874 research outputs found

    Generalization in chess thinking

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    In this work we deal with generalization in chess thinking. Generalization is a complex process based on information people acquired during previous experiences. In the field of chess, chess books, chess education and personal game practice supply the information for generalization to occur. The way in which generalization is performed in chess is still a topic that deserves more research. In this article we dwell on early theories about chess thinking. We underline the role played by what we call configural concepts, in which geometrical patterns and logical expected developments coexist. We suggest that the idea of configural concepts, along with generalization and abduction constitute the basis of chess thinking

    Generalización en el pensamiento al jugar ajedrez

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    In this work we deal with generalization in chess thinking. Generalization is a complex process based on information people acquired during previous experiences. In the field of chess, chess books, chess education and personal game practice supply the information for generalization to occur. The way in which generalization is performed in chess is still a topic that deserves more research. In this article we dwell on early theories about chess thinking. We underline the role played by what we call configural concepts, in which geometrical patterns and logical expected developments coexist. We suggest that the idea of configural concepts, along with generalization and abduction constitute the basis of chess thinking.En este trabajo abordamos la generalización en el pensamiento en el juego del ajedrez. La generalización es un complejo proceso basado en información adquirida durante experiencias previas. En el campo del ajedrez, los libros de ajedrez, la educación en el ajedrez y la práctica personal con el juego aportan la información que posibilita la generalización. La forma en que la generalización se produce en el ajedrez es todavía un tema que merece más investigación. En este artículo consideramos teorías tempranas sobre el pensamiento en el ajedrez. Subrayamos el papel que juegan lo que llamamos conceptos configurales, en los cuales coexisten los patrones geométricos y desarrollos lógicos esperados. Sugerimos que la idea de conceptos configurales, junto con la generalización y la abducción constituyen la base del pensamiento en el ajedrez

    Generalization in chess thinking

    Get PDF
    In this work we deal with generalization in chess thinking. Generalization is a complex process based on information people acquired during previous experiences. In the field of chess, chess books, chess education and personal game practice supply the information for generalization to occur. The way in which generalization is performed in chess is still a topic that deserves more research. In this article we dwell on early theories about chess thinking. We underline the role played by what we call configural concepts, in which geometrical patterns and logical expected developments coexist. We suggest that the idea of configural concepts, along with generalization and abduction constitute the basis of chess thinking.Generalización en el pensamiento al jugar ajedrezEn este trabajo abordamos la generalización en el pensamiento en el juego del ajedrez. La generalización es un complejo proceso basado en información adquirida durante experiencias previas. En el campo del ajedrez, los libros de ajedrez, la educación en el ajedrez y la práctica personal con el juego aportan la información que posibilita la generalización. La forma en que la generalización se produce en el ajedrez es todavía un tema que merece más investigación. En este artículo consideramos teorías tempranas sobre el pensamiento en el ajedrez. Subrayamos el papel que juegan lo que llamamos conceptos configurales, en los cuales coexisten los patrones geométricos y desarrollos lógicos esperados. Sugerimos que la idea de conceptos configurales, junto con la generalización y la abducción constituyen la base del pensamiento en el ajedrez.Handle: http://hdl.handle.net/10481/34995WOS-ESCINº de citas en WOS (2017): 1 (Citas de 2º orden, 1

    CMB Observations: improvements of the performance of correlation radiometers by signal modulation and synchronous detection

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    Observation of the fine structures (anisotropies, polarization, spectral distortions) of the Cosmic Microwave Background (CMB) is hampered by instabilities, 1/f noise and asymmetries of the radiometers used to carry on the measurements. Addition of modulation and synchronous detection allows to increase the overall stability and the noise rejection of the radiometers used for CMB studies. In this paper we discuss the advantages this technique has when we try to detect CMB polarization. The behaviour of a two channel correlation receiver to which phase modulation and synchronous detection have been added is examined. Practical formulae for evaluating the improvements are presented.Comment: 18 pages, 3 figures, New Astronomy accepte

    Nab-paclitaxel for the treatment of triple-negative breast cancer: Rationale, clinical data and future perspectives

