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In this study, we investigate quartz-based luminescence optical dating of Iron Age deposits at the archaeological site of Tell Damiyah in the Jordan valley. Ten samples, taken from different occupation layers from two different excavation areas, proved to have good luminescence characteristics (fast-component dominated, dose recovery ratio 1.032 ± 0.010, n=24). The optical ages are completely consistent with both available 14C ages and ages based on stylistic elements; it appears that this material was fully reset at deposition, although it is recognised that the agreement with age control is somewhat dependent on the assumed field water content of the samples. Further comparison with different OSL signals from feldspar, or investigations based on dose distributions from individual grains would be desirable to independently confirm the resetting of this material. It is concluded that the sediments of Tell Damiyah are very suitable for luminescence dating. Despite the relatively large associated age uncertainties of between 5 and 10%, OSL at tell sites has the potential to provide ages for material very difficult to date by conventional methods, and to identify reworked mixtures of older artifacts in a younger depositional setting.
Background: Endovascular thrombectomy (EVT) has shown efficacy in acute ischemic stroke (AIS) patients with infective endocarditis (IE). The possibility to undertake advanced histopathological clot analysis following EVT offers a new avenue to establish the etiological basis of the stroke – which is often labelled “cryptogenic.” In this paper, we present our findings from four consecutive patients with IE who underwent EVT following an AIS at our tertiary referral comprehensive stroke centre. Methods: Comprehensive histopathological analysis of clot retrieved after EVT, including morphology, was undertaken. Results: The consistent observation was the presence of dense paucicellular fibrinoid material mixed/interspersed with clusters of bacterial cocci. This clot morphology may be specific to septic embolus due to IE unlike incidental bacteraemia and could possibly explain the refractoriness of such clots to systemic thrombolysis. Conclusion: Detailed morphological and histopathological analysis of EVT-retrieved clots including Gram staining can assist in etiological classification of the clot. Understanding the composition of the clot may be of clinical value in early diagnostics and mapping treatment planning in IE.
Objectives: We assessed trends in the incidence, prevalence, and post-diagnosis mortality of parkinsonism in Ontario, Canada over 18 years. We also explored the influence of a range of risk factors for brain health on the trend of incident parkinsonism. Methods: We established an open cohort by linking population-based health administrative databases from 1996 to 2014 in Ontario. The study population comprised residents aged 20–100 years with an incident diagnosis of parkinsonism ascertained using a validated algorithm. We calculated age- and sex-standardized incidence, prevalence, and mortality of parkinsonism, stratified by young onset (20–39 years) and mid/late onset (≥40 years). We assessed trends in incidence using Poisson regression, mortality using negative binomial regression, and prevalence of parkinsonism and pre-existing conditions (e.g., head injury) using the Cochran–Armitage trend test. To better understand trends in the incidence of mid/late-onset parkinsonism, we adjusted for various pre-existing conditions in the Poisson regression model. Results: From 1996 to 2014, we identified 73,129 incident cases of parkinsonism (source population of ∼10.5 million), of whom 56% were male, mean age at diagnosis was 72.6 years, and 99% had mid/late-onset parkinsonism. Over 18 years, the age- and sex-standardized incidence decreased by 13.0% for mid/late-onset parkinsonism but remained unchanged for young-onset parkinsonism. The age- and sex-standardized prevalence increased by 22.8%, while post-diagnosis mortality decreased by 5.5%. Adjustment for pre-existing conditions did not appreciably explain the declining incidence of mid/late-onset parkinsonism. Conclusion: Young-onset and mid/late-onset parkinsonism exhibited differing trends in incidence over 18 years in Ontario. Further research to identify other factors that may appreciably explain trends in incident parkinsonism is warranted.
There is increasing evidence for shared genetic susceptibility between schizophrenia and bipolar disorder. Although genetic variants only convey subtle increases in risk individually, their combination into a polygenic risk score constitutes a strong disease predictor.
To investigate whether schizophrenia and bipolar disorder polygenic risk scores can distinguish people with broadly defined psychosis and their unaffected relatives from controls.
Using the latest Psychiatric Genomics Consortium data, we calculated schizophrenia and bipolar disorder polygenic risk scores for 1168 people with psychosis, 552 unaffected relatives and 1472 controls.
