Maritime Population Research Articles

Identifying children with medical complexity in administrative datasets in a Canadian context: study protocol

IntroductionChildren with medical complexity and their families are an important population of interest within the Canadian healthcare system. Despite representing less than 1% of the paediatric population, children with medical...

The heart of the maritime world: London’s ‘mercantile’ coffee houses in the Seven Years’ War and the American War of Independence, 1756–83

Abstract This article focuses on the role of mercantile coffee houses during the Seven Years’ War and the American War of Independence. The purpose is to examine mercantile coffee houses as public and private spaces, and to examine why people chose them as spaces in which to conduct business. The article examines how London’s mercantile coffee houses enabled the maritime population to understand, and remain informed about, maritime affairs during both wars. This includes how their presence facilitated the co-ordination of transoceanic trade, how their existence concentrated people in one place, and how they helped facilitate maritime and naval logistics.

Skin Diseases Affecting High-Level Competition Sailors: Descriptive Study Carried Out During the 2012 AG2R Transatlantic Boat Race

The primary objective of this study was to identify skin disorders encountered in a population of sport sailors. Unlike merchant mariners and fishermen, there is sparse literature on this maritime population. Secondary objectives were to uncover on-board conditions that may contribute to dermatological problems in this population. We conducted a prospective study during the 2012 AG2R transatlantic race. Sixteen two-man crews participated in this race, all using the same model of sailboat (Bénéteau Figaro 2). Clinical examinations were conducted, photographs taken, and questionnaires containing 34 questions were handed out before departure and on arrival, 22 to 24 days later. Twenty-eight of 32 skippers (88%) participated in departure data collection, and 18 (56%) completed data collection on arrival. The average age of sailors was 34 years (SD = 8). Compared with skin diseases documented on departure, there was an increased amount of folliculitis on the buttocks, fungal infections, and hyperkeratosis of the hands on arrival. Furthermore, several new skin problems were found postrace: skin scaling, skin erosions on the buttocks, dyshidrosis, thermal burns, and sunburns. The use of protective gear and sunscreen was common, but on-board hygiene was poor with infrequent bathing and clothing changes. Skin conditions are nearly universal in this maritime population. Further assessments are needed to know if long-term use of protective gear; improved hygiene; use of barrier creams; and proper on-board care of fungal infections, wounds, and burns could reduce the number and severity of skin problems encountered in sport sailors.

Inferring the genetic history of lactase persistence along the Italian peninsula from a large genomic interval surrounding the LCT gene.

Although genetic variants related to lactase persistence in European populations were supposed to have firstly undergone positive selection in farmers from the Balkans and Central Europe, demographic and evolutionary dynamics that subsequently shaped the distribution of this adaptive trait across the continent have still to be elucidated. To deepen the knowledge about potential routes of diffusion of lactase persistence to Western Europe we investigated variation at a large genomic region surrounding the LCT gene along the Italian peninsula, a geographical area that played a key role in population movements responsible for Neolithic diffusion across Europe. By genotyping 40 highly selected SNPs in more than 400 Italian individuals we described gradients of nucleotide and haplotype variation potentially related to lactase persistence and compared them with those observed in several European and Mediterranean human groups. Multiple migratory events responsible for earlier introduction of the examined alleles in Italy than in Northern European regions could be invoked. Different demic processes occurred along the western and eastern sides of the peninsula were also inferred via linkage disequilibrium and population structure analyses. The appreciable genetic continuum observed between people from Northern or Central-Western Italy and Central European populations suggested a local arrival of lactase persistence-related variants mainly via overland routes. On the contrary, diversity of Central-Eastern and Southern Italian groups entailed also gene flow from South-Eastern Mediterranean regions, in accordance to the earlier entrance of the Neolithic in Southern Italy via maritime population movements along the Mediterranean coastlines.

The peopling of the Fuego-Patagonian fjords by littoral hunter–gatherers after the mid-Holocene H1 eruption of Hudson Volcano