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    Triple-negative breast cancer (TNBC) accounts for ∼10-20% of breast cancers and is associated with relatively poor prognosis, earlier disease recurrence and higher number of visceral metastases. Despite an increasing understanding of the molecular heterogeneity of TNBC, clinical trials of targeted agents have thus far been disappointing; chemotherapy, in particular with anthracycline and taxanes, remains the backbone medical management for both early and metastatic TNBC. Nab-paclitaxel is a solvent-free, albumin-bound, nanoparticle formulation of paclitaxel and represents a novel formulation of an established, effective chemotherapeutic agent. Nab-paclitaxel has been specifically designed to overcome the limitations of conventional taxane formulations, including the barriers to effective drug delivery of highly lipophilic agents. It has shown significant efficacy and better tolerability than conventional taxanes in metastatic breast cancer and is approved for use in this setting. Increasing evidence suggests that nab-paclitaxel is effective in patients with more aggressive tumours, as seen in TNBC. Indeed, results of Phase II/III studies indicate that nab-paclitaxel may be effective as neoadjuvant treatment of TNBC. This article reviews the rationale and evidence supporting a role for nab-paclitaxel in the treatment of TNBC, including ongoing studies such as ADAPT-TN and tnAcity. In addition, the article reviews ongoing research into targeted therapies and immuno-oncology for the treatment of TNBC, and explores the potential role, current evidence and ongoing studies of nab-paclitaxel as the chemotherapy partner in combination with immunotherapy, where the unique properties of this taxane, including the lack of requirement for steroid pre-medication, may present an advantage

    The Araucaria Project. First Cepheid Distance to the Sculptor Group Galaxy NGC 7793 from Variables discovered in a Wide-Field Imaging Survey

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    We have detected, for the first time, Cepheid variables in the Sculptor Group spiral galaxy NGC 7793. From wide-field images obtained in the optical V and I bands on 56 nights in 2003-2005, we have discovered 17 long-period (24-62 days) Cepheids whose periods and mean magnitudes define tight period-luminosity relations. We use the (V-I) Wesenheit index to determine a reddening-free true distance modulus to NGC 7793 of 27.68 ± 0.05 mag (internal error) ± 0.08 mag (systematic error). The comparison of the reddened distance moduli in V and I with the one derived from the Wesenheit magnitude indicates that the Cepheids in NGC 7793 are affected by an average total reddening of E(B-V)=0.08 mag, 0.06 of which is produced inside the host galaxy. As in the earlier Cepheid studies of the Araucaria Project, the reported distance is tied to an assumed LMC distance modulus of 18.50. The quoted systematic uncertainty takes into account effects like blending and possible inhomogeneous filling of the Cepheid instability strip on the derived distance. The reported distance value does not depend on the (unknown) metallicity of the Cepheids according to recent theoretical and empirical results. Our Cepheid distance is shorter, but within the errors consistent with the distance to NGC 7793 determined earlier with the TRGB and Tully-Fisher methods.The NGC 7793 distance of 3.4 Mpc is almost identical to the one our project had found from Cepheid variables for NGC 247, another spiral member of the Sculptor Group located close to NGC 7793 on the sky. Two other conspicuous spiral galaxies in the Sculptor Group, NGC 55 and NGC 300, are much nearer (1.9 Mpc), confirming the picture of a very elongated structure of the Sculptor Group in the line of sight put forward by Jerjen et al. and others

    Lessons from April 6, 2009 L'Aquila earthquake to enhance microzoning studies in near-field urban areas

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    AbstractThis study focuses on two weak points of the present procedure to carry out microzoning study in near-field areas: (1) the Ground Motion Prediction Equations (GMPEs), commonly used in the reference seismic hazard (RSH) assessment; (2) the ambient noise measurements to define the natural frequency of the near surface soils and the bedrock depth. The limitations of these approaches will be discussed throughout the paper based on the worldwide and Italian experiences performed after the 2009 L'Aquila earthquake and then confirmed by the most recent 2012 Emilia Romagna earthquake and the 2016–17 Central Italy seismic sequence. The critical issues faced are (A) the high variability of peak ground acceleration (PGA) values within the first 20–30 km far from the source which are not robustly interpolated by the GMPEs, (B) at the level 1 microzoning activity, the soil seismic response under strong motion shaking is characterized by microtremors' horizontal to vertical spectral ratios (HVSR) according to Nakamura's method. This latter technique is commonly applied not being fully compliant with the rules fixed by European scientists in 2004, after a 3-year project named Site EffectS assessment using AMbient Excitations (SESAME). Hereinafter, some "best practices" from recent Italian and International experiences of seismic hazard estimation and microzonation studies are reported in order to put forward two proposals: (a) to formulate site-specific GMPEs in near-field areas in terms of PGA and (b) to record microtremor measurements following accurately the SESAME advice in order to get robust and repeatable HVSR values and to limit their use to those geological contests that are actually horizontally layered

    Knockdown of TPI in human dermal microvascular endothelial cells and its impact on angiogenesis in vitro

