Evidence for episodic acidification effects on migrating Atlantic salmon Salmo salar smolts

USGS Publications Warehouse

Kelly, John T; Lerner, Darrren T.; O'Dea, Michael F.; Regish, Amy M.; Monette, Michelle Y.; Hawkes, J.P.; Nislow, Keith H.; McCormick, Stephen

2015-01-01

Field studies were conducted to determine levels of gill aluminium as an index of acidification effects on migrating Atlantic salmon Salmo salar smolts in the north-eastern U.S.A. along mainstem river migration corridors in several major river basins. Smolts emigrating from the Connecticut River, where most (but not all) tributaries were well buffered, had low or undetectable levels of gill aluminium and high gill Na+/K+-ATPase (NKA) activity. In contrast, smolts emigrating from the upper Merrimack River basin where most tributaries are characterized by low pH and high inorganic aluminium had consistently elevated gill aluminium and lower gill NKA activity, which may explain the low adult return rates of S. salar stocked into the upper Merrimack catchment. In the Sheepscot, Narraguagus and Penobscot Rivers in Maine, river and year-specific effects on gill aluminium were detected that appeared to be driven by underlying geology and high spring discharge. The results indicate that episodic acidification is affecting S. salar smolts in poorly buffered streams in New England and may help explain variation in S. salar survival and abundance among rivers and among years, with implications for the conservation and recovery of S. salar in the north-eastern U.S.A. These results suggest that the physiological condition of outmigrating smolts may serve as a large-scale sentinel of landscape-level recovery of atmospheric pollution in this and other parts of the North Atlantic region.

Evidence for episodic acidification effects on migrating Atlantic salmon Salmo salar smolts.

PubMed

Kelly, J T; Lerner, D T; O'Dea, M F; Regish, A M; Monette, M Y; Hawkes, J P; Nislow, K H; McCormick, S D

2015-11-01

Field studies were conducted to determine levels of gill aluminium as an index of acidification effects on migrating Atlantic salmon Salmo salar smolts in the north-eastern U.S.A. along mainstem river migration corridors in several major river basins. Smolts emigrating from the Connecticut River, where most (but not all) tributaries were well buffered, had low or undetectable levels of gill aluminium and high gill Na(+) /K(+) -ATPase (NKA) activity. In contrast, smolts emigrating from the upper Merrimack River basin where most tributaries are characterized by low pH and high inorganic aluminium had consistently elevated gill aluminium and lower gill NKA activity, which may explain the low adult return rates of S. salar stocked into the upper Merrimack catchment. In the Sheepscot, Narraguagus and Penobscot Rivers in Maine, river and year-specific effects on gill aluminium were detected that appeared to be driven by underlying geology and high spring discharge. The results indicate that episodic acidification is affecting S. salar smolts in poorly buffered streams in New England and may help explain variation in S. salar survival and abundance among rivers and among years, with implications for the conservation and recovery of S. salar in the north-eastern U.S.A. These results suggest that the physiological condition of outmigrating smolts may serve as a large-scale sentinel of landscape-level recovery of atmospheric pollution in this and other parts of the North Atlantic region. © 2015 The Fisheries Society of the British Isles.

Photoperiod control of downstream movements of Atlantic salmon Salmo salar smolts

USGS Publications Warehouse

Zydlewski, Gayle B.; Stich, Daniel S.; McCormick, Stephen D.

2014-01-01

This study provides the first direct observations that photoperiod controls the initiation of downstream movement in Atlantic salmon Salmo salar smolts. Under simulated natural day length (LDN) conditions and seasonal increases in temperature, smolts increased their downstream movements five-fold for a period of 1 month in late spring. Under the same conditions, parr did not show changes in downstream movement behaviour. When given a shortened day length (10L:14D) beginning in late winter, smolts did not increase the number of downstream movements. An early increase in day length (16L:8D) in late winter resulted in earlier initiation and termination of downstream movements compared to the LDN group. Physiological status and behaviour were related but not completely coincident: gill Na+/K+-ATPase activity increased in all treatments and thyroid hormone was elevated prior to movement in 16L:8D treatment. The most parsimonious model describing downstream movement of smolts included synergistic effects of photoperiod treatment and temperature, indicating that peak movements occurred at colder temperatures in the 16L:8D treatment than in LDN, and temperature did not influence movement of smolts in the 10L:14D treatment. The complicated interactions of photoperiod and temperature are not surprising since many organisms have evolved to rely on correlations among environmental cues and windows of opportunity to time behaviours associated with life-history transitions. These complicated interactions, however, have serious implications for phenological adjustments and persistence ofS. salar populations in response to climate change.

SalmonDB: a bioinformatics resource for Salmo salar and Oncorhynchus mykiss

PubMed Central

Di Génova, Alex; Aravena, Andrés; Zapata, Luis; González, Mauricio; Maass, Alejandro; Iturra, Patricia

2011-01-01

SalmonDB is a new multiorganism database containing EST sequences from Salmo salar, Oncorhynchus mykiss and the whole genome sequence of Danio rerio, Gasterosteus aculeatus, Tetraodon nigroviridis, Oryzias latipes and Takifugu rubripes, built with core components from GMOD project, GOPArc system and the BioMart project. The information provided by this resource includes Gene Ontology terms, metabolic pathways, SNP prediction, CDS prediction, orthologs prediction, several precalculated BLAST searches and domains. It also provides a BLAST server for matching user-provided sequences to any of the databases and an advanced query tool (BioMart) that allows easy browsing of EST databases with user-defined criteria. These tools make SalmonDB database a valuable resource for researchers searching for transcripts and genomic information regarding S. salar and other salmonid species. The database is expected to grow in the near feature, particularly with the S. salar genome sequencing project. Database URL: http://genomicasalmones.dim.uchile.cl/ PMID:22120661

SalmonDB: a bioinformatics resource for Salmo salar and Oncorhynchus mykiss.

PubMed

Di Génova, Alex; Aravena, Andrés; Zapata, Luis; González, Mauricio; Maass, Alejandro; Iturra, Patricia

2011-01-01

SalmonDB is a new multiorganism database containing EST sequences from Salmo salar, Oncorhynchus mykiss and the whole genome sequence of Danio rerio, Gasterosteus aculeatus, Tetraodon nigroviridis, Oryzias latipes and Takifugu rubripes, built with core components from GMOD project, GOPArc system and the BioMart project. The information provided by this resource includes Gene Ontology terms, metabolic pathways, SNP prediction, CDS prediction, orthologs prediction, several precalculated BLAST searches and domains. It also provides a BLAST server for matching user-provided sequences to any of the databases and an advanced query tool (BioMart) that allows easy browsing of EST databases with user-defined criteria. These tools make SalmonDB database a valuable resource for researchers searching for transcripts and genomic information regarding S. salar and other salmonid species. The database is expected to grow in the near feature, particularly with the S. salar genome sequencing project. Database URL: http://genomicasalmones.dim.uchile.cl/

Multi-temporal remote sensing analysis of salars in El Loa Province, Chile: Implications for water resource management

NASA Astrophysics Data System (ADS)

Markovich, K.; Pierce, S. A.

2011-12-01

Salar de Ascotán and Salar de Carcote are internally drained, evaporative basins located in the Atacama Desert, 200 km northeast of Antofogasta in Region II, Chile. The two salars are part of a regional groundwater system that recharges in the adjacent uplands to the east and terminates in the regional topographic low at Salar de Uyuni, Bolivia. This regional groundwater system is discharged locally as spring-fed perennial surface water that flows across the salar surface and either evaporates, or reinfiltrates, in lagoon-like environments. This perennial surface water supports diverse flora and fauna in the salar basins, including flamingo, vicuña, and the endemic fish species Orestias ascotanensis. Mining projects in the region began pumping the groundwater system in the Ascotán basin in the mid-1990's, leading to concern about the preservation of spring-fed surface flows. While hydrologic and ecologic monitoring efforts have been coordinated, data collection is limited to in-situ measurements and antecedent records precede extraction by approximately six months. Remote sensing can provide a means for large scale monitoring of the salars, as well as providing additional historical data to support environmental management of the systems. This comparative study utilizes satellite imagery to detect changes in surface water extent in the two salars and evaluate the results for possible correlation with climatic and/or anthropogenic factors. Landsat TM and ETM+ images from the time period of 1986-2011 are analyzed for surface water extent, and geographic information technologies are used to integrate the remotely sensed data with in-situ measurements. Early results indicate that surface water extent on the salar surface has diminished from 1986 and present day conditions. The decrease is most pronounced in the Ascotán basin, suggesting a possible correlation to anthropogenic influences. Also, the rate of decrease in surface water presence is most elevated in the

Environmental change influences the life history of salmon Salmo salar in the North Atlantic Ocean.

PubMed

Jonsson, B; Jonsson, N; Albretsen, J

2016-02-01

Annual mean total length (LT) of wild one-sea-winter (1SW) Atlantic salmon Salmo salar of the Norwegian River Imsa decreased from 63 to 54 cm with a corresponding decrease in condition factor (K) for cohorts migrating to sea from 1976 to 2010. The reduction in LT is associated with a 40% decline in mean individual mass, from 2 to 1·2 kg. Hatchery fish reared from parental fish of the same population exhibited similar changes from 1981 onwards. The decrease in LT correlated negatively with near-surface temperatures in the eastern Norwegian Sea, thought to be the main feeding area of the present stock. Furthermore, S. salar exhibited significant variations in the proportion of cohorts attaining maturity after only one winter in the ocean. The proportion of S. salar spawning as 1SW fish was lower both in the 1970s and after 2000 than in the 1980s and 1990s associated with a gradual decline in post-smolt growth and smaller amounts of reserve energy in the fish. In wild S. salar, there was a positive association between post-smolt growth and the sea survival back to the River Imsa for spawning. In addition, among smolt year-classes, there were significant positive correlations between wild and hatchery S. salar in LT, K and age at maturity. The present changes may be caused by ecosystem changes following the collapse and rebuilding of the pelagic fish abundance in the North Atlantic Ocean, a gradual decrease in zooplankton abundance and climate change with increasing surface temperature in the Norwegian Sea. Thus, the observed variation in the life-history traits of S. salar appears primarily associated with major changes in the pelagic food web in the ocean. © 2016 The Fisheries Society of the British Isles.

Modeling the Salar de Uyuni, Bolivia as an Equipotential Surface of Earth's Gravity Field

NASA Technical Reports Server (NTRS)

Borsa, Adrian; Bills, Bruce

2004-01-01

The salar de Uyuni is a massive dry salt lake that lies at the lowest point of an internal/drainage basin in the Bolivian Altiplano. Its topography is remarkable for its extraordinary flatness over almost a full degree of latitude and longitude. We surveyed a 54 x 45 km region of the salar with kinematic GPS in September, 2002 and found a topographic range of only 80 cm over the entire surveyed area. Furthermore, the survey revealed distinct surface features with several dominant wavelengths and orientations. Some of these appear to be aligned with orographic features that intersect the salar, leading us to conjecture that they are the surface expression of high-density mountains that have been buried by low-density basin sediments. Over the oceans, a similar correspondence between basin bathymetry and surface topography is exploited to map the seafloor using sea-surface satellite altimetry measurements, with the sea surface following geoid undulations due to the underwater mass distribution. On the salar, annual flooding creates a shallow lake whose surface also lies on a equipotential surface shaped by the distribution of underlying mass. The link to the actual salar surface is via the dissolution and redeposition of salt by the lake waters, which appears to push the system to an equilibrium of constant water depth and the coincidence of the shapes of the lake surface and bottom. To test our hypothesis about the origin of the surface features on the salar, we compare our GPS survey elevations with the equipotential surface generated from local gravity measurements in conjunction with gravity and potential values from the EGM96 global geopotential model. 50% of the variance of the GPS elevations can be explained by equipotential surface undulations from the EGM96 model alone, and an additional 40% is explained by the shorter-wavelength equipotential surface derived from local gravity. We examine the unexplained 10% of elevation variance from the standpoint of

Physiological preparedness and performance of Atlantic salmon Salmo salar smolts in relation to behavioural salinity preferences and thresholds.

PubMed

Stich, D S; Zydlewski, G B; Zydlewski, J D

2016-02-01

This study investigated the relationships between behavioural responses of Atlantic salmon Salmo salar smolts to saltwater (SW) exposure and physiological characteristics of smolts in laboratory experiments. It concurrently described the behaviour of acoustically tagged smolts with respect to SW and tidal cycles during estuary migration. Salmo salar smolts increased their use of SW relative to fresh water (FW) from April to June in laboratory experiments. Mean preference for SW never exceeded 50% of time in any group. Preference for SW increased throughout the course of smolt development. Maximum continuous time spent in SW was positively related to gill Na(+), K(+)-ATPase (NKA) activity and osmoregulatory performance in full-strength SW (measured as change in gill NKA activity and plasma osmolality). Smolts decreased depth upon reaching areas of the Penobscot Estuary where SW was present, and all fish became more surface oriented during passage from head of tide to the ocean. Acoustically tagged, migrating smolts with low gill NKA activity moved faster in FW reaches of the estuary than those with higher gill NKA activity. There was no difference in movement rate through SW reaches of the estuary based on gill NKA activity. Migrating fish moved with tidal flow during the passage of the lower estuary based on the observed patterns in both vertical and horizontal movements. The results indicate that smolts select low-salinity water during estuary migration and use tidal currents to minimize energetic investment in seaward migration. Seasonal changes in osmoregulatory ability highlight the importance of the timing of stocking and estuary arrival. © 2015 The Fisheries Society of the British Isles.

The origin of brines and salts in Chilean salars: a hydrochemical review

NASA Astrophysics Data System (ADS)

Risacher, François; Alonso, Hugo; Salazar, Carlos

2003-11-01

Northern Chile is characterized by a succession of north-south-trending ranges and basins occupied by numerous saline lakes and salt crusts, collectively called salars. Fossil salt crusts are found to the west in the extremely arid Central Valley, while active salars receiving permanent inflows fill many intravolcanic basins to the east in the semiarid Cordillera. Sea salts and desert dust are blown eastward over the Cordillera, where they constitute an appreciable fraction of the solute load of very dilute waters (salt content<0.1 g/l). The weathering of volcanic rocks contributes most components to inflow waters with salt content ranging from 0.1 to 0.6 g/l. However, the average salt content of all inflows is much higher: about 3.2 g/l. Chemical composition, Cl/Br ratio, and 18O- 2H isotope contents point to the mixing of very dilute meteoric waters with present lake brines for the origin of saline inflows. Ancient gypsum in deep sedimentary formations seems to be the only evaporitic mineral recycled in present salars. Saline lakes and subsurface brines are under steady-state regime. The average residence time of conservative components ranges from a few years to some thousands years, which indicates a permanent leakage of the brines through bottom sediments. The infiltrating brines are recycled in the hydrologic system where they mix with dilute meteoric waters. High heat flow is the likely driving force that moves the deep waters in this magmatic arc region. Active Chilean salars cannot be considered as terminal lakes nor, strictly speaking, as closed basin lakes. Almost all incoming salts leave the basin and are transported elsewhere. Moreover, the dissolution of fossil salt crusts in some active salars also carries away important fluxes of components in percolating brines. Evaporative concentration of inflow waters leads to sulfate-rich or calcium-rich, near-neutral brines. Alkaline brines are almost completely lacking. The alkalinity/calcium ratio of inflow

Geochemical evolution of brines in the Salar of Uyuni, Bolivia.

USGS Publications Warehouse

Rettig, S.L.; Jones, B.F.; Risacher, F.

1980-01-01

Recent analyses of brines from the Salars of Uyuni and Coipasa have been compared with published data for Lakes Titicaca and Poopo to evaluate solute compositional trends in these remnants of two large Pleistocene lakes once connected by overflow from the N to the S of the Bolivian Altiplano. From Titicaca to Poopo the water shows an increase in Cl and N somewhat greater than the total solutes. Ca and SO4 increase to a lesser extent than total dissolved solids, and carbonate species are relatively constant. Between Poopo and Coipasa proportions of Ca, SO4 and CO3 continue to decrease. At Coipasa and Uyuni, the great salars frequently evaporate to halite saturation. Halite crystallization is accompanied by an increased K, Mg and SO4 in residual brines. - from Authors

Counterintuitive migration patterns by Atlantic salmon Salmo salar smolts in a large lake.

PubMed

Honkanen, H M; Rodger, J R; Stephen, A; Adams, K; Freeman, J; Adams, C E

2018-06-21

What little is known about the seaward migration of Salmo salar smolt migration through standing waters indicates that it is both slow and results in high mortality rates, compared with riverine migration. This may be partly because smolts in lakes need to swim more actively and require more complex directional cues than they do in rivers. In this telemetry study of smolt migration through Loch Lomond, S. salar smolts made repeated movements in directions away from the outflowing river, which considerably increased migration time. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

The biogeography of the atlantic salmon (Salmo salar) gut microbiome.

PubMed

Llewellyn, Martin S; McGinnity, Philip; Dionne, Melanie; Letourneau, Justine; Thonier, Florian; Carvalho, Gary R; Creer, Simon; Derome, Nicolas

2016-05-01

Although understood in many vertebrate systems, the natural diversity of host-associated microbiota has been little studied in teleosts. For migratory fishes, successful exploitation of multiple habitats may affect and be affected by the composition of the intestinal microbiome. We collected 96 Salmo salar from across the Atlantic encompassing both freshwater and marine phases. Dramatic differences between environmental and gut bacterial communities were observed. Furthermore, community composition was not significantly impacted by geography. Instead life-cycle stage strongly defined both the diversity and identity of microbial assemblages in the gut, with evidence for community destabilisation in migratory phases. Mycoplasmataceae phylotypes were abundantly recovered in all life-cycle stages. Patterns of Mycoplasmataceae phylotype recruitment to the intestinal microbial community among sites and life-cycle stages support a dual role for deterministic and stochastic processes in defining the composition of the S. salar gut microbiome.

Consistent melanophore spot patterns allow long-term individual recognition of Atlantic salmon Salmo salar.

PubMed

Stien, L H; Nilsson, J; Bui, S; Fosseidengen, J E; Kristiansen, T S; Øverli, Ø; Folkedal, O

2017-12-01

The present study shows that permanent melanophore spot patterns in Atlantic salmon Salmo salar make it possible to use images of the operculum to keep track of individual fish over extended periods of their life history. Post-smolt S. salar (n = 246) were initially photographed at an average mass of 98 g and again 10 months later after rearing in a sea cage, at an average mass of 3088 g. Spots that were present initially remained and were the most overt (largest) 10 months later, while new and less overt spots had developed. Visual recognition of spot size and position showed that fish with at least four initial spots were relatively easy to identify, while identifying fish with less than four spots could be challenging. An automatic image analysis method was developed and shows potential for fast match processing of large numbers of fish. The current findings promote visual recognition of opercular spots as a welfare-friendly alternative to tagging in experiments involving salmonid fishes. © The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the British Isles.

Microbial diversity of the hypersaline and lithium-rich Salar de Uyuni, Bolivia.

PubMed

Haferburg, Götz; Gröning, Janosch A D; Schmidt, Nadja; Kummer, Nicolai-Alexeji; Erquicia, Juan Carlos; Schlömann, Michael

2017-06-01

Salar de Uyuni, situated in the Southwest of the Bolivian Altiplano, is the largest salt flat on Earth. Brines of this athalassohaline hypersaline environment are rich in lithium and boron. Due to the ever- increasing commodity demand, the industrial exploitation of brines for metal recovery from the world's biggest lithium reservoir is likely to increase substantially in the near future. Studies on the composition of halophilic microbial communities in brines of the salar have not been published yet. Here we report for the first time on the prokaryotic diversity of four brine habitats across the salar. The brine is characterized by salinity values between 132 and 177 PSU, slightly acidic to near-neutral pH and lithium and boron concentrations of up to 2.0 and 1.4g/L, respectively. Community analysis was performed after sequencing the V3-V4 region of the 16S rRNA genes employing the Illumina MiSeq technology. The mothur software package was used for sequence processing and data analysis. Metagenomic analysis revealed the occurrence of an exclusively archaeal community comprising 26 halobacterial genera including only recently identified genera like Halapricum, Halorubellus and Salinarchaeum. Despite the high diversity of the halobacteria-dominated community in sample P3 (Shannon-Weaver index H'=3.12 at 3% OTU cutoff) almost 40% of the Halobacteriaceae-assigned sequences could not be classified on the genus level under stringent filtering conditions. Even if the limited taxonomic resolution of the V3-V4 region for halobacteria is considered, it seems likely to discover new, hitherto undescribed genera of the family halobacteriaceae in this particular habitat of Salar de Uyuni in future. Copyright © 2017 Elsevier GmbH. All rights reserved.

Atlantic salmon (Salmo salar) smolt production: the relative importance of survival and body growth

USGS Publications Warehouse

Horton, G.E.; Letcher, B.H.; Bailey, M.M.; Kinnison, M.T.

2009-01-01

The complex life history of Atlantic salmon (Salmo salar) coupled with interacting abiotic and biotic factors leads to extreme demographic variability across the species' range. Our goal was to evaluate the relative importance of survival and body growth in determining smolt production across space and time. We used passive integrated transponder tags and capture-mark-recapture analyses to estimate survival, emigration, and growth for six cohorts of presmolt Atlantic salmon in two streams (three cohorts per stream) in New England, USA. We observed remarkable among-cohort consistency in mean monthly survival during a 17-month period from age-0+ autumn to age-2+ spring yet high variability in monthly survival over shorter time intervals (seasons). Despite this latter variability, survival did not translate into amongcohort differences in proportions of age-2+ versus age-3+ smolts. Alternatively, the high variability across seasons and cohorts in mean individual growth rate did lead to differences in within-cohort proportions of age-2+ versus age-3+ smolts (regardless of stream). We conclude that in our two small study streams, variability in growth and size impacted smolt age and, ultimately, smolt production. Density-dependent effects on growth at the scale of the entire study site represent a possible mechanism underlying our observations.

Evidence of Atlantic salmon Salmo salar fry movement between fresh water and a brackish environment.

PubMed

Taal, I; Rohtla, M; Saks, L; Svirgsden, R; Kesler, M; Matetski, L; Vetemaa, M

2017-08-01

This study reports descent of Atlantic salmon Salmo salar fry from their natal streams to brackish waters of the Baltic Sea and their use of this environment as an alternative rearing habitat before ascending back to freshwater streams. To the authors' knowledge, residency in a brackish environment has not previously been demonstrated in S. salar fry. Recruitment success and evolutionary significance of this alternative life-history strategy are presently not known. © 2017 The Fisheries Society of the British Isles.

The biogeography of the atlantic salmon (Salmo salar) gut microbiome

PubMed Central

Llewellyn, Martin S; McGinnity, Philip; Dionne, Melanie; Letourneau, Justine; Thonier, Florian; Carvalho, Gary R; Creer, Simon; Derome, Nicolas

2016-01-01

Although understood in many vertebrate systems, the natural diversity of host-associated microbiota has been little studied in teleosts. For migratory fishes, successful exploitation of multiple habitats may affect and be affected by the composition of the intestinal microbiome. We collected 96 Salmo salar from across the Atlantic encompassing both freshwater and marine phases. Dramatic differences between environmental and gut bacterial communities were observed. Furthermore, community composition was not significantly impacted by geography. Instead life-cycle stage strongly defined both the diversity and identity of microbial assemblages in the gut, with evidence for community destabilisation in migratory phases. Mycoplasmataceae phylotypes were abundantly recovered in all life-cycle stages. Patterns of Mycoplasmataceae phylotype recruitment to the intestinal microbial community among sites and life-cycle stages support a dual role for deterministic and stochastic processes in defining the composition of the S. salar gut microbiome. PMID:26517698

Predictability of multispecies competitive interactions in three populations of Atlantic salmon Salmo salar.

PubMed

Houde, A L S; Wilson, C C; Neff, B D

2015-04-01

Juvenile Atlantic salmon Salmo salar from three allopatric populations (LaHave, Sebago and Saint-Jean) were placed into artificial streams with combinations of four non-native salmonids: brown trout Salmo trutta, rainbow trout Oncorhynchus mykiss, Chinook salmon Oncorhynchus tshawytscha and coho salmon Oncorhynchus kisutch. Non-additive effects, as evidenced by lower performance than predicted from weighted summed two-species competition trials, were detected for S. salar fork length (LF ) and mass, but not for survival, condition factor or riffle use. These data support emerging theory on niche overlap and species richness as factors that can lead to non-additive competition effects. © 2015 The Fisheries Society of the British Isles.

A review of factors influencing maturation of atlantic salmon salmo salar with focus on water recirculation aquaculture system environments

USDA-ARS?s Scientific Manuscript database

Maturation of Atlantic salmon Salmo salar is an extremely complex process, particularly in aquaculture systems, with many variables (known or otherwise) having the capacity to influence the timing and prevalence of maturation, and acting as promoters and/or inhibitors of sexual development. The vast...

Remodeling of the notochord during development of vertebral fusions in Atlantic salmon (Salmo salar).

PubMed

Ytteborg, Elisabeth; Torgersen, Jacob Seilø; Pedersen, Mona E; Baeverfjord, Grete; Hannesson, Kirsten O; Takle, Harald

2010-12-01

Histological characterization of spinal fusions in Atlantic salmon (Salmo salar) has demonstrated shape alterations of vertebral body endplates, a reduced intervertebral space, and replacement of intervertebral cells by ectopic bone. However, the significance of the notochord during the fusion process has not been addressed. We have therefore investigated structural and cellular events in the notochord during the development of vertebral fusions. In order to induce vertebral fusions, Atlantic salmon were exposed to elevated temperatures from fertilization until they attained a size of 15g. Based on results from radiography, intermediate and terminal stages of the fusion process were investigated by immunohistochemistry and real-time quantitative polymerase chain reaction. Examination of structural extracellular matrix proteins such as Perlecan, Aggrecan, Elastin, and Laminin revealed reduced activity and reorganization at early stages in the pathology. Staining for elastic fibers visualized a thinner elastic membrane surrounding the notochord of developing fusions, and immunohistochemistry for Perlecan showed that the notochordal sheath was stretched during fusion. These findings in the outer notochord correlated with the loss of Aggrecan- and Substance-P-positive signals and the further loss of vacuoles from the chordocytes in the central notochord. At more progressed stages of fusion, chordocytes condensed, and the expression of Aggrecan and Substance P reappeared. The hyperdense regions seem to be of importance for the formation of notochordal tissue into bone. Thus, the remodeling of notochord integrity by reduced elasticity, structural alterations, and cellular changes is probably involved in the development of vertebral fusions.

Sulphated glycosaminoglycans and proteoglycans in the developing vertebral column of juvenile Atlantic salmon (Salmo salar).

PubMed

Hannesson, Kirsten O; Ytteborg, Elisabeth; Takle, Harald; Enersen, Grethe; Bæverfjord, Grete; Pedersen, Mona E

2015-08-01

In the present study, the distribution of sulphated glycosaminoglycans (GAGs) in the developing vertebral column of Atlantic salmon (Salmo salar) at 700, 900, 1100 and 1400 d° was examined by light microscopy. The mineralization pattern was outlined by Alizarin red S and soft structures by Alcian blue. The temporal and spatial distribution patterns of different types of GAGs: chondroitin-4-sulphate/dermatan sulphate, chondroitin-6-sulphate, chondroitin-0-sulphate and keratan sulphate were addressed by immunohistochemistry using monoclonal antibodies against the different GAGs. The specific pattern obtained with the different antibodies suggests a unique role of the different GAG types in pattern formation and mineralization. In addition, the distribution of the different GAG types in normal and malformed vertebral columns from 15 g salmon was compared. A changed expression pattern of GAGs was found in the malformed vertebrae, indicating the involvement of these molecules during the pathogenesis. The molecular size of proteoglycans (PGs) in the vertebrae carrying GAGs was analysed with western blotting, and mRNA transcription of the PGs aggrecan, decorin, biglycan, fibromodulin and lumican by real-time qPCR. Our study reveals the importance of GAGs in development of vertebral column also in Atlantic salmon and indicates that a more comprehensive approach is necessary to completely understand the processes involved.

Genetic differentiation and forensic efficiency evaluation for Chinese Salar ethnic minority based on a 5-dye multiplex insertion and deletion panel.

PubMed

Ma, Ruilin; Shen, Chunmei; Wei, Yuanyuan; Jin, Xiaoye; Guo, Yuxin; Mu, Yuling; Sun, Siqi; Chen, Chong; Cui, Wei; Wei, Zhaoming; Lian, Zhenmin

2018-06-20

The present study investigated the genetic diversities of 30 autosomal insertion and deletion (InDel) loci of Investigator DIPplex kit (Qiagen) in Chinese Salar ethnic minority and explored the genetic relationships between the studied Salar group and other populations. The allelic frequencies of deletion alleles at the 30 InDel loci were in the range of 0.1739 (HLD64) to 0.8478 (HLD39). The discrimination power, polymorphism information content and probability of exclusion ranged from 0.4101 (HLD39) to 0.6447 (HLD136), 0.2247 (HLD39) to 0.3750 (HLD92) and 0.0400 (HLD39) to 0.2806 (HLD92), respectively. The observed and expected heterozygosity were in the range of 0.2348 (HLD39) to 0.5913 (HLD92), and 0.2580 (HLD39) to 0.5000 (HLD92), respectively. The cumulative discrimination power and probability of exclusion of the 30 loci reached 0.999999999993418 and 0.99039, respectively. The results of population genetic differentiation comparisons revealed that Salar group had similar allele distributions with Qinghai Tibetan, Xibe and Yi groups. Population Bayesian cluster analysis showed that there were similar ancestry components between Salar group and most Chinese populations. Besides, the principal components analysis and phylogenetic reconstructions further indicated that Salar group had intimate genetic relationships with Qinghai Tibetan and Xibe groups. In short, the results of the current studies indicated the genetic distributions of the 30 InDel loci in Salar group were relatively high genetic polymorphisms, which could be used in forensic individual identifications and as a supplementary tool for complex paternity testing. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of the marine feeding area on the muscle and egg fatty-acid composition of Atlantic salmon Salmo salar spawners estimated from the scale stable isotopes.

PubMed

Torniainen, J; Kainz, M J; Jones, R I; Keinänen, M; Vuorinen, P J; Kiljunen, M

2017-05-01

Fatty acids in muscle tissue and eggs of female Atlantic salmon Salmo salar spawners were analysed to evaluate the dietary quality of their final feeding areas in the Baltic Sea. The final likely feeding area was identified by comparing stable carbon and nitrogen isotope composition of the outermost growth region (final annulus) of scales of returned S. salar with that of reference S. salar caught from different feeding areas. Some overlap of stable-isotope reference values among the three areas, in addition to prespawning fasting, decreased the ability of muscle tri-acylglycerols to discriminate the final likely feeding area and the area's dietary quality. Among three long-chained polyunsaturated fatty acids, docosahexaenoic acid (DHA; 22:6n-3), eicosapentaenoic acid (EPA; 20:5n-3) and arachidonic acid (ARA; 20:4n-6), the proportions of ARA in total lipids of spawning S. salar muscle and eggs showed a significant negative correlation with increasing probability of S. salar having returned from the Baltic Sea main basin (i.e. the Baltic Sea proper). The results suggest that ARA in muscle and eggs is the best dietary indicator for dietary characteristics of final marine feeding area dietary characteristics among S. salar in the Baltic Sea. © 2017 The Fisheries Society of the British Isles.

Effects of rearing density and dietary fat content on burst-swim performance and oxygen transport capacity in juvenile Atlantic salmon Salmo salar.

PubMed

Hammenstig, D; Sandblom, E; Axelsson, M; Johnsson, J I

2014-10-01

The effects of hatchery rearing density (conventional or one third of conventional density) and feeding regime (high or reduced dietary fat levels) on burst-swim performance and oxygen transport capacity were studied in hatchery-reared Atlantic salmon Salmo salar, using wild fish as a reference group. There was no effect of rearing density or food regime on swimming performance in parr and smolts. The maximum swimming speed of wild parr was significantly higher than that of hatchery-reared conspecifics, while no such difference remained at the smolt stage. In smolts, relative ventricle mass was higher in wild S. salar compared with hatchery-reared fish. Moreover, wild S. salar had lower maximum oxygen consumption following a burst-swim challenge than hatchery fish. There were no effects of hatchery treatment on maximum oxygen consumption or relative ventricle mass. Haemoglobin and haematocrit levels, however, were lower in low-density fish than in fish reared at conventional density. Furthermore, dorsal-fin damage, an indicator of aggression, was similar in low-density reared and wild fish and lower than in S. salar reared at conventional density. Together, these results suggest that reduced rearing density is more important than reduced dietary fat levels in producing an S. salar smolt suitable for supplementary release. © 2014 The Fisheries Society of the British Isles.

Prolactin-releasing peptide is a potent mediator of the innate immune response in leukocytes from Salmo salar.

PubMed

Romero, Alex; Manríquez, René; Alvarez, Claudio; Gajardo, Cristina; Vásquez, Jorge; Kausel, Gudrun; Monrás, Mónica; Olavarría, Víctor H; Yáñez, Alejandro; Enríquez, Ricardo; Figueroa, Jaime

2012-06-30

Prolactin (PRL)-releasing peptide (PrRP) is a strong candidate stimulator of pituitary PRL transcription and secretion in teleosts. However, the role in control of extrapituitary PRL expression or its effects on innate immunity are unclear even in mammals. To study the possible presence of PrRP in peripheral organs, PrRP expression patterns and their effect on innate immunity were characterised in SHK-1 cells and head kidney (HK) leukocytes purified from the salmonid, Salmo salar. We detected immunoreactive cells in leukocytes from blood and HK of S. salar and found that PrRP mRNA was abundantly expressed in these cells. We have recently reported that physiological concentrations of native PRL, downstream of neuropeptide PrRP were able to induce expression of pro-inflammatory cytokines and the production of reactive oxygen species (ROS) in HK leukocytes and macrophages from S. salar and Sparus aurata. It is of interest to note that in this work we have revealed that synthetic PrRP was able to induce expression of pro-inflammatory cytokines (interleukins) IL-1β, IL-6, IL-8, IL-12 and PRL. We also show here that PrRP increased both (ROS) production and phagocytosis. Taken together, our results demonstrate for the first time that PrRP may be a local modulator of innate immune responses in leukocytes from S. salar. Copyright © 2012 Elsevier B.V. All rights reserved.

Effects of training on functional variables of muscles in reared Atlantic salmon Salmo salar smolts: connection to downstream migration pattern.

PubMed

Anttila, K; Jokikokko, E; Erkinaro, J; Järvilehto, M; Mänttäri, S

2011-02-01

The relative amount of muscle contraction regulating dihydropyridine and ryanodine receptors in the swimming muscles of trained reared Atlantic salmon Salmo salar smolts was compared with those of untrained and wild smolts. After an optimized 2 week training period, i.e. swimming with a velocity of 1·5 body lengths per second for 6 h per day, the level of both receptors was significantly higher in the muscles of trained S. salar than in the untrained ones before they were released into the natural environment. This difference persisted after downstream migration in the river. The highest level of receptors was observed in wild S. salar. Swimming performance was also higher in trained fish compared to untrained ones. Furthermore, swimming performance was positively associated with the level of receptors in both red and white muscle types. Downstream migration after release into the wild was significantly slower in trained smolts than in untrained fish. This indicates that trained smolts were most probably swimming harder against the current in the river than untrained smolts. The possible advantages for a slower migration in the river are discussed. This study shows that the prerequisites for effective contraction of the swimming muscles are better met in trained S. salar compared to untrained fish, and the muscles of trained smolts more closely resemble those of wild smolts. The results also imply that the capacity of untrained, reared smolts to swim against the current is not equal to that of their trained or wild counterparts which affects the downstream migration pattern of S. salar smolts. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Plasticity in response to feed availability: Does feeding regime influence the relative growth performance of domesticated, wild and hybrid Atlantic salmon Salmo salar parr?

PubMed

Harvey, A C; Solberg, M F; Glover, K A; Taylor, M I; Creer, S; Carvalho, G R

2016-09-01

Growth of farmed, wild and F1 hybrid Atlantic salmon parr Salmo salar was investigated under three contrasting feeding regimes in order to understand how varying levels of food availability affects relative growth. Treatments consisted of standard hatchery feeding (ad libitum), access to feed for 4 h every day, and access to feed for 24 h on three alternate days weekly. Mortality was low in all treatments, and food availability had no effect on survival of all groups. The offspring of farmed S. salar significantly outgrew the wild S. salar, while hybrids displayed intermediate growth. Furthermore, the relative growth differences between the farmed and wild S. salar did not change across feeding treatments, indicating a similar plasticity in response to feed availability. Although undertaken in a hatchery setting, these results suggest that food availability may not be the sole driver behind the observed reduced growth differences found between farmed and wild fishes under natural conditions. © 2016 The Fisheries Society of the British Isles.

Density-dependent effects of Caligus rogercresseyi infestation on the immune responses of Salmo salar.

PubMed

Boltaña, Sebastian; Sanchez, Marcos; Valenzuela, Valentina; Gallardo-Escárate, Cristian

2016-12-01

Sea lice infestations are a particular concern in the salmonid aquaculture industry due to damaging effects on fish growth, disease/infection susceptibility, and survival. Despite the impacts of sea lice parasitism, few studies have determined corresponding physiological thresholds, or the quantity of sea lice that can trigger measurable effects in the host immune response. The present study evaluated the mRNA expressions of immune-related genes in Salmo salar (Atlantic salmon) under infestation challenges with contrasting loads of the sea louse Caligus rogercresseyi. Specifically, two groups of S. salar were infected with either 35 (i.e. low parasitic load) or 100 (i.e. high parasitic load) copepodids per fish. At 14 days post-infestation, the mRNA levels of immune-related genes (e.g. related to oxidative stress, pro- and inflammatory responses, and the adaptive T H 1/T H 2 pathways) were assessed through RT-qPCR. Significant differences were found in relation to parasitic load, suggesting density-dependent effects that activated the S. salar immune system. Higher parasitic load promoted strong inflammatory and oxidative stress responses that were correlated with the T H 1 immune response. This study highlights the molecular signatures for distinct parasitic loads, providing new perspectives towards fully understanding parasite-host interactions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Stress response of Salmo salar (Linnaeus 1758) when heavily infested by Caligus rogercresseyi (Boxshall & Bravo 2000) copepodids.

PubMed

González, Margarita P; Vargas-Chacoff, Luis; Marín, Sandra L

2016-02-01

The year-round presence of ovigerous females of the parasite Caligus rogercresseyi in the fish farms of southern Chile results in a continuous source of the copepodid (infestive) stage of this louse. The short generation time in spring-summer could lead to high abundances of this copepodid, potentially leading to high infestation levels for fish. Knowing how heavy lice infestations affect Salmo salar can help determine how to time antiparasitic treatments so as to both minimize the treatment impact and reduce lice infestation levels for fish. This study aimed to describe the effects of high infestations of the copepodid stage of C. rogercresseyi on the physiology of S. salar. Two groups of S. salar were used: an infested group (75 copepodids per fish) and a control group (not infested). Sixty-five days after the first infestation, the infested fish group was re-infested at an infestation pressure of 200 copepodids per fish. Sampling was done prior to and following the second infestation, at 56 and 67 days (the latter 2 days following the second infestation). Several physiological variables were measured: cortisol (primary stress response) and glucose, proteins, amino acids, triglycerides, lactate, osmolality levels, and number and diameter of skin mucous cells (secondary stress responses). The plasma cortisol, glucose, and triglyceride levels were altered in the heavily infested fish, as was the diameter of skin mucous cells. These results suggest that heavy infestations of C. rogercresseyi lead to an acute stress response, metabolic reorganization, and increased mucus production in S. salar under heavy infestation conditions.

Growth of Atlantic salmon, Salmo salar fed diets containing barley protein concentrate

USDA-ARS?s Scientific Manuscript database

Atlantic salmon (Salmo salar) is an important cultured carnivorous species that in the past has not tolerated high levels of most plant protein feed ingredients in the diet. In order to increase efficiency, sustainability and production to meet global demand, new sources of protein must be incorpo...

Diel and seasonal variation in food habits of Atlantic salmon parr in a small stream

USGS Publications Warehouse

Grader, M.; Letcher, B.H.

2006-01-01

The diel and seasonal food habits of young-of-year (YOY) and post-young-of-year (PYOY) Atlantic salmon (Salmo salar) parr were assayed over the course of 11 months in the West Brook, Massachusetts USA. Gut fullness of YOY salmon did not vary significantly among months. PYOY salmon exhibited significant seasonal differences in gut fullness, with peak fullness occurring in the spring and late fall. Significant diel differences in PYOY gut fullness occurred in June and April, with peak fullness always occurring at dawn. Prey composition varied substantially among months. Dominant prey items of PYOY salmon were baetid mayflies in June, July, and August, limnephilid caddisflies in October and November, and ephemerellid mayflies in February and April. Few differences in prey composition between PYOY and YOY salmon were observed. Fish growth was unrelated to prey availability, but gut fullness explained up to 97% of growth variation across seasons. Results suggest that spring and fall are critical periods of feeding for PYOY salmon and that diel feeding intensity shifts seasonally.

Kinetics of arsenite removal by halobacteria from a highland Andean Chilean Salar

PubMed Central

2013-01-01

Background The purpose of this study was to identify arsenite-oxidizing halobacteria in samples obtained from Salar de Punta Negra, II Region of Chile. Seven bacterial isolates, numbered as isolates I to VII, grown in a culture medium with 100 ppm as NaAsO2 (As (III)) were tested. Bacterial growth kinetics and the percent of arsenite removal (PAR) were performed simultaneously with the detection of an arsenite oxidase enzyme through Dot Blot analysis. Results An arsenite oxidase enzyme was detected in all isolates, expressed constitutively after 10 generations grown in the absence of As (III). Bacterial growth kinetics and corresponding PAR values showed significant fluctuations over time. PARs close to 100% were shown by isolates V, VI, and VII, at different times of the bacterial growth phase; while isolate II showed PAR values around 40%, remaining constant over time. Conclusion Halobacteria from Salar de Punta Negra showed promising properties as arsenite removers under control conditions, incubation time being a critical parameter. PMID:23547876

Evidence for long-term change in length, mass and migration phenology of anadromous spawners in French Atlantic salmon Salmo salar.

PubMed

Bal, G; Montorio, L; Rivot, E; Prévost, E; Baglinière, J-L; Nevoux, M

2017-06-01

This study provides new data on Atlantic salmon Salmo salar life-history traits across France. Using a long-term recreational angling database (1987-2013) covering 34 rivers in three regions (genetic units), a decline in individual length, mass and a delayed adult return to French rivers was reported. Temporal similarities in trait variations between regions may be attributed to common change in environmental conditions at sea. The relative rate of change in phenotypic traits was more pronounced in early maturing fish [1 sea-winter (1SW) fish] than in late maturing fish (2SW fish). Such contrasted response within populations highlights the need to account for the diversity in life histories when exploring mechanisms of phenotypic change in S. salar. Such detailed life-history data on returning S. salar have not previously been reported from France. This study on French populations also contributes to reducing the gap in knowledge by providing further empirical evidence of a global pattern in S. salar across its distribution range. Results are consistent with the hypothesis that the observed changes in life-history traits are primarily associated with environmental changes in the North Atlantic Ocean. They also emphasize the presence of less important, but still significant contrasts between region and life history. © 2017 The Fisheries Society of the British Isles.

Divergent trends in life-history traits between Atlantic salmon Salmo salar of wild and hatchery origin in the Baltic Sea.

PubMed

Vainikka, A; Kallio-Nyberg, I; Heino, M; Koljonen, M-L

2010-02-01

Four Atlantic salmon Salmo salar stocks in the Baltic Sea, varying in their breeding history, were studied for changes in life-history traits over the years 1972-1995. Total length (L(T)) at age of captured (L(TC)) fish had increased throughout the study period, partly due to increased temperature and increased L(T) at release, (L(TR)) but also due to remaining cohort effects that could represent unaccounted environmental or genetic change. Simultaneously, maturation probabilities controlled for water temperature, L(TC) and L(TR) had increased in all stocks. The least change was observed in the River Tornionjoki S. salar that was subject only to supportive stockings originating from wild parents. These results suggest a long-term divergence between semi-natural and broodstock-based S. salar stocks. Increased L(T) at age explained advanced maturation only marginally, and it remains an open question to what extent the generally increased probabilities to mature at early age reflected underlying genetic changes.

Topography of the Flattest Surface on Earth: using ICESAT, GPS, and MISR to Measure Salt Surface Topography on Salar de Uyuni, Bolivia

NASA Technical Reports Server (NTRS)

Comstock, Robert L.; Bills, Bruce G.

2004-01-01

Salt flats are aptly named: they are composed largely of salt, and are maintained as nearly equipotential surfaces via frequent flooding. The salar de Uyuni, on the Altiplano in southwestern Bolivia, is the largest salt flat on Earth, with an area of 9,800 sq km. Except for a few bedrock islands, it has less than 40 cm of relief. The upper-most salt unit averages 5 m thick and contains 50 cu km of nearly pure halite. It includes most of the salt that was in solution in paleolake Minchin, which attained a maximum area of 60,000 sq km and a maximum depth of 150 m, roughly 15 kyr ago. Despite approx. 10 m of differential isostatic rebound since deposition, the salar surface has been actively maintained as an extraordinarily flat and smooth surface by annual flooding during the rainy season. We have used the strong optical absorption properties of water in the visible band to map spatial variations in water depth during a time when the salar was flooded. As water depth increases, the initially pure white surface appears both darker and bluer. We utilized MISR images taken during the interval from April to November 2001. The red and infra-red bands (672 and 867 nm wavelength) were most useful since the water depth is small and the absorption at those wavelengths is quite strong. Nadir pointed MISR images have 275 m spatial resolution. To aid in our evaluation of water depth variations over the saiar surface, we utilized two sources of direct topographic measurements: several ICESAT altimetry tracks cross the area, and a 40x50 km GPS grid was surveyed to calibrate ICESAT. A difficulty in using these data types is that both give salt surface elevations relative to the ellipsoid, whereas the water surface will, in the absence of wind or tidal disturbances, follow an equipotential surface. Geoid height is not known to the required accuracy of a few cm in the central Andes. As a result, before comparing optical absorption from MISR to salt surface topography from GPS or

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.

An evolutionary view on tooth development and replacement in wild Atlantic salmon (Salmo salar L.).

PubMed

Huysseune, A; Witten, P E

2008-01-01

To gain an insight into the evolution of tooth replacement mechanisms, we studied the development of first-generation and replacement teeth on the dentary of wild Atlantic salmon (Salmo salar L.), a protacanthopterygian teleost, using serially sectioned heads of early posthatching stages as well as adults. First-generation teeth develop within the oral epithelium. The anlage of the replacement tooth is first seen as a placode-like thickening of the outer dental epithelium of the predecessor, at its lingual and caudal side. Ongoing development of the replacement tooth germ is characterized by the elaboration of a population of epithelial cells, termed here the middle dental epithelium, apposed to the inner dental epithelium on the lingual side of the tooth germ. Before the formation of the new successor, a single-layered outer dental epithelium segregates from the middle dental epithelium. The dental organs of the predecessor and the successor remain broadly interconnected. The absence of a discrete successional dental lamina in salmon stands in sharp contrast to what is observed in other teleosts, even those that share with salmon the extraosseous formation of replacement teeth. The mode of tooth replacement in Atlantic salmon displays several characters similar to those observed in the shark Squalus acanthias. To interpret similarities in tooth replacement between Atlantic salmon and chondrichthyans as a case of convergence, or to see them as a result of a heterochronic shift, requires knowledge on the replacement process in more basal actinopterygian lineages. The possibility that the middle dental epithelium functionally substitutes for a successional lamina, and could be a source of stem cells, whose descendants subsequently contribute to the placode of the new replacement tooth, needs to be explored.

The effect of catch-and-release angling at high water temperatures on behaviour and survival of Atlantic salmon Salmo salar during spawning migration.

PubMed

Havn, T B; Uglem, I; Solem, Ø; Cooke, S J; Whoriskey, F G; Thorstad, E B

2015-08-01

In this study, behaviour and survival following catch-and-release (C&R) angling was investigated in wild Atlantic salmon Salmo salar (n = 75) angled on sport fishing gear in the River Otra in southern Norway at water temperatures of 16.3-21.1 °C. Salmo salar were tagged externally with radio transmitters and immediately released back into the river to simulate a realistic C&R situation. The majority of S. salar (91%) survived C&R. Most S. salar that were present in the River Otra during the spawning period 3-4 months later were located at known spawning grounds. Downstream movements (median furthest position: 0.5 km, range: 0.1-11.0 km) during the first 4 days after release were recorded for 72% of S. salar, presumably stress-induced fallback associated with C&R. Individuals that fell back spent a median of 15 days before commencing their first upstream movement after release, and 34 days before they returned to or were located above their release site. Mortality appeared to be somewhat elevated at the higher end of the temperature range (14% at 18-21 °C), although sample sizes were low. In conclusion, C&R at water temperatures up to 18 °C had small behavioural consequences and was associated with low mortality (7%). Nevertheless, low levels of mortality occur due to C&R angling and these losses should be accounted for by management authorities in rivers where C&R is practised. Refinement of best practices for C&R may help to reduce mortality, particularly at warmer temperatures. © 2015 The Fisheries Society of the British Isles.

Assessment of interbreeding and introgression of farm genes into a small Scottish Atlantic salmon Salmo salar stock: ad hoc samples - ad hoc results?

PubMed

Verspoor, E; Knox, D; Marshall, S

2016-12-01

An eclectic set of tissues and existing data, including purposely collected samples, spanning 1997-2006, was used in an ad hoc assessment of hybridization and introgression of farmed wild Atlantic salmon Salmo salar in the small Loch na Thull (LnT) catchment in north-west Scotland. The catchment is in an area of marine farm production and contains freshwater smolt rearing cages. The LnT S. salar stock was found to be genetically distinctive from stocks in neighbouring rivers and, despite regular reports of feral farm S. salar, there was no evidence of physical or genetic mixing. This cannot be completely ruled out, however, and low level mixing with other local wild stocks has been suggested. The LnT population appeared underpinned by relatively smaller effective number of breeders (N eb ) and showed relatively low levels of genetic diversity, consistent with a small effective population size. Small sample sizes, an incomplete farm baseline and the use of non-diagnostic molecular markers, constrain the power of the analysis but the findings strongly support the LnT catchment having a genetically distinct wild S. salar population little affected by interbreeding with feral farm escapes. © 2016 The Fisheries Society of the British Isles.

Development of schooling behaviour during the downstream migration of Atlantic salmon Salmo salar smolts in a chalk stream.

PubMed

Riley, W D; Ibbotson, A T; Maxwell, D L; Davison, P I; Beaumont, W R C; Ives, M J

2014-10-01

The downstream migratory behaviour of wild Atlantic salmon Salmo salar smolts was monitored using passive integrated transponder (PIT) antennae systems over 10 years in the lower reaches of a small chalk stream in southern England, U.K. The timing of smolt movements and the likely occurrence of schooling were investigated and compared to previous studies. In nine of the 10 consecutive years of study, the observed diel downstream patterns of S. salar smolt migration appeared to be synchronized with the onset of darkness. The distribution of time intervals between successive nocturnal detections of PIT-tagged smolts was as expected if generated randomly from observed hourly rates. There were, however, significantly more short intervals than expected for smolts detected migrating during the day. For each year from 2006 to 2011, the observed 10th percentile of the daytime intervals was <4 s, compared to ≥55 s for the simulated random times, indicating greater incidence of groups of smolts. Groups with the shortest time intervals between successive PIT tag detections originated from numerous parr tagging sites (used as a proxy for relatedness). The results suggest that the ecological drivers influencing daily smolt movements in the lower reaches of chalk stream catchments are similar to those previously reported at the onset of migration for smolts leaving their natal tributaries; that smolts detected migrating during the night are moving independently following initiation by a common environmental factor (presumably darkness), whereas those detected migrating during the day often move in groups, and that such schools may not be site (kin)-structured. The importance of understanding smolt migratory behaviour is considered with reference to stock monitoring programmes and enhancing downstream passage past barriers. © 2014 Crown copyright. Journal of Fish Biology © 2014 The Fisheries Society of the British Isles.

Seasonal variation in size-dependent survival of juvenile Atlantic salmon (Salmo salar): Performance of multistate capture-mark-recapture models

USGS Publications Warehouse

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

2008-01-01

We estimated the magnitude and shape of size-dependent survival (SDS) across multiple sampling intervals for two cohorts of stream-dwelling Atlantic salmon (Salmo salar) juveniles using multistate capture-mark-recapture (CMR) models. Simulations designed to test the effectiveness of multistate models for detecting SDS in our system indicated that error in SDS estimates was low and that both time-invariant and time-varying SDS could be detected with sample sizes of >250, average survival of >0.6, and average probability of capture of >0.6, except for cases of very strong SDS. In the field (N ??? 750, survival 0.6-0.8 among sampling intervals, probability of capture 0.6-0.8 among sampling occasions), about one-third of the sampling intervals showed evidence of SDS, with poorer survival of larger fish during the age-2+ autumn and quadratic survival (opposite direction between cohorts) during age-1+ spring. The varying magnitude and shape of SDS among sampling intervals suggest a potential mechanism for the maintenance of the very wide observed size distributions. Estimating SDS using multistate CMR models appears complementary to established approaches, can provide estimates with low error, and can be used to detect intermittent SDS. ?? 2008 NRC Canada.

Some quantitative indicators of postovulatory aging and its effect on larval and juvenile development of Atlantic salmon (Salmo salar).

PubMed

Mommens, Maren; Storset, Arne; Babiak, Igor

2015-07-01

Modern out-of-season egg production in Atlantic salmon (Salmo salar) increases the risk of postovulatory aging (POA) of oocytes. Postovulatory aging is known to influence oocyte quality in salmonids, but reliable tests for POA are lacking in Atlantic salmon egg production. To address this problem, we have collected oocytes from the same 20 Atlantic salmon females sequentially in approximately 1-week intervals, from the start of ovulation until 28 days postovulation (dpo), to determine the effect of natural retention of matured oocytes in body coelomic cavity on further performance of embryos and juveniles produced from those oocytes. Also, we investigated oocyte water hardening and several coelomic fluid parameters as potential quantitative indicators of POA. Oocyte quality decreased significantly from 22 dpo onward, as inferred from decrease in fertilization success and survival of embryos, alevins, and juveniles and increase in alevin and juvenile deformity rates. The occurrence of head deformities was significantly related to postovulatory age of oocytes. Coelomic fluid pH decreased significantly at 28 dpo and correlated positively with fertilization rates (r = 0.45), normal eyed embryo rates (r = 0.67), and alevin relative survival rates (r = 0.63) and negatively correlated with total alevin deformity rates (r = -0.59). Oocyte weight gain at 60 minutes decreased significantly at 28 dpo and correlated negatively with total alevin deformities and the occurrence of cranial nodules (r = -0.99). Generally, quality of ovulated oocytes remained stable for the first 2 weeks after ovulation. Later on, POA negatively influenced Atlantic salmon embryo, alevin, and juvenile performance. For the first time, we show a long-term effect of POA on salmonid juvenile performance. Standardized pH measurements of coelomic fluid could potentially improve embryo and juvenile production by identifying low-quality oocytes at an early stage during the production. Copyright © 2015

COMplementary Primer ASymmetric PCR (COMPAS-PCR) Applied to the Identification of Salmo salar, Salmo trutta and Their Hybrids

PubMed Central

2016-01-01

Avoiding complementarity between primers when designing a PCR assay constitutes a central rule strongly anchored in the mind of the molecular scientist. 3’-complementarity will extend the primers during PCR elongation using one another as template, consequently disabling further possible involvement in traditional target amplification. However, a 5’-complementarity will leave the primers unchanged during PCR cycles, albeit sequestered to one another, therefore also suppressing target amplification. We show that 5’-complementarity between primers may be exploited in a new PCR method called COMplementary-Primer-Asymmetric (COMPAS)-PCR, using asymmetric primer concentrations to achieve target PCR amplification. Moreover, such a design may paradoxically reduce spurious non-target amplification by actively sequestering the limiting primer. The general principles were demonstrated using 5S rDNA direct repeats as target sequences to design a species-specific assay for identifying Salmo salar and Salmo trutta using almost fully complementary primers overlapping the same target sequence. Specificity was enhanced by using 3’-penultimate point mutations and the assay was further developed to enable identification of S. salar x S. trutta hybrids by High Resolution Melt analysis in a 35 min one-tube assay. This small paradigm shift, using highly complementary primers for PCR, should help develop robust assays that previously would not be considered. PMID:27783658

Influence of Development and Dietary Phospholipid Content and Composition on Intestinal Transcriptome of Atlantic Salmon (Salmo salar)

PubMed Central

De Santis, Christian; Taylor, John F.; Martinez-Rubio, Laura; Boltana, Sebastian; Tocher, Douglas R.

2015-01-01

The inclusion of intact phospholipids in the diet is essential during larval development and can improve culture performance of many fish species. The effects of supplementation of dietary phospholipid from marine (krill) or plant (soy lecithin) sources were investigated in Atlantic salmon, Salmo salar. First feeding fry were fed diets containing either krill oil or soybean lecithin supplying phospholipid at 2.6%, 3.2%, 3.6% and 4.2% of diet. Fish were sampled at ~ 2.5 g (~1,990°day post fertilization, dpf) and ~10 g (2,850°dpf). By comparison of the intestinal transcriptome in specifically chosen contrasts, it was determined that by 2,850°dpf fish possessed a profile that resembled that of mature and differentiated intestinal cell types with a number of changes specific to glycerophospholipid metabolism. It was previously shown that intact phospholipids and particularly phosphatidylcholine are essential during larval development and that this requirement is associated with the inability of enterocytes in young fry to endogenously synthesize sufficient phospholipid for the efficient export of dietary lipid. In the immature phase (~1,990°dpf), the dietary phospholipid content as well as its class composition impacted on several biochemical and morphological parameters including growth, but these differences were not associated with differences in intestinal transcriptomes. The results of this study have made an important contribution to our understanding of the mechanisms associated with lipid transport and phospholipid biosynthesis in early life stages of fish. PMID:26488165

A primary phosphorus-deficient skeletal phenotype in juvenile Atlantic salmon Salmo salar: the uncoupling of bone formation and mineralization.

PubMed

Witten, P E; Owen, M A G; Fontanillas, R; Soenens, M; McGurk, C; Obach, A

2016-02-01

To understand the effect of low dietary phosphorus (P) intake on the vertebral column of Atlantic salmon Salmo salar, a primary P deficiency was induced in post-smolts. The dietary P provision was reduced by 50% for a period of 10 weeks under controlled conditions. The animal's skeleton was subsequently analysed by radiology, histological examination, histochemical detection of minerals in bones and scales and chemical mineral analysis. This is the first account of how a primary P deficiency affects the skeleton in S. salar at the cellular and at the micro-anatomical level. Animals that received the P-deficient diet displayed known signs of P deficiency including reduced growth and soft, pliable opercula. Bone and scale mineral content decreased by c. 50%. On radiographs, vertebral bodies appear small, undersized and with enlarged intervertebral spaces. Contrary to the X-ray-based diagnosis, the histological examination revealed that vertebral bodies had a regular size and regular internal bone structures; intervertebral spaces were not enlarged. Bone matrix formation was continuous and uninterrupted, albeit without traces of mineralization. Likewise, scale growth continues with regular annuli formation, but new scale matrix remains without minerals. The 10 week long experiment generated a homogeneous osteomalacia of vertebral bodies without apparent induction of skeletal malformations. The experiment shows that bone formation and bone mineralization are, to a large degree, independent processes in the fish examined. Therefore, a deficit in mineralization must not be the only cause of the alterations of the vertebral bone structure observed in farmed S. salar. It is discussed how the observed uncoupling of bone formation and mineralization helps to better diagnose, understand and prevent P deficiency-related malformations in farmed S. salar. © 2015 The Authors.Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of The Fisheries Society of the

Identification and expressional analysis of NLRC5 inflammasome gene in smolting Atlantic salmon (Salmo salar).

PubMed

Pontigo, Juan Pablo; Agüero, María José; Sánchez, Patricio; Oyarzún, Ricardo; Vargas-Lagos, Carolina; Mancilla, Jorge; Kossmann, Hans; Morera, Francisco J; Yáñez, Alejandro J; Vargas-Chacoff, Luis

2016-11-01

The NOD-like receptors (NLRs) were recently identified as an intracellular pathogen recognition receptor family in vertebrates. While the immune system participation of NLRs has been characterized and analyzed in various mammalian models, few studies have considered NLRs in teleost species. Therefore, this study analyzed the Atlantic salmon (Salmo salar) NLRC5. Structurally, Atlantic salmon NLRC5 presented leucine-rich repeat subfamily genes. Phylogenetically, NLRC5 was moderately conserved between S. salar and other species. Real-time quantitative PCR revealed NLRC5 expression in almost all analyzed organs, with greatest expressions in the head kidney, spleen, and hindgut. Furthermore, NLRC5 gene expression decreased during smolt stage. These data suggest that NLRC5 participates in the Atlantic salmon immune response and is regulated, at least partly, by the smoltification process, suggesting that there is a depression of immune system from parr at smolt stage. This is the first report on the NLRC5 gene in salmonid smolts. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effects of feeding regimes and early maturation on migratory behaviour of landlocked hatchery-reared Atlantic salmon Salmo salar smolts.

PubMed

Norrgård, J R; Bergman, E; Schmitz, M; Greenberg, L A

2014-10-01

The migratory behaviour of hatchery-reared landlocked Atlantic salmon Salmo salar raised under three different feeding regimes was monitored through the lower part of the River Klarälven, Sweden. The smolts were implanted with acoustic transmitters and released into the River Klarälven, 25 km upstream of the outlet in Lake Vänern. Early mature males, which had matured the previous autumn, were also tagged and released. To monitor migration of the fish, acoustic receivers were deployed along the migratory route. The proportion of S. salar that reached Lake Vänern was significantly greater for fish fed fat-reduced feed than for fish given rations with higher fat content, regardless of ration size. Fish from the early mature male group remained in the river to a greater extent than fish from the three feeding regimes. Smolt status (degree of silvering), as visually assessed, did not differ among the feeding regime groups, and moreover, fully-silvered fish, regardless of feeding regime, migrated faster and had a greater migration success than fish with less developed smolt characteristics. Also, successful migrants had a lower condition factor than unsuccessful ones. These results indicate that the migration success of hatchery-reared S. smolts released to the wild can be enhanced by relatively simple changes in feeding regimes and by matching stocking time with smolt development. © 2014 The Fisheries Society of the British Isles.

Interaction between migration behaviour and estuarine mortality in cultivated Atlantic salmon Salmo salar smolts.

PubMed

Vollset, K W; Mahlum, S; Davidsen, J G; Skoglund, H; Barlaup, B T

2016-10-01

Migration behaviour and estuarine mortality of cultivated Atlantic salmon Salmo salar smolts in a 16 km long estuary were studied using two methods: (1) acoustic telemetry and (2) group tagging in combination with trap nets. Progression rates of surviving individuals through the estuary were relatively slow using both methods [0·38 L T (total length) s -1 v. 0·25 L T  s -1 ]. In 2012, the progression rate was slow from the river to the estuary (0·55 L T  s -1 ) and the first part of the estuary (0·31 L T  s -1 ), but increased thereafter (1·45-2·21 L T  s -1 ). In 2013, the progression rate was fast from the river to the estuary (4·31 L T  s -1 ) but was slower thereafter (0·18-0·91 L T  s -1 ). Survival to the fjord was higher in 2012 (47%) compared to 2013 (6%). Fast moving individuals were more likely to migrate successfully through the estuary compared to slower moving individuals. Adult recapture of coded-wire-tagged S. salar was generally low (0·00-0·04%). Mortality hot spots were related to topographically distinct areas such as the river outlet (in 2012) or the sill separating the estuary and the fjord (in 2013). At the sill, an aggregation of cod Gadus morhua predating on cultivated smolts was identified. The results indicate that slow progression rates through the estuary decreases the likelihood of smolts being detected outside the estuary. The highly stochastic and site-specific mortality patterns observed in this study highlight the complexity in extrapolating mortality patterns of single release groups to the entire smolt run of wild S. salar. © 2016 The Fisheries Society of the British Isles.

Passing a seawater challenge test is not indicative of hatchery-reared Atlantic salmon Salmo salar smolts performing as well at sea as their naturally produced conspecifics.

PubMed

Jensen, A J; Berg, M; Bremset, G; Finstad, B; Hvidsten, N A; Jensås, J G; Johnsen, B O; Lund, E

2016-06-01

Despite satisfactory reactions to seawater challenge tests indicative of appropriate physiological state, hatchery-reared Atlantic salmon Salmo salar smolts stocked in the Eira River in Norway between 2001 and 2011 performed less well at sea in terms of growth, age at maturity and survival than smolts of natural origin. The mean rates of return to the river for hatchery-reared and naturally produced S. salar were 0·98 and 2·35%. In the Eira River, c. 50 000 hatchery-reared S. salar smolts of local origin were stocked annually to compensate for reduced natural smolt production following regulation for hydroelectric purposes, while a mean of 17 262 smolts were produced naturally in the river. This study demonstrates that, although captive S. salar perform well in seawater challenge tests, hatchery-reared smolts are not necessarily as adaptable to marine life as their naturally produced counterparts. These findings suggest that production of hatchery-reared smolts more similar to naturally produced individuals in morphology, physiology and behaviour will be necessary to improve success of hatchery releases. Where possible, supplementary or alternative measures, including habitat restoration, could be implemented to ensure the long-term viability of wild stocks. © 2016 The Fisheries Society of the British Isles.

Epithelial Label-Retaining Cells Are Absent during Tooth Cycling in Salmo salar and Polypterus senegalus.

PubMed

Vandenplas, Sam; Willems, Maxime; Witten, P Eckhard; Hansen, Tom; Fjelldal, Per Gunnar; Huysseune, Ann

2016-01-01

The Atlantic salmon (Salmo salar) and African bichir (Polypterus senegalus) are both actinopterygian fish species that continuously replace their teeth without the involvement of a successional dental lamina. Instead, they share the presence of a middle dental epithelium: an epithelial tier enclosed by inner and outer dental epithelium. It has been hypothesized that this tier could functionally substitute for a successional dental lamina and might be a potential niche to house epithelial stem cells involved in tooth cycling. Therefore, in this study we performed a BrdU pulse chase experiment on both species to (1) determine the localization and extent of proliferating cells in the dental epithelial layers, (2) describe cell dynamics and (3) investigate if label-retaining cells are present, suggestive for the putative presence of stem cells. Cells proliferate in the middle dental epithelium, outer dental epithelium and cervical loop at the lingual side of the dental organ to form a new tooth germ. Using long chase times, both in S. salar (eight weeks) and P. senegalus (eight weeks and twelve weeks), we could not reveal the presence of label-retaining cells in the dental organ. Immunostaining of P. senegalus dental organs for the transcription factor Sox2, often used as a stem cell marker, labelled cells in the zone of outer dental epithelium which grades into the oral epithelium (ODE transition zone) and the inner dental epithelium of a successor only. The location of Sox2 distribution does not provide evidence for epithelial stem cells in the dental organ and, more specifically, in the middle dental epithelium. Comparison of S. salar and P. senegalus reveals shared traits in tooth cycling and thus advances our understanding of the developmental mechanism that ensures lifelong replacement.

Epithelial Label-Retaining Cells Are Absent during Tooth Cycling in Salmo salar and Polypterus senegalus

PubMed Central

Vandenplas, Sam; Willems, Maxime; Witten, P. Eckhard; Hansen, Tom; Fjelldal, Per Gunnar; Huysseune, Ann

2016-01-01

The Atlantic salmon (Salmo salar) and African bichir (Polypterus senegalus) are both actinopterygian fish species that continuously replace their teeth without the involvement of a successional dental lamina. Instead, they share the presence of a middle dental epithelium: an epithelial tier enclosed by inner and outer dental epithelium. It has been hypothesized that this tier could functionally substitute for a successional dental lamina and might be a potential niche to house epithelial stem cells involved in tooth cycling. Therefore, in this study we performed a BrdU pulse chase experiment on both species to (1) determine the localization and extent of proliferating cells in the dental epithelial layers, (2) describe cell dynamics and (3) investigate if label-retaining cells are present, suggestive for the putative presence of stem cells. Cells proliferate in the middle dental epithelium, outer dental epithelium and cervical loop at the lingual side of the dental organ to form a new tooth germ. Using long chase times, both in S. salar (eight weeks) and P. senegalus (eight weeks and twelve weeks), we could not reveal the presence of label-retaining cells in the dental organ. Immunostaining of P. senegalus dental organs for the transcription factor Sox2, often used as a stem cell marker, labelled cells in the zone of outer dental epithelium which grades into the oral epithelium (ODE transition zone) and the inner dental epithelium of a successor only. The location of Sox2 distribution does not provide evidence for epithelial stem cells in the dental organ and, more specifically, in the middle dental epithelium. Comparison of S. salar and P. senegalus reveals shared traits in tooth cycling and thus advances our understanding of the developmental mechanism that ensures lifelong replacement. PMID:27049953

Microbial community composition and trophic role along a marked salinity gradient in Laguna Puilar, Salar de Atacama, Chile.

PubMed

Dorador, Cristina; Fink, Patrick; Hengst, Martha; Icaza, Gonzalo; Villalobos, Alvaro S; Vejar, Drina; Meneses, Daniela; Zadjelovic, Vinko; Burmann, Lisa; Moelzner, Jana; Harrod, Chris

2018-05-09

The geological, hydrological and microbiological features of the Salar de Atacama, the most extensive evaporitic sedimentary basin in the Atacama Desert of northern Chile, have been extensively studied. In contrast, relatively little attention has been paid to the composition and roles of microbial communities in hypersaline lakes which are a unique feature in the Salar. In the present study biochemical, chemical and molecular biological tools were used to determine the composition and roles of microbial communities in water, microbial mats and sediments along a marked salinity gradient in Laguna Puilar which is located in the "Los Flamencos" National Reserve. The bacterial communities at the sampling sites were dominated by members of the phyla Bacteroidetes, Chloroflexi, Cyanobacteria and Proteobacteria. Stable isotope and fatty acid analyses revealed marked variability in the composition of microbial mats at different sampling sites both horizontally (at different sites) and vertically (in the different layers). The Laguna Puilar was shown to be a microbially dominated ecosystem in which more than 60% of the fatty acids at particular sites are of bacterial origin. Our pioneering studies also suggest that the energy budgets of avian consumers (three flamingo species) and dominant invertebrates (amphipods and gastropods) use minerals as a source of energy and nutrients. Overall, the results of this study support the view that the Salar de Atacama is a heterogeneous and fragile ecosystem where small changes in environmental conditions may alter the balance of microbial communities with possible consequences at different trophic levels.

Pop-up satellite archival tag effects on the diving behaviour, growth and survival of adult Atlantic salmon Salmo salar at sea.

PubMed

Hedger, R D; Rikardsen, A H; Thorstad, E B

2017-01-01

The effects of large, externally attached pop-up satellite archival tags (PSATs) were compared with those of small implanted data storage tags (DSTs) on adult Atlantic salmon Salmo salar during their ocean migration in regards to depth utilization, diving depth, diving rate, diving speed and temperatures experienced. Additionally the return rate and growth of individuals tagged with PSATs was compared with those of small acoustic tags and DSTs. Overall, the depth distribution of individuals tagged with PSATs was similar to that of those tagged with DSTs, reflecting the pelagic nature of S. salar at sea. Individuals tagged with PSATs, however, dived less frequently and to shallower depths, and dived and surfaced at slower velocities. Sea surface temperatures experienced by individuals tagged with PSATs were similar to those experienced by those tagged with DSTs for the same time of year, suggesting that there were no large differences in the ocean migration. Return rates did not depend on whether individuals were tagged with PSATs or not, indicating that survival at sea was not impacted by PSATs in comparison to small internal tags. Individuals tagged with PSATs, however, had a smaller increase in body mass than those tagged with acoustic tags or DSTs. It was concluded that PSATs are suitable for use in researching large-scale migratory behaviour of adult S. salar at sea, but that some effects on their behaviour from tagging must be expected. Effects of PSATs may be largest in the short term when S. salar are swimming in bursts at high speeds. Even though individuals tagged with PSATs performed deep and frequent dives, the results of this study suggest that untagged individuals would perform even deeper and more frequent dives than tagged individuals. © 2016 The Fisheries Society of the British Isles.

Fast detection of Piscirickettsia salmonis in Salmo salar serum through MALDI-TOF-MS profiling.

PubMed

Olate, Verónica R; Nachtigall, Fabiane M; Santos, Leonardo S; Soto, Alex; Araya, Macarena; Oyanedel, Sandra; Díaz, Verónica; Marchant, Vanessa; Rios-Momberg, Mauricio

2016-03-01

Piscirickettsia salmonis is a pathogenic bacteria known as the aetiological agent of the salmonid rickettsial syndrome and causes a high mortality in farmed salmonid fishes. Detection of P. salmonis in farmed fishes is based mainly on molecular biology and immunohistochemistry techniques. These techniques are in most of the cases expensive and time consuming. In the search of new alternatives to detect the presence of P. salmonis in salmonid fishes, this work proposed the use of MALDI-TOF-MS to compare serum protein profiles from Salmo salar fish, including experimentally infected and non-infected fishes using principal component analysis (PCA). Samples were obtained from a controlled bioassay where S. salar was challenged with P. salmonis in a cohabitation model and classified according to the presence or absence of the bacteria by real time PCR analysis. MALDI spectra of the fish serum samples showed differences in its serum protein composition. These differences were corroborated with PCA analysis. The results demonstrated that the use of both MALDI-TOF-MS and PCA represents a useful tool to discriminate the fish status through the analysis of salmonid serum samples. Copyright © 2016 John Wiley & Sons, Ltd.

Quaternary shortening in the central Puna Plateau of NW Argentina: Preliminary results from the Salar de Pocitos, Salta province (24.5° S, 67° W)

NASA Astrophysics Data System (ADS)

Freymark, Jessica; Strecker, Manfred R.; Bookhagen, Bodo; Bekeschus, Benjamin; Eckelmann, Felix; Alonso, Ricardo

2013-04-01

differential basin-wide deformation. Although it is not possible yet to develop a reliable terrace chronology, taken together, the western terraces are higher than possibly equivalent terraces in the east, suggesting ongoing tilting related to protracted folding of the anticline in the west. In addition, orientations of faults, joints and tilted deposits were measured and analyzed. We show (preliminary) results and interpretations of these measurements. Tilted volcanic ash and sediment deposits have different dips and it appears that a distinct deformation stage is related to the regional anticline west of the Salar. A tectonic joint system and various small reverse faults also indicate active shortening in the area of the Salar de Pocitos from the Tertiary to the present-day. Reference: Cladouhos, T.T.; Allmendinger, R.W.; Coira, B. and Farrar, E. (1994): Late Cenozoic deformation in the Central Andes: fault kinematics from the northern Puna, northwestern Argentina and southwestern Bolivia (Journal of South American Earth Sciences, Vol. 7, No. 2., pp. 209-228)

Growth hormone transgenesis does not influence territorial dominance or growth and survival of first-feeding Atlantic salmon Salmo salar in food-limited stream microcosms.

