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PubMed1997

An analysis of the self of the western physician: a study on the evolution of homo Hippocratus.

This paper is about western physicians in general, and the Israeli variant in particular. The theoretical focus will be on the nature and dynamics of the medical professional self within this interplay between the cultural concepts of universality and difference. The discussion will address the genesis of this professional self and the implications of its extraordinary strength and tenacity, which has endured for centuries in different local contexts wherever western medicine has existed. The impetus for this study is the subdued rumbling which is echoing throughout the profession suggesting that this self is no longer the "Rock of Gibraltar" that it seemed in the past.

Greece↗
PubMed2004

Cephalolepidapedon saba Yamaguti, 1970 (Digenea: Lepocreadiidae), the redescription of a species newly reported in European waters.

The lepocreadiid Cephalolepidapedon saba Yamaguti, 1970 is redescribed from Scomber japonicus in the western Mediterranean. The circum-oral spine rings and terminal genitalia are described in detail for the first time and the short excretory vesicle is confirmed. This is the first record of this distinctive parasite from European waters. It is concluded that it is a recent introduction to the area probably via the Straits of Gibraltar.

Animals↗
PubMed2002

Extensive population subdivision of the cuttlefish Sepia officinalis (Mollusca: Cephalopoda) around the Iberian Peninsula indicated by microsatellite DNA variation.

The Atlantic Ocean-Mediterranean Sea junction has been proposed as an important phylogeographical area on the basis of concordance in genetic patterns observed at allozyme, mtDNA and microsatellite DNA markers in several marine species. This study presents microsatellite DNA data for a mobile invertebrate species in this area, the cuttlefish Sepia officinalis, allowing comparison of this relatively new class of DNA marker with previous allozyme results, and examination of the relative effects on gene flow of the Strait of Gibraltar and the Almería-Oran oceanographic front. Genetic variation at seven microsatellite loci screened in six samples from NE Atlantic and Mediterranean coasts of the Iberian Peninsula was high (mean Na = 9.6, mean H(e) = 0.725). Microsatellites detected highly significant subpopulation structuring (F(ST)= 0.061; R(ST) = 0.104), consistent with an isolation-by-distance model of low levels of gene flow. Distinct and significant clinal changes in allele frequencies between Atlantic and Mediterranean samples found at five out of seven loci, however indicate these results might be also consistent with an alternative model of secondary contact and introgression between previously isolated and divergent populations, as previously proposed for other marine species from the Atlantic-Mediterranean area. A pronounced 'step' change between SW Mediterranean samples associated with the Almería-Oran front suggests this oceanographic feature may represent a contemporary barrier to gene flow.

Animals↗
PubMed1998

Low substitution rates in mitochondrial DNA in Mediterranean carabid beetles.

The estimation of DNA substitution rates requires calibration with the geological events which caused the separation of populations. We used the disintegration of the landbridges between Morocco and Gibraltar as well as the Balearics and Spain at the end of the Messinian event (5.3 myr) in order to calibrate the DNA sequence data of the NADH-dehydrogenase subunit 1 (ND1) in West Mediterranean Carabus species. The rates of molecular evolution we found are much lower than those reported in the literature and also vary from species to species. Therefore, in insects the calculation of divergence periods using a constant 2% substitution rate per myr is questionable.

Animals↗
PubMed1998

Mitochondrial DNA diversity and historical biogeography of a wet forest-restricted frog (Litoria pearsoniana) from mid-east Australia.

