76 research outputs found
Les Hipparion du Portugal
This paper is concerned with Hipparion from Ribatejo, Portugal, and with the stratigraphy of the Neogene series of this region.
The first two chapters are an introduction and an historical review. Paleontological study includes both a revision of the specimens accounted by ROMAN (1907) and the description of new material. Two forms were recognized, an early H. cf. primigenium, lower Vallesian in age, NM 9 mammal unit (from Archino, Vila Nova da Rainha, Aveiras de Cima), and a more advanced H. primigenium cf. melendezi. Upper Vallesian, NM 10 (possibly lowermost Turolian, NM 11) (at Azambujeira and Marmeleira).
A synthesis of Middle and Upper Miocene from Ribatejo is also presented.
Levels with H. p. cf. melendezi are somewhat older than «Upper Pontian», as it was previously acknowledged, they attain at the best the lowermost Turolian (approximately corresponding to «Upper Pontian»). Even higher levels may be Turolian in age, though they are not yet accurately dated.
Almost all the localities are shown (tableau 11) according to its stratigraphical position; age, correspondance to mammal units from NM 5 to NM 10 (and may be also from NM 11 to NM 12), and correlation with marine formations near Lisbon are also taken in account.
The stratigraphical position of localities such as Póvoa de Santarém, Quinta do Marmelal, Pero Filho, Azambujeira (lower levels), and Fonte do Pinheiro was revised; the stratigraphical position of Marmeleira was ascertained.
The localities so far known correspond to NM 5 (?), NM 6, NM 8, NM 9, NM 10 and possibly to NM II and NM 12.
A new interpretation (M. T. ANTUNES) of localities with oysters from Ribatejo allows a better correlation with vertebrate localities. Relationships with Serravallian transgression seem well established.
Only two localities, Vila Nova da Rainha and Foz do Alviela, may possibly be correlated to V-b division of Lisbon (Langhian) with «Hispanotherium fauna». All the other localities are younger than Serravallian oyster beds.
Undirect correlation shows that NM 6 localities are somewhat younger than the apogee ef Serravallian transgression (corresponding approximately to Blow's N 11 to N 13 zones based on planctonic foraminifera)
Y-Chromosome Based Evidence for Pre-Neolithic Origin of the Genetically Homogeneous but Diverse Sardinian Population: Inference for Association Scans
The island of Sardinia shows a unique high incidence of several autoimmune diseases with multifactorial inheritance, particularly type 1 diabetes and multiple sclerosis. The prior knowledge of the genetic structure of this population is fundamental to establish the optimal design for association studies in these diseases. Previous work suggested that the Sardinians are a relatively homogenous population, but some reports were contradictory and data were largely based on variants subject to selection. For an unbiased assessment of genetic structure, we studied a combination of neutral Y-chromosome variants, 21 biallelic and 8 short tandem repeats (STRs) in 930 Sardinian males. We found a high degree of interindividual variation but a homogenous distribution of the detected variability in samples from three separate regions of the island. One haplogroup, I-M26, is rare or absent outside Sardinia and is very common (0.37 frequency) throughout the island, consistent with a founder effect. A Bayesian full likelihood analysis (BATWING) indicated that the time from the most recent common ancestor (TMRCA) of I-M26, was 21.0 (16.0â25.5) thousand years ago (KYA) and that the population began to expand 14.0 (7.8â22.0) KYA. These results suggest a largely pre-Neolithic settlement of the island with little subsequent gene flow from outside populations. Consequently, Sardinia is an especially attractive venue for case-control genome wide association scans in common multifactorial diseases. Concomitantly, the high degree of interindividual variation in the current population facilitates fine mapping efforts to pinpoint the aetiologic polymorphisms
The Age of the 20 Meter Solo River Terrace, Java, Indonesia and the Survival of Homo erectus in Asia
Homo erectus was the first human lineage to disperse widely throughout the Old World, the only hominin in Asia through much of the Pleistocene, and was likely ancestral to H. sapiens. The demise of this taxon remains obscure because of uncertainties regarding the geological age of its youngest populations. In 1996, some of us co-published electron spin resonance (ESR) and uranium series (U-series) results indicating an age as young as 35â50 ka for the late H. erectus sites of Ngandong and Sambungmacan and the faunal site of Jigar (Indonesia). If correct, these ages favor an African origin for recent humans who would overlap with H. erectus in time and space. Here, we report 40Ar/39Ar incremental heating analyses and new ESR/U-series age estimates from the â20 m terrace" at Ngandong and Jigar. Both data sets are internally consistent and provide no evidence for reworking, yet they are inconsistent with one another. The 40Ar/39Ar analyses give an average age of 546±12 ka (sd±5 se) for both sites, the first reliable radiometric indications of a middle Pleistocene component for the terrace. Given the technical accuracy and consistency of the analyses, the argon ages represent either the actual age or the maximum age for the terrace and are significantly older than previous estimates. Most of the ESR/U-series results are older as well, but the oldest that meets all modeling criteria is 143 ka+20/â17. Most samples indicated leaching of uranium and likely represent either the actual or the minimum age of the terrace. Given known sources of error, the U-series results could be consistent with a middle Pleistocene age. However, the ESR and 40Ar/39Ar ages preclude one another. Regardless, the age of the sites and hominins is at least bracketed between these estimates and is older than currently accepted
