Egyptian economy].

PubMed

Abdel Fadil, M

1985-01-01

This work analyzes the effects of emigration from Egypt on the distribution of income and the consumption model of the Egyptian economy. The increasing role of remittances as a principal source of household income has disturbed the old division of income among socioeconomic groups. It is difficult to estimate the volume of remittances with any precision because of the variety of ways in which they can be made. Official statistics tend to underestimate their value by ignoring black market transactions, remittances of merchandise, and other forms. An estimate was made of the value of remittances in 1980 taking account of wage levels of 5 different types of workers in the principal employing countries, their average propensities to save, and the employment structure of migrants by socioprofessional groups. The average educational level of emigrants appears to have declined somewhat between 1972-78. Average monthly income for emigrants was estimated to range from 792 Egyptian pounds for technical and professional workers to 252 for unskilled workers and the propensity to save was estimated to range from 40% for technical and scientific workers to 15% for unskilled workers. The total income remitted in 1980 in millions of Egyptian pounds was estimated at 912 for 240,000 technical and scienfific workers, 739 for 360,000 intermediate level workers, 415 for 300,000 artisans and workers, 60 for 60,000 chauffeurs, and 109 for 240,000 unskilled workers. Although remittances have elevated the per capita income of the low income groups, their impact has been diminished by severe inflationary pressures which have led to a decline in living levels and a less complete satisfaction of basic needs. Salary levels of construction workers were 7-9 times higher in Egyptian pounds in 1977 in 3 countries of immigration than in Egypt, while they were 7-10 times higher in 4 countries for university professors. Remittances are used by families receiving them for subsistence or investment; lower income groups are more likely to use a large proportion for support and to buy locally produced goods, while higher income groups tend to save more and to purchase a larger proportion of imported goods. 1 of the significant effects of remittances is to orient individual consumption toward luxury consumer goods, which in turn entails a progressive substitution of imported for local goods and a growing disparity between the consumption of those who succeed in migrating and those who don't. Remittances sent by low income emigrants for family support are the only mechanism with a stimulating effect on the demand for local goods of mediocre quality; all the other mechanisms stimulate the demand for high quality imported goods and services which have a negligible stimulating effect for the poorest segments of the population, rural or urban.

Factors Influencing Curricular Reform; An Irish Perspective

ERIC Educational Resources Information Center

Ferris, Helena; Joyce, Pauline

2015-01-01

There are various influences and obstacles when planning an educational curriculum. The imprint of globalisation on the landscape of Irish medicine highlights the importance of delivering a diverse curriculum with international dimensions so that knowledge and skills can transfer across borders. It is also clear that medical emigration has a…

Density-Dependent Growth in Invasive Lionfish (Pterois volitans)

PubMed Central

Benkwitt, Cassandra E.

2013-01-01

Direct demographic density dependence is necessary for population regulation and is a central concept in ecology, yet has not been studied in many invasive species, including any invasive marine fish. The red lionfish (Pterois volitans) is an invasive predatory marine fish that is undergoing exponential population growth throughout the tropical western Atlantic. Invasive lionfish threaten coral-reef ecosystems, but there is currently no evidence of any natural population control. Therefore, a manipulative field experiment was conducted to test for density dependence in lionfish. Juvenile lionfish densities were adjusted on small reefs and several demographic rates (growth, recruitment, immigration, and loss) were measured throughout an 8-week period. Invasive lionfish exhibited direct density dependence in individual growth rates, as lionfish grew slower at higher densities throughout the study. Individual growth in length declined linearly with increasing lionfish density, while growth in mass declined exponentially with increasing density. There was no evidence, however, for density dependence in recruitment, immigration, or loss (mortality plus emigration) of invasive lionfish. The observed density-dependent growth rates may have implications for which native species are susceptible to lionfish predation, as the size and type of prey that lionfish consume is directly related to their body size. The absence of density-dependent loss, however, contrasts with many native coral-reef fish species and suggests that for the foreseeable future manual removals may be the only effective local control of this invasion. PMID:23825604

Density-dependent growth in invasive Lionfish (Pterois volitans).

PubMed

Benkwitt, Cassandra E

2013-01-01

Direct demographic density dependence is necessary for population regulation and is a central concept in ecology, yet has not been studied in many invasive species, including any invasive marine fish. The red lionfish (Pterois volitans) is an invasive predatory marine fish that is undergoing exponential population growth throughout the tropical western Atlantic. Invasive lionfish threaten coral-reef ecosystems, but there is currently no evidence of any natural population control. Therefore, a manipulative field experiment was conducted to test for density dependence in lionfish. Juvenile lionfish densities were adjusted on small reefs and several demographic rates (growth, recruitment, immigration, and loss) were measured throughout an 8-week period. Invasive lionfish exhibited direct density dependence in individual growth rates, as lionfish grew slower at higher densities throughout the study. Individual growth in length declined linearly with increasing lionfish density, while growth in mass declined exponentially with increasing density. There was no evidence, however, for density dependence in recruitment, immigration, or loss (mortality plus emigration) of invasive lionfish. The observed density-dependent growth rates may have implications for which native species are susceptible to lionfish predation, as the size and type of prey that lionfish consume is directly related to their body size. The absence of density-dependent loss, however, contrasts with many native coral-reef fish species and suggests that for the foreseeable future manual removals may be the only effective local control of this invasion.

Emigration dynamics from and within South Asia.

PubMed

Shah, N M

1995-01-01

This review of current knowledge about emigration dynamics from and within South Asia (Bangladesh, India, Pakistan, and Sri Lanka) opens with a brief history of the three phases of emigration from the area since the 1830s (plantation labor; postindependence to the UK, US, Canada, and Australia; and labor migration to the oil-exporting countries). The influence of the creation of Pakistan and Bangladesh is also covered as are British colonial and commonwealth policies. It is noted that migration data are incomplete and that India exhibits an ambivalence about collecting such information. The discussion then turns to emigration since 1970 and considers permanent migration from South Asia to the traditional receivers; South Asian asylum seekers in Europe; South Asian refugees, illegal migrants, migrant workers (flows and destinations), the stock of contract migrant workers (and their characteristics); returnee migrant workers; and skill levels. Analysis is provided of macro level determinants of emigrations such as gross national product (level and growth), the general demographic and social situation, labor force growth and structure, poverty and inequality, and internal and international migration. Environmental factors causing displacement in Southern Asia include floods, cyclones, river bank erosion, drought, and desertification. Global warming could displace millions of people in the region, and development projects have contributed to displacement. The remainder of the report covers political and ethnic factors, micro-factors influencing migration decision-making, the policies of sending and receiving countries, the consequences of emigration, and the potential for migration in the future.

Prevalence of multiple sclerosis in Iranian emigrants: review of the evidence.

PubMed

Nasr, Zahra; Majed, Masoud; Rostami, Abdolmohamad; Sahraian, Mohamad Ali; Minagar, Alireza; Amini, Arman; McGee, Jeanine C; Etemadifar, Masoud

2016-11-01

Iran has the highest prevalence of multiple sclerosis (MS) in the Middle East and Asia. Rate of emigration has been significantly raised among Iranians and though, multiple studies have been published on prevalence of MS among Iranian emigrants. Here we systematically reviewed these publications. We performed a comprehensive literature search was performed on April 30, 2015 in data bases of MEDLINE, EMBASE, Scopus and Google Scholar for the terms 'multiple sclerosis', 'incidence', 'prevalence', 'epidemiology', 'migration', 'emigrant', 'immigrant', 'Iran', 'Parsis' and 'Persian'. Study location, prevalence day or period, and age of at disease onset were recorded for all the included publications. Nine publications from Sweden, Canada, Norway, UK, and India were included. Only three reported age-adjusted prevalence and six reported age of disease onset. MS prevalence among Iranian emigrants varied from 21 per 100,000 people in Bombay, India in 1985 to 433 per 100,000 people in British Columbia, Canada in 2012. Five studies reported the prevalence in the region of interest, ranging from 1.33 in Bombay, India to 240 in British Columbia, Canada. Five studies also reported the prevalence of MS in the population of the destination country, and in all of them, the prevalence of MS was higher in Iranian immigrants compared to native people. Prevalence studies performed in Iran and also on Iranian emigrants indicate roles for both genetic and environmental factors in MS susceptibility. Data might indicate that living in a high-risk area increases the susceptibility to MS.

Combining band recovery data and Pollock's robust design to model temporary and permanent emigration

USGS Publications Warehouse

Lindberg, M.S.; Kendall, W.L.; Hines, J.E.; Anderson, M.G.

2001-01-01

Capture-recapture models are widely used to estimate demographic parameters of marked populations. Recently, this statistical theory has been extended to modeling dispersal of open populations. Multistate models can be used to estimate movement probabilities among subdivided populations if multiple sites are sampled. Frequently, however, sampling is limited to a single site. Models described by Burnham (1993, in Marked Individuals in the Study of Bird Populations, 199-213), which combined open population capture-recapture and band-recovery models, can be used to estimate permanent emigration when sampling is limited to a single population. Similarly, Kendall, Nichols, and Hines (1997, Ecology 51, 563-578) developed models to estimate temporary emigration under Pollock's (1982, Journal of Wildlife Management 46, 757-760) robust design. We describe a likelihood-based approach to simultaneously estimate temporary and permanent emigration when sampling is limited to a single population. We use a sampling design that combines the robust design and recoveries of individuals obtained immediately following each sampling period. We present a general form for our model where temporary emigration is a first-order Markov process, and we discuss more restrictive models. We illustrate these models with analysis of data on marked Canvasback ducks. Our analysis indicates that probability of permanent emigration for adult female Canvasbacks was 0.193 (SE = 0.082) and that birds that were present at the study area in year i - 1 had a higher probability of presence in year i than birds that were not present in year i - 1.

A closure test for time-specific capture-recapture data

USGS Publications Warehouse

Stanley, T.R.; Burnham, K.P.

1999-01-01

The assumption of demographic closure in the analysis of capture-recapture data under closed-population models is of fundamental importance. Yet, little progress has been made in the development of omnibus tests of the closure assumption. We present a closure test for time-specific data that, in principle, tests the null hypothesis of closed-population model M(t) against the open-population Jolly-Seber model as a specific alternative. This test is chi-square, and can be decomposed into informative components that can be interpreted to determine the nature of closure violations. The test is most sensitive to permanent emigration and least sensitive to temporary emigration, and is of intermediate sensitivity to permanent or temporary immigration. This test is a versatile tool for testing the assumption of demographic closure in the analysis of capture-recapture data.

Estimating freshwater productivity, overwinter survival, and migration patterns of Klamath River Coho Salmon

USGS Publications Warehouse

Manhard, Christopher V.; Som, Nicholas A.; Perry, Russell W.; Faukner, Jimmy; Soto, Toz

2018-01-01

An area of great importance to resource management and conservation biology in the Klamath Basin is balancing water usage against the life history requirements of threatened Coho Salmon. One tool for addressing this topic is a freshwater dynamics model to forecast Coho Salmon productivity based on environmental inputs. Constructing such a forecasting tool requires local data to quantify the unique life history processes of Coho Salmon inhabiting this region. Here, we describe analytical methods for estimating a series of sub-models, each capturing a different life history process, which will eventually be synchronized as part of a freshwater dynamics model for Klamath River Coho Salmon. Specifically, we draw upon extensive population monitoring data collected in the basin to estimate models of freshwater productivity, overwinter survival, and migration patterns. Our models of freshwater productivity indicated that high summer temperatures and high winter flows can both adversely affect smolt production and that such relationships are more likely in tributaries with naturally regulated flows due to substantial intraannual environmental variation. Our models of overwinter survival demonstrated extensive variability in survival among years, but not among rearing locations, and demonstrated that a substantial proportion (~ 20%) of age-0+ fish emigrate from some rearing sites in the winter. Our models of migration patterns indicated that many age-0+ fish redistribute in the basin during the summer and winter. Further, we observed that these redistributions can entail long migrations in the mainstem where environmental stressors likely play a role in cueing refuge entry. Finally, our models of migration patterns indicated that changes in discharge are important in cueing the seaward migration of smolts, but that the nature of this behavioral response can differ dramatically between tributaries with naturally and artificially regulated flows. Collectively, these analyses demonstrate that environmental variation interacts with most phases of the freshwater life history of Klamath River Coho Salmon and that anthropogenic environmental variation can have a particularly large bearing on productivity.

Polish Complementary Schools in Iceland and England

ERIC Educational Resources Information Center

Zielinska, Malgorzata; Kowzan, Piotr; Ragnarsdóttir, Hanna

2014-01-01

Since 2004, the opening of labour markets has spurred a considerable number of Poles to emigrate e.g. to Iceland and England. Families with school age children have had the challenge of adapting to foreign environments and school systems. Polish complementary schools have played an important, albeit ambivalent, role in this process. Through focus…

[The emigration of physicians in Venezuela].

PubMed

Hernández, Tulia; Ortiz Gómez, Yamileth

2011-08-01

Ascertain the factors that could affect the intention of Venezuelan health professionals to emigrate to other countries. Exploratory study that applied a semistructured interview and survey, respectively, to a population consisting of four health professionals and 36 medical students. The interview data were analyzed by deductive and inductive categorization and the survey data by means of univariate and bivariate analysis. It was observed that 13.8% of the students generally intended to emigrate, with differences between the two study groups. It was found that work-related issues had a high motivating effect (16.6%), particularly the possibility of balancing work with personal life, better pay, access to continuing education, working in a better health system, and having the basic resources necessary for professional practice. It was determined that professional reasons had a moderate motivating effect (13.8%), whereas personal and contextual reasons had little influence (less than 3%). Although the interviews of physicians who had obtained their medical degree revealed clashes involving political and economic interests, only 5.5% of the students surveyed considered the political or economic situation a determinant in the emigration of professionals. It is recommended that the management and professional development of medical personnel be strengthened, reconciling their expectations with the legal framework and needs of the health system. A formal system for tracking the emigration of professionals and broadening the study of the causative factors at the national level should be set up, since better knowledge about the phenomena linked with emigration would help generate and support proposals to guarantee self-sufficiency with respect to human resources for health.

Influence of parental education on Honduran medical students' labour perspectives: rural work and emigration.

PubMed

Zambrano, Lysien I; Pereyra-Elías, Reneé; Reyes-García, Selvin Z; Fuentes, Itzel; Mayta-Tristán, Percy

2015-01-01

We sought to evaluate the intentions of Honduran medical students to emigrate or to work in a rural setting, and their association with parental education. We performed a cross-sectional, analytic study at a Honduran medical school. Student participants completed a structured questionnaire, which assessed their intentions to emigrate or work in a rural setting after finishing medical school and the highest level of education achieved by their parents. We calculated crude and adjusted prevalence ratios with their respective 95% confidence intervals. Of 868 surveys distributed, 564 were completed. The mean age of the participants was 21 (standard deviation 3) years, and 62.2% were female. Of the respondents, 16.6% intended to emigrate to work and 11.2% intended to work in a rural setting. Higher paternal education (i.e., technical, university and postgraduate training) was associated with a higher rate of intention to emigrate. Students whose fathers underwent postgraduate education were less likely to intend to work in a rural setting. For maternal education, only the postgraduate level was associated with the outcomes in some of the tested models. The frequency of students intending to emigrate was relatively low. However, the frequency of students being willing to work in rural settings was also low. Students whose parents had higher levels of education were more likely to intend to work abroad and less likely to intend to work in a rural area. These factors should be considered in medical schools' selection processes to improve retention and ensure adequate distribution of physicians.

Predictable interregional movements by female northern pintails during winter

USGS Publications Warehouse

Cox, R.R.; Afton, A.D.

2000-01-01

Factors influencing initiation of regional and interregional movements by nonbreeding ducks are poorly understood, especially during winter. During winters 1990-1991 through 1992-1993, we radiotagged 347 female Northern Pintails (Anas acuta) in southwestern Louisiana and monitored their movements to three regions: (1) the Gulf Coast Region of Louisiana and Texas (outside of southwestern Louisiana), (2) the Rice Prairie Region of Texas, and (3) the Mississippi Alluvial Valley. We found that adult females were 1.9 times more likely than were immatures to emigrate from southwestern Louisiana during winter. During winters 1990-1991 and 1991-1992, females were more likely to emigrate during stormy than during fair weather, whereas they were more likely to emigrate during fair weather in 1992-1993. Females were more likely to emigrate during duck-hunting seasons than during nonhunting seasons, regardless of weather. Daily emigration probabilities did not differ in relation to body condition when released (body mass adjusted for body size) or to number of previous emigration events. Each winter, large numbers of females consistently moved from the Gulf Coast Region to areas with abundant rice (Oryza sativa) agriculture within the Mississippi Alluvial Valley. We conclude that destination of interregional movements by this population of Northern Pintails is highly predictable, and that initiation of such movements is influenced by female age and long-term winter precipitation patterns in the Mississippi Alluvial Valley. Furthermore, timing of these movements is predictable, based not on calendar date, but rather on duck-hunting seasons and, usually, the environmental cues to habitat availability provided by stormy weather.

Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (South Atlantic) - Atlantic sturgeon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Den Avyle, M.J.

1984-07-01

The Atlantic sturgeon, Acipenser oxyrhynchus oxyrhynchus, is an anadromous species that occupies rivers, estuaries, and nearshore waters along the entire Atlantic coast of the United States. The species once supported significant commercial fisheries throughout its range, but stocks have declined because of overfishing, deterioration of water quality, and damming of rivers. Atlantic sturgeon spawn in rivers and the young remain in freshwater for several years prior to emigration to the ocean. Little is known about spawning areas and associated environmental factors. Females typically do not mature until age X and the age at first spawning ranges from 5 to 13more » years for males and 7 to 19 years for females. Longevity may frequently exceed 25 years. Immature and adult sturgeons are bottom feeders and consume a variety of mollusks, crustaceans, worms, and other small bottom-dwelling invertebrates and fishes. Little is know about competitors, predators, or effects of environmental factors on recruitment. The long period required to reach maturity, possibly irregular spawning thereafter, and prolonged reliance on river systems make juvenile and adult Atlantic sturgeon highly susceptible to habitat alterations, pollution, and over exploitation. 49 references, 2 figures, 4 tables.« less

Bulgarian Turkish emigration and return.

PubMed

Vasileva, D

1992-01-01

The main factors which determined the 1989 migration of Turks in Bulgaria back to Turkey are discussed. Background history is provided. After World War I, Turks in bulgaria comprised 10% of the total population. Bulgarian policy had been, up to the 1980s to send Rumelian Turks back, but the policy after 1980 was one of a national revival process to integrate Turks into the developed socialist society. Muslim traditions, customs, and Turkish language were interfered with. International disfavor resulted. In May 1989, the Communist Party declared, in an effort to show democratic ideals, open borders. Thus began the new emigration wave. 369,839 people fled to the Turkish border. 43% of the 9.47 ethnic Turks in bulgaria went to Turkey within 4 months. The numbers decreased in November, and soon after the communist regime ended. New laws were adopted allowing Turks to assume their original Turkish names. The huge migration was clearly political, and as such, the emigrant Turks should be determined as refugees and asylum seekers. The provocation of ethnic Turks was used by the communist regime to solve potential social conflicts. Not only did Turks flee to escape from violence or for religious, cultural, and moral reasons but also due to free market initiatives begun in Turkey in the early 1980s which improved Turkish quality of life. Food and consumer goods were cheaper and economic advantages were perceived. Emigrants were primarily peasants with lower levels of education, professional qualifications, and labor skills. 154,937 (42%) returned to bulgaria and 58% stayed in Turkey to comprise 25% of the former Turkish population. During this period, tensions between countries was high.l Bulgarians actively encouraged emigration and Turkey welcomed it. The emigrants to Turkey were seen as foreigners (muhacir or gocmen) but were received with good will and were readily accepted into menial positions. Emigrants were confronted with political, linguistic, and cultural differences. The unifying factor was the Islamic religion. For those returning to Bulgaria, the change in regime meant the government worked to solve the emigrants' housing problems and teaching Turkish in primary and secondary schools. The result of this massive migration has been a change in the demographics and social structure of Bulgaria, and the realization that forceful migration is inefficient in solving problems.

Survival of hatchery Gulf sturgeon (Acipenser oxyrinchus desotoi Mitchill, 1815) in the Suwannee River, Florida: a 19-year evaluation

USGS Publications Warehouse

Sulak, Kenneth J.; Randall, Michael T.; Clugston, James P.

2014-01-01

An experimental release of 1192 hatchery-reared, individually PIT tagged, 220 days old (296–337 mm TL) Gulf sturgeon, Acipenser oxyrinchus desotoi, was undertaken in 1992 in the Suwannee River, Florida. The original objectives of the 1992 release experiment were to: (1) evaluate survival rate of cultured Gulf sturgeon in the wild vs survival rate of their wild 1992 cohort counterparts, (2) determine the differential effect of release site within the river upon long-term survival, and (3) evaluate comparative growth rates of recaptured hatchery vs captured wild 1992 cohort Gulf sturgeon. The present investigation addressed those original objectives, plus an additional fourth objective: (4) evaluation of hatchery fish recapture rate change over the 19-year experiment. The primary objective was to determine efficacy of potential conservation aquaculture for this species in terms of long-term survival in the wild. Follow-up 1993–2011 gill net sampling in freshwater reaches (rkm 4–237) and the estuarine river mouth (rkm −6 to 4) yielded recaptures representing 13.0% of the total released. Mean annual hatchery fish mortality (including emigration) rate estimated for the 19-year period (1993–2011) was more than twice that for same cohort wild fish. Mark-recapture survival probability (phi) for hatchery fish, 1993–2011, was substantially lower (0.733) than for their wild counterparts (0.888). Mean annual hatchery fish recapture rate, as a percentage of all 1992 cohort fish recaptures, declined significantly after age-7, coinciding with age of onset of migration into the open Gulf of Mexico. Hypothesized causal factors may be differentially lower fitness in the marine habitat or permanent outmigration due to natal river imprinting failure. Hatchery fish recapture rates varied significantly for fish from the ten release sites, being highest near the river mouth, and lowest for the furthest upriver sites in the Suwannee River and its Santa Fe River tributary. Hatchery fish also displayed a significantly lower growth rate than their wild counterparts through age 3000 days. Cumulative hatchery fish mortality of 99.87% over 19 years predicts <3 individuals would have survived through 2011. From the results of the 1992 release experiment, hatchery supplementation as a Gulf sturgeon conservation measure does not appear to be an effective option.

Activation of calcitonin gene-related peptide receptor during ozone inhalation contributes to airway epithelial injury and repair.

PubMed

Oslund, Karen L; Hyde, Dallas M; Putney, Leialoha F; Alfaro, Mario F; Walby, William F; Tyler, Nancy K; Schelegle, Edward S

2009-10-01

The authors investigated the importance of the neuropeptide, calcitonin gene-related peptide (CGRP), in epithelial injury, repair, and neutrophil emigration after ozone exposure. Wistar rats were administered either a CGRP-receptor antagonist (CGRP(8-37)) or saline and exposed to 8 hours of 1-ppm ozone or filtered air with an 8-hour postexposure period. Immediately after exposure, ethidium homodimer was instilled into lungs as a marker of necrotic airway epithelial cells. After fixation, airway dissected lung lobes were stained for 5'-bromo-2'-deoxyuridine, a marker of epithelial proliferation. Positive epithelial cells were quantified in specific airway generations. Rats treated with CGRP(8-37) had significantly reduced epithelial injury in terminal bronchioles and reduced epithelial proliferation in proximal airways and terminal bronchioles. Bronchoalveolar lavage and sections of terminal bronchioles showed no significant difference in the number of neutrophils emigrating into airways in CGRP(8-37)-treated rats. The airway epithelial cell line, HBE-1, showed no difference in the number of oxidant stress positive cells during exposure to hydrogen peroxide and a range of CGRP(8-37) doses, demonstrating no antioxidant effect of CGRP(8-37). We conclude that activation of CGRP receptors during ozone inhalation contributes to airway epithelial injury and subsequent epithelial proliferation, a critical component of repair, but does not influence neutrophil emigration into airways.

Migration intentions and illicit substance use among youth in central Mexico.

PubMed

Marsiglia, Flavio Francisco; Kulis, Stephen; Hoffman, Steven; Calderón-Tena, Carlos Orestes; Becerra, David; Alvarez, Diana

2011-01-01

This study explored intentions to emigrate and substance use among youth (ages 14-24) from a central Mexico state with high emigration rates. Questionnaires were completed in 2007 by 702 students attending a probability sample of alternative secondary schools serving remote or poor communities. Linear and logistic regression analyses indicated that stronger intentions to emigrate predicted greater access to drugs, drug offers, and use of illicit drugs (marijuana, cocaine, inhalants), but not alcohol or cigarettes. Results are related to the healthy migrant theory and its applicability to youth with limited educational opportunities. The study's limitations are noted.

Emigration from Israel 1950-1981: a simulation study.

PubMed

Jacobsen, C; Bronson, R

1988-01-01

"Using our mathematical model of a general theory of normative regulation, we have reproduced over 80% of the variance in the cumulative percentages of emigrants [from Israel], as well as the yearly percentages from 1950 to 1981. These results suggest that, except for a limited period following the 'Six-Day War' of 1967, no situation-specific explanations are needed to account for the trends in emigration from Israel, and the phenomenon can be adequately accounted for by the general theory of normative regulation in modern industrialized societies. Some practical conclusions to mitigate the process are drawn from these findings." excerpt

Immigration, Work, and Health: A Literature Review of Immigration Between Mexico and the United States

PubMed Central

Flynn, Michael A.; Carreón, Tania; Eggerth, Donald E.; Johnson, Antoinette I.

2015-01-01

Understanding the influence someone’s job or career has on their health goes beyond the physical, emotional and social hazards, risks and conditions that they face at work. One’s job or career also exerts a significant influence over other aspects of life that contribute or detract from their health and that of their family. Work is the major incentive for Latin American migration to the United States. Latino immigrants experience increasingly poorer outcomes for physical health and chronic diseases the longer they remain in the U.S. The strong link between work and immigration suggests that, for many Latin Americans, immigration can be understood as a career path which puts them, and their family members, in situations that can change their physical, emotional, and social health as a condition of their employment. Given the large number of Latin Americans who emigrate for work, it is essential that the unique physical, mental and social impacts of emigration are accounted for when working with clients impacted by emigration at the individual, family and community level as well as those social workers practicing at the system level. This paper is a literature review that explores the impact that emigrating for work has on the health of those that emigrate and their family members that stay behind. PMID:28260831

Take-Off Time of the First Generation of the Overwintering Small Brown Planthopper, Laodelphax striatellus in the Temperate Zone in East Asia

PubMed Central

Sanada-Morimura, Sachiyo; Otuka, Akira; Matsumura, Masaya; Etoh, Tomoki; Zhu, Yeqin; Zhou, Yijun; Zhang, Gufeng

2015-01-01

Overseas migration of the small brown planthopper, Laodelphax striatellus (Fallén), occurs during the winter wheat harvest season in East Asia. Knowing the take-off time of emigrating L. striatellus is crucial for predicting such migrations with a simulation technique because winds, carriers of migratory insects, change continuously. Several methods were used in China and Japan from late May to early June 2012 and again in 2013 to identify the precise timing of take-off. These methods included: a tow net trap mounted to a pole at 10 m above the ground, a helicopter-towed net trap, and a canopy trap (which also had video monitoring) set over wheat plants. Laodelphax striatellus emigrated from wheat fields mainly in the early evening, before dusk. The insects also emigrated during the daytime but rarely emigrated at dawn, showing a pattern that is unlike the bimodal emigration at dusk and dawn of two other rice planthoppers, the brown planthopper, Nilaparvata lugens (Stål), and the white-backed planthopper, Sogatella furcifera (Horváth). There was no significant difference in the temporal pattern of take-off behavior between females and males of Japanese L. striatellus populations. PMID:25780936

Motivational goals, group identifications, and psychosocial adjustment of returning migrants: The case of Jews returning to Russia.

PubMed

Tartakovsky, Eugene; Patrakov, Eduard; Nikulina, Marina

2017-12-01

The present study investigated the motivational goals, group identifications, and psychosocial adjustment of Jews who returned to Russia after emigrating from the republics of the Former Soviet Union to different countries (n = 151). To gain a deeper understanding of these returning migrants, their traits were compared with those of Jews living in Russia who did not emigrate (n = 935). Compared to locals, returnees reported a higher preference for the openness to change and self-enhancement values and a lower preference for the conservation values; there was no difference in the self-transcendence values. Returning migrants had a relatively weak affiliation with the home country: they had a weaker identification with the home country than with the country of emigration, their identification with Russians was weaker than that among Jews who did not emigrate from Russia, and their intention to emigrate (again) from Russia was greater than that among locals. However, the Jewish identification of returning migrants was similar to that of locals. The adjustment of returning migrants varied across different dimensions: their economic adjustment was better than that of locals; however, the interpersonal adjustment of returnees was less successful than among locals. © 2016 International Union of Psychological Science.

Spring Outmigration of Wild and Hatchery Chinook Salmon and Steelhead Trout Smolts from the Imnaha River, Oregon; 1996 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blenden, Michael L.; Rocklage, Stephen J.; Kucera, Paul A.

1997-04-01

For the third consecutive year, the Nez Perce Tribe, in conjunction with the Fish Passage Center, participated in the smolt monitoring program in the Imnaha River. A rotary screw trap was used to collect emigrating wild and hatchery chinook salmon (Oncorhynchus tshawytscha) and steelhead trout (Oncorhynchus mykiss) smolts from February 23 to June 24, 1996. A total of 1,797 wild chinook salmon, 11,896 hatchery chinook salmon, 3,786 wild steelhead trout, and 31,094 hatchery steelhead trout smolts were captured during outmigration studies on the Imnaha River in 1996. Mortality associated with trapping, handling and tagging was low, being 1.4% for wildmore » chinook, 0.18% for hatchery chinook, 0.21% for wild steelhead and 0.28% for hatchery steelhead trout smolts.« less

Women in 19th Century Irish immigration.

PubMed

Jackson, P

1984-01-01

By the 1950s--100 years after the great famine of 1845-49-- 57% of emigrants from the 26 countries of Ireland were women. In the latter 1/2 of the 19th Century, increasing proportions of women emigrated, until they outnumbered men. For women it was more than a flight from poverty. It was also an escape from an increasingly patriarchal society, whose asymetrical development as a colony curtailed women's social space, even in their traditional role as wife and mother. The famine, which is the single greatest influence forcing emigration, undermined the social fabric of an agrarian society, hastening the process of agricultural transformation. The growth of a new class of Irish a British grazier landlords resulted in a situation of acute land scarcity, encouraging tendencies to cling to one's land holding without dividing it. This, combined with new inheritance practices, gave rise to widespread arranged marriages as a means of land consolidation, and the dowry system. The spontaneous marriage practices of famine days also were replaced by a postponement of marriage. These trends severely reduced the choices exerted by women. The absence of big industrialized cities, which might have absorbed displaced rural populations, removed available options, particularly for women. The system of land monopoly and inheritance revolving around male heads of households reinforced partriarchal relations, within a framework of rigid sexual norms, whose enforcement was easy because the church, which played an important role in the emergence of these values, was a major landowner in itself. The subordinated, invisible status of women in post-famine Ireland, and growing barriers to easy access to marriage partners, to waged employment and self-expression, all helped ensure the higher and higher emigration rates of women. The economic transformation of Irish agriculture accelerated the establishment of oppressive values and helped depreciate the position of women to a very low level. The exodus of women from post-famine Ireland represented a refusal to accept the servile role accorded them.

Higher mobility of butterflies than moths connected to habitat suitability and body size in a release experiment

PubMed Central

Kuussaari, Mikko; Saarinen, Matias; Korpela, Eeva-Liisa; Pöyry, Juha; Hyvönen, Terho

2014-01-01

Mobility is a key factor determining lepidopteran species responses to environmental change. However, direct multispecies comparisons of mobility are rare and empirical comparisons between butterflies and moths have not been previously conducted. Here, we compared mobility between butterflies and diurnal moths and studied species traits affecting butterfly mobility. We experimentally marked and released 2011 butterfly and 2367 moth individuals belonging to 32 and 28 species, respectively, in a 25 m × 25 m release area within an 11-ha, 8-year-old set-aside field. Distance moved and emigration rate from the release habitat were recorded by species. The release experiment produced directly comparable mobility data in 18 butterfly and 9 moth species with almost 500 individuals recaptured. Butterflies were found more mobile than geometroid moths in terms of both distance moved (mean 315 m vs. 63 m, respectively) and emigration rate (mean 54% vs. 17%, respectively). Release habitat suitability had a strong effect on emigration rate and distance moved, because butterflies tended to leave the set-aside, if it was not suitable for breeding. In addition, emigration rate and distance moved increased significantly with increasing body size. When phylogenetic relatedness among species was included in the analyses, the significant effect of body size disappeared, but habitat suitability remained significant for distance moved. The higher mobility of butterflies than geometroid moths can largely be explained by morphological differences, as butterflies are more robust fliers. The important role of release habitat suitability in butterfly mobility was expected, but seems not to have been empirically documented before. The observed positive correlation between butterfly size and mobility is in agreement with our previous findings on butterfly colonization speed in a long-term set-aside experiment and recent meta-analyses on butterfly mobility. PMID:25614794

A Robust Design Capture-Recapture Analysis of Abundance, Survival and Temporary Emigration of Three Odontocete Species in the Gulf of Corinth, Greece

PubMed Central

Bonizzoni, Silvia; Bearzi, Giovanni; Eddy, Lavinia; Gimenez, Olivier

2016-01-01

While the Mediterranean Sea has been designated as a Global Biodiversity Hotspot, assessments of cetacean population abundance are lacking for large portions of the region, particularly in the southern and eastern basins. The challenges and costs of obtaining the necessary data often result in absent or poor abundance information. We applied capture-recapture models to estimate abundance, survival and temporary emigration of odontocete populations within a 2,400 km2 semi-enclosed Mediterranean bay, the Gulf of Corinth. Boat surveys were conducted in 2011–2015 to collect photo-identification data on striped dolphins Stenella coeruleoalba, short-beaked common dolphins Delphinus delphis (always found together with striped dolphins in mixed groups) and common bottlenose dolphins Tursiops truncatus, totaling 1,873 h of tracking. After grading images for quality and marking distinctiveness, 23,995 high-quality photos were included in a striped and common dolphin catalog, and 2,472 in a bottlenose dolphin catalog. The proportions of striped and common dolphins were calculated from the photographic sample and used to scale capture-recapture estimates. Best-fitting robust design capture-recapture models denoted no temporary emigration between years for striped and common dolphins, and random temporary emigration for bottlenose dolphins, suggesting different residency patterns in agreement with previous studies. Average estimated abundance over the five years was 1,331 (95% CI 1,122–1,578) striped dolphins, 22 (16–32) common dolphins, 55 (36–84) “intermediate” animals (potential striped x common dolphin hybrids) and 38 (32–46) bottlenose dolphins. Apparent survival was constant for striped, common and intermediate dolphins (0.94, 95% CI 0.92–0.96) and year-dependent for bottlenose dolphins (an average of 0.85, 95% CI 0.76–0.95). Our work underlines the importance of long-term monitoring to contribute reliable baseline information that can help assess the conservation status of wildlife populations. PMID:27926926

Froebel Crosses the Alps: Introducing the Kindergarten in Italy

ERIC Educational Resources Information Center

Albisetti, James C.

2009-01-01

The kindergarten was, in all countries but Germany, a foreign import. The most familiar aspect of its diffusion to American scholars is the spread of Froebel's teachings into England and the United States by emigrants who had left the German Confederation after the failure of the revolutions of 1848-49. Familiar as well are the propaganda efforts…

Children of Immigrants in Trento: Educational Achievement through the Lens of Friendship

ERIC Educational Resources Information Center

Mantovani, Debora; Martini, Elisa

2008-01-01

During the past three decades, Italy has changed from a country of emigration to one of immigration. This has produced significant changes in the country's social, cultural and economic structures and poses major new challenges to the education system. An important indicator of the changing situation is the increasing number of immigrant children…

Spatial variation and density-dependent dispersal in competitive coexistence.

PubMed Central

Amarasekare, Priyanga

2004-01-01

It is well known that dispersal from localities favourable to a species' growth and reproduction (sources) can prevent competitive exclusion in unfavourable localities (sinks). What is perhaps less well known is that too much emigration can undermine the viability of sources and cause regional competitive exclusion. Here, I investigate two biological mechanisms that reduce the cost of dispersal to source communities. The first involves increasing the spatial variation in the strength of competition such that sources can withstand high rates of emigration; the second involves reducing emigration from sources via density-dependent dispersal. I compare how different forms of spatial variation and modes of dispersal influence source viability, and hence source-sink coexistence, under dominance and pre-emptive competition. A key finding is that, while spatial variation substantially reduces dispersal costs under both types of competition, density-dependent dispersal does so only under dominance competition. For instance, when spatial variation in the strength of competition is high, coexistence is possible (regardless of the type of competition) even when sources experience high emigration rates; when spatial variation is low, coexistence is restricted even under low emigration rates. Under dominance competition, density-dependent dispersal has a strong effect on coexistence. For instance, when the emigration rate increases with density at an accelerating rate (Type III density-dependent dispersal), coexistence is possible even when spatial variation is quite low; when the emigration rate increases with density at a decelerating rate (Type II density-dependent dispersal), coexistence is restricted even when spatial variation is quite high. Under pre-emptive competition, density-dependent dispersal has only a marginal effect on coexistence. Thus, the diversity-reducing effects of high dispersal rates persist under pre-emptive competition even when dispersal is density dependent, but can be significantly mitigated under dominance competition if density-dependent dispersal is Type III rather than Type II. These results lead to testable predictions about source-sink coexistence under different regimes of competition, spatial variation and dispersal. They identify situations in which density-independent dispersal provides a reasonable approximation to species' dispersal patterns, and those under which consideration of density-dependent dispersal is crucial to predicting long-term coexistence. PMID:15306322

Assessing the impacts of river regulation on native bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) habitats in the upper Flathead River, Montana, USA

USGS Publications Warehouse

Muhlfeld, Clint C.; Jones, Leslie A.; Kotter, D.; Miller, William J.; Geise, Doran; Tohtz, Joel; Marotz, Brian

2012-01-01

Hungry Horse Dam on the South Fork Flathead River, Montana, USA, has modified the natural flow regimen for power generation, flood risk management and flow augmentation for anadromous fish recovery in the Columbia River. Concern over the detrimental effects of dam operations on native resident fishes prompted research to quantify the impacts of alternative flow management strategies on threatened bull trout (Salvelinus confluentus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi) habitats. Seasonal and life‐stage specific habitat suitability criteria were combined with a two‐dimensional hydrodynamic habitat model to assess discharge effects on usable habitats. Telemetry data used to construct seasonal habitat suitability curves revealed that subadult (fish that emigrated from natal streams to the river system) bull trout move to shallow, low‐velocity shoreline areas at night, which are most sensitive to flow fluctuations. Habitat time series analyses comparing the natural flow regimen (predam, 1929–1952) with five postdam flow management strategies (1953–2008) show that the natural flow conditions optimize the critical bull trout habitats and that the current strategy best resembles the natural flow conditions of all postdam periods. Late summer flow augmentation for anadromous fish recovery, however, produces higher discharges than predam conditions, which reduces the availability of usable habitat during this critical growing season. Our results suggest that past flow management policies that created sporadic streamflow fluctuations were likely detrimental to resident salmonids and that natural flow management strategies will likely improve the chances of protecting key ecosystem processes and help to maintain and restore threatened bull trout and westslope cutthroat trout populations in the upper Columbia River Basin.

[Emigration from the Maghreb since 1946].

PubMed

Verhaeren R-e

1995-01-01

"Just after the Second World War, during the period of rapid economic growth, North African emigration, to France in particular, increases considerably. Later on, during the crisis, emigration still increases, but is directed towards other European countries. The crisis moreover reveals that these workforce migrations not only play a major role of regulation of the conditions [of] the job market, but also play a role of structural complementarity of national workforces, at least as far as certain levels of the market are concerned; and this to the extent that a high national unemployment rate can co-exist with a high rate of employment of foreign workers." (EXCERPT)

Migration Intentions and Illicit Substance Use among Youth in Central Mexico

PubMed Central

Marsiglia, Flavio Francisco; Kulis, Stephen; Hoffman, Steven; Calderón-Tena, Carlos Orestes; Becerra, David; Alvarez, Diana

2011-01-01

This study explored intentions to emigrate and substance use among youth (ages 14–24) from a central Mexico state with high emigration rates. Questionnaires were completed in 2007 by 702 students attending a probability sample of alternative secondary schools serving remote or poor communities. Linear and logistic regression analyses indicated that stronger intentions to emigrate predicted greater access to drugs, drug offers, and use of illicit drugs (marijuana, cocaine, inhalants), but not alcohol or cigarettes. Results are related to the healthy migrant theory and its applicability to youth with limited educational opportunities. The study’s limitations are noted. PMID:21955065

Linkages among climate change, crop yields and Mexico–US cross-border migration

PubMed Central

Feng, Shuaizhang; Krueger, Alan B.; Oppenheimer, Michael

2010-01-01

Climate change is expected to cause mass human migration, including immigration across international borders. This study quantitatively examines the linkages among variations in climate, agricultural yields, and people's migration responses by using an instrumental variables approach. Our method allows us to identify the relationship between crop yields and migration without explicitly controlling for all other confounding factors. Using state-level data from Mexico, we find a significant effect of climate-driven changes in crop yields on the rate of emigration to the United States. The estimated semielasticity of emigration with respect to crop yields is approximately −0.2, i.e., a 10% reduction in crop yields would lead an additional 2% of the population to emigrate. We then use the estimated semielasticity to explore the potential magnitude of future emigration. Depending on the warming scenarios used and adaptation levels assumed, with other factors held constant, by approximately the year 2080, climate change is estimated to induce 1.4 to 6.7 million adult Mexicans (or 2% to 10% of the current population aged 15–65 y) to emigrate as a result of declines in agricultural productivity alone. Although the results cannot be mechanically extrapolated to other areas and time periods, our findings are significant from a global perspective given that many regions, especially developing countries, are expected to experience significant declines in agricultural yields as a result of projected warming. PMID:20660749

Linkages among climate change, crop yields and Mexico-US cross-border migration.

PubMed

Feng, Shuaizhang; Krueger, Alan B; Oppenheimer, Michael

2010-08-10

Climate change is expected to cause mass human migration, including immigration across international borders. This study quantitatively examines the linkages among variations in climate, agricultural yields, and people's migration responses by using an instrumental variables approach. Our method allows us to identify the relationship between crop yields and migration without explicitly controlling for all other confounding factors. Using state-level data from Mexico, we find a significant effect of climate-driven changes in crop yields on the rate of emigration to the United States. The estimated semielasticity of emigration with respect to crop yields is approximately -0.2, i.e., a 10% reduction in crop yields would lead an additional 2% of the population to emigrate. We then use the estimated semielasticity to explore the potential magnitude of future emigration. Depending on the warming scenarios used and adaptation levels assumed, with other factors held constant, by approximately the year 2080, climate change is estimated to induce 1.4 to 6.7 million adult Mexicans (or 2% to 10% of the current population aged 15-65 y) to emigrate as a result of declines in agricultural productivity alone. Although the results cannot be mechanically extrapolated to other areas and time periods, our findings are significant from a global perspective given that many regions, especially developing countries, are expected to experience significant declines in agricultural yields as a result of projected warming.

78 FR 54909 - Notice of Availability of the Proposed Winnemucca District Resource Management Plan and Final...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-06

... Rock Desert-Highrock Canyon, Emigrant Trails National Conservation Area (NCA), except for... Rock Desert-High Rock Canyon Emigrant Trails National Conservation Area and Associated Wilderness, and..., closed, or subject to special stipulations or mitigation measures relating to minerals; and management of...

The Bounded Polity: The Limits to Mexican Emigrant Political Participation

ERIC Educational Resources Information Center

Waldinger, Roger; Soehl, Thomas

2013-01-01

International migration yields pervasive cross-border social engagements, yet homeland political involvements are modest to minimal. This contrast reflects the ways in which the distinctive characteristics of expatriate political life impede participation in the polity that emigrants have left behind. As polities are bounded, moving to the…

Development and validation of a quantitative PCR to detect Parvicapsula minibicornis and comparison to histologically ranked infection of juvenile Chinook salmon, Oncorhynchus tshawytscha (Walbaum), from the Klamath River, USA

USGS Publications Warehouse

True, K.; Purcell, M.K.; Foott, J.S.

2009-01-01

Parvicapsula minibicornis is a myxosporean parasite that is associated with disease in Pacific salmon during their freshwater life history phase. This study reports the development of a quantitative (real-time) polymerase chain reaction (QPCR) to detect P. minibicornis DNA. The QPCR assay targets the 18S ribosomal subunit gene. A plasmid DNA control was developed to calibrate cycle threshold (CT) score to plasmid molecular equivalent (PME) units, a measure of gene copy number. Assay validation revealed that the QPCR was sensitive and able to detect 50 ag of plasmid DNA, which was equivalent to 12.5 PME. The QPCR assay could detect single P. minibicornis actinospores well above assay sensitivity, indicating a single spore contains at least 100 times the 18S DNA copies required for detection. The QPCR assay was repeatable and highly specific; no detectable amplification was observed using DNA from related myxozoan parasites. The method was validated using kidney tissues from 218 juvenile Chinook salmon sampled during the emigration period of March to July 2005 from the Klamath River. The QPCR assay was compared with histological examination. The QPCR assay detected P. minibicornis infection in 88.1% of the fish sampled, while histological examination detected infection in 71.1% of the fish sampled. Good concordance was found between the methods as 80% of the samples were in agreement. The majority of the disconcordant fish were positive by QPCR, with low levels of P. minibicornis DNA, but negative by histology. The majority of the fish rated histologically as having subclinical or clinical infections had high QPCR levels. The results of this study demonstrate that QPCR is a sensitive quantitative tool for evaluating P. minibicornis infection in fish health monitoring studies. ?? 2008 Blackwell Publishing Ltd.

Education and the Knowledge Military

DTIC Science & Technology

2010-04-01

residents emigrated from developing countries with undeveloped education systems and work in service related fields. They come to America for various...Cooperation and Development Countries (OECD) in a 2006 international assessment. 5 An increasingly diverse country , demographics are particularly important...seaboard of a country is one of its frontiers” and the easier the access to this frontier through deep water ports the greater the ability to

Age-specific survival of tundra swans on the lower Alaska Peninsula

USGS Publications Warehouse

Meixell, Brandt W.; Lindberg, Mark S.; Conn, Paul B.; Dau, Christian P.; Sarvis, John E.; Sowl, Kristine M.

2013-01-01

The population of Tundra Swans (Cygnus columbianus columbianus) breeding on the lower Alaska Peninsula represents the southern extremity of the species' range and is uniquely nonmigratory. We used data on recaptures, resightings, and recoveries of neck-collared Tundra Swans on the lower Alaska Peninsula to estimate collar loss, annual apparent survival, and other demographic parameters for the years 1978–1989. Annual collar loss was greater for adult males fitted with either the thinner collar type (0.34) or the thicker collar type (0.15) than for other age/sex classes (thinner: 0.10, thicker: 0.04). The apparent mean probability of survival of adults (0.61) was higher than that of immatures (0.41) and for both age classes varied considerably by year (adult range: 0.44–0.95, immature range: 0.25–0.90). To assess effects of permanent emigration by age and breeding class, we analyzed post hoc the encounter histories of swans known to breed in our study area. The apparent mean survival of known breeders (0.65) was generally higher than that of the entire marked sample but still varied considerably by year (range 0.26–1.00) and indicated that permanent emigration of breeding swans was likely. We suggest that reductions in apparent survival probability were influenced primarily by high and variable rates of permanent emigration and that immigration by swans from elsewhere may be important in sustaining a breeding population at and near Izembek National Wildlife Refuge.

Emigration flows from North Africa to Europe.

PubMed

Kassar, Hassène; Marzouk, Diaa; Anwar, Wagida A; Lakhoua, Chérifa; Hemminki, Kari; Khyatti, Meriem

2014-08-01

The region of North Africa (NA) represents a striking locality regarding migration with several migration patterns, namely emigration in the form of labour export to Europe and North America and, to a lesser extent, to the Arab Gulf area. The latter has increased enormously in the last decade because of the political instability in most of the NA countries. The aim of the present chapter was to explore the patterns of migration stocks and flows in NA countries, based on several websites, systematic review of journals, comparable data available by the United Nations and by the International Organization of Migration. The NA region has become an area of transit migration and labour migration. Emigrant flows from NA countries towards Europe and North America are increasing this decade more than towards the Arab Gulf countries after being replaced by Asian labour. The recent increase in the proportion of women among the migrant population is remarkable. Remittances sent by African migrants have become an important source of external finance for countries of origin. Transient and irregular migration to Egypt originates at the borders with Sudan, Palestine and Libya with destination to the Euro Mediterranean countries. In Tunisia and Morocco, irregular migrants originate from Sub-Saharan Africa to the northern borders. The NA countries serve as departure rather than destination countries, and migration flows to the Euro-Mediterranean countries through legal or illegal routes. © The Author 2014. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Using open robust design models to estimate temporary emigration from capture-recapture data.

PubMed

Kendall, W L; Bjorkland, R

2001-12-01

Capture-recapture studies are crucial in many circumstances for estimating demographic parameters for wildlife and fish populations. Pollock's robust design, involving multiple sampling occasions per period of interest, provides several advantages over classical approaches. This includes the ability to estimate the probability of being present and available for detection, which in some situations is equivalent to breeding probability. We present a model for estimating availability for detection that relaxes two assumptions required in previous approaches. The first is that the sampled population is closed to additions and deletions across samples within a period of interest. The second is that each member of the population has the same probability of being available for detection in a given period. We apply our model to estimate survival and breeding probability in a study of hawksbill sea turtles (Eretmochelys imbricata), where previous approaches are not appropriate.

Using open robust design models to estimate temporary emigration from capture-recapture data

USGS Publications Warehouse

Kendall, W.L.; Bjorkland, R.

2001-01-01

Capture-recapture studies are crucial in many circumstances for estimating demographic parameters for wildlife and fish populations. Pollock's robust design, involving multiple sampling occasions per period of interest, provides several advantages over classical approaches. This includes the ability to estimate the probability of being present and available for detection, which in some situations is equivalent to breeding probability. We present a model for estimating availability for detection that relaxes two assumptions required in previous approaches. The first is that the sampled population is closed to additions and deletions across samples within a period of interest. The second is that each member of the population has the same probability of being available for detection in a given period. We apply our model to estimate survival and breeding probability in a study of hawksbill sea turtles (Eretmochelys imbricata), where previous approaches are not appropriate.

The role of ethnic relations and education systems in migration from Southeast Asia to Australia.

