4,205 research outputs found
Causes and circumstances of maritime casualties and crew fatalities in British merchant shipping since 1925
Background: To determine the causes and circumstances of vessel accidents that led to fatalities in Britishmerchant shipping since 1925, and among British seafarers who were employed in non-United Kingdomshipping since 1985. Secondly, to establish trends in vessel accidents and crew fatalities, and associationswith type of casualty and location, type of ship, cargo carried and season.Materials and methods: Reviews of annual mortality returns, marine accident investigation reports, deathinquiry files, Lloydâs casualty returns, online newspapers, shipwreck websites and other searches over theperiod from 1925 to 2017 but excluding 1939 to 1946.
Results: The study identified 362 ship accidents in British shipping that led to 2760 crew and 605 passengerfatalities. There have been large reductions in both ship casualty and crew fatality rates, which havebeen greatest for vessels that were stranded, wrecked or foundered, particularly small coastal tradingcargo ships. Reductions since the 1980s have coincided with proportionate increases in ship accidentsand consequential crew fatalities among British seafarers employed in âopen registerâ shipping. Strongseasonal and geographical patterns show that most fatalities through foundering or wrecking occurredduring winter months around Europe.
Conclusions: Reductions in ship accidents and crew fatalities reflect major developments and improvementsin ship navigational aids, improvements in rescue services and ship designs, and reductions in thevolume of small coastal trading ships. Some disasters in âopen registryâ shipping occurred in controversialcircumstances, suggesting that substandard shipping has been flagged out or that lower cost but lesscompetent crews have been employed
Work related mortality among merchant seafarers employed in UK Royal Fleet Auxillary shipping from 1976 to 2005
Background: Over 2300 merchant seafarers are currently employed on board UK
Royal Fleet Auxiliary (RFA) ships. However, little is known about work related
mortality among these seafarers, and whether it is lower than among seafarers in
merchant fleets.
Objectives: To establish the causes and circumstances of all work related deaths
among seafarers who were employed in RFA ships from 1976 to 2005, to compare
mortality rates with those in other merchant fleets, and to identify implications for
maritime health.
Methods: A population based study of work related mortality over 30 years.
Results: A total of 60 deaths among seafarers in RFA ships were caused by
disease (30), accidents (19), suicide (6), homicide (one), and inconclusive causes (4).
Six of the 19 fatal accidents were directly related to work duties (occupational
accidents), 12 occurred during off-duty time and one resulted from a shipping disaster.
The fatal accident rate was about one half, and the fatal work related accident rate was
about one quarter, of corresponding rates in UK merchant shipping from 1976-2002;and they were much lower than those in merchant fleets internationally. The fatal
accident rate in RFA shipping also fell by about 80% over the 30 year study period.
Conclusions: The lower fatal accident rates in RFA shipping, particularly for work
related accidents, presumably reflect a lower incidence of hazardous working practices,
arising from better training and career pathways for seafarers in RFA shipping, as well
as better maintained ships with higher manning levels than in merchant shipping
Cardiovascular disease mortality in British merchant shipping and among British seafarers ashore in Britain
Background. The objective was to investigate trends in work-related mortality from cardiovascular
disease (CVD) among seafarers employed in British merchant shipping from 1919 to 2005, to
compare CVD mortality among British seafarers at work in British shipping - and ashore in
Britain - with that in the general British population, and to investigate work-related CVD mortality
in British shipping during recent years according to factors such as rank, nationality, location,
and type of ship.
Material and methods. A longitudinal study based on examination of death inquiry files and
death registers, official death returns, and information from occupational mortality decennial
supplements. The main outcome measures were population-based mortality rates and standardised
mortality ratios.
Results. There was an increase in work-related CVD mortality throughout much of the period
from 1919 to 1962, but a subsequent reduction to 2005. Work-related mortality from CVD and
ischaemic heart disease (IHD) was lower among seafarers employed in British shipping than in
the corresponding general population (SMRs = 0.35 to 0.46), but mortality from CVD among
British seafarers ashore in Britain was often increased. An elevated risk of work-related CVD
mortality was also identified among the crews of North Sea offshore ships.