Early Holocene (>8500 cal BP) littoral sites are well documented along the Pacific coast of Chile north of 32°S, but they do not occur south of this latitude. It has been proposed that canoe Indians of Fuego-Patagonia, the earliest evidence for which is mid-Holocene (Punta Santa Ana; 7440 cal BP), adapted themselves to the sea from terrestrial hunter–gatherer populations already living since >13,000 cal BP in southernmost South America south of 52°S. This adaption may have taken place first in the area around Seno Otway, near the earliest maritime cultural sites, where transit to and from the interior pampas was relatively easy and forest providing trees for canoes existed. Seno Otway is also the proposed source for green obsidian, a distinctive lithic material found in many of the oldest maritime sites, including Túnel 1 and Imiwaia 1 along the Canal Beagle >300 km to the southeast. This green obsidian was previously exploited and transported long distances by terrestrial hunter–gatherers, as evidenced by its presence in the Period III (9500–7400 cal BP) levels of Pali Aike and Fell's Cave located >200 km east of Seno Otway. However, this obsidian does not occur in Period IV (after 7400 cal BP), when it and other obsidian types from distant sources are absent among the lithic tools found in these two sites. This hiatus in the long distant terrestrial transport of obsidian in southernmost Patagonia has been attributed to the catastrophic environmental effects of the H1 eruption of Hudson volcano (46°S) at ∼7750 cal BP. This eruption, which was more than five time larger than the 1991 eruption of the same volcano, covered much of Tierra del Fuego with up to >20 cm of tephra, and the Seno Otway area with at least >4 cm of tephra. As well as interrupting long distance terrestrial transport of obsidian over all of southernmost Patagonia, it may have devastated for an extended time period the flora and fauna supporting the local terrestrial hunter–gatherers in this area, particularly in Tierra del Fuego, which was already isolated by the opening of the Strait of Magellan at ∼9240 cal BP. Here it may have actually extinguished this culture completely. However, it was unlikely to have affected marine species. We propose that this volcanic eruption was a significant trigger to the development of the maritime population from the older terrestrial hunter–gatherers.

In vitro activation of cord blood mononuclear cells and cytokine production in a remote coastal population exposed to organochlorines and methyl mercury.

Remote coastal populations that rely on seafood for subsistence often receive unusually high doses of organochlorines and methyl mercury. Immunosuppression resulting from prenatal exposure to organochlorines has been reported in wildlife species and humans. In this study, we assessed lymphocyte activation and associated cytokine secretion in 47 newborns from a remote maritime population living on the Mid and Lower North Shore regions of the St. Lawrence River (Québec, Canada; subsistence fishing group) and 65 newborns from nearby urban settings (reference group). Cord blood samples were collected for organochlorine and mercury analyses and also to isolate cord blood mononuclear cells (CBMCs) for the in vitro assessment of cytokine production and expression of surface markers after mitogenic stimulation (CD4(+)CD45RO(+), CD8(+)CD45RO(+), CD3(+)CD25(+), and CD8(+)HLA-DR(+)). Blood mercury and plasma concentrations of polychlorinated biphenyls (PCBs), 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene (p,p'-DDE), and hexachlorobenzene (HCB) were significantly higher in the subsistence fishing group than in the reference group (p < 0.001). No difference was observed between the two groups regarding subsets of lymphocytes showing markers of activation. In vitro secretion of cytokines by CBMCs after mitogenic stimulation was lower in the subsistence fishing group than in the reference group (p < 0.05). Moreover, we found an inverse correlation between tumor necrosis factor-alpha (TNF-alpha) secretion and plasma PCB, p,p'-DDE, and HCB concentrations (p < 0.05). Our data support a negative association between TNF-alpha secretion by CBMCs and prenatal organochlorine exposure. If the relationship between organochlorine and TNF-alpha secretion is causal, it would suggest a role for this important proinflammatory cytokine in mediating organochlorine-induced immunotoxicity in infants developmentally exposed to these compounds.

CORD BLOOD LYMPHOCYTE FUNCTIONS IN NEWBORNS FROM A REMOTE MARITIME POPULATION EXPOSED TO ORGANOCHLORINES AND METHYLMERCURY

The consumption of fish and sea mammals can be an important source of exposure to organochlorine compounds (OCs) and heavy metals in populations relying on seafood for subsistence. Exposure to these substances, especially during the prenatal period, has been shown to induce immunotoxic effects in mammals. Immunological status was assessed in 48 newborns from a remote maritime population living on the Lower and Mid North Shore of the St. Lawrence River (subsistence fishing group) and 60 newborns from the coastal urban center of Sept-Îles (reference group). Women were recruited upon arrival at Sept-Îles regional hospital to give birth. Cord blood samples were collected for organochlorine and heavy metal analyses and to isolate lymphocytes for immunological assays (proportions and functional responses of the main cellular subsets T, B, and NK (natural killer) cells. Concentrations of polychlorinated biphenyls (PCBs) and mercury were respectively three-and twofold higher, significantly greater, in the subsistence fishing group than in the reference group. Compared to the reference group, the subsistence fishing group showed significant decreases in the proportion of the naive helper T-cell subset CD4 + CD45RA + , T-cell proliferation following an in vitro mitogenic stimulation, and plasma immunoglobulin M (IgM) level, while plasma IgG level was increased. NK cytolytic activities were similar in both groups. The proportion of CD4 + CD45RA + cells was inversely correlated to mercury and PCBs, while T-cell clonal expansion was negatively associated with PCBs and p,p '-DDE. Mercury was inversely correlated to plasma IgM. Data show that subtle functional alterations of the developing human immune system may result from in utero exposure to OCs and mercury. Epidemiological studies are needed to determine the relevance of these alterations in predicting detrimental health effects in the developing child.

