Miracle-dz/UniFAR-FTUs huggingface dataset:
Optimal trade-off between sampling rate and quantization precision in Sigma-Delta A/D conversion

The optimal sampling frequency in a Sigma-Delta analog-to-digital converter with a fixed bitrate at the output is studied. We consider the mean squared error performance metric where the input signal statistics are known. Fixing the output bitrate introduces a trade-off between the sampling rate and the number of bits used to quantize each sample. That is, while increasing the sampling rate reduces the in-band quantization noise, it also reduces the number of bits available to quantize each sample and therefore increases the magnitude of the quantization noise. The optimal sampling rate is the result of the interplay between these two phenomena. In this work we analyze the sampling rate of a Sigma-Delta modulator of arbitrary order under the approximation that the quantization error behaves like additive white noise that is uncorrelated with the signal. We show that for a signal with a spectrum that is constant over its bandwidth, the optimal sampling rate is either the Nyquist rate or the maximal sampling rate corresponding to the output bitrate. The choice between the two is approximately a function of the Sigma-Delta system order and the bitrate per unit bandwidth.
Retrospective Cohort Study of Methotrexate Use in the Treatment of Pediatric Crohn's Disease

Background:Methotrexate (MTX) use as an alternative to thiopurines in the treatment of Crohn's disease (CD) in children is increasing. This study was undertaken to assess safety and efficacy of MTX in children with CD. Methods:Patients treated with MTX with a minimum of 1-year follow-up were identified in the Pediatric IBD Collaborative Research Group Registry, a prospective inception cohort study started in 2002. The clinical efficacy and safety of MTX were analyzed retrospectively. Results:Two hundred ninety patients treated with MTX were identified. One hundred seventy-two patients received at least 3 months of MTX without thiopurine or biologicals and had ≥1 year of follow-up. Eighty-one of 172 patients (47%) received MTX as first immunomodulator (IMM), of which 22 (27%) achieved ≥12 months of sustained clinical remission without surgery, thiopurine, biologicals, or corticosteroids. Those receiving MTX as second IMM achieved similar remission rate (35%, P = not significant). Fourteen percent received MTX as first IMM in 2002 and 60% in 2010 (P = 0.005). Disease location did not affect outcomes. MTX doses were equivalent in both groups. Fifteen percent of patients developed an alanine aminotransferase >60 international units/liter and 12% developed a white blood cell <4000 cells per microliter while on MTX. Only 4% of these discontinued MTX completely. A small group of 6 centers, which contributed only about one-third of patients with CD in the registry, contributed nearly two-thirds of the patients receiving MTX (P < 0.001). Conclusions:MTX use as first choice IMM is increasing in pediatric CD. MTX provided sustained clinical remission in nearly one-third of patients with minimal toxicity. There is large center-to-center variability in its use.
Active Imitation Learning of Hierarchical Policies

In this paper, we study the problem of imitation learning of hierarchical policies from demonstrations. The main difficulty in learning hierarchical policies by imitation is that the high level intention structure of the policy, which is often critical for understanding the demonstration, is unobserved. We formulate this problem as active learning of Probabilistic State-Dependent Grammars (PSDGs) from demonstrations. Given a set of expert demonstrations, our approach learns a hierarchical policy by actively selecting demonstrations and using queries to explicate their intentional structure at selected points. Our contributions include a new algorithm for imitation learning of hierarchical policies and principled heuristics for the selection of demonstrations and queries. Experimental results in five different domains exhibit successful learning using fewer queries than a variety of alternatives.
Dyslipidaemia, statins and rheumatoid arthritis

