scholarly journals The influence of the freshwater environment and the biological characteristics of Atlantic salmon smolts on their subsequent marine survival

2012 ◽  
Vol 69 (9) ◽  
pp. 1563-1573 ◽  
Author(s):  
Ian C. Russell ◽  
Miran W. Aprahamian ◽  
Jon Barry ◽  
Ian C. Davidson ◽  
Peder Fiske ◽  
...  

Abstract Russell, I. C., Aprahamian, M. W., Barry, J., Davidson, I. C., Fiske, P., Ibbotson, A. T., Kennedy, R. J., Maclean, J. C., Moore, A., Otero, J., Potter, E. C. E., and Todd, C. D. 2012. The influence of the freshwater environment and the biological characteristics of Atlantic salmon smolts on their subsequent marine survival. – ICES Journal of Marine Science, 69: 1563–1573. Atlantic salmon have declined markedly in the past 20–30 years throughout their range. Much of the focus for this decline has been on increased mortality during the marine phase of the life cycle. However, marine mortality does not operate independently of factors acting in freshwater and the biological characteristics of smolts migrating to sea. Over recent decades, juvenile salmon in many rivers have grown faster and migrated to sea at a younger age, so have been typically smaller than earlier. This has shortened the generation time for many individuals and may dampen the impact of increased marine mortality, assuming that expected higher in-river survival prior to smolting is not outweighed by increased mortality of smaller smolts at sea. Over the same period, smolt run-timing across the geographic range has been earlier, at an average rate of almost 3 d per decade. This has given rise to growing concerns about smolts potentially missing the optimum environmental migration “window”, the timing of which may also be changing. Contaminants and other factors operating in freshwater also impact smolt quality with adverse consequences for their physiological readiness for life at sea. Given that managers have very limited ability to influence the broad scale factors limiting salmon survival at sea, it is vital that freshwater habitats are managed to both maximize the smolt output and to minimize the impact of factors acting in freshwater that may compromise salmon once they migrate to sea.

Sexual Health ◽  
2012 ◽  
Vol 9 (3) ◽  
pp. 247 ◽  
Author(s):  
Megan S. C. Lim ◽  
Jane L. Goller ◽  
Rebecca Guy ◽  
Judy Gold ◽  
Mark Stoove ◽  
...  

Background Chlamydia is the most commonly notified infection in Australia. Prevention strategies should be informed by routine data on at-risk populations. Methods: We calculated chlamydia positivity and correlates of infection using multivariable logistic regression for data collected between April 2006 and June 2009. Results: Chlamydia positivity was 5.6% in 12 233 females, 7.7% in 10 316 heterosexual males and 6.2% in 7872 men who have sex with men (MSM). Correlates of chlamydia positivity among females included younger age (odds ratio (OR) 2.27, 95% confidence interval (CI) 1.92–2.69), being born overseas (OR 1.50, 95% CI 1.25–1.82), multiple sex partners in the past year (OR 1.72, 95% CI 1.40–2.11) and inconsistent condom use with regular sex partners (OR 3.44 ,95% CI 1.65–7.20). Sex work was protective for females (OR 0.68, 95% CI 0.53–0.86). Among heterosexual males, correlates of positivity were younger age (OR 1.87, 95% CI 1.62–2.17), being born overseas (OR 1.35, 95% CI 1.16–1.58), symptoms at the time of testing (OR 1.64, 95% CI 1.40–1.92) and multiple sex partners in the past year (OR 1.83, 95% CI 1.46–2.30). Correlates of positivity among MSM were being born overseas (OR 1.23, 95% CI 1.00–1.51), being HIV-positive (OR 1.80, 95%CI 1.32–2.47), and reporting six or more anal sex partners in the past 6 months (OR 4.45, 95% CI 1.37–14.5). Conclusions: Our analysis identified subgroups at the highest risk of chlamydia in Victoria. These estimates will provide important baseline information to measure the impact of chlamydia control strategies.


