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Tradução de: Ciucu, C. (2010). Les penseurs du néant: Heidegger et la mystique juive du Moyen Âge. Yod, 5, 215-233, por Lucas de Lima Cavalcanti DOI: https://doi.org/10.4000/YOD.676

A recent conjecture of Di Francesco states that the number of domino tilings of a certain family of regions on the square lattice is given by a product formula reminiscent of the one giving the number of alternating sign matrices. These regions, denoted ${\mathcal T}_n$, are obtained by starting with a square of side-length $2n$, cutting it in two along a diagonal by a zigzag path with step length two, and gluing to one of the resulting regions half of an Aztec diamond of order $n-1$. Inspired by the regions ${\mathcal T}_n$, we construct a family $C_{m,n}^{a,b,c,d}$ of cruciform regions generalizing the Aztec diamonds and we prove that their number of domino tilings is given by a simple product formula. Since (as it follows from our results) the number of domino tilings of ${\mathcal T}_n$ is a divisor of the number of tilings of the cruciform region $C_{2n-1,2n-1}^{n-1,n,n,n-2}$, the special case of our formula corresponding to the latter can be viewed as partial progress towards proving Di Francesco's conjecture., 14 pages

When the arrival processes are Poisson, queueing networks are well-understood in terms of the product-form structure of the number of jobs $N_i$ at the individual queues; much less is known about the waiting time $W$ across the whole network. In turn, for non-Poisson arrivals, little is known about either $N_i$'s or $W$. This paper considers a tandem network $$GI/G/1\rightarrow \cdot/G/1\rightarrow\dots\rightarrow\cdot/G/1$$ with general arrivals and light-tailed service times. The main result is that the tail $\P(W>x)$ has a polynomial-exponential (Poly-Exp) structure by constructing upper bounds of the form $$(a_{I}x^{I}+\dots+a_1x+a_0)e^{-\theta x}~.$$ The degree $I$ of the polynomial depends on the number of bottleneck queues, their positions in the tandem, and also on the `light-tailedness' of the service times. The bounds hold in non-asymptotic regimes (i.e., for \textit{finite} $x$), are shown to be sharp, and improve upon alternative results based on large deviations by (many) orders of magnitude. The overall technique is also particularly robust as it immediately extends, for instance, to non-renewal arrivals.

We consider regions obtained from 120 degree rotationally invariant hexagons by removing a core and three equal satellites (all equilateral triangles) so that the resulting region is both vertically symmetric and 120 degree rotationally invariant, and give simple product formulas for the number of their lozenge tilings. We describe a new method of approach for proving these formulas, and give the full details for an illustrative special case. As a byproduct, we are also able to generalize this special case in a different direction, by finding a natural counterpart of a twenty year old formula due to Ciucu, Eisenk\"olbl, Krattenthaler and Zare, which went unnoticed until now. The general case of the original problem will be treated in a subsequent paper. We then work out consequences for the correlation of holes, which were the original motivation for this study., Comment: Added Theorem 3

Guaifenesin (GFS), phenylephrine (PHE) and paracetamol (PAR), drugs used in combination for the relief of cold and flu symptoms, were determined at electrochemically pretreated pencil graphite electrode. Differential pulse voltammetry (DPV) was used for the first time for the concomitant determination of the target compounds based on the electro-oxidation of PAR at 0.43 V, PHE at 0.74 V and GFS at 1.14 V in Britton–Robinson buffer pH 6.0. Under optimized experimental conditions, two linear ranges were obtained for PAR (2.50 × 10−6 M–1.00 × 10−5 M and 1.00 × 10−5 M–1.00 × 10−4 M) and for PHE and GFS linearity was proved between 5.00 × 10−6 M–2.00 × 10−4 M and 2.50 × 10−6 M–2.00 × 10−4 M, respectively. The detection limits were 8.12 × 10−7 M for PAR, 1.80 × 10−6 M for PHE and 8.29 × 10−7 M for GFS. The selective and sensitive DPV method and the electrochemically treated electrode were employed for simultaneous analysis of the analytes in pharmaceutical samples with good recoveries.

