Miracle-dz/UniFAR-FTUs huggingface dataset:
Inapproximability for Metric Embeddings into R^d

We consider the problem of computing the smallest possible distortion for embedding of a given n-point metric space into R.d, where d is fixed (and small). For d = 1, it was known that approximating the minimum distortion with a factor better than roughly n1/12 is NP-hard. From this result we derive inapproximability with factor roughly n1/(22d-10) for every fixed d ges 2, by a conceptually very simple reduction. However, the proof of correctness involves a nontrivial result in geometric topology (whose current proof is based on ideas due to Jussi Vaisala). For d ges 3,we obtain a stronger inapproximability result by a different reduction: assuming PneNP, no polynomial- time algorithm can distinguish between spaces embeddable in R.d with constant distortion from spaces requiring distortion at least nc/d, for a constant c > 0. The exponent c/d has the correct order of magnitude, since every n-point metric space can be embedded in Rd with distortion O(n2/d log3/2 n) and such an embedding can be constructed in polynomial time by random projection. For d = 2, we give an example of a metric space that requires a large distortion for embedding in R2, while all not too large subspaces of it embed almost isometrically.
Variance analysis of x-ray CT sinograms in the presence of electronic noise background.

PURPOSE Low-dose x-ray computed tomography (CT) is clinically desired. Accurate noise modeling is a fundamental issue for low-dose CT image reconstruction via statistics-based sinogram restoration or statistical iterative image reconstruction. In this paper, the authors analyzed the statistical moments of low-dose CT data in the presence of electronic noise background. METHODS The authors first studied the statistical moment properties of detected signals in CT transmission domain, where the noise of detected signals is considered as quanta fluctuation upon electronic noise background. Then the authors derived, via the Taylor expansion, a new formula for the mean-variance relationship of the detected signals in CT sinogram domain, wherein the image formation becomes a linear operation between the sinogram data and the unknown image, rather than a nonlinear operation in the CT transmission domain. To get insight into the derived new formula by experiments, an anthropomorphic torso phantom was scanned repeatedly by a commercial CT scanner at five different mAs levels from 100 down to 17. RESULTS The results demonstrated that the electronic noise background is significant when low-mAs (or low-dose) scan is performed. CONCLUSIONS The influence of the electronic noise background should be considered in low-dose CT imaging.
An Adaptive Fuzzy-Inference-Rule-Based Flexible Model for Automatic Elastic Image Registration

In this study, a fuzzy-inference-rule-based flexible model (FIR-FM) for automatic elastic image registration is proposed. First, according to the characteristics of elastic image registration, an FIR-FM is proposed to model the complex geometric transformation and feature variation in elastic image registration. Then, by introducing the concept of motion estimation and the corresponding sum-of-squared-difference (SSD) objective function, the parameter learning rules of the proposed model are derived for general image registration. Based on the likelihood objective function, particular attention is also paid to the derivation of parameter learning rules for the case of partial image registration. Thus, an FIR-FM-based automatic elastic image registration algorithm is presented here. It is distinguished by its 1) strong ability in approximating complex nonlinear transformation inherited from fuzzy inference; 2) efficiency and adaptability in obtaining precise model parameters through effective parameter learning rules; and 3) completely automatic registration process that avoids the requirement of manual control, as in many traditional landmark-based algorithms. Our experiments show that the proposed method has an obvious advantage in speed and is comparable in registration accuracy as compared with a state-of-the-art algorithm.
Silicon-Neuron Junction: Capacitive Stimulation of an Individual Neuron on a Silicon Chip.