PubMed

Moreau, D T R; Fleming, I A; Fletcher, G L; Brown, J A

2011-03-01

This study explored the relative competitive ability and performance of first-feeding growth hormone (GH) transgenic and non-transgenic Atlantic salmon Salmo salar fry under low food conditions. Pair-wise dominance trials indicated a strong competitive advantage for residents of a contested foraging territory. Transgenic and non-transgenic individuals, however, were equally likely to be dominant. Similarly, in stream environments with limited food, the transgene did not influence the growth in mass or survival at high or low fry densities. Fry in low-density treatments, however, performed better than fry in high-density treatments. These results indicate that, under the environment examined, the growth performance of GH-transgenic and non-transgenic S. salar may be similar during first feeding, an intense period of selection in their life history. Similarities in competitive ability and growth performance with wild-type fish suggest that the capacity of transgenic S. salar to establish in natural streams may not be inhibited during early life history. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

[Intracellular Protein Degradation in Growth of Atlantic Salmon, Salmo salar L].

PubMed

Lysenko, L A; Kantserova, N P; Krupnova, M Yu; Veselov, A E; Nemova, N N

2015-01-01

A brief review on the common characteristics and specific features of proteolytic machinery in fish skeletal muscles (based on Atlantic salmon, Salmo salar L., Salmonidae) has been given. Among a variety of proteases in the muscle tissue, those determining protein degradation level in developing and intensively growing muscles in salmon young and by this way regulating protein retention intensity and growth at all namely lysosomal cathepsins B and D and calcium-dependent proteases (calpains) were comprehensively studied. Revealed age-related differences in intracellular protease activity in salmon skeletal muscles indicate the role of proteolysis regulation in growth in general and a specific role of the individual proteolytic enzymes in particular. The data on negative correlation of cathepsin D and calpain activity levels in muscles and the rate of weight increase in juvenile salmon were obtained. A revealed positive correlation of cathepsin B activity and morphometric parameters in fish young presumably indicates its primary contribution to non-myofibrillar protein turnover.

Systemic granuloma observed in Atlantic salmon Salmo salar raised to market size in a freshwater recirculation aquaculture system

USDA-ARS?s Scientific Manuscript database

Systemic granuloma was observed in sampled adult Atlantic salmon Salmo salar raised to harvest size in a freshwater recirculation aquaculture system. The prevalence of this condition was estimated at 10-20% of the population, with affected individuals grossly demonstrating pathology in varying degre...

Skill and tactical development during a sport education season.

PubMed

Hastie, P A

1998-12-01

The purpose of this study was to examine the development of skill competence and tactical sophistication during a games unit conducted following the features of sport education provided by Siedentop (1994). One team of six players was followed through a 30-lesson season of "Ultimate." Using Gréhaigne, Godbout, and Bouthier's (1997) formula for an efficiency index, together with a number of other measures of skill and tactical competence, it was determined that these students made significant improvements in selection and execution dimensions of the game. Furthermore, lower skilled students did not feel marginalized within their teams and believed they had equal opportunities for improvement. The key reasons for developing competence in this setting were the sufficient length of the season to allow for significant practice opportunities and the consistent team membership throughout season, which allowed all players to develop a sense of usefulness. This curriculum model provides one way students can develop skills through a system of game playing, provided sport education units are structured to prevent the more skillful players from dominating the games.

Physiological preparedness and performance of Atlantic salmon Salmo salar smolts in relation to behavioural salinity preferences and thresholds

USGS Publications Warehouse

Stich, D.S.; Zydlewski, G.B.; Zydlewski, Joseph D.

2015-01-01

This study investigated the relationships between behavioural responses of Atlantic salmon Salmo salarsmolts to saltwater (SW) exposure and physiological characteristics of smolts in laboratory experiments. It concurrently described the behaviour of acoustically tagged smolts with respect to SW and tidal cycles during estuary migration. Salmo salar smolts increased their use of SW relative to fresh water (FW) from April to June in laboratory experiments. Mean preference for SW never exceeded 50% of time in any group. Preference for SW increased throughout the course of smolt development. Maximum continuous time spent in SW was positively related to gill Na+, K+-ATPase (NKA) activity and osmoregulatory performance in full-strength SW (measured as change in gill NKA activity and plasma osmolality). Smolts decreased depth upon reaching areas of the Penobscot Estuary where SW was present, and all fish became more surface oriented during passage from head of tide to the ocean. Acoustically tagged, migrating smolts with low gill NKA activity moved faster in FW reaches of the estuary than those with higher gill NKA activity. There was no difference in movement rate through SW reaches of the estuary based on gill NKA activity. Migrating fish moved with tidal flow during the passage of the lower estuary based on the observed patterns in both vertical and horizontal movements. The results indicate that smolts select low-salinity water during estuary migration and use tidal currents to minimize energetic investment in seaward migration. Seasonal changes in osmoregulatory ability highlight the importance of the timing of stocking and estuary arrival.

Morphological differences in parr of Atlantic salmon Salmo salar from three regions in Norway.

PubMed

Solem, O; Berg, O K

2011-05-01

Morphological characters were compared in parr (total length 33-166 mm) of Atlantic salmon Salmo salar sampled from eight wild populations in three regions, three in northern, two in the middle and three in southern Norway, covering a distance of 1700 km (from 70° N to 58° N). On the basis of morphological characters 94·6% of the individuals were correctly classified into the three regions. Discrimination between populations within these three regions also had a high degree of correct classification (89·0-95·8%). Principle component analysis identified largest differences to be in head characters, notably eye diameter and jawbone, with the smallest diameter and head size among the northernmost populations. Fish from the southern rivers had a deeper body form whereas fish from the middle region had larger heads and pectoral fins. This illustrates that S. salar already in the early parr stage has morphological traits, which can be used in discrimination between regions and populations and that these differences are discernible in spite of the volume of escaped farmed fish spawning in Norwegian rivers during the past 30 years. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

A quantitative history of precipitation and hydrologic variability for the last 45 ka: Lake Titicaca, Salar de Coipasa and Salar de Uyuni, Peru and Bolivia

NASA Astrophysics Data System (ADS)

Nunnery, A.; Baker, P. A.; Coe, M. T.; Fritz, S. C.; Rigsby, C. A.

2011-12-01

Precipitation on the Bolivian/Peruvian Altiplano is dominantly controlled by the South American summer Monsoon (SASM). Over long timescales moisture transport to the Altiplano by the SASM fluctuates in intensity due to precessional insolation forcing as well as teleconnections to millennial scale abrupt temperature shifts in the North Atlantic. These long-term changes in moisture transport have been observed in multiple paleoclimate and paleo-lake level records as advances and retreats of large lakes in the terminal basin (the Salar de Uyuni). Several previous studies using energy/water balance models have been applied to paleoclimate records in attempts to provide quantitative constraints on past precipitation and temperature (P and T). For example, Blodgett et al. concluded that high paleolake stands, first dated at ca. 16,000 cal. yr BP, required P 20% higher and T 5°C colder than modern. We expand on this work conducting two experiments. The first uses a latitudinal paleohydrologic profile to reconstruct hydrological history. The second uses a terrestrial hydrology model (THMB) to "predict" lake level given changes in P and T. The profile is constructed using records from Lake Titicaca (LT), Salar de Coipasa (SC) and Salar de Uyuni (SU). LT carbonate and diatom records indicate a deep, overflowing lake for much of the last 100 ka with a distinct dry, closed-basin phase in the early to mid Holocene. A continuous sediment core from SC indicates lake level fluctuations between deep and shallow phases for the last 45 ka. A natural gamma radiation log from SU, where large paleolakes alternated with shallow salt pans characteristic of drier and/or warmer periods, shows alternation between wet and dry phases through time. These three records give evidence to the complex nature of Altiplano hydrology, most notably the ability to sustain lakes in the SC basin while exhibiting dry conditions in SU. For the second experiment, THMB, which estimates water balance and

Genome Sequence of Streptococcus phocae subsp. salmonis Strain C-4T, Isolated from Atlantic Salmon (Salmo salar)

PubMed Central

Suarez, Rudy; Lazo, Eduardo; Bravo, Diego; Llegues, Katerina O.; Romalde, Jesús L.; Godoy, Marcos G.

2014-01-01

Streptococcus phocae subsp. salmonis is a fish pathogen that has an important impact on the Chilean salmon industry. Here, we report the genome sequence of the type strain C-4T isolated from Atlantic salmon (Salmo salar), showing a number of interesting features and genes related to its possible virulence factors. PMID:25502668

Weight loss and fillet quality characteristics of Atlantic salmon (Salmo salar) after purging for 5, 10, 15 or 20 days

USDA-ARS?s Scientific Manuscript database

Atlantic salmon, Salmo salar, are typically cultured in marine net pens. However, technological advancements in recirculating aquaculture systems have increased the feasibility of culturing Atlantic salmon in land-based systems to alleviate environmental and disease issues limiting sustainability. ...

Gill pathology in Scottish farmed Atlantic salmon, Salmo salar L., associated with the microsporidian Desmozoon lepeophtherii Freeman et Sommerville, 2009.

PubMed

Matthews, C G G; Richards, R H; Shinn, A P; Cox, D I

2013-10-01

Gill disorders have emerged in recent years as a significant problem in the production of marine-stage Atlantic salmon Salmo salar L. The multi-aetiological condition 'proliferative gill inflammation' (PGI) has been reported to cause heavy losses in western Norway, yet reports of Scottish cases of the disease have remained anecdotal. In the present study, histopathological material from a marine production site in the Scottish Highlands experiencing mortalities due to a seasonal gill disease with proliferative-type pathology was examined using light microscopy, special staining techniques and transmission electron microscopy (TEM). The microsporidian Desmozoon lepeophtherii Freeman et Sommerville, 2009 (syn. Paranucleospora theridion) was identified by staining using a Gram Twort method and TEM associated with distinctive proliferative and necrotic pathology confined to the interlamellar Malpighian cell areas of the primary filaments. Epitheliocystis was not a feature of the gill pathology observed. It is believed this is the first report of D. lepeophtherii being identified associated with pathology in a Scottish gill disease case, and supports anecdotal reports that a disease at least partly synonymous with PGI as described by Norwegian researchers is present in Scottish aquaculture. © 2013 John Wiley & Sons Ltd.

The Seasons of Competency Development for Women.

ERIC Educational Resources Information Center

Loeffler, T. A.

2000-01-01

Discusses stages of competency development, using the seasons of the year as a metaphor. Identifies educational strategies that outdoor educators can use at each stage to help women overcome gender role socialization pressures that discourage them from achieving or recognizing their true competency levels. (TD)

Effects of storage time on the motility, mortality and calcium levels of Atlantic salmon Salmo salar spermatozoa.

PubMed

Parodi, J; Guerra, G; Cuevas, M; Ramírez-Reveco, A; Romero, F

2017-04-01

This study estimates spermatozoa mortality, morphology, motility and intracellular calcium levels in Atlantic salmon Salmo salar milt after prolonged storage. Milt samples were preserved at 4° C for 25 days and then evaluated for mortality. Motility remained high for the first 3 days and the mortality was low during the first 5 days of storage. A decrease of >50% in calcium content was observed after 5 days of storage. When spermatozoa were activated, calcium levels increased >200% in relative fluorescence units (RFU); this rate of increase was lost when the samples were stored for extended periods of time and was only partially manifested in a zero calcium solution. The results suggest that in vitro storage of S. salar spermatozoa at 4° C for a period of 3 days preserves motility and limits mortality to levels similar to those of fresh spermatozoa. This method also maintains intracellular calcium storage critical for spermatozoa performance. © 2017 The Fisheries Society of the British Isles.

Proactive responses to human impacts that balance development and Atlantic salmon (Salmo salar) conservation: An integrative model

USGS Publications Warehouse

Wilzbach, M.A.; Mather, M. E.; Folt, C.L.; Moore, A.; Naiman, R.J.; Youngson, A.F.; McMenemy, J.

1998-01-01

Incorporating human impacts into conservation plans is critical to protect natural resources. Using a model that examines how anthropogenic changes might be proactively influenced to promote conservation, we argue that a denser human population does not spell inevitable doom for Atlantic salmon (Salmo salar). Humans affect the Atlantic salmon ecosystem deleteriously through landscape alteration, exploitation, external inputs, and resource competition. An intact ecosystem provides positive feedback to society by providing food, ecosystem services, and improving the quality of life. As Atlantic salmon and associated ecosystem benefits are increasingly valued by society, policies, laws, and regulations that protect salmon populations and habitats are codified into a 'control system' or institutional infrastructure. Via research that helps maintain wild salmon populations and in informing the public about the benefits of a healthy Atlantic salmon ecosystem, scientists can influence public attitudes and facilitate the implementation of environmental policies that moderate harmful anthropogenic changes. Because exchange among scientists is of paramount importance in increasing our understanding of important interrelationships between humans and fish, we recommend the establishment of an international salmon organizational for research.

Mercury bioaccumulation in wood frogs developing in seasonal pools

USGS Publications Warehouse

Loftin, Cynthia S.; Calhoun, Aram J.K.; Nelson, Sarah J.; Elskus, Adria; Simon, Kevin S.

2012-01-01

Seasonal woodland pools contribute significant biomass to terrestrial ecosystems through production of pool-breeding amphibians. The movement of amphibian metamorphs potentially transports toxins bioaccumulated during larval development in the natal pool into the surrounding terrestrial environment. We documented total mercury (THg) in seasonal woodland pool water, sediment, litter, and Lithobates sylvaticus LeConte (Wood Frog) in Acadia National Park, ME. THg concentrations in pool water varied over the study season, increasing during April—June and remaining high in 2 of 4 pools upon October refill. Water in pools surrounded by softwoods had lower pH, greater dissolved organic carbon, and greater THg concentrations than pools surrounded by hardwoods, with seasonal patterns in sediment THg but not litter THg. THg increased rapidly from near or below detection in 1–2 week old embryos (<0.2 ng; 0–0.49 ppb wet weight) to 17.1–54.2 ppb in tadpoles within 6 weeks; 7.2–42.0% of THg was methyl Hg in tadpoles near metamorphosis. Metamorphs emigrating from seasonal pools may transfer mercury into terrestrial food webs.

The mating brain: early maturing sneaker males maintain investment into the brain also under fast body growth in Atlantic salmon (Salmo salar).

PubMed

Kotrschal, Alexander; Trombley, Susanne; Rogell, Björn; Brannström, Ioana; Foconi, Eric; Schmitz, Monika; Kolm, Niclas

It has been suggested that mating behaviours require high levels of cognitive ability. However, since investment into mating and the brain both are costly features, their relationship is likely characterized by energetic trade-offs. Empirical data on the subject remains equivocal. We investigated if early sexual maturation was associated with brain development in Atlantic salmon ( Salmo salar ), in which males can either stay in the river and sexually mature at a small size (sneaker males) or migrate to the sea and delay sexual maturation until they have grown much larger (anadromous males). Specifically, we tested how sexual maturation may induce plastic changes in brain development by rearing juveniles on either natural or ad libitum feeding levels. After their first season we compared brain size and brain region volumes across both types of male mating tactics and females. Body growth increased greatly across both male mating tactics and females during ad libitum feeding as compared to natural feeding levels. However, despite similar relative increases in body size, early maturing sneaker males maintained larger relative brain size during ad libitum feeding levels as compared to anadromous males and females. We also detected several differences in the relative size of separate brain regions across feeding treatments, sexes and mating strategies. For instance, the relative size of the cognitive centre of the brain, the telencephalon, was largest in sneaker males. Our data support that a large relative brain size is maintained in individuals that start reproduction early also during fast body growth. We propose that the cognitive demands during complex mating behaviours maintain a high level of investment into brain development in reproducing individuals.

Movement, migration, and smolting of Atlantic salmon (Salmo salar)

USGS Publications Warehouse

McCormick, S.D.; Hansen, Lonnie P.; Quinn, T.P.; Saunders, R.L.

1998-01-01

A variety of movements characterize the behavioral plasticity of Atlantic salmon (Salmo salar) in fresh water, including movements of fry from redds, establishment of feeding territories, spawning movements of sexually mature male parr, movement to and from winter habitat, and smolt migration in spring. Smolting is an adaptive specialization for downstream migration, seawater entry, and marine residence. While still in fresh water, smolts become silvery and streamlined, lose their positive rheotaxis and territoriality, and begin schooling. Physiological changes include increased salinity tolerance, olfactory sensitivity, metabolic rate, scope for growth, and altered hemoglobin and visual pigments. Through their impact on the neuroendocrine system, photoperiod and temperature regulate physiological changes, whereas temperature and water flow may initiate migration. Smolt survival is affected by a limited period of readiness (a physiological 'smolt window') and the timing of seawater entry with environmental conditions such as temperature, food, and predators (an ecological 'smolt window'). Smolt development is adversely affected by acidity, pollutants, and improper rearing conditions, and is often more sensitive than other life stages. Unfortunately, the migration corridor of smolts (mainstems of rivers and estuaries) are the most heavily impacted by pollution, dams, and other anthropogenic activities that may be directly lethal or increase mortality by delaying or inhibiting smolt migration.

Assessing groundwater recharge in an Andean closed basin using isotopic characterization and a rainfall-runoff model: Salar del Huasco basin, Chile

NASA Astrophysics Data System (ADS)

Uribe, Javier; Muñoz, José F.; Gironás, Jorge; Oyarzún, Ricardo; Aguirre, Evelyn; Aravena, Ramón

2015-11-01

Closed basins are catchments whose drainage networks converge to lakes, salt flats or alluvial plains. Salt flats in the closed basins in arid northern Chile are extremely important ecological niches. The Salar del Huasco, one of these salt flats located in the high plateau (Altiplano), is a Ramsar site located in a national park and is composed of a wetland ecosystem rich in biodiversity. The proper management of the groundwater, which is essential for the wetland function, requires accurate estimates of recharge in the Salar del Huasco basin. This study quantifies the spatio-temporal distribution of the recharge, through combined use of isotopic characterization of the different components of the water cycle and a rainfall-runoff model. The use of both methodologies aids the understanding of hydrological behavior of the basin and enabled estimation of a long-term average recharge of 22 mm/yr (i.e., 15 % of the annual rainfall). Recharge has a high spatial variability, controlled by the geological and hydrometeorological characteristics of the basin, and a high interannual variability, with values ranging from 18 to 26 mm/yr. The isotopic approach allowed not only the definition of the conceptual model used in the hydrological model, but also eliminated the possibility of a hydrogeological connection between the aquifer of the Salar del Huasco basin and the aquifer that feeds the springs of the nearby town of Pica. This potential connection has been an issue of great interest to agriculture and tourism activities in the region.

The notochord in Atlantic salmon (Salmo salar L.) undergoes profound morphological and mechanical changes during development.

PubMed

Kryvi, Harald; Rusten, Iselin; Fjelldal, Per Gunnar; Nordvik, Kari; Totland, Geir K; Karlsen, Tine; Wiig, Helge; Long, John H

2017-11-01

We present the development of the notochord of the Atlantic salmon (Salmo salar L.), from early embryo to sexually mature fish. Over the salmon's lifespan, profound morphological changes occur. Cells and gross structures of the notochord reorganize twice. In the embryo, the volume of the notochord is dominated by large, vacuolated chordocytes; each cell can be modeled as a hydrostat organized into a larger cellular-hydrostat network, structurally bound together with desmosomes. After the embryo hatches and grows into a fry, vacuolated chordocytes disappear, replaced by extracellular lacunae. The formation of mineralized, segmental chordacentra stiffens the notochord and creates intervertebral joints, where tissue strain during lateral bending is now focused. As development proceeds towards the parr stage, a process of devacuolization and intracellular filament accumulation occur, forming highly dense, non-vacuolated chordocytes. As extracellular lacunae enlarge, they are enclosed by dense filamentous chordocytes that form transverse intervertebral septa, which are connected to the intervertebral ligaments, and a longitudinal notochordal strand. In the vertebral column of pelagic adults, large vacuolated chordocytes reappear; cells of this secondary population have a volume up to 19 000 times larger than the primary vacuolated chordocytes of the early notochord. In adults the lacunae have diminished in relative size. Hydrostatic pressure within the notochord increases significantly during growth, from 525 Pa in the alevins to 11 500 Pa in adults, at a rate of increase with total body length greater than that expected by static stress similarity. Pressure and morphometric measurements were combined to estimate the stress in the extracellular material of the notochordal sheath and intervertebral ligaments and the flexural stiffness of the axial skeleton. The functional significance of the morphological changes in the axial skeleton is discussed in relation to the

A new specific reference gene based on growth hormone gene (GH1) used for detection and relative quantification of Aquadvantage® GM salmon (Salmo salar L.) in food products.

PubMed

Hafsa, Ahmed Ben; Nabi, Nesrine; Zellama, Mohamed Salem; Said, Khaled; Chaouachi, Maher

2016-01-01

Genetic transformation of fish is mainly oriented towards the improvement of growth for the benefit of the aquaculture. Actually, Atlantic salmon (Salmo salar) is the species most transformed to achieve growth rates quite large compared to the wild. To anticipate the presence of contaminations with GM salmon in fish markets and the lack of labeling regulations with a mandatory threshold, the proper methods are needed to test the authenticity of the ingredients. A quantitative real-time polymerase chain reaction (QRT-PCR) method was used in this study. Ct values were obtained and validated using 15 processed food containing salmon. The relative and absolute limits of detection were 0.01% and 0.01 ng/μl of genomic DNA, respectively. Results demonstrate that the developed QRT-PCR method is suitable specifically for identification of S. salar in food ingredients based on the salmon growth hormone gene 1 (GH1). The processes used to develop the specific salmon reference gene case study are intended to serve as a model for performing quantification of Aquadvantage® GM salmon on future genetically modified (GM) fish to be commercialized. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effects of ozonation on select waterborne steroid hormones in recirculation aquaculture systems containing sexually mature Atlantic salmon Salmo salar

USDA-ARS?s Scientific Manuscript database

A controlled 3-month study was conducted in 6 replicated water recirculation aquaculture systems (RAS) containing a mixture of sexually mature and immature Atlantic salmon Salmo salar to determine whether water ozonation is associated with a reduction in waterborne hormones. Post-smolt Atlantic salm...

Production of market-size North American strain Atlantic salmon Salmo salar in a land-based recirculation aquaculture system using freshwater

USDA-ARS?s Scientific Manuscript database

There is interest in culturing Atlantic salmon Salmo salar to market-size in land-based, closed containment systems that use recirculation aquaculture systems (RAS), as this technology often enables facilities to locate near major markets, obtain permits, exclude obligate pathogens, and/or reduce en...

Leaf development and demography explain photosynthetic seasonality in Amazon evergreen forests

USGS Publications Warehouse

Wu, Jin; Albert, Lauren; Lopes, Aline; Restrepo-Coupe, Natalia; Hayek, Matthew; Wiedemann, Kenia T.; Guan, Kaiyu; Stark, Scott C.; Christoffersen, Bradley; Prohaska, Neill; Tavares, Julia V.; Marostica, Suelen; Kobayashi, Hideki; Ferreira, Maurocio L.; Campos, Kleber Silva; da Silva, Rodrigo; Brando, Paulo M.; Dye, Dennis G.; Huxman, Travis E.; Huete, Alfredo; Nelson, Bruce; Saleska, Scott

2016-01-01

In evergreen tropical forests, the extent, magnitude, and controls on photosynthetic seasonality are poorly resolved and inadequately represented in Earth system models. Combining camera observations with ecosystem carbon dioxide fluxes at forests across rainfall gradients in Amazônia, we show that aggregate canopy phenology, not seasonality of climate drivers, is the primary cause of photosynthetic seasonality in these forests. Specifically, synchronization of new leaf growth with dry season litterfall shifts canopy composition toward younger, more light-use efficient leaves, explaining large seasonal increases (~27%) in ecosystem photosynthesis. Coordinated leaf development and demography thus reconcile seemingly disparate observations at different scales and indicate that accounting for leaf-level phenology is critical for accurately simulating ecosystem-scale responses to climate change.

Genome Sequence of Streptococcus phocae subsp. salmonis Strain C-4T, Isolated from Atlantic Salmon (Salmo salar).

PubMed

Avendaño-Herrera, Ruben; Suarez, Rudy; Lazo, Eduardo; Bravo, Diego; Llegues, Katerina O; Romalde, Jesús L; Godoy, Marcos G

2014-12-11

Streptococcus phocae subsp. salmonis is a fish pathogen that has an important impact on the Chilean salmon industry. Here, we report the genome sequence of the type strain C-4(T) isolated from Atlantic salmon (Salmo salar), showing a number of interesting features and genes related to its possible virulence factors. Copyright © 2014 Avendaño-Herrera et al.

Phosphorus flux due to Atlantic salmon (Salmo salar) in an oligotrophic upland stream: effects of management and demography

Treesearch

Keith H. Nislow; John D. Armstrong; Simon McKelvey

2004-01-01

Little is known concerning the role of Atlantic salmon (Salmo salar) in the transport of nutrients to and from river systems. We used demographic data from the River Bran, an oligotrophic river in Scotland, UK, to construct a budget for the transport of phosphorus (P) and applied it to investigate the effects of management strategies and demographic...

Variation in freshwater growth and development among five New England Atlantic salmon (Salmo salar) populations reared in a common environment

USGS Publications Warehouse

Obedzinski, M.; Letcher, B.H.

2004-01-01

We examined phenotypic variation in growth and development from the eyed-egg stage to the age-1+ smolt stage among five New England populations of Atlantic salmon (Salmo salar: East Machias, Narraguagus, Sheepscot, Penobscot, Connecticut) reared in a common laboratory environment. Study populations originated from rivers varying in size, latitude, and level of hatchery supplementation and included one reintroduced population (Connecticut was a recipient of Penobscot origin stock). Phenotypic trait differences were found among populations, and the degree of stock variation depended on ontogeny. Eggs were smaller and hatched sooner in the Penobscot (a northern, intensively managed population), but no stock differences were detected in size or growth efficiency from the onset of exogenous feeding to age 0+ summer. Differences again emerged in age 0+ autumn, with the degree of bimodality in length-frequency distributions differing among stocks; the Connecticut had the highest proportion of upper-mode fish and, ultimately, age-1+ smolts. Although genetic effects could not be entirely separated from maternal effects for egg size variation, it is likely that differences in hatch timing and smolt age had a genetic basis. Early emphasis on age-1+ hatchery-reared smolts in the Connecticut may have led to divergence in smolt age between the Penobscot and Connecticut populations in less than eight generations. ?? 2004 NRC Canada.

Apoptosis inhibition of Atlantic salmon (Salmo salar) peritoneal macrophages by Piscirickettsia salmonis.

PubMed

Díaz, S; Rojas, M E; Galleguillos, M; Maturana, C; Smith, P I; Cifuentes, F; Contreras, I; Smith, P A

2017-12-01

To improve the understanding of the piscirickettsiosis pathogenesis, the in vivo apoptosis modulation of peritoneal macrophages and lymphocytes was studied in juvenile Salmo salar intraperitoneally injected with Piscirickettsia salmonis. Five fish were sampled at post-exposure days 1, 5, 8 (preclinical), 20 (clinical) and 40 (post-clinical period of the disease), and the leucocytes of their coelomic washings were analysed by flow cytometry (using the JC-1 cationic dye), TUNEL and cytology to detect apoptotic cells. A selective and temporal pattern of apoptosis modulation by P. salmonis infection was observed. Apoptosis in lymphocytes was not affected, whereas it was inhibited in macrophages but only during the preclinical stage of the induced piscirickettsiosis. Hence, it is postulated that P. salmonis inhibits macrophage apoptosis at the beginning of the disease development to survive, multiply and probably be transported inside these phagocytes; once this process is complete, macrophage apoptosis is no longer inhibited, thus facilitating the exit of the bacteria from the infected cells for continuing their life cycle. © 2017 John Wiley & Sons Ltd.

Late Quaternary Paleoclimatic History of Tropical South America From Drilling Lake Titicaca and the Salar de Uyuni

NASA Astrophysics Data System (ADS)

Baker, P. A.; Fritz, S. C.; Seltzer, G. O.; Rigsby, C. A.; Lowenstein, T. K.; Ku, R.

2003-12-01

Seven drill cores were recovered from Lake Titicaca during the NSF/ICDP/DOSECC drilling expedition of 2001. Sub-lake floor drilling depths ranged from 53 to 139 m; water depths ranged from 40 to 232 m; recoveries ranged from 75 to 112 percent. Our most detailed multi-proxy analyses to date have been done on Core 2B raised from the central basin of the lake from 232 m water depth, drilled to 139.26 m sub-lakefloor with 140.61 m of total sediment recovered (101 percent). A basal age of 200 Ka is estimated by linear extrapolation from radiocarbon measurements in the upper 25 m of core; Ar-Ar dating of interbedded ashes and U/Th dating of abiogenic aragonites are underway. The volume and lake level of Lake Titicaca have undergone large changes several times during the late Quaternary. Proxies for these water level changes (each of different fidelity) include the ratio of planktonic-to-benthic diatoms, sedimentary carbonate content, and stable isotopic content of organic carbon. The most recent of these changes, has been described previously from earlier piston cores. In the early and middle Holocene the lake fell below its outlet to 85 m below modern level, lake salinity increased several-fold, and the Salar de Uyuni, which receives overflow from Titicaca, dessicated. In contrast, Lake Titicaca was deep, fresh, and overflowing (southward to the Salar de Uyuni) throughout the last glacial maximum from prior to 25,000 BP to at least 15,000 BP. According to extrapolated ages, the penultimate major lowstand of Lake Titicaca occurred prior to 60,000 BP, when seismic evidence indicates that lake level was about 200 m lower than present. Near the end of this lowstand, the lake also became quite saline. There are at least three, and possibly more, older lowstands, each separated temporally by periods in which the lake freshened dramatically and overflowed. These results will be compared with results from previous drilling in the Salar de Uyuni.

[Seasonal development of phloem in Scots pine stems].

PubMed

Antonova, G F; Stasova, V V

2006-01-01

The formation of phloem was studied for two years in stems of 50 to 60 year old trees of Scots pine (Pinus sylvestris L.) growing in nature. The development of phloem of the current year begins 10 to 20 days before the xylem formation and is completed with the termination of shoot growth in the end of June. Observations over the seasonal activity of cambium producing sieve-like cells of phloem and duration of their differentiation as compared to the xylem derivatives of cambium have shown that the maxima of formation of phloem and xylem cells could coincide or not coincide by season, while the activities of their differentiation were always at antiphase. The sieve-like cells of early phloem were separated from those of late phloem by a layer of tannin-containing cells, which are formed simultaneously with the formation of late xylem cells by the cambium. Seasonal dynamics of accumulation of starch grain in structural elements of the phloem is related to the xylem development. The content of metabolites in differentiating and mature phloem elements, in the cambium zone, and in the xylem cells growing in the radial direction depended on cell specificity, stage of their development, and type of forming wood, early or late, which differ in the cell wall parameters and, hence, requirement of assimilates. Significant differences were described between the content of low molecular weigh carbohydrates, amino acids, organic acids, and phenol compounds using two methods of calculation: per dry weight and per cell.

Long noncoding RNAs (lncRNAs) dynamics evidence immunomodulation during ISAV-Infected Atlantic salmon (Salmo salar)

PubMed Central

Boltaña, Sebastian; Valenzuela-Miranda, Diego; Aguilar, Andrea; Mackenzie, Simon; Gallardo-Escárate, Cristian

2016-01-01

Despite evidence for participation in the host response to infection, the roles of many long non-coding RNAs (lncRNAs) remain unknown. Therefore, the aims of this study were to identify lncRNAs in Atlantic salmon (Salmo salar) and evaluate their transcriptomic regulation during ISA virus (ISAV) infection, an Orthomyxoviridae virus associated with high mortalities in salmonid aquaculture. Using next-generation sequencing, whole-transcriptome analysis of the Salmo salar response to ISAV infection was performed, identifying 5,636 putative lncRNAs with a mean length of 695 base pairs. The transcriptional modulation evidenced a similar number of differentially expressed lncRNAs in the gills (3,294), head-kidney (3,275), and liver (3,325) over the course of the infection. Moreover, analysis of a subset of these lncRNAs showed the following: (i) Most were similarly regulated in response to ISA virus infection; (ii) The transcript subsets were uniquely modulated in each tissue (gills, liver, and head-kidney); and (iii) A subset of lncRNAs were upregulated for each tissue and time analysed, indicating potential markers for ISAV infection. These findings represent the first discovery of widespread differential expression of lncRNAs in response to virus infection in non-model species, suggesting that lncRNAs could be involved in regulating the host response during ISAV infection. PMID:26939752

Long noncoding RNAs (lncRNAs) dynamics evidence immunomodulation during ISAV-Infected Atlantic salmon (Salmo salar).

PubMed

Boltaña, Sebastian; Valenzuela-Miranda, Diego; Aguilar, Andrea; Mackenzie, Simon; Gallardo-Escárate, Cristian

2016-03-04

Despite evidence for participation in the host response to infection, the roles of many long non-coding RNAs (lncRNAs) remain unknown. Therefore, the aims of this study were to identify lncRNAs in Atlantic salmon (Salmo salar) and evaluate their transcriptomic regulation during ISA virus (ISAV) infection, an Orthomyxoviridae virus associated with high mortalities in salmonid aquaculture. Using next-generation sequencing, whole-transcriptome analysis of the Salmo salar response to ISAV infection was performed, identifying 5,636 putative lncRNAs with a mean length of 695 base pairs. The transcriptional modulation evidenced a similar number of differentially expressed lncRNAs in the gills (3,294), head-kidney (3,275), and liver (3,325) over the course of the infection. Moreover, analysis of a subset of these lncRNAs showed the following: (i) Most were similarly regulated in response to ISA virus infection; (ii) The transcript subsets were uniquely modulated in each tissue (gills, liver, and head-kidney); and (iii) A subset of lncRNAs were upregulated for each tissue and time analysed, indicating potential markers for ISAV infection. These findings represent the first discovery of widespread differential expression of lncRNAs in response to virus infection in non-model species, suggesting that lncRNAs could be involved in regulating the host response during ISAV infection.

Development and validation of a high density SNP genotyping array for Atlantic salmon (Salmo salar).

PubMed

Houston, Ross D; Taggart, John B; Cézard, Timothé; Bekaert, Michaël; Lowe, Natalie R; Downing, Alison; Talbot, Richard; Bishop, Stephen C; Archibald, Alan L; Bron, James E; Penman, David J; Davassi, Alessandro; Brew, Fiona; Tinch, Alan E; Gharbi, Karim; Hamilton, Alastair

2014-02-06

Dense single nucleotide polymorphism (SNP) genotyping arrays provide extensive information on polymorphic variation across the genome of species of interest. Such information can be used in studies of the genetic architecture of quantitative traits and to improve the accuracy of selection in breeding programs. In Atlantic salmon (Salmo salar), these goals are currently hampered by the lack of a high-density SNP genotyping platform. Therefore, the aim of the study was to develop and test a dense Atlantic salmon SNP array. SNP discovery was performed using extensive deep sequencing of Reduced Representation (RR-Seq), Restriction site-Associated DNA (RAD-Seq) and mRNA (RNA-Seq) libraries derived from farmed and wild Atlantic salmon samples (n = 283) resulting in the discovery of > 400 K putative SNPs. An Affymetrix Axiom® myDesign Custom Array was created and tested on samples of animals of wild and farmed origin (n = 96) revealing a total of 132,033 polymorphic SNPs with high call rate, good cluster separation on the array and stable Mendelian inheritance in our sample. At least 38% of these SNPs are from transcribed genomic regions and therefore more likely to include functional variants. Linkage analysis utilising the lack of male recombination in salmonids allowed the mapping of 40,214 SNPs distributed across all 29 pairs of chromosomes, highlighting the extensive genome-wide coverage of the SNPs. An identity-by-state clustering analysis revealed that the array can clearly distinguish between fish of different origins, within and between farmed and wild populations. Finally, Y-chromosome-specific probes included on the array provide an accurate molecular genetic test for sex. This manuscript describes the first high-density SNP genotyping array for Atlantic salmon. This array will be publicly available and is likely to be used as a platform for high-resolution genetics research into traits of evolutionary and economic importance in salmonids and in aquaculture

Development and validation of a high density SNP genotyping array for Atlantic salmon (Salmo salar)

PubMed Central

2014-01-01

Background Dense single nucleotide polymorphism (SNP) genotyping arrays provide extensive information on polymorphic variation across the genome of species of interest. Such information can be used in studies of the genetic architecture of quantitative traits and to improve the accuracy of selection in breeding programs. In Atlantic salmon (Salmo salar), these goals are currently hampered by the lack of a high-density SNP genotyping platform. Therefore, the aim of the study was to develop and test a dense Atlantic salmon SNP array. Results SNP discovery was performed using extensive deep sequencing of Reduced Representation (RR-Seq), Restriction site-Associated DNA (RAD-Seq) and mRNA (RNA-Seq) libraries derived from farmed and wild Atlantic salmon samples (n = 283) resulting in the discovery of > 400 K putative SNPs. An Affymetrix Axiom® myDesign Custom Array was created and tested on samples of animals of wild and farmed origin (n = 96) revealing a total of 132,033 polymorphic SNPs with high call rate, good cluster separation on the array and stable Mendelian inheritance in our sample. At least 38% of these SNPs are from transcribed genomic regions and therefore more likely to include functional variants. Linkage analysis utilising the lack of male recombination in salmonids allowed the mapping of 40,214 SNPs distributed across all 29 pairs of chromosomes, highlighting the extensive genome-wide coverage of the SNPs. An identity-by-state clustering analysis revealed that the array can clearly distinguish between fish of different origins, within and between farmed and wild populations. Finally, Y-chromosome-specific probes included on the array provide an accurate molecular genetic test for sex. Conclusions This manuscript describes the first high-density SNP genotyping array for Atlantic salmon. This array will be publicly available and is likely to be used as a platform for high-resolution genetics research into traits of evolutionary and economic importance in

Piscine myocarditis virus (PMCV) in wild Atlantic salmon Salmo salar.

PubMed

Garseth, Ase Helen; Biering, Eirik; Tengs, Torstein

2012-12-27

Cardiomyopathy syndrome (CMS) is a severe cardiac disease of sea-farmed Atlantic salmon Salmo salar L., but CMS-like lesions have also been found in wild Atlantic salmon. In 2010 a double-stranded RNA virus of the Totiviridae family, provisionally named piscine myocarditis virus (PMCV), was described as the causative agent of CMS. In the present paper we report the first detection of PMCV in wild Atlantic salmon. The study is based on screening of 797 wild Atlantic salmon by real-time RT-PCR. The samples were collected from 35 different rivers along the coast of Norway, and all individuals included in the study were classified as wild, based on visual appearance and scale reading. Two samples tested positive during PCR analysis, and the results were confirmed by sequencing.

From the viral perspective: infectious salmon anemia virus (ISAV) transcriptome during the infective process in Atlantic salmon (Salmo salar).

PubMed

Valenzuela-Miranda, Diego; Cabrejos, María Eugenia; Yañez, José Manuel; Gallardo-Escárate, Cristian

2015-04-01

The infectious salmon anemia virus (ISAV) is a severe disease that mainly affects the Atlantic salmon (Salmo salar) aquaculture industry. Although several transcriptional studies have aimed to understand Salmon-ISAV interaction through the evaluation of host-gene transcription, none of them has focused their attention upon the viral transcriptional dynamics. For this purpose, RNA-Seq and RT-qPCR analyses were conducted in gills, liver and head-kidney of S. salar challenged by cohabitation with ISAV. Results evidence the time and tissue transcript patterns involved in the viral expression and how the transcription levels of ISAV segments are directly linked with the protein abundance found in other virus of the Orthomyxoviridae family. In addition, RT-qPCR result evidenced that quantification of ISAV through amplification of segment 3 would result in a more sensitive approach for detection and quantification of ISAV. This study offers a more comprehensive approach regarding the ISAV infective process and gives novel knowledge for its molecular detection. Copyright © 2014 Elsevier B.V. All rights reserved.

HPLC confirmatory method development for the determination of seven quinolones in salmon tissue (Salmo salar L.) validated according to the European Union Decision 2002/657/EC.

PubMed

Evaggelopoulou, Evaggelia N; Samanidou, Victoria F

2013-01-15

A confirmatory high pressure liquid chromatographic method for the determination of seven quinolone antibiotics in tissue of Atlantic salmon (Salmo salar L.) was developed. Ciprofloxacin (CIP), danofloxacin (DAN), enrofloxacin (ENR), sarafloxacin (SAR), oxolinic acid (OXO), nalidixic acid (NAL) and flumequine (FLU) were separated on a Perfectsil ODS-2 120 (250 mm × 4 mm, 5 μm) column by gradient elution with a mobile phase consisting of 0.1% trifluoroacetic acid (pH=1), acetonitrile and methanol at 25°C within 22 min. Analytes were monitored at 255 nm (for the determination of OXO, NAL and FLU) and 275 nm (for CIP, DAN, ENR and SAR) by means of photodiode array detector. Examined quinolones were isolated from salmon tissue by extraction with citrate buffer solution (pH=4.7) and purified by solid phase extraction using Oasis HLB (200mg/6 mL) cartridges. The developed method was fully validated in terms of selectivity, linearity, accuracy, precision, stability and sensitivity according to the European Union Decision 2002/657/EC. The accuracy of the method was additionally proved by its application to certified reference material of salmon tissue (BCR® 725). Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of TLR agonists and viral infection on cytokine and TLR expression in Atlantic salmon (Salmo salar).

PubMed

Arnemo, Marianne; Kavaliauskis, Arturas; Gjøen, Tor

2014-10-01

The development of efficient and cheap vaccines against several aquatic viruses is necessary for a sustainable fish farming industry. Toll-like receptor (TLR) ligands have already been used as good adjuvants in human vaccines. With more understanding of TLR expression, function, and ligand specificity in fish, more efficient adjuvants for fish viral vaccines can be developed. In this paper, we examine all known TLRs in Atlantic salmon (Salmo salar) and demonstrate that head kidney and spleen are the main organs expressing TLRs in salmon. We also show that adherent head kidney leucocytes from salmon are able to respond to many of the known agonists for human TLRs, and that viral infection can induce up-regulation of several TLRs. These findings substantiate these receptors' role in immune responses to pathogens in salmonids making their ligands attractive as vaccine adjuvant candidates. Copyright © 2014 Elsevier Ltd. All rights reserved.

Protective oral vaccination against infectious salmon anaemia virus in Salmo salar.

PubMed

Caruffo, Mario; Maturana, Carlos; Kambalapally, Swetha; Larenas, Julio; Tobar, Jaime A

2016-07-01

Infectious salmon anemia (ISA) is a systemic disease caused by an orthomyxovirus, which has a significant economic impact on the production of Atlantic salmon (Salmo salar). Currently, there are several commercial ISA vaccines available, however, those products are applied through injection, causing stress in the fish and leaving them susceptible to infectious diseases due to the injection process and associated handling. In this study, we evaluated an oral vaccine against ISA containing a recombinant viral hemagglutinin-esterase and a fusion protein as antigens. Our findings indicated that oral vaccination is able to protect Atlantic salmon against challenge with a high-virulence Chilean isolate. The oral vaccination was also correlated with the induction of IgM-specific antibodies. On the other hand, the vaccine was unable to modulate expression of the antiviral related gene Mx, showing the importance of the humoral response to the disease survival. This study provides new insights into fish protection and immune response induced by an oral vaccine against ISA, but also promises future development of preventive solutions or validation of the current existing therapies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Why aren't there more Atlantic salmon (Salmo salar)?

USGS Publications Warehouse

Parrish, D.L.; Behnke, R.J.; Gephard, S.R.; McCormick, S.D.; Reeves, G.H.

1998-01-01

Numbers of wild anadromous Atlantic salmon (Salmo salar) have declined demonstrably throughout their native range. The current status of runs on rivers historically supporting salmon indicate widespread declines and extirpations in Europe and North America primarily in southern portions of the range. Many of these declines or extirpations can be attributed to the construction of mainstem dams, pollution (including acid rain), and total dewatering of streams. Purported effects on declines during the 1960s through the 1990s include overfishing, and more recently, changing ocean conditions, and intensive aquaculture. Most factors affecting salmon numbers do not act singly, but rather in concert, which masks the relative contribution of each factor. Salmon researchers and managers should not look for a single culprit in declining numbers of salmon, but rather, seek solutions through rigorous data gathering and testing of multiple effects integrated across space and time.

Genetic background and embryonic temperature affect DNA methylation and expression of myogenin and muscle development in Atlantic salmon (Salmo salar).

PubMed

Burgerhout, Erik; Mommens, Maren; Johnsen, Hanne; Aunsmo, Arnfinn; Santi, Nina; Andersen, Øivind

2017-01-01

The development of ectothermic embryos is strongly affected by incubation temperature, and thermal imprinting of body growth and muscle phenotype has been reported in various teleost fishes. The complex epigenetic regulation of muscle development in vertebrates involves DNA methylation of the myogenin promoter. Body growth is a heritable and highly variable trait among fish populations that allows for local adaptations, but also for selective breeding. Here we studied the epigenetic effects of embryonic temperature and genetic background on body growth, muscle cellularity and myogenin expression in farmed Atlantic salmon (Salmo salar). Eggs from salmon families with either high or low estimated breeding values for body growth, referred to as Fast and Slow genotypes, were incubated at 8°C or 4°C until the embryonic 'eyed-stage' followed by rearing at the production temperature of 8°C. Rearing temperature strongly affected the growth rates, and the 8°C fish were about twice as heavy as the 4°C fish in the order Fast8>Slow8>Fast4>Slow4 prior to seawater transfer. Fast8 was the largest fish also at harvest despite strong growth compensation in the low temperature groups. Larval myogenin expression was approximately 4-6 fold higher in the Fast8 group than in the other groups and was associated with relative low DNA methylation levels, but was positively correlated with the expression levels of the DNA methyltransferase genes dnmt1, dnmt3a and dnmt3b. Juvenile Fast8 fish displayed thicker white muscle fibres than Fast4 fish, while Slow 8 and Slow 4 showed no difference in muscle cellularity. The impact of genetic background on the thermal imprinting of body growth and muscle development in Atlantic salmon suggests that epigenetic variation might play a significant role in the local adaptation to fluctuating temperatures over short evolutionary time.

Investigating the influence of nitrate nitrogen on post-smolt Atlantic salmon Salmo salar reproductive physiology in freshwater recirculation aquaculture systems

USDA-ARS?s Scientific Manuscript database

An 8-month trial was carried out to assess the effects of NO3-N on a variety of performance and physiological outcomes in post-smolt Atlantic salmon Salmo salar (initial weight 102 plus or minus 1 g) reared in six replicated laboratory-scale water recirculation aquaculture systems (RAS). Three RAS r...

Growth evaluation of Atlantic Salmon (Salmo salar) raised in seawater or freshwater and fed either fishmeal based or marine-free diets

USDA-ARS?s Scientific Manuscript database

A forty week feeding study was conducted with Atlantic salmon (Salmo salar) smolts in two recirculating aquaculture systems. Two identical systems were used and contained either freshwater (0 ppt) or seawater (about 30 ppt). Fish were fed one of two diets, a control diet containing fishmeal and fi...

Growth evaluation of atlantic salmon (Salmo salar) raised in seawater or freshwater and fed either fishmeal based on marine-free diets

USDA-ARS?s Scientific Manuscript database

A forty week feeding study was conducted with Atlantic salmon (Salmo salar) smolts in two recirculating aquaculture systems. Twelve salmon (average initial weight 117 g; initial density 9.4 kg/m3) were stocked per tank. Two identical systems were used and contained either freshwater (0 ppt) or sea...

Immunoglobulin isotypes in Atlantic salmon, Salmo salar.

PubMed

Hordvik, Ivar

2015-02-27

There are three major immunoglobulin (Ig) isotypes in salmonid fish: IgM, IgD and IgT, defined by the heavy chains μ, δ and τ, respectively. As a result of whole genome duplication in the ancestor of the salmonid fish family, Atlantic salmon (Salmo salar) possess two highly similar Ig heavy chain gene complexes (A and B), comprising two μ genes, two δ genes, three intact τ genes and five τ pseudogenes. The μA and μB genes correspond to two distinct sub-populations of serum IgM. The IgM-B sub-variant has a characteristic extra cysteine near the C-terminal part of the heavy chain and exhibits a higher degree of polymer disulfide cross-linking compared to IgM-A. The IgM-B:IgM-A ratio in serum is typically 60:40, but skewed ratios are also observed. The IgT isotype appears to be specialized to mucosal immune responses in salmonid fish. The concentration of IgT in serum is 100 to 1000 times lower than IgM. Secreted forms of IgD have been detected in rainbow trout, but not yet in Atlantic salmon.

Potential use of the invasive European green crab (Carcinus maenas) as an ingredient in Atlantic Salmon (Salmo salar) diets; a preliminary analysis

USDA-ARS?s Scientific Manuscript database

Atlantic salmon (Salmo salar) is an important cultured carnivorous species with wide comsumer acceptance. With the finite supply of available fishmeal and fish oil available for aquafeeds, research on and utilization of alternative protein and lipid sources is expandingWe examined the nutritional p...

Trans-generational maternal effect: temperature influences egg size of the offspring in Atlantic salmon Salmo salar.

PubMed

Jonsson, B; Jonsson, N

2016-08-01

Effect of increased temperature during egg maturation on the mass of single eggs produced by the offspring was investigated experimentally in Atlantic salmon Salmo salar. Mass of eggs produced by next-generation females was larger when their mothers experienced warmer water during the last two months of egg maturation, relative to those that experienced unheated river water. There was no similar trans-generational paternal effect on offspring egg mass. © 2016 The Fisheries Society of the British Isles.

Cloning of the prepro C-RFa gene and brain localization of the active peptide in Salmo salar.

PubMed

Montefusco-Siegmund, R A; Romero, A; Kausel, G; Muller, M; Fujimoto, M; Figueroa, J

2006-08-01

In all vertebrates, the synthesis and release of prolactin (Prl) from pituitary lactotroph cells is tightly controlled by hypothalamic factors. We have cloned and characterized a hypothalamic cDNA from Atlantic salmon (Salmo salar) encoding C-RFa, a peptide structurally related to mammalian Prl-releasing peptide (PrRP). The deduced preprohormone precursor is composed of 155 amino acid residues presenting a 87.1% similarity to chum salmon C-RFa and a 100% similarity to all fish C-RFa in the bioactive precursor motifs. C-RFa-immunoreactive perikarya and fibres were located in the brain of S. salar, especially in the hypothalamus, olfactory tract, optic tectum and cerebellum. In contrast, immunolabelled fibres were not observed in the pituitary stalk or in the hypophysis. However, interestingly, we detected immunolabelled cells in the rostral pars distalis of the pituitary in the basolateral region in which Prl is synthesized. These results were confirmed by obtaining a strong signal by using reverse transcription/polymerase chain reaction (RT-PCR) on mRNA from both hypothalamus and pituitary. These data show, for the first time, by immunohistochemistry and RT-PCR, that C-RFa is produced in pituitary cells. Finally, based on these results, a possible function for C-RFa as a locally produced PrRP in this teleost is discussed.

A critical life stage of the Atlantic salmon Salmo salar: behaviour and survival during the smolt and initial post-smolt migration.

PubMed

Thorstad, E B; Whoriskey, F; Uglem, I; Moore, A; Rikardsen, A H; Finstad, B

2012-07-01

The anadromous life cycle of Atlantic salmon Salmo salar involves long migrations to novel environments and challenging physiological transformations when moving between salt-free and salt-rich waters. In this article, (1) environmental factors affecting the migration behaviour and survival of smolts and post-smolts during the river, estuarine and early marine phases, (2) how behavioural patterns are linked to survival and (3) how anthropogenic factors affect migration and survival are synthesized and reviewed based on published literature. The timing of the smolt migration is important in determining marine survival. The timing varies among rivers, most likely as a consequence of local adaptations, to ensure sea entry during optimal periods. Smolts and post-smolts swim actively and fast during migration, but in areas with strong currents, their own movements may be overridden by current-induced transport. Progression rates during the early marine migration vary between 0.4 and 3.0 body lengths s(-1) relative to the ground. Reported mortality is 0.3-7.0% (median 2.3) km(-1) during downriver migration, 0.6-36% (median 6.0) km(-1) in estuaries and 0.3-3.4% (median 1.4) km(-1) in coastal areas. Estuaries and river mouths are the sites of the highest mortalities, with predation being a common cause. The mortality rates varied more among studies in estuaries than in rivers and marine areas, which probably reflects the huge variation among estuaries in their characteristics. Behaviour and survival during migration may also be affected by pollution, fish farming, sea lice Lepeophtheirus salmonis, hydropower development and other anthropogenic activities that may be directly lethal, delay migration or have indirect effects by inhibiting migration. Total mortality reported during early marine migration (up to 5-230 km from the river mouths) in the studies available to date varies between 8 and 71%. Hence, the early marine migration is a life stage with high mortalities, due

Genomic adaptation of the ISA virus to Salmo salar codon usage.

PubMed

Tello, Mario; Vergara, Francisco; Spencer, Eugenio

2013-07-05

The ISA virus (ISAV) is an Orthomyxovirus whose genome encodes for at least 10 proteins. Low protein identity and lack of genetic tools have hampered the study of the molecular mechanism behind its virulence. It has been shown that viral codon usage controls several processes such as translational efficiency, folding, tuning of protein expression, antigenicity and virulence. Despite this, the possible role that adaptation to host codon usage plays in virulence and viral evolution has not been studied in ISAV. Intergenomic adaptation between viral and host genomes was calculated using the codon adaptation index score with EMBOSS software and the Kazusa database. Classification of host genes according to GeneOnthology was performed using Blast2go. A non parametric test was applied to determine the presence of significant correlations among CAI, mortality and time. Using the codon adaptation index (CAI) score, we found that the encoding genes for nucleoprotein, matrix protein M1 and antagonist of Interferon I signaling (NS1) are the ISAV genes that are more adapted to host codon usage, in agreement with their requirement for production of viral particles and inactivation of antiviral responses. Comparison to host genes showed that ISAV shares CAI values with less than 0.45% of Salmo salar genes. GeneOntology classification of host genes showed that ISAV genes share CAI values with genes from less than 3% of the host biological process, far from the 14% shown by Influenza A viruses and closer to the 5% shown by Influenza B and C. As well, we identified a positive correlation (p<0.05) between CAI values of a virus and the duration of the outbreak disease in given salmon farms, as well as a weak relationship between codon adaptation values of PB1 and the mortality rates of a set of ISA viruses. Our analysis shows that ISAV is the least adapted viral Salmo salar pathogen and Orthomyxovirus family member less adapted to host codon usage, avoiding the general behavior of

Integrating across scales: Effectively applying science for the successful conservation of Atlantic salmon (Salmo salar)

USGS Publications Warehouse

Mather, M. E.; Parrish, D.L.; Folt, C.L.; DeGraaf, R.M.

1998-01-01

Atlantic salmon (Salmo salar) is an excellent species on which to focus synthetic, integrative investigations because it is an economically important species that captures the public imagination, is heavily impacted by humans, uses several ecosystems over its life, and is the subject of a large body of extant literature. The following 24 papers were solicited to provide the biological basis for effective and innovative approaches that biologists, managers, and social scientists can use to develop policies that sustain Atlantic salmon and related species. Together these papers highlight the need for and benefits of (a) synthesizing within populations, (b) choosing the appropriate scale, (c) comparing across populations using rigorous, focused, question-oriented methods, (d) integrating across disciplines, (e) incorporating the human perspective, (f) linking multiple ecosystems, and (g) applied problem solving. To show how Atlantic salmon can guide research and conservation efforts for other species in other systems, we review the justification for the supplement and summarize the defining concepts that emerge from the volume.

Reconstructing paleo-precipitation amounts using a terrestrial hydrologic model: Lake Titicaca and the Salar de Uyuni, Peru and Bolivia

NASA Astrophysics Data System (ADS)

Nunnery, J. A.; Baker, P. A.; Coe, M. T.; Fritz, S. C.

2010-12-01

The Peruvian/Bolivian Altiplano has provided many information-rich records bearing on the history of the South American summer monsoon (SASM), a large-scale circulation system that is responsible for much of the precipitation over the Amazon basin and the southern tropics and subtropics. Examples of these paleoclimate time series include long, drill core records from Lake Titicaca (extending back to ca. 400 Ka, Fritz et al., 2007), the long drill core record from Salar de Uyuni (> 250 Ka, Baker et al., 2001; Fritz et al., 2004), paleo-lake level records from the Salar de Uyuni (e.g. Bills et al., 2004; Placzek et al, 2006); drill core records from the Rio Desaguadero valley (Rigsby et al., 2003), and ice core records from Quelccaya, Illimani, and Sajama (Thompson et al., 2000; Ramirez et al., 2003). Several previous studies using energy and water balance models have been applied to these records in attempts to provide quantitative constraints on paleo-temperature and paleo-precipitation (e.g. Kessler, 1984; Hastenrath and Kutzbach, 1985; Cross et al, 2001; Rowe and Dunbar, 2004; Arnold, 2002; Blodgett et al., 1997). For example, Blodgett et al. concluded that high paleolake stands in the Bolivian Altiplano, dated at ca. 16,000 cal. Yr BP (Bills et al., 1994) required precipitation 20% higher than modern at temperatures 5°C colder than modern. However, their model did not take into account the major overflow from Lake Titicaca. Using the THMB hydrologic model, we show that overflow from Lake Titicaca is necessary to produce and sustain large lakes in the Salar de Uyuni basin. This hydrological connection (via the Rio Desaguadero) between the northern and southern Altiplano likely was only established about 60,000 years ago. Prior to that, there were no sustained, large and deep paleolakes on the southern Altiplano. Rather, drill core evidence indicates a very long sequence of shallow, hypersaline lakes and playas.

Seasonal Solar Thermal Absorption Energy Storage Development.

PubMed

Daguenet-Frick, Xavier; Gantenbein, Paul; Rommel, Mathias; Fumey, Benjamin; Weber, Robert; Gooneseker, Kanishka; Williamson, Tommy

2015-01-01

This article describes a thermochemical seasonal storage with emphasis on the development of a reaction zone for an absorption/desorption unit. The heat and mass exchanges are modelled and the design of a suitable reaction zone is explained. A tube bundle concept is retained for the heat and mass exchangers and the units are manufactured and commissioned. Furthermore, experimental results of both absorption and desorption processes are presented and the exchanged power is compared to the results of the simulations.

Effects of ocean acidification on salinity tolerance and seawater growth of Atlantic salmon Salmo salar smolts.

PubMed

Mccormick, S D; Regish, A M

2018-06-23

Human activity has resulted in increasing atmospheric carbon dioxide (CO 2 ), which will result in reduced pH and higher levels of CO 2 in the ocean, a process known as ocean acidification. Understanding the effects of ocean acidification (OA) on fishes will be important to predicting and mitigating its consequences. Anadromous species such as salmonids may be especially at risk because of their rapid movements between fresh water and seawater, which could minimize their ability to acclimate. In the present study, we examine the effect of future OA on the salinity tolerance and early seawater growth of Atlantic salmon Salmo salar smolts. Exposure to 61.81 Pa and 102.34 Pa CO 2 did not alter salinity tolerance but did result in slightly lower plasma chloride levels in smolts exposed to seawater compared with controls (39.59 Pa). Gill Na + -K + -ATPase activity, plasma cortisol, glucose and haematocrit after seawater exposure were not altered by elevated CO 2 . Growth rate in the first 2 weeks of seawater exposure was greater at 102.34 Pa CO 2 than under control conditions. This study of the effects of OA on S. salar during the transition from fresh water to seawater indicates that elevated CO 2 is not likely to affect osmoregulation negatively and may improve early growth in seawater. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Whole body-element composition of Atlantic salmon Salmo salar influenced by migration direction and life stage in three distinct populations.

PubMed

Ebel, J D; Leroux, S J; Robertson, M J; Dempson, J B

2016-11-01

Body-element content was measured for three life stages of wild Atlantic salmon Salmo salar from three distinct Newfoundland populations as individuals crossed between freshwater and marine ecosystems. Life stage explained most of the variation in observed body-element concentration whereas river of capture explained very little variation. Element composition of downstream migrating post-spawn adults (i.e. kelts) and juvenile smolts were similar and the composition of these two life stages strongly differed from adults migrating upstream to spawn. Low variation within life stages and across populations suggests that S. salar may exert rheostatic control of their body-element composition. Additionally, observed differences in trace element concentration between adults and other life stages were probably driven by the high carbon concentration in adults because abundant elements, such as carbon, can strongly influence the observed concentrations of less abundant elements. Thus, understanding variation among individuals in trace elements composition requires the measurement of more abundant elements. Changes in element concentration with ontogeny have important consequences the role of fishes in ecosystem nutrient cycling and should receive further attention. © 2016 The Fisheries Society of the British Isles.

Predation on stocked Atlantic salmon (Salmo salar) fry

USGS Publications Warehouse

Henderson, J.N.; Letcher, B.H.

2003-01-01

We studied predator-prey interactions between juvenile Atlantic salmon (Salmo salar) and trout in three Massachusetts, U.S.A., streams and in artificial streams. We sampled stomach contents of age-1+ and older salmon and trout (Salvelinus fontinalis, Salmo trutta) following salmon fry stocking in the spring of 1997 and 1998. Between 4.3 and 48.6% of the stocked fry were consumed within the first 2 days after stocking, and total fry mortality from predation varied from 4.3 to 60.7%. No significant differences were found between stomach weights of predators (without fry weight) that consumed fry and those that did not. Artificial stream experiments testing effects of habitat complexity and predator species on predator consumption rates revealed that consumption rates were not different between brook (S. fontinalis) and brown (S. trutta) trout (p = 0.59). Predation rate tended to decrease as the percentage of riffle habitat increased but the decrease was not significant (p = 0.22). Our results indicate that predation on stocked Atlantic salmon fry can be substantial (up to 60%), appears to be short lived (2 days), and is not related in a simple way to abiotic and biotic factors.

Migration and survival of Atlantic salmon Salmo salar smolts in a large natural lake.

PubMed

Kennedy, R J; Rosell, R; Millane, M; Doherty, D; Allen, M

2018-06-08

An investigation with acoustic telemetry of the passage of Salmo salar smolts through a large natural lake found heavy mortality occurred at the river-to-lake confluences (mean 31 . 2 % km -1 ), but was lower in the main body of the lake (mean 2 . 4 % km -1 ). Predation was a significant pressure on emigrating smolts as tagged pike Esox lucius aggregated at river-to-lake confluences during the peak of the smolt run. Tagged smolts mainly emmigrated into the lake in the late evening after dusk, possibly as a predator-avoidance behaviour. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Fillet quality and processing attributes of postsmolt Atlantic salmon, Salmo salar, fed a fishmeal-free diet and a fishmeal-based diet in recirculation aquaculture systems

USDA-ARS?s Scientific Manuscript database

Many studies have evaluated the adequacy of alternate ingredient diets for Atlantic salmon, Salmo salar, mainly with focus on fish performance and health; however, comprehensive analysis of fillet quality is lacking, particularly for salmon fed these diets in recirculation aquaculture systems (RAS)....

Genetic background and embryonic temperature affect DNA methylation and expression of myogenin and muscle development in Atlantic salmon (Salmo salar)

PubMed Central

Burgerhout, Erik; Mommens, Maren; Johnsen, Hanne; Aunsmo, Arnfinn; Santi, Nina

2017-01-01

The development of ectothermic embryos is strongly affected by incubation temperature, and thermal imprinting of body growth and muscle phenotype has been reported in various teleost fishes. The complex epigenetic regulation of muscle development in vertebrates involves DNA methylation of the myogenin promoter. Body growth is a heritable and highly variable trait among fish populations that allows for local adaptations, but also for selective breeding. Here we studied the epigenetic effects of embryonic temperature and genetic background on body growth, muscle cellularity and myogenin expression in farmed Atlantic salmon (Salmo salar). Eggs from salmon families with either high or low estimated breeding values for body growth, referred to as Fast and Slow genotypes, were incubated at 8°C or 4°C until the embryonic ‘eyed-stage’ followed by rearing at the production temperature of 8°C. Rearing temperature strongly affected the growth rates, and the 8°C fish were about twice as heavy as the 4°C fish in the order Fast8>Slow8>Fast4>Slow4 prior to seawater transfer. Fast8 was the largest fish also at harvest despite strong growth compensation in the low temperature groups. Larval myogenin expression was approximately 4–6 fold higher in the Fast8 group than in the other groups and was associated with relative low DNA methylation levels, but was positively correlated with the expression levels of the DNA methyltransferase genes dnmt1, dnmt3a and dnmt3b. Juvenile Fast8 fish displayed thicker white muscle fibres than Fast4 fish, while Slow 8 and Slow 4 showed no difference in muscle cellularity. The impact of genetic background on the thermal imprinting of body growth and muscle development in Atlantic salmon suggests that epigenetic variation might play a significant role in the local adaptation to fluctuating temperatures over short evolutionary time. PMID:28662198

Contemporary sand wedge development in seasonally frozen ground and paleoenvironmental implications

NASA Astrophysics Data System (ADS)

Wolfe, Stephen A.; Morse, Peter D.; Neudorf, Christina M.; Kokelj, Steven V.; Lian, Olav B.; O'Neill, H. Brendan

2018-05-01

Contemporary sand wedges and sand veins are active in seasonally frozen ground within the extensive discontinuous permafrost zone in Northwest Territories, Canada. The region has a subarctic continental climate with 291 mm a-1 precipitation, -4.1 °C mean annual air temperature, warm summers (July mean 17.0 °C), and cold winters (January mean -26.6 °C). Five years of continuous observations indicate that interannual variation of the ground thermal regime is dominantly controlled by winter air temperature and snow cover conditions. At sandy sites, thin snow cover and high thermal conductivity promote rapid freezing, high rates of ground cooling, and low near-surface ground temperatures (-15 to -25 °C), resulting in thermal contraction cracking to depths of 1.2 m. Cracking potentials are high in sandy soils when air temperatures are <-30 °C on successive days, mean freezing season air temperatures are ≤-17 °C, and snow cover is <0.15 m thick. In contrast, surface conditions in peatlands maintain permafrost, but thermal contraction cracking does not occur because thicker snow cover and the thermal properties of peat prolong freezeback and maintain higher winter ground temperatures. A combination of radiocarbon dating, optical dating, and stratigraphic observations were used to differentiate sand wedge types and formation histories. Thermal contraction cracks that develop in the sandy terrain are filled by surface (allochthonous) and/or host (autochthonous) material during the thaw season. Epigenetic sand wedges infilled with allochthonous sand develop within former beach sediments beneath an active eolian sand sheet. Narrower and deeper syngenetic wedges developed within aggrading eolian sand sheets, whereas wider and shallower antisyngenetic wedges developed in areas of active erosion. Thermal contraction cracking beneath vegetation-stabilized surfaces leads to crack infilling by autochthonous host and overlying organic material, with resultant downturning and

Genomic adaptation of the ISA virus to Salmo salar codon usage

PubMed Central

2013-01-01

Background The ISA virus (ISAV) is an Orthomyxovirus whose genome encodes for at least 10 proteins. Low protein identity and lack of genetic tools have hampered the study of the molecular mechanism behind its virulence. It has been shown that viral codon usage controls several processes such as translational efficiency, folding, tuning of protein expression, antigenicity and virulence. Despite this, the possible role that adaptation to host codon usage plays in virulence and viral evolution has not been studied in ISAV. Methods Intergenomic adaptation between viral and host genomes was calculated using the codon adaptation index score with EMBOSS software and the Kazusa database. Classification of host genes according to GeneOnthology was performed using Blast2go. A non parametric test was applied to determine the presence of significant correlations among CAI, mortality and time. Results Using the codon adaptation index (CAI) score, we found that the encoding genes for nucleoprotein, matrix protein M1 and antagonist of Interferon I signaling (NS1) are the ISAV genes that are more adapted to host codon usage, in agreement with their requirement for production of viral particles and inactivation of antiviral responses. Comparison to host genes showed that ISAV shares CAI values with less than 0.45% of Salmo salar genes. GeneOntology classification of host genes showed that ISAV genes share CAI values with genes from less than 3% of the host biological process, far from the 14% shown by Influenza A viruses and closer to the 5% shown by Influenza B and C. As well, we identified a positive correlation (p<0.05) between CAI values of a virus and the duration of the outbreak disease in given salmon farms, as well as a weak relationship between codon adaptation values of PB1 and the mortality rates of a set of ISA viruses. Conclusions Our analysis shows that ISAV is the least adapted viral Salmo salar pathogen and Orthomyxovirus family member less adapted to host codon

Discovery and characterization of miRNA genes in atlantic salmon (Salmo salar) by use of a deep sequencing approach

PubMed Central

2013-01-01

Background MicroRNAs (miRNAs) are an abundant class of endogenous small RNA molecules that downregulate gene expression at the posttranscriptional level. They play important roles in multiple biological processes by regulating genes that control developmental timing, growth, stem cell division and apoptosis by binding to the mRNA of target genes. Despite the position Atlantic salmon (Salmo salar) has as an economically important domesticated animal, there has been little research on miRNAs in this species. Knowledge about miRNAs and their target genes may be used to control health and to improve performance of economically important traits. However, before their biological function can be unravelled they must be identified and annotated. The aims of this study were to identify and characterize miRNA genes in Atlantic salmon by deep sequencing analysis of small RNA libraries from nine different tissues. Results A total of 180 distinct mature miRNAs belonging to 106 families of evolutionary conserved miRNAs, and 13 distinct novel mature miRNAs were discovered and characterized. The mature miRNAs corresponded to 521 putative precursor sequences located at unique genome locations. About 40% of these precursors were part of gene clusters, and the majority of the Salmo salar gene clusters discovered were conserved across species. Comparison of expression levels in samples from different tissues applying DESeq indicated that there were tissue specific expression differences in three conserved and one novel miRNA. Ssa-miR 736 was detected in heart tissue only, while two other clustered miRNAs (ssa-miR 212 and132) seems to be at a higher expression level in brain tissue. These observations correlate well with their expected functions as regulators of signal pathways in cardiac and neuronal cells, respectively. Ssa-miR 8163 is one of the novel miRNAs discovered and its function remains unknown. However, differential expression analysis using DESeq suggests that this miRNA is

Effects of smallmouth bass (Micropterus dolomeiu) on Atlantic salmon (Salmo salar) habitat use and diel movements in an artificial stream.

USGS Publications Warehouse

Zydlewski, Joseph D.; Coghlan, Stephen M.; Trial, Joan G.; Wathen, Gus

2012-01-01

Invasive smallmouth bass Micropterus dolomieu have been introduced to some of the last remaining watersheds that contain wild anadromous Atlantic salmon Salmo salar, yet little is known about the interactions between these species. We used an artificial stream equipped with passive integrated transponder tag antenna arrays to monitor habitat use and movements of age-0 Atlantic salmon and age-0 smallmouth bass in sympatry and allopatry. We used additive and substitutive designs to test for changes in habitat use, diel movements, and diel activity patterns of prior-resident Atlantic salmon or smallmouth bass resulting from the addition of conspecifics or heterospecifics. Atlantic salmon prior residents did not change their habitat use in the presence of conspecific or heterospecific invaders. However, Atlantic salmon invaders did lessen riffle habitat use by smallmouth bass prior residents during daytime. Atlantic salmon and smallmouth bass displayed different diel activity patterns of movement (Atlantic salmon were more nocturnal; smallmouth bass were more diurnal), which were affected by heterospecific introductions. Because the two species tended to favor different habitat types and displayed different diel activity patterns, we suggest that under the conditions tested, the level of interspecific competition for habitat was low. Age-0 Atlantic salmon and smallmouth bass may be able to avoid intense interspecific competition through spatial and temporal habitat partitioning. These data do not, however, predict the potential for competition under different seasonal or ontogenetic circumstances.

Stress response of Salmo salar (Linnaeus 1758) facing low abundance infestation of Caligus rogercresseyi (Boxshall & Bravo 2000), an object in the tank, and handling.

PubMed

González Gómez, M P; Marín Arribas, S L; Vargas-Chacoff, L

2016-07-01

This study looks at how low infestation loads of adult Caligus rogercresseyi and other stressors affect the physiology of Salmo salar. Experimental fish groups were with (infested) or without (control) exposure to the parasite. The parasite cohort was followed for 78 days post-infestation (dpi), and only adult lice were observed. Additional stressors were applied at 60 and 75 dpi. The analysis included measurements of fish physiology and weight. Low-level infestations by adult C. rogercresseyi for more than 50 dpi induced moderate stress in S. salar as well as a high energy demand and increased small skin mucous cells. Threshold lice loads were identified, and above those loads, a high stress response was observed. Additional stressors altered fish physiology, inducing downregulation of the cortisol response after the first stressor and upregulation after the second stressor, but infested fish responded more strongly. Parasitism by C. rogercresseyi is energetically demanding, affecting the primary and secondary responses (e.g. cortisol and glucose levels), as well as the tertiary response (fish weight). © 2015 John Wiley & Sons Ltd.

ISA virus regulates the generation of reactive oxygen species and p47phox expression in a p38 MAPK-dependent manner in Salmo salar.

PubMed

Olavarría, Víctor H; Valdivia, Sharin; Salas, Boris; Villalba, Melina; Sandoval, Rodrigo; Oliva, Harold; Valdebenito, Samuel; Yañez, Alejandro

2015-02-01

Several viruses, including Orthomyxovirus, utilize cellular reactive oxygen species (ROS) for viral genomic replication and survival within host cells. However, the role of ROS in early events of viral entry and signal induction has not been elucidated. Here, we show that ISA virus (ISAV) induces ROS production very early during infection of CHSE-214 and SHK-1Ycells, and that production is sustained over the observed 24h post-infection. The mitogen-activated protein kinase (MAPK) family is responsible for important signaling pathways. In this study, we report that ISAV activates ERK and p38 in Salmo salar. In salmonid macrophages, while ERK was required for SOD, GLURED, p47phox expression, p38 regulated the ROS production by the NADPH oxidase complex activation. These results, together with the presence of several consensus target motifs for p38 MAPK in the promoter of the S. salar p47phox gene, suggest that p38 MAPK regulates p47phox gene expression in fish through the activation of this key transcription factor. Copyright © 2014 Elsevier Ltd. All rights reserved.

New immunomodulatory role of neuropeptide Y (NPY) in Salmo salar leucocytes.

PubMed

González-Stegmaier, Roxana; Villarroel-Espíndola, Franz; Manríquez, René; López, Mauricio; Monrás, Mónica; Figueroa, Jaime; Enríquez, Ricardo; Romero, Alex

2017-11-01

Neuropeptide Y (NPY) plays different roles in mammals such as: regulate food intake, memory retention, cardiovascular functions, and anxiety. It has also been shown in the modulation of chemotaxis, T lymphocyte differentiation, and leukocyte migration. In fish, NPY expression and functions have been studied but its immunomodulatory role remains undescribed. This study confirmed the expression and synthesis of NPY in S. salar under inflammation, and validated a commercial antibody for NPY detection in teleost. Additionally, immunomodulatory effects of NPY were assayed in vitro and in vivo. Phagocytosis and superoxide anion production in leukocytes and SHK cells were induced under stimulation with a synthetic peptide. IL-8 mRNA was selectively and strongly induced in the spleen, head kidney, and isolated cells, after in vivo challenge with NPY. All together suggest that NPY is expressed in immune tissues and modulates the immune response in teleost fish. Copyright © 2017 Elsevier Ltd. All rights reserved.

Oxygen consumption, ammonia excretion and protein use in response to thermal changes in juvenile Atlantic salmon Salmo salar.