The paper presents a new eye image segmentation method used to extract the pupil contour based on the modified U-Net CNN architecture. The analysis was performed using two databases which contain IR images with a spatial resolution of 640x480 pixels. The first database was acquired in our laboratory and contains 400 eye images and the second database is a selection of 400 images from the publicly available CASIA Iris Lamp database. The results obtained by applying the segmentation based on the CNN architecture were compared to manually-annotated ground truth data. The results obtained are comparable to the state of the art. The purpose of the paper is to present the implementation of a robust segmentation algorithm based on the U-Net convolutional neural network that can be used in eye tracking applications such as human computer interface, communication devices for people with disabilities, marketing research or clinical studies. The proposed method improves uppon existing U-Net CNN architectures in terms of efficiency, by reducing the total number of parameters used from 31 millions to 38k. The advantages of using a number of parameters approximatly 815 times lower than the original U-Net CNN architecture are reduced computing resources consumption and a lower inference time.

We analyze a data-processing system with $n$ clients producing jobs which are processed in \textit{batches} by $m$ parallel servers; the system throughput critically depends on the batch size and a corresponding sub-additive speedup function. In practice, throughput optimization relies on numerical searches for the optimal batch size, a process that can take up to multiple days in existing commercial systems. In this paper, we model the system in terms of a closed queueing network; a standard Markovian analysis yields the optimal throughput in $\omega\left(n^4\right)$ time. Our main contribution is a mean-field model of the system for the regime where the system size is large. We show that the mean-field model has a unique, globally attractive stationary point which can be found in closed form and which characterizes the asymptotic throughput of the system as a function of the batch size. Using this expression we find the \textit{asymptotically} optimal throughput in $O(1)$ time. Numerical settings from a large commercial system reveal that this asymptotic optimum is accurate in practical finite regimes., Comment: 15 pages

In earlier work we showed that in the bulk, the correlation of gaps in dimer systems on the hexagonal lattice is governed, in the fine mesh limit, by Coulomb's law for 2D electrostatics. We also proved that the scaling limit of the discrete field ${\bold F}$ of average tile orientations is, up to a multiplicative constant, the electric field produced by a 2D system of charges corresponding to the gaps. In this paper we show that in the bulk, the relative change $T_{\al,\be}$ in correlation caused by displacing a hole by a fixed vector $(\al,\be)$ is, in the fine mesh limit, the projection on $(\al,\be)$ of a new field ${\bold T}$, which is also equal up to a multiplicative constant to the electric field of the corresponding system of charges. We also discuss the differences between the fields ${\bold T}$ and ${\bold F}$ and present conjectures for their fine mesh limits in the more general case of a dimer system with boundary. The new field ${\bold T}$ can be viewed as capturing the instantaneous pull on each gap in the surrounding fluctuating sea of dimers. From the point of view of the parallel to physics, the electrostatic force emerges then as an entropic force., Comment: 29 pages

Life expectancy has increased worldwide and, along with it, a greater prevalence of age-dependent disorders, chronic illnesses and comorbidities can be observed. In 2019, in both Europe and the Americas, dementias ranked 3rd among the top 10 causes of death. Parkinson's disease (PD) is the second most frequent type of neurodegenerative disease. In the last decades, globally, the number of people suffering from PD has more than doubled to over 6 million. Of all the neurological disorders, PD increased with the fastest rate. This troubling trend highlights the stringent need for accurate diagnostic biomarkers, especially in the early stages of the disease and to evaluate treatment response. To gain a broad and complex understanding of the recent advances in the '-omics' research fields, electronic databases such as PubMed, Google Academic, and Science Direct were searched for publications regarding metabolomic studies on PD to identify specific biomarkers for PD, and especially PD with associated psychiatric symptomatology. Discoveries in the fields of metagenomics, transcriptomics and proteomics, may lead to an improved comprehension of the metabolic pathways involved in disease etiology and progression and contribute to the discovery of novel therapeutic targets for effective treatment options.

