pinecone/core-2020-05-10-deduplication huggingface dataset:
On the multiaxial fatigue assessment of complex three-dimensional stress concentrators

This paper assesses and quantifies the detrimental effects of complex tri-dimensional notches subjected to uniaxial and multiaxial fatigue loading. A number of experimental results taken from the technical literature and generated by testing specimens containing complex geometrical features were reanalysed using a critical distance/plane method. The investigated notched samples were tested under uniaxial and multiaxial constant amplitude load histories, considering also the effects of non-zero mean stresses as well as non-proportional loading. The common feature of the considered notched geometries was that the position of the critical location changed as the degree of multiaxiality of the applied loading varied. The relevant linear-elastic stress fields in the vicinity of the crack initiation points were calculated by the Finite Element method and subsequently post-processed using the Modified Wöhler Curve Method in conjunction with the Theory of Critical Distances (the latter theory being applied in the form of the Point Method). This validation exercise confirms the accuracy and reliability of our multiaxial fatigue life assessment technique, which can be efficiently used in situations of practical interest by directly post-processing the relevant linear-elastic stress fields calculated with commercial Finite Element software packages.Safe Technology Limite
Composition of the essential oil and micromorphology of trichomes of Teucrium salviastrum, an endemic species from Portugal

The morphology, distribution and release mechanism of the glandular trichomes of Teucrium salviastrum Schreber were studied, along with the chemical composition of the essential oils. Peltate and capitate trichomes are present on both vegetative and reproductive organs. In this study, particular emphasis is given to the capitate trichomes with long multicellular stalks. These trichomes are very abundant, and the secretion material is released by cuticule rupture on the top of the head cells. Also noteworthy is the presence of peltate trichomes on the upper surface of the ovary. Although already described in some Lamiaceae, these trichomes have not been recorded previously on any other Teucrium species. The composition of the essential oil was studied using mainly GC and GC-MS. The oils isolated from leaves, collected during the flowering and post-flowering phases of the plant, as well as the oil isolated from the flower heads, exhibited a similar chemical composition. Nevertheless, the oils showed remarkable differences in composition when compared to those reported in the literature for the same species. The present study has shown that our oil consisted mainly of E-beta-farnesene (26.1-29.3%), E-caryophyllene (19.1-24.1%) and germacrene D (13.7-21.6%). The major compound of our samples, E-beta-farnesene, is reported for the first time for this species. Copyright © 2002 John Wiley & Sons, Ltd.http://dx.doi.org/10.1002/ffj.106
Involvement of endoplasmic reticulum Ca2+ release through ryanodine and inositol 1,4,5-triphosphate receptors in the neurotoxic effects induced by the amyloid-beta peptide

Studies with in-vitro-cultured neurons treated with amyloid-beta (Abeta) peptides demonstrated neuronal loss by apoptosis that is due, at least in part, to the perturbation of intracellular Ca2+ homeostasis. In addition, it was shown that an endoplasmic reticulum (ER)-specific apoptotic pathway mediated by caspase-12, which is activated upon the perturbation of ER Ca2+ homeostasis, may contribute to Abeta toxicity. To elucidate the involvement of deregulation of ER Ca2+ homeostasis in neuronal death induced by Abeta peptides, we have performed a comparative study using the synthetic peptides Abeta25-35 or Abeta1-40 and thapsigargin, a selective inhibitor of Ca2+ uptake into the ER. Incubation of cortical neurons with thapsigargin (2.5 muM) increased the intracellular Ca2+ levels and activated caspase-3, leading to a significant increase in the number of apoptotic cells. Similarly, upon incubation of cortical cultures with the Abeta peptides (Abeta25-35, 25 muM; Abeta1-40, 0.5 muM), we observed a significant increase in [Ca2+]i, in caspase-3-like activity, and in number of neurons exhibiting apoptotic morphology. The role of ER Ca2+ release through ryanodine receptors (RyR) or inositol 1,4,5-trisphosphate receptors (IP3R) in Abeta neurotoxicity has been also investigated. Dantrolene and xestospongin C, inhibitors of ER Ca2+ release through RyR or IP3R, were able to prevent the increase in [Ca2+]i and the activation of caspase-3 and to protect partially against apoptosis induced by treatment with Abeta25-35 or Abeta1-40. In conclusion, our results demonstrate that the release of Ca2+ from the ER, mediated by both RyR and IP3R, is involved in Abeta toxicity and can contribute, together with the activation of other intracellular neurotoxic mechanisms, to Abeta-induced neuronal death. This study suggests that Abeta accumulation may have a key role in the pathogenesis of AD as a result of deregulation of ER Ca2+ homeostasis. © 2004 Wiley-Liss, Inc.http://dx.doi.org/10.1002/jnr.2013
Amyloid ß-Peptide Promotes Permeability Transition Pore in Brain Mitochondria

