Miracle-dz/UniFAR-FTUs huggingface dataset:
Growth of Semipolar GaN 55 MOVPE Growth of Semipolar GaN on Patterned Sapphire Wafers : Influence of Substrate Miscut

We describe epitaxial methods for two different semipolar GaN orientations on patterned sapphire substrates: With (101̄2) (r-plane) sapphire substrates we achieve planar (112̄2) GaN layers with smooth surfaces on a large scale. In the case of (112̄3) (n-plane) patterned wafers the growth of (101̄1) GaN is possible. We optimized the growth conditions for (112̄2) GaN (especially the growth temperature) yielding a coalesced, planar semipolar surface. Thereafter we transferred the knowledge from (112̄2) oriented growth to (101̄1) oriented growth and investigated the general influence of substrate miscuts on surface and crystal qualities, respectively. Due to the fact that the angle between (101̄1) and (0001) in the case of GaN and the angle between (112̄3) and (0001) in the case of sapphire are slightly different, we detected an imperfect surface. Choosing the right substrate miscut angle the crystal and / or the surface quality of GaN could be improved. The third important point is the non-homogeneous defect density distribution in the crystal. The right miscut could help to push the growth of the areas with less defects over the areas with a high defect density to improve the total crystal quality.
The Effect of Reduced Dynamic Range on Speech Understanding: Implications for Patients with Cochlear Implants

Objective: To determine the effect of reduced dynamic range on speech understanding when the speech signals are processed in a manner similar to a 6‐channel cochlear implant speech processor. Design: Signals were processed in a manner similar to a 6‐channel cochlear implant processor and output as a sum of sine waves with frequencies equal to the center frequencies of the analysis filters. The amplitudes of the sine waves were compressed in a systematic fashion to simulate the effect of reduced dynamic range. The compressed signals were presented to 10 normal‐hearing listeners for identification. Results: There was a significant effect of compression for all test materials. The effect of the compression on speech understanding was different for the three test materials (vowels, consonants, and sentences). Vowel recognition was affected the most by the compression, and consonant recognition was affected the least by the compression. Feature analysis indicated that the reception of place information was affected the most. Sentence recognition was moderately affected by the compression. Conclusions: Dynamic range should affect the speech perception abilities of cochlear implant users. Our results suggest that a relatively wide dynamic range is needed for a high level of vowel recognition and a relatively small dynamic range is sufficient to maintain consonant recognition. We infer from this outcome that, if other factors were held equal, an implant patient with a small dynamic range could achieve moderately high scores on tests of consonant recognition but poor performance on vowel recognition, and that it is more likely for an implant patient with a large dynamic range to obtain high scores on vowel recognition than for an implant patient with a small dynamic range.
Noncommutative theories and general coordinate transformations

We study the class of noncommutative theories in d dimensions whose spatial coordinates (x{sub i}){sub i=1}{sup d} can be obtained by performing a smooth change of variables on (y{sub i}){sub i=1}{sup d}, the coordinates of a standard noncommutative theory, which satisfy the relation [y{sub i},y{sub j}]=i{theta}{sub ij}, with a constant {theta}{sub ij} tensor. The x{sub i} variables verify a commutation relation which is, in general, space dependent. We study the main properties of this special kind of noncommutative theory and show explicitly that, in two dimensions, any theory with a space-dependent commutation relation can be mapped to another where that {theta}{sub ij} is constant.
Airflow Dynamics of Human Jets: Sneezing and Breathing - Potential Sources of Infectious Aerosols

Natural human exhalation flows such as coughing, sneezing and breathing can be considered as ‘jet-like’ airflows in the sense that they are produced from a single source in a single exhalation effort, with a relatively symmetrical, conical geometry. Although coughing and sneezing have garnered much attention as potential, explosive sources of infectious aerosols, these are relatively rare events during daily life, whereas breathing is necessary for life and is performed continuously. Real-time shadowgraph imaging was used to visualise and capture high-speed images of healthy volunteers sneezing and breathing (through the nose – nasally, and through the mouth - orally). Six volunteers, who were able to respond to the pepper sneeze stimulus, were recruited for the sneezing experiments (2 women: 27.5±6.36 years; 4 men: 29.25±10.53 years). The maximum visible distance over which the sneeze plumes (or puffs) travelled was 0.6 m, the maximum sneeze velocity derived from these measured distances was 4.5 m/s. The maximum 2-dimensional (2-D) area of dissemination of these sneezes was 0.2 m2. The corresponding derived parameter, the maximum 2-D area expansion rate of these sneezes was 2 m2/s. For nasal breathing, the maximum propagation distance and derived velocity were 0.6 m and 1.4 m/s, respectively. The maximum 2-D area of dissemination and derived expansion rate were 0.11 m2 and 0.16 m2/s, respectively. Similarly, for mouth breathing, the maximum propagation distance and derived velocity were 0.8 m and 1.3 m/s, respectively. The maximum 2-D area of dissemination and derived expansion rate were 0.18 m2 and 0.17 m2/s, respectively. Surprisingly, a comparison of the maximum exit velocities of sneezing reported here with those obtained from coughing (published previously) demonstrated that they are relatively similar, and not extremely high. This is in contrast with some earlier estimates of sneeze velocities, and some reasons for this difference are discussed.
The Impact of Transculturality on Student Experience of Higher Education

