172 research outputs found

    Self-bound Interacting QCD Matter in Compact Stars

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    The quark gluon plasma (QGP) at zero temperature and high baryon number is a system that may be present inside compact stars. It is quite possible that this cold QGP shares some relevant features with the hot QGP observed in heavy ion collisions, being also a strongly interacting system. In a previous work we have derived from the QCD Lagrangian an equation of state (EOS) for the cold QGP, which can be considered an improved version of the MIT bag model EOS. Compared to the latter, our equation of state reaches higher values of the pressure at comparable baryon densities. This feature is due to perturbative corrections and also to non-perturbative effects. Here we apply this EOS to the study of neutron stars, discussing the absolute stability of quark matter and computing the mass-radius relation for self-bound (strange) stars. The maximum masses of the sequences exceed two solar masses, in agreement with the recently measured values of the mass of the pulsar PSR J1614-2230, and the corresponding radii around 10-11 km

    Form and Function: A Study on the Distribution of the Inflectional Endings in Italian Nouns and Adjectives

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    Inflectional values, such as singular and plural, sustain agreement relations between constituents in sentences, allowing sentence parsing and prediction in online processing. Ideally, these processes would be facilitated by a consistent and transparent correspondence between the inflectional values and their form: for example, the value of plural should always be expressed by the same ending, and that ending should only express plural. Experimental research reports higher processing costs in the presence of a non-transparent relation between forms and values. While this effect was found in several languages, and typological research shows that consistency is far from common in morphological paradigms, it is still somewhat difficult to precisely quantify the transparency degree of the inflected forms. Furthermore, to date, no accounts have quantified the transparency in inflection with regard to the declensional classes and the extent to which it is expressed across different parts of speech, depending on whether these act as controllers of the agreement (e.g., nouns) or as targets (e.g., adjectives). We present a case study on Italian, a language that marks gender and number features in nouns and adjectives. This work provides measures of the distribution of forms in the noun and adjective inflection in Italian, and quantifies the degree of form-value transparency with respect to inflectional endings and declensional classes. In order to obtain these measures, we built Flex It, a dedicated large-scale database of inflectional morphology of Italian, and made it available, in order to sustain further theoretical and empirical research

    Effects of animacy on the processing of morphological Number: A cognitive inheritance?

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    Language encodes into morphology part of the information present in the referential world. Some features are marked in the great majority of languages, such as the numerosity of the referents that is encoded in morphological Number. Other features do not surface as frequently in morphological markings, yet they are pervasive in natural languages. This is the case of animacy, that can ground Gender systems as well as constrain the surfacing of Number. The diffusion of numerosity and animacy could mirror their biological