A novel and rapid voltammetric assay for the simultaneous determination of monolinuron (MLN) and linuron (LIN) using an electrochemically pretreated pencil graphite electrode (PGE*) is reported for the first time. Enhanced oxidation peak currents of MLN and LIN were observed at PGE* when compared with electrochemically non-pretreated PGE. Differential pulse voltammetric (DPV) results showed distinct anodic peaks at 1.064 V and 1.170 V for MLN and LIN, respectively. Under optimum conditions, the detection limits were 3.7 × 10−7 mol L−1 and 5.8 × 10−7 mol L−1 for MLN and LIN respectively. The DPV method was applied for the quantitative determination of the mentioned compounds in spiked tap water samples enriched by solid phase extraction. The voltammetric results were in good agreement with high-performance liquid chromatography data.

Developing Artificial Intelligence is a labor intensive task. It implies both storage and computational resources. In this paper, we present a state-of-the-art service based infrastructure for deploying, managing and serving computational models alongside their respective data-sets and virtual environments. Our architecture uses key-based values to store specific graphs and datasets into memory for fast deployment and model training, furthermore leveraging the need for manual data reduction in the drafting and retraining stages. To develop the platform, we used clustering and orchestration to set up services and containers that allow deployment within seconds. In this article, we cover high performance computing concepts such as swarming, GPU resource management for model implementation in production environments with emphasis on standardized development to reduce integration tasks and performance optimization.

Psychotic disorders represent a serious health concern. At this moment, anamnestic data, international criteria for diagnosis/classification from the Diagnostic and Statistical Manual of Mental Disorders-5 and the International Classification of Diseases-10 and diagnostic scales are used to establish a diagnosis. The most commonly used biomarkers in psychotic illnesses are those regarding the neuroimmune system, metabolic abnormalities, neurotrophins and neurotransmitter systems and proteomics. A current issue faced by clinicians is the lack of biomarkers to help develop a more accurate diagnosis, with the possibility of initiating the most effective treatment. The detection of biological markers for psychosis has the potential to contribute to improvements in its diagnosis, prognosis and treatment effectiveness. The mixture of multiple biomarkers may improve the ability to differentiate and classify these patients. In this sense, the aim of this study was to analyze the literature concerning the potential biomarkers that could be used in medical practice and to review the newest developments in electrochemical sensors used for dopamine detection, one of the most important exploited biomarkers.

Task replication has been advocated as a practical solution to reduce response times in parallel systems. The analysis of replication-based systems typically rests on some strong assumptions: Poisson arrivals, exponential service times, or independent service times of the replicas. This study is motivated not only by several studies which indicate that these assumptions are unrealistic, but also by some elementary observations highlighting some contriving behaviour. For instance, when service times are not exponential, adding a replication factor can stabilize an unstable system, i.e., having infinite delays, but a tempting higher replication factor can push the system back in a perilous unstable state. This behaviour disappears however if the replicas are sufficiently correlated, in which case any replication factor would even be detrimental.Motivated by the need to dispense with such common yet unrealistic and misleading assumptions, we provide a robust theoretical framework to compute stochastic bounds on response time distributions in general replication systems subject to Markovian arrivals, quite general service times, and correlated replicas. Numerical results show that our bounds are accurate and improve state-of-the-art bounds in the case of Markovian arrivals by as much as three orders of magnitude. We apply our results to a practical application and highlight that correctly setting the replication factor crucially depends on both the service time distributions of the replicas and the degree of correlation amongst.\ud