PubMed

Kieffer, J D; Wakefield, A M

2009-02-01

Experiments were designed to examine the effects of various temperature challenges on oxygen consumption and ammonia excretion rates and protein utilization in juvenile Atlantic salmon Salmo salar. Fish acclimated to 15 degrees C were acutely and abruptly exposed to either 20 or 25 degrees C for a period of 3 h. To simulate a more environmentally relevant temperature challenge, a third group of fish was exposed to a gradual increase in temperature from 15 to 20 degrees C over a period of 3 h (c. 1.7 degrees C h(-1)). Oxygen consumption and ammonia excretion rates were monitored before, during and after the temperature shift. From the ammonia excretion and oxygen consumption rates, protein utilization rates were calculated. Acute temperature changes (15-20 degrees C or 15-25 degrees C) caused large and immediate increases in the oxygen consumption rates. When the temperature was gradually changed (i.e. 1.7 degrees C h(-1)), however, the rates of oxygen consumption and ammonia excretion were only marginally altered. When fish were exposed to warmer temperatures (i.e. 15-20 degrees C or 15-25 degrees C) protein use generally remained at pre-exposure (15 degrees C) levels. A rapid transfer back to 15 degrees C (20-15 degrees C or 25-15 degrees C) generally increased protein use in S. salar. These results indicate that both the magnitude and the rate of temperature change are important in describing the physiological response in juvenile salmonids.

Seawater tolerance in Atlantic salmon, Salmo salar L., brown trout, Salmo trutta L., and S. salar × S. trutta hybrids smolt.

PubMed

Urke, H A; Koksvik, J; Arnekleiv, J V; Hindar, K; Kroglund, F; Kristensen, T

2010-12-01

High levels of hybridization between Atlantic salmon (Salmo salar) and brown trout (Salmo trutta) have been reported in the Gyrodactylus salaris infected Rivers Vefsna and Driva in Norway. The survival and behaviour during the sea phase of such hybrids is unknown. The reported work documents ionoregulatory status after 24 h seawater challenge tests (24hSW) and gill Na+/K+-ATPase (NKA) activity of migrating wild smolts of Atlantic salmon, brown trout and hybrids at two sampling dates during the 2006 smolt run in River Driva. Salmon, trout and hybrids contributed to 27, 52 and 21% of the catches, respectively. The large contribution of hybrids suggests both a high hybridization rate and a high survival rate from fry to smolt. Both salmon and hybrids had a well-developed seawater tolerance at the time of downstream migration, revealed by small ionoregulatory effects and no or low mortality rates during the 24hSW tests. The trout were not fully adapted to seawater, and high mortality rates were observed (71 and 92%) during the 24hSW tests. The NKA activity was not significantly different between salmon and hybrids. Most of the hybrids were physiologically capable of direct entry to full strength seawater. The incomplete seawater tolerance in trout compared to salmon corresponds well with differences in life-history patterns between these two species. The life history strategy of the hybrids during the sea phase is not known, and further investigations on the marine behaviour and survival is needed to evaluate the role of hybrids in the risk of spreading G. salaris to nearby river systems.

The effects of long-term 20 mg/L carbon dioxide exposure on the health and performance of Atlantic salmon Salmo salar post-smolts in water recirculation aquaculture systems

USDA-ARS?s Scientific Manuscript database

Previous research and experience has linked elevated dissolved carbon dioxide (CO2) to reduced growth performance, poor feed conversion, and a variety of health issues in farm-raised fish, including Atlantic salmon Salmo salar. Supplemental control measures in water recirculation aquaculture systems...

Personal, Seasonal Suns

ERIC Educational Resources Information Center

Sutley, Jane

2010-01-01

This article presents an art project designed for upper-elementary students to (1) imagine visual differences in the sun's appearance during the four seasons; (2) develop ideas for visually translating their personal experiences regarding the seasons to their sun drawings; (3) create four distinctive seasonal suns using colors and imagery to…

Skeletal muscle protease activities in the early growth and development of wild Atlantic salmon (Salmo salar L.).

PubMed

Lysenko, Liudmila A; Kantserova, Nadezda P; Kaivarainen, Elena I; Krupnova, Marina Yu; Nemova, Nina N

2017-09-01

Growth-related dynamics of intracellular protease activities in four year classes of the Atlantic salmon (Salmo salar L. 1758) parr and smolts inhabiting salmon rivers of northwestern Russia (the White Sea basin) were studied. Cathepsin B, cathepsin D, proteasome, and calpain activities in the skeletal muscles of salmon were assessed to investigate their relative contribution to the total protein degradation as well as to young fish growth process. It was confirmed that calpain activity dominates in salmon muscles while proteasome plays a minor role, in contrast to terrestrial vertebrates. Calpain and proteasome activities were maximal at the early post-larval stage (in parrs 0+) and declined with age (parrs 1+ through 2+) dropping to the lowest level in salmon smolts. Annual growth increments and proteolytic activities of calpains and proteasome in the muscles of salmon juveniles changed with age in an orchestrated manner, while lysosomal cathepsin activities increased with age. Comparing protease activities and growth increments in salmon parr and smolts we suggested that the partial suppression of the protein degradation could be a mechanism stimulating efficient growth in smoltifying salmon. Growth and smoltification-related dynamics of protease activities was quite similar in salmon populations from studied spawning rivers, such as Varzuga and Indera; however, some habitat-related differences were observed. Growth increments and protease activities varied in salmon parr 0+ (but not on later ages) inhabiting either main rivers or small tributaries apparently due to habitat difference on the resources for fish growth. Copyright © 2017 Elsevier Inc. All rights reserved.

Differential response of continental stock complexes of Atlantic salmon (Salmo salar) to the Atlantic Multidecadal Oscillation

NASA Astrophysics Data System (ADS)

Friedland, Kevin D.; Shank, Burton V.; Todd, Christopher D.; McGinnity, Philip; Nye, Janet A.

2014-05-01

Atlantic salmon, Salmo salar, in the North Atlantic are managed as a set of population complexes distributed in North America and Europe. In recent years, these complexes have experienced reduced marine survival and many populations within the complexes are at risk, especially those at the southern ends of the species amphi-Atlantic range. Atlantic salmon is an anadromous fish dividing its life history between residence in freshwater and the marine environment. The freshwater portion of the life history includes spawning and the rearing of juveniles where in-river production has tended to be relatively stable, whereas the first year at sea, termed the post-smolt year, is characterized by more variable rates of mortality. Although their habitats are widely separated geographically along the North Atlantic seaboards, strong recruitment coherence exists between North American and European stock complexes. This recruitment coherence is correlated with ocean temperature variation associated with the Atlantic Multidecadal Oscillation (AMO). The North Atlantic Oscillation (NAO) appears to be relatively unimportant as a driver of salmon abundance. The mechanism determining the link between AMO-related thermal variation and abundance appears to differ fundamentally for the two continental stock groupings. Whereas ocean climate variability during the first springtime months of juvenile salmon migration to sea appears to be important to the survival of North American stocks, summer climate variation appears to be central to adult recruitment variation for European stocks. This contrast in seasonal effects appears to be related to the varying roles of predation pressure and size-related mortality on the continental stock complexes. The anticipated warming due to global climate change will impose thermal conditions on salmon populations outside historical context and challenge the ability of many populations to persist.

Development of seasonal flow outlook model for Ganges-Brahmaputra Basins in Bangladesh

NASA Astrophysics Data System (ADS)

Hossain, Sazzad; Haque Khan, Raihanul; Gautum, Dilip Kumar; Karmaker, Ripon; Hossain, Amirul

2016-10-01

Bangladesh is crisscrossed by the branches and tributaries of three main river systems, the Ganges, Bramaputra and Meghna (GBM). The temporal variation of water availability of those rivers has an impact on the different water usages such as irrigation, urban water supply, hydropower generation, navigation etc. Thus, seasonal flow outlook can play important role in various aspects of water management. The Flood Forecasting and Warning Center (FFWC) in Bangladesh provides short term and medium term flood forecast, and there is a wide demand from end-users about seasonal flow outlook for agricultural purposes. The objective of this study is to develop a seasonal flow outlook model in Bangladesh based on rainfall forecast. It uses European Centre for Medium-Range Weather Forecasts (ECMWF) seasonal precipitation, temperature forecast to simulate HYDROMAD hydrological model. Present study is limited for Ganges and Brahmaputra River Basins. ARIMA correction is applied to correct the model error. The performance of the model is evaluated using coefficient of determination (R2) and Nash-Sutcliffe Efficiency (NSE). The model result shows good performance with R2 value of 0.78 and NSE of 0.61 for the Brahmaputra River Basin, and R2 value of 0.72 and NSE of 0.59 for the Ganges River Basin for the period of May to July 2015. The result of the study indicates strong potential to make seasonal outlook to be operationalized.

Modeling seasonal water balance based on catchments' hedging strategy on evapotranspiration for climate seasonality

NASA Astrophysics Data System (ADS)

Wu, S.; Zhao, J.; Wang, H.

2017-12-01

This paper develops a seasonal water balance model based on the hypothesis that natural catchments utilize hedging strategy on evapotranspiration for climate seasonality. According to the monthly aridity index, one year is split into wet season and dry season. A seasonal water balance model is developed by analogy to a two-stage reservoir operation model, in which seasonal rainfall infiltration, evapotranspiration and saturation-excess runoff is corresponding to the inflow, release and surplus of the catchment system. Then the optimal hedging between wet season and dry season evapotranspiration is analytically derived with marginal benefit principle. Water budget data sets of 320 catchments in the United States covering the period from 1980 to 2010 are used to evaluate the performance of this model. The Nash-Sutcliffe Efficiency coefficient for evapotranspiration is higher than 0.5 in 84% of the study catchments; while the runoff is 87%. This paper validates catchments' hedging strategy on evapotranspiration for climate seasonality and shows its potential application for seasonal water balance, which is valuable for water resources planning and management.

Draft Genome Sequence of the Fish Pathogen Yersinia ruckeri Strain 37551, Serotype O1b, Isolated from Diseased, Vaccinated Atlantic Salmon (Salmo salar) in Chile

PubMed Central

Navas, Esteban; Bohle, Harry; Henríquez, Patricio; Grothusen, Horst; Bustamante, Fernando; Bustos, Patricio

2014-01-01

We sequenced the genome of a motile O1b Yersinia ruckeri field isolate from Chile, which is causing enteric redmouth disease (ERM) in vaccinated Atlantic salmon (Salmo salar). The draft genome has 3,775,486 bp, a G+C content of 47.1%, and is predicted to contain 3,406 coding sequences. PMID:25169862

Development of intestinal ion-transporting mechanisms during smoltification and seawater acclimation in Atlantic salmon Salmo salar

USGS Publications Warehouse

Sundh, Henrik; Nilsen, Tom O.; Lindström, Jenny; Hasselberg-Frank, Linda; Stefansson, Sigurd O.; McCormick, Stephen D.; Sundell, K.

2014-01-01

This study investigated the expression of ion transporters involved in intestinal fluid absorption and presents evidence for developmental changes in abundance and tissue distribution of these transporters during smoltification and seawater (SW) acclimation of Atlantic salmonSalmo salar. Emphasis was placed on Na+, K+-ATPase (NKA) and Na+, K+, Cl− co-transporter (NKCC) isoforms, at both transcriptional and protein levels, together with transcription of chloride channel genes. The nka α1c was the dominant isoform at the transcript level in both proximal and distal intestines; also, it was the most abundant isoform expressed in the basolateral membrane of enterocytes in the proximal intestine. This isoform was also abundantly expressed in the distal intestine in the lower part of the mucosal folds. The protein expression of intestinal Nkaα1c increased during smoltification. Immunostaining was localized to the basal membrane of the enterocytes in freshwater (FW) fish, and re-distributed to a lateral position after SW entry. Two other Nka isoforms, α1a and α1b, were expressed in the intestine but were not regulated to the same extent during smoltification and subsequent SW transfer. Their localization in the intestinal wall indicates a house-keeping function in excitatory tissues. The absorptive form of the NKCC-like isoform (sub-apically located NKCC2 and/or Na+, Cl−co-transporter) increased during smoltification and further after SW transfer. The cellular distribution changed from a diffuse expression in the sub-apical regions during smoltification to clustering of the transporters closer to the apical membrane after entry to SW. Furthermore, transcript abundance indicates that the mechanisms necessary for exit of chloride ions across the basolateral membrane and into the lateral intercellular space are present in the form of one or more of three different chloride channels: cystic fibrosis transmembrane conductance regulator I and II and chloride channel

Chemical physiological and morphological studies of feral baltic salmon (Salmo salar) suffering from abnormal fry mortality

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

Norrgren, L.; Andersson, T.; Bergqvist, P.A.

In 1974, abnormally high mortality was recorded among yolk-sac fry of Baltic salmon (Salmo salar) originating from feral females manually stripped and fertilized with milt from feral males. The cause of this mortality, designated M74, is unknown. The hypothesis is that xenobiotic compounds responsible for reproduction failure in higher vertebrates in the Baltic Sea also interfere with reproduction in Baltic salmon. The significance of M74 should not be underestimated, because the syndrome has caused up to 75% yearly mortality of developing Baltic salmon yolk-sac larvae in a fish hatchery dedicated to production of smolt during the last two decades. Themore » author cannot exclude the possibility that only a relatively low number of naturally spawned eggs develop normally because of M74. No individual pollutant has been shown to be responsible for the development of M74 syndrome. However, a higher total body burden of organochlorine substances may be responsible for the M74 syndrome. The presence of induced hepatic cytochrome P450 enzymes in both yolk-sac fry suffering from M74 and adult feral females producing offspring affected by M74 supports this hypothesis. In addition, the P450 enzyme activity in offspring from feral fish is higher than the activity in yolk-sac fry from hatchery-raised fish, suggesting that feral Baltic salmon are influenced by organic xenobiotics.« less

Seasonal Habitat Use by Greater Sage-Grouse (Centrocercus urophasianus) on a Landscape with Low Density Oil and Gas Development.

PubMed

Rice, Mindy B; Rossi, Liza G; Apa, Anthony D

2016-01-01

Fragmentation of the sagebrush (Artemisia spp.) ecosystem has led to concern about a variety of sagebrush obligates including the greater sage-grouse (Centrocercus urophasianus). Given the increase of energy development within greater sage-grouse habitats, mapping seasonal habitats in pre-development populations is critical. The North Park population in Colorado is one of the largest and most stable in the state and provides a unique case study for investigating resource selection at a relatively low level of energy development compared to other populations both within and outside the state. We used locations from 117 radio-marked female greater sage-grouse in North Park, Colorado to develop seasonal resource selection models. We then added energy development variables to the base models at both a landscape and local scale to determine if energy variables improved the fit of the seasonal models. The base models for breeding and winter resource selection predicted greater use in large expanses of sagebrush whereas the base summer model predicted greater use along the edge of riparian areas. Energy development variables did not improve the winter or the summer models at either scale of analysis, but distance to oil/gas roads slightly improved model fit at both scales in the breeding season, albeit in opposite ways. At the landscape scale, greater sage-grouse were closer to oil/gas roads whereas they were further from oil/gas roads at the local scale during the breeding season. Although we found limited effects from low level energy development in the breeding season, the scale of analysis can influence the interpretation of effects. The lack of strong effects from energy development may be indicative that energy development at current levels are not impacting greater sage-grouse in North Park. Our baseline seasonal resource selection maps can be used for conservation to help identify ways of minimizing the effects of energy development.

Influence of season of birth on growth and reproductive development of Brahman bulls.

PubMed

Tatman, Shawn R; Neuendorff, Don A; Wilson, Timothy W; Randel, Ronald D

2004-07-01

Seasonal effects on reproduction are more dramatic in Bos indicus than Bos taurus cattle. This experiment evaluated reproductive development of fall- (n=7) versus spring- (n = 10) born Brahman bulls to determine if season of birth affects reproductive development. Measurements of growth and reproductive development began after weaning and continued at bi-weekly intervals until each bull reached sexual maturity. Different stages of sexual development were classified according to characteristics of the ejaculate and included first sperm in the ejaculate, puberty (> 50 x 10(6) sperm/ejaculate), and sexual maturity (two ejaculates with > 500 = 10(6) sperm/ejaculate). Average daily increases in all measured traits were similar in fall- and spring-born bulls and there were no differences in age, body weight, scrotal circumference, or paired testis volume between groups at first sperm or puberty. However, fall-born bulls were older (P < 0.05) than spring-born bulls at sexual maturity (553 days versus 481 days, respectively) as the interval between puberty and sexual maturity was longer (P < 0.05) in fall- than in spring-born bulls (82 days versus 54 days, respectively). The prolonged interval between puberty and sexual maturity in fall-born calves coincided with a short photoperiod (winter) whereas the short interval between puberty and sexual maturity in spring-born calves coincided with a long photoperiod (summer). In conclusion, season of birth affected sexual development; photoperiod might be involved in regulating testicular function immediately after puberty in Brahman bulls.

Atlantic salmon reovirus infection causes a CD8 T cell myocarditis in Atlantic salmon (Salmo salar L.).

PubMed

Mikalsen, Aase B; Haugland, Oyvind; Rode, Marit; Solbakk, Inge Tom; Evensen, Oystein

2012-01-01

Heart and skeletal inflammation (HSMI) of farmed Atlantic salmon (Salmo salar L.) is a disease characterized by a chronic myocarditis involving the epicardium and the compact and spongious part of the heart ventricle. Chronic myositis of the red skeletal muscle is also a typical finding of HSMI. Piscine reovirus (PRV) has been detected by real-time PCR from farmed and wild salmon with and without typical changes of HSMI and thus the causal relationship between presence of virus and the disease has not been fully determined. In this study we show that the Atlantic salmon reovirus (ASRV), identical to PRV, can be passaged in GF-1 cells and experimental challenge of naïve Atlantic salmon with cell culture passaged reovirus results in cardiac and skeletal muscle pathology typical of HSMI with onset of pathology from 6 weeks, peaking by 9 weeks post challenge. ASRV replicates in heart tissue and the peak level of virus replication coincides with peak of heart lesions. We further demonstrate mRNA transcript assessment and in situ characterization that challenged fish develop a CD8+ T cell myocarditis.

Immunomodulatory effect of prolactin on Atlantic salmon (Salmo salar) macrophage function.

PubMed

Paredes, Marco; Gonzalez, Katerina; Figueroa, Jaime; Montiel-Eulefi, Enrique

2013-10-01

The in vitro and in vivo effect of prolactin (PRL) on kidney macrophages from Atlantic salmon (Salmo salar) was investigated under the assumption that PRL stimulates immune innate response in mammals. Kidney macrophages were treated two ways: first, cultured in RPMI 1640 medium containing 10, 25, 50 and 100 ng/mL of PRL and second, isolated from a fish with a PRL-injected dose of 100 ng/Kg. Reduced nitro blue tetrazolium (formazan) was used to produce intracellular superoxide anion. Phagocytic activity of PRL was determined in treated cells by optical microscopy observation of phagocytized Congo red-stained yeast. Kidney lysozyme activity was measured in PRL-injected fish. In vitro and in vivo macrophages treated with PRL presented an enhanced superoxide anion production, elevated phagocytic index and increased phagocytic activity. Treated fish showed higher levels of lysozyme activity in the head kidney compared to the control. These results indicate that PRL-stimulated innate immune response in Atlantic salmon and future studies will allow us to assess the possibility of using PRL as an immunostimulant in the Chilean salmon industry.

Developing Novel Reservoir Rule Curves Using Seasonal Inflow Projections

NASA Astrophysics Data System (ADS)

Tseng, Hsin-yi; Tung, Ching-pin

2015-04-01

Due to significant seasonal rainfall variations, reservoirs and their flexible operational rules are indispensable to Taiwan. Furthermore, with the intensifying impacts of climate change on extreme climate, the frequency of droughts in Taiwan has been increasing in recent years. Drought is a creeping phenomenon, the slow onset character of drought makes it difficult to detect at an early stage, and causes delays on making the best decision of allocating water. For these reasons, novel reservoir rule curves using projected seasonal streamflow are proposed in this study, which can potentially reduce the adverse effects of drought. This study dedicated establishing new rule curves which consider both current available storage and anticipated monthly inflows with leading time of two months to reduce the risk of water shortage. The monthly inflows are projected based on the seasonal climate forecasts from Central Weather Bureau (CWB), which a weather generation model is used to produce daily weather data for the hydrological component of the GWLF. To incorporate future monthly inflow projections into rule curves, this study designs a decision flow index which is a linear combination of current available storage and inflow projections with leading time of 2 months. By optimizing linear relationship coefficients of decision flow index, the shape of rule curves and the percent of water supply in each zone, the best rule curves to decrease water shortage risk and impacts can be developed. The Shimen Reservoir in the northern Taiwan is used as a case study to demonstrate the proposed method. Existing rule curves (M5 curves) of Shimen Reservoir are compared with two cases of new rule curves, including hindcast simulations and historic seasonal forecasts. The results show new rule curves can decrease the total water shortage ratio, and in addition, it can also allocate shortage amount to preceding months to avoid extreme shortage events. Even though some uncertainties in

A national-scale seasonal hydrological forecast system: development and evaluation over Britain

NASA Astrophysics Data System (ADS)

Bell, Victoria A.; Davies, Helen N.; Kay, Alison L.; Brookshaw, Anca; Scaife, Adam A.

2017-09-01

forecast skill (mostly in areas of high rainfall to the north and west) and only 30 % of the skill arises from hydrological memory (typically groundwater-dominated areas). Given the high spatial heterogeneity in typical patterns of UK rainfall and evaporation, future development of skilful spatially distributed seasonal forecasts could lead to substantial improvements in seasonal flow forecast capability, potentially benefitting practitioners interested in predicting hydrological extremes, not only in the UK but also across Europe.

Draft Genome Sequence of the Fish Pathogen Yersinia ruckeri Strain 37551, Serotype O1b, Isolated from Diseased, Vaccinated Atlantic Salmon (Salmo salar) in Chile.

PubMed

Navas, Esteban; Bohle, Harry; Henríquez, Patricio; Grothusen, Horst; Bustamante, Fernando; Bustos, Patricio; Mancilla, Marcos

2014-08-28

We sequenced the genome of a motile O1b Yersinia ruckeri field isolate from Chile, which is causing enteric redmouth disease (ERM) in vaccinated Atlantic salmon (Salmo salar). The draft genome has 3,775,486 bp, a G+C content of 47.1%, and is predicted to contain 3,406 coding sequences. Copyright © 2014 Navas et al.

Development of a European Ensemble System for Seasonal Prediction: Application to crop yield

NASA Astrophysics Data System (ADS)

Terres, J. M.; Cantelaube, P.

2003-04-01

Western European agriculture is highly intensive and the weather is the main source of uncertainty for crop yield assessment and for crop management. In the current system, at the time when a crop yield forecast is issued, the weather conditions leading up to harvest time are unknown and are therefore a major source of uncertainty. The use of seasonal weather forecast would bring additional information for the remaining crop season and has valuable benefit for improving the management of agricultural markets and environmentally sustainable farm practices. An innovative method for supplying seasonal forecast information to crop simulation models has been developed in the frame of the EU funded research project DEMETER. It consists in running a crop model on each individual member of the seasonal hindcasts to derive a probability distribution of crop yield. Preliminary results of cumulative probability function of wheat yield provides information on both the yield anomaly and the reliability of the forecast. Based on the spread of the probability distribution, the end-user can directly quantify the benefits and risks of taking weather-sensitive decisions.

Transcriptomic Responses of Atlantic Salmon (Salmo salar) to Environmental Enrichment during Juvenile Rearing

PubMed Central

Evans, Melissa L.; Hori, Tiago S.; Rise, Matthew L.; Fleming, Ian A.

2015-01-01

Captive rearing programs (hatcheries) are often used in conservation and management efforts for at-risk salmonid fish populations. However, hatcheries typically rear juveniles in environments that contrast starkly with natural conditions, which may lead to phenotypic and/or genetic changes that adversely affect the performance of juveniles upon their release to the wild. Environmental enrichment has been proposed as a mechanism to improve the efficacy of population restoration efforts from captive-rearing programs; in this study, we examine the influence of environmental enrichment during embryo and yolk-sac larval rearing on the transcriptome of Atlantic salmon (Salmo salar). Full siblings were reared in either a hatchery environment devoid of structure or an environment enriched with gravel substrate. At the end of endogenous feeding by juveniles, we examined patterns of gene transcript abundance in head tissues using the cGRASP-designed Agilent 4×44K microarray. Significance analysis of microarrays (SAM) indicated that 808 genes were differentially transcribed between the rearing environments and a total of 184 gene ontological (GO) terms were over- or under-represented in this gene list, several associated with mitosis/cell cycle and muscle and heart development. There were also pronounced differences among families in the degree of transcriptional response to rearing environment enrichment, suggesting that gene-by-environment effects, possibly related to parental origin, could influence the efficacy of enrichment interventions. PMID:25742646

Transcriptomic responses of Atlantic salmon (Salmo salar) to environmental enrichment during juvenile rearing.

PubMed

Evans, Melissa L; Hori, Tiago S; Rise, Matthew L; Fleming, Ian A

2015-01-01

Captive rearing programs (hatcheries) are often used in conservation and management efforts for at-risk salmonid fish populations. However, hatcheries typically rear juveniles in environments that contrast starkly with natural conditions, which may lead to phenotypic and/or genetic changes that adversely affect the performance of juveniles upon their release to the wild. Environmental enrichment has been proposed as a mechanism to improve the efficacy of population restoration efforts from captive-rearing programs; in this study, we examine the influence of environmental enrichment during embryo and yolk-sac larval rearing on the transcriptome of Atlantic salmon (Salmo salar). Full siblings were reared in either a hatchery environment devoid of structure or an environment enriched with gravel substrate. At the end of endogenous feeding by juveniles, we examined patterns of gene transcript abundance in head tissues using the cGRASP-designed Agilent 4×44K microarray. Significance analysis of microarrays (SAM) indicated that 808 genes were differentially transcribed between the rearing environments and a total of 184 gene ontological (GO) terms were over- or under-represented in this gene list, several associated with mitosis/cell cycle and muscle and heart development. There were also pronounced differences among families in the degree of transcriptional response to rearing environment enrichment, suggesting that gene-by-environment effects, possibly related to parental origin, could influence the efficacy of enrichment interventions.

Salmo salar and Esox lucius full-length cDNA sequences reveal changes in evolutionary pressures on a post-tetraploidization genome

PubMed Central

2010-01-01

Background Salmonids are one of the most intensely studied fish, in part due to their economic and environmental importance, and in part due to a recent whole genome duplication in the common ancestor of salmonids. This duplication greatly impacts species diversification, functional specialization, and adaptation. Extensive new genomic resources have recently become available for Atlantic salmon (Salmo salar), but documentation of allelic versus duplicate reference genes remains a major uncertainty in the complete characterization of its genome and its evolution. Results From existing expressed sequence tag (EST) resources and three new full-length cDNA libraries, 9,057 reference quality full-length gene insert clones were identified for Atlantic salmon. A further 1,365 reference full-length clones were annotated from 29,221 northern pike (Esox lucius) ESTs. Pairwise dN/dS comparisons within each of 408 sets of duplicated salmon genes using northern pike as a diploid out-group show asymmetric relaxation of selection on salmon duplicates. Conclusions 9,057 full-length reference genes were characterized in S. salar and can be used to identify alleles and gene family members. Comparisons of duplicated genes show that while purifying selection is the predominant force acting on both duplicates, consistent with retention of functionality in both copies, some relaxation of pressure on gene duplicates can be identified. In addition, there is evidence that evolution has acted asymmetrically on paralogs, allowing one of the pair to diverge at a faster rate. PMID:20433749

Global Seasonality of Rotavirus Disease

PubMed Central

Patel, Manish M.; Pitzer, Virginia; Alonso, Wladimir J.; Vera, David; Lopman, Ben; Tate, Jacqueline; Viboud, Cecile; Parashar, Umesh D.

2012-01-01

Background A substantial number of surveillance studies have documented rotavirus prevalence among children admitted for dehydrating diarrhea. We sought to establish global seasonal patterns of rotavirus disease before widespread vaccine introduction. Methods We reviewed studies of rotavirus detection in children with diarrhea published since 1995. We assessed potential relationships between seasonal prevalence and locality by plotting the average monthly proportion of diarrhea cases positive for rotavirus according to geography, country development, and latitude. We used linear regression to identify variables that were potentially associated with the seasonal intensity of rotavirus. Results Among a total of 99 studies representing all six geographical regions of the world, patterns of year-round disease were more evident in low- and low-middle income countries compared with upper-middle and high income countries where disease was more likely to be seasonal. The level of country development was a stronger predictor of strength of seasonality (P=0.001) than geographical location or climate. However, the observation of distinctly different seasonal patterns of rotavirus disease in some countries with similar geographical location, climate and level of development indicate that a single unifying explanation for variation in seasonality of rotavirus disease is unlikely. Conclusion While no unifying explanation emerged for varying rotavirus seasonality globally, the country income level was somewhat more predictive of the likelihood of having seasonal disease than other factors. Future evaluation of the effect of rotavirus vaccination on seasonal patterns of disease in different settings may help understand factors that drive the global seasonality of rotavirus disease. PMID:23190782

Impacts of episodic acidification on in-stream survival and physiological impairment of Atlantic salmon (Salmo salar) smolts

USGS Publications Warehouse

McCormick, S.D.; Keyes, A.; Nislow, K.H.; Monette, M.Y.

2009-01-01

We conducted field studies to determine the levels of acid and aluminum (Al) that affect survival, smolt development, ion homeostasis, and stress in Atlantic salmon (Salmo salar) smolts in restoration streams of the Connecticut River in southern Vermont, USA. Fish were held in cages in five streams encompassing a wide range of acid and Al levels for two 6-day intervals during the peak of smolt development in late April and early May. Physiological parameters were unchanged from initial sampling at the hatchery and the high water quality reference site (pH > 7.0, inorganic Al < 12 μg·L-1). Mortality, substantial loss of plasma chloride, and gill Na+/K+-ATPase activity, and elevated gill Al occurred at sites with the lowest pH (5.4-5.6) and highest inorganic Al (50-80 μg·L-1). Moderate loss of plasma chloride, increased plasma cortisol and glucose, and moderately elevated gill Al occurred at less severely impacted sites. Gill Al was a better predictor of integrated physiological impacts than water chemistry alone. The results indicate that Al and low pH under field conditions in some New England streams can cause mortality and impair smolt development in juvenile Atlantic salmon and provide direct evidence that episodic acidification is impacting conservation and recovery of Atlantic salmon in the northeastern USA.

Developing Curriculum for Canadian Schools: What We Learned from the Atlantic Salmon

ERIC Educational Resources Information Center

Anderson, Gary J.; And Others

1977-01-01

The process of developing a distinctively Canadian junior high school curriculum unit integrating subject content of history, science, and geography around a common theme is discussed. The unit focuses on the life cycle and environment of the Atlantic Salmon, Salmo salar. (MJB)

Endocrine systems in juvenile anadromous and landlocked Atlantic salmon (Salmo salar): Seasonal development and seawater acclimation

USGS Publications Warehouse

Nilsen, Tom O.; Ebbesson, Lars O.E.; Kiilerich, P.; Bjornsson, B. Th; Madsen, Steffen S.; McCormick, S.D.; Stefansson, S.O.

2008-01-01

??-HSD2 and MR mRNA levels increased after four days in SW in both strains, whereas only the anadromous strain maintained elevated gill GR and 11??-HSD2 mRNA levels after one month in SW. The results indicate that hormones and receptors of the GH and cortisol axes are present at significantly lower levels during spring development and SW acclimation in landlocked relative to anadromous salmon. These findings suggest that attenuation of GH and cortisol axes may, at least partially, result in reduced preparatory upregulation of key gill ion-secretory proteins, possibly a result of reduced selection pressure for marine adaptations in landlocked salmon. ?? 2007 Elsevier Inc. All rights reserved.

Historical record of Yersinia ruckeri and Aeromonas salmonicida among sea-run Atlantic salmon (Salmo salar) in the Penobscot River

USGS Publications Warehouse

Cipriano, R.C.; Coll, J.

2005-01-01

Despite restoration efforts, only about 2,000 Atlantic salmon (Salmo salar) salmon have annually returned to New England Rivers and more than 71% of these fish migrate to the Penobscot River alone. This report provides a historical compilation on the prevalence's of both Yersinia ruckeri, cause of enteric redmouth disease, and Aeromonas salmonicida, cause of furunculosis, among mature sea-run Atlantic salmon that returned to the Penobscot River from 1976 to 2003. Aeromonas salmonicida was detected in 28.6% and Yersinia ruckeri was detected among 50% of the yearly returns. Consequently, Atlantic salmon that return to the river are potential reservoirs of infection.

Changing Seasons

ERIC Educational Resources Information Center

Karolak, Eric

2011-01-01

In some ways, there is a season of change at the national level in early childhood. Some things are wrapping up while some developments aim to prepare the "field" for improvements in the next year and beyond, just as a garden plot is readied for the next planting season. Change is in the air, and there's hope of renewal, but what changes and how…

Active shortening and intermontane basin formation in the central Puna Plateau: Salar de Pocitos, NW Argentina (24° 37S, 67° 03W)

NASA Astrophysics Data System (ADS)

Strecker, M. R.; Bookhagen, B.; Alonso, R.

2012-12-01

With average elevations of about 3.7 km, the semi-arid to arid Puna Plateau is a first-order morphotectonic province of the southern central Andes and is an integral part of the world's second largest orogenic plateau. With few exceptions, this region consists of internally drained, partly coalesced sedimentary basins that are mainly bordered by 5- to 6-km high reverse-fault bounded basement ranges or volcanic edifices. The basins contain continental evaporites, volcanic and clastic deposits, typically between 3 and 5 km thick, and record protracted sedimentation since the Eo-Oligocene. While these basins and ranges are related to contraction, extensional tectonics associated with mafic volcanism characterizes the eastern and southern sectors of the Puna Plateau, while the eastern flanks of the plateau and the adjacent foreland are subjected to shortening. The changeover from contraction to extension in the Puna appears to have been diachronous. Along the SE plateau margin the changeover based on previously published age dating took place between 7 and 5 Ma, while areas in the central and northern Puna document shortening until 6 and 9 Ma, respectively. In the latter two areas, however, evidence for extension comparable to the eastern and southeastern plateau is scarce. This is compatible with our new observations from the Salar de Pocitos area in the western interior of the plateau, which has been characterized by protracted shortening from the Tertiary to the present-day. The N-S oriented Salar de Pocitos basin (435 km2) is the vestige of a formerly contiguous sedimentary basin that extended to the Salar de Arizaro in the west. Unlike many other basins in this region, the Pocitos basin is bordered by the limb of an anticline developed in Tertiary sedimentary rocks on the west, while the east side comprises the reverse-faulted range front of Sierra Qda. Honda. To the north the basin is closed by transverse-oriented late Miocene volcanic edifices, and to the south

Seasonal variation of fecal contamination in drinking water sources in developing countries: a systematic review.

PubMed

Kostyla, Caroline; Bain, Rob; Cronk, Ryan; Bartram, Jamie

2015-05-01

Accounting for fecal contamination of drinking water sources is an important step in improving monitoring of global access to safe drinking water. Fecal contamination varies with time while its monitoring is often infrequent. We sought to understand seasonal trends in fecal contamination to guide best practices to capture seasonal variation and ascertain the extent to which the results of a single sample may overestimate compliance with health guidelines. The findings from 22 studies from developing countries written in English and identified through a systematic review were analyzed. Fecal contamination in improved drinking water sources was shown to follow a statistically significant seasonal trend of greater contamination during the wet season (p<0.001). This trend was consistent across fecal indicator bacteria, five source types, twelve Köppen-Geiger climate zones, and across both rural and urban areas. Guidance on seasonally representative water quality monitoring by the World Health Organization and national water quality agencies could lead to improved assessments of access to safe drinking water. Copyright © 2015 Elsevier B.V. All rights reserved.

Seasonal thermal storage: Swedish practice, developments and cost projections

NASA Astrophysics Data System (ADS)

Margen, P.

1981-06-01

The types of heat store being developed in Sweden for seasonal storage of heat are discussed. This type of storage allows summer excess heat from industrial waste heat plants, garbage burning plants and future central solar heat stations to be stored for winter use on district heating networks. Whereas above ground steel or concrete tanks are usually too expensive insulated earth pits, uninsulated rock caverns and deep ground schemes using rock or clay promise to achieve sufficiently low costs to justify storage when supplied with free or cheap summer treat. For all these concepts demonstration plants were or are being built in Sweden.

Pseudo-membranes on internal organs associated with Rhodococcus qingshengii infection in Atlantic salmon (Salmo salar).

PubMed

Avendaño-Herrera, Rubén; Balboa, Sabela; Doce, Alejandra; Ilardi, Pedro; Lovera, Pablo; Toranzo, Alicia E; Romalde, Jesús L

2011-01-10

This paper describes a pathological condition in intensive reared Atlantic salmon (Salmo salar), restricted to the appearance of pseudo-membranes covering internal organs (i.e. spleen, liver, heart and others) associated with the presence of large numbers of a Gram-positive bacteria. Isolate 79043-3, obtained as pure culture from affected fish, was subjected to a polyphasic taxonomic study in order to determine its exact taxonomic position, as well as to experimental challenges leading to determine its pathogenic potential for cultured fish. Based on this characterization, we report the first isolation of Rhodococcus qingshengii, from a farmed population of Atlantic salmon in Chile. Virulence studies demonstrated that the isolate fulfilled the Koch's postulates, suggesting that this bacterial species could be considered as an opportunistic pathogen for Atlantic salmon. Copyright © 2010 Elsevier B.V. All rights reserved.

Migratory behaviour and survival rates of wild northern Atlantic salmon Salmo salar post-smolts: Effects of environmental factors

USGS Publications Warehouse

Davidsen, J.G.; Rikardsen, A.H.; Halttunen, E.; Thorstad, E.B.; Okland, F.; Letcher, B.H.; Skarhamar, J.; Naesje, T.F.

2009-01-01

To study smolt behaviour and survival of a northern Atlantic salmon Salmo salar population during river descent, sea entry and fjord migration, 120 wild S. salar were tagged with acoustic tags and registered at four automatic listening station arrays in the mouth of the north Norwegian River Alta and throughout the Alta Fjord. An estimated 75% of the post-smolts survived from the river mouth, through the estuary and the first 17 km of the fjord. Survival rates in the fjord varied with fork length (LF), and ranged from 97??0 to 99??5% km-1. On average, the post-smolts spent 1??5 days (36 h, range 11-365 h) travelling from the river mouth to the last fjord array, 31 km from the river mouth. The migratory speed was slower (1??8 LF s-1) in the first 4 km after sea entry compared with the next 27 km (3??0 LF s-1). Post-smolts entered the fjord more often during the high or ebbing tide (70%). There was no clear diurnal migration pattern within the river and fjord, but most of the post-smolts entered the fjord at night (66%, 2000-0800 hours), despite the 24 h daylight at this latitude. The tidal cycle, wind-induced currents and the smolts' own movements seemed to influence migratory speeds and routes in different parts of the fjord. A large variation in migration patterns, both in the river and fjord, might indicate that individuals in stochastic estuarine and marine environments are exposed to highly variable selection regimes, resulting in different responses to environmental factors on both temporal and spatial scales. Post-smolts in the northern Alta Fjord had similar early marine survival rates to those observed previously in southern fjords; however, fjord residency in the north was shorter. ?? 2009 The Fisheries Society of the British Isles.

Detection of emamectin benzoate tolerance emergence in different life stages of sea lice, Lepeophtheirus salmonis, on farmed Atlantic salmon, Salmo salar L.

PubMed

Jones, P G; Hammell, K L; Gettinby, G; Revie, C W

2013-03-01

Emamectin benzoate has been used to treat sea lice, Lepeophtheirus salmonis, infestations on farmed Atlantic salmon, Salmo salar. Recent evidence suggests a reduction in effectiveness in some locations. A major challenge in the detection of tolerance emergence can be the typically low proportion of resistant individuals in a population during the early phases. The objectives of this study were to develop a method for determining differences in temporal development of tolerance between sea lice life stages and to explore how these differences might be used to improve the monitoring of treatment effectiveness in a clinical setting. This study examined two data sets based on records of sea lice abundance following emamectin benzoate treatments from the west coast of Scotland (2002-2006) and from New Brunswick, Canada (2004-2008). Life stages were categorized into two groups (adult females and the remaining mobile stages) to examine the trends in mean abundance and treatment effectiveness. Differences in emamectin benzoate effectiveness were found between the two groups by year and location, suggesting that an important part of monitoring drug resistance development in aquatic ectoparasites may be the need to focus on key life stages. © 2013 Blackwell Publishing Ltd.

Effect of low sea water temperature on water balance in the Atlantic salmon, (Salmo salar L.).

PubMed

Lega, Y V; Chernitsky, A G; Belkovsky, N M

1992-08-01

The water balance in Atlantic salmon (Salmo salar L.) overwintering in sea water (34 ‰) was investigated. With a decrease of temperature from 5.6 to 1.0°C the drinking rate decreased from 13.9 to 5.7 ml/kg/day, and the absolute amount of water absorbed decreased from 8.9 to 5.0 ml/kg/day. A decrease in temperature led, however, to an increase in the proportion of water absorbed in the intestines from 60 to 96%. Blood serum osmolarity increased from 320 to 440 mosm/1 with decreasing temperature and there was a reduction in tissue water content from 75 to 69% The disturbance of water balance at low temperature may be one of the factors responsible for mortality of salmon overwintering in sea water.

Hepatic Proteome Analysis of Atlantic Salmon (Salmo salar) After Exposure to Environmental Concentrations of Human Pharmaceuticals*

PubMed Central

Hampel, Miriam; Alonso, Esteban; Aparicio, Irene; Santos, Juan Luis; Leaver, Michael

2015-01-01

Pharmaceuticals are pseudopersistent aquatic pollutants with unknown effects at environmentally relevant concentrations. Atlantic salmon (Salmo salar) were exposed to Acetaminophen: 54.77 ± 34.67; Atenolol: 11.08 ± 7.98, and Carbamazepine: 7.85 ± 0.13 μg·L−1 for 5 days. After Acetaminophen treatment, 19 proteins were differently expressed, of which 11 were significant with respect to the control group (eight up-regulated and three down-regulated). After Atenolol treatment, seven differently expressed proteins were obtained in comparison with the control, of which six could be identified (four up-regulated and two down-regulated). Carbamazepine exposure resulted in 15 differently expressed proteins compared with the control, with 10 of them identified (seven up-regulated and three down-regulated). Out of these, three features were common between Acetaminophen and Carbamazepine and one between Carbamazepine and Atenolol. One feature was common across all treatments. Principal component analysis and heat map clustering showed a clear grouping of the variability caused by the applied treatments. The obtained data suggest (1) that exposure to environmentally relevant concentrations of the pharmaceuticals alters the hepatic protein expression profile of the Atlantic salmon; and (2) the existence of treatment specific processes that may be useful for biomarker development. PMID:25394398

Cardiomyopathy syndrome in Atlantic salmon Salmo salar L.: A review of the current state of knowledge.

PubMed

Garseth, Å H; Fritsvold, C; Svendsen, J C; Bang Jensen, B; Mikalsen, A B

2018-01-01

Cardiomyopathy syndrome (CMS) is a severe cardiac disease affecting Atlantic salmon Salmo salar L. The disease was first recognized in farmed Atlantic salmon in Norway in 1985 and subsequently in farmed salmon in the Faroe Islands, Scotland and Ireland. CMS has also been described in wild Atlantic salmon in Norway. The demonstration of CMS as a transmissible disease in 2009, and the subsequent detection and initial characterization of piscine myocarditis virus (PMCV) in 2010 and 2011 were significant discoveries that gave new impetus to the CMS research. In Norway, CMS usually causes mortality in large salmon in ongrowing and broodfish farms, resulting in reduced fish welfare, significant management-related challenges and substantial economic losses. The disease thus has a significant impact on the Atlantic salmon farming industry. There is a need to gain further basic knowledge about the virus, the disease and its epidemiology, but also applied knowledge from the industry to enable the generation and implementation of effective prevention and control measures. This review summarizes the currently available, scientific information on CMS and PMCV with special focus on epidemiology and factors influencing the development of CMS. © 2017 The Authors. Journal of Fish Diseases Published by John Wiley & Sons Ltd.

Seasonal and cumulative loblolly pine development under two stand density and fertility levels through four growing seasons

Treesearch

James D. Haywood

1994-01-01

A loblolly pine stand was subjected to two cultural treatments to determine treatment effects in the 9th through 12th growing seasons. Thining resulted in less spring height growth in the 9th and 10th growing seasons than no thinning, but thinning resulted in more diameter growth each year. Fertilization increased height and diameter growth beginning in the 10th...

Real-time real-world analysis of seasonal influenza vaccine effectiveness: method development and assessment of a population-based cohort in Stockholm County, Sweden, seasons 2011/12 to 2014/15.

PubMed

Leval, Amy; Hergens, Maria Pia; Persson, Karin; Örtqvist, Åke

2016-10-27

Real-world estimates of seasonal influenza vaccine effectiveness (VE) are important for early detection of vaccine failure. We developed a method for evaluating real-time in-season vaccine effectiveness (IVE) and overall seasonal VE. In a retrospective, register-based, cohort study including all two million individuals in Stockholm County, Sweden, during the influenza seasons from 2011/12 to 2014/15, vaccination status was obtained from Stockholm's vaccine register. Main outcomes were hospitalisation or primary care visits for influenza (International Classification of Disease (ICD)-10 codes J09-J11). VE was assessed using Cox multivariate stratified and non-stratified analyses adjusting for age, sex, socioeconomic status, comorbidities and previous influenza vaccinations. Stratified analyses showed moderate VE in prevention of influenza hospitalisations among chronically ill adults ≥ 65 years in two of four seasons, and lower but still significant VE in one season; 53% (95% confidence interval (CI): 33-67) in 2012/13, 55% (95% CI: 25-73) in 2013/14 and 18% (95% CI: 3-31) in 2014/15. In conclusion, seasonal influenza vaccination was associated with substantial reductions in influenza-specific hospitalisation, particularly in adults ≥ 65 years with underlying chronic conditions. With the use of population-based patient register data on influenza-specific outcomes it will be possible to obtain real-time estimates of seasonal influenza VE. This article is copyright of The Authors, 2016.

Real-time real-world analysis of seasonal influenza vaccine effectiveness: method development and assessment of a population-based cohort in Stockholm County, Sweden, seasons 2011/12 to 2014/15

PubMed Central

Leval, Amy; Hergens, Maria Pia; Persson, Karin; Örtqvist, Åke

2016-01-01

Real-world estimates of seasonal influenza vaccine effectiveness (VE) are important for early detection of vaccine failure. We developed a method for evaluating real-time in-season vaccine effectiveness (IVE) and overall seasonal VE. In a retrospective, register-based, cohort study including all two million individuals in Stockholm County, Sweden, during the influenza seasons from 2011/12 to 2014/15, vaccination status was obtained from Stockholm’s vaccine register. Main outcomes were hospitalisation or primary care visits for influenza (International Classification of Disease (ICD)-10 codes J09-J11). VE was assessed using Cox multivariate stratified and non-stratified analyses adjusting for age, sex, socioeconomic status, comorbidities and previous influenza vaccinations. Stratified analyses showed moderate VE in prevention of influenza hospitalisations among chronically ill adults ≥ 65 years in two of four seasons, and lower but still significant VE in one season; 53% (95% confidence interval (CI): 33–67) in 2012/13, 55% (95% CI: 25–73) in 2013/14 and 18% (95% CI: 3–31) in 2014/15. In conclusion, seasonal influenza vaccination was associated with substantial reductions in influenza-specific hospitalisation, particularly in adults ≥ 65 years with underlying chronic conditions. With the use of population-based patient register data on influenza-specific outcomes it will be possible to obtain real-time estimates of seasonal influenza VE. PMID:27813473

Comparative Transcriptome Analysis of Chinary, Assamica and Cambod tea (Camellia sinensis) Types during Development and Seasonal Variation using RNA-seq Technology

NASA Astrophysics Data System (ADS)

Kumar, Ajay; Chawla, Vandna; Sharma, Eshita; Mahajan, Pallavi; Shankar, Ravi; Yadav, Sudesh Kumar

2016-11-01

Tea quality and yield is influenced by various factors including developmental tissue, seasonal variation and cultivar type. Here, the molecular basis of these factors was investigated in three tea cultivars namely, Him Sphurti (H), TV23 (T), and UPASI-9 (U) using RNA-seq. Seasonal variation in these cultivars was studied during active (A), mid-dormant (MD), dormant (D) and mid-active (MA) stages in two developmental tissues viz. young and old leaf. Development appears to affect gene expression more than the seasonal variation and cultivar types. Further, detailed transcript and metabolite profiling has identified genes such as F3‧H, F3‧5‧H, FLS, DFR, LAR, ANR and ANS of catechin biosynthesis, while MXMT, SAMS, TCS and XDH of caffeine biosynthesis/catabolism as key regulators during development and seasonal variation among three different tea cultivars. In addition, expression analysis of genes related to phytohormones such as ABA, GA, ethylene and auxin has suggested their role in developmental tissues during seasonal variation in tea cultivars. Moreover, differential expression of genes involved in histone and DNA modification further suggests role of epigenetic mechanism in coordinating global gene expression during developmental and seasonal variation in tea. Our findings provide insights into global transcriptional reprogramming associated with development and seasonal variation in tea.

Comparative Transcriptome Analysis of Chinary, Assamica and Cambod tea (Camellia sinensis) Types during Development and Seasonal Variation using RNA-seq Technology.

PubMed

Kumar, Ajay; Chawla, Vandna; Sharma, Eshita; Mahajan, Pallavi; Shankar, Ravi; Yadav, Sudesh Kumar

2016-11-17

Tea quality and yield is influenced by various factors including developmental tissue, seasonal variation and cultivar type. Here, the molecular basis of these factors was investigated in three tea cultivars namely, Him Sphurti (H), TV23 (T), and UPASI-9 (U) using RNA-seq. Seasonal variation in these cultivars was studied during active (A), mid-dormant (MD), dormant (D) and mid-active (MA) stages in two developmental tissues viz. young and old leaf. Development appears to affect gene expression more than the seasonal variation and cultivar types. Further, detailed transcript and metabolite profiling has identified genes such as F3'H, F3'5'H, FLS, DFR, LAR, ANR and ANS of catechin biosynthesis, while MXMT, SAMS, TCS and XDH of caffeine biosynthesis/catabolism as key regulators during development and seasonal variation among three different tea cultivars. In addition, expression analysis of genes related to phytohormones such as ABA, GA, ethylene and auxin has suggested their role in developmental tissues during seasonal variation in tea cultivars. Moreover, differential expression of genes involved in histone and DNA modification further suggests role of epigenetic mechanism in coordinating global gene expression during developmental and seasonal variation in tea. Our findings provide insights into global transcriptional reprogramming associated with development and seasonal variation in tea.

Single nucleotide polymorphism (SNP) discovery in duplicated genomes: intron-primed exon-crossing (IPEC) as a strategy for avoiding amplification of duplicated loci in Atlantic salmon (Salmo salar) and other salmonid fishes

PubMed Central

Ryynänen, Heikki J; Primmer, Craig R

2006-01-01

Background Single nucleotide polymorphisms (SNPs) represent the most abundant type of DNA variation in the vertebrate genome, and their applications as genetic markers in numerous studies of molecular ecology and conservation of natural populations are emerging. Recent large-scale sequencing projects in several fish species have provided a vast amount of data in public databases, which can be utilized in novel SNP discovery in salmonids. However, the suggested duplicated nature of the salmonid genome may hamper SNP characterization if the primers designed in conserved gene regions amplify multiple loci. Results Here we introduce a new intron-primed exon-crossing (IPEC) method in an attempt to overcome this duplication problem, and also evaluate different priming methods for SNP discovery in Atlantic salmon (Salmo salar) and other salmonids. A total of 69 loci with differing priming strategies were screened in S. salar, and 27 of these produced ~13 kb of high-quality sequence data consisting of 19 SNPs or indels (one per 680 bp). The SNP frequency and the overall nucleotide diversity (3.99 × 10-4) in S. salar was lower than reported in a majority of other organisms, which may suggest a relative young population history for Atlantic salmon. A subset of primers used in cross-species analyses revealed considerable variation in the SNP frequencies and nucleotide diversities in other salmonids. Conclusion Sequencing success was significantly higher with the new IPEC primers; thus the total number of loci to screen in order to identify one potential polymorphic site was six times less with this new strategy. Given that duplication may hamper SNP discovery in some species, the IPEC method reported here is an alternative way of identifying novel polymorphisms in such cases. PMID:16872523

Effects of episodic acidification on Atlantic salmon (Salmo salar) smolts

USGS Publications Warehouse

Magee, J.A.; Obedzinski, M.; McCormick, S.D.; Kocik, J.F.

2003-01-01

The effect of episodic acidification on Atlantic salmon (Salmo salar) smolt physiology and survival in fresh water (FW) and seawater (SW) was investigated. Smolts were held in either ambient (control, pH 6.0-6.6), acidified (chronic, pH 4.4-6.1), or episodically acidified (episodic, pH reduction from control levels to pH ???5.2 for 48 h once weekly) river water for 31 days and then transferred to 34??? SW. Smolts fed little while in acidified conditions and chronic smolts did not grow in length or weight. In FW, chronic smolts experienced increases in hematocrit and plasma potassium and reductions in plasma sodium and chloride. Upon transfer to SW, chronic and episodic smolts experienced reductions in hematocrit, increases in plasma sodium, chloride, and potassium levels, and suffered mortalities. Gill Na+,K+-ATPase and citrate synthase activities were reduced by exposure to acid. For most parameters, the effect of episodic acid exposure was less than that of chronic acidification. Exposure to acidic conditions, even when short in duration and followed by a 30-h recovery period in suitable water (pH 6.5), led to a 35% mortality of smolts upon transfer to SW. This study highlights the importance of measuring and assessing sublethal stresses in FW and their ultimate effects in marine ecosystems.

Multigenic Delineation of Lower Jaw Deformity in Triploid Atlantic Salmon (Salmo salar L.)

PubMed Central

Amoroso, Gianluca; Ventura, Tomer; Elizur, Abigail; Carter, Chris G.

2016-01-01

Lower jaw deformity (LJD) is a skeletal anomaly affecting farmed triploid Atlantic salmon (Salmo salar L.) which leads to considerable economic losses for industry and has animal welfare implications. The present study employed transcriptome analysis in parallel with real-time qPCR techniques to characterise for the first time the LJD condition in triploid Atlantic salmon juveniles using two independent sample sets: experimentally-sourced salmon (60 g) and commercially produced salmon (100 g). A total of eleven genes, some detected/identified through the transcriptome analysis (fbn2, gal and gphb5) and others previously determined to be related to skeletal physiology (alp, bmp4, col1a1, col2a1, fgf23, igf1, mmp13, ocn), were tested in the two independent sample sets. Gphb5, a recently discovered hormone, was significantly (P < 0.05) down-regulated in LJD affected fish in both sample sets, suggesting a possible hormonal involvement. In-situ hybridization detected gphb5 expression in oral epithelium, teeth and skin of the lower jaw. Col2a1 showed the same consistent significant (P < 0.05) down-regulation in LJD suggesting a possible cartilaginous impairment as a distinctive feature of the condition. Significant (P < 0.05) differential expression of other genes found in either one or the other sample set highlighted the possible effect of stage of development or condition progression on transcription and showed that anomalous bone development, likely driven by cartilage impairment, is more evident at larger fish sizes. The present study improved our understanding of LJD suggesting that a cartilage impairment likely underlies the condition and col2a1 may be a marker. In addition, the involvement of gphb5 urges further investigation of a hormonal role in LJD and skeletal physiology in general. PMID:27977809

Multigenic Delineation of Lower Jaw Deformity in Triploid Atlantic Salmon (Salmo salar L.).

PubMed

Amoroso, Gianluca; Ventura, Tomer; Cobcroft, Jennifer M; Adams, Mark B; Elizur, Abigail; Carter, Chris G

2016-01-01

Lower jaw deformity (LJD) is a skeletal anomaly affecting farmed triploid Atlantic salmon (Salmo salar L.) which leads to considerable economic losses for industry and has animal welfare implications. The present study employed transcriptome analysis in parallel with real-time qPCR techniques to characterise for the first time the LJD condition in triploid Atlantic salmon juveniles using two independent sample sets: experimentally-sourced salmon (60 g) and commercially produced salmon (100 g). A total of eleven genes, some detected/identified through the transcriptome analysis (fbn2, gal and gphb5) and others previously determined to be related to skeletal physiology (alp, bmp4, col1a1, col2a1, fgf23, igf1, mmp13, ocn), were tested in the two independent sample sets. Gphb5, a recently discovered hormone, was significantly (P < 0.05) down-regulated in LJD affected fish in both sample sets, suggesting a possible hormonal involvement. In-situ hybridization detected gphb5 expression in oral epithelium, teeth and skin of the lower jaw. Col2a1 showed the same consistent significant (P < 0.05) down-regulation in LJD suggesting a possible cartilaginous impairment as a distinctive feature of the condition. Significant (P < 0.05) differential expression of other genes found in either one or the other sample set highlighted the possible effect of stage of development or condition progression on transcription and showed that anomalous bone development, likely driven by cartilage impairment, is more evident at larger fish sizes. The present study improved our understanding of LJD suggesting that a cartilage impairment likely underlies the condition and col2a1 may be a marker. In addition, the involvement of gphb5 urges further investigation of a hormonal role in LJD and skeletal physiology in general.

Genomic signatures of parasite-driven natural selection in north European Atlantic salmon (Salmo salar).

PubMed

Zueva, Ksenia J; Lumme, Jaakko; Veselov, Alexey E; Kent, Matthew P; Primmer, Craig R

2018-06-01

Understanding the genomic basis of host-parasite adaptation is important for predicting the long-term viability of species and developing successful management practices. However, in wild populations, identifying specific signatures of parasite-driven selection often presents a challenge, as it is difficult to unravel the molecular signatures of selection driven by different, but correlated, environmental factors. Furthermore, separating parasite-mediated selection from similar signatures due to genetic drift and population history can also be difficult. Populations of Atlantic salmon (Salmo salar L.) from northern Europe have pronounced differences in their reactions to the parasitic flatworm Gyrodactylus salaris Malmberg 1957 and are therefore a good model to search for specific genomic regions underlying inter-population differences in pathogen response. We used a dense Atlantic salmon SNP array, along with extensive sampling of 43 salmon populations representing the two G. salaris response extremes (extreme susceptibility vs resistant), to screen the salmon genome for signatures of directional selection while attempting to separate the parasite effect from other factors. After combining the results from two independent genome scan analyses, 57 candidate genes potentially under positive selection were identified, out of which 50 were functionally annotated. This candidate gene set was shown to be functionally enriched for lymph node development, focal adhesion genes and anti-viral response, which suggests that the regulation of both innate and acquired immunity might be an important mechanism for salmon response to G. salaris. Overall, our results offer insights into the apparently complex genetic basis of pathogen susceptibility in salmon and highlight methodological challenges for separating the effects of various environmental factors. Copyright © 2018 Elsevier B.V. All rights reserved.

Forecasting seasonal outbreaks of influenza.

PubMed

Shaman, Jeffrey; Karspeck, Alicia

2012-12-11

Influenza recurs seasonally in temperate regions of the world; however, our ability to predict the timing, duration, and magnitude of local seasonal outbreaks of influenza remains limited. Here we develop a framework for initializing real-time forecasts of seasonal influenza outbreaks, using a data assimilation technique commonly applied in numerical weather prediction. The availability of real-time, web-based estimates of local influenza infection rates makes this type of quantitative forecasting possible. Retrospective ensemble forecasts are generated on a weekly basis following assimilation of these web-based estimates for the 2003-2008 influenza seasons in New York City. The findings indicate that real-time skillful predictions of peak timing can be made more than 7 wk in advance of the actual peak. In addition, confidence in those predictions can be inferred from the spread of the forecast ensemble. This work represents an initial step in the development of a statistically rigorous system for real-time forecast of seasonal influenza.

Forecasting seasonal outbreaks of influenza

PubMed Central

Shaman, Jeffrey; Karspeck, Alicia

2012-01-01

Influenza recurs seasonally in temperate regions of the world; however, our ability to predict the timing, duration, and magnitude of local seasonal outbreaks of influenza remains limited. Here we develop a framework for initializing real-time forecasts of seasonal influenza outbreaks, using a data assimilation technique commonly applied in numerical weather prediction. The availability of real-time, web-based estimates of local influenza infection rates makes this type of quantitative forecasting possible. Retrospective ensemble forecasts are generated on a weekly basis following assimilation of these web-based estimates for the 2003–2008 influenza seasons in New York City. The findings indicate that real-time skillful predictions of peak timing can be made more than 7 wk in advance of the actual peak. In addition, confidence in those predictions can be inferred from the spread of the forecast ensemble. This work represents an initial step in the development of a statistically rigorous system for real-time forecast of seasonal influenza. PMID:23184969

Carcass analog addition enhances juvenile Atlantic salmon (Salmo salar) growth and condition

USGS Publications Warehouse

Guyette, Margaret Q.; Loftin, Cynthia S.; Zydlewski, Joseph D.

2013-01-01

Our study used historic marine-derived nutrient (MDN) delivery timing to simulate potential effects of restored connectivity on juvenile Atlantic salmon (ATS; Salmo salar) growth and condition. Four headwater streams were stocked with ATS young of the year (YOY) and received carcass analog additions (0.10 kg·m–2 wetted area) in treatment reaches to match the timing of sea lamprey (Petromyzon marinus) spawning. Individual ATS mass was 33%–48% greater and standard length was 9%–15% greater in treatment reaches relative to control reaches for 4 months following nutrient additions. Percent total lipids in YOY ATS were twice as great in treatment reaches 1 month following carcass analog additions and remained elevated in treatment fish for 2 more months. Absolute growth rates, based on otolith microstructure analysis, correlated with water temperature fluctuations in all reaches and were elevated by an average of 0.07 mm·day–1 in treatment reaches for 1 month following carcass analog additions. Simulated sea lamprey MDNs increased juvenile ATS growth, which, via potential increases in overwinter survival and decreases in smolt age, may contribute to population persistence and ecosystem productivity.

Molecular mechanism of dietary phospholipid requirement of Atlantic salmon, Salmo salar, fry.

PubMed

Carmona-Antoñanzas, G; Taylor, J F; Martinez-Rubio, L; Tocher, D R

2015-11-01

The phospholipid (PL) requirement in fish is revealed by enhanced performance when larvae are provided PL-enriched diets. To elucidate the molecular mechanism underlying PL requirement in Atlantic salmon, Salmo salar, were fed a minimal PL diet and tissue samples from major lipid metabolic sites were dissected from fry and parr. In silico analysis and cloning techniques demonstrated that salmon possess a full set of enzymes for the endogenous production of PL. The gene expression data indicated that major PL biosynthetic genes of phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn) and phosphatidylinositol (PtdIns) display lower expression in intestine during the early developmental stage (fry). This is consistent with the hypothesis that the intestine of salmon is immature at the early developmental stage with limited capacity for endogenous PL biosynthesis. The results also indicate that intact PtdCho, PtdEtn and PtdIns are required in the diet at this stage. PtdCho and sphingomyelin constitute the predominant PL in chylomicrons, involved in the transport of dietary lipids from the intestine to the rest of the body. As sphingomyelin can be produced from PtdCho in intestine of fry, our findings suggest that supplementation of dietary PtdCho alone during early developmental stages of Atlantic salmon would be sufficient to promote chylomicron formation. This would support efficient transport of dietary lipids, including PL precursors, from the intestine to the liver where biosynthesis of PtdEtn, PtdSer, and PtdIns is not compromised as in intestine facilitating efficient utilisation of dietary energy and the endogenous production of membrane PL for the rapidly growing and developing animal. Copyright © 2015. Published by Elsevier B.V.

Seasonal Changes in Soil Moisture Content in Northern Chile and Southern California Inferred from SAR data

NASA Astrophysics Data System (ADS)

Scott, C. P.; Lohman, R. B.

2015-12-01

InSAR-based studies of the seismic cycle have focused primarily on the interferometric phase observations, which place constraints on the amount of uplift or subsidence of the ground surface. Recently, coseismic InSAR coherence has also been used to rapidly identify urban damage, surface ruptures, cracking, and soil liquefaction. Here we demonstrate that time-variable correlation and amplitude data contain additional information about surficial processes and material properties that may affect ground deformation and seismic hazard. In the use of correlation for hazard response, distinguishing the coseismic signal from other changes in surface properties associated with variations in soil moisture content, vegetation and snow cover, and wind is critical. Building SAR-based catalogues of ground properties will therefore improve the reliability of rapid response and aid in the designing of future SAR missions to better map surface ruptures, off-fault deformation, and coseismic damage. In this project, we characterize the seasonal variations in the soil moisture content in the Northern Chilean Coastal Cordillera and Southern California. The extreme climate of the Atacama Desert characterized by hyperaridity and coastal fog during the non-summer months creates an ideal landscape for exploring surface properties. We produce interferograms using L-band ALOS data (λ = 23.6 cm) that span 46 days to three years and have perpendicular baselines less than 1500 m. We observe a strong seasonal dependence on correlation that extends to the maximum elevation of the fog penetration. Interferograms with only austral summer acquisitions are more correlated than interferograms with one or both acquisitions in the autumn, winter or spring, even when the summer interferograms span multiple years. We propose that the seasonal dependence is due to small changes in the radar path length caused by variable soil moisture content in the very shallow subsurface. We further consider local

Arteriosclerosis in the ventral aorta and epicarditis in the bulbus arteriosus of Atlantic salmon (Salmo salar L).

PubMed

Dalum, A S; Kristthorsdottir, K H; Griffiths, D J; Bjørklund, K; Poppe, T T

2017-06-01

Spontaneous mortality of seemingly healthy, farmed Atlantic salmon (Salmo salar L) is an increasing problem in Norwegian aquaculture. In this study, we present a morphological study of the previously undescribed syndrome of arteriosclerosis of the ventral aorta and epicarditis of the adjacent bulbus arteriosus found in farmed Atlantic salmon, with wild-captured fish as a control group. Both the ventral aorta and epicardium are vital for correct arterial compliance and vascular resistance in the respiratory capillaries of the gills. We discuss the possible implications of ventral aorta arteriosclerosis and epicarditis for blood vascular health and in particular for the increasing frequency of spontaneous gill bleeding in farmed salmon. As both these conditions primarily occur in farmed salmon, we suggest that they should be considered pathological. © 2016 John Wiley & Sons Ltd.

The effect of shelter on welfare of juvenile Atlantic salmon Salmo salar reared under a feed restriction regimen.

PubMed

Persson, L; Alanärä, A

2014-09-01

This study investigated whether shelter (presence or absence) affected the frequency of fin damage in Atlantic salmon Salmo salar exposed to feed restrictions (0·73 or 0·33% of body mass day(-1) ). The presence of shelter had a positive effect on the pectoral fins at both feed ration levels and on the dorsal fin at the higher ration level but it had a negative effect on survival. The reduced feed rations resulted in fish of the same size and nutritional status as wild fish. The provision of shelter has potential to mitigate the negative effects of feed restrictions on fin quality, but the optimal shelter design requires some additional investigation. © 2014 The Fisheries Society of the British Isles.

Seasonal life history trade-offs in two leafwing butterflies: Delaying reproductive development increases life expectancy.

PubMed

McElderry, Robert M

2016-04-01

Surviving inhospitable periods or seasons may greatly affect fitness. Evidence of this exists in the prevalence of dormant stages in the life cycles of most insects. Here I focused on butterflies with distinct seasonal morphological types (not a genetic polymorphism) in which one morphological type, or form, delays reproduction until favorable conditions return, while the other form develops in an environment that favors direct reproduction. For two butterflies, Anaea aidea and A. andria, I tested the hypothesis that the development of each seasonal form involves a differential allocation of resources to survival at eclosion. I assayed differences in adult longevity among summer and winter forms in either a warm, active environment or a cool, calm environment. Winter form adults lived 40 times longer than summer form but only in calm, cool conditions. The magnitude of this difference provided compelling evidence that the winter form body plan and metabolic strategy (i.e. resource conservatism) favor long term survival. This research suggests that winter form adults maintain lowered metabolic rate, a common feature of diapause, to conserve resources and delay senescence while overwintering. Copyright © 2016 Elsevier Ltd. All rights reserved.

Coronary changes in the Atlantic salmon Salmo salar L: characterization and impact of dietary fatty acid compositions.

PubMed

Dalum, A; Tangen, R; Falk, K; Hordvik, I; Rosenlund, G; Torstensen, B; Koppang, E O

2016-01-01

Consumption of fatty acids from fishes is widely regarded as beneficial for preventing cardiovascular disorders. Nevertheless, salmonids themselves are victims of vascular diseases. As the pathogenesis and nature of these changes are elusive, they are here addressed using novel morphological and transcriptional approaches. Coronary arteries of wild Atlantic salmon Salmo salar L., (n = 12) were investigated using histological and immunohistochemical techniques, and RT-qPCR was employed to investigate expression of stretch-induced genes. In an experimental trial, fish were fed diets with different fatty acids composition, and histological features of the coronary arteries (n = 36) were investigated. In addition, the heart fatty acid profile (n = 60) was analysed. There were no differences in morphological or immunological features between wild fish and groups of experimental fish. Arteriosclerotic lesions consisted of smooth muscle cells in dissimilar differential stages embedded in considerable amounts of extracellular matrix in a similar fashion to what is seen in early stages of human atherosclerosis. No fat accumulations were observed, and very few inflammatory cells were present. In affected arteries, there was an induction of stretch-related genes, pointing to a stress-related response. We suggest that salmon may have a natural resistance to developing atherosclerosis, which corresponds well with their high investment in lipid metabolism. © 2014 John Wiley & Sons Ltd.

Small mammal use of native warm-season and non-native cool-season grass forage fields

USGS Publications Warehouse

Ryan L Klimstra,; Christopher E Moorman,; Converse, Sarah J.; Royle, J. Andrew; Craig A Harper,

2015-01-01

Recent emphasis has been put on establishing native warm-season grasses for forage production because it is thought native warm-season grasses provide higher quality wildlife habitat than do non-native cool-season grasses. However, it is not clear whether native warm-season grass fields provide better resources for small mammals than currently are available in non-native cool-season grass forage production fields. We developed a hierarchical spatially explicit capture-recapture model to compare abundance of hispid cotton rats (Sigmodon hispidus), white-footed mice (Peromyscus leucopus), and house mice (Mus musculus) among 4 hayed non-native cool-season grass fields, 4 hayed native warm-season grass fields, and 4 native warm-season grass-forb ("wildlife") fields managed for wildlife during 2 summer trapping periods in 2009 and 2010 of the western piedmont of North Carolina, USA. Cotton rat abundance estimates were greater in wildlife fields than in native warm-season grass and non-native cool-season grass fields and greater in native warm-season grass fields than in non-native cool-season grass fields. Abundances of white-footed mouse and house mouse populations were lower in wildlife fields than in native warm-season grass and non-native cool-season grass fields, but the abundances were not different between the native warm-season grass and non-native cool-season grass fields. Lack of cover following haying in non-native cool-season grass and native warm-season grass fields likely was the key factor limiting small mammal abundance, especially cotton rats, in forage fields. Retention of vegetation structure in managed forage production systems, either by alternately resting cool-season and warm-season grass forage fields or by leaving unharvested field borders, should provide refugia for small mammals during haying events.

Dietary soybean protein concentrate-induced intestinal disorder in marine farmed Atlantic salmon, Salmo salar is associated with alterations in gut microbiota.

PubMed

Green, Timothy J; Smullen, Richard; Barnes, Andrew C

2013-09-27

The aquaculture industry has made substantial progress in reducing the fishmeal content of feeds for carnivorous species, driven by demand for improved sustainability and reduced cost. Soybean protein concentrate (SPC) is an attractive replacement for fishmeal, but intestinal disorders have been reported in Atlantic salmon (Salmo salar) fed these diets at high seawater temperatures, with preliminary evidence suggesting SPC induces these disorders by altering the intestinal microbiota. We compared the intestinal microbiota of marine-farmed S. salar fed experimental diets with varying levels of SPC in mid- and late-summer. Terminal restriction fragment length polymorphism (T-RFLP) and 16S rRNA clone library analysis revealed the microbiota adherent to the intestinal tract of salmon is complex at the population level, but simple and highly variable at the individual level. Temporal changes were observed with the bacterial diversity increasing in the intestinal tract in late summer. A Verrucomicrobia was the most frequently observed ribotype in early summer, whilst an Aliivibrio was the most frequently observed ribotype in late summer. Feeding SPC to salmon increased the bacterial diversity of the intestinal tract and resulted in the presence of bacteria not normally associated with marine fish (Escherichia and Propionibacterium). These diet-induced changes to the intestinal-microbiome could be ameliorated by inclusion of a prebiotic (mannan-oligosaccharide or MOS) to the diet. None of the experimental diets induced inflammation of the intestine as assessed by histopathology and expression of inflammatory cytokines. Our results support the "dysbiosis" hypothesis that SPC adversely affects the intestinal microbiota of Atlantic salmon. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Maladaptation and phenotypic mismatch in hatchery-reared Atlantic salmon Salmo salar released in the wild.

PubMed

Stringwell, R; Lock, A; Stutchbury, C J; Baggett, E; Taylor, J; Gough, P J; Garcia de Leaniz, C

2014-12-01

Changes in body shape, fluctuating asymmetry (FA) and crypsis were compared among Atlantic salmon Salmo salar fry kept as controls in captivity and those released and subsequently recaptured in the wild according to a before-after-control-impact (BACI) design. Hatchery fish that survived in the wild became more cryptic and displayed a much lower incidence of fin erosion and of asymmetric individuals than control fish kept in captivity. Significant differences in body shape were also apparent, and survivors had longer heads, thicker caudal peduncles and a more streamlined body shape than hatchery controls as early as 20 days following stocking, most likely as a result of phenotypic plasticity and non-random, selective mortality of maladapted phenotypes. Hatchery-reared fish typically perform poorly in the wild and the results of this study indicate that this may be due to phenotypic mismatch, i.e. because hatcheries generate fish that are phenotypically mismatched to the natural environment. © 2014 The Fisheries Society of the British Isles.

First description of atypical furunculosis in freshwater farmed Atlantic salmon, Salmo salar L., in Chile.

PubMed

Godoy, M; Gherardelli, V; Heisinger, A; Fernández, J; Olmos, P; Ovalle, L; Ilardi, P; Avendaño-Herrera, R

2010-05-01

We report the first isolation, identification and characterization of a group of Chilean strains of atypical Aeromonas salmonicida isolated from freshwater farmed Atlantic salmon, Salmo salar. Affected fish showed superficial ulcers and pale liver with or without petechial haemorrhages. Outbreaks of the disease occurred in two farms in the south of Chile about 2200 km apart. Five strains were isolated in pure culture and identified by serological assays and immunofluorescence tests as belonging to Aeromonas salmonicida. Although the bacterial isolates were phenotypically homogeneous, minor differences with the reference strain A. salmonicida subsp. salmonicida ATCC 33658 were noted. Three specific primer sets and partial 16S rRNA gene sequencing allowed the identification of the Chilean isolates as atypical A. salmonicida, with A. salmonicida subsp. achromogenes and A. salmonicida subsp. masoucida as their closest relatives (100% sequence similarity). Molecular typing indicated that the atypical isolates belong to two genetic groups that were associated with the geographical origin.

Sub-seasonal-to-seasonal Reservoir Inflow Forecast using Bayesian Hierarchical Hidden Markov Model

NASA Astrophysics Data System (ADS)

Mukhopadhyay, S.; Arumugam, S.