Cardiovascular morbidity and mortality are enhanced in rheumatoid arthritis (RA) and there is increasing evidence that this is due to the inflammatory process as well as to an increased prevalence of traditional cardiovascular risk factors, such as dyslipidaemia.1–3 Several investigators have indeed demonstrated dyslipidaemia, defined as higher total cholesterol and/or triglycerides and/or lower high-density lipoprotein (HDL) cholesterol levels in comparison to control subjects, in RA and this appears to be the consequence of systemic release of inflammatory cytokines such as tumour necrosis factor (TNF)α, interleukin (IL)1 and IL6, leading to a proatherogenic state with insulin resistance, endothelial cell activation and hypercoagulation as other consequences. The dyslipidaemia in RA is dependent on disease activity, ie, a higher disease activity is associated with lower total cholesterol levels and even more depressed HDL cholesterol levels, leading to a higher (ie, unfavourable) atherogenic index.4 Moreover, it appears that dyslipidaemia is already present in early RA and the question arises whether or not this phenomenon starts in the preclinical phase of RA. Hence, we investigated the lipid profile over time and its relationship with inflammation and serological markers, in subjects who later developed RA.5 The lipid profile was determined in 1078 serial blood bank samples, of 79 blood donors who later developed RA. These samples were compared with 1071 control samples of unselected blood donors, matched for age and sex. The samples of future patients with RA displayed, on average, 4% higher total cholesterol, 9% lower HDL cholesterol and 17% higher triglyceride levels compared to matched controls (p⩽0.05), at least 10 years before the onset of RA symptoms. Although the differences in the various lipid values were small they may have clinical relevance, in the light of results from other studies. For instance, in a placebo-controlled study with fibrates, the …
Emergence of foveal image sampling from learning to attend in visual scenes

We describe a neural attention model with a learnable retinal sampling lattice. The model is trained on a visual search task requiring the classification of an object embedded in a visual scene amidst background distractors using the smallest number of fixations. We explore the tiling properties that emerge in the model's retinal sampling lattice after training. Specifically, we show that this lattice resembles the eccentricity dependent sampling lattice of the primate retina, with a high resolution region in the fovea surrounded by a low resolution periphery. Furthermore, we find conditions where these emergent properties are amplified or eliminated providing clues to their function.
ERP critical success factors: an exploration of the contextual factors in public sector institutions

New information technologies have brought public-sector higher education institutions (HEIs) into increased competition, while their government funding in parallel has been continually eroded. In response to these growing pressures, there has been a call for HEIs to improve operational efficiency and to reduce duplication of resources by implementing advanced information systems that span the institution and improve processes. In response, HEIs have turned their efforts to implementing complex enterprise resource planning (ERP) systems. These systems are seen as the solution to address the growing governmental information requirements and to improve competitiveness, but do these systems represent a viable proposition for the diverse higher education sector with its traditionally strong and fragmented structure and culture? This paper investigates whether ERP systems offer a feasible information systems strategy for HEIs, using a 'critical success factor' model. Four in-depth case studies were conducted in HEIs that were in the process of implementing ERP systems. Numerous complexities, especially cultural and political ones, arose in light of the traditional structure of HEIs. The findings suggest that a careful use of communication and change management procedures to handle the business process reengineering (BPR) impact of ERP systems can alleviate some of the problems, but a more fundamental issue concerning the cost feasibility of system integration, training and user licenses may, in the end, impede ERP system utilization.
A Complex Interplay between Personality Domains, Marital Status and a Variant in CHRNA5 on the Risks of Cocaine, Nicotine Dependences and Cocaine-Induced Paranoia

Background Personality correlates highly with both cocaine and nicotine dependencies (CD, ND), and their co-morbid psychopathologies. However, little is known about the nature of these relationships. This study examined if environment (marriage) or genetics (a single SNP, CHRNA5*rs16969968) would moderate the correlation of personality with CD, ND and cocaine-induced paranoia (CIP) in African and European Americans (AAs, EAs). Methods 1432 EAs and 1513 AAs were examined using logistic regression. Personality was assessed by NEO-PI-R, while CD, ND and CIP were diagnosed according to DSM-IV. ND and CD were examined as binary traits and for the analysis of CIP, subjects were divided into 3 groups: (A) Controls with no CIP; (B) CD cases without CIP; and (C) CD cases with CIP. Multiple testing was Bonferroni-corrected. Results For CD and ND in the EA population, marital status proved to be a significant moderator in their relationship with openness only (OR = 1.90, 95%CI = 1.36–2.64, p = 1.54e-04 and OR = 2.12, 95%CI = 1.52–2.90, p = 4.65e-06 respectively). For CIP, marriage was observed to moderate its correlation with openness and neuroticism (OR = 1.39, 95%CI = 1.18–1.63, p = 7.64e-04 and OR = 1.26, 95%CI = 1.12–1.42, p = 1.27e-03 respectively). The correlations moderated by rs16969968 were those of conscientiousness and CD (OR = 1.62, 95%CI: 1.23–2.12, p = 8.94e-04) as well as CIP (OR = 1.21, 95%CI: 1.11–1.32, p = 4.93e-04 when comparing group A versus group C). No significant interactions were observed in AA population. The Bonferroni-corrected significance threshold was set to be 1.67e-03. Conclusion The role of personality in CD and CIP may be interceded by both environment and genetics, while in ND by environment only.
Isolation niches particle swarm optimization applied to traffic lights controlling

