Two Approaches to Dislocation Nucleation in the Supported Heteroepitaxial Equilibrium Islanding Phenomenon

We study the dislocation formation in 2D nanoscopic islands with two methods, the Molecular Static method and the Phase Field Crystal method. It is found that both methods indicate the same qualitative stages of the nucleation process. The dislocations nucleate at the film-substrate contact point and the energy decreases monotonously when the dislocations are farther away from the island-wetting film contact points than the distance of the highest energy barrier.Comment: 4 page

Voodoo - a vector algebra for portable database performance on modern hardware

In-memory databases require careful tuning and many engineering tricks to achieve good performance. Such database performance engineering is hard: a plethora of data and hardware-dependent optimization techniques form a design space that is difficult to navigate for a skilled engineer --- even more so for a query compiler. To facilitate performance-oriented design exploration and query plan compilation, we present Voodoo, a declarative intermediate algebra that abstracts the detailed architectural properties of the hardware, such as multi- or many-core architectures, caches and SIMD registers, without losing the ability to generate highly tuned code. Because it consists of a collection of declarative, vector-oriented operations, Voodoo is easier to reason about and tune than low-level C and related hardware-focused extensions (Intrinsics, OpenCL, CUDA, etc.). This enables our Voodoo compiler to produce (OpenCL) code that rivals and even outperforms the fastest state-of-the-art in memory databases for both GPUs and CPUs. In addition, Voodoo makes it possible to express techniques as diverse as cache-conscious processing, predication and vectorization (again on both GPUs and CPUs) with just a few lines of code. Central to our approach is a novel idea we termed control vectors, which allows a code generating frontend to expose parallelism to the Voodoo compiler in a abstract manner, enabling portable performance across hardware platforms. We used Voodoo to build an alternative backend for MonetDB, a popular open-source in-memory database. Our backend allows MonetDB to perform at the same level as highly tuned in-memory databases, including HyPeR and Ocelot. We also demonstrate Voodoo's usefulness when investigating hardware conscious tuning techniques, assessing their performance on different queries, devices and data

XNect: Real-time Multi-person 3D Human Pose Estimation with a Single RGB Camera

We present a real-time approach for multi-person 3D motion capture at over 30 fps using a single RGB camera. It operates in generic scenes and is robust to difficult occlusions both by other people and objects. Our method operates in subsequent stages. The first stage is a convolutional neural network (CNN) that estimates 2D and 3D pose features along with identity assignments for all visible joints of all individuals. We contribute a new architecture for this CNN, called SelecSLS Net, that uses novel selective long and short range skip connections to improve the information flow allowing for a drastically faster network without compromising accuracy. In the second stage, a fully-connected neural network turns the possibly partial (on account of occlusion) 2D pose and 3D pose features for each subject into a complete 3D pose estimate per individual. The third stage applies space-time skeletal model fitting to the predicted 2D and 3D pose per subject to further reconcile the 2D and 3D pose, and enforce temporal coherence. Our method returns the full skeletal pose in joint angles for each subject. This is a further key distinction from previous work that neither extracted global body positions nor joint angle results of a coherent skeleton in real time for multi-person scenes. The proposed system runs on consumer hardware at a previously unseen speed of more than 30 fps given 512x320 images as input while achieving state-of-the-art accuracy, which we will demonstrate on a range of challenging real-world scenes

Rhomboid family member 2 regulates cytoskeletal stress-associated Keratin 16.

Keratin 16 (K16) is a cytoskeletal scaffolding protein highly expressed at pressure-bearing sites of the mammalian footpad. It can be induced in hyperproliferative states such as wound healing, inflammation and cancer. Here we show that the inactive rhomboid protease RHBDF2 (iRHOM2) regulates thickening of the footpad epidermis through its interaction with K16. K16 expression is absent in the thinned footpads of irhom2-/- mice compared with irhom2+/+mice, due to reduced keratinocyte proliferation. Gain-of-function mutations in iRHOM2 underlie Tylosis with oesophageal cancer (TOC), characterized by palmoplantar thickening, upregulate K16 with robust downregulation of its type II keratin binding partner, K6. By orchestrating the remodelling and turnover of K16, and uncoupling it from K6, iRHOM2 regulates the epithelial response to physical stress. These findings contribute to our understanding of the molecular mechanisms underlying hyperproliferation of the palmoplantar epidermis in both physiological and disease states, and how this 'stress' keratin is regulated

Cryptic photosynthesis, Extrasolar planetary oxygen without a surface biological signature

