539 research outputs found

    HISTOLOGÍA DE HUESOS HUMANOS SECOS (UNA REVISIÓN)

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    Despite archaeological preservation conditions, the histomorphology of human dry bone still contains useful information on the physiological and pathological status of deceased individuals. Histology can therefore be a helpful addition to routine archaeological methods. But practice has shown  that, for many archaeologists, unfamiliarity with this technique shaped a pointless obstacle to add it to their tool box. Thus, after having addressed the restrictions associated with histological analysis in general, we will show  that the preparation  of sections/slides  does not need to be diff icult, expensive or time-consuming.  Then  we  will  provide  an introduction  to the histological  application  of assessing age at death of the deceased.  It’s must be its theoretical basis, its value in comparison  to other  methods  and  its limits  are  discussed. Finally, we will elaborate on the effectiveness of histology as an indicator of pathological processes, and explain that only a small number of disorders have distinct ‘pathognonomic’ microscopic features. In  all other cases, the histological findings must be combined with gross anatomical and radiological findings from the same individual to come to a conclusive diagnosis  or to a shortened  list  of differential  (alternative)  diagnoses.Independientemente de las condiciones de conservaciĂłn arqueolĂłgica, la histomorfologĂ­a de hueso seco humano conserva informaciĂłn Ăștil sobre el estado f isiolĂłgico y patolĂłgico de las personas fallecidas. Por lo tanto la utilizaciĂłn del anĂĄlisis histolĂłgico puede ser una adiciĂłn Ăștil a los mĂ©todos arqueolĂłgicos de rutina. No obstante, en la prĂĄctica se ha demostrado, que para muchos arqueĂłlogos la falta de familiaridad con esta tĂ©cnica constituye un obstĂĄculo para su utilizaciĂłn. Por lo tanto, despuĂ©s de haber abordado  las restricciones  asociadas  al anĂĄlisis histolĂłgico  en general, vamos a demostrar que la preparaciĂłn de secciones / diapositivas no tiene por quĂ© ser difĂ­cil, costoso o requerir mucho tiempo para su utilizaciĂłn. En este trabajo se expone una intro- ducciĂłn a la aplicaciĂłn de la evaluaciĂłn histolĂłgica para poder determinar la edad de la persona fallecida. Se discute su base teĂłrica, su valor en comparaciĂłn  con otros mĂ©todos y sus lĂ­mites. Por Ășltimo, vamos a tratar la ef icacia de la histologĂ­a como indicador de procesos patolĂłgicos y  mostrar  que  sĂłlo  un  pequeño  nĂșmero  de  trastornos  tienen  caracterĂ­sticas  microscĂłpicas ‘patognonomicas’  diferenciadas.  En todos  los demĂĄs  casos  los datos  histolĂłgicos  deben  ser combinados  con los resultados anatĂłmicos macroscĂłpicos  y radiolĂłgicos  del mismo individuo para obtener  un diagnĂłstico concluyente o una lista abreviada de diferentes (alternativos) diagnĂłsticos

    First LOFAR observations at very low frequencies of cluster-scale non-thermal emission: the case of Abell 2256

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    Abell 2256 is one of the best known examples of a galaxy cluster hosting large-scale diffuse radio emission that is unrelated to individual galaxies. It contains both a giant radio halo and a relic, as well as a number of head-tail sources and smaller diffuse steep-spectrum radio sources. The origin of radio halos and relics is still being debated, but over the last years it has become clear that the presence of these radio sources is closely related to galaxy cluster merger events. Here we present the results from the first LOFAR Low band antenna (LBA) observations of Abell 2256 between 18 and 67 MHz. To our knowledge, the image presented in this paper at 63 MHz is the deepest ever obtained at frequencies below 100 MHz in general. Both the radio halo and the giant relic are detected in the image at 63 MHz, and the diffuse radio emission remains visible at frequencies as low as 20 MHz. The observations confirm the presence of a previously claimed ultra-steep spectrum source to the west of the cluster center with a spectral index of -2.3 \pm 0.4 between 63 and 153 MHz. The steep spectrum suggests that this source is an old part of a head-tail radio source in the cluster. For the radio relic we find an integrated spectral index of -0.81 \pm 0.03, after removing the flux contribution from the other sources. This is relatively flat which could indicate that the efficiency of particle acceleration at the shock substantially changed in the last \sim 0.1 Gyr due to an increase of the shock Mach number. In an alternative scenario, particles are re-accelerated by some mechanism in the downstream region of the shock, resulting in the relatively flat integrated radio spectrum. In the radio halo region we find indications of low-frequency spectral steepening which may suggest that relativistic particles are accelerated in a rather inhomogeneous turbulent region.Comment: 13 pages, 13 figures, accepted for publication in A\&A on April 12, 201

