268 research outputs found
The role of cryptotephra in refining the chronology of Late Pleistocene human evolution and cultural change in North Africa
© 2014.Sites in North Africa hold key information for dating the presence of Homo sapiens and the distribution of Middle Stone Age (MSA), Middle Palaeolithic (MP) and Later Stone Age (LSA) cultural activity in the Late Pleistocene. Here we present new and review recently published tephrochronological evidence for five cave sites in North Africa with long MSA/MP and LSA cultural sequences. Four tephra horizons have been identified at the Haua Fteah (Cyrenaica, Libya). They include cryptotephra evidence for the Campanian Ignimbrite (CI) eruption dating to ~39 ka that allows correlation with other Palaeolithic sequences in the eastern Mediterranean and as far north as Russia. Cryptotephra have also been recorded from the Moroccan sites of Taforalt, Rhafas and Dar es-Soltane 1. At Taforalt the geochemical composition suggests a provenance in the Azores, while examples from Sodmein (Egypt) appear to derive from central Anatolia and another unknown source. In these latter examples chemical compositional data from relevant proximal volcanic centres is currently lacking so the identification of tephra in layers of known age and cultural association provides the first reliable age determinations for distal volcanic events and their geographical extent. The future potential for tephrochronological research in North Africa is also discussed
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A 19 to 17 Ma amagmatic extension event at the Mid-Atlantic Ridge: Ultramafic mylonites from the Vema Lithospheric Section
A >300 km long lithospheric section (Vema Lithospheric Section or VLS) is exposed south of the Vema transform at 11°N in the Atlantic. It is oriented along a seafloor spreading flow line and represents ∼26 Ma of accretion at a single 80 km long segment (EMAR) of the Mid-Atlantic Ridge. The basal part of the VLS exposes a mantle unit made mostly of relatively undeformed coarse-grained/porphyroclastic peridotites that were sampled at close intervals. Strongly deformed mylonitic peridotites were found at 14 contiguous sites within a ∼80 km stretch (∼4.7 Ma interval); they are dominant in a time interval of 1.4 Ma, from crustal ages of 16.8 to 18.2 Ma (mylonitic stretch). Some of the mylonites are "dry," showing anhydrous high-T deformation, but most contain amphibole. The mylonitic peridotites tend to be less depleted than the porphyroclastic peridotites on the basis of mineral major and trace elements composition, suggesting that the mylonites parent was a subridge mantle that underwent a relatively low degree of melting. The Sr, Nd, and O isotopic composition of the amphiboles is MORB-like and suggests either that seawater did not contribute to their isotopic signature or that their isotopic ratios re-equilibrated during fluid circulation in the upper mantle. Four 40Ar/39Ar ages, on three amphiboles separated from the peridotites, are close to crustal ages predicted from magnetic anomalies, confirming that the amphiboles formed close to ridge axis. We propose that crustal accretion at the EMAR segment has been mostly symmetrical for the 26 Ma of its recorded history, except for the ∼1.4 Ma interval of prevalent ultramafic mylonites (mylonitic stretch) that may record a period of quasi-amagmatic asymmetric accretion of oceanic lithosphere close to the ridge–Vema transform intersection, possibly with development of detachment faults. This interval may correspond to a thermal minimum of the subridge upwelling mantle, marking the transition from a period of decreasing to one of increasing mantle melting below the EMAR segment
Una proposta di formazione dagli specializzandi per gli specializzandi: i "gruppi incognitivi"
PREMESSA: Dalla curiosit\ue0 e dai dubbi per questioni che quotidianamente incontriamo nella pratica clinica \ue8 nata l'idea di costruire un gruppo che, attraverso il confronto tra noi Specializzandi e la condivisione di approfondimenti su temi specifici, potesse dare delle risposte e stimolare nuovi interrogativi. Si \ue8 dato cos\uec vita a questo gruppo, chiamato, un po' socraticamente, gruppo incognitivo. Questi gli obiettivi originari: 1. soddisfare, in aggiunta all'offerta del regolare piano accademico, il nostro bisogno di "formazione continua", 2. Confrontarsi tra Specializzandi su questioni pragmatiche, 3. "imparare ad insegnare", attraverso la preparazione di una lezione e quindi la sua esposizione, 4. realizzare un compendio che potesse essere utilizzato "al letto del malato" e quindi fruito anche da chi non avesse la possibilit\ue0 di partecipare agli incontri
OBIETTIVO: Tutti gli specializzandi della scuola di Specialit\ue0 in Geriatria sono stati invitati, di volta in volta, a partecipare agli incontri e a preparare una lezione da presentare al gruppo su un argomento di loro scelta. La partecipazione agli incontri era su base volontaria. La possibilit\ue0 di partecipare agli incontri era stata estesa anche a strutturati e studenti di medicina. Per ogni incontro si chiedeva di presentare un file in formato Word, di poche pagine, che sintetizzasse in versione schematica quanto espresso nella lezione. Gli specializzandi hanno utilizzato libri di testo, articoli scientifici e contenuti di Uptodate. Il luogo degli incontri \ue8 stato la biblioteca della scuola di Specialit\ue0 di Geriatria ove avevamo a disposizione un supporto multimediale per la proiezione delle presentazioni. La durata degli incontri \ue8 stata variabile, a seconda della complessit\ue0 dell'argomento e della scelta di colui che esponeva, nella media circa 80 minuti.