MtDNA sequencing was used to investigate the genetic population structure of Litoria pearsoniana, a wet forest-restricted hylid frog, endemic to southeast Queensland and northeast New South Wales, Australia. L. pearsoniana is regarded as endangered under Queensland legislation. Significant genetic divergence among populations of frogs from different rainforest isolates was identified, but the lack of reciprocal monophyly among adjacent isolates suggests this is the result of a relatively recent disruption to gene flow. A paired catchment study within a single rainforest isolate, the Conondale Range, revealed no substantial genetic structuring, indicating the occurrence of terrestrial dispersal among nearby streams either in the recent past or currently. Two major reciprocally monophyletic clades of mtDNA alleles were identified. These corresponded to two geographical regions separated by the Brisbane River valley; one consisting of the Conondale and D'Aguilar Ranges, and the other of the southern isolates in the Main, Border and Gibraltar Ranges. Sequence divergence between the two regions was more consistent with a late Miocene or Pliocene rather than late Pleistocene separation, and is similar to that found among phylogeographic divisions of rainforest reptiles and amphibians in north Queensland rainforests. The molecular evidence for long-term separation of these two regions is corroborated by the pattern of species turnover in the distributions of species of rainforest-restricted amphibians and reptiles. Bioclimatic modelling suggests that appropriate conditions for L. pearsoniana would have been restricted to isolated refugees in each phylogeographic division under cooler and drier climates, such as predicted for the last glacial maximum. Currently isolated montane areas may have been connected transiently during the past 2000 years. Identification of long-term zoogeographic divisions among southeast Queensland rainforest herpetofauna has important implications for conservation and management. Conservation management of L. pearsoniana should be applied at the scale of major rainforest isolates and the conservation status of the species should be assessed independently north and south of the historical division.

Animals↗
PubMed1999

Genetic differentiation in the striped dolphin Stenella coeruleoalba from European waters according to mitochondrial DNA (mtDNA) restriction analysis.

We used mitochondrial DNA (mtDNA) restriction analysis to study genetic variation in 98 striped dolphins (Stenella coeruleoalba) stranded on coasts from different European countries and from animals caught by fisheries. A total of 63 different restriction sites was mapped after digestion of mtDNA with 15 restriction endonucleases that yielded a total of 27 haplotypes. No haplotype was shared between Mediterranean and Atlantic areas. All the analyses indicate the existence of two different populations with a very limited gene flow across the Strait of Gibraltar.

Animals↗
PubMed2003

Phylogeography of maritime pine inferred with organelle markers having contrasted inheritance.

Range-wide variation of maritime pine was studied at maternally inherited and paternally inherited markers (mitochondrial DNA and chloroplast DNA). While chloroplast DNA exhibits the highest diversity, phylogeographic inferences from this marker are blurred by homoplasy and extensive pollen flow. In contrast, the only three mitochondrial haplotypes found provide a clear picture of nonoverlapping areas colonized from different refugia, with no single population having a mixed composition (GST = 1). Comparison of the genetic structure inferred from both organelle genomes allows the investigation of differential seed and pollen dispersal, pointing to pollen, but not seed, dispersal across the Strait of Gibraltar (from Morocco into Iberia). A comparison with already available genetic information, especially that of one of the maritime pine's most threatening insect pests, the bast scale Matsucoccus feytaudi, further completes the picture.

DNA Primers↗
PubMed2003

The influence of the Miocene Mediterranean desiccation on the geographical expansion and genetic variation of Androcymbium gramineum (Cav.) McBride (Colchicaceae).

Chloroplast DNA (cpDNA) restriction site and isozyme data were combined to explore the spatial-temporal influence of the Messinian desiccation in the Mediterranean on the disjunct distribution of Androcymbium gramineum in Almería and Morocco (north and south of the straits of Gibraltar, respectively). Lack of evidence for different selective pressures, divergence time estimates based on the calibration of the isozyme molecular clock with the cpDNA data, the basal position of Almerian populations in the A. gramineum clade, and the much higher isozyme polymorphism in Almería suggest that (i) only a southern European range of A. gramineum existed before the Messinian [ approximately 11.2 million years ago (Ma), in the middle Miocene] and (ii) the desiccation of the Mediterranean basin about 5.5-4.5 Ma induced the migration of A. gramineum from Almería to Morocco (between 4.9 and 4.6 Ma, according to our time estimates). After the split into two allopatric units following the refilling of the Mediterranean, the major influence of drift associated with Plio-Pleistocene recurrent glaciation cycles and range expansions/contractions probably fostered the substantial interpopulation genetic differentiation observed within Almería (CGST = 0.41, average DNei = 0.185) and, to a lesser extent, within Morocco (CGST = 0.24, average DNei = 0.089), but did not hinder the maintenance of considerable levels of genetic variation in either geographical area (A = 2.14, HE = 0.230 and A = 1.90, HE = 0.213, respectively).

Climate↗
PubMed2003

Discord in the family Sparidae (Teleostei): divergent phylogeographical patterns across the Atlantic-Mediterranean divide.