PubMed

Sullivan, G; Gunasekaran, S

1993-08-01

"After a brief discussion of the geographical, cultural, and historical characteristics of Southeast Asia [and Hong Kong], a review is provided of the evolution of Australian immigration policy which, in our view, is a strong pull factor. This is followed by stock and flow analyses of Asian-born residents in Australia. The motivations for emigration in countries which exhibit substantial emigration rates are considered next and the article ends with the conclusion that demand factors and social networks play a decisive role in the decision to emigrate." Factors affecting migration significantly include political conditions and ethnic relations in countries of origin, and educational and career opportunities in the country of destination. excerpt

Evaluation of Fish Passage Sites in the Walla Walla River Basin, 2008

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chamness, Mickie A.

2008-08-29

In 2008, Pacific Northwest National Laboratory evaluated the Hofer Dam fish screen and provided technical assistance at two other fish passage sites as requested by the Bonneville Power Administration, the Walla Walla Watershed Council, or the Confederated Tribes of the Umatilla Indian Reservation. Evaluation of new sites such as Hofer Dam focuses on their design, construction, operation, and maintenance to determine if they effectively provide juvenile salmonids with safe passage through irrigation diversions. There were two requests for technical assistance in 2008. In the first, the Confederated Tribes of the Umatilla Indian Reservation requested an evaluation of the Nursery Bridgemore » fish screens associated with the fish ladder on the east side of the Walla Walla River. One set of brushes that clean the screens was broken for an extended period. Underwater videography and water velocity measurements were used to determine there were no potential adverse effects on juvenile salmonids when the west set of screens was clean enough to pass water normally. A second request, received from the National Marine Fisheries Service and the Walla Walla Watershed Council, asked for evaluation of water velocities through relatively new head gates above and adjacent to the Eastside Ditch fish screens on the Walla Walla River. Water moving through the head gates and not taken for irrigation is diverted to provide water for the Nursery Bridge fish ladder on the east side of the river. Elevations used in the design of the head gates were incorrect, causing excessive flow through the head gates that closely approached or exceeded the maximum swimming burst speed of juvenile salmonids. Hofer Dam was evaluated in June 2008. PNNL researchers found that conditions at Hofer Dam will not cause impingement or entrainment of juvenile salmonids but may provide habitat for predators and lack strong sweeping flows to encourage juvenile salmonid passage downstream. Further evaluation of velocities at the Eastside Ditch and wasteway gates should occur as changes are made to compensate for the design problems. These evaluations will help determine whether further changes are required. Hofer Dam also should be evaluated again under more normal operating conditions when the river levels are typical of those when fish are emigrating and the metal plate is not affecting flows.« less

Majority Children's Evaluation of Acculturation Preferences of Immigrant and Emigrant Peers

ERIC Educational Resources Information Center

Verkuyten, Maykel; Thijs, Jochem; Sierksma, Jellie

2014-01-01

Using an experimental design, native majority group children (8-13 years, N = 842) evaluated acculturation strategies (assimilation, integration, and separation) adopted by immigrant and emigrant peers. There were medium to large effects of the perceived acculturation strategies on children's peer evaluations. Overall, assimilation was valued…

A Web-Based Resource for Investigating Environmental Change: The Emigrant Pass Observatory

ERIC Educational Resources Information Center

Davis, Michael G.; Chapman, David S.

2012-01-01

We present a user-friendly, data-driven Web site (http://thermal.gg.utah.edu/facilities/epo/) for a geothermal, climate change observatory that is educational for the general public, students, and researchers alike. The Emigrant Pass Observatory (EPO), located in the Grouse Creek Mountains in northwestern Utah, gathers both meteorological data…

The Uncertain Connection: Free Trade and Rural Mexican Migration to the United States.

ERIC Educational Resources Information Center

Cornelius, Wayne A.; Martin, Philip L.

1993-01-01

Argues that it is easy to overestimate the additional emigration from rural Mexico that could occur as a result of North American Free Trade Agreement (NAFTA) related economic restructuring in Mexico. Four major reasons why Mexican emigration may not increase dramatically are suggested. Phase-in recommendations related to implementation are…

Migration as an Agent of Change in Caribbean Island Ecosystems.

ERIC Educational Resources Information Center

Marshall, Dawn

1982-01-01

There is need to assess the impact of migration on the Caribbean ecosystems. As a 150-year-old institution, emigration is related to the carrying capacity of the islands and the need to export the surplus population when capacity is threatened. Emigration, however, is a deterrent to development and individual independence. (KC)

Influential Factors in Incomplete Acquisition and Attrition of Young Heritage Speakers' Vocabulary Knowledge

ERIC Educational Resources Information Center

Gharibi, Khadijeh; Boers, Frank

2017-01-01

This study investigates whether young heritage speakers, either simultaneous or sequential bilinguals, have limited vocabulary knowledge in their family language compared to matched monolingual counterparts and, if so, what factors help to account for this difference. These factors include age, age at emigration, length of emigration, frequency of…

Reintegration of Emigrant Manpower and Promotion of Local Opportunities for Development (REMPLOD)

ERIC Educational Resources Information Center

Penninx, Rinus; And Others

1976-01-01

The REMPLOD project (Reintegration of Emigrant Manpower and the Promotion of Local Opportunities for Development) investigates ways in which foreign workers can contribute to development processes in their countries of origin (Morocco, Tunisia and Turkey). Three experts involved with the Turkish project make recommendations on the Turkish-Dutch…

Russian women emigrées in psychology: informal Jewish networks.

PubMed

Woodward, William R

2010-05-01

This paper uses archival sources and autobiographies to give a fuller account of the lives of three Russian women psychologists, each of whom voluntarily emigrated several years before the Third Reich. As such, their stories contribute to gender history, emigration history, and ethnic history. The characteristics of second-generation women in psychology seem to apply to this sample; they accepted applied or secondary positions in psychology or allied fields and came late to tenure-track positions. Some first-generation characteristics fit them also: choosing career over marriage, accepting the "family claim," and living "fractured lives." Emigrée history reveals that these women found careers in the United States that could not have happened in the smaller, more restricted higher education networks of Europe. Female friendships and family ties to the Old World sustained them. All struggled with professional networking and had varying success, depending heavily upon the patronage of sympathetic male psychologists. Ethnic history shows that none identified strongly with Judaism, yet all benefited from Jewish mentors and networks of patronage. Evidence of gendered or racial discrimination in hiring practices is sparse, though it surely existed.

Comparing the Reproductive Success of Yakima River Hatchery and Wild-Origin Spring Chinook; Yakima/Klickitat Fisheries Project Monitoring and Evaluation Report 4 of 7, 2003-2004 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schroder, S.L.; Knudsen, C.M.; Watson, B.D.

In September of 2003, twenty-nine hatchery and twenty-eight wild spring chinook adults were placed into the observation stream located at the Cle Elum Supplementation Research Facility. In, addition 20 precocious males, 7 hatchery and 13 wild, were simultaneously released into the structure. As in previous years, the fish had small amounts of fin material removed prior to being introduced into the stream so that microsatellite DNA based pedigree analyses could be performed on their subsequent progeny. The entire 127 m long by 7.9 m wide stream was made available to this group of fish. Continuous behavioral observations were made whilemore » the females prepared nests and spawned. Moreover, standard measurements of adult longevity, spawning participation, water velocity, redd sizes, gravel composition, water temperature and flow were taken. Fry produced from these fish started to emigrate from the stream in early January 2004. They were trapped and sub-sampled for later microsatellite DNA analyses. In mid May of 2004 fry emergence from the channel was complete and residual fish were captured by seine and electro-fishing so that the entire juvenile population could be proportionately sampled. Audiotape records of the behavior of wild and hatchery adults spawning in the observation stream in 2001 were transcribed into continuous ethograms. Courting, agonistic, and location data were extracted from these chronological records and analyzed to characterize the reproductive behavior of both hatchery and wild fish. In addition, a ''gold standard'' pedigree analysis was completed on the fry originating from the adults placed into the observation stream in 2001. Behavioral and morphological data collected on hatchery and wild males were linked to the results of the pedigree analysis to ascertain what factors affected their reproductive success (RS) or capacity to produce fry. Individual RS values were calculated for each male placed into the observation stream and the coefficient of variation calculated from these values was greater than 100%. To determine what might be responsible for this degree of variation we examined the relative importance of a variety of physical and behavioral traits. Relative body size, for example, was found not be an important predictor of reproductive success. Instead, the capacity to court females and dominate sexual rivals was directly associated with male RS. However, males that had low dominance scores were also successful at producing offspring. These individuals utilized alternative behavioral strategies to gain close proximity to females and were successful in their attempts to fertilize eggs. Observations made on the color patterns of males showed dominance was closely linked with the possession of an overall black or dark brown color pattern. In addition, we discovered that males that had multiple mates achieved higher RS values than those who spawned with fewer females. The approach we are taking to compare the reproductive competency of hatchery and wild fish is to first determine the factors that are strongly linked to reproductive behavior and then assess whether significant differences occur in the expression of these traits based on the fish origin. Transcriptions of audiotapes are continuing and a second gold standard pedigree analyses on the fry produced from adults placed into the observation stream in 2002 is nearing completion. Future work will be directed at discovering the factors that affect female RS values. In the fall of 2004 we will again liberate hatchery and wild fish simultaneously into the entire observation stream to continue our efforts to objectively determine if differences in RS are caused by fish origin.« less

Forced emigration, favourable outcomes.

PubMed

Pearn, J

2001-10-01

The discipline of public health and preventive medicine in Australia and New Zealand had its genesis in the advocacy of 18th and 19th century military pioneers. Military (Royal Navy and British Army) surgeons were posted to Australia as part of their non-discretionary duty. Civilian doctors emigrated variously for adventure, escapism and gold fever. One group, a particularly influential group disproportionate to their numbers, came in one sense as forced emigrants because of chronic respiratory disease in general, and tuberculosis in particular. Tuberculosis was an occupational hazard of 19th century medical and surgical practice throughout western Europe. This paper analyses six examples of such emigration which had, perhaps unforeseen at the time, significant results in the advancement of public health. Such emigration was in one sense voluntary, but in another was forced upon the victims in their quest for personal survival. In Australia, such medical individuals became leading advocates and successful catalysts for change in such diverse fields as social welfare, public health, the preventive aspects of medical practice, child health, nutrition and medical education. A number of such public health pioneers today have no physical memorials; but their influence is to be seen in the ethos of medical practice in Australia and New Zealand today. Their memory is further perpetuated in the names of Australian native wildflowers and trees that symbolise not only a healthy environment but the long-term investment, accrued with interest, of the institution of public health measures for which their advocacy achieved much success.

α4-Integrin Mediates Neutrophil-Induced Free Radical Injury to Cardiac Myocytes

PubMed Central

Poon, Betty Y.; Ward, Christopher A.; Cooper, Conan B.; Giles, Wayne R.; Burns, Alan R.; Kubes, Paul

2001-01-01

Previous work has demonstrated that circulating neutrophils (polymorphonuclear leukocytes [PMNs]) adhere to cardiac myocytes via β2-integrins and cause cellular injury via the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase enzyme system. Since PMNs induced to leave the vasculature (emigrated PMNs) express the α4-integrin, we asked whether (a) these PMNs also induce myocyte injury via NADPH oxidase; (b) β2-integrins (CD18) still signal oxidant production, or if this process is now coupled to the α4-integrin; and (c) dysfunction is superoxide dependent within the myocyte or at the myocyte–PMN interface. Emigrated PMNs exposed to cardiac myocytes quickly induced significant changes in myocyte function. Myocyte shortening was decreased by 30–50% and rates of contraction and relaxation were reduced by 30% within the first 10 min. Both α4-integrin antibody (Ab)-treated PMNs and NADPH oxidase–deficient PMNs were unable to reduce myocyte shortening. An increased level of oxidative stress was detected in myocytes within 5 min of PMN adhesion. Addition of an anti–α4-integrin Ab, but not an anti-CD18 Ab, prevented oxidant production, suggesting that in emigrated PMNs the NADPH oxidase system is uncoupled from CD18 and can be activated via the α4-integrin. Addition of exogenous superoxide dismutase (SOD) inhibited all parameters of dysfunction measured, whereas overexpression of intracellular SOD within the myocytes did not inhibit the oxidative stress or the myocyte dysfunction caused by the emigrated PMNs. These findings demonstrate that profound molecular changes occur within PMNs as they emigrate, such that CD18 and associated intracellular signaling pathways leading to oxidant production are uncoupled and newly expressed α4-integrin functions as the ligand that signals oxidant production. The results also provide pathological relevance as the emigrated PMNs have the capacity to injure cardiac myocytes through the α4-integrin–coupled NADPH oxidase pathway that can be inhibited by extracellular, but not intracellular SOD. PMID:11238444

U-Pb Zircon Geochronology of the Emigrant Gap Composite Pluton, Northern Sierra Nevada, California: Implications for the Nevadan Orogeny

USGS Publications Warehouse

Girty, G. H.; Yoshinobu, S.; Wracher, M.D.; Girty, M.S.; Bryan, K.A.; Skinner, J.E.; McNulty, B.A.; Bracchi, K.A.; Harwood, D.S.; Hanson, R.E.

1993-01-01

The undeformed Emigrant Gap composite pluton postdates the Lower to Middle Jurassic Sailor Canyon and Middle Jurassic Tuttle Lake Formations. According to earlier workers, these latterformations contain main and late phase Nevadan-aged (155 +/-3 Ma) spaced, slaty, phyllitic, and crenulation cleavage. Recently discovered fossils indicate that the upper part of the Sailor Canyon Formation can be no older than early Bajocian and no younger than Bathonian. The Tuttle Lake Formation stratigraphically overlies the Sailor Canyon Formation and thus probably includes middle to late Bajocian and/or Bathonian strata.The results of U-Pb work suggest that the Emigrant Gap composite pluton is composed of units that range in age from 168 +/-2 Ma (latest Bathonian to early Callovian) to 163-164 Ma (late Callovian). These new data, when combined with observations summarized above, imply that the Tuttle Lake Formation is older than the undeformed oldest unit of the Emigrant Gap composite pluton (i.e., latest Bathonian or early Callovian), and thus was probably deposited and deformed sometime between middle Bajocian and middle late Bathonian time. Hence, the cleavage contained within the Sailor Canyon and Tuttle Lake Formations could not have formed during the Late Jurassic Nevadan orogeny 155 +/-3 Ma as suggested by earlier workers.Within the foothills belt, just to the west of the Emigrant Gap composite pluton, a pronounced contractional deformation occurred sometime between 200 and 163 Ma (Early to Middle Jurassic). This middle Mesozoic deformation apparently was the result of a collision between an oceanic arc and continental North America. Because of the gross similarity in timing of structures produced during this collision and structures in the wall rocks of the Emigrant Gap composite pluton, we suggest that the latter Middle Jurassic structures are also the result of arc-continent collision, albeit a slightly more continentward expression.

Gulf money in Kerala: coping with the problems of plenty.

PubMed

Kurian, R; Thakore, D

The recent phenomenon of emigration from Kerala to the Gulf countries and the increasing inflow of remittances is having a tremendous impact on Kerala's economy. The state planning board reports that the remittances from the Gulf to this tiny state are Rs. 400 crones/year. An annual inflow of this amount cannot help influence the fortunes of the population. Although emigration from Kerala is not new, the current outflow reached massive proportions only in the wake of the intensive construction boom in the West Asian countries, after a huge volume of petro dollars flowed into those countries in the aftermath of the 1973 hike in oil price. In December 1977 a total of 135,000 Keralities were employed in foreign countries, mainly in West Asia. These adventurous migrants, in their quest for a wage, emigrated mainly from 4 areas in the state: Varkala in Trivandrum district; Thiruvalla in Alleppey district; Chavakkad in Trichur district; and almost all parts of Malappuram district. The bulk of the remittances are sent to households and next of kin concentrated in these areas. This unprecedented inflow of remittances has kindled the hopes of politicians and administrators of tapping these resources to solve the problems of economic development of the state. 1 category of emigrants come from poor households, are poorly educated, and are masons, carpenters, or even unskilled laborers. Because of their ignorance and gullibility they are exploited by middlemen who charge them Rs. 12,000 for a no objection certificate (NOC). Moneylenders are also doing a thriving business. Another type of emigrant is from relatively well off households, better educated, and able to obtain better jobs. There are also rich businessmen and contractors among them. It is this category of better educated emigrant who is able to save a substantial part of his income. State administrative circles note that remittances at best can provide only the financial capital. According to T.C. Razajm a businessman in Abu Dhabi since 1965, emigrants will invest in an industry only if they are convinced of the viability of the project, have a say in its management, and if there is reservation of jobs in the enterprise for their competent dependants. Thus far, the money mobilized into industry seems to be only a tiny proportion of the remittances. A major avenue of investment for the emigrants is real estate and, consequently, the prices of land have registered a marked increase. Even the service sector -- taxis and travel agencies -- have received a sizable boost because of the inflow of Gulf money into the state. According to G. Narayana Pillai, culturally and socially the new found wealth will not bring about any substantial social improvement.

Stochastic Forecasting of Labor Supply and Population: An Integrated Model.

PubMed

Fuchs, Johann; Söhnlein, Doris; Weber, Brigitte; Weber, Enzo

2018-01-01

This paper presents a stochastic model to forecast the German population and labor supply until 2060. Within a cohort-component approach, our population forecast applies principal components analysis to birth, mortality, emigration, and immigration rates, which allows for the reduction of dimensionality and accounts for correlation of the rates. Labor force participation rates are estimated by means of an econometric time series approach. All time series are forecast by stochastic simulation using the bootstrap method. As our model also distinguishes between German and foreign nationals, different developments in fertility, migration, and labor participation could be predicted. The results show that even rising birth rates and high levels of immigration cannot break the basic demographic trend in the long run. An important finding from an endogenous modeling of emigration rates is that high net migration in the long run will be difficult to achieve. Our stochastic perspective suggests therefore a high probability of substantially decreasing the labor supply in Germany.

Emigration, Generation, and Collective Memories: The Presence of the Past for Emigrants from the Former Soviet Union

ERIC Educational Resources Information Center

Corning, Amy D.

2010-01-01

Research on memory of public events consistently reveals generational effects, where individuals remember best the events from their "critical years" of adolescence and early adulthood--a phenomenon attributed to privileged encoding or retrieval of memories due to primacy of experience. Prior research, however, has not decoupled the…

Long-distance dispersal of spruce budworm (Choristoneura fumiferana Clemens) in Minnesota (USA) and Ontario (Canada) via the atmospheric pathway

Treesearch

Brian R. Sturtevant; Gary L. Achtemeier; Joseph J. Charney; Dean P. Anderson; Barry J. Cooke; Phillip A. Townsend

2013-01-01

Dispersal can play an important role in the population dynamics of forest insects, but the role of long-distance immigration and emigration remains unclear due to the difficulty of quantifying dispersal distance and direction. We designed an agent-based spruce budworm flight behavior model that, when interfaced with temperature, wind speed, and precipitation output...

Elderly Japanese emigrants to Brazil before World War II: I. Clinical profiles based on specific historical background.

PubMed

Meguro, M; Meguro, K; Caramelli, P; Ishizaki, J; Ambo, H; Chubaci, R Y; Hamada, G S; Nitrini, R; Yamadori, A

2001-08-01

To research the demographic and clinical profiles of elderly Japanese emigrants, who arrived in Brazil before World War II, in order to give them appropriate psychogeriatric care. Elderly Japanese immigrants aged 65 years and over, belonging to the Miyagi Association in the São Paulo Metropolitan Area, were targeted. They emigrated from Miyagi Prefecture to Brazil and are now living in the area. We were able to interview 166 respondents. All data were gathered using standardized interview methods covering (a) free interview about the immigration history, (b) demographics, and (c) physical status. Through the free interview, we found their immigration histories, which affected their clinical profiles. The mean age and educational level were 77.5 years and 6.3 years, respectively. Sixty per cent of them immigrated when they were younger than 14. Ninety-four per cent of them still keep Japanese nationality. Fifty-seven per cent of them usually use Japanese, while 10% of them use Portuguese. Although their emigration histories were hard, 76% of them perceived their health as being excellent or relatively good. The percentages of subjects with histories of disease were hypertension, 52.5%; cardiac disease, 20.8%; diabetes mellitus, 24.2%; and hyperlipidemia, 25.0%, which were affected by the Brazilian environment. The elderly Japanese who emigrated to Brazil before World War II have a unique historical and demographic background. Their clinical profiles cannot be fully understood without knowing their histories. They definitely need high quality international psychogeriatric care. Copyright 2001 John Wiley & Sons, Ltd.

"I Fear the Consequences to Our Animals": Emigrants and Their Livestock on the Overland Trails

ERIC Educational Resources Information Center

Ahmad, Diana L.

2012-01-01

The diaries, letters, and guidebooks written by the emigrants who crossed North America on the overland trails during the mid-nineteenth century reveal a new awareness of the animals that journeyed with them. Often written as advice to those who might follow them, the travelers worried about their animals in ways beyond what theologians and…

22 CFR 99.2 - Reporting requirements for adoption cases involving children emigrating from the United States.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-Convention case, the reporting provider is the one that has child placement responsibility, as evidenced by... (generally the time the child is matched with adoptive parents); (2) Date of U.S. final adoption or date on... involving children emigrating from the United States. 99.2 Section 99.2 Foreign Relations DEPARTMENT OF...

22 CFR 99.2 - Reporting requirements for adoption cases involving children emigrating from the United States.

Code of Federal Regulations, 2014 CFR

2014-04-01

...-Convention case, the reporting provider is the one that has child placement responsibility, as evidenced by... (generally the time the child is matched with adoptive parents); (2) Date of U.S. final adoption or date on... involving children emigrating from the United States. 99.2 Section 99.2 Foreign Relations DEPARTMENT OF...

22 CFR 99.2 - Reporting requirements for adoption cases involving children emigrating from the United States.

Code of Federal Regulations, 2013 CFR

2013-04-01

...-Convention case, the reporting provider is the one that has child placement responsibility, as evidenced by... (generally the time the child is matched with adoptive parents); (2) Date of U.S. final adoption or date on... involving children emigrating from the United States. 99.2 Section 99.2 Foreign Relations DEPARTMENT OF...

22 CFR 99.2 - Reporting requirements for adoption cases involving children emigrating from the United States.

Code of Federal Regulations, 2011 CFR

2011-04-01

...-Convention case, the reporting provider is the one that has child placement responsibility, as evidenced by... (generally the time the child is matched with adoptive parents); (2) Date of U.S. final adoption or date on... involving children emigrating from the United States. 99.2 Section 99.2 Foreign Relations DEPARTMENT OF...

22 CFR 99.2 - Reporting requirements for adoption cases involving children emigrating from the United States.

Code of Federal Regulations, 2012 CFR

2012-04-01

...-Convention case, the reporting provider is the one that has child placement responsibility, as evidenced by... (generally the time the child is matched with adoptive parents); (2) Date of U.S. final adoption or date on... involving children emigrating from the United States. 99.2 Section 99.2 Foreign Relations DEPARTMENT OF...

From Emigration to Immigration: New Dawn for an Intercultural 21st Century Ireland

ERIC Educational Resources Information Center

Mutwarasibo, Fidele

2005-01-01

Within the course of a decade Ireland has emerged from being a country of emigration to a country of immigration. Since the mid-1990s, Ireland has undergone rapid economic expansion with the recent economic growth resulting in approximately 252,000 migrants entering Ireland over the last 6 years, according to the Irish Times (2003). While a large…

Emigrant Creek cattle allotment: lessons from 30 years of photomonitoring.

Treesearch

Frederick C. Hall

2005-01-01

Emigrant Creek cattle allotment is located 48 km northwest of Burns, Oregon. It was photo sampled at nine original sites, starting in 1975. Photos were taken three times per year: June 15 prior to cattle grazing, August 1 at pasture rotation, and October 1 at the end of grazing. An additional four photopoints were established following disturbance from flooding and...

[Development and application of a web-based expert system using artificial intelligence for management of mental health by Korean emigrants].

PubMed

Bae, Jeongyee

2013-04-01

The purpose of this project was to develop an international web-based expert system using principals of artificial intelligence and user-centered design for management of mental health by Korean emigrants. Using this system, anyone can access the system via computer access to the web. Our design process utilized principles of user-centered design with 4 phases: needs assessment, analysis, design/development/testing, and application release. A survey was done with 3,235 Korean emigrants. Focus group interviews were also conducted. Survey and analysis results guided the design of the web-based expert system. With this system, anyone can check their mental health status by themselves using a personal computer. The system analyzes facts based on answers to automated questions, and suggests solutions accordingly. A history tracking mechanism enables monitoring and future analysis. In addition, this system will include intervention programs to promote mental health status. This system is interactive and accessible to anyone in the world. It is expected that this management system will contribute to Korean emigrants' mental health promotion and allow researchers and professionals to share information on mental health.

On the evolution of specialization with a mechanistic underpinning in structured metapopulations.

PubMed

Nurmi, Tuomas; Parvinen, Kalle

2008-03-01

We analyze the evolution of specialization in resource utilization in a discrete-time metapopulation model using the adaptive dynamics approach. The local dynamics in the metapopulation are based on the Beverton-Holt model with mechanistic underpinnings. The consumer faces a trade-off in the abilities to consume two resources that are spatially heterogeneously distributed to patches that are prone to local catastrophes. We explore the factors favoring the spread of generalist or specialist strategies. Increasing fecundity or decreasing catastrophe probability favors the spread of the generalist strategy and increasing environmental heterogeneity enlarges the parameter domain where the evolutionary branching is possible. When there are no catastrophes, increasing emigration diminishes the parameter domain where the evolutionary branching may occur. Otherwise, the effect of emigration on evolutionary dynamics is non-monotonous: both small and large values of emigration probability favor the spread of the specialist strategies whereas the parameter domain where evolutionary branching may occur is largest when the emigration probability has intermediate values. We compare how different forms of spatial heterogeneity and different models of local growth affect the evolutionary dynamics. We show that even small changes in the resource dynamics may have outstanding evolutionary effects to the consumers.

Inference about density and temporary emigration in unmarked populations

USGS Publications Warehouse

Chandler, Richard B.; Royle, J. Andrew; King, David I.

2011-01-01

Few species are distributed uniformly in space, and populations of mobile organisms are rarely closed with respect to movement, yet many models of density rely upon these assumptions. We present a hierarchical model allowing inference about the density of unmarked populations subject to temporary emigration and imperfect detection. The model can be fit to data collected using a variety of standard survey methods such as repeated point counts in which removal sampling, double-observer sampling, or distance sampling is used during each count. Simulation studies demonstrated that parameter estimators are unbiased when temporary emigration is either "completely random" or is determined by the size and location of home ranges relative to survey points. We also applied the model to repeated removal sampling data collected on Chestnut-sided Warblers (Dendroica pensylvancia) in the White Mountain National Forest, USA. The density estimate from our model, 1.09 birds/ha, was similar to an estimate of 1.11 birds/ha produced by an intensive spot-mapping effort. Our model is also applicable when processes other than temporary emigration affect the probability of being available for detection, such as in studies using cue counts. Functions to implement the model have been added to the R package unmarked.

Aeromonas salmonicida Infection Only Moderately Regulates Expression of Factors Contributing to Toll-Like Receptor Signaling but Massively Activates the Cellular and Humoral Branches of Innate Immunity in Rainbow Trout (Oncorhynchus mykiss)

PubMed Central

Brietzke, Andreas; Korytář, Tomáš; Jaros, Joanna; Köllner, Bernd; Goldammer, Tom; Seyfert, Hans-Martin; Rebl, Alexander

2015-01-01

Toll-like receptors (TLRs) are known to detect a defined spectrum of microbial structures. However, the knowledge about the specificity of teleost Tlr factors for distinct pathogens is limited so far. We measured baseline expression profiles of 18 tlr genes and associated signaling factors in four immune-relevant tissues of rainbow trout Oncorhynchus mykiss. Intraperitoneal injection of a lethal dose of Aeromonas salmonicida subsp. salmonicida induced highly increased levels of cytokine mRNAs during a 72-hour postinfection (hpi) period. In contrast, only the fish-specific tlr22a2 and the downstream factor irak1 featured clearly increased transcript levels, while the mRNA concentrations of many other tlr genes decreased. Flow cytometry quantified cell trafficking after infection indicating a dramatic influx of myeloid cells into the peritoneum and a belated low level immigration of lymphoid cells. T and B lymphocytes were differentiated with RT-qPCR revealing that B lymphocytes emigrated from and T lymphocytes immigrated into head kidney. In conclusion, no specific TLR can be singled out as a dominant receptor for A. salmonicida. The recruitment of cellular factors of innate immunity rather than induced expression of pathogen receptors is hence of key importance for mounting a first immune defense against invading A. salmonicida. PMID:26266270

Spatial and temporal variation of diet within a presumed metapopulation of Adelie penguins

USGS Publications Warehouse

Ainley, D.G.; Ballard, G.; Barton, K.J.; Karl, B.J.; Rau, G.H.; Ribic, C.A.; Wilson, P.R.

2003-01-01

We investigated temporal and spatial variability in the diet of chick-provisioning Ade??lie Penguins (Pygoscelis adeliae) breeding at all colonies within one isolated cluster in the southwestern Ross Sea, Antarctica, 1994-2000. We wished to determine if prey quality explained different population growth and emigration rates among colonies. Diet composition was described both by conventional means (stomach samples) and by analysis of stable isotopes in chick tissues (toenails of individuals killed by skuas [Stercorarius maccormicki]). Diets were similar among the four study colonies compared to the disparity apparent among 14 widely spaced sites around the continent. Calorimetry indicated that fish are more energetically valuable than krill, implying that if diet varied by colony, diet quality could attract recruits and help to explain differential rates of colony growth. However, a multiple-regression analysis indicated that diet varied as a function of year, time within the year, and percent of foraging area covered by sea ice, but not by colony location. Stable isotopes revealed similarity of diet at one colony where conventional sampling was not possible. We confirmed that sea ice importantly affects diet composition of this species in neritic waters, and found that (1) quality of summer diet cannot explain different population growth rates among colonies, and (2) stable isotope analysis of chick tissues (toenails) is a useful tool to synoptically describe diet in this species over a large area.

Brain drain: final year medical students' intentions of training abroad.

PubMed

Bojanic, Ana; Bojanic, Katarina; Likic, Robert

2015-06-01

In Croatia, a new European Union (EU) member state since July 2013, there is already a shortage of around 3280 doctors to reach the European average. To investigate the emigration intentions of the current cohort of final year medical students at Zabreb School of Medicine. An electronic questionnaire was used in June 2013 to assess the attitudes of 232 final year medical students towards working conditions abroad and expectations for career opportunities in Croatia following accession to the EU. With an overall response rate of 87%, more than half of the surveyed students (106/202, 53%) intended to travel abroad, either for specialty (52/202, 26%) or subspecialty (54/202, 27%) training. More female students (58/135, 43%) than male students (17/62, 27%) indicated they would not emigrate. Most attractive emigration destinations were: Germany (34/121, 28%), USA (19/121, 16%), the UK (19/121, 16%), Switzerland (16/121, 13%) and Canada (11/121, 9%). The most important goals that respondents aimed to achieve through training abroad were to excel professionally (45/120, 38%), to prosper financially (20/120, 17%) and to acquire new experiences and international exposure (31/120, 26%). Students' motivating factors, goals for and positive beliefs about training abroad, as well as negative expectations regarding career opportunities in Croatia, may point towards actions that could be taken to help make Croatia a country that facilitates medical education and professional career development of young doctors. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Effects of food limitation and emigration on self-thinning in experimental minnow cohorts

USGS Publications Warehouse

Dunham, J.B.; Dickerson, B. R.; Beever, E.; Duncan, R. D.; Vinyard, G.L.

2000-01-01

5. Most of the support for FST in mobile animals comes from observational data on mean body mass and population density. Potentially important mechanisms, including the manner in which individuals are lost or retained in populations, are usually not investigated directly. Such tests of FST can only provide equivocal support. Detailed observational study and controlled experiments are needed to understand casual mechanisms.

Aboriginal Community Education Officers' Border Work: Culturally Safe Practices for Supporting Migrating Indigenous Students from Country into Urban and Semi-Rural Schools

ERIC Educational Resources Information Center

MacGill, Bindi

2012-01-01

Since 2001 there has been an increase in migration patterns by Indigenous families from remote communities to urban and semi-rural locations. Indigenous student emigration from remote Indigenous schools to urban and semi-rural schools is an emerging crisis as there are routinely inadequate service providers for Indigenous emigres. Migration away…

78 FR 28146 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Shrimp Fishery of the Gulf of...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-14

... major period of emigration of these shrimp from Texas estuaries to the Gulf of Mexico (Gulf) so the... to project when brown shrimp in Texas bays and estuaries will reach a mean size of 3.54 in (90 mm), and begin strong emigrations out of the bays and estuaries during maximum duration ebb tides. Sampling...

Pestalozzi in Dewey's Realm? Bauhaus Master Josef Albers among the German-Speaking Emigres' Colony at Black Mountain College (1933-1949)

ERIC Educational Resources Information Center

Fussl, Karl Heinz

2006-01-01

This article deals with German academic emigres who fled Hitler after 1933 and established their refuge at the American-based Black Mountain College in North Carolina, founded as an alternative to traditional institutions of higher education in that very year. Of particular consideration are the contributions of noted Bauhaus master Josef Albers…

The cost of health professionals' brain drain in Kenya.

PubMed

Kirigia, Joses Muthuri; Gbary, Akpa Raphael; Muthuri, Lenity Kainyu; Nyoni, Jennifer; Seddoh, Anthony

2006-07-17

Past attempts to estimate the cost of migration were limited to education costs only and did not include the lost returns from investment. The objectives of this study were: (i) to estimate the financial cost of emigration of Kenyan doctors to the United Kingdom (UK) and the United States of America (USA); (ii) to estimate the financial cost of emigration of nurses to seven OECD countries (Canada, Denmark, Finland, Ireland, Portugal, UK, USA); and (iii) to describe other losses from brain drain. The costs of primary, secondary, medical and nursing schools were estimated in 2005. The cost information used in this study was obtained from one non-profit primary and secondary school and one public university in Kenya. The cost estimates represent unsubsidized cost. The loss incurred by Kenya through emigration was obtained by compounding the cost of educating a medical doctor and a nurse over the period between the average age of emigration (30 years) and the age of retirement (62 years) in recipient countries. The total cost of educating a single medical doctor from primary school to university is 65,997 US dollars; and for every doctor who emigrates, a country loses about 517,931 US dollars worth of returns from investment. The total cost of educating one nurse from primary school to college of health sciences is 43,180 US dollars; and for every nurse that emigrates, a country loses about 338,868 US dollars worth of returns from investment. Developed countries continue to deprive Kenya of millions of dollars worth of investments embodied in her human resources for health. If the current trend of poaching of scarce human resources for health (and other professionals) from Kenya is not curtailed, the chances of achieving the Millennium Development Goals would remain bleak. Such continued plunder of investments embodied in human resources contributes to further underdevelopment of Kenya and to keeping a majority of her people in the vicious circle of ill-health and poverty. Therefore, both developed and developing countries need to urgently develop and implement strategies for addressing the health human resource crisis.

The cost of health professionals' brain drain in Kenya

PubMed Central

Kirigia, Joses Muthuri; Gbary, Akpa Raphael; Muthuri, Lenity Kainyu; Nyoni, Jennifer; Seddoh, Anthony

2006-01-01

Background Past attempts to estimate the cost of migration were limited to education costs only and did not include the lost returns from investment. The objectives of this study were: (i) to estimate the financial cost of emigration of Kenyan doctors to the United Kingdom (UK) and the United States of America (USA); (ii) to estimate the financial cost of emigration of nurses to seven OECD countries (Canada, Denmark, Finland, Ireland, Portugal, UK, USA); and (iii) to describe other losses from brain drain. Methods The costs of primary, secondary, medical and nursing schools were estimated in 2005. The cost information used in this study was obtained from one non-profit primary and secondary school and one public university in Kenya. The cost estimates represent unsubsidized cost. The loss incurred by Kenya through emigration was obtained by compounding the cost of educating a medical doctor and a nurse over the period between the average age of emigration (30 years) and the age of retirement (62 years) in recipient countries. Results The total cost of educating a single medical doctor from primary school to university is US$ 65,997; and for every doctor who emigrates, a country loses about US$ 517,931 worth of returns from investment. The total cost of educating one nurse from primary school to college of health sciences is US$ 43,180; and for every nurse that emigrates, a country loses about US$ 338,868 worth of returns from investment. Conclusion Developed countries continue to deprive Kenya of millions of dollars worth of investments embodied in her human resources for health. If the current trend of poaching of scarce human resources for health (and other professionals) from Kenya is not curtailed, the chances of achieving the Millennium Development Goals would remain bleak. Such continued plunder of investments embodied in human resources contributes to further underdevelopment of Kenya and to keeping a majority of her people in the vicious circle of ill-health and poverty. Therefore, both developed and developing countries need to urgently develop and implement strategies for addressing the health human resource crisis. PMID:16846492

Migration and coronary heart disease: A study of Finnish twins living in Sweden and their co-twins residing in Finland.

PubMed

Hedlund, Ebba; Kaprio, Jaakko; Lange, Anders; Koskenvuo, Markku; Jartti, Laura; Rönnemaa, Tapani; Hammar, Niklas

2007-01-01

Finland and Sweden are neighbouring countries with a substantially higher incidence and mortality from coronary heart disease (CHD) in Finland. Migration from Finland to Sweden has resulted in a population of about 187,000 Finnish immigrants, with a higher risk of CHD than Swedes. The aim of the present study was to analyse the prevalence of CHD in migrants to Sweden compared with co-twins remaining in Finland. The study population consisted of twin pairs of the Finnish Twin Cohort Study where at least one twin had lived one year or more in Sweden, including 1,534 subjects and 251 complete twin pairs discordant regarding residency in Sweden. Emigrant twins were compared with nonmigrant co-twins regarding prevalence of CHD in 1998. CHD prevalence was assessed by self-reported questionnaires validated using information from a clinical examination. Self-reported CHD showed a good correspondence with clinical diagnosis. Differences in social and behavioural risk factors for CHD among men were small but emigrants were more physically active than non-migrants. Female emigrants had less overweight and better education, but were more often working class than non-migrants. Intra-pair comparisons restricted to migration discordant pairs showed a tendency towards a reduced prevalence of CHD in the migrant co-twins (0.6; 0.3-1.4). In analyses of all subjects disregarding pair status, emigrants showed a reduced prevalence of CHD compared with subjects always living in Finland (0.6; 0.4-0.9). Emigration from Finland to Sweden may be associated with a reduced prevalence of CHD. The causes are most likely multifactorial and may involve changes in dietary habits, physical activity, psychosocial factors, and inflammation.

Some issues in Middle Eastern international migration.

PubMed

Sirageldin, I

1983-01-01

2 controversial issues related to the consequences of Middle Eastern international migration were examined: its effect on the development policies of the labor importing countries with a special reference to the case of Kuwait; and its effect on the growth potential of the labor exporting countries with special reference to recent development in Egypt's agricultural reproductivity. A preliminary note comments on the analytical nature of international labor migration in the Middle East and on the public view of emigrants as export commodities. The basic parameters of a desired population parity are interrelated. It is possible to influence the labor ratio (R2) as well as the nonKuwait crude labor participation rate (R3) through a migration policy. Thus, given a policy objective of some desired balance stated in trms of 1 or more of the identified parameters, it is possible to analyze the consequences of alternative migration strategies. It is important to consider the role of relative productivity (R6). An attempt to change R6 has implications for both the design of a migration policy and a national policy of human capital formation. Other factors may not be immediately related to a migration policy. The question then is whether these ratios are sensitive to policy intervention. In a simulation exercise it was assumed that the Kuwaiti crude labor force participation rate (R4) will increase by 13% during a period of 10 years. R4 increases if relatively more people work. Women are 1 segment of the labor force that is not adequately represented, partly because of traditions, lack of skills, and the presence of high fertility. None of these can change in the short run without an active policy of social reform. Yet, the assumption seems to be in the right direction. A policy that attempts to reduce R4 through increasing fertility in Kuwait is clearly against the tide. In sum, the labor importing countries faced with recent unfavorable demographic realities will actively develop population policies that are consistent with their socioeconomic plans. The flow of labor immigration is a tool that can be manipulated on relatively short notice, and the economic cost of such a policy is relatively simple to estimate. In examining labor exporting countries, the focus is narrowed to 1 sector (agriculture) and with 1 issue their emigration behavior are being blamed simultaneously for the decline of the agricultural sector. Some hypotheses are offered. Clearly, emigration in the case of Egyptian agriculture must be evaluated in terms of the gross benefit of remittances and in terms of their effect on local production in the short-and longterm. It seems that population and development policies must take care of the effect of emigration on agricultural productivity through 2 channels: the effect of remittances on expenditure and labor market behavior; and its effect on fertility behavior.

The Peruvian diaspora: portrait of a migratory process.

PubMed

Durand, Jorge

2010-01-01

Since the 1980s and especially the 1990s, Peru has become a nation of emigrants. Emigration has become massive over the past two decades, and the Peruvian populations of the United States, Japan, and Spain have tripled in less than a decade. A survey of households in five localities, three urban and two rural, in and around Lima helps to reveal the special character of this emigration. It tends to involve older and better-educated individuals than are typical of international migration and to target a wider variety of destinations. Moreover, it is a multiclass phenomenon. The economic, political, and social crisis brought about by a change in the economic model, two decades of terrorism, and a succession of failed democratic administrations has affected the society as a whole, and international migration seems to operate as an escape valve.

Population viability of Arctic grayling in the Gibbon River, Yellowstone National Park

USGS Publications Warehouse

Steed, Amber C.; Zale, Alexander V.; Koel, Todd M.; Kalinowski, Steven T.

2010-01-01

The fluvial Arctic grayling Thymallus arcticus is restricted to less than 5% of its native range in the contiguous United States and was relisted as a category 3 candidate species under the U.S. Endangered Species Act in 2010. Although fluvial Arctic grayling of the lower Gibbon River, Yellowstone National Park, Wyoming, were considered to have been extirpated by 1935, anglers and biologists have continued to report catching low numbers of Arctic grayling in the river. Our goal was to determine whether a viable population of fluvial Arctic grayling persisted in the Gibbon River or whether the fish caught in the river were downstream emigrants from lacustrine populations in headwater lakes. We addressed this goal by determining relative abundances, sources, and evidence for successful spawning of Arctic grayling in the Gibbon River. During 2005 and 2006, Arctic grayling comprised between 0% and 3% of the salmonid catch in riverwide electrofishing (mean < 1%; SE < 1%) and snorkeling (mean = 1%; SE = 1%) surveys; Arctic grayling constituted 0–14% of the salmonid catch obtained by targeted angling (3 of 22 fish; mean = 4%; SE = 5%). Low values of the genetic differentiation index (F ST = 0.0021 ± 0.002 [mean ± 95% confidence interval]) between headwater lake and river Arctic grayling indicated that fish from throughout the Gibbon River system probably belonged to the same population. Back-calculated lengths at most ages were similar among all fish, and successful spawning within the Gibbon River below the headwater lakes was not documented. Few Arctic grayling adults and no fry were detected in the Gibbon River, implying that a reproducing fluvial population does not exist there. These findings have implications for future Endangered Species Act considerations and management of fluvial Arctic grayling within and outside of Yellowstone National Park. Our comprehensive approach is broadly applicable to the management of sparsely detected aquatic species worldwide.

JPRS Report, West Europe

DTIC Science & Technology

1987-06-05

Economy Through 1989 (Jan Magnus Fahlstrom; DAGENS NYHETER, 9 Apr 87) 98 SOCIAL SWEDEN Lapps Weigh Emigration Following Chernobyl Devastation...after Chernobyl the Soviet state is a bogeyman for the rest of the world—in human terms, economically and in the area of envir- onmental technology...election year." 11798 , CS0: 3650/102 99 „«„■P»T SWEDEN SOCIAL LAPPS WEIGH EMIGRATION FOLLOWING CHERNOBYL DEVASTATION Stockholm DAGENS NYHETER

Migration Flow and Its Impact on Tuberculosis Notification in Portugal.

PubMed

Dias, Ana; Gaio, Rita; Sousa, Pedro; Gomes, Marta; Oliveira, Olena; Duarte, Raquel

2018-01-01

Tuberculosis notification in Portugal has decreased in the last few years. As a consequence of the economic crisis, emigration has increased and immigration has decreased. Immigrants are a risk group for tuberculosis. Most emigrants are 20-44 years old and belong to the age group most affected by tuberculosis. To describe the decrease in tuberculosis notification in Portugal over the last years from a demographical point of view. Mathematical analysis was performed to quantify the effect of the migration movements (separately and simultaneously) on tuberculosis notification in Portugal from 2008 to 2014. We calculated the estimated tuberculosis notification for each year during the period of study: 1) fixing immigration rate and tuberculosis rate in immigrants at 2008 values; 2) fixing emigration rate and tuberculosis rate in emigrants at 2008 values; 3) fixing both phenomenons at 2008 values. The differences between the observed and the estimated numbers were small (≤0.5 cases/100000 inhabitants). Impact of the migration movements on tuberculosis notification rate does not seem to be significant when analyzed for each phenomenon individually and simultaneously, by our model. This might mean that we have to concentrate our efforts in other risk factors for tuberculosis. Copyright © 2017 SEPAR. Publicado por Elsevier España, S.L.U. All rights reserved.

Modulation of leukocyte adhesion in rat mesenteric venules by aspirin and salicylate.

PubMed

Asako, H; Kubes, P; Wallace, J; Wolf, R E; Granger, D N

1992-07-01

Erythrocyte velocity, vessel diameter, leukocyte rolling velocity, and number of adherent and emigrated leukocytes were measured in postcapillary venules both before and during superfusion of rat mesentery with either aspirin or sodium salicylate. In some experiments, animals were treated with either a leukotriene (LT)-synthesis inhibitor (L-663,536), an LTD4 antagonist (MK-571), an LTB4 antagonist (SC-41930), misoprostol, or prostaglandin (PG) I2, then the aspirin protocol was repeated. Superfusion of aspirin but not sodium salicylate resulted in increased leukocyte adherence and a reduced leukocyte rolling velocity but did not affect leukocyte emigration. Aspirin-induced leukocyte adhesion was effectively prevented by the LT-synthesis inhibitor and LTB4 antagonist but not by the LTD4 antagonist. Misoprostol and PGI2 also prevented the aspirin-induced adhesion responses. Superfusion of the mesentery with either platelet-activating factor (PAF) or LTB4 enhanced leukocyte adherence and emigration while reducing leukocyte rolling velocity. Sodium salicylate prevented all of the adhesion responses elicited by LTB4. Although salicylate did not affect the PAF-induced leukocyte adherence and rolling responses, it completely prevented the increased leukocyte emigration. These results indicate that aspirin promotes, whereas sodium salicylate inhibits, leukocyte-endothelial cell adhesive interactions at therapeutically relevant concentrations.

Human Resources for Health Challenges in Nigeria and Nurse Migration.

PubMed

Salami, Bukola; Dada, Foluke O; Adelakun, Folake E

2016-05-01

The emigration of sub-Saharan African health professionals to developed Western nations is an aspect of increasing global mobility. This article focuses on the human resources for health challenges in Nigeria and the emigration of nurses from Nigeria as the country faces mounting human resources for health challenges. Human resources for health issues in Nigeria contribute to poor population health in the country, alongside threats from terrorism, infectious disease outbreaks, and political corruption. Health inequities within Nigeria mirror the geographical disparities in human resources for health distribution and are worsened by the emigration of Nigerian nurses to developed countries such as the United States and the United Kingdom. Nigerian nurses are motivated to emigrate to work in healthier work environments, improve their economic prospects, and advance their careers. Like other migrant African nurses, they experience barriers to integration, including racism and discrimination, in receiving countries. We explore the factors and processes that shape this migration. Given the forces of globalization, source countries and destination countries must implement policies to more responsibly manage migration of nurses. This can be done by implementing measures to retain nurses, promote the return migration of expatriate nurses, and ensure the integration of migrant nurses upon arrival in destination countries. © The Author(s) 2016.

Emigration of Natural and Hatchery Chinook Salmon and Steelhead Smolts from the Imnaha River, Oregon, Progress Report 2000-2002.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cleary, Peter; Kucera, Paul; Blenden, Michael

This report summarizes the emigration studies of the Nez Perce Tribe in the Imnaha River subbasin during the 2001 and 2002 migration years. A migration year for the Imnaha River is defined here as beginning July 31 of the previous year and ending July 30 the following year. The conclusion of the studies at the end of migration year 2002 marked the 11th year of the Nez Perce Tribe's Lower Snake River Emigration Studies. The Nez Perce Tribe has participated in the Fish Passage Center's Smolt Monitoring Program for nine of the 11 years. These studies collect and tag juvenilemore » chinook salmon and steelhead at two locations in the fall, rkm 74 and rkm 7, and at rkm 7 during the spring. Data from captured and tagged fish provide an evaluation of hatchery production and releases strategies, post release survival of hatchery chinook salmon, abundance of natural chinook salmon, and downstream survival and arrival timing of natural and hatchery chinook salmon and steelhead. The hydrologic conditions that migrating fish encountered in 2001 were characterized as a drought and conditions in 2002 were characterized as below average. Hatchery chinook salmon had a mean fork length that was 34 mm greater in 2001 and 35 mm greater in 2002 than the mean fork length of natural chinook smolts. Hatchery steelhead smolt mean fork lengths were 39 mm greater than natural steelhead smolts in 2001 and 44 mm greater than natural steelhead smolt fork lengths in 2002. A significant difference (p < 0.05) between hatchery and natural chinook salmon and steelhead fork lengths has been documented by these emigration studies from 1997 to 2002. Hatchery chinook salmon were volitionally released in 2001 and 2002 and the 90% arrivals for 2001 and 2002 at the lower rkm 7 trap were within the range of past observations of 22 to 38 days observed in 1999 and 2000. We estimated that 93.9% of the 123,014 hatchery chinook salmon released in 2001 survived to the lower trap and 90.2% of the 303,769 hatchery chinook salmon released in 2002 survived to the lower trap. Post release survival estimates for hatchery chinook salmon were within the range of past estimates; 88.4% in 1998 to 100.9% in 1994. An estimated 7,646 to 23,249 (95% C.I.) natural chinook salmon smolts migrated past the lower Imnaha River trap from April 4 to April 22. An additional 6,767 to 14,706 (95% C.I.) natural chinook salmon smolts migrated past the lower Imnaha River trap from April 23 to May 14, 2002. Natural chinook salmon captured and tagged at the upper rkm 74 trap survived to Lower Granite Dam (LGR) at a rate of 28.8% during migration year 2001 and 21.9% during migration year 2002. The survival estimate for fall tagged natural chinook salmon from the lower trap to LGR was 41.9% in 2001 and 33.3% in 2002. Differences between survival from release to LGR for fall tagged natural chinook salmon from the lower trap have been 5.9% to 16.9% higher than for fall tagged natural chinook salmon from the upper trap from 1994 to 2002. Spring PIT tag release groups of natural chinook salmon, hatchery chinook salmon, and hatchery steelhead produced estimates of survival from the trap to LGR within the range of past estimates since 1993. Estimated survival from release to LGR for 2001 and 2002 were as follows: 83.7% and 86.9% for natural chinook salmon, 80.3% and 77.3% for hatchery chinook salmon, 82.7% and 81.8% for natural steelhead, and 82.0% and 83.0% for hatchery steelhead. Estimates of survival for spring tagged fish from the trap to Lower Monumental Dam (LMO) during the drought of 2001 were the lowest estimates of survival from 1998 to 2002 for natural chinook salmon, and from1997 to 2002 for natural and hatchery steelhead. Estimates of migration year 2001 survival from the trap to LMO were as follows: 65.6% - natural chinook salmon, 68.9% - hatchery chinook salmon, 49.7% natural steelhead, and 42.9% - hatchery steelhead. Estimates of migration year 2002 survival from the trap to LMO were as follows: 76.8% - natural chinook salmon, 68.1% - hatchery chinook salmon, 69.9% natural steelhead, and 78.0% - hatchery steelhead. A smolt-to-adult return rate (SAR) index from LGR to LGR was calculated for migrating pre-smolt and smolt natural chinook salmon, that were PIT tagged in the fall and spring at the lower trap, for brood years 1996 to 1998 (migration years 1998 to 2000). The SARs are representative of in-river Imnaha natural chinook salmon. The LGR to LGR SAR index for presmolt chinook salmon is as follows: 3.08% (BY 1996), 2.41% (BY 1997), and 2.98% (BY 1998). Smolt-to-adult return rate index for spring tagged smolts was lower: 1.75% (BY 1996), 2.24% (BY 1997) and 2.94% (BY 1998). Fall tagged natural chinook salmon from the upper and lower trap and spring tagged natural chinook salmon from the lower trap all had significantly different (p < 0.05) median and cumulative arrival timing at LGR during migration year 2001.« less

Unusual dynamics of extinction in a simple ecological model.