To keep balance of global and local searching ability, and to overcome the slow convergence and prematurely of particle swarm optimization, a new algorithm that isolation niches embedded in particle swarm optimization (INPSO) is introduced. Solving the heavy traffic problem in existing condition is also worth considering. In this paper, the method of two-intersections traffic controlling is proposed. Using improved PSO, the time of green and red lights could be optimized to make the average waiting time of vehicles shorter and the interferential phenomenon of cars in sections reduced. The simulation results show that it is an effective method.
Kinderanästhesie – Perioperatives Wärmemanagement bei Kindern

Zusammenfassung Sinkt die Körpertemperatur des Patienten während einer Operation zu stark ab, kann dies zu Komplikationen führen und das Outcome des Patienten beeinträchtigen. Da gerade Kinder sehr schnell auskühlen, müssen diese besonders gut gegen eine Hypothermie geschützt werden – von der Vorbereitung zur Anästhesie bis zum Aufwachen nach dem Eingriff. Die perioperative Temperaturmessung ist zum Vermeiden einer unbeabsichtigten Hypothermie unabdingbar, und der Aufwand zum Wärmeerhalt muss umso größer sein, je jünger und unreifer Säuglinge sind. Intraoperativ eignen sich dazu Inkubatoren. Bei Kleinkindern sind konvektive Systeme am weitesten verbreitet und auch effektiv in Kombination mit Flüssigkeitswärmung. Postoperatives „shivering“ sollte man behandeln, z.B. mit Pethidin oder Clonidin.
Intracellular Reactive Oxygen Species Activate Src Tyrosine Kinase during Cell Adhesion and Anchorage-Dependent Cell Growth

ABSTRACT Src tyrosine kinases are central components of adhesive responses and are required for cell spreading onto the extracellular matrix. Among other intracellular messengers elicited by integrin ligation are reactive oxygen species, which act as synergistic mediators of cytoskeleton rearrangement and cell spreading. We report that after integrin ligation, the tyrosine kinase Src is oxidized and activated. Src displays an early activation phase, concurrent with focal adhesion formation and driven mainly by Tyr527 dephosphorylation, and a late phase, concomitant with reactive oxygen species production, cell spreading, and integrin-elicited kinase oxidation. In addition, our results suggest that reactive oxygen species are key mediators of in vitro and in vivo v-Src tumorigenic properties, as both antioxidant treatments and the oxidant-insensitive C245A and C487A Src mutants greatly decrease invasivity, serum-independent and anchorage-independent growth, and tumor onset. Therefore we propose that, in addition to the known phosphorylation/dephosphorylation circuitry, redox regulation of Src activity is required during both cell attachment to the extracellular matrix and tumorigenesis.
Instabilities and shape analyses of elastic shells