Background: Higher education outdoor studies programs retain a critical interest in student experiences as they seek to prepare citizens in a globalized, yet simultaneously neo-nationalist, world. Purpose: This research explored the impact of transculturality on the student experience of outdoor studies in the Transcultural European Outdoor Studies (TEOS) Masters, a course hosted by three universities in three countries. Methodology/Approach: A longitudinal study of the student experience, using a conceptual framework of self, place, transculturality, and outdoor learning theory underpins the research. Semistructured online interviews and one face-to-face retrospective interview were conducted with four participants throughout the course (Semesters 1, 2, 3), plus an additional five participants prior to the end of Semester 3. Findings/Conclusions: The findings elucidate students’ transcultural self-growth and transcultural capabilities, including resilience, intelligence, and fatigue. Implications: Although challenges exist for course design, considerations of transcultural pedagogy and curricula, reflective practices, support for students and teaching staff, cultural learning experiences (including language acquisition), and a willingness to move beyond traditional models of curricula at the university level are recommended.
Adhesion of osteoblasts to a nanorough titanium implant surface

This work considers the adhesion of cells to a nanorough titanium implant surface with sharp edges. The basic assumption was that the attraction between the negatively charged titanium surface and a negatively charged osteoblast is mediated by charged proteins with a distinctive quadrupolar internal charge distribution. Similarly, cation-mediated attraction between fibronectin molecules and the titanium surface is expected to be more efficient for a high surface charge density, resulting in facilitated integrin mediated osteoblast adhesion. We suggest that osteoblasts are most strongly bound along the sharp convex edges or spikes of nanorough titanium surfaces where the magnitude of the negative surface charge density is the highest. It is therefore plausible that nanorough regions of titanium surfaces with sharp edges and spikes promote the adhesion of osteoblasts.
"E-courses Unified Process" For Development of Online Courses

With the advancement in computers and technology, traditional way of education has changed from being confined to a classroom to an open anytime, anywhere learning. The system of education and learning has been changed with the introduction of E-Learning system. Over the past few years, there has been a tremendous growth in the development of E-Learning system and applications. There is an increased importance associated with the E- Learning courseware for the successful implementation of educational process. In spite of the importance, there are still some E-Learning courseware that fail to meet the teaching and learning objectives and expectations. These failures can be overcome by the introduction of software development methodology in the development of E- Learning courses. Keeping this idea in mind, this study proposes "E-courses unified process" which is a modification of well-known software development model; the unified process. This proposed process is based on five activities or workflows; requirement gathering, Analysis and design, Content development and assessment, production and implementation and test and Evaluation. Each of these activities is carried out with the four phases of the Unified process which are inception, elaboration, construction and transition.
Geodesic plasma flows instabilities of Riemann twisted solar loops

Riemann and sectional curvatures of magnetic twisted flux tubes in Riemannian manifold are computed to investigate the stability of the plasma astrophysical tubes. The geodesic equations are used to show that in the case of thick magnetic tubes, the curvature of planar (Frenet torsion-free) tubes have the effect ct of damping the flow speed along the tube. Stability of geodesic flows in the Riemannian twisted thin tubes (almost filaments), against constant radial perturbations is investigated by using the method of negative sectional curvature for unstable flows. No special form of the flow like Beltrami flows is admitted, and the proof is general for the case of thin magnetic flux tubes. In the magnetic equilibrium state, the twist of the tube is shown to display also a damping effect on the toroidal velocity of the plasma flow. It is found that for positive perturbations and angular speed of the flow, instability is achieved, since the sectional Ricci curvature of the magnetic twisted tube metric is negative. Solar flare production may appear from these geometrical instabilities of the twisted solar loops.
Prototypic Seizure Activity Driven by Mature Hippocampal Fast-Spiking Interneurons