In this work the effect of the neurotoxic amino acid sequence, Aß25–35, on brain mitochondrial permeability transition pore (PTP) was studied. For the purpose, the mitochondrial transmembrane potential (??m), mitochondrial respiration and the calcium fluxes were examined. It was observed that Aß25–35, in the presence of Ca2+, decreased the ??m, the capacity of brain mitochondria to accumulate calcium and led to a complete uncoupling of the respiration. However, the reverse sequence of the peptide Aß25–35 (Aß35–25) did not promote the PTP. The alterations promoted by Aß35–25 and/or Ca2+ could be reversed when Ca2+ was removed by EGTA or when ADP plus oligomycin were present. The pre-treatment with CsA or ADP plus oligomycin prevented the ??m drop and preserved the capacity of mitochondria to accumulate Ca2+. These results suggest that Aß25–35 can promote the PTP induced by Ca2+.http://dx.doi.org/10.1023/A:101553680830
Regulation by Magnesium of Potato Tuber Mitochondrial Respiratory Activities

Dehydrogenase activities of potato tuber mitochondria and corresponding phosphorylation rates were measured for the dependence on external and mitochondrial matrix Mg2+. Magnesium stimulated state 3 and state 4 respiration, with significantly different concentrations of matrix Mg2+ required for optimal activities of the several substrates. Maximal stimulation of respiration with all substrates was obtained at 2-mM external Mg2+. However, respiration of malate, citrate, and a-ketoglutarate requires at least 4-mM Mg2+ inside mitochondria for maximization of dehydrogenase activities. The phosphorylation system, requires a low level of internal Mg2+ (0.25 mM) to reach high activity, as judged by succinate-dependent respiration. However, mitochondria respiring on citrate or a-ketoglutarate only sustain high levels of phosphorylation with at least 4-mM matrix Mg2+. Respiration of succinate is active without external and matrix Mg2+, although stimulated by the cation. Respiration of a-ketoglutarate was strictly dependent on external Mg2+ required for substrate transport into mitochondria, and internal Mg2+ is required for dehydrogenase activity. Respiration of citrate and malate also depend on internal Mg2+ but, unlike a-ketoglutarate, some activity still remains without external Mg2+. All the substrates revealed insensitive to external and internal mitochondrial Ca2+, except the exogenous NADH dehydrogenase, which requires either external Ca2+ or Mg2+ for detectable activity. Calcium is more efficient than Mg2+, both having cumulative stimulation. Unlike Ca2+, Mn2+ could substitute for Mg2+, before and after addition of A23, showing its ability to regulate phosphorylation and succinate dehydrogenase activities, with almost the same efficiency as Mg2+.http://dx.doi.org/10.1007/s10863-004-8999-
The problem of camouflaging via mirror reflections

This work is related to billiards and their applications in geometric optics. It is known that perfectly invisible bodies with mirror surface do not exist. It is therefore natural to search for bodies that are, in a sense, close to invisible. We introduce a  visibility index of a body measuring the mean angle of deviation of incident light rays, and derive a lower estimate for this index. This estimate is a function of the body's volume and of the minimal radius of a ball containing the body. This result is far from being final and opens a possibility for further research
Collaborative video searching on a tabletop