PubMed Central

Sinha, S; Parthasarathy, S

1996-01-01

Studies on natural populations and harvesting biological resources have led to the view, commonly held, that (i) populations exhibiting chaotic oscillations run a high risk of extinction; and (ii) a decrease in emigration/exploitation may reduce the risk of extinction. Here we describe a simple ecological model with emigration/depletion that shows behavior in contrast to this. This model displays unusual dynamics of extinction and survival, where populations growing beyond a critical rate can persist within a band of high depletion rates, whereas extinction occurs for lower depletion rates. Though prior to extinction at lower depletion rates the population exhibits chaotic dynamics with large amplitudes of variation and very low minima, at higher depletion rates the population persists at chaos but with reduced variation and increased minima. For still higher values, within the band of persistence, the dynamics show period reversal leading to stability. These results illustrate that chaos does not necessarily lead to population extinction. In addition, the persistence of populations at high depletion rates has important implications in the considerations of strategies for the management of biological resources. PMID:8643661

Proceedings of the Annual Meeting of the Association for Education in Journalism and Mass Communication (75th, Montreal, Quebec, Canada, August 5-8, 1992). Part I: Journalism History, Section A.

ERIC Educational Resources Information Center

Association for Education in Journalism and Mass Communication.

Section A of the Journalism History section of the proceedings contains the following 10 papers: "Mixed Messages in a Progressive Newspaper: The Milwaukee Journal and Woman Suffrage, 1911-1912" (Elizabeth Burt); "The Search for Unity: The Importance of the Black Press in the Emigration/Colonization Issues of the 1800s" (Bernell…

Verification of a ‘freshwater-type’ life history variant of juvenile American shad in the Columbia River

USGS Publications Warehouse

Wetzel, Lisa A.; Larsen, Kimberly A.; Parsley, Michael J.; Zimmerman, Christian E.

2011-01-01

American shad are native to the Atlantic coast of North America and were successfully introduced to the Pacific coast in the 1870s. They are now more abundant in the Columbia River than are its native salmon. As in their native range, Columbia River American shad are anadromous and have been assumed to solely exhibit an ‘ocean-type’ life history, characterized by a short period of juvenile rearing in freshwater, followed by seaward migration and saltwater entry before age-1, with sexually mature individuals returning to freshwater to spawn beginning at age-3. During October 2007, emigrating juvenile American shad were captured in the juvenile fish monitoring facility at Bonneville Dam (river kilometer 235) on the Columbia River. Their length frequencies revealed the presence of two modes; the lower mode averaged 77 mm fork length (FL) and the upper mode averaged 184 mm FL. A subsample of fish from each mode was aged using otoliths. Otoliths from the lower mode (n=10) had no annuli, indicating that they were all age-0, while otoliths from the upper mode (n=25) had one or two annuli, indicating that they were either age-1 or age-2, respectively. Spawning adults collected in June 2007 averaged 393 mm FL (range 305-460 mm; n=21) and were estimated to range in age from 3-6. Elemental analyses of juvenile and adult otoliths provide evidence for deviations from the typical migration pattern expected for this species, including extensive freshwater rearing of up to two years. This evidence shows that a ‘freshwater-type’ of juvenile American shad exists as year-round or transient residents in the Columbia River basin. The ecological role of this life history variant within the fish community is unknown.

Snake River Sockeye Salmon Habitat and Limnological Research; 2001 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohler, Andre E.; Taki, Doug; Griswold, Robert G.

2004-08-01

In March 1990, the Shoshone-Bannock Tribes petitioned the National Marine Fisheries Service (NMFS) to list the Snake River sockeye salmon Oncorhynchus nerka as endangered. As a result of that petition the Snake River sockeye salmon was officially listed as endangered in November 1991 under the Endangered Species Act (56 FR 58619). In 1991, the Snake River Sockeye Salmon Habitat and Limnological Research Program was implemented (Project Number 91-71, Intergovernmental Contract Number DE-BI79-91bp22548). This project is part of an interagency effort to prevent the extinction of the Redfish Lake stock of O. nerka. The Bonneville Power Administration (BPA) provides funding formore » this interagency recovery program through the Northwest Power Planning Council Fish and Wildlife Program (Council). Collaborators in the recovery effort include the National Marine Fisheries Service (NMFS), the Idaho Department of Fish and Game (IDFG), the University of Idaho (UI), U.S. Forest Service (USFS), and the Shoshone-Bannock Tribe (SBT). This report summarizes activities conducted by Shoshone-Bannock Tribal Fisheries Department personnel during the 2001 calendar year. Project objectives include: (1) monitor over-winter survival and emigration of juvenile anadromous O. nerka stocked from the captive rearing program; (2) fertilize Redfish Lake, fertilization of Pettit and Alturas lakes was suspended for this year; (3) conduct kokanee (non-anadromous O. nerka) population surveys; (4) monitor spawning kokanee escapement and estimate fry recruitment on Fishhook, Alturas Lake, and Stanley Lake creeks; (5) evaluate potential competition and predation interactions between stocked juvenile O. nerka and a variety of fish species in Redfish, Pettit, and Alturas lakes; (6) monitor limnological parameters of Sawtooth Valley lakes to assess lake productivity.« less

Evaluation of stream flow effects on smolt survival in the Yakima River basin, Washington

USGS Publications Warehouse

Courter,; Garrison,; Kock, Tobias J.; Perry, Russell W.

2012-01-01

Yearling Chinook smolt survival and travel time estimates from 2012 suggest that migration rates and survival rates in the Roza Reach may be associated with stream flow, water temperature, release timing (i.e. migratory disposition), and fish size, but the extent to which each variable influenced survival is yet to be determined. The lowest survival rate (61%) and longest travel time (median 2.26 days) was observed in Release Group 1, which had the smallest size distribution and experienced the lowest flows, lowest temperatures, and earliest release date among the three groups. Release Groups 2 and 3 survived at 96% and 98% respectively and traveled through the Roza Reach in less than eight hours. The primary focus of years two and three of this study will be to collect data that minimizes the effect of confounding explanatory variables, so that flow effects on emigration survival can be quantified independent of these other influential factors.

Stochastic differential equation model for linear growth birth and death processes with immigration and emigration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Granita, E-mail: granitafc@gmail.com; Bahar, A.

This paper discusses on linear birth and death with immigration and emigration (BIDE) process to stochastic differential equation (SDE) model. Forward Kolmogorov equation in continuous time Markov chain (CTMC) with a central-difference approximation was used to find Fokker-Planckequation corresponding to a diffusion process having the stochastic differential equation of BIDE process. The exact solution, mean and variance function of BIDE process was found.

Speed versus accuracy in decision-making ants: expediting politics and policy implementation.

PubMed

Franks, Nigel R; Dechaume-Moncharmont, François-Xavier; Hanmore, Emma; Reynolds, Jocelyn K

2009-03-27

Compromises between speed and accuracy are seemingly inevitable in decision-making when accuracy depends on time-consuming information gathering. In collective decision-making, such compromises are especially likely because information is shared to determine corporate policy. This political process will also take time. Speed-accuracy trade-offs occur among house-hunting rock ants, Temnothorax albipennis. A key aspect of their decision-making is quorum sensing in a potential new nest. Finding a sufficient number of nest-mates, i.e. a quorum threshold (QT), in a potential nest site indicates that many ants find it suitable. Quorum sensing collates information. However, the QT is also used as a switch, from recruitment of nest-mates to their new home by slow tandem running, to recruitment by carrying, which is three times faster. Although tandem running is slow, it effectively enables one successful ant to lead and teach another the route between the nests. Tandem running creates positive feedback; more and more ants are shown the way, as tandem followers become, in turn, tandem leaders. The resulting corps of trained ants can then quickly carry their nest-mates; but carried ants do not learn the route. Therefore, the QT seems to set both the amount of information gathered and the speed of the emigration. Low QTs might cause more errors and a slower emigration--the worst possible outcome. This possible paradox of quick decisions leading to slow implementation might be resolved if the ants could deploy another positive-feedback recruitment process when they have used a low QT. Reverse tandem runs occur after carrying has begun and lead ants back from the new nest to the old one. Here we show experimentally that reverse tandem runs can bring lost scouts into an active role in emigrations and can help to maintain high-speed emigrations. Thus, in rock ants, although quick decision-making and rapid implementation of choices are initially in opposition, a third recruitment method can restore rapid implementation after a snap decision. This work reveals a principle of widespread importance: the dynamics of collective decision-making (i.e. the politics) and the dynamics of policy implementation are sometimes intertwined, and only by analysing the mechanisms of both can we understand certain forms of adaptive organization.

For money or service?: a cross-sectional survey of preference for financial versus non-financial rural practice characteristics among Ghanaian medical students.

PubMed

Johnson, Jennifer C; Nakua, Emmanuel; Dzodzomenyo, Mawuli; Agyei-Baffour, Peter; Gyakobo, Mawuli; Asabir, Kwesi; Kwansah, Janet; Kotha, S Rani; Snow, Rachel C; Kruk, Margaret E

2011-11-03

Health worker shortage and maldistribution are among the biggest threats to health systems in Africa. New medical graduates are prime targets for recruitment to deprived rural areas. However, little research has been done to determine the influence of workers' background and future plans on their preference for rural practice incentives and characteristics. The purpose of this study was to identify determinants of preference for rural job characteristics among fourth year medical students in Ghana. We asked fourth-year Ghanaian medical students to rank the importance of rural practice attributes including salary, infrastructure, management style, and contract length in considering future jobs. We used bivariate and multivariate ordinal logistic regression to estimate the association between attribute valuation and students' socio-demographic background, educational experience, and future career plans. Of 310 eligible fourth year medical students, complete data was available for 302 students (97%). Students considering emigration ranked salary as more important than students not considering emigration, while students with rural living experience ranked salary as less important than those with no rural experience. Students willing to work in a rural area ranked infrastructure as more important than students who were unwilling, while female students ranked infrastructure as less important than male students. Students who were willing to work in a rural area ranked management style as a more important rural practice attribute than those who were unwilling to work in a rural area. Students studying in Kumasi ranked contract length as more important than those in Accra, while international students ranked contract length as less important than Ghanaian students. Interventions to improve rural practice conditions are likely to be more persuasive than salary incentives to Ghanaian medical students who are willing to work in rural environments a priori. Policy experiments should test the impact of these interventions on actual uptake by students upon graduation.

For money or service? a cross-sectional survey of preference for financial versus non-financial rural practice characteristics among ghanaian medical students

PubMed Central

2011-01-01

Background Health worker shortage and maldistribution are among the biggest threats to health systems in Africa. New medical graduates are prime targets for recruitment to deprived rural areas. However, little research has been done to determine the influence of workers' background and future plans on their preference for rural practice incentives and characteristics. The purpose of this study was to identify determinants of preference for rural job characteristics among fourth year medical students in Ghana. Methods We asked fourth-year Ghanaian medical students to rank the importance of rural practice attributes including salary, infrastructure, management style, and contract length in considering future jobs. We used bivariate and multivariate ordinal logistic regression to estimate the association between attribute valuation and students' socio-demographic background, educational experience, and future career plans. Results Of 310 eligible fourth year medical students, complete data was available for 302 students (97%). Students considering emigration ranked salary as more important than students not considering emigration, while students with rural living experience ranked salary as less important than those with no rural experience. Students willing to work in a rural area ranked infrastructure as more important than students who were unwilling, while female students ranked infrastructure as less important than male students. Students who were willing to work in a rural area ranked management style as a more important rural practice attribute than those who were unwilling to work in a rural area. Students studying in Kumasi ranked contract length as more important than those in Accra, while international students ranked contract length as less important than Ghanaian students. Conclusions Interventions to improve rural practice conditions are likely to be more persuasive than salary incentives to Ghanaian medical students who are willing to work in rural environments a priori. Policy experiments should test the impact of these interventions on actual uptake by students upon graduation. PMID:22050704

The importance of environmental quality and catch potential to fishing site selection by freshwater anglers in Mississippi

USGS Publications Warehouse

Schramm, H.L.; Gerard, P.D.; Gill, D.A.

2003-01-01

We measured the importance of 24 fishing site attributes to Mississippi freshwater anglers. Factor analysis identified four multiattribute factors as important in the selection of fishing location: CLEAN ENVIRONMENT CATCH, COST AND HARVEST and AMENITIES AND SAFETY. In general, the importance of site selection factors differed little among anglers grouped by preferred type of fish, preferred fishing location (lakes and reservoirs, rivers and streams, ponds, or reservoir tailwaters), usual manner of fishing (engine-powered boat, nonpowered boat, or shore), or change in fishing frequency. COST AND HARVEST was more important to anglers with high harvest orientations. We found low correlations between site selection factor importance scores and angler age, fishing frequency, fishing expenditures, or fishing motivation factors. We suggest that the general lack of differences in site selection factors among angler groups indicates that management strategies to improve fishing site attributes should benefit all angler groups. Clean fishing environments and awareness of the availability of desired sport fishes were "very" or "extremely" important to fishing site selection by more than 70% of Mississippi freshwater anglers and should be priority management objectives.

The Post-Military West: Globalization’s Impact on U.S. Strategic Culture

DTIC Science & Technology

2009-03-01

culture, it is an important condition to monitor, since strategic culture shapes policy-making and influences how a country fights its wars.1 This SRP...of the societies, culture and politics of other countries . Due to this interconnectedness, crises anywhere in the world can affect security everywhere...Third World countries , seeking a way out of poverty, head west to join relatives and friends who emigrated before them. Compared with European immigrants

Weather, hydroregime, and breeding effort influence juvenile recruitment of anurans: implications for climate change

DOE PAGES

Greenberg, C. H.; Zarnoch, S. J.; Austin, J. D.

2017-05-03

Amphibians that primarily breed in ephemeral wetlands are especially vulnerable to climate change because they rely on rainfall or temperature to initiate breeding and create suitable hydroregimes (water duration, timing, frequency, depth) for reproductive success. Hydroregime effects on reproductive success are likely to differ among species because of differences in reproductive strategies: the length and timing of breeding period, rate of larval development, and timing of metamorphosis. We applied an information-theoretic approach to 22 consecutive years of continuous amphibian trapping data at eight ephemeral wetlands to test hypotheses regarding environmental (hydroregime, weather) and biological (adult breeding effort) factors affecting juvenilemore » recruitment (JR) by six focal species representing four reproductive strategies. We hypothesized that (1) JR by species with similar reproductive strategies would be influenced by similar variables; (2) JR would be higher for all species when models encompassed the maximum time span of potential tadpole occurrence and development; and (3) JR rates within individual wetlands and breeding cycles would correlate most closely between species with similar breeding strategies. The best model for all focal species (except Scaphiopus holbrookii) encompassed the maximum time span and indicated that ≥1 hydroregime variable, total precipitation, or both were important drivers of reproductive success; average air temperature was not. Continuous hydroperiod through peak juvenile emigration was an important predictor of JR for species with prolonged breeding periods, slow larval development, and a “fixed” late spring start date for juvenile emigration (regardless of when oviposition occurred, or cohort age; Lithobates capito, Lithobates sphenocephalus), but not for species with rapid larval development and continual emigration as cohorts complete metamorphosis ( Anaxyrus terrestris, Anaxyrus quercicus, Gastrophryne carolinensis, S. holbrookii). Total rainfall was positively associated with recruitment for most species; depth characteristics affected species differently. Annual JR was positively correlated among species with similar reproductive strategies. Our results indicate that weather and hydroregime characteristics interact with reproductive strategies that differ among amphibian species and influence reproductive plasticity, opportunity, and success. In conclusion, effects of altered weather patterns associated with climate change on amphibian reproductive success may correspond more closely among species having similar reproductive strategies, with critical implications for population trends and assemblages.« less

Weather, hydroregime, and breeding effort influence juvenile recruitment of anurans: implications for climate change

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenberg, C. H.; Zarnoch, S. J.; Austin, J. D.

Amphibians that primarily breed in ephemeral wetlands are especially vulnerable to climate change because they rely on rainfall or temperature to initiate breeding and create suitable hydroregimes (water duration, timing, frequency, depth) for reproductive success. Hydroregime effects on reproductive success are likely to differ among species because of differences in reproductive strategies: the length and timing of breeding period, rate of larval development, and timing of metamorphosis. We applied an information-theoretic approach to 22 consecutive years of continuous amphibian trapping data at eight ephemeral wetlands to test hypotheses regarding environmental (hydroregime, weather) and biological (adult breeding effort) factors affecting juvenilemore » recruitment (JR) by six focal species representing four reproductive strategies. We hypothesized that (1) JR by species with similar reproductive strategies would be influenced by similar variables; (2) JR would be higher for all species when models encompassed the maximum time span of potential tadpole occurrence and development; and (3) JR rates within individual wetlands and breeding cycles would correlate most closely between species with similar breeding strategies. The best model for all focal species (except Scaphiopus holbrookii) encompassed the maximum time span and indicated that ≥1 hydroregime variable, total precipitation, or both were important drivers of reproductive success; average air temperature was not. Continuous hydroperiod through peak juvenile emigration was an important predictor of JR for species with prolonged breeding periods, slow larval development, and a “fixed” late spring start date for juvenile emigration (regardless of when oviposition occurred, or cohort age; Lithobates capito, Lithobates sphenocephalus), but not for species with rapid larval development and continual emigration as cohorts complete metamorphosis ( Anaxyrus terrestris, Anaxyrus quercicus, Gastrophryne carolinensis, S. holbrookii). Total rainfall was positively associated with recruitment for most species; depth characteristics affected species differently. Annual JR was positively correlated among species with similar reproductive strategies. Our results indicate that weather and hydroregime characteristics interact with reproductive strategies that differ among amphibian species and influence reproductive plasticity, opportunity, and success. In conclusion, effects of altered weather patterns associated with climate change on amphibian reproductive success may correspond more closely among species having similar reproductive strategies, with critical implications for population trends and assemblages.« less

Migrant Selection and the Health of U.S. Immigrants From the Former Soviet Union

PubMed Central

Elo, Irma T.

2012-01-01

Few prior studies have investigated the health of U.S. immigrants from the former Soviet Union (FSU). Utilizing data from the 2000 U.S. census and the 2000–2007 National Health Interview Survey (NIHS), we compare levels of disability of FSU immigrants with U.S.-born whites (ages 50–84). Our findings suggest an “epidemiologic paradox” in that FSU immigrants possess higher levels of education compared with U.S.-born whites, but report considerably higher disability with and without adjustment for education. Nonetheless, FSU immigrants report lower levels of smoking and heavy alcohol use compared with U.S.-born whites. We further investigate disability by period of arrival among FSU immigrants. Changes in Soviet emigration policies conceivably altered the level of health selectivity among émigrés. We find evidence that FSU immigrants who emigrated during a period when a permission to emigrate was hard to obtain (1970–1986) displayed less disability compared with those who emigrated when these restrictions were less stringent (1987–2000). Finally, we compare disability among Russian-born U.S. immigrants with that of those residing in Russia as a direct test of health selectivity. We find that Russian immigrants report lower levels of disability compared with Russians in Russia, suggesting that they are positively selected for health despite their poor health relative to U.S.-born whites. PMID:22421810

Expectations and reality: a case study of return migration from the United States to Southern Italy.

PubMed

Cerase, F P

1974-01-01

A summary of Italy's emigration flows shows that Southern Italy sent her people abroad in great number, and, at the same time, return migration to Italy has been characteristic of a minority, e.g., an estimated 3000 from the US alone, 1964-68. Italy's modernization proceeded unevenly, the South remaining agricultural and for the most part, economically backward. Any form of identification with Italy as a country did not affect the Southern peasant thus preparing his/her way to emigrate as soon as any opportunity presented itself. Due to all the conditions which facilitated emigration from Italy on an individualistic and nonideological basis and without an understanding of the economic forces pushing the emigrant out, and in view of the lack of understanding of how the New World economy of the US was constituted, it is no surprise that the return migration of some remained as much ad hoc and based solely on individual motivations as was the emigration. The 2 fundamental approaches to the concept of immigrant both start by considering the immigrant in his/her new situation. 1 approach views the immigrant's success in the new situation as dependent upon acquiring values and patterns of behavior which would resolve his/her problems in the new society. According to the other approach, in order to resolve the problems of his/her new situation the immigrant must become critically aware of the consequences of his/her actions. The 1st view of conceiving integration has been prevalent, particularly in the study of international migration. And, mass migration from Italy, from the emigrant's perspective, is connected to a repeatedly unsuccessful search for economic success and failure to reach prevailing cultural objectives. The act of emigration, of abandonment, may thus be seen as the resolution of the disparity between the means at the emigrant's disposal and the objectives he/she seeks. The great majority succeed but some fail, and if they have a home and family to return to, they begin to think of returning. Returned migrants interviewed experienced an abrupt passage from a rural to an urban and industrial world. Few of the immigrants whose background was in a fa rm occupation engaged in farming upon arrival in the US. The factor determining whether the immigrant surmounts the problems of the 1st phase of his/her experience is his/her work. If the work the immigrant has found makes him/her part of the production process, the money earned makes him/her part of the consumption process. And, this is the 1st turning point in the experience as an immigrant. A return of conservativism is given when the immigrant continues to consider his/her earnings and investments in terms of the traditional scheme appropriate to the home country. Return of innovation is the term given to those who were unwilling or unable to accept fully their expected position in the new society and tended to detach themselves, even to the point of return to the mother country. The consequences of returns to the native society are summarized. In sum, it appears that returned migrants cannot function as vehicles of social development.

Emigration dynamics in the Arab region. IOM / UNFPA workshop, 7-8 October 1996, Geneva, Switzerland.

PubMed

Appleyard, R

1996-01-01

This paper describes the four research monographs on emigration that were presented at the December 1995 Regional Workshop in the Arab Region. The workshop was an exchange of views and discussion of policy implications of emigration. Monographs were presented by Dr. Mayar Farrag on emigration in Egypt, Professor Nadji Safir on migration in the Maghreb, Dr. Setenay Shami on emigration dynamics in Jordan, and Dr. Lynn Evans on behalf of Dr. Ivy Papps on migration in Gulf Cooperation Council (GCC) countries. Dr. Farrag identified three periods of migration. During the mid-1960s to the mid-1970s, migrants were officially encouraged by Egypt to fill education positions. During the 1970s, many migrants left for the oil-producing countries on a temporary basis. Since the mid-1980s, the influences on Egyptian migration have been the economic recession and oil prices in the Gulf states, the completion of infrastructure projects in most Gulf states, and the replacement of foreign labor with nationals. Dr. Farrag recommended improving the migrants' skills in English and technology in order to maintain a dominant flow of temporary migrants to the Gulf region. Professor Safir reported that persons from the Maghreb region (Tunisia, Algeria, and Morocco) migrated to France before independence and subsequently to West Germany and the Benelux countries. Algeria had the highest migration potential, and Morocco had the highest migration. Morocco had established networks in destination countries, high population growth rates, and high unemployment. Maghreb countries are receiving migrants from the south. Professor Safir recommended regional integration. Dr. Shami separated step migration from stepwise migration, which complicates push-pull theories. Dr. Papps argued that use of foreign labor may not be the best option for development, and that sending countries should be more aware of skill needs in GCC countries.

75 FR 38070 - Implementation of Fish and Fish Product Import Provisions of the Marine Mammal Protection Act

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-01

.... 0907301201-91203-01] RIN 0648-AY15 Implementation of Fish and Fish Product Import Provisions of the Marine..., foreign nations that export fish and fish products to the United States, and other interested parties to...) of the Marine Mammal Protection Act for imports of fish and fish products. On April 30, 2010, NMFS...

[Colombian migration to the Venezuelan agrarian sector: a binational context].

PubMed

Mora, J; Gomez, A

1980-01-01

The authors attempt to determine the reasons for the chronic national labor shortage in the Venezuelan agrarian sector and for the large-scale emigration of Colombians to work in Venezuelan agriculture. The income of agricultural wage earners and the conditions of labor force reproduction in Venezuela are discussed as factors contributing to the labor shortage. With reference to Colombia, the rapid growth of international commerce and the policy of limiting wages are suggested as factors which contribute to emigration

[The members of the exiled Hungarian school, mourning and renewal].

PubMed

Brabant, E

1988-01-01

A historical survey of the Hungarian psycho-analytical movement, followed by a description of the two successive waves of emigration. After some biographical details about three analysts who emigrated--Alice Balint, Michael Balint and Géza Roheim--exile is considered from the viewpoint of regretting the past and subsequent "renewal". Its effect is traced in the work of Balint and Roheim. Finally exile is seen as an ordeal creative of Freudian thought and as an experience common to all human beings.

Migration, urban growth, and development: Pakistan's experience.

PubMed

Shah, N M; Karim, M S

1982-11-01

The authors "focus primarily on voluntary, peacetime migration [in Pakistan], both internal and international, and attempt to analyze some of its possible socioeconomic consequences." The importance of the role of migration in urban population growth is discussed, with attention to implications for social and economic development. The impact of large-scale emigration of workers to the Middle East is also assessed. The analysis is based on data from the 1951, 1961, 1972, and 1981 censuses as well as from secondary sources. excerpt

Comparing population size estimators for plethodontid salamanders

USGS Publications Warehouse

Bailey, L.L.; Simons, T.R.; Pollock, K.H.

2004-01-01

Despite concern over amphibian declines, few studies estimate absolute abundances because of logistic and economic constraints and previously poor estimator performance. Two estimation approaches recommended for amphibian studies are mark-recapture and depletion (or removal) sampling. We compared abundance estimation via various mark-recapture and depletion methods, using data from a three-year study of terrestrial salamanders in Great Smoky Mountains National Park. Our results indicate that short-term closed-population, robust design, and depletion methods estimate surface population of salamanders (i.e., those near the surface and available for capture during a given sampling occasion). In longer duration studies, temporary emigration violates assumptions of both open- and closed-population mark-recapture estimation models. However, if the temporary emigration is completely random, these models should yield unbiased estimates of the total population (superpopulation) of salamanders in the sampled area. We recommend using Pollock's robust design in mark-recapture studies because of its flexibility to incorporate variation in capture probabilities and to estimate temporary emigration probabilities.

Gender, Power, and Emigration From Mexico.

PubMed

Nobles, Jenna; McKelvey, Christopher

2015-10-01

The prevailing model of migration in developing countries conceives of a risk-diversifying household in which members act as a single entity when making migration decisions. Ethnographic studies challenge this model by documenting gender hierarchy in family decisions and arguing that, in many contexts, men and women have differing views on the value of migration. We assess these perspectives using longitudinal survey data from Mexico. We show that Mexican households are heterogeneous in terms of women's decision-making authority and control over resources, and this variation predicts the subsequent emigration of their male partners to the United States. We then use data from a policy experiment to demonstrate that an exogenous increase in a woman's control over household resources decreases the probability that her spouse migrates. Our findings support the presence of important gender differences in how migration is valued. They also suggest that women's role in these decisions is inadvertently underrepresented in studies of migrant families. Staying is also a migration decision, and it is more likely in homes in which women have greater authority. From a policy perspective, the results suggest that Mexican migration is influenced not only by increases in household resources but also by which members of the household control them.

Gender, Power, and Emigration From Mexico

PubMed Central

Nobles, Jenna; McKelvey, Christopher

2015-01-01

The prevailing model of migration in developing countries conceives of a risk-diversifying household in which members act as a single entity when making migration decisions. Ethnographic studies challenge this model by documenting gender hierarchy in family decisions and arguing that, in many contexts, men and women have differing views on the value of migration. We assess these perspectives using longitudinal survey data from Mexico. We show that Mexican households are heterogeneous in terms of women's decision-making authority and control over resources, and this variation predicts the subsequent emigration of their male partners to the United States. We then use data from a policy experiment to demonstrate that an exogenous increase in a woman's control over household resources decreases the probability that her spouse migrates. Our findings support the presence of important gender differences in how migration is valued. They also suggest that women's role in these decisions is inadvertently underrepresented in studies of migrant families. Staying is also a migration decision, and it is more likely in homes in which women have greater authority. From a policy perspective, the results suggest that Mexican migration is influenced not only by increases in household resources but also by which members of the household control them. PMID:26100982

9 CFR 93.903 - Import permits for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Import permits for live fish... ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN ANIMAL, BIRD, AND... General Provisions for Svc-Regulated Fish Species § 93.903 Import permits for live fish, fertilized eggs...

9 CFR 93.903 - Import permits for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Import permits for live fish... ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN ANIMAL, BIRD, AND... General Provisions for Svc-Regulated Fish Species § 93.903 Import permits for live fish, fertilized eggs...

9 CFR 93.903 - Import permits for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Import permits for live fish... ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN ANIMAL, BIRD, AND... General Provisions for Svc-Regulated Fish Species § 93.903 Import permits for live fish, fertilized eggs...

Spanish youth is emigrating: A bibliometric approach to the media coverage.

PubMed

Selva, Clara; Recordà, Aniol

2018-01-01

Recent years have witnessed the emigration of young Spanish people searching for labor opportunities. A decade after the beginning of the worldwide economic crisis in 2007, the rapid deterioration of living conditions and lack of opportunities for personal development combined with the breakdown of professional expectations have led thousands of young people to emigrate from Spain, creating the so-called youth exodus. The press has paid recurrent attention to this phenomenon, often using eye-catching headlines such as 'Brain Drain'. Given the regular interest of the media in this phenomenon, the objective of this research is to analyze the media coverage of the drain of Spanish talent capital, or the emigration of young Spanish people seeking a better future, to create a distributive map that defines the characteristics and trends of this coverage. The analyzed corpus comprises 346 articles from eight Spanish and eleven international newspapers. The articles were coded based on descriptive variables (i.e., author, publication year, newspaper and language) and categorical variables (i.e., section, method, approach to the phenomenon, assessment of the phenomenon and overview of the phenomenon). The results indicate a significant increase in press coverage over the past few years and reveal associations between assessment of the phenomenon and year and between assessment of the phenomenon and section. As a result of this research, new investigative lines are unveiled regarding the social construction of the phenomenon in the media and the identity and individual construction of the 'truncated careers' of young Spanish people.

Seasonal thermal ecology of adult walleye (Sander vitreus) in Lake Huron and Lake Erie.

PubMed

Peat, Tyler B; Hayden, Todd A; Gutowsky, Lee F G; Vandergoot, Christopher S; Fielder, David G; Madenjian, Charles P; Murchie, Karen J; Dettmers, John M; Krueger, Charles C; Cooke, Steven J

2015-10-01

The purpose of this study was to characterize thermal patterns and generate occupancy models for adult walleye from lakes Erie and Huron with internally implanted biologgers coupled with a telemetry study to assess the effects of sex, fish size, diel periods, and lake. Sex, size, and diel periods had no effect on thermal occupancy of adult walleye in either lake. Thermal occupancy differed between lakes and seasons. Walleye from Lake Erie generally experienced higher temperatures throughout the spring and summer months than did walleye in Lake Huron, due to limnological differences between the lakes. Tagged walleye that remained in Saginaw Bay, Lake Huron (i.e., adjacent to the release location), as opposed to those migrating to the main basin of Lake Huron, experienced higher temperatures, and thus accumulated more thermal units (the amount of temperature units amassed over time) throughout the year. Walleye that migrated toward the southern end of Lake Huron occupied higher temperatures than those that moved toward the north. Consequently, walleye that emigrated from Saginaw Bay experienced thermal environments that were more favorable for growth as they spent more time within their thermal optimas than those that remained in Saginaw Bay. Results presented in this paper provide information on the thermal experience of wild fish in a large lake, and could be used to refine sex- and lake-specific bioenergetics models of walleye in the Great Lakes to enable the testing of ecological hypotheses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Seasonal thermal ecology of adult walleye (Sander vitreus) in Lake Huron and Lake Erie

USGS Publications Warehouse

Peat, Tyler B; Hayden, Todd A.; Gutowsky, Lee F G; Vandergoot, Christopher S.; Fielder, David G.; Madenjian, Charles P.; Murchie, Karen J; Dettmers, John M.; Krueger, Charles C.; Cooke, Steven J.

2015-01-01

The purpose of this study was to characterize thermal patterns and generate occupancy models for adult walleye from lakes Erie and Huron with internally implanted biologgers coupled with a telemetry study to assess the effects of sex, fish size, diel periods, and lake. Sex, size, and diel periods had no effect on thermal occupancy of adult walleye in either lake. Thermal occupancy differed between lakes and seasons. Walleye from Lake Erie generally experienced higher temperatures throughout the spring and summer months than did walleye in Lake Huron, due to limnological differences between the lakes. Tagged walleye that remained in Saginaw Bay, Lake Huron (i.e., adjacent to the release location), as opposed to those migrating to the main basin of Lake Huron, experienced higher temperatures, and thus accumulated more thermal units (the amount of temperature units amassed over time) throughout the year. Walleye that migrated toward the southern end of Lake Huron occupied higher temperatures than those that moved toward the north. Consequently, walleye that emigrated from Saginaw Bay experienced thermal environments that were more favorable for growth as they spent more time within their thermal optimas than those that remained in Saginaw Bay. Results presented in this paper provide information on the thermal experience of wild fish in a large lake, and could be used to refine sex- and lake-specific bioenergetics models of walleye in the Great Lakes to enable the testing of ecological hypotheses.

Sluiceway Operations to Pass Juvenile Salmonids at The Dalles Dam, Columbia River, USA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Gary E.; Khan, Fenton; Skalski, J. R.

Existing ice and trash sluiceways are commonly used to pass juvenile salmonids downstream at hydropower dams through a benign, non-turbine route. At The Dalles Dam on the Columbia River, managers undertook optimizing operations of sluiceway weirs to maximize survival of juvenile salmonids at the powerhouse. We applied fixed-location hydroacoustic methods to compare fish passage rates and sluiceway efficiencies for two weir configurations during 2004 and 2005: three weirs versus six weirs, located at the mid- versus east powerhouse, respectively. We also analyzed horizontal distributions of passage at the sluiceway and turbines and the effects of operating turbines beneath open sluicewaymore » gates to provide supporting data relevant to operations optimization. Based on the findings, we recommend the following for long-term operations for the sluiceway at The Dalles Dam: open six rather than three sluiceway weirs to take advantage of the maximum hydraulic capacity of the sluiceway; open the three weirs above the western-most operating main turbine unit (MU) and the three weirs at MU 8 where turbine passage rates are relatively high; operate the turbine units below open sluiceway weirs as a standard procedure; operate the sluiceway 24 h/d year-round to maximize its benefits to juvenile salmonids; and use the same operations for spring and summer emigrants. These operational concepts are transferable to dams where sluiceway surface flow outlets are used protect downstream migrating fishes.« less

The macrodynamics of international migration as a socio-cultural diffusion process. Part B: applications.

PubMed

Diamantides, N D

1992-12-01

"This study formulates a model of the macrodynamics of international migration using a differential equation to capture the push-pull forces that propel it. The model's architecture rests on the functioning of information feedback between settled friends and family at the destination and potential emigrants at the origin.... Two specific paradigms of diverse nature serve to demonstrate the model's tenets and pertinence, one being Greek emigration to the United States since 1820, and the other total out-migration from Cyprus since statehood (1946)." excerpt

The metrics and correlates of physician migration from Africa.

PubMed

Arah, Onyebuchi A

2007-05-17

Physician migration from poor to rich countries is considered an important contributor to the growing health workforce crisis in the developing world. This is particularly true for Africa. The perceived magnitude of such migration for each source country might, however, depend on the choice of metrics used in the analysis. This study examined the influence of choice of migration metrics on the rankings of African countries that suffered the most physician migration, and investigated the correlates of physician migration. Ranking and correlational analyses were conducted on African physician migration data adjusted for bilateral net flows, and supplemented with developmental, economic and health system data. The setting was the 53 African birth countries of African-born physicians working in nine wealthier destination countries. Three metrics of physician migration were used: total number of physician émigrés; emigration fraction defined as the proportion of the potential physician pool working in destination countries; and physician migration density defined as the number of physician émigrés per 1000 population of the African source country. Rankings based on any of the migration metrics differed substantially from those based on the other two metrics. Although the emigration fraction and physician migration density metrics gave proportionality to the migration crisis, only the latter was consistently associated with source countries' workforce capacity, health, health spending, economic and development characteristics. As such, higher physician migration density was seen among African countries with relatively higher health workforce capacity (0.401 < or = r < or = 0.694, p < or = 0.011), health status, health spending, and development. The perceived magnitude of physician migration is sensitive to the choice of metrics. Complementing the emigration fraction, the physician migration density is a metric which gives a different but proportionate picture of which African countries stand to lose relatively more of its physicians with unchecked migration. The nature of health policies geared at health-worker migration can be expected to depend on the choice of migration metrics.

Species Profiles: Life histories and environmental requirements (Gulf of Mexico): Brown shrimp

USGS Publications Warehouse

Lassuy, Dennis R.

1983-01-01

Species profiles are literature summaries on the taxonomy, morphology, range, life history, and environmental requirements of coastal aquatic species. They are designed to assist in environmental impact assessment. The brown shrimp, Penaeus aztecus, is the major species in the Gulf of Mexico shrimp fishery, the most valuable $302 million in 1980) commercial fishery in the United States. It is heavily preyed on by many fishes. Spawning occurs offshore from about September to May and most postlarvae move into estuaries from February through April. Within the estuary they occupy shallow water near marshes with soft substrate. Juveniles emigrate from estuaries to offshore areas from May through August. They grow as fast as 3.3 mm per day in estuaries. Adults concentrate around the 55-m contour offshore. Postlarval and juvenile shrimp are normal1y taken in water temperatures above 10?C and rapid growth occurs above 18?C. Few shrimp are collected below 5 ppt salinity. Brown shrimp are benthic feeders and prefer soft substrates. High populatiorls are associated with coastal marshes.

Does size matter? A test of size-specific mortality in Atlantic salmon Salmo salar smolts tagged with acoustic transmitters.

PubMed

Newton, M; Barry, J; Dodd, J A; Lucas, M C; Boylan, P; Adams, C E

2016-09-01

Mortality rates of wild Atlantic salmon Salmo salar smolts implanted with acoustic transmitters were assessed to determine if mortality was size dependent. The routinely accepted, but widely debated, '2% transmitter mass: body mass' rule in biotelemetry was tested by extending the transmitter burden up to 12·7% of body mass in small [mean fork length (LF ) 138·3 mm, range 115-168 mm] downstream migrating S. salar smolts. Over the short timescale of emigration (range 11·9-44·5 days) through the lower river and estuary, mortality was not related to S. salar size, nor was a relationship found between mortality probability and transmitter mass: body mass or transmitter length: LF ratios. This study provides further evidence that smolt migration studies can deviate from the '2% rule' of thumb, to more appropriate study-specific measures, which enables the use of fishes representative of the body size in natural populations without undue effects. © 2016 The Fisheries Society of the British Isles.

Could Hypomanic Traits Explain Selective Migration? Verifying the Hypothesis by the Surveys on Sardinian Migrants

PubMed Central

MG, Carta; MF, Moro; V, Kovess; MV, Brasesco; KM, Bhat; MC, Angermeyer; HS, Akiskal

2012-01-01

Introduction: A recent survey put forward the hypothesis that the emigration that occurred from Sardinia from the 1960’s to the 1980’s, selected people with a hypomanic temperament. The paper aims to verify if the people who migrated from Sardinia in that period have shown a high risk of mood disorders in the surveys carried out in their host countries, and if the results are consistent with this hypothesis. Methods: This is systematic review. Results: In the 1970’s when examining the attitudes towards migration in Sardinian couples waiting to emigrate, Rudas found that the decision to emigrate was principally taken by males. Female showed lower self-esteem than male emigrants. A study on Sardinian immigrants in Argentina carried out in 2001-02, at the peak of the economic crisis, found a high risk of depressive disorders in women only. These results were opposite to the findings recorded ten years earlier in a survey on Sardinian immigrants in Paris, where the risk of Depressive Episode was higher in young men only. Discussion: Data point to a bipolar disorder risk for young (probably hypomanic) male migrants in competitive, challenging conditions; and a different kind of depressive episodes for women in trying economic conditions. The results of the survey on Sardinian migrants are partially in agreement with the hypothesis of a selective migration of people with a hypomanic temperament. Early motivations and self-esteem seem related to the ways mood disorders are expressed, and to the vulnerability to specific triggering situations in the host country. PMID:23248679

Could hypomanic traits explain selective migration? Verifying the hypothesis by the surveys on sardinian migrants.

PubMed

Giovanni, Carta Mauro; Francesca, Moro Maria; Viviane, Kovess; Brasesco, Maria Veronica; Bhat, Krishna M; Matthias, Angermeyer C; Akiskal, Hagop S

2012-01-01

A recent survey put forward the hypothesis that the emigration that occurred from Sardinia from the 1960's to the 1980's, selected people with a hypomanic temperament. The paper aims to verify if the people who migrated from Sardinia in that period have shown a high risk of mood disorders in the surveys carried out in their host countries, and if the results are consistent with this hypothesis. This is systematic review. In the 1970's when examining the attitudes towards migration in Sardinian couples waiting to emigrate, Rudas found that the decision to emigrate was principally taken by males. Female showed lower self-esteem than male emigrants. A study on Sardinian immigrants in Argentina carried out in 2001-02, at the peak of the economic crisis, found a high risk of depressive disorders in women only. These results were opposite to the findings recorded ten years earlier in a survey on Sardinian immigrants in Paris, where the risk of Depressive Episode was higher in young men only. Data point to a bipolar disorder risk for young (probably hypomanic) male migrants in competitive, challenging conditions; and a different kind of depressive episodes for women in trying economic conditions. The results of the survey on Sardinian migrants are partially in agreement with the hypothesis of a selective migration of people with a hypomanic temperament. Early motivations and self-esteem seem related to the ways mood disorders are expressed, and to the vulnerability to specific triggering situations in the host country.

The melanocortin MC1 receptor agonist BMS-470539 inhibits leucocyte trafficking in the inflamed vasculature

PubMed Central

Leoni, G; Voisin, M-B; Carlson, K; Getting, SJ; Nourshargh, S; Perretti, M

2010-01-01

Background and purpose: Over three decades of research evaluating the biology of melanocortin (MC) hormones and synthetic peptides, activation of the MC type 1 (MC1) receptor has been identified as a viable target for the development of novel anti-inflammatory therapeutic agents. Here, we have tested a recently described selective agonist of MC1 receptors, BMS-470539, on leucocyte/post-capillary venule interactions in murine microvascular beds. Experimental approach: Intravital microscopy of two murine microcirculations were utilized, applying two distinct modes of promoting inflammation. The specificity of the effects of BMS-470539 was assessed using mice bearing mutant inactive MC1 receptors (the recessive yellow e/e colony). Key results: BMS-470539, given before an ischaemia–reperfusion protocol, inhibited cell adhesion and emigration with no effect on cell rolling, as assessed 90 min into the reperfusion phase. These properties were paralleled by inhibition of tissue expression of both CXCL1 and CCL2. Confocal investigations of inflamed post-capillary venules revealed immunostaining for MC1 receptors on adherent and emigrated leucocytes. Congruently, the anti-inflammatory properties of BMS-470539 were lost in mesenteries of mice bearing the inactive mutant MC1 receptors. Therapeutic administration of BMS-470539 stopped cell emigration, but did not affect cell adhesion in the cremasteric microcirculation inflamed by superfusion with platelet-activating factor. Conclusions and implications: Activation of MC1 receptors inhibited leucocyte adhesion and emigration. Development of new chemical entities directed at MC1 receptors could be a viable approach in the development of novel anti-inflammatory therapeutic agents with potential application to post-ischaemic conditions. PMID:20331604

Radiation-Driven Migration: The Case of Minamisoma City, Fukushima, Japan, after the Fukushima Nuclear Accident

PubMed Central

Zhang, Hui; Yan, Wanglin; Oba, Akihiro; Zhang, Wei

2014-01-01

The emigration of residents following the Fukushima nuclear accident has resulted in aging and depopulation problems in radiation-contaminated areas. The recovery of affected areas, and even those areas with low radioactive pollution levels, is still heavily affected by this problem. This slow recovery consequently affects immigration patterns. This review aims to present possible factors that have contributed to this dilemma. We first present an overview of the evacuation protocol that was administered in the study area following the Fukushima accident. We then analyze characteristics of the subsequent exodus by comparing population data for both before and after the accident. Based on the findings of existing literature, we identify three causes of emigration: (1) The health risks of living in a low radiation zone are still unknown; (2) The post-disaster psychological disturbance and distrust of government information promotes the emigration of evacuees; (3) an absence of economic vitality and of a leading industry renders the area less attractive to individuals residing outside of the city. Further research is needed on this issue, especially with respect to countermeasures for addressing this problem. PMID:25207491

FGF and retinoic acid activity gradients control the timing of neural crest cell emigration in the trunk

PubMed Central

Martínez-Morales, Patricia L.; Diez del Corral, Ruth; Olivera-Martínez, Isabel; Quiroga, Alejandra C.; Das, Raman M.; Barbas, Julio A.; Storey, Kate G.

2011-01-01

Coordination between functionally related adjacent tissues is essential during development. For example, formation of trunk neural crest cells (NCCs) is highly influenced by the adjacent mesoderm, but the molecular mechanism involved is not well understood. As part of this mechanism, fibroblast growth factor (FGF) and retinoic acid (RA) mesodermal gradients control the onset of neurogenesis in the extending neural tube. In this paper, using gain- and loss-of-function experiments, we show that caudal FGF signaling prevents premature specification of NCCs and, consequently, premature epithelial–mesenchymal transition (EMT) to allow cell emigration. In contrast, rostrally generated RA promotes EMT of NCCs at somitic levels. Furthermore, we show that FGF and RA signaling control EMT in part through the modulation of elements of the bone morphogenetic protein and Wnt signaling pathways. These data establish a clear role for opposition of FGF and RA signaling in control of the timing of NCC EMT and emigration and, consequently, coordination of the development of the central and peripheral nervous system during vertebrate trunk elongation. PMID:21807879

Spatial econometric model of natural disaster impacts on human migration in vulnerable regions of Mexico.

PubMed

Saldaña-Zorrilla, Sergio O; Sandberg, Krister

2009-10-01

Mexico's vast human and environmental diversity offers an initial framework for comprehending some of the prevailing great disparities between rich and poor. Its socio-economic constructed vulnerability to climatic events serves to expand this understanding. Based on a spatial econometric model, this paper tests the contribution of natural disasters to stimulating the emigration process in vulnerable regions of Mexico. Besides coping and adaptive capacity, it assesses the effects of economic losses due to disasters as well as the adverse production and trade conditions of the 1990s on emigration rates in 2000 at the municipality level. Weather-related disasters were responsible for approximately 80 per cent of economic losses in Mexico between 1980 and 2005, mostly in the agricultural sector, which continues to dominate many parts of the country. It is dramatic that this sector generates around only four per cent of gross domestic product but provides a livelihood to about one-quarter of the national population. It is no wonder, therefore, that most emigration from this country arises in vulnerable rural areas.

Perceived importance of sustainability and ethics related to fish: a consumer behavior perspective.

PubMed

Verbeke, Wim; Vanhonacker, Filiep; Sioen, Isabelle; Van Camp, John; De Henauw, Stefaan

2007-11-01

Although sustainability and ethics are of increasing public importance, little research has been conducted to reveal its association with fish consumer behavior. Cross-sectional data were collected through a postal self-administered survey (June 2005) from a sample of 381 Flemish women aged 20-50 years. Consumers attach high perceived importance to sustainability and ethics related to fish. However, this perceived importance is neither correlated with fish consumption frequency nor with general attitude toward eating fish. Refusing to eat wild fish is grounded in sustainability and ethical concerns, whereas the decision not to eat farmed fish is associated with a lower expected intrinsic quality rather than shaped by importance attached to sustainability and ethical issues.

78 FR 66760 - Proposed Information Collection; Injurious Wildlife; Importation Certification for Live Fish and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-06

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[The migration crisis of the summer of 1994. Balance and perspectives of Cuban emigration flows: 1984-1996].

PubMed

Rodriguez Chavez, E

1996-01-01

"The article argues that the rafters crisis of 1994 and the resulting migration agreements between the United States and Cuba in 1994 and 1995 were a radical turn in policies and migration flows between the two countries. The article also describes the general evolution of Cuban migration flows towards the U.S. from the 1984 bilateral agreement up to 1996. As a context, it describes the structural elements of recent Cuban emigration and the place Cubans occupy in the general immigration from Latin America and the Caribbean." (EXCERPT)

A personality theory of U.S. migration geography.

PubMed

Stetzer, F C

1985-01-01

"Neoclassical models of migration fail to account adequately for individual differences in propensity to migrate, rates of emigration from states and cities, and the generally high rates of population circulation common in the United States. This article proposes that migration propensity is related to an individual's personality. Using the facts that personality traits are generationally regenerative, both through inheritance and culture, and that the United States was settled in a series of migration waves from east to west, this theory predicts a spatial structuring of emigration rates which closely correspond to actual rates for states and major cities." excerpt

Cutting edge: Contact with secondary lymphoid organs drives postthymic T cell maturation.