The Strait of Gibraltar has been proposed to be the divide between two marine biogeographical regions, the Mediterranean Sea and the Northeast Atlantic. Intraspecific studies have shown, for several of the examined species, a reduction of gene flow between the two basins. The present study examines genetic variation at nuclear and mitochondrial loci in five marine teleost species belonging to the family Sparidae. Four samples for each species were analysed spanning the Northeast Atlantic and the Mediterranean. For all individuals 17 allozyme loci were scored and a combined single strand conformation polymorphism-sequencing approach was used to survey approximately 190 bp of the mitochondrial DNA (mtDNA) D-loop region. All five species share similar biological features. For three species, namely Lithognathus mormyrus, Spondyliosoma cantharus, and Dentex dentex, large mtDNA divergence was observed between Atlantic and Mediterranean samples. Little or no mtDNA differentiation was found in the other two species, Pagrus pagrus and Pagellus bogaraveo. Allozyme data revealed strong differentiation when comparing Atlantic and Mediterranean samples of L. mormyrus and D. dentex, moderate for P. pagrus, and no differentiation for P. bogaraveo and S. cantharus. These results provide evidence for a sharp phylogeographical break (sensu Avise) between the Atlantic and the Mediterranean for two (or possibly three) sparid species of the five investigated. At the same time, the obtained results for the other two species raise the question on which ecological/historical factors might have caused the observed discrepancy in the geographical distribution of genetic variation among otherwise biologically similar species.

Animals↗
PubMed2005

Generation, propagation, and breaking of internal solitary waves.

Tidal, two-layer flow over topography generates a kink of the interface separating an upstream interfacial elevation from a depression above the topography. Upstream undular bores and solitary waves of large amplitude are generated from the interfacial kink. The waves propagate upstream when the tide turns. Interfacial simulations of this kind of generation process fit with the observations at Knight Inlet in British Columbia, in the Sulu Sea experiment, and undular bores generated by internal tides in the Strait of Gibraltar. Fully nonlinear interfacial computations compare successfully with experimental observations of solitary waves in the laboratory and in the field for wave amplitudes ranging from small to maximal values. The waves exhibit only minor sensitivity to a finite thickness of the pycnocline. Analytical solitary waves are recaptured in the small amplitude limit. Shear-induced breaking appears first in the top part of the pycnocline and is expressed in terms of the Richardson number. Convective breaking in the top part of the water column occurs beyond a threshold amplitude when a pronounced stratification continues all the way to the ocean surface.

Algorithms↗
PubMedDate not supplied

Genetic relationships among Berbers and South Spaniards based on CD4 microsatellite/Alu haplotypes.

BACKGROUND: CD4 STR/Alu haplotype diversity, both for its qualitative and quantitative properties, has been widely used in molecular anthropology to clarify the degree of genetic relationships among human populations. AIM: CD4 STR/Alu variation was studied in two West Mediterranean samples, Andalusians from La Alpujarra region on the north side of the Gibraltar Strait and Berbers from the south, to ascertain the pattern of affinities between them. SUBJECTS AND METHODS: Alu and microsatellite alleles were tested in 99 Andalusians from La Alpujarra region (Southeast Spain) and 124 Middle Atlas Berbers (Morocco). RESULTS: Two new combinations of Alu and STR alleles (75(+) and 80(-)) were found in Berbers. The CD4 STR/Alu haplotype distribution in South Spaniards is similar to that of other Europeans, the only special feature is the slight presence of the 90(+) and 130(+) typical Sub-Saharan haplotypes. The Berber sample is characterized by a high number of different haplotypes (18) with intermediate heterozygosity values (0.846) in comparison with other North African groups, and by a high frequency of the 110(-) combination that has been proposed as representative of an ancient Northwest African population. CONCLUSION: A geographical gradient of Sub-Saharan gene contribution has been detected in North Africa. The Middle Atlas Berbers showed an intermediate value in comparison with the high and low values found in Mauritanians and Moroccan Berbers, respectively. The analysis of the CD4 STR/Alu haplotype variation failed to indicate any particular relationship between South Spaniards and North Africans.

Alu Elements↗
PubMed1998

The function of Barbary macaque copulation calls.