1983 ◽  
Vol 40 (4) ◽  
pp. 462-473 ◽  
Author(s):  
W. D. Watt ◽  
C. D. Scott ◽  
W. J. White

River pH's in Nova Scotia are closely related to geology, and seasonal pH variation is well correlated with river discharge rates. In the geologically sensitive areas (granite and metamorphic rocks), river pH's have fallen significantly over the past 27 yr at an apparent average rate of 0.017 pH units/year. Concomitant with this decrease are a decline in [Formula: see text] concentrations and increases in Al+++ and [Formula: see text]. On average, 73% of the increase in acid is attributable to increased [Formula: see text]. Changes in Na+, K+, Ca++, and Mg++ concentrations were not significant. In rivers presently at mean annual pH's < 4.7, the Atlantic salmon (Salmo salar) runs have disappeared and are presumed extinct. Rivers in the pH range 4.7–5.0 show a decline in salmon angling returns of 2.8%/yr, beginning about 1954, and low densities of juvenile salmon. Rivers presently of pH > 5.0 generally have normal juvenile densities and show no significant trend in angling returns.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246659
Author(s):  
Brandon Chasco ◽  
Brian Burke ◽  
Lisa Crozier ◽  
Rich Zabel

Large-scale atmospheric conditions in the Northeast Pacific Ocean affect both the freshwater environment in the Columbia River Basin and marine conditions along the coasts of Oregon, Washington, and British Columbia, resulting in correlated conditions in the two environments. For migrating species, such as salmonids that move through multiple habitats, these correlations can amplify the impact of good or poor physical conditions on growth and survival, as movements among habitats may not alleviate effects of anomalous conditions. Unfortunately, identifying the mechanistic drivers of salmon survival in space and time is hindered by these cross-habitat correlations. To address this issue, we modeled the marine survival of Snake River spring/summer Chinook salmon with multiple indices of the marine environment and an explicit treatment of the effect of arrival timing from freshwater to the ocean, and found that both habitats contribute to marine survival rates. We show how this particular carryover effect of freshwater conditions on marine survival varies by year and rearing type (hatchery or wild), with a larger effect for wild fish. As environmental conditions change, incorporating effects from both freshwater and marine habitats into salmon survival models will become more important, and has the additional benefit of highlighting how management actions that affect arrival timing may improve marine survival.


Author(s):  
Leslie M. Loew

A major application of potentiometric dyes has been the multisite optical recording of electrical activity in excitable systems. After being championed by L.B. Cohen and his colleagues for the past 20 years, the impact of this technology is rapidly being felt and is spreading to an increasing number of neuroscience laboratories. A second class of experiments involves using dyes to image membrane potential distributions in single cells by digital imaging microscopy - a major focus of this lab. These studies usually do not require the temporal resolution of multisite optical recording, being primarily focussed on slow cell biological processes, and therefore can achieve much higher spatial resolution. We have developed 2 methods for quantitative imaging of membrane potential. One method uses dual wavelength imaging of membrane-staining dyes and the other uses quantitative 3D imaging of a fluorescent lipophilic cation; the dyes used in each case were synthesized for this purpose in this laboratory.


GeroPsych ◽  
2011 ◽  
Vol 24 (3) ◽  
pp. 143-154 ◽  
Author(s):  
Elmar Gräßel ◽  
Raffaela Adabbo

The burden of caregivers has been intensively researched for the past 30 years and has resulted in a multitude of individual findings. This review illustrates the significance of the hypothetical construct of perceived burden for the further development and design of the homecare situation. Following explanations regarding the term informal caregiver, we derive the construct burden from its conceptual association with the transactional stress model of Lazarus and Folkman. Once the extent and characteristics of burden have been set forth, we then present the impact of perceived burden as the care situation. The question of predictors of burden will lead into the last section from which implications can be derived for homecare and relief of caregivers.


2004 ◽  
Vol 34 (136) ◽  
pp. 339-356
Author(s):  
Tobias Wölfle ◽  
Oliver Schöller

Under the term “Hilfe zur Arbeit” (aid for work) the federal law of social welfare subsumes all kinds of labour disciplining instruments. First, the paper shows the historical connection of welfare and labour disciplining mechanisms in the context of different periods within capitalist development. In a second step, against the background of historical experiences, we will analyse the trends of “Hilfe zur Arbeit” during the past two decades. It will be shown that by the rise of unemployment, the impact of labour disciplining aspects of “Hilfe zur Arbeit” has increased both on the federal and on the municipal level. For this reason the leverage of the liberal paradigm would take place even in the core of social rights.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 519-532 ◽  
Author(s):  
Mark Crisp ◽  
Richard Riehle