2017-12-01

Sub-seasonal-to-seasonal (S2S) (15-90 days) streamflow forecasting is an emerging area of research that provides seamless information for reservoir operation from weather time scales to seasonal time scales. From an operational perspective, sub-seasonal inflow forecasts are highly valuable as these enable water managers to decide short-term releases (15-30 days), while holding water for seasonal needs (e.g., irrigation and municipal supply) and to meet end-of-the-season target storage at a desired level. We propose a Bayesian Hierarchical Hidden Markov Model (BHHMM) to develop S2S inflow forecasts for the Tennessee Valley Area (TVA) reservoir system. Here, the hidden states are predicted by relevant indices that influence the inflows at S2S time scale. The hidden Markov model also captures the both spatial and temporal hierarchy in predictors that operate at S2S time scale with model parameters being estimated as a posterior distribution using a Bayesian framework. We present our work in two steps, namely single site model and multi-site model. For proof of concept, we consider inflows to Douglas Dam, Tennessee, in the single site model. For multisite model we consider reservoirs in the upper Tennessee valley. Streamflow forecasts are issued and updated continuously every day at S2S time scale. We considered precipitation forecasts obtained from NOAA Climate Forecast System (CFSv2) GCM as predictors for developing S2S streamflow forecasts along with relevant indices for predicting hidden states. Spatial dependence of the inflow series of reservoirs are also preserved in the multi-site model. To circumvent the non-normality of the data, we consider the HMM in a Generalized Linear Model setting. Skill of the proposed approach is tested using split sample validation against a traditional multi-site canonical correlation model developed using the same set of predictors. From the posterior distribution of the inflow forecasts, we also highlight different system behavior

Prokaryotic diversity and biogeochemical characteristics of benthic microbial ecosystems at La Brava, a hypersaline lake at Salar de Atacama, Chile.

PubMed

Farias, Maria Eugenia; Rasuk, Maria Cecilia; Gallagher, Kimberley L; Contreras, Manuel; Kurth, Daniel; Fernandez, Ana Beatriz; Poiré, Daniel; Novoa, Fernando; Visscher, Pieter T

2017-01-01

Benthic microbial ecosystems of Laguna La Brava, Salar de Atacama, a high altitude hypersaline lake, were characterized in terms of bacterial and archaeal diversity, biogeochemistry, (including O2 and sulfide depth profiles and mineralogy), and physicochemical characteristics. La Brava is one of several lakes in the Salar de Atacama where microbial communities are growing in extreme conditions, including high salinity, high solar insolation, and high levels of metals such as lithium, arsenic, magnesium, and calcium. Evaporation creates hypersaline conditions in these lakes and mineral precipitation is a characteristic geomicrobiological feature of these benthic ecosystems. In this study, the La Brava non-lithifying microbial mats, microbialites, and rhizome-associated concretions were compared to each other and their diversity was related to their environmental conditions. All the ecosystems revealed an unusual community where Euryarchaeota, Crenarchaeota, Acetothermia, Firmicutes and Planctomycetes were the most abundant groups, and cyanobacteria, typically an important primary producer in microbial mats, were relatively insignificant or absent. This suggests that other microorganisms, and possibly novel pathways unique to this system, are responsible for carbon fixation. Depth profiles of O2 and sulfide showed active production and respiration. The mineralogy composition was calcium carbonate (as aragonite) and increased from mats to microbialites and rhizome-associated concretions. Halite was also present. Further analyses were performed on representative microbial mats and microbialites by layer. Different taxonomic compositions were observed in the upper layers, with Archaea dominating the non-lithifying mat, and Planctomycetes the microbialite. The bottom layers were similar, with Euryarchaeota, Crenarchaeota and Planctomycetes as dominant phyla. Sequences related to Cyanobacteria were very scarce. These systems may contain previously uncharacterized

Prokaryotic diversity and biogeochemical characteristics of benthic microbial ecosystems at La Brava, a hypersaline lake at Salar de Atacama, Chile

PubMed Central

Rasuk, Maria Cecilia; Gallagher, Kimberley L.; Contreras, Manuel; Kurth, Daniel; Fernandez, Ana Beatriz; Poiré, Daniel; Novoa, Fernando; Visscher, Pieter T.

2017-01-01

Benthic microbial ecosystems of Laguna La Brava, Salar de Atacama, a high altitude hypersaline lake, were characterized in terms of bacterial and archaeal diversity, biogeochemistry, (including O2 and sulfide depth profiles and mineralogy), and physicochemical characteristics. La Brava is one of several lakes in the Salar de Atacama where microbial communities are growing in extreme conditions, including high salinity, high solar insolation, and high levels of metals such as lithium, arsenic, magnesium, and calcium. Evaporation creates hypersaline conditions in these lakes and mineral precipitation is a characteristic geomicrobiological feature of these benthic ecosystems. In this study, the La Brava non-lithifying microbial mats, microbialites, and rhizome-associated concretions were compared to each other and their diversity was related to their environmental conditions. All the ecosystems revealed an unusual community where Euryarchaeota, Crenarchaeota, Acetothermia, Firmicutes and Planctomycetes were the most abundant groups, and cyanobacteria, typically an important primary producer in microbial mats, were relatively insignificant or absent. This suggests that other microorganisms, and possibly novel pathways unique to this system, are responsible for carbon fixation. Depth profiles of O2 and sulfide showed active production and respiration. The mineralogy composition was calcium carbonate (as aragonite) and increased from mats to microbialites and rhizome-associated concretions. Halite was also present. Further analyses were performed on representative microbial mats and microbialites by layer. Different taxonomic compositions were observed in the upper layers, with Archaea dominating the non-lithifying mat, and Planctomycetes the microbialite. The bottom layers were similar, with Euryarchaeota, Crenarchaeota and Planctomycetes as dominant phyla. Sequences related to Cyanobacteria were very scarce. These systems may contain previously uncharacterized

Piscine orthoreovirus (PRV) in red and melanised foci in white muscle of Atlantic salmon (Salmo salar).

PubMed

Bjørgen, Håvard; Wessel, Øystein; Fjelldal, Per Gunnar; Hansen, Tom; Sveier, Harald; Sæbø, Håkon Rydland; Enger, Katrine Bones; Monsen, Eirik; Kvellestad, Agnar; Rimstad, Espen; Koppang, Erling Olaf

2015-09-08

Melanised focal changes (black spots) are common findings in the white skeletal muscle of seawater-farmed Atlantic salmon (Salmo salar). Fillets with melanised focal changes are considered as lower quality and cause large economic losses. It has been suggested that red focal changes (red spots) precede the melanised focal changes. In the present work, we examined different populations of captive and wild salmon for the occurrence of both types of changes, which were investigated for the presence of different viruses by immunohistochemistry and RT-qPCR. The occurrence of red or melanised foci varied significantly between the populations, from none in wild fish control group, low prevalence of small foci in fish kept in in-house tanks, to high prevalence of large foci in farm-raised salmon. Large amounts of Piscine orthoreovirus (PRV) antigen were detected in all foci. No other viruses were detected. Red focal changes contained significantly higher levels of PRV RNA than apparently non-affected areas in white muscle of the same individuals. Some changes displayed a transient form between a red and melanised pathotype, indicating a progression from an acute to a chronic manifestation. We conclude that PRV is associated with the focal pathological changes in the white muscle of farmed Atlantic salmon and is a premise for the development of focal melanised changes.

Antigenic and molecular characterization of Vibrio ordalii strains isolated from Atlantic salmon Salmo salar in Chile.

PubMed

Silva-Rubio, Andrés; Acevedo, Claudia; Magariños, Beatriz; Jaureguiberry, Beltrán; Toranzo, Alicia E; Avendaño-Herrera, Ruben

2008-03-03

Biochemical, serological and molecular properties of a group of 14 Vibrio ordalii strains isolated from cultured Atlantic salmon Salmo salar in Chile in recent years were studied. The characteristics of isolates were compared with the type strain V. ordalii ATCC 33509T. The Chilean V. ordalii represented a biochemically homogenous group; however, some minor differences with the type strain were observed. The serological relationships among isolates, as well as the study of their antigenic determinant (LPS) revealed a strong reaction with antisera raised against Atlantic salmon strains and the antiserum raised against Listonella anguillarum serotype O2. However, LPS electrophoretic patterns were completely different from the V. ordalii type strain, regardless of the serum employed, suggesting the possibility that the Chilean strains constitute a new serological subgroup within this bacterial species. Genetic analyses by PFGE, RAPD, REP-PCR and ERIC-PCR demonstrated that all V. ordalii strains were genetically homogenous, displaying similar DNA patterns, regardless of the techniques used. Moreover, the analysis of DNA banding patterns generated by ERIC-PCR and REP-PCR also clearly separated the type strain from the Chilean strains. This is the first report of characterization of V. ordalii strains from the Southeastern Pacific area, the results of which should facilitate the development of vaccines for protecting cultured Atlantic salmon against vibriosis in this area.

Quality grading of Atlantic salmon (Salmo salar) by computer vision.

PubMed

Misimi, E; Erikson, U; Skavhaug, A

2008-06-01

In this study, we present a promising method of computer vision-based quality grading of whole Atlantic salmon (Salmo salar). Using computer vision, it was possible to differentiate among different quality grades of Atlantic salmon based on the external geometrical information contained in the fish images. Initially, before the image acquisition, the fish were subjectively graded and labeled into grading classes by a qualified human inspector in the processing plant. Prior to classification, the salmon images were segmented into binary images, and then feature extraction was performed on the geometrical parameters of the fish from the grading classes. The classification algorithm was a threshold-based classifier, which was designed using linear discriminant analysis. The performance of the classifier was tested by using the leave-one-out cross-validation method, and the classification results showed a good agreement between the classification done by human inspectors and by the computer vision. The computer vision-based method classified correctly 90% of the salmon from the data set as compared with the classification by human inspector. Overall, it was shown that computer vision can be used as a powerful tool to grade Atlantic salmon into quality grades in a fast and nondestructive manner by a relatively simple classifier algorithm. The low cost of implementation of today's advanced computer vision solutions makes this method feasible for industrial purposes in fish plants as it can replace manual labor, on which grading tasks still rely.

Characterization of Mycobacterium salmoniphilum as causal agent of mycobacteriosis in Atlantic salmon, Salmo salar L., from a freshwater recirculation system.

PubMed

Aro, L; Correa, K; Martínez, A; Ildefonso, R; Yáñez, J M

2014-04-01

Thirty Atlantic salmon, Salmo salar L., with low corporal condition relative to other fish present in the culture system, were sampled from a freshwater recirculation pisciculture located in Chile. The most characteristic signs and lesions were cachexia and presence of multiple greyish-white granulomas within internal organs. The external and internal lesions, along with the microscopic, histologic and biochemical findings, were consistent with mycobacteriosis. The identification of Mycobacterium salmoniphilum as the causal agent of the lesions was possible through the use of molecular analyses. This study represents the first report of Mycobacterium salmoniphilum in a freshwater recirculation system and the first case of fish mycobacteriosis described in Chile. © 2013 John Wiley & Sons Ltd.

Ova fecundity in Scottish Atlantic salmon Salmo salar: predictions, selective forces and causal mechanisms.

PubMed

Bacon, P J; MacLean, J C; Malcolm, I A; Gurney, W S C

2012-08-01

Ova fecundities of Scottish Atlantic salmon Salmo salar, predicted from log(10) regression of ova numbers and female fork length (L(F)), differed widely between upland and lowland stocks within the same river, whereas sea-age, river and year factors had insignificant effects on fecundity once L(F) was accounted for. For upland fish, the relationship between log(10)L(F) and log(10) ova mass (M(O)) was stable between two datasets collected 40 years apart. Although upland and lowland females both produced comparable log(10)M(O) (log(10)L(F))(-1), lowland females partitioned this into 45% more, but smaller ova, whereas upland females produced fewer, but larger, eggs. The possible causes and implications of this are discussed for evolutionary perspectives (lifetime production), population structure (local tributary v. large catchments; environmental effects), population dynamics and stability (density-dependent control mechanisms) and fisheries management (stock-recruitment; short and long-term stock sustainability). © 2012 Marine Scotland. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Reproductive performance of alternative male phenotypes of growth hormone transgenic Atlantic salmon (Salmo salar)

PubMed Central

Moreau, Darek T R; Conway, Corinne; Fleming, Ian A

2011-01-01

Growth hormone (GH) transgenic Atlantic salmon (Salmo salar) is one of the first transgenic animals being considered for commercial farming, yet ecological and genetic concerns remain should they enter the wild and interact reproductively with wild fish. Here, we provide the first empirical data reporting on the breeding performance of GH transgenic Atlantic salmon males, including that of an alternative male reproductive phenotype (i.e. small, precocially mature parr), in pair-wise competitive trials within a naturalised stream mesocosm. Wild anadromous (i.e. large, migratory) males outperformed captively reared transgenic counterparts in terms of nest fidelity, quivering frequency and spawn participation. Similarly, despite displaying less aggression, captively reared nontransgenic mature parr were superior competitors to their transgenic counterparts in terms of nest fidelity and spawn participation. Moreover, nontransgenic parr had higher overall fertilisation success than transgenic parr, and their offspring were represented in more spawning trials. Although transgenic males displayed reduced breeding performance relative to nontransgenics, both male reproductive phenotypes demonstrated the ability to participate in natural spawning events and thus have the potential to contribute genes to subsequent generations. PMID:25568019

The effect of stocking with 0+ year age-class Atlantic salmon Salmo salar fry: a case study from the River Bush, Northern Ireland.

PubMed

Kennedy, R J; Crozier, W W; Allen, M

2012-10-01

An enhancement programme based on stocking 0+ year age-class Atlantic salmon Salmo salar, conducted in the River Bush, Northern Ireland, U.K. over the period 1996-2005, was reviewed with reference to the performance and biological characteristics of wild fish. Wild ova to 0+ year fry (summer) survival was c. 8% with subsequent wild 0+ year fry-to-smolt survival c. 9%. Stocked unfed 0+ year juveniles gave c. 1% survival to smolt whilst fed 0+ year S. salar stocked in late summer exhibited survival at c. 5%. Stocking with unfed and fed fry contributed to increased smolt production and helped attain local management objectives between 2001 and 2005. Significant differences in biological characteristics were observed between wild and stocked-origin fish. Wild-smolt cohorts were dominated by 2+ year age-class fish on the River Bush whilst smolts originating from fed fry mostly comprised younger 1+ year individuals. The mean mass of 1+ year smolts derived from stocked fed fry was significantly lower than that of wild 1+ year smolts, although these differences were not evident between older age classes. Differences in run timing between wild smolts and smolts derived from stocked fry were also apparent with the stocked-origin fish tending to run earlier than wild fish. Although the stocking exercise was useful in terms of maximizing freshwater production, concerns over the quality of stocked-origin recruits and the long term consequences for productivity are highlighted. © 2012 The Authors. Journal of Fish Biology © 2012 The Fisheries Society of the British Isles.

Agrilus auroguttatus (Coleoptera: Buprestidae) seasonal development within Quercus agrifolia (Fagales: Fagaceae) in southern California

Treesearch

L.J. Haavik; T.W. Coleman; M.L. Flint; R.C. Venette; S.J. Seybold

2013-01-01

We investigated seasonal development of the goldspotted oak borer, Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae), and physical conditions of the phloem within a preferred host species, coast live oak, Quercus agrifolia Née. We sampled infested trees on a monthly basis at two sites in southern California throughout...

Glandular kallikrein in the innate immune system of Atlantic salmon (Salmo salar).

PubMed

Haussmann, D; Figueroa, J

2011-02-15

Glandular Kallikrein is a serine-protease with trypsin-like activity and is able to generate bioactive peptides from inactive precursors. We have evaluated the presence of this protease in the different organs of the Atlantic salmon (Salmo salar). The results clearly indicate that GK and PRL are generated in the same pituitary cells based on a co-localization by confocal microscopy. Based on probed cross-reactivity between C. striata and C. carpio glandular anti-GK antibodies, we used a homologous antibody to detect the presence of GK in several salmon tissues. We have evaluated the GK expression in healthy and defied fish. P. salmonis and V. ordalii. The GK immunoreaction in organs such as leukocytes, gills and skin is considerably increased in defied fish compared to healthy fish. This increase was present in the cells of the excretory kidney and in the intercellular tissue, where the development of hematopoietic and lymphocytic lines in fish take place. One of the most interesting organs to study was the skin, bearing in mind that this is a primary barrier to all pathogens. The skin of the defied fish exhibited an increase in immunoreactivity for glandular kallikrein similar to the protease found in mucus. An immunoreactive tissue kallikrein-like protein was identified and partially separated by perfusion chromatography. Enzymatic activity of salmon muscle prokallikrein was determined before and after trypsin activation. Kallikrein activity was characterized with respect to their ability to cleave the chromogenic leaving group, p-nitroanilide, from the peptidyl kallikrein and trypsin substrate. These findings constitute a important contribution to reveal the role of kallikrein in the innate immune system of fish. Copyright © 2010 Elsevier B.V. All rights reserved.

Factors affecting variation in mortality of marine Atlantic salmon Salmo salar in Scotland.

PubMed

Soares, Silvia; Murray, Alexander G; Crumlish, Mags; Turnbull, James F; Green, Darren M

2013-03-26

Databases of site production have an important role to play in the investigation and understanding of diseases, since they store valuable amounts of disease and management data. Diseases pose an important constraint to economic expansion of aquaculture. They are dependent on the complex interacting factors of pathogen, environment, and host, and the causes of death can be related to nutritional, environmental, and genetic factors of the host or infectious agents. We examined the drivers of mortality from a single site-production database, which represented one-third of Scottish farmed salmon Salmo salar L. production in 2005, to determine whether mortality 'benchmarking' data could be generalised across sites and production cycles. We show that farm mortality records play an important role in studying mortality losses and identifying of management problems in production. We found that mortalities varied across the months of the year and with the time of year of initial stocking. Production cycles that started in the third quarter of the year had the highest mortality overall. Furthermore, we found site-to-site variation in mortality that may have been caused by either random occurrence of epidemics and environmental events or other local effects.

Water contaminated with Didymosphenia geminata generates changes in Salmo salar spermatozoa activation times.

PubMed

Olivares, Pamela; Orellana, Paola; Guerra, Guillermo; Peredo-Parada, Matías; Chavez, Viviana; Ramirez, Alfredo; Parodi, Jorge

2015-06-01

Didimosphenia geminata ("didymo"), has become a powerful and devastating river plague in Chile. A system was developed in D. geminata channels with the purpose evaluating the effects of water polluted with didymo on the activation of Atlantic salmon (Salmo salar) spermatozoa. Results indicate that semen, when activated with uncontaminated river water had an average time of 60±21s. When using Powermilt, (a commercial activator), times of 240±21s are achieved, while rivers contaminated with D. geminata achieve a motility time of 30±12s. Interestingly enough, the kinetic parameters of VSL, VCL and VAP showed no significant changes under all of the conditions. Furthermore, the presence of D. geminata reduces activation time of the samples as the cells age, indicating increased effects in spermatozoa that are conserved for more than 5 days. D. geminata has antioxidant content, represented by polyphenols; 200ppm of polyphenol were obtained in this study per 10g of microalgae. Spermatozoa exposed to these extracts showed a reduction in mobility time in a dose dependent manner, showing an IC50 of 15ppm. The results suggest an effect on spermatozoa activation, possibly due to the release of polyphenols present in contaminated rivers, facilitating the alteration of sperm motility times, without affecting the viability or kinetics of the cells. These findings have important implications for current policy regarding the control of the algae. Current control measures focus on the number of visible species, and not on the compounds that they release, which this study shows, also have a problematic effect on salmon production. Copyright © 2015 Elsevier B.V. All rights reserved.

Genetics Home Reference: seasonal affective disorder

MedlinePlus

... seasonal affective disorder are complex. A shortage of sunlight contributes to the development of the disorder in the fall and winter months, and too much sunlight is associated with seasonal affective disorder in the ...

Intestinal morphology of the wild Atlantic salmon (Salmo salar).

PubMed

Løkka, Guro; Austbø, Lars; Falk, Knut; Bjerkås, Inge; Koppang, Erling Olaf

2013-08-01

The worldwide-industrialized production of Atlantic salmon (Salmo salar) has increased dramatically during the last decades, followed by diseases related to the on-going domestication process as a growing concern. Even though the gastrointestinal tract seems to be a target for different disorders in farmed fish, a description of the normal intestinal status in healthy, wild salmon is warranted. Here, we provide such information in addition to suggesting a referable anatomical standardization for the intestine. In this study, two groups of wild Atlantic salmon were investigated, consisting of post smolts on feed caught in the sea and of sexually mature, starved individuals sampled from a river. The two groups represent different stages in the anadromous salmon life cycle, which also are part of the production cycle of farmed salmon. Selected regions of gastrointestinal tract were subjected to morphological investigations including immunohistochemical, scanning electron microscopic, and morphometric analyses. A morphology-based nomenclature was established, defining the cardiac part of the stomach and five different regions of the Atlantic salmon intestine, including pyloric caeca, first segment of the mid-intestine with pyloric caeca, first segment of the mid-intestine posterior to pyloric caeca, second segment of the mid-intestine and posterior intestinal segment. In each of the above described regions, for both groups of fish, morphometrical measurements and regional histological investigations were performed with regards to magnitude and direction of mucosal folding as well as the composition of the intestinal wall. Additionally, immunohistochemistry showing cells positive for cytokeratins, α-actin and proliferating cell nuclear antigen, in addition to alkaline phosphatase reactivity in the segments is presented. Copyright © 2013 Wiley Periodicals, Inc., a Wiley Company.

Genome-wide transcription analysis of histidine-related cataract in Atlantic salmon (Salmo salar L)

PubMed Central

Waagbø, Rune; Breck, Olav; Stavrum, Anne-Kristin; Petersen, Kjell; Olsvik, Pål A.

2009-01-01

Purpose Elevated levels of dietary histidine have previously been shown to prevent or mitigate cataract formation in farmed Atlantic salmon (Salmo salar L). The aim of this study was to shed light on the mechanisms by which histidine acts. Applying microarray analysis to the lens transcriptome, we screened for differentially expressed genes in search for a model explaining cataract development in Atlantic salmon and possible markers for early cataract diagnosis. Methods Adult Atlantic salmon (1.7 kg) were fed three standard commercial salmon diets only differing in the histidine content (9, 13, and 17 g histidine/kg diet) for four months. Individual cataract scores for both eyes were assessed by slit-lamp biomicroscopy. Lens N-acetyl histidine contents were measured by high performance liquid chromatography (HPLC). Total RNA extracted from whole lenses was analyzed using the GRASP 16K salmonid microarray. The microarray data were analyzed using J-Express Pro 2.7 and validated by quantitative real-time polymerase chain reaction (qRT–PCR). Results Fish developed cataracts with different severity in response to dietary histidine levels. Lens N-acetyl histidine contents reflected the dietary histidine levels and were negatively correlated to cataract scores. Significance analysis of microarrays (SAM) revealed 248 significantly up-regulated transcripts and 266 significantly down-regulated transcripts in fish that were fed a low level of histidine compared to fish fed a higher histidine level. Among the differentially expressed transcripts were metallothionein A and B as well as transcripts involved in lipid metabolism, carbohydrate metabolism, regulation of ion homeostasis, and protein degradation. Hierarchical clustering and correspondence analysis plot confirmed differences in gene expression between the feeding groups. The differentially expressed genes could be categorized as “early” and “late” responsive according to their expression pattern relative to

Identification of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss) by using polymerase chain reaction amplification and restriction analysis of the mitochondrial cytochrome b gene.

PubMed

Carrera, E; García, T; Céspedes, A; González, I; Sanz, B; Hernández, P E; Martín, R

1998-04-01

Restriction site analysis of polymerase chain reaction (PCR) products from a conserved region of the cytochrome b gene has been used for the identification of fresh and smoked samples of Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss). Digestion of the 359-bp PCR product with the endonucleases EcoRV and TaqI yielded specific banding patterns for salmon and trout. This genetic marker can be very useful for detecting fraudulent substitution of the cheaper smoked trout for the more expensive smoked salmon.

Continuous monitoring of seasonal phenological development by BBCH code

NASA Astrophysics Data System (ADS)

Cornelius, Christine; Estrella, Nicole; Menzel, Annette

2010-05-01

Phenology, the science of recurrent seasonal natural events, is a proxy for changes in ecosystems due to recent global climate change. Phenological studies mostly deal with data considering the beginning of different development stages e.g. budburst or the beginning of flowering. Just few studies focus on the end of phenological stages, such as the end of flowering or seed dispersal. Information about the entire development cycle of plants, including data of the end of stages, are received by observing plants according to the extended BBCH-scale (MEIER 1997). The scale is a standardized growth stage key which allows a less labor intensive, weekly observation rhythm. Every week frequencies of all occurring phenological stages are noted. These frequencies then constitute the basis to interpolate the development of each phenological stage, even though it was not being seen during field work. Due to the lack of studies using this kind of key for observations over the entire development cycle there is no common methodology to analyze the data. So our objective was to find a method of analysis, with which onset dates as well as endpoints of each development stage could be defined. Three different methods of analysis were compared. Results show that there is no significant difference in onset dates of phenological stages between all methods tested. However, the method of pooled pre/post stage development seems to be most suitable for climate change studies, followed by the method of cumulative stage development and the method of weighted plant development.

Genetic variation in threshold reaction norms for alternative reproductive tactics in male Atlantic salmon, Salmo salar.

PubMed

Piché, Jacinthe; Hutchings, Jeffrey A; Blanchard, Wade

2008-07-07

Alternative reproductive tactics may be a product of adaptive phenotypic plasticity, such that discontinuous variation in life history depends on both the genotype and the environment. Phenotypes that fall below a genetically determined threshold adopt one tactic, while those exceeding the threshold adopt the alternative tactic. We report evidence of genetic variability in maturation thresholds for male Atlantic salmon (Salmo salar) that mature either as large (more than 1 kg) anadromous males or as small (10-150 g) parr. Using a common-garden experimental protocol, we find that the growth rate at which the sneaker parr phenotype is expressed differs among pure- and mixed-population crosses. Maturation thresholds of hybrids were intermediate to those of pure crosses, consistent with the hypothesis that the life-history switch points are heritable. Our work provides evidence, for a vertebrate, that thresholds for alternative reproductive tactics differ genetically among populations and can be modelled as discontinuous reaction norms for age and size at maturity.

Seasonal and cumulative loblolly pine development under two stand density and fertility levels

Treesearch

James D. Haywood

1992-01-01

An 8 year-old loblolly pine (Pinus taeda L.) stand was subjected to two cultural treatments for examination of seasonal and cumulative pine development. In the first treatment, pine density was either reduced by removal cutting to 2% trees per acre, at a 12- by 124 spacing, or left uncut with an original density of 1,210 trees per acre at a 6- by 6-...

Microbial Activity Response to Solar Radiation across Contrasting Environmental Conditions in Salar de Huasco, Northern Chilean Altiplano.

PubMed

Hernández, Klaudia L; Yannicelli, Beatriz; Olsen, Lasse M; Dorador, Cristina; Menschel, Eduardo J; Molina, Verónica; Remonsellez, Francisco; Hengst, Martha B; Jeffrey, Wade H

2016-01-01

In high altitude environments, extreme levels of solar radiation and important differences of ionic concentrations over narrow spatial scales may modulate microbial activity. In Salar de Huasco, a high-altitude wetland in the Andean mountains, the high diversity of microbial communities has been characterized and associated with strong environmental variability. Communities that differed in light history and environmental conditions, such as nutrient concentrations and salinity from different spatial locations, were assessed for bacterial secondary production (BSP, 3 H-leucine incorporation) response from short-term exposures to solar radiation. We sampled during austral spring seven stations categorized as: (a) source stations, with recently emerged groundwater (no-previous solar exposure); (b) stream running water stations; (c) stations connected to source waters but far downstream from source points; and (d) isolated ponds disconnected from ground sources or streams with a longer isolation and solar exposure history. Very high values of 0.25 μE m -2 s -1 , 72 W m -2 and 12 W m -2 were measured for PAR, UVA, and UVB incident solar radiation, respectively. The environmental factors measured formed two groups of stations reflected by principal component analyses (near to groundwater sources and isolated systems) where isolated ponds had the highest BSP and microbial abundance (35 microalgae taxa, picoeukaryotes, nanoflagellates, and bacteria) plus higher salinities and PO 4 3- concentrations. BSP short-term response (4 h) to solar radiation was measured by 3 H-leucine incorporation under four different solar conditions: full sun, no UVB, PAR, and dark. Microbial communities established in waters with the longest surface exposure (e.g., isolated ponds) had the lowest BSP response to solar radiation treatments, and thus were likely best adapted to solar radiation exposure contrary to ground source waters. These results support our light history (solar exposure

Microbial Activity Response to Solar Radiation across Contrasting Environmental Conditions in Salar de Huasco, Northern Chilean Altiplano

PubMed Central

Hernández, Klaudia L.; Yannicelli, Beatriz; Olsen, Lasse M.; Dorador, Cristina; Menschel, Eduardo J.; Molina, Verónica; Remonsellez, Francisco; Hengst, Martha B.; Jeffrey, Wade H.

2016-01-01

In high altitude environments, extreme levels of solar radiation and important differences of ionic concentrations over narrow spatial scales may modulate microbial activity. In Salar de Huasco, a high-altitude wetland in the Andean mountains, the high diversity of microbial communities has been characterized and associated with strong environmental variability. Communities that differed in light history and environmental conditions, such as nutrient concentrations and salinity from different spatial locations, were assessed for bacterial secondary production (BSP, 3H-leucine incorporation) response from short-term exposures to solar radiation. We sampled during austral spring seven stations categorized as: (a) source stations, with recently emerged groundwater (no-previous solar exposure); (b) stream running water stations; (c) stations connected to source waters but far downstream from source points; and (d) isolated ponds disconnected from ground sources or streams with a longer isolation and solar exposure history. Very high values of 0.25 μE m-2 s-1, 72 W m-2 and 12 W m-2 were measured for PAR, UVA, and UVB incident solar radiation, respectively. The environmental factors measured formed two groups of stations reflected by principal component analyses (near to groundwater sources and isolated systems) where isolated ponds had the highest BSP and microbial abundance (35 microalgae taxa, picoeukaryotes, nanoflagellates, and bacteria) plus higher salinities and PO43- concentrations. BSP short-term response (4 h) to solar radiation was measured by 3H-leucine incorporation under four different solar conditions: full sun, no UVB, PAR, and dark. Microbial communities established in waters with the longest surface exposure (e.g., isolated ponds) had the lowest BSP response to solar radiation treatments, and thus were likely best adapted to solar radiation exposure contrary to ground source waters. These results support our light history (solar exposure) hypothesis

Standard seasons

NASA Astrophysics Data System (ADS)

Tuller, Stanton E.

1990-09-01

A renewed interest in climatic definitions of the seasons has surfaced in recent years. However, people usually associate biological phenomena and climate with the seasons. Standard seasons, defined as the periods of the year when the climate is within specified bounds, can be delimited in terms of biological phenomena if climatic thresholds are known for the groups of interest. By focusing attention on the time variation they illustrate climatic variation from a different perspective. An example of the type of information provided by standard seasons on the regional scale is given using human thermal standard seasons in the Pacific Basin. The latitudinal control of climate is indicated by the length of the hot and cold seasons. The moderation of maritime climates is seen in the shortness and slower rate of advance and retreat of the hot and cold seasons, and the extended length of the neutral (or spring) season. Standard seasons have widespread application in indicating the times of the year favorable or unfavorable for particular populations or activities. Bioclimatologists can contribute to season definition by expanding the range of information on climate-organism interaction on which seasonal thresholds are based and may find standard seasons useful in presenting the results of many types of investigations.

Freshwater-Brine Mixing Zone Hydrodynamics in Salt Flats (Salar de Atacama)

NASA Astrophysics Data System (ADS)

Marazuela, M. A.; Vázquez-Suñé, E.; Custodio, E.; Palma, T.; García-Gil, A.

2017-12-01

The increase in the demand of strategic minerals for the development of medicines and batteries require detailed knowledge of the salt flats freshwater-brine interface to make its exploitation efficient. The interface zone is the result of a physical balance between the recharged and evaporated water. The sharp interface approach assumes the immiscibility of the fluids and thus neglects the mixing between them. As a consequence, for miscible fluids it is more accurate and often needed to use the mixing zone concept, which results from the dynamic equilibrium of flowing freshwater and brine. In this study, we consider two and three-dimensional scale approaches for the management of the mixing zone. The two-dimensional approach is used to understand the dynamics and the characteristics of the salt flat mixing zone, especially in the Salar de Atacama (Atacama salt flat) case. By making use of this model we analyze and quantify the effects of the aquitards on the mixing zone geometry. However, the understanding of the complex physical processes occurring in the salt flats and the management of these environments requires the adoption of three-dimensional regional scale numerical models. The models that take into account the effects of variable density represent the best management tool, but they require large computational resources, especially in the three-dimensional case. In order to avoid these computational limitations in the modeling of salt flats and their valuable ecosystems, we propose a three-step methodology, consisting of: (1) collection, validation and interpretation of the hydrogeochemical data, (2) identification and three-dimensional mapping of the mixing zone on the land surface and in depth, and (3) application of a water head correction to the freshwater and mixed water heads in order to compensate the density variations and to transform them to brine water heads. Finally, an evaluation of the sensibility of the mixing zone to anthropogenic and

Operational seasonal forecasting of crop performance.

PubMed

Stone, Roger C; Meinke, Holger

2005-11-29

Integrated, interdisciplinary crop performance forecasting systems, linked with appropriate decision and discussion support tools, could substantially improve operational decision making in agricultural management. Recent developments in connecting numerical weather prediction models and general circulation models with quantitative crop growth models offer the potential for development of integrated systems that incorporate components of long-term climate change. However, operational seasonal forecasting systems have little or no value unless they are able to change key management decisions. Changed decision making through incorporation of seasonal forecasting ultimately has to demonstrate improved long-term performance of the cropping enterprise. Simulation analyses conducted on specific production scenarios are especially useful in improving decisions, particularly if this is done in conjunction with development of decision-support systems and associated facilitated discussion groups. Improved management of the overall crop production system requires an interdisciplinary approach, where climate scientists, agricultural scientists and extension specialists are intimately linked with crop production managers in the development of targeted seasonal forecast systems. The same principle applies in developing improved operational management systems for commodity trading organizations, milling companies and agricultural marketing organizations. Application of seasonal forecast systems across the whole value chain in agricultural production offers considerable benefits in improving overall operational management of agricultural production.

Operational seasonal forecasting of crop performance

PubMed Central

Stone, Roger C; Meinke, Holger

2005-01-01

Integrated, interdisciplinary crop performance forecasting systems, linked with appropriate decision and discussion support tools, could substantially improve operational decision making in agricultural management. Recent developments in connecting numerical weather prediction models and general circulation models with quantitative crop growth models offer the potential for development of integrated systems that incorporate components of long-term climate change. However, operational seasonal forecasting systems have little or no value unless they are able to change key management decisions. Changed decision making through incorporation of seasonal forecasting ultimately has to demonstrate improved long-term performance of the cropping enterprise. Simulation analyses conducted on specific production scenarios are especially useful in improving decisions, particularly if this is done in conjunction with development of decision-support systems and associated facilitated discussion groups. Improved management of the overall crop production system requires an interdisciplinary approach, where climate scientists, agricultural scientists and extension specialists are intimately linked with crop production managers in the development of targeted seasonal forecast systems. The same principle applies in developing improved operational management systems for commodity trading organizations, milling companies and agricultural marketing organizations. Application of seasonal forecast systems across the whole value chain in agricultural production offers considerable benefits in improving overall operational management of agricultural production. PMID:16433097

Dietary accumulation efficiencies and biotransformation of polybrominated diphenyl ethers in farmed Atlantic salmon (Salmo salar).

PubMed

Isosaari, P; Lundebye, A-K; Ritchie, G; Lie, O; Kiviranta, H; Vartiainen, T

2005-09-01

The consumer safety of farm-raised salmon could be improved by determining the transfer efficiency of hazardous pollutants from fish feed to the salmon. A controlled feeding trial for 30 weeks was carried out to investigate the transfer of polybrominated diphenyl ethers (PBDEs) in Atlantic salmon (Salmo salar). Using three feed concentrations, an average of 95% of the total PBDE content of feed accumulated in whole salmon. Skinned fillet accumulated 42-59% of the PBDE intake. Equal partitioning according to the lipid content of the tissue was demonstrated. The formation of less brominated PBDEs via preferential debromination from the meta-position was thought to explain the exceptional accumulation efficiencies of BDE 47, BDE 66, BDE 75, BDE 119 and BDE 183 that were either >100% or else increasing with the exposure dose. Monitoring of a larger number of PBDE congeners is recommended to verify the biotransformation routes. The PBDE concentration in salmon of different ages, fed on a known concentration of PBDEs in fish feed, could be predicted by using the accumulation efficiencies determined in this study.

Ichthyobodo salmonis sp. n. (Ichthyobodonidae, Kinetoplastida), an euryhaline ectoparasite infecting Atlantic salmon (Salmo salar L.)

PubMed Central

ISAKSEN, TROND E.; KARLSBAKK, EGIL; WATANABE, KUNINORI; NYLUND, ARE

2011-01-01

SUMMARY Phylogenetic analyses of SSU rDNA sequences have previously revealed the existence of 2 Ichthyobodo species able to infect Atlantic salmon (Salmo salar L.). Ichthyobodo necator sensu stricto (s.s.) is assumed to be a freshwater parasite, while a genetically distinct but undescribed species, Ichthyobodo sp. II sensu Todal et al. (2004) have been detected on Atlantic salmon in both fresh- and seawater. In the present study a morphological description of Ichthyobodo sp. II from the gills of salmon reared in fresh-, brackish- and seawater is presented, using both light- and electron microscopy. Comparative morphometry show that Ichthyobodo sp. II from both freshwater and seawater displays a different cell shape, and is significantly smaller than I. necator s.s. Also, ultrastructural characteristics distinguish these two species, notably differences in the attachment region and the presence of spine-like surface projections in Ichthyobodo sp. II. Based on both unique SSU rDNA sequences and morphological characteristics, we conclude that Ichthyobodo sp. II. represents a novel species for which we propose the name Ichthyobodo salmonis sp. n. PMID:21756424

Computer vision-based sorting of Atlantic salmon (Salmo salar) fillets according to their color level.

PubMed

Misimi, E; Mathiassen, J R; Erikson, U

2007-01-01

Computer vision method was used to evaluate the color of Atlantic salmon (Salmo salar) fillets. Computer vision-based sorting of fillets according to their color was studied on 2 separate groups of salmon fillets. The images of fillets were captured using a digital camera of high resolution. Images of salmon fillets were then segmented in the regions of interest and analyzed in red, green, and blue (RGB) and CIE Lightness, redness, and yellowness (Lab) color spaces, and classified according to the Roche color card industrial standard. Comparisons of fillet color between visual evaluations were made by a panel of human inspectors, according to the Roche SalmoFan lineal standard, and the color scores generated from computer vision algorithm showed that there were no significant differences between the methods. Overall, computer vision can be used as a powerful tool to sort fillets by color in a fast and nondestructive manner. The low cost of implementing computer vision solutions creates the potential to replace manual labor in fish processing plants with automation.

GloFAS-Seasonal: Operational Seasonal Ensemble River Flow Forecasts at the Global Scale

NASA Astrophysics Data System (ADS)

Emerton, Rebecca; Zsoter, Ervin; Smith, Paul; Salamon, Peter

2017-04-01

Seasonal hydrological forecasting has potential benefits for many sectors, including agriculture, water resources management and humanitarian aid. At present, no global scale seasonal hydrological forecasting system exists operationally; although smaller scale systems have begun to emerge around the globe over the past decade, a system providing consistent global scale seasonal forecasts would be of great benefit in regions where no other forecasting system exists, and to organisations operating at the global scale, such as disaster relief. We present here a new operational global ensemble seasonal hydrological forecast, currently under development at ECMWF as part of the Global Flood Awareness System (GloFAS). The proposed system, which builds upon the current version of GloFAS, takes the long-range forecasts from the ECMWF System4 ensemble seasonal forecast system (which incorporates the HTESSEL land surface scheme) and uses this runoff as input to the Lisflood routing model, producing a seasonal river flow forecast out to 4 months lead time, for the global river network. The seasonal forecasts will be evaluated using the global river discharge reanalysis, and observations where available, to determine the potential value of the forecasts across the globe. The seasonal forecasts will be presented as a new layer in the GloFAS interface, which will provide a global map of river catchments, indicating whether the catchment-averaged discharge forecast is showing abnormally high or low flows during the 4-month lead time. Each catchment will display the corresponding forecast as an ensemble hydrograph of the weekly-averaged discharge forecast out to 4 months, with percentile thresholds shown for comparison with the discharge climatology. The forecast visualisation is based on a combination of the current medium-range GloFAS forecasts and the operational EFAS (European Flood Awareness System) seasonal outlook, and aims to effectively communicate the nature of a seasonal

Technical pre-analytical effects on the clinical biochemistry of Atlantic salmon (Salmo salar L.).

PubMed

Braceland, M; Houston, K; Ashby, A; Matthews, C; Haining, H; Rodger, H; Eckersall, P D

2017-01-01

Clinical biochemistry has long been utilized in human and veterinary medicine as a vital diagnostic tool, but despite occasional studies showing its usefulness in monitoring health status in Atlantic salmon (Salmo salar L.), it has not yet been widely utilized within the aquaculture industry. This is due, in part, to a lack of an agreed protocol for collection and processing of blood prior to analysis. Moreover, while the analytical phase of clinical biochemistry is well controlled, there is a growing understanding that technical pre-analytical variables can influence analyte concentrations or activities. In addition, post-analytical interpretation of treatment effects is variable in the literature, thus making the true effect of sample treatment hard to evaluate. Therefore, a number of pre-analytical treatments have been investigated to examine their effect on analyte concentrations and activities. In addition, reference ranges for salmon plasma biochemical analytes have been established to inform veterinary practitioners and the aquaculture industry of the importance of clinical biochemistry in health and disease monitoring. Furthermore, a standardized protocol for blood collection has been proposed. © 2016 The Authors Journal of Fish Diseases Published by John Wiley & Sons Ltd.

Surface properties of Streptococcus phocae strains isolated from diseased Atlantic salmon, Salmo salar L.

PubMed

González-Contreras, A; Magariños, B; Godoy, M; Irgang, R; Toranzo, A E; Avendaño-Herrera, R

2011-03-01

Streptococcus phocae is an emerging pathogen for Chilean Atlantic salmon, Salmo salar, but the factors determining its virulence are not yet elucidated. In this work, cell surface-related properties such as hydrophobicity and haemagglutination, adhesion to mucus and cell lines, capsule detection, survival and biofilm formation in skin mucus and serum resistance of the isolates responsible for outbreaks in Atlantic salmon and seals were examined. Adhesion to hydrocarbons and the results of salt aggregation tests indicated most of the S. phocae were strongly hydrophobic. All isolates exhibited a similar ability to attach to the Chinook salmon embryo (CHSE) cells line, but were not able to enter CHSE cells. Haemagglutination was not detected. Our data clearly indicate that S. phocae can resist the killing activity of mucus and serum and proliferate in them, which could be associated with the presence of a capsular layer around the cells. Pathogenicity studies using seal and fish isolates demonstrated mortality or pathological signs in fish injected only with the Atlantic salmon isolate. No mortalities or histopathological alterations were observed in fish injected with extracellular products. © 2011 Blackwell Publishing Ltd.

Sequencing and Characterisation of an Extensive Atlantic Salmon (Salmo salar L.) MicroRNA Repertoire

PubMed Central

Bekaert, Michaël; Lowe, Natalie R.; Bishop, Stephen C.; Bron, James E.; Taggart, John B.; Houston, Ross D.

2013-01-01

Atlantic salmon (Salmo salar L.), a member of the family Salmonidae, is a totemic species of ecological and cultural significance that is also economically important in terms of both sports fisheries and aquaculture. These factors have promoted the continuous development of genomic resources for this species, furthering both fundamental and applied research. MicroRNAs (miRNA) are small endogenous non-coding RNA molecules that control spatial and temporal expression of targeted genes through post-transcriptional regulation. While miRNA have been characterised in detail for many other species, this is not yet the case for Atlantic salmon. To identify miRNAs from Atlantic salmon, we constructed whole fish miRNA libraries for 18 individual juveniles (fry, four months post hatch) and characterised them by Illumina high-throughput sequencing (total of 354,505,167 paired-ended reads). We report an extensive and partly novel repertoire of miRNA sequences, comprising 888 miRNA genes (547 unique mature miRNA sequences), quantify their expression levels in basal conditions, examine their homology to miRNAs from other species and identify their predicted target genes. We also identify the location and putative copy number of the miRNA genes in the draft Atlantic salmon reference genome sequence. The Atlantic salmon miRNAs experimentally identified in this study provide a robust large-scale resource for functional genome research in salmonids. There is an opportunity to explore the evolution of salmonid miRNAs following the relatively recent whole genome duplication event in salmonid species and to investigate the role of miRNAs in the regulation of gene expression in particular their contribution to variation in economically and ecologically important traits. PMID:23922936

Aluminum exposure impacts brain plasticity and behavior in Atlantic salmon (Salmo salar).

PubMed

Grassie, C; Braithwaite, V A; Nilsson, J; Nilsen, T O; Teien, H-C; Handeland, S O; Stefansson, S O; Tronci, V; Gorissen, M; Flik, G; Ebbesson, L O E

2013-08-15

Aluminum (Al) toxicity occurs frequently in natural aquatic ecosystems as a result of acid deposition and natural weathering processes. Detrimental effects of Al toxicity on aquatic organisms are well known and can have consequences for survival. Fish exposed to Al in low pH waters will experience physiological and neuroendocrine changes that disrupt homeostasis and alter behavior. To investigate the effects of Al exposure on both the brain and behavior, Atlantic salmon (Salmo salar) kept in water treated with Al (pH 5.7, 0.37±0.04 μmol 1(-1) Al) for 2 weeks were compared with fish kept in under control conditions (pH 6.7, <0.04 μmol 1(-1) Al). Fish exposed to Al and acidic conditions had increased Al accumulation in the gills and decreased gill Na(+), K(+)-ATPase activity, which impaired osmoregulatory capacity and caused physiological stress, indicated by elevated plasma cortisol and glucose levels. Here we show for the first time that exposure to Al in acidic conditions also impaired learning performance in a maze task. Al toxicity also reduced the expression of NeuroD1 transcript levels in the forebrain of exposed fish. As in mammals, these data show that exposure to chronic stress, such as acidified Al, can reduce neural plasticity during behavioral challenges in salmon, and may impair the ability to cope with new environments.

Antibody against infectious salmon anaemia virus among feral Atlantic salmon (Salmo salar)

USGS Publications Warehouse

Cipriano, R.C.

2009-01-01

Archived sera from Atlantic salmon (Salmo salar) that returned to the Penobscot River (Maine), Merrimack River (Massachusetts), and Connecticut River (in Massachusetts) from 1995 to 2002 were analysed for antibodies against infectious salmon anaemia virus (ISAV) using an enzyme-linked immunosorbent assay (ELISA). Up to 60 samples were archived per river system per year. In a given year, the number of fish sampled by ELISA for ISAV antibodies in the Penobscot River ranged from 2.9 to 11.2, and the range of salmon sampled in the Merrimack River and the Connecticut River was 31.3-100 and 20.0-67.5, respectively. Archived sera were not available for the 1995 and 2002 year classes from the Connecticut River. In all, 1141 samples were processed; 14 serum samples tested positive for antibodies to ISAV. In the Penobscot River, serum from one fish tested positive in each of the 1995 and 1999 year-class returns, and sera from two fish tested positive in the 1998 returns. In the Merrimack River, sera from four fish tested positive in each of the 1996 and 1997 returns, and sera from two fish were positive in the 2002 return. None of the archived sera from Atlantic salmon that returned to the Connecticut River tested positive. ?? 2009 United States Government, Department of the Interior.

Seasonality in ocean microbial communities.

PubMed

Giovannoni, Stephen J; Vergin, Kevin L

2012-02-10

Ocean warming occurs every year in seasonal cycles that can help us to understand long-term responses of plankton to climate change. Rhythmic seasonal patterns of microbial community turnover are revealed when high-resolution measurements of microbial plankton diversity are applied to samples collected in lengthy time series. Seasonal cycles in microbial plankton are complex, but the expansion of fixed ocean stations monitoring long-term change and the development of automated instrumentation are providing the time-series data needed to understand how these cycles vary across broad geographical scales. By accumulating data and using predictive modeling, we gain insights into changes that will occur as the ocean surface continues to warm and as the extent and duration of ocean stratification increase. These developments will enable marine scientists to predict changes in geochemical cycles mediated by microbial communities and to gauge their broader impacts.

Ectoparasite Caligus rogercresseyi modifies the lactate response in Atlantic salmon (Salmo salar) and Coho salmon (Oncorhynchus kisutch).

PubMed

Vargas-Chacoff, L; Muñoz, J L P; Hawes, C; Oyarzún, R; Pontigo, J P; Saravia, J; González, M P; Mardones, O; Labbé, B S; Morera, F J; Bertrán, C; Pino, J; Wadsworth, S; Yáñez, A

2017-08-30

Although Caligus rogercresseyi negatively impacts Chilean salmon farming, the metabolic effects of infection by this sea louse have never been completely characterized. Therefore, this study analyzed lactate responses in the plasma, as well as the liver/muscle lactate dehydrogenase (LDH) activity and gene expression, in Salmo salar and Oncorhynchus kisutch infested by C. rogercresseyi. The lactate responses of Atlantic and Coho salmon were modified by the ectoparasite. Both salmon species showed increasing in plasma levels, whereas enzymatic activity increased in the muscle but decreased in the liver. Gene expression was overexpressed in both Coho salmon tissues but only in the liver for Atlantic salmon. These results suggest that salmonids need more energy to adapt to infection, resulting in increased gene expression, plasma levels, and enzyme activity in the muscles. The responses differed between both salmon species and over the course of infection, suggesting potential species-specific responses to sea-lice infection. Copyright © 2017 Elsevier B.V. All rights reserved.

Developing the Capacity of Farmers to Understand and Apply Seasonal Climate Forecasts through Collaborative Learning Processes

ERIC Educational Resources Information Center

Cliffe, Neil; Stone, Roger; Coutts, Jeff; Reardon-Smith, Kathryn; Mushtaq, Shahbaz

2016-01-01

Purpose: This paper documents and evaluates collaborative learning processes aimed at developing farmer's knowledge, skills and aspirations to use seasonal climate forecasting (SCF). Methodology: Thirteen workshops conducted in 2012 engaged over 200 stakeholders across Australian sugar production regions. Workshop design promoted participant…

Temperature requirements of Atlantic salmon Salmo salar, brown trout Salmo trutta and Arctic charr Salvelinus alpinus: predicting the effects of climate change.

PubMed

Elliott, J M; Elliott, J A

2010-11-01

Atlantic salmon Salmo salar, brown trout Salmo trutta (including the anadromous form, sea trout) and Arctic charr Salvelinus alpinus (including anadromous fish) provide important commercial and sports fisheries in Western Europe. As water temperature increases as a result of climate change, quantitative information on the thermal requirements of these three species is essential so that potential problems can be anticipated by those responsible for the conservation and sustainable management of the fisheries and the maintenance of biodiversity in freshwater ecosystems. Part I compares the temperature limits for survival, feeding and growth. Salmo salar has the highest temperature tolerance, followed by S. trutta and finally S. alpinus. For all three species, the temperature tolerance for alevins is slightly lower than that for parr and smolts, and the eggs have the lowest tolerance; this being the most vulnerable life stage to any temperature increase, especially for eggs of S. alpinus in shallow water. There was little evidence to support local thermal adaptation, except in very cold rivers (mean annual temperature <6·5° C). Part II illustrates the importance of developing predictive models, using data from a long-term study (1967-2000) of a juvenile anadromous S. trutta population. Individual-based models predicted the emergence period for the fry. Mean values over 34 years revealed a large variation in the timing of emergence with c. 2 months between extreme values. The emergence time correlated significantly with the North Atlantic Oscillation Index, indicating that interannual variations in emergence were linked to more general changes in climate. Mean stream temperatures increased significantly in winter and spring at a rate of 0·37° C per decade, but not in summer and autumn, and led to an increase in the mean mass of pre-smolts. A growth model for S. trutta was validated by growth data from the long-term study and predicted growth under possible future

Comparison of damage to live v. euthanized Atlantic salmon Salmo salar smolts from passage through an Archimedean screw turbine.

PubMed

Brackley, R; Lucas, M C; Thomas, R; Adams, C E; Bean, C W

2018-05-01

This study assessed the usefulness of passing euthanized Atlantic salmon Salmo salar smolts through an Archimedean screw turbine to test for external damage, as compared with live, actively swimming smolts. Scale loss was the only observed effect. Severe scale loss was 5·9 times more prevalent in euthanized turbine-passed fish (45%) than the live fish (7·6%). Additionally, distinctive patterns of scale loss, consistent with grinding between the turbine helices and housing trough, were observed in 35% of euthanized turbine-passed smolts. This distinctive pattern of scale loss was not seen in live turbine-passed smolts, nor in control groups (live and euthanized smolts released downstream of the turbine), which suggests that the altered behaviour of dead fish in turbine flows generates biased injury outcomes. © 2018 The Fisheries Society of the British Isles.

The root transcriptome for North American ginseng assembled and profiled across seasonal development

PubMed Central

2013-01-01

Background Ginseng including North American ginseng (Panax quinquefolius L.) is one of the most widely used medicinal plants. Its success is thought to be due to a diverse collection of ginsenosides that serve as its major bioactive compounds. However, few genomic resources exist and the details concerning its various biosynthetic pathways remain poorly understood. As the root is the primary tissue harvested commercially for ginsenosides, next generation sequencing was applied to the characterization and assembly of the root transcriptome throughout seasonal development. Transcripts showing homology to ginsenoside biosynthesis enzymes were profiled in greater detail. Results RNA extracts from root samples from seven development stages of North American ginseng were subjected to 454 sequencing, filtered for quality and used in the de novo assembly of a collective root reference transcriptome consisting of 41,623 transcripts. Annotation efforts using a number of public databases resulted in detailed annotation information for 34,801 (84%) transcripts. In addition, 3,955 genes were assigned to metabolic pathways using the Kyoto Encyclopedia of Genes and Genomes. Among our results, we found all of the known enzymes involved in the ginsenoside backbone biosynthesis and used co-expression analysis to identify a number of candidate sequences involved in the latter stages ginsenoside biosynthesis pathway. Transcript profiles suggest ginsenoside biosynthesis occurs at distinct stages of development. Conclusions The assembly generated provides a comprehensive annotated reference for future transcriptomic study of North American ginseng. A collection of putative ginsenoside biosynthesis genes were identified and candidate genes predicted from the lesser understood downstream stages of biosynthesis. Transcript expression profiles across seasonal development suggest a primary dammarane-type ginsenoside biosynthesis occurs just prior to plant senescence, with secondary

Developing Multi-model Ensemble for Precipitation and Temperature Seasonal Forecasts: Implications for Karkheh River Basin in Iran

NASA Astrophysics Data System (ADS)

Najafi, Husain; Massah Bavani, Ali Reza; Wanders, Niko; Wood, Eric; Irannejad, Parviz; Robertson, Andrew

2017-04-01

Water resource managers can utilize reliable seasonal forecasts for allocating water between different users within a water year. In the west of Iran where a decline of renewable water resources has been observed, basin-wide water management has been the subject of many inter-provincial conflicts in recent years. The problem is exacerbated when the environmental water requirements is not provided leaving the Hoor-al-Azim marshland in the downstream dry. It has been argued that information on total seasonal rainfall can support the Iranian Ministry of Energy within the water year. This study explores the skill of the North America Multi Model Ensemble for Karkheh River Basin in the of west Iran. NMME seasonal precipitation and temperature forecasts from eight models are evaluated against PERSIANN-CDR and Climate Research Unit (CRU) datasets. Analysis suggests that anomaly correlation for both precipitation and temperature is greater than 0.4 for all individual models. Lead time-dependent seasonal forecasts are improved when a multi-model ensemble is developed for the river basin using stepwise linear regression model. MME R-squared exceeds 0.6 for temperature for almost all initializations suggesting high skill of NMME in Karkheh river basin. The skill of MME for rainfall forecasts is high for 1-month lead time for October, February, March and October initializations. However, for months when the amount of rainfall accounts for a significant proportion of total annual rainfall, the skill of NMME is limited a month in advance. It is proposed that operational regional water companies incorporate NMME seasonal forecasts into water resource planning and management, especially during growing seasons that are essential for agricultural risk management.

Seasonal variation in sports participation.

PubMed

Schüttoff, Ute; Pawlowski, Tim

2018-02-01

This study explores indicators describing socio-demographics, sports participation characteristics and motives which are associated with variation in sports participation across seasons. Data were drawn from the German Socio-Economic Panel which contains detailed information on the sports behaviour of adults in Germany. Overall, two different measures of seasonal variation are developed and used as dependent variables in our regression models. The first variable measures the coefficient of (seasonal) variation in sport-related energy expenditure per week. The second variable measures whether activity drops below the threshold as defined by the World Health Organization (WHO). Results suggest that the organisational setting, the intensity and number of sports practised, and the motive for participation are strongly correlated with the variation measures used. For example, both, participation in a sports club and a commercial facility, are associated with reduced seasonal variation and a significantly higher probability of participating at a volume above the WHO threshold across all seasons. These findings give some impetus for policymaking and the planning of sports programmes as well as future research directions.

Prototype demonstration of a geographic information system application for seasonal analysis of traffic data : development of seasonal factors and seasonal adjustment of roadways

DOT National Transportation Integrated Search

1999-08-15

The Traffic Survey Unit plans to establish a methodology in which it can assign each Portable Traffic Counter (PTC) station a seasonal group profile through a means of statistical and geographical analysis. An ArcView Geographic Information Systems a...

Injection-salting of pre rigor fillets of Atlantic salmon (Salmo salar).

PubMed

Birkeland, Sveinung; Akse, Leif; Joensen, Sjurdur; Tobiassen, Torbjørn; Skåra, Torstein

2007-01-01

The effects of temperature (-1, 4, and 10 degrees C), brine concentration (12% and 25% NaCl), injection volumes, and needle densities were investigated on fillet weight gain (%), salt content (%), fillet contraction (%), and muscle gaping in pre rigor brine-injected fillets of Atlantic salmon (Salmo salar). Increased brine concentration (12% to 25%) significantly increased the initial (< 5 min after injection) and final contraction (24 h after injection) of pre rigor fillets. Increased brine concentration significantly reduced weight gain and increased salt content but had no significant effect on muscle gaping. The temperatures tested did not significantly affect weight gain, fillet contraction, or gaping score. Significant regressions (P < 0.01) between the injection volume and weight gain (range: 2.5% to 15.5%) and salt content (range: 1.7% to 6.5%) were observed for injections of pre rigor fillets. Double injections significantly increased the weight gain and salt content compared to single injections. Initial fillet contraction measured 30 min after brine injection increased significantly (P < 0.01) with increasing brine injection volume but no significant difference in the fillet contraction was observed 12 h after brine injection (range: 7.9% to 8.9%). Brine-injected post rigor control fillets obtained higher weight gain, higher salt content, more muscle gaping, and significantly lower fillet contraction compared to the pre rigor injected fillets. Injection-salting is an applicable technology as a means to obtain satisfactory salt contents and homogenously distribute the salt into the muscle of pre rigor fillets of Atlantic salmon before further processing steps such as drying and smoking.

Influence of fluoride on aluminum toxicity to Atlantic salmon (Salmo salar)

USGS Publications Warehouse

Hamilton, Steven J.; Haines, Terry A.

1995-01-01

Atlantic salmon (Salmo salar) alevins were exposed to various aluminum (0–4700 μg/L) and four fluoride (0–500 μg/L) concentrations at two pH values (5.5 and 6.5) for 4- and 30-d periods. In the 4-d tests, aluminum with fluoride was less toxic at pH 6.5 than at pH 5.5, whereas without fluoride, pH had no effect. In the 30-d test, mortality in all treatments was 17–21% at pH 5.5, but only 3–7% at pH 6.5. Fish length and weight after 30 d were reduced in all fluoride–aluminum treatments at pH 5.5, but only in the 200-μg/L aluminum without fluoride treatment at pH 6.5. At pH 5.5 and 6.5 without aluminum, histomorphological examinations revealed no abnormalities in gill tissue. However, in aluminum exposure with no fluoride, gill filaments and secondary lamellae were swollen and thickened. Addition of fluoride at pH 6.5 alleviated some gill damage. At pH 5.5 and 200 μg/L aluminum, addition of 100 μg/L fluoride reduced swelling of gill lamellae, but 200 μg/L fluoride did not reduce swelling. Low fluoride concentrations (< 100 μg/L) may reduce gill morphological damage in fish exposed to aluminum in acidic waters, whereas high fluoride concentrations (> 100 μg/L) may not reduce aluminum-induced effects.

The Skin-Mucus Microbial Community of Farmed Atlantic Salmon (Salmo salar)

PubMed Central

Minniti, Giusi; Hagen, Live Heldal; Porcellato, Davide; Jørgensen, Sven Martin; Pope, Phillip B.; Vaaje-Kolstad, Gustav

2017-01-01

The skin of the teleost is a flexible and scaled structure that protects the fish toward the external environment. The outermost surface of the skin is coated with mucus, which is believed to be colonized by a diverse bacterial community (commensal and/or opportunistic). Little is known about such communities and their role in fish welfare. In aquaculture, fish seem to be more susceptible to pathogens compared to wild fish. Indeed common fish farming practices may play important roles in promoting their vulnerability, possibly by causing changes to their microbiomes. In the present study, 16S rRNA gene amplicon sequencing was employed to analyze the composition of the farmed Salmo salar skin-mucus microbiome before and after netting and transfer. The composition of the bacterial community present in the rearing water was also investigated in order to evaluate its correlation with the community present on the fish skin. Our results reveal variability of the skin-mucus microbiome among the biological replicates before fish handling. On the contrary, after fish handling, the skin-mucus community exhibited structural similarity among the biological replicates and significant changes were observed in the bacterial composition compared to the fish analyzed prior to netting and transfer. Limited correlation was revealed between the skin-mucus microbiome and the bacterial community present in the rearing water. Finally, analysis of skin-mucus bacterial biomasses indicated low abundance for some samples, highlighting the need of caution when interpreting community data due to the possible contamination of water-residing bacteria. PMID:29104567

Chryseobacterium chaponense sp. nov., isolated from farmed Atlantic salmon (Salmo salar).

PubMed

Kämpfer, Peter; Fallschissel, Kerstin; Avendaño-Herrera, Ruben

2011-03-01

Two bacterial strains, designated Sa 1147-06(T) and Sa 1143-06, were isolated from Atlantic salmon (Salmo salar) farmed in Lake Chapo, Chile, and were studied using a polyphasic approach. Both isolates were very similar; cells were rod-shaped, formed yellow-pigmented colonies and were Gram-reaction-negative. Based on 16S rRNA gene sequence analysis, strains Sa 1147-06(T) and Sa 1143-06 shared 100  % sequence similarity and showed 98.9 and 97.5 % sequence similarity to Chryseobacterium jeonii AT1047(T) and Chryseobacterium antarcticum AT1013(T), respectively. Sequence similarities to all other members of the genus Chryseobacterium were below 97.3  %. The major fatty acids of strain Sa 1147-06(T) were iso-C₁₃:₀, iso-C₁₅:₀, anteiso-C₁₅:₀ and iso-C₁₇:₁ω9c, with iso-C₁₅:₀ 3-OH, iso-C₁₆:₀ 3-OH and iso-C₁₇:₀ 3-OH constituting the major hydroxylated fatty acids. DNA-DNA hybridizations with C. jeonii JMSNU 14049(T) and C. antarcticum JMNSU 14040(T) gave relatedness values of 20.7  % (reciprocal 15.1  %) and 15.7 % (reciprocal 25.7  %), respectively. Together, the DNA-DNA hybridization results and differentiating biochemical properties showed that strains Sa 1147-06(T) and Sa 1143-06 represent a novel species, for which the name Chryseobacterium chaponense sp. nov. is proposed. The type strain is Sa 1147-06(T) (=DSM 23145(T) =CCM 7737(T)).

Seasonal development of ozone-induced foliar injury on tall milkweed (Asclepias exaltata) in Great Smoky Mountains National Park.

PubMed

Souza, Lara; Neufeld, Howard S; Chappelka, Arthur H; Burkey, Kent O; Davison, Alan W

2006-05-01

The goals of this study were to document the development of ozone-induced foliar injury, on a leaf-by-leaf basis, and to develop ozone exposure relationships for leaf cohorts and individual tall milkweeds (Asclepias exaltata L.) in Great Smoky Mountains National Park. Plants were classified as either ozone-sensitive or insensitive based on the amount of foliar injury. Sensitive plants developed injury earlier in the season and to a greater extent than insensitive plants. Older leaf cohorts were more likely to belong to high injury classes by the end of each of the two growing seasons. In addition, leaf loss was more likely for older cohorts (2000) and lower leaf positions (2001) than younger cohorts and upper leaves, respectively. Most leaves abscised without prior ozone-like stippling or chlorosis. Failure to take this into account can result in underestimation of the effects of ozone on these plants.

Transcriptomic and physiological responses to fishmeal substitution with plant proteins in formulated feed in farmed Atlantic salmon (Salmo salar)

PubMed Central

2012-01-01

Background Aquaculture of piscivorous fish is in continual expansion resulting in a global requirement to reduce the dependence on wild caught fish for generation of fishmeal and fish oil. Plant proteins represent a suitable protein alternative to fish meal and are increasingly being used in fish feed. In this study, we examined the transcriptional response of Atlantic salmon (Salmo salar) to a high marine protein (MP) or low fishmeal, higher plant protein replacement diet (PP), formulated to the same nutritional specification within previously determined acceptable maximum levels of individual plant feed materials. Results After 77 days of feeding the fish in both groups doubled in weight, however neither growth performance, feed efficiency, condition factor nor organ indices were significantly different. Assessment of histopathological changes in the heart, intestine or liver did not reveal any negative effects of the PP diet. Transcriptomic analysis was performed in mid intestine, liver and skeletal muscle, using an Atlantic salmon oligonucleotide microarray (Salar_2, Agilent 4x44K). The dietary comparison revealed large alteration in gene expression in all the tissues studied between fish on the two diets. Gene ontology analysis showed, in the mid intestine of fish fed PP, higher expression of genes involved in enteritis, protein and energy metabolism, mitochondrial activity/kinases and transport, and a lower expression of genes involved in cell proliferation and apoptosis compared to fish fed MP. The liver of fish fed PP showed a lower expression of immune response genes but a higher expression of cell proliferation and apoptosis processes that may lead to cell reorganization in this tissue. The skeletal muscle of fish fed PP vs MP was characterized by a suppression of processes including immune response, energy and protein metabolism, cell proliferation and apoptosis which may reflect a more energy efficient tissue. Conclusions The PP diet resulted in

Transcriptomic and physiological responses to fishmeal substitution with plant proteins in formulated feed in farmed Atlantic salmon (Salmo salar).

PubMed

Tacchi, Luca; Secombes, Christopher J; Bickerdike, Ralph; Adler, Michael A; Venegas, Claudia; Takle, Harald; Martin, Samuel A M

2012-08-01

Aquaculture of piscivorous fish is in continual expansion resulting in a global requirement to reduce the dependence on wild caught fish for generation of fishmeal and fish oil. Plant proteins represent a suitable protein alternative to fish meal and are increasingly being used in fish feed. In this study, we examined the transcriptional response of Atlantic salmon (Salmo salar) to a high marine protein (MP) or low fishmeal, higher plant protein replacement diet (PP), formulated to the same nutritional specification within previously determined acceptable maximum levels of individual plant feed materials. After 77 days of feeding the fish in both groups doubled in weight, however neither growth performance, feed efficiency, condition factor nor organ indices were significantly different. Assessment of histopathological changes in the heart, intestine or liver did not reveal any negative effects of the PP diet. Transcriptomic analysis was performed in mid intestine, liver and skeletal muscle, using an Atlantic salmon oligonucleotide microarray (Salar_2, Agilent 4x44K). The dietary comparison revealed large alteration in gene expression in all the tissues studied between fish on the two diets. Gene ontology analysis showed, in the mid intestine of fish fed PP, higher expression of genes involved in enteritis, protein and energy metabolism, mitochondrial activity/kinases and transport, and a lower expression of genes involved in cell proliferation and apoptosis compared to fish fed MP. The liver of fish fed PP showed a lower expression of immune response genes but a higher expression of cell proliferation and apoptosis processes that may lead to cell reorganization in this tissue. The skeletal muscle of fish fed PP vs MP was characterized by a suppression of processes including immune response, energy and protein metabolism, cell proliferation and apoptosis which may reflect a more energy efficient tissue. The PP diet resulted in significant effects on transcription

Genetic characterization of Streptococcus phocae strains isolated from Atlantic salmon, Salmo salar L., in Chile.

PubMed

Valdés, I; Jaureguiberry, B; Romalde, J L; Toranzo, A E; Magariños, B; Avendaño-Herrera, R

2009-04-01

Streptococcus phocae is a beta-haemolytic bacterium frequently involved in disease outbreaks in seals causing pneumonia or respiratory infection. Since 1999, this pathogen has been isolated from diseased Atlantic salmon, Salmo salar, causing serious economic losses in the salmon industry in Chile. In this study, we used different molecular typing methods, such as pulsed-field gel electrophoresis (PFGE), randomly amplified polymorphic DNA (RAPD), enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR), repetitive extragenic palindromic PCR (REP-PCR) and restriction of 16S-23S rDNA intergenic spacer regions to evaluate the genetic diversity in S. phocae. Thirty-four strains isolated in different years were analysed. The S. phocae type strain ATCC 51973(T) was included for comparative purposes. The results demonstrated genetic homogeneity within the S. phocae strains isolated in Chile over several years, suggesting the existence of clonal relationships among S. phocae isolated from Atlantic salmon. The type strain ATCC 51973(T) presented a different genetic pattern with the PFGE, RAPD, ERIC-PCR and REP-PCR methods. However, the fingerprint patterns of two seal isolates were distinct from those of the type strain.

Validation of miRNA genes suitable as reference genes in qPCR analyses of miRNA gene expression in Atlantic salmon (Salmo salar).

PubMed

Johansen, Ilona; Andreassen, Rune

2014-12-23

MicroRNAs (miRNAs) are an abundant class of endogenous small RNA molecules that downregulate gene expression at the post-transcriptional level. They play important roles by regulating genes that control multiple biological processes, and recent years there has been an increased interest in studying miRNA genes and miRNA gene expression. The most common method applied to study gene expression of single genes is quantitative PCR (qPCR). However, before expression of mature miRNAs can be studied robust qPCR methods (miRNA-qPCR) must be developed. This includes identification and validation of suitable reference genes. We are particularly interested in Atlantic salmon (Salmo salar). This is an economically important aquaculture species, but no reference genes dedicated for use in miRNA-qPCR methods has been validated for this species. Our aim was, therefore, to identify suitable reference genes for miRNA-qPCR methods in Salmo salar. We used a systematic approach where we utilized similar studies in other species, some biological criteria, results from deep sequencing of small RNAs and, finally, experimental validation of candidate reference genes by qPCR to identify the most suitable reference genes. Ssa-miR-25-3p was identified as most suitable single reference gene. The best combinations of two reference genes were ssa-miR-25-3p and ssa-miR-455-5p. These two genes were constitutively and stably expressed across many different tissues. Furthermore, infectious salmon anaemia did not seem to affect their expression levels. These genes were amplified with high specificity, good efficiency and the qPCR assays showed a good linearity when applying a simple cybergreen miRNA-PCR method using miRNA gene specific forward primers. We have identified suitable reference genes for miRNA-qPCR in Atlantic salmon. These results will greatly facilitate further studies on miRNA genes in this species. The reference genes identified are conserved genes that are identical in their mature

Development and Validation of a Learning Progression for Change of Seasons, Solar and Lunar Eclipses, and Moon Phases

ERIC Educational Resources Information Center

Testa, Italo; Galano, Silvia; Leccia, Silvio; Puddu, Emanuella

2015-01-01

In this paper, we report about the development and validation of a learning progression about the Celestial Motion big idea. Existing curricula, research studies on alternative conceptions about these phenomena, and students' answers to an open questionnaire were the starting point to develop initial learning progressions about change of seasons,…

Seasonal development of Leptotrombidium akamushi (Acari: Trombiculidae) under field temperatures.

PubMed

Takahashi, M; Morita, K; Tsuji, O; Misumi, H; Otsuji, J; Hori, E; Kawanura, A; Tanaka, H

1995-11-01

Engorged larvae of Leptotrombidium akamushi (Brumpt), a vector of scrub typhus, were reared in small plastic containers placed on the ground and fed fresh eggs of the collembolan Sinella curviseta Brook. Engorged larvae obtained in October developed into deutonymphs through protonymphs approximately 1 mo before winter and became dormant in the cold winter season (approximately 3 mo). Most deutonymphs developed into tritonymphs in April and adults in May. Females began laying eggs in mid-June and the numbers of unfed larvae showed a peak in August. The mites reared from July rapidly developed into adults by August, and laid eggs in September. Larvae were most abundant in October, and adults became dormant in the winter. The same adults laid eggs from early May to late June and, upon hatching, the larval population peaked in early July of the 2nd summer. Most larvae died before the 2nd winter. Eggs hatched approximately 3 wk after oviposition and longevity of unfed larvae was 2 mo. Because of this very short incubation period, L. akamushi larvae occur in the summer, whereas L. pallidum Nagayo, Miyagawa, Mitamura & Tamiya, and L. scutellare Nagayo, Miyagawa, Mitamura, Tamiya & Tenjin occur in the autumn, although 3 species lay eggs from May to August.

Linkage maps of the Atlantic salmon (Salmo salar) genome derived from RAD sequencing

PubMed Central

2014-01-01

Background Genetic linkage maps are useful tools for mapping quantitative trait loci (QTL) influencing variation in traits of interest in a population. Genotyping-by-sequencing approaches such as Restriction-site Associated DNA sequencing (RAD-Seq) now enable the rapid discovery and genotyping of genome-wide SNP markers suitable for the development of dense SNP linkage maps, including in non-model organisms such as Atlantic salmon (Salmo salar). This paper describes the development and characterisation of a high density SNP linkage map based on SbfI RAD-Seq SNP markers from two Atlantic salmon reference families. Results Approximately 6,000 SNPs were assigned to 29 linkage groups, utilising markers from known genomic locations as anchors. Linkage maps were then constructed for the four mapping parents separately. Overall map lengths were comparable between male and female parents, but the distribution of the SNPs showed sex-specific patterns with a greater degree of clustering of sire-segregating SNPs to single chromosome regions. The maps were integrated with the Atlantic salmon draft reference genome contigs, allowing the unique assignment of ~4,000 contigs to a linkage group. 112 genome contigs mapped to two or more linkage groups, highlighting regions of putative homeology within the salmon genome. A comparative genomics analysis with the stickleback reference genome identified putative genes closely linked to approximately half of the ordered SNPs and demonstrated blocks of orthology between the Atlantic salmon and stickleback genomes. A subset of 47 RAD-Seq SNPs were successfully validated using a high-throughput genotyping assay, with a correspondence of 97% between the two assays. Conclusions This Atlantic salmon RAD-Seq linkage map is a resource for salmonid genomics research as genotyping-by-sequencing becomes increasingly common. This is aided by the integration of the SbfI RAD-Seq SNPs with existing reference maps and the draft reference genome, as well

Differential metabolite levels in response to spawning-induced inappetence in Atlantic salmon Salmo salar.