RISULTATI: Da Ottobre 2014 a Maggio 2015 abbiamo svolto 13 incontri con contenuti trasversali. Di seguito l'elenco degli argomenti: malnutrizione nell'anziano, i criteri di Beers e i farmaci inappropriati nell'anziano, gli inibitori dell'acetilcolinesterasi (nota AIFA e scheda tecnica dei farmaci), algoritmo Advance Life Support, infezioni delle vie urinarie, terapia farmacologica dei disturbi del comportamento e psicologici nella demenza, reverse therapy della emorragie maggiori correlate agli anticoagulanti diretti ed indiretti, tachicardie sopraventricolari e ventricolari, dispnea acuta, polmonite, endocarditi, reazioni cutanee da farmaco (quest'ultimo presentato da una specializzanda in Dermatologia). Ogni incontro era monotematico e veniva presentato da uno o due specializzandi. Di solito l'argomento veniva esposto dalla stessa persona che l'aveva proposto. Tra i limiti di questo progetto l'"autoreferenzialit\ue0" in quanto le informazioni veicolate non sono state passate al vaglio di un specialista in materia, pertanto non sempre siamo riusciti a dare una risposta soddisfacente a tutti gli interrogativi emersi. Questo \ue8 stato comunque di stimolo per ulteriori approfondimenti.
CONCLUSIONI: Abbiamo realizzato una compendio che raccoglie i contenuti degli incontri esposti sopra. Come gi\ue0 accennato sopra, ci\uf2 che rende questi contenuti particolarmente fruibili \ue8 la loro pragmaticit\ue0 per la pratica clinica. Abbiamo in previsione di proseguire con un secondo ciclo di incontri da settembre 2015. Tra gli argomenti gi\ue0 in programma: iponatremia, questioni di bioetica, reazioni trasfusionali, principi base di neuroimaging. L'obiettivo con il prossimo anno \ue8 quello di coinvolgere specializzandi di altre Scuole. L'ultimo incontro tenuto da una Specializzanda di Dermatologia ha avuto un impatto molto positivo e desideriamo ripetere l'esperienza
Sleep disturbances, fatigue and psychological health in women with endometriosis: a matched pair case–control study
Research question: What are the associations between endometriosis, pelvic pain symptoms, fatigue and sleep? Psychological health and quality of life in endometriosis patients with good versus bad quality of sleep were also examined. Design: This matched pair case–control study included 123 consecutive endometriosis patients and 123 women without a history of endometriosis (matched to patients for age and body mass index). Endometriosis-related pelvic pain severity was rated on a 0–10 numerical rating scale. Fatigue was measured on a 1–5 Likert scale. Women also completed a set of self-report questionnaires for assessing sleep disturbances (Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Insomnia Severity Index), psychological health (Hospital Anxiety and Depression Scale) and quality of life (Short Form-12). Results: Painful endometriosis had an impact on fatigue (P = 0.006; η2p = 0.041) and sleep (P < 0.001; η2p = 0.051). Women with painful endometriosis reported significantly greater fatigue, poorer quality of sleep, higher daytime sleepiness and more severe insomnia than women without significant pain symptoms and controls. Poorer quality of sleep among endometriosis patients was associated with greater fatigue (P < 0.001; η2p = 0.130), poorer psychological health (P < 0.001; η2p = 0.135), and lower quality of life (P < 0.001; η2p = 0.240). Conclusions: Pelvic pain (rather than endometriosis in itself) is associated with fatigue and sleep disturbances, with poor sleep having a detrimental impact on women's psychological health and quality of life
The RESET project: constructing a European tephra lattice for refined synchronisation of environmental and archaeological events during the last c. 100 ka
This paper introduces the aims and scope of the RESET project (. RESponse of humans to abrupt Environmental Transitions), a programme of research funded by the Natural Environment Research Council (UK) between 2008 and 2013; it also provides the context and rationale for papers included in a special volume of Quaternary Science Reviews that report some of the project's findings. RESET examined the chronological and correlation methods employed to establish causal links between the timing of abrupt environmental transitions (AETs) on the one hand, and of human dispersal and development on the other, with a focus on the Middle and Upper Palaeolithic periods. The period of interest is the Last Glacial cycle and the early Holocene (c. 100-8 ka), during which time a number of pronounced AETs occurred. A long-running topic of debate is the degree to which human history in Europe and the