The classical 1961 solution to the problem of determining the number of perfect matchings (or dimer coverings) of a rectangular grid graph -- due independently to Kasteleyn and to Temperley and Fisher -- consists of changing the sign of some of the entries in the adjacency matrix so that the Pfaffian of the new matrix gives the number of perfect matchings, and then evaluating this Pfaffian. Another classical method is to use the Lindstr\"om-Gessel-Viennot theorem on non-intersecting lattice paths to express the number of perfect matchings as a determinant, and then evaluate this determinant. In this paper we present a new method for solving the two dimensional dimer problem, which relies on the Cauchy-Binet theorem. It only involves facts that were known in the mid 1930's when the dimer problem was phrased, so it could have been discovered while the dimer problem was still open. We provide explicit product formulas for both the square and the hexagonal lattice. One advantage of our formula for the square lattice compared to the original formula of Kasteleyn, Temperley and Fisher is that ours has a linear number of factors, while the number of factors in the former is quadratic. Our result for the hexagonal lattice yields a formula for the number of periodic stepped surfaces that fit in an infinite tube of given cross-section, which can be regarded as a counterpart of MacMahon's boxed plane partition theorem., Comment: 26 pages, 10 figures

[ES] Este proyecto titulado `Las nuevas sexualidades en el arte contemporáneo¿ consiste en un libro ilustrado dedicado a la educación sexual. Es un trabajo personal que fomenta el aprendizaje y la adquisición de conocimiento de términos que crean controversia, empleando las habilidades logradas durante los cuatro años cursados en el Grado de Bellas Artes. En la primera parte se presentan los objetivos, la metodología del trabajo, así como el marco teórico y referencial, continuando con los términos y conceptos que se han seleccionado para ser ilustrados. En la segunda parte se desarrolla la fase de investigación y creación del libro ilustrado. La fase de investigación trata la búsqueda de definiciones de los términos y el estudio para relacionarlas con un estilo ilustrativo adecuado para desarrollar una armonía en conjunto de todos los conceptos utilizados. La fase de creación muestra la producción y el proceso de las ilustraciones e ideas, los bocetos previos, la técnica y la elaboración del libro ilustrado final., [EN] This project entitled `New sexualities in contemporary art¿ consists of an illustrated book dedicated to sexual education. It is a personal work that encourages learning and the acquisition of knowledge of terms that create controversy, using the skills achieved during the four years of the Fine Arts Degree. In the first part the objectives, the work methodology, as well as the theoretical and referential framework are presented, continuing with the terms and concepts that have been selected to be illustrated. The second part develops the research and creation phase of the illustrated book. The research phase deals with the search for definitions of the terms and the study to relate them to a suitable illustrative style to develop a harmony as a whole of all the concepts used. The creation phase shows the production and the process of the illustrations and ideas, the preliminary sketches, the technique and the elaboration of the final picture book.

A High-Granularity Timing Detector (HGTD) is proposed based on the Low-Gain Avalanche Detector (LGAD) for the ATLAS experiment to satisfy the time resolution requirement for the up-coming High Luminosity at LHC (HL-LHC). We report on beam test results for two proto-types LGADs (BV60 and BV170) developed for the HGTD. Such modules were manufactured by the Institute of High Energy Physics (IHEP) of Chinese Academy of Sciences (CAS) collaborated with Novel Device Laboratory (NDL) of the Beijing Normal University. The beam tests were performed with 5 GeV electron beam at DESY. The timing performance of the LGADs was compared to a trigger counter consisting of a quartz bar coupled to a SiPM readout while extracting reference SiPM by fitting with a Gaussian function. The time resolution was obtained as 41 ps and 63 ps for the BV60 and the BV170, respectively. To meet the timing resolution requirement of up-coming High Luminosity LHC (HL-LHC), a new detector based on the Low-Gain Avalanche Detector(LGAD), High-Granularity Timing Detector (HGTD), is under intensive research in ATLAS. Two types of IHEP-NDL LGADs(BV60 and BV170) for this update is being developed by Institute of High Energy Physics (IHEP) of Chinese Academic of Sciences (CAS) cooperated with Novel Device Laboratory (NDL) of Beijing Normal University and they are now under detailed study. These detectors are tested with $5GeV$ electron beam at DESY. A SiPM detector is chosen as a reference detector to get the timing resolution of LGADs. The fluctuation of time difference between LGAD and SiPM is extracted by fitting with a Gaussian function. Constant fraction discriminator (CFD) method is used to mitigate the effect of time walk. The timing resolution of $41 \pm 1 ps$ and $63 \pm 1 ps$ are obtained for BV60 and BV170 respectively.