PubMed

Houston, Evan G; Nechanitzky, Robert; Fink, Pamela J

2008-10-15

T cell development, originally thought to be completed in the thymus, has recently been shown to continue for several weeks in the lymphoid periphery. The forces that drive this peripheral maturation are unclear. The use of mice transgenic for GFP driven by the RAG2 promoter has enabled the ready identification and analysis of recent thymic emigrants. Here, we show that recent thymic emigrant maturation is a progressive process and is promoted by T cell exit from the thymus. Further, we show that this maturation occurs within secondary lymphoid organs and does not require extensive lymphocyte recirculation.

Abundance, Timing of Migration, and Egg-to-Smolt Survival of Juvenile Chum Salmon, Kwethluk River, Alaska, 2007 and 2008

USGS Publications Warehouse

Burril, Sean E.; Zimmerman, Christian E.; Finn, James E.; ,; Gillikin, Daniel; ,

2010-01-01

To better understand and partition mortality among life stages of chum salmon (Oncorhynchus keta), we used inclined-plane traps to monitor the migration of juveniles in the Kwethluk River, Alaska in 2007 and 2008. The migration of juvenile chum salmon peaked in mid-May and catch rates were greatest when water levels were rising. Movement of chum salmon was diurnal with highest catch rates occurring during the hours of low light (that is, 22:00 to 10:00). Trap efficiency ranged from 0.37 to 4.04 percent (overall efficiency = 1.94 percent). Total abundance of juvenile chum salmon was estimated to be 2.0 million fish in 2007 and 2.9 million fish in 2008. On the basis of the estimate of chum salmon females passing the Kwethluk River weir and age-specific fecundity, we estimated the potential egg deposition (PED) upstream of the weir and trapping site. Egg-to-smolt survival, calculated by dividing the estimate of juvenile chum salmon emigrating past the weir site by the estimate of PED, was 4.6 percent in 2007 and 5.2 percent in 2008. In addition to chum salmon, Chinook salmon O. tshawytscha), coho salmon (O. kisutch), sockeye salmon (O. nerka), and pink salmon (O. gorbuscha), as well as ten other fish species, were captured in the traps. As with chum salmon, catch of these species increased during periods of increasing discharge and peaked during hours of low light. This study successfully determined the characteristics of juvenile salmon migrations and estimated egg-to-smolt survival for chum salmon. This is the first estimate of survival for any juvenile salmon in the Arctic-Yukon-Kuskokwim region of Alaska and demonstrates an approach that can help to partition mortality between freshwater and marine life stages, information critical to understanding the dynamics of salmon in this region.

Snake River Sockeye Salmon Habitat and Limnological Research; 2002 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kohler, Andre E.; Taki, Doug; Griswold, Robert G.

2004-08-01

In March 1990, the Shoshone-Bannock Tribes petitioned the National Marine Fisheries Service (NMFS) to list the Snake River sockeye salmon (Oncorhynchus nerka) as endangered. As a result of that petition the Snake River sockeye salmon was officially listed as endangered in November 1991 under the Endangered Species Act (56 FR 58619). In 1991, the Snake River Sockeye Salmon Habitat and Limnological Research Program was implemented (Project Number 91-71, Intergovernmental Contract Number DE-BI79-91bp22548). This project is part of an interagency effort to prevent the extinction of the Redfish Lake stock of O. nerka. The Shoshone-Bannock Tribal goal for this project ismore » two tiered: The immediate goal is to increase the population of Snake River sockeye salmon while preserving the unique genetic characteristics of the Evolutionarily Significant Unit (ESU). The Tribes long term goal is to maintain a viable population that warrants delisting and provides Tribal harvest opportunities. The Bonneville Power Administration (BPA) provides funding for this interagency recovery program through the Northwest Power Planning Council Fish and Wildlife Program (NPPCFWP). Collaborators in the recovery effort include the National Marine Fisheries Service (NMFS), the Idaho Department of Fish and Game (IDFG), the University of Idaho (UI), U.S. Forest Service (USFS), and the Shoshone-Bannock Tribe (SBT). This report summarizes activities conducted by Shoshone-Bannock Tribal Fisheries Department personnel during the 2002 calendar year. Project objectives include: (1) monitor over-winter survival and emigration of juvenile anadromous O. nerka stocked from the captive rearing program; (2) fertilize Redfish Lake (3) conduct kokanee salmon (non-anadromous O. nerka) population surveys; (4) monitor spawning kokanee escapement and estimate fry recruitment on Fishhook, Alturas Lake, and Stanley Lake creeks; (5) evaluate potential competition and predation between stocked juvenile O. nerka and a variety of fish species in Redfish, Pettit, and Alturas lakes; and (6) monitor limnological parameters of Sawtooth Valley lakes to assess lake productivity.« less

Temporal changes in fishing motivation among fishing club anglers in the United States

USGS Publications Warehouse

Schramm, H.L.; Gerard, P.D.

2004-01-01

Responses from freshwater anglers (n = 4287) to a nationwide survey of the US fishing club members were used to assess differences in the importance of 16 fishing motivation items between 1987 and 1997, dates that preceded and followed a period of substantial decline in recreational fishing participation in the US. Comparison of respondents' motivations for fishing in 1997 and 10 years earlier indicated consistency in the paramount importance of being outdoors, relaxation and the experience of the catch. However, the importance of family recreation and being with friends in 1987 were replaced by escape items in 1997. Anglers with fewer dependents and living in areas with higher population density were more likely to decrease the importance of family recreation. Younger anglers were more likely to decrease the importance of being with friends. Anglers who had higher household income, fished more and had higher fishing expenditures were more likely to decrease the importance of obtaining fish to eat. The results of this study suggest that managers should be less concerned about angler opposition to liberal regulations that allow anglers to harvest fish, and that heightened efforts to recruit and retain recreational anglers, which presently focus on family recreation, should be broadened to include outdoor experience, relaxation and escape aspects of fishing. ?? 2004 Blackwell Publishing Ltd.

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Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-23

...-0078; Injurious Wildlife; Importation Certification for Live Fish and Fish Eggs AGENCY: Fish and... Wildlife; Importation Certification for Live Fish and Fish Eggs, 50 CFR 16.13. Service Form Number(s): 3...

Intermediate disturbance in experimental landscapes improves persistence of beetle metapopulations.

PubMed

Govindan, Byju N; Feng, Zhilan; DeWoody, Yssa D; Swihart, Robert K

2015-03-01

Human-dominated landscapes often feature patches that fluctuate in suitability through space and time, but there is little experimental evidence relating the consequences of dynamic patches for species persistence. We used a spatially and temporally dynamic metapopulation model to assess and compare metapopulation capacity and persistence for red flour beetles (Tribolium castaneum) in experimental landscapes differentiated by resource structure, patch dynamics (destruction and restoration), and connectivity. High connectivity increased the colonization rate of beetles, but this effect was less pronounced in heterogeneous relative to homogeneous landscapes. Higher connectivity and faster patch dynamics increased extinction rates in landscapes. Lower connectivity promoted density-dependent emigration. Heterogeneous landscapes containing patches of different carrying capacity enhanced landscape-level occupancy probability. The highest metapopulation capacity and persistence was observed in landscapes with heterogeneous patches, low connectivity, and slow patch dynamics. Control landscapes with no patch dynamics exhibited rapid declines in abundance and approached extinction due to increased adult mortality in the matrix, higher pupal cannibalism by adults, and extremely low rates of exchange between remaining habitable patches. Our results highlight the role of intermediate patch dynamics, intermediate connectivity, and the nature of density dependence of emigration for persistence of species in heterogeneous landscapes. Our results also demonstrate the importance of incorporating local dynamics into the estimation of metapopulation capacity for conservation planning.

Assessment of formaldehyde levels in local and imported fresh fish in Ghana: a case study in the Tamale Metropolis of Ghana.

PubMed

Saba, Courage Kosi Setsoafia; Atayure, Seidu Isaac; Adzitey, Frederick

2015-03-01

Fish is an important source of protein all over the world, including in Ghana. The fishery sector plays a major role in meeting the domestic need of animal protein and also contributes greatly in foreign exchange earnings. The domestic supply of fish does not meet the demand, so Ghana imports fish and fish products from other countries. Media reports in Ghana have alleged the use of formaldehyde to preserve fish for increased shelf life and to maintain freshness. This research, therefore, sought to establish the levels of formaldehyde in imported and local fresh fish in the Tamale Metropolis by using a ChemSee formaldehyde and formalin detection test kit. Positive and negative controls were performed by using various concentrations of formalin (1, 10, 30, 50, 100, and 300 ppm) and sterile distilled water, respectively. Three times over a 6-month period, different fish species were obtained from five wholesale cold stores (where fish are sold in cartons) and some local sales points (where locally caught fish are sold). A total of 32 samples were taken during three different sampling sessions: 23 imported fish (mackerel, herring, horse mackerel, salmon, and redfish) and 9 local tilapia. The fish were cut, and 50 g was weighed and blended with an equal volume (50 ml) of sterile distilled water. Samples were transferred to test tubes and centrifuged. A test strip was dipped into the supernatant and observed for a color change. A change in color from white to pink or purple indicated the presence of formaldehyde in fish. The study showed that no formaldehyde was present in the imported and local fish obtained. The appropriate regulatory agencies should carry out this study regularly to ensure that fish consumed in Ghana is safe for consumption.

Dynamics of microorganism populations in recirculating nutrient solutions

NASA Technical Reports Server (NTRS)

Strayer, R. F.

1994-01-01

This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet CELSS tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

Growth characteristics and otolith analysis on age-0 American shad

USGS Publications Warehouse

Sauter, Sally T.; Wetzel, Lisa A.

2011-01-01

Otolith microstructure analysis provides useful information on the growth history of fish (Campana and Jones 1992, Bang and Gronkjaer 2005). Microstructure analysis can be used to construct the size-at-age growth trajectory of fish, determine daily growth rates, and estimate hatch date and other ecologically important life history events (Campana and Jones 1992, Tonkin et al. 2008). This kind of information can be incorporated into bioenergetics modeling, providing necessary data for estimating prey consumption, and guiding the development of empirically-based modeling scenarios for hypothesis testing. For example, age-0 American shad co-occur with emigrating juvenile fall Chinook salmon originating from Hanford Reach and the Snake River in the lower Columbia River reservoirs during the summer and early fall. The diet of age-0 American shad appears to overlap with that of juvenile fall Chinook salmon (Chapter 1, this reoprt), but juvenile fall Chinook salmon are also known to feed on age-0 American shad in the reservoirs (USGS unpublished data). Abundant, energy-dense age-0 American shad may provide juvenile fall Chinook salmon opportunities for rapid growth during the time period when large number of age-0 American shad are available. Otolith analysis of hatch dates and the growth curve of age-0 American shad could be used to identify when eggs, larvae, and juveniles of specific size classes are temporally available as food for fall Chinook salmon in the lower Columbia River reservoirs. This kind of temporally and spatially explicit life history information is important to include in bioenergetics modeling scenarios. Quantitive estimates of prey consumption could be used with spatially-explicit estimates of prey abundance to construct a quantitative assessment of the age-0 American shad impact on a reservoir food web.

Analysis of the age-0 American shad growth trajectory or individual growth records may show evidence of differential growth rates over time that may be linked to environmental conditions such as water temperature (Leach and Houde 1999, Meekan et al. 2003), size-selective mortality (Folkvord et al. 1997), developmental changes in metabolic rate (Bang and Gronkjaer 2005, Bochdanksy et al. 2005), feeding ability (Schmitt and Holbrook 1984, Luecke 1986, Johnson and Dropkin 1995, Johnson and Dropkin 1996), and intra- and inter-specific competition (Crecco and Savoy 1987, Marchand and Boisclair 1998, Gadomski and Wagner 2009). For example, environmental conditions associated with John Day reservoir may eliminate or reduce the availability of many aquatic and terrestrial insect prey types (Rondorf et al. 1990). Many juvenile fishes, including age-0 American shad and juvenile fall Chinook salmon may be foraging on limited insect prey in John Day Reservoir (Gadomski and Wagner 2009). Because larger insect prey has higher energy densities than most zooplankton prey, and insect availability may be limited in John Day reservoir, the growth of American shad may be constrained once fish grow to a size where they could exploit larger, more energy-dense insect prey (Mayer and Wahl 1997).

Similarly, as age-0 American shad grow, they are able to forage on larger zooplankton with higher energy densities than smaller individuals of the same species, or other smaller-bodied zooplankton species (Schael et al. 1991, Mayer and Wahl 1997). Intra- and inter-specific demand for larger-bodied and higher energy zooplankton prey may reduce the availability of these prey items (Tabor et al. 1996). Constrained growth increments on the otolith microstructure of juvenile American shad or other planktivorous fish could help identify important interactions between fishes that may be linked to the year class strength of age-0 American shad and prey partitioning in John Day reservoir.

The objective of this study was to determine time of hatch and size-at-age of age-0 American shad in lower Columbia River reservoirs for use with the American shad and fall Chinook salmon bioenergetic models. Size-at-age data on age-0 American shad can be used to generate quantitative estimates of prey consumption with the American shad bioenergetics model. Otolith microstructure analysis was used to provide reference points on the temporal availability of early life stages and sizes of American shad in the reservoir (Limburg 1996a,b, Limburg et al. 1999). Additional analyses on the age-0 American shad growth trajectory in John Day reservoir may reveal differential growth patterns during the early life history of these fish that are linked to developmental differences between individual fish, transient environmental conditions, or food web constraints (Limburg 1996a).

Movements and habitat use by PIT-tagged Atlantic salmon parr in early winter: The influence of anchor ice

USGS Publications Warehouse

Roussel, J.-M.; Cunjak, R.A.; Newbury, R.; Caissie, D.; Haro, A.

2004-01-01

1. Movements and habitat use by Atlantic salmon parr in Catamaran Brook, New Brunswick, were studied using Passive Integrated Transponder technology. The fish were tagged in the summer of 1999, and a portable reading system was used to collect data on individual positions within a riffle-pool sequence in the early winter of 1999. Two major freezing events occurred on November 11-12 (Ice 1) and November 18-19 (Ice 2) that generated significant accumulations of anchor ice in the riffle. 2. Individually tagged parr (fork length 8.4-12.6 cm, n = 15) were tracked from 8 to 24 November 1999. Over this period, emigration (40%) was higher from the pool than from the riffle. Of the nine parr that were consistently located, seven parr moved <5 m up- or downstream, and two parr moved more than 10 m (maximum 23 m). Parr moved significantly more by night than by day, and diel habitat shifts were more pronounced in the pool with some of the fish moving closer to the bank at night. 3. During Ice 2, there was relatively little movement by most of the parr in the riffle beneath anchor ice up to 10 cm in thickness. Water temperature was 0.16??C above the freezing point beneath anchor ice, suggesting the existence of suitable habitats where salmon parr can avoid supercooling conditions and where they can have access to low velocity shelters. To our knowledge, these are the first data on habitat use by Atlantic salmon parr under anchor ice.

Benefits of prescribed flows for salmon smolt survival enhancement vary longitudinally in a highly managed river system

USGS Publications Warehouse

Courter, Ian; Garrison, Thomas; Kock, Tobias J.; Perry, Russell W.; Child, David; Hubble, Joel

2016-01-01

The influence of streamflow on survival of emigrating juvenile Pacific salmonids Oncorhynchus spp. (smolts) is a major concern for water managers throughout the northeast Pacific Rim. However, few studies have quantified flow effects on smolt survival, and available information does not indicate a consistent flow–survival relationship within the typical range of flows under management control. In the Yakima Basin, Washington, the potential effects of streamflow alterations on smolt survival have been debated for over 20 years. Using a series of controlled flow releases from upper basin reservoirs and radiotelemetry, we quantified the relationship between flow and yearling Chinook salmon smolt survival in the 208 km reach between Roza Dam and the Yakima River mouth. A multistate mark–recapture model accounted for weekly variation in flow conditions experienced by tagged fish in four discrete river segments. Smolt survival was significantly associated with streamflow in the Roza Reach [river kilometre (rkm) 208–189] and marginally associated with streamflow in the Sunnyside Reach (rkm 169–77). However, smolt survival was not significantly associated with flow in the Naches and Prosser Reaches (rkm 189–169 and rkm 77–3). This discrepancy indicates potential differences in underlying flow-related survival mechanisms, such as predation or passage impediments. Our results clarify trade-offs between flow augmentation for fisheries enhancement and other beneficial uses, and our study design provides a framework for resolving uncertainties about streamflow effects on migratory fish survival in other river systems. 

[Impact of people's social behavior on schistosomiasis transmission in the Three Gorges Reservoir area].

PubMed

Zhang, Hui-Juan; Zhu, Rong; Wu, Cheng-Guo; Guo, Jia-Gang

2007-06-01

To investigate the changes in natural ecology and social environment after the construction of the dam in the Three Gorges Reservoir area, and to understand the social behavior status and education backgrounds of the local residents, and to analyze the potential impact of these factors on schistosomiasis spreading. Data of nature and social economy after the construction of the dam in the Three Gorge area were collected, and a cross-sectional study with questionnaire survey on information including social demographic characteristics, people's production and life style, knowledge about schistosomiasis was conducted among natives, emigrations. After the construction of the dam, as the stream became slower, the water-level fluctuating zone on the bank of the reservoir was formed. The main source of drinking water and daily life activity are mainly depends on the river supplying (accounting about 68.7% and 75.8%, respectively); due to the needs of farming, washing cloths and vegetables, 45.6% of resident had a close contact with river water. People with away-from-home employment among emigrations were increased from 5.7% to 18.7%. The proportion of using hygienic lavatory was 88.6%. The main source of water for drinking and daily life among emigrations was tap water (85.4% and 87.0%). The residents had no awareness about the health hazard for schistosomiasis, with less health information The natural environment of reservoir areas and the life style are risk factors for the spread of schistosomiasis. The improved sanitation condition and the economy construction after the construction of the dam is propitious to keeping away from the introduction of schistosomiasis. However, people with away-from-home employment among emigrations are still at risk of schistosomiasis.

Preparing for export? Medical and nursing student migration intentions post-qualification in South Africa

PubMed Central

Reardon, Candice

2013-01-01

Abstract Background The migration of health professionals can have a profound impact on health systems around the globe. The International Organization for Migration's (IOM) Mobility of Health Professionals Research Project (MoHProf) aimed to improve knowledge about the migration of healthcare professionals and understand migration intentions and factors influencing the migration of medical and nursing students. Objectives The study aimed to determine the proportion of nursing and medical students who were intending to emigrate, their attitudes and beliefs about, and the factors influencing their decision to emigrate. Method This study was conducted at three medical schools and one nursing school in South Africa (n = 298) amongst 260 medical and 38 nursing students. One hundred and twenty-five students were in the final year of their studies and 143 were in their prefinal year. Thirty students did not indicate the year of their studies. Every student present on the day of data collection completed a questionnaire comprising psychometric and survey-based questions. Descriptive and inferential statistics were used to analyse the data. Results More than a third (37%) of the respondents intended to work or specialise abroad. The majority of medical (58.9%) and nursing (66.6%) students intended to leave SA within five years of completing their medical or nursing studies. The perception of poor working conditions within the health sector, such as long work hours, high patient loads, inadequate resources and occupational hazards, influenced medical students to consider emigrating from South Africa. Conclusion The high number of medical and nursing students intending to emigrate requires a reassessment of effectiveness of retention strategies for doctors and nurses in the South African healthcare system and actions to improve working conditions in the public healthcare sector.

Density-dependent natal dispersal patterns in a leopard population recovering from over-harvest.

PubMed

Fattebert, Julien; Balme, Guy; Dickerson, Tristan; Slotow, Rob; Hunter, Luke

2015-01-01

Natal dispersal enables population connectivity, gene flow and metapopulation dynamics. In polygynous mammals, dispersal is typically male-biased. Classically, the 'mate competition', 'resource competition' and 'resident fitness' hypotheses predict density-dependent dispersal patterns, while the 'inbreeding avoidance' hypothesis posits density-independent dispersal. In a leopard (Panthera pardus) population recovering from over-harvest, we investigated the effect of sex, population density and prey biomass, on age of natal dispersal, distance dispersed, probability of emigration and dispersal success. Over an 11-year period, we tracked 35 subadult leopards using VHF and GPS telemetry. Subadult leopards initiated dispersal at 13.6 ± 0.4 months. Age at commencement of dispersal was positively density-dependent. Although males (11.0 ± 2.5 km) generally dispersed further than females (2.7 ± 0.4 km), some males exhibited opportunistic philopatry when the population was below capacity. All 13 females were philopatric, while 12 of 22 males emigrated. Male dispersal distance and emigration probability followed a quadratic relationship with population density, whereas female dispersal distance was inversely density-dependent. Eight of 12 known-fate females and 5 of 12 known-fate male leopards were successful in settling. Dispersal success did not vary with population density, prey biomass, and for males, neither between dispersal strategies (philopatry vs. emigration). Females formed matrilineal kin clusters, supporting the resident fitness hypothesis. Conversely, mate competition appeared the main driver for male leopard dispersal. We demonstrate that dispersal patterns changed over time, i.e. as the leopard population density increased. We conclude that conservation interventions that facilitated local demographic recovery in the study area also restored dispersal patterns disrupted by unsustainable harvesting, and that this indirectly improved connectivity among leopard populations over a larger landscape.

Identifying key demographic parameters of a small island-associated population of Indo-Pacific bottlenose dolphins (Reunion, Indian Ocean).

PubMed

Dulau, Violaine; Estrade, Vanessa; Fayan, Jacques

2017-01-01

Photo-identification surveys of Indo-Pacific bottlenose dolphins were conducted from 2009 to 2014 off Reunion Island (55°E33'/21°S07'), in the Indian Ocean. Robust Design models were applied to produce the most reliable estimate of population abundance and survival rate, while accounting for temporary emigration from the survey area (west coast). The sampling scheme consisted of a five-month (June-October) sampling period in each year of the study. The overall population size at Reunion was estimated to be 72 individuals (SE = 6.17, 95%CI = 61-85), based on a random temporary emigration (γ") of 0.096 and a proportion of 0.70 (SE = 0.03) distinct individuals. The annual survival rate was 0.93 (±0.018 SE, 95%CI = 0.886-0.958) and was constant over time and between sexes. Models considering gender groups indicated different movement patterns between males and females. Males showed null or quasi-null temporary emigration (γ" = γ' < 0.01), while females showed a random temporary emigration (γ") of 0.10, suggesting that a small proportion of females was outside the survey area during each primary sampling period. Sex-specific temporary migration patterns were consistent with movement and residency patterns observed in other areas. The Robust Design approach provided an appropriate sampling scheme for deriving island-associated population parameters, while allowing to restrict survey effort both spatially (i.e. west coast only) and temporally (five months per year). Although abundance and survival were stable over the six years, the small population size of fewer than 100 individuals suggested that this population is highly vulnerable. Priority should be given to reducing any potential impact of human activity on the population and its habitat.

Density-Dependent Natal Dispersal Patterns in a Leopard Population Recovering from Over-Harvest

PubMed Central

Fattebert, Julien; Balme, Guy; Dickerson, Tristan; Slotow, Rob; Hunter, Luke

2015-01-01

Natal dispersal enables population connectivity, gene flow and metapopulation dynamics. In polygynous mammals, dispersal is typically male-biased. Classically, the ‘mate competition’, ‘resource competition’ and ‘resident fitness’ hypotheses predict density-dependent dispersal patterns, while the ‘inbreeding avoidance’ hypothesis posits density-independent dispersal. In a leopard (Panthera pardus) population recovering from over-harvest, we investigated the effect of sex, population density and prey biomass, on age of natal dispersal, distance dispersed, probability of emigration and dispersal success. Over an 11-year period, we tracked 35 subadult leopards using VHF and GPS telemetry. Subadult leopards initiated dispersal at 13.6 ± 0.4 months. Age at commencement of dispersal was positively density-dependent. Although males (11.0 ± 2.5 km) generally dispersed further than females (2.7 ± 0.4 km), some males exhibited opportunistic philopatry when the population was below capacity. All 13 females were philopatric, while 12 of 22 males emigrated. Male dispersal distance and emigration probability followed a quadratic relationship with population density, whereas female dispersal distance was inversely density-dependent. Eight of 12 known-fate females and 5 of 12 known-fate male leopards were successful in settling. Dispersal success did not vary with population density, prey biomass, and for males, neither between dispersal strategies (philopatry vs. emigration). Females formed matrilineal kin clusters, supporting the resident fitness hypothesis. Conversely, mate competition appeared the main driver for male leopard dispersal. We demonstrate that dispersal patterns changed over time, i.e. as the leopard population density increased. We conclude that conservation interventions that facilitated local demographic recovery in the study area also restored dispersal patterns disrupted by unsustainable harvesting, and that this indirectly improved connectivity among leopard populations over a larger landscape. PMID:25875293

9 CFR 93.903 - Import permits for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., fertilized eggs, and gametes. 93.903 Section 93.903 Animals and Animal Products ANIMAL AND PLANT HEALTH... General Provisions for Svc-Regulated Fish Species § 93.903 Import permits for live fish, fertilized eggs, and gametes. (a) Live fish, fertilized eggs, or gametes of SVC-susceptible species imported into the...

9 CFR 93.903 - Import permits for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., fertilized eggs, and gametes. 93.903 Section 93.903 Animals and Animal Products ANIMAL AND PLANT HEALTH... General Provisions for Svc-Regulated Fish Species § 93.903 Import permits for live fish, fertilized eggs, and gametes. (a) Live fish, fertilized eggs, or gametes of SVC-susceptible species imported into the...

Amino Acid compositions of 27 food fishes and their importance in clinical nutrition.

PubMed

Mohanty, Bimal; Mahanty, Arabinda; Ganguly, Satabdi; Sankar, T V; Chakraborty, Kajal; Rangasamy, Anandan; Paul, Baidyanath; Sarma, Debajit; Mathew, Suseela; Asha, Kurukkan Kunnath; Behera, Bijay; Aftabuddin, Md; Debnath, Dipesh; Vijayagopal, P; Sridhar, N; Akhtar, M S; Sahi, Neetu; Mitra, Tandrima; Banerjee, Sudeshna; Paria, Prasenjit; Das, Debajeet; Das, Pushpita; Vijayan, K K; Laxmanan, P T; Sharma, A P

2014-01-01

Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs.

Amino Acid Compositions of 27 Food Fishes and Their Importance in Clinical Nutrition

PubMed Central

Mahanty, Arabinda; Sankar, T. V.; Chakraborty, Kajal; Rangasamy, Anandan; Paul, Baidyanath; Sarma, Debajit; Mathew, Suseela; Asha, Kurukkan Kunnath; Behera, Bijay; Aftabuddin, Md.; Debnath, Dipesh; Vijayagopal, P.; Sridhar, N.; Akhtar, M. S.; Sahi, Neetu; Mitra, Tandrima; Banerjee, Sudeshna; Das, Debajeet; Das, Pushpita; Vijayan, K. K.; Laxmanan, P. T.; Sharma, A. P.

2014-01-01

Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs. PMID:25379285

The ethnic composition of migration in the former Soviet Union.

PubMed

Robertson, L R

1996-02-01

"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." excerpt

Use of olfactory cues by newly metamorphosed wood frogs (Lithobates sylvaticus) during emigration

USGS Publications Warehouse

Zydlewski, Joseph D.; Popescu, Viorel D.; Brodie, Bekka S.; Hunter, Malcom L.

2012-01-01

Juvenile amphibians are capable of long-distance upland movements, yet cues used for orientation during upland movements are poorly understood. We used newly metamorphosed Wood Frogs (Lithobates sylvaticus) to investigate: (1) the existence of innate (i.e., inherited) directionality, and (2) the use of olfactory cues, specifically forested wetland and natal pond cues during emigration. In a circular arena experiment, animals with assumed innate directionality did not orient in the expected direction (suggested by previous studies) when deprived of visual and olfactory cues. This suggests that juvenile Wood Frogs most likely rely on proximate cues for orientation. Animals reared in semi-natural conditions (1500 l cattle tanks) showed a strong avoidance of forested wetland cues in two different experimental settings, although they had not been previously exposed to such cues. This finding is contrary to known habitat use by adult Wood Frogs during summer. Juvenile Wood Frogs were indifferent to the chemical signature of natal pond (cattle tank) water. Our findings suggest that management strategies for forest amphibians should consider key habitat features that potentially influence the orientation of juveniles during emigration movements, as well as adult behavior.

Part of a global workforce: migration of British-trained pharmacists.

PubMed

Hassell, Karen; Nichols, Liza; Noyce, Peter

2008-04-01

Many countries, including the UK, have identified a shortage of pharmacists, partly due to emigration. This study was undertaken to examine the extent and nature of migration taking place among British-qualified pharmacists. Mixed methods, including secondary analysis of quantitative data, qualitative research and a large self-completion survey of all British-registered pharmacists with an overseas address. Almost 11% of British-registered pharmacists reside overseas. Nearly three-quarters are British-trained and most are UK nationals. The US, Canada and Australia are the main destinations. The majority work as pharmacists in health services, but sizeable proportions are either retired, not working for other reasons or work in industry. Those who emigrate include those returning home, moving for career opportunities, for lifestyle reasons or as a 'spouse trailer'. For many the move abroad is a permanent one. Great Britain is both a source and destination country for migrating pharmacists. Emigration currently exceeds immigration. Pharmacists are not migrating to developing countries, so the profession may want to consider ways of contributing to the health care systems in developing countries which are the source of some of the immigrant pharmacists to Great Britain.

[Poles, the authors of doctor theses of the faculty of medicine in Strasburg].

PubMed

Gepner-Wozniewska, M; Pruszyńska, A

1996-01-01

Among Poles emigrating from Poland in XIX century (after November and January insurrection) there have been physicians and students of medicine - practising in insurgent troops - and young people, who after arrival in France started medical studies at the medical faculties of Paris, Montpellier, and Strasburg. In Strasburg between 1833 and 1870 there have been promoted 1440 doctors of medicine, including 15 Polish emigrants (three have been granted diplomas before coming to France) and two sons of emigrants. Generally all of them were subsidized by the French government and released from additional payments. At the university they were treated favourably and they were even taking advantage of some conveniences. From the archival materials of the Faculty of Medicine and dossiers of students - refugees from the Department Archives of Bas-Rhin in Strasburg, there was possible to reconstruct the fragments of their biographies, even with such details as notes of exems or outward appearance. In biographical notes there have been presented 17 authors of the doctor's theses defended in Strasburg between 1833 and 1870 (12 were granted the diplomas between 1853 and 1847, five others - between 1867 and 1870).

9 CFR 93.902 - Ports designated for the importation of live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... of live fish, fertilized eggs, and gametes. 93.902 Section 93.902 Animals and Animal Products ANIMAL... importation of live fish, fertilized eggs, and gametes. (a) The following ports are designated as ports of entry for live fish, fertilized eggs, and gametes of SVC-susceptible species imported under this subpart...

9 CFR 93.902 - Ports designated for the importation of live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2011 CFR

2011-01-01

... of live fish, fertilized eggs, and gametes. 93.902 Section 93.902 Animals and Animal Products ANIMAL... importation of live fish, fertilized eggs, and gametes. (a) The following ports are designated as ports of entry for live fish, fertilized eggs, and gametes of SVC-susceptible species imported under this subpart...

Effect of size of unfed fry at release on survival and growth of juvenile steelhead in streams and a hatchery (Study sites: Dworshak Hatchery, Silver Creek, and Twenty-Mile Creek; Stock: Dworshak hatchery; Year classes: 1996 and 1999): Chapter 7

USGS Publications Warehouse

Rubin, Stephen P.; Reisenbichler, Reginald R.; Wetzel, Lisa A.; Stenberg, Karl D.

2012-01-01

We tested whether differences in size of unfed fry at release affected survival and growth of juvenile steelhead Oncorhynchus mykiss in hatchery ponds and streams. Differences in fry size were produced by selecting and spawning females that differed in the mean size of their eggs. Experiments were initiated in 1996 and 1999 with hatchery steelhead returning to the Clearwater River, Idaho. Fry size groups were small (mean fork length=26.7 mm, mean weight=0.149 g) and large (28.1 mm, 0.197 g) in 1996 and small (27.5 mm, 0.159 g), medium (28.2 mm, 0.190 g), and large (28.9 mm, 0.201 g) in 1999. Survival in the hatchery to near the end of the standard one year rearing period and in streams to late summer, three months after release, was higher for the large than for the small group in 1996 but was similar among groups in 1999. Survival in streams to age - 1 appeared to show the same pattern (large>small in 1996; no difference in 1999), but differences among fry size groups in emigration as well as mortality may have been involved. The inconsistency between years may have resulted because some 1996 female parents of the small group had exceptionally small eggs and were a year younger than the other 1996 females and all 1999 females. Growth in the hatchery was similar among groups in both years whereas growth in streams was faster for the large than for the small group in both years and intermediate for the medium group in 1999. Growth in streams appeared to be limited by food availability. Initially large fry probably out - competed smaller fry for limited food; however, we found no evidence that dispersal from release sites or emigration from streams was caused by competitive displacement of small by larger fish. 

Integrated Status and Effectiveness Monitoring Program; Expansion of Existing Smolt Trapping Program in Nason Creek, 2005 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prevatte, Scott A.

2006-03-01

In the fall of 2004, as one part of a Basin-Wide Monitoring Program developed by the Upper Columbia Regional Technical Team and Upper Columbia Salmon Recovery Board, the Yakama Nation Fisheries Resource Management program began monitoring downstream migration of ESA listed Upper Columbia River spring chinook salmon and Upper Columbia River steelhead in Nason Creek, a tributary to the Wenatchee River. This report summarizes juvenile spring chinook salmon and steelhead trout migration data collected in Nason Creek during 2005 and also incorporates data from 2004. We used species enumeration at the trap and efficiency trials to describe emigration timing andmore » to estimate population size. Data collection was divided into spring/early summer and fall periods with a break during the summer months occurring due to low stream flow. Trapping began on March 1st and was suspended on July 29th when stream flow dropped below the minimum (30 cfs) required to rotate the trap cone. The fall period began on September 28th with increased stream flow and ended on November 23rd when snow and ice began to accumulate on the trap. During the spring and early summer we collected 311 yearling (2003 brood) spring chinook salmon, 86 wild steelhead smolts and 453 steelhead parr. Spring chinook (2004 brood) outgrew the fry stage of fork length < 60 mm during June and July, 224 were collected at the trap. Mark-recapture trap efficiency trials were performed over a range of stream discharge stages whenever ample numbers of fish were being collected. A total of 247 spring chinook yearlings, 54 steelhead smolts, and 178 steelhead parr were used during efficiency trials. A statically significant relationship between stream discharge and trap efficiency has not been identified in Nason Creek, therefore a pooled trap efficiency was used to estimate the population size of both spring chinook (14.98%) and steelhead smolts (12.96%). We estimate that 2,076 ({+-} 119 95%CI) yearling spring chinook and 688 ({+-} 140 95%CI) steelhead smolts emigrated past the trap during the spring/early summer sample period along with 10,721 ({+-} 1,220 95%CI) steelhead parr. During the fall we collected 924 subyearling (2004 brood) spring chinook salmon and 1,008 steelhead parr of various size and age classes. A total of 732 spring chinook subyearlings and 602 steelhead parr were used during 13 mark-recapture trap efficiency trials. A pooled trap efficiency of 24.59% was used to calculate the emigration of spring chinook and 17.11% was used for steelhead parr during the period from September 28th through November 23rd. We estimate that 3758 ({+-} 92 95%CI) subyearling spring chinook and 5,666 ({+-} 414 95%CI) steelhead parr migrated downstream past the trap along with 516 ({+-} 42 95%CI) larger steelhead pre-smolts during the 2005 fall sample period.« less

Divorce in contemporary Japan.

PubMed

Fukurai, H; Alston, J

1990-10-01

Data from the 1985-86 Japanese census are analysed to explore the determinants of the divorce rates in Japan's forty-seven prefectures, using two theoretical models: (a) the social integration model, which is shown to have a greater utility in predicting Japanese divorce levels than (b), the human capital model. Female emigration patterns play a significant role in affecting the divorce rate. Population increase and net household income are also important predictors of the Japanese divorce rate and urbanization has a great influence in modern Japan. Demographic and aggregate variables such as migration, urbanization, and socioeconomic factors are useful when organized under a social integration model.

The migratory impact of minimum wage legislation: Puerto Rico, 1970-1987.

PubMed

Santiago, C E

1993-01-01

"This study examines the impact of minimum wage setting on labor migration. A multiple time series framework is applied to monthly data for Puerto Rico from 1970-1987. The results show that net emigration from Puerto Rico to the United States fell in response to significant changes in the manner in which minimum wage policy was conducted, particularly after 1974. The extent of commuter type labor migration between Puerto Rico and the United States is influenced by minimum wage policy, with potentially important consequences for human capital investment and long-term standards of living." excerpt

Spring Chinook Salmon Oncorhynchus tshawytscha Supplementation in the Clearwater Subbasin ; Nez Perce Tribal Hatchery Monitoring and Evaluation Project, 2007 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Backman, Thomas; Sprague, Sherman; Bretz, Justin

The Nez Perce Tribal Hatchery (NPTH) program has the following goals (BPA, et al., 1997): (1) Protect, mitigate, and enhance Clearwater Subbasin anadromous fish resources; (2) Develop, reintroduce, and increase natural spawning populations of salmon within the Clearwater Subbasin; (3) Provide long-term harvest opportunities for Tribal and non-Tribal anglers within Nez Perce Treaty lands within four generations (20 years) following project initiation; (4) Sustain long-term fitness and genetic integrity of targeted fish populations; (5) Keep ecological and genetic impacts to non-target populations within acceptable limits; and (6) Promote Nez Perce Tribal management of Nez Perce Tribal Hatchery Facilities and productionmore » areas within Nez Perce Treaty lands. The NPTH program was designed to rear and release 1.4 million fall and 625,000 spring Chinook salmon. Construction of the central incubation and rearing facility NPTH and spring Chinook salmon acclimation facilities were completed in 2003 and the first full term NPTH releases occurred in 2004 (Brood Year 03). Monitoring and evaluation plans (Steward, 1996; Hesse and Cramer, 2000) were established to determine whether the Nez Perce Tribal Hatchery program is achieving its stated goals. The monitoring and evaluation action plan identifies the need for annual data collection and annual reporting. In addition, recurring 5-year program reviews will evaluate emerging trends and aid in the determination of the effectiveness of the NPTH program with recommendations to improve the program's implementation. This report covers the Migratory Year (MY) 2007 period of the NPTH Monitoring & Evaluation (M&E) program. There are three NPTH spring Chinook salmon treatment streams: Lolo Creek, Newsome Creek, and Meadow Creek. In 2007, Lolo Creek received 140,284 Brood Year (BY) 2006 acclimated pre-smolts at an average weight of 34.9 grams per fish, Newsome Creek received 77,317 BY 2006 acclimated pre-smolts at an average of 24.9 grams per fish, and Meadow Creek received 53,425 BY 2006 direct stream release parr at an average of 4.7 grams per fish. Natural and hatchery origin spring Chinook salmon pre-smolt emigrants were monitored from September - November 2006 and smolts from March-June 2007. Data on adult returns were collected from May-September. A suite of performance measures were calculated including total adult and spawner escapement, juvenile production, and survival probabilities. These measures were used to evaluate the effectiveness of supplementation and provide information on the capacity of the natural environment to assimilate and support supplemented salmon populations.« less

Relative and combined effects of habitat and fishing on reef fish communities across a limited fishing gradient at Ningaloo.

PubMed

Wilson, Shaun K; Babcock, Russ C; Fisher, Rebecca; Holmes, Thomas H; Moore, James A Y; Thomson, Damian P

2012-10-01

Habitat degradation and fishing are major drivers of temporal and spatial changes in fish communities. The independent effects of these drivers are well documented, but the relative importance and interaction between fishing and habitat shifts is poorly understood, particularly in complex systems such as coral reefs. To assess the combined and relative effects of fishing and habitat we examined the composition of fish communities on patch reefs across a gradient of high to low structural complexity in fished and unfished areas of the Ningaloo Marine Park, Western Australia. Biomass and species richness of fish were positively correlated with structural complexity of reefs and negatively related to macroalgal cover. Total abundance of fish was also positively related to structural complexity, however this relationship was stronger on fished reefs than those where fishing is prohibited. The interaction between habitat condition and fishing pressure is primarily due to the high abundance of small bodied planktivorous fish on fished reefs. However, the influence of management zones on the abundance and biomass of predators and target species is small, implying spatial differences in fishing pressure are low and unlikely to be driving this interaction. Our results emphasise the importance of habitat in structuring reef fish communities on coral reefs especially when gradients in fishing pressure are low. The influence of fishing effort on this relationship may however become more important as fishing pressure increases. Copyright © 2012 Elsevier Ltd. All rights reserved.

Dynamics of microorganism populations in recirculating nutrient solutions

NASA Technical Reports Server (NTRS)

Strayer, R. F.

1994-01-01

This overview covers the basic microbial ecology of recirculating hydroponic solutions. Examples from NASA and Soviet Controlled Ecological Life Support Systems (CELSS) tests and the commercial hydroponic industry will be used. The sources of microorganisms in nutrient solutions include air, water, seeds, plant containers and plumbing, biological vectors, and personnel. Microbial fates include growth, death, and emigration. Important microbial habitats within nutrient delivery systems are root surfaces, hardware surfaces (biofilms), and solution suspension. Numbers of bacteria on root surfaces usually exceed those from the other habitats by several orders of magnitude. Gram negative bacteria dominate the microflora with fungal counts usually much lower. Trends typically show a decrease in counts with increasing time unless stressed plants increase root exudates. Important microbial activities include carbon mineralization and nitrogen transformations. Important detrimental interactions include competition with plants, and human and plant pathogenesis.

Isolation and in vitro maintenance of trypanosomes from naturally infected and commercially important Brazilian fish.

PubMed

Lemos, Moara; Souto-Padrón, Thaïs

2014-10-01

Fish trypanosomes are widely distributed in commercially important fish, with high prevalence in some Brazilian species. This study provides the first record of the isolation and in vitro maintenance of trypanosomes from Brazilian fish. We produced 49 trypanosome isolates from naturally infected catfish (Hypostomus affinis and Hypostomus luetkeni), using 9 different culture media (out of 31 tested). Trypanosomes were maintained in culture for at least 15 mo and were successfully cryopreserved. Culture forms-epimastigotes and short trypomastigotes-were capable of dividing in vitro. Our study is an important step in the investigation of ultrastructure, taxonomy, and phylogeny of trypanosomes from commercially important Brazilian fish.

Detection of dwarf gourami iridovirus (Infectious spleen and kidney necrosis virus) in populations of ornamental fish prior to and after importation into Australia, with the first evidence of infection in domestically farmed Platy (Xiphophorus maculatus).

PubMed

Rimmer, Anneke E; Becker, Joy A; Tweedie, Alison; Lintermans, Mark; Landos, Matthew; Stephens, Fran; Whittington, Richard J

2015-11-01

The movement of ornamental fish through international trade is a major factor for the transboundary spread of pathogens. In Australia, ornamental fish which may carry dwarf gourami iridovirus (DGIV), a strain of Infectious spleen and kidney necrosis virus (ISKNV), have been identified as a biosecurity risk despite relatively stringent import quarantine measures being applied. In order to gain knowledge of the potential for DGIV to enter Australia, imported ornamental fish were sampled prior to entering quarantine, during quarantine, and post quarantine from wholesalers and aquatic retail outlets in Australia. Samples were tested by quantitative polymerase chain reaction (qPCR) for the presence of megalocytivirus. Farmed and wild ornamental fish were also tested. Megalocytivirus was detected in ten of fourteen species or varieties of ornamental fish. Out of the 2086 imported gourami tested prior to entering quarantine, megalocytivirus was detected in 18.7% of fish and out of the 51 moribund/dead ornamental fish tested during the quarantine period, 68.6% were positive for megalocytivirus. Of fish from Australian wholesalers and aquatic retail outlets 14.5% and 21.9%, respectively, were positive. Out of 365 farmed ornamental fish, ISKNV-like megalocytivirus was detected in 1.1%; these were Platy (Xiphophorus maculatus). Megalocytivirus was not detected in free-living breeding populations of Blue gourami (Trichopodus trichopterus) caught in Queensland. This study showed that imported ornamental fish are vectors for DGIV and it was used to support an import risk analysis completed by the Australian Department of Agriculture. Subsequently, the national biosecurity policy was revised and from 1 March 2016, a health certification is required for susceptible families of fish to be free of this virus prior to importation. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Patterns of Larval Sucker Emigration from the Sprague and Lower Williamson Rivers of the Upper Klamath Basin, Oregon, Prior to the Removal of Chiloquin Dam - 2006 Annual Report

USGS Publications Warehouse

Ellsworth, Craig M.; Tyler, Torrey J.; VanderKooi, Scott P.; Markle, Douglas F.

2009-01-01

In 2006, we collected larval Lost River sucker Deltistes luxatus (LRS), shortnose sucker Chasmistes brevirostris (SNS), and Klamath largescale sucker Catostomus snyderi (KLS) emigrating from spawning areas in the Williamson and Sprague Rivers. This work is part of a multi-year effort to characterize the relative abundance, drift timing, and length frequencies of larval suckers in this watershed prior to the removal of Chiloquin Dam on the lower Sprague River. Additional larval drift samples were collected from the Fremont Bridge on Lakeshore Drive on the south end of Upper Klamath Lake near its outlet to the Link River. Because of difficulties in distinguishing KLS larvae from SNS larvae, individuals identified as either of these two species were grouped together and reported as KLS-SNS in this report. We found that larval densities varied by site with the highest densities being collected at the most upstream site on the Sprague River at river kilometer (rkm) 108.0 near Beatty, Oregon (Beatty), and the most downstream sites near Chiloquin, Oregon; one site on the Sprague River at rkm 0.7 (Chiloquin) and the other site on the Williamson River at rkm 7.4 (Williamson). Larval catches were relatively small and sporadic at two other sites on the Sprague River located between Chiloquin and Beatty (Power Station at rkm 9.5 and Lone Pine at rkm 52.7) and one site on the Sycan River at rkm 4.7. Most larvae (79 percent) collected in 2006 were identified as LRS. More larvae and eggs were collected at Chiloquin than at any other site. The seasonal timing of larval drift varied by location; larvae generally were captured earlier at upstream sites than at downstream sites. Cumulative catch percentages of drifting larvae suggest that larval LRS emigrated earlier than KLS-SNS larvae at every site. Drift of LRS larvae at Beatty began 3 to 4 weeks earlier than at Chiloquin or Williamson. At Chiloquin, peak larval catches occurred 3 and 5 weeks after peak egg catches. The daily peak in larval drift at Chiloquin occurred approximately 1.5 to 2.0 hours after sunset. Nightly peak larval drift varied by location; larvae were captured earlier in the evening at sites closer to known spawning locations than sites farther away from these areas. The highest numerical catches of sucker-sized eggs were at Chiloquin indicating that this site is in close proximity to a spawning area. Numerical catches of older, more developed larval and juvenile suckers also were highest at Chiloquin. This may be due to the turbulent nature of this site, which could have swept larger fish into the drift. Proportional catches of older, more developed larval and juvenile suckers were highest at Sycan, Lone Pine, Power Station, and Fremont Bridge. This indicates these sites are located nearer to sucker nursery areas rather than spawning areas. Very few larval LRS were collected at Fremont Bridge at the south end of Upper Klamath Lake. Larval KLS-SNS densities at Fremont Bridge were the third highest of the seven sampling sites. Peak drift of larval KLS-SNS at Fremont Bridge occurred the week after peak drift of larval KLS-SNS at Williamson. Although inter-annual variation continues to appear in the larval drift data, our results continue to show consistent patterns of larval emigration in the drainage basin. In combination with data collected from the spawning movements and destinations of radio-tagged and PIT-tagged adult suckers, this larval drift data will provide a baseline standard by which to determine the effects of dam removal on the spawning distribution of endangered Klamath Basin suckers in the Sprague River.

Macrobenthos and megabenthos responses to long-term, large-scale hypoxia on the Louisiana continental shelf.

PubMed

Briggs, Kevin B; Craig, J Kevin; Shivarudrappa, S; Richards, T M

2017-02-01

The macrobenthos and megabenthos responses to long-term, recurring hypoxia on the Louisiana continental shelf were compared at four locations with different historical (2000-2010) episodes of annual exposure to bottom-water hypoxia. Measurements of abundance, biomass, species diversity, and community composition of the two size classes of benthos suggested that the macrobenthic response is driven chiefly by tolerance to hypoxia, whereas the megabenthic response was affected by the ability to migrate and the availability/unavailability of macrobenthos prey at the sediment surface. The site exposed to the historically lowest average bottom-water dissolved oxygen (BWDO) concentration exhibited the lowest species diversity for macrobenthos and the highest species diversity for megabenthos, exemplifying the differential effects of hypoxia on different size classes. The high diversity and smaller average size of the megabenthos at the lowest DO site was due to high abundance of invertebrates and a preponderance of small, less vagile fishes that appeared to remain in the area after larger dominant sciaenids had presumably emigrated. The average size and the depth of habitation in the sediment of macrobenthos prey may have also influenced the abundance and biomass of megabenthos foragers. Published by Elsevier Ltd.

Mucous lysozyme levels in hatchery coho salmon (Oncorhynchus kisutch) and spring chinook salmon (O. tshawytscha) early in the parr-smolt transformation

USGS Publications Warehouse

Schrock, R.M.; Smith, S.D.; Maule, A.G.; Doulos, S.K.; Rockowski, J.J.

2001-01-01

Mucous lysozyme concentrations were determined in juvenile coho salmon (Oncorhynchus kisutch) and spring chinook salmon (O. tshawytscha) to establish reference levels during the time associated with the parr-smolt transformation. The first reported naris and vent mucous lysozyme levels are provided for spring chinook salmon and coho salmon. Naris mucous lysozyme levels ranged between 300 and 700 ??g ml-1, vent mucous lysozyme from 100 to 300 ??g ml-1, and skin mucous lysozyme levels were below 130 ??g ml-1. Lysozyme levels in the two species showed the same relationship with the highest levels in naris mucous, and the lowest in skin mucous. A seasonal decrease occurred in both species with a significant decrease in naris mucous lysozyme between February and March. Gill ATPase levels used to monitor smolt development during the same period did not reach ranges reported for smolts for either species during emigration. Identification of seasonal levels of lysozyme activity in mucous provides an alternative determination of developmental status prior to release of fish from the hatchery when salmonids are still undergoing the parr-smolt transformation. ?? 2001 Elsevier Science B.V.

Migration of moth species in a network of small islands.