    Diffuse idiopathic skeletal hyperostosis in ancient clergymen

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    Diffuse idiopathic skeletal hyperostosis (DISH) is a common but often unrecognized systemic disorder observed mainly in the elderly. DISH is diagnosed when the anterior longitudinal ligament of the spine is ossified on at least four contiguous spinal levels or when multiple peripheral enthesopathies are present. The etiology of DISH is unknown but previous studies have shown a strong association with obesity and insulin-independent diabetes mellitus. DISH can lead to back pain, dysphagia, myelopathy, musculoskeletal impairment and grossly unstable spine fractures after minor trauma. In archeological studies a high prevalence of DISH has been demonstrated in ancient clergymen. The present study describes the pathological changes of human remains excavated from the abbey court (Pandhof) in the city of Maastricht, The Netherlands. Human remains of 51 individuals buried between 275 and 1795 ce were excavated and examined. The remains were investigated according to a standardized physical anthropological report and individuals demonstrating ossification of spinal ligaments and/or multiple peripheral enthesopathies were included in the study group. The authors reviewed all available material and after reaching consensus, each abnormality found was given a diagnosis and subsequently recorded. After examination, 28 individuals were considered to be adult males; 11 adult females; three adults of indeterminate sex and nine individuals were of sub adult age. The mean age at death for adults was 36.8 years. Seventeen adult individuals (40.4% of all adults), displayed ossifications of at least four contiguous spinal levels and/or multiple enthesopathies of the appendicular skeleton and were therefore, assigned the diagnosis DISH. The mean age of these individuals was 49.5 ± 13.0 years. In at least three of these individuals, DISH had led to extensive ossification and subsequent ankylosis of axial and peripheral skeletal structures. In this population of (presumably) clergymen and high-ranking citizens, DISH was observed in unusual high numbers at a relatively young age. Some of the examined cases suggest that DISH may be a seriously incapacitating disorder when the more advanced stages of the disease have been reached. It is hypothesized that “a monastic way of life” can predispose to DISH. Present demographic trends in obesity and diabetes mellitus as potential co-factors for the development of DISH warrant further study to investigate its future prevalence

    Imaging Jupiter's radiation belts down to 127 MHz with LOFAR

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    Context. Observing Jupiter's synchrotron emission from the Earth remains today the sole method to scrutinize the distribution and dynamical behavior of the ultra energetic electrons magnetically trapped around the planet (because in-situ particle data are limited in the inner magnetosphere). Aims. We perform the first resolved and low-frequency imaging of the synchrotron emission with LOFAR at 127 MHz. The radiation comes from low energy electrons (~1-30 MeV) which map a broad region of Jupiter's inner magnetosphere. Methods (see article for complete abstract) Results. The first resolved images of Jupiter's radiation belts at 127-172 MHz are obtained along with total integrated flux densities. They are compared with previous observations at higher frequencies and show a larger extent of the synchrotron emission source (>=4 RJR_J). The asymmetry and the dynamic of east-west emission peaks are measured and the presence of a hot spot at lambda_III=230 {\deg} ±\pm 25 {\deg}. Spectral flux density measurements are on the low side of previous (unresolved) ones, suggesting a low-frequency turnover and/or time variations of the emission spectrum. Conclusions. LOFAR is a powerful and flexible planetary imager. The observations at 127 MHz depict an extended emission up to ~4-5 planetary radii. The similarities with high frequency results reinforce the conclusion that: i) the magnetic field morphology primarily shapes the brightness distribution of the emission and ii) the radiating electrons are likely radially and latitudinally distributed inside about 2 RJR_J. Nonetheless, the larger extent of the brightness combined with the overall lower flux density, yields new information on Jupiter's electron distribution, that may shed light on the origin and mode of transport of these particles.Comment: 10 pages, 12 figures, accepted for publication in A&A (27/11/2015) - abstract edited because of limited character