Computing probabilistic end-to-end delay bounds is an old, yet still challenging problem. Stochastic network calculus enables closed-form delay bounds for a large class of arrival processes. However, it encounters difficulties in dealing with dependent flows, as standard techniques require to apply Holder’s inequality. In this paper, we present an alternative bounding technique that, under specific conditions, treats them as if flows were independent. We show in two case studies that it often provides better delay bounds while simultaneously significantly improving the computation time.

A novel voltammetric assay for captopril (CAP) determination by using an electrochemically pretreated pencil graphite electrode (PGE*) is presented. The electrochemical oxidation reaction of CAP was investigated with PGE* by using cyclic voltammetry and linear sweep voltammetry techniques. CAP was electrochemically inactive at the non-pretreated pencil graphite electrode surface, while a sharp anodic wave with an anodic peak potential at around 200 mV resulted by using the PGE*. According to kinetic studies upon the electrode behavior, a new reaction mechanism for electrochemical oxidation of captopril is proposed. The sensor was examined as a selective, simple and precise new electrochemical disposable electrode for the determination of CAP in pharmaceutical samples in complex medical cases associated with sleep apnea, with good results.

Hexagons with four-lobed regions called shamrocks removed from their center were introduced in their 2013 paper by Ciucu and Krattenthaler, where product formulas for the number of their lozenge tilings were provided. In analogy with the plane partitions which they generalize, we consider the problem of enumerating the lozenge tilings which are invariant under some symmetries of the underlying region. This leads to six symmetry classes besides the base case of requiring no symmetry. In this paper we provide product formulas for two of these symmetry classes (namely, the ones generalizing cyclically symmetric, and cyclically symmetric and transpose complementary plane partitions).

This study reports on deposition of asymmetrical substituted meso-phenyl porphyrin, 5-(4-carboxyphenyl)-10,15,20-triphenylporphyrin (CPTPP) thin films by matrix-assisted pulsed laser evaporation (MAPLE) on screen-printed electrodes, aiming for histamine detection. Raman spectrometry confirmed that CPTPP chemical structure was preserved in MAPLE-deposited thin films at 200 mJ/cm2 laser fluence. Atomic force microscopy topography revealed that MAPLE-deposited thin films have a better coverage on the working electrode made of carbon compared to the ones obtained by dropcasting. Cyclic voltammetry demonstrated that CPTPP is an appropriate mediator for histamine detection in trichloroacetic acid solution. We proved that MAPLE serves as a soft technique in fabrication of porphyrin thin films and patterns.

The paper deals with the spatial distribution of root density in highbush blueberry plantations of various ages for a proper planting distance recommendation and a better irrigation and fertilization management. The environmental conditions consist of sandy-loamy soils and a continental temperate climate. Two highbush blueberry cultivars were studied, ‘Bluecrop’ and ‘Blueray’. Root density (RD) and density of root cross-sectional area (RCSA) were investigated for various root diameters. It was found that the prevalent type of roots in highbush blueberry crops is the hair type, with root diameters less than 0.1 mm. Both RD and RCSA decreased with distance from plant and with soil depth; the 38-year-old crop showed a more developed root system versus the 8‑year-old crop. In both cases the roots did not grow more than 0.6 m laterally and more than 0.7 m deep. According to these results, the planting distances in highbush blueberry could be reduced to substantially increase the number of plants/ha and fruit yield. Irrigation application should be carried out to wet a proper soil volume, about 0.6–0.7 m deep for older crops, and about 0.5 m deep for younger crops.