The integration of electronic circuitry and neuronal networks requires a bidirectional electrical communication between silicon elements and nerve cells. In recent years, the successful assembly of a neuron-to-silicon junction was reported with direct signal transfer from an individual neuron to a microscopic metal-free fieldeffect transistor [1,2]. In the present paper, we describe a complementary system, the direct silicon-to-neuron junction. An individual Retzius cell of the leech (diameter about 70 mm) is stimulated extracellularly from a microspot (diameter about 50 mm) of p-type silicon which is perfectly insulated by silicon oxide (dc resistance . 1 TV) [Fig. 1(a)]. The stimulation was achieved by capacitive coupling which is effective in our system due to the tight association of oxidized silicon and neuron. There is no Faradaic current flowing across the electrode/electrolyte interface in contrast to all systems with a metallic interface [3–8]. Thus any toxic electrochemical effects can be avoided. Silicon electrode. —Chips (30 3 10 mm) were cut from n-type Si wafers with a (100) surface and a resistance of 5–10 V cm (Aurel GmbH, Landsberg, FRG). We opened 16 radial lanes in a mask oxide grown in wet O2 at 1000 ±C by etching with ammonium fluoride solution (AF 87.5.12,5, Merck, Darmstadt). The lanes were 2.5 mm long (from 0.5 to 3 mm from the center of chip). Their width was 60 mm for the first millimeter and widened up to 700 mm at the periphery. These lanes were p-doped with boron [1,2]. Their dc resistance was about 400 V. A field oxide (1 mm) was grown at 1000 ±C. Stimulation spots (diameter 20–50 mm) were etched at the inner end of the lanes and covered by a thin layer of oxide (about 10 nm) grown in dry oxygen at 1100 ±C in a rapid thermal processing oven (AST, Dornstadt, FRG). After opening contact sites at the peripheral ends of the lanes, they were wire bonded. Finally, a Plexiglass chamber (radius 1.5 mm) was attached using silicone glue (Raumedic, Rehau, FRG). It separates the region of the stimulating spots from the ends of the conductive lanes which were connected to external electronics. Neuron-chip assembly. —Retzius cells were dissociated from Hirudo medicinalis [9] and kept in a plastic petri dish in a culture medium (L-15, Gibco, Life Technologies
CD24 Controls Expansion and Persistence of Autoreactive T Cells in the Central Nervous System during Experimental Autoimmune Encephalomyelitis

In the development of experimental autoimmune encephalomyelitis (EAE), a model for multiple sclerosis (MS), autoreactive T cells must be activated and clonally expand in the lymphoid organs, and then migrate into the central nervous system (CNS) where they undergo further activation. It is unclear whether the autoreactive T cells further expand in the CNS and if so, what interactions are required for this process. We have demonstrated previously that expression by the host cells of the heat-stable antigen (CD24), which was recently identified as a genetic modifier for MS, is essential for their susceptibility to EAE. Here we show that CD24 is essential for local clonal expansion and persistence of T cells after their migration into the CNS, and that expression of CD24 on either hematopoietic cells or nonhematopoietic antigen-presenting cells in the recipient is sufficient to confer susceptibility to EAE.
Survey on Multiclass Classification Methods

Supervised learning is based on the target value or the desired outputs. Various successful techniques have been proposed to solve the problem in the binary classification case. The multiclass classification case is more delicate one. In this short survey we investigate the various techniques for solving the multiclass classification problem. Various authors and research modified the multiclass classification approach such as one against one, one against all and Directed Acyclic Graph (DAG) which creates many binary classifiers and combines their results to determine the class label of a test pixel. They also describe the various extensible methods that are extended from binary class to solve the multiclass problem and also explain the method in which the classes are arranged into a tree.
Biofortification of UK food crops with selenium