PubMed

Cipriano, Rocco C; Smith, McKenzie L; Vermeersch, Kathleen A; Dove, Alistair D M; Styczynski, Mark P

2015-03-01

Atlantic salmon Salmo salar undergo months-long inappetence during spawning, but it is not known whether this inappetence is a pathological state or one for which the fish are adapted. Recent work has shown that inappetent whale sharks can exhibit circulating metabolite profiles similar to ketosis known to occur in humans during starvation. In this work, metabolite profiling was used to explore differences in analyte profiles between a cohort of inappetent spawning run Atlantic salmon and captively reared animals that were fed up to and through the time of sampling. The two classes of animals were easily distinguished by their metabolite profiles. The sea-run fish had elevated ɷ-9 fatty acids relative to the domestic feeding animals, while other fatty acid concentrations were reduced. Sugar alcohols were generally elevated in inappetent animals, suggesting potentially novel metabolic responses or pathways in fish that feature these compounds. Compounds expected to indicate a pathological catabolic state were not more abundant in the sea-run fish, suggesting that the animals, while inappetent, were not stressed in an unnatural way. These findings demonstrate the power of discovery-based metabolomics for exploring biochemistry in poorly understood animal models. Copyright © 2015 Elsevier Inc. All rights reserved.

Seasonal Extratropical Storm Activity Potential Predictability and its Origins during the Cold Seasons

NASA Astrophysics Data System (ADS)

Pingree-Shippee, K. A.; Zwiers, F. W.; Atkinson, D. E.

2016-12-01

Extratropical cyclones (ETCs) often produce extreme hazardous weather conditions, such as high winds, blizzard conditions, heavy precipitation, and flooding, all of which can have detrimental socio-economic impacts. The North American east and west coastal regions are both strongly influenced by ETCs and, subsequently, land-based, coastal, and maritime economic sectors in Canada and the USA all experience strong adverse impacts from extratropical storm activity from time to time. Society would benefit if risks associated with ETCs and storm activity variability could be reliably predicted for the upcoming season. Skillful prediction would enable affected sectors to better anticipate, prepare for, manage, and respond to storm activity variability and the associated risks and impacts. In this study, the potential predictability of seasonal variations in extratropical storm activity is investigated using analysis of variance to provide quantitative and geographical observational evidence indicative of whether it may be possible to predict storm activity on the seasonal timescale. This investigation will also identify origins of the potential predictability using composite analysis and large-scale teleconnections (Southern Oscillation, Pacific Decadal Oscillation, and North Atlantic Oscillation), providing the basis upon which seasonal predictions can be developed. Seasonal potential predictability and its origins are investigated for the cold seasons (OND, NDJ, DJF, JFM) during the 1979-2015 time period using daily mean sea level pressure, absolute pressure tendency, and 10-m wind speed from the ECMWF ERA-Interim reanalysis as proxies for extratropical storm activity. Results indicate potential predictability of seasonal variations in storm activity in areas strongly influenced by ETCs and with origins in the investigated teleconnections. For instance, the North Pacific storm track has considerable potential predictability and with notable origins in the SO and PDO.

Effects of temperature and salinity on larval survival and development in the invasive shrimp Palaemon macrodactylus (Caridea: Palaemonidae) along the reproductive season

NASA Astrophysics Data System (ADS)

Guadalupe Vázquez, M.; Bas, Claudia C.; Kittlein, Marcelo; Spivak, Eduardo D.

2015-05-01

The invasive shrimp Palaemon macrodactylus is associated mainly with brackish waters. Previous studies raised the question if tolerance to low salinities differs between larvae and adults. To answer this question, the combined effects of two temperatures (20 and 25 °C) and four salinities (5, 12, 23 and 34 psu) on survival and development of larvae that hatched at the beginning, in the midpoint and near the end of a reproductive season (denoted early, middle season and late larvae respectively) were examined. The three types of larvae were able to survive and reach juvenile phase at salinities between 12 and 34 psu and at both temperatures. At 5 psu all larvae died, but 45% molted at least once. Temperature and salinity to a lesser extent, had effects on the duration of development and on the number of larval stages in all larval types. Development was longer at the lower temperature, especially in middle season and late larvae. Most early larvae reached the juvenile phase through 5 larval stages; the number of larval stages of middle season and late larvae was higher at 20 °C and in late larvae also low salinity produced extra stages. Low salinity (12 psu) and, in early and middle season larvae, low temperature produced lighter and smaller individuals. Response of larvae to environmental factors seems to be related in part to the previous conditions (maternal effects and/or embryo development conditions). The narrower salinity tolerance of larvae compared to adults and the ability of zoea I to survive at least some days at 5 psu may be related with an export larval strategy.

Increased reactivity and monoamine dysregulation following stress in triploid Atlantic salmon (Salmo salar).

PubMed

Fraser, Thomas William Kenneth; Vindas, Marco Antonio; Fjelldal, Per Gunnar; Winberg, Svante; Thörnqvist, Per-Ove; Øverli, Øyvind; Skjæraasen, Jon-Egil; Hansen, Tom Jonny; Mayer, Ian

2015-07-01

Artificial triploid salmonids are sterile and therefore commercially bred to prevent genetic interactions between wild and domestic fish strains. The full biological effects of having an extra chromosome set are largely unknown, but triploids are considered to be more sensitive to sub-optimal environmental conditions and to be stressed by the presence of diploid conspecifics. Brain serotonergic and dopaminergic activity are known to regulate the stress response in vertebrates, but monoamine systems in diploid and triploid fish have yet to be compared. Here we study monoamine neurochemistry in the telencephalon and brain stem of juvenile diploid and triploid Atlantic salmon (Salmo salar) in response to stress (unstressed vs stressed individuals) and holding (separate- vs mixed-ploidy) conditions. Both diploids and triploids showed an increase in serotonergic activity following stress, but the increase was significantly greater in the telencephalon of triploids compared to diploids. Furthermore, while telencephalic dopaminergic activity was significantly increased in diploids following stress, there was no response in triploids. Holding conditions had a significant effect on dopaminergic activity in the brain stem of diploids only, with lower values in mixed- compared to separate-ploidy conditions. These results suggest artificially produced triploids experience increased reactivity and monoaminergic dysregulation following stress that may impede their welfare and performance. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of the Seasonal Beliefs Questionnaire: A Measure of Cognitions Specific to Seasonal Affective Disorder

DTIC Science & Technology

2005-01-01

depressive symptoms (i.e., anergia, hypersomnia, and hyperphagia ), coinciding with fall and/or winter (Kasper et al., 1989a). S-SAD has a higher...food cravings” ( hyperphagia ). There are a few SATS items that represent SAD-specific cognitions consistent with Rohan’s (2001) model (e.g...in seasonal depression (i.e., anergia, hypersomnia, and hyperphagia ). The Hamilton Rating Scale for Depression (HAM-D) has been the gold standard for

Challenging the present definition of "normal" vitamin D levels obtained by a single blood test. Can we develop a formula to predict vitamin D levels in the 4 seasons from a single season's measure?

PubMed

Tandeter, Howard

2014-08-01

Publications on the health effects of vitamin D (25(OH) D) had almost triplicate in the last 10years, not only for its known "calcemic effects" (calcium, phosphor, PTH), but for the more recent findings on its "non-calcemic effects" (all-cause and cardiovascular mortality, and relation with certain types of cancer). Part of these publications deal with the definition of what is a "normal" circulating level of 25(OH) D that may distinguish between health and disease. The literature also deals with seasonal variations of vitamin D, showing levels that rise in summer and fall in winter and with DBP phenotypes and geographical location that affect seasonality of 25(OH) D measurements. Despite the knowledge of the existence of these phenomena many studies on vitamin D fail to acknowledge the time of the year the blood sample was extracted. Thus, when we compare results from different studies without defining the season that the samples were drawn, we compare incomparable figures. Furthermore, it is quite absurd to define "normal levels" as a static measure (over or under a certain value) using a single blood test when the value measured is known to change with seasons. Knowing that people have different vitamin D levels in different seasons of the year, we should ask ourselves which of these measurements should be used to define a "real" or "normal" level? Is it the lower one? Is there a "mean measure" that should be used for this matter? If yes, how do we obtain it? Do we have to make 4 seasonal measurements in each patient? Alternatively, might there be a possibility of developing a formula to help us obtain the mean from a single season's measure or one season's prediction from another season's measurement? And knowing that DBP phenotypes and geographical location affect seasonality of 25(OH) D measurements; shouldn't we include this in the equation? In this article I will discuss the hypothetical existence of an Individual Mean Annual vitamin D level that I will

Considering Seasons.

ERIC Educational Resources Information Center

Gonzalez-Mena, Janet

1994-01-01

Argues that the traditional way that the four seasons are taught is culturally biased and does not reflect the actual seasons in many parts of the United States and other nations. Suggests that early childhood programs should take into account the diversity of seasonal transitions. (MDM)

Comparative responses to endocrine disrupting compounds in early life stages of Atlantic salmon, Salmo salar

USGS Publications Warehouse

Duffy, Tara A.; Iwanowicz, Luke R.; McCormick, Stephen D.

2014-01-01

Atlantic salmon (Salmo salar) are endangered anadromous fish that may be exposed to feminizing endocrine disrupting compounds (EDCs) during early development, potentially altering physiological capacities, survival and fitness. To assess differential life stage sensitivity to common EDCs, we carried out short-term (four day) exposures using three doses each of 17α-ethinylestradiol (EE2), 17β-estradiol (E2), and nonylphenol (NP) on four early life stages; embryos, yolk-sac larvae, feeding fry and one year old smolts. Differential response was compared using vitellogenin (Vtg, a precursor egg protein) gene transcription. Smolts were also examined for impacts on plasma Vtg, cortisol, thyroid hormones (T4/T3) and hepatosomatic index (HSI). Compound-related mortality was not observed in any life stage, but Vtg mRNA was elevated in a dose-dependent manner in yolk-sac larvae, fry and smolts but not in embyos. The estrogens EE2 and E2 were consistently stronger inducers of Vtg than NP. Embryos responded significantly to the highest concentration of EE2 only, while older life stages responded to the highest doses of all three compounds, as well as intermediate doses of EE2 and E2. Maximal transcription was greater for fry among the three earliest life stages, suggesting fry may be the most responsive life stage in early development. Smolt plasma Vtg was also significantly increased, and this response was observed at lower doses of each compound than was detected by gene transcription suggesting this is a more sensitive indicator at this life stage. HSI was increased at the highest doses of EE2 and E2 and plasma T3 decreased at the highest dose of EE2. Our results indicate that all life stages after hatching are potentially sensitive to endocrine disruption by estrogenic compounds and that physiological responses were altered over a short window of exposure, indicating the potential for these compounds to impact fish in the wild.

Comparative responses to endocrine disrupting compounds in early life stages of Atlantic salmon, Salmo salar.

PubMed

Duffy, T A; Iwanowicz, L R; McCormick, S D

2014-07-01

Atlantic salmon (Salmo salar) are endangered anadromous fish that may be exposed to feminizing endocrine disrupting compounds (EDCs) during early development, potentially altering physiological capacities, survival and fitness. To assess differential life stage sensitivity to common EDCs, we carried out short-term (4 day) exposures using three doses each of 17 α-ethinylestradiol (EE2), 17 β-estradiol (E2), and nonylphenol (NP) on four early life stages; embryos, yolk-sac larvae, feeding fry and 1 year old smolts. Differential response was compared using vitellogenin (Vtg, a precursor egg protein) gene transcription. Smolts were also examined for impacts on plasma Vtg, cortisol, thyroid hormones (T4/T3) and hepatosomatic index (HSI). Compound-related mortality was not observed in any life stage, but Vtg mRNA was elevated in a dose-dependent manner in yolk-sac larvae, fry and smolts but not in embryos. The estrogens EE2 and E2 were consistently stronger inducers of Vtg than NP. Embryos responded significantly to the highest concentration of EE2 only, while older life stages responded to the highest doses of all three compounds, as well as intermediate doses of EE2 and E2. Maximal transcription was greater for fry among the three earliest life stages, suggesting fry may be the most responsive life stage in early development. Smolt plasma Vtg was also significantly increased, and this response was observed at lower doses of each compound than was detected by gene transcription suggesting plasma Vtg is a more sensitive indicator at this life stage. HSI was increased at the highest doses of EE2 and E2, and plasma T3 was decreased at the highest dose of EE2. Our results indicate that all life stages are potentially sensitive to endocrine disruption by estrogenic compounds and that physiological responses were altered over a short window of exposure, indicating the potential for these compounds to impact fish in the wild. Copyright © 2014 Elsevier B.V. All rights

Seasonal ozone levels and control by seasonal meteorology

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

Pagnotti, V.

1990-02-01

Meteorological data, particularly 850-MB level temperatures, for Fort Totten, New York (1980) and Atlantic City, New Jersey (1981-1988) were examined for any relationship to seasonal ozone levels. Other radiosonde stations in the Northeast were utilized for 1983 and 1986, years of widely differing ozone levels. Statistics for selected parameters and years are presented. Emphasis is placed on recurring warm temperature regimes in high ozone years. Successive occurrences or episodes of high temperatures characterize seasonally high ozone years. Seasonally persistent high temperatures are related to seasonally chronic high ozone. An example is presented relating the broad-scale climatologically anomalous pattern of highmore » temperatures to anomalous circulation patterns at the 700-MB level.« less

Continuous light affects mineralization and delays osteoid incorporation in vertebral bone of Atlantic salmon (Salmo salar L.).

PubMed

Wargelius, Anna; Fjelldal, Per Gunnar; Nordgarden, Ulla; Hansen, Tom

2009-03-01

In order to study the effects of photoperiod on fish bone, Atlantic salmon (Salmo salar L.) were exposed to two light regimes (natural and continuous light) from January until June. During the experimental period, several parameters related to the inorganic (minerals) and organic (osteoid) phases were measured. Changes in the organic phase were related to mechanical strength (yield-load) and the expression of the genes sonic hedgehog (shh) and collagen type I alpha 2 (col I). Co-variation between yield-load and the expression of both shh and col I were detected in both groups. It was also shown that fish on the continuous light regime had delayed activation of osteoid incorporation. Mineralization properties were measured with stiffness, mineral incorporation per day and expression of alkaline phosphatase (alp) and matrix Gla protein (mgp). Stiffness, mineral incorporation and gene expression followed the same trend in both light groups in late spring, whereas an increase in the expression of mgp and alp was detected in April, followed by significantly higher stiffness at last sampling in both light groups. These results indicate that constant light affects mineralization and delays osteoid incorporation in Atlantic salmon during the spring. However, in this experiment light treatment did not promote the development of vertebral deformities. Our results also suggest that shh can be used as a marker of osteoblast proliferation and col I a marker of osteoid incorporation, and that both alp and mgp expression could be associated with a rapid increase in mineralization in Atlantic salmon vertebrae.

Survival of Atlantic salmon Salmo salar smolts through a hydropower complex

USGS Publications Warehouse

Stich, D.S.; Bailey, M.M.; Zydlewski, Joseph D.

2014-01-01

This study evaluated Atlantic salmon Salmo salar smolt survival through the lower Penobscot River, Maine, U.S.A., and characterized relative differences in proportional use and survival through the main-stem of the river and an alternative migration route, the Stillwater Branch. The work was conducted prior to removal of two main-stem dams and operational changes in hydropower facilities in the Stillwater Branch. Survival and proportional use of migration routes in the lower Penobscot were estimated from multistate (MS) models based on 6 years of acoustic telemetry data from 1669 smolts and 2 years of radio-telemetry data from 190 fish. A small proportion (0·12, 95% c.i. = 0·06–0·25) of smolts used the Stillwater Branch, and mean survival through the two operational dams in this part of the river was relatively high (1·00 and 0·97). Survival at Milford Dam, the dam that will remain in the main-stem of the Penobscot River, was relatively low (0·91), whereas survival through two dams that were removed was relatively high (0·99 and 0·98). Smolt survival could decrease in the Stillwater Branch with the addition of two new powerhouses while continuing to meet fish passage standards. The effects of removing two dams in the main-stem are expected to be negligible for smolt survival based on high survival observed from 2005 to 2012 at those locations. Survival through Milford Dam was been well below current regulatory standards, and thus improvement of passage at this location offers the best opportunity for improving overall smolt survival in the lower river.

Food price seasonality in Africa: Measurement and extent.

PubMed

Gilbert, Christopher L; Christiaensen, Luc; Kaminski, Jonathan

2017-02-01

Everyone knows about seasonality. But what exactly do we know? This study systematically measures seasonal price gaps at 193 markets for 13 food commodities in seven African countries. It shows that the commonly used dummy variable or moving average deviation methods to estimate the seasonal gap can yield substantial upward bias. This can be partially circumvented using trigonometric and sawtooth models, which are more parsimonious. Among staple crops, seasonality is highest for maize (33 percent on average) and lowest for rice (16½ percent). This is two and a half to three times larger than in the international reference markets. Seasonality varies substantially across market places but maize is the only crop in which there are important systematic country effects. Malawi, where maize is the main staple, emerges as exhibiting the most acute seasonal differences. Reaching the Sustainable Development Goal of Zero Hunger requires renewed policy attention to seasonality in food prices and consumption.

Seasonality and autoimmune diseases: The contribution of the four seasons to the mosaic of autoimmunity.

PubMed

Watad, Abdulla; Azrielant, Shir; Bragazzi, Nicola Luigi; Sharif, Kassem; David, Paula; Katz, Itay; Aljadeff, Gali; Quaresma, Mariana; Tanay, Galya; Adawi, Mohammad; Amital, Howard; Shoenfeld, Yehuda

2017-08-01

Autoimmune diseases (ADs) are a heterogeneous groups of diseases that occur as a results of loss of tolerance to self antigens. While the etiopathogeneis remain obscure, different environmental factors were suggested to have a role in the development of autoimmunity, including infections, low vitamin D levels, UV radiation, and melatonin. Interestingly, such factors possess seasonal variation patterns that could influence disease development, severity and progression. Vitamin D levels which reach a nadir during late winter and early spring is correlated with increased disease activity, clinical severity as well as relapse rates in several disease entities including multiple sclerosis (MS), non-cutaneous flares of systemic lupus erythematosus (SLE), psoriasis, and rheumatoid arthritis (RA). Additionally, immunomodulatory actions of melatonin secretion ameliorate the severity of several ADs including MS and SLE. Melatonin levels are lowest during spring, a finding that correlates with the highest exacerbation rates of MS. Further, melatonin is postulated to be involved in the etiopathogenesis of inflammatory bowel diseases (IBD) through it influence on adhesion molecule and therefore transcription factor expression. Moreover, infections can mount to ADs through pro-inflammatory cytokine release and human antigen mimicry. Seasonal patterns of infectious diseases are correlated with the onset and exacerbation of ADs. During the winter, increased incidence of Epstein-Barr virus (EBV) infectious are associated with MS and SLE flares/onset respectively. In addition, higher Rotavirus infections during the winter precedes type 1 diabetes mellitus onset (T1DM). Moreover, Escherichia coli (E. coli) infection prior to primary biliary cirrhosis (PBC) and T1DM disease onset subsequent to Coxachievirus infections are seen to occur during late summer, a finding that correlate with infectious agents' pattern of seasonality. In this review, the effects of seasonality on the onset

Intestinal microbiota of healthy and unhealthy Atlantic salmon Salmo salar L. in a recirculating aquaculture system

NASA Astrophysics Data System (ADS)

Wang, Chun; Sun, Guoxiang; Li, Shuangshuang; Li, Xian; Liu, Ying

2017-04-01

The present study sampled the intestinal content of healthy and unhealthy Atlantic salmon (Salmo salar L.), the ambient water of unhealthy fish, and the biofilter material in the recirculating aquaculture system (RAS) to understand differences in the intestinal microbiota. The V4-V5 regions of the prokaryotic 16S rRNA genes in the samples were analyzed by MiSeq high-throughput sequencing. The fish were adults with no differences in body length or weight. Representative members of the intestinal microbiota were identified. The intestinal microbiota of the healthy fish included Proteobacteria (44.33%), Actinobacteria (17.89%), Bacteroidetes (15.25%), and Firmicutes (9.11%), among which the families Micrococcaceae and Oxalobacteraceae and genera Sphingomonas, Streptomyces, Pedobacter, Janthinobacterium, Burkholderia, and Balneimonas were most abundant. Proteobacteria (70.46%), Bacteroidetes (7.59%), and Firmicutes (7.55%) dominated the microbiota of unhealthy fish, and Chloroflexi (2.71%), and Aliivibrio and Vibrio as well as genera in the family Aeromonadaceae were most strongly represented. Overall, the intestinal hindgut microbiota differed between healthy and unhealthy fish. This study offers a useful tool for monitoring the health status of fish and for screening the utility of probiotics by studying the intestinal microbiota.

Intestinal microbiota of healthy and unhealthy Atlantic salmon Salmo salar L. in a recirculating aquaculture system

NASA Astrophysics Data System (ADS)

Wang, Chun; Sun, Guoxiang; Li, Shuangshuang; Li, Xian; Liu, Ying

2018-03-01

The present study sampled the intestinal content of healthy and unhealthy Atlantic salmon ( Salmo salar L.), the ambient water of unhealthy fish, and the biofilter material in the recirculating aquaculture system (RAS) to understand differences in the intestinal microbiota. The V4-V5 regions of the prokaryotic 16S rRNA genes in the samples were analyzed by MiSeq high-throughput sequencing. The fish were adults with no differences in body length or weight. Representative members of the intestinal microbiota were identified. The intestinal microbiota of the healthy fish included Proteobacteria (44.33%), Actinobacteria (17.89%), Bacteroidetes (15.25%), and Firmicutes (9.11%), among which the families Micrococcaceae and Oxalobacteraceae and genera Sphingomonas, Streptomyces, Pedobacter, Janthinobacterium, Burkholderia, and Balneimonas were most abundant. Proteobacteria (70.46%), Bacteroidetes (7.59%), and Firmicutes (7.55%) dominated the microbiota of unhealthy fish, and Chloroflexi (2.71%), and Aliivibrio and Vibrio as well as genera in the family Aeromonadaceae were most strongly represented. Overall, the intestinal hindgut microbiota differed between healthy and unhealthy fish. This study offers a useful tool for monitoring the health status of fish and for screening the utility of probiotics by studying the intestinal microbiota.

Labeling research in support of through-the-season area estimation

NASA Technical Reports Server (NTRS)

Colwell, R. N. (Principal Investigator); Hay, C. M.; Sheffner, E. J.

1982-01-01

The development of LANDSAT-based through-the-season labeling procedures for corn and soybeans is discussed. A model for predicting labeling accuracy within key time periods throughout the growing season is outlined. Two methods for establishing the starting point of one key time period, viz., early season, are described. In addition, spectral-temporal characteristics for separating crops in the early season time period are discussed.

The effect of triploidy and vaccination on neutrophils and B-cells in the peripheral blood and head kidney of 0+ and 1+ Atlantic salmon (Salmo salar L.) post-smolts.

PubMed

Fraser, Thomas W K; Rønneseth, Anita; Haugland, Gyri T; Fjelldal, Per Gunnar; Mayer, Ian; Wergeland, Heidrun I

2012-07-01

Sterile triploid fish are being used in aquaculture to prevent early unwanted sexual maturation and the genetic interaction between wild and cultured fish; however, triploid fish are typically considered to be more susceptible to disease than diploid counterparts. Proportions of leucocytes from the head kidney and peripheral blood were identified using monoclonal antibodies and flow cytometry in triploid and diploid, vaccinated and unvaccinated, out-of-season (0+) and 1+ Atlantic salmon (Salmo salar L.) three weeks post seawater transfer. Triploid 1+ fish were significantly (P<0.05) heavier than diploid fish at the time of sampling, whereas triploid 0+ had a significantly lower condition factor than diploids. Ploidy had a significant effect on the proportion of B-cells in the blood of both 0+ and 1+ fish, and the head kidney of 1+ fish, with triploids having lower proportions of B-cells to diploids in both smolt groups. In addition, a significant ploidy×vaccination interaction effect was observed in the response of neutrophils in the blood (vaccinated diploids had a higher mean proportion than diploid unvaccinated) and B-cells in the head kidney (in vaccinated fish, triploids had a lower mean proportion than diploids) in 0+ smolts. Vaccination was found to significantly increase the proportion of B-cells in the head kidney of 1+ smolts in both ploidy. Size (fish weight) was positively correlated with neutrophil proportions in 1+ fish. Our findings are discussed in relation to the physiological differences related to ploidy. The results suggest that ploidy as well as smelting regime influences the immune system of Atlantic salmon post-smolts. Copyright © 2012 Elsevier Ltd. All rights reserved.

Barriers to pandemic influenza vaccination and uptake of seasonal influenza vaccine in the post-pandemic season in Germany.

PubMed

Böhmer, Merle M; Walter, Dietmar; Falkenhorst, Gerhard; Müters, Stephan; Krause, Gérard; Wichmann, Ole

2012-10-31

vaccination may have contributed to both a very low uptake of pandemic vaccines and a decreased uptake of seasonal influenza vaccines in the first post-pandemic season. In the upcoming years, the uptake of seasonal influenza vaccines should be carefully monitored in all target groups to identify if this trend continues and to guide public health authorities in developing more effective vaccination and communication strategies for seasonal influenza vaccination.

Spatiotemporal dynamics of the Atlantic salmon (Salmo salar) Greenland fishery inferred from mixed-stock analysis

USGS Publications Warehouse

Gauthier-Ouellet, M.; Dionne, M.; Caron, F.; King, T.L.; Bernatchez, L.

2009-01-01

Mixed-stock fisheries refer to the exploitation of admixed fish stocks coming from different origins. We identified the North American origin of 2835 Atlantic salmon (Salmo salar) in the Greenland mixed-stock fishery during 11 years (1995-2006) at three localities using 13 microsatellites. The study included 52 baseline populations representing nine genetically distinct regional groups. The contribution of each group ranged from <1% (Maine) to 40% (Southern Qu??bec). Decreasing temporal contributions were observed for Southern Qu??bec (-22.0%) and New Brunswick (-17.4%), whereas an increasing contribution for Labrador (+14.9%) was observed during the time course of the study. The estimated regional contribution to the Greenland fishery was significantly correlated to the number of multi-sea-winter salmon regionally produced in 2002 (r = 0.79) and 2004 (r = 0.92). No difference in contribution was found between the three Greenland sampling localities. Ungava and Southern Qu??bec regions showed the highest mortality estimates caused by the fishery, ranging from 12.10% to 18.08%, for both years tested. No regional group was overrepresented in landings compared with their respective productivity. Yet, management precautions should still be taken as the fishery strongly selects large females, which could have evolutionary impacts on populations over the long term.

Testing mate choice and overdominance at MH in natural families of Atlantic salmon Salmo salar.

PubMed

Tentelier, C; Barroso-Gomila, O; Lepais, O; Manicki, A; Romero-Garmendia, I; Jugo, B M

2017-04-01

This study aimed to test mate choice and selection during early life stages on major histocompatibility (MH) genotype in natural families of Atlantic salmon Salmo salar spawners and juveniles, using nine microsatellites to reconstruct families, one microsatellite linked to an MH class I gene and one minisatellite linked to an MH class II gene. MH-based mate choice was only detected for the class I locus on the first year, with lower expected heterozygosity in the offspring of actually mated pairs than predicted under random mating. The genotype frequencies of MH-linked loci observed in the juveniles were compared with frequencies expected from Mendelian inheritance of parental alleles to detect selection during early life stages. No selection was detected on the locus linked to class I gene. For the locus linked to class II gene, observed heterozygosity was higher than expected in the first year and lower in the second year, suggesting overdominance and underdominance, respectively. Within family, juveniles' body size was linked to heterozygosity at the same locus, with longer heterozygotes in the first year and longer homozygotes in the second year. Selection therefore seems to differ from one locus to the other and from year to year. © 2017 The Fisheries Society of the British Isles.

Patterns of Piscirickettsia salmonis load in susceptible and resistant families of Salmo salar.

PubMed

Dettleff, Phillip; Bravo, Cristian; Patel, Alok; Martinez, Victor

2015-07-01

The pathogen Piscirickettsia salmonis produces a systemic aggressive infection that involves several organs and tissues in salmonids. In spite of the great economic losses caused by this pathogen in the Atlantic salmon (Salmo salar) industry, very little is known about the resistance mechanisms of the host to this pathogen. In this paper, for the first time, we aimed to identify the bacterial load in head kidney and muscle of Atlantic salmon exhibiting differential familiar mortality. Furthermore, in order to assess the patterns of gene expression of immune related genes in susceptible and resistant families, a set of candidate genes was evaluated using deep sequencing of the transcriptome. The results showed that the bacterial load was significantly lower in resistant fish, when compared with the susceptible individuals. Based on the candidate genes analysis, we infer that the resistant hosts triggered up-regulation of specific genes (such as for example the LysC), which may explain a decrease in the bacterial load in head kidney, while the susceptible fish presented an exacerbated innate response, which is unable to exert an effective response against the bacteria. Interestingly, we found a higher bacterial load in muscle when compared with head kidney. We argue that this is possible due to the availability of an additional source of iron in muscle. Besides, the results show that the resistant fish could not be a likely reservoir of the bacteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of shifting seasonal rainfall patterns on net primary productivity and carbon storage in tropical seasonally dry ecosystems

NASA Astrophysics Data System (ADS)

Rohr, T.; Manzoni, S.; Feng, X.; Menezes, R.; Porporato, A. M.

2013-12-01

Although seasonally dry ecosystems (SDEs), identified by prolonged drought followed by a short, but intense, rainy season, cover large regions of the tropics, their biogeochemical response to seasonal rainfall and soil carbon (C) sequestration potential are not well characterized. Both productivity and soil respiration are positively affected by seasonal soil moisture availability, creating a delicate balance between C deposition through litterfall and C losses through heterotrophic respiration. As climate change projections for the tropics predict decreased annual rainfall and increased dry season length, it is critical to understand how variations in seasonal rainfall distributions control this balance. To address this question, we develop a minimal model linking the seasonal behavior of the ensemble soil moisture, plant productivity, the related soil C inputs through litterfall, and soil C dynamics. The model is parameterized for a case study from a drought-deciduous caatinga ecosystem in northeastern Brazil. Results indicate that when altering the seasonal rainfall patterns for a fixed annual rainfall, both plant productivity and soil C sequestration potential are largely, and nonlinearly, dependent on wet season duration. Moreover, total annual rainfall plays a dominant role in describing this relationship, leading at times to the emergence of distinct optima in both primary production and C sequestration. Examining these results in the context of climate-driven changes to wet season duration and mean annual precipitation indicate that the initial hydroclimatic regime of a particular ecosystem is an important factor to predict both the magnitude and direction of the effects of shifting seasonal distributions on productivity and C storage. Although highly productive ecosystems will likely experience declining C storage with predicted climate shifts, those currently operating well below peak production can potentially see improved C stocks with the onset of

Silver spoons in the rough: can environmental enrichment improve survival of hatchery Atlantic salmon Salmo salar in the wild?

PubMed

Roberts, L J; Taylor, J; Gough, P J; Forman, D W; Garcia de Leaniz, C

2014-12-01

This study tested the 'silver spoon' hypothesis which posits that individuals that develop under favourable conditions should enjoy a fitness advantage later in life because they are more likely to recognize and settle in high-quality habitats. Atlantic salmon Salmo salar of two age classes (0+ and 1+ years) were reared in environmentally enriched or standard hatchery tanks for a short period (c. 10 weeks), were then released into a natural river and sampled on repeated occasions to test for silver-spoon effects. Compared with controls, enriched fish had a 6.4% higher recapture rate and settled in higher velocity habitats when they were stocked as 0+ year fry, but not when they were stocked as 1+ year parr. The opportunity for selection was generally higher for environmentally enriched fish than for controls, and also higher for 0+ than for 1+ year fish. Selection favoured individuals with high condition factor, extensive fat reserves and longer than average pectoral fins in both age classes but favoured a small body size in 1+ year and a large body size in 0+ year releases. Stomach analysis showed that enriched fish ate more, and adapted quicker to natural prey than controls. These results provide support for silver-spoon effects in fish and indicate that enrichment can improve post-release performance in conservation programmes, but seemingly only if fish are not kept in captivity for too long. © 2014 The Fisheries Society of the British Isles.

Seasonal Prediction of Taiwan's Streamflow Using Teleconnection Patterns

NASA Astrophysics Data System (ADS)

Chen, Chia-Jeng; Lee, Tsung-Yu

2017-04-01

Seasonal streamflow as an integrated response to complex hydro-climatic processes can be subject to activity of prevailing weather systems potentially modulated by large-scale climate oscillations (e.g., El Niño-Southern Oscillation, ENSO). To develop a seamless seasonal forecasting system in Taiwan, this study assesses how significant Taiwan's precipitation and streamflow in different seasons correlate with selected teleconnection patterns. Long-term precipitation and streamflow data in three major precipitation seasons, namely the spring rains (February to April), Mei-Yu (May and June), and typhoon (July to September) seasons, are derived at 28 upstream and 13 downstream catchments in Taiwan. The three seasons depict a complete wet period of Taiwan as well as many regions bearing similar climatic conditions in East Asia. Lagged correlation analysis is then performed to investigate how the precipitation and streamflow data correlate with predominant teleconnection indices at varied lead times. Teleconnection indices are selected only if they show certain linkage with weather systems and activity in the three seasons based on previous literature. For instance, the ENSO and Quasi-Biennial Oscillation, proven to influence East Asian climate across seasons and summer typhoon activity, respectively, are included in the list of climate indices for correlation analysis. Significant correlations found between Taiwan's precipitation and streamflow and teleconnection indices are further examined by a climate regime shift (CRS) test to identify any abrupt changes in the correlations. The understanding of existing CRS is useful for informing the forecasting system of the changes in the predictor-predictand relationship. To evaluate prediction skill in the three seasons and skill differences between precipitation and streamflow, hindcasting experiments of precipitation and streamflow are conducted using stepwise linear regression models. Discussion and suggestions for coping

Interannual and seasonal changes in the south seasonal polar cap of Mars: Observations from MY 28-31 using MARCI

NASA Astrophysics Data System (ADS)

Calvin, W. M.; Cantor, B. A.; James, P. B.

2017-08-01

The Mars Color Imager (MARCI) camera on the Mars Reconnaissance Orbiter provides daily synoptic coverage that allows monitoring of seasonal cap retreat and interannual changes that occur between Mars Years (MY) and over the southern summer. We present the first analysis of this data for the southern seasonal cap evolution observed in MY 28, 29, 30 and 31 (2/2007 to 07/2013). Observation over multiple Mars years allows us to compare changes between years as well as longer-term evolution of the high albedo deposits at the poles. Seasonal cap retreat is similar in all years and to retreats observed in other years by both optical and thermal instruments. The cryptic terrain has a fairly consistent boundary in each year, but numerous small-scale variations occur in each MY observed. Additionally, numerous small dark deposits are identified outside the classically identified cyptic region, including Inca City and other locations not previously noted. The large water ice outlier is observed to retain seasonal frost the longest (outside the polar dome) and is also highly variable in each MY. The development of the cryptic/anti-cryptic hemispheres is inferred to occur due to albedo variations that develop after dust venting starts and may be caused by recondensation of CO2 ice on the brightest and coldest regions controlled by topographic winds. Ground ice may play a role in which regions develop cryptic terrain, as there is no elevation control on either cryptic terrain or the late season brightest deposits.

Seasonality of childhood infectious diseases in Niono, Mali.

PubMed

Findley, S E; Medina, D C; Sogoba, N; Guindo, B; Doumbia, S

2010-01-01

Common childhood diseases vary seasonally in Mali, much of the Sahel, and other parts of the world, yet patterns for multiple diseases have rarely been simultaneously described for extended periods at single locations. In this retrospective longitudinal (1996-2004) investigation, we studied the seasonality of malaria, acute respiratory infection and diarrhoea time-series in the district of Niono, Sahelian Mali. We extracted and analysed seasonal patterns from each time-series with the Multiplicative Holt-Winters and Wavelet Transform methods. Subsequently, we considered hypothetical scenarios where successful prevention and intervention measures reduced disease seasonality by 25 or 50% to assess the impact of health programmes on annual childhood morbidity. The results showed that all three disease time-series displayed remarkable seasonal stability. Malaria, acute respiratory infection and diarrhoea peaked in December, March (and September) and August, respectively. Finally, the annual childhood morbidity stemming from each disease diminished 7-26% in the considered hypothetical scenarios. We concluded that seasonality may assist with guiding the development of integrated seasonal disease calendars for programmatic child health promotion activities.

Ecohydrology and biogeochemistry of seasonally-dry ecosystems

NASA Astrophysics Data System (ADS)

Feng, X.; Porporato, A. M.

2010-12-01

The composition and the dynamic in various types of seasonally dry ecosystems are largely determined by rainfall seasonality and distribution. The intermittency of rainfall in these ecosystems has played a dominant role in the life cycle of native plants such that phenological events such as growth or reproduction have oftentimes become synchronized with the onset of the dry or the wet season. Characteristic amongst such types of ecosystems are the tropical dry and Mediterranean ecosystems, both of which receive similar amount of precipitation yet are markedly distinct in their synchronization of rainfall fluctuations and temperature. Seasonally dry ecosystems cover more than 16 million square kilometers in the tropics, with short but intense wet seasons followed by long dry seasons and elevated temperature throughout the year. Native vegetation grows during the wet season and adopts dormancy or seasonal deciduousness to cope with the dry season. In the Mediterranean climates, precipitations and temperature are out of phase, with wet temperate winters and hot dry summers. Dimorphic root systems are prevalent, where deep rooted plants exploit the winter recharge while the shallow rooted species take advantage of the infrequent summer rains. Using a stochastic soil moisture model we analyze how temporal shifts, or the lack thereof, in temperature and precipitation patterns affect the development of water stress during the dry season and its feedbacks on soil-plant biogeochemistry. We especially focus on the role of differences in temperature and seasonal potential evapotranspiration between tropical dry and Mediterranean climates. We also compare irrigation needs and the effects of projected climatic conditions in those regions. Understanding how plants adopt different water use strategies in the context of shifted climatic patterns will shed light on how these regions of high biodiversity may cope with rapidly-changing climatic conditions.

Present status and approaches for the sustainable development of community based fish culture in seasonal floodplains of Bangladesh.

PubMed

Rahman, M F; Jalal, K C A; Jahan, Nasrin; Kamaruzzaman, B Y; Ara, R; Arshad, A

2012-06-15

Coordination among the different stakeholders at policy planning, implementation and target beneficiary level, particularly among the agencies responsible for development and management of water resources, agriculture and fisheries, is essential for overall sustainable development. Stocking of larger fingerlings at suitable stocking densities of endemic (rohu, catla, mrigal) and exotic (silver carp, bighead carp, common carp/mirror carp) species should be stocked at varying proportion. Floodplain fish production depends only on the natural fertility of the water bodies. Technological interventions should include the installation of low cost bamboo fencing at water inlet and outlet points and setting of ring culverts for maintaining suitable levels of water for fish culture without hampering the production of rice and other crops in the intervention areas, selective stocking with native and exotic carps, restricted fishing for certain period of time and guarding. It is expected to exert positive influences in enhancing the standing crop and biodiversity of non-stocked species of fishes in the intervention seasonal floodplain. Entry of fish larvae, hatchlings and young fry of wild non-stocked fishes into the seasonal floodplains because of large fence spacing (approximately 1.0 cm), could restrict fishing for certain period, undisturbed habitat and guarding could contribute to higher productivity and enhancement of fish biodiversity in the seasonal floodplains. Proper motivation and effective cooperation of the beneficiaries are extremely important to culture fish in the seasonal floodplains under community based management system. Institutional support and constant vigilance from the Department of Fisheries (DoF) and local administrations are indispensable to ensure the sustainability of fish culture initiatives in the seasonal floodplains. Active participation and involvement of the local community people in all stages of fish culture operation beginning from

Extraction of gelatin from salmon (Salmo salar) fish skin using trypsin-aided process: optimization by Plackett-Burman and response surface methodological approaches.

PubMed

Fan, HuiYin; Dumont, Marie-Josée; Simpson, Benjamin K

2017-11-01

Gelatin from salmon ( Salmo salar ) skin with high molecular weight protein chains ( α -chains) was extracted using trypsin-aided process. Response surface methodology was used to optimise the extraction parameters. Yield, hydroxyproline content and protein electrophoretic profile via sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of gelatin were used as responses in the optimization study. The optimum conditions were determined as: trypsin concentration at 1.49 U/g; extraction temperature at 45 °C; and extraction time at 6 h 16 min. This response surface optimized model was significant and produced an experimental value (202.04 ± 8.64%) in good agreement with the predicted value (204.19%). Twofold higher yields of gelatin with high molecular weight protein chains were achieved in the optimized process with trypsin treatment when compared to the process without trypsin.

Aspects of seasonality.

PubMed

Battey, N H

2000-11-01

The seasons are astronomical, astrological, meteorological, biological, and agricultural. From a perspective outside the biological sciences, the questions of interest about plant seasonality are linked to this wider context. In this review I try to see flowering time, as one important aspect of seasonality, from an outsider's point of view, and describe what is known about it in different types of plants. What is known about it is conditioned by what particular scientists have asked about it, so the variety of approaches to seasonality is another point of emphasis. Detailed consideration is given to flowering seasonality in perennials compared with annuals, and both molecular and whole plant perspectives are presented.

Distinct patterns of seasonal Greenland glacier velocity

PubMed Central

Moon, Twila; Joughin, Ian; Smith, Ben; van den Broeke, Michiel R; van de Berg, Willem Jan; Noël, Brice; Usher, Mika

2014-01-01

Predicting Greenland Ice Sheet mass loss due to ice dynamics requires a complete understanding of spatiotemporal velocity fluctuations and related control mechanisms. We present a 5 year record of seasonal velocity measurements for 55 marine-terminating glaciers distributed around the ice sheet margin, along with ice-front position and runoff data sets for each glacier. Among glaciers with substantial speed variations, we find three distinct seasonal velocity patterns. One pattern indicates relatively high glacier sensitivity to ice-front position. The other two patterns are more prevalent and appear to be meltwater controlled. These patterns reveal differences in which some subglacial systems likely transition seasonally from inefficient, distributed hydrologic networks to efficient, channelized drainage, while others do not. The difference may be determined by meltwater availability, which in some regions may be influenced by perennial firn aquifers. Our results highlight the need to understand subglacial meltwater availability on an ice sheet-wide scale to predict future dynamic changes. Key Points First multi-region seasonal velocity measurements show regional differences Seasonal velocity fluctuations on most glaciers appear meltwater controlled Seasonal development of efficient subglacial drainage geographically divided PMID:25821275

Impact of Watershed Development on Sediment Transport and Seasonal Flooding in the Main Stream of the Mekong River

NASA Astrophysics Data System (ADS)

Kameyama, S.; Nohara, S.; Sato, T.; Fujii, Y.; Kudo, K.

2009-12-01

The Mekong River watershed is undergoing rapid economic progress and population growth, raising conflicts between watershed development and environmental conservation. A typical conflict is between the benefits of dam construction versus the benefits of watershed ecological services. In developed countries, this conflict is changing to a coordinated search for outcomes that are mutually acceptable to all stakeholders. In the Mekong River, however, government policy gives priority to watershed development for ensuring steady energy supplies. Since the 1990s, a series of dams called “the Mekong Cascade” have been under construction. Dam construction has multiple economic values as electric power supply, irrigation water, flood control, etc. On the other hand, the artificial flow discharge controls of dam moderate seasonal hydrologic patterns of the Asian monsoon region. Dam operations can change the sediment transport regime and river structure. Furthermore, their impacts on watershed ecosystems and traditional economic activities of fisheries and agriculture in downstream areas may be severe. We focus on dam impacts on spatio-temporal patterns of sediment transport and seasonal flood in riparian areas downstream from Mekong River dams. Our study river section is located on 100 km down stream from the Golden Triangle region of Myanmar, Laos, and Thailand. We selected a 10-km section in this main channel to simulate seasonal flooding. We modeled the river hydrology in the years 1991 and 2002, before and after the Manwan dam construction (1986-1993). For this simulation, we adapted three models (distributed runoff model, 1-D hydrological model, and 2-D flood simulation with sediment movement algorithm.) Input data on river structure, water velocity, and flow volume were acquired from field survey data in November 2007 and 2008. In the step of parameter decision, we adopted the shuffled complex evolution method. To validate hydrologic parameters, we used annual

Dry-season ultraviolet radiation primes litter for wet season decomposition in a Mediterranean grassland

NASA Astrophysics Data System (ADS)

Baker, N. R.; Allison, S. D.

2013-12-01

Traditional decomposition models developed in mesic ecosystems often consistently underestimate rates of decomposition in more arid ecosystems such as deserts and Mediterranean grasslands. Photodegradation of plant litter by ultraviolet radiation (UV) is hypothesized to be one of the mechanisms accounting for the greater-than-expected rates of decomposition observed in these ecosystems. Putatively, photodegradation preferentially degrades complex aromatic compounds in litter such as lignin, whose decomposition is considered a rate-limiting step in the microbial decomposition of plant litter. This study tested the effects of attenuated ultraviolet radiation on the decomposition of two litter types over the course of a year in a Southern California Mediterranean grassland. The two types of litter differed primarily in lignin content to test for a differential effect of UV on high-lignin versus low-lignin litter. Rates of litter mass loss, changes in litter chemistry, and changes in microbial activity and microbial biomass were observed, and assays of extracellular enzymes were conducted at 5 points through the year, beginning during the dry season and continuing until the end of the following dry season. Litter exposed to attenuated ultraviolet radiation during the dry season had lower rates of mass loss than litter exposed to ambient radiation (6.1% vs. 8.6%, respectively, p < 0.04). Extracellular enzyme activities were significantly affected by UV attenuation, as low lignin samples exposed to attenuated UV displayed elevated cellulase enzyme activity potential during the wet season, while high lignin samples displayed decreased oxidative enzyme activity potential during the wet season. For example, potential activity of the cellulase cellobiohydrolase in low-lignin, ambient UV samples was 5286 μmol/hr*g during the wet season, compared to 7969 μmol/hr*g in attenuated UV samples (p < 0.003). Conversely, potential activity of the oxidative enzyme peroxidase in high

Survival of Atlantic salmon Salmo salar smolts through a hydropower complex.

PubMed

Stich, D S; Bailey, M M; Zydlewski, J D

2014-10-01

This study evaluated Atlantic salmon Salmo salar smolt survival through the lower Penobscot River, Maine, U.S.A., and characterized relative differences in proportional use and survival through the main-stem of the river and an alternative migration route, the Stillwater Branch. The work was conducted prior to removal of two main-stem dams and operational changes in hydropower facilities in the Stillwater Branch. Survival and proportional use of migration routes in the lower Penobscot were estimated from multistate (MS) models based on 6 years of acoustic telemetry data from 1669 smolts and 2 years of radio-telemetry data from 190 fish. A small proportion (0·12, 95% c.i. = 0·06-0·25) of smolts used the Stillwater Branch, and mean survival through the two operational dams in this part of the river was relatively high (1·00 and 0·97). Survival at Milford Dam, the dam that will remain in the main-stem of the Penobscot River, was relatively low (0·91), whereas survival through two dams that were removed was relatively high (0·99 and 0·98). Smolt survival could decrease in the Stillwater Branch with the addition of two new powerhouses while continuing to meet fish passage standards. The effects of removing two dams in the main-stem are expected to be negligible for smolt survival based on high survival observed from 2005 to 2012 at those locations. Survival through Milford Dam was been well below current regulatory standards, and thus improvement of passage at this location offers the best opportunity for improving overall smolt survival in the lower river. © 2014 The Fisheries Society of the British Isles.

Season-to-Season Variations of Physiological Fitness Within a Squad of Professional Male Soccer Players

PubMed Central

Clark, Niall A.; Edwards, Andrew M.; Morton, R. Hugh; Butterly, Ronald J.

2008-01-01

more sensitive of training state confirming our earlier observations. The professional players tended to attain optimal performances at the mid-season interval over the 3 seasons, presumably prior to the development of accumulative fatigue. PMID:24150149

Operational Space Weather Needs - Perspectives from SEASONS 2014

NASA Astrophysics Data System (ADS)

Comberiate, J.; Kelly, M. A.; Paxton, L. J.; Schaefer, R. K.; Bust, G. S.; Sotirelis, T.; Fox, N. J.

2014-12-01

A key challenge for the operational space weather community is the gap between the latest scientific data, models, methods, and indices and those that are currently used in operational systems. The November 2014 SEASONS (Space Environment Applications, Systems, and Operations for National Security) Workshop at JHU/APL in Laurel, Maryland, brings together representatives from the operational and scientific communities. The theme of SEASONS 2014 is "Beyond Climatology," with a focus on how space weather events threaten operational assets and disrupt missions. Here we present perspectives from SEASONS 2014 on new observations, models in development, and forecasting methods that are of interest to the operational space weather community. Highlighted topics include ionospheric data assimilation and forecasting models, HF propagation models, radiation belt observations, and energetic particle modeling. The SEASONS 2014 web site can be found at https://secwww.jhuapl.edu/SEASONS/

Mystery of Seasonality: Getting the Rhythm of Nature

PubMed Central

Naumova, Elena N.

2008-01-01

Seasonality, a systematic periodic occurrence of events over the course of a year, is a well-known phenomenon in life and health sciences. Understanding seasonal fluctuations in diseases patterns presents us with a major challenge. To develop efficient strategies for disease prevention and control, we need to grasp the main determinants of temporal variations and their interactions. This paper will introduce the notion of seasonality by outlining several of its factors, using as illustrations respiratory and enteric water- or food-borne infections. PMID:16681184

Seasonal prolactin secretion and its role in seasonal reproduction: a review.

PubMed

Curlewis, J D

1992-01-01

The majority of seasonally breeding mammals show a seasonal pattern of prolactin secretion with peak concentrations in spring or summer and a nadir in autumn or winter. Photoperiod influences prolactin secretion via its effects on the secretion of the pineal hormone melatonin. Preliminary evidence suggests that the effects of melatonin on both prolactin and gonadotrophin secretion are via a common target area, possibly within the anterior hypothalamus, and that differences in response to photoperiod may be due to differences in the processing and/or interpretation of the melatonin signal. In contrast to seasonal gonadotrophin secretion, the seasonal changes in prolactin are not due to changes in the sensitivity of a feedback loop and so must be due to direct effects on the hypothalamic pathways that control prolactin secretion. Little else can be said with confidence about the neuroendocrine mechanisms that lead to the seasonal changes in prolactin secretion. Dopamine and noradrenaline turnover in the arcuate nucleus and median eminence decrease under short daylength. If catecholamine turnover in these structures is positively correlated with catecholamine concentrations in the long or short hypophysial portal vessels, it is unlikely that the decrease in prolactin concentration in winter is due to the effects of increased concentrations of dopamine or noradrenaline in the portal vessels. There is, however, evidence for increased pituitary sensitivity to dopamine under short daylength, so increased dopamine concentrations may not be required for suppression of prolactin secretion at this time. In addition to the diminished secretion of prolactin under short daylength, rate of prolactin synthesis and pituitary content of prolactin also decline although the mechanisms that regulate these changes are poorly understood. Although all seasonal breeders show a seasonal change in prolactin secretion, there are continuously breeding species in which prolactin secretion is

Learning about Seasons: A Guide for Teachers and Curriculum Developers

ERIC Educational Resources Information Center

Sneider, Cary; Bar, Varda; Kavanagh, Claudine

2011-01-01

The video "A Private Universe" evokes surprise and dismay among educators and scientists by demonstrating that even the brightest students fail to grasp a seemingly simple and fundamental concept--the reason for seasons. This literature review describes the findings of 41 studies that collectively illustrate why the concept proves difficult to…

Development and testing of cool-season grass species, varieties, and hybrids for biomass feedstock production in western North America

USDA-ARS?s Scientific Manuscript database

Development and testing of cool-season grasses is needed to improve forage production and expand the range of bioenergy feedstocks throughout western North America. Basin wildrye (Leymus cinereus) and creeping wildrye (Leymus triticoides) are native to semiarid environments of western North America...

First oxygenated gasoline season shakes out differently than expected

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

Dale, C.; Hackworth, J.H.; Shore, J.M.

1993-10-25

The U.S.'s first oxygenated gasoline season began Nov. 1, 1992. Refiners and marketers achieved compliance with these new specs with little upset to the gasoline production and distribution system. But although the season went smoothly, it did not shake out exactly as projected. Demand for oxygenated gasoline and, in particular, methyl tertiary butyl ether (MTBE), was lower than expected. Prior to the season, refiners were concerned that oxygenates might be in short supply. No supply shortages developed, however, and prices of both oxygenates and gasoline decreased during the season. The paper discusses gasoline demand, administration of the oxygenated gasoline program,more » spillover, reduced demand, ethanol, oxygenate supply, prices, ethanol tax credit, refinery economics, and the outlook for next season.« less

Networked web-cameras monitor congruent seasonal development of birches with phenological field observations

NASA Astrophysics Data System (ADS)

Peltoniemi, Mikko; Aurela, Mika; Böttcher, Kristin; Kolari, Pasi; Loehr, John; Karhu, Jouni; Kubin, Eero; Linkosalmi, Maiju; Melih Tanis, Cemal; Nadir Arslan, Ali

2017-04-01

Ecosystems' potential to provide services, e.g. to sequester carbon is largely driven by the phenological cycle of vegetation. Timing of phenological events is required for understanding and predicting the influence of climate change on ecosystems and to support various analyses of ecosystem functioning. We established a network of cameras for automated monitoring of phenological activity of vegetation in boreal ecosystems of Finland. Cameras were mounted on 14 sites, each site having 1-3 cameras. In this study, we used cameras at 11 of these sites to investigate how well networked cameras detect phenological development of birches (Betula spp.) along the latitudinal gradient. Birches are interesting focal species for the analyses as they are common throughout Finland. In our cameras they often appear in smaller quantities within dominant species in the images. Here, we tested whether small scattered birch image elements allow reliable extraction of color indices and changes therein. We compared automatically derived phenological dates from these birch image elements to visually determined dates from the same image time series, and to independent observations recorded in the phenological monitoring network from the same region. Automatically extracted season start dates based on the change of green color fraction in the spring corresponded well with the visually interpreted start of season, and field observed budburst dates. During the declining season, red color fraction turned out to be superior over green color based indices in predicting leaf yellowing and fall. The latitudinal gradients derived using automated phenological date extraction corresponded well with gradients based on phenological field observations from the same region. We conclude that already small and scattered birch image elements allow reliable extraction of key phenological dates for birch species. Devising cameras for species specific analyses of phenological timing will be useful for

Applying Fourier Transform Mid Infrared Spectroscopy to Detect the Adulteration of Salmo salar with Oncorhynchus mykiss

PubMed Central

Moreira, Maria João

2018-01-01

The aim of this study was to evaluate the potential of Fourier transform infrared (FTIR) spectroscopy coupled with chemometric methods to detect fish adulteration. Muscles of Atlantic salmon (Salmo salar) (SS) and Salmon trout (Onconrhynchus mykiss) (OM) muscles were mixed in different percentages and transformed into mini-burgers. These were stored at 3 °C, then examined at 0, 72, 160, and 240 h for deteriorative microorganisms. Mini-burgers was submitted to Soxhlet extraction, following which lipid extracts were analyzed by FTIR. The principal component analysis (PCA) described the studied adulteration using four principal components with an explained variance of 95.60%. PCA showed that the absorbance in the spectral region from 721, 1097, 1370, 1464, 1655, 2805, to 2935, 3009 cm−1 may be attributed to biochemical fingerprints related to differences between SS and OM. The partial least squares regression (PLS-R) predicted the presence/absence of adulteration in fish samples of an external set with high accuracy. The proposed methods have the advantage of allowing quick measurements, despite the storage time of the adulterated fish. FTIR combined with chemometrics showed that a methodology to identify the adulteration of SS with OM can be established, even when stored for different periods of time. PMID:29621135

Seasonal abundance and development of the Asian longhorned beetle and natural enemy prevalence in different forest types in China

Treesearch

Houping Liu; Leah S. Bauer; Tonghai Zhao; Ruitong Gao; Therese M. Poland

2016-01-01

Seasonal abundance and population development of the Asian longhorned beetle (ALB), Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), and prevalence of its natural enemies were studied on Hankow willow (Salix matsudana Koidz.) at an urban forest site (Anci) and a rural forest site (Tangerli) in Hebei province...

Annual Demographic Data for Migrant Family Housing Centers: 1985 Harvest Season.

ERIC Educational Resources Information Center

California State Dept. of Housing and Community Development, Sacramento.

California, largest employer of seasonal labor in the United States, employs an average of 119,600 seasonal farmworkers per year. To ease problems of housing this seasonal workforce, the State Department of Housing and Community Development's Office of Migrant Services contracts with local government agencies to provide decent/affordable housing…

Acute lion's mane jellyfish, Cyanea capillata (Cnideria: Scyphozoa), exposure to Atlantic salmon (Salmo salar L.).

PubMed

Powell, M D; Åtland, Å; Dale, T

2018-05-01

Jellyfish-induced gill pathology relies upon occasional diagnostic observations yet the extent and impact of jellyfish blooms on aquaculture may be significant. Idiopathic gill lesions are often observed in apparently healthy fish. This study exposed Atlantic salmon (Salmo salar L.) smolts to macerated Cyanea capillata at 2.5 and 5 g/L for 2 hr under controlled laboratory conditions. Blood chemistry and gill histopathology were examined over a subsequent 4-week period. Fish showed an acute response to the presence of jellyfish, including characteristic external "whiplash" discoloration of the skin and acute increases in blood electrolytes and CO 2 concentration; however, these were resolved within 4 days after exposure. Histopathologically, gills showed first an acute oedema with epithelial separation followed by focal haemorrhage and thrombus formation, and then progressive inflammatory epithelial hyperplasia that progressively resolved over the 4 weeks post-exposure. Results were consistent with the envenomation of gills with cytotoxic neurotoxins and haemolysins known to be produced by C. capillata. This study suggests that many focal hyperplastic lesions on gills, especially those involving focal thrombi, may be the result of jellyfish stings. Thus, the presence of jellyfish and their impact may be severe and understated in terms of marine fish aquaculture and fish welfare. © 2018 John Wiley & Sons Ltd.

Tissue astaxanthin and canthaxanthin distribution in rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar).

PubMed

Page, G I; Davies, S J

2006-01-01

A comparative investigation of tissue carotenoid distribution between rainbow trout, Oncorhynchus mykiss, and Atlantic salmon, Salmo salar, was undertaken to identify the relative efficiency of utilization of astaxanthin and canthaxanthin. Higher apparent digestibility coefficients (ADCs) (96% in trout vs. 28-31% in salmon; P<0.05), and pigment retention efficiencies (11.5-12.5% in trout vs. 5.5% in salmon; P<0.05), for both astaxanthin and canthaxanthin, were observed for rainbow trout. Astaxanthin deposition was higher than canthaxanthin in rainbow trout, while the reverse was true for Atlantic salmon, suggesting species-specificity in carotenoid utilization. The white muscle (95% in trout vs. 93% in salmon) and kidneys (0.5% in trout vs. 0.2% in salmon) represented higher proportions of the total body carotenoid pool in rainbow trout than in Atlantic salmon (P<0.05), whereas the liver was a more important storage organ in Atlantic salmon (2-6% in salmon vs. 0.2% in trout; P<0.05). The liver and kidney appeared to be important sites of carotenoid catabolism based on the relative proportion of the peak chromatogram of the fed carotenoid in both species, with the pyloric caecae and hind gut being more important in Atlantic salmon than in the rainbow trout. Liver catabolism is suspected to be a critical determinant in carotenoid clearance, with higher catabolism expected in Atlantic salmon than in rainbow trout.

Physiology and behaviour of Atlantic salmon (Salmo salar) smolts during commercial land and sea transport.

PubMed

Nomura, M; Sloman, K A; von Keyserlingk, M A G; Farrell, A P

2009-02-16

This study examined the physiology (plasma cortisol, glucose, lactate, potassium, sodium and chloride concentrations) and behaviour (underwater video footage) of commercially produced Atlantic salmon (Salmo salar) smolts during transport from freshwater farms to saltwater net pens. Smolts were transported by truck in closed tanks from two freshwater farms to the dock (30-60 min), and then in the flow-through cargo holds of a live-haul vessel, the Sterling Carrier, to the saltwater net pens (~2 h). Some fish were dockside in the vessel for up to 8 h while successive deliveries were loaded into the holds. Fish and water were sampled both before and after truck transport, and then at several time points aboard the vessel. Analysis of plasma constituents showed modest primary and secondary stress responses due to loading and truck transport, and the recovery that occurred dockside in the live-haul vessel was maintained when the vessel was underway. Underwater video footage revealed behavioural differences between fish from the two freshwater facilities that were not evident from the physiological measurements, but the behaviours observed during transport on a live-haul vessel were consistent with a non-stressful environment. Although smolts were subjected to moderately stressful conditions during loading and trucking, they began to recover rapidly aboard the Sterling Carrier. We therefore conclude that smolt transport, as currently conducted by our industry partner, appears to reflect good fish welfare.

Statistical prediction of seasonal discharge in Central Asia for water resources management: development of a generic (pre-)operational modeling tool

NASA Astrophysics Data System (ADS)

Apel, Heiko; Baimaganbetov, Azamat; Kalashnikova, Olga; Gavrilenko, Nadejda; Abdykerimova, Zharkinay; Agalhanova, Marina; Gerlitz, Lars; Unger-Shayesteh, Katy; Vorogushyn, Sergiy; Gafurov, Abror

2017-04-01

The semi-arid regions of Central Asia crucially depend on the water resources supplied by the mountainous areas of the Tien-Shan and Pamirs. During the summer months the snow and glacier melt dominated river discharge originating in the mountains provides the main water resource available for agricultural production, but also for storage in reservoirs for energy generation during the winter months. Thus a reliable seasonal forecast of the water resources is crucial for a sustainable management and planning of water resources. In fact, seasonal forecasts are mandatory tasks of all national hydro-meteorological services in the region. In order to support the operational seasonal forecast procedures of hydromet services, this study aims at the development of a generic tool for deriving statistical forecast models of seasonal river discharge. The generic model is kept as simple as possible in order to be driven by available hydrological and meteorological data, and be applicable for all catchments with their often limited data availability in the region. As snowmelt dominates summer runoff, the main meteorological predictors for the forecast models are monthly values of winter precipitation and temperature as recorded by climatological stations in the catchments. These data sets are accompanied by snow cover predictors derived from the operational ModSnow tool, which provides cloud free snow cover data for the selected catchments based on MODIS satellite images. In addition to the meteorological data antecedent streamflow is used as a predictor variable. This basic predictor set was further extended by multi-monthly means of the individual predictors, as well as composites of the predictors. Forecast models are derived based on these predictors as linear combinations of up to 3 or 4 predictors. A user selectable number of best models according to pre-defined performance criteria is extracted automatically by the developed model fitting algorithm, which includes a test

The complete genome sequence of CrRV-Ch01, a new member of the family Rhabdoviridae in the parasitic copepod Caligus rogercresseyi present on farmed Atlantic salmon (Salmo salar) in Chile.

PubMed

Økland, Arnfinn Lodden; Skoge, Renate Hvidsten; Nylund, Are

2018-06-01

We have determined the complete genome sequence of a new rhabdovirus, tentatively named Caligus rogercresseyi rhabdovirus Ch01 (CrRV-Ch01), which was found in the parasite Caligus rogercresseyi, present on farmed Atlantic salmon (Salmo salar) in Chile. The genome encodes the five canonical rhabdovirus proteins in addition to an unknown protein, in the order N-P-M-U (unknown)-G-L. Phylogenetic analysis showed that the virus clusters with two rhabdoviruses (Lepeophtheirus salmonis rhabdovirus No9 and Lepeophtheirus salmonis rhabdovirus No127) obtained from another parasitic caligid, Lepeophtheirus salmonis, present on farmed Atlantic salmon on the west coast of Norway.

Vegetation response to rainfall seasonality and interannual variability in tropical dry forests

NASA Astrophysics Data System (ADS)

Feng, X.; Silva Souza, R. M.; Souza, E.; Antonino, A.; Montenegro, S.; Porporato, A. M.

2015-12-01

We analyzed the response of tropical dry forests to seasonal and interannual rainfall variability, focusing on the caatinga biome in semi-arid in Northeast Brazil. We selected four sites across a gradient of rainfall amount and seasonality and analyzed daily rainfall and biweekly Normalized Difference Vegetation Index (NDVI) in the period 2000-2014. The seasonal and interannual rainfall statistics were characterized using recently developed metrics describing duration, location, and intensity of wet season and compared them with those of NDVI time series and modelled soil moisture. A model of NDVI was also developed and forced by different rainfall scenarios (combination amount of rainfall and duration of wet season). The results show that the caatinga tends to have a more stable response characterized by longer and less variable growing seasons (of duration 3.1±0.1 months) compared to the rainfall wet seasons (2.0±0.5 months). Even for more extreme rainfall conditions, the ecosystem shows very little sensitivity to duration of wet season in relation to the amount of rainfall, however the duration of wet season is most evident for wetter sites. This ability of the ecosystem in buffering the interannual variability of rainfall is corroborated by the stability of the centroid location of the growing season compared to the wet season for all sites. The maximal biomass production was observed at intermediate levels of seasonality, suggesting a possible interesting trade-off in the effects of intensity (i.e., amount) and duration of the wet season on vegetation growth.

Seasonality of Kawasaki Disease: A Global Perspective

PubMed Central

Burns, Jane C.; Herzog, Lauren; Fabri, Olivia; Tremoulet, Adriana H.; Rodó, Xavier; Uehara, Ritei; Burgner, David; Bainto, Emelia; Pierce, David; Tyree, Mary; Cayan, Daniel

2013-01-01

Background Understanding global seasonal patterns of Kawasaki disease (KD) may provide insight into the etiology of this vasculitis that is now the most common cause of acquired heart disease in children in developed countries worldwide. Methods Data from 1970-2012 from 25 countries distributed over the globe were analyzed for seasonality. The number of KD cases from each location was normalized to minimize the influence of greater numbers from certain locations. The presence of seasonal variation of KD at the individual locations was evaluated using three different tests: time series modeling, spectral analysis, and a Monte Carlo technique. Results A defined seasonal structure emerged demonstrating broad coherence in fluctuations in KD cases across the Northern Hemisphere extra-tropical latitudes. In the extra-tropical latitudes of the Northern Hemisphere, KD case numbers were highest in January through March and approximately 40% higher than in the months of lowest case numbers from August through October. Datasets were much sparser in the tropics and the Southern Hemisphere extra-tropics and statistical significance of the seasonality tests was weak, but suggested a maximum in May through June, with approximately 30% higher number of cases than in the least active months of February, March and October. The seasonal pattern in the Northern Hemisphere extra-tropics was consistent across the first and second halves of the sample period. Conclusion Using the first global KD time series, analysis of sites located in the Northern Hemisphere extra-tropics revealed statistically significant and consistent seasonal fluctuations in KD case numbers with high numbers in winter and low numbers in late summer and fall. Neither the tropics nor the Southern Hemisphere extra-tropics registered a statistically significant aggregate seasonal cycle. These data suggest a seasonal exposure to a KD agent that operates over large geographic regions and is concentrated during winter

Seasonality of Kawasaki disease: a global perspective.

PubMed

Burns, Jane C; Herzog, Lauren; Fabri, Olivia; Tremoulet, Adriana H; Rodó, Xavier; Uehara, Ritei; Burgner, David; Bainto, Emelia; Pierce, David; Tyree, Mary; Cayan, Daniel

2013-01-01

Understanding global seasonal patterns of Kawasaki disease (KD) may provide insight into the etiology of this vasculitis that is now the most common cause of acquired heart disease in children in developed countries worldwide. Data from 1970-2012 from 25 countries distributed over the globe were analyzed for seasonality. The number of KD cases from each location was normalized to minimize the influence of greater numbers from certain locations. The presence of seasonal variation of KD at the individual locations was evaluated using three different tests: time series modeling, spectral analysis, and a Monte Carlo technique. A defined seasonal structure emerged demonstrating broad coherence in fluctuations in KD cases across the Northern Hemisphere extra-tropical latitudes. In the extra-tropical latitudes of the Northern Hemisphere, KD case numbers were highest in January through March and approximately 40% higher than in the months of lowest case numbers from August through October. Datasets were much sparser in the tropics and the Southern Hemisphere extra-tropics and statistical significance of the seasonality tests was weak, but suggested a maximum in May through June, with approximately 30% higher number of cases than in the least active months of February, March and October. The seasonal pattern in the Northern Hemisphere extra-tropics was consistent across the first and second halves of the sample period. Using the first global KD time series, analysis of sites located in the Northern Hemisphere extra-tropics revealed statistically significant and consistent seasonal fluctuations in KD case numbers with high numbers in winter and low numbers in late summer and fall. Neither the tropics nor the Southern Hemisphere extra-tropics registered a statistically significant aggregate seasonal cycle. These data suggest a seasonal exposure to a KD agent that operates over large geographic regions and is concentrated during winter months in the Northern Hemisphere extra-tropics.

Effects of individual variation in length, condition and run-time on return rates of wild-reared Atlantic salmon Salmo salar smolts.

PubMed

Armstrong, J D; McKelvey, S; Smith, G W; Rycroft, P; Fryer, R J

2018-03-01

Groups of wild-reared Atlantic salmon Salmo salar smolts were captured during their seaward migration on a tributary of the River Conon, Scotland, U.K., from 1999 to 2014 and tagged with passive integrated transponders (PIT). Fish that subsequently returned to the river after growing at sea were recorded automatically by a PIT-detector in a fish pass. Return rate was related directly to length and condition and inversely to day of the year that the smolt was tagged. Over years, as the study progressed, there was a significant increase in the proportion of smolts returning after two or more years at sea and no trend in returns of salmon having spent one winter at sea. There was no trend in the date of return of salmon across the study period. Fish that had spent more winters at sea returned earlier in the year. © 2018 Crown Copyright. Journal of Fish Biology © 2018 The Fisheries Society of the British Isles.

Laboratory evaluation of sample collection methods (organs vs swabs) for Tasmanian salmon reovirus detection in farmed Atlantic salmon, Salmo salar L.

PubMed

Zainathan, S C; Carson, J; Crane, M St J; Nowak, B F

2013-04-01

The use of swabs relative to organs as a sample collection method for the detection of Tasmanian salmon reovirus (TSRV) in farmed Tasmanian Atlantic salmon, Salmo salar L., was evaluated by RT-qPCR. Evaluation of individual and pooled sample collection (organs vs swabs) was carried out to determine the sensitivity of the collection methods and the effect of pooling of samples for the detection of TSRV. Detection of TSRV in individual samples was as sensitive when organs were sampled compared to swabs, and in pooled samples, organs demonstrated a sensitivity of one 10-fold dilution higher than sampling of pooled swabs. Storage of swabs at 4 °C for t = 24 h demonstrated results similar to those at t = 0. Advantages of using swabs as a preferred sample collection method for the detection of TSRV compared to organ samples are evident from these experimental trials. © 2012 Blackwell Publishing Ltd.

High intensity, short duration rotational grazing on reclaimed cool season fescue/legume pastures: I. System development

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

Erickson, W.R.; Carlson, K.E.

The Pittsburg & Midway Coal Mining Co.`s ({open_quotes}P&M{close_quotes}) Midway Mine lies 50 miles south of Kansas City, Kansas, straddling the border of Kansas and Missouri. P&M actively mined the area until 1989, when the mine was closed and reclaimed. Approximately 3,750 acres of surface mined land were topsoiled and revegetated to cool season fescue/legume pasture. Various pasture management methods are being utilized to meet reclamation success standards and achieve final bond release. The effectiveness and costs of various cool season fescue/legume pasture management methods are evaluated and contrasted. These methods include sharecropping, bush hogging, burning and livestock grazing. It presentsmore » guidelines used to develop a site specific rotational livestock grazing programs with land owners or contractors, and local, state and federal agencies. Rotational grazing uses both cow/calf or feeder livestock operations. Key managerial elements used to control grazing activities, either by the landowner or a contractor, are reviewed. Methods used to determine stocking levels for successful rotational grazing on this type of pasture are presented. Rotational grazing of livestock has proven to be the most effective method for managing established cool season fescue/legume pastures at this site. Initial stocking rates of 1 A.U.M. per 5 acres have been modified to a current stocking rate of 1 A.U.M. per 2.5 acres. Supporting physical and chemical data are presented and discussed.« less

Transcriptome sequencing of Atlantic salmon (Salmo salar L.) notochord prior to development of the vertebrae provides clues to regulation of positional fate, chordoblast lineage and mineralisation

PubMed Central

2014-01-01

Background In teleosts such as Atlantic salmon (Salmo salar L.), segmentation and subsequent mineralisation of the notochord during embryonic stages are essential for normal vertebrae formation. However, the molecular mechanisms leading to segmentation and mineralisation of the notochord are poorly understood. The aim of this study was to identify genes/pathways acting in gradients over time and along the anterior-posterior axis during notochord segmentation and immediately prior to mineralisation of the vertebral bodies in Atlantic salmon. Results Notochord samples were collected from unsegmented, pre-segmented and segmented developmental stages. In each stage, the cellular core of the notochord was cut into three pieces along the longitudinal axis (anterior, mid, posterior). RNA was sequenced (22 million pair-end 100 bp/ library) and mapped to the salmon genome. 66569 transcripts were predicted and 55775 were annotated. In order to identify possible gradients leading to segmentation of the notochord, all 71 notochord-expressed hox genes were investigated, most of them displaying a typical anterior-posterior expression pattern along the notochord axis. The clustering of hox genes revealed a pattern that could be related to notochord segmentation. We further investigated how mineralisation is initiated in the notochord, and several factors related to chondrogenic lineage were identified (sox9, sox5, sox6, tgfb3, ihhb and col2a1), suggesting a cartilage-like character of the notochord. KEGG analysis of differentially expressed genes between stages revealed down-regulation of pathways associated with ECM, cell division, metabolism and development at onset of notochord segmentation. This implies that inhibitory signals produce segmentation of the notochord. One such potential inhibitory signal was identified, col11a2, which was detected in segments of non-mineralising notochord. Conclusions An incomplete salmon genome was successfully used to analyse RNA-seq data

Transcriptome sequencing of Atlantic salmon (Salmo salar L.) notochord prior to development of the vertebrae provides clues to regulation of positional fate, chordoblast lineage and mineralisation.