Aleutian Island prehistory: Living in insular extremes

Peoples of the Aleutian Islands lived under a number of stressful environmental constraints, including extreme isolation, volcanic eruptions, seismic activity (including tsunamis), frequent storms, rough seas, gale‐force winds, frequent fog and precipitation, and an exclusive marine diet. Nevertheless, the Aleutian Islands supported a large maritime population during late prehistoric times. Cultural adaptations to these conditions included the use of relatively large coastal settlements, semisubterranean houses, tailored warm and waterproof clothing, sophisticated skin boats for hunting, fishing, and traveling, broad species utilization of food and raw materials, food storage, fuel for heating and cooking, and refuge rocks or islets for protection against raids.

Seven Chinchorro mummies and the prehistory of northern Chile.

The mummification methods of an ancient maritime population on the northern coast of Chile are reviewed and the findings in an additional seven individuals are reported. Members of this cultural group, Chinchorro, practiced a selective, elaborate form of artificial mummification which persisted more than 4,000 years. Its complexity diminished with time, gradually disappearing after 2,000 B.C. One of the seven individuals herein reported is a rather poorly but spontaneously ("naturally") preserved body that may represent the oldest mummy reported to date--about 9,000 years old. Chemical reconstruction of their diet demonstrates that the principal component was derived from marine resources with only minor supplementation from terrestrial hunting as well as food gathering from river mouth vegetal sources, confirming the marine dependence of their adaptational strategy.

Morphometrics of American Lobster (Homarus americanus) Larvae in Relation to Stock Determinations in the Maritimes, Canada

Morphological characteristics of the first larval stage of the American lobster (Homarus americanus) enabled the separation of the Maritime population with stepwise discriminant function analysis into three groups: the southern Gulf of St. Lawrence and its outflow around Cape Breton Island, the Atlantic inshore region of Nova Scotia, and the offshore banks bordering the Gulf of Maine. Once the effect of environmental temperature on larval size was removed, the differences between Georges and Browns banks and the Atlantic inshore disappeared. The remaining differences, chiefly in the dimensions of the second and fifth abdominal segments and the rostrum, between larvae from the Cape Breton sites and elsewhere may be due to other environmental factors or partial genetic isolation. Conservation and management practices over the past century have increased gene flow between regions, and most of this appears to be from the release of Gulf of St. Lawrence lobsters in the Gulf of Maine. A reassessment of previous studies on adult morphology, benthic movements, larval dispersal, enzyme electrophoresis, and commercial landing patterns supports the separation of the Gulf of St. Lawrence stock from the rest of the Canadian Maritimes.

Prevalence of Hypercholesterolemia in a Maritime Population

The problem of hypercholesterolemia is of growing concern and public awareness. The cholesterol determinations of 567 maritime personnel, dependent upon a shipboard diet for a major portion of the year, were reviewed. Total cholesterol levels were borderline in 32.7% and high in 28.2% of the population, using definitions of the National Cholesterol Education Program. There was an age-related increase in average total cholesterol levels. The levels of low-density lipoprotein cholesterol and high-density lipoprotein cholesterol in this population are also reported where available. The opportunities for intervention in this population are unique, as are the potential impediments to intervention.

Comparative Patterns of Nestling Growth in White-Crowned Sparrows

To examine the hypothesis that the growth rates of emberizines are physiologically maximized and hence geographically invariant, we weighed the eggs and nestlings of White-crowned Sparrows (Zonotrichia leucophrys) from subarctic, subalpine, and low-altitude montane populations. We augmented these data with published information on another subalpine population and a Pacific maritime population. Clutch sizes ranged from a mode of three in the south to five in the north. Geographic variation in fresh egg weight was closely correlated with the size of the adult female. Other sources of variation, if any, were small. The mean incubation period was geographically invariant (about 12.2 d). The weight (water) loss of eggs during incubation averaged 18.4%, without statistically significant differences among four localities. There were no consistent differences in the synchrony of hatching in clutches of three, four or five eggs. Runt nestlings resulting from late hatching were atypical in the mainly five-egg clutches in the subarctic, but were more common in the unusual five-egg clutches of subalpine populations. The postnatal growth curves of nestlings in all six sample populations were virtually congruent, and thus independent of mean brood size and locality. We believe that it is unlikely that this would occur in such diverse populations unless growth rate were physiologically maximized. We would expect to find greater diversity if growth rates were submaximal and "optimized" in relation to the local environment.

Photosynthetic system II: racial differentiation in Typha latifolia.

The rate of reduction of 2,6-dichlorophenol-indophenol by illuminated chloroplasts isolated from ecological races of Typha latifolia was negatively correlated with length of growing season at the site of origin. Efficiency of the photochemical apparatus for this reaction was twice as high in a high-altitude population from Wyoming as in a maritime population from California.