The origins and persistence of Homo floresiensis on Flores: biogeographical and ecological perspectives
The finding of archaeological evidence predating 1 Ma and a small hominin species (Homo floresiensis) on Flores, Indonesia, has stimulated much research on its origins and ancestry. Here we take a different approach and examine two key questions â 1) how did the ancestors of H. floresiensis reach Flores and 2) what are the prospects and difficulties of estimating the likelihood of hominin persistence for over 1 million years on a small island? With regard to the first question, on the basis of the biogeography we conclude that the mammalian, avian, and reptilian fauna on Flores arrived from a number of sources including Java, Sulawesi and Sahul. Many of the terrestrial taxa were able to float or swim (e.g. stegodons, giant tortoises and the Komodo dragon), while the rodents and hominins probably accidentally rafted from Sulawesi, following the prevailing currents. The precise route by which hominins arrived on Flores cannot at present be determined, although a route from South Asia through Indochina, Sulawesi and hence Flores is tentatively supported on the basis of zoogeography. With regards to the second question, we find the archaeological record equivocal. A basic energetics model shows that a greater number of small-bodied hominins could persist on Flores than larger-bodied hominins (whether H. floresiensis is a dwarfed species or a descendent of an early small-bodied ancestor is immaterial here), which may in part explain their apparent long-term success. Yet the frequent tsunamis and volcanic eruptions in the region would certainly have affected all the taxa on the island, and at least one turnover event is recorded, when Stegodon sondaari became extinct. The question of the likelihood of persistence may be unanswerable until we know much more about the biology of H. floresiensis
Influences of Domestication and Island Evolution on Dental Growth in Sheep
Funder: Department of Zoology, University of CambridgeFunder: Leverhulme Trust; doi: http://dx.doi.org/10.13039/501100000275Abstract: Domestication and island evolution can lead to changes of life history along the slow-fast gradient. Shifts of life history patterns, in turn, are potentially related to alterations of patterns and timing of tooth eruption. Schultzâs rule predicts an earlier eruption of molars relative to premolars as fecundity increases during the domestication process. On the other hand, evolution on a predator-free, resource limited island might lead to a generally slow life history and delayed tooth eruption, as in the Plio-Pleistocene Balearic caprine Myotragus. In this study, we investigate tooth eruption and its relation to life history in a unique sheep population that is an example of both domestication and island evolution: the ancient and feral Soay sheep (Ovis aries) of the St. Kilda archipelago, Scotland. Tooth eruption timing and sequence is investigated in a comparative framework featuring new data on other domestic sheep (O. aries), including European mouflon (O. a. musimon), as well as wild sheep (O. vignei, O. cycloceros, O. arkal, O. orientalis, O. ammon). These data indicate that the order of eruption is similar in wild and domestic sheep, despite the fundamental life history changes that came about with domestication. However, in contrast to other domestic sheep breeds, Soay sheep erupt their teeth at an absolute older age and also tend to grow more slowly, which resembles the evolutionary trend in island-adapted Myotragus. Despite these similarities, Soay sheep do not share the slow life history pattern inferred for Myotragus, highlighting the distinctive nature of tooth eruption in Soay sheep
Kostnaden för förmaksflimmer i Ăstergötland
Förmaksflimmer (FF) Ă€r den vanligaste förekomna arytmin i Sverige. Att ha FF innebĂ€r en ökad risk för att drabbas av stroke och den huvudsakliga behandlingen gĂ„r dĂ€rför ut pĂ„ att motverka stroke genom antikoagulationsbehandling med warfarin. Det finns tidigare ingen berĂ€kning pĂ„ hur mycket FF kostar i Sverige och med anledning av att nya behandlingsmetoder och lĂ€kemedel kan förvĂ€ntas komma inom en snar framtid finns ett behov av att veta hur mycket resurser som FF förbrukar idag. Syftet med den hĂ€r rapporten var dĂ€rför att berĂ€kna kostnaden för FF i Ăstergötland. Detta gjordes genom att samtliga relevanta kostnadsposter identifierades och kvantifierades till lĂ€mpliga enheter. DĂ€refter berĂ€knades kostnaden i en modell, bĂ„de för dagens situation men ocksĂ„ genom en prognos för de nĂ€rmaste Ă„ren. Fokus har