A variety of epileptic seizure models have shown that activation of glutamatergic pyramidal cells is usually required for rhythm generation and/or synchronization in hippocampal seizure-like oscillations in vitro. However, it still remains unclear whether GABAergic interneurons may be able to drive the seizure-like oscillations without glutamatergic transmission. Here, we found that electrical stimulation in rat hippocampal CA1 slices induced a putative prototype of seizure-like oscillations (“prototypic afterdischarge,” 1.8–3.8 Hz) in mature pyramidal cells and interneurons in the presence of ionotropic glutamate receptor antagonists. The prototypic afterdischarge was abolished by GABAA receptor antagonists or gap junction blockers, but not by a metabotropic glutamate receptor antagonist or a GABAB receptor antagonist. Gramicidin-perforated patch-clamp and voltage-clamp recordings revealed that pyramidal cells were depolarized and frequently excited directly through excitatory GABAergic transmissions in each cycle of the prototypic afterdischarge. Interneurons that were actively spiking during the prototypic afterdischarge were mostly fast-spiking (FS) interneurons located in the strata oriens and pyramidale. Morphologically, these interneurons that might be “potential seizure drivers” included basket, chandelier, and bistratified cells. Furthermore, they received direct excitatory GABAergic input during the prototypic afterdischarge. The O-LM cells and most of the interneurons in the strata radiatum and lacunosum moleculare were not essential for the generation of prototypic afterdischarge. The GABA-mediated prototypic afterdischarge was observed later than the third postnatal week in the rat hippocampus. Our results suggest that an FS interneuron network alone can drive the prototypic form of electrically induced seizure-like oscillations through their excitatory GABAergic transmissions and presumably through gap junction-mediated communications.
Learning Anomalies in IDSs by Means of Multivariate Finite Mixture Models

In this work a fast method for the unsupervised fitting of a set of data by means of Gaussian mixtures has been studied and developed. It allows to implement applications to Information Security, with major on anomaly detection Intrusion Detection Systems (IDSs). Its key feature is the online selection of the number of mixture components together with the fitting parameter of each component. With many components the description is accurate. However, the computational burden increases as well. The best compromise between the description accuracy and the computational complexity is given by a derivation of the Minimum Message Length (MML) information criterion. The normal network behavior is assumed to be interpreted by the cluster with the highest covariance matrix, while the other smaller components are considered representing anomalies. We tested our technique with the well known KDD99 Cup data set, in order to clearly compare our findings with the other state of the art methods. Our results show the effectiveness of this algorithm in finding anomalies within normal network traffic, and encourage for further improvements.
The mystery of missing heritability: Genetic interactions create phantom heritability

Human genetics has been haunted by the mystery of “missing heritability” of common traits. Although studies have discovered >1,200 variants associated with common diseases and traits, these variants typically appear to explain only a minority of the heritability. The proportion of heritability explained by a set of variants is the ratio of (i) the heritability due to these variants (numerator), estimated directly from their observed effects, to (ii) the total heritability (denominator), inferred indirectly from population data. The prevailing view has been that the explanation for missing heritability lies in the numerator—that is, in as-yet undiscovered variants. While many variants surely remain to be found, we show here that a substantial portion of missing heritability could arise from overestimation of the denominator, creating “phantom heritability. ” Specifically, (i) estimates of total heritability implicitly assume the trait involves no genetic interactions (epistasis) among loci; (ii) this assumption is not justified, because models with interactions are also consistent with observable data; and (iii) under such models, the total heritability may be much smaller and thus the proportion of heritability explained much larger. For example, 80% of the currently missing heritability for Crohn's disease could be due to genetic interactions, if the disease involves interaction among three pathways. In short, missing heritability need not directly correspond to missing variants, because current estimates of total heritability may be significantly inflated by genetic interactions. Finally, we describe a method for estimating heritability from isolated populations that is not inflated by genetic interactions.
Missing the Starting Gun. Entry Timing Decisions into New Market Niches

This study analyzes incumbent entry timing decisions in new markets in the case of Encryption Software (ES). In ES first technological movers were slow to enter the downstream market, losing their initial advantages to the benefit of newcomers. This work tests the hypothesis that this wait-and-see strategy was an optimal choice compared to the assumption of inertia embedded in the decision process of potential entrants. We find that entry decision is not the outcome of firm rational balancing among different strategic variables, but it is more similar to a heuristic process that fails to accommodate the full logic of decision.
Protection of Islet Grafts Through Transforming Growth Factor-β–Induced Tolerogenic Dendritic Cells

In type 1 diabetes, the insulin-producing β-cells are destroyed by the immune system. One way of restoring glucose control is to transplant β-cells from a donor. Although this procedure may restore endogenous insulin production, immunosuppressive treatment is needed to prevent the recipient from rejecting the donor-derived islets. We investigated the possibilities of transient expression of the immunosuppressive cytokine transforming growth factor (TGF)-β within islets to achieve long-term graft tolerance. We found that brief expression of TGF-β prevented rejection of syngeneic islets, that there was reduction of dendritic cell (DC) activation in the graft, and that there was reduced reactivation of T cells in the graft-draining lymph nodes. In vitro exposure of bone marrow–derived DCs to TGF-β reduced expression of costimulatory molecules CD80 and CD86, as well as production of proinflammatory cytokines such as interleukin-12 p70 in DCs, but did not alter levels of major histocompatibility complex classes I and II. Furthermore, the capacity of TGF-β–treated bone marrow–derived DCs to activate both CD4+ and CD8+ T cells was reduced. Adding TGF-β–conditioned tolerogenic DCs to the grafted islets led to long-term survival of the graft, demonstrating that TGF-β–induced tolerogenic DCs can provide an effective means to restore immune tolerance in an already established autoimmune disease.
The relationship between V6 and PO in macaque extrastriate cortex