Almost all system and application design for multimedia systems is based around a single user working in isolation to perform some task yet much of the work for which we use computers to help us, is based on working collaboratively with colleagues. Groupware systems do support user collaboration but typically this is supported through software and users still physically work independently. Tabletop systems, such as the DiamondTouch from MERL, are interface devices which support direct user collaboration on a tabletop. When a tabletop is used as the interface for a multimedia system, such as a video search system, then this kind of direct collaboration raises many questions for system design. In this paper we present a tabletop system for supporting a pair of users in a video search task and we evaluate the system not only in terms of search performance but also in terms of user–user interaction and how different user personalities within each pair of searchers impacts search performance and user interaction. Incorporating the user into the system evaluation as we have done here reveals several interesting results and has important ramifications for the design of a multimedia search system
Analgesics for postoperative pain after tonsillectomy and\ud
adenoidectomy in children

This is the protocol for a review and there is no abstract. The objectives are as follows:\ud
To assess the effectiveness of analgesics for management of post-operative pain in children who have undergone a tonsillectomy or adenoidectomy, or both. The questions to be addressed are:\ud
1. What analgesics (or combination of analgesics) are effective for the treatment of post-operative pain in children who have undergone a tonsillectomy or adenoidectomy, or both?\ud
2. What adverse effects, if any, are associated with the use of individual or combined analgesics for treatment of post-operative pain in children who have undergone a tonsillectomy or adenoidectomy, or both
Calibration and characterisation with a new laser-based magnetostriction measurement system

A laser-based magnet measurement system has been developed to measure the magnetostrictive strain of large cylindrical samples. The measurement system incorporates a solenoid capable of generating a maximum magnetic field intensity of 3000 Oe and a laser displacement sensor. For calibration and evaluation purposes, the positive magnetostrictions of two different types of giant magnetostrictive Tb–Dy–Fe-based materials were accessed with this system. A magnetostrictive strain of 622 ppm was obtained at 3000 Oe for TbxDy1-xFe2-y, compared with 725 ppm for Tb0.27Dy0.73Fe2. A rod of sintered cobalt ferrite was also measured. This exhibited negative magnetostriction, with a maximum contraction of 260 ppm at 3000 Oe
Detection of internal quality in seedless watermelon by acoustic impulse response

Recent commercialisation of seedless watermelon varieties relies on the guarantee of a high quality product. Several internal defects may deteriorate greatly this fruit: (a) creases and/or large voids in the flesh, (b) overripeness and (c) bruises due to impact. The objective of this research was to develop a feasible non-destructive procedure for detecting these defects in individual fruits, based on acoustic impulse response.\ud
A device consisting of a microphone, structural elements and a mechanical impact generator was designed and tested. Good and defective seedless watermelons were tested with the acoustic device. Spectral parameters were examined as potential non-destructive predictors of internal disorders. Waveband magnitude parameters, obtained by summing the magnitude of the spectrum between two frequencies in a specified band width (always including between 40 and 500 Hz), were the acoustic parameters showing the best ability to detect internal disorders
S 2p photoabsorption of the SF5CF3 molecule: Experiment, theory and comparison with SF6

The S 2p core excitation spectrum of the SF5CF3 molecule has been measured in the total ion yield mode. It resembles a lot the analogous spectrum of SF6, also recorded in this study, displaying intense transitions to the empty molecular orbitals both below and above the S 2p ionization potential (IP) and weak transitions to the Rydberg orbitals. The S 2p photoabsorption spectra of SF6 and SF5CF3 have been calculated using time-dependent density functional theory, whereby the spin–orbit coupling was included for the transitions below the S 2p IP. The agreement between experiment and theory is good for both molecules, which allows us to assign the main S 2p absorption features in SF5CF3
Analysis of glass fiber reinforced cement (GRC) fracture surfaces