Se is an essential element for animals. In man low dietary Se intakes are associated with health disorders including oxidative stress-related conditions, reduced fertility and immune functions and an increased risk of cancers. Although the reference nutrient intakes for adult females and males in the UK are 60 and 75 μg Se/d respectively, dietary Se intakes in the UK have declined from >60 μg Se/d in the 1970s to 35 μg Se/d in the 1990s, with a concomitant decline in human Se status. This decline in Se intake and status has been attributed primarily to the replacement of milling wheat having high levels of grain Se and grown on high-Se soils in North America with UK-sourced wheat having low levels of grain Se and grown on low-Se soils. An immediate solution to low dietary Se intake and status is to enrich UK-grown food crops using Se fertilisers (agronomic biofortification). Such a strategy has been adopted with success in Finland. It may also be possible to enrich food crops in the longer term by selecting or breeding crop varieties with enhanced Se-accumulation characteristics (genetic biofortification). The present paper will review the potential for biofortification of UK food crops with Se.
Combining dependency information and generalization in a pattern-based approach to the classification of lexical-semantic relation instances

This work addresses the classification of word pairs as instances of lexical-semantic relations. The classification is approached by leveraging patterns of co-occurrence contexts from corpus data. The significance of using dependency information, of augmenting the set of dependency paths provided to the system, and of generalizing patterns using part-of-speech information for the classification of lexical-semantic relation instances is analyzed. Results show that dependency information is decisive to achieve better results both in precision and recall, while generalizing features based on dependency information by replacing lexical forms with their part-of-speech increases the coverage of classification systems. Our experiments also make apparent that approaches based on the context where word pairs co-occur are upper-bound-limited by the times these appear in the same sentence. Therefore strategies to use information across sentence boundaries are necessary.
Very low phase-noise fully-integrated coupled VCOs

With the aim of achieving very low phase noise, two area and power consumption efficient methods of coupling two or more identical VCOs are presented. To verify the principles, a set of fully integrated, coupled VCOs of the cross-coupled differential pair type, was manufactured in a commercial SiGe HBT technology. The measured phase noise at 100 kHz offset frequency was -106 dBc/Hz at 6 GHz using two coupled VCOs and -103 dBc/Hz at 12 GHz using four coupled VCOs. A phase noise reduction of 1-6 dB was achieved relative to a single VCO of the same topology. In one of the two methods, output signals are additionally obtained in quadrature.
Microbial Simulation Experiment on Enhancing Coalbed Methane Production

Coalbed Methane(CBM) production enhancement for single wells is a big problem to CBM industrialization. Low production is due to insufficient gas generation by thermogenic. Luckily, Biogenic gas was found in many areas and its supply is assumed to improve coalbed methane production. Therefore, microbial simulation experiment will demonstrate the effectiveness of the assumption. From microbial simulation experiment on different coal ranks, it is found that microbes can use coals to produce biogas under laboratory conditions. With different temperatures for different experiments, it turns out that the gas production at 35 °C is greater than that at 15 °C, indicating that 35 °C is more suitable for microbes to produce gas. According to quantitative experiments, adding exogenous nutrients or exogenous bacteria can improve CBM production. Moreover, the production enhancement ratio can reach up to 115% under the condition of adding exogenous bacterial species, while the ratio for adding nutrients can be up to 144%.
Technology Corner: Brute Force Password Generation - Basic Iterative and Recursive Algorithms

Most information systems are secured at minimum by some form of password protection. For various reasons a password may be unavailable, requiring some form of password recovery procedure. One such procedure is software-based automated password recovery, where a program attempts to log into a system by repeatedly trying different password combinations. At the core of such software is a password generator. This article describes the basic iterative and recursive algorithms for generating all possible passwords of a given length, which is commonly referred to as brute-force password generation. The paper ends with a discussion of alternative password recovery procedures one should attempt before brute-force password recovery.
The Rise of Megaregions

The concept of megaregions is increasingly put forward among academics and policy makers as a new scale of economic co-ordination and social organisation. A megaregion is most commonly understood as an economic unit that comprises an agglomeration of cities and its less dense hinterlands, which are linked through infrastructure, economic connections, settlement patterns and land use, topography, an environmental system or a shared culture and history that together shape a common interest for the wider region. While there is an extensive literature on the potential benefits of a megaregion, work has been more limited in terms of identifying megaregions in an international context. This paper introduces an approach to delineate potential megaregions in the OECD.
A certificate revocation scheme for wireless ad hoc networks