This thesis presents research results on the deformation of elastic shells, especially concerning buckling and wrinkling instabilities. The theoretical description of such deformations is used to develop methods of shape analysis, which serve to infer material properties from simple experimental observations of deformed shells. When an initially spherical shell is deflated, two successive instabilities can typically be observed. In a first buckling transition, an axisymmetric dimple appears. It grows with proceeding deflation and acquires a polygonal shape in a secondary buckling transition. The onset of the first instability is well known. Here, we draw a complete picture of axisymmetric buckled shapes from the onset to a fully collapsed state, where opposite sides of the shell are in contact. Furthermore, it is shown that the stability of buckled shapes with respect to further spontaneous deflation depends decisively on whether the interior shell volume is prescribed (buckled shapes are stable), the pressure difference is fixed (shapes are unstable and collapse immediately after the onset) or the deflation is controlled by osmosis (intermediate between the former cases). For the description of axisymmetric buckled shapes, we use two approaches: firstly non-linear shell theory and secondly a simple analytic model proposed originally by Pogorelov. The secondary buckling instability has so far only been observed in simulations and experiments. Here, we provide a theoretical explanation and analyse its onset quantitatively. A compressive circumferential stress in the vicinity of the dimple edge is identified as the driving force of the secondary buckling transition. Using the stability equations for shallow shells, we derive a critical circumferential stress which leads to wrinkles along the dimple edge, similar to the Euler buckling of straight rods. Subsequently, we introduce a model for capsules that are created from liquid drops by an interfacial reaction and hang from a capillary. The interior liquid can be removed by suction through the capillary, which usually leads to wrinkling of the capsule membrane. The theoretical model is applied to completely characterise the elastic moduli of the membrane by an analysis of the capsule contour and wrinkle wavelength detected in experimental images. A test on two different capsule systems, polymerised polysiloxane capsules and bubbles coated with a layer of the protein hydrophobin, proves the concept of the proposed elastometry method. In the analysis of the hydrophobin capsule, we find an interesting non-linear elastic response which can be attributed to the molecular structure of the proteins consisting of a hard core and a softer shell. This motivates the development of a custom elasticity model based on the microscopic view of a bead-spring model including steric repulsions and can in part explain the experimental results of the hydrophobin capsule.
Conflicting actions of parathyroid hormone-related protein and serum calcium as regulators of 25-hydroxyvitamin D(3)-1 alpha-hydroxylase expression in a nude rat model of humoral hypercalcemia of malignancy.

In patients with humoral hypercalcemia of malignancy (HHM), serum levels of 1,25-dihydroxyvitamin D (1,25(OH)(2)D) are generally low, although the pathophysiology of the impaired vitamin D metabolism is not fully understood. In the present study, we have investigated vitamin D metabolism in our newly developed rat model of HHM in which a human infantile fibrosarcoma producing parathyroid hormone-related protein (PTHrP), named OMC-1, was inoculated s.c. into athymic nude rats. In OMC-1-bearing rats, the serum concentration of 1,25(OH)(2)D was markedly reduced when the animals exhibited severe hypercalcemia (Ca > or =15 mg/dl), while it was rather elevated in those with mild hypercalcemia. To further examine whether serum Ca levels affect 1,25(OH)(2)D concentration, we administered bisphosphonate YM529 to OMC-1-bearing rats when they exhibited severe hypercalcemia. The restoration of the serum Ca level by administration of YM529 was accompanied by a marked increase in the 1,25(OH)(2)D level, suggesting that the serum Ca level itself plays an important role in the regulation of the 1,25(OH)(2)D level in these rats. On the other hand, when the OMC-1-bearing rats were treated with a neutralizing antibody against PTHrP, serum 1,25(OH)(2)D levels remained low despite the reduction in serum Ca levels. Expression of 25-hydroxyvitamin D-1 alpha-hydroxylase (1 alpha-hydroxylase) in kidney was decreased in OMC-1-bearing rats with severe hypercalcemia, and markedly enhanced after treatment with bisphosphonate. This enhancement in 1 alpha-hydroxylase expression was not observed after treatment with the antibody against PTHrP. These results suggest that PTHrP was responsible for the enhanced expression of 1 alpha-hydroxylase in YM529-treated rats, and that hypercalcemia played a role in reducing the serum 1,25(OH)(2)D level in OMC-1-bearing rats by suppressing the PTHrP-induced expression of the 1 alpha-hydroxylase gene.
On the Accuracy of Type-2 Fuzzy Sets

Geometric Type-2 fuzzy sets allow us to model type-2 fuzzy sets using geometry providing significant improvement in speed of computation. This paper explores in detail how well the geometric approach models continuous type-2 fuzzy sets from an accuracy perspective. A new methodology is introduced for conducting the comparison. This methodology is used on some example sets and the performance of the geometric model is given. It shows that, in broad terms, geometric type-2 fuzzy sets are more accurate than the discrete equivalent.
Celluloses filled ENR/PVC membranes for palm oil mill effluent (POME) treatment