Glass fiber reinforced cement (GRC) is a composite material produced by the union of a cement mortar matrix and chopped glass fibers. Its good mechanical properties deteriorate with time. This phenomenon has been studied performing a tensile test program on both young and aged samples of GRC produced by using different chemical additives. Once the tests were carried out, a microstructural analysis of fracture surfaces was performed using a scanning electronic microscope (SEM). Pictures taken showed that the addition of metakaolin enables more fibers to be pulled out from the matrix instead of being broken in aged GRC samples. However, the increase in the number of such fibers pulled out did not prevent the embrittlement of GRC. Also, all the other chemical additions used did not show any improvement in the mechanical properties of GRC
The Absolute Line Quadric and Camera Autocalibration

We introduce a geometrical object providing the same information as the absolute conic: the absolute line quadric (ALQ). After the introduction of the necessary exterior algebra and Grassmannian geometry tools, we analyze the Grassmannian of lines of P^3 from both the projective and Euclidean points of view. The exterior algebra setting allows then to introduce the ALQ as a quadric arising very naturally from the dual absolute quadric. We fully characterize the ALQ and provide clean relationships to solve the inverse problem, i.e., recovering the Euclidean structure of space from the ALQ. Finally we show how the ALQ turns out to be particularly suitable to address the Euclidean autocalibration of a set of cameras with square pixels and otherwise varying intrinsic parameters, providing new linear and non-linear algorithms for this problem. We also provide experimental results showing the good performance of the techniques
Microstructure, magnetic and mechanical properties of Ni-Zn ferrites prepared by Powder Injection Moulding

Nowadays, the electronic industry demands small and complex parts as a consequence of the miniaturization of electronic devices. Powder injection moulding (PIM) is an emerging technique for the manufacturing of magnetic ceramics. In this paper, we analyze the sintering process, between 900 °C and 1300 °C, of Ni–Zn ferrites prepared by PIM. In particular, the densification behaviour, microstructure and mechanical properties of samples with toroidal and bar geometry were analyzed at different temperatures. Additionally, the magnetic behaviour (complex permeability and magnetic losses factor) of these compacts was compared with that of samples prepared by conventional powder compaction. Finally, the mechanical behaviour (elastic modulus, flexure strength and fracture toughness) was analyzed as a function of the powder loading of feedstock. The final microstructure of prepared samples was correlated with the macroscopic behaviour. A good agreement was established between the densities and population of defects found in the materials depending on the sintering conditions. In general, the final mechanical and magnetic properties of PIM samples were enhanced relative those obtained by uniaxial compaction
Data-Intensive architecture for scientific knowledge discovery

This paper presents a data-intensive architecture that demonstrates the ability to support applications from a wide range of application domains, and support the different types of users involved in defining, designing and executing data-intensive processing tasks. The prototype architecture is introduced, and the pivotal role of DISPEL as a canonical language is explained. The architecture promotes the exploration and exploitation of distributed and heterogeneous data and spans the complete knowledge discovery process, from data preparation, to analysis, to evaluation and reiteration. The architecture evaluation included large-scale applications from astronomy, cosmology, hydrology, functional genetics, imaging processing and seismology
Steady-state thermal analysis of an innovative receiver for linear Fresnel reflectors

The study of the performance of an innovative receiver for linear Fresnel reflectors is carried out in this paper, and the results are analyzed with a physics perspective of the process. The receiver consists of a bundle of tubes parallel to the mirror arrays, resulting on a smaller cross section for the same receiver width as the number of tubes increases, due to the diminution of their diameter. This implies higher heat carrier fluid speeds, and thus, a more effective heat transfer process, although it conveys higher pumping power as well. Mass flow is optimized for different tubes diameters, different impinging radiation intensities and different fluid inlet temperatures. It is found that the best receiver design, namely the tubes diameter that maximizes the exergetic efficiency for given working conditions, is similar for the cases studied. There is a range of tubes diameters that imply similar efficiencies, which can drive to capital cost reduction thanks to the flexibility of design. In addition, the length of the receiver is also optimized, and it is observed that the optimal length is similar for the working conditions considered. As a result of this study, it is found that this innovative receiver provides an optimum design for the whole day, even though impinging radiation intensity varies notably. Thermal features of this type of receiver could be the base of a new generation of concentrated solar power plants with a great potential for cost reduction, because of the simplicity of the system and the lower weigh of the components, plus the flexibility of using the receiver tubes for different streams of the heat carrier fluid
QuantiDOPA: A Quantification Software for Dopaminergic Neurotransmission SPECT