In previous work we showed that gaps in dimer systems on the hexagonal and square lattices interact according to two dimensional electrostatics. In this paper we show that this holds for all weighted doubly periodic planar bipartite graphs in the generic liquid phase of the Kenyon-Okounkov-Sheffield classification of dimer models.

This paper introduces DNA-wrapped multi-walled carbon nanotube (MWCNT)-modified genosensor for the detection of Escherichia coli (E. coli) from polymerase chain reaction (PCR)-amplified real samples while Staphylococcus aureus (S. aureus) was used to investigate the selectivity of the biosensor. The capture probe specifically recognizing E. coli DNA and it was firstly interacted with MWCNTs for wrapping of single-stranded DNA (ssDNA) onto the nanomaterial. DNA-wrapped MWCNTs were then immobilised on the surface of disposable pencil graphite electrode (PGE) for the detection of DNA hybridization. Electrochemical behaviors of the modified PGEs were investigated using Raman spectroscopy and differential pulse voltammetry (DPV). The sequence selective DNA hybridization was determined and evaluated by changes in the intrinsic guanine oxidation signal at about 1.0 V by DPV. Numerous factors affecting the hybridization were optimized such as target concentration, hybridization time, etc. The designed DNA sensor can well detect E. coli DNA in 20 min detection time with 0.5 pmole of detection limit in 30 mu L of sample volume.

A novel voltammetric assay for the simultaneous determination of hydroquinone (HQ), catechol (CC) and resorcinol (RS) by using an electrochemically treated pencil graphite electrode modified with cobalt-phthalocyanine is described. Differential pulse voltammetric results showed three well-distinct oxidation peaks for HQ, CC and RS at 102 mV, 203 mV and 591 mV (vs. Ag/AgCl), respectively. Thus, the method can be applied to direct simultaneous determination without previous separation. The detection limits are 3.38 × 10−7 mol L−1 for HQ, 3.40 × 10−7 mol L−1 for CC and 7.23 × 10−7 mol L−1 for RS. The method was successfully applied to the direct determination of dihydroxybenzene isomers in tea samples, and the results were compared with chromatographic data.

A differential pulse voltammetric method for the determination of kojic acid (KA) was developed. The electrochemical behavior of KA at a multi-walled carbon nanotubes modified screen-printed electrode (MWCNTs-SPCE) was explored. A single irreversible oxidation peak was observed at a potential of 0.791 V and 0.989 V on the MWCNTs-SPCE and screen-printed carbon electrode (SPCE), respectively. Under the optimized conditions, the anodic peak current of KA recorded by differential pulse voltammetry varies linearly with KA concentration in the range 0.02–5 mM with a detection limit of 0.016 mM. The MWCNTs-SPCE was used for quantitative analysis of KA in food samples and the results indicate the feasibility of the amperometric method for KA analysis in routine detection.

The ability to predict the wind speed has an important role for renewable energy industry which relies on wind speed forecasts in order to calculate the power a wind farm can produce in an area. There are several well-known methods to predict wind speed, but in this paper we focus on short-term wind forecasting using Markov chains. Often gaps can be found in the time series of the wind speed measurements and repeating the measurements is usually not a valid option. In this study it is shown that using Markov chains these gaps from the time series can be filled (they can be generated in an efficient way), but only when the missing data is for a short period of time. Also, the developed Matlab programms that are used in the case study, are included in the paper beeing presented and commented by the authors. In the case study data from a wind farm in Italy is used. The available data are as average wind speed at an interval of 10 minutes in the time period 11/23/2005 - 4/27/2006.

In this paper we introduce a counterpart structure to the shamrocks studied in the paper A dual of Macmahon's theorem on plane partitions by M. Ciucu and C. Krattenthaler (2013) [5] , which, just like the latter, can be included at the center of a lattice hexagon on the triangular lattice so that the region obtained from the hexagon by removing it has its number of lozenge tilings given by a simple product formula. The new structure, called a fern, consists of an arbitrary number of equilateral triangles of alternating orientations lined up along a lattice line. The shamrock and the fern seem to be the only such connected structures with this property. It would be interesting to understand the reason for this.