In a wide variety of animal species, females produce vocalizations specific to mating contexts. It has been proposed that these copulation calls function to incite males to compete for access to the calling female. Two separate advantages of inciting male-male competition in this way have been put forward. The first suggests that as a result of calling, females are only mated by the highest ranking male in the vicinity (indirect mate choice hypothesis). The second proposes that copulation calling results in a female being mated by many males, thus promoting competition at the level of sperm (sperm competition hypothesis). In this paper, I give results from the first experimental study to test these hypotheses. Playback was used to examine the function of copulation calls of female Barbary macaques (Macaca sylvanus) in Gibraltar. Although rank did not affect lone males' likelihood of approaching copulation calls, when playbacks were given to pairs of males only the higher ranking individual approached. Moreover, females were mated significantly sooner after playback of their copulation call than after playback of a control stimulus. These results suggest that the copulation calls of female Barbary macaques play a key role in affecting patterns of male reproductive behaviour, not only providing an indirect mechanism of female choice, but also promoting sperm competition by reducing the interval between copulations. Potential fitness benefits of inciting male-male competition at these two levels are discussed.

Animals↗
PubMed2004

Genetic diversity and population structure of the commercially harvested sea urchin Paracentrotus lividus (Echinodermata, Echinoidea).

The population structure of the edible Atlanto-Mediterranean sea urchin Paracentrotus lividus is described by analysing sequence variation in a fragment of the mitochondrial gene cytochrome c oxidase subunit I in 127 individuals from 12 localities across south-west Europe. The study revealed high levels of genetic diversity but low levels of genetic structure, suggesting a large degree of gene flow between populations and panmixis within each, the Mediterranean and Atlantic basins. However, we found significant genetic differentiation between the two basins probably due to restricted gene flow across the geographical boundary imposed by the area of the Strait of Gibraltar. Populations of P. lividus appeared to have experienced a recent demographic expansion in the late Pleistocene. We provide new evidence on the population structure of this commercial species, predicting a healthy stock of this sea urchin on the Mediterranean and Atlantic coasts.

Animals↗
PubMed2005

Gene-flow patterns in Atlantic and Mediterranean populations of the Lusitanian sea star Asterina gibbosa.

In this study, the population structure of the Lusitanian sea star Asterina gibbosa was assessed using amplified fragment length polymorphism (AFLP). One hundred and twenty-two AFLP loci were analysed in 159 individuals from eight populations from across the species' range and revealed high levels of genetic diversity, with all individuals but two harbouring a unique banding pattern. As reported for other marine invertebrates, we found high levels of genetic differentiation between the Atlantic and Mediterranean basins, suggesting that the Strait of Gibraltar represents a major barrier to dispersal for this sea star. Our assignment studies suggest that, in the Atlantic, a measurable degree of gene flow occurs between populations, which could result in the isolation-by-distance pattern of differentiation observed in this basin. In contrast, no evidence of contemporary gene flow was found in the Mediterranean, suggesting contrasting patterns of dispersal of Asterina gibbosa in the Atlantic and Mediterranean basins.

Animals↗
PubMed2005

Historical colonization and demography of the Mediterranean damselfish, Chromis chromis.

The desiccation of the Mediterranean Sea during the Messinian Salinity Crisis 6.0-5.3 million years ago (Ma), caused a major extinction of the marine ichthyofauna of the Mediterranean. This was followed by an abrupt replenishment of the Mediterranean from the Atlantic after the opening of the Strait of Gibraltar. In this study, we combined demographic and phylogeographic approaches using mitochondrial and nuclear DNA markers to test the alternative hypotheses of where (Atlantic or Mediterranean) and when (before or after the Messinian Salinity Crisis) speciation occurred in the Mediterranean damselfish, Chromis chromis. The closely related geminate transisthmian pair Chromis multilineata and Chromis atrilobata was used as a way of obtaining an internally calibrated molecular clock. We estimated C. chromis speciation timing both by determining the time of divergence between C. chromis and its Atlantic sister species Chromis limbata (0.93-3.26 Ma depending on the molecular marker used, e.g. 1.23-1.39 Ma for the control region), and by determining the time of coalescence for C. chromis based on mitochondrial control region sequences (0.14-0.21 Ma). The time of speciation of C. chromis was always posterior to the replenishment of the Mediterranean basin, after the Messinian Salinity Crisis. Within the Mediterranean, C. chromis population structure and demographic characteristics revealed a genetic break at the Peloponnese, Greece, with directional and eastbound gene flow between western and eastern groups. The eastern group was found to be more recent and with a faster growing population (coalescent time = 0.09-0.13 Ma, growth = 485.3) than the western group (coalescent time = 0.13-0.20 Ma, growth = 325.6). Our data thus suggested a western origin of C. chromis, most likely within the Mediterranean. Low sea water levels during the glacial periods, the hydrographic regime of the Mediterranean and dispersal restriction during the short pelagic larval phase of C. chromis (18-19 days) have probably played an important role in C. chromis historical colonization.