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    Introduction: Angiogenic behaviour has been shown as highly versatile among Endothelial cells (ECs) causing problems of in vitro assays of angiogenesis considering their reproducibility. It is indispensable to investigate influencing factors of the angiogenic potency of ECs. Objective: The present study aimed to analyse the impact of knocking down triosephosphate isomerase (TPI) on in vitro angiogenesis and simultaneously on vimentin (VIM) and adenosylmethionine synthetase isoform type 2 (MAT2A) expression. Furthermore, native expression profiles of TPI, VIM and MAT2A in the course of angiogenesis in vitro were examined. Methods: Two batches of human dermal microvascular ECs were cultivated over 50 days and stimulated to undergo angiogenesis. A shRNA-mediated knockdown of TPI was performed. During cultivation, time-dependant morphological changes were detected and applied for EC-staging as prerequisite for quantifying in vitro angiogenesis. Additionally, mRNA and protein levels of all proteins were monitored. Results: Opposed to native cells, knockdown cells were not able to enter late stages of angiogenesis and primarily displayed a downregulation of VIM and an uprise in MAT2A expression. Native cells increased their TPI expression and decreased their VIM expression during the course of angiogenesis in vitro. For MAT2A, highest expression was observed to be in the beginning and at the end of angiogenesis. Conclusion: Knocking down TPI provoked expressional changes in VIM and MAT2A and a deceleration of in vitro angiogenesis, indicating that TPI represents an angiogenic protein. Native expression profiles lead to the assumption of VIM being predominantly relevant in beginning stages, MAT2A in beginning and late stages and TPI during the whole course of angiogenesis in vitro

    Lower mortality rate in elderly patients with community-onset pneumonia on treatment with aspirin

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    BACKGROUND: Pneumonia is complicated by high rate of mortality and cardiovascular events (CVEs). The potential benefit of aspirin, which lowers platelet aggregation by inhibition of thromboxane A2 production, is still unclear. The aim of the study was to assess the impact of aspirin on mortality in patients with pneumonia. METHODS AND RESULTS: Consecutive patients admitted to the University-Hospital Policlinico Umberto I (Rome, Italy) with community-onset pneumonia were recruited and prospectively followed up until discharge or death. The primary end point was the occurrence of death up to 30 days after admission; the secondary end point was the intrahospital incidence of nonfatal myocardial infarction and ischemic stroke. One thousand and five patients (age, 74.7±15.1 years) were included in the study: 390 were receiving aspirin (100 mg/day) at the time of hospitalization, whereas 615 patients were aspirin free. During the follow-up, 16.2% of patients died; among these, 19 (4.9%) were aspirin users and 144 (23.4%; P<0.001) were aspirin nonusers. Overall, nonfatal CVEs occurred in 7% of patients, 8.3% in nonaspirin users, and 4.9% in aspirin users (odds ratio, 1.77; 95% confidence interval, 1.03 to 3.04; P=0.040). The Cox regression analysis showed that pneumonia severity index (PSI), severe sepsis, pleural effusion, and PaO(2)/FiO(2) ratio <300 negatively influenced survival, whereas aspirin therapy was associated with improved survival. Compared to patients receiving aspirin, the propensity score adjusted analysis confirmed that patients not taking aspirin had a hazard ratio of 2.07 (1.08 to 3.98; P=0.029) for total mortality. CONCLUSIONS: This study shows that chronic aspirin use is associated with lower mortality rate within 30 days after hospital admission in a large cohort of patients with pneumonia

    Solid State Structure of 2,2,4,4,6,6-Hexa(β-naphthyloxo)cyclophosphazatriene and Dipole Moments of Hexa(aryloxo)cyclophosphazatrienes

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    The crystal and molecular structure of [NP(OC10H7)2]3 was determined by X-ray analysis. The dipole moments of this compound and of the hexa(phenoxo)cyclotriphosphazatrienes of formula [NP(OC6H3XX′Y)2]3 (X = X′ = H, Y = p-Br; X = m-CH3,. X′ = H. Y = p-Cl; X = X′ = m-CH3, Y = p-Cl; X = X′ = m-CH3, Y = H; X = X′ = H, Y = p-CH(CH3)2; X = X′ = H, Y = p-C(CH3)3) were measured in benzene at 25°C. Crystals of [NP(OC10H7)2]3 are monoclinic with unit cell dimensions a = 24.870(15), b = 7.712(8), c = 27.687(14) Å, β = 115.85(7)°; space group P21/c. The structure was refined to an agreement factor of 0.09. The phosphazene ring deviates (max. deviation 17°) from planarity. and mean distances (A) and angles (°) are P-N 1.58(1). P-O 1.58(1), O-C 1.41(2); P-N-P 120(1), N-P-N 119(1), P-O-C 124(2). The conformations of the naphthyloxo groups at P(2) and P(3) are similar, and different from the group at P(1). Dipole moment analysis showed that the solid state conformation changes in the solution state. The measured value was in agreement with a symmetric conformation in which at the O-P-O plane each naphthyloxo group is rotated by ca. 40-50° from the anti-coplanar arrangement relative to this plane. The dipole moment data for the p-substituted phenoxo derivatives agree with such a conformation, but the analysis of the dipole moment values of phosphazenes having phenoxo groups bearing more than one substituent group and p-CH(CH3)2 substituent failed to do so due to the inherent limitations of the method
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