The cerebral cortex of three macaque monkeys, electrophysiologically studied in chronic preparations in order to recognize functionally the medial parieto‐occipital area V6, was reconstructed using the software CARET. Locations of cells recorded from area V6 (n = 553) and from neighbouring cortical areas V2/V3 and V6A (n = 1341) were displayed on surface‐based reconstructions of individual brains, and on a surface‐based atlas of the macaque cerebral cortex. Results show that area V6 occupies the ventral part and fundus of the parieto‐occipital sulcus, as well as the ventral part of the precuneate cortex. V6 borders areas V2/V3 posteriorly and laterally, and area V6A anteriorly. The visualization of individual cases on a common template (atlas), and the use of atlas datasets, allowed us to compare data coming from different individuals and different laboratories. In particular, a comparison of the location and extent of the medial parieto‐occipital areas V6 and PO indicates that area PO occupies different locations according to different authors but in general includes parts of both areas V6 and V6A. We therefore suggest that the term V6 is a more appropriate designation of the visuotopically‐organized area located on the anterior wall of the parieto‐occipital sulcus.
Design and Performance of an Optimal Inertial Power Harvester for Human-Powered Devices

We present an empirical study of the long-term practicality of using human motion to generate operating power for body-mounted consumer electronics and health sensors. We have collected a large continuous acceleration data set from eight experimental subjects going about their normal daily routine for three days each. Each subject is instrumented with a data collection apparatus that simultaneously logs 3-axis, 80 Hz acceleration data from six body locations. We use this data set to optimize a first-principles physical model of the commonly used velocity damped resonant generator (VDRG) by selecting physical parameters such as resonant frequency and damping coefficient to maximize the harvested power. Our results show that with reasonable assumptions on size, mass, placement, and efficiency of VDRG harvesters, most body-mounted wireless sensors and even some consumer electronics devices can be powered continuously and indefinitely from everyday motion. We have optimized the power harvesters for each individual and for each body location. In addition, we present the potential of designing a damping- and frequency-tunable power harvester that could mitigate the power reduction of a generator generalized for "average” subjects. We present the full details on the collection of the acceleration data sets, the development of the VDRG model, and a numerical simulator, and discuss some of the future challenges that remain in this promising field of research.
Testing the hypothesis that diphtheria–tetanus–pertussis vaccine has negative non-specific and sex-differential effects on child survival in high-mortality countries

Background Measles vaccines (MV) have sex-differential effects on mortality not explained by protection against measles infection. Objective The authors examined whether whole-cell diphtheria–tetanus–pertussis (DTP) vaccine has sex-differential and non-specific effects. Data sources and eligibility Following previous reviews and a new search, the effect of DTP on mortality up to the next vaccination was assessed in all studies where DTP was given after BCG or DTP was given after MV and there was prospective follow-up after ascertainment of vaccination status. Setting High-mortality countries in Africa and Asia. Methods The initial observation of negative effect of DTP generated six hypotheses, which were examined in all available studies and two randomised trials reducing the time of exposure to DTP. Main outcome Consistency between studies. Results In the first study, DTP had negative effects on survival in contrast to the beneficial effects of BCG and MV. This pattern was repeated in the six other studies available. Second, the two ‘natural experiments’ found significantly higher mortality for DTP-vaccinated compared with DTP-unvaccinated children. Third, the female–male mortality ratio was increased after DTP in all nine studies; in contrast, the ratio was decreased after BCG and MV in all studies. Fourth, the increased female mortality associated with high-titre measles vaccine was found only among children who had received DTP after high-titre measles vaccine. Fifth, in six randomised trials of early MV, female but not male mortality was increased if DTP was likely to be given after MV. Sixth, the mortality rate declined markedly for girls but not for boys when DTP-vaccinated children received MV. The authors reduced exposure to DTP as most recent vaccination by administering a live vaccine (MV and BCG) shortly after DTP. Both trials reduced child mortality. Conclusions These observations are incompatible with DTP merely protecting against the targeted diseases. With herd immunity to whooping cough, DTP is associated with higher mortality for girls. Randomised studies of DTP are warranted to measure the true impact on survival.