Conclusions. This study shows a healthy worker effect against CVD mortality among seafarers at
work in British shipping, but increased risks among British seafarers ashore in Britain, which
would include seafarers discharged through CVD morbidity and other illnesses. The high risks of
CVD mortality among seafarers in North Sea supply ships may reflect particular work-related
hazards in this sector
Mortality from accidents, disease, suicide and homicide in the British fishing industry from 1900 to 2010
Background: To establish the causes of mortality in the British fishing industry from 1900 up to 2010, to investigate long term trends in mortality and to identify causal factors in the mortality patterns and rates.
Materials and methods: A longitudinal study, based on examinations of official death inquiry files, marine accident investigation files and reports, death registers and annual death returns.
Results: Mortality rates from accidents while working at sea remain high in the British fishing industry. Over the twentieth century there has been a progressive fall in the numbers of deaths, much of this relates to changes in fishing methods and in the types of vessels used. However in recent years, and with a fleet of smaller vessels, the mortality rates from accidents have shown little change and a larger proportion of deaths than in the past have arisen from personal injuries and drowning as compared to vessel losses. Disease makes a relatively small contribution to mortality at sea and this has dwindled with the decline in distant water fishing. Suicide and homicide both feature in a small way, but rates cannot readily be compared with those ashore.
Conclusions: The pattern of change in vessels, fisheries and fishing techniques over the study period are complex. However, improved injury and drowning prevention is the most important way to reduce deaths, coupled with attention to vessel stability and maintenance. The social, economic and organisational features of the fishing industry mean that securing improvements in these areas is a major challenge.
Evaluating multiple causes of persistent low microwave backscatter from Amazon forests after the 2005 drought
Amazonia has experienced large-scale regional droughts that affect forest productivity and biomass stocks. Space-borne remote sensing provides basin-wide data on impacts of meteorological anomalies, an important complement to relatively limited ground observations across the Amazonâs vast and remote humid tropical forests. Morning overpass QuikScat Ku-band microwave backscatter from the forest canopy was anomalously low during the 2005 drought, relative to the full instrument record of 1999â2009, and low morning backscatter persisted for 2006â2009, after which the instrument failed. The persistent low backscatter has been suggested to be indicative of increased forest vulnerability to future drought. To better ascribe the cause of the low post-drought backscatter, we analyzed multiyear, gridded remote sensing data sets of precipitation, land surface temperature, forest cover and forest cover loss, and microwave backscatter over the 2005 drought region in the southwestern Amazon Basin (4°-12°S, 66°-76°W) and in adjacent 8°x10° regions to the north and east. We found moderate to weak correlations with the spatial distribution of persistent low backscatter for variables related to three groups of forest impacts: the 2005 drought itself, loss of forest cover, and warmer and drier dry seasons in the post-drought vs. the pre-drought years. However, these variables explained only about one quarter of the variability in depressed backscatter across the southwestern drought region. Our findings indicate that drought impact is a complex phenomenon and that better understanding can only come from more extensive ground data and/or analysis of frequent, spatially-comprehensive, high-resolution data or imagery before and after droughts
Modeling the Disappearance of the Neanderthals Using Concepts of Population Dynamics and Ecology
Current hypotheses regarding the disappearance of Neanderthals (NEA) in Europe fall into two main categories: climate change, and competition. Here we review current research and existing mathematical models that deal with this question, and we propose an approach that incorporates and permits the investigation of the current hypotheses. We have developed a set of differential equations that model population dynamics of anatomically modern humans (AMH) and NEA, their ecological relations to prey species, and their mutual interactions. The model allows investigators to explore each of the two main categories or combinations of both, as well as various forms of competition and/or interference within the context of competition.
The model is designed to include a wide variety of hypotheses and associated archaeological evidence, not focused on a particular hypothesis regarding NEA extinction. It therefore provides investigators with a model to impartially examine various hypotheses (individually or in combination) regarding climatic effects, differential resource use, differences in birth/death rates and carrying capacities, competition, interference, disease, interbreeding, and cultural distinctions that might have led to the extinction of NEA. Moreover, the model accommodates the design of scenarios concerningâfor exampleâpopulation growth, hunting, competitive interactions, cultural differences, and climatic influences to investigate which concepts best explain the rapid disappearance of NEA.