The increasing prominence of wireless ad hoc networks is stimulating greater interest in developing adequate security mechanisms for securing applications involving these innovative networks paradigms. To-date, the proposed security schemes either provide inadequate security or they are too costly computationally, and therefore impractical for most ad hoc network applications.Adapting wired network security schemes---particularly those involved digital certificates---to wireless ad hoc networks environments, poses many difficulties, primarily for two reasons: the limitation of computational resources, and the absence of centralized entities for performing critical key management tasks such as certificate revocation.In this paper, we propose a certificate revocation scheme for wireless ad hoc networks. Our revocation scheme not only provides a measure of protection against malicious accusation attacks, but it also effectively eliminates the window of opportunity whereby revoked certificates can be used to access network services.
Coding for fast content download

We study the fundamental trade-off between storage and content download time. We show that the download time can be significantly reduced by dividing the content into chunks, encoding it to add redundancy and then distributing it across multiple disks. We determine the download time for two content access models - the fountain and fork-join models that involve simultaneous content access, and individual access from enqueued user requests respectively. For the fountain model we explicitly characterize the download time, while in the fork-join model we derive the upper and lower bounds. Our results show that coding reduces download time, through the diversity of distributing the data across more disks, even for the total storage used.
A Low-Complexity Multiple Error Correcting Architecture Using Novel Cross Parity Codes Over GF $(2^{m})$

This paper presents a novel low-complexity cross parity code, with a wide range of multiple bit error correction capability at a lower overhead, for improving the reliability in circuits over GF(2m). For an m input circuit, the proposed scheme can correct m ≤ Dw ≤ 3m/2 -1 multiple error combinations out of all the possible 2m - 1 errors, which is superior to many existing approaches. From the mathematical and practical evaluations, the best case error correction is m/2 bit errors. Tests on 80-bit parallel and, for the first time, on 163-bit Federal Information Processing Standard/National Institute of Standards and Technology (FIPS/NIST) standard word-level Galois field (GF) multipliers, suggest that it requires only 106% and 170% area overheads, respectively, which is lower than the existing approaches, while error injection-based behavioral analysis demonstrates its wider error correction capability.
The Gaia Project - technique, performance and status

Gaia is a satellite mission of the ESA, aiming at absolute astrometric measurements of about one billion stars (all stars down to 20th magnitude, with unprecedented accuracy. Additionally, magnitudes and colors will be obtained for all these stars, while radial-velocities and spectral properties will be determined only for bright objects (V < 17.5). At 15th magnitude Gaia aims at an angular accuracy of 20 microarcseconds (μ as). This goal can only be reached if the geometry of the telescopes, the detectors, and the pointing of Gaia at each moment (“attitude”) can be inferred from the Gaia measurements itself with μ as accuracy. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Cultural Identity in Conservation of the Cultural Landscape values in Uraman Takht Village—Iran

Identity is the basis and foundation of the cultural landscape. Despite the emphasis of international documents and charters on its various aspects and necessity, today, the cultural landscape is threatened by extinction due to changes of many parameters. Accordingly, it is crucial to find an approach that can sustain cultural identity and its values in the changing world of the twenty-first century. Given the qualitative and the changing nature of cultural identity, achieving an approach which can lead to its continuation is not straightforward. By reviewing and analyzing international conventions and documents, on the one hand, and expert opinions, on the other hand, the present study, therefore, aimed to find out how the approach of cultural landscape values conservation can lead to the continuation of cultural identity in the natural and cultural heritage of Uraman Takht. This paper employed qualitative research methods as a basis for data collection and analysis, which primarily involved the use of content analysis along with field observations and interviews with stakeholders and indigenous residents.
Interactions of the CelS binding ligand with various receptor domains of the Clostridium thermocellum cellulosomal scaffolding protein, CipA