Quantification of neurotransmission Single-Photon Emission Computed Tomography (SPECT) studies of the dopaminergic system can be used to track, stage and facilitate early diagnosis of the disease. The aim of this study was to implement QuantiDOPA, a semi-automatic quantification software of application in clinical routine to reconstruct and quantify neurotransmission SPECT studies using radioligands which bind the dopamine transporter (DAT). To this end, a workflow oriented framework for the biomedical imaging (GIMIAS) was employed. QuantiDOPA allows the user to perform a semiautomatic quantification of striatal uptake by following three stages: reconstruction, normalization and quantification. QuantiDOPA is a useful tool for semi-automatic quantification inDAT SPECT imaging and it has revealed simple and flexibl
Non uniform embedding based on relevance analysis with reduced computational complexity: application to the detection of pathologies from biosignal recordings

Nonlinear analysis tools for studying and characterizing the dynamics of physiological signals have gained popularity, mainly because tracking sudden alterations of the inherent complexity of biological processes might be an indicator of altered physiological states.\ud
Typically, in order to perform an analysis with such tools, the physiological variables that describe the biological process under study are used to reconstruct the underlying dynamics of the biological processes. For that goal, a procedure called time-delay or uniform embedding is usually employed.\ud
Nonetheless, there is evidence of its inability for dealing with non-stationary signals, as those recorded from many physiological processes.\ud
To handle with such a drawback, this paper evaluates the utility of non-conventional time series reconstruction procedures based on non uniform embedding, applying them to automatic pattern recognition tasks. The paper compares a state of the art non uniform approach with a novel scheme\ud
which fuses embedding and feature selection at once, searching for better reconstructions of the dynamics of the system. Moreover, results are also compared with two classic uniform embedding techniques. Thus, the goal is comparing uniform and non uniform reconstruction techniques, including the one proposed in this work, for pattern recognition in biomedical signal processing tasks. Once the state space is reconstructed, the scheme followed characterizes with three classic nonlinear dynamic features (Largest Lyapunov Exponent, Correlation Dimension and Recurrence Period Density Entropy), while classification is carried out by means of a simple k-nn classifier. In order to test its generalization capabilities, the approach was tested with three different physiological databases (Speech Pathologies, Epilepsy and Heart Murmurs).\ud
In terms of the accuracy obtained to automatically detect the presence of pathologies, and for the three types of biosignals analyzed, the non uniform techniques used in this work lightly outperformed the results obtained using the uniform methods, suggesting their usefulness to characterize non-stationary biomedical signals in pattern recognition applications. On the other hand, in view of the\ud
results obtained and its low computational load, the proposed technique suggests its applicability for the\ud
applications under study
Non-Destructive Global and Localized 2D T1/T2 NMR Relaxometry to Resolve Microstructure in Apples Affected by Watercore

Apples can be considered as having a complex system formed by several structures at different organization levels: macroscale (>100 μm) and microscale (<100 μm). This\ud
work implements 2D T1/T2 global and localized relaxometry\ud
sequences on whole apples to be able to perform an intensive\ud
non-destructive and non-invasive microstructure study. The 2D T1/T2 cross-correlation spectroscopy allows the extraction of quantitative information about the water compartmentation in different subcellular organelles. A clear difference is found as sound apples show neat peaks for water in different subcellular compartments, such as vacuolar, cytoplasmatic and extracellular water, while in watercore-affected tissues such compartments\ud
appear merged. Localized relaxometry allows for the\ud
predefinition of slices in order to understand the microstructure of a particular region of the fruit, providing information that cannot be derived from global 2D T1/T2 relaxometry