PubMed

Wang, Shou; Furmanek, Tomasz; Kryvi, Harald; Krossøy, Christel; Totland, Geir K; Grotmol, Sindre; Wargelius, Anna

2014-02-19

In teleosts such as Atlantic salmon (Salmo salar L.), segmentation and subsequent mineralisation of the notochord during embryonic stages are essential for normal vertebrae formation. However, the molecular mechanisms leading to segmentation and mineralisation of the notochord are poorly understood. The aim of this study was to identify genes/pathways acting in gradients over time and along the anterior-posterior axis during notochord segmentation and immediately prior to mineralisation of the vertebral bodies in Atlantic salmon. Notochord samples were collected from unsegmented, pre-segmented and segmented developmental stages. In each stage, the cellular core of the notochord was cut into three pieces along the longitudinal axis (anterior, mid, posterior). RNA was sequenced (22 million pair-end 100 bp/ library) and mapped to the salmon genome. 66569 transcripts were predicted and 55775 were annotated. In order to identify possible gradients leading to segmentation of the notochord, all 71 notochord-expressed hox genes were investigated, most of them displaying a typical anterior-posterior expression pattern along the notochord axis. The clustering of hox genes revealed a pattern that could be related to notochord segmentation. We further investigated how mineralisation is initiated in the notochord, and several factors related to chondrogenic lineage were identified (sox9, sox5, sox6, tgfb3, ihhb and col2a1), suggesting a cartilage-like character of the notochord. KEGG analysis of differentially expressed genes between stages revealed down-regulation of pathways associated with ECM, cell division, metabolism and development at onset of notochord segmentation. This implies that inhibitory signals produce segmentation of the notochord. One such potential inhibitory signal was identified, col11a2, which was detected in segments of non-mineralising notochord. An incomplete salmon genome was successfully used to analyse RNA-seq data from the cellular core of the

Consumer Acceptance Comparison Between Seasoned and Unseasoned Vegetables

PubMed Central

Feng, Yiming; Albiol Tapia, Marta; Okada, Kyle; Castaneda Lazo, Nuria Blanca; Chapman‐Novakofski, Karen; Phillips, Carter

2018-01-01

Abstract Recent findings show that approximately 87% of the U.S. population fail to meet the vegetable intake recommendations, with unpleasant taste of vegetables being listed as the primary reason for this shortfall. In this study, spice and herb seasoning was used to enhance palatability of vegetables, in order to increase consumer acceptance. In total, 749 panelists were screened and recruited as specific vegetable likers of the vegetable being tested or general vegetable likers. Four sessions were designed to evaluate the effect of seasoning within each type of vegetable, including broccoli, cauliflower, carrot, and green bean. Each panelist was only allowed to participate in one test session to evaluate only one vegetable type, so as to mitigate potential learning effect. Overall, the results showed that seasoned vegetables were significantly preferred over unseasoned vegetables (P < 0.001), indicating the sensory properties were significantly improved with seasoning. When general vegetable likers and specific vegetable likers were compared in terms of their preference between seasoned and unseasoned vegetables, the pattern varied across different vegetables; however, general trend of seasoned vegetable being preferred remained. The findings from this study demonstrate the effect of seasoning in enhancing consumer liking of vegetables, which may lead to increased consumption to be assessed in future studies. Practical Application To improve the sensory properties of vegetables, masking the bitter taste of vegetables using spice and herb seasoning are gaining increasing attention. Our findings suggest that the overall liking of vegetables could be improved by incorporating spice and herb seasonings that are specifically formulated for each vegetable. Ultimately, developing and commercializing spice and herb seasonings may aid to increase vegetable consumption, as well as expanding the vegetable seasoning market. PMID:29337353

Consumer Acceptance Comparison Between Seasoned and Unseasoned Vegetables.

PubMed

Feng, Yiming; Albiol Tapia, Marta; Okada, Kyle; Castaneda Lazo, Nuria Blanca; Chapman-Novakofski, Karen; Phillips, Carter; Lee, Soo-Yeun

2018-02-01

Recent findings show that approximately 87% of the U.S. population fail to meet the vegetable intake recommendations, with unpleasant taste of vegetables being listed as the primary reason for this shortfall. In this study, spice and herb seasoning was used to enhance palatability of vegetables, in order to increase consumer acceptance. In total, 749 panelists were screened and recruited as specific vegetable likers of the vegetable being tested or general vegetable likers. Four sessions were designed to evaluate the effect of seasoning within each type of vegetable, including broccoli, cauliflower, carrot, and green bean. Each panelist was only allowed to participate in one test session to evaluate only one vegetable type, so as to mitigate potential learning effect. Overall, the results showed that seasoned vegetables were significantly preferred over unseasoned vegetables (P < 0.001), indicating the sensory properties were significantly improved with seasoning. When general vegetable likers and specific vegetable likers were compared in terms of their preference between seasoned and unseasoned vegetables, the pattern varied across different vegetables; however, general trend of seasoned vegetable being preferred remained. The findings from this study demonstrate the effect of seasoning in enhancing consumer liking of vegetables, which may lead to increased consumption to be assessed in future studies. To improve the sensory properties of vegetables, masking the bitter taste of vegetables using spice and herb seasoning are gaining increasing attention. Our findings suggest that the overall liking of vegetables could be improved by incorporating spice and herb seasonings that are specifically formulated for each vegetable. Ultimately, developing and commercializing spice and herb seasonings may aid to increase vegetable consumption, as well as expanding the vegetable seasoning market. © 2018 The Authors Journal of Food Science published by Wiley Periodicals, Inc

The Making of National Seasonal Wildfire Outlooks

NASA Astrophysics Data System (ADS)

Garfin, G. M.; Brown, T. J.

2015-12-01

Bridging the gap between research-based experiments and fully operational products has been likened to crossing the valley of death. In this talk, we document the development of pre-season fire potential outlooks, informed by seasonal climate predictions, through a long-term collaboration between NOAA RISA teams, the Program for Climate, Ecosystem and Fire Applications (Desert Research Institute), the National Interagency Fire Center's Predictive Services program and multiple collaborators. To transition experimental outlooks into a sustained, monthly operational product, we co-developed a temporary institution, the National Seasonal Assessment Workshops, as a platform for cross-disciplinary knowledge exchange, training, and experimentation in consensus forecast processes and product development. In our retrospective evaluation of the process, we identified several factors that supported the transition from research to operations. These include: the development of new institutions; focus on a geographic scale commensurate with the needs of federal and state land management agencies; participatory and deliberative engagements; cooperation by many partners with perspectives on the connections between climate and wildland fire management; and iterative engagement sustained by funding and human resource commitments from the key partners. Through co-production of the outlooks and the institution, we created a cross-disciplinary community of practice, thus, increasing the capacity of fire management practitioners to use climate information in decision making. This experiment in developing a collaborative climate service was not an unqualified success. For example, while practitioners almost always *consult* official probabilistic climate forecasts, based on the output from dynamical and statistical models, they sometimes *act* on information from self-constructed forecasts, based on analysis of analogue years. We recommend research to further examine the distribution and

Seasonality, household food security, and nutritional status in Dinajpur, Bangladesh.

PubMed

Hillbruner, Chris; Egan, Rebecca

2008-09-01

The influence of seasonality on food security and nutritional status is widely accepted. However, research has typically focused on rural households and has not explored the specific mechanisms underlying seasonal effects. To investigate the role of seasonality in determining the food security and nutritional status of low-income urban households and to isolate specific pathways through which seasonality has its impact. Secondary panel data from CARE/IFPRI were utilized. Three rounds of data were collected from approximately 600 households in low-income areas of Dinajpur, Bangladesh, from 2002 through 2003, twice during the monsoon season and once in the dry season. Household-level surveys collected data on income and expenditure, employment, urban agriculture, health, and assets. Height and weight measurements were taken from children between the ages of 6 and 72 months. Paired t-tests and logistic fixed-effects modeling were then used to explore the role of seasonality. The prevalence rates of food insecurity, wasting, and inadequate growth were all significantly higher during the monsoon season as compared with the dry season. Dietary diversity and lost work due to the weather were identified as specific pathways through which season affected household food security. However, mechanisms hypothesized to contribute to seasonal declines in nutritional status, such as child illness, were not found to be significant. Season had a significant effect on both food security and nutritional status in Dinajpur, with households consistently worse off during the monsoon season. Initiatives to promote food market development, support employment during the hunger season, and prevent seasonal declines in nutritional status should be implemented.

Epidemic seasonal infertility — a hypothesis for the cause of seasonal variation of births

NASA Astrophysics Data System (ADS)

Miura, T.; Shimura, M.

1980-03-01

A hypothesis is proposed to explain the seasonality of births and its variations, that some unrecognized epidemic infertile factors have existed seasonally. In that case, certain women born in a particular low birth rate season must be those who survived these infertile factors in very early stage of their fetal lives. Then in later years, when they become pregnant, they may possibly be immune or different in their susceptibility to these infertile factors. Therefore, mothers born in a particular low birth rate season would tend to bear babies more frequently in that season than the others. To examine this hypothesis, birth records in 1930 of two maternity hospitals in Tokyo were investigated. These years were chosen for a period when seasonality of birth was most prominent in Japan. First babies were excluded to eliminate disturbances by season of marriages and other possible non-biological factors. The results show that among 1038 mothers born in a low birthrate season, May July, 245 (23.6%) had babies in May July, while the other mothers had significantly less babies (19.0%, 819/4302, P<0.001) in the same season. This may imply that seasonality of birth may have been influenced by some immunogenic infertile factors epidemic in a particular season.

Strategies to overcome seasonal anestrus in water buffalo.

PubMed

de Carvalho, Nelcio Antonio Tonizza; Soares, Julia Gleyci; Baruselli, Pietro Sampaio

2016-07-01

Reproductive seasonality in buffalo (Bubalus bubalis) is characterized by behavioral, endocrine, and reproductive changes that occur over distinct periods of the year. During the nonbreeding season (spring and summer), the greater light-dark ratio (long days) suppresses estrus behavior and the occurrence of ovulation. Anestrous buffaloes have insufficient pulsatile of LH to support the final stages of follicular development, and subsequently, estrus behavior and ovulation do not occur, limiting reproductive efficiency, especially in artificial insemination (AI) programs. A number of therapeutic strategies designed to synchronize follicular wave emergence and ovulation have allowed for the use of AI throughout the year, overcoming seasonal anestrus in buffalo. These therapies also improve reproductive performance by increasing the service rate and pregnancy per AI in buffalo herds, regardless of reproductive seasonality. Copyright © 2016 Elsevier Inc. All rights reserved.

Seasonality of absolute humidity explains seasonality of influenza-like illness in Vietnam.

PubMed

Thai, Pham Quang; Choisy, Marc; Duong, Tran Nhu; Thiem, Vu Dinh; Yen, Nguyen Thu; Hien, Nguyen Tran; Weiss, Daniel J; Boni, Maciej F; Horby, Peter

2015-12-01

Experimental and ecological studies have shown the role of climatic factors in driving the epidemiology of influenza. In particular, low absolute humidity (AH) has been shown to increase influenza virus transmissibility and has been identified to explain the onset of epidemics in temperate regions. Here, we aim to study the potential climatic drivers of influenza-like illness (ILI) epidemiology in Vietnam, a tropical country characterized by a high diversity of climates. We specifically focus on quantifying and explaining the seasonality of ILI. We used 18 years (1993-2010) of monthly ILI notifications aggregated by province (52) and monthly climatic variables (minimum, mean, maximum temperatures, absolute and relative humidities, rainfall and hours of sunshine) from 67 weather stations across Vietnam. Seasonalities were quantified from global wavelet spectra, using the value of the power at the period of 1 year as a measure of the intensity of seasonality. The 7 climatic time series were characterized by 534 summary statistics which were entered into a regression tree to identify factors associated with the seasonality of AH. Results were extrapolated to the global scale using simulated climatic times series from the NCEP/NCAR project. The intensity of ILI seasonality in Vietnam is best explained by the intensity of AH seasonality. We find that ILI seasonality is weak in provinces experiencing weak seasonal fluctuations in AH (annual power <17.6), whereas ILI seasonality is strongest in provinces with pronounced AH seasonality (power >17.6). In Vietnam, AH and ILI are positively correlated. Our results identify a role for AH in driving the epidemiology of ILI in a tropical setting. However, in contrast to temperate regions, high rather than low AH is associated with increased ILI activity. Fluctuation in AH may be the climate factor that underlies and unifies the seasonality of ILI in both temperate and tropical regions. Alternatively, the mechanism of action of

A comparison of neutral and immune genetic variation in Atlantic salmon, Salmo salar L. in Chilean aquaculture facilities.

PubMed

Portnoy, David S; Hollenbeck, Christopher M; Vidal, R Rodrigo; Gold, John R

2014-01-01

Genetic diversity was assessed in samples of cultured Atlantic salmon, Salmo salar L., obtained from facilities in Chile between 2005 and 2010, a period of time during which the infectious pathogens Infectious Salmon Anemia (ISA) virus, Caligus rogercresseyi (sea lice), and Piscirickettsia salmonis (salmon rickettsial syndrome) were common. Two panels of microsatellite markers were utilized: one with microsatellites with no known gene associations (neutral) and one featuring microsatellites linked to putative immune-related genes (immune-related). Allelic richness and gene diversity across samples were significantly greater in neutral loci as compared to immune-related loci. Both diversity measures were homogeneous among samples for immune-related loci and heterogeneous among samples for neutral loci. Immune-related loci were identified as F(ST) outliers in pairwise comparisons of samples at a 10-fold higher frequency than neutral loci. These results indicate that neutral and immune-related portions of the Atlantic salmon genome may have differed in response to the gauntlet of pathogens and that monitoring of specific, well characterized immune-related loci as well as neutral loci in cultured species could be useful when disease control and prevention is a goal.

A Comparison of Neutral and Immune Genetic Variation in Atlantic Salmon, Salmo salar L. in Chilean Aquaculture Facilities

PubMed Central

Portnoy, David S.; Hollenbeck, Christopher M.; Vidal, R. Rodrigo; Gold, John R.

2014-01-01

Genetic diversity was assessed in samples of cultured Atlantic salmon, Salmo salar L., obtained from facilities in Chile between 2005 and 2010, a period of time during which the infectious pathogens Infectious Salmon Anemia (ISA) virus, Caligus rogercresseyi (sea lice), and Piscirickettsia salmonis (salmon rickettsial syndrome) were common. Two panels of microsatellite markers were utilized: one with microsatellites with no known gene associations (neutral) and one featuring microsatellites linked to putative immune-related genes (immune-related). Allelic richness and gene diversity across samples were significantly greater in neutral loci as compared to immune-related loci. Both diversity measures were homogeneous among samples for immune-related loci and heterogeneous among samples for neutral loci. Immune-related loci were identified as FST outliers in pairwise comparisons of samples at a 10-fold higher frequency than neutral loci. These results indicate that neutral and immune-related portions of the Atlantic salmon genome may have differed in response to the gauntlet of pathogens and that monitoring of specific, well characterized immune-related loci as well as neutral loci in cultured species could be useful when disease control and prevention is a goal. PMID:24918941

Seasonal infectious disease epidemiology

PubMed Central

Grassly, Nicholas C; Fraser, Christophe

2006-01-01

Seasonal change in the incidence of infectious diseases is a common phenomenon in both temperate and tropical climates. However, the mechanisms responsible for seasonal disease incidence, and the epidemiological consequences of seasonality, are poorly understood with rare exception. Standard epidemiological theory and concepts such as the basic reproductive number R0 no longer apply, and the implications for interventions that themselves may be periodic, such as pulse vaccination, have not been formally examined. This paper examines the causes and consequences of seasonality, and in so doing derives several new results concerning vaccination strategy and the interpretation of disease outbreak data. It begins with a brief review of published scientific studies in support of different causes of seasonality in infectious diseases of humans, identifying four principal mechanisms and their association with different routes of transmission. It then describes the consequences of seasonality for R0, disease outbreaks, endemic dynamics and persistence. Finally, a mathematical analysis of routine and pulse vaccination programmes for seasonal infections is presented. The synthesis of seasonal infectious disease epidemiology attempted by this paper highlights the need for further empirical and theoretical work. PMID:16959647

Seasonality, mobility, and livability.

DOT National Transportation Integrated Search

2012-01-31

Signature project 4a, Seasonality, Mobility, and Livability investigated the effects of weather, season, built environment, community amenities, attitudes, and demographics on mobility and quality of life (QOL). A four season panel survey exami...

Immunomodulatory Effects of Dietary Seaweeds in LPS Challenged Atlantic Salmon Salmo salar as Determined by Deep RNA Sequencing of the Head Kidney Transcriptome

PubMed Central

Palstra, Arjan P.; Kals, Jeroen; Blanco Garcia, Ainhoa; Dirks, Ron P.; Poelman, Marnix

2018-01-01

Seaweeds may represent immuno-stimulants that could be used as health-promoting fish feed components. This study was performed to gain insights into the immunomodulatory effects of dietary seaweeds in Atlantic salmon. Specifically tested were 10% inclusion levels of Laminaria digitata (SW1) and a commercial blend of seaweeds (Oceanfeed®) (SW2) against a fishmeal based control diet (FMC). Differences between groups were assessed in growth, feed conversion ratio and blood parameters hematocrit and hemoglobin. After a LPS challenge of fish representing each of the three groups, RNAseq was performed on the head kidney as major immune organ to determine transcriptomic differences in response to the immune activation. Atlantic salmon fed with dietary seaweeds did not show major differences in performance in comparison with fishmeal fed fish. RNAseq resulted in ∼154 million reads which were mapped against a NCBI Salmo salar reference and against a de novo assembled S. salar reference for analyses of expression of immune genes and ontology of immune processes among the 87,600 cDNA contigs. The dietary seaweeds provoked a more efficient immune response which involved more efficient identification of the infection site, and processing and presentation of antigens. More specifically, chemotaxis and the chemokine-mediated signaling were improved and therewith the defense response to Gram-positive bacterium reduced. Specific Laminaria digitata effects included reduction of the interferon-gamma-mediated signaling. Highly upregulated and specific for this diet was the expression of major histocompatibility complex class I-related gene protein. The commercial blend of seaweeds caused more differential expression than Laminaria digitata and improved immune processes such as receptor-mediated endocytosis and cell adhesion, and increased the expression of genes involved in response to lipopolysaccharide and inflammatory response. Particularly, expression of many important immune

Content changes of bitter compounds in 'Guoqing No.1' Satsuma mandarin (Citrus unshiu Marc.) during fruit development of consecutive 3 seasons.

PubMed

Li, Shaojie; Wang, Zhuang; Ding, Fan; Sun, Da; Ma, Zhaocheng; Cheng, Yunjiang; Xu, Juan

2014-02-15

The main bitter compounds (nomilin, limonin and naringin) in the fruit tissues of 'Guoqing No.1' Satsuma mandarin (Citrus unshiu Marc.) were determined throughout the fruit development of 3 consecutive growing seasons. Although fluctuating largely at the corresponding developing stages of the 3 years, the contents of these compounds in fruit tissues mostly displayed a declining trend, which implied that the rhythm of the metabolism of these bitter compounds was not consistent among years and was largely growing season dependent. Regarding their distribution, fruit flavedo might be a weak sink that contained the lowest level of naringin, while the segment membrane accumulated large amount of limonin and nomilin, which indicated a possible tissue bias pattern for biosynthesis or accumulation of those compounds. Partial correlation coefficient analysis revealed a synergistic accumulation of naringin and the two limonoid aglycones in fruit tissues during fruit development, indicating an integrated metabolism of flavonoids and limonoids. Copyright © 2013 Elsevier Ltd. All rights reserved.

Tectonic Evolution of the Central Andes during Mesozoic-Cenozoic times: Insights from the Salar de Atacama Basin

NASA Astrophysics Data System (ADS)

Peña Gomez, M. A.; Bascunan, S. A.; Becerra, J.; Rubilar, J. F.; Gómez, I.; Narea, K.; Martínez, F.; Arriagada, C.; Le Roux, J.; Deckart, K.

2015-12-01

The classic Salar de Atacama Basin, located in the Central Andes of northern Chile, holds a remarkable yet not fully understood record of tectonic events since mid-Cretaceous times. Based on the growing amount of data collected over the last years, such as high-detail maps and U-Pb geochronology, we present an updated model for the development of this area after the Triassic. A major compressional event is recorded around the mid-Late Cretaceous (ca. 107 Ma) with the deposition of synorogenic continental successions reflecting the uplift of the Coastal Cordillera area farther to the west, and effectively initiating the foreland basin. The deformation front migrated eastwards during the Late Campanian (ca. 79 Ma), where it exhumed and deformed the Late Cretaceous magmatic arc and the crystalline basement of Cordillera de Domeyko. The K-T Event (ca. 65 Ma), recently identified in the basin, involved the same source areas, though the facies indicate a closer proximity to the source. The compressional record of the basin is continued by the Eocene Incaic Event (ca. 45 Ma), with deep exhumation of the Cordillera de Domeyko and the cannibalization of previous deposits. A change to an extensional regime during the Oligocene (ca. 28 Ma) is shown by the deposition of more than 4 km of evaporitic and clastic successions. A partial inversion of the basin occurred during the Miocene (ca.10 Ma-present), as shown by the deformation seen in the Cordillera de la Sal. As such, the basin shows that the uplift of the Cordillera de Domeyko was not one isolated episode, but a prolonged and complex event, punctuated by episodes of major deformation. It also highlights the need to take into account the Mesozoic-Cenozoic deformation events for any model trying to explain the building of the modern-day Andes.

Spatial and temporal genetic structure of a river-resident Atlantic salmon (Salmo salar) after millennia of isolation

PubMed Central

Sandlund, Odd Terje; Karlsson, Sten; Thorstad, Eva B; Berg, Ole Kristian; Kent, Matthew P; Norum, Ine C J; Hindar, Kjetil

2014-01-01

The river-resident Salmo salar (“småblank”) has been isolated from other Atlantic salmon populations for 9,500 years in upper River Namsen, Norway. This is the only European Atlantic salmon population accomplishing its entire life cycle in a river. Hydropower development during the last six decades has introduced movement barriers and changed more than 50% of the river habitat to lentic conditions. Based on microsatellites and SNPs, genetic variation within småblank was only about 50% of that in the anadromous Atlantic salmon within the same river. The genetic differentiation (FST) between småblank and the anadromous population was 0.24. This is similar to the differentiation between anadromous Atlantic salmon in Europe and North America. Microsatellite analyses identified three genetic subpopulations within småblank, each with an effective population size Ne of a few hundred individuals. There was no evidence of reduced heterozygosity and allelic richness in contemporary samples (2005–2008) compared with historical samples (1955–56 and 1978–79). However, there was a reduction in genetic differentiation between sampling localities over time. SNP data supported the differentiation of småblank into subpopulations and revealed downstream asymmetric gene flow between subpopulations. In spite of this, genetic variation was not higher in the lower than in the upper areas. The meta-population structure of småblank probably maintains genetic variation better than one panmictic population would do, as long as gene flow among subpopulations is maintained. Småblank is a unique endemic island population of Atlantic salmon. It is in a precarious situation due to a variety of anthropogenic impacts on its restricted habitat area. Thus, maintaining population size and avoiding further habitat fragmentation are important. PMID:24967074

In vitro modulation of Drimys winteri bark extract and the active compound polygodial on Salmo salar immune genes after exposure to Saprolegnia parasitica.

PubMed

Pereira-Torres, D; Gonçalves, A T; Ulloa, V; Martínez, R; Carrasco, H; Olea, A F; Espinoza, L; Gallardo-Escárate, C; Astuya, A

2016-12-01

The rapid development of the aquaculture industry has global concerns with health management and control strategies to prevent and/or treat diseases and increase sustainability standards. Saprolegniosis is a disease caused by Saprolegnia parasitica, and is characterized by promoting an immunosuppression in the host. This study evaluated in vitro the extract and one active compound (polygodial) of Drimys winteri, a Chilean medicinal tree as a potential early immunostimulatory aid in Saprolegniosis control. Atlantic salmon (Salmo salar) head kidney cells (ASK-1) were incubated with both extract and pure polygodial before exposure to S. parasitica mycelium, and the expression of the immune-related genes interleukin 1β (IL-1β), interferon α (IFNα), and major histocompatibility complex II (MHCII) was evaluated. Both evidenced immunomodulatory capacities by increasing gene expressions. This immunomodulation related to a mitigatory action counteracting the immunosuppressing effects of S. parasitica. Despite that most immune-related genes were up-regulated, the down-regulation of MHCII, characteristic of S. parasitica infection, was lessened by pre-incubation with the compounds. This study provides the first insight on the potential of D. winteri bark extract as a possible immunomodulatory and defensive strategy against this oomycete infection in fish. Copyright © 2016 Elsevier Ltd. All rights reserved.

Seasonally-Dynamic Presence-Only Species Distribution Models for a Cryptic Migratory Bat Impacted by Wind Energy Development

PubMed Central

Hayes, Mark A.; Cryan, Paul M.; Wunder, Michael B.

2015-01-01

Understanding seasonal distribution and movement patterns of animals that migrate long distances is an essential part of monitoring and conserving their populations. Compared to migratory birds and other more conspicuous migrants, we know very little about the movement patterns of many migratory bats. Hoary bats (Lasiurus cinereus), a cryptic, wide-ranging, long-distance migrant, comprise a substantial proportion of the tens to hundreds of thousands of bat fatalities estimated to occur each year at wind turbines in North America. We created seasonally-dynamic species distribution models (SDMs) from 2,753 museum occurrence records collected over five decades in North America to better understand the seasonal geographic distributions of hoary bats. We used 5 SDM approaches: logistic regression, multivariate adaptive regression splines, boosted regression trees, random forest, and maximum entropy and consolidated outputs to generate ensemble maps. These maps represent the first formal hypotheses for sex- and season-specific hoary bat distributions. Our results suggest that North American hoary bats winter in regions with relatively long growing seasons where temperatures are moderated by proximity to oceans, and then move to the continental interior for the summer. SDMs suggested that hoary bats are most broadly distributed in autumn—the season when they are most susceptible to mortality from wind turbines; this season contains the greatest overlap between potentially suitable habitat and wind energy facilities. Comparing wind-turbine fatality data to model outputs could test many predictions, such as ‘risk from turbines is highest in habitats between hoary bat summering and wintering grounds’. Although future field studies are needed to validate the SDMs, this study generated well-justified and testable hypotheses of hoary bat migration patterns and seasonal distribution. PMID:26208098

Seasonally-dynamic presence-only species distribution models for a cryptic migratory bat impacted by wind energy development

USGS Publications Warehouse

Hayes, Mark A.; Cryan, Paul M.; Wunder, Michael B.

2015-01-01

Understanding seasonal distribution and movement patterns of animals that migrate long distances is an essential part of monitoring and conserving their populations. Compared to migratory birds and other more conspicuous migrants, we know very little about the movement patterns of many migratory bats. Hoary bats (Lasiurus cinereus), a cryptic, wide-ranging, long-distance migrant, comprise a substantial proportion of the tens to hundreds of thousands of bat fatalities estimated to occur each year at wind turbines in North America. We created seasonally-dynamic species distribution models (SDMs) from 2,753 museum occurrence records collected over five decades in North America to better understand the seasonal geographic distributions of hoary bats. We used 5 SDM approaches: logistic regression, multivariate adaptive regression splines, boosted regression trees, random forest, and maximum entropy and consolidated outputs to generate ensemble maps. These maps represent the first formal hypotheses for sex- and season-specific hoary bat distributions. Our results suggest that North American hoary bats winter in regions with relatively long growing seasons where temperatures are moderated by proximity to oceans, and then move to the continental interior for the summer. SDMs suggested that hoary bats are most broadly distributed in autumn—the season when they are most susceptible to mortality from wind turbines; this season contains the greatest overlap between potentially suitable habitat and wind energy facilities. Comparing wind-turbine fatality data to model outputs could test many predictions, such as ‘risk from turbines is highest in habitats between hoary bat summering and wintering grounds’. Although future field studies are needed to validate the SDMs, this study generated well-justified and testable hypotheses of hoary bat migration patterns and seasonal distribution.

Seasonally-Dynamic Presence-Only Species Distribution Models for a Cryptic Migratory Bat Impacted by Wind Energy Development.

PubMed

Hayes, Mark A; Cryan, Paul M; Wunder, Michael B

2015-01-01

Understanding seasonal distribution and movement patterns of animals that migrate long distances is an essential part of monitoring and conserving their populations. Compared to migratory birds and other more conspicuous migrants, we know very little about the movement patterns of many migratory bats. Hoary bats (Lasiurus cinereus), a cryptic, wide-ranging, long-distance migrant, comprise a substantial proportion of the tens to hundreds of thousands of bat fatalities estimated to occur each year at wind turbines in North America. We created seasonally-dynamic species distribution models (SDMs) from 2,753 museum occurrence records collected over five decades in North America to better understand the seasonal geographic distributions of hoary bats. We used 5 SDM approaches: logistic regression, multivariate adaptive regression splines, boosted regression trees, random forest, and maximum entropy and consolidated outputs to generate ensemble maps. These maps represent the first formal hypotheses for sex- and season-specific hoary bat distributions. Our results suggest that North American hoary bats winter in regions with relatively long growing seasons where temperatures are moderated by proximity to oceans, and then move to the continental interior for the summer. SDMs suggested that hoary bats are most broadly distributed in autumn-the season when they are most susceptible to mortality from wind turbines; this season contains the greatest overlap between potentially suitable habitat and wind energy facilities. Comparing wind-turbine fatality data to model outputs could test many predictions, such as 'risk from turbines is highest in habitats between hoary bat summering and wintering grounds'. Although future field studies are needed to validate the SDMs, this study generated well-justified and testable hypotheses of hoary bat migration patterns and seasonal distribution.

Evidence for an autumn downstream migration of Atlantic salmon Salmo salar (Linnaeus) and brown trout Salmo trutta (Linnaeus) parr to the Baltic Sea

NASA Astrophysics Data System (ADS)

Taal, Imre; Kesler, Martin; Saks, Lauri; Rohtla, Mehis; Verliin, Aare; Svirgsden, Roland; Jürgens, Kristiina; Vetemaa, Markus; Saat, Toomas

2014-06-01

In the eastern Baltic rivers, anadromous salmonid parr are known to smoltify and migrate to the sea from March until June, depending on latitude, climate and hydrological conditions. In this study, we present the first records of autumn descent of brown trout Salmo trutta and Atlantic salmon Salmo salar from the Baltic Sea Basin. Otolith microchemistry analyses revealed that these individuals hatched in freshwater and had migrated to the brackish water shortly prior to capture. The fish were collected in 2006, 2008, 2009 and 2013 from Eru Bay (surface salinity 4.5-6.5 ‰), Gulf of Finland. This relatively wide temporal range of observations indicates that the autumn descent of anadromous salmonids is not a random event. These results imply that autumn descent needs more consideration in the context of the effective stock management, assessment and restoration of Baltic salmonid populations and their habitats.

Serological and molecular heterogeneity among Yersinia ruckeri strains isolated from farmed Atlantic salmon Salmo salar in Chile.

PubMed

Bastardo, A; Bohle, H; Ravelo, C; Toranzo, A E; Romalde, J L

2011-02-22

We investigated 11 strains of Yersinia ruckeri, the causative agent of enteric redmouth disease (ERM), that had been isolated from Atlantic salmon Salmo salar L. farmed in Chile and previously vaccinated against ERM. Phylogenetic analysis of the 16S rRNA gene sequences confirmed the identification of the salmon isolates as Y. ruckeri. A comparative analysis of the biochemical characteristics was made by means of traditional and commercial miniaturised methods. All studied isolates were motile and Tween 80 positive, and were identified as biotype 1. In addition, drug susceptibility tests determined high sensitivity to sulphamethoxazole/trimethroprim, oxytetracycline, ampicillin and enrofloxacin in all isolates. Serological assays showed the presence of O1a, O1b and O2b serotypes, with a predominance of the O1b serotype in 9 strains. Analysis of the lipopolysaccharide profiles and the correspondent immunoblot confirmed these results. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) of the outer membrane proteins revealed that all Chilean strains had profiles with a molecular weight range between 34 and 55 kDa, with 3 distinct groups based on differences in the major bands. Genotyping analyses by enterobacterial repetitive intergenic consensus (ERIC-) and repetitive extragenic palindromic (REP-)PCR techniques clearly indicated intraspecific genetic diversity among Chilean Y. ruckeri strains.

Seasonal reproduction of vampire bats and its relation to seasonality of bovine rabies.

PubMed

Lord, R D

1992-04-01

Studies of pregnancy and lactation in vampire bats (Desmodus rotundus) in northern Argentina over a 4 yr period showed an inverse relationship between prevalence of pregnancy and lactation, the consequence of birth and onset of lactation, which was correlated with the wet season. The seasonal influx of young susceptibles into the vampire population in the wet season coincided with the well known increase in vampire transmitted rabies in that season.

Effect of chitosan-based coatings on the shelf life of salmon (Salmo salar).

PubMed

Souza, Bartolomeu W S; Cerqueira, Miguel A; Ruiz, Héctor A; Martins, Joana T; Casariego, Alicia; Teixeira, José A; Vicente, António A

2010-11-10

This study aimed at determining the effect of chitosan coating on shelf life extension of salmon ( Salmo salar ) fillets. The success of edible coatings depends highly on their effective wetting capacity of the surfaces on which they are applied. In this context in a first stage the surface properties of salmon fillets and the wetting capacity of the coatings on fish were evaluated. In terms of wettability there were no significant differences (p > 0.05) between the solutions presenting higher values (solutions 1-4); therefore, solution 1 with a spreading coefficient (Ws) of -4.73 mN m(-1), was chosen to be subsequently analyzed and applied on fish fillets. For shelf life analyses the fillets were coated and stored at 0 °C for 18 days. The control and coated fish samples were analyzed periodically for total aerobic plate count (TPC), pH, total volatile base nitrogen (TVB-N), trimethylamine (TMA), thiobarbituric acid (TBA), and ATP breakdown products (K value). The results showed that fish samples coated with chitosan presented a significant reduction (p < 0.05) for pH and K value after 6 days and for TVB, TMA, and TBA values after 9 days of storage, when compared to control samples. In terms of microbial growth, a slower increase in TPC was observed for the coated fish, indicating that chitosan-based coatings were effective in extending for an additional 3 days the shelf life of the salmon. These results demonstrate that chitosan-based coatings may be an alternative for extending the shelf life of salmon fillets during storage at 0 °C.

Osmoregulation in Atlantic salmon Salmo salar smolts transferred to seawater at different temperatures.

PubMed

Handeland, S O; Imsland, A K; Nilsen, T O; Ebbesson, L O E; Hosfeld, C D; Pedrosa, C; Toften, H; Stefansson, S O

2014-10-01

In order to investigate how changes in gill Na(+) , K(+) -ATPase (NKA) α1a and α1b subunits, Na(+) , K(+) , 2Cl(-) co-transporter (NKCC1) and the apical cystic fibrosis trans-membrane conductance regulator-I (CFTR-I) transcripts in wild strain of Atlantic salmon, Salmo salar, smolts are affected by temperature during spring, hatchery-reared parr (mean ± s.e. fork length = 14·1 ± 0·5; mean ± s.e. body mass = 28·5 ± 4·5 g) originating from broodstock from the Vosso river (western Norway) were acclimated to three temperature regimes (4·1, 8·1 and 12·9° C) in May and reared under gradually increasing salinity between May and June. Changes in plasma Na(+) , haematocrit (Hct) and PCO2 were monitored in order to assess and compare key physiological changes with the transcriptional changes in key ion transporters. The temperatures reflect the natural temperature range in the River Vosso during late spring. Overall, higher gill NKA α1b mRNA levels, gill NKCC1a levels and CFTR-I levels were observed in the 4·1° C group compared to the 11·9° C group. This coincided with a 2-3 week period with decreased Hct and PCO2 and may indicate a critical window when smolts suffer from reduced physical performance during migration. Further research is needed to confirm the potential interaction between ecological and physiological conditions on mortality of hatchery-reared smolts from River Vosso during their natural migration. © 2014 The Fisheries Society of the British Isles.

Seasonal forecasts of impact-relevant climate information indices developed as part of the EUPORIAS project

NASA Astrophysics Data System (ADS)

Spirig, Christoph; Bhend, Jonas

2015-04-01

Climate information indices (CIIs) represent a way to communicate climate conditions to specific sectors and the public. As such, CIIs provide actionable information to stakeholders in an efficient way. Due to their non-linear nature, such CIIs can behave differently than the underlying variables, such as temperature. At the same time, CIIs do not involve impact models with different sources of uncertainties. As part of the EU project EUPORIAS (EUropean Provision Of Regional Impact Assessment on a Seasonal-to-decadal timescale) we have developed examples of seasonal forecasts of CIIs. We present forecasts and analyses of the skill of seasonal forecasts for CIIs that are relevant to a variety of economic sectors and a range of stakeholders: heating and cooling degree days as proxies for energy demand, various precipitation and drought-related measures relevant to agriculture and hydrology, a wild fire index, a climate-driven mortality index and wind-related indices tailored to renewable energy producers. Common to all examples is the finding of limited forecast skill over Europe, highlighting the challenge for providing added-value services to stakeholders operating in Europe. The reasons for the lack of forecast skill vary: often we find little skill in the underlying variable(s) precisely in those areas that are relevant for the CII, in other cases the nature of the CII is particularly demanding for predictions, as seen in the case of counting measures such as frost days or cool nights. On the other hand, several results suggest there may be some predictability in sub-regions for certain indices. Several of the exemplary analyses show potential for skillful forecasts and prospect for improvements by investing in post-processing. Furthermore, those cases for which CII forecasts showed similar skill values as those of the underlying meteorological variables, forecasts of CIIs provide added value from a user perspective.

Rural food security, subsistence agriculture, and seasonality

PubMed Central

Sibhatu, Kibrom T.

2017-01-01

Many of the world’s food-insecure and undernourished people are smallholder farmers in developing countries. This is especially true in Africa. There is an urgent need to make smallholder agriculture and food systems more nutrition-sensitive. African farm households are known to consume a sizeable part of what they produce at home. Less is known about how much subsistence agriculture actually contributes to household diets, and how this contribution changes seasonally. We use representative data from rural Ethiopia covering every month of one full year to address this knowledge gap. On average, subsistence production accounts for 58% of rural households’ calorie consumption, that is, 42% of the calories consumed are from purchased foods. Some seasonal variation occurs. During the lean season, purchased foods account for more than half of all calories consumed. But even during the main harvest and post-harvest season, purchased foods contribute more than one-third to total calorie consumption. Markets are even more important for dietary quality. During all seasons, purchased foods play a much larger role for dietary diversity than subsistence production. These findings suggest that strengthening rural markets needs to be a key element in strategies to improve food security and dietary quality in the African small-farm sector. PMID:29049329

Rural food security, subsistence agriculture, and seasonality.

PubMed

Sibhatu, Kibrom T; Qaim, Matin

2017-01-01

Many of the world's food-insecure and undernourished people are smallholder farmers in developing countries. This is especially true in Africa. There is an urgent need to make smallholder agriculture and food systems more nutrition-sensitive. African farm households are known to consume a sizeable part of what they produce at home. Less is known about how much subsistence agriculture actually contributes to household diets, and how this contribution changes seasonally. We use representative data from rural Ethiopia covering every month of one full year to address this knowledge gap. On average, subsistence production accounts for 58% of rural households' calorie consumption, that is, 42% of the calories consumed are from purchased foods. Some seasonal variation occurs. During the lean season, purchased foods account for more than half of all calories consumed. But even during the main harvest and post-harvest season, purchased foods contribute more than one-third to total calorie consumption. Markets are even more important for dietary quality. During all seasons, purchased foods play a much larger role for dietary diversity than subsistence production. These findings suggest that strengthening rural markets needs to be a key element in strategies to improve food security and dietary quality in the African small-farm sector.

Seasonal Forecast Skill And Teleconnections Over East Africa

NASA Astrophysics Data System (ADS)

MacLeod, D.; Palmer, T.

2017-12-01

Many people living in East Africa are significantly exposed to risks arising from climate variability. The region experiences two rainy seasons and poor performance of either or both of these (such as seen recently in 2016/17) reduces agricultural productivity and threatens food security. In combination with other factors this can lead to famine. By utilizing seasonal climate forecasts, preparatory actions can be taken in order to mitigate the risks arising from such climate variability. As part of the project ForPAc: "Towards forecast-based preparedness action", we are working with humanitarian agencies in Kenya to build such early warning systems on subseasonal-to-seasonal timescales. Here, the seasonal predictability and forecast skill of the two East African rainy seasons will be presented. Results from the new ECMWF operational forecasting system SEAS5 will be shown and compared to the previous System 4. Analysis of a new 110 year long atmosphere-only simulation will also be discussed, demonstrating impacts of atmosphere-ocean coupling as well as putting operational forecast skill in a long-term context. Particular focus will be given to the model representation of teleconnections of seasonal climate with global sea surface temperatures; highlighting sources of forecast error and informing future model development.

Infectious haematopoietic necrosis epidemic (2001 to 2003) in farmed Atlantic salmon Salmo salar in British Columbia.

PubMed

Saksida, S M

2006-10-27

I investigated a recent infectious haematopoietic necrosis disease (IHN) epidemic in farmed Atlantic salmon Salmo salar in British Columbia (BC), Canada. All companies with infected farms (n = 36) participated in the study. Over 12 million Atlantic salmon on infected farms died or were culled during the epidemic with cumulative mortality on the farms averaging 58%. The first reported case of IHN occurred in August 2001 and the last outbreak in June 2003. Outbreaks on the farms lasted between 20 and 22 wk. Genetic sequencing by other researchers, revealed that 2 different IHN isolates contributed to this epidemic, one linked to all cases in 4 areas, the other associated with all cases in a fifth area. Spatial and temporal patterns of the farm outbreaks were examined to determine possible methods of spread between the farms. Evidence presented herein appears to show that farming practices themselves contributed significantly to the spread between farms both within and between areas. Natural waterborne transmission may have played a role in the spread of the virus between farms located in close proximity to each other. The data collected from this epidemic are compared with reports which examined the first reported epidemic in Atlantic salmon in BC (1992 to 1996). Evidence is presented for the hypothesis that wild fish species may have been the source of introduction of the virus into the farmed Atlantic salmon population.

Prokaryotic diversity and community composition in the Salar de Uyuni, a large scale, chaotropic salt flat.

PubMed

dC Rubin, Sergio S; Marín, Irma; Gómez, Manuel J; Morales, Eduardo A; Zekker, Ivar; San Martín-Uriz, Patxi; Rodríguez, Nuria; Amils, Ricardo

2017-09-01

Salar de Uyuni (SdU), with a geological history that reflects 50 000 years of climate change, is the largest hypersaline salt flat on Earth and is estimated to be the biggest lithium reservoir in the world. Its salinity reaches saturation levels for NaCl, a kosmotropic salt, and high concentrations of MgCL 2 and LiCl, both salts considered important chaotrophic stressors. In addition, extreme temperatures, anoxic conditions, high UV irradiance, high albedo and extremely low concentrations of phosphorous, make SdU a unique natural extreme environment in which to contrast hypotheses about limiting factors of life diversification. Geophysical studies of brines from different sampling stations show that water activity is rather constant along SdU. Geochemical measurements show significant differences in magnesium concentration, ranging from 0.2 to 2M. This work analyses the prokaryotic diversity and community structure at four SdU sampling stations, selected according to their location and ionic composition. Prokaryotic communities were composed of both Archaea (with members of the classes Halobacteria, Thermoplasmata and Nanohaloarchaea, from the Euryarchaeota and Nanohaloarcheota phyla respectively) and Bacteria (mainly belonging to Bacteroidetes and Proteobacteria phyla). The important differences in composition of microbial communities inversely correlate with Mg 2+ concentration, suggesting that prokaryotic diversity at SdU is chaotropic dependent. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

'Good genes as heterozygosity': the major histocompatibility complex and mate choice in Atlantic salmon (Salmo salar).

PubMed

Landry, C; Garant, D; Duchesne, P; Bernatchez, L

2001-06-22

According to the theory of mate choice based on heterozygosity, mates should choose each other in order to increase the heterozygosity of their offspring. In this study, we tested the 'good genes as heterozygosity' hypothesis of mate choice by documenting the mating patterns of wild Atlantic salmon (Salmo salar) using both major histocompatibility complex (MHC) and microsatellite loci. Specifically, we tested the null hypotheses that mate choice in Atlantic salmon is not dependent on the relatedness between potential partners or on the MHC similarity between mates. Three parameters were assessed: (i) the number of shared alleles between partners (x and y) at the MHC (M(xy)), (ii) the MHC amino-acid genotypic distance between mates' genotypes (AA(xy)), and (iii) genetic relatedness between mates (r(xy)). We found that Atlantic salmon choose their mates in order to increase the heterozygosity of their offspring at the MHC and, more specifically, at the peptide-binding region, presumably in order to provide them with better defence against parasites and pathogens. This was supported by a significant difference between the observed and expected AA(xy) (p = 0.0486). Furthermore, mate choice was not a mechanism of overall inbreeding avoidance as genetic relatedness supported a random mating scheme (p = 0.445). This study provides the first evidence that MHC genes influence mate choice in fish.

Comparison of fatty acids and lipids of smolting hatchery-fed and wild Atlantic salmon Salmo salar.

PubMed

Ackman, R G; Takeuchi, T

1986-02-01

In Atlantic Canada the Atlantic salmon Salmo salar change from the parr stage to the smolt stage while still in fresh water, preparatory to migration to salt water. In some stocks this takes place during the second overwintering. In several hatcheries where the water temperature drops to 0-0.5 C and the ponds ice over, there is a high incidence of erosion of the dorsal and pectoral fins and sometimes of the caudal fin. No disease organism has been identified, and the lesions heal over in most cases. Dietary fatty acids were thought to be a factor. A detailed study of lipid recoveries and classes has shown that in the skins of abnormal fish the total lipid is 7.8% compared to 4.7% in control fish. Unexpectedly, an analysis of one lot of healthy smoltstage wild fish showed that whole bodies have only a quarter of the lipid of comparable hatchery fish. Comparison of fatty acids showed that wild fish lipids include a higher proportion of arachidonic acid than those of the hatchery fish. In the latter, linoleic acid is provided readily by diet but the elongation to arachidonic acid evidently does not proceed. These results suggest that the smolt lipid is involved intimately with either the cause of the dermal lesion or is a defense mechanism, possibly mediated through oxygenase activity.

Molecular modeling of class I and II alleles of the major histocompatibility complex in Salmo salar.

PubMed

Cárdenas, Constanza; Bidon-Chanal, Axel; Conejeros, Pablo; Arenas, Gloria; Marshall, Sergio; Luque, F Javier

2010-12-01

Knowledge of the 3D structure of the binding groove of major histocompatibility (MHC) molecules, which play a central role in the immune response, is crucial to shed light into the details of peptide recognition and polymorphism. This work reports molecular modeling studies aimed at providing 3D models for two class I and two class II MHC alleles from Salmo salar (Sasa), as the lack of experimental structures of fish MHC molecules represents a serious limitation to understand the specific preferences for peptide binding. The reliability of the structural models built up using bioinformatic tools was explored by means of molecular dynamics simulations of their complexes with representative peptides, and the energetics of the MHC-peptide interaction was determined by combining molecular mechanics interaction energies and implicit continuum solvation calculations. The structural models revealed the occurrence of notable differences in the nature of residues at specific positions in the binding groove not only between human and Sasa MHC proteins, but also between different Sasa alleles. Those differences lead to distinct trends in the structural features that mediate the binding of peptides to both class I and II MHC molecules, which are qualitatively reflected in the relative binding affinities. Overall, the structural models presented here are a valuable starting point to explore the interactions between MHC receptors and pathogen-specific interactions and to design vaccines against viral pathogens.

Seasonal variation of polycyclic aromatic hydrocarbons (PAHs) emissions in China.

PubMed

Zhang, Yanxu; Tao, Shu

2008-12-01

A regression model based on the provincial energy consumption data was developed to calculate the monthly proportions of residential energy consumption compared to the total year volume. This model was also validated by comparing with some survey and statistical data. With this model, a PAHs emission inventory with seasonal variation was developed. The seasonal variations of different sources in different regions of China and the spatial distribution of the major sources in different seasons were also achieved. The PAHs emissions were larger in the winter than in the summer, with a difference of about 1.3-folds between the months with the largest and the smallest emissions. Residential solid fuel combustion dominated the pattern of seasonal variation with the winter-time emissions as much as 1.6 times as that in the summer, while the emissions from wild fires and open fire straw burning was mainly concentrated during the spring and summer.

Factors associated with differential uptake of seasonal influenza immunizations among underserved communities during the 2009-2010 influenza season.

PubMed

Vlahov, David; Bond, Keosha T; Jones, Kandice C; Ompad, Danielle C

2012-04-01

Influenza vaccination coverage remains low and disparities persist. In New York City, a community-based participatory research project (Project VIVA) worked to address this issue in Harlem and the South Bronx by supplementing existing vaccination programs with non-traditional venues (i.e., community-based organizations). We conducted a 10 min survey to assess access to influenza vaccine as well as attitudes and beliefs towards influenza vaccination that could inform intervention development for subsequent seasons. Among 991 participants recruited using street intercept techniques, 63% received seasonal vaccine only, 11% seasonal and H1N1, and 26% neither; 89% reported seeing a health care provider (HCP) during the influenza season. Correlates of immunization among those with provider visits during the influenza season included being US-born, interest in getting the vaccine, concern about self or family getting influenza, an HCP's recommendation and comfort with government. Among those without an HCP visit, factors associated with immunization included being US born, married, interest in getting the vaccine, understanding influenza information, and concern about getting influenza. Factors associated with lack of interest in influenza vaccine included being born outside the US, Black and uncomfortable with government. In medically underserved areas, having access to routine medical care and understanding the medical implications of influenza play an important role in enhancing uptake of seasonal influenza vaccination. Strategies to improve vaccination rates among Blacks and foreign-born residents need to be addressed. The use of non-traditional venues to provide influenza vaccinations in underserved communities has the potential to reduce health disparities.

Effects of feeding and stocking density on digestion of cultured Atlantic salmon Salmo salar L.

NASA Astrophysics Data System (ADS)

Sun, Guoxiang; Zheng, Jimeng; Liu, Baoliang; Liu, Ying

2014-11-01

The combined effects of feeding rate (0.8%, 1.0%, and 1.2% initial body weight/day), feeding frequency (two, three, and four times/day) and stocking density (10, 15, and 20 kg/m3) in recirculating aquaculture systems (RAS) on growth performance, digestion and waste generation of Atlantic salmon ( Salmo salar L.) were investigated in an 8-week orthogonal experiment (L9(3)3) with a constant daily water renewal at 7.50% of total volume. No mortality occurred during the experimental period. Feed conversion ratio (FCR) varied from 0.90 to 1.13 and specific growth rate (SGR) ranged from 0.48% to 0.69%/day. SGR, thermal growth coefficient (TGC) and FCR were not significantly ( P>0.05) affected by the three factors, while net protein utilization (NPU) was significantly ( P<0.05) affected. Apparent digestibility coefficients (ADC) of dry matter in the present study were in the range 66.12%-73.55%. ADC in protein, lipid and energy were statistically different among all treatments and in the range of 90.07%-93.67%, 81.54%-89.15%, and 67.55%-71.87%, respectively. The proportion of mean total ammonia nitrogen excreted ranged from 1.37% to 1.64% of feed nitrogen at steady state, and the concentration of nitrogenous and phosphorus compounds were differently correlated to the three factors. The results will provide valuable reference data for culture management decisions in the Atlantic salmon farming industry.

From Novice to Seasoned Practitioner: a Qualitative Investigation of Genetic Counselor Professional Development.

PubMed

Zahm, Kimberly Wehner; Veach, Patricia McCarthy; Martyr, Meredith A; LeRoy, Bonnie S

2016-08-01

Research on genetic counselor professional development would characterize typical developmental processes, inform training and supervision, and promote life-long development opportunities. To date, however no studies have comprehensively examined this phenomenon. The aims of this study were to investigate the nature of professional development for genetic counselors (processes, influences, and outcomes) and whether professional development varies across experience levels. Thirty-four genetic counselors participated in semi-structured telephone interviews exploring their perspectives on their professional development. Participants were sampled from three levels of post-degree genetic counseling experience: novice (0-5 years), experienced (6-14 years), and seasoned (>15 years). Using modified Consensual Qualitative Research and grounded theory methods, themes, domains, and categories were extracted from the data. The themes reflect genetic counselors' evolving perceptions of their professional development and its relationship to: (a) being a clinician, (b) their professional identity, and (c) the field itself. Across experience levels, prevalent influences on professional development were interpersonal (e.g., experiences with patients, genetic counseling colleagues) and involved professional and personal life events. Common developmental experiences included greater confidence and less anxiety over time, being less information-driven and more emotion-focused with patients, delivering "bad news" to patients remains challenging, and individuals' professional development experiences parallel genetic counseling's development as a field. With a few noteworthy exceptions, professional development was similar across experience levels. A preliminary model of genetic counselor professional development is proposed suggesting development occurs in a non-linear fashion throughout the professional lifespan. Each component of the model mutually influences the others, and there

Geometry and the Physics of Seasons

ERIC Educational Resources Information Center

Khavrus, Vyacheslav; Shelevytsky, Ihor

2012-01-01

By means of a simple mathematical model recently developed by the authors (2010 "Phys. Educ." 45 641), the passage of the seasons on the Earth is simulated for arbitrary latitudes, taking into account sunlight attenuation in the atmosphere. The method developed can be used to predict a realistic value of the solar energy input (insolation) that…

Modeling gypsy moth seasonality

Treesearch

J. A. Logan; D. R. Gray

1991-01-01

Maintaining an appropriate seasonality is perhaps the most basic ecological requisite for insects living in temperate environments. The basic ecological importance of seasonality is enough to justify expending considerable effort to accurately model the processes involved. For insects of significant economic consequence, seasonality assumes additional importance...

Seasonally asymmetric enhancement of northern vegetation productivity

NASA Astrophysics Data System (ADS)

Park, T.; Myneni, R.

2017-12-01

Multiple evidences of widespread greening and increasing terrestrial carbon uptake have been documented. In particular, enhanced gross productivity of northern vegetation has been a critical role leading to observed carbon uptake trend. However, seasonal photosynthetic activity and its contribution to observed annual carbon uptake trend and interannual variability are not well understood. Here, we introduce a multiple-source of datasets including ground, atmospheric and satellite observations, and multiple process-based global vegetation models to understand how seasonal variation of land surface vegetation controls a large-scale carbon exchange. Our analysis clearly shows a seasonally asymmetric enhancement of northern vegetation productivity in growing season during last decades. Particularly, increasing gross productivity in late spring and early summer is obvious and dominant driver explaining observed trend and variability. We observe more asymmetric productivity enhancement in warmer region and this spatially varying asymmetricity in northern vegetation are likely explained by canopy development rate, thermal and light availability. These results imply that continued warming may facilitate amplifying asymmetric vegetation activity and cause these trends to become more pervasive, in turn warming induced regime shift in northern land.

Development of the Seasonal Migrant Agricultural Worker Stress Scale in Sanliurfa, Southeast Turkey.

PubMed

Simsek, Zeynep; Ersin, Fatma; Kirmizitoprak, Evin

2016-01-01

Stress is one of the main causes of health problems, especially mental disorders. These health problems cause a significant amount of ability loss and increase cost. It is estimated that by 2020, mental disorders will constitute 15% of the total disease burden, and depression will rank second only after ischemic heart disease. Environmental experiences are paramount in increasing the liability of mental disorders in those who constantly face sustained high levels of stress. The objective of this study was to develop a stress scale for seasonal migrant agricultural workers aged 18 years and older. The sample consisted of 270 randomly selected seasonal migrant agricultural workers. The average age of the participants was 33.1 ± 14, and 50.7% were male. The Cronbach alpha coefficient and test-retest methods were used for reliability analyses. Although the factor analysis was performed for the structure validity of the scale, the Kaiser-Meyer-Olkin coefficient and Bartlett test were used to determine the convenience of the data for the factor analysis. In the reliability analyses, the Cronbach alpha coefficient of internal consistency was calculated as .96, and the test-retest reliability coefficient was .81. In the exploratory factor analysis for validity of the scale, four factors were obtained, and the factors represented workplace physical conditions (25.7% of the total variance), workplace psychosocial and economic factors (19.3% of the total variance), workplace health problems (15.2% of the total variance), and school problems (10.1% of the total variance). The four factors explained 70.3% of the total variance. As a result of the expert opinions and analyses, a stress scale with 48 items was developed. The highest score to be obtained from the scale was 144, and the lowest score was 0. The increase in the score indicates the increase in the stress levels. The findings show that the scale is a valid and reliable assessment instrument that can be used in

House and stable fly (Diptera: Muscidae) seasonal abundance, larval development substrates, and natural parasitism on small equine farms in Florida

USDA-ARS?s Scientific Manuscript database

This 1-year study was designed to determine adult fly population levels and development substrates on four small equine farms. Results showed that pest flies were present year-round, but differences existed in population levels among farms and seasons. Fly larvae were not found on two of the farms, ...

The seasonal-cycle climate model

NASA Technical Reports Server (NTRS)

Marx, L.; Randall, D. A.

1981-01-01

The seasonal cycle run which will become the control run for the comparison with runs utilizing codes and parameterizations developed by outside investigators is discussed. The climate model currently exists in two parallel versions: one running on the Amdahl and the other running on the CYBER 203. These two versions are as nearly identical as machine capability and the requirement for high speed performance will allow. Developmental changes are made on the Amdahl/CMS version for ease of testing and rapidity of turnaround. The changes are subsequently incorporated into the CYBER 203 version using vectorization techniques where speed improvement can be realized. The 400 day seasonal cycle run serves as a control run for both medium and long range climate forecasts alsensitivity studies.

Discrimination of chicken seasonings and beef seasonings using electronic nose and sensory evaluation.

PubMed

Tian, Huaixiang; Li, Fenghua; Qin, Lan; Yu, Haiyan; Ma, Xia

2014-11-01

This study examines the feasibility of electronic nose as a method to discriminate chicken and beef seasonings and to predict sensory attributes. Sensory evaluation showed that 8 chicken seasonings and 4 beef seasonings could be well discriminated and classified based on 8 sensory attributes. The sensory attributes including chicken/beef, gamey, garlic, spicy, onion, soy sauce, retention, and overall aroma intensity were generated by a trained evaluation panel. Principal component analysis (PCA), discriminant factor analysis (DFA), and cluster analysis (CA) combined with electronic nose were used to discriminate seasoning samples based on the difference of the sensor response signals of chicken and beef seasonings. The correlation between sensory attributes and electronic nose sensors signal was established using partial least squares regression (PLSR) method. The results showed that the seasoning samples were all correctly classified by the electronic nose combined with PCA, DFA, and CA. The electronic nose gave good prediction results for all the sensory attributes with correlation coefficient (r) higher than 0.8. The work indicated that electronic nose is an effective method for discriminating different seasonings and predicting sensory attributes. © 2014 Institute of Food Technologists®

Seasonal affective disorder and non-seasonal affective disorders: results from the NESDA study

PubMed Central

Roest, Annelieke M.; Bos, Elisabeth H.; Meesters, Ybe; Penninx, Brenda W.J.H.; Nolen, Willem A.; de Jonge, Peter

2017-01-01

Background Seasonal affective disorder (SAD) is considered to be a subtype of depression. Aims To compare the clinical picture of SAD to non-seasonal affective disorders (non-SADs). Method Diagnoses according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) were established in 2185 participants of the Netherlands Study of Depression and Anxiety. The Seasonal Pattern Assessment Questionnaire was administered to diagnose SAD. Symptoms of depression and anxiety were measured with the Inventory of Depressive Symptoms, the Beck Anxiety Inventory and the Fear Questionnaire. Results Participants with SAD, participants with a lifetime bipolar disorder and participants with a lifetime comorbid anxiety and depressive disorder scored highest in terms of psychopathology in the past year. The seasonal distribution of major depressive episodes was not different for participants with or without SAD. Conclusions SAD may be a measure of severity of depression with a subjectively perceived worsening of symptoms in the winter months. Declaration of interest Y.M. has received research funding and served as a consultant for Royal Philips Electronics NV and The Litebook Company Ltd. W.A.N. has received grants from the Netherlands Organization for Health Research and Development, the European Union, the Stanley Medical Research Institute, Astra Zeneca, Eli Lilly, GlaxoSmithKline and Wyeth; has received honoraria/speaker’s fees from Astra Zeneca, Pfizer, Servier and Wyeth; and has served in advisory boards for Astra Zeneca, Pfizer and Servier. Copyright and usage © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license. PMID:28904813

Mate choice for major histocompatibility complex genetic divergence as a bet-hedging strategy in the Atlantic salmon (Salmo salar).

PubMed

Evans, Melissa L; Dionne, Mélanie; Miller, Kristina M; Bernatchez, Louis

2012-01-22

Major histocompatibility complex (MHC)-dependent mating preferences have been observed across vertebrate taxa and these preferences are expected to promote offspring disease resistance and ultimately, viability. However, little empirical evidence linking MHC-dependent mate choice and fitness is available, particularly in wild populations. Here, we explore the adaptive potential of previously observed patterns of MHC-dependent mate choice in a wild population of Atlantic salmon (Salmo salar) in Québec, Canada, by examining the relationship between MHC genetic variation and adult reproductive success and offspring survival over 3 years of study. While Atlantic salmon choose their mates in order to increase MHC diversity in offspring, adult reproductive success was in fact maximized between pairs exhibiting an intermediate level of MHC dissimilarity. Moreover, patterns of offspring survival between years 0+ and 1+, and 1+ and 2+ and population genetic structure at the MHC locus relative to microsatellite loci indicate that strong temporal variation in selection is likely to be operating on the MHC. We interpret MHC-dependent mate choice for diversity as a likely bet-hedging strategy that maximizes parental fitness in the face of temporally variable and unpredictable natural selection pressures.

Mate choice for major histocompatibility complex genetic divergence as a bet-hedging strategy in the Atlantic salmon (Salmo salar)

PubMed Central

Evans, Melissa L.; Dionne, Mélanie; Miller, Kristina M.; Bernatchez, Louis

2012-01-01

Major histocompatibility complex (MHC)-dependent mating preferences have been observed across vertebrate taxa and these preferences are expected to promote offspring disease resistance and ultimately, viability. However, little empirical evidence linking MHC-dependent mate choice and fitness is available, particularly in wild populations. Here, we explore the adaptive potential of previously observed patterns of MHC-dependent mate choice in a wild population of Atlantic salmon (Salmo salar) in Québec, Canada, by examining the relationship between MHC genetic variation and adult reproductive success and offspring survival over 3 years of study. While Atlantic salmon choose their mates in order to increase MHC diversity in offspring, adult reproductive success was in fact maximized between pairs exhibiting an intermediate level of MHC dissimilarity. Moreover, patterns of offspring survival between years 0+ and 1+, and 1+ and 2+ and population genetic structure at the MHC locus relative to microsatellite loci indicate that strong temporal variation in selection is likely to be operating on the MHC. We interpret MHC-dependent mate choice for diversity as a likely bet-hedging strategy that maximizes parental fitness in the face of temporally variable and unpredictable natural selection pressures. PMID:21697172

Seasonal thermal energy storage

NASA Astrophysics Data System (ADS)

Minor, J. E.

1980-03-01

The Seasonal Thermal Energy Storage (STES) Program demonstrates the economic storage and retrieval of thermal energy on a seasonal basis, using heat or cold available from waste or other sources during a surplus period to reduce peak period demand, reduce electric utilities peaking problems, and contribute to the establishment of favorable economics for district heating and cooling systems for commercialization of the technology. The STES Program utilizes ground water systems (aquifers) for thermal energy storage. The STES Program is divided into an Aquifer Thermal Energy Storage (ATES) Demonstration Task for demonstrating the commercialization potential of aquifer thermal energy storage technology using an integrated system approach to multiple demonstration projects and a parallel Technical Support Task designed to provide support to the overall STES Program, and to reduce technological and institutional barriers to the development of energy storage systems prior to significant investment in demonstration or commercial facilities.

Home in the heat: Dramatic seasonal variation in home range of desert golden eagles informs management for renewable energy development

USGS Publications Warehouse

Braham, Melissa A.; Miller, Tricia A.; Duerr, Adam E.; Lanzone, Michael J.; Fesnock, Amy; LaPre, Larry; Driscoll, Daniel; Katzner, Todd E.

2015-01-01

Renewable energy is expanding quickly with sometimes dramatic impacts to species and ecosystems. To understand the degree to which sensitive species may be impacted by renewable energy projects, it is informative to know how much space individuals use and how that space may overlap with planned development. We used global positioning system–global system for mobile communications (GPS-GSM) telemetry to measure year-round movements of golden eagles (Aquila chrysaetos) from the Mojave Desert of California, USA. We estimated monthly space use with adaptive local convex hulls to identify the temporal and spatial scales at which eagles may encounter renewable energy projects in the Desert Renewable Energy Conservation Plan area. Mean size of home ranges was lowest and least variable from November through January and greatest in February–March and May–August. These monthly home range patterns coincided with seasonal variation in breeding ecology, habitat associations, and temperature. The expanded home ranges in hot summer months included movements to cooler, prey-dense, mountainous areas characterized by forest, grasslands, and scrublands. Breeding-season home ranges (October–May) included more lowland semi-desert and rock vegetation. Overlap of eagle home ranges and focus areas for renewable energy development was greatest when eagle home ranges were smallest, during the breeding season. Golden eagles in the Mojave Desert used more space and a wider range of habitat types than expected and renewable energy projects could affect a larger section of the regional population than was previously thought.

Seasonality and dietary requirements: will eating seasonal food contribute to health and environmental sustainability?

PubMed

Macdiarmid, Jennie I

2014-08-01

Eating more seasonal food is one proposal for moving towards more sustainable consumption patterns, based on the assumption that it could reduce the environmental impact of the diet. The aim of the present paper is to consider the implications of eating seasonal food on the different elements of sustainability (i.e. health, economics, society), not just the environment. Seasonality can be defined as either globally seasonal (i.e. produced in the natural production season but consumed anywhere in the world) or locally seasonal (i.e. produced in the natural production season and consumed within the same climatic zone). The environmental, health, economic and societal impact varies by the definition used. Global seasonality has the nutritional benefit of providing a more varied and consistent supply of fresh produce year round, but this increases demand for foods that in turn can have a high environmental cost in the country of production (e.g. water stress, land use change with loss of biodiversity). Greenhouse gas emissions of globally seasonal food are not necessarily higher than food produced locally as it depends more on the production system used than transportation. Eating more seasonal food, however, is only one element of a sustainable diet and should not overshadow some of the potentially more difficult dietary behaviours to change that could have greater environmental and health benefits (e.g. reducing overconsumption or meat consumption). For future guidelines for sustainable diets to be realistic they will need to take into account modern lifestyles, cultural and social expectations in the current food environment.

Seasonal Variation in Epidemiology

ERIC Educational Resources Information Center

Marrero, Osvaldo

2013-01-01

Seasonality analyses are important in medical research. If the incidence of a disease shows a seasonal pattern, then an environmental factor must be considered in its etiology. We discuss a method for the simultaneous analysis of seasonal variation in multiple groups. The nuts and bolts are explained using simple trigonometry, an elementary…

Seasonal fuel consumption, stoves, and end-uses in rural households of the far-western development region of Nepal

NASA Astrophysics Data System (ADS)

Lam, Nicholas L.; Upadhyay, Basudev; Maharjan, Shovana; Jagoe, Kirstie; Weyant, Cheryl L.; Thompson, Ryan; Uprety, Sital; Johnson, Michael A.; Bond, Tami C.

2017-12-01

Understanding how fuels and stoves are used to meet a diversity of household needs is an important step in addressing the factors leading to continued reliance on polluting devices, and thereby improving household energy programs. In Nepal and many other countries dependent on solid fuel, efforts to mitigate the impacts of residential solid fuel use have emphasized cooking while focusing less on other solid fuel dependent end-uses. We employed a four-season fuel assessment in a cohort of 110 households residing in two elevation regions of the Far-Western Development Region (Province 7) of Nepal. Household interviews and direct fuel weights were used to assess seasonality in fuel consumption and its association with stoves that met cooking and non-cooking needs. Per-capita fuel consumption in winter was twice that of other measured seasons, on average. This winter increase was attributed to greater prevalence of use and fuel consumption by supplemental stoves, not the main cooking stove. End-use profiles showed that fuel was used in supplemental stoves to meet the majority of non-meal needs in the home, notably water heating and preparation of animal food. This emphasis on fuels, stoves, and the satisfaction of energy needs—rather than just stoves or fuels—leads to a better understanding of the factors leading to device and fuel choice within households.

NOAA predicts near-normal or below-normal 2014 Atlantic hurricane season

Science.gov Websites

Related link: Atlantic Basin Hurricane Season Outlook Discussion El Niño/Southern Oscillation (ENSO predicts near-normal or below-normal 2014 Atlantic hurricane season El Niño expected to develop and . The main driver of this year's outlook is the anticipated development of El Niño this summer. El NiÃ

Seasonal vegetation differences from ERTS imagery

NASA Technical Reports Server (NTRS)

Ashley, M. D.; Rea, J.

1975-01-01

Knowledge of the times when crop and forest vegetation experience seasonally related changes in development is important in understanding growth and yield relationships. This article describes how densitometry of earth resources technology satellite (ERTS-1) multispectral scanner (MSS) imagery can be used to identify such phenological events. Adjustments for instrument calibration, aperture size, gray-scale differences between overpasses, and normalization of changing solar elevation are considered in detail. Seasonal vegetation differences can be identified by densitometry of band 5 (0.6-0.7 microns) and band 7 (0.8-1.1 microns) MSS imagery. Band-to-band ratios of the densities depicted the changes more graphically than the individual band readings.

Reduction in antipredator response detected between first and second generations of endangered juvenile Atlantic salmon Salmo salar in a captive breeding and rearing programme.

PubMed

de Mestral, L G; Herbinger, C M

2013-11-01

Behaviour trials determining antipredator response were conducted on first and second generation juveniles from a captive breeding and rearing programme for endangered Inner Bay of Fundy Atlantic salmon Salmo salar. Second generation captive fry displayed significantly higher levels of risk-taking behaviour before and after exposure to a simulated avian predator. Because the first and second generation fry were reared under the same environmental conditions and differed only in the number of generations spent in captivity, these results suggest that rapid genetic changes, possibly due to domestication selection, may have occurred. Antipredator response was also assessed in fully wild and highly domesticated experimental groups: wild fry displayed the greatest antipredator response and domesticated fry displayed the highest levels of risk-taking behaviour. These results add to the growing evidence documenting rapid genetic change in response to rearing in a captive environment. © 2013 The Fisheries Society of the British Isles.

Effects of ocean initial perturbation on developing phase of ENSO in a coupled seasonal prediction model

NASA Astrophysics Data System (ADS)

Lee, Hyun-Chul; Kumar, Arun; Wang, Wanqiu

2018-03-01

Coupled prediction systems for seasonal and inter-annual variability in the tropical Pacific are initialized from ocean analyses. In ocean initial states, small scale perturbations are inevitably smoothed or distorted by the observational limits and data assimilation procedures, which tends to induce potential ocean initial errors for the El Nino-Southern Oscillation (ENSO) prediction. Here, the evolution and effects of ocean initial errors from the small scale perturbation on the developing phase of ENSO are investigated by an ensemble of coupled model predictions. Results show that the ocean initial errors at the thermocline in the western tropical Pacific grow rapidly to project on the first mode of equatorial Kelvin wave and propagate to the east along the thermocline. In boreal spring when the surface buoyancy flux weakens in the eastern tropical Pacific, the subsurface errors influence sea surface temperature variability and would account for the seasonal dependence of prediction skill in the NINO3 region. It is concluded that the ENSO prediction in the eastern tropical Pacific after boreal spring can be improved by increasing the observational accuracy of subsurface ocean initial states in the western tropical Pacific.

Seasonality of cavitation and frost fatigue in Acer mono Maxim.

PubMed

Zhang, Wen; Feng, Feng; Tyree, Melvin T

2017-12-08

Although cavitation is common in plants, it is unknown whether the cavitation resistance of xylem is seasonally constant or variable. We tested the changes in cavitation resistance of Acer mono before and after a controlled cavitation-refilling and freeze-thaw cycles for a whole year. Cavitation resistance was determined from 'vulnerability curves' showing the percent loss of conductivity versus xylem tension. Cavitation fatigue was defined as a reduction of cavitation resistance following a cavitation-refilling cycle, whereas frost fatigue was caused by a freeze-thaw cycle. A. mono developed seasonal changes in native embolisms; values were relatively high during winter but relatively low and constant throughout the growing season. Cavitation fatigue occurred and changed seasonally during the 12-month cycle; the greatest fatigue response occurred during summer and the weakest during winter, and the transitions occurred during spring and autumn. A. mono was highly resistant to frost damage during the relatively mild winter months; however, a quite different situation occurred during the growing season, as the seasonal trend of frost fatigue was strikingly similar to that of cavitation fatigue. Seasonality changes in cavitation resistance may be caused by seasonal changes in the mechanical properties of the pit membranes. © 2017 John Wiley & Sons Ltd.

Potential for western US seasonal snowpack prediction

USGS Publications Warehouse

Kapnick, Sarah B.; Yang, Xiaosong; Vecchi, Gabriel A.; Delworth, Thomas L.; Gudgel, Rich; Malyshev, Sergey; Milly, Paul C. D.; Shevliakova, Elena; Underwood, Seth; Margulis, Steven A.

2018-01-01

Western US snowpack—snow that accumulates on the ground in the mountains—plays a critical role in regional hydroclimate and water supply, with 80% of snowmelt runoff being used for agriculture. While climate projections provide estimates of snowpack loss by the end of th ecentury and weather forecasts provide predictions of weather conditions out to 2 weeks, less progress has been made for snow predictions at seasonal timescales (months to 2 years), crucial for regional agricultural decisions (e.g., plant choice and quantity). Seasonal predictions with climate models first took the form of El Niño predictions 3 decades ago, with hydroclimate predictions emerging more recently. While the field has been focused on single-season predictions (3 months or less), we are now poised to advance our predictions beyond this timeframe. Utilizing observations, climate indices, and a suite of global climate models, we demonstrate the feasibility of seasonal snowpack predictions and quantify the limits of predictive skill 8 month sin advance. This physically based dynamic system outperforms observation-based statistical predictions made on July 1 for March snowpack everywhere except the southern Sierra Nevada, a region where prediction skill is nonexistent for every predictor presently tested. Additionally, in the absence of externally forced negative trends in snowpack, narrow maritime mountain ranges with high hydroclimate variability pose a challenge for seasonal prediction in our present system; natural snowpack variability may inherently be unpredictable at this timescale. This work highlights present prediction system successes and gives cause for optimism for developing seasonal predictions for societal needs.

Developmental Hypoxia Has Negligible Effects on Long-Term Hypoxia Tolerance and Aerobic Metabolism of Atlantic Salmon (Salmo salar).

PubMed

Wood, Andrew T; Clark, Timothy D; Andrewartha, Sarah J; Elliott, Nicholas G; Frappell, Peter B

Exposure to developmental hypoxia can have long-term impacts on the physiological performance of fish because of irreversible plasticity. Wild and captive-reared Atlantic salmon (Salmo salar) can be exposed to hypoxic conditions during development and continue to experience fluctuating oxygen levels as juveniles and adults. Here, we examine whether developmental hypoxia impacts subsequent hypoxia tolerance and aerobic performance of Atlantic salmon. Individuals at 8°C were exposed to 50% (hypoxia) or 100% (normoxia) dissolved oxygen (DO) saturation (as percent of air saturation) from fertilization for ∼100 d (800 degree days) and then raised in normoxic conditions for a further 15 mo. At 18 mo after fertilization, aerobic scope was calculated in normoxia (100% DO) and acute (18 h) hypoxia (50% DO) from the difference between the minimum and maximum oxygen consumption rates ([Formula: see text] and [Formula: see text], respectively) at 10°C. Hypoxia tolerance was determined as the DO at which loss of equilibrium (LOE) occurred in a constantly decreasing DO environment. There was no difference in [Formula: see text], [Formula: see text], or aerobic scope between fish raised in hypoxia or normoxia. There was some evidence that hypoxia tolerance was lower (higher DO at LOE) in hypoxia-raised fish compared with those raised in normoxia, but the magnitude of the effect was small (12.52% DO vs. 11.73% DO at LOE). Acute hypoxia significantly reduced aerobic scope by reducing [Formula: see text], while [Formula: see text] remained unchanged. Interestingly, acute hypoxia uncovered individual-level relationships between DO at LOE and [Formula: see text], [Formula: see text], and aerobic scope. We discuss our findings in the context of developmental trajectories and the role of aerobic performance in hypoxia tolerance.