On the Earth, photosynthetic organisms are responsible for the production of virtually all of the oxygen in the atmosphere. On the land, vegetation reflects in the visible, leading to a red edge that developed about 450 Myr ago and has been proposed as a biosignature for life on extrasolar planets. However, in many regions of the Earth, and particularly where surface conditions are extreme, for example in hot and cold deserts, photosynthetic organisms can be driven into and under substrates where light is still sufficient for photosynthesis. These communities exhibit no detectable surface spectral signature to indicate life. The same is true of the assemblages of photosynthetic organisms at more than a few metres depth in water bodies. These communities are widespread and dominate local photosynthetic productivity. We review known cryptic photosynthetic communities and their productivity. We link geomicrobiology with observational astronomy by calculating the disk-averaged spectra of cryptic habitats and identifying detectable features on an exoplanet dominated by such a biota. The hypothetical cryptic photosynthesis worlds discussed here are Earth-analogs that show detectable atmospheric biomarkers like our own planet, but do not exhibit a discernable biological surface feature in the disc-averaged spectrum.Comment: 23 pages, 2 figures, Astrobiology (TBP) - updated Table 1, typo in detectable O2 correcte

A cluster-randomized controlled trial evaluating the effect of culturally-appropriate hypertension education among Afro-Surinamese and Ghanaian patients in Dutch general practice: study protocol

<p>Abstract</p> <p>Background</p> <p>Individuals of African descent living in western countries have increased rates of hypertension and hypertension-related complications. Poor adherence to hypertension treatment (medication and lifestyle changes) has been identified as one of the most important modifiable causes for the observed disparities in hypertension related complications, with patient education being recommended to improve adherence. Despite evidence that culturally-appropriate patient education may improve the overall quality of care for ethnic minority patients, few studies have focused on how hypertensive individuals of African descent respond to this approach. This paper describes the design of a study that compares the effectiveness of culturally-appropriate hypertension education with that of the standard approach among Surinamese and Ghanaian hypertensive patients with an elevated blood pressure in Dutch primary care practices.</p> <p>Methods/Design</p> <p>A cluster-randomized controlled trial will be conducted in four primary care practices in Amsterdam, all offering hypertension care according to Dutch clinical guidelines. After randomization, patients in the usual care sites (n = 2) will receive standard hypertension education. Patients in the intervention sites (n = 2) will receive three culturally-appropriate hypertension education sessions, culturally-specific educational materials and targeted lifestyle support. The primary outcome will be the proportion of patients with a reduction in systolic blood pressure ≥ 10 mmHg at eight months after the start of the trial. The secondary outcomes will be the proportion of patients with self-reported adherence to (i) medication and (ii) lifestyle recommendations at eight months after the start of the trial. The study will enrol 148 patients (74 per condition, 37 per site). Eligibility criteria for patients of either sex will be: current diagnosis of hypertension, self-identified Afro-Surinamese or Ghanaian, ≥ 20 years, and baseline blood pressure ≥ 140/90 mmHg. Primary and secondary outcomes will be measured at baseline and at 3 1/2, 6 1/2, and eight months. Other measurements will be performed at baseline and eight months.</p> <p>Discussion</p> <p>The findings will provide new knowledge on how to improve blood pressure control and patient adherence in ethnic minority persons with a high risk of negative hypertension-related health outcomes.</p> <p>Trial registration</p> <p>ISRCTN35675524</p

Zur Diagnostik des Diabetes insipidus unter besonderer Berücksichtigung hypophysektomierter Patienten