    New Roads Open Up for Implementing Immunotherapy in Mesothelioma

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    Treatment options for malignant mesothelioma are limited, and the results with conventional therapies have been rather disappointing to this date. Chemotherapy is the only evidence-based treatment for mesothelioma patients in good clinical condition, with an increase in median survival of only 2 months. Therefore, there is urgent need for a different approach to battle this malignancy. As chronic inflammation precedes mesothelioma, the immune system plays a key role in the initiation of this type of tumour. Also, many immunological cell types can be found within the tumour at different stages of the disease. However, mesothelioma cells can evade the surveillance capacity of the immune system. They build a protective tumour microenvironment to harness themselves against the immune system's attacks, in which they even abuse immune cells to act against the antitumour immune response. In our opinion, modulating the immune system simultaneously with the targeting of mesothelioma tumour cells might prove to be a superior treatment. However, this strategy is challenging since the tumour microenvironment possesses numerous forms of defence strategies. In this paper, we will discuss the interplay between immunological cells that can either inhibit or stimulate tumour growth and the challenges associated with immunotherapy. We will provide possible strategies and discuss opportunities to overcome these problems

    A horizontally polarizing liquid trap enhances the tabanid-capturing efficiency of the classic canopy trap.

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    Host-seeking female tabanid flies, that need mammalian blood for the development of their eggs, can be captured by the classic canopy trap with an elevated shiny black sphere as a luring visual target. The design of more efficient tabanid traps is important for stock-breeders to control tabanids, since these blood-sucking insects can cause severe problems for livestock, especially for horse- and cattle-keepers: reduced meat/milk production in cattle farms, horses cannot be ridden, decreased quality of hides due to biting scars. We show here that male and female tabanids can be caught by a novel, weather-proof liquid-filled black tray laid on the ground, because the strongly and horizontally polarized light reflected from the black liquid surface attracts water-seeking polarotactic tabanids. We performed field experiments to reveal the ideal elevation of the liquid trap and to compare the tabanid-capturing efficiency of three different traps: (1) the classic canopy trap, (2) the new polarization liquid trap, and (3) the combination of the two traps. In field tests, we showed that the combined trap captures 2.4-8.2 times more tabanids than the canopy trap alone. The reason for the larger efficiency of the combined trap is that it captures simultaneously the host-seeking female and the water-seeking male and female tabanids. We suggest supplementing the traditional canopy trap with the new liquid trap in order to enhance the tabanid-capturing efficiency

    Optimized Trigger for Ultra-High-Energy Cosmic-Ray and Neutrino Observations with the Low Frequency Radio Array

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    When an ultra-high energy neutrino or cosmic ray strikes the Lunar surface a radio-frequency pulse is emitted. We plan to use the LOFAR radio telescope to detect these pulses. In this work we propose an efficient trigger implementation for LOFAR optimized for the observation of short radio pulses.Comment: Submitted to Nuclear Instruments and Methods in Physics Research Section

    A qualitative study of Telehealth patient information leaflets (TILs) : are we giving patients enough information?

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    BACKGROUND: The provision of patient information leaflets regarding telehealth has been perceived by potential consumers as a strategy to promote awareness and adoption of telehealth services. However, such leaflets need to be designed carefully if adoption and awareness among potential users is to be promoted. Therefore, the aims of this study were: first, to see how telehealth was portrayed in some of the existing telehealth leaflets (THLs). Second, to explore patients' perceptions of the existing THLs and their engagement with the concept and how THLs can be optimised. METHODS: A two-step approach was employed to address the aims of this study. The first phase involved the use of discourse analysis to compare 12 electronically and publically available THLs, with the existing THL guidance "Involve Yorkshire and Humber". The second phase involved conducting 14 semi-structured interviews with potential telehealth users/patients to gauge their perception and engagement with the concept, using the two leaflets that were mostly matching with the guidance used. Six interviews were audio-recorded and eight had detailed jotted notes. The interviews were transcribed and thematically analysed to identify key themes. RESULTS: The discourse analysis showed certain gaps and variations within the screened leaflets when addressing the following aspects: cost of the telehealth service, confidentiality, patients' choices in addition to equipment use and technical support. Analysis of the interviews revealed patients' need for having clear and sufficient information about the telehealth service within the THLs; in addition to, patients' preference for the use of simpler terminologies for telehealth description and the provision of clear simple texts with pictorial presentations. The interviews also revealed certain limitations against adoption of telehealth by the participants, such as: lack of privacy and confidentiality of information, fear of technology breakdown and equipment failure, loss of face-to-face contact with healthcare professionals and being too dependent on the telehealth service. CONCLUSION: The current study showed a great variation among the screened THLs and highlighted certain gaps within the content and presentation of these leaflets. However, the study also highlighted certain key issues to be considered when designing THLs in the future to enhance telehealth uptake and use by patients