PubMed

Nieminen, Marko

1996-12-01

Rapidly increasing fragmentation of natural landscapes decreases the ability of many species to reach the smaller and more isolated patches of habitat in a metapopulation. The densities of local populations of several moth species and the butterfly Hipparchia semele in a network of small islands, and the rates of inter-island movement and movement patterns, were investigated, to determine the factors affecting the rate and pattern of movements. The estimated population densities ranged from 0.001 to 0.2 individuals/m 2 . The observed emigration and immigration rates depended on island isolation and various traits of the species, with great variability in migration rates among species. Thin-bodied, slow-flying species did not move among the islands, whereas many robust, fast-flying species moved among the islands relatively frequently. Migration rate increased significantly with body size and was significantly higher in oligophagous than in polyphagous species, suggesting that these factors are important determinants of the migration rate of the species. Migration rate was low when the surface temperature of the sea was low, and a greater proportion of individuals emigrated from small than large patches of habitat. The migration distances of female noctuids were shorter than those of males and those of both sexes of the butterfly H. semele. The observed movement patterns are consistent with a metapopulation structure in most of the moth species.

International migration data: their problems and usefulness in Venezuela.

PubMed

Torrealba, R

1987-01-01

During the 1940s and 1950s Venezuela was an important destination for migrants from Southern Europe, a flow that disappeared almost entirely during the 1960s, to be replaced by border movements and the largely illegal migration of Colombians. The oil boom of the 1970s saw an increase of the latter, which may have subsided during the 1980s due to the more difficult economic conditions that have also led to significant emigration levels of Venezuelans and former immigrants. Methods of data collection systems that provide information on migrants include the National Population and Housing Census, the National Household Survey, migration surveys, arrival and departure statistics, registration systems operated by the Direccion General Sectorial de identificacion y Control de Extranjeros, the 1980 regularization drive, statistics gathered by the Ministry of Labor, and vital and civil registration statistics. The lack of effective coordination among the different government agencies gathering information and the administrative nature of the data collected give rise to problems of comparability. Mechanisms to publish and disseminate the data available are not well developed, so that researchers often have no access to potentially useful sources of information. Problems of timeliness in the publication of the most widely used information are also present, as is the large gap existing in data pertaining to emigration, be it of Venezuelan nationals or of immigrants leaving the country.

A novel application of multi-event modeling to estimate class segregation in a highly migratory oceanic vertebrate.

PubMed

Chapple, T K; Chambert, T; Kanive, P E; Jorgensen, S J; Rotella, J J; Anderson, S D; Carlisle, A B; Block, B A

2016-12-01

Spatial segregation of animals by class (i.e., maturity or sex) within a population due to differential rates of temporary emigration (TE) from study sites can be an important life history feature to consider in population assessment and management. However, such rates are poorly known; new quantitative approaches to address these knowledge gaps are needed. We present a novel application of multi-event models that takes advantage of two sources of detections to differentiate temporary emigration from apparent absence to quantify class segregation within a study population of double-marked (photo-identified and tagged with coded acoustic transmitters) white sharks (Carcharodon carcharias) in central California. We use this model to test if sex-specific patterns in TE result in disparate apparent capture probabilities (p o ) between male and female white sharks, which can affect the observed sex ratio. The best-supported model showed a contrasting pattern of Pr(TE) from coastal aggregation sites between sexes (for males Pr[TE] = 0.015 [95% CI = 0.00, 0.31] and Pr[TE]= 0.57 [0.40, 0.72] for females), but not maturity classes. Additionally, by accounting for Pr(TE) and imperfect detection, we were able to estimate class-specific values of true capture probability (p * ) for tagged and untagged sharks. The best-supported model identified differences between maturity classes but no difference between sexes or tagging impacts (tagged mature sharks p *  = 0.55 (0.46-0.63) and sub-adult sharks p*   = 0.36 (0.25, 0.50); and untagged mature sharks p *  = 0.50 (0.39-0.61) and sub-adults p *  = 0.18 (0.10, 0.31). Estimated sex-based differences in p o were linked to sex-specific differences in Pr(TE) but not in p * ; once the Pr(TE) is accounted for, the p * between sexes was not different. These results indicate that the observed sex ratio is not a consequence of unequal detectability and sex-specific values of Pr(TE) are important drivers of the observed male-dominated sex ratio. Our modeling approach reveals complex class-specific patterns in Pr(TE) and p * in a mark-recapture data set, and highlights challenges for the population modeling and conservation of white sharks in central California. The model we develop here can be used to estimate rates of temporary emigration and class segregation when two detection methods are used. © 2016 by the Ecological Society of America.

Evaluation of Bull Trout Movements in the Tucannon and Lower Snake Rivers, 2002-2006 Project Completion Summary.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faler, Michael P.; Mendel, Glen; Fulton, Carl

2008-11-20

The Columbia River Distinct Population Segment of bull trout (Salvelinus confluentus) was listed as threatened under the Endangered Species Act in 1998. One of the identified major threats to the species is fragmentation resulting from dams on over-wintering habitats of migratory subpopulations. A migratory subgroup in the Tucannon River appeared to utilize the Snake River reservoirs for adult rearing on a seasonal basis. As a result, a radio telemetry study was conducted on this subgroup from 2002-2006, to help meet Reasonable and Prudent Measures, and Conservation Recommendations associated with the lower Snake River dams in the FCRPS Biological Opinion, andmore » to increase understanding of bull trout movements within the Tucannon River drainage. We sampled 1,109 bull trout in the Tucannon River; 124 of these were surgically implanted with radio tags and PIT tagged, and 681 were only PIT tagged. The remaining 304 fish were either recaptures, or released unmarked. Bull trout seasonal movements within the Tucannon River were similar to those described for other migratory bull trout populations. Bull trout migrated upstream in spring and early summer to the spawning areas in upper portions of the Tucannon River watershed. They quickly moved off the spawning areas in the fall, and either held or continued a slower migration downstream through the winter until early the following spring. During late fall and winter, bull trout were distributed in the lower half of the Tucannon River basin, down to and including the mainstem Snake River below Little Goose Dam. We were unable to adequately radio track bull trout in the Snake River and evaluate their movements or interactions with the federal hydroelectric dams for the following reasons: (1) none of our radio-tagged fish were detected attempting to pass a Snake River dam, (2) our radio tags had poor transmission capability at depths greater than 12.2 m, and (3) the sample size of fish that actually entered the Snake River was small (n=6). In spite of this project's shortcomings, bull trout continue to be observed in low numbers at Snake River dam fish facilities. It is highly possible that bull trout observed at the Snake River dam fish facilities are originating from sources other than the Tucannon River. We suggest that these fish might come from upstream sources like the Clearwater or Salmon rivers in Idaho, and are simply following the outmigration of juvenile anadromous fish (a food supply) as they emigrate toward the Pacific Ocean. Based on our study results, we recommend abandoning radio telemetry as a tool to monitor bull trout movements in the mainstem Snake River. We do recommend continuing PIT tagging and tag interrogation activities to help determine the origin of bull trout using the Snake River hydropower facilities. As a complementary approach, we also suggest the use of genetic assignment tests to help determine the origin of these fish. Lastly, several recommendations are included in the report to help manage and recover bull trout in the Tucannon subbasin.« less

UVA radiation impairs phenotypic and functional maturation of human dermal dendritic cells.

PubMed

Furio, Laetitia; Berthier-Vergnes, Odile; Ducarre, Blandine; Schmitt, Daniel; Peguet-Navarro, Josette

2005-11-01

There is now strong evidence that the ultraviolet A (UVA) part of the solar spectrum contributes to the development of skin cancers. Its effect on the skin immune system, however, has not been fully investigated. Here, we analyzed the effects of UVA radiation on dermal dendritic cells (DDC), which, in addition, provided further characterization of these cells. Dermal sheets were obtained from normal human skin and irradiated, or not, with UVA at 2 or 12 J per cm2. After a 2 d incubation, the phenotype of emigrant cells was analyzed by double immunostaining and flow cytometry. Results showed that migratory DDC were best characterized by CD1c expression and that only few cells co-expressed the Langerhans cell marker Langerin. Whereas the DC extracted from the dermis displayed an immature phenotype, emigrant DDC showed increased expression of HLA-DR and acquired co-stimulation and maturation markers. We showed here that UVA significantly decreased the number of viable emigrant DDC, a process related to increased apoptosis. Furthermore, UVA irradiation impaired the phenotypic and functional maturation of migrating DDC into potent antigen-presenting cells, in a concentration-dependent manner. The results provide further evidence that UVA are immunosuppressive and suggest an additional mechanism by which solar radiation impairs immune response.

Blood lead level analysis among refugee children resettled in New Hampshire and Rhode Island.

PubMed

Raymond, Jaime S; Kennedy, Chinaro; Brown, Mary Jean

2013-01-01

To examine the association between refugee status and elevated blood lead levels (EBLLs) among children living in two U.S. cities and to assess the effect of the Centers for Disease Control and Prevention recommendations for BLL testing of newly emigrated refugee children for EBLLs. A longitudinal study was conducted of 1,007 refugee children and 953 nonrefugee children living, when blood testing occurred, in the same buildings in Manchester, New Hampshire and Providence, Rhode Island. Surveillance and blood lead data were collected from both sites, including demographic information, BLLs, sample type, refugee status, and age of housing. Refugee children living in Manchester were statistically significantly more likely to have an EBLL compared with nonrefugee children even after controlling for potential confounders. We did not find this association in Providence. Compared with before enactment, the mean time of refugee children to fall below 10 μg/dL was significantly shorter after the recommendations to test newly emigrated children were enacted. Refugee children living in Manchester were significantly more likely to have an EBLL compared with nonrefugee children. And among refugee children, we found a statistically significant difference in the mean days to BLL decline <10 μg/dL before and after recommendations to test newly emigrated children. © 2012 Wiley Periodicals, Inc.

Fish and shellfish allergy.

PubMed

Wild, Laurianne G; Lehrer, Samuel B

2005-01-01

Fish and shellfish are important in the American diet and economy. Nearly $27 billion are spent each year in the United States on seafood products. Fish and shellfish are also important causes of food hypersensitivity. In fact, shellfish constitute the number one cause of food allergy in the American adult. During the past decade, much has been learned about allergens in fish and shellfish. The major allergens responsible for cross-reactivity among distinct species of fish and amphibians are parvalbumins. The major shellfish allergen has been identified as tropomyosin. Many new and important potential cross-reacting allergens have been identified within the fish family and between shellfish, arachnids, and insects. Extensive research is currently underway for the development of safer and more effective methods for the diagnosis and management of fish and shellfish hypersensitivity.

Criteria for reducing predation by northern squawfish near juvenile salmonid bypass outfalls at Columbia River dams

USGS Publications Warehouse

Shively, Rip S.; Poe, Thomas P.; Sheer, Mindi B.; Peters, Rock

1996-01-01

Predation by northern squawfish (Ptychocheilus oregonensis) has been documented to be significant on emigrating juvenile salmonids near juvenile bypass outfalls at hydroelectric dams on the Columbia River. Criteria for siting juvenile fish bypass outfalls to reduce predation were developed using locational data from radio-tagged northern squawfish in The Dalles Dam trailrace, Columbia River. Radio transmitters were surgically implanted in 164 northern squawfish in 1993 and 1994, and their movements and distribution were monitored. Position estimates of northern squawfish were compared with data from a physical hydraulic model of the dam to estimate water velocities where northern squawfish were located. Eighty-two percent of northern squawfish position estimates were in water velocities ≤110 cm/s in 1993 and ≤90 cm/s in 1994. Fish locations were usually associated with water depths ≤10 m (84% in 1993 and 82% in 1994); 90% were within 110 m of the shore or dam structure in 1993, and 86% were within 80 m in 1994. In a related study at John Day Dam, Columbia River, where the juvenile bypass outfall is located 40 m from shore, water depth is 10 m and water velocities typically exceed 75 cm/s, only 13 of 1443 (0.9%) contacts on radio-tagged northern squawfish were located within 200 m of the bypass outfall. We recommend that new or modified juvenile bypass outfalls on the Columbia River be located in water velocities of ≥100 cm/s, ≥75 m from the shore or dam structure, and in water ≥10 m deep.

Identifying key demographic parameters of a small island–associated population of Indo-Pacific bottlenose dolphins (Reunion, Indian Ocean)

PubMed Central

Estrade, Vanessa; Fayan, Jacques

2017-01-01

Photo-identification surveys of Indo-Pacific bottlenose dolphins were conducted from 2009 to 2014 off Reunion Island (55°E33’/21°S07’), in the Indian Ocean. Robust Design models were applied to produce the most reliable estimate of population abundance and survival rate, while accounting for temporary emigration from the survey area (west coast). The sampling scheme consisted of a five-month (June–October) sampling period in each year of the study. The overall population size at Reunion was estimated to be 72 individuals (SE = 6.17, 95%CI = 61–85), based on a random temporary emigration (γ”) of 0.096 and a proportion of 0.70 (SE = 0.03) distinct individuals. The annual survival rate was 0.93 (±0.018 SE, 95%CI = 0.886–0.958) and was constant over time and between sexes. Models considering gender groups indicated different movement patterns between males and females. Males showed null or quasi-null temporary emigration (γ” = γ’ < 0.01), while females showed a random temporary emigration (γ”) of 0.10, suggesting that a small proportion of females was outside the survey area during each primary sampling period. Sex-specific temporary migration patterns were consistent with movement and residency patterns observed in other areas. The Robust Design approach provided an appropriate sampling scheme for deriving island-associated population parameters, while allowing to restrict survey effort both spatially (i.e. west coast only) and temporally (five months per year). Although abundance and survival were stable over the six years, the small population size of fewer than 100 individuals suggested that this population is highly vulnerable. Priority should be given to reducing any potential impact of human activity on the population and its habitat. PMID:28640918

Nonacademic Attributes Predict Medical and Nursing Student Intentions to Emigrate or to Work Rurally: An Eight-Country Survey in Asia and Africa

PubMed Central

Silvestri, David M.; Blevins, Meridith; Wallston, Kenneth A.; Afzal, Arfan R.; Alam, Nazmul; Andrews, Ben; Derbew, Miliard; Kaur, Simran; Mipando, Mwapatsa; Mkony, Charles A.; Mwachaka, Philip M.; Ranjit, Nirju; Vermund, Sten H.

2017-01-01

We sought to identify independent, nonacademic predictors of medical and nursing student intent to migrate abroad or from rural to urban areas after graduation in low- and middle-income countries (LMIC). This was a cross-sectional survey of 3,199 first- and final-year medical and nursing students at 16 training institutions in eight LMIC. Questionnaires assessed demographics, career intentions, and preferences regarding selected career, location, and work-related attributes. Using principal component analysis, student preferences were reduced into four discrete categories of priorities: 1) work environment resources, 2) location livability, 3) altruistic job values, and 4) individualistic job values. Students' preferences were scored in each category. Using students' characteristics and priority scores, multivariable proportional odds models were used to derive independent predictors of intentions to emigrate for work outside the country, or to work in a rural area in their native country. Students prioritizing individualistic values more often planned international careers (adjusted odds ratio [aOR] = 1.44, 95% confidence interval [CI] = 1.16–1.78), whereas those prioritizing altruistic values preferred rural careers (aOR = 1.82, 95% CI = 1.50–2.21). Trainees prioritizing high-resource environments preferentially planned careers abroad (aOR = 1.38, 95% CI = 1.12–1.69) and were unlikely to seek rural work (aOR = 0.60, 95% CI = 0.49–0.73). Independent of their priorities, students with prolonged prior rural residence were unlikely to plan emigration (aOR = 0.67, 95% CI = 0.50–0.90) and were more likely to plan a rural career (aOR = 1.53, 95% CI = 1.16–2.03). We conclude that use of nonacademic attributes in medical and nursing admissions processes would likely increase retention in high-need rural areas and reduce emigration “brain drain” in LMIC. PMID:28719284

Physician migration at its roots: a study on the emigration preferences and plans among medical students in Romania.

PubMed

Suciu, Şoimita Mihaela; Popescu, Codruta Alina; Ciumageanu, Mugur Daniel; Buzoianu, Anca Dana

2017-01-19

Migration of healthcare workers is receiving increased attention worldwide. In Europe, the creation of a border-free labor market and its expansion with the EU enlargements of 2004, 2007, and 2013 endowed health professionals with the right to provide services and to relocate to another EU Member State. For the Romanian doctors, the EU-wide recognition of the medical degree obtained in Romania has created new opportunities, while inadequate working conditions and relatively low salaries pushed many of them to search for employment abroad. As there is considerable uncertainty about the magnitude of the Romanian physicians' exodus, we performed a survey to assess the emigration intention of future Romanian doctors. The study was conducted over three consecutive years: 2013, 2014, and 2015 at the University of Medicine and Pharmacy "Iuliu Hatieganu" Cluj-Napoca, Romania. The self-administrated questionnaire included 19 questions regarding students' emigration intentions. All the 957 license-degree students participated in the study. In this study, 84.7% of subjects planned on seeking employment abroad after graduation. A large number of the students who have participated in the study have already started preparing for emigration, 21.7% of those who wished to migrate had already performed at least one Erasmus mobility in their country of choice, 44.5% have been enrolled in a language course, and 42.7% have searched for jobs on the Internet. The majority of Romanian medical students considering migration see it as a serious alternative to the continuation of their professional training started in Romania. The findings of this study are upsetting and can impact both policy crafting and future research. Structural reforms in the healthcare provisions are needed in order to facilitate the retention of medical personnel. Romanian policy makers need to devise a comprehensive national health workforce plan to deal with physician migration.

Fish collagen is an important panallergen in the Japanese population.

PubMed

Kobayashi, Y; Akiyama, H; Huge, J; Kubota, H; Chikazawa, S; Satoh, T; Miyake, T; Uhara, H; Okuyama, R; Nakagawara, R; Aihara, M; Hamada-Sato, N

2016-05-01

Collagen was identified as a fish allergen in early 2000s. Although its allergenic potential has been suggested to be low, risks associated with collagen as a fish allergen have not been evaluated to a greater extent. In this study, we aimed to clarify the importance of collagen as a fish allergen. Our results showed that 50% of Japanese patients with fish allergy had immunoglobulin E (IgE) against mackerel collagen, whereas 44% had IgE against mackerel parvalbumin. IgE inhibition assay revealed high cross-reactivity of mackerel collagen to 22 fish species (inhibition rates: 87-98%). Furthermore, a recently developed allergy test demonstrated that collagen triggered IgE cross-linking on mast cells. These data indicate that fish collagen is an important and very common panallergen in fish consumed in Japan. The high rate of individuals' collagen allergy may be attributable to the traditional Japanese custom of raw fish consumption. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

9 CFR 93.911 - Ports designated for the importation of live VHS-regulated fish species.

Code of Federal Regulations, 2012 CFR

2012-01-01

... of live VHS-regulated fish species. 93.911 Section 93.911 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Vhs-Regulated Fish Species § 93.911 Ports designated for the...

9 CFR 93.911 - Ports designated for the importation of live VHS-regulated fish species.

Code of Federal Regulations, 2014 CFR

2014-01-01

... of live VHS-regulated fish species. 93.911 Section 93.911 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Vhs-Regulated Fish Species § 93.911 Ports designated for the...

9 CFR 93.911 - Ports designated for the importation of live VHS-regulated fish species.

Code of Federal Regulations, 2013 CFR

2013-01-01

... of live VHS-regulated fish species. 93.911 Section 93.911 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Vhs-Regulated Fish Species § 93.911 Ports designated for the...

9 CFR 93.911 - Ports designated for the importation of live VHS-regulated fish species.

Code of Federal Regulations, 2010 CFR

2010-01-01

... of live VHS-regulated fish species. 93.911 Section 93.911 Animals and Animal Products ANIMAL AND... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Vhs-Regulated Fish Species § 93.911 Ports designated for the...

Abiotic and biotic controls of cryptobenthic fish assemblages across a Caribbean seascape

USGS Publications Warehouse

Harborne, A.R.; Jelks, H.L.; Smith-Vaniz, W.F.; Rocha, L.A.

2012-01-01

The majority of fish studies on coral reefs consider only non-cryptic species and, despite their functional importance, data on cryptic species are scarce. This study investigates inter-habitat variation in Caribbean cryptobenthic fishes by re-analysing a comprehensive data set from 58 rotenone stations around Buck Island, U.S. Virgin Islands. Boosted regression trees were used to associate the density and diversity of non-piscivorous cryptobenthic fishes, both in the entire data set and on reef habitats alone, with 14 abiotic and biotic variables. The study also models the habitat requirements of the three commonest species. Dead coral cover was the first or second most important variable in six of the eight models constructed. For example, within the entire data set, the number of species and total fish density increased approximately linearly with increasing dead coral cover. Dead coral was also important in multivariate analyses that discriminated 10 assemblages within the entire data set. On reef habitats, the number of species and total fish density increased dramatically when dead coral exceeded ~55 %. Live coral cover was typically less important for explaining variance in fish assemblages than dead coral, but live corals were important for maintaining high fish diversity. Coral species favoured by cryptobenthic species may be particularly susceptible to mortality, but dead coral may also provide abundant food and shelter for many fishes. Piscivore density was a key variable in the final models, but typically increased with increasing cryptobenthic fish diversity and abundance, suggesting both groups of fishes are responding to the same habitat variables. The density of territorial damselfishes reduced the number of cryptobenthic fish species on reef habitats. Finally, habitats delineated by standard remote sensing techniques supported distinct cryptobenthic fish assemblages, suggesting that such maps can be used as surrogates of general patterns of cryptic fish biodiversity in conservation planning.

Identification of enolases and aldolases as important fish allergens in cod, salmon and tuna: component resolved diagnosis using parvalbumin and the new allergens.

PubMed

Kuehn, A; Hilger, C; Lehners-Weber, C; Codreanu-Morel, F; Morisset, M; Metz-Favre, C; Pauli, G; de Blay, F; Revets, D; Muller, C P; Vogel, L; Vieths, S; Hentges, F

2013-07-01

The majority of fish-allergic patients are sensitized to parvalbumin, known to be the cause of important IgE cross-reactivity among fish species. Little is known about the importance of fish allergens other than parvalbumin. The aim of this study was to characterize hitherto undefined fish allergens in three commonly consumed fish species, cod, salmon and tuna, and to evaluate their importance for in vitro IgE-diagnosis in addition to parvalbumin and fish gelatin. Sixty-two patients were diagnosed by clinical history, skin prick tests and specific IgE to fish extracts. Two new fish allergens from cod, salmon and tuna were identified by microsequencing. These proteins were characterized by immunoblot, ELISA and mediator release assay. Purified parvalbumin, enolase, aldolase and fish gelatin were used for quantification of specific IgE in ELISA. Parvalbumin and two other allergens of 50 and 40 kDa were detected in IgE-immunoblots of cod, salmon and tuna extracts by most patient sera. The 50 and 40 kDa proteins were identified as beta-enolase and fructose-bisphosphate aldolase A respectively. Both purified enzymes showed allergenic activity in the mediator release assay. Indeed, 72.6% of the patients were sensitized to parvalbumin, 20% of these had specific IgE to salmon parvalbumin only. IgE to enolases were found in 62.9% (0.5-95.0 kUA /L), to aldolases in 50.0% (0.4-26.0 kUA /L) and to fish gelatin in 19.3% (0.4-20.0 kUA /L) of the patients. Inter-species cross-reactivity, even though limited, was found for enolases and aldolases by IgE-inhibition ELISA. Fish enolase and aldolase have been identified as important new fish allergens. In fish allergy diagnosis, IgE to enolase and aldolase are especially relevant when IgE to parvalbumin are absent. © 2013 John Wiley & Sons Ltd.

Low GI Food with Barley in Space Foods

NASA Astrophysics Data System (ADS)

Katayama, Naomi; Sugimoto, Manabu; Hashimoto, Hirofumi; Kihara, Makoto; Yamashita, Masamichi; Space Agriculture Task Force

The construction of the life-support system to perform space, moon base, Mars emigration is demanded. The space foods will play a very important role of life support on this occasion. Particularly, in environment of the microgravity, our metabolism becomes less than the face of the Earth. The management of the blood sugar level is very important. We need to eat the meal which will be rise in blood sugar level slowly. The barley which includes much water-soluble dietary fibers is helpful to make low GI space food. After eating 30% barley with unpolished rice, blood sugar level was rise slowly. The cooking process is very important to our body in thinking about digestion and absorption. Soft foods, long-heated foods and grind-foods are easy to digest. After eating these-foods, our blood sugar level will rise, easily. We introduce the space foods with 30% wheat that the blood sugar level is hard to rising.

Tandem carrying, a new foraging strategy in ants: description, function, and adaptive significance relative to other described foraging strategies

NASA Astrophysics Data System (ADS)

Guénard, Benoit; Silverman, Jules

2011-08-01

An important aspect of social insect biology lies in the expression of collective foraging strategies developed to exploit food. In ants, four main types of foraging strategies are typically recognized based on the intensity of recruitment and the importance of chemical communication. Here, we describe a new type of foraging strategy, "tandem carrying", which is also one of the most simple recruitment strategies, observed in the Ponerinae species Pachycondyla chinensis. Within this strategy, workers are directly carried individually and then released on the food resource by a successful scout. We demonstrate that this recruitment is context dependent and based on the type of food discovered and can be quickly adjusted as food quality changes. We did not detect trail marking by tandem-carrying workers. We conclude by discussing the importance of tandem carrying in an evolutionary context relative to other modes of recruitment in foraging and nest emigration.

9 CFR 93.902 - Ports designated for the importation of live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... of live fish, fertilized eggs, and gametes. 93.902 Section 93.902 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Svc-Regulated Fish Species § 93.902 Ports designated for the...

9 CFR 93.902 - Ports designated for the importation of live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2012 CFR

2012-01-01

... of live fish, fertilized eggs, and gametes. 93.902 Section 93.902 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Svc-Regulated Fish Species § 93.902 Ports designated for the...

9 CFR 93.902 - Ports designated for the importation of live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... of live fish, fertilized eggs, and gametes. 93.902 Section 93.902 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN... Animal Species General Provisions for Svc-Regulated Fish Species § 93.902 Ports designated for the...

Molecular confirmation of infectious spleen and kidney necrosis virus (ISKNV) in farmed and imported ornamental fish in Australia.

PubMed

Mohr, Peter G; Moody, Nicholas J G; Williams, Lynette M; Hoad, John; Cummins, David M; Davies, Kelly R; StJ Crane, Mark

2015-10-16

Viruses of the genus Megalocytivirus have not been detected in wild populations of fish in Australia but circulate in imported ornamental fish. In 2012, detection of a megalocytivirus in healthy platys Xiphophorus maculatus was reported from a farm in Australia during surveillance testing as part of a research project undertaken at the University of Sydney. Confirmatory testing of the original samples at the AAHL Fish Diseases Laboratory verified the presence of an infectious spleen and kidney necrosis virus (ISKNV)-like virus. Additional sampling at the positive farm confirmed the persistence of the virus in the platys, with 39 of 265 (14.7%) samples testing positive. Comparison of 3 separate gene regions of the virus with those of ISKNV confirmed the detection of a virus indistinguishable from ISKNV. Subsequently, ISKNV was also detected in a range of imported ornamental fish from several countries between 2013 and 2014, by screening with real-time PCR and confirmation by conventional PCR and sequence analysis. Accordingly, the current importation of live ornamental fish acts as a potential perpetual source for the establishment of ISKNV viruses within Australia. The testing of the farmed and imported ornamental fish verified the utility of the probe-based real-time PCR assay for screening of ornamental fish for Megalocytivirus.

Investigation of various epidemic diseases in some countries by mathematical models SI and SIS

NASA Astrophysics Data System (ADS)

Ćilli, A.; Ergen, K.

2017-02-01

In this study, efficiency of SI and SIS mathematical models were defined in the prediction of the number of infected people with malaria and Acquired Immune Deficiency Syndrome (AIDS) as infectious diseases. Afghanistan and Angola were selected for their geographical and economical features. Although the models do not predict exact numbers for each year, in a long term and in a normal conditions (unless there are external parameters such as natural disaster, war, emigration and terrorism) they can predict the trend for the diseases and can tell when to disappear. Therefore, updating data are of importance to achieve the powerful prediction.

[Epidemic research in the south of Fujian Province in modern times from the viewpoints of overseas communication].

PubMed

Lin, Nan; Zhang, Sun-Biao; Zeng, Yi-Ling

2012-09-01

Under the particular geographical environment and social structure, different spatiality of epidemics was observed in the south of Fujian Province. Some important factors cannot be ignored in the study of local epidemics, such as its developed overseas communication, prosperous commercial activities between the East and the West and deep-rooted overseas emigration tradition. In modern times, public health ideas, therapies and prevention measures of west medicine were introduced, taking epidemic disease prevention as a turning point in this area, which promoted medical development of this area objectively, and valuable experience in disease prevention was accumulated.

Signal integration and cross-talk during thymocyte migration and emigration

PubMed Central

Love, Paul E.; Bhandoola, Avinash

2013-01-01

The thymus produces self-tolerant functionally competent T cells. This occurs by the import of multipotent hematopoietic progenitors that are signalled to adopt the T cell fate. Expression of T cell specific genes, including those encoding the T cell receptor (TCR), is followed by positive and negative selection and the eventual export of mature T cells. Significant progress has been made in elucidating the signals that direct progenitor cell trafficking to, within and out of the thymus. These advances are the subject of this Review, with a particular focus on the role of reciprocal cooperative and regulatory interactions between TCR and chemokine receptor-mediated signalling. PMID:21701522

A Closer Look at the Junior Doctor Crisis in the United Kingdom's National Health Services: Is Emigration Justifiable?

PubMed

Teo, Wendy Zi Wei

2018-07-01

This article attempts to tackle the ethically and morally troubling issue of emigration of physicians from the United Kingdom, and whether it can be justified. Unlike most research that has already been undertaken in this field, which looks at migration from developing countries to developed countries, this article takes an in-depth look at the migration of physicians between developed countries, in particular from the United Kingdom (UK) to other developed countries such as Canada, Australia, New Zealand, and the United States (US). This examination was written in response to a current and critical crisis in the National Health Service (NHS), where impending contract changes may bring about a potential exodus of junior doctors.

The biology of recent thymic emigrants.

PubMed

Fink, Pamela J

2013-01-01

The generation of the TCRαβ lineage of T cells occurs in the thymus through a series of orchestrated developmental events that result in a carefully selected population of CD4 or CD8 lineage-committed TCR(+) thymocytes capable of recognizing foreign antigen in the context of self MHC. T cells first exit the thymus in a phenotypically and functionally immature state and require an approximately 3-week period of post-thymic maturation before transitioning into the mature T cell compartment. A greater understanding of recent thymic emigrant biology has come with the development of methods to exclusively identify and isolate this population for further characterization. I now review current knowledge about the phenotype and function of this key but understudied population of peripheral T cells.

International migration and the propagation of HIV in sub-Saharan Africa.

PubMed

Docquier, F; Vasilakis, Ch; Tamfutu Munsi, D

2014-05-01

In this paper, we identify and quantify the role of international migration in the propagation of HIV across sub-Saharan African countries. We use panel data on bilateral migration flows and HIV prevalence rates covering 44 countries after 1990. Controlling for unobserved heterogeneity, reverse causality, reflection issues, incorrect treatment of country fixed effects and spatial autocorrelation, we find evidence of a highly robust emigration-induced propagation mechanism. On the contrary, immigration has no significant effect. Numerical experiments reveal that the long-run effect of emigration accounts for more than 4 percent of the number of HIV cases in 15 countries (and more than 20 percent in 6 countries). Copyright © 2014 Elsevier B.V. All rights reserved.

The uncertain connection: free trade and rural Mexican migration to the United States.

PubMed

Cornelius, W A; Martin, P L

1993-01-01

"Will a North American Free Trade Agreement (NAFTA) decrease Mexican migration to the United States, as the U.S. and Mexican governments assert, or increase migration beyond the movement that would otherwise occur, as NAFTA critics allege? This article argues that it is easy to overestimate the additional emigration from rural Mexico owing to NAFTA-related economic restructuring in Mexico. The available evidence suggests four major reasons why Mexican emigration may not increase massively, despite extensive restructuring and displacement from traditional agriculture....NAFTA-related economic displacement in Mexico may yield an initial wave of migration to test the U.S. labor market, but this migration should soon diminish if the jobs that these migrants seek shift to Mexico." excerpt

Modeling the macrodynamics of international migration: determinants of emigration from Cyprus, 1946-85.

PubMed

Diamantides, N D; Constantinou, S T

1989-07-01

"A model is presented of international migration that is based on the concept of a pool of potential emigrants at the origin created by push-pull forces and by the establishment of information feedback between origin and destination. The forces can be economic, political, or both, and are analytically expressed by the 'mediating factor'. The model is macrodynamic in nature and provides both for the main secular component of the migratory flow and for transient components caused by extraordinary events. The model is expressed in a Bernoulli-type differential equation through which quantitative weights can be derived for each of the operating causes. Out-migration from the Republic of Cyprus is used to test the tenets of the model." excerpt

An Ocean Mural.

ERIC Educational Resources Information Center

Graham, Frank; Graham, Ada

1998-01-01

Introduces a class project on oceans, fishes, and fishing industries around the world. Groups of students make a mural of the world, filling the oceans with accurate drawings of fish, fishing boats, and fishing equipment. Students learn about the importance of fish in various cultures and about the migration routes of fish. Includes a resource…

50 CFR 14.23 - Live farm-raised fish and farm-raised fish eggs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... OF WILDLIFE AND PLANTS IMPORTATION, EXPORTATION, AND TRANSPORTATION OF WILDLIFE Importation and... and farm-raised fish eggs meet the definition of “bred in captivity” as stated in 50 CFR 17.3. Except...

The effects of habitat restoration on endangered fishes in the Upper Klamath Basin

NASA Astrophysics Data System (ADS)

Vanderkooi, S.; Burdick, S.; Ellsworth, C.

2009-12-01

The Klamath Basin has been prominent in the debate over the use of water in the arid west for nearly a decade. Principle competing demands include threatened and endangered species, agriculture, recreation, and Tribal rights. In an effort to recover two endangered fish species, the Lost River sucker and the shortnose sucker, several large-scale restoration projects have recently been undertaken in the basin. These include restoration of 7000 acres of drained wetlands in the Williamson River Delta in 2007 and 2008 and the removal of Chiloquin Dam on the Sprague River in 2008. The objectives of these projects include increasing amounts of usable aquatic habitats, restoring watershed function, improving water quality, and improving access to and connectivity among habitats. The U.S. Geological Survey is involved in a series of collaborative, interdisciplinary research efforts to evaluate the effectiveness of these restoration projects. Effectiveness is being evaluated by physical, biological and ecological metrics. Our focus is on the biology and ecology of endangered suckers. In the Williamson River Delta, we’re collecting data on the distribution, habitat use, relative abundance, and health and condition of early life-history stages of endangered suckers. Results to date indicate larval as well as age-0 and age-1 juvenile suckers are using newly created habitats in the delta. Preliminary results from comparisons of age-0 suckers captured within and outside of the delta suggest those using the restored habitats are in better condition. In the Sprague River, we’re studying the behavior, run timing, and distribution of adult suckers during spawning migrations as well as the relative abundance, species composition, and timing of emigrating larval suckers. Preliminary results indicate adult suckers migrated into the reach previously impounded by Chiloquin Dam in greater numbers than in the past. While these results indicate a positive response to dam removal, population-level effects of such restoration projects on suckers will not be fully evident for years to come because of the long life span and slow maturation rates of these fish. Continued monitoring of physical and biological changes due to restoration is essential to determining the effectiveness of these actions and informing future efforts.

50 CFR 16.13 - Importation of live or dead fish, mollusks, and crustaceans, or their eggs.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., and crustaceans, or their eggs. 16.13 Section 16.13 Wildlife and Fisheries UNITED STATES FISH AND... Wildlife § 16.13 Importation of live or dead fish, mollusks, and crustaceans, or their eggs. (a) Upon an... their gametes or fertilized eggs, may be imported, transported, and possessed in captivity without a...

78 FR 13301 - Notice of Request for Extension of Approval of an Information Collection; Spring Viremia of Carp...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-27

... Restrictions on Certain Live Fish, Fertilized Eggs, and Gametes AGENCY: Animal and Plant Health Inspection... with the regulations for the importation of live fish, fertilized eggs, and gametes to prevent the... for the importation of live fish, fertilized eggs, and gametes, contact Dr. Christa Speekmann, Import...

Mangroves enhance the biomass of coral reef fish communities in the Caribbean.

PubMed

Mumby, Peter J; Edwards, Alasdair J; Arias-González, J Ernesto; Lindeman, Kenyon C; Blackwell, Paul G; Gall, Angela; Gorczynska, Malgosia I; Harborne, Alastair R; Pescod, Claire L; Renken, Henk; Wabnitz, Colette C C; Llewellyn, Ghislane

2004-02-05

Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs.

Mangroves enhance the biomass of coral reef fish communities in the Caribbean

NASA Astrophysics Data System (ADS)

Mumby, Peter J.; Edwards, Alasdair J.; Ernesto Arias-González, J.; Lindeman, Kenyon C.; Blackwell, Paul G.; Gall, Angela; Gorczynska, Malgosia I.; Harborne, Alastair R.; Pescod, Claire L.; Renken, Henk; C. C. Wabnitz, Colette; Llewellyn, Ghislane

2004-02-01

Mangrove forests are one of the world's most threatened tropical ecosystems with global loss exceeding 35% (ref. 1). Juvenile coral reef fish often inhabit mangroves, but the importance of these nurseries to reef fish population dynamics has not been quantified. Indeed, mangroves might be expected to have negligible influence on reef fish communities: juvenile fish can inhabit alternative habitats and fish populations may be regulated by other limiting factors such as larval supply or fishing. Here we show that mangroves are unexpectedly important, serving as an intermediate nursery habitat that may increase the survivorship of young fish. Mangroves in the Caribbean strongly influence the community structure of fish on neighbouring coral reefs. In addition, the biomass of several commercially important species is more than doubled when adult habitat is connected to mangroves. The largest herbivorous fish in the Atlantic, Scarus guacamaia, has a functional dependency on mangroves and has suffered local extinction after mangrove removal. Current rates of mangrove deforestation are likely to have severe deleterious consequences for the ecosystem function, fisheries productivity and resilience of reefs. Conservation efforts should protect connected corridors of mangroves, seagrass beds and coral reefs.

Bioenergetics in ecosystems

USGS Publications Warehouse

Madenjian, Charles P.; Farrell, Anthony P.

2011-01-01

A bioenergetics model for a fish can be defined as a quantitative description of the fish’s energy budget. Bioenergetics modeling can be applied to a fish population in a lake, river, or ocean to estimate the annual consumption of food by the fish population; such applications have proved to be useful in managing fisheries. In addition, bioenergetics models have been used to better understand fish growth and consumption in ecosystems, to determine the importance of the role of fish in cycling nutrients within ecosystems, and to identify the important factors regulating contaminant accumulation in fish from lakes, rivers, and oceans.

The Impacts of wetland restoration on Fish Productivity in Nigeria

NASA Astrophysics Data System (ADS)

Ayorinde, O. A.; Okunade, K. M.; Agboola, D. M.; Adesokan, Z. A.

2016-02-01

Wetland is one of the resources of high value which has been exposed to indiscriminate use. It is an important ecosystem to fish and loss or degradation of wetland will have a direct consequence on sustainable fisheries. This paper reviewed the term "wetland", its functions and values, importance to fish production in Nigeria and threats to its sustainability. The term "wetland" has been defined by various researchers especially based on their profession and their needs but up till today there is no single definition accepted by all users. In Nigeria, the most commonly adopted is that of RAMSAR convention. Wetland has both marketed and non-marketed functions and values. They provide essential link in the life cycle of 75 percent of the fish and shell fish commercially harvested in the world and are vital to fish health. Despite the importance, there have been exceptional losses of wetlands. Lagos state alone has witnessed more than 96 percent loss. Major threats to wetlands are: agriculture, development, pollution and climate change. Therefore proper management of the wetland ecosystem is important in other to ensure continuous fish production.

Global assessment of the status of coral reef herbivorous fishes: evidence for fishing effects.

PubMed

Edwards, C B; Friedlander, A M; Green, A G; Hardt, M J; Sala, E; Sweatman, H P; Williams, I D; Zgliczynski, B; Sandin, S A; Smith, J E

2014-01-07

On coral reefs, herbivorous fishes consume benthic primary producers and regulate competition between fleshy algae and reef-building corals. Many of these species are also important fishery targets, yet little is known about their global status. Using a large-scale synthesis of peer-reviewed and unpublished data, we examine variability in abundance and biomass of herbivorous reef fishes and explore evidence for fishing impacts globally and within regions. We show that biomass is more than twice as high in locations not accessible to fisheries relative to fisheries-accessible locations. Although there are large biogeographic differences in total biomass, the effects of fishing are consistent in nearly all regions. We also show that exposure to fishing alters the structure of the herbivore community by disproportionately reducing biomass of large-bodied functional groups (scraper/excavators, browsers, grazer/detritivores), while increasing biomass and abundance of territorial algal-farming damselfishes (Pomacentridae). The browser functional group that consumes macroalgae and can help to prevent coral-macroalgal phase shifts appears to be most susceptible to fishing. This fishing down the herbivore guild probably alters the effectiveness of these fishes in regulating algal abundance on reefs. Finally, data from remote and unfished locations provide important baselines for setting management and conservation targets for this important group of fishes.

50 CFR 300.189 - Prohibitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Customs territory of the United States of fish or fish products regulated under this subpart except shark... accept an imported consignment of fish or fish products regulated under this subpart, except shark fins...-export any fish or fish product regulated under this subpart without a valid trade permit issued under...

50 CFR 300.189 - Prohibitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Customs territory of the United States of fish or fish products regulated under this subpart except shark... accept an imported consignment of fish or fish products regulated under this subpart, except shark fins...-export any fish or fish product regulated under this subpart without a valid trade permit issued under...

Seeking greener pastures? The relationship between career satisfaction and the intention to emigrate: a survey of Ghanaian physicians.

PubMed

Opoku, Samuel T; Apenteng, Bettye A

2014-09-01

A significant number of physicians from developing nations emigrate to developed nations in search of better career opportunities. In addition to crippling the health systems of developing nations, the emigration of physicians from sub-Saharan African (SSA) countries results in a loss of return on investment to these nations. The purpose of this study was to identify the relationship between career satisfaction and the intention of active Ghanaian physicians to leave the country within the next 5 years. This study was a cross-sectional correlational study using data from a survey of practicing physicians in Ghana. The primary independent variables examined were dimensions of career satisfaction, assessed using an abridged form of the Physician Work Life Survey. Data from the multivariate ordered logistic regression model indicated that physicians who were house officers or medical officers and those who reported dissatisfaction with their compensation were more likely to report that they were thinking about leaving Ghana within the next 5 years. Health policies aimed at increasing monetary compensation and providing junior physicians with the resources needed to excel in their careers may improve the retention of physicians in Ghana. © The Author 2014. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Temporal variability of local abundance, sex ratio and activity in the Sardinian chalk hill blue butterfly

USGS Publications Warehouse

Casula, P.; Nichols, J.D.

2003-01-01

When capturing and marking of individuals is possible, the application of newly developed capture-recapture models can remove several sources of bias in the estimation of population parameters such as local abundance and sex ratio. For example, observation of distorted sex ratios in counts or captures can reflect either different abundances of the sexes or different sex-specific capture probabilities, and capture-recapture models can help distinguish between these two possibilities. Robust design models and a model selection procedure based on information-theoretic methods were applied to study the local population structure of the endemic Sardinian chalk hill blue butterfly, Polyommatus coridon gennargenti. Seasonal variations of abundance, plus daily and weather-related variations of active populations of males and females were investigated. Evidence was found of protandry and male pioneering of the breeding space. Temporary emigration probability, which describes the proportion of the population not exposed to capture (e.g. absent from the study area) during the sampling process, was estimated, differed between sexes, and was related to temperature, a factor known to influence animal activity. The correlation between temporary emigration and average daily temperature suggested interpreting temporary emigration as inactivity of animals. Robust design models were used successfully to provide a detailed description of the population structure and activity in this butterfly and are recommended for studies of local abundance and animal activity in the field.

Dispersal Timing: Emigration of Insects Living in Patchy Environments.

PubMed

Lakovic, Milica; Poethke, Hans-Joachim; Hovestadt, Thomas

2015-01-01

Dispersal is a life-history trait affecting dynamics and persistence of populations; it evolves under various known selective pressures. Theoretical studies on dispersal typically assume 'natal dispersal', where individuals emigrate right after birth. But emigration may also occur during a later moment within a reproductive season ('breeding dispersal'). For example, some female butterflies first deposit eggs in their natal patch before migrating to other site(s) to continue egg-laying there. How breeding compared to natal dispersal influences the evolution of dispersal has not been explored. To close this gap we used an individual-based simulation approach to analyze (i) the evolution of timing of breeding dispersal in annual organisms, (ii) its influence on dispersal (compared to natal dispersal). Furthermore, we tested (iii) its performance in direct evolutionary contest with individuals following a natal dispersal strategy. Our results show that evolution should typically result in lower dispersal under breeding dispersal, especially when costs of dispersal are low and population size is small. By distributing offspring evenly across two patches, breeding dispersal allows reducing direct sibling competition in the next generation whereas natal dispersal can only reduce trans-generational kin competition by producing highly dispersive offspring in each generation. The added benefit of breeding dispersal is most prominent in patches with small population sizes. Finally, the evolutionary contests show that a breeding dispersal strategy would universally out-compete natal dispersal.

[Career Satisfaction of Medical Residents in Portugal].

PubMed

Martins, Maria João; Laíns, Inês; Brochado, Bruno; Oliveira-Santos, Manuel; Teixeira, Pedro Pinto; Brandão, Mariana; Cerqueira, Rui João; Castro-Ferreira, Ricardo; Bernardes, Carlos; Menezes, Miguel Nobre; Baptista, Bernardo Soares; Ladeiras-Lopes, Ricardo; Rei, Mariana Cruz; Rosa, Gilberto Pires da; Martins, José Luís; Mendonça Sanches, Maria; Ferreira-Pinto, Manuel J; Rato, Margarida; Costa e Silva, Miguel; Policiano, Catarina; Beato, João; Barbosa-Breda, João; Torres, João Pimentel; Leal, Inês; Rosa, Sílvia Aguiar; Ribeiro, Bárbara Carvalho; Costa, Francisco Rego; Palmela, Carolina; Gonçalves, Tiago Cúrdia; Morais, Luis; Marques, Tiago Reis

2015-01-01

The satisfaction with the medical profession has been identified as an essential factor for the quality of care, the wellbeing of patients and the healthcare systems' stability. Recent studies have emphasized a growing discontent of physicians, mainly as a result of changes in labor relations. To assess the perception of Portuguese medical residents about: correspondence of residency with previous expectations; degree of satisfaction with the specialty, profession and place of training; reasons for dissatisfaction; opinion regarding clinical practice in Portugal and emigration intents. Cross-sectional study. Data collection was conducted through the "Satisfaction with Specialization Survey", created in an online platform, designed for this purpose, between May and August 2014. From a total population of 5788 medical residents, 804 (12.25 %) responses were obtained. From this sample, 77% of the responses were from residents in the first three years. Results showed that 90% of the residents are satisfied with their specialty, 85% with the medical profession and 86% with their place of training. Nevertheless, results showed a decrease in satisfaction over the final years of residency. The overall assessment of the clinical practice scenario in Portugal was negative and 65% of residents have plans to emigrate after completing their residency. Portuguese residents revealed high satisfaction levels regarding their profession. However, their views on Portuguese clinical practice and the results concerning the intent to emigrate highlight the need to take steps to reverse this scenario.

[The diagnosis of malaria by the thick film and the QBC: a comparative study of both technics].

PubMed

Cabezos, J; Bada, J L

1993-06-12

The diagnosis of paludism is important because of the severity of the clinical picture caused by Plasmodium falciparum, the increasing number of travellers to endemic zones and the emigration from these zones. A comparative study of the QBC techniques (staining with acridin orange and observation with ultraviolet light) and the thick film with Giemsa staining was carried out. The QBC and thick film were performed parallelly for 17 months in a total of 623 samples pertaining to subjects from endemic zones of paludism (emigrants, immigrants and travellers). Of the 623 samples studied 49 were positive for paludism by both techniques. Ten were positive with only the thick film and six were positive only with QBC. The sensitivity of QBC versus thick film was 83% and specificity 98.9%. The time used to determine diagnosis with the QBC technique ranged from 6 to 12 minutes from withdrawal of the sample, while with the thick film the time spent was more than 2 hours. The cases positive by thick film and negative with QBC corresponded to patients with very low parasitation. The intensity of parasitation was difficult to determine quantitatively by QBC. Although the QBC technique has the advantage of speed it is inexact with respect to the quantification of parasitemia. Moreover, it is less sensitive than the thick film in patient with very low parasitations and cannot thus substitute the thick film.

Biphasic influence of Miz1 on neural crest development by regulating cell survival and apical adhesion complex formation in the developing neural tube

PubMed Central

Kerosuo, Laura; Bronner, Marianne E.

2014-01-01

Myc interacting zinc finger protein-1 (Miz1) is a transcription factor known to regulate cell cycle– and cell adhesion–related genes in cancer. Here we show that Miz1 also plays a critical role in neural crest development. In the chick, Miz1 is expressed throughout the neural plate and closing neural tube. Its morpholino-mediated knockdown affects neural crest precursor survival, leading to reduction of neural plate border and neural crest specifier genes Msx-1, Pax7, FoxD3, and Sox10. Of interest, Miz1 loss also causes marked reduction of adhesion molecules (N-cadherin, cadherin6B, and α1-catenin) with a concomitant increase of E-cadherin in the neural folds, likely leading to delayed and decreased neural crest emigration. Conversely, Miz1 overexpression results in up-regulation of cadherin6B and FoxD3 expression in the neural folds/neural tube, leading to premature neural crest emigration and increased number of migratory crest cells. Although Miz1 loss effects cell survival and proliferation throughout the neural plate, the neural progenitor marker Sox2 was unaffected, suggesting a neural crest–selective effect. The results suggest that Miz1 is important not only for survival of neural crest precursors, but also for maintenance of integrity of the neural folds and tube, via correct formation of the apical adhesion complex therein. PMID:24307680

Behavioral tradeoff in estuarine larvae favors seaward migration over minimizing visibility to predators

PubMed Central

Morgan, Steven G.; Anastasia, Jean R.

2008-01-01

The ability of microscopic larvae to control their fate and replenish populations in dynamic marine environments has been a long-running topic of debate of central importance to understanding the ecology and evolution of life in the sea and managing resources in a changing global environment. After decades of research documenting behaviors that keep larvae close to natal populations, it is becoming apparent that larval behaviors in a broader spectrum of species promote long-distance migrations to offshore nursery grounds. Larvae must exert considerable control over their movements. We now show that larval emigration from estuaries is favored even over minimizing visibility to predators. An endogenous tidal vertical migration that would expedite seaward migration of Uca pugilator larvae was maintained experimentally across two tidal regimes. The periodicity of the rhythm doubled to match the local tidal regime, but larvae ascended to the surface during the daytime rather than at night. This process would conserve larval emigration but increase the visibility to predators across part of the species range. The periodicity of tidal vertical migration by Sesarma cinereum larvae failed to double and was inappropriately timed relative to both environmental cycles in the absence of a diel cycle. The timing system regulating tidally timed behaviors in these two species of crabs evidently differed. Phenotypic plasticity can conserve larval transport of both species when tidal and diel cycles are present. It may be widespread in the sea where diverse habitats are encountered across extensive species ranges. PMID:18172217

Behavioral tradeoff in estuarine larvae favors seaward migration over minimizing visibility to predators.