Verschiedene, am gleichen Patienten durchgeführte Stimulationsteste für die ADH-Sekretion (17-Std.-Durstversuch, Carter-Robbins-Test, osmotische Diurese) zeigen eine ausgezeichnete Korrelation. Auf Grund dieser Ergebnisse werden Richtlinien zur möglichst einfachen Diagnostik einer Konzentrationsstörung vorgeschlagen. In den meisten Fällen kann allein schon auf Grund eines exakt durchgeführten Durstversuchs eine Konzentrationsstörung nachgewiesen (höchste Urinosmolalität 750 mOsm/kg) werden. Lediglich bei einer höchsten Urinosmolalität im 17-Std.-Durstversuch zwischen 500 und 750 mOsm/kg müssen aufwendigere und den Patienten mehr belastende Tests (z. B. Carter-Robbins-Test) eingesetzt werden, um das Vorliegen bzw. den Grad einer Konzentrationsstörung endgültig diagnostizieren zu können. ADH-Injektionen dienen dabei zur Differenzierung zwischen einem ADH-Mangel und einer mangelhaften ADH-Ansprechbarkeit der Niere. Unsere Untersuchungen an hypophysektomierten Patienten (N=29) zeigen auch bei Patienten ohne polyurisch-polydiptisches Syndrom (N=22) eine gegenüber Normalpersonen signifikant eingeschränkte Konzentrationsleistung im 17-Std.-Durstversuch.The results of three different stimulation tests for ADH (17 hours thirst period, Carter-Robbins-test, osmotic diuresis) correlate well in the same patient. Because of this we propose a simplified procedure for the detection of failure to produce a concentrated urine. In most cases merely on the basis of a precisely executed thirst period test, one can either recognize an abnormality of concentration (highest urine osmolality less than 500 mOsm/kg), or exlude it (highest urine osmolality greater than 750 mOsm/kg). Only when the highest urine osmolality lies between 500 and 750 mOsm/kg after a 17 hour thirst must more painstaking tests (e.g. Carter-Robbins test) be employed to determine both the presence of and the degree of a failure to produce a concentrated urine. An injection of ADH can be used to differentiate between a deficiency of ADH and a defective response of the kidneys to ADH. Our investigations on hypophysectomized patients (n=29) showed that also in patients without the syndrome of polyuria-polydypsia (n=22), there was a significantly reduced capacity to concentrate urine during a 17 hour thirst period, as compared with normal people

Stabilization of semiconductor surfaces through bulk dopants

We show by employing density-functional theory (DFT) calculations (including a hybrid functional) that ZnO surfaces can be stabilized by bulk dopants. As an example, we study the bulk-terminated ZnO (0001) surface covered with half a monolayer of hydrogen. We demonstrate that deviations from this half-monolayer coverage can be stabilized by electrons or holes from bulk dopants. The electron chemical potential therefore becomes a crucial parameter that cannot be neglected in semiconductor surface studies. As one result, we nd that to form the defect-free surface with a half-monolayer coverage of hydrogen for n-type ZnO, ambient hydrogen background pressures are more conducive than high vacuum pressures

Concurrent sodium channelopathies and amyotrophic lateral sclerosis supports shared pathogenesis

Amyotrophic lateral sclerosis (ALS) is an invariably fatal adult-onset neurodegenerative disorder; approximately 10% of ALS is monogenic but all ALS exhibits significant heritability. The skeletal muscle sodium channelopathies are a group of inherited, non-dystrophic ion channel disorders caused by heterozygous point mutations in the SCN4A gene, leading to clinical manifestations of congenital myotonia, paramyotonia, and periodic paralysis syndromes. We provide clinical and genetic evidence of concurrence of these two rare disorders which implies a possible shared underlying pathophysiology in two patients. We then identify an enrichment of ALS-associated mutations in another sodium channel, SCN7A, from whole genome sequencing data of 4495 ALS patients and 1925 controls passing multiple testing correction (67 variants, p = 0.0002, Firth logistic regression). These findings suggest dysfunctional sodium channels may play a role upstream in the pathogenesis of ALS in a subset of patients, potentially opening the door to novel personalized medicine approaches

Optical coherence tomography (OCT) to image active and inactive retinoblastomas as well as retinomas.

To illustrate Optical Coherence Tomography (OCT) images of active and inactive retinoblastoma (Rb) tumours. Current observational study included patients diagnosed with retinoblastoma and retinoma who were presented at Amsterdam UMC and Jules-Gonin Eye Hospital, between November 2010 and October 2017. Patients aged between 0 and 4 years were imaged under general anaesthesia with handheld OCT in supine position. Patients older than 4 years were imaged with the conventional OCT (Heidelberg Engineering, Heidelberg Spectralis, Germany). All patients included were divided into two groups: active and inactive tumours (retinoma and regression patterns). Patients' medical records and OCT images were analysed during meetings via discussions by ophthalmologists and physicists. Twelve Dutch and 8 Swiss patients were divided into two groups: 2 patients with active tumour versus 18 patients with inactive tumour. Subsequently, inactive group could be divided in two groups, which consisted of 10 patients with retinoma and 8 patients with different regression pattern types. Of all included patients, 15 were male (75%). Median age at diagnosis was 18.0 months (range 0.19-715.2 months). A total of 12 retinoblastoma (active and inactive) and 8 retinoma foci were investigated by OCT. No distinction could be made between active and inactive tumours using only OCT. Optical coherence tomography alone cannot distinguish between active and inactive Rbs. However, handheld OCT adds useful information to the established imaging techniques in the monitoring and follow-up of retinoblastoma patients. With this study, we provide an overview of OCT images of active and inactive Rbs