    LOFAR detections of low-frequency radio recombination lines towards Cassiopeia A

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    Cassiopeia A was observed using the low-band antennas of the LOw Frequency ARray (LOFAR) with high spectral resolution. This allowed a search for radio recombination lines (RRLs) along the line-of-sight to this source. Five carbon {αα} RRLs were detected in absorption between 40 and 50 MHz with a signal-to-noise ratio of {gt}5 from two independent LOFAR data sets. The derived line velocities (vLSR_{LSR} ~{} - 50 km s−1^{-1}) and integrated optical depths (~{}13 s−1^{-1}) of the RRLs in our spectra, extracted over the whole supernova remnant, are consistent within each LOFAR data set and with those previously reported. For the first time, we are able to extract spectra against the brightest hotspot of the remnant at frequencies below 330 MHz. These spectra show significantly higher (15-80 percent) integrated optical depths, indicating that there is small-scale angular structure of the order of ~{}1 pc in the absorbing gas distribution over the face of the remnant. We also place an upper limit of 3 { imes} 10−4^{-4} on the peak optical depths of hydrogen and helium RRLs. These results demonstrate that LOFAR has the desired spectral stability and sensitivity to study faint recombination lines in the decameter band

    The rationale and design of the perindopril genetic association study (PERGENE): A pharmacogenetic analysis of angiotensin-converting enzyme inhibitor therapy in patients with stable coronary artery disease

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    Background: Angiotensin-converting enzyme (ACE) inhibitors reduce clinical symptoms and improve outcome in patients with hypertension, heart failure, and stable coronary artery disease (CAD) and are among the most frequently used drugs in these patient groups. For hypertension, treatment is guided by the level of blood pressure. In the secondary prevention setting, there are no means of guiding therapy. Prior attempts to target ACE-inhibitors to those patients that are most likely to benefit have not been successful, mainly due to the consistency in the treatment effect in clinical subgroups. Still, for prolonged prophylactic treatment with ACE-inhibitors it would be best to target treatment to only those patients most likely to benefit, which would considerably lower the number needed to treat and increase cost-effectiveness. A new approach for such "tailored-therapy" may be to integrate information on the genetic variation between patients. Until now, pharmacogenetic research of the efficacy of ACE-inhibitor therapy in CAD patients is still in a preliminary stage. Methods: The PERindopril GENEtic association study (PERGENE) is a substudy of the EUROPA trial, a randomized double-blind placebo-controlled multicentre clinical trial which demonstrated a beneficial effect of the ACE-inhibitor perindopril in reducing cardiovascular morbidity and mortality in 12.218 patients with stable coronary artery disease (mean follow-up 4.2 years). Blood tubes were received from patients at the beginning of the EUROPA trial and buffy coats were stored at -40°C at the central core laboratory. Candidate genes were selected in the renin-angiotensin-system and bradykinin pathways. Polymorphisms were selected based on haplotype tagging principles using the HapMap genome project, Seattle and other up-to-date genetic database platforms to comprehensively cover all common genetic variation within the genes. Selection also took into consideration the functionality of SNP's, location within the gene (promoter) and existing relevant literature. The main outcome measure of PERGENE is the effect of genetic factors on the treatment benefit with ACE-inhibitors. The size of this pharmacogenetic substudy allows detection with a statistical power of 98% to detect a difference in hazard ratios (treatment effect) of 20% between genotypes with minor allele frequency of 0.20 (two-sided alpha 0.05). Conclusion: The PERGENE study is a large cardiovascular pharmacogenetic study aimed to assess the feasibility of pharmacogenetic profiling of the treatment effect of ACE-inhibitor use with the perspective to individualize treatment in patients with stable coronary artery disease
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