PubMed

Morgan, Steven G; Anastasia, Jean R

2008-01-08

The ability of microscopic larvae to control their fate and replenish populations in dynamic marine environments has been a long-running topic of debate of central importance to understanding the ecology and evolution of life in the sea and managing resources in a changing global environment. After decades of research documenting behaviors that keep larvae close to natal populations, it is becoming apparent that larval behaviors in a broader spectrum of species promote long-distance migrations to offshore nursery grounds. Larvae must exert considerable control over their movements. We now show that larval emigration from estuaries is favored even over minimizing visibility to predators. An endogenous tidal vertical migration that would expedite seaward migration of Uca pugilator larvae was maintained experimentally across two tidal regimes. The periodicity of the rhythm doubled to match the local tidal regime, but larvae ascended to the surface during the daytime rather than at night. This process would conserve larval emigration but increase the visibility to predators across part of the species range. The periodicity of tidal vertical migration by Sesarma cinereum larvae failed to double and was inappropriately timed relative to both environmental cycles in the absence of a diel cycle. The timing system regulating tidally timed behaviors in these two species of crabs evidently differed. Phenotypic plasticity can conserve larval transport of both species when tidal and diel cycles are present. It may be widespread in the sea where diverse habitats are encountered across extensive species ranges.

An overview of the ongoing insights in selenium research and its role in fish nutrition and fish health.

PubMed

Khan, Kifayat Ullah; Zuberi, Amina; Fernandes, João Batista Kochenborger; Ullah, Imdad; Sarwar, Huda

2017-12-01

In the present review, the ongoing researches about selenium research in fish nutrition have been comprehensively discussed. Selenium research is getting popularity in fish nutrition as it is required for the normal growth and proper physiological and biochemical functions in fish. Its deficiency or surplus amounts create severe problems in fish. It is available as inorganic form, organic form, and nano form. In fish, most of the previous research is about the selenium requirements for fish by using only one selenium source mainly the inorganic one. Selenium shows maximum biological activity and bioavailability when it is supplied in proper form. However, to differentiate the more bioavailable and less toxic form of selenium, sufficient information is needed about the comparative bioavailability of different selenium forms in different fish species. In fish, important data about the new forms of selenoproteins is still scarce. Therefore, it is necessary to focus on the determination and elucidation of the new selenoproteins in fish through the utilization of recent approaches of molecular biology and proteomics. The adaptation of these new approaches will replace the old fashioned methodologies regarding the selenium research in fish nutrition. Moreover, the use of molecular biology and proteomics-based new approaches in combination with selenium research will help in optimizing the area of fish nutrition and will improve the feed intake, growth performance, and more importantly the flesh quality which has a promising importance in the consumer market.

Community- and government-managed marine protected areas increase fish size, biomass and potential value

PubMed Central

Chirico, Angelica A. D.; McClanahan, Timothy R.; Eklöf, Johan S.

2017-01-01

Government-managed marine protected areas (MPAs) can restore small fish stocks, but have been heavily criticized for excluding resource users and creating conflicts. A promising but less studied alternative are community-managed MPAs, where resource users are more involved in MPA design, implementation and enforcement. Here we evaluated effects of government- and community-managed MPAs on the density, size and biomass of seagrass- and coral reef-associated fish, using field surveys in Kenyan coastal lagoons. We also assessed protection effects on the potential monetary value of fish; a variable that increases non-linearly with fish body mass and is particularly important from a fishery perspective. We found that two recently established community MPAs (< 1 km2 in size, ≤ 5 years of protection) harbored larger fish and greater total fish biomass than two fished (open access) areas, in both seagrass beds and coral reefs. As expected, protection effects were considerably stronger in the older and larger government MPAs. Importantly, across management and habitat types, the protection effect on the potential monetary value of the fish was much stronger than the effects on fish biomass and size (6.7 vs. 2.6 and 1.3 times higher value in community MPAs than in fished areas, respectively). This strong effect on potential value was partly explained by presence of larger (and therefore more valuable) individual fish, and partly by higher densities of high-value taxa (e.g. rabbitfish). In summary, we show that i) small and recently established community-managed MPAs can, just like larger and older government-managed MPAs, play an important role for local conservation of high-value fish, and that ii) these effects are equally strong in coral reefs as in seagrass beds; an important habitat too rarely included in formal management. Consequently, community-managed MPAs could benefit both coral reef and seagrass ecosystems and provide spillover of valuable fish to nearby fisheries. PMID:28806740

Community- and government-managed marine protected areas increase fish size, biomass and potential value.

PubMed

Chirico, Angelica A D; McClanahan, Timothy R; Eklöf, Johan S

2017-01-01

Government-managed marine protected areas (MPAs) can restore small fish stocks, but have been heavily criticized for excluding resource users and creating conflicts. A promising but less studied alternative are community-managed MPAs, where resource users are more involved in MPA design, implementation and enforcement. Here we evaluated effects of government- and community-managed MPAs on the density, size and biomass of seagrass- and coral reef-associated fish, using field surveys in Kenyan coastal lagoons. We also assessed protection effects on the potential monetary value of fish; a variable that increases non-linearly with fish body mass and is particularly important from a fishery perspective. We found that two recently established community MPAs (< 1 km2 in size, ≤ 5 years of protection) harbored larger fish and greater total fish biomass than two fished (open access) areas, in both seagrass beds and coral reefs. As expected, protection effects were considerably stronger in the older and larger government MPAs. Importantly, across management and habitat types, the protection effect on the potential monetary value of the fish was much stronger than the effects on fish biomass and size (6.7 vs. 2.6 and 1.3 times higher value in community MPAs than in fished areas, respectively). This strong effect on potential value was partly explained by presence of larger (and therefore more valuable) individual fish, and partly by higher densities of high-value taxa (e.g. rabbitfish). In summary, we show that i) small and recently established community-managed MPAs can, just like larger and older government-managed MPAs, play an important role for local conservation of high-value fish, and that ii) these effects are equally strong in coral reefs as in seagrass beds; an important habitat too rarely included in formal management. Consequently, community-managed MPAs could benefit both coral reef and seagrass ecosystems and provide spillover of valuable fish to nearby fisheries.

Finite metapopulation models with density-dependent migration and stochastic local dynamics

PubMed Central

Saether, B.-E.; Engen, S.; Lande, R.

1999-01-01

The effects of small density-dependent migration on the dynamics of a metapopulation are studied in a model with stochastic local dynamics. We use a diffusion approximation to study how changes in the migration rate and habitat occupancy affect the rates of local colonization and extinction. If the emigration rate increases or if the immigration rate decreases with local population size, a positive expected rate of change in habitat occupancy is found for a greater range of habitat occupancies than when the migration is density-independent. In contrast, the reverse patterns of density dependence in respective emigration and immigration reduce the range of habitat occupancies where the metapopulation will be viable. This occurs because density-dependent migration strongly influences both the establishment and rescue effects in the local dynamics of metapopulations.

Multistate modelling extended by behavioural rules: An application to migration.

PubMed

Klabunde, Anna; Zinn, Sabine; Willekens, Frans; Leuchter, Matthias

2017-10-01

We propose to extend demographic multistate models by adding a behavioural element: behavioural rules explain intentions and thus transitions. Our framework is inspired by the Theory of Planned Behaviour. We exemplify our approach with a model of migration from Senegal to France. Model parameters are determined using empirical data where available. Parameters for which no empirical correspondence exists are determined by calibration. Age- and period-specific migration rates are used for model validation. Our approach adds to the toolkit of demographic projection by allowing for shocks and social influence, which alter behaviour in non-linear ways, while sticking to the general framework of multistate modelling. Our simulations yield that higher income growth in Senegal leads to higher emigration rates in the medium term, while a decrease in fertility yields lower emigration rates.

[Career guidance for registered nurse in the UK].

PubMed

Simón Melchor, Lucía; Simón Melchor, Alba

2014-04-01

Cuts in temporary contracts has had big consequences for newly qualified nurses with regards to finding employment. This cut in contracts has resulted in a doubling in the rate of unemployment in this profession. In the past nurses emigrated to other countries for purposes like knowledge of the language or to extend their training and experience, however today the emigration has become the only way out for many professional nurses. The reputation of nurses in Spain is recognised internationally, with the UK being one of the countries with the largest demand for Spanish nurses. Due to the great amount of job opportunities that are emerging in the UK, nurses need help and guidance in their careers, and also nurses need training in areas such as Professional Body, developing a curriculum, facing an interview etc...

[Economic aspects of migration: remittances by migrant workers].

PubMed

Prskawetz, A

1995-01-01

"Worldwide annual remittances...by migrant workers to their home countries amount to some 70 billion U.S. dollars, exceeded by oil export earnings only.... The amount of remittances depends on the income of both the migrants and their family members.... Remittances meant for investment at home are determined by interest rates, foreign exchange regulations, exchange rates, monetary stability etc. in the immigration and emigration countries. Home remittances and saving habits of emigrants also depend on whether or not they expect to return to their home countries and the prospects of family reunification, all of which is directly linked to the (immigration) policy and economic conditions of both the countries of origin and residence." The factors influencing remittances flowing into and out of Austria are analyzed using data from the Austrian National Bank. (EXCERPT)

Retention of Habitat Complexity Minimizes Disassembly of Reef Fish Communities following Disturbance: A Large-Scale Natural Experiment

PubMed Central

Emslie, Michael J.; Cheal, Alistair J.; Johns, Kerryn A.

2014-01-01

High biodiversity ecosystems are commonly associated with complex habitats. Coral reefs are highly diverse ecosystems, but are under increasing pressure from numerous stressors, many of which reduce live coral cover and habitat complexity with concomitant effects on other organisms such as reef fishes. While previous studies have highlighted the importance of habitat complexity in structuring reef fish communities, they employed gradient or meta-analyses which lacked a controlled experimental design over broad spatial scales to explicitly separate the influence of live coral cover from overall habitat complexity. Here a natural experiment using a long term (20 year), spatially extensive (∼115,000 kms2) dataset from the Great Barrier Reef revealed the fundamental importance of overall habitat complexity for reef fishes. Reductions of both live coral cover and habitat complexity had substantial impacts on fish communities compared to relatively minor impacts after major reductions in coral cover but not habitat complexity. Where habitat complexity was substantially reduced, species abundances broadly declined and a far greater number of fish species were locally extirpated, including economically important fishes. This resulted in decreased species richness and a loss of diversity within functional groups. Our results suggest that the retention of habitat complexity following disturbances can ameliorate the impacts of coral declines on reef fishes, so preserving their capacity to perform important functional roles essential to reef resilience. These results add to a growing body of evidence about the importance of habitat complexity for reef fishes, and represent the first large-scale examination of this question on the Great Barrier Reef. PMID:25140801

Retention of habitat complexity minimizes disassembly of reef fish communities following disturbance: a large-scale natural experiment.

PubMed

Emslie, Michael J; Cheal, Alistair J; Johns, Kerryn A

2014-01-01

High biodiversity ecosystems are commonly associated with complex habitats. Coral reefs are highly diverse ecosystems, but are under increasing pressure from numerous stressors, many of which reduce live coral cover and habitat complexity with concomitant effects on other organisms such as reef fishes. While previous studies have highlighted the importance of habitat complexity in structuring reef fish communities, they employed gradient or meta-analyses which lacked a controlled experimental design over broad spatial scales to explicitly separate the influence of live coral cover from overall habitat complexity. Here a natural experiment using a long term (20 year), spatially extensive (∼ 115,000 kms(2)) dataset from the Great Barrier Reef revealed the fundamental importance of overall habitat complexity for reef fishes. Reductions of both live coral cover and habitat complexity had substantial impacts on fish communities compared to relatively minor impacts after major reductions in coral cover but not habitat complexity. Where habitat complexity was substantially reduced, species abundances broadly declined and a far greater number of fish species were locally extirpated, including economically important fishes. This resulted in decreased species richness and a loss of diversity within functional groups. Our results suggest that the retention of habitat complexity following disturbances can ameliorate the impacts of coral declines on reef fishes, so preserving their capacity to perform important functional roles essential to reef resilience. These results add to a growing body of evidence about the importance of habitat complexity for reef fishes, and represent the first large-scale examination of this question on the Great Barrier Reef.

Potential of fish scales as a filling material in surface coating of cellulosic paper.

PubMed

Ural, Elif; Kandirmaz, Emine A

2018-01-01

Paper is one of the important inputs for the printing industry, and the most important leading parameter in the printing process is its brightness. Brightness can be brought to paper using coatings and sizing. Desired surface properties and, most importantly, surface roughness can be achieved by changing the contents of the coating and sizing of the materials it contains. The use of biomaterials is becoming more important in the paper industry, as they represent substances with a lower carbon footprint. Fish scales are already used as a filling material, cosmetic material and fish food, as well as for determining the age of fish. Fish scales were brought to different sizes by a milling process. Paper formulations including different amounts of fish scales were prepared with fish scales, and coatings on raw paper were subjected to test printings in IGT-C1, with formulations and physical characteristics of coatings such as brightness, lightfastness, strength, adhesion etc. being determined. Regarding the value of yellowness, mixtures of 2.5%-10% can be used. The maximum value of brightness was obtained from a mixture of 10%. Aging visibly changed the colors. The coatings obtained were brighter than the initial coating compositions. The top quality formulation was the coating with 5% medium-sized fish scale particles.

Relative importance of population size, fishing pressure and temperature on the spatial distribution of nine Northwest Atlantic groundfish stocks.

PubMed

Adams, Charles F; Alade, Larry A; Legault, Christopher M; O'Brien, Loretta; Palmer, Michael C; Sosebee, Katherine A; Traver, Michele L

2018-01-01

The spatial distribution of nine Northwest Atlantic groundfish stocks was documented using spatial indicators based on Northeast Fisheries Science Center spring and fall bottom trawl survey data, 1963-2016. We then evaluated the relative importance of population size, fishing pressure and bottom temperature on spatial distribution with an information theoretic approach. Northward movement in the spring was generally consistent with prior analyses, whereas changes in depth distribution and area occupancy were not. Only two stocks exhibited the same changes in spatiotemporal distribution in the fall as compared with the spring. Fishing pressure was the most important predictor of the center of gravity (i.e., bivariate mean location of the population) for the majority of stocks in the spring, whereas in the fall this was restricted to the east-west component. Fishing pressure was also the most important predictor of the dispersion around the center of gravity in both spring and fall. In contrast, biomass was the most important predictor of area occupancy for the majority of stocks in both seasons. The relative importance of bottom temperature was ranked highest in the fewest number of cases. This study shows that fishing pressure, in addition to the previously established role of climate, influences the spatial distribution of groundfish in the Northwest Atlantic. More broadly, this study is one of a small but growing body of literature to demonstrate that fishing pressure has an effect on the spatial distribution of marine resources. Future work must consider both fishing pressure and climate when examining mechanisms underlying fish distribution shifts.

Relative importance of population size, fishing pressure and temperature on the spatial distribution of nine Northwest Atlantic groundfish stocks

PubMed Central

Alade, Larry A.; Legault, Christopher M.; O’Brien, Loretta; Palmer, Michael C.; Sosebee, Katherine A.; Traver, Michele L.

2018-01-01

The spatial distribution of nine Northwest Atlantic groundfish stocks was documented using spatial indicators based on Northeast Fisheries Science Center spring and fall bottom trawl survey data, 1963–2016. We then evaluated the relative importance of population size, fishing pressure and bottom temperature on spatial distribution with an information theoretic approach. Northward movement in the spring was generally consistent with prior analyses, whereas changes in depth distribution and area occupancy were not. Only two stocks exhibited the same changes in spatiotemporal distribution in the fall as compared with the spring. Fishing pressure was the most important predictor of the center of gravity (i.e., bivariate mean location of the population) for the majority of stocks in the spring, whereas in the fall this was restricted to the east-west component. Fishing pressure was also the most important predictor of the dispersion around the center of gravity in both spring and fall. In contrast, biomass was the most important predictor of area occupancy for the majority of stocks in both seasons. The relative importance of bottom temperature was ranked highest in the fewest number of cases. This study shows that fishing pressure, in addition to the previously established role of climate, influences the spatial distribution of groundfish in the Northwest Atlantic. More broadly, this study is one of a small but growing body of literature to demonstrate that fishing pressure has an effect on the spatial distribution of marine resources. Future work must consider both fishing pressure and climate when examining mechanisms underlying fish distribution shifts. PMID:29698454

Persistent halogenated compounds in aquaculture environments of South China: implications for global consumers' health risk via fish consumption.

PubMed

Yu, Huan-Yun; Zhang, Bao-Zhong; Giesy, John P; Zeng, Eddy Y

2011-10-01

This study examined the potential sources of persistent halogenated compounds (PHCs), including organochlorine pesticides, mainly DDXs (sum of o,p'- and p,p'-DDT, -DDD, and -DDE and p,p'-DDMU) and polybrominated diphenyl ethers, to typical aquaculture environments of South China, determined the relative importance of gill diffusion and fish feeding for exposure of fish to these contaminants and assessed potential health risk for global consumers via consumption of fish from South China. Fish feed is generally a direct and important source of PHCs in both freshwater and seawater aquaculture. In addition, gill diffusion is the predominant uptake route for PHCs (except p,p'-DDMU, o,p'-DDD and -DDT) in farmed freshwater fish, whereas accumulation from the diet is the major route for farmed marine fish. Risks to health of global consumers via consumption of fish from South China are minimal. However, increased risk can be foreseen due to continuous use of brominated fire retardants and electronic waste importation to China. Copyright © 2011 Elsevier Ltd. All rights reserved.

Influence of habitat structure on fish assemblage of an artificial reef in southern Brazil.

PubMed

Hackradt, Carlos Werner; Félix-Hackradt, Fabiana Cézar; García-Charton, José Antonio

2011-12-01

Habitat complexity strongly influences reef fish community composition. An understanding of the underlying reasons for this relationship is important for evaluating the suitability of artificial reef (AR) habitats as a marine resource management tool. We studied the influence of AR habitat structure on fish assemblage composition off the southern coast of Brazil. We found that reef blocks with greater area and number of holes possessed the greatest fish species richness and abundance. Reef blocks with greater complexity had higher abundance of almost 30% of fish species present. Natural reef (NR) and AR were different in their fish species composition, trophic structure and categories of water column occupancy by fish (spatial categories). Although NR was more diverse and harboured more trophic levels, AR presented the higher abundances and the presence of distinct fish species that underlined their importance at a regional scale. The greater availability of sheltering habitat where hard substrate is scarce, together with their frequent use by economically important species, make AR a useful tool for coastal management when certain ecological conditions are met. Copyright © 2011 Elsevier Ltd. All rights reserved.

Non-farmed fish contribute to greater micronutrient intakes than farmed fish: results from an intra-household survey in rural Bangladesh.

PubMed

Bogard, Jessica R; Marks, Geoffrey C; Mamun, Abdullah; Thilsted, Shakuntala H

2017-03-01

Fish is the most important animal-source food (ASF) in Bangladesh, produced from capture fisheries (non-farmed) and aquaculture (farmed) sub-sectors. Large differences in micronutrient content of fish species from these sub-sectors exist. The importance of fish in diets of vulnerable groups compared with other ASF; contribution from non-farmed and farmed species to nutrient intakes; and differences in fish consumption among age, gender, wealth groups and geographic regions were analysed, using quantitative intra-household fish consumption data, focusing on the first 1000 d of life. Two-stage stratified sample. Nationally representative of rural Bangladesh. Households (n 5503) and individuals (n 24 198). Fish consumption in poor households was almost half that in wealthiest households; and lower in females than males in all groups, except the wealthiest, and for those aged ≥15 years (P<0·01). In infants of complementary feeding age, 56 % did not consume ASF on the survey day, despite 78 % of mothers knowing this was recommended. Non-farmed fish made a larger contribution to Fe, Zn, Ca, vitamin A and vitamin B12 intakes than farmed fish (P<0·0001). Policies and programmes aimed to increase fish consumption as a means to improve nutrition in rural Bangladesh should focus on women and young children, and on the poorest households. Aquaculture plays an important role in increasing availability and affordability of fish; however, non-farmed fish species are better placed to contribute to greater micronutrient intakes. This presents an opportunity for aquaculture to contribute to improved nutrition, utilising diverse production technologies and fish species, including small fish.

FVID: Fishing Vessel Type Identification Based on VMS Trajectories

NASA Astrophysics Data System (ADS)

Huang, Haiguang; Hong, Feng; Liu, Jing; Liu, Chao; Feng, Yuan; Guo, Zhongwen

2018-05-01

Vessel Monitoring System (VMS) provides a new opportunity for quantified fishing research. Many approaches have been proposed to recognize fishing activities with VMS trajectories based on the types of fishing vessels. However, one research problem is still calling for solutions, how to identify the fishing vessel type based on only VMS trajectories. This problem is important because it requires the fishing vessel type as a preliminary to recognize fishing activities from VMS trajectories. This paper proposes fishing vessel type identification scheme (FVID) based only on VMS trajectories. FVID exploits feature engineering and machine learning schemes of XGBoost as its two key blocks and classifies fishing vessels into nine types. The dataset contains all the fishing vessel trajectories in the East China Sea in March 2017, including 10031 pre-registered fishing vessels and 1350 unregistered vessels of unknown types. In order to verify type identification accuracy, we first conduct a 4-fold cross-validation on the trajectories of registered fishing vessels. The classification accuracy is 95.42%. We then apply FVID to the unregistered fishing vessels to identify their types. After classifying the unregistered fishing vessel types, their fishing activities are further recognized based upon their types. At last, we calculate and compare the fishing density distribution in the East China Sea before and after applying the unregistered fishing vessels, confirming the importance of type identification of unregistered fishing vessels.

Industrial Based Migration in India. A Case Study of Dumdum "Dunlop Industrial Zone"

NASA Astrophysics Data System (ADS)

Das, Biplab; Bandyopadhyay, Aditya; Sen, Jayashree

2012-10-01

Migration is a very important part in our present society. Basically Millions of people moved during the industrial revolution. Some simply moved from a village to a town in the hope of finding work whilst others moved from one country to another in search of a better way of life. The main reason for moving home during the 19th century was to find work. On one hand this involved migration from the countryside to the growing industrial cities, on the other it involved rates of migration, emigration, and the social changes that were drastically affecting factors such as marriage,birth and death rates. These social changes taking place as a result of capitalism had far ranging affects, such as lowering the average age of marriage and increasing the size of the average family.Migration was not just people moving out of the country, it also invloved a lot of people moving into Britain. In the 1840's Ireland suffered a terrible famine. Faced with a massive cost of feeding the starving population many local landowners paid for labourers to emigrate.There was a shift away from agriculturally based rural dwelling towards urban habitation to meet the mass demand for labour that new industry required. There became great regional differences in population levels and in the structure of their demography. This was due to rates of migration, emigration, and the social changes that were drastically affecting factors such as marriage, birth and death rates. These social changes taking place as a result of capitalism had far ranging affects, such as lowering the average age of marriage and increasing the size of the average family. There is n serious disagreement as to the extent of the population changes that occurred but one key question that always arouses debate is that of whether an expanding population resulted in economic growth or vice versa, i.e. was industrialization a catalyst for population growth? A clear answer is difficult to decipher as the two variables are so closely and fundamentally interlinked, but it seems that both factors provided impetus for each otherís take off. If anything, population and economic growth were complimentary towards one another rather than simply being causative factors.

Internationally recruited nurses from India and the Philippines in the United Kingdom: the decision to emigrate

PubMed Central

Alonso-Garbayo, Álvaro; Maben, Jill

2009-01-01

Background The United Kingdom has recruited nurses from countries with a reported surplus in their nursing workforce, such as India and the Philippines. However, little is known about the decision to emigrate made by nurses from these countries. One theory suggests that individuals weigh the benefits and costs of migration: the push and pull factors. This paper challenges the restricted economic focus of this predominant theory and compares the diverse motivations of nurses from different countries as well as those of nurses with previous migratory experience and first-time migrants. Methods This research was undertaken in a National Health Service acute trust in London by means of a qualitative interpretative approach. Data were collected through face-to-face longitudinal and cross-sectional interviews with internationally recruited nurses from India (n = 6) and the Philippines (n = 15); and analysis of their narratives was used to generate data about their expectations and experiences. Data were analysed by means of a framework approach that allowed for intra-case and cross-case analysis. Results From an individual perspective, nurses in this study reported economic reasons as the main trigger for migration in the first instance. Yet this doesn't entirely explain the decision to move from previous migratory destinations (e.g. Saudi Arabia) where economic needs are already fulfilled. In these cases migration is influenced by professional and social aspirations that highlight the influence of the cultural environment – specifically some religious and gender-related issues. Family support and support from migratory networks in the country of origin and destination were also important elements conducive to and supportive of migration. Nurses from India report coming to the United Kingdom to stay, while Filipina nurses come as temporary migrants sending remittances to support their families in the Philippines. Conclusion This study shows the diverse motivations of nurses from different countries and with different migratory backgrounds and provides evidence that factors other than economic factors influence nurses' decision to emigrate. This information can help developing countries increase retention of this essential and often scarce resource and can also help the United Kingdom's National Health Service to improve the experience of internationally recruited nurses and therefore increase their retention in the United Kingdom. PMID:19393080

Organotin intake through fish consumption in Finland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Airaksinen, Riikka, E-mail: Riikka.Airaksinen@thl.fi; Rantakokko, Panu; Turunen, Anu W.

Background: Organotin compounds (OTCs) are a large class of synthetic chemicals with widely varying properties. Due to their potential adverse health effects, their use has been restricted in many countries. Humans are exposed to OTCs mostly through fish consumption. Objectives: The aim of this study was to describe OTC exposure through fish consumption and to assess the associated potential health risks in a Finnish population. Methods: An extensive sampling of Finnish domestic fish was carried out in the Baltic Sea and freshwater areas in 2005-2007. In addition, samples of imported seafood were collected in 2008. The chemical analysis was performedmore » in an accredited testing laboratory during 2005-2008. Average daily intake of the sum of dibutyltin (DBT), tributyltin (TBT), triphenyltin (TPhT) and dioctyltin (DOT) ({Sigma}OTCs) for the Finnish population was calculated on the basis of the measured concentrations and fish consumption rates. Results: The average daily intake of {Sigma}OTCs through fish consumption was 3.2 ng/kg bw day{sup -1}, which is 1.3% from the Tolerable Daily Intake (TDI) of 250 ng/kg bw day{sup -1} set by the European Food Safety Authority. In total, domestic wild fish accounted for 61% of the {Sigma}OTC intake, while the intake through domestic farmed fish was 4.0% and the intake through imported fish was 35%. The most important species were domestic perch and imported salmon and rainbow trout. Conclusions: The Finnish consumers are not likely to exceed the threshold level for adverse health effects due to OTC intake through fish consumption.« less

Active and passive migration in boring isopods Limnoria spp. (Crustacea, Peracarida) from kelp holdfasts

NASA Astrophysics Data System (ADS)

Miranda, Leonardo; Thiel, Martin

2008-10-01

Many boring isopods inhabit positively buoyant substrata (wood and algae), which float after detachment, permitting passive migration of inhabitants. Based on observations from previous studies, it was hypothesized that juvenile, subadult and male isopods migrate actively, and will rapidly abandon substrata after detachment. In contrast, reproductive females and small offspring were predicted to remain in floating substrata and thus have a high probability to disperse passively via rafting. In order to test this hypothesis, a colonization and an emigration experiment were conducted with giant kelp ( Macrocystis integrifolia), the holdfasts of which are inhabited by boring isopods from the genus Limnoria. A survey of benthic substrata in the kelp forest confirmed that limnoriids inhabited the holdfasts and did not occur in holdfast-free samples. Results of the colonization experiment showed that all life history stages of the boring isopods immigrated into young, largely uncolonized holdfasts, and after 16 weeks all holdfasts were densely colonized. In the emigration experiment, all life history stages of the isopods rapidly abandoned the detached holdfasts — already 5 min after detachment only few individuals remained in the floating holdfasts. After this initial rapid emigration of isopods, little changes in isopod abundance occurred during the following 24 h, and at the end of the experiment some individuals of all life history stages still remained in the holdfasts. These results indicate that all life history stages of Limnoria participate in both active migration and passive dispersal. It is discussed that storm-related dynamics within kelp forests may contribute to intense mixing of local populations of these burrow-dwelling isopods, and that most immigrants to young holdfasts probably are individuals emigrating from old holdfasts detached during storm events. The fact that some individuals of all life history stages and both sexes remain in floating holdfasts suggests that limnoriids could successfully reproduce during rafting journeys in floating kelp, facilitating long-distance dispersal. We propose that the coexistence of different modes of dispersal (short distance local migrations and long-distance regional dispersal) within these kelp-dwelling isopods might be advantageous in an environment where unpredictable El Niño events can cause extinction of local kelp forests.

Habitat quality of a subarctic nursery ground for 0-group plaice ( Pleuronectes platessa L.)

NASA Astrophysics Data System (ADS)

Freitas, Vânia; Campos, Joana; Skreslet, Stig; van der Veer, Henk W.

2010-07-01

Habitat quality of a subarctic nursery ground in northern Norway for 0-group plaice Pleuronectes platessa was investigated by following settlement, mortality and growth during 2005 and 2006. Newly settled individuals were first observed in the end of May to early June and settlement lasted until mid-July. Densities peaked in early July and were comparable to those reported in temperate nursery grounds. Mortality estimates after settlement differed between 0.062 d -1 in 2005 and 0.025 d -1 in 2006. Potential predators appeared to be rather similar as those reported in other areas: the brown shrimp Crangoncrangon, the shore crab Carcinus maenas and demersal fish species (gadoids). Population mean growth indicated linear growth until August leveling-off afterwards. 0-group plaice reached a lower mean size (5-6 cm) at the end of the growing season than in temperate areas probably due to later settlement timing in combination with lower summer-autumn water temperatures. The comparison of observed growth rates with predictions of maximum growth models indicated a similar pattern as observed in temperate nursery grounds: Growth appeared to be maximal except for the period after summer. Whether or not this was related to changes in food quality throughout the season, to interspecies competition or to emigration remains to be elucidated.

Pilot study to access the role of Ceratomyxa shasta infection in mortality of fall-run Chinook smolts migrating through the lower Klamath River in 2008

USGS Publications Warehouse

Foott, Scott; Stutzer, Greg; Fogerty, R.; Hansel, Hal; Juhnke, Steven; Beeman, John W.

2009-01-01

Apparent survival and migration rate of radio-tagged hatchery subyearling Chinook salmon released at Iron Gate Hatchery was monitored in the Klamath River to see if the timing of mortality coincided with observations of ceratomyxosis in re-captured coded wire tag cohorts. Despite rapid emigration, these relatively large (mean fork length 92 mm) smolts had a cumulative apparent survival to the estuary of 0.074 (SE 0.024) and standardized rates of survival per 100 km tended to decrease linearly with distance from the hatchery. The last fish detection occurred 26 days after release but median travel time between Iron Gate Hatchery (rkm 309) and the last receiver near the Klamath estuary (Blake’s Riffle rkm 13) was about 10 days. The majority of apparent mortality (8-10 d post-release) occurred before disease from Ceratomyxa shasta infection is expected after exposure to infectious waters. Despite numerous observations of ceratomyxosis in the Klamath R. during June, an obvious link between disease and apparent survival was not present in this study. Future studies should examine the acute (e.g., predator types and densities) and chronic (e.g., swimming performance impairment due to disease) mortality factors for juvenile Chinook salmon smolts in the Klamath River.

Factors for improved fish passage waterway construction.

DOT National Transportation Integrated Search

2011-06-01

Streambeds are important fish passageways in Oregon; they provide for the necessary habitats and spawning cycles of a healthy fish population. Oregon state law requires that hydraulic structures located in water properly provide fish passage. Increas...

50 CFR 300.205 - Denial of port privileges and import restrictions on fish or fish products.

Code of Federal Regulations, 2012 CFR

2012-10-01

... positively certified by the Secretary of Commerce, and fishing vessels of the nation are allowed entry to any... fish and fish products. Services, including the refueling and re-supplying of such fishing vessels, may... nations are ineligible for entry into the United States and U.S. territories, the Secretary of Commerce...

50 CFR 300.205 - Denial of port privileges and import restrictions on fish or fish products.

Code of Federal Regulations, 2011 CFR

2011-10-01

... positively certified by the Secretary of Commerce, and fishing vessels of the nation are allowed entry to any... fish and fish products. Services, including the refueling and re-supplying of such fishing vessels, may... nations are ineligible for entry into the United States and U.S. territories, the Secretary of Commerce...

Effectiveness of an existing estuarine no-take fish sanctuary within the Kennedy Space Center, Florida

USGS Publications Warehouse

Johnson, D.R.; Funicelli, N.A.; Bohnsack, James A.

1999-01-01

Approximately 22% of the waters of the Merritt Island National Wildlife Refuge, which encompasses the Kennedy Space Center, Florida, have been closed to public access and fishing since 1962. These closed areas offer an opportunity to test the effectiveness of 'no-take' sanctuaries by analyzing two replicated estuarine areas. Areas open and closed to fishing were sampled from November 1986 to January 1990 with 653 random trammel-net sets, each enclosing 3,721 m2. Samples from no-fishing areas had significantly (P < 0.05) greater abundance and larger fishes than fished areas. Relative abundance (standardized catch per unit effort, CPUE) in protected areas (6.4 fish/set) was 2.6 times greater than in the fished areas (2.4 fish/set) for total game fish, 2.4 times greater for spotted seatrout Cynoscion nebulosus, 6.3 times greater for red drum Sciaenops ocellatus, 12.8 times greater for black drum Pogonias cromis, 5.3 times greater for common snook Centropomus undecimalis, and 2.6 times greater for striped mullet Mugil cephalus. Fishing had the primary effect on CPUE, independent of habitat and other environmental factors. Salinity and depth were important secondary factors affecting CPUE, followed by season or month, and temperature. The importance of specific factors varied with each species. Median and maximum size of red drum, spotted seatrout, black drum, and striped mullet were also significantly greater in the unfished areas. More and larger fish of spawning age were observed in the unfished areas for red drum, spotted seatrout, and black drum. Tagging studies documented export of important sport fish from protected areas to fished areas.

Spatial and temporal patterns of mercury concentrations in freshwater fish across the Western United States and Canada

USGS Publications Warehouse

Eagles-Smith, Collin A.; Ackerman, Joshua T.; Willacker, James J.; Tate, Michael T.; Lutz, Michelle A; Fleck, Jacob; Stewart, Robin; Wiener, James G.; Evers, David C.; Lepak, Jesse M.; Davis, Jay A.; Pritz, Colleen Flanagan

2016-01-01

Methylmercury contamination of fish is a global threat to environmental health. Mercury (Hg) monitoring programs are valuable for generating data that can be compiled for spatially broad syntheses to identify emergent ecosystem properties that influence fish Hg bioaccumulation. Fish total Hg (THg) concentrations were evaluated across the Western United States (US) and Canada, a region defined by extreme gradients in habitat structure and water management. A database was compiled with THg concentrations in 96,310 fish that comprised 206 species from 4262 locations, and used to evaluate the spatial distribution of fish THg across the region and effects of species, foraging guilds, habitats, and ecoregions. Areas of elevated THg exposure were identified by developing a relativized estimate of fish mercury concentrations at a watershed scale that accounted for the variability associated with fish species, fish size, and site effects. THg concentrations in fish muscle ranged between 0.001 and 28.4 (μg/g wet weight (ww)) with a geometric mean of 0.17. Overall, 30% of individual fish samples and 17% of means by location exceeded the 0.30 μg/g ww US EPA fish tissue criterion. Fish THg concentrations differed among habitat types, with riverine habitats consistently higher than lacustrine habitats. Importantly, fish THg concentrations were not correlated with sediment THg concentrations at a watershed scale, but were weakly correlated with sediment MeHg concentrations, suggesting that factors influencing MeHg production may be more important than inorganic Hg loading for determining fish MeHg exposure. There was large heterogeneity in fish THg concentrations across the landscape; THg concentrations were generally higher in semi-arid and arid regions such as the Great Basin and Desert Southwest, than in temperate forests. Results suggest that fish mercury exposure is widespread throughout Western US and Canada, and that species, habitat type, and region play an important role in influencing ecological risk of mercury in aquatic ecosystems.

Fish and fish oil in health and disease prevention

USDA-ARS?s Scientific Manuscript database

Fish is an important dietary component due to its contribution of valuable nutrients. In addition to the high quality protein and micronutrients provided, fish is the primary source of long-chain omega-3 fatty acids which are found in oils of ‘fatty’ cold water fish. Biomedical evidence supports th...

Kelt Reconditioning: A Research Project to Enhance Iteroparity in Columbia Basin Steelhead (Oncorhynchus mykiss), 2003 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatch, Douglas R.; Branstetter, Ryan; Blodgett, Joe

Repeat spawning is a life history strategy that is expressed by some species from the family Salmonidae. Rates of repeat spawning for post-development Columbia River steelhead Oncorhynchus mykiss populations range from 1.6 to 17%. It is expected that currently observed iteroparity rates for wild steelhead in the Basin are severely depressed due to development and operation of the hydropower system and various additional anthropogenic factors. Increasing the natural expression of historical repeat spawning rates using fish culturing methods could be a viable technique to assist the recovery of depressed steelhead populations. Reconditioning is the process of culturing post-spawned fish (kelts)more » in a captive environment until they are able to reinitiate feeding, growth, and redevelop mature gonads. Kelt reconditioning techniques were initially developed for Atlantic salmon Salmo salar and sea-trout S. trutta. The recent Endangered Species Act listing of many Columbia Basin steelhead populations has prompted interest in developing reconditioning methods for wild steelhead populations within the Basin. To test kelt steelhead reconditioning as a potential recovery tool, we captured wild emigrating steelhead kelts from the Yakima River and evaluated reconditioning (short and long-term) success and diet formulations at Prosser Hatchery on the Yakima River. Steelhead kelts from the Yakima River were collected at the Chandler Juvenile Monitoring Facility (CJMF, located on the Yakima River at river kilometer 75.6) from 12 March to 28 May 2003. In total, 690 kelts were collected for reconditioning at Prosser Hatchery. Captive specimens represented 30.8% (690 of 2,235) of the entire 2002-2003 Yakima River wild steelhead population, based on fish ladder counts at Prosser Dam. All steelhead kelts were reconditioned in circular tanks, fed freeze-dried krill and received hw-wiegandt multi vit dietary supplement; long-term steelhead kelts also received Moore-Clark pellets. Oxytetracycline was administered to reconditioned fish to boost immune system response following the stress of initial capture. Formalin was also administered to prevent outbreaks of fungus and we also intubated the fish that were collected with Ivermectin{trademark} to control internal parasites (e.g., Salmincola spp.). Captured kelts were separated into two experimental groups: short-term and long-term reconditioning. Success indicators for the short-term experiment include the proportion of fish that survived the reconditioning process and the proportion of fish that initiated a feeding response. Short-term kelts were reconditioned for 3 to 7 weeks. Surviving specimens were released for natural spawning on June 4, 2003. Survival-to-release was very good for the short-term experiment, with a rate of 89.9%. Long-term steelhead kelts were held for 5-9 months then released on December 8, 2003. Long-term success indicators include the proportion of fish that survived the reconditioning process and the proportion of surviving fish that successfully remature. Survival and rematuration for long-term kelts increased as well with 62.4% surviving to release and 91.7% rematuring. A total of 47 reconditioned kelts were radio tagged to assess their spawning migration behavior and success following release from Prosser Hatchery and to evaluate in-season homing fidelity. As in previous years, the kelts reconditioned during this project will substantially bolster the number of repeat spawners in the Yakima River. Valuable knowledge regarding kelt husbandry, condition, and rearing environments were obtained during this research endeavor. The authors were very pleased with the high survival rates. Information collected during this feasibility study has been significantly incorporated into the experimental design for upcoming years of research, and is expected to continue to increase survival of long-term reconditioned fish and successful expression of iteroparity.« less

Culvert roughness elements for native Utah fish passage : phase II.

DOT National Transportation Integrated Search

2012-04-01

Native fishes have become an increasingly important concern when designing fish passable culverts. Many operational culverts constrict waterways which increase velocities and prevent upstream passage of small fish species. The current method to ensur...

Environmental Factors Affecting Large-Bodied Coral Reef Fish Assemblages in the Mariana Archipelago

PubMed Central

Richards, Benjamin L.; Williams, Ivor D.; Vetter, Oliver J.; Williams, Gareth J.

2012-01-01

Large-bodied reef fishes represent an economically and ecologically important segment of the coral reef fish assemblage. Many of these individuals supply the bulk of the reproductive output for their population and have a disproportionate effect on their environment (e.g. as apex predators or bioeroding herbivores). Large-bodied reef fishes also tend to be at greatest risk of overfishing, and their loss can result in a myriad of either cascading (direct) or indirect trophic and other effects. While many studies have investigated habitat characteristics affecting populations of small-bodied reef fishes, few have explored the relationship between large-bodied species and their environment. Here, we describe the distribution of the large-bodied reef fishes in the Mariana Archipelago with an emphasis on the environmental factors associated with their distribution. Of the factors considered in this study, a negative association with human population density showed the highest relative influence on the distribution of large-bodied reef fishes; however, depth, water temperature, and distance to deep water also were important. These findings provide new information on the ecology of large-bodied reef fishes can inform discussions concerning essential fish habitat and ecosystem-based management for these species and highlight important knowledge gaps worthy of additional research. PMID:22384014

Trophic characteristics of a mangrove fish community in Southwest Thailand: Important mangrove contribution and intraspecies feeding variability

NASA Astrophysics Data System (ADS)

Zagars, Matiss; Ikejima, Kou; Kasai, Akihide; Arai, Nobuaki; Tongnunui, Prasert

2013-03-01

Mangrove production has been found to make a major contribution to the nutrition of a fish community in the Sikao Creek mangrove estuary, Southwest Thailand. Gut content analysis and carbon and nitrogen stable isotope analysis were used to assess fish feeding behavior and trophic reliance on different primary producers (mangrove leaves, phytoplankton, microphytobenthos) focusing on 19 dominant fish species, and 4 potential fish food items. Cluster analysis identified 5 trophic groups and the IsoSource model indicated the importance of primary food sources in trophically supporting different fish species. Most analyzed fish species had carbon isotopic signatures that were more depleted than those reported in previous studies, and the IsoSource model indicated that mangrove leaves were an important primary food source. This may be a specific characteristic of our study site, which is not well connected to other productive coastal habitats that provide alternative primary food sources. Thus we suggest that food chains in trophically isolated mangrove estuaries of southwest Thailand are more dependent on mangrove tree production. We also assessed the relationship of individuality in fish feeding habits and variability of δ13C values and showed that several mangrove fish species have significant intraspecies variability in feeding habits, possibly due to high intraspecific competition.

Seed dispersal by fishes in tropical and temperate fresh waters: The growing evidence

NASA Astrophysics Data System (ADS)

Horn, Michael H.; Correa, Sandra Bibiana; Parolin, Pia; Pollux, B. J. A.; Anderson, Jill T.; Lucas, Christine; Widmann, Peter; Tjiu, Albertus; Galetti, Mauro; Goulding, Michael

2011-11-01

Fruit-eating by fishes represents an ancient (perhaps Paleozoic) interaction increasingly regarded as important for seed dispersal (ichthyochory) in tropical and temperate ecosystems. Most of the more than 275 known frugivorous species belong to the mainly Neotropical Characiformes (pacus, piranhas) and Siluriformes (catfishes), but cypriniforms (carps, minnows) are more important in the Holarctic and Indomalayan regions. Frugivores are among the most abundant fishes in Neotropical floodplains where they eat the fruits of a wide variety of trees and shrubs. By consuming fruits, fishes gain access to rich sources of carbohydrates, lipids and proteins and act as either seed predators or seed dispersers. With their often high mobility, large size, and great longevity, fruit-eating fishes can play important roles as seed dispersers and exert strong influences on local plant-recruitment dynamics and regional biodiversity. Recent feeding experiments focused on seed traits after gut passage support the idea that fishes are major seed dispersers in floodplain and riparian forests. Overfishing, damming, deforestation and logging potentially diminish ichthyochory and require immediate attention to ameliorate their effects. Much exciting work remains in terms of fish and plant adaptations to ichthyochory, dispersal regimes involving fishes in different ecosystems, and increased use of nondestructive methods such as stomach lavage, stable isotopes, genetic analyses and radio transmitters to determine fish diets and movements.

Environmental factors affecting large-bodied coral reef fish assemblages in the Mariana Archipelago.

PubMed

Richards, Benjamin L; Williams, Ivor D; Vetter, Oliver J; Williams, Gareth J

2012-01-01

Large-bodied reef fishes represent an economically and ecologically important segment of the coral reef fish assemblage. Many of these individuals supply the bulk of the reproductive output for their population and have a disproportionate effect on their environment (e.g. as apex predators or bioeroding herbivores). Large-bodied reef fishes also tend to be at greatest risk of overfishing, and their loss can result in a myriad of either cascading (direct) or indirect trophic and other effects. While many studies have investigated habitat characteristics affecting populations of small-bodied reef fishes, few have explored the relationship between large-bodied species and their environment. Here, we describe the distribution of the large-bodied reef fishes in the Mariana Archipelago with an emphasis on the environmental factors associated with their distribution. Of the factors considered in this study, a negative association with human population density showed the highest relative influence on the distribution of large-bodied reef fishes; however, depth, water temperature, and distance to deep water also were important. These findings provide new information on the ecology of large-bodied reef fishes can inform discussions concerning essential fish habitat and ecosystem-based management for these species and highlight important knowledge gaps worthy of additional research.

Real-time distribution of pelagic fish: combining hydroacoustics, GIS and spatial modelling at a fine spatial scale.

PubMed

Muška, Milan; Tušer, Michal; Frouzová, Jaroslava; Mrkvička, Tomáš; Ricard, Daniel; Seďa, Jaromír; Morelli, Federico; Kubečka, Jan

2018-03-29

Understanding spatial distribution of organisms in heterogeneous environment remains one of the chief issues in ecology. Spatial organization of freshwater fish was investigated predominantly on large-scale, neglecting important local conditions and ecological processes. However, small-scale processes are of an essential importance for individual habitat preferences and hence structuring trophic cascades and species coexistence. In this work, we analysed the real-time spatial distribution of pelagic freshwater fish in the Římov Reservoir (Czechia) observed by hydroacoustics in relation to important environmental predictors during 48 hours at 3-h interval. Effect of diurnal cycle was revealed of highest significance in all spatial models with inverse trends between fish distribution and predictors in day and night in general. Our findings highlighted daytime pelagic fish distribution as highly aggregated, with general fish preferences for central, deep and highly illuminated areas, whereas nighttime distribution was more disperse and fish preferred nearshore steep sloped areas with higher depth. This turnover suggests prominent movements of significant part of fish assemblage between pelagic and nearshore areas on a diel basis. In conclusion, hydroacoustics, GIS and spatial modelling proved as valuable tool for predicting local fish distribution and elucidate its drivers, which has far reaching implications for understanding freshwater ecosystem functioning.

Reinterpreting recent thymic emigrant function: defective or adaptive?

PubMed

Cunningham, Cody A; Helm, Eric Y; Fink, Pamela J

2018-04-01

Recent thymic emigrants (RTEs) are those peripheral T cells that have most recently completed thymic development and egress. Over the past decade, significant advances have been made in understanding the cell-extrinsic and cell-intrinsic requirements for RTE maturation to mature naïve (MN) T cells and in detailing the functional differences that characterize these two T cell populations. Much of this work has suggested that RTEs are hypo-functional versions of more mature T cells. However, recent evidence has indicated that rather than being defective T cells, RTEs are exquisitely adapted to their cellular niche. In this review, we argue that RTEs are not flawed mature T cells but are adapted to fill an underpopulated T cell compartment, while maintaining self tolerance and possessing the capacity to mount robust immune responses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sex and drug risk behavior pre- and post-emigration among Latino migrant men in post-Hurricane Katrina New Orleans.

PubMed

Mills, Jennifer; Burton, Nicole; Schmidt, Norine; Salinas, Oscar; Hembling, John; Aran, Alberto; Shedlin, Michele; Kissinger, Patricia

2013-06-01

High rates of sex and drug risk behaviors have been documented among Latino migrant men in the US. Whether these behaviors were established in the migrants' home countries or were adopted in the US has not been described and has implications for prevention strategies. Quarterly surveys were conducted to gather information on selected sex and drug risk practices of Latino migrant men who arrived in New Orleans after Hurricane Katrina seeking work. Both kappa scores and McNemar's tests were performed to determine if practice of these behaviors in home country was similar to practice post-emigration to the US. Female sex worker (FSW) patronage, same sex encounters (MSM), and crack cocaine use was more likely to occur post- rather than pre-emigration. Of those who ever engaged in these selected behaviors, most adopted the behavior in the US (i.e., 75.8% of FSW patrons, 72.7% of MSM participants, and 85.7% of crack cocaine users), with the exception of binge drinking (26.8%). Men who were living with a family member were less likely to adopt FSW patronage OR = 0.27, CI = 0.10-0.76, whereas men who earned >$465 per week were more likely to adopt crack cocaine use OR = 6.29 CI = 1.29, 30.57. Interventions that facilitate the maintenance of family cohesion and provide strategies for financial management may be useful for reducing sex and drug risk among newly arrived migrants.

Thailand's responses to transnational migration during economic growth and economic downturn.

PubMed

Chantavanich, S

1999-04-01

This paper gives an historical overview of immigration to Thailand since the 1970s and emigration since the 1960s. It describes migration policies since the 1930s. Final discussion focuses on the impact of economic contraction on migration. Immigration to Thailand dates back to the 1760s when a huge wave of Chinese emigrated to Thailand. The flow continued until about 1850 and resumed during 1905-17. The next big waves of immigrants were after 1975, when refugees fled Indochina, and in the 1990s, when migrants flocked from neighboring countries drawn to the booming economy. Thai professionals left in the 1960s for the USA. During the 1980s, many left for work in the Middle East. During the 1990s, Thai migrants moved within the East and Southeastern Asian countries and the USA or Europe, and they included many women and illegal migrants. Emigrants leave as arranged by the government, by employers, by recruitment agencies, and as trainees. The first official act was in 1950 and revised in 1979. Many work permits were approved in the 1990s, especially for unskilled labor. There are supports for Thai migrants abroad, but little is offered to foreigners at home. By 1997, the country's recession led to nonrenewal of many work permits. The 1998 economic crisis led to a new labor policy that deported illegal and unskilled migrant workers in order to create jobs for Thais. Policy encouraged Thais to seek work overseas.

Contribution of fish to intakes of micronutrients important for fetal development: a dietary survey of pregnant women in the Republic of Seychelles.