In this paper, we developed and validated a posture detection system based on two sensor modules and positioning sensors. This device acquires in real-time values recorded by the sensors and based on these values, after filtering and data processing using a series of calculation algorithms, archives information on postural position changes over a period. Also, the aim is to obtain additional positioning functions, for example a function for checking the body posture and the selfcorrection posture for diminishing the wrong posture, by default for strengthening the back muscles and achieving health benefits. These benefits and implicitly, the improvement of the health status, can be obtained through the use of body posture monitoring devices. The final product is portable non-invasive device, has a small size and relatively low weight, suitable for attachment to the human body, and is characterized by high accuracy.

In this paper we propose a pipeline for brain mapping using a decentralized database with a blockchain architecture. We use a two-layer model for a distributed imaging data ledger capable of version control and authoring augmented data. Our platform is capable of direct volume rendering inside a browser window using WebGL. The data visualization pipeline allows for real-time multi-intensity transfer functions and global opacity of a given imaging recording. The platform is intended as a collaboration tool for multiple imaging laboratories and institutes and aims to help in organizing augmented data and multiple level-of-detail recordings used on a wide array of devices. We believe our platform will aid in brain mapping efforts for classification, measurement and visualization of cortical structures trough the aid of virtual reality and a scalable backend based on a standard blockchain technology.

Our paper presents a biomonitoring platform comprised of a software backend and an affordable wearable monitoring device. The biomonitoring field demands for large scale solutions involving plug and play devices in order to conduct ample studies.Our software platform is aimed at a scalable web backend with dedicated microservices for storing and processing real time data streams coming from a multitude of sensors. The hardware module was developed using an ergonomic design fit for outdoor environments and a fast connection using Bluetooth 4.0. We integrated sensors for electrocardiogram, oxygen saturation and heart rate.Our proposed platform allows for real time data monitoring of multiple subjects in an active environment.

The paper proposes a hand gesture recognition system based on support vector machine classification. The analysis was performed on two publicly available databases and one acquired in our laboratory. Methods based on computer vision provide improved results for the analysis of the databases in the literature. The analysis of the database acquired in our laboratory also provides very good classification precision of 95.7% when using HOG descriptors. This database has a higher degree of complexity due to the image size, the representation in the RGB color space, the presence of artifacts and the number of classes analyzed.

We present a way to integrate real-time multi-intensity transfer functions in a web browser environment using WebGL. We apply a two-pass rendering in order to establish the opacity and color of the given MRI recording. This pipeline helps viewing high resolution voxel domains and the adjustment of a transfer function for highlighting specific features types of a given DICOM recording. With recent advancements in the augmented and virtual reality domains medical imaging has become a center stage subject by brining the data closer to the patient and the doctor. Besides virtual reality, visualizing brain reconstructions is vital in brain mapping and neuro research. In conclusion we show a viable approach in rendering, processing and visualizing MRI data in real time in a Web browser.

This paper proposes an efficient convolutional neural network architecture for apparent age estimation from single face image capable of top performance without the use of a pretraining stage. The architecture consists of 9 convolution layers and 2 max pool layers and requires only 79k parameters. We also improve the results by applying a weighted class distribution which assures that overwhelmingly represented classes do not skew the prediction results. These are compared to other results in literature for both methods that use pretraining and those that do not. The proposed method achieves estimation errors comparable to the human reference and to existing methods while being characterized by efficiency at both training and testing, it employs orders of magnitude fewer parameters and much less training time than other state-of-the-art methods.