The Clostridium thermocellum cellulosomal scaffolding protein, CipA, acts as an anchor on the cellulose surface for the various catalytic subunits of the cellulosome, a large extracellular cellulase complex. CipA contains nine repeated domains that serve as receptors for the cellulosomal catalytic subunits, each of which carries a conserved, duplicated ligand sequence (DS). Four representative CipA receptor domains with sequence dissimilarity were cloned and expressed in Escherichia coli. The interaction of these cloned receptor domains with the duplicated ligand sequence of CelS (expressed as a thioredoxin fusion protein, TRX-DSCelS), was studied by nondenaturing polyacrylamide gel electrophoresis. TRX-DSCelS formed a stable complex with each of the four receptor domains, indicating that CelS, the most abundant cellulosomal catalytic subunit, binds nonselectively to all of the CipA receptors. Conversely, the duplicated sequence of CipA (in the form of TRX-DSCipA), which is homologous to that of CelS, did not bind to any of the receptors under the experimental conditions.
Constructing similarity networks using the Fisher information metric

The Fisher information metric defines a Riemannian space where distances reflect similarity with respect to a given probability distribution. This metric can be used during the process of building a relational network, resulting in a structure that is informed about the similarity criterion. Furthermore, the relational nature of this network allows for an intuitive interpretation of the data through their location within the network and the way it relates to the most representative cases or prototypes.
L’agroecologia come nuovo paradigma per l’agricoltura sostenibile. Un breve quadro teorico. [Agroecology as a new paradigm for sustainable agriculture. A short theoretical framework]

This paper aim at analyze the concept of sustainable agriculture developing the base of agroecology as scientific multifunctional approach to obtain sustainable agroecosystem. Agroecology has been recognized as both a scientific method and a set of practical activities to study and project sustainability in agriculture at several scale, but unfortunately it is still unknown or restricted to the international cooperation sector. At the beginning of this paper it is studied the theoretical framework of agroecology as an holistic system of study and the evolution of its concept along time. Then it is examined the concept of agroecosystem showing some agroecological practices and examples of agroecology experiences realized around the world.
Desvenlafaxine Versus Placebo in the Treatment of Children and Adolescents with Major Depressive Disorder

Abstract Objective: To evaluate the short-term efficacy and safety of desvenlafaxine versus placebo in the treatment of children and adolescents with major depressive disorder (MDD). Methods: Outpatient children (7–11 years) and adolescents (12–17 years) who met DSM-IV-TR criteria for MDD and had screening and baseline Children's Depression Rating Scale-Revised (CDRS-R) total scores >40 were randomly assigned to 8 weeks of treatment with placebo, low exposure desvenlafaxine (20, 30, or 35 mg/day based on baseline weight), or higher exposure desvenlafaxine (25, 35, or 50 mg/day based on baseline weight). The primary efficacy endpoint was change from baseline in CDRS-R total score at week 8, analyzed using a mixed-effects model for repeated measures. Secondary efficacy assessments included Clinical Global Impressions-Severity and Clinical Global Impressions-Improvement scales. Safety assessments included adverse events and the Columbia-Suicide Severity Rating Scale. Results: The safety population included 363 patients (children, n = 109; adolescents, n = 254). No statistical separation from placebo was observed for either desvenlafaxine group for CDRS-R total score or for any secondary efficacy endpoint. At week 8, adjusted mean (standard error) changes from baseline in CDRS-R total score for the desvenlafaxine low exposure, desvenlafaxine high exposure, and placebo groups were −23.7 (1.1), −24.4 (1.1), and −22.9 (1.1), respectively. The incidence of adverse events was similar among groups. Conclusion: Low and high exposure desvenlafaxine groups did not demonstrate efficacy for the treatment of MDD in children and adolescents in this double-blind, placebo-controlled trial. Desvenlafaxine (20–50 mg/day) was generally safe and well tolerated with no new safety signals identified in pediatric patients with MDD in this study.