PubMed

Bonham, Maxine P; Duffy, Emeir M; Robson, Paula J; Wallace, Julie M; Myers, Gary J; Davidson, Philip W; Clarkson, Tom W; Shamlaye, Conrad F; Strain, J J; Livingstone, M Barbara E

2009-09-01

To characterise the diets of pregnant women in the Republic of Seychelles and to determine the contribution of fish to intakes of nutrients important for fetal and neonatal development. Observational, prospective study. Seychelles Child Development Centre, Mahé, Republic of Seychelles. Pregnant women (n 300) were recruited at their first visit to an antenatal clinic. At 28 weeks' gestation subjects completed a 4 d diet diary (n 273) and intakes were analysed using dietary analysis software. Mean (sd) energy intake was 9.0 (2.5) MJ/d and fat intakes were higher than UK recommendations for almost two-thirds of the cohort. Fish consumption was lower than in previous surveys, suggesting a move towards a more Westernised diet. Low intakes of a number of nutrients important during pregnancy for fetal development (Fe, Zn, Se and iodine) were observed. However, women who met the current recommendations for these nutrients consumed significantly more fish than those who did not (97 v. 73 g/d). The present study highlights the importance of fish in the diet of pregnant Seychellois women for ensuring adequate intakes of micronutrients important in fetal development. Dietary patterns in Seychelles, however, are in a state of transition, with a move towards a Western-style diet as evidenced by higher fat and lower fish intakes. If these dietary trends continue and fish consumption declines further, micronutrient status may be compromised. These findings suggest caution in establishing public health policies that promote limitation of fish intake during pregnancy.

Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes

USGS Publications Warehouse

Eagles-Smith, Collin A.; Herring, Garth; Johnson, Branden L.; Graw, Rick

2016-01-01

Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish.

Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes.

PubMed

Eagles-Smith, Collin A; Herring, Garth; Johnson, Branden; Graw, Rick

2016-05-01

Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish. Published by Elsevier Ltd.

Attitudes of undergraduate medical students of Addis Ababa University towards medical practice and migration, Ethiopia.

PubMed

Deressa, Wakgari; Azazh, Aklilu

2012-08-06

The health care system of Ethiopia is facing a serious shortage of health workforce. While a number of strategies have been developed to improve the training and retention of medical doctors in the country, understanding the perceptions and attitudes of medical students towards their training, future practice and intent to migrate can contribute in addressing the problem. This study was carried out to assess the attitudes of Ethiopian medical students towards their training and future practice of medicine, and to identify factors associated with the intent to practice in rural or urban settings, or to migrate abroad. A cross-sectional study was conducted in June 2009 among 600 medical students (Year I to Internship program) of the Faculty of Medicine at Addis Ababa University in Ethiopia. A pre-tested self-administered structured questionnaire was used for data collection. Descriptive statistics were used for data summarization and presentation. Degree of association was measured by Chi Square test, with significance level set at p < 0.05. Bivariate and multivariate logistic regression analyses were used to assess associations. Only 20% of the students felt 'excellent' about studying medicine; followed by 'very good' (19%), 'good' (30%), 'fair' (21%) and 'bad' (11%). About 35% of respondents responded they felt the standard of medical education was below their expectation. Only 30% of the students said they would like to initially practice medicine in rural settings in Ethiopia. However, students with rural backgrounds were more likely than those with urban backgrounds to say they intended to practice medicine in rural areas (adjusted OR = 2.50, 95% CI = 1.18-5.26). Similarly, students in clinical training program preferred to practice medicine in rural areas compared to pre-clinical students (adjusted OR = 1.83, 95% CI = 1.12-2.99). About 53% of the students (57% males vs. 46% females, p = 0.017) indicated aspiration to emigrate following graduation, particularly to the United States of America (42%) or European countries (15%). The attitude towards emigration was higher among Year IV (63%) and Internship (71%) students compared to Year I to Year III students (45-54%). Male students were more likely to say they would emigrate than females (adjusted OR = 1.57, 95% CI = 1.10-2.29). Likewise, students with clinical training were more likely to want to emigrate than pre-clinical students, although the difference was marginally significant (adjusted OR = 1.58, 95% CI = 1.00-2.49). The attitudes of the majority of Ethiopian medical students in the capital city towards practicing medicine in rural areas were found to be poor, and the intent to migrate after completing medical training was found to be very high among the study participants, creating a huge potential for brain drain. This necessitates the importance of improving the quality of education and career choice satisfaction, creating conducive training and working conditions including retention efforts for medical graduates to serve their nation. It follows that recruiting altruistic and rural background students into medical schools is likely to produce graduates who are more likely to practice medicine in rural settings.

Protocol for Monitoring Fish Assemblages in Pacific Northwest National Parks

USGS Publications Warehouse

Brenkman, Samuel J.; Connolly, Patrick J.

2008-01-01

Rivers and streams that drain from Olympic, Mount Rainier, and North Cascades National Parks are among the most protected corridors in the lower 48 States, and represent some of the largest tracts of contiguous, undisturbed habitat throughout the range of several key fish species of the Pacific Northwest. These watersheds are of high regional importance as freshwater habitat sanctuaries for native fish, where habitat conditions are characterized as having little to no disturbance from development, channelization, impervious surfaces, roads, diversions, or hydroelectric projects. Fishery resources are of high ecological and cultural importance in Pacific Northwest National Parks, and significantly contribute to economically important recreational, commercial, and tribal fisheries. This protocol describes procedures to monitor trends in fish assemblages, fish abundance, and water temperature in eight rivers and five wadeable streams in Olympic National Park during summer months, and is based on 4 years of field testing. Fish assemblages link freshwater, marine, and terrestrial ecosystems. They also serve as focal resources of national parks and are excellent indicators of ecological conditions of rivers and streams. Despite the vital importance of native anadromous and resident fish populations, there is no existing monitoring program for fish assemblages in the North Coast and Cascades Network. Specific monitoring objectives of this protocol are to determine seasonal and annual trends in: (1) fish species composition, (2) timing of migration of adult fish, (3) relative abundance, (4) age and size structure, (5) extent of non-native and hatchery fish, and (6) water temperature. To detect seasonal and annual trends in fish assemblages in reference sites, we rely on repeated and consistent annual sampling at each monitoring site. The general rationale for the repeated sampling of reference sites is to ensure that we account for the high interannual variability in fish movements and abundances in rivers. One underlying assumption is that the monitoring program is designed in perpetuity, and consequently our capability to detect trends substantially increases with time. The protocol describes sampling designs, methods, training procedures, safety considerations, data management, data analysis, and reporting. The allocation of sampling effort represents a balance between ecological considerations, a sound monitoring approach, and practical limitations caused by logistical constraints and a limited annual budget of $55,000. The widespread declines of native fish species in western North America highlights the importance and urgency of understanding trends in fish assemblages from undisturbed habitats. Seasonal and annual trends in fish assemblages will provide insights at the individual, population, and assemblage level. This protocol will allow managers to detect increases and decreases in abundance of priority management species, and occurrence of non-native, hatchery, and federally listed fish. The detection of trends in fish assemblages will allow for specific management actions that may include: implementation of more appropriate fishing regulations, evaluation of existing hatchery releases, control of non-native fish species, and prioritization of habitat restoration projects. Dissemination and communication of scientific findings on North Coast and Cascades Network fish assemblages will be a core product of this protocol, which will have much relevance to decision makers, park visitors, researchers, and educators.

9 CFR 93.904 - Health certificate for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Health certificate for live fish... ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN ANIMAL, BIRD, AND... General Provisions for Svc-Regulated Fish Species § 93.904 Health certificate for live fish, fertilized...

Possible Role of Fish as Transport Hosts for Dracunculus spp. Larvae.

PubMed

Cleveland, Christopher A; Eberhard, Mark L; Thompson, Alec T; Smith, Stephen J; Zirimwabagabo, Hubert; Bringolf, Robert; Yabsley, Michael J

2017-09-01

To inform Dracunculus medinensis (Guinea worm) eradication efforts, we evaluated the role of fish as transport hosts for Dracunculus worms. Ferrets fed fish that had ingested infected copepods became infected, highlighting the importance of recommendations to cook fish, bury entrails, and prevent dogs from consuming raw fish and entrails.

Fish mycobacteriosis (Tuberculosis)

USGS Publications Warehouse

Parisot, T.J.; Wood, J.W.

1959-01-01

The etiologic agent for the bacterial disease, "fish tuberculosis" (more correctly "mycobacteriosis"), was first observed in carp in 189& from a pond in France. Subsequently similar agents have been isolated from or observed in fish in fresh water, salt water, and brackish water, in fish in aquaria, hatcheries, and natural habitat~ (wild populations of fish). The disease has been recognized as an important infection among hatchery reared salmonid fishes on the West Coast of the United States, and in aquarium fishes such as the neon tetra, the Siamese fighting fish, and in salt water fish held in zoological displays.

Movement and survival of an amphibian in relation to sediment and culvert design

USGS Publications Warehouse

Honeycutt, R.K; Lowe, W.H.; Hossack, Blake R.

2016-01-01

Habitat disturbance from stream culverts can affect aquatic organisms by increasing sedimentation or forming barriers to movement. Land managers are replacing many culverts to reduce these negative effects, primarily for stream fishes. However, these management actions are likely to have broad implications for many organisms, including amphibians in small streams. To assess the effects of culverts on movement and survival of the Idaho giant salamander (Dicamptodon aterrimus), we used capture-mark-recapture surveys and measured sediment in streams with 2 culvert types (i.e., unimproved culverts, improved culverts) and in streams without culverts (i.e., reference streams). We predicted culverts would increase stream sediment levels, limit movement, and reduce survival of Idaho giant salamanders. We also determined the effect of sediment levels on survival of salamanders because although sediment is often associated with distribution and abundance of stream amphibians, links with vital rates remain unclear. To estimate survival, we used a spatial Cormack–Jolly–Seber (CJS) model that explicitly incorporated information on movement, eliminating bias in apparent survival estimated from traditional (i.e., non-spatial) CJS models caused by permanent emigration beyond the study area. To demonstrate the importance of using spatial data in studies of wildlife populations, we compared estimates from the spatial CJS to estimates of apparent survival from a traditional CJS model. Although high levels of sediment reduced survival of salamanders, culvert type was unrelated to sediment levels or true survival of salamanders. Across all streams, we documented only 15 movement events between study reaches. All movement events were downstream, and they occurred disproportionately in 1 stream, which precluded measuring the effect of culvert design on movement. Although movement was low overall, the variance among streams was high enough to bias estimates of apparent survival compared to true survival. Our results suggest that where sedimentation occurs from roads and culverts, survival of the Idaho giant salamander could be reduced. Though culverts clearly do not completely block downstream movements of Idaho giant salamanders, the degree to which culvert improvements affect movements under roads in comparison to unimproved culverts remains unclear, especially for rare, but potentially important, upstream movements.

Vigorous dynamics underlie a stable population of the endangered snow leopard Panthera uncia in Tost Mountains, South Gobi, Mongolia.

PubMed

Sharma, Koustubh; Bayrakcismith, Rana; Tumursukh, Lkhagvasumberel; Johansson, Orjan; Sevger, Purevsuren; McCarthy, Tom; Mishra, Charudutt

2014-01-01

Population monitoring programmes and estimation of vital rates are key to understanding the mechanisms of population growth, decline or stability, and are important for effective conservation action. We report, for the first time, the population trends and vital rates of the endangered snow leopard based on camera trapping over four years in the Tost Mountains, South Gobi, Mongolia. We used robust design multi-season mark-recapture analysis to estimate the trends in abundance, sex ratio, survival probability and the probability of temporary emigration and immigration for adult and young snow leopards. The snow leopard population remained constant over most of the study period, with no apparent growth (λ = 1.08+-0.25). Comparison of model results with the "known population" of radio-collared snow leopards suggested high accuracy in our estimates. Although seemingly stable, vigorous underlying dynamics were evident in this population, with the adult sex ratio shifting from being male-biased to female-biased (1.67 to 0.38 males per female) during the study. Adult survival probability was 0.82 (SE+-0.08) and that of young was 0.83 (SE+-0.15) and 0.77 (SE +-0.2) respectively, before and after the age of 2 years. Young snow leopards showed a high probability of temporary emigration and immigration (0.6, SE +-0.19 and 0.68, SE +-0.32 before and after the age of 2 years) though not the adults (0.02 SE+-0.07). While the current female-bias in the population and the number of cubs born each year seemingly render the study population safe, the vigorous dynamics suggests that the situation can change quickly. The reduction in the proportion of male snow leopards may be indicative of continuing anthropogenic pressures. Our work reiterates the importance of monitoring both the abundance and population dynamics of species for effective conservation.

Assessing the relative importance of local and regional processes on the survival of a threatened salmon population.

PubMed

Miller, Jessica A; Teel, David J; Peterson, William T; Baptista, Antonio M

2014-01-01

Research on regulatory mechanisms in biological populations often focuses on environmental covariates. An integrated approach that combines environmental indices with organismal-level information can provide additional insight on regulatory mechanisms. Survival of spring/summer Snake River Chinook salmon (Oncorhynchus tshawytscha) is consistently low whereas some adjacent populations with similar life histories experience greater survival. It is not known if populations with differential survival respond similarly during early marine residence, a critical period in the life history. Ocean collections, genetic stock identification, and otolith analyses were combined to evaluate the growth-mortality and match-mismatch hypotheses during early marine residence of spring/summer Snake River Chinook salmon. Interannual variation in juvenile attributes, including size at marine entry and marine growth rate, was compared with estimates of survival and physical and biological metrics. Multiple linear regression and multi-model inference were used to evaluate the relative importance of biological and physical metrics in explaining interannual variation in survival. There was relatively weak support for the match-mismatch hypothesis and stronger evidence for the growth-mortality hypothesis. Marine growth and size at capture were strongly, positively related to survival, a finding similar to spring Chinook salmon from the Mid-Upper Columbia River. In hindcast models, basin-scale indices (Pacific Decadal Oscillation (PDO) and the North Pacific Gyre Oscillation (NPGO)) and biological indices (juvenile salmon catch-per-unit-effort (CPUE) and a copepod community index (CCI)) accounted for substantial and similar portions of variation in survival for juvenile emigration years 1998-2008 (R2>0.70). However, in forecast models for emigration years 2009-2011, there was an increasing discrepancy between predictions based on the PDO (50-448% of observed value) compared with those based on the NPGO (68-212%) or biological indices (CPUE and CCI: 83-172%). Overall, the PDO index was remarkably informative in earlier years but other basin-scale and biological indices provided more accurate indications of survival in recent years.

Vigorous Dynamics Underlie a Stable Population of the Endangered Snow Leopard Panthera uncia in Tost Mountains, South Gobi, Mongolia

PubMed Central

Sharma, Koustubh; Bayrakcismith, Rana; Tumursukh, Lkhagvasumberel; Johansson, Orjan; Sevger, Purevsuren; McCarthy, Tom; Mishra, Charudutt

2014-01-01

Population monitoring programmes and estimation of vital rates are key to understanding the mechanisms of population growth, decline or stability, and are important for effective conservation action. We report, for the first time, the population trends and vital rates of the endangered snow leopard based on camera trapping over four years in the Tost Mountains, South Gobi, Mongolia. We used robust design multi-season mark-recapture analysis to estimate the trends in abundance, sex ratio, survival probability and the probability of temporary emigration and immigration for adult and young snow leopards. The snow leopard population remained constant over most of the study period, with no apparent growth (λ = 1.08+−0.25). Comparison of model results with the “known population” of radio-collared snow leopards suggested high accuracy in our estimates. Although seemingly stable, vigorous underlying dynamics were evident in this population, with the adult sex ratio shifting from being male-biased to female-biased (1.67 to 0.38 males per female) during the study. Adult survival probability was 0.82 (SE+−0.08) and that of young was 0.83 (SE+−0.15) and 0.77 (SE +−0.2) respectively, before and after the age of 2 years. Young snow leopards showed a high probability of temporary emigration and immigration (0.6, SE +−0.19 and 0.68, SE +−0.32 before and after the age of 2 years) though not the adults (0.02 SE+−0.07). While the current female-bias in the population and the number of cubs born each year seemingly render the study population safe, the vigorous dynamics suggests that the situation can change quickly. The reduction in the proportion of male snow leopards may be indicative of continuing anthropogenic pressures. Our work reiterates the importance of monitoring both the abundance and population dynamics of species for effective conservation. PMID:25006879

SOCIOECONOMIC, CULTURAL, AND BEHAVIORAL FACTORS AFFECTING HISPANIC HEALTH OUTCOMES

PubMed Central

MORALES, LEO S.; LARA, MARIELENA; KINGTON, RAYNARD S.; VALDEZ, ROBERT O.; ESCARCE, JOSÉ J.

2006-01-01

Evidence suggests that social and economic factors are important determinants of health. Yet, despite higher poverty rates, less education, and worse access to health care, health outcomes of many Hispanics living in the United States today are equal to, or better than, those of non-Hispanic whites. This paradox is described in the literature as the epidemiological paradox or Hispanic health paradox. In this paper, the authors selectively review data and research supporting the existence of the epidemiological paradox. They find substantial support for the existence of the epidemiological paradox, particularly among Mexican Americans. Census undercounts of Hispanics, misclassification of Hispanic deaths, and emigration of Hispanics do not fully account for the epidemiological paradox. Identifying protective factors underlying the epidemiological paradox, while improving access to care and the economic conditions among Hispanics, are important research and policy implications of this review. PMID:12407964

DHA and EPA Content and Fatty Acid Profile of 39 Food Fishes from India

PubMed Central

Mahanty, Arabinda; Sankar, T. V.; Anandan, R.; Paul, B. N.; Sarma, Debajit; Syama Dayal, J.; Venkateshwarlu, G.; Mathew, Suseela; Karunakaran, D.; Chanda, Soumen; Shahi, Neetu; Das, Puspita; Das, Partha; Akhtar, Md Shahbaz; Vijayagopal, P.; Sridhar, N.

2016-01-01

Docosahexaenoic acid (DHA) is the principal constituent of a variety of cells especially the brain neurons and retinal cells and plays important role in fetal brain development, development of motor skills, and visual acuity in infants, lipid metabolism, and cognitive support and along with eicosapentaenoic acid (EPA) it plays important role in preventing atherosclerosis, dementia, rheumatoid arthritis, Alzheimer's disease, and so forth. Being an essential nutrient, it is to be obtained through diet and therefore searching for affordable sources of these ω-3 polyunsaturated fatty acids (PUFA) is important for consumer guidance and dietary counseling. Fish is an important source of PUFA and has unique advantage that there are many food fish species available and consumers have a wide choice owing to availability and affordability. The Indian subcontinent harbors a rich fish biodiversity which markedly varies in their nutrient composition. Here we report the DHA and EPA content and fatty acid profile of 39 important food fishes (including finfishes, shellfishes, and edible molluscs from both marine water and freshwater) from India. The study showed that fishes Tenualosa ilisha, Sardinella longiceps, Nemipterus japonicus, and Anabas testudineus are rich sources of DHA and EPA. Promotion of these species as DHA rich species would enhance their utility in public health nutrition. PMID:27579313

DHA and EPA Content and Fatty Acid Profile of 39 Food Fishes from India.

PubMed

Mohanty, Bimal Prasanna; Ganguly, Satabdi; Mahanty, Arabinda; Sankar, T V; Anandan, R; Chakraborty, Kajal; Paul, B N; Sarma, Debajit; Syama Dayal, J; Venkateshwarlu, G; Mathew, Suseela; Asha, K K; Karunakaran, D; Mitra, Tandrima; Chanda, Soumen; Shahi, Neetu; Das, Puspita; Das, Partha; Akhtar, Md Shahbaz; Vijayagopal, P; Sridhar, N

2016-01-01

Docosahexaenoic acid (DHA) is the principal constituent of a variety of cells especially the brain neurons and retinal cells and plays important role in fetal brain development, development of motor skills, and visual acuity in infants, lipid metabolism, and cognitive support and along with eicosapentaenoic acid (EPA) it plays important role in preventing atherosclerosis, dementia, rheumatoid arthritis, Alzheimer's disease, and so forth. Being an essential nutrient, it is to be obtained through diet and therefore searching for affordable sources of these ω-3 polyunsaturated fatty acids (PUFA) is important for consumer guidance and dietary counseling. Fish is an important source of PUFA and has unique advantage that there are many food fish species available and consumers have a wide choice owing to availability and affordability. The Indian subcontinent harbors a rich fish biodiversity which markedly varies in their nutrient composition. Here we report the DHA and EPA content and fatty acid profile of 39 important food fishes (including finfishes, shellfishes, and edible molluscs from both marine water and freshwater) from India. The study showed that fishes Tenualosa ilisha, Sardinella longiceps, Nemipterus japonicus, and Anabas testudineus are rich sources of DHA and EPA. Promotion of these species as DHA rich species would enhance their utility in public health nutrition.

Fish Rhabdoviruses

USGS Publications Warehouse

Kurath, G.; Winton, J.

2008-01-01

Many important viral pathogens of fish are members of the family Rhabdoviridae. The viruses in this large group cause significant losses in populations of wild fish as well as among fish reared in aquaculture. Fish rhabdoviruses often have a wide host and geographic range, and infect aquatic animals in both freshwater and seawater. The fish rhabdoviruses comprise a diverse collection of isolates that can be placed in one of two quite different groups: isolates that are members of the established genusNovirhabdovirus, and those that are most similar to members of the genus Vesiculovirus. Because the diseases caused by fish rhabdoviruses are important to aquaculture, diagnostic methods for their detection and identification are well established. In addition to regulations designed to reduce the spread of fish viruses, a significant body of research has addressed methods for the control or prevention of diseases caused by fish rhabdoviruses, including vaccination. The number of reported fish rhabdoviruses continues to grow as a result of the expansion of aquaculture, the increase in global trade, the development of improved diagnostic methods, and heightened surveillance activities. Fish rhabdoviruses serve as useful components of model systems to study vertebrate virus disease, epidemiology, and immunology.

Host defense against systemic infection with Streptococcus pneumoniae is impaired in E-, P-, and E-/P-selectin-deficient mice.

PubMed Central

Munoz, F M; Hawkins, E P; Bullard, D C; Beaudet, A L; Kaplan, S L

1997-01-01

Endothelial selectins mediate rolling of leukocytes on endothelium, a crucial step for leukocyte firm adhesion and emigration into sites of tissue injury and infection. To characterize the role of the endothelial selectins during bacterial sepsis in vivo, Streptococcus pneumoniae (1-10 x 10(6) colony-forming units) was inoculated intraperitoneally into wild-type mice and mice with E-, P-, or E-/P-selectin deficiencies. Mice were followed 10 d for morbidity, survival, clearance of bacteremia, and leukocyte migration to the peritoneal cavity and organs 48 h after infection. All selectin-deficient mice showed a more pronounced morbidity, a significantly higher mortality associated with persistent bacteremia, and a higher bacterial load when compared with wild-type mice. These differences were most remarkable in the E-selectin-deficient mice, which showed the highest rate of mortality and bacteremia (P

The consequences of Ireland's culture of medical migration.

PubMed

Humphries, Niamh; Crowe, Sophie; McDermott, Cian; McAleese, Sara; Brugha, Ruairi

2017-12-28

In recent years, Ireland has experienced a large-scale, outward migration of doctors. This presents a challenge for national policy makers and workforce planners seeking to build a self-sufficient medical workforce that trains and retains enough doctors to meet demand. Although, traditionally, medical migration has been considered beneficial to the Irish health system, austerity has brought a greater level of uncertainty to the health system and, with it, a need to reappraise the professional culture of migration and its impact on the Irish health system. This paper illustrates how a culture of migration informs career and migration plans. It draws on quantitative data-registration and migration data from source and destination countries-and qualitative data-in-depth interviews with 50 doctors who had undertaken postgraduate medical training in Ireland. Of 50 respondents, 42 highlighted the importance of migration. The culture of medical migration rests on two assumptions-that international training/experience is beneficial to all doctors and that those who emigrate will return to Ireland with additional skills and experience. This assumption of return is challenged by a new generation of doctors whose professional lives have been shaped by globalisation and by austerity. Global comparisons reveal the comparatively poor working conditions, training and career opportunities in Ireland and the relative attractiveness of a permanent career abroad. In light of these changes, there is a need to critically appraise the culture of medical migration to determine if and in what circumstances migration is appropriate to the needs of the Irish health system. The paper considers the need to reappraise the culture of medical migration and the widespread emigration that it promotes.

Feasibility of cohort studies in Estonia

PubMed Central

Innos, K.; Rahu, M.; Rahu, K.

1999-01-01

OBJECTIVES: To describe the methodology and feasibility of follow up for vital status in retrospective cohort studies in Estonia. METHODS: A cohort of 7412 workers who had been employed at two factories in Tallinn between 1946 and 1988 was followed up for vital status from the date of first employment until death, emigration, or the end of the study, 31 December 1995, whichever occurred first. The cohort was electronically linked with the National Population Registry of Estonia that was created in 1992 and includes personal identification numbers of Estonian citizens and residents, and the Mortality Database that contains information from death certificates issued in 1983-95. A manual search was carried out on several non-computerised population data sources and archives. RESULTS: By 31 December 1995, the vital status of 6780 (91.5%) subjects could be traced (4495 (60.6%) subjects were alive, 1993 (26.9%) had died, and 292 (3.9%) had emigrated). Analysis by calendar period of leaving work showed that the proportion of subjects traced was lowest in the group of workers who had left work between 1946 and 1955 (58.4%), especially those whose age at leaving work was < 30 (53.2%) or > 60 years (42.3%). Among subjects who left work in 1956-65, 1966-75, and 1976-88, the follow up rate was 84.7%, 94.6%, and 98.2%, respectively. CONCLUSIONS: The findings, which are especially important for occupational epidemiology, confirm the feasibility of conducting retrospective cohort studies in Estonia. Most of the issues discussed in the paper apply to other former Soviet countries.   PMID:10472323

Characteristics of Patients at First Visit to a Polio Clinic in Sweden

PubMed Central

Vreede, Katarina Skough; Sunnerhagen, Katharina S.

2016-01-01

Aim Describe polio patients visiting a polio clinic in Sweden, a country where vaccination was introduced in 1957. Design A consecutive cohort study. Patients Prior polio patients. Methods All patients (n = 865) visiting the polio clinic at Sahlgrenska University Hospital, Gothenburg Sweden, between 1994 and 2012 were included in this study. Data at first visit regarding patient characteristics, polio classification, data of electromyography, origin, assistive devices and gait speed as well as muscle strength were collected for these patients. Twenty-three patients were excluded because no polio diagnosis could be established. A total of 842 patients with confirmed polio remained in the study. Results More than twenty percent of the patients were from countries outside the Nordic region and considerably younger than those from the Nordic region. The majority of the emigrants were from Asia and Africa followed by Europe (outside the Nordic region). Of all patients included ninety-seven percent (n = 817) had polio in the lower extremity and almost 53% (n = 444) had polio in the upper extremity while 28% (n = 238) had polio in the trunk, according to clinical classification of polio. Compared with a sample of the normal population, the polio patients walked 61–71% slower, and were 53–77% weaker in muscle strength of the knee and foot as well as grip strength. Conclusion The younger patients with polio emigrating from countries with different cultures may lead to a challenge for the multi professional teams working with post-polio rehabilitation and are of importance when planning for the care of polio patients the coming years. PMID:26981623

Characteristics of Patients at First Visit to a Polio Clinic in Sweden.

PubMed

Vreede, Katarina Skough; Sunnerhagen, Katharina S

2016-01-01

Describe polio patients visiting a polio clinic in Sweden, a country where vaccination was introduced in 1957. A consecutive cohort study. Prior polio patients. All patients (n = 865) visiting the polio clinic at Sahlgrenska University Hospital, Gothenburg Sweden, between 1994 and 2012 were included in this study. Data at first visit regarding patient characteristics, polio classification, data of electromyography, origin, assistive devices and gait speed as well as muscle strength were collected for these patients. Twenty-three patients were excluded because no polio diagnosis could be established. A total of 842 patients with confirmed polio remained in the study. More than twenty percent of the patients were from countries outside the Nordic region and considerably younger than those from the Nordic region. The majority of the emigrants were from Asia and Africa followed by Europe (outside the Nordic region). Of all patients included ninety-seven percent (n = 817) had polio in the lower extremity and almost 53% (n = 444) had polio in the upper extremity while 28% (n = 238) had polio in the trunk, according to clinical classification of polio. Compared with a sample of the normal population, the polio patients walked 61-71% slower, and were 53-77% weaker in muscle strength of the knee and foot as well as grip strength. The younger patients with polio emigrating from countries with different cultures may lead to a challenge for the multi professional teams working with post-polio rehabilitation and are of importance when planning for the care of polio patients the coming years.

Spatial variability in fish species assemblage and community structure in four subtropical lagoons of the Okavango Delta, Botswana

NASA Astrophysics Data System (ADS)

Mosepele, K.; Mosepele, B.; Bokhutlo, T.; Amutenya, K.

The species assemblage and community structure of four lagoons was assessed through time series data collected between 2001 and 2005 in the Okavango Delta. The main aim of this study was to evaluate the importance of lagoons as fish habitats in the Delta. Therefore, this study assessed the importance of these habitats through determining fish species diversity, composition, relative abundance, and community structure between the lagoons. Forty six species belonging to 11 families and five orders were collected over the study period. Main results showed that Cichlidae was the most important family and had the highest species richness in the lagoons. Significant differences ( p < 0.05) were observed in species richness, faunal composition, and diversity among some of the lagoons. Moreover, there were also variations in species composition, and also significant differences in mean length and weight of some selected fish species in the four lagoons. This study showed that lagoons are important repositories of food fish to local communities. Moreover, a management of the fish stocks based on restricting fishing in some lagoons as protected areas is not feasible because of these significant differences in species assemblages between lagoons. Furthermore, lagoons are subject to multiple where most of the lodges are constructed, which makes subsequently makes them vulnerable to pollution. Therefore, the integrity of lagoon habitats needs to be maintained so that their ecosystem functioning (i.e. fish repositories) is maintained.

Ornamental fish as a source of plasmid-mediated quinolone resistance genes and antibiotic resistance plasmids.

PubMed

Dobiasova, Hana; Kutilova, Iva; Piackova, Veronika; Vesely, Tomas; Cizek, Alois; Dolejska, Monika

2014-07-16

Growing ornamental fish industry is associated with public health concerns including extensive antibiotic use accompanied by increasing antibiotic resistance. The aim of this study was to analyze Aeromonas isolates from imported tropical ornamental fish and coldwater koi carps bred in the Czech Republic to assess the potential risk of ornamental fish as a source of plasmid-mediated quinolone resistance genes (PMQR) and antibiotic resistance plasmids. A collection of Aeromonas spp. with reduced susceptibility to ciprofloxacin (MIC ≥ 0.05 mg/L) was selected for the detection of PMQR genes. Isolates harbouring PMQR genes were further analyzed for the additional antibiotic resistance, integron content, clonality, biofilm production and transferability of PMQR genes by conjugation and transformation. Comparative analysis of plasmids carrying PMQR genes was performed. Fifteen (19%, n=80) isolates from koi carps and 18 (24%, n=76) isolates from imported ornamental fish were positive for qnrS2, aac(6')-Ib-cr or qnrB17 genes. PMQR-positive isolates from imported ornamental fish showed higher MIC levels to quinolones, multiresistance and diverse content of antibiotic resistance genes and integrons compared to the isolates from the carps. Related IncU plasmids harbouring qnrS2 and aac(6')-Ib-cr genes were found in Aeromonas spp. from imported ornamental fish and koi carps from various geographical areas. Ornamental fish may represent a potential source of multiresistant bacteria and mobile genetic elements for the environment and for humans. Copyright © 2014 Elsevier B.V. All rights reserved.

Ethnotaxonomical considerations and usage of ichthyofauna in a fishing community in Ceará State, Northeast Brazil.

PubMed

Pinto, Márcia Freire; Mourão, José da Silva; Alves, Rômulo Romeu Nóbrega

2013-03-08

Artisanal fishery is one of the most important economic activities for human populations living in coastal areas. The traditional knowledge that fishermen have of fishes is of utmost importance for the establishment of conservation strategies for many species. This study aimed to analyse the knowledge of and utilization of fishes by the artisanal fishermen in a fishing community on the coast of Ceará State (Northeast Brazil). In 2011, a number of semi-structured interviews were performed with fishermen with more than 20 years of fishery experience. The interviews were about fisheries (collecting spots, artefacts, etc.) and fish use. The fishes cited by the fishermen were identified scientifically and ethnotaxonomically. Considered masters of fishery, they cited 162 vernacular names of fishes, which corresponded to 290 different species, also including other animals such as dolphins, porpoises, whales and manatees. The criteria for the classification of the fishes were well known and utilised by the fishermen, and they were based on morphology, behaviour, habitat and the importance of commercial and fishing activities. Four hierarchical categories were identified in their classification system: kingdom, life-form, generic and specific. The fish nomenclature created by the fishermen was mostly composed of generic and monotypic names. The main uses of fish were for food and commercial purposes. The results stress the richness and complexity of the knowledge of the artisanal fishermen of Redonda Beach, and they provide support for the possibility of future studies and for the development of management plans and the management of wildlife resources.

Ethnotaxonomical considerations and usage of ichthyofauna in a fishing community in Ceará State, Northeast Brazil

PubMed Central

2013-01-01

Background Artisanal fishery is one of the most important economic activities for human populations living in coastal areas. The traditional knowledge that fishermen have of fishes is of utmost importance for the establishment of conservation strategies for many species. This study aimed to analyse the knowledge of and utilization of fishes by the artisanal fishermen in a fishing community on the coast of Ceará State (Northeast Brazil). Methods In 2011, a number of semi-structured interviews were performed with fishermen with more than 20 years of fishery experience. The interviews were about fisheries (collecting spots, artefacts, etc.) and fish use. The fishes cited by the fishermen were identified scientifically and ethnotaxonomically. Results Considered masters of fishery, they cited 162 vernacular names of fishes, which corresponded to 290 different species, also including other animals such as dolphins, porpoises, whales and manatees. The criteria for the classification of the fishes were well known and utilised by the fishermen, and they were based on morphology, behaviour, habitat and the importance of commercial and fishing activities. Four hierarchical categories were identified in their classification system: kingdom, life-form, generic and specific. The fish nomenclature created by the fishermen was mostly composed of generic and monotypic names. The main uses of fish were for food and commercial purposes. Conclusions The results stress the richness and complexity of the knowledge of the artisanal fishermen of Redonda Beach, and they provide support for the possibility of future studies and for the development of management plans and the management of wildlife resources. PMID:23497491

Importance of benthic prey for fishes in coral reef-associated sediments

USGS Publications Warehouse

DeFelice, R.C.; Parrish, J.D.

2003-01-01

The importance of open, sandy substrate adjacent to coral reefs as habitat and a food source for fishes has been little studied in most shallow tropical waters in the Pacific, including Hawai'i. In this study, in Hanalei Bay, Hiwai'i, we identified and quantified the major invertebrate fauna (larger than 0.5 mm) in the well-characterized sands adjoining the shallow fringing reefs. Concurrently, we identified the fish species that seemed to make substantial use of these sand habitats, estimated their density there, sampled their gut contents to examine trophic links with the sand habitat, and made other observations and collections to determine the times, locations, and types of activity there. A variety of (mostly small) polychaeres were dominant in the sediments at most sampling stations, along with many small crustaceans (e.g., amphipods, isopods, ostracods, and small shrimps) and fair numbers of mollusks (especially bivalves) and small echinoids. Fish guts examined contained ???77% of the total number of benthic taxa collected, including nearly all those just listed. However, fish consumption was selective, and the larger shrimps, crabs, and small cryptic fishes were dominant in the diets of most of the numerous predator taxa. Diets of benthic-feeding fishes showed relatively low specific overlap. The fish fauna in this area included substrate-indifferent pelagics, species with various degrees of reef relatedness, reef-restricted species, and (at the other extreme) permanent cryptic sand dwellers. Data on occurrence and movements of fishes indicated that a band of sandy substrate several tens of meters wide next to the reef was an active area for fishes, and activity was considerably different at different times of day and for fish of different ages. These results imply an important trophic role for the benthos in these near-reef habitats in support of reef-associated fishes.

9 CFR 93.905 - Declaration and other documents for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2010 CFR

2010-01-01

... live fish, fertilized eggs, and gametes. 93.905 Section 93.905 Animals and Animal Products ANIMAL AND... for live fish, fertilized eggs, and gametes. (a) For all live fish, fertilized eggs, and gametes... fish, fertilized eggs, or gametes, the number, species, and the purpose of the importation, the name of...

9 CFR 93.905 - Declaration and other documents for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2011 CFR

2011-01-01

... live fish, fertilized eggs, and gametes. 93.905 Section 93.905 Animals and Animal Products ANIMAL AND... for live fish, fertilized eggs, and gametes. (a) For all live fish, fertilized eggs, and gametes... fish, fertilized eggs, or gametes, the number, species, and the purpose of the importation, the name of...

9 CFR 93.905 - Declaration and other documents for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Animal Species General Provisions for Svc-Regulated Fish Species § 93.905 Declaration and other documents... entry, the name and address of the importer, the name and address of the broker, the origin of the live fish, fertilized eggs, or gametes, the number, species, and the purpose of the importation, the name of...

9 CFR 93.905 - Declaration and other documents for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Animal Species General Provisions for Svc-Regulated Fish Species § 93.905 Declaration and other documents... entry, the name and address of the importer, the name and address of the broker, the origin of the live fish, fertilized eggs, or gametes, the number, species, and the purpose of the importation, the name of...

9 CFR 93.905 - Declaration and other documents for live fish, fertilized eggs, and gametes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Animal Species General Provisions for Svc-Regulated Fish Species § 93.905 Declaration and other documents... entry, the name and address of the importer, the name and address of the broker, the origin of the live fish, fertilized eggs, or gametes, the number, species, and the purpose of the importation, the name of...

Modeling fish community dynamics in Florida Everglades: Role of temperature variation

USGS Publications Warehouse

Al-Rabai'ah, H. A.; Koh, H. L.; DeAngelis, Donald L.; Lee, Hooi-Ling

2002-01-01

The model shows that the temperature dependent starvation mortality is an important factor that influences fish population densities. It also shows high fish population densities at some temperature ranges when this consumption need is minimum. Several sensitivity analyses involving variations in temperature terms, food resources and water levels are conducted to ascertain the relative importance of temperature dependence terms.

MitoFish and MiFish Pipeline: A Mitochondrial Genome Database of Fish with an Analysis Pipeline for Environmental DNA Metabarcoding.

PubMed

Sato, Yukuto; Miya, Masaki; Fukunaga, Tsukasa; Sado, Tetsuya; Iwasaki, Wataru

2018-06-01

Fish mitochondrial genome (mitogenome) data form a fundamental basis for revealing vertebrate evolution and hydrosphere ecology. Here, we report recent functional updates of MitoFish, which is a database of fish mitogenomes with a precise annotation pipeline MitoAnnotator. Most importantly, we describe implementation of MiFish pipeline for metabarcoding analysis of fish mitochondrial environmental DNA, which is a fast-emerging and powerful technology in fish studies. MitoFish, MitoAnnotator, and MiFish pipeline constitute a key platform for studies of fish evolution, ecology, and conservation, and are freely available at http://mitofish.aori.u-tokyo.ac.jp/ (last accessed April 7th, 2018).

Contribution of fish to intakes of micronutrients important for fetal development: a dietary survey of pregnant women in the Republic of Seychelles

PubMed Central

Bonham, Maxine P; Duffy, Emeir M; Robson, Paula J; Wallace, Julie M; Myers, Gary J; Davidson, Philip W; Clarkson, Tom W; Shamlaye, Conrad F; Strain, JJ; Livingstone, M Barbara E

2013-01-01

Objectives To characterise the diets of pregnant women in the Republic of Seychelles and to determine the contribution of fish to intakes of nutrients important for fetal and neonatal development. Design Observational, prospective study. Setting Seychelles Child Development Centre, Mahé, Republic of Seychelles. Subjects and methods Pregnant women (n 300) were recruited at their first visit to an antenatal clinic. At 28 weeks’ gestation subjects completed a 4 d diet diary (n 273) and intakes were analysed using dietary analysis software. Results Mean (SD) energy intake was 9·0 (2·5) MJ/d and fat intakes were higher than UK recommendations for almost two-thirds of the cohort. Fish consumption was lower than in previous surveys, suggesting a move towards a more Westernised diet. Low intakes of a number of nutrients important during pregnancy for fetal development (Fe, Zn, Se and iodine) were observed. However, women who met the current recommendations for these nutrients consumed significantly more fish than those who did not (97 v. 73 g/d). Conclusions The present study highlights the importance of fish in the diet of pregnant Seychellois women for ensuring adequate intakes of micronutrients important in fetal development. Dietary patterns in Seychelles, however, are in a state of transition, with a move towards a Western-style diet as evidenced by higher fat and lower fish intakes. If these dietary trends continue and fish consumption declines further, micronutrient status may be compromised. These findings suggest caution in establishing public health policies that promote limitation of fish intake during pregnancy. PMID:18986594

Management of Ciguatoxin Risk in Eastern Australia

PubMed Central

Farrell, Hazel; Murray, Shauna A.; Zammit, Anthony; Edwards, Alan W.

2017-01-01

Between 2014 and 2016, five cases of ciguatera fish poisoning (CFP), involving twenty four individuals, were linked to Spanish Mackerel (Scomberomorus commerson) caught in the coastal waters of the state of New South Wales (NSW) on the east coast of Australia. Previously, documented cases of CFP in NSW were few, and primarily linked to fish imported from other regions. Since 2015, thirteen individuals were affected across four additional CFP cases in NSW, linked to fish imported from tropical locations. The apparent increase in CFP in NSW from locally sourced catch, combined with the risk of CFP from imported fish, has highlighted several considerations that should be incorporated into risk management strategies to minimize CFP exposure for seafood consumers. PMID:29135913

Combined DNA-RNA Fluorescent In situ Hybridization (FISH) to Study X Chromosome Inactivation in Differentiated Female Mouse Embryonic Stem Cells

PubMed Central

Barakat, Tahsin Stefan; Gribnau, Joost

2014-01-01

Fluorescent in situ hybridization (FISH) is a molecular technique which enables the detection of nucleic acids in cells. DNA FISH is often used in cytogenetics and cancer diagnostics, and can detect aberrations of the genome, which often has important clinical implications. RNA FISH can be used to detect RNA molecules in cells and has provided important insights in regulation of gene expression. Combining DNA and RNA FISH within the same cell is technically challenging, as conditions suitable for DNA FISH might be too harsh for fragile, single stranded RNA molecules. We here present an easily applicable protocol which enables the combined, simultaneous detection of Xist RNA and DNA encoded by the X chromosomes. This combined DNA-RNA FISH protocol can likely be applied to other systems where both RNA and DNA need to be detected. PMID:24961515

Biological and communication skills needed for introduced fish biologists

USGS Publications Warehouse

Bonar, Scott A.

2016-01-01

What skills and knowledge will a new graduate seeking employment need to work with introduced fishes? Clearly, success in introduced species management—similar to other disciplines in fisheries—requires a mixture of scientific and communication skills. However, specific abilities especially important to a biologist who manages introduced fishes should be highlighted. Unlike most other management strategies, stocking an introduced species can result in unintended and irreversible impacts, so particular care must be employed when stocking is considered. Furthermore, fish populations in areas outside of the introduced species management area might also be affected, usually negatively, if the introduced fish escapes. Therefore, rock-solid knowledge of basic aquatic ecology, including risk management; fish taxonomy (so the wrong fish species is not mistakenly stocked!); familiarity with human values of both the time and the place (which requires communication skills); and a strong understanding of human history are all important.

Rapid changes in small fish mercury concentrations in estuarine wetlands: Implications for wildlife risk and monitoring programs

USGS Publications Warehouse

Eagles-Smith, Collin A.; Ackerman, Joshua T.

2009-01-01

Small fish are commonly used to assess mercury (Hg) risk to wildlife and monitor Hg in wetlands. However, limited research has evaluated short-term Hg variability in small fish, which can have important implications for monitoring programs and risk assessment. We conducted a time-series study of Hg concentrations in two small fish species representing benthic (longjaw mudsuckers [Gillichthys mirabilis]) and pelagic (threespine sticklebacks [Gasterosteus aculeatus]) food-webs within three wetland habitats in San Francisco Bay Estuary. We simultaneously monitored prey deliveries, nest initiation, and chick hatching dates of breeding Forster's terns (Sterna forsteri), the most abundant nesting piscivore in the region. Mudsuckers and sticklebacks were the predominant prey fish, comprising 36% and 25% of tern diet, and Hg concentrations averaged (geometric mean ?? SE, ??g/g dw) 0.44 ?? 0.01 and 0.68 ?? 0.03, respectively. Fish Hg concentrations varied substantially over time following a quadratic form in both species, increasing 40% between March and May then decreasing 40% between May and July. Importantly, Forster's terns initiated 68% of nests and 31% of chicks hatched during the period of peak Hg concentrations in prey fish. These results illustrate the importance of short-term temporal variation in small fish Hg concentrations for both Hg monitoring programs and assessing wildlife risk.

Evaluating microcystin exposure risk through fish consumption.

PubMed

Poste, Amanda E; Hecky, Robert E; Guildford, Stephanie J

2011-07-01

Microcystin is a cyanobacterial hepatotoxin that is found worldwide, and poses a serious threat to the ecological communities in which it is found as well as to those who rely on these waters for drinking, sanitation, or as a food source. Microcystin is known to accumulate in fish and other aquatic biota, however the prevalence of microcystin in fish tissue and the human health risks posed by microcystin exposure through fish consumption remain poorly resolved. Here we show that microcystin is pervasive in water and fish from several tropical (Ugandan) and temperate (North American) lakes, including lakes that support some of the largest freshwater fisheries in the world. We establish that fish consumption can be an important and sometimes dominant route of microcystin exposure for humans, and can cause consumers to exceed recommended total daily intake guidelines for microcystin. These results highlight the importance of monitoring microcystin concentrations in fish, and the need to consider potential exposure to microcystin through fish consumption in order to adequately assess human exposure risk.

Evaluating microcystin exposure risk through fish consumption

PubMed Central

Poste, Amanda E.; Hecky, Robert E.; Guildford, Stephanie J.

2011-01-01

Microcystin is a cyanobacterial hepatotoxin that is found worldwide, and poses a serious threat to the ecological communities in which it is found as well as to those who rely on these waters for drinking, sanitation, or as a food source. Microcystin is known to accumulate in fish and other aquatic biota, however the prevalence of microcystin in fish tissue and the human health risks posed by microcystin exposure through fish consumption remain poorly resolved. Here we show that microcystin is pervasive in water and fish from several tropical (Ugandan) and temperate (North American) lakes, including lakes that support some of the largest freshwater fisheries in the world. We establish that fish consumption can be an important and sometimes dominant route of microcystin exposure for humans, and can cause consumers to exceed recommended total daily intake guidelines for microcystin. These results highlight the importance of monitoring microcystin concentrations in fish, and the need to consider potential exposure to microcystin through fish consumption in order to adequately assess human exposure risk. PMID:21671629

Ethnoichthyology of the indigenous Truká people, Northeast Brazil.

PubMed

Santos, Carlos Alberto Batista; Alves, Rômulo Romeu Nóbrega

2016-01-06

Historically, fishing is an important activity for riverine communities established along the São Francisco River, including indigenous communities. In the present study, we researched fishing activities in two villages of the Truká ethnic group, both located in the State of Pernambuco along the sub-middle section of the São Francisco River, Northeast Brazil. We recorded the richness and uses of the fished species and the ecological knowledge on these species, the fishing techniques employed and the perception of the indigenous people regarding current environmental impacts on the São Francisco River that influence local fishing. The information was obtained through interviews with 33 Truká fishers (27 men and six women), including 17 interviewees from Central Village (Cabrobó) and 16 from Tapera Village (Orocó). Using five fishing techniques, the interviewees caught 25 fish species, including 21 native and four exotic species. All species are used as food, and two species are used in traditional Truká medicine. The interviewees revealed that fishing currently has less importance in their subsistence. They indicated that this situation is occurring because of several factors, such as the introduction of exotic species, pollution and urbanization, that have impacted the São Francisco River, resulting in a decline of fishing resources. Nevertheless, we found that the indigenous people who are still fishing have a broad knowledge of the habitat and ecology of the target fishing. Although fishing is declining in importance among the Truká, we found that the individuals who are still practicing this activity have a broad knowledge about the habitat and ecology of the target species and apply that knowledge to fishing methods. Knowledge about the ecology of the species and the environmental impacts that have affected them can support basic research on local fish populations and research investigating the environmental impacts, resource management and sustainable exploitation of fisheries resources.

Interculture: Some Concepts for Describing the Situation of Immigrants.

ERIC Educational Resources Information Center

Ekstrand, Lars Henric; And Others

1981-01-01

Attempts to find new ways of describing and analyzing dynamic interactions in country of origin, host country, and immigrant community caused by migration. Analyzes linguistic models, concept of culture, emigration psychology, and identity formation. (Author/BK)

22 CFR 99.3 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-04-01

... 22 Foreign Relations 1 2010-04-01 2010-04-01 false [Reserved] 99.3 Section 99.3 Foreign Relations DEPARTMENT OF STATE LEGAL AND RELATED SERVICES REPORTING ON CONVENTION AND NON-CONVENTION ADOPTIONS OF EMIGRATING CHILDREN § 99.3 [Reserved] ...

Emigration from Within.

PubMed

Szekacs-Weisz, Judit

2016-12-01

Listening to the stories of people belonging to different generations in motion-both in our consulting rooms and our personal lives-served as introductory lectures into the fundamental aspects of changing context. Through these rich and diverse stories, one enters a territory which is not only multilingual but multidimensional: defined and shaped by historical, political, economic and socio-cultural transformations. Giving voice to these silent stories proved helpful for us when going behind walls that traditional analysis could not always penetrate, partly because, in many cases, analysts and analysands have been struggling with the same untouchable issues. It is our professional task to find creative ways to make sense of past and recent experiences of emigration, new prejudices, discriminative forms and attitudes-in order to achieve a better psychoanalytical understanding of the external and internal confusion that has been brought about by the immense changes during the past centuries and the present one.

Global trade in ornamental fish from an Australian perspective: the case for revised import risk analysis and management strategies.