In this paper we enumerate the centrally symmetric lozenge tilings of a hexagon with a fern removed from its center. The proof is based on a variant of Kuo's graphical condensation method. An unexpected connection with the total number of tilings is established~---~when suitably normalized, the number of centrally symmetric tilings is equal to the square root of the total number of tilings. The results we present can be regarded as a new extension of the enumeration of self-complementary plane partitions that fit in a box., 14 pages

In this paper we enumerate the centrally symmetric lozenge tilings of a hexagon with a shamrock removed from its center. Our proof is based on a variant of Kuo's graphical condensation method in which only three of the four involved vertices are on the same face. As a special case, we obtain a new proof of the enumeration of the self-complementary plane partitions., 15 pages

As part of our ongoing work on the enumeration of symmetry classes of lozenge tilings of hexagons with certain four-lobed structures removed from their center, we consider the case of the tilings which are both vertically and horizontally symmetric. In order to handle this, we need an extension of Kuo's graphical condensation method, which works in the presence of free boundary. Our results allow us to compute exactly the correlation in a sea of dimers of a macroscopic dent in a 90 degree wedge with mixed boundary conditions. We use previous results to compute the correlation of the corresponding symmetrized system with no boundary, and show that its fourth root has the same log-asymptotics as the correlation of the dent in the 90 degree wedge. This is the first result of this kind involving a macroscopic defect. It suggests that the connections between dimer systems with gaps and 2D electrostatics may be deeper that previously thought., 17 pages

In this paper, we present a web platform for volume rendering of MRI data. Our platform are designed for mobile and desktop devices and VR applications. Unlike a classical desktop application which is platform dependent, we developed a series of software services in order to optimize and deliver fast and efficient volumetric data. The proposed platform is the summary of our initial efforts to implement raytracing algorithms in practical situations. We consider our platform and implementation a viable solution for volumetric rendering of MRI data in web environments.

Currently, stress is one of the main factors which causes most physical and mental illnesses. It has become part of our everyday life and is considered a physiological response to different physical, emotional or mental challenges causing the occurrence of discomfort states, tension or even of the burn-out syndrome. Since in every day of our lives all activities are carried out under the influence of a higher or lower level of stress, we decided to investigate the daily stress experienced by ordinary people, during typical days of their lives, by using an acquisition and quantification system. The current paper aim is to investigate the stress level of a group of patients during a word colour test by testing these patience’s ability to concentrate, in both resting and under stress conditions, using a simple and easy to implement acquisition and quantification system. Our primary goal is to achieve conclusive results to demonstrate the impact of stress on health both on the short and long-term and to make the population more aware of the harmful lifestyle it has the impact of any type of stress on our health. 'Prevention is better than cure.'

The paper proposes an efficient convolutional neural network for pupil detection capable of state-of-the art accuracy without pretraining. The system architecture consists of twelve convolution layers and two max pool layers with only 108450 prediction parameters. The validation conducted on ExCuSe datasets show that our solution achieves state-of-the-art performance in terms of detection rate within a pixel error bound.

In this paper we consider arbitrary hexagons on the triangular lattice with three arbitrary bowtie-shaped holes, whose centers form an equilateral triangle. The number of lozenge tilings of such general regions is not expected --- and indeed is not --- given by a simple product formula. However, when considering a certain natural normalized counterpart of any such region, we prove that the ratio between the number of tilings of the original and the number of tilings of the normalized region is given by a simple, conceptual product formula. Several seemingly unrelated previous results from the literature --- including Lai's formula for hexagons with three dents and Ciucu and Krattenthaler's formula for hexagons with a removed shamrock --- follow as immediate consequences of our result., In this new version we provide details of the proof which were overlooked in the first version. These are important because at the induction step of our proof one needs to ascertain that the second factor on the left hand side of equation (8.4) is not equal to zero

Simultaneous determination of catecholamine neurotransmitters epinephrine (EP) and norepinephrine (NP) using an electrochemically activated pencil graphite electrode (PGE*) is reported. Response characteristics of the PGE* toward the mentioned compounds were investigated by cyclic square wave voltammetry. In a mixture of analytes the peak currents of EP and NP increased with concentrations between 2.5 × 10−6 and 2.5 × 10−4 M. Detection limits of 8.32 × 10−7 M for EP and 9.92 × 10−7 M for NP were attained. The method was applied for their quantification in pharmaceutical and human plasma samples.