varit pĂ„ de komplikationer som FF ger ökad risk för, samt behandlingar för att minska denna risk. Behandlingen syftar oftast inte till att bota sjĂ€lva flimret utan till att motverka de risker för komplikationer som FF för med sig. Tre möjliga alternativ för patienter med FF inkluderades i berĂ€kningen; behandling med warfarin, behandling med ASA eller ingen behandling. Endast patienter med mĂ„ttlig eller hög risk för stroke inkluderades i berĂ€kningen. Endast omkring 50 procent av alla patienterna fĂ„r idag warfarin vilket betyder att underbehandling föreligger eftersom nĂ€stan alla patienter med FF Ă€r rekommenderade att behandlas med warfarin.Den totala kostnaden för FF i Ăstergötland har berĂ€knats till 137 miljoner kronor Ă„r 2006 och prognostiserats till 155 miljoner kronor Ă„r 2008 och 177 miljoner kronor Ă„r 2010, vilket Ă€r en ökning med nĂ€stan 30 procent pĂ„ fyra Ă„r. Om endast de direkta kostnaderna inkluderas Ă€r kostnaden 115 miljoner kronor Ă„r 2006. Kostnaden för stroke Ă€r den största enskilda kostnaden och stĂ„r för 84 procent av den totala kostnaden nĂ€r Ă€ven de indirekta kostnaderna inkluderas. Eftersom prevalensen av FF stiger hos personer över 60 Ă„r och Ă€r mycket hög hos personer över 80 Ă„r förvĂ€ntas antalet personer med FF öka i takt med att andelen Ă€ldre i samhĂ€llet ökar. Denna ökning förvĂ€ntas fortsĂ€tta under lĂ„ng tid vilket leder till kraftigt ökade kostnader för samhĂ€llet till följd av FF. Eftersom nya behandlingar för att bĂ„de bota flimret samt att motverka stroke Ă€r under utveckling Ă€r det dock möjligt att detta pĂ„ sikt kan hĂ„lla ner kostnaderna jĂ€mfört med berĂ€kningen i denna rapport.Atrial fibrillation (AF) is the most common arrhythmic disease in Sweden. Persons with AF have a significant increased risk of stroke and the main treatment is therefore intended to prevent stroke by anticoagulation with warfarin. There is no existing calculation of the cost of AF in Sweden today and since new treatments soon may become available there is a need to know the societal cost of AF. The aim of this report was therefore to calculate the cost of AF in the Ăstergötland County in Sweden. This was done by identifying all relevant costs and by quantifying and valuing them. The cost of AF was calculated by using a model, which was also used to forecast the cost of the coming years. The focus in the calculation has been on the side effects caused by AF and treatments intended to lower the risks for these events. The treatment of AF is often not aimed at curing the disease but rather to prevent the negative events connected to it. Three possible treatments for a person with AF have been included in the calculation; treatment with warfarin, treatment with ASA or no treatment. Only patients with moderate or high risk for stroke were included in the calculation. Only about 50 per cent of the patients receive treatment with warfarin although the recommendation is that most persons with AF should receive Warfarin, and this low use of warfarin may cause extra costs for the society. The total cost of AF in Ăstergötland has been calculated to SEK 137 million in year 2006 and the prognosis for 2008 is SEK 155 million and SEK 177 million in year 2010, which is an increase of almost 30 per cent within these four years. If only direct costs were included, the result for 2006 is SEK 115 millions. The cost for stroke is the main cost and counts for 84 per cent of the total cost for AF when also the indirect costs are included. Because the prevalence of AF is increasing for persons above 60 years and is very high among persons over 80 years, the expected number of persons with AF is increasing as the number of elderly persons in the society is increasing. This generates large and increasing costs for the society. Due to potential new treatments of either curing the disease or by lowering the risks for stroke, it is possible that the societal costs may be less in the long run compared to the calculation in this report
Validation of a Dutch language screening instrument for 5-year-old preterm infants.
Item does not contain fulltextAIM: The validation of the Dutch Taal Screenings Test (TST), a language-screening test, which is included in a follow-up instrument developed to enable paediatricians to assess 5-y-old preterm infants for their motor, cognitive and speech and language development. METHODS: The speech and language development of 145 5-y-old infants born before 32 wk of gestation and/or with a birth weight of less than 1500 g was assessed by a paediatrician using the TST and by a speech therapist using standardized language tests. RESULTS: All correlations between the instruments were significant. Using the original cut-off point of the TST for abnormal speech and language development (18 points), the paediatrician will only identify 62% of the children who need speech therapy. For this group of children, a cut-off point of 17 is more effective. The positive predictive value of the TST improved from 77% to 82% by using a parent and school questionnaire to evaluate in a more subjective way the speech and language development. CONCLUSION: Using the TST, paediatricians will be able to identify speech or language problems in 5-y-old preterm infants
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