Membranes from composite materials have been used especially in water treatment applications. In this paper the composite membranes of celluloses filled ENR/PVC were successfully prepared for POME treatment application. The preparation of the membrane involves solution blending, casting, phase inversion and drying methods. Two types of fillers, cellulose (Cell) and cellulose grafting polymethyl methacrylate (Cell-g-PMMA) were added into ENR/PVC matrix in various compositions (1, 5, 10, 15 and 20 wt%) to determine the effect of the filler to the performance of the membrane. The membranes were characterized by using FTIR and SEM. Membrane properties in terms of porosity and water flux were examined using mathematical calculation. FTIR spectrum shows the existence of stretching vibration from the functional group of ester carbonyl, –C=O at peak 1725 cm−1 that belongs to Cell-g-PMMA filler in ENR/PVC/Cell-g-PMMA membrane which makes the membranes slightly hydrophobic. SEM micrographs exhibit that pores were f.
Transfusion and mechanical ventilation: two interrelated causes of acute lung injury?

To the Editor: We read with interest the recent article by Smith and colleagues (1), who demonstrated an increase in brain tissue oxygen partial pressure (PbtO2) following red blood cell transfusion (RBCT). Given the paucity of literature on the cerebral physiologic response to RBCT, this article is certainly very welcomed. However, there are a couple of methodologic issues that should be addressed. The authors’ study population is heterogeneous, consisting of patients with closed head injuries, subdural hematomas, and subarachnoid hemorrhages. Despite another recent article by Smith suggesting that increased intracranial pressure in the subarachnoid hemorrhage population is common (2), the most common etiology is likely obstructive hydrocephalus, with true parenchymal edema being less common (3). It remains unclear weather the pathophysiological process underlying these two etiologies of brain injury are similar. As such, they may respond differently in terms of regional blood flow and oxygen extraction, confounding the results. The authors correctly point out that parenchymal oxygen monitoring does not detect cellular hypoxia. Their assertion that local oxygen tension may reflect global oxygenation remains unproven. Lower PbtO2 values have been shown to correlate with increased intracranial pressure and decreased cerebral perfusion pressure but not jugular vein oxygen saturation (4). The latter is arguably a better surrogate for cerebral cellular hypoxia. As such, improved PbtO2 values seen with RBCT may simply reflect improved cerebral perfusion. The authors argue against this by stating that their patients had normal volume status. However, in the head-injured population, cerebral autoregulation is impaired, and any increase in circulating volume may in fact increase cerebral blood flow and thus increase PbtO2. It would have been interesting to have a control group transfused with colloid and assess its effect on PbtO2 values. Smith et al. raise the interesting possibility that PbtO2 values may someday be used to guide RBCT in these patients. Given the current state of knowledge about RBCT in the head-injured population, any guidance would be very well received. Notwithstanding these comments, the work by Smith et al. is a welcome addition to an area of study that requires a great deal more investigation. The authors have no financial interests to disclose.
Cloud-based Semantic Service-Oriented Content Provisioning Architecture for Mobile Learning

Exploiting mobile technologies for educational purposes has promises of realizing ubiquitous, unobtrusive, personal and situated learning. The advent of cloud computing has meant that all the information on web, and proprietary sources of information are available instantly. But mobile learning is non-trivial due to the challenges in the process of designing, communicating and presenting traditional e-learning resources to mobile learners. In this paper, we propose a generic semanticsbased service-oriented infrastructure and show how semantic technologies, when used together with a cloud-based SOA, can provide mobile users with a fresh learning experience. The proposed architecture comprises a knowledge aggregation subsystem and a querying subsystem that are loosely coupled, and hence enables rapid deployment across domains with suitable domain ontologies. Furthermore, the service-oriented approach enables a pluggable platform that supports seamless integration of legacy content from possibly multiple vendors for customizable delivery. For illustration, we consider a mobile learning scenario in a zoo, and demonstrate how a mobile user can interact with the proposed system for m-learning.