Mediterranean region during the Palaeolithic was shaped by these AETs, but this has proved difficult to assess because of poor dating control. In an attempt to move the science forward, RESET examined the potential that tephra isochrons, and in particular non-visible ash layers (cryptotephras), might offer for synchronising palaeo-records with a greater degree of finesse. New tephrostratigraphical data generated by the project augment previously-established tephra frameworks for the region, and underpin a more evolved tephra 'lattice' that links palaeo-records between Greenland, the European mainland, sub-marine sequences in the Mediterranean and North Africa. The paper also outlines the significance of other contributions to this special volume: collectively, these illustrate how the lattice was constructed, how it links with cognate tephra research in Europe and elsewhere, and how the evidence of tephra isochrons is beginning to challenge long-held views about the impacts of environmental change on humans during the Palaeolithic. © 2015 Elsevier Ltd.RESET was funded through Consortium Grants awarded by the Natural Environment Research Council, UK, to a collaborating team drawn from four institutions: Royal Holloway University of London (grant reference NE/E015905/1), the Natural History Museum, London (NE/E015913/1), Oxford University (NE/E015670/1) and the University of Southampton, including the National Oceanography Centre (NE/01531X/1). The authors also wish to record their deep gratitude to four members of the scientific community who formed a consultative advisory panel during the lifetime of the RESET project: Professor Barbara Wohlfarth (Stockholm University), Professor Jørgen Peder Steffensen (Niels Bohr Institute, Copenhagen), Dr. Martin Street (Romisch-Germanisches Zentralmuseum, Neuwied) and Professor Clive Oppenheimer (Cambridge University). They provided excellent advice at key stages of the work, which we greatly valued. We also thank Jenny Kynaston (Geography Department, Royal Holloway) for construction of several of the figures in this paper, and Debbie Barrett (Elsevier) and Colin Murray Wallace (Editor-in-Chief, QSR) for their considerable assistance in the production of this special volume.Peer Reviewe
Randomized controlled trials in pediatric complementary and alternative medicine: Where can they be found?
BACKGROUND: The safety and effectiveness of CAM interventions are of great relevance to pediatric health care providers. The objective of this study is to identify sources of reported randomized controlled trials (RCTs) in the field of pediatric complementary and alternative medicine (CAM). METHODS: Reports of RCTs were identified by searching Medline and 12 additional bibliographic databases and by reviewing the reference lists of previously identified pediatric CAM systematic reviews. RESULTS: We identified 908 reports of RCTs that included children under 18 and investigated a CAM therapy. Since 1965, there has been a steady growth in the number of these trials that are being published. The four journals that published the most reported RCTs are The American Journal of Clinical Nutrition, Pediatrics, Journal of Pediatrics, and Lancet. Medline, CAB Health, and Embase were the best database sources for identifying these studies; they indexed 93.2%, 58.4% and 42.2 % respectively of the journals publishing reports of pediatric CAM RCTs. CONCLUSIONS: Those working or interested in the field of pediatric CAM should routinely search Medline, CAB Health and Embase for literature in the field. The four core journals identified above should be included in their collection
Asymptomatic bacteriuria in sickle cell disease: a cross-sectional study
BACKGROUND: It is known that there is significant morbidity associated with urinary tract infection and with renal dysfunction in sickle cell disease (SCD). However, it is not known if there are potential adverse outcomes associated with asymptomatic bacteriuria (ASB) infections in sickle cell disease if left untreated. This study was undertaken to determine the prevalence of ASB, in a cohort of patients with SCD. METHODS: This is a cross-sectional study of patients in the Jamaican Sickle Cell Cohort. Aseptically collected mid-stream urine (MSU) samples were obtained from 266 patients for urinalysis, culture and sensitivity analysis. Proteinuria was measured by urine dipsticks. Individuals with abnormal urine culture results had repeat urine culture. Serum creatinine was measured and steady state haematology and uric acid concentrations were obtained from clinical records. This was completed at a primary