(13)C NMR pattern recognition techniques for the classification of Atlantic salmon (Salmo salar L.) according to their wild, farmed, and geographical origin.

PubMed

Aursand, Marit; Standal, Inger B; Praël, Angelika; McEvoy, Lesley; Irvine, Joe; Axelson, David E

2009-05-13

(13)C nuclear magnetic resonance (NMR) in combination with multivariate data analysis was used to (1) discriminate between farmed and wild Atlantic salmon ( Salmo salar L.), (2) discriminate between different geographical origins, and (3) verify the origin of market samples. Muscle lipids from 195 Atlantic salmon of known origin (wild and farmed salmon from Norway, Scotland, Canada, Iceland, Ireland, the Faroes, and Tasmania) in addition to market samples were analyzed by (13)C NMR spectroscopy and multivariate analysis. Both probabilistic neural networks (PNN) and support vector machines (SVM) provided excellent discrimination (98.5 and 100.0%, respectively) between wild and farmed salmon. Discrimination with respect to geographical origin was somewhat more difficult, with correct classification rates ranging from 82.2 to 99.3% by PNN and SVM, respectively. In the analysis of market samples, five fish labeled and purchased as wild salmon were classified as farmed salmon (indicating mislabeling), and there were also some discrepancies between the classification and the product declaration with regard to geographical origin.

Contrasting patterns of litterfall seasonality and seasonal changes in litter decomposability in a tropical rainforest region

NASA Astrophysics Data System (ADS)

Parsons, S. A.; Valdez-Ramirez, V.; Congdon, R. A.; Williams, S. E.

2014-09-01

The seasonality of litter inputs in forests has important implications for understanding ecosystem processes and biogeochemical cycles. We quantified the drivers of seasonality in litterfall and leaf decomposability using plots throughout the Australian wet tropical region. Litter fell mostly in the summer (wet, warm) months in the region, but other peaks occurred throughout the year. Litterfall seasonality was modelled well with the level of deciduousness of the site (plots with more deciduous species had lower seasonality than evergreen plots), temperature (higher seasonality in the uplands), disturbance (lower seasonality with more early secondary species) and soil fertility (higher seasonality with higher N : P/P limitation) (SL total litterfall model 1 = deciduousness + soil N : P + early secondary sp.: r2 = 0.63, n = 30; model 2 = temperature + early secondary sp. + soil N : P: r2 = 0.54, n = 30; SL leaf = temperature + early secondary sp. + rainfall seasonality: r2 = 0.39, n = 30). Leaf litter decomposability was lower in the dry season than in the wet season, driven by higher phenolic concentrations in the dry, with the difference exacerbated particularly by lower dry season moisture. Our results are contrary to the global trend for tropical rainforests; in that seasonality of litterfall input was generally higher in wetter, cooler, evergreen forests, compared to generally drier, warmer, semi-deciduous sites that had more uniform monthly inputs. We consider this due to more diverse litter shedding patterns in semi-deciduous and raingreen rainforest sites, and an important consideration for ecosystem modellers. Seasonal changes in litter quality are likely to have impacts on decomposition and biogeochemical cycles in these forests due to the litter that falls in the dry season being more recalcitrant to decay.

Seasonal land-cover regions of the United States

USGS Publications Warehouse

Loveland, Thomas R.; Merchant, James W.; Brown, Jesslyn F.; Ohlen, Donald O.; Reed, Bradley C.; Olson, Paul; Hutchinson, John

1995-01-01

Global-change investigations have been hindered by deficiencies in the availability and quality of land-cover data. The U.S. Geological Survey and the University of Nebraska-Lincoln have collaborated on the development of a new approach to land-cover characterization that attempts to address requirements of the global-change research community and others interested in regional patterns of land cover. An experimental 1 -kilometer-resolution database of land-cover characteristics for the coterminous U.S. has been prepared to test and evaluate the approach. Using multidate Advanced Very High Resolution Radiometer (AVHRR) satellite data complemented by elevation, climate, ecoregions, and other digital spatial datasets, the authors define 152, seasonal land-cover regions. The regionalization is based on a taxonomy of areas with respect to data on land cover, seasonality or phenology, and relative levels of primary production. The resulting database consists of descriptions of the vegetation, land cover, and seasonal, spectral, and site characteristics for each region. These data are used in the construction of an illustrative 1:7,500,000-scaIe map of the seasonal land-cover regions as well as of smaller-scale maps portraying general land cover and seasonality. The seasonal land-cover characteristics database can also be tailored to provide a broad range of other landscape parameters useful in national and global-scale environmental modeling and assessment.

Effects of the seasonal cycle on superrotation in planetary atmospheres

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

Mitchell, Jonathan L.; Vallis, Geoffrey K.; Potter, Samuel F.

2014-05-20

The dynamics of dry atmospheric general circulation model simulations forced by seasonally varying Newtonian relaxation are explored over a wide range of two control parameters and are compared with the large-scale circulation of Earth, Mars, and Titan in their relevant parameter regimes. Of the parameters that govern the behavior of the system, the thermal Rossby number (Ro) has previously been found to be important in governing the spontaneous transition from an Earth-like climatology of winds to a superrotating one with prograde equatorial winds, in the absence of a seasonal cycle. This case is somewhat unrealistic as it applies only ifmore » the planet has zero obliquity or if surface thermal inertia is very large. While Venus has nearly vanishing obliquity, Earth, Mars, and Titan (Saturn) all have obliquities of ∼25° and varying degrees of seasonality due to their differing thermal inertias and orbital periods. Motivated by this, we introduce a time-dependent Newtonian cooling to drive a seasonal cycle using idealized model forcing, and we define a second control parameter that mimics non-dimensional thermal inertia of planetary surfaces. We then perform and analyze simulations across the parameter range bracketed by Earth-like and Titan-like regimes, assess the impact on the spontaneous transition to superrotation, and compare Earth, Mars, and Titan to the model simulations in the relevant parameter regime. We find that a large seasonal cycle (small thermal inertia) prevents model atmospheres with large thermal Rossby numbers from developing superrotation by the influences of (1) cross-equatorial momentum advection by the Hadley circulation and (2) hemispherically asymmetric zonal-mean zonal winds that suppress instabilities leading to equatorial momentum convergence. We also demonstrate that baroclinic instabilities must be sufficiently weak to allow superrotation to develop. In the relevant parameter regimes, our seasonal model simulations compare

The impact of Aeromonas salmonicida infection on innate immune parameters of Atlantic salmon (Salmo salar L).

PubMed

Du, Yishuai; Yi, Mengmeng; Xiao, Peng; Meng, Lingjie; Li, Xian; Sun, Guoxiang; Liu, Ying

2015-05-01

Enzyme activities and gene expression of a number of innate immune parameters in the serum, mucus and skin of Atlantic salmon (Salmo salar) were investigated after challenge with a pathogenic strain of Aeromonas salmonicida (A. salmonicida). Fish were injected in the dorsal muscle with either 100 μl bacterium solution, about 3.05 × 10(7) CFU/ml A. salmonicida, or 100 μl 0.9% NaCl (as control group) and tissue samples were collected at days 0, 2, 4 and 6 post-injection. Lysozyme (LSZ) and alkaline phosphatase (AKP) activities in serum, mucus and skin, and LSZ and AKP mRNA expression in skin of the challenged fish were higher than those of the control at most of the experimental time, with significant differences at several time points (P < 0.05), indicating the involvement of LSZ and AKP in the innate immunity of Atlantic salmon to A. salmonicida. Superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities in mucus and skin, along with the SOD, POD and CAT mRNA expression in skin significantly decreased at day 4 and 6, indicating the decreased antioxidant capacity of the challenged fish. Glutamate pyruvate transaminase (GPT) and glutamic oxalacetic transaminase (GOT) activities in serum, mucus and skin of the challenged group were all higher than those of the control after the injection, and at several time points significant differences were found between the two groups, suggesting organs of fish were impaired after the pathogen infection. The changes of the GPT and GOT activities could be used as potential biomarkers for the impairment of physiological functions caused by the pathogen infection. Identified biomarkers of the immune responses will contribute to the early-warning system of the disease. So this study will not only provide a theoretical basis for vaccine development, but also provide basic data for the establishment of early warning systems for diseases caused by A. salmonicida in Atlantic salmon rearing. Copyright © 2015 Elsevier

Seasonal reproductive development of Lampsilis cardium, Amblema plicata plicata, and Potamilus alatus

USGS Publications Warehouse

Holland Bartels, L. E.; Kammer, T.W.

1989-01-01

Adult specimens of three species of freshwater mussels common to the upper Mississippi River were examined histologically to determine seasonal patterns of development in gametogenesis and release of glochidia. Full maturation of gonadal materials in Lampsilis cardium (formerly L. ovata ventricosa), a long-term breeder, occurred when ambient river temperatures reached 24 degree to 26 degree C, between late July and early August. By mid-August, glochidia were present in the marsupia. Glochidia were released from late May through mid-June of the following year once water temperatures reached 20 degree C. The long-term breeder Potamilus alatus demonstrated full gonadal maturation earlier than seen in L. cardium with reproduction completed by late July (26 degree C). Glochidia of P. alatus were released over a period similar to that observed for L. cardium, late May through early July of the following year. Fully mature Amblema plicata plicata, a short-term breeder, were collected from late May through early July (18 degree to 21 degree C). (DBO).

Characterization of myocardial lesions associated with cardiomyopathy syndrome in Atlantic salmon, Salmo salar L., using laser capture microdissection.

PubMed

Wiik-Nielsen, J; Løvoll, M; Fritsvold, C; Kristoffersen, A B; Haugland, Ø; Hordvik, I; Aamelfot, M; Jirillo, E; Koppang, E O; Grove, S

2012-12-01

Cardiomyopathy syndrome (CMS) in Atlantic salmon, Salmo salar L., is characterized by focal infiltration in the spongy myocardium and endocardium of the heart. The origin of the mononuclear infiltrate is unknown. Using experimentally infected fish, we investigated localization of the causative agent, piscine myocarditis virus (PMCV), within the heart and characterized the cell population associated with myocardial lesions. Cellular and transcriptional characteristics in the lesions were compared with adjacent non-infiltrated tissues using laser capture microdissection, RT-qPCR and immunohistochemistry. Our results reveal that PMCV is almost exclusively present in myocardial lesions. The inflammatory infiltrate comprises a variety of leucocyte populations, including T cells, B cells, MHC class II(+) and CD83(+) cells, most likely of the macrophage line. Correlation analyses demonstrated co-ordinated leucocyte activity at the site of the virus infection. Cellular proliferation and/or DNA repair was demonstrated within the myocardial lesions. Different cell populations, mainly myocytes, stained positive for proliferating cell nuclear antigen (PCNA). Densities of endothelial cells and fibroblasts were not significantly increased. The simultaneous presence of PMCV and various inflammatory cells in all myocardial lesions analysed may indicate that both viral lytic and immunopathological effects may contribute to the pathogenesis of CMS. © 2012 Blackwell Publishing Ltd.

Sequential protein extraction as an efficient method for improved proteome coverage in larvae of Atlantic salmon (Salmo salar).

PubMed

Nuez-Ortín, Waldo G; Carter, Chris G; Nichols, Peter D; Wilson, Richard

2016-07-01

Understanding diet- and environmentally induced physiological changes in fish larvae is a major goal for the aquaculture industry. Proteomic analysis of whole fish larvae comprising multiple tissues offers considerable potential but is challenging due to the very large dynamic range of protein abundance. To extend the coverage of the larval phase of the Atlantic salmon (Salmo salar) proteome, we applied a two-step sequential extraction (SE) method, based on differential protein solubility, using a nondenaturing buffer containing 150 mM NaCl followed by a denaturing buffer containing 7 M urea and 2 M thiourea. Extracts prepared using SE and one-step direct extraction were characterized via label-free shotgun proteomics using nanoLC-MS/MS (LTQ-Orbitrap). SE partitioned the proteins into two fractions of approximately equal amounts, but with very distinct protein composition, leading to identification of ∼40% more proteins than direct extraction. This fractionation strategy enabled the most detailed characterization of the salmon larval proteome to date and provides a platform for greater understanding of physiological changes in whole fish larvae. The MS data are available via the ProteomeXchange Consortium PRIDE partner repository, dataset PXD003366. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Iron assimilation and siderophore production by Vibrio ordalii strains isolated from diseased Atlantic salmon Salmo salar in Chile.

PubMed

Ruiz, Pamela; Balado, Miguel; Toranzo, Alicia E; Poblete-Morales, Matías; Lemos, Manuel L; Avendaño-Herrera, Ruben

2016-03-30

Vibrio ordalii is the causative agent of vibriosis in several cultured salmonid species worldwide. Despite its impact on aquaculture, relatively little information is available about its virulence factors. The present study demonstrates for the first time that V. ordalii possesses different systems of iron acquisition, one involving siderophore synthesis and another one that uses direct binding of heme to use iron. Using 6 strains of V. ordalii from Atlantic salmon Salmo salar and the V. ordalii type strain, we could demonstrate that all strains could grow in presence of the chelating agent 2,2'-dipyridyl and produced siderophores in solid and liquid media. Cross-feeding assays among V. ordalii strains evidenced variability in the siderophores produced. Bioassays and PCR data suggest that V. ordalii could produce a siderophore with a structure similar to piscibactin, although the production of a second siderophore in certain strains cannot be discarded. Furthermore, all strains were able to use hemin and hemoglobin as the only iron sources, although the cell yield was higher when using hemoglobin. A hemin-binding assay indicated the presence of constitutive heme-binding molecules at the cell surface of V. ordalii. Virulence tests using rainbow trout as a model of infection revealed a clear relationship between iron-uptake ability and pathogenicity in V. ordalii.

Genome-wide SNP analysis reveals a genetic basis for sea-age variation in a wild population of Atlantic salmon (Salmo salar).

PubMed

Johnston, Susan E; Orell, Panu; Pritchard, Victoria L; Kent, Matthew P; Lien, Sigbjørn; Niemelä, Eero; Erkinaro, Jaakko; Primmer, Craig R

2014-07-01

Delaying sexual maturation can lead to larger body size and higher reproductive success, but carries an increased risk of death before reproducing. Classical life history theory predicts that trade-offs between reproductive success and survival should lead to the evolution of an optimal strategy in a given population. However, variation in mating strategies generally persists, and in general, there remains a poor understanding of genetic and physiological mechanisms underlying this variation. One extreme case of this is in the Atlantic salmon (Salmo salar), which can show variation in the age at which they return from their marine migration to spawn (i.e. their 'sea age'). This results in large size differences between strategies, with direct implications for individual fitness. Here, we used an Illumina Infinium SNP array to identify regions of the genome associated with variation in sea age in a large population of Atlantic salmon in Northern Europe, implementing individual-based genome-wide association studies (GWAS) and population-based FST outlier analyses. We identified several regions of the genome which vary in association with phenotype and/or selection between sea ages, with nearby genes having functions related to muscle development, metabolism, immune response and mate choice. In addition, we found that individuals of different sea ages belong to different, yet sympatric populations in this system, indicating that reproductive isolation may be driven by divergence between stable strategies. Overall, this study demonstrates how genome-wide methodologies can be integrated with samples collected from wild, structured populations to understand their ecology and evolution in a natural context. © 2014 John Wiley & Sons Ltd.

Identification and characterisation of TLR18-21 genes in Atlantic salmon (Salmo salar).

PubMed

Lee, P T; Zou, J; Holland, J W; Martin, S A M; Collet, B; Kanellos, T; Secombes, C J

2014-12-01

Teleost fish possess many types of toll-like receptor (TLR) some of which exist in other vertebrate groups and some that do not (ie so-called "fish-specific" TLRs). In this study, we identified in Atlantic salmon (Salmo salar) whole-genome shotgun (WGS) contigs seven TLRs that are not found in mammals, including six types of fish-specific TLRs (one TLR18, one TLR19, and four TLR20 members (two of which are putative soluble forms (s)) and one TLR21. Phylogenetic analysis revealed that teleost TLR19-21 are closely related with murine TLR11-TLR13, whilst teleost TLR18 groups with mammalian TLR1, 2, 6 and 10. A typical TLR protein domain structure was found in all these TLRs with the exception of TLR20b(s) and TLR20c(s). TLR-GFP expression plasmids transfected into SHK-1 cells showed that salmon TLR19, TLR20a and TLR20d were preferentially localised to the intracellular compartment. Real time PCR analysis suggested that salmon TLR19-TLR21 are mainly expressed in immune related organs, such as spleen, head kidney and gills, while TLR18 transcripts are more abundant in muscle. In vitro stimulation of primary head kidney cells with type I IFN, IFNγ and IL-1β had no impact on TLR expression. Infectious salmon anaemia virus (ISAV) infection, in vivo, down-regulated TLR20a, TLR20b(s), TLR20d and TLR21 in infected salmon kidney tissue. In contrast, up-regulation of TLR19 and TLR20a expression was found in posterior kidney in rainbow trout with clinical proliferative kidney disease (PKD). Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of a decision support tool for seasonal water supply management incorporating system uncertainties and operational constraints

NASA Astrophysics Data System (ADS)

Wang, H.; Asefa, T.

2017-12-01

A real-time decision support tool (DST) for water supply system would consider system uncertainties, e.g., uncertain streamflow and demand, as well as operational constraints and infrastructure outage (e.g., pump station shutdown, an offline reservoir due to maintenance). Such DST is often used by water managers for resource allocation and delivery for customers. Although most seasonal DST used by water managers recognize those system uncertainties and operational constraints, most use only historical information or assume deterministic outlook of water supply systems. This study presents a seasonal DST that incorporates rainfall/streamflow uncertainties, seasonal demand outlook and system operational constraints. Large scale climate-information is captured through a rainfall simulator driven by a Bayesian non-homogeneous Markov Chain Monte Carlo model that allows non-stationary transition probabilities contingent on Nino 3.4 index. An ad-hoc seasonal demand forecasting model considers weather conditions explicitly and socio-economic factors implicitly. Latin Hypercube sampling is employed to effectively sample probability density functions of flow and demand. Seasonal system operation is modelled as a mixed-integer optimization problem that aims at minimizing operational costs. It embeds the flexibility of modifying operational rules at different components, e.g., surface water treatment plants, desalination facilities, and groundwater pumping stations. The proposed framework is illustrated at a wholesale water supplier in Southeastern United States, Tampa Bay Water. The use of the tool is demonstrated in proving operational guidance in a typical drawdown and refill cycle of a regional reservoir. The DST provided: 1) probabilistic outlook of reservoir storage and chance of a successful refill by the end of rainy season; 2) operational expectations for large infrastructures (e.g., high service pumps and booster stations) throughout the season. Other potential use

Contrasting patterns of litterfall seasonality and seasonal changes in litter decomposability in a tropical rainforest region

NASA Astrophysics Data System (ADS)

Parsons, S. A.; Valdez-Ramirez, V.; Congdon, R. A.; Williams, S. E.

2014-06-01

The seasonality of litter inputs in forests has important implications for understanding ecosystem processes and biogeochemical cycles. We quantified the drivers of seasonality in litterfall and leaf decomposability, using plots throughout the Australian wet tropical region. Litter fell mostly in the summer (wet, warm) months in the region, but other peaks occurred throughout the year. Litterfall seasonality was modelled well with the level of deciduousness of the site (plots with more deciduous species had lower seasonality than evergreen plots), temperature (higher seasonality in the uplands), disturbance (lower seasonality with more early secondary species) and soil fertility (higher seasonality with higher N : P/P limitation) (SL total litterfall model 1 = deciduousness + soil N : P + early secondary sp: r2 = 0.63, n = 30 plots; model 2 = temperature + early secondary sp. + soil N : P: r2 = 0.54, n = 30; SL leaf = temperature + early secondary sp. + rainfall seasonality: r2 = 0.39, n = 30). Leaf litter decomposability was lower in the dry season than in the wet season, driven by higher phenolic concentrations in the dry, with the difference exacerbated particularly by lower dry season moisture. Our results are contrary to the global trend for tropical rainforests; in that seasonality of litterfall inputs were generally higher in wetter, cooler, evergreen forests, compared to generally drier, warmer, semi-deciduous sites that had more uniform monthly inputs. We consider this due to more diverse litter shedding patterns in semi-deciduous and raingreen rainforest sites, and an important consideration for ecosystem modellers. Seasonal changes in litter quality are likely to have impacts on decomposition and biogeochemical cycles in these forests due to the litter that falls in the dry being more recalcitrant to decay.

Climate Prediction Center - Seasonal Color Maps

Science.gov Websites

HOME > Outlook Maps > Monthly to Seasonal Outlooks > Seasonal Outlooks > Color Monthly & ; Seasonal Outlooks Monthly & Seasonal Climate Outlooks Banner Issued: 17 May 2018 [EXPERIMENTAL TWO

Development of an Experimental African Drought Monitoring and Seasonal Forecasting System: A First Step towards a Global Drought Information System

NASA Astrophysics Data System (ADS)

Wood, E. F.; Chaney, N.; Sheffield, J.; Yuan, X.

2012-12-01

Extreme hydrologic events in the form of droughts are a significant source of social and economic damage. Internationally, organizations such as UNESCO, the Group on Earth Observations (GEO), and the World Climate Research Programme (WCRP) have recognized the need for drought monitoring, especially for the developing world where drought has had devastating impacts on local populations through food insecurity and famine. Having the capacity to monitor droughts in real-time, and to provide drought forecasts with sufficient warning will help developing countries and international programs move from the management of drought crises to the management of drought risk. While observation-based assessments, such as those produced by the US Drought Monitor, are effective for monitoring in countries with extensive observation networks (of precipitation in particular), their utility is lessened in areas (e.g., Africa) where observing networks are sparse. For countries with sparse networks and weak reporting systems, remote sensing observations can provide the real-time data for the monitoring of drought. More importantly, these datasets are now available for at least a decade, which allows for the construction of a climatology against which current conditions can be compared. In this presentation we discuss the development of our multi-lingual experimental African Drought Monitor (ADM) (see http://hydrology.princeton.edu/~nchaney/ADM_ML). At the request of UNESCO, the ADM system has been installed at AGRHYMET, a regional climate and agricultural center in Niamey, Niger and at the ICPAC climate center in Nairobi, Kenya. The ADM system leverages off our U.S. drought monitoring and forecasting system (http://hydrology.princeton.edu/forecasting) that uses the NLDAS data to force the VIC land surface model (LSM) at 1/8th degree spatial resolution for the estimation of our soil moisture drought index (Sheffield et al., 2004). For the seasonal forecast of drought, CFSv2 climate

Development of an inorganic and organic aerosol model (CHIMERE 2017β v1.0): seasonal and spatial evaluation over Europe

NASA Astrophysics Data System (ADS)

Couvidat, Florian; Bessagnet, Bertrand; Garcia-Vivanco, Marta; Real, Elsa; Menut, Laurent; Colette, Augustin

2018-01-01

A new aerosol module was developed and integrated in the air quality model CHIMERE. Developments include the use of the Model of Emissions and Gases and Aerosols from Nature (MEGAN) 2.1 for biogenic emissions, the implementation of the inorganic thermodynamic model ISORROPIA 2.1, revision of wet deposition processes and of the algorithms of condensation/evaporation and coagulation and the implementation of the secondary organic aerosol (SOA) mechanism H2O and the thermodynamic model SOAP. Concentrations of particles over Europe were simulated by the model for the year 2013. Model concentrations were compared to the European Monitoring and Evaluation Programme (EMEP) observations and other observations available in the EBAS database to evaluate the performance of the model. Performances were determined for several components of particles (sea salt, sulfate, ammonium, nitrate, organic aerosol) with a seasonal and regional analysis of results. The model gives satisfactory performance in general. For sea salt, the model succeeds in reproducing the seasonal evolution of concentrations for western and central Europe. For sulfate, except for an overestimation of sulfate in northern Europe, modeled concentrations are close to observations and the model succeeds in reproducing the seasonal evolution of concentrations. For organic aerosol, the model reproduces with satisfactory results concentrations for stations with strong modeled biogenic SOA concentrations. However, the model strongly overestimates ammonium nitrate concentrations during late autumn (possibly due to problems in the temporal evolution of emissions) and strongly underestimates summer organic aerosol concentrations over most of the stations (especially in the northern half of Europe). This underestimation could be due to a lack of anthropogenic SOA or biogenic emissions in northern Europe. A list of recommended tests and developments to improve the model is also given.

Monitoring Start of Season in Alaska

NASA Astrophysics Data System (ADS)

Robin, J.; Dubayah, R.; Sparrow, E.; Levine, E.

2006-12-01

In biomes that have distinct winter seasons, start of spring phenological events, specifically timing of budburst and green-up of leaves, coincides with transpiration. Seasons leave annual signatures that reflect the dynamic nature of the hydrologic cycle and link the different spheres of the Earth system. This paper evaluates whether continuity between AVHRR and MODIS normalized difference vegetation index (NDVI) is achievable for monitoring land surface phenology, specifically start of season (SOS), in Alaska. Additionally, two thresholds, one based on NDVI and the other on accumulated growing degree-days (GDD), are compared to determine which most accurately predicts SOS for Fairbanks. Ratio of maximum greenness at SOS was computed from biweekly AVHRR and MODIS composites for 2001 through 2004 for Anchorage and Fairbanks regions. SOS dates were determined from annual green-up observations made by GLOBE students. Results showed that different processing as well as spectral characteristics of each sensor restrict continuity between the two datasets. MODIS values were consistently higher and had less inter-annual variability during the height of the growing season than corresponding AVHRR values. Furthermore, a threshold of 131-175 accumulated GDD was a better predictor of SOS for Fairbanks than a NDVI threshold applied to AVHRR and MODIS datasets. The NDVI threshold was developed from biweekly AVHRR composites from 1982 through 2004 and corresponding annual green-up observations at University of Alaska-Fairbanks (UAF). The GDD threshold was developed from 20+ years of historic daily mean air temperature data and the same green-up observations. SOS dates computed with the GDD threshold most closely resembled actual green-up dates observed by GLOBE students and UAF researchers. Overall, biweekly composites and effects of clouds, snow, and conifers limit the ability of NDVI to monitor phenological changes in Alaska.

Decomposition of Sources of Errors in Seasonal Streamflow Forecasting over the U.S. Sunbelt

NASA Technical Reports Server (NTRS)

Mazrooei, Amirhossein; Sinah, Tusshar; Sankarasubramanian, A.; Kumar, Sujay V.; Peters-Lidard, Christa D.

2015-01-01

Seasonal streamflow forecasts, contingent on climate information, can be utilized to ensure water supply for multiple uses including municipal demands, hydroelectric power generation, and for planning agricultural operations. However, uncertainties in the streamflow forecasts pose significant challenges in their utilization in real-time operations. In this study, we systematically decompose various sources of errors in developing seasonal streamflow forecasts from two Land Surface Models (LSMs) (Noah3.2 and CLM2), which are forced with downscaled and disaggregated climate forecasts. In particular, the study quantifies the relative contributions of the sources of errors from LSMs, climate forecasts, and downscaling/disaggregation techniques in developing seasonal streamflow forecast. For this purpose, three month ahead seasonal precipitation forecasts from the ECHAM4.5 general circulation model (GCM) were statistically downscaled from 2.8deg to 1/8deg spatial resolution using principal component regression (PCR) and then temporally disaggregated from monthly to daily time step using kernel-nearest neighbor (K-NN) approach. For other climatic forcings, excluding precipitation, we considered the North American Land Data Assimilation System version 2 (NLDAS-2) hourly climatology over the years 1979 to 2010. Then the selected LSMs were forced with precipitation forecasts and NLDAS-2 hourly climatology to develop retrospective seasonal streamflow forecasts over a period of 20 years (1991-2010). Finally, the performance of LSMs in forecasting streamflow under different schemes was analyzed to quantify the relative contribution of various sources of errors in developing seasonal streamflow forecast. Our results indicate that the most dominant source of errors during winter and fall seasons is the errors due to ECHAM4.5 precipitation forecasts, while temporal disaggregation scheme contributes to maximum errors during summer season.

Electro-optical seasonal weather and gender data collection

NASA Astrophysics Data System (ADS)

McCoppin, Ryan; Koester, Nathan; Rude, Howard N.; Rizki, Mateen; Tamburino, Louis; Freeman, Andrew; Mendoza-Schrock, Olga

2013-05-01

This paper describes the process used to collect the Seasonal Weather And Gender (SWAG) dataset; an electro-optical dataset of human subjects that can be used to develop advanced gender classification algorithms. Several novel features characterize this ongoing effort (1) the human subjects self-label their gender by performing a specific action during the data collection and (2) the data collection will span months and even years resulting in a dataset containing realistic levels and types of clothing corresponding to the various seasons and weather conditions. It is envisioned that this type of data will support the development and evaluation of more robust gender classification systems that are capable of accurate gender recognition under extended operating conditions.

Molecular cloning of Salmo salar Toll-like receptors (TLR1, TLR22, TLR5M and TLR5S) and expression analysis in SHK-1 cells during Piscirickettsia salmonis infection.

PubMed

Salazar, C; Haussmann, D; Kausel, G; Figueroa, J

2016-02-01

In fish, the innate immune system is the primary response against infection. Toll-like receptors (TLRs) recognize pathogens through pathogen-associated molecular patterns (PAMPs), and some target molecules of TLRs are homologous between fish and mammals. Piscirickettsia salmonis is one of the main pathogens affecting the salmon industry in Chile. Better knowledge of mechanisms underlying its invasive capacity and recognition of target cells is crucial for vaccine development. Therefore, Salmo salar L. TLR1, TLR22, membrane TLR5M and soluble TLR5S sequences were cloned, and expression kinetics were analysed by RT-qPCR in salmon head kidney cells (SHK-1) infected with three different P. salmonis preparations: alive, formaldehyde treated, extract. Clearly, all analysed TLRs were expressed and transcription level changes were revealed at 2 hpi, 12 or 16 hpi and 24 hpi depending on P. salmonis infection scheme. Increased IL1-beta expression confirmed TLR pathway response. Furthermore, significant expression modulations of several members of the TLR pathway in this in vitro model suggest that P. salmonis extract rather than formaldehyde-inactivated bacteria might strengthen the salmon immune system. © 2015 John Wiley & Sons Ltd.

Natural selection constrains personality and brain gene expression differences in Atlantic salmon (Salmo salar).

PubMed

Thörnqvist, Per-Ove; Höglund, Erik; Winberg, Svante

2015-04-01

In stream-spawning salmonid fishes there is a considerable variation in the timing of when fry leave the spawning nests and establish a feeding territory. The timing of emergence from spawning nests appears to be related to behavioural and physiological traits, e.g. early emerging fish are bolder and more aggressive. In the present study, emerging Atlantic salmon (Salmo salar L.) alevins were sorted into three fractions: early, intermediate and late emerging. At the parr stage, behaviour, stress responses, hindbrain monoaminergic activity and forebrain gene expression were explored in fish from the early and late emerging fractions (first and last 25%). The results show that when subjected to confinement stress, fish from the late emerging fraction respond with a larger activation of the brain serotonergic system than fish from the early fraction. Similarly, in late emerging fish, stress resulted in elevated expression of mRNA coding for serotonin 1A receptors (5-HT1A), GABA-A receptor-associated protein and ependymin, effects not observed in fish from the early emerging fraction. Moreover, fish from the early emerging fraction displayed bolder behaviour than their late emerging littermates. Taken together, these results suggest that time of emergence, boldness and aggression are linked to each other, forming a behavioural syndrome in juvenile salmon. Differences in brain gene expression between early and late emerging salmon add further support to a relationship between stress coping style and timing of emergence. However, early and late emerging salmon do not appear to differ in hypothalamus-pituitary-interrenal (HPI) axis reactivity, another characteristic of divergent stress coping styles. © 2015. Published by The Company of Biologists Ltd.

Contagious Yawning and Seasonal Climate Variation

PubMed Central

Gallup, Andrew C.; Eldakar, Omar Tonsi

2011-01-01

Recent evidence suggests that yawning is a thermoregulatory behavior. To explore this possibility further, the frequency of contagious yawning in humans was measured while outdoors in a desert climate in the United States during two distinct temperature ranges and seasons (winter: 22°C; early summer: 37°C). As predicted, the proportion of pedestrians who yawned in response to seeing pictures of people yawning differed significantly between the two conditions (winter: 45%; summer: 24%). Across conditions yawning occurred at lower ambient temperatures, and the tendency to yawn during each season was associated with the length of time spent outside prior to being tested. Participants were more likely to yawn in the milder climate after spending long periods of time outside, while prolonged exposure to ambient temperatures at or above body temperature was associated with reduced yawning. This is the first report to show that the incidence of yawning in humans is associated with seasonal climate variation, further demonstrating that yawn-induced contagion effects can be mediated by factors unrelated to individual social characteristics or cognitive development. PMID:21960970

Population regulation and character displacement in a seasonal environment.

PubMed

Goldberg, Emma E; Lande, Russell; Price, Trevor D

2012-06-01

Competition has negative effects on population size and also drives ecological character displacement, that is, evolutionary divergence to utilize different portions of the resource spectrum. Many species undergo an annual cycle composed of a lean season of intense competition for resources and a breeding season. We use a quantitative genetic model to study the effects of differential reproductive output in the summer or breeding season on character displacement in the winter or nonbreeding season. The model is developed with reference to the avian family of Old World leaf warblers (Phylloscopidae), which breed in the temperate regions of Eurasia and winter in tropical and subtropical regions. Empirical evidence implicates strong winter density-dependent regulation driven by food shortage, but paradoxically, the relative abundance of each species appears to be determined by conditions in the summer. We show how population regulation in the two seasons becomes linked, with higher reproductive output by one species in the summer resulting in its evolution to occupy a larger portion of niche space in the winter. We find short-term ecological processes and longer-term evolutionary processes to have comparable effects on a species population size. This modeling approach can also be applied to other differential effects of productivity across seasons.

Intra-seasonal rainfall variability during the maize growing season in the northern lowlands of Lesotho

NASA Astrophysics Data System (ADS)

Tongwane, Mphethe Isaac; Moeletsi, Mokhele Edmond

2015-05-01

Intra-seasonal rainfall distribution was identified as a priority gap that needs to be addressed for southern Africa to cope with agro-meteorological risks. The region in the northwest of Lesotho is appropriate for crop cultivation due to its relatively favourable climatic conditions and soils. High rainfall variability is often blamed for poor agricultural production in this region. This study aims to determine the onset of rains, cessation of rains and rainy season duration using historical climate data. Temporal variability of these rainy season characteristics was also investigated. The earliest and latest onset dates of the rainy season are during the last week of October at Butha-Buthe and the third week of November at Mapoteng, respectively. Cessation of the season is predominantly in the first week of April making the season approximately 137-163 days long depending on the location. Average seasonal rainfall ranged from 474 mm at Mapoteng to 668 mm at Butha-Buthe. Onset and cessation of the rainfall season vary by 4-7 weeks and 1 week, respectively. Mean coefficient of variation of seasonal rainfall is 39 %, but monthly variations are higher. These variations make annual crop management and planning difficult each year. Trends show a decrease in the rainfall amounts but improvements in both the temporal distribution of annual rainfall, onset and cessation dates.

Earth observation taken by the Expedition 33 crew.

NASA Image and Video Library

2012-09-20

ISS033-E-006202 (20 Sept. 2012) --- Salar de Coipasa, Bolivia is featured in this image photographed by an Expedition 33 crew member on the International Space Station. The Salar de Coipasa, located in the Altiplano region of western Bolivia, covers an area of approximately 2,500 square kilometers. The word ?salar? describes arid closed basins in which evaporation of mineral-rich waters leads to the formation of thick, flat-laying salt deposits. Salar de Coipasa is located to the southwest of the saline Lake Poopo and northwest of the largest salt flat in the world, Salar de Uyuni. At Coipasa, a crust composed of halite?common table salt?provides the brilliant white coloration characteristic of the Altiplano salars (right). While the environment of Salar de Coipasa is arid, it does receive constant water from the Lauca River flowing from the north; this feeds Lake (Lago) Coipasa that fills the northern end of the basin with shallow water (center). However, the water flow can drop off sharply during periods of drought. The waters of Lake Coipasa, and the white salt crust of the salar, also serve to highlight dark river sediments flowing into the basin along the northeastern shore. Dark volcanic rocks contrast sharply with the surrounding salt crust at right. While the western Andes Mountains contain many active volcanoes, the nearby Tata Sabaya volcano has not been historically active.

Intra-seasonal rainfall characteristics and their importance to the seasonal prediction problem

NASA Astrophysics Data System (ADS)

Tennant, Warren J.; Hewitson, Bruce C.

2002-07-01

Daily station rainfall data in South Africa from 1936 to 1999 are combined into homogeneous rainfall regions using Ward's clustering method. Various rainfall characteristics are calculated for the summer season, defined as December to February. These include seasonal rainfall total, region-average number of station rain days exceeding 1 and 20 mm, region-average of periods between rain days at stations >1 and >20 mm, region-average of wet spell length (sequential days of station rainfall >1 and >20 mm), correlation of daily station rainfall within a region and correlation of seasonal station rainfall anomalies within a region.Rank-ordered rainfall characteristic data generally form an s-shaped curve, and significance testing of discontinuities in these curves suggests that normal rainfall conditions in South Africa consist of a combined middle three quintiles separated from the outer quintiles, rather than the traditional middle tercile.The relationships between the various rainfall characteristics show that seasons with a high total rainfall generally have a higher number of heavy rain days (>20 mm) and not necessarily an increase in light rain days. The length of the period between rain days has a low correlation to season totals, demonstrating that seasons with a high total rainfall may still contain prolonged dry periods. These additional rainfall characteristics are important to end-users, and the analysis undertaken here offers a valuable starting point for seeking physical relationships between rainfall characteristics and the general circulation. Preliminary studies show that the vertical mean wind is related to rainfall characteristics in South Africa. Given that general circulation models capture this part of the circulation adequately, seasonal forecasts of rainfall characteristics become plausible.

Seasonal and Non-Seasonal Generalized Pareto Distribution to Estimate Extreme Significant Wave Height in The Banda Sea

NASA Astrophysics Data System (ADS)

Nursamsiah; Nugroho Sugianto, Denny; Suprijanto, Jusup; Munasik; Yulianto, Bambang

2018-02-01

The information of extreme wave height return level was required for maritime planning and management. The recommendation methods in analyzing extreme wave were better distributed by Generalized Pareto Distribution (GPD). Seasonal variation was often considered in the extreme wave model. This research aims to identify the best model of GPD by considering a seasonal variation of the extreme wave. By using percentile 95 % as the threshold of extreme significant wave height, the seasonal GPD and non-seasonal GPD fitted. The Kolmogorov-Smirnov test was applied to identify the goodness of fit of the GPD model. The return value from seasonal and non-seasonal GPD was compared with the definition of return value as criteria. The Kolmogorov-Smirnov test result shows that GPD fits data very well both seasonal and non-seasonal model. The seasonal return value gives better information about the wave height characteristics.

Baking reduces prostaglandin, resolvin, and hydroxy-fatty acid content of farm-raised Atlantic salmon (Salmo salar).

PubMed

Raatz, Susan K; Golovko, Mikhail Y; Brose, Stephen A; Rosenberger, Thad A; Burr, Gary S; Wolters, William R; Picklo, Matthew J

2011-10-26

The consumption of seafood enriched in n-3 polyunsaturated fatty acids (PUFA) is associated with a decreased risk of cardiovascular disease. Several n-3 oxidation products from eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (22:6n-3) have known protective effects in the vasculature. It is not known whether the consumption of cooked seafood enriched in n-3 PUFA causes appreciable consumption of lipid oxidation products. We tested the hypothesis that baking Atlantic salmon (Salmo salar) increases the level of n-3 and n-6 PUFA oxidation products over raw salmon. We measured the contents of several monohydroxy-fatty acids (MHFA), prostanoids, and resolvins. Our data demonstrate that baking did not change the overall total levels of MHFA. However, baking resulted in selective regioisomeric loss of hydroxy fatty acids from arachidonic acid (20:4n-6) and EPA, while significantly increasing hydroxyl-linoleic acid levels. The contents of prostanoids and resolvins were reduced several-fold with baking. The inclusion of a coating on the salmon prior to baking reduced the loss of some MHFA but had no effect on prostanoid losses incurred by baking. Baking did not decrease n-3 PUFA contents, indicating that baking of salmon is an acceptable means of preparation that does not alter the potential health benefits of high n-3 seafood consumption. The extent to which the levels of MHFA, prostanoids, and resolvins in the raw or baked fish have physiologic consequence for humans needs to be determined.

Seasonal Affective Disorder

PubMed Central

Rohan, Kelly J.

2005-01-01

Seasonal affective disorder (SAD), characterized by fall/winter major depression with spring/summer remission, is a prevalent mental health problem. SAD etiology is not certain, but available models focus on neurotransmitters, hormones, circadian rhythm dysregulation, genetic polymorphisms, and psychological factors. Light therapy is established as the best available treatment for SAD. Alternative and/or supplementary approaches involving medications, cognitive-behavioral therapy, and exercise are currently being developed and evaluated. Given the complexity of the disorder, interdisciplinary research stands to make a significant contribution to advancing our understanding of SAD conceptualization and treatment. PMID:21179639

Influence of air-drying temperature on drying kinetics, colour, firmness and biochemical characteristics of Atlantic salmon (Salmo salar L.) fillets.

PubMed

Ortiz, Jaime; Lemus-Mondaca, Roberto; Vega-Gálvez, Antonio; Ah-Hen, Kong; Puente-Diaz, Luis; Zura-Bravo, Liliana; Aubourg, Santiago

2013-08-15

In this work the drying kinetics of Atlantic salmon (Salmo salar L.) fillets and the influence of air drying temperature on colour, firmness and biochemical characteristics were studied. Experiments were conducted at 40, 50 and 60°C. Effective moisture diffusivity increased with temperature from 1.08×10(-10) to 1.90×10(-10) m(2) s(-1). The colour difference, determined as ΔE values (from 9.3 to 19.3), as well as firmness (from 25 to 75 N mm(-1)) of dried samples increased with dehydration temperature. The lightness value L(∗) and yellowness value b(∗) indicated formation of browning products at higher drying temperatures, while redness value a(∗) showed dependence on astaxanthin value. Compared with fresh fish samples, palmitic acid and tocopherol content decreased in a 20% and 40%, respectively, with temperature. While eicosapentaenoic acid (EPA) content remained unchanged and docosahexaenoic acid (DHA) content changed slightly. Anisidine and thiobarbituric acid values indicated the formation of secondary lipid oxidation products, which is more relevant for longer drying time than for higher drying temperatures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Development of a monthly to seasonal forecast framework tailored to inland waterway transport in central Europe

NASA Astrophysics Data System (ADS)

Meißner, Dennis; Klein, Bastian; Ionita, Monica

2017-12-01

limitations on longer lead times in central Europe, this study reveals the existence of a valuable predictability of streamflow on monthly up to seasonal timescales along the Rhine, upper Danube and Elbe waterways, and the Elbe achieves the highest skill and economic value. (3) The more physically based and the statistical approach are able to improve the predictive skills and economic value compared to climatology and the ESP approach. The specific forecast skill highly depends on the forecast location, the lead time and the season. (4) Currently, the statistical approach seems to be most skilful for the three waterways investigated. The lagged relationship between the monthly and/or seasonal streamflow and the climatic and/or oceanic variables vary between 1 month (e.g. local precipitation, temperature and soil moisture) up to 6 months (e.g. sea surface temperature). Besides focusing on improving the forecast methodology, especially by combining the individual approaches, the focus is on developing useful forecast products on monthly to seasonal timescales for waterway transport and to operationalize the related forecasting service.

Cardiomyopathy Syndrome of Atlantic Salmon (Salmo salar L.) Is Caused by a Double-Stranded RNA Virus of the Totiviridae Family▿

PubMed Central

Haugland, Øyvind; Mikalsen, Aase B.; Nilsen, Pål; Lindmo, Karine; Thu, Beate J.; Eliassen, Trygve M.; Roos, Norbert; Rode, Marit; Evensen, Øystein

2011-01-01

Cardiomyopathy syndrome (CMS) of farmed and wild Atlantic salmon (Salmo salar L.) is a disease of yet unknown etiology characterized by a necrotizing myocarditis involving the atrium and the spongious part of the heart ventricle. Here, we report the identification of a double-stranded RNA virus likely belonging to the family Totiviridae as the causative agent of the disease. The proposed name of the virus is piscine myocarditis virus (PMCV). On the basis of the RNA-dependent RNA polymerase (RdRp) sequence, PMCV grouped with Giardia lamblia virus and infectious myonecrosis virus of penaeid shrimp. The genome size of PMCV is 6,688 bp, with three open reading frames (ORFs). ORF1 likely encodes the major capsid protein, while ORF2 encodes the RdRp, possibly expressed as a fusion protein with the ORF1 product. ORF3 seems to be translated as a separate protein not described for any previous members of the family Totiviridae. Following experimental challenge with cell culture-grown virus, histopathological changes are observed in heart tissue by 6 weeks postchallenge (p.c.), with peak severity by 9 weeks p.c. Viral genome levels detected by real-time reverse transcription (RT)-PCR peak earlier at 6 to 7 weeks p.c. The virus genome is detected by in situ hybridization in degenerate cardiomyocytes from clinical cases of CMS. Virus genome levels in the hearts from clinical field cases correlate well with the severity of histopathological changes in heart tissue. The identification of the causative agent for CMS is important for improved disease surveillance and disease control and will serve as a basis for vaccine development against the disease. PMID:21411528

Seasonal mortality in zoo ruminants.

PubMed

Carisch, Lea; Müller, Dennis W H; Hatt, Jean-Michel; Bingaman Lackey, Laurie; Rensch, E Eberhard; Clauss, Marcus; Zerbe, Philipp

2017-01-01

While seasonality has often been investigated with respect to reproduction, seasonality of mortality has received less attention. We investigated whether a seasonal signal of mortality exists in wild ruminants kept in zoos, using data from 60,591 individuals of 88 species. We quantified the mortality in the 3 consecutive months with the highest above-baseline mortality (3 MM). 3 MM was not related to relative life expectancy of species, indicating that seasonal mortality does not necessarily impact husbandry success. Although 3 MM was mainly observed in autumn/winter months, there was no evidence for an expected negative relationship with the latitude of the species' natural habitat and no positive relationship between 3 MM and the mean temperature in that habitat, indicating no evidence for species from lower latitudes/warmer climates being more susceptible to seasonal mortality under zoo conditions. 3 MM was related to reproductive biology, with seasonally reproducing species also displaying more seasonal mortality. This pattern differed between groups: In cervids, the onset of seasonal mortality appeared linked to the onset of rut in both sexes. This was less evident in bovids, where in a number of species (especially caprids), the onset of female seasonal mortality was linked to the lambing period. While showing that the origin of a species from warmer climate zones does not constrain husbandry success in ruminants in terms of an increased seasonal mortality, the results suggest that husbandry measures aimed at protecting females from rutting males are important, especially in cervids. Zoo Biol. 36:74-86, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Seasonal Variations in Color Preference.

PubMed

Schloss, Karen B; Nelson, Rolf; Parker, Laura; Heck, Isobel A; Palmer, Stephen E

2017-08-01

We investigated how color preferences vary according to season and whether those changes could be explained by the ecological valence theory (EVT). To do so, we assessed the same participants' preferences for the same colors during fall, winter, spring, and summer in the northeastern United States, where there are large seasonal changes in environmental colors. Seasonal differences were most pronounced between fall and the other three seasons. Participants liked fall-associated dark-warm colors-for example, dark-red, dark-orange (brown), dark-yellow (olive), and dark-chartreuse-more during fall than other seasons. The EVT could explain these changes with a modified version of Palmer and Schloss' (2010) weighted affective valence estimate (WAVE) procedure that added an activation term to the WAVE equation. The results indicate that color preferences change according to season, as color-associated objects become more/less activated in the observer. These seasonal changes in color preferences could not be characterized by overall shifts in weights along cone-contrast axes. Copyright © 2016 Cognitive Science Society, Inc.

ASSOCIATIONS BETWEEN SEASONAL SLEEP CHANGE AND INDOOR TANNING1,2

PubMed Central

CULNAN, ELIZABETH; KLOSS, JACQUELINE D.; DARLOW, SUSAN; HECKMAN, CAROLYN J.

2015-01-01

Summary Identification of risk factors for indoor tanning may ultimately aid the development of better indoor tanning prevention strategies, which is pertinent given the association between indoor tanning and skin cancer. This study aimed to examine the relationship between seasonal sleep change and indoor tanning. Women tanners (N= 139) completed self-report measures including items relating to seasonal sleep changes, seasonal affective disorder (SAD), reasons for tanning, tanning during the winter months, and the Tanning Pathology Scale (TAPS), which measures problematic tanning motives and symptoms of tanning dependence. It was hypothesized that seasonal sleep change and SAD would be associated with greater indoor tanning during the winter, more tanning to improve mood and to relax, and higher scores on the TAPS. Findings indicated that more seasonal sleep change was associated with tanning to improve mood and higher scores on the TAPS. Similarly, the presence of SAD was related to tanning to improve mood, tanning to relax, and more problematic tanning. PMID:25730744

Respiratory syncytial virus seasonality and its implications on prevention strategies.

PubMed

Janet, Sophie; Broad, Jonathan; Snape, Matthew D

2018-01-02

With maternal and infant vaccines against respiratory syncytial virus (RSV) in development, it is timely to consider how the deployment of these vaccines might vary according to local RSV disease seasonality. In temperate regions RSV infection is predictably limited to a period of 3 to 5 months, while in tropical regions disease seasonality is often both more variable and more prolonged. Accordingly, in tropical regions a year-round immunisation schedule for both maternal and infant immunisation might be appropriate. In contrast, in temperate regions the benefit of year-round maternal immunisation would be heavily dependent on the duration of protection this provided, potentially necessitating a strategy directed at children due to be born in the months immediately prior to the RSV season. This review will consider the impact of seasonality on maternal and infant immunisation strategies against RSV, and the potential of an alternative approach of passive immunisation for all infants immediately prior to the RSV season.

The Impact of a Kinesthetic Approach to Teaching Earth's Seasons

NASA Astrophysics Data System (ADS)

Slater, Stephanie; Morrow, C. A.

2010-01-01

The AAAS Benchmarks and NRC National Science Education Standards clearly prescribe that all American middle school students should understand that Earth's seasons are caused by variations in the amount of sunlight that hits Earth's surface due to tilt. An explanation for the cause of the seasons that is consistent with a scientifically accurate viewpoint would involve how the amount of sunlight reaching Earth's surface at different latitudes and is directly related to the planet's tilt. However, the most common alternative explanation given is the changing distance between the Sun and Earth. Previous research, as well as common experience, indicates that conventional instructional approaches on the concept of seasons are rarely sufficient in achieving scientifically accurate or durable conceptual change. Given the highly spatial nature of the concept, and the highly socially nature of human beings, some curriculum developers have turned to kinesthetic instructional approaches as a means to develop students' spatial reasoning and problem solving skills while confronting misconceptions and allowing students to socially construct scientifically accurate models of the seasons. We report results from a quantitative study on the impact on understanding of ninth grade students using kinesthetic approach to instruction for the traditionally challenging topic of Earth's seasons. The guiding research question was: To what extent does the kinesthetic astronomy instructional approach assist students in correcting misconceptions about the cause of the seasons? Using a single-group, multiple measures quasi-experimental study design, data was collected pre- and post-instruction using written, student-supplied-response assessments. Additionally, a third assessment was conducted 8 weeks after instruction in an attempt to measure durability. The results showed that statistically significant conceptual change occurred across three subtopics supporting seasons and were stable over 8

Understanding seasonal mobilities, health and wellbeing to Sanya, China.

PubMed

Kou, Lirong; Xu, Honggang; Hannam, Kevin

2017-03-01

Both the ageing of the Chinese population and elderly mobility impact on the Chinese social infrastructure, triggering challenges to maintain elderly wellbeing. This paper reflects on the notion that seasonal mobility promotes wellbeing, and explores how two crucial factors, namely, forced migration and health conditions, influence the relations between seasonal retirement mobility and wellbeing. This study analyses amenity-led seasonal retired mobilities to Sanya as a case study, and adopts and develops a conceptual framework for relations between mobility and wellbeing in terms of daily activity, sociality, and context through seasonal mobility. Qualitative methods including participant observation, non-participant observation, in-depth interviews, and mobile ethnography were used to collect data. This revealed the heterogeneity of health conditions, and the constrained mobilities of seasonal retirees. Health and willingness for mobility are shown as significant factors in influencing the relations between mobility and wellbeing, which are in turn complicated and dynamic. Seasonal mobilities bring about difficulties for retirees particularly in terms of their efforts to reconstruct their previous life and self-continuities. However, it is argued that these retirees can merely maintain temporary and superficial wellbeing due to constant health concerns and uncertainties over potential temporary or permanent return to their places of origin. Those with serious health problems have more limitations, sacrificing other aspects of wellbeing for physical health. Practical implications from state, destination, and individual levels to better facilitate seasonal mobility and promote wellbeing are provided. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of planted loblolly, longleaf, and slash pine development through 10 growing seasons in central Louisiana--an argument for longleaf pine

Treesearch

James D. Haywood; Mary Anne S. Sayer; Shi-Jean Susana Sung

2015-01-01

Two studies were established in central Louisiana to compare development of planted loblolly (Pinus taeda L.), longleaf (P. palustris Mill.), and slash (P. elliottii Engelm.) pine. Study 1 was on a Beauregard silt loam, and Study 2 was on Ruston and McKamie fine sandy loams. After 10 growing seasons,...

Annual Demographic Data for Migrant Family Housing Centers: 1986 Harvest Season.

ERIC Educational Resources Information Center

California State Dept. of Housing and Community Development, Sacramento.

California, largest employer of seasonal labor in the United States, employs an average of 119,600 seasonal farmworkers per year. Since 1966 the State Department of Housing and Community Development's Office of Migrant Services has contracted with local government agencies to provide decent/affordable housing for approximately 50,220 families…

Development of a Seasonal Extratropical Cyclone Activity Outlook for the North Pacific, Bering Sea, and Alaskan Regions

NASA Astrophysics Data System (ADS)

Shippee, N. J.; Atkinson, D. E.; Walsh, J. E.; Partain, J.; Gottschalck, J.; Marra, J. J.

2013-12-01

along with that of the NPI. For example, where the December through March NPI anomaly is negative, indicating a strong Aleutian Low, and PDO anomaly is positive, storminess is increased in the Aleutians and the Bering Sea and storms more rapidly exit the Gulf of Alaska. In similar fashion, when the phases of the NPI and PDO anomaly are switched, the storminess increases into the Gulf of Alaska with slower moving storms and longer residence time in the Gulf of Alaska. Methods used to develop the seasonal outlooks and the overall results of the will be overviewed in this presentation.

Effect of rainfall seasonality on carbon storage in tropical dry ecosystems

NASA Astrophysics Data System (ADS)

Rohr, Tyler; Manzoni, Stefano; Feng, Xue; Menezes, Rômulo S. C.; Porporato, Amilcare

2013-07-01

seasonally dry conditions are typical of large areas of the tropics, their biogeochemical responses to seasonal rainfall and soil carbon (C) sequestration potential are not well characterized. Seasonal moisture availability positively affects both productivity and soil respiration, resulting in a delicate balance between C deposition as litterfall and C loss through heterotrophic respiration. To understand how rainfall seasonality (i.e., duration of the wet season and rainfall distribution) affects this balance and to provide estimates of long-term C sequestration, we develop a minimal model linking the seasonal behavior of the ensemble soil moisture, plant productivity, related C inputs through litterfall, and soil C dynamics. A drought-deciduous caatinga ecosystem in northeastern Brazil is used as a case study to parameterize the model. When extended to different patterns of rainfall seasonality, the results indicate that for fixed annual rainfall, both plant productivity and soil C sequestration potential are largely, and nonlinearly, dependent on wet season duration. Moreover, total annual rainfall is a critical driver of this relationship, leading at times to distinct optima in both production and C storage. These theoretical predictions are discussed in the context of parameter uncertainties and possible changes in rainfall regimes in tropical dry ecosystems.

Enhancing seasonal climate prediction capacity for the Pacific countries

NASA Astrophysics Data System (ADS)

Kuleshov, Y.; Jones, D.; Hendon, H.; Charles, A.; Cottrill, A.; Lim, E.-P.; Langford, S.; de Wit, R.; Shelton, K.

2012-04-01

Seasonal and inter-annual climate variability is a major factor in determining the vulnerability of many Pacific Island Countries to climate change and there is need to improve weekly to seasonal range climate prediction capabilities beyond what is currently available from statistical models. In the seasonal climate prediction project under the Australian Government's Pacific Adaptation Strategy Assistance Program (PASAP), we describe a comprehensive project to strengthen the climate prediction capacities in National Meteorological Services in 14 Pacific Island Countries and East Timor. The intent is particularly to reduce the vulnerability of current services to a changing climate, and improve the overall level of information available assist with managing climate variability. Statistical models cannot account for aspects of climate variability and change that are not represented in the historical record. In contrast, dynamical physics-based models implicitly include the effects of a changing climate whatever its character or cause and can predict outcomes not seen previously. The transition from a statistical to a dynamical prediction system provides more valuable and applicable climate information to a wide range of climate sensitive sectors throughout the countries of the Pacific region. In this project, we have developed seasonal climate outlooks which are based upon the current dynamical model POAMA (Predictive Ocean-Atmosphere Model for Australia) seasonal forecast system. At present, meteorological services of the Pacific Island Countries largely employ statistical models for seasonal outlooks. Outcomes of the PASAP project enhanced capabilities of the Pacific Island Countries in seasonal prediction providing National Meteorological Services with an additional tool to analyse meteorological variables such as sea surface temperatures, air temperature, pressure and rainfall using POAMA outputs and prepare more accurate seasonal climate outlooks.

Seasonality of Suicidal Behavior

PubMed Central

Woo, Jong-Min; Okusaga, Olaoluwa; Postolache, Teodor T.

2012-01-01

A seasonal suicide peak in spring is highly replicated, but its specific cause is unknown. We reviewed the literature on suicide risk factors which can be associated with seasonal variation of suicide rates, assessing published articles from 1979 to 2011. Such risk factors include environmental determinants, including physical, chemical, and biological factors. We also summarized the influence of potential demographic and clinical characteristics such as age, gender, month of birth, socioeconomic status, methods of prior suicide attempt, and comorbid psychiatric and medical diseases. Comprehensive evaluation of risk factors which could be linked to the seasonal variation in suicide is important, not only to identify the major driving force for the seasonality of suicide, but also could lead to better suicide prevention in general. PMID:22470308

Asymmetric seasonal march from autumn to the next spring in East Asia (Toward interdisciplinary education on the climate systems and the "seasonal feeling" such as around the Japan Islands area)

NASA Astrophysics Data System (ADS)

Kato, Kuranoshin; Kato, Haruko; Sato, Sari; Akagi, Rikako; Haga, Yuichi; Miyake, Shoji

2014-05-01

There are many steps of seasonal transitions in East Asia, greatly influenced by the considerable phase differences of seasonal cycle among the Asian monsoon subsystems, resulting in the variety of "seasonal feeling" around the Japan Islands. For example, the "wintertime pressure pattern" begins to prevail already from November due to the seasonal development of the Siberian Air mass and the Siberian High, although the air temperature around the Japan Islands is still rather higher than in midwinter. On the other hand, since the southward retreat of the warm moist air mass in the western Pacific area delays rather greatly to the advances of those northern systems. Thus it would be interesting to re-examine the whole seasonal cycle around the Japan Islands at the view point of how the phase differences among seasonal marches of the Asian monsoon subsystems affect the variety of the seasonal cycle there, together with their effects on the "seasonal feeling". As such, the present study will examine the asymmetric seasonal march from autumn to the next spring through midwinter around the Japan Islands as an interesting example, and will also report the joint activity with music, and so on, toward the development of an interdisciplinary study plan on such topics for the students in junior high school, high school and the faculty of education of the university. The wintertime weather pattern, i.e., precipitation in the Japan Sea side and clear day in the Pacific side of the Japan Islands, prevails from early November to early March, reflected by the seasonal cycle of the Siberian Air Mass and the Siberian High. However, the air temperature shows the minimum from late January to early February around the Japan Islands. In other words, although the dominant weather patterns around November and in early March are nearly the same as each other, air temperature is still lower in early March (early spring). In spite of that, the solar radiation is rather stronger in early

Seasonal Influenza Questions & Answers

MedlinePlus

... not a stomach or intestinal disease. Do other respiratory viruses circulate during the flu season? In addition to flu viruses, several other respiratory viruses also circulate during the flu season and ...

Ecophysiological and phenological strategies in seasonally-dry ecosystems: an ecohydrological approach

NASA Astrophysics Data System (ADS)

Vico, Giulia; Manzoni, Stefano; Thompson, Sally; Molini, Annalisa; Porporato, Amilcare

2015-04-01

Seasonally-dry climates are particularly challenging for vegetation, as they are characterized by prolonged dry periods and often marked inter-annual variability. During the dry season plants face predictable physiological stress due to lack of water, whereas the inter-annual variability in rainfall timing and amounts requires plants to develop flexible adaptation strategies. The variety of strategies observed across seasonally-dry (Mediterranean and tropical) ecosystems is indeed wide - ranging from near-isohydric species that adjust stomatal conductance to avoid drought, to anisohydric species that maintain gas exchange during the dry season. A suite of phenological strategies are hypothesized to be associated to ecophysiological strategies. Here we synthetize current knowledge on ecophysiological and phenological adaptations through a comprehensive ecohydrological model linking a soil water balance to a vegetation carbon balance. Climatic regimes are found to select for different phenological strategies that maximize the long-term plant carbon uptake. Inter-annual variability of the duration of the wet season allows coexistence of different drought-deciduous strategies. In contrast, short dry seasons or access to groundwater favour evergreen species. Climatic changes causing more intermittent rainfall and/or shorter wet seasons are predicted to favour drought-deciduous species with opportunistic water use.

Does catch and release affect the mating system and individual reproductive success of wild Atlantic salmon (Salmo salar L.)?

PubMed

Richard, Antoine; Dionne, Mélanie; Wang, Jinliang; Bernatchez, Louis

2013-01-01

In this study, we documented the breeding system of a wild population of Atlantic salmon (Salmo salar L.) by genetically sampling every returning adult and assessed the determinants of individual fitness. We then quantified the impacts of catch and release (C&R) on mating and reproductive success. Both sexes showed high variance in individual reproductive success, and the estimated standardized variance was higher for males (2.86) than for females (0.73). We found a weak positive relationship between body size and fitness and observed that fitness was positively correlated with the number of mates, especially in males. Mature male parr sired 44% of the analysed offspring. The impact of C&R on the number of offspring was size dependent, as the reproductive success of larger fish was more impaired than smaller ones. Also, there was an interactive negative effect of water temperature and air exposure time on reproductive success of C&R salmon. This study improves our understanding of the complex reproductive biology of the Atlantic salmon and is the first to investigate the impact of C&R on reproductive success. Our study expands the management toolbox of appropriate C&R practices that promote conservation of salmon populations and limit negative impacts on mating and reproductive success. © 2012 Blackwell Publishing Ltd.

Seasonal hydrologic responses to climate change in the Pacific Northwest

NASA Astrophysics Data System (ADS)

Vano, Julie A.; Nijssen, Bart; Lettenmaier, Dennis P.

2015-04-01

Increased temperatures and changes in precipitation will result in fundamental changes in the seasonal distribution of streamflow in the Pacific Northwest and will have serious implications for water resources management. To better understand local impacts of regional climate change, we conducted model experiments to determine hydrologic sensitivities of annual, seasonal, and monthly runoff to imposed annual and seasonal changes in precipitation and temperature. We used the Variable Infiltration Capacity (VIC) land-surface hydrology model applied at 1/16° latitude-longitude spatial resolution over the Pacific Northwest (PNW), a scale sufficient to support analyses at the hydrologic unit code eight (HUC-8) basin level. These experiments resolve the spatial character of the sensitivity of future water supply to precipitation and temperature changes by identifying the seasons and locations where climate change will have the biggest impact on runoff. The PNW exhibited a diversity of responses, where transitional (intermediate elevation) watersheds experience the greatest seasonal shifts in runoff in response to cool season warming. We also developed a methodology that uses these hydrologic sensitivities as basin-specific transfer functions to estimate future changes in long-term mean monthly hydrographs directly from climate model output of precipitation and temperature. When principles of linearity and superposition apply, these transfer functions can provide feasible first-order estimates of the likely nature of future seasonal streamflow change without performing downscaling and detailed model simulations.

A learning progression based teaching module on the causes of seasons

NASA Astrophysics Data System (ADS)

Galano, S.

2016-03-01

In this paper, we report about designing and validating a teaching learning module based on a learning progression and focused on the causes of seasons. An initial learning progression about the Celestial Motion big idea -causes of seasons, lunar and solar eclipse and Moon phases- was developed and validated. Existing curricula, research studies on alternative conceptions about these phenomena, and students' answers to an open questionnaire were the starting point to develop initial learning progressions; then, a two-tier multiple-choice questionnaire was designed to validate and improve it. The questionnaire was submitted to about 300 secondary-school students whose answers were used to revise the hypothesized learning progressions. This improved version of the learning progression was used to design a module focused on the causes of seasons in which students were engaged in quantitative measurements with a photovoltaic panel to explain changes of the Sun rays' flow on the Earth's surface over the year. The efficacy of our module in improving students' understanding of the phenomenon of the seasons was tested using our questionnaire as pre- and post-test.

Determination of Spring Onset and Growing Season Duration using Satellite Measurements

NASA Technical Reports Server (NTRS)

Min, Q.; Lin, Bing

2006-01-01

An integrated approach to retrieve microwave emissivity difference vegetation index (EDVI) over land regions has been developed from combined multi-platform/multi-sensor satellite measurements, including SSM/I measurements. A possible relationship of the remotely sensed EDVI and the leaf physiology of canopy is exploited at the Harvard Forest site for two growing seasons. This study finds that the EDVI is sensitive to leaf development through vegetation water content of the crown layer of the forest canopy, and has demonstrated that the spring onset and growing season duration can be determined accurately from the time series of satellite estimated EDVI within uncertainties about 3 and 7 days for spring onsets and growing season duration, respectively, compared to in-situ observations. The leaf growing stage may also be quantitatively monitored by a normalized EDVI. Since EDVI retrievals from satellite are generally possible during both daytime and nighttime under non-rain conditions, the EDVI technique studied here may provide higher temporal resolution observations for monitoring the onset of spring and the duration of growing season compared to currently operational satellite methods.

50 CFR 622.403 - Seasons.

Code of Federal Regulations, 2014 CFR

2014-10-01

... of the Gulf of Mexico and South Atlantic § 622.403 Seasons. (a) EEZ off the southern Atlantic states... and off the Gulf states, other than Florida—(1) Commercial and recreational fishing season. The...-day special recreational fishing season. (ii) EEZ off the Gulf states, other than Florida. There is a...

50 CFR 622.403 - Seasons.

Code of Federal Regulations, 2013 CFR

2013-10-01

... of the Gulf of Mexico and South Atlantic § 622.403 Seasons. (a) EEZ off the southern Atlantic states... and off the Gulf states, other than Florida—(1) Commercial and recreational fishing season. The...-day special recreational fishing season. (ii) EEZ off the Gulf states, other than Florida. There is a...

Ramadan fasting and pregnancy: implications for fetal development in summer season.

PubMed

Sakar, Mehmet Nafi; Gultekin, Huseyin; Demir, Bulent; Bakir, Vuslat Lale; Balsak, Deniz; Vuruskan, Erkut; Acar, Hicran; Yucel, Oguz; Yayla, Murat

2015-05-01

In the Islamic religion, Ramadan is a month in the year that is passed by fasting. Healthy adult individuals are prohibited to eat, drink, and smoke from sunrise to sunset. In the present study, our aim was to assess the relation of Ramadan fasting with fetal development and maternal-fetal Doppler indices in pregnant women. This is a prospective case-control study carried out in the month of Ramadan in 2013 (9 July-7 August). One hundred and six pregnant women at the second and third trimesters of pregnancy were enrolled into the study. The sample size of the fasting group was 83 and the non-fasting group sample size was also 83. Fetal biometric measurements, such as biparietal diameter, head circumference, abdominal circumference, femur length, estimated fetal weight, amniotic fluid index, and Doppler indices of both uterine and umbilical arteries were evaluated by gray scala and color Doppler ultrasound at the beginning and end of Ramadan. At the end of the Ramadan, increase in biparietal diameter, head circumference, and femur length showed a statistically significant difference from initial measurements (P<0.05). When fasting and non-fasting groups were compared separately, an increase in amniotic fluid index was statistically significant in the non-fasting group (P<0.05). We demonstrated some adverse effects of Ramadan fasting on fetal development. In the Islamic religion, pregnant individuals have the privilege of not fasting; therefore, they should consider postponing fasting to the postpartum period, especially in the summer season. If they are willing to do so, an appropriate nutritional program should be recommended.

Geography and Weather: Seasons.

ERIC Educational Resources Information Center

Collins, H. Thomas; Mogil, H. Michael

1989-01-01

Discussed are the reasons for the changing of the seasons on earth. Included are 27 activities which can be used to teach geography and the seasons. Diagrams of planetary motion and climatographs are presented. (CW)

Dietary fatty acids and inflammation in the vertebral column of Atlantic salmon, Salmo salar L., smolts: a possible link to spinal deformities.

PubMed

Gil Martens, L; Lock, E J; Fjelldal, P G; Wargelius, A; Araujo, P; Torstensen, B E; Witten, P E; Hansen, T; Waagbø, R; Ørnsrud, R

2010-12-01

Vegetable oils (Vo) are an alternative to fish oil (Fo) in aquaculture feeds. This study aimed to evaluate the effect of dietary soybean oil (Vo diet), rich in linoleic acid, and of dietary fish oil (Fo diet) on the development of spinal deformities under bacterial lipopolysaccharide (LPS)-induced chronic inflammation conditions in Atlantic salmon, Salmo salar L. Fish [25 g body weight (BW)] were fed the experimental diets for 99 days. On day 47 of feeding (40 g BW), fish were subjected to four experimental regimes: (i) intramuscular injections with LPS, (ii) sham-injected phosphate-buffered saline (PBS), (iii) intraperitoneally injected commercial oil adjuvant vaccine, or (iv) no treatment. The fish continued under a common feeding regime in sea water for 165 more days. Body weight was temporarily higher in the Vo group than in the Fo group prior to immunization and was also affected by the type of immunization. At the end of the trial, no differences were seen between the dietary groups. The overall prevalence of spinal deformities was approximately 14% at the end of the experiment. The Vo diet affected vertebral shape but did not induce spinal deformities. In groups injected with LPS and PBS, spinal deformities ranged between 21% and 38%, diet independent. Deformed vertebrae were located at or in proximity to the injection point. Assessment of inflammatory markers revealed high levels of plasma prostaglandin E₂ (PGE₂) in the Vo-fed and LPS-injected groups, suggesting an inflammatory response to LPS. Cyclooxigenase 2 (COX-2) mRNA expression in bone was higher in fish fed Fo compared to Vo-fed fish. Gene expression of immunoglobulin M (IgM) was up-regulated in bone of all LPS-injected groups irrespective of dietary oil. In conclusion, the study suggests that Vo is not a risk factor for the development of inflammation-related spinal deformities. At the same time, we found evidence that localized injection-related processes could trigger the development of

Season of Sampling and Season of Birth Influence Serotonin Metabolite Levels in Human Cerebrospinal Fluid

PubMed Central

Luykx, Jurjen J.; Bakker, Steven C.; Lentjes, Eef; Boks, Marco P. M.; van Geloven, Nan; Eijkemans, Marinus J. C.; Janson, Esther; Strengman, Eric; de Lepper, Anne M.; Westenberg, Herman; Klopper, Kai E.; Hoorn, Hendrik J.; Gelissen, Harry P. M. M.; Jordan, Julian; Tolenaar, Noortje M.; van Dongen, Eric P. A.; Michel, Bregt; Abramovic, Lucija; Horvath, Steve; Kappen, Teus; Bruins, Peter; Keijzers, Peter; Borgdorff, Paul; Ophoff, Roel A.; Kahn, René S.

2012-01-01

Background Animal studies have revealed seasonal patterns in cerebrospinal fluid (CSF) monoamine (MA) turnover. In humans, no study had systematically assessed seasonal patterns in CSF MA turnover in a large set of healthy adults. Methodology/Principal Findings Standardized amounts of CSF were prospectively collected from 223 healthy individuals undergoing spinal anesthesia for minor surgical procedures. The metabolites of serotonin (5-hydroxyindoleacetic acid, 5-HIAA), dopamine (homovanillic acid, HVA) and norepinephrine (3-methoxy-4-hydroxyphenylglycol, MPHG) were measured using high performance liquid chromatography (HPLC). Concentration measurements by sampling and birth dates were modeled using a non-linear quantile cosine function and locally weighted scatterplot smoothing (LOESS, span = 0.75). The cosine model showed a unimodal season of sampling 5-HIAA zenith in April and a nadir in October (p-value of the amplitude of the cosine = 0.00050), with predicted maximum (PCmax) and minimum (PCmin) concentrations of 173 and 108 nmol/L, respectively, implying a 60% increase from trough to peak. Season of birth showed a unimodal 5-HIAA zenith in May and a nadir in November (p = 0.00339; PCmax = 172 and PCmin = 126). The non-parametric LOESS showed a similar pattern to the cosine in both season of sampling and season of birth models, validating the cosine model. A final model including both sampling and birth months demonstrated that both sampling and birth seasons were independent predictors of 5-HIAA concentrations. Conclusion In subjects without mental illness, 5-HT turnover shows circannual variation by season of sampling as well as season of birth, with peaks in spring and troughs in fall. PMID:22312427

Towards Onboard Orbital Tracking of Seasonal Polar Volatiles on Mars

NASA Technical Reports Server (NTRS)

Wagstaff, Kiri L.; Castano, Rebecca; Chien, Steve; Ivanov, anton B.; Titus, Timothy N.

2005-01-01

Current conditions on Mars support both a residual polar cap, composed mainly of water ice, and a seasonal cap, composed of CO2, which appears and disappears each winter. Kieffer and Titus characterized the recession of the seasonal south polar cap using an arctangent curve fit based on data from the Thermal Emission Spectrometer on Mars Global Surveyor [1]. They also found significant interannual deviations, at the regional scale, in the recession rate [2]. Further observations will enable the refinement of our models of polar cap evolution in both hemispheres. We have developed the Bimodal Image Temperature (BIT) Histogram Analysis method for the automated detection and tracking of the seasonal polar ice caps on Mars. It is specifically tailored for possible use onboard a spacecraft. We have evaluated BIT on uncalibrated data collected by the Thermal Emission Imaging System (THEMIS) instrument [3] on the Mars Odyssey spacecraft. In this paper, we focus on the northern seasonal cap, but our approach is directly applicable to the future analysis of the southern seasonal ice cap as well.

Response of Amazon Fires to the 2015/2016 El Niño and Evaluation of a Seasonal Fire Season Severity Forecast

NASA Astrophysics Data System (ADS)

Randerson, J. T.

2016-12-01

Recent work has established that year-to-year variability in drought and fire within the Amazon responds to a dual forcing from ocean-atmosphere interactions in the tropical Pacific and North Atlantic. Teleconnections between the Pacific and the Amazon are strongest between October and March, when El Niño contributes to below-average precipitation during the wet season. A reduced build-up of soil moisture during the wet season, in turn, may limit water availability and transpiration in tropical forests during the following dry season, lowering surface humidity, drying fuels, and allowing fires to spread more easily through the understory. The delayed influence of soil moisture through this land - atmosphere coupling provides a means to predict fire season severity 3-6 months before the onset of the dry season. With the aim of creating new opportunities for forest conservation, we have developed an experimental seasonal fire forecasting system for the Amazon. The 2016 fire season severity forecast, released in June by UCI and NASA, predicts unusually high risk across eastern Peru, northern Bolivia, and Brazil. Several surface and satellite data streams confirm that El Niño teleconnections had a significant impact on wet season hydrology within the Amazon. Rainfall observations from the Global Precipitation Climatology Centre provided evidence that cumulative precipitation deficits during August-April were 1 to 2 standard deviations below the long-term mean for most of the basin. These observations were corroborated by strong negative terrestrial water storage anomalies measured by the Gravity Recovery and Climate Experiment, and by fluorescence and vegetation index observations from other sensors that indicated elevated canopy stress. By August 3rd, satellite observations showed above average fire activity in most, but not all, forecast regions. Using additional satellite observations that become available later this year, we plan to describe the full spatial and

A non-lethal method to estimate CYP1A expression in laboratory and wild Atlantic salmon (Salmo salar)

USGS Publications Warehouse

Rees, C.B.; McCormick, S.D.; Li, W.

2005-01-01

Expression of cytochrome P4501A (CYP1A) has been used as a biomarker for possible exposure to contaminants such as PCBs and dioxins in teleost fish. Using a quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR) and a non-lethal gill biopsy, we estimated levels of CYP1A mRNA expression in Atlantic salmon (Salmo salar). Groups of ten Atlantic salmon juveniles (48–76 g) received an intraperitoneal injection of 50 μg g− 1 β-naphthoflavone (BNF) or vehicle. Their gill tissues were repeatedly sampled by non-lethal biopsies on day 0, 1, 2 and 7. Control fish expressed basal levels of CYP1A over the duration of sampling. BNF-treated salmon demonstrated similar levels of CYP1A to control fish at day 0 and higher levels over the course of each additional sampling point. Gill biopsies from wild salmon sampled from Millers River (South Royalston, Worcester County, MA, USA), known to contain PCBs, showed significantly higher CYP1A levels over an uncontaminated reference stream, Fourmile Brook (Northfield, Franklin County, MA, USA). We conclude that gill biopsies coupled with Q-RT-PCR analysis is a valuable tool in environmental assessment of wild Atlantic salmon populations and has the potential to be applied to other populations of fish as well.

Sorting Out Seasonal Allergies

MedlinePlus

... Dr. Georgeson. “Seasonal allergies—many times caused by pollen from trees, weeds and grasses—are triggered during ... or spring.” “For people with seasonal allergies, this pollen reacts with antibodies in the body, causing histamine ...

SNP-array reveals genome-wide patterns of geographical and potential adaptive divergence across the natural range of Atlantic salmon (Salmo salar).

PubMed

Bourret, Vincent; Kent, Matthew P; Primmer, Craig R; Vasemägi, Anti; Karlsson, Sten; Hindar, Kjetil; McGinnity, Philip; Verspoor, Eric; Bernatchez, Louis; Lien, Sigbjørn

2013-02-01

Atlantic salmon (Salmo salar) is one of the most extensively studied fish species in the world due to its significance in aquaculture, fisheries and ongoing conservation efforts to protect declining populations. Yet, limited genomic resources have hampered our understanding of genetic architecture in the species and the genetic basis of adaptation to the wide range of natural and artificial environments it occupies. In this study, we describe the development of a medium-density Atlantic salmon single nucleotide polymorphism (SNP) array based on expressed sequence tags (ESTs) and genomic sequencing. The array was used in the most extensive assessment of population genetic structure performed to date in this species. A total of 6176 informative SNPs were successfully genotyped in 38 anadromous and freshwater wild populations distributed across the species natural range. Principal component analysis clearly differentiated European and North American populations, and within Europe, three major regional genetic groups were identified for the first time in a single analysis. We assessed the potential for the array to disentangle neutral and putative adaptive divergence of SNP allele frequencies across populations and among regional groups. In Europe, secondary contact zones were identified between major clusters where endogenous and exogenous barriers could be associated, rendering the interpretation of environmental influence on potentially adaptive divergence equivocal. A small number of markers highly divergent in allele frequencies (outliers) were observed between (multiple) freshwater and anadromous populations, between northern and southern latitudes, and when comparing Baltic populations to all others. We also discuss the potential future applications of the SNP array for conservation, management and aquaculture. © 2012 Blackwell Publishing Ltd.

Seasonality in pulmonary tuberculosis among migrant workers entering Kuwait

PubMed Central

Akhtar, Saeed; Mohammad, Hameed GHH

2008-01-01

Background There is paucity of data on seasonal variation in pulmonary tuberculosis (TB) in developing countries contrary to recognized seasonality in the TB notification in western societies. This study examined the seasonal pattern in TB diagnosis among migrant workers from developing countries entering Kuwait. Methods Monthly aggregates of TB diagnosis results for consecutive migrants tested between January I, 1997 and December 31, 2006 were analyzed. We assessed the amplitude (α) of the sinusoidal oscillation and the time at which maximum (θ°) TB cases were detected using Edwards' test. The adequacy of the hypothesized sinusoidal curve was assessed by χ2 goodness-of-fit test. Results During the 10 year study period, the proportion (per 100,000) of pulmonary TB cases among the migrants was 198 (4608/2328582), (95% confidence interval: 192 – 204). The adjusted mean monthly number of pulmonary TB cases was 384. Based on the observed seasonal pattern in the data, the maximum number of TB cases was expected during the last week of April (θ° = 112°; P < 0.001). The amplitude (± se) (α = 0.204 ± 0.04) of simple harmonic curve showed 20.4% difference from the mean to maximum TB cases. The peak to low ratio of adjusted number of TB cases was 1.51 (95% CI: 1.39 – 1.65). The χ2 goodness-of-test revealed that there was no significant (P > 0.1) departure of observed frequencies from the fitted simple harmonic curve. Seasonal component explained 55% of the total variation in the proportions of TB cases (100,000) among the migrants. Conclusion This regularity of peak seasonality in TB case detection may prove useful to institute measures that warrant a better attendance of migrants. Public health authorities may consider re-allocation of resources in the period of peak seasonality to minimize the risk of Mycobacterium tuberculosis infection to close contacts in this and comparable settings in the region having similar influx of immigrants from high TB burden

Enhancing Seasonal Water Outlooks: Needs and Opportunities in the Critical Runoff Season

NASA Astrophysics Data System (ADS)

Ray, A. J.; Barsugli, J. J.; Yocum, H.; Stokes, M.; Miskus, D.

2017-12-01

The runoff season is a critical period for the management of water supply in the western U.S., where in many places over 70% of the annual runoff occurs in the snowmelt period. Managing not only the volume, but the intra-seasonal timing of the runoff is important for optimizing storage, as well as achieving other goals such as mitigating flood risk, and providing peak flows for riparian habitat management, for example, for endangered species. Western river forecast centers produce volume forecasts for western reservoirs that are key input into many water supply decisions, and also short term river forecasts out to 10 days. The early volume forecasts each year typically begin in December, and are updated throughout the winter and into the runoff season (April-July for many areas, but varies). This presentation will discuss opportunities for enhancing this existing suite of RFC water outlooks, including the needs for and potential use for "intraseasonal" products beyond those provided by the Ensemble Streamflow Prediction system and the volume forecasts. While precipitation outlooks have little skill for many areas and seasons, and may not contribute significantly to the outlook, late winter and spring temperature forecasts have meaningful skill in certain areas and sub-seasonal to seasonal time scales. This current skill in CPC temperature outlooks is an opportunity to translate these products into information about the snowpack and potential runoff timing, even where the skill in precipitation is low. Temperature is important for whether precipitation falls as snow or rain, which is critical for streamflow forecasts, especially in the melt season in snowpack-dependent watersheds. There is a need for better outlooks of the evolution of snowpack, conditions influencing the April-July runoff, and the timing of spring peak or shape of the spring hydrograph. The presentation will also discuss a our work with stakeholders of the River Forecast Centers and the NIDIS

Seasonal differences in leaf-level physiology give lianas a competitive advantage over trees in a tropical seasonal forest.

PubMed

Cai, Zhi-Quan; Schnitzer, Stefan A; Bongers, Frans

2009-08-01

Lianas are an important component of most tropical forests, where they vary in abundance from high in seasonal forests to low in seasonal forests. We tested the hypothesis that the physiological ability of lianas to fix carbon (and thus grow) during seasonal drought may confer a distinct advantage in seasonal tropical forests, which may explain pan-tropical liana distributions. We compared a range of leaf-level physiological attributes of 18 co-occurring liana and 16 tree species during the wet and dry seasons in a tropical seasonal forest in Xishuangbanna, China. We found that, during the wet season, lianas had significantly higher CO(2) assimilation per unit mass (A(mass)), nitrogen concentration (N(mass)), and delta(13)C values, and lower leaf mass per unit area (LMA) than trees, indicating that lianas have higher assimilation rates per unit leaf mass and higher integrated water-use efficiency (WUE), but lower leaf structural investments. Seasonal variation in CO(2) assimilation per unit area (A(area)), phosphorus concentration per unit mass (P(mass)), and photosynthetic N-use efficiency (PNUE), however, was significantly lower in lianas than in trees. For instance, mean tree A(area) decreased by 30.1% from wet to dry season, compared with only 12.8% for lianas. In contrast, from the wet to dry season mean liana delta(13)C increased four times more than tree delta(13)C, with no reduction in PNUE, whereas trees had a significant reduction in PNUE. Lianas had higher A(mass) than trees throughout the year, regardless of season. Collectively, our findings indicate that lianas fix more carbon and use water and nitrogen more efficiently than trees, particularly during seasonal drought, which may confer a competitive advantage to lianas during the dry season, and thus may explain their high relative abundance in seasonal tropical forests.

Seasonal Difference in Postthyroidectomy Hypocalcemia: A Montreal-Based Study.

PubMed

Mascarella, Marco A; Forest, Véronique-Isabelle; Nhan, Carol; Leboeuf, Rébecca; Tamilia, Michael; Mlynarek, Alex M; Payne, Richard J

2016-02-01

Hypocalcemia following thyroidectomy often prolongs hospital stay and is potentially life-threatening. The objective of this study is to determine whether the season when thyroidectomy is performed is associated with postoperative hypocalcemia. Retrospective case series of patients undergoing thyroid surgery from 2009 to 2015. Tertiary care academic institution in Montreal, Canada. A consecutive sample of 823 patients undergoing thyroidectomy by a single high-volume otolaryngologist for a suspected or confirmed thyroid malignancy. Patient demographics, procedure type, calcium and vitamin D supplementation, and seasonal rate of hypocalcemia postthyroidectomy were calculated and compared. Average seasonal rates of postthyroidectomy hypocalcemia in the winter, spring, summer, and autumn were, respectively, 8.3% (8 of 216), 7.3% (12 of 165), 1.5% (3 of 201), and 3.5% (8 of 228; P < .005). Patients operated in the winter were 5.6 times more likely to develop hypocalcemia as compared with those in the summer (P < .01; 95% confidence interval: 1.7-18.7). In a multiple regression analysis factoring in season when surgery was performed, procedure type, and preoperative vitamin D/calcium supplementation, surgery occurring in the winter predicted a hypocalcemia event (correlation coefficient [SE]: 0.72 [0.024], P = .026; 0.006 [0.025], P = .81; 0.004 [0.019], P = .82, respectively). In this study, patients undergoing thyroidectomy in the winter months were more likely to develop postoperative hypocalcemia when compared with those operated in the summer. Further studies are needed to understand the role of vitamin D in the observed seasonal difference in hypocalcemia rates. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

The North American Multi-Model Ensemble (NMME): Phase-1 Seasonal to Interannual Prediction, Phase-2 Toward Developing Intra-Seasonal Prediction

NASA Technical Reports Server (NTRS)

Kirtman, Ben P.; Min, Dughong; Infanti, Johnna M.; Kinter, James L., III; Paolino, Daniel A.; Zhang, Qin; vandenDool, Huug; Saha, Suranjana; Mendez, Malaquias Pena; Becker, Emily;

Crew Earth Observations over Bolivia taken during Expedition 12

NASA Image and Video Library

2005-11-03

ISS012-E-06456 (3 Nov. 2005) --- Salar de Uyuni, the largest Salar (salt flat) in the world, located within the Altiplano of Bolivia, South America is featured in this image photographed by an Expedition 12 crewmember on the International Space Station. The Altiplano is a high plateau formed during uplift of the Andes Mountains. The plateau harbors fresh and saltwater lakes, together with Salars, that are surrounded by mountains with no drainage outlets--all at elevations greater than 3,659 meters (12,000 feet) above mean sea level. The Salar de Uyuni covers approximately 8,000 square kilometers (3,100 square miles), and it is a major transport route across the Bolivian Altiplano due to its flatness. This image features the northern end of the Salar and the dormant volcano Mount Tunupa (image center). This mountain is high enough to support a summit glacier, and enough rain falls on the windward slopes to provide water for small communities along the base. The dark volcanic rocks comprising Mt. Tunupa are in sharp contrast with the white, mineral-crusted surface of the Salar. The major minerals are halite--common table salt--and gypsum--a common component of drywall. Relict shorelines visible in the surface salt deposits (lower right of the image) attest to the occasional presence of small amounts of water in the Salar. Sediments in the Salar basin record fluctuations in water levels that occurred as the lake that once occupied the Salar evaporated. These sediments provide a valuable paleoclimate record for the region. The dynamic geological history of the Altiplano is recorded in isolated "islands" within the salt flat (image left); these islands are typically built from fossil coral reefs covered by Andean volcanic rocks.

Seasonal Variability of Saturn's Atmosphere

NASA Technical Reports Server (NTRS)

Yanamandra-Fisher, Padma A.; Simon, Amy; Delcroix, Marc; Orton, Glenn S.; Trinh, Shirley

2012-01-01

The seasonal variability of Saturn's clouds and weather layer, currently displaying a variety of phenomena (convective storms, planetary waves, giant storms and lightning-induced events, etc.) is not yet fully understood. Variations of Saturn's radiance at 5.2 microns, a spectral region dominated by thermal emission in an atmospheric window containing weak gaseous absorption, contain a strong axisymmetric component as well as large discrete features at low and mid-latitudes that are several degrees colder than the planetary average and uncorrelated with features at shorter wavelengths that are dominated by reflected sunlight (Yanamandra-Fisher et al., 2001. Icarus, Vol. 150). The characterization of several fundamental atmospheric properties and processes, however, remains incomplete, namely: How do seasons affect (a) the global distribution of gaseous constituents and aerosols; and (b) temperatures and the stability against convection and large scale-atmospheric transport? Do 5-micron clouds have counterparts at other altitude levels? What changes occur during the emergence of Great White Storms? Data acquired at the NASA/IRTF and NAOJ/Subaru from 1995 - 2011; since 2004, high-resolution multi-spectral and high-spatial imaging data acquired by the NASA/ESA Cassini mission, represents half a Saturnian year or two seasons. With the addition of detailed multi-spectral data sets acquired by amateur observers, we study these dramatic phenomena to better understand the timeline of the evolution of these events. Seasonal (or temporal) trends in the observables such as albedo of the clouds, thermal fields of the atmosphere as function of altitude, development of clouds, hazes and global abundances of various hydrocarbons in the atmosphere can now be modeled. We will present results of our ongoing investigation for the search and characterization of periodicities over half a Saturnian year, based on a non-biased a priori approach and time series techniques (such as

The occurrence of Dechlorane Plus and related norbornene-based flame retardants in Baltic wild salmon (Salmo salar).

PubMed

Rjabova, Jekaterina; Bartkevics, Vadims; Zacs, Dzintars

2016-03-01

Twenty five Baltic wild salmon (Salmo salar) specimens were analysed for the content of Dechlorane-related compounds (DRCs). Out of the ten analysed DRCs, seven compounds were detected in the muscle tissues of salmon, including Dechlorane (Dec) 602, Dec 603, syn- and anti-stereoisomers of Dechlorane Plus (DP), Dechlorane Plus monoadduct (1,3-DPMA), hexachlorocyclopentadienyl-dibromocyclooctane (DBHCTD), and Mirex. The concentrations of Dec 604 and two DP dechlorinated compounds - decachloropentacyclooctadecadiene (Cl10DP) and undecachloropentacyclooctadecadiene (Cl11DP) - were below the limit of detection in all samples. The aggregated concentrations of DRCs (ΣDRC) were in the range of 551-3339 pg g(-1) fresh weight (f.w.) with 1,3-DPMA being the predominant DRC component contributing up to 70% to the ΣDRC. The fractional abundance of syn- and anti-DP stereoisomers showed a pronounced enrichment of anti-DP and was close to the composition of OxyChem(®) DP commercial product. The obtained concentrations of DRCs were substantially lower than those reported in previous studies of biotic samples (among them fish, mollusks, white stork and peregrine falcon eggs) from inland freshwater reservoirs in more industrialised areas throughout Europe and North America. A statistically significant relationships between the concentrations of Dec 602 and the concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) was observed. Copyright © 2016 Elsevier Ltd. All rights reserved.

Global seasonal climate predictability in a two tiered forecast system: part I: boreal summer and fall seasons

NASA Astrophysics Data System (ADS)

Misra, Vasubandhu; Li, H.; Wu, Z.; DiNapoli, S.

2014-03-01

This paper shows demonstrable improvement in the global seasonal climate predictability of boreal summer (at zero lead) and fall (at one season lead) seasonal mean precipitation and surface temperature from a two-tiered seasonal hindcast forced with forecasted SST relative to two other contemporary operational coupled ocean-atmosphere climate models. The results from an extensive set of seasonal hindcasts are analyzed to come to this conclusion. This improvement is attributed to: (1) The multi-model bias corrected SST used to force the atmospheric model. (2) The global atmospheric model which is run at a relatively high resolution of 50 km grid resolution compared to the two other coupled ocean-atmosphere models. (3) The physics of the atmospheric model, especially that related to the convective parameterization scheme. The results of the seasonal hindcast are analyzed for both deterministic and probabilistic skill. The probabilistic skill analysis shows that significant forecast skill can be harvested from these seasonal hindcasts relative to the deterministic skill analysis. The paper concludes that the coupled ocean-atmosphere seasonal hindcasts have reached a reasonable fidelity to exploit their SST anomaly forecasts to force such relatively higher resolution two tier prediction experiments to glean further boreal summer and fall seasonal prediction skill.

On jointly optimising the changes of seasonable goods and inventory replenishment

NASA Astrophysics Data System (ADS)

Li, Zhaolin; Tao, Feng; Sun, Daewon

2012-06-01

Retailers often need to replace soon-to-be-unseasonable products with new seasonable goods when the season changes. The trade-off for such activities involves choosing between the salvage loss of the unseasonable product and the profit of selling the seasonable product early. This article develops a periodic-review inventory model for planning the changes of seasonable goods with state-dependent demand and cost parameters. We show that the single-period optimal policy for product changes is a threshold policy based on the initial inventory of the unseasonable goods. The corresponding optimal inventory policy follows a Purchase-Keep-Dispose policy if the incumbent product is kept or a base-stock policy if the incumbent product is replaced. Numerically, we find that the structure of the multi-period optimal policy resembles that of the single-period model. We propose a heuristic to solve the multi-period model and demonstrate its effectiveness. Our research provides insights into dynamically managing seasonable goods.

Intestinal Fluid Permeability in Atlantic Salmon (Salmo salar L.) Is Affected by Dietary Protein Source.

PubMed

Hu, Haibin; Kortner, Trond M; Gajardo, Karina; Chikwati, Elvis; Tinsley, John; Krogdahl, Åshild

2016-01-01

In Atlantic salmon (Salmo salar L.), and also in other fish species, certain plant protein ingredients can increase fecal water content creating a diarrhea-like condition which may impair gut function and reduce fish growth. The present study aimed to strengthen understanding of the underlying mechanisms by observing effects of various alternative plant protein sources when replacing fish meal on expression of genes encoding proteins playing key roles in regulation of water transport across the mucosa of the distal intestine (DI). A 48-day feeding trial was conducted with five diets: A reference diet (FM) in which fish meal (72%) was the only protein source; Diet SBMWG with a mix of soybean meal (30%) and wheat gluten (22%); Diet SPCPM with a mix of soy protein concentrate (30%) and poultry meal (6%); Diet GMWG with guar meal (30%) and wheat gluten (14.5%); Diet PM with 58% poultry meal. Compared to fish fed the FM reference diet, fish fed the soybean meal containing diet (SBMWG) showed signs of enteritis in the DI, increased fecal water content of DI chyme and higher plasma osmolality. Altered DI expression of a battery of genes encoding aquaporins, ion transporters, tight junction and adherens junction proteins suggested reduced transcellular transport of water as well as a tightening of the junction barrier in fish fed the SBMWG diet, which may explain the observed higher fecal water content and plasma osmolality. DI structure was not altered for fish fed the other experimental diets but alterations in target gene expression and fecal water content were observed, indicating that alterations in water transport components may take place without clear effects on intestinal structure.

The impact of escaped farmed Atlantic salmon (Salmo salar L.) on catch statistics in Scotland.

PubMed

Green, Darren M; Penman, David J; Migaud, Herve; Bron, James E; Taggart, John B; McAndrew, Brendan J

2012-01-01

In Scotland and elsewhere, there are concerns that escaped farmed Atlantic salmon (Salmo salar L.) may impact on wild salmon stocks. Potential detrimental effects could arise through disease spread, competition, or inter-breeding. We investigated whether there is evidence of a direct effect of recorded salmon escape events on wild stocks in Scotland using anglers' counts of caught salmon (classified as wild or farmed) and sea trout (Salmo trutta L.). This tests specifically whether documented escape events can be associated with reduced or elevated escapes detected in the catch over a five-year time window, after accounting for overall variation between areas and years. Alternate model frameworks were somewhat inconsistent, however no robust association was found between documented escape events and higher proportion of farm-origin salmon in anglers' catch, nor with overall catch size. A weak positive correlation was found between local escapes and subsequent sea trout catch. This is in the opposite direction to what would be expected if salmon escapes negatively affected wild fish numbers. Our approach specifically investigated documented escape events, contrasting with earlier studies examining potentially wider effects of salmon farming on wild catch size. This approach is more conservative, but alleviates some potential sources of confounding, which are always of concern in observational studies. Successful analysis of anglers' reports of escaped farmed salmon requires high data quality, particularly since reports of farmed salmon are a relatively rare event in the Scottish data. Therefore, as part of our analysis, we reviewed studies of potential sensitivity and specificity of determination of farmed origin. Specificity estimates are generally high in the literature, making an analysis of the form we have performed feasible.

The Impact of Escaped Farmed Atlantic Salmon (Salmo salar L.) on Catch Statistics in Scotland

PubMed Central

Green, Darren M.; Penman, David J.; Migaud, Herve; Bron, James E.; Taggart, John B.; McAndrew, Brendan J.

2012-01-01

In Scotland and elsewhere, there are concerns that escaped farmed Atlantic salmon (Salmo salar L.) may impact on wild salmon stocks. Potential detrimental effects could arise through disease spread, competition, or inter-breeding. We investigated whether there is evidence of a direct effect of recorded salmon escape events on wild stocks in Scotland using anglers' counts of caught salmon (classified as wild or farmed) and sea trout (Salmo trutta L.). This tests specifically whether documented escape events can be associated with reduced or elevated escapes detected in the catch over a five-year time window, after accounting for overall variation between areas and years. Alternate model frameworks were somewhat inconsistent, however no robust association was found between documented escape events and higher proportion of farm-origin salmon in anglers' catch, nor with overall catch size. A weak positive correlation was found between local escapes and subsequent sea trout catch. This is in the opposite direction to what would be expected if salmon escapes negatively affected wild fish numbers. Our approach specifically investigated documented escape events, contrasting with earlier studies examining potentially wider effects of salmon farming on wild catch size. This approach is more conservative, but alleviates some potential sources of confounding, which are always of concern in observational studies. Successful analysis of anglers' reports of escaped farmed salmon requires high data quality, particularly since reports of farmed salmon are a relatively rare event in the Scottish data. Therefore, as part of our analysis, we reviewed studies of potential sensitivity and specificity of determination of farmed origin. Specificity estimates are generally high in the literature, making an analysis of the form we have performed feasible. PMID:22970132

The 2015 global production capacity of seasonal and pandemic influenza vaccine.

PubMed

McLean, Kenneth A; Goldin, Shoshanna; Nannei, Claudia; Sparrow, Erin; Torelli, Guido

2016-10-26

A global shortage and inequitable access to influenza vaccines has been cause for concern for developing countries who face dire consequences in the event of a pandemic. The Global Action Plan for Influenza Vaccines (GAP) was launched in 2006 to increase global capacity for influenza vaccine production to address these concerns. It is widely recognized that well-developed infrastructure to produce seasonal influenza vaccines leads to increased capacity to produce pandemic influenza vaccines. This article summarizes the results of a survey administered to 44 manufacturers to assess their production capacity for seasonal influenza and pandemic influenza vaccine production. When the GAP was launched in 2006, global production capacity for seasonal and pandemic vaccines was estimated to be 500million and 1.5billion doses respectively. Since 2006 there has been a significant increase in capacity, with the 2013 survey estimating global capacity at 1.5billion seasonal and 6.2billion pandemic doses. Results of the current survey showed that global seasonal influenza vaccine production capacity has decreased since 2013 from 1.504billion doses to 1.467billion doses. However, notwithstanding the overall global decrease in seasonal vaccine capacity there were notable positive changes in the distribution of production capacity with increases noted in South East Asia (SEAR) and the Western Pacific (WPR) regions, albeit on a small scale. Despite a decrease in seasonal capacity, there has been a global increase of pandemic influenza vaccine production capacity from 6.2 billion doses in 2013 to 6.4 billion doses in 2015. This growth can be attributed to a shift towards more quadrivalent vaccine production and also to increased use of adjuvants. Pandemic influenza vaccine production capacity is at its highest recorded levels however challenges remain in maintaining this capacity and in ensuring access in the event of a pandemic to underserved regions. Copyright © 2016. Published by

Season-dependent effects of elevated temperature on stress biomarkers, energy metabolism and gamete development in mussels.

PubMed

Múgica, M; Sokolova, I M; Izagirre, U; Marigómez, I

2015-02-01

In coastal areas, sessile species can be severely affected by thermal stress associated to climate change. Presently, the effect of elevated temperature on metabolic, cellular and tissue-level responses of mussels was determined to assess whether the responses vary seasonally with seawater temperature and reproductive stage. Mussels were collected in fall, winter and summer, and (a) maintained at 16, 12, and 20 °C respectively or (b) subject to gradual temperature elevation for 8 days (+1 °C per day; from 16 to 24 °C in fall, from 12 to 20 °C in winter and from 20 to 28 °C in summer) and further maintained at 24 °C (fall), 20 °C (winter) and 28 °C (summer) for the following 6 days. Temperature elevation induced membrane destabilization, lysosomal enlargement, and reduced the aerobic scope in fall and summer whereas in winter no significant changes were found. Changes at tissue-level were only evident at 28 °C. Gamete development was impaired irrespective of season. Since the threshold of negative effects of warming was close to ambient temperatures in summer (24 °C or above) studied mussel populations would be vulnerable to the global climate change. Copyright © 2014 Elsevier Ltd. All rights reserved.

Baking Reduces Prostaglandin, Resolvin, and Hydroxy-Fatty Acid Content of Farm-Raised Atlantic Salmon (Salmo salar)

PubMed Central

Raatz, Susan K.; Golovko, Mikhail Y.; Brose, Stephen A.; Rosenberger, Thad A.; Burr, Gary S.; Wolters, William R.; Picklo, Matthew J.

2011-01-01

Consumption of seafood enriched in n-3 polyunsaturated fatty acids (PUFA) is associated with a decreased risk of cardiovascular disease. Several n-3 oxidation products from eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) have known protective effects in the vasculature. It is not known whether consumption of cooked seafood enriched in n-3 PUFA causes appreciable consumption of lipid oxidation products. We tested the hypothesis that baking Atlantic salmon (Salmo salar) increases the level of n-3 and n-6 PUFA oxidation products over raw salmon. We measured the content of several monohydroxy-fatty acids (MHFA), prostanoids, and resolvins. Our data demonstrate that baking did not change the overall total levels of MHFA. However, baking resulted in selective regio-isomeric loss of hydroxy fatty acids from arachidonic acid (20:4n-6), and EPA while significantly increasing hydroxyl-linoleic acid levels. The content of prostanoids and resolvins were reduced several-fold with baking. The inclusion of coating upon the salmon prior to baking reduced the loss of some MHFA but had no effect upon prostanoid losses incurred by baking. Baking did not decrease n-3 PUFA content indicating that baking of salmon is an acceptable means of preparation that does not alter the potential health benefits of high n-3 seafood consumption. The extent to which the levels of MHFA, prostanoids and resolvins in the raw or baked fish have physiologic consequence for humans needs to be determined. PMID:21919483

Seasonal Population Dynamics of Three Potato Pests in Washington State.

PubMed

D'Auria, Elizabeth M; Wohleb, Carrie H; Waters, Timothy D; Crowder, David W

2016-08-01

Pest phenology models allow producers to anticipate pest outbreaks and deploy integrated pest management (IPM) strategies. Phenology models are particularly useful for cropping systems with multiple economically damaging pests throughout a season. Potato (Solanum tuberosum L.) crops of Washington State, USA, are attacked by many insect pests including the potato tuberworm (Phthorimaea operculella Zeller), the beet leafhopper (Circulifer tenellus Baker), and the green peach aphid (Myzus persicae Sulzer). Each of these pests directly damages potato foliage or tubers; C. tenellus and M. persicae also transmit pathogens that can drastically reduce potato yields. We monitored the seasonal population dynamics of these pests by conducting weekly sampling on a network of commercial farms from 2007 to 2014. Using these data, we developed phenology models to characterize the seasonal population dynamics of each pest based on accumulated degree-days (DD). All three pests exhibited consistent population dynamics across seasons that were mediated by temperature. Of the three pests, C. tenellus was generally the first detected in potato crops, with 90% of adults captured by 936 DD. In contrast, populations of P. operculella and M. persicae built up more slowly over the course of the season, with 90% cumulative catch by 1,590 and 2,634 DD, respectively. Understanding these seasonal patterns could help potato producers plan their IPM strategies while allowing them to move away from calendar-based applications of insecticides. More broadly, our results show how long-term monitoring studies that explore dynamics of multiple pest species can aid in developing IPM strategies in crop systems. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Mineralization of the vertebral bodies in Atlantic salmon (Salmo salar L.) is initiated segmentally in the form of hydroxyapatite crystal accretions in the notochord sheath

PubMed Central

Wang, Shou; Kryvi, Harald; Grotmol, Sindre; Wargelius, Anna; Krossøy, Christel; Epple, Mattias; Neues, Frank; Furmanek, Tomasz; Totland, Geir K

2013-01-01

We performed a sequential morphological and molecular biological study of the development of the vertebral bodies in Atlantic salmon (Salmo salar L.). Mineralization starts in separate bony elements which fuse to form complete segmental rings within the notochord sheath. The nucleation and growth of hydroxyapatite crystals in both the lamellar type II collagen matrix of the notochord sheath and the lamellar type I collagen matrix derived from the sclerotome, were highly similar. In both matrices the hydroxyapatite crystals nucleate and accrete on the surface of the collagen fibrils rather than inside the fibrils, a process that may be controlled by a template imposed by the collagen fibrils. Apatite crystal growth starts with the formation of small plate-like structures, about 5 nm thick, that gradually grow and aggregate to form extensive multi-branched crystal arborizations, resembling dendritic growth. The hydroxyapatite crystals are always oriented parallel to the long axis of the collagen fibrils, and the lamellar collagen matrices provide oriented support for crystal growth. We demonstrate here for the first time by means of synchroton radiation based on X-ray diffraction that the chordacentra contain hydroxyapatite. We employed quantitative real-time PCR to study the expression of key signalling molecule transcripts expressed in the cellular core of the notochord. The results indicate that the notochord not only produces and maintains the notochord sheath but also expresses factors known to regulate skeletogenesis: sonic hedgehog (shh), indian hedgehog homolog b (ihhb), parathyroid hormone 1 receptor (pth1r) and transforming growth factor beta 1 (tgfb1). In conclusion, our study provides evidence for the process of vertebral body development in teleost fishes, which is initially orchestrated by the notochord. PMID:23711083

Summer of Seasons Workshop Program for Emerging Educators in Earth System Science

NASA Technical Reports Server (NTRS)

Chaudhury, S. Raj

2002-01-01

Norfolk State University BEST Lab successfully hosted three Summer of Seasons programs from 1998-2001. The Summer of Seasons program combined activities during the summer with additional seminars and workshops to provide broad outreach in the number of students and teachers who participated. Lessons learned from the each of the first two years of this project were incorporated into the design of the final year's activities. The "Summer of Seasons" workshop program provided emerging educators with the familiarity and knowledge to utilize in the classroom curriculum materials developed through NASA sponsorship on Earth System Science. A special emphasis was placed on the use of advanced technologies to dispel the commonly held misconceptions regarding seasonal, climactic and global change phenomena.

It's a Fine Season for Masks.

ERIC Educational Resources Information Center

Kennedy, Patricia

1999-01-01

Describes an art lesson, inspired by Giuseppe Arcimboldo's "Seasons" series, in which students construct masks representing one of the four seasons. Discusses the process and lists words and phrases associated with each season. (CMK)

How to Control Your Seasonal Allergies

MedlinePlus

... turn Javascript on. Feature: Managing Allergies How to Control Your Seasonal Allergies Past Issues / Spring 2013 Table ... asthma. Read More "Managing Allergies" Articles How to Control Your Seasonal Allergies / Allergy Diagnosis and Treatment / Seasonal ...

Hindcasting of Equatorial Spread F Using Seasonal Empirical Models

NASA Astrophysics Data System (ADS)

Aswathy, R. P.; Manju, G.

2018-02-01

The role of gravity waves in modulating equatorial spread F (ESF) day-to-day variability is investigated using ionosonde data at Trivandrum (geographic coordinates, 8.5°N, 77°E; mean geomagnetic latitude -0.3°N) a magnetic equatorial location. A novel empirical model that incorporates the combined effects of electrodynamics and gravity waves in modulating ESF occurrence during autumnal equinox season was presented by Aswathy and Manju (2017). In the present study, the height variations of the requisite gravity wave seed perturbations for ESF are examined for the vernal equinoxes, summer solstices, and winter solstices of different years. Subsequently, the empirical model, incorporating the electrodynamical effects and the gravity wave modulation, valid for each of the seasons is developed. Accordingly, for each season, the threshold curve may be demarcated provided the solar flux index (F10.7) is known. The empirical models are validated using the data for high, moderate, and low solar activity years corresponding to each season. In the next stage, this model is to be fine tuned to facilitate the prediction of ESF well before its onset.

Ozone measurements in Amazonia - Dry season versus wet season

NASA Technical Reports Server (NTRS)

Kirchhoff, V. W. J. H.; Da Silva, I. M. O.; Browell, Edward V.

1990-01-01

Recent ozone measurements taken in the Amazonian rain forest environment during the wet season (April-May 1987) are described, revealling new aspects of the regional atmospheric chemistry. The measurements were part of the Amazon Boundary Layer Experiment (ABLE 2B) mission and utilized UV absorption as a measurement technique to obtain surface ozone data; 20 ozonesondes were launched in order to obtain vertical ozone profiles used to describe the upper troposphere and stratosphere. The major differences in comparison to a previous dry season experiment, which found ozone concentrations to be lower in the whole troposphere by nearly a factor of 2, are stressed.

Importance of Dry-Season Precipitation to the Water Resources of Monteverde, Costa Rica

NASA Astrophysics Data System (ADS)

Guswa, A. J.; Rhodes, A. L.

2005-12-01

Monteverde, Costa Rica harbors montane forests that exemplify the delicate balances among climate, hydrology, habitat, and development. Most of the annual precipitation to this region arrives during the wet season, but the importance of orographic precipitation during the dry and transitional seasons should not be underestimated. Changes in regional land-cover and global climate may lead to reduced precipitation and cloud cover and a subsequent decline in endemic species, and a boom in ecotourism has put stress on water resources. A recent attempt to withdraw water from a local stream led to a standoff between conservationists and business developers, and there is a clear need for hydrologic data and understanding in support of policy. Through signals observed in the stable isotopic composition of precipitation and streamflow, we seek to understand how precipitation from the drier seasons propagates through the hydrologic cycle. In precipitation, δ18O and δ2H are heaviest during the dry and transitional seasons and light during the rainy season, consistent with the condensation mechanisms and degree of rainout typical of these periods. The signal in d-excess indicates a contribution of recycled water to precipitation in Monteverde from late in the rainy season through the dry season. Attenuated versions of these seasonal signals propagate through to the stream samples and provide a means of determining the importance of dry-season precipitation to water resources for the region. Results from six catchments on the leeward slope indicate that the Brillante Gap in the continental divide exerts strong control on the input of orographic precipitation to the region. Disparities in the temporal signals of precipitation and streamflow isotopes indicate non-linear behavior in the hydrologic processes that move water through these catchments.

Atlantic salmon, Salmo salar L. are broadly susceptible to isolates representing the North American genogroups of infectious hematopoietic necrosis virus

USGS Publications Warehouse

Kurath, Gael; Winton, James R.; Dale, Ole B.; Purcell, Maureen K.; Falk, Knut; Busch, Robert D.

2016-01-01

Beginning in 1992, three epidemic waves of infectious hematopoietic necrosis, often with high mortality, occurred in farmed Atlantic salmon Salmo salar L. on the west coast of North America. We compared the virulence of eleven strains of infectious hematopoietic necrosis virus (IHNV), representing the U, M and L genogroups, in experimental challenges of juvenile Atlantic salmon in freshwater. All strains caused mortality and there was wide variation within genogroups: cumulative mortality for five U-group strains ranged from 20 to 100%, four M-group strains ranged 30-63% and two L-group strains varied from 41 to 81%. Thus, unlike Pacific salmonids, there was no apparent correlation of virulence in a particular host species with virus genogroup. The mortality patterns indicated two different phenotypes in terms of kinetics of disease progression and final per cent mortality, with nine strains having moderate virulence and two strains (from the U and L genogroups) having high virulence. These phenotypes were investigated by histopathology and immunohistochemistry to describe the variation in the course of IHNV disease in Atlantic salmon. The results from this study demonstrate that IHNV may become a major threat to farmed Atlantic salmon in other regions of the world where the virus has been, or may be, introduced.

Evidence for cumulative temperature as an initiating and terminating factor in downstream migratory behavior of Atlantic salmon (Salmo salar) smolts

USGS Publications Warehouse

Zydlewski, G.B.; Haro, A.; McCormick, S.D.

2005-01-01

Temperature control of Atlantic salmon (Salmo salar) smolt migration was tested using a novel technique allowing nearly continuous monitoring of behavior with complete control over environmental conditions. Parr and presmolts were implanted with passive integrated transponder tags, placed in simulated streams, and monitored for upstream and downstream movements. Beginning 18 April, temperature was increased 1??C every third day (advanced), fourth day (ambient), and tenth day (delayed). Smolt downstream movements were initially low, peaked in mid-May, and subsequently declined under all conditions. Parr downstream movements were significantly lower than those of smolts in all treatments (0.8 ?? 0.5 movement??day-1 versus 26.5 ?? 4.5 movements??day-1, mean ?? SE) and showed no increase. At delayed temperatures, smolts sustained downstream movements through July; those under ambient and advanced conditions ceased activity by mid-June. Initiation and termination of downstream movements occurred at significantly different temperatures but at the same number of degree-days in all treatments. Physiological changes associated with smolting (gill Na+,K +-ATPase activity and plasma thyroxine) were coincident with behavioral changes. This is the first evidence of a behavioral component to the smolt window. We found that temperature experience over time is more relevant to initiation and termination of downstream movement than a temperature threshold. ?? 2005 NRC Canada.

Variation in wind and piscivorous predator fields affecting the survival of Atlantic salmon, Salmo salar, in the Gulf of Maine

USGS Publications Warehouse

Friedland, K.D.; Manning, J.P.; Link, Jason S.; Gilbert, J.R.; Gilbert, A.T.; O'Connell, A.F.

2012-01-01

Observations relevant to the North American stock complex of Atlantic salmon, Salmo salar L., suggest that marine mortality is influenced by variation in predation pressure affecting post-smolts during the first months at sea. This hypothesis was tested for Gulf of Maine (GOM) stocks by examining wind pseudostress and the distribution of piscivorous predator fields potentially affecting post-smolts. Marine survival has declined over recent decades with a change in the direction of spring winds, which is likely extending the migration of post-smolts by favouring routes using the western GOM. In addition to changes in spring wind patterns, higher spring sea surface temperatures have been associated with shifting distributions of a range of fish species. The abundance of several pelagic piscivores, which based on their feeding habits may predate on salmon post-smolts, has increased in the areas that serve as migration corridors for post-smolts. In particular, populations of silver hake, Merluccius bilinearis (Mitchell), red hake, Urophycis chuss (Walbaum), and spiny dogfish, Squalus acanthias L., increased in size in the portion of the GOM used by post-smolts. Climate variation and shifting predator distributions in the GOM are consistent with the predator hypothesis of recruitment control suggested for the stock complex.

The culturable intestinal microbiota of triploid and diploid juvenile Atlantic salmon (Salmo salar) - a comparison of composition and drug resistance

PubMed Central

2011-01-01

Background With the increased use of ploidy manipulation in aquaculture and fisheries management this investigation aimed to determine whether triploidy influences culturable intestinal microbiota composition and bacterial drug resistance in Atlantic salmon (Salmo salar). The results could provide answers to some of the physiological differences observed between triploid and diploid fish, especially in terms of fish health. Results No ploidy effect was observed in the bacterial species isolated, however, triploids were found to contain a significant increase in total gut microbiota levels, with increases in Pseudomonas spp., Pectobacterium carotovorum, Psychrobacter spp., Bacillus spp., and Vibrio spp., (12, 42, 9, 10, and 11% more bacteria in triploids than diploids, respectively), whereas a decrease in Carnobacterium spp., within triploids compared to diploids was close to significant (8% more bacteria in diploids). With the exception of gentamicin, where no bacterial resistance was observed, bacterial isolates originating from triploid hosts displayed increased resistance to antibacterials, three of which were significant (tetracycline, trimethoprim, and sulphonamide). Conclusion Results indicate that triploidy influences both the community and drug resistance of culturable intestinal microbiota in juvenile salmon. These results demonstrate differences that are likely to contribute to the health of triploid fish and have important ramifications on the use of antibacterial drugs within aquaculture. PMID:22094054

The relationship between flesh quality and numbers of Kudoa thyrsites plasmodia and spores in farmed Atlantic salmon, Salmo salar L.

PubMed

Dawson-Coates, J A; Chase, J C; Funk, V; Booy, M H; Haines, L R; Falkenberg, C L; Whitaker, D J; Olafson, R W; Pearson, T W

2003-08-01

Atlantic salmon, Salmo salar L., were exposed to Kudoa thyrsites (Myxozoa, Myxosporea)-containing sea water for 15 months, and then harvested and assessed for parasite burden and fillet quality. At harvest, parasites were enumerated in muscle samples from a variety of somatic and opercular sites, and mean counts were determined for each fish. After 6 days storage at 4 degrees C, fillet quality was determined by visual assessment and by analysis of muscle firmness using a texture analyzer. Fillet quality could best be predicted by determining mean parasite numbers and spore counts in all eight tissue samples (somatic and opercular) or in four fillet samples, as the counts from opercular samples alone showed greater variability and thus decreased reliability. The variability in both plasmodia and spore numbers between tissue samples taken from an individual fish indicated that the parasites were not uniformly distributed in the somatic musculature. Therefore, to best predict the probable level of fillet degradation caused by K. thyrsites infections, multiple samples must be taken from each fish. If this is performed, a mean plasmodia count of 0.3 mm(-2) or a mean spore count of 4.0 x 10(5) g(-1) of tissue are the levels where the probability of severe myoliquefaction becomes a significant risk.

Effects of age and season on haematological parameters of donkeys during the rainy and cold-dry seasons.

PubMed

Zakari, Friday Ocheja; Ayo, Joseph Olusegun; Rekwot, Peter Ibrahim; Kawu, Mohammed Umar

2015-12-01

The aim of the study was to investigate the effects of age and season on haematological parameters of donkeys at rest during the rainy and cold-dry seasons. Thirty healthy donkeys divided into three groups based on their age served as the subjects. During each season, blood sample was collected from each donkey thrice, 2 weeks apart, for haematological analysis, and the dry-bulb temperature (DBT), relative humidity (RH) and temperature-humidity index (THI) were obtained thrice each day during the experimental period using standard procedures. During the rainy season, the mean DBT (33.05 ± 0.49 °C), RH (73.63 ± 1.09 %) and THI (84.39 ± 0.71) were higher (P < 0.0001) than the corresponding values of 24.00 ± 0.44 °C, 36.80 ± 0.92 % and 64.80 ± 0.62, during the cold-dry season. Packed cell volume (PCV), erythrocyte count [red blood cell (RBC)], haemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), platelet count (PLT), leucocyte count [white blood cell (WBC)], lymphocyte count (LYM) and neutrophil/lymphocyte ratio (N/L) were higher (P < 0.05) in adults than foals during the rainy season. The MCV, MCH, WBC, NEU, LYM and PLT of adult and yearling donkeys were higher (P < 0.05) during the rainy than the cold-dry season. The PCV, RBC, Hb, MCV, MCH, and NEU of foals were higher in the rainy than the cold-dry season. The N/L of adult and foal donkeys were higher (P < 0.05) in the rainy than in the cold-dry season. In conclusion, PCV, RBC, Hb and LYM were considerably higher in foals than yearlings or adults during the rainy season, while erythrocytic indices and platelet counts were higher in adults or yearlings than in foals in both seasons. Erythrocytic indices, PLT and N/L were higher in the rainy than the cold-dry season in adults, yearlings and foals.

Effects of age and season on haematological parameters of donkeys during the rainy and cold-dry seasons

NASA Astrophysics Data System (ADS)

Zakari, Friday Ocheja; Ayo, Joseph Olusegun; Rekwot, Peter Ibrahim; Kawu, Mohammed Umar

2015-12-01

The aim of the study was to investigate the effects of age and season on haematological parameters of donkeys at rest during the rainy and cold-dry seasons. Thirty healthy donkeys divided into three groups based on their age served as the subjects. During each season, blood sample was collected from each donkey thrice, 2 weeks apart, for haematological analysis, and the dry-bulb temperature (DBT), relative humidity (RH) and temperature-humidity index (THI) were obtained thrice each day during the experimental period using standard procedures. During the rainy season, the mean DBT (33.05 ± 0.49 °C), RH (73.63 ± 1.09 %) and THI (84.39 ± 0.71) were higher ( P < 0.0001) than the corresponding values of 24.00 ± 0.44 °C, 36.80 ± 0.92 % and 64.80 ± 0.62, during the cold-dry season. Packed cell volume (PCV), erythrocyte count [red blood cell (RBC)], haemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), platelet count (PLT), leucocyte count [white blood cell (WBC)], lymphocyte count (LYM) and neutrophil/lymphocyte ratio (N/L) were higher ( P < 0.05) in adults than foals during the rainy season. The MCV, MCH, WBC, NEU, LYM and PLT of adult and yearling donkeys were higher ( P < 0.05) during the rainy than the cold-dry season. The PCV, RBC, Hb, MCV, MCH, and NEU of foals were higher in the rainy than the cold-dry season. The N/L of adult and foal donkeys were higher ( P < 0.05) in the rainy than in the cold-dry season. In conclusion, PCV, RBC, Hb and LYM were considerably higher in foals than yearlings or adults during the rainy season, while erythrocytic indices and platelet counts were higher in adults or yearlings than in foals in both seasons. Erythrocytic indices, PLT and N/L were higher in the rainy than the cold-dry season in adults, yearlings and foals.

Skilful seasonal forecasts of streamflow over Europe?

NASA Astrophysics Data System (ADS)

Arnal, Louise; Cloke, Hannah L.; Stephens, Elisabeth; Wetterhall, Fredrik; Prudhomme, Christel; Neumann, Jessica; Krzeminski, Blazej; Pappenberger, Florian

2018-04-01

This paper considers whether there is any added value in using seasonal climate forecasts instead of historical meteorological observations for forecasting streamflow on seasonal timescales over Europe. A Europe-wide analysis of the skill of the newly operational EFAS (European Flood Awareness System) seasonal streamflow forecasts (produced by forcing the Lisflood model with the ECMWF System 4 seasonal climate forecasts), benchmarked against the ensemble streamflow prediction (ESP) forecasting approach (produced by forcing the Lisflood model with historical meteorological observations), is undertaken. The results suggest that, on average, the System 4 seasonal climate forecasts improve the streamflow predictability over historical meteorological observations for the first month of lead time only (in terms of hindcast accuracy, sharpness and overall performance). However, the predictability varies in space and time and is greater in winter and autumn. Parts of Europe additionally exhibit a longer predictability, up to 7 months of lead time, for certain months within a season. In terms of hindcast reliability, the EFAS seasonal streamflow hindcasts are on average less skilful than the ESP for all lead times. The results also highlight the potential usefulness of the EFAS seasonal streamflow forecasts for decision-making (measured in terms of the hindcast discrimination for the lower and upper terciles of the simulated streamflow). Although the ESP is the most potentially useful forecasting approach in Europe, the EFAS seasonal streamflow forecasts appear more potentially useful than the ESP in some regions and for certain seasons, especially in winter for almost 40 % of Europe. Patterns in the EFAS seasonal streamflow hindcast skill are however not mirrored in the System 4 seasonal climate hindcasts, hinting at the need for a better understanding of the link between hydrological and meteorological variables on seasonal timescales, with the aim of improving climate

FORWINE - Statistical Downscaling of Seasonal forecasts for wine

NASA Astrophysics Data System (ADS)

Cardoso, Rita M.; Soares, Pedro M. M.; Miranda, Pedro M. A.

2016-04-01

The most renowned viticulture regions in the Iberian Peninsula have a long standing tradition in winemaking and are considered world-class grapevine (Vitis Vinifera L.) producing regions. Portugal is the 11th wine producer in the world, with internationally acclaimed wines, such as Port wine, and vineyards across the whole territory. Climate is widely acknowledged of one of the most important factors for grapevine development and growth (Fraga et al. 2014a and b; Jackson et al. 1993; Keller 2010). During the growing season (April-October in the Northern Hemisphere) of this perennial and deciduous crop, the climatic conditions are responsible for numerous morphologically and physiological changes. Anomalously low February-March mean temperature, anomalously high May mean temperature and anomalously high March precipitation tend to be favourable to wine production in the Douro Valley. Seasonal forecast of precipitation and temperature tailored to fit critical thresholds, for crucial seasons, can be used to inform management practices (viz. phytosanitary measures, land operations, marketing campaigns) and develop a wine production forecast. Statistical downscaling of precipitation, maximum, minimum temperatures is used to model wine production following Santos et al. (2013) and to calculate bioclimatic indices. The skill of the ensemble forecast is evaluated through anomaly correlation, ROC area, spread-error ratio and CRPS

Seasonal trends in eDNA detection and occupancy of bigheaded carps

USGS Publications Warehouse

Erickson, Richard A.; Merkes, Christopher; Jackson, Craig; Goforth, Reuben; Amberg, Jon J.

2017-01-01

Bigheaded carps, which include silver and bighead carp, are threatening to invade the Great Lakes. These species vary seasonally in distribution and abundance due to environmental conditions such as precipitation and temperature. Monitoring this seasonal movement is important for management to control the population size and spread of the species. We examined if environmental DNA (eDNA) approaches could detect seasonal changes of these species. To do this, we developed a novel genetic marker that was able to both detect and differentiate bighead and silver carp DNA. We used the marker, combined with a novel occupancy model, to study the occurrence of bigheaded carps at 3 sites on the Wabash River over the course of a year. We studied the Wabash River because of concerns that carps may be able to use the system to invade the Great Lakes via a now closed (ca. 2017) connection at Eagle Marsh between the Wabash River's watershed and the Great Lakes' watershed. We found seasonal trends in the probability of detection and occupancy that varied across sites. These findings demonstrate that eDNA methods can detect seasonal changes in bigheaded carps densities and suggest that the amount of eDNA present changes seasonally. The site that was farthest upstream and had the lowest carp densities exhibited the strongest seasonal trends for both detection probabilities and sample occupancy probabilities. Furthermore, other observations suggest that carps seasonally leave this site, and we were able to detect this with our eDNA approach.

Seasonal Storminess in the North Pacific, Bering Sea, and Alaskan Regions

NASA Astrophysics Data System (ADS)

Shippee, N. J.; Atkinson, D. E.; Walsh, J. E.; Partain, J.; Gottschalck, J.; Marra, J.

2012-12-01

Annually, extra-tropical cyclones present a high impact natural hazard to the North Pacific, Bering Sea, and Alaskan regions. In these regions, extensive subsistence and commercial fishing, new oil and gas field development, tourism, growing interest in and exploitation of new commercial shipping potential, and increasing military and Coast Guard activity, all represent potential parties impacted by storms in these waters. It is of interest to many parties to begin developing capacity to provide some indication of storm activity at a monthly- to seasonal-outlook (30 to 90 days) timeframe. Using storm track data from NOAA's Climate Prediction Center for the North Pacific and Alaskan region, an experimental seasonal storminess outlook product, using eigen-based methods similar to the operational seasonal temperature and precipitation products currently produced at NOAA CPC, has been created and tested in hindcast mode using predicted states of ENSO, the Pacific Decadal Oscillation (PDO), the Pacific-North American Pattern (PNA), and the Arctic Oscillation (AO). A sample of the seasonal storminess outlook product will be shown along with a discussion of the utility of individual teleconnection patterns in the generation of the product.

Thlaspi arvense (Pennycress): An off-season energy crop within the corn-soybean rotation

USDA-ARS?s Scientific Manuscript database

Pennycress is being developed as an off-season rotation crop between annual corn and soybean production. This rotation scheme may offer distinct advantages to farmers by providing additional farm income from an otherwise fallow season with little impact on the subsequent soybean production. The seed...

Assessing the thermal dissipation sap flux density method for monitoring cold season water transport in seasonally snow-covered forests

DOE PAGES

Chan, Allison M.; Bowling, David R.

2017-05-26

Productivity of conifers in seasonally snow-covered forests is high before and during snowmelt when environmental conditions are optimal for photosynthesis. Climate change is altering the timing of spring in many locations, and changes in the date of transition from winter dormancy can have large impacts on annual productivity. Sap flow methods provide a promising approach to monitor tree activity during the cold season and the winter–spring and fall–winter transitions. Although sap flow techniques have been widely used, cold season results are generally not reported. Here we examine the feasibility of using the Granier thermal dissipation (TD) sap flux density methodmore » to monitor transpiration and dormancy of evergreen conifers during the cold season. We conducted a laboratory experiment which demonstrated that the TD method reliably detects xylem water transport (when it occurs) both at near freezing temperature and at low flow rate, and that the sensors can withstand repeated freeze–thaw events. However, the dependence between sensor output and water transport rate in these experiments differed from the established TD relation. In field experiments, sensors installed in two Abies forests lasted through two winters and a summer with low failure. The baseline (no-flow) sensor output varied considerably with temperature during the cold season, and a new baseline algorithm was developed to accommodate this variation. The Abies forests differed in elevation (2070 and 2620 m), and there was a clear difference in timing of initiation and cessation of transpiration between them. We conclude that the TD method can be reliably used to examine water transport during cold periods with associated low flow conditions« less

Assessing the thermal dissipation sap flux density method for monitoring cold season water transport in seasonally snow-covered forests

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

Chan, Allison M.; Bowling, David R.

Productivity of conifers in seasonally snow-covered forests is high before and during snowmelt when environmental conditions are optimal for photosynthesis. Climate change is altering the timing of spring in many locations, and changes in the date of transition from winter dormancy can have large impacts on annual productivity. Sap flow methods provide a promising approach to monitor tree activity during the cold season and the winter–spring and fall–winter transitions. Although sap flow techniques have been widely used, cold season results are generally not reported. Here we examine the feasibility of using the Granier thermal dissipation (TD) sap flux density methodmore » to monitor transpiration and dormancy of evergreen conifers during the cold season. We conducted a laboratory experiment which demonstrated that the TD method reliably detects xylem water transport (when it occurs) both at near freezing temperature and at low flow rate, and that the sensors can withstand repeated freeze–thaw events. However, the dependence between sensor output and water transport rate in these experiments differed from the established TD relation. In field experiments, sensors installed in two Abies forests lasted through two winters and a summer with low failure. The baseline (no-flow) sensor output varied considerably with temperature during the cold season, and a new baseline algorithm was developed to accommodate this variation. The Abies forests differed in elevation (2070 and 2620 m), and there was a clear difference in timing of initiation and cessation of transpiration between them. We conclude that the TD method can be reliably used to examine water transport during cold periods with associated low flow conditions« less

Quantitative PCR analysis of CYP1A induction in Atlantic salmon (Salmo salar)

USGS Publications Warehouse

Rees, C.B.; McCormick, S.D.; Vanden, Heuvel J.P.; Li, W.

2003-01-01

Environmental pollutants are hypothesized to be one of the causes of recent declines in wild populations of Atlantic salmon (Salmo salar) across Eastern Canada and the United States. Some of these pollutants, such as polychlorinated biphenyls and dioxins, are known to induce expression of the CYP1A subfamily of genes. We applied a highly sensitive technique, quantitative reverse transcription-polymerase chain reaction (RT-PCR), for measuring the levels of CYP1A induction in Atlantic salmon. This assay was used to detect patterns of CYP1A mRNA levels, a direct measure of CYP1A expression, in Atlantic salmon exposed to pollutants under both laboratory and field conditions. Two groups of salmon were acclimated to 11 and 17??C, respectively. Each subject then received an intraperitoneal injection (50 mg kg-1) of either ??-naphthoflavone (BNF) in corn oil (10 mg BNF ml-1 corn oil) or corn oil alone. After 48 h, salmon gill, kidney, liver, and brain were collected for RNA isolation and analysis. All tissues showed induction of CYP1A by BNF. The highest base level of CYP1A expression (2.56??1010 molecules/??g RNA) was found in gill tissue. Kidney had the highest mean induction at five orders of magnitude while gill tissue showed the lowest mean induction at two orders of magnitude. The quantitative RT-PCR was also applied to salmon sampled from two streams in Massachusetts, USA. Salmon liver and gill tissue sampled from Millers River (South Royalston, Worcester County), known to contain polychlorinated biphenyls (PCBs), showed on average a two orders of magnitude induction over those collected from a stream with no known contamination (Fourmile Brook, Northfield, Franklin County). Overall, the data show CYP1A exists and is inducible in Atlantic salmon gill, brain, kidney, and liver tissue. In addition, the results obtained demonstrate that quantitative PCR analysis of CYP1A expression is useful in studying ecotoxicity in populations of Atlantic salmon in the wild. ?? 2003

Effects of seasonal and climate variations on calves' thermal comfort and behaviour.

PubMed

Tripon, Iulian; Cziszter, Ludovic Toma; Bura, Marian; Sossidou, Evangelia N

2014-09-01

The aim of this study was to measure the effect of season and climate variations on thermal comfort and behaviour of 6-month-old dairy calves housed in a semi-opened shelter to develop animal-based indicators for assessing animal thermal comfort. The ultimate purpose was to further exploit the use of those indicators to prevent thermal stress by providing appropriate care to the animals. Measurements were taken for winter and summer seasons. Results showed that season significantly influenced (P ≤ 0.01) the lying down behaviour of calves by reducing the time spent lying, from 679.9 min in winter to 554.1 min in summer. Moreover, season had a significant influence (P ≤ 0.01) on feeding behaviour. In detail, the total length of feeding periods was shorter in winter, 442.1 min in comparison to 543.5 min in summer. Time spent drinking increased significantly (P ≤ 0.001), from 11.9 min in winter to 26.9 min in summer. Furthermore, season had a significant influence (P ≤ 0.001) on self grooming behaviour which was 5.5 times longer in duration in winter than in summer (1,336 s vs 244 s). It was concluded that calves' thermal comfort is affected by seasonal and climate variations and that this can be assessed by measuring behaviour with animal-based indicators, such as lying down, resting, standing up, feeding, rumination, drinking and self grooming. The indicators developed may be a useful tool to prevent animal thermal stress by providing appropriate housing and handling to calves under seasonal and climate challenge.

Highly spatially- and seasonally-resolved predictive contamination maps for persistent organic pollutants: development and validation.

PubMed

Ballabio, Cristiano; Guazzoni, Niccoló; Comolli, Roberto; Tremolada, Paolo

2013-08-01

A reliable spatial assessment of the POPs contamination in soils is essential for burden studies and flux evaluations. Soil characteristics and properties vary enormously even within small spatial scale and over time; therefore soil capacity of accumulating POPs varies greatly. In order to include this very high spatial and temporal variability, models can be used for assessing soil accumulation capacity in a specific time and space and, from it, the spatial distribution and temporal trends of POPs concentrations. In this work, predictive contamination maps of the accumulation capacity of soils were developed at a space resolution of 1×1m with a time frame of one day, in a study area located in the central Alps. Physical algorithms for temperature and organic carbon estimation along the soil profile and across the year were fitted to estimate the horizontal, vertical and seasonal distribution of the contamination potential for PCBs in soil (Ksa maps). The resulting maps were cross-validated with an independent set of PCB contamination data, showing very good agreement (e.g. for CB-153, R(2)=0.80, p-value≤2.2·10(-06)). Slopes of the regression between predicted Ksa and experimental concentrations were used to map the soil contamination for the whole area, taking into account soil characteristics and temperature conditions. These maps offer the opportunity to evaluate burden (concentration maps) and fluxes (emission maps) with highly resolved temporal and spatial detail. In addition, in order to explain the observed low autumn PCB concentrations in soil related to the high Ksa values of this period, a dynamic model of seasonal variation of soil concentrations was developed basing on rate parameters fitted on measured concentrations. The model was able to describe, at least partially, the observed different behavior between the quite rapid discharge phase in summer and the slow recharge phase in autumn. Copyright © 2013 Elsevier B.V. All rights reserved.

Simulation of seasonal anomalies of atmospheric circulation using coupled atmosphere-ocean model

NASA Astrophysics Data System (ADS)

Tolstykh, M. A.; Diansky, N. A.; Gusev, A. V.; Kiktev, D. B.

2014-03-01

A coupled atmosphere-ocean model intended for the simulation of coupled circulation at time scales up to a season is developed. The semi-Lagrangian atmospheric general circulation model of the Hydrometeorological Centre of Russia, SLAV, is coupled with the sigma model of ocean general circulation developed at the Institute of Numerical Mathematics, Russian Academy of Sciences (INM RAS), INMOM. Using this coupled model, numerical experiments on ensemble modeling of the atmosphere and ocean circulation for up to 4 months are carried out using real initial data for all seasons of an annual cycle in 1989-2010. Results of these experiments are compared to the results of the SLAV model with the simple evolution of the sea surface temperature. A comparative analysis of seasonally averaged anomalies of atmospheric circulation shows prospects in applying the coupled model for forecasts. It is shown with the example of the El Niño phenomenon of 1997-1998 that the coupled model forecasts the seasonally averaged anomalies for the period of the nonstationary El Niño phase significantly better.

The importance of interactions among nutrition, seasonality and socio-sexual factors in the development of hormone-free methods for controlling fertility.

PubMed

Scaramuzzi, R J; Martin, G B

2008-07-01

Around the world, consumers are demanding animal products that are produced to agreed standards for human health, environmental management and animal welfare. This has led to the development in Australia of the concept of 'clean, green and ethical' (CGE) animal production based on the manipulation of nutrition ('focus feeding') and the application of phenomena, such as the 'male effect', to provide 'natural' methods for managing small ruminant production systems. With respect to the management of fertility, CGE involves utilization of the inherited responses of animals to environmental factors to manipulate their reproductive processes. The successful development and implementation of this new generation of management tools depends on a thorough yet holistic understanding of the interactions among environmental factors and the ways these interactions affect reproductive physiology and behaviour of the animal. For sheep and goats, a central aspect of CGE management is the way in which ovarian function is affected by three major factors (nutrition, photoperiod and socio-sexual signals) and by interactions among them. Nutrition can exert two profound yet contrasting types of effect on ovarian activity: (i) the complete inhibition of reproduction by undernutrition through the hypothalamic mechanism that controls ovulation and (ii) the enhancement of fecundity by nutritional supplementation, through a direct ovarian mechanism, in females that are already ovulating. A similarly profound control over ovarian function in female sheep and goats is exerted by the well-known endocrine responses to photoperiod (seasonality) and to male socio-sexual signals. The 'male effect' already has a long history as a valuable technique for inducing a synchronized fertile ovulation during seasonal and post-partum anoestrus in sheep and goats. Importantly, experimentation has shown that these three major environmental factors interact, synergistically and antagonistically, but the precise

40 CFR 97.388 - CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 22 2013-07-01 2013-07-01 false CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units. 97.388 Section 97.388 Protection of Environment... NOX AND SO2 TRADING PROGRAMS CAIR NOX Ozone Season Opt-in Units § 97.388 CAIR NOX Ozone Season...

40 CFR 97.388 - CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 22 2012-07-01 2012-07-01 false CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units. 97.388 Section 97.388 Protection of Environment... NOX AND SO2 TRADING PROGRAMS CAIR NOX Ozone Season Opt-in Units § 97.388 CAIR NOX Ozone Season...

40 CFR 97.388 - CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 21 2014-07-01 2014-07-01 false CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units. 97.388 Section 97.388 Protection of Environment... NOX AND SO2 TRADING PROGRAMS CAIR NOX Ozone Season Opt-in Units § 97.388 CAIR NOX Ozone Season...

40 CFR 97.388 - CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 20 2010-07-01 2010-07-01 false CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units. 97.388 Section 97.388 Protection of Environment... NOX AND SO2 TRADING PROGRAMS CAIR NOX Ozone Season Opt-in Units § 97.388 CAIR NOX Ozone Season...

40 CFR 97.388 - CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 21 2011-07-01 2011-07-01 false CAIR NOX Ozone Season allowance allocations to CAIR NOX Ozone Season opt-in units. 97.388 Section 97.388 Protection of Environment... NOX AND SO2 TRADING PROGRAMS CAIR NOX Ozone Season Opt-in Units § 97.388 CAIR NOX Ozone Season...

Incorporating Temperature-driven Seasonal Variation in Survival, Growth, and Reproduction Models for Small Fish

EPA Science Inventory

Seasonal variation in survival and reproduction can be a large source of prediction uncertainty in models used for conservation and management. A seasonally varying matrix population model is developed that incorporates temperature-driven differences in mortality and reproduction...

Identification and Migration of Primordial Germ Cells in Atlantic Salmon, Salmo salar: Characterization of Vasa, Dead End, and Lymphocyte Antigen 75 Genes

PubMed Central

Nagasawa, Kazue; Fernandes, Jorge MO; Yoshizaki, Goro; Miwa, Misako; Babiak, Igor

2013-01-01

No information exists on the identification of primordial germ cells (PGCs) in the super-order Protacanthopterygii, which includes the Salmonidae family and Atlantic salmon (Salmo salar L.), one of the most commercially important aquatic animals worldwide. In order to identify salmon PGCs, we cloned the full-length cDNA of vasa, dead end (dnd), and lymphocyte antigen 75 (ly75/CD205) genes as germ cell marker candidates, and analyzed their expression patterns in both adult and embryonic stages of Atlantic salmon. Semi-quantitative RT-PCR results showed that salmon vasa and dnd were specifically expressed in testis and ovary, and vasa, dnd, and ly75 mRNA were maternally deposited in the egg. vasa mRNA was consistently detected throughout embryogenesis while dnd and ly75 mRNA were gradually degraded during cleavages. In situ analysis revealed the localization of vasa and dnd mRNA and Ly75 protein in PGCs of hatched larvae. Whole-mount in situ hybridization detected vasa mRNA during embryogenesis, showing a distribution pattern somewhat different to that of zebrafish; specifically, at mid-blastula stage, vasa-expressing cells were randomly distributed at the central part of blastodisc, and then they migrated to the presumptive region of embryonic shield. Therefore, the typical vasa localization pattern of four clusters during blastulation, as found in zebrafish, was not present in Atlantic salmon. In addition, salmon PGCs could be specifically labeled with a green fluorescence protein (GFP) using gfp-rt-vasa 3′-UTR RNA microinjection for further applications. These findings may assist in understanding PGC development not only in Atlantic salmon but also in other salmonids. PMID:23239145

Seasonal mapping of NICU temperature.

PubMed

Thomas, Karen A; Magbalot, Almita; Shinabarger, Kelley; Mokhnach, Larisa; Anderson, Marilyn; Diercks, Kristi; Millar, April; Thorngate, Lauren; Walker, Wendy; Dilback, Nancy; Berkan, Maureen

2010-04-01

To create a thermal map of ambient air, radiant, and evaporative temperatures and humidity throughout the NICU nursery by season across a calendar year. Each cubicle of the 32-bed NICU, distributed across 5 rooms, in a level III nursery was measured. Temperatures were recorded at a consistent time on one day during January, April, July, and October. An electronic monitor (QUESTemp degrees 34; Quest Technologies, Oconomowoc, Wisconsin) was used to measure dry bulb, wet bulb, and globe thermometer temperatures. Analysis of variance revealed statistically significant (P < .000) differences in season, room, and season by room interaction. Room ambient air temperatures differed by less than 2 degrees F across season. Radiant temperature paralleled air temperature. Humidity, the predominant difference across season, produced evaporative temperatures considerably lower than room air temperature, and the gradient between mean nursery dry bulb temperature and wet bulb temperature was 9.3 degrees F in summer and 16.8 degrees F in winter. The thermal map revealed seasonal thermal differences, particularly in humidity level and evaporative temperature. Room temperature alone does not reflect the total thermal environment. Recommendations include periodic assessment of nurseries along with air, evaporative, and radiant temperatures as well as humidity to fully appreciate the impact of the thermal environment on infants.

Seasonal mapping of NICU temperature.

PubMed

Thomas, Karen A; Magbalot, Almita; Shinabarger, Kelley; Mokhnach, Larisa; Anderson, Marilyn; Diercks, Kristi; Millar, April; Thorngate, Lauren; Walker, Wendy; Dilback, Nancy; Berkan, Maureen

2010-10-01

To create a thermal map of ambient air, radiant, and evaporative temperatures and humidity throughout the NICU nursery by season across a calendar year. Each cubicle of the 32-bed NICU, distributed across 5 rooms, in a level III nursery was measured. Temperatures were recorded at a consistent time on one day during January, April, July, and October. : An electronic monitor (QUESTemp ° 34; Quest Technologies, Oconomowoc, Wisconsin) was used to measure dry bulb, wet bulb, and globe thermometer temperatures. Analysis of variance revealed statistically significant (P ≤ .000) differences in season, room, and season by room interaction. Room ambient air temperatures differed by less than 2 ° F across season. Radiant temperature paralleled air temperature. Humidity, the predominant difference across season, produced evaporative temperatures considerably lower than room air temperature, and the gradient between mean nursery dry bulb temperature and wet bulb temperature was 9.3 ° F in summer and 16.8 ° F in winter. The thermal map revealed seasonal thermal differences, particularly in humidity level and evaporative temperature. Room temperature alone does not reflect the total thermal environment. Recommendations include periodic assessment of nurseries along with air, evaporative, and radiant temperatures as well as humidity to fully appreciate the impact of the thermal environment on infants.

Evapotranspiration seasonality across the Amazon Basin

NASA Astrophysics Data System (ADS)

Eiji Maeda, Eduardo; Ma, Xuanlong; Wagner, Fabien Hubert; Kim, Hyungjun; Oki, Taikan; Eamus, Derek; Huete, Alfredo

2017-06-01

Evapotranspiration (ET) of Amazon forests is a main driver of regional climate patterns and an important indicator of ecosystem functioning. Despite its importance, the seasonal variability of ET over Amazon forests, and its relationship with environmental drivers, is still poorly understood. In this study, we carry out a water balance approach to analyse seasonal patterns in ET and their relationships with water and energy drivers over five sub-basins across the Amazon Basin. We used in situ measurements of river discharge, and remotely sensed estimates of terrestrial water storage, rainfall, and solar radiation. We show that the characteristics of ET seasonality in all sub-basins differ in timing and magnitude. The highest mean annual ET was found in the northern Rio Negro basin (˜ 1497 mm year-1) and the lowest values in the Solimões River basin (˜ 986 mm year-1). For the first time in a basin-scale study, using observational data, we show that factors limiting ET vary across climatic gradients in the Amazon, confirming local-scale eddy covariance studies. Both annual mean and seasonality in ET are driven by a combination of energy and water availability, as neither rainfall nor radiation alone could explain patterns in ET. In southern basins, despite seasonal rainfall deficits, deep root water uptake allows increasing rates of ET during the dry season, when radiation is usually higher than in the wet season. We demonstrate contrasting ET seasonality with satellite greenness across Amazon forests, with strong asynchronous relationships in ever-wet watersheds, and positive correlations observed in seasonally dry watersheds. Finally, we compared our results with estimates obtained by two ET models, and we conclude that neither of the two tested models could provide a consistent representation of ET seasonal patterns across the Amazon.

Modeling seasonal variation of hip fracture in Montreal, Canada.

PubMed

Modarres, Reza; Ouarda, Taha B M J; Vanasse, Alain; Orzanco, Maria Gabriela; Gosselin, Pierre

2012-04-01

The investigation of the association of the climate variables with hip fracture incidences is important in social health issues. This study examined and modeled the seasonal variation of monthly population based hip fracture rate (HFr) time series. The seasonal ARIMA time series modeling approach is used to model monthly HFr incidences time series of female and male patients of the ages 40-74 and 75+ of Montreal, Québec province, Canada, in the period of 1993-2004. The correlation coefficients between meteorological variables such as temperature, snow depth, rainfall depth and day length and HFr are significant. The nonparametric Mann-Kendall test for trend assessment and the nonparametric Levene's test and Wilcoxon's test for checking the difference of HFr before and after change point are also used. The seasonality in HFr indicated sharp difference between winter and summer time. The trend assessment showed decreasing trends in HFr of female and male groups. The nonparametric test also indicated a significant change of the mean HFr. A seasonal ARIMA model was applied for HFr time series without trend and a time trend ARIMA model (TT-ARIMA) was developed and fitted to HFr time series with a significant trend. The multi criteria evaluation showed the adequacy of SARIMA and TT-ARIMA models for modeling seasonal hip fracture time series with and without significant trend. In the time series analysis of HFr of the Montreal region, the effects of the seasonal variation of climate variables on hip fracture are clear. The Seasonal ARIMA model is useful for modeling HFr time series without trend. However, for time series with significant trend, the TT-ARIMA model should be applied for modeling HFr time series. Copyright © 2011 Elsevier Inc. All rights reserved.