In addition, our model is a modification of the classical Lotka-Volterra model for a wide range of any two populations competing for a common resource. Specifically, our model explicitly includes the resource as an additional variable, a dependence of important population parameters on resource, as well as accommodates treating one of the populations as invasive
Natural Hyperthermia and Expression of the Heat Shock Protein Hsp70 Affect Developmental Abnormalities in Drosophila Melanogaster
We Demonstrate that Natural Heat Stress on Wild Larval Drosophila Melanogaster Results in Severe Developmental Defects in \u3e10% of Eclosing Adults, and that Increased Copy Number of the Gene Encoding the Major Inducible Heat Shock Protein of D. Melanogaster, Hsp70, is Sufficient to Reduce the Incidence of Such Abnormalities. Specifically, Non-Adult D. Melanogaster Inhabiting Necrotic Fruit Experienced Severe, Often Lethal Heat Stress in Natural Settings. Adult Flies Eclosing from Wild Larvae that Had Survived Natural Heat Stress Exhibited Severe Developmental Anomalies of Wing and Abdominal Morphology, Which Should Dramatically Affect Fitness. the Frequency of Developmental Abnormalities Varied Along Two Independent Natural Thermal Gradients, exceeding 10% in Adults Eclosing from Larvae Developing in Warm, Sunlit Fruit. When Exposed to Natural Heat Stress, D. Melanogaster Larvae with the Wild-Type Number of Hsp70 Genes (N=10) Developed Abnormal Wings Significantly More Frequently Than a Transgenic Sister Strain with 22 Copies of the Hsp70 Gene
Effects of Flight on Gene Expression and Aging in the Honey Bee Brain and Flight Muscle
Honey bees move through a series of in-hive tasks (e.g., ânursingâ) to outside tasks (e.g., âforagingâ) that are coincident with physiological changes and higher levels of metabolic activity. Social context can cause worker bees to speed up or slow down this process, and foragers may revert back to their earlier in-hive tasks accompanied by reversion to earlier physiological states. To investigate the effects of flight, behavioral state and age on gene expression, we used whole-genome microarrays and real-time PCR. Brain tissue and flight muscle exhibited different patterns of expression during behavioral transitions, with expression patterns in the brain reflecting both age and behavior, and expression patterns in flight muscle being primarily determined by age. Our data suggest that the transition from behaviors requiring little to no flight (nursing) to those requiring prolonged flight bouts (foraging), rather than the amount of previous flight per se, has a major effect on gene expression. Following behavioral reversion there was a partial reversion in gene expression but some aspects of forager expression patterns, such as those for genes involved in immune function, remained. Combined with our real-time PCR data, these data suggest an epigenetic control and energy balance role in honey bee functional senescence
Changing Fitness Consequences of Hsp70 Copy Number in Transgenic Drosophila Larvae Undergoing Natural Thermal Stress
1. Transgenic Manipulation of the Gene Copy Number of Hsp70, Which Encodes the Major Inducible Heat-Shock Protein of Drosophila Melanogaster (Hsp70), Affects Both Hsp70 Levels and Inducible Thermotolerance in the Laboratory; Here Parallel Effects in Transgenic Drosophila Larvae Undergoing Natural or Simulated Natural Thermal Stress Are Demonstrated. 2. Necrotic Fruit Was Infested with Larvae of Either of Two Transgenic Strains, One Transformed with 12 Extra Copies of the Hsp70 Gene (Extra-Copy Strain) and a Sister Strain Possessing Only the Wild-Type Number (10) of Hsp70 Genes (Excision Strain), and Then Allowed to Heat to Variable Extents. 3. as the Intensity of Thermal Stress Increased, the Consequences of Extra Hsp70 Copies Reversed. after No or Moderate Thermal Stress, Excision Larvae Survived Better Than Did Extra Copy Larvae. by Contrast, Extra Copy Larvae Tolerated Intense Hyperthermia Better Than Did Excision Larvae. 4. These Results Establish that the Hsp70-Mediated Enhancement of Stress Tolerance, Previously Demonstrated Only for Artificial Stress Regimes in the Laboratory, Extends to Natural Stress Regimes. 5. Mortality Due to overexpression of Hsp70, However, Also Increases under Mild Natural Stress Regimes, Buttressing the Ecological Relevance of a Hypothesized Evolutionary Trade-Off of the Benefits and Adverse Consequences of Hsp70 Expression
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