Animals↗
PubMed2006

HLA class II genetic diversity in southern Tunisia and the Mediterranean area.

North Africa is populated by many Arab- and Berber-speaking populations whose genetic history is still poorly understood. In this study, we analyse the HLA-DRB1 and DQB1 molecular diversity in three populations from the south of Tunisia--Berbers from Jerba, Berbers from Matmata and Arabs from Gabes--and we compare them to a large set of populations from the whole Mediterranean region. Among the three populations studied, the Berbers from Jerba are the most peculiar, as they diverge significantly from other North Africans while being genetically highly diversified and close to populations from the Near East. Thus, Jerba may have been a crossing point, in historical times, where colonization from the eastern Mediterranean area left significant genetic traces. By contrast, the populations from Matmata and Gabes are genetically similar to other Arab and Berber-speaking populations from different areas of the Maghrib, despite some peculiar allele and haplotype frequencies. At a larger scale, northwest Africa and southwest Europe are closely related according to these polymorphisms, while the populations from the eastern Mediterranean area are much more differentiated. The close genetic relatedness found for HLA among populations of the western Mediterranean region challenges previous results based on Y chromosome analyses, where the Gibraltar Strait appeared to constitute a main genetic barrier.

Alleles↗
PubMed1977

Motor neurone disease and multiple sclerosis among immigrants to Britain.

Hospital discharge rates for various immigrant groups resident in Greater London and the West Midlands were studied to compare the incidence of two diseases of the nervous system-motor neurone disease (MND) and multiple sclerosis (MS). For both these conditions immigrants from Europe, Ireland, America and from the old commonwealth countries of Canada, Australia, and New Zealand had discharge rates that were similar to those for people born in the United Kingdom. In contrast, immigrants from the new commonwealth countries of Asia, Africa, America (including the West Indies), and Europe (Gibraltar, Malta, and Gozo) had a greatly reduced risk of MS but a very similar risk of MND compared with those born in the United Kingdom. MS but not MND was rare among immigrants of Asian or African ethnic origin and uncommon among immigrants from the West Indies. Deaths attributed to MS and MND have also been studied. During a three-year period there were no deaths reported for MS among immigrants of Asian and African ethnic origin and 14 were expected. There were two deaths from MND among these immigrants and five were expected. Among the immigrants from the West Indies two deaths were attributed to MS and 13 were expected, and there were three deaths attributed to MND and four were expected. The contrast between MND and MS in hospital morbidity and mortality confirms that MS among immigrants to Britain is rare in those of Asian and African ethnic origin.

Adolescent↗
PubMed2002

Y-chromosome analysis in Egypt suggests a genetic regional continuity in Northeastern Africa.

The geographic location of Egypt, at the interface between North Africa, the Middle East, and southern Europe, prompted us to investigate the genetic diversity of this population and its relationship with neighboring populations. To assess the extent to which the modern Egyptian population reflects this intermediate geographic position, ten Unique Event Polymorphisms (UEPs), mapping to the nonrecombining portion of the Y chromosome, have been typed in 164 Y chromosomes from three North African populations. The analysis of these binary markers, which define 11 Y-chromosome lineages, were used to determine the haplogroup frequencies in Egyptians, Moroccan Arabs, and Moroccan Berbers and thereby define the Y-chromosome background in these regions. Pairwise comparisons with a set of 15 different populations from neighboring European, North African, and Middle Eastern populations and geographic analysis showed the absence of any significant genetic barrier in the eastern part of the Mediterranean area, suggesting that genetic variation and gene flow in this area follow the "isolation-by-distance" model. These results are in sharp contrast with the observation of a strong north-south genetic barrier in the western Mediterranean basin, defined by the Gibraltar Strait. Thus, the Y-chromosome gene pool in the modern Egyptian population reflects a mixture of European, Middle Eastern, and African characteristics, highlighting the importance of ancient and recent migration waves, followed by gene flow, in the region.

Arabs↗