PubMed

Whittington, R J; Chong, R

2007-09-14

Over 1 billion ornamental fish comprising more than 4000 freshwater and 1400 marine species are traded internationally each year, with 8-10 million imported into Australia alone. Compared to other commodities, the pathogens and disease translocation risks associated with this pattern of trade have been poorly documented. The aim of this study was to conduct an appraisal of the effectiveness of risk analysis and quarantine controls as they are applied according to the Sanitary and Phytosanitary (SPS) agreement in Australia. Ornamental fish originate from about 100 countries and hazards are mostly unknown; since 2000 there have been 16-fold fewer scientific publications on ornamental fish disease compared to farmed fish disease, and 470 fewer compared to disease in terrestrial species (cattle). The import quarantine policies of a range of countries were reviewed and classified as stringent or non-stringent based on the levels of pre-border and border controls. Australia has a stringent policy which includes pre-border health certification and a mandatory quarantine period at border of 1-3 weeks in registered quarantine premises supervised by government quarantine staff. Despite these measures there have been many disease incursions as well as establishment of significant exotic viral, bacterial, fungal, protozoal and metazoan pathogens from ornamental fish in farmed native Australian fish and free-living introduced species. Recent examples include Megalocytivirus and Aeromonas salmonicida atypical strain. In 2006, there were 22 species of alien ornamental fish with established breeding populations in waterways in Australia and freshwater plants and molluscs have also been introduced, proving a direct transmission pathway for establishment of pathogens in native fish species. Australia's stringent quarantine policies for imported ornamental fish are based on import risk analysis under the SPS agreement but have not provided an acceptable level of protection (ALOP) consistent with government objectives to prevent introduction of pests and diseases, promote development of future aquaculture industries or maintain biodiversity. It is concluded that the risk analysis process described by the Office International des Epizooties under the SPS agreement cannot be used in a meaningful way for current patterns of ornamental fish trade. Transboundary disease incursions will continue and exotic pathogens will become established in new regions as a result of the ornamental fish trade, and this will be an international phenomenon. Ornamental fish represent a special case in live animal trade where OIE guidelines for risk analysis need to be revised. Alternatively, for countries such as Australia with implied very high ALOP, the number of species traded and the number of sources permitted need to be dramatically reduced to facilitate hazard identification, risk assessment and import quarantine controls.

Genetic and genomic analyses for economically important traits and their applications in molecular breeding of cultured fish.

PubMed

Tong, JinGou; Sun, XiaoWen

2015-02-01

The traits of cultured fish must continually be genetically improved to supply high-quality animal protein for human consumption. Economically important fish traits are controlled by multiple gene quantitative trait loci (QTL), most of which have minor effects, but a few genes may have major effects useful for molecular breeding. In this review, we chose relevant studies on some of the most intensively cultured fish and concisely summarize progress on identifying and verifying QTLs for such traits as growth, disease and stress resistance and sex in recent decades. The potential applications of these major-effect genes and their associated markers in marker-assisted selection and molecular breeding, as well as future research directions are also discussed. These genetic and genomic analyses will be valuable for elucidating the mechanisms modulating economically important traits and to establish more effective molecular breeding techniques in fish.

A Capital case for common names of species of fishes--a white crappie or a White Crappie

Treesearch

Joseph S. Nelson; Wayne C. Stames; Melvin L. Warren

2002-01-01

Common names of fishes are an important and often primary means of fish biologists communicating with each other and with the public. Although common names will never replace scientific names, they are indispensable in many areas such as fisheries science, management, administration, and education. In recognition of the important role common names play in communicating...

Science advancements key to increasing management value of life stage monitoring networks for endangered Sacramento River winter-run Chinook salmon in California

USGS Publications Warehouse

Johnson, Rachel C.; Windell, Sean; Brandes, Patricia L.; Conrad, J. Louise; Ferguson, John; Goertler, Pascale A. L.; Harvey, Brett N.; Heublein, Joseph; Isreal, Joshua A.; Kratville, Daniel W.; Kirsch, Joseph E.; Perry, Russell W.; Pisciotto, Joseph; Poytress, William R.; Reece, Kevin; Swart, Brycen G.

2017-01-01

A robust monitoring network that provides quantitative information about the status of imperiled species at key life stages and geographic locations over time is fundamental for sustainable management of fisheries resources. For anadromous species, management actions in one geographic domain can substantially affect abundance of subsequent life stages that span broad geographic regions. Quantitative metrics (e.g., abundance, movement, survival, life history diversity, and condition) at multiple life stages are needed to inform how management actions (e.g., hatcheries, harvest, hydrology, and habitat restoration) influence salmon population dynamics. The existing monitoring network for endangered Sacramento River winterrun Chinook Salmon (SRWRC, Oncorhynchus tshawytscha) in California’s Central Valley was compared to conceptual models developed for each life stage and geographic region of the life cycle to identify relevant SRWRC metrics. We concluded that the current monitoring network was insufficient to diagnose when (life stage) and where (geographic domain) chronic or episodic reductions in SRWRC cohorts occur, precluding within- and among-year comparisons. The strongest quantitative data exist in the Upper Sacramento River, where abundance estimates are generated for adult spawners and emigrating juveniles. However, once SRWRC leave the upper river, our knowledge of their identity, abundance, and condition diminishes, despite the juvenile monitoring enterprise. We identified six system-wide recommended actions to strengthen the value of data generated from the existing monitoring network to assess resource management actions: (1) incorporate genetic run identification; (2) develop juvenile abundance estimates; (3) collect data for life history diversity metrics at multiple life stages; (4) expand and enhance real-time fish survival and movement monitoring; (5) collect fish condition data; and (6) provide timely public access to monitoring data in open data formats. To illustrate how updated technologies can enhance the existing monitoring to provide quantitative data on SRWRC, we provide examples of how each recommendation can address specific management issues.

SEASONAL INFLUENCES ON PCB RETENTION AND BIOTRANSFORMATION IN FISH

PubMed Central

James, Margaret O.; Kleinow, Kevin M.

2013-01-01

There is extensive evidence that fish from waters with PCB-contaminated sediments accumulate PCBs and related chemicals, and that people who eat fish from contaminated waters have higher body burdens of PCBs and PCB metabolites than those who do not. PCBs and their metabolites are potentially toxic, thus it is important to human health to understand the uptake, biotransformation and elimination of PCBs in fish, since these processes determine the extent of accumulation. The intestinal uptake of PCBs present in the diet of fish into fish tissues is a process that is influenced by the lipid composition of the diet. Biotransformation of PCBs in fish, as in mammals, facilitates elimination, although many PCB congeners are recalcitrant to biotransformation in fish and mammals. Sequential biotransformation of PCBs by cytochrome P450 and conjugation pathways is even less efficient in fish than in mammalian species, thus contributing to the retention of PCBs in fish tissues. A very important factor influencing overall PCB disposition in fish is water temperature. Seasonal changes in water temperature produce adaptive physiological and biochemical changes in fish. While uptake of PCBs from the diet is similar in fish acclimated to winter or summer temperatures, there is evidence that elimination of PCBs occurs much more slowly when the fish is acclimated at low temperatures than at warmer temperatures. Research to date suggests that the processes of elimination of PCBs are modulated by several factors in fish including seasonal changes in water temperature. Thus, the body burden of PCBs in fish from a contaminated location is likely to vary with season. PMID:23494683

How stock of origin affects performance of individuals across a meta-ecosystem: an example from sockeye salmon.

PubMed

Griffiths, Jennifer R; Schindler, Daniel E; Seeb, Lisa W

2013-01-01

Connectivity among diverse habitats can buffer populations from adverse environmental conditions, influence the functioning of meta-ecosystems, and ultimately affect the reliability of ecosystem services. This stabilizing effect on populations is proposed to derive from complementarity in growth and survival conditions experienced by individuals in the different habitats that comprise meta-ecosystems. Here we use the fine scale differentiation of salmon populations between diverse lake habitats to assess how rearing habitat and stock of origin affect the body condition of juvenile sockeye salmon. We use genetic markers (single nucleotide polymorphisms) to assign individuals of unknown origin to stock group and in turn characterize ecologically relevant attributes across habitats and stocks. Our analyses show that the body condition of juvenile salmon is related to the productivity of alternative habitats across the watershed, irrespective of their stock of origin. Emigrants and residents with genetic origins in the high productivity lake were also differentiated by their body condition, poor and high respectively. These emigrants represented a substantial proportion of juvenile sockeye salmon rearing in the lower productivity lake habitat. Despite emigrants originating from the more productive lake, they did not differ in body condition from the individuals spawned in the lower productivity, recipient habitat. Genetic tools allowed us to assess the performance of different stocks groups across the diverse habitats comprising their meta-ecosystem. The ability to characterize the ecological consequences of meta-ecosystem connectivity can help develop strategies to protect and restore ecosystems and the services they provide to humans.

[Clinical, biochemical and allergological indices characterizing occupational diseases of the bronchial and pulmonary system in employees at aluminium production].

PubMed

Kudaeva, I V; Dyakovich, O A; Beygel, E A; Masnavieva, L B; Naumova, O V; Budarina, L A

There are many harmful factors that possess a damaging impact on the body of employees at aluminum production. It leads to the development of bronchial asthma (BA), chronic nonobstructive bronchitis (CNB) and chronic obstructive pulmonary disease (COPD). The pathogenesis of these disorders, as well as sensitizing effect offluorine in the aluminum production is not fully understood. The purpose of this work was to study the characteristics of laboratory indices in patients with occupational diseases of the respiratory system. In workers of aluminum production with the diagnosis of occupational diseases of respiratory system (15 patients with a diagnosis of asthma, 30 CNB cases, 20 COPD patients) we evaluated the content of total protein, total cholesterol, high density lipoprotein cholesterol (HDLC), total calcium, phosphorus, ceruloplasmin, hematological indices and performed emigration of leukocytes braking test (TTEEL). Clinical and biochemical profile ofpersons with occupational asthma was characterized by a low level of total calcium and ceruloplasmin, a high concentration of phosphorus in the blood serum and inhibition of leukocyte emigration in the test with sodium fluoride. For aluminum production CNB workers characteristic active proatherogenic process was pronounced by a decrease in the HDLC level and an increase in atherogenic index; higher hematocrit value and concentration of erythrocytes, and more than 50% of cases of sensitization to the presence of sodium fluoride. COPD cases had occupational lower average concentration of hemoglobin in the erythrocyte, total protein in serum, as well as polymorphic variant response to sodium fluoride in the form of a depression and activation of leucocytes emigration.

Winter severity and phenology of spring emergence from the nest in freshwater turtles.

PubMed

Baker, Patrick Joseph; Iverson, John B; Lee, Richard E; Costanzo, Jon P

2010-07-01

Although many species of freshwater turtles emigrate to water soon after hatching, the offspring of some species overwinter on land and move to aquatic habitats in the following spring. Timing of emigration can affect the hatchlings' fitness, but the factors underlying phenology of nest emergence are incompletely understood. We tested the supposition that cold stress imposed during hibernation can influence the timing of nest emergence in three species of turtles in the central USA. In each year of the 6-year study, Chrysemys picta emerged in late March and early April and, on average, these hatchlings left their nests 2 weeks earlier than those of Graptemys geographica and 4 weeks earlier than those of Trachemys scripta. Emergence of conspecific hatchlings from different nests usually occurred over 3-7 weeks, but in some years lasted several additional weeks. Relatively few nests had siblings that emerged on the same day (i.e., synchronously); complete emergence of the typical sibling group required 1 to 2 weeks. In winter, subzero cold occurred with regularity in the nests of all species, though C. picta experienced the lowest temperatures owing to their shallower nests. However, for no species did emergence date or length of the emergence period correlate with winter minimum temperature and, at the level of the individual nest, neither did emergence synchrony or duration. Despite encountering lower temperatures, hatchlings of C. picta emigrated from their nests before those of sympatric species, suggesting that the fitness benefits of early emergence may lead to the improvement of cold-hardiness adaptations in northern populations of turtles.

How Stock of Origin Affects Performance of Individuals across a Meta-Ecosystem: An Example from Sockeye Salmon

PubMed Central

Griffiths, Jennifer R.; Schindler, Daniel E.; Seeb, Lisa W.

2013-01-01

Connectivity among diverse habitats can buffer populations from adverse environmental conditions, influence the functioning of meta-ecosystems, and ultimately affect the reliability of ecosystem services. This stabilizing effect on populations is proposed to derive from complementarity in growth and survival conditions experienced by individuals in the different habitats that comprise meta-ecosystems. Here we use the fine scale differentiation of salmon populations between diverse lake habitats to assess how rearing habitat and stock of origin affect the body condition of juvenile sockeye salmon. We use genetic markers (single nucleotide polymorphisms) to assign individuals of unknown origin to stock group and in turn characterize ecologically relevant attributes across habitats and stocks. Our analyses show that the body condition of juvenile salmon is related to the productivity of alternative habitats across the watershed, irrespective of their stock of origin. Emigrants and residents with genetic origins in the high productivity lake were also differentiated by their body condition, poor and high respectively. These emigrants represented a substantial proportion of juvenile sockeye salmon rearing in the lower productivity lake habitat. Despite emigrants originating from the more productive lake, they did not differ in body condition from the individuals spawned in the lower productivity, recipient habitat. Genetic tools allowed us to assess the performance of different stocks groups across the diverse habitats comprising their meta-ecosystem. The ability to characterize the ecological consequences of meta-ecosystem connectivity can help develop strategies to protect and restore ecosystems and the services they provide to humans. PMID:23505539

Winter severity and phenology of spring emergence from the nest in freshwater turtles

NASA Astrophysics Data System (ADS)

Baker, Patrick Joseph; Iverson, John B.; Lee, Richard E.; Costanzo, Jon P.

2010-07-01

Although many species of freshwater turtles emigrate to water soon after hatching, the offspring of some species overwinter on land and move to aquatic habitats in the following spring. Timing of emigration can affect the hatchlings’ fitness, but the factors underlying phenology of nest emergence are incompletely understood. We tested the supposition that cold stress imposed during hibernation can influence the timing of nest emergence in three species of turtles in the central USA. In each year of the 6-year study, Chrysemys picta emerged in late March and early April and, on average, these hatchlings left their nests 2 weeks earlier than those of Graptemys geographica and 4 weeks earlier than those of Trachemys scripta. Emergence of conspecific hatchlings from different nests usually occurred over 3-7 weeks, but in some years lasted several additional weeks. Relatively few nests had siblings that emerged on the same day (i.e., synchronously); complete emergence of the typical sibling group required 1 to 2 weeks. In winter, subzero cold occurred with regularity in the nests of all species, though C. picta experienced the lowest temperatures owing to their shallower nests. However, for no species did emergence date or length of the emergence period correlate with winter minimum temperature and, at the level of the individual nest, neither did emergence synchrony or duration. Despite encountering lower temperatures, hatchlings of C. picta emigrated from their nests before those of sympatric species, suggesting that the fitness benefits of early emergence may lead to the improvement of cold-hardiness adaptations in northern populations of turtles.

Sex and drug risk behavior pre- and post-emigration among Latino migrant men in post-Hurricane Katrina New Orleans

PubMed Central

Mills, Jennifer; Burton, Nicole; Schmidt, Norine; Salinas, Oscar; Hembling, John; Aran, Alberto; Shedlin, Michele; Kissinger, Patricia

2012-01-01

High rates of sex and drug risk behaviors have been documented among Latino migrant men in the U.S. Whether these behaviors were established in the migrants’ home countries or were adopted in the U.S. has not been described and has implications for prevention strategies. Quarterly surveys were conducted to gather information on selected sex and drug risk practices of Latino migrant men who arrived in New Orleans after Hurricane Katrina seeking work. Both kappa scores and McNemar’s tests were performed to determine if practice of these behaviors in home country was similar to practice post-emigration to the U.S. Female sex worker (FSW) patronage, same sex encounters (MSM), and crack cocaine use was more likely to occur post-rather than pre-emigration. Of those who ever engaged in these selected behaviors, most adopted the behavior in the U.S. (i.e. 75.8% of FSW patrons, 72.7% of MSM participants, and 85.7% of crack cocaine users), with the exception of binge drinking (26.8%). Men who were living with a family member were less likely to adopt FSW patronage OR=0.27, CI=0.10-0.76, whereas men who earned >$465 per week were more likely to adopt crack cocaine use OR=6.29 CI=1.29, 30.57. Interventions that facilitate the maintenance of family cohesion and provide strategies for financial management may be useful for reducing sex and drug risk among newly arrived migrants. PMID:22669638

RNA-Seq identifies SNPs associated with muscle yield and quality in rainbow trout

USDA-ARS?s Scientific Manuscript database

Rainbow trout (Oncorhynchus mykiss) is one of the top five sport fish species in North America and the second most widely cultivated fish species for food. Quality attributes of fish flesh are important determinants of profitability for the food fish aquaculture industry. Single nucleotide polymorph...

Dietary Nutrients, Additives, and Fish Health

USDA-ARS?s Scientific Manuscript database

Aquaculture will play a major role in global food security by 2050. Production of fish will need to double by 2050 to meet global demand for this important source of protein. Proper fish nutrition is essential for the overall health and well-being of fish. Sustainable and profitable production is...

Comparative Analysis of Lipid Content and Fatty Acid Composition of Commercially Important Fish and Shellfish from Sri Lanka and Japan.

PubMed

Devadason, Chandravathany; Jayasinghe, Chamila; Sivakanesan, Ramiah; Senarath, Samanthika; Beppu, Fumiaki; Gotoh, Naohiro

2016-01-01

Sri Lanka is surrounded by the Indian Ocean, allowing plenty of fishes to be caught. Moreover, these fishes represent one of the undocumented fish resources in the world and their detailed lipid profiles have not been previously examined. In this study, the lipid content and fatty acid composition of 50 commercially important fishes from the Indian Ocean (Sri Lanka) and the Pacific Ocean (Japan) were compared. The total lipid content and fatty acid composition, including eicosapentaenoic acid (C20:5n-3, EPA) and docosahexaenoic acid (C22:6n-3, DHA), differed significantly among species. Fish from the Pacific Ocean had higher proportions of fatty acids, including EPA and DHA. Herrings and mackerels from both oceanic areas demonstrated high levels of EPA and DHA, and n-3/n-6 ratio. Brackish and freshwater fishes from both groups showed low levels of PUFAs. Fish from the Indian Ocean were high in n-6 fatty acids. Monounsaturated fatty acid levels were high in omnivorous fish from the Pacific Ocean, and saturated fatty acid levels were high in fish from the Indian Ocean. The results of this study will be of value in determining the dietary usefulness of fish caught in Sri Lanka.

Multi-Ecosystem Assessment of Mercury Bioaccumulation in Fishes: Habitat, Landscape, and Biogeochemical Drivers of Fish Mercury

NASA Astrophysics Data System (ADS)

Eagles-Smith, C.; Ackerman, J.; Herring, G.; Willacker, J.; Flanagan, C.

2014-12-01

Mercury (Hg) is a globally distributed contaminant that threatens ecosystem health across aquatic environments. The complexity of the Hg cycle and its primary drivers, coupled with dynamic food web processes that govern biomagnification, result in marked spatial variability in Hg bioaccumulation across aquatic ecosystems. However, it is unclear if patterns of bioaccumulation are consistent in magnitude and direction across ecosystem types. We synthesized data from several studies spanning more than 200 individual sites, comprising four distinct ecosystem classifications (estuaries, sub-alpine lakes, rivers, and managed wetlands). Within each ecosystem, we compared fish Hg concentrations among replicated sub-habitats and also evaluated the influence of land use, landscape composition, and biogeochemical drivers on fish Hg concentrations. We found substantial variability in fish Hg concentrations among adjacent sub-habitats within ecosystems. In estuarine environments, fish Hg concentrations were 7.4x higher in seasonal-saline wetlands than adjacent tidal wetland habitats. In riverine alcoves, preliminary data suggest that fish Hg concentrations were 1.5x higher than in fishes from paired mainstem river habitat. Among managed wetland habitats, fish Hg concentrations in rice fields were 2x higher than those in managed seasonal wetlands that were subjected to identical wetting and drying patterns. Across ecosystems, dissolved organic carbon (DOC) concentrations in surface waters were consistently correlated with fish Hg concentrations, highlighting its importance in Hg methylation and transport processes. Yet, the strength and direction of the relationships varied among habitat types. For example, fish Hg concentrations were positively correlated with DOC concentrations in riverine environments, whereas we found a negative correlation in alpine lakes. Instead, the most important determinant of fish Hg concentrations in alpine lakes was conifer tree density within a lake's catchment, resulting in a 4x increase in fish Hg concentration in lakes with the lowest to the highest catchment conifer tree density. Together, this integrated ecosystem analysis highlights the importance of understanding small-scale variation in bioaccumulation processes in order to better predict Hg risk.

Using Marine and Freshwater Fish Environmental Intelligence Networks Under Different Climate Change Scenarios to Evaluate the Effectiveness of the Minamata Convention on Mercury

NASA Astrophysics Data System (ADS)

Bank, M. S.

2017-12-01

The Minamata Convention on Mercury was recently ratified and will go into effect on August 16, 2017. As noted in the convention text, fish are an important source of nutrition to consumers worldwide and several marine and freshwater species represent important links in the global source-receptor dynamics of methylmercury. However, despite its importance, a coordinated global program for marine and freshwater fish species using accredited laboratories, reproducible data and reliable models is still lacking. In recent years fish mercury science has evolved significantly with its use of advanced technologies and computational models to address this complex and ubiquitous environmental and public health issue. These advances in the field have made it essential that transparency be enhanced to ensure that fish mercury studies used in support of the convention are truly reproducible and scientifically sound. One primary goal of this presentation is to evaluate fish bioinformatics and methods, results and inferential reproducibility as it relates to aggregated uncertainty in mercury fish research models, science, and biomonitoring. I use models, environmental intelligence networks and simulations of the effects of a changing climate on methylmercury in marine and freshwater fish to examine how climate change and the convention itself may create further uncertainties for policymakers to consider. Lastly, I will also present an environmental intelligence framework for fish mercury bioaccumulation models and biomonitoring in support of the evaluation of the effectiveness of the Minamata Convention on Mercury.

Relation of physical and chemical characteristics of streams to fish communities in the Red River of the North basin, Minnesota and North Dakota, 1993-95

USGS Publications Warehouse

Goldstein, R.M.; Stauffer, J.C.; Larson, P.R.; Lorenz, D.L.

1996-01-01

Within the instream habitat data set, measures of habitat volume (channel width and depth) and habitat diversity were most significant in explaining the variability of the fish communities. The amount of nonagricultural land and riparian zone integrity from the terrestrial habitat data set were also useful in explaining fish community composition. Variability of mean monthly discharge and the frequency of high and low discharge events during the three years prior to fish sampling were the most influential of the hydrologic variables.The first two axes of the canonical correspondence analysis accounted for 43.3 percent of the variation in the fish community and 52.5 percent of the variation in the environmental-species relation. Water-quality indicators such as the percent of fine material in suspended sediment, minimum dissolved oxygen concentrations, minimum concentrations of dissolved organic carbon, and the range of concentrations of major ions and nutrients were the variables that were most important in the canonical correspondence analysis of water-quality data with fish. No single environmental variable or data set appeared to be more important than another in explaining variation in the fish community. The environmental factors affecting the fish communities of the Red River of the North are interrelated. For the most part, instream environmental conditions (instream habitat, hydrology, and water chemistry) appear to be more important in explaining variability in fish community composition than factors related to the agricultural nature of the basin.

Undocumented Aliens: A Study of Mexican Families.

ERIC Educational Resources Information Center

Salcido, Ramon M.

1979-01-01

The personal histories described here confirm that the primary impetus of undocumented aliens to emigrate is the desire for jobs and better socioeconomic opportunities. Amnesty, aid to families with dependent children, and increased social services are recommended. (Author/BEF)

An energy-circuit population model for great egrets (Ardea alba) at Lake Okeechobee, Florida, U.S.A

USGS Publications Warehouse

Smith, Jeff P.

1997-01-01

I simulated the annual population cycles of Great Egrets (Ardea alba) at Lake Okeechobee, Florida, to provide a framework for evaluating the local population dynamics of nesting and foraging wading birds. The external forcing functions were solar energy, minimum air temperature, water depth, surface-water drying rate, and season. Solar input controlled the production of prey at moderate to high lake stages, but water area exerted primary control during a two-year drought. Modeling prey production as a linear function of water area resulted in underestimation of prey density during the drought, suggesting that prey organisms maintained high fecundity while concentrated in submerged vegetation at the lakeward fringe of the littoral zone. Simulation confirmed that large influxes of wading birds during the drought were the combined result of a regional refuge response and the availability of concentrated prey. Modeling immigration and emigration as primarily functions of the surface-water drying rate, rather than lake stage, resulted in a closer match of observed and simulated population trends for foraging birds, suggesting that the pattern of surface-water fluctuations was a more important factor than water depth. Simulation indicated an abrupt-threshold response rather than a linear association between foraging efficiency and low temperatures, which reduce activity levels of forage fishes. Great Egret breeder recruitment is primarily a function of prey availability, climate, and hydrologic trends, but simulation confirmed the concurrent involvement of a seasonal or physiological-readiness factor. An attractor function driven by high winter lake stages was necessary to reproduce observed patterns of breeder recruitment, suggesting that Great Egrets initiate nesting based on environmental cues that lead to peak food availability when nestlings are present. Poor correspondence of reproductive effort and nest productivity suggested that the drought compromised the birds' predictive abilities. The need to model breeder recruitment as a function of a maximum rate rather than the size of the local foraging population suggested that birds may nest on the lake even though on-lake foraging conditions are poor. Simulated and observed estimates of egg and hatching production did not match, suggesting that the causes of failure during incubation were complex or more localized than could be accounted for with lakewide hydrologic and climatic data. A forced increase in prey consumption of 12% was necessary to reproduce observed, high levels of nest productivity in 1990, which corresponded to the finding that panhandled fish constituted 10–12% of the biomass fed to Great Egret nestlings that year.

Effects of nutritional status on metabolic rate, exercise and recovery in a freshwater fish.

PubMed

Gingerich, Andrew James; Philipp, David P; Suski, Cory D

2010-03-01

The influence of feeding on swimming performance and exercise recovery in fish is poorly understood. Examining swimming behavior and physiological status following periods of feeding and fasting is important because wild fish often face periods of starvation. In the current study, researchers force fed and fasted groups of largemouth bass (Micropterus salmoides) of similar sizes for a period of 16 days. Following this feeding and fasting period, fish were exercised for 60 s and monitored for swimming performance and physiological recovery. Resting metabolic rates were also determined. Fasted fish lost an average of 16 g (nearly 12%) of body mass, while force fed fish maintained body mass. Force fed fish swam 28% further and required nearly 14 s longer to tire during exercise. However, only some physiological conditions differed between feeding groups. Resting muscle glycogen concentrations was twofold greater in force fed fish, at rest and throughout recovery, although it decreased in both feeding treatments following exercise. Liver mass was nearly three times greater in force fed fish, and fasted fish had an average of 65% more cortisol throughout recovery. Similar recovery rates of most physiological responses were observed despite force fed fish having a metabolic rate 75% greater than fasted fish. Results are discussed as they relate to largemouth bass starvation in wild systems and how these physiological differences might be important in an evolutionary context.

Estimating the impact of oyster restoration scenarios on transient fish production

USGS Publications Warehouse

McCoy, Elizabeth; Borrett, Stuart R.; LaPeyre, Megan K.; Peterson, Bradley J.

2017-01-01

Oyster reef restoration projects are increasing in number both to enhance oyster density and to retain valuable ecosystem services provided by oyster reefs. Although some oyster restoration projects have demonstrated success by increasing density and biomass of transient fish, it still remains a challenge to quantify the effects of oyster restoration on transient fish communities. We developed a bioenergetics model to assess the impact of selected oyster reef restoration scenarios on associated transient fish species. We used the model to analyze the impact of changes in (1) oyster population carrying capacity; (2) oyster population growth rate; and (3) diet preference of transient fish on oyster reef development and associated transient fish species. Our model results indicate that resident fish biomass is directly affected by oyster restoration and oyster biomass, and oyster restoration can have cascading impacts on transient fish biomass. Furthermore, the results highlight the importance of a favorable oyster population growth rate during early restoration years, as it can lead to rapid increases in mean oyster biomass and biomass of transient fish species. The model also revealed that a transient fish's diet solely dependent on oyster reef-derived prey could limit the biomass of transient fish species, emphasizing the importance of habitat connectivity in estuarine areas to enhance transient fish species biomass. Simple bioenergetics models can be developed to understand the dynamics of a system and make qualitative predictions of management and restoration scenarios.

Laboratory Class Project: Using a Cichlid Fish Display Tank to Teach Students about Complex Behavioral Systems.

PubMed

Nolan, Brian C

2010-01-01

Laboratory activities serve several important functions in undergraduate science education. For neuroscience majors, an important and sometimes underemphasized tool is the use of behavioral observations to help inform us about the consequences of changes that are occurring on a neuronal level. To help address this concern, the following laboratory exercise is presented. The current project tested the prediction that the most dominant fish in a tank of cichlids will have gained the most benefits of its position resulting in the greatest growth and hence, become the largest fish. More specifically: (1) is there evidence that a social hierarchy exists among the fish in our tank based on the number of aggressive acts among the four largest fish; (2) if so, does the apparent rank correspond to the size of the fish as predicted by previous studies? Focal sampling and behavior sampling of aggressive acts between fish were utilized in the data collection. Collectively, the data suggest a social dominance hierarchy may be in place with the following rank order from highest to lowest: Fish A > Fish B > Fish D > Fish C. While the largest (Fish A) seems to be at the top, Fish C ended up being ranked lower than Fish D despite the fact that Fish C is larger. Overall, the project was considered a success by the instructor and students. The students offered several suggestions that could improve future versions of this type of project, in particular concerning the process of constructing a poster about the project. The implications of the data and student learning outcomes are discussed.

Habitat heterogeneity: importance of salt marsh pools and high marsh surfaces to fish production in two Gulf of Maine salt marshes

Treesearch

R.A. MacKenzie; M. Dionne

2008-01-01

Both permanent high marsh pools and the intertidal surfaces of Spartina patens high marshes in southern Maine, USA, proved to be important habitat for resident mummichog Fundulus heteroclitus production. Manipulations of fish movement onto high marsh Surfaces revealed similar growth rates and production among fish that were (1) restricted to pools, (2) had access to...

St. Louis River fish migrations: Gains and losses of ecosystem ...

EPA Pesticide Factsheets

The Twin Ports fishery has undergone change from a migratory fish-based fishery to a Lake Superior-based fishery, and is now returning to a diverse fishery that includes fish of both life histories. These changes reflect past disturbances to the Great Lakes ecosystem as well as recent water quality improvement and efforts to restore habitat in the St. Louis River. Migratory fishes are an important ecosystem service for the St. Louis River, and improvements to the ecosystem quality within the St. Louis River Area of Concern has benefited migratory fishes. The coastal wetlands within the lower river provide direct support to a variety of high-value, recreationally-important fish species, including walleye, northern pike, and bass. Moreover, these wetlands serve as nursery habitat for a broader suite of high-value, commercially-important species. Restoration has likely improved the value of these coastal wetlands because low-value rough species tend to be more prevalent in degraded coastal wetlands, whereas high-value commercial and game fishes are more prevalent in high-quality coastal wetlands. There have been losses in ecosystem services, as well. Owing to legacy contamination of mercury and PCBs, migratory fishes in the St. Louis River have sufficiently high contaminant burdens to warrant consumption advisories, and recent movement research demonstrates that there is a positive relationship between increased use of St. Louis River habitat (versus Lake Superior)

Crop nutrient recovery from applied fish coproducts

USDA-ARS?s Scientific Manuscript database

The Alaska fishing industry produces over 1,000,000 metric tons of fish byproducts annually, and most of them are not used. Most food in Alaska is imported. Fish byproducts are rich in plant essential nutrients and can be used as nutrient sources for crop production. The objective of the study was t...

Fishery-independent data reveal negative effect of human population density on Caribbean predatory fish communities.

PubMed

Stallings, Christopher D

2009-01-01

Understanding the current status of predatory fish communities, and the effects fishing has on them, is vitally important information for management. However, data are often insufficient at region-wide scales to assess the effects of extraction in coral reef ecosystems of developing nations. Here, I overcome this difficulty by using a publicly accessible, fisheries-independent database to provide a broad scale, comprehensive analysis of human impacts on predatory reef fish communities across the greater Caribbean region. Specifically, this study analyzed presence and diversity of predatory reef fishes over a gradient of human population density. Across the region, as human population density increases, presence of large-bodied fishes declines, and fish communities become dominated by a few smaller-bodied species. Complete disappearance of several large-bodied fishes indicates ecological and local extinctions have occurred in some densely populated areas. These findings fill a fundamentally important gap in our knowledge of the ecosystem effects of artisanal fisheries in developing nations, and provide support for multiple approaches to data collection where they are commonly unavailable.

Fishery-Independent Data Reveal Negative Effect of Human Population Density on Caribbean Predatory Fish Communities

PubMed Central

Stallings, Christopher D.

2009-01-01

Background Understanding the current status of predatory fish communities, and the effects fishing has on them, is vitally important information for management. However, data are often insufficient at region-wide scales to assess the effects of extraction in coral reef ecosystems of developing nations. Methodology/Principal Findings Here, I overcome this difficulty by using a publicly accessible, fisheries-independent database to provide a broad scale, comprehensive analysis of human impacts on predatory reef fish communities across the greater Caribbean region. Specifically, this study analyzed presence and diversity of predatory reef fishes over a gradient of human population density. Across the region, as human population density increases, presence of large-bodied fishes declines, and fish communities become dominated by a few smaller-bodied species. Conclusions/Significance Complete disappearance of several large-bodied fishes indicates ecological and local extinctions have occurred in some densely populated areas. These findings fill a fundamentally important gap in our knowledge of the ecosystem effects of artisanal fisheries in developing nations, and provide support for multiple approaches to data collection where they are commonly unavailable. PMID:19421312

Biotechnology applied to fish reproduction: tools for conservation.

PubMed

de Siqueira-Silva, Diógenes Henrique; Saito, Taiju; Dos Santos-Silva, Amanda Pereira; da Silva Costa, Raphael; Psenicka, Martin; Yasui, George Shigueki

2018-04-29

This review discusses the new biotechnological tools that are arising and promising for conservation and enhancement of fish production, mainly regarding the endangered and the most economically important species. Two main techniques, in particular, are available to avoid extinction of endangered fish species and to improve the production of commercial species. Germ cell transplantation technology includes a number of approaches that have been studied, such as the transplantation of embryo-to-embryo blastomere, embryo-to-embryo differentiated PGC, larvae to larvae and embryo differentiated PGC, transplantation of spermatogonia from adult to larvae or between adults, and oogonia transplantation. However, the success of germ cell transplantation relies on the prior sterilization of fish, which can be performed at different stages of fish species development by means of several protocols that have been tested in order to achieve the best approach to produce a sterile fish. Among them, fish hybridization and triploidization, germline gene knockdown, hyperthermia, and chemical treatment deserve attention based on important results achieved thus far. This review currently used technologies and knowledge about surrogate technology and fish sterilization, discussing the stronger and the weaker points of each approach.

Gross functional anatomy: Integumentary system: Chapter 5

USGS Publications Warehouse

Elliott, Diane G.; Ostrander, Gary K.

2000-01-01

The integument or skin of a fish is the envelope for the body that separates and protects the animal from its environment, but it also provides the means through which most of the contacts with the outer world are made. The integument is continuous with the lining of all the body openings, and also covers the fins. The skin of a fish is a multifunctional organ, and may serve important roles in protection, communication, sensory perception, locomotion, respiration, ion regulation, excretion, and thermal regulation. The most obvious functions of fish integument are protective. For example, mucous secretions help to keep the skin surface free of pathogens by means of constant sloughing and renewal and the presence of antimicrobial substances. Integumentary features can assist a fish during locomotion. The slippery mucus of some fishes has marked friction-reducing properties that enable a fish to move at greater speed with less expenditure of energy. The integument is an important adjunct to the breathing equipment of some fish species. Gas exchange across the skin is known to play a significant role in the respiration of larval fish.

Understanding barotrauma in fish passing hydro structures: a global strategy for sustainable development of water resources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, Richard S.; Colotelo, Alison HA; Pflugrath, Brett D.

2014-03-24

Freshwater fishes are one of the most imperiled groups of vertebrates and species declines have been linked to a number of anthropogenic influences. This is alarming as the diversity and stability of populations are at risk. In addition, freshwater fish serve as important protein sources, particularly in developing countries. One of the focal activities thought to influence freshwater fish population declines is water resource development, which is anticipated to increase over the next several decades. For fish encountering hydro structures, such as passing through hydroturbines, there may be a rapid decrease in pressure which can lead to injuries commonly referredmore » to as barotraumas. The authors summarize the research to date that has examined the effects of rapid pressure changes on fish and outline the most important factors to consider (i.e., swim bladder morphology, depth of acclimation, migration pattern and life stage) when examining the susceptibility of barotraumas for fish of interest.« less

Identification of lymphocystis disease virus from paradise fish Macropodus opercularis (LCDV-PF).

PubMed

Xu, Liwen; Feng, Juan; Huang, Youhua

2014-09-01

Iridoviruses are large DNA viruses that are subdivided into five genera: Ranavirus, Megalocytivirus, Lymphocystivirus, Chloriridovirus and Iridovirus. The iridovirus lymphocystis disease virus (LCDV) is an important fish pathogen that can infect marine and freshwater fish worldwide. In this study, we have identified the pathogen in paradise fish (Macropodus opercularis) with lymphocystis. On the skin and fins of diseased paradise fish, a large number of nodules were observed. H&E staining showed that the nodules were composed of encapsulated hypertrophied cells. Using electron microscopy, numerous virus particles with a diameter of >210 nm and with hexagonal profiles were observed in the cytoplasm. Phylogenetic analysis based on the major capsid protein (MCP), DNA polymerase and myristylated membrane protein (MMP) genes revealed that LCDV from paradise fish (LCDV-PF) was closely related to lymphocystis disease virus from China (LCDV-C), followed by lymphocystis disease virus 1 (LCDV-1). Taken together, our data provide the first molecular evidence that, in addition to megalocytivirus, LCDV is an important iridoviral pathogen in paradise fish besides megalocytivirus.

Histamine (Scombroid) Fish Poisoning: a Comprehensive Review.

PubMed

Feng, Charles; Teuber, Suzanne; Gershwin, M Eric

2016-02-01

Histamine fish poisoning, also known as scombroid poisoning, is the most common cause of ichythyotoxicosis worldwide and results from the ingestion of histamine-contaminated fish in the Scombroidae and Scomberesocidae families, including mackerel, bonito, albacore, and skipjack. This disease was first described in 1799 in Britain and re-emerged in the medical literature in the 1950s when outbreaks were reported in Japan. The symptoms associated with histamine fish poisoning are similar to that of an allergic reaction. In fact, such histamine-induced reactions are often misdiagnosed as IgE-mediated fish allergy. Indeed, histamine fish poisoning is still an underrecognized disease. In this review, we discuss the epidemiology, pathophysiology, evaluation, and treatment of scombroid disease. Because more than 80% of fish consumed in the USA is now imported from other countries, the disease is intimately linked with the global fish trade (National Marine Fisheries Service, 2012). Preventing future scombroid outbreaks will require that fishermen, public health officials, restaurant workers, and medical professionals work together to devise international safety standards and increase awareness of the disease. The implications of scombroid poisoning go far beyond that of fish and have broader implications for the important issues of food safety.

'Fish matters': the relevance of fish skin biology to investigative dermatology.

PubMed

Rakers, Sebastian; Gebert, Marina; Uppalapati, Sai; Meyer, Wilfried; Maderson, Paul; Sell, Anne F; Kruse, Charli; Paus, Ralf

2010-04-01

Fish skin is a multi-purpose tissue that serves numerous vital functions including chemical and physical protection, sensory activity, behavioural purposes or hormone metabolism. Further, it is an important first-line defense system against pathogens, as fish are continuously exposed to multiple microbial challenges in their aquatic habitat. Fish skin excels in highly developed antimicrobial features, many of which have been preserved throughout evolution, and infection defense principles employed by piscine skin are still operative in human skin. This review argues that it is both rewarding and important for investigative dermatologists to revive their interest in fish skin biology, as it provides insights into numerous fundamental issues that are of major relevance to mammalian skin. The basic molecular insights provided by zebrafish in vivo-genomics for genetic, regeneration and melanoma research, the complex antimicrobial defense systems of fish skin and the molecular controls of melanocyte stem cells are just some of the fascinating examples that illustrate the multiple potential uses of fish skin models in investigative dermatology. We synthesize the essentials of fish skin biology and highlight selected aspects that are of particular comparative interest to basic and clinically applied human skin research.

Environmental factors structuring fish composition and assemblages in a small macrotidal estuary (eastern English Channel)

NASA Astrophysics Data System (ADS)

Selleslagh, Jonathan; Amara, Rachid

2008-09-01

The fish assemblage structure was analyzed along an estuarine gradient of a small macrotidal estuary (the Canche, France). Fishes were collected every two months between May 2006 and July 2007 from 12 sampling stations using a 1.5-m beam trawl with a 5 mm mesh size in the cod end. To complement this information, sampling was also performed using 15-m fyke nets (8 mm mesh size in the cod end). For each sample, abiotic (temperature, salinity, pH, oxygen, turbidity, river flow, wind speed and depth) and biotic (macro crustacean species abundances) were recorded. Throughout the study, 28 fish species belonging to 20 families were collected. Fish catches were dominated by juveniles, especially Young-Of-the-Year (YOY) for the majority of the species. According to the Index of Relative Importance (IRI), common goby Pomatoschistus microps, flounder Platichtys flesus, sprat Sprattus sprattus, sea-bass Dicentrarchus labrax and plaice Pleuronectes platessa were the most abundant species, together accounting for 99.2% of the total IRI. Estuarine residents (ER = 66.2%) and marine juvenile migrants species (MJ = 31.4%) were the most important ecological guilds. The structure of the fish assemblage and its relationship to environmental variables was examined using multivariate techniques. Cluster and non-metric multidimensional scaling (nMDS) analysis defined six distinct groups in the Canche estuary, which are discriminated by specific species (SIMPER). Spatio-temporal variations in fish assemblage structure reflect the density peaks of the most abundant species. Spearman rank correlations and canonical correspondence analysis (CCA) showed that among the ten environmental variables examined, temperature, salinity and Crangon crangon (a potential predator for YOY fish or prey for older ones) are the three most important factors influencing fish species richness and abundances. Our observations reinforce the idea that certain fish species may have different life history styles in different geographic areas. The present study highlights the necessity of a better knowledge of the connectivity between estuaries and adjacent marine areas. The Canche constitutes an important ecosystem for fishes and as it is subject to little anthropogenic disturbance; its ichthyofauna can be viewed as a reference or normal assemblage for small temperate macrotidal estuaries.

Zimbabwe: The Power Sharing Agreement and Implications for U.S. Policy

DTIC Science & Technology

2010-02-24

Zimbabweans have emigrated in the last decade, including up to half of the country’s doctors and nurses . Hospitals and clinics lack basic medicines... rescheduling , or 111 Seventy-seven individuals were named in the executive order (EO

[Female employment and emigration: from the countries of Africa and Asia to Rome].

PubMed

Arena, G

1983-06-01

Recent trends in female labor migration from third world countries to Rome, Italy, are analyzed. The impact of the demand for various types of labor and of religious background is considered. (summary in ENG, FRE)

Importance of fishing as a segmentation variable in the application of a social worlds model

USGS Publications Warehouse

Gigliotti, Larry M.; Chase, Loren

2017-01-01

Market segmentation is useful to understanding and classifying the diverse range of outdoor recreation experiences sought by different recreationists. Although many different segmentation methodologies exist, many are complex and difficult to measure accurately during in-person intercepts, such as that of creel surveys. To address that gap in the literature, we propose a single-item measure of the importance of fishing as a surrogate to often overly- or needlesslycomplex segmentation techniques. The importance of fishing item is a measure of the value anglers place on the activity or a coarse quantification of how central the activity is to the respondent’s lifestyle (scale: 0 = not important, 1 = slightly, 2 = moderately, 3 = very, and 4 = fishing is my most important recreational activity). We suggest the importance scale may be a proxy measurement for segmenting anglers using the social worlds model as a theoretical framework. Vaske (1980) suggested that commitment to recreational activities may be best understood in relation to social group participation and the social worlds model provides a rich theoretical framework for understanding social group segments. Unruh (1983) identified four types of actor involvement in social worlds: strangers, tourists, regulars, and insiders, differentiated by four characteristics (orientation, experiences, relationships, and commitment). We evaluated the importance of fishing as a segmentation variable using data collected by a mixed-mode survey of South Dakota anglers fishing in 2010. We contend that this straightforward measurement may be useful for segmenting outdoor recreation activities when more complicated segmentation schemes are not suitable. Further, this index, when coupled with the social worlds model, provides a valuable framework for understanding the segments and making management decisions.

Biodiversity enhances reef fish biomass and resistance to climate change.

PubMed

Duffy, J Emmett; Lefcheck, Jonathan S; Stuart-Smith, Rick D; Navarrete, Sergio A; Edgar, Graham J

2016-05-31

Fishes are the most diverse group of vertebrates, play key functional roles in aquatic ecosystems, and provide protein for a billion people, especially in the developing world. Those functions are compromised by mounting pressures on marine biodiversity and ecosystems. Because of its economic and food value, fish biomass production provides an unusually direct link from biodiversity to critical ecosystem services. We used the Reef Life Survey's global database of 4,556 standardized fish surveys to test the importance of biodiversity to fish production relative to 25 environmental drivers. Temperature, biodiversity, and human influence together explained 47% of the global variation in reef fish biomass among sites. Fish species richness and functional diversity were among the strongest predictors of fish biomass, particularly for the large-bodied species and carnivores preferred by fishers, and these biodiversity effects were robust to potentially confounding influences of sample abundance, scale, and environmental correlations. Warmer temperatures increased biomass directly, presumably by raising metabolism, and indirectly by increasing diversity, whereas temperature variability reduced biomass. Importantly, diversity and climate interact, with biomass of diverse communities less affected by rising and variable temperatures than species-poor communities. Biodiversity thus buffers global fish biomass from climate change, and conservation of marine biodiversity can stabilize fish production in a changing ocean.

Comparative genome analysis of 52 fish species suggests differential associations of repetitive elements with their living aquatic environments.

PubMed

Yuan, Zihao; Liu, Shikai; Zhou, Tao; Tian, Changxu; Bao, Lisui; Dunham, Rex; Liu, Zhanjiang

2018-02-13

Repetitive elements make up significant proportions of genomes. However, their roles in evolution remain largely unknown. To provide insights into the roles of repetitive elements in fish genomes, we conducted a comparative analysis of repetitive elements of 52 fish species in 22 orders in relation to their living aquatic environments. The proportions of repetitive elements in various genomes were found to be positively correlated with genome sizes, with a few exceptions. More importantly, there appeared to be specific enrichment between some repetitive element categories with species habitat. Specifically, class II transposons appear to be more abundant in freshwater bony fish than in marine bony fish when phylogenetic relationship is not considered. In contrast, marine bony fish harbor more tandem repeats than freshwater species. In addition, class I transposons appear to be more abundant in primitive species such as cartilaginous fish and lamprey than in bony fish. The enriched association of specific categories of repetitive elements with fish habitats suggests the importance of repetitive elements in genome evolution and their potential roles in fish adaptation to their living environments. However, due to the restriction of the limited sequenced species, further analysis needs to be done to alleviate the phylogenetic biases.

Biodiversity enhances reef fish biomass and resistance to climate change

PubMed Central

Duffy, J. Emmett; Lefcheck, Jonathan S.; Navarrete, Sergio A.; Edgar, Graham J.

2016-01-01

Fishes are the most diverse group of vertebrates, play key functional roles in aquatic ecosystems, and provide protein for a billion people, especially in the developing world. Those functions are compromised by mounting pressures on marine biodiversity and ecosystems. Because of its economic and food value, fish biomass production provides an unusually direct link from biodiversity to critical ecosystem services. We used the Reef Life Survey’s global database of 4,556 standardized fish surveys to test the importance of biodiversity to fish production relative to 25 environmental drivers. Temperature, biodiversity, and human influence together explained 47% of the global variation in reef fish biomass among sites. Fish species richness and functional diversity were among the strongest predictors of fish biomass, particularly for the large-bodied species and carnivores preferred by fishers, and these biodiversity effects were robust to potentially confounding influences of sample abundance, scale, and environmental correlations. Warmer temperatures increased biomass directly, presumably by raising metabolism, and indirectly by increasing diversity, whereas temperature variability reduced biomass. Importantly, diversity and climate interact, with biomass of diverse communities less affected by rising and variable temperatures than species-poor communities. Biodiversity thus buffers global fish biomass from climate change, and conservation of marine biodiversity can stabilize fish production in a changing ocean. PMID:27185921

Interactive effects of live coral and structural complexity on the recruitment of reef fishes

NASA Astrophysics Data System (ADS)

Coker, D. J.; Graham, N. A. J.; Pratchett, M. S.

2012-12-01

Corals reefs are subjected to multiple disturbances that modify levels of coral cover and structural complexity of the reef matrix, and in turn influence the structure of associated fish communities. With disturbances predicted to increase, insight into how changes in substrate condition will influence the recruitment of many fishes is essential for understanding the recovery of reef fish populations following biological and physical disturbances. While studies have revealed that both live coral cover and structural complexity are important for many fishes, there is a lack of understanding regarding how a combination of these changes will impact the recruitment of fishes. This study used experimentally constructed patch reefs consisting of six different habitat treatments; three levels of live coral cover (high, medium, low) crossed with two levels of structural complexity (high, low), to test the independent and combined effects of live coral cover and structural complexity on the recruitment and recovery of fish communities. The abundance and species diversity of fishes varied significantly among the six habitat treatments, but differences were not clearly associated with either coral cover or structural complexity and varied through time. More striking, however, was a significant difference in the composition of fish assemblages among treatments, due mostly to disproportionate abundance of coral-dwelling fishes on high coral cover, high complexity reefs. Overall, it appears that coral cover had a more important influence than structural complexity, at least for the contrasting levels of structural complexity achieved on experimental patch reefs. Furthermore, we found that live coral cover is important for the recruitment of some non-coral-dependent fishes. This study confirms that live coral cover is critical for the maintenance of high biodiversity on tropical coral reefs, and that sustained and ongoing declines in coral cover will adversely affect recruitment for many different species of reef fishes.

Microplastics in gut contents of coastal freshwater fish from Río de la Plata estuary.

PubMed

Pazos, Rocío S; Maiztegui, Tomás; Colautti, Darío C; Paracampo, Ariel H; Gómez, Nora

2017-09-15

The presence of microplastics (MPs) in gut contents of coastal freshwater fish of the Rio de la Plata estuary was studied. Samples were taken in six sites where 87 fish belonging to 11 species and four feeding habits were captured. Presence of MPs was verified in the 100% of fish. The fibres represented the 96% of MPs found. The number of MPs in gut contents was significantly higher close to sewage discharge. There was not found relationship between number of MPs and fish length, weight or feeding habit. The spatial differences in mean number of MPs in fish observed in this study, suggest that environmental availability of MPs could be of great importance to explain the differences found among sampling sites analysed. This work represents the first study about the interaction between MPs and aquatic organisms in this important estuarine ecosystem of South America. Copyright © 2017 Elsevier Ltd. All rights reserved.