Patients with broadly defined psychosis had dramatic increases in schizophrenia and bipolar polygenic risk scores, as did their relatives, albeit to a lesser degree. However, the accuracy of predictive models was modest.
Although polygenic risk scores are not ready for clinical use, it is hoped that as they are refined they could help towards risk reduction advice and early interventions for psychosis.
Declaration of interest
R.M.M. has received honoraria for lectures from Janssen, Lundbeck, Lilly, Otsuka and Sunovian.
There is no consensus as to whether magnetic resonance imaging (MRI) should be used as part of the initial clinical evaluation of patients with first-episode psychosis (FEP).
(a) To assess the logistical feasibility of routine MRI; (b) to define the clinical significance of radiological abnormalities in patients with FEP.
Radiological reports from MRI scans of two FEP samples were reviewed; one comprised 108 patients and 98 healthy controls recruited to a research study and the other comprised 241 patients scanned at initial clinical presentation plus 66 healthy controls.
In the great majority of patients, MRI was logistically feasible. Radiological abnormalities were reported in 6% of the research sample and in 15% of the clinical sample (odds ratio (OR) = 3.1, 95% CI 1.26–7.57, χ2(1) = 6.63, P = 0.01). None of the findings necessitated a change in clinical management.
Rates of neuroradiological abnormalities in FEP are likely to be underestimated in research samples that often exclude patients with organic abnormalities. However, the majority of findings do not require intervention.
We show that geophysical methods offer an effective means of quantifying snow thickness and density. Opportunistic (efficient but non-optimized) seismic refraction and ground-penetrating radar (GPR) surveys were performed on Storglaciären, Sweden, co-located with a snow pit that shows the snowpack to be 1.73 m thick, with density increasing from ∼120 to ∼500 kg m–3 (with a +50 kg m–3 anomaly between 0.73 and 0.83 m depth). Depths estimated for two detectable GPR reflectors, 0.76 ±0.02 and 1.71 ± 0.03 m, correlate extremely well with ground-truth observations. Refraction seismic predicts an interface at 1.90 ± 0.31 m depth, with a refraction velocity (3730 ± 190 ms–1) indicative of underlying glacier ice. For density estimates, several standard velocity-density relationships are trialled. In the best case, GPR delivers an excellent density estimate for the upper snow layer (observed = 321 ± 74 kg m–3, estimated = 319 ± 10 kgm–3) but overestimates the density of the lower layer by 20%. Refraction seismic delivers a bulk density of 404 ±22 kgm–3 compared with a ground-truth average of 356 ± 22 kg m–3. We suggest that geophysical surveys are an effective complement to mass-balance measurements (particularly for controlling estimates of snow thickness between pits) but should always be validated against ground-truth observations.
Background: The role of aggressive surgical manipulation with clot evacuation, arachnoid dissection, and papaverine-guided adventitial dissection of large vessels during ruptured aneurysm surgery in reducing vasospasm is controversial. Here we describe a single-institution experience in aneurysm surgery outcomes with and without aggressive surgery. Methods: We performed retrospective analysis of all patients >18 years of age with subarachnoid hemorrhage (SAH) from anterior circulation aneurysms between 2008 and 2013 at the University of New Mexico Hospital. Vasospasm was characterized on days 3 through 14 after SAH based on: (1) angiography, (2) vasospasm requiring angiographic intervention, (3) development of delayed ischemic neurologic deficit (DIND), and (4) radiological appearance of new strokes. Results: Of 159 patients, 114 (71.6%) had “aggressive” and 45 (28.3%) had standard microsurgery. More than 60% of patients presented with a Hunt and Hess score of ≥3 and a Fisher grade (FG) of 4. Compared with standard surgery, there was a statistically significant decrease in the incidence of DIND in patients undergoing aggressive surgery (18.4% vs 37.8%, p=0.01). Moreover, there was a reduction in the number of new strokes by 30% in the aggressive surgery group with moderate or higher degrees of vasospasm (46.0% vs 76.5%, p=0.06). In the same group with FG 4 SAH, however, this difference was more than 50% (30% vs 64.7%, p=0.02). Conclusions: We conclude that aggressive surgical manipulation during aneurysm surgery results in lower incidence of DIND and new strokes. This effect is most pronounced in patients with FG 4 SAH.