care health clinic dedicated to sickle cell diseases in Kingston, Jamaica. There were 133 males and 133 females in the sample studied. The mean age (mean ± sd) of participants was 26.6 ± 2.5 years. The main outcome measures were the culture of ≥ 10(5 )colony forming units of a urinary tract pathogen per milliliter of urine from a MSU specimen on a single occasion (probable ASB) or on consecutive occasions (confirmed ASB). RESULTS: Of the 266 urines collected, 234 were sterile and 29 had significant bacteriuria yielding a prevalence of probable ASB of 10.9% (29/266). Fourteen patients had confirmed ASB (prevalence 5.3%) of which 13 had pyuria. Controlling for genotype, females were 14.7 times more likely to have confirmed ASB compared to males (95%CI 1.8 to 121.0). The number of recorded visits for symptomatic UTI was increased by a factor of 2.5 (95% CI 1.4 to 4.5, p < 0.005) but serum creatinine, uric acid and haematology values were not different in patients with confirmed ASB compared with those with sterile urine. There was no association with history of gram negative sepsis. CONCLUSION: ASB is a significant problem in individuals with SCD and may be the source of pathogens in UTI. However, further research is needed to determine the clinical significance of ASB in SCD
Optical integration of SPO mirror modules in the ATHENA telescope
ATHENA (Advanced Telescope for High-ENergy Astrophysics) is the next high-energy astrophysical mission selected by the European Space Agency for launch in 2028. The X-ray telescope consists of 1062 silicon pore optics mirror modules with a target angular resolution of 5 arcsec. Each module must be integrated on a 3 m structure with an accuracy of 1.5 arcsec for alignment and assembly. This industrial and scientific team is developing the alignment and integration process of the SPO mirror modules based on ultra-violet imaging at the 12 m focal plane. This technique promises to meet the accuracy requirement while, at the same time, allowing arbitrary integration sequence and mirror module exchangeability. Moreover, it enables monitoring the telescope point spread function during the planned 3-year integration phase
Disrupted endothelial cell heterogeneity and network organization impair vascular function in prediabetic obesity
Background: Obesity is a major risk factor for diabetes and cardiovascular diseases such as hypertension, heart failure, and stroke. Impaired endothelial function occurs in the earliest stages of obesity and underlies vascular alterations that give rise to cardiovascular disease. However, the mechanisms that link weight gain to endothelial dysfunction are ill-defined. Increasing evidence suggests that endothelial cells are not a population of uniform cells but are highly heterogeneous and are organized as a communicating multicellular network that controls vascular function. Purpose: To investigate the hypothesis that disrupted endothelial heterogeneity and network-level organization contribute to impaired vascular reactivity in obesity. Methods and Results: To study obesity-related vascular function without complications associated with diabetes, a state of prediabetic obesity was induced in rats. Small artery diameter recordings confirmed nitric-oxide mediated vasodilator responses were dependent on increases in endothelial calcium levels and were impaired in obese animals. Single-photon imaging revealed a linear relationship between blood vessel relaxation and population-wide calcium responses. Obesity did not alter the slope of this relationship, but impaired calcium responses in the endothelial cell network. The network comprised structural and functional components. The structural architecture, a hexagonal lattice network of connected cells, was unchanged in obesity. The functional network contained sub-populations of clustered specialized agonist-sensing cells from which signals were communicated through the network. In obesity there were fewer but larger clusters of sensory cells and communication path lengths between clusters increased. Communication between neighboring cells was unaltered in obesity. Altered network organization resulted in impaired, population-level calcium signaling and deficient endothelial control of vascular tone. Conclusions: The distribution of cells in the endothelial network is critical in determining overall vascular response. Altered cell heterogeneity and arrangement in obesity decreases endothelial function and provides a novel framework for understanding compromised endothelial function in cardiovascular disease
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