Polyaminopolyamide-epichlorohydrin (PAE) resins are the predominant commercial products used to manufacture wet-strengthened paper products for grades requiring wet-strength permanence. Since their development in the late 1950s, the first generation (G1) resins have proven to be one of the most cost-effective technologies available to provide wet strength to paper. Throughout the past three decades, regulatory directives and sustainability initiatives from various organizations have driven the development of cleaner and safer PAE resins and paper products. Early efforts in this area focused on improving worker safety and reducing the impact of PAE resins on the environment. These efforts led to the development of resins containing significantly reduced levels of 1,3-dichloro-2-propanol (1,3-DCP) and 3-monochloropropane-1,2-diol (3-MCPD), potentially carcinogenic byproducts formed during the manufacturing process of PAE resins. As the levels of these byproducts decreased, the environmental, health, and safety (EH&S) profile of PAE resins and paper products improved. Recent initiatives from major retailers are focusing on product ingredient transparency and quality, thus encouraging the development of safer product formulations while maintaining performance. PAE resin research over the past 20 years has been directed toward regulatory requirements to improve consumer safety and minimize exposure to potentially carcinogenic materials found in various paper products. One of the best known regulatory requirements is the recommendations of the German Federal Institute for Risk Assessment (BfR), which defines the levels of 1,3-DCP and 3-MCPD that can be extracted by water from various food contact grades of paper. These criteria led to the development of third generation (G3) products that contain very low levels of 1,3-DCP (typically <10 parts per million in the as-received/delivered resin). This paper outlines the PAE resin chemical contributors to adsorbable organic halogens and 3-MCPD in paper and provides recommendations for the use of each PAE resin product generation (G1, G1.5, G2, G2.5, and G3).


1996 ◽  
Vol 35 (2) ◽  
pp. 189-190
Author(s):  
Mir Annice Mahmood

This book, hereinafter referred to as the Guide, has been developed for those social analysts (e.g., anthropologists, sociologists, and human geographers) who have had little or no practical experience in applying their knowledge as development practitioners. In the past, development projects would be analysed from a narrow financial and economic perspective. But with the evolution of thinking on development, this narrow financial and economic aspect has now been broadened to include the impact on society as the very meaning of development has now come to symbolise social change. Thus, development is not restricted only to plans and figures; the human environment in its entirety is now considered for analysis while designing and implementing development projects.


2021 ◽  
Author(s):  
Ekaterina Mosolova ◽  
Dmitry Sosin ◽  
Sergey Mosolov

During the COVID-19 pandemic, healthcare workers (HCWs) have been subject to increased workload while also exposed to many psychosocial stressors. In a systematic review we analyze the impact that the pandemic has had on HCWs mental state and associated risk factors. Most studies reported high levels of depression and anxiety among HCWs worldwide, however, due to a wide range of assessment tools, cut-off scores, and number of frontline participants in the studies, results were difficult to compare. Our study is based on two online surveys of 2195 HCWs from different regions of Russia during spring and autumn epidemic outbreaks revealed the rates of anxiety, stress, depression, emotional exhaustion and depersonalization and perceived stress as 32.3%, 31.1%, 45.5%, 74.2%, 37.7% ,67.8%, respectively. Moreover, 2.4% of HCWs reported suicidal thoughts. The most common risk factors include: female gender, nurse as an occupation, younger age, working for over 6 months, chronic diseases, smoking, high working demands, lack of personal protective equipment, low salary, lack of social support, isolation from families, the fear of relatives getting infected. These results demonstrate the need for urgent supportive programs for HCWs fighting COVID-19 that fall into higher risk factors groups.


2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Turkan Ahmet

The past few decades of ongoing war in Iraq has had a dramatic impact on the health of Iraq’s population. Wars are known to have negative effects on the social and physical environments of individuals, as well as limit their access to the available health care services. This paper explores the personal experiences of my family members, who were exposed to war, as well as includes information that has been reviewed form many academic sources. The data aided in providing recommendations and developing strategies, on both local and international levels, to improve the health status of the populations exposed to war.


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