The use of proper motions and parallaxes for large numbers of stars, obtainable from a combination of Schmidt telescopes and automatic plate scanners, is discussed. The importance of deriving the zero points of both absolute proper motion, and of parallactic motion, is emphasised. Calibrations of proper motion and of parallaxes should be based on dispersions of proper motion. These methods are illustrated by results from a study in the South Galactic Cap.
We present a study based on four inland eolian locations in Eastern, Central and Southeastern Lithuania belonging to the northeastern part of the ‘European Sand Belt’ (ESB). Although there have been several previous studies of the ESB, this north-eastern extension has not been investigated before in any detail. The sedimentary structural–textural features are investigated and a chronology was derived using optically stimulated luminescence on both quartz and feldspar. The sedimentary structures and the rounding and surface characteristics of the quartz grains argue for a predominance of eolian transport. Additionally, some structural alternations and a significant contribution of non-eolian grains are interpreted as inherited local glacial/glaciofluvial-bearing lithologies.
Three main (glaciolacustrine–) eolian phases are distinguished based on the position in the landscape and the luminescence ages: (1) An older eolian series around 15 to 16 ka, possibly correlated with the cold GS-2a event according to the GRIP stratigraphy, and (2) a younger eolian series around 14.0 ka, possibly representing the GI-1d and 1c events. The older eolian series is underlain by (3) a glaciolacustrine–eolian series for which the period of deposition remains uncertain due to the significant discrepancy between the ages based on quartz and feldspar.
The position taken by Mr Darwin is, that all species have arisen by the natural process of ordinary generation. That the differences which we now see in them have arisen from slight variations in individuals having from time to time occurred, which have been perpetuated by inheritance, by successive stages and slow degrees, through unlimited spaces of time. Some of these slight variations he considers to originate in causes beyond our power of explanation, and which, although not the work of chance, we may call chance, for want of a better appellation—others to arise from habit, or from the excessive use or disuse of certain organs; but that when such a variation has once appeared, it is preserved by hereditary descent through a principle which he calls “natural selection,” and which he deduces as a corollary from the struggle for existence which we see constantly going on around us.
Mr Murray commences with a resumé of what is known regarding the growth of eyes in insects, from the first stage in the larva, when many are without eyes, till their exclusion from the chrysalis, when they usually appear well provided with compound eyes. He reviews the nervous system in different species, and gives some details as to those species which live in dark places, and which have small eyes and a less-developed optic nerve, contrary to what one would at first suppose. The next portion of his paper is devoted to explaining his views of the structure of the eye in insects, and its relation to the eye in vertebrate animals.
In a paper which I read last year before this Society, “On the Structure and Functions of the Branchial Sac of the Simple Ascidise,” I stated that I had fed and injected ascidiæ with indigo and other coloured sea-water, and that in those so fed, the coloured material was never found on the exterior of the sac, but always deposited on the inner wall, and that injection by the mouth into the sac failed to push the coloured matter through its walls, except by rupturing them.
These experiments were not isolated or few in number. I showed the results to various friends—among others, Professor Goodsir, Dr Wright, and Dr Cleland—and never, in any of the experiments which I made, did a single instance occur of the indigo passing through the stigmata of the sac; and, in that paper, I naturally reasoned from this fact.
The object of this paper was to determine whether the pediculi infesting the different races of man were of the same or of distinct species, and thereby to ascertain whether any inference could be drawn therefrom, bearing upon the disputed question of the unity of the human species.
The chief portion of this paper is occupied with an inquiry into the truth of Milne Edwards' theory, that the branchial sac of the Ascidians is perforated throughout by apertures, or what he called branchial stigmata.
Some experiments and observations made by Mr Murray last season had induced him to regard this view with doubt. In considering the question, he first examined the evidence that was recorded in support of it. Putting aside those writers who had taken M. Edwards' theory on trust, he could only find four observers who seem to have critically tested it, viz.,—Dr Lister, with whom the idea originated: who, while stating that the walls of the sac appeared to be traversed by open spaces, yet states that at times he thought he saw something like a veil stretching across them, and that the particles in suspension in the water were observed to course past these spaces without entering; which would appear to be inconsistent with the idea of the water entering, for the course of the water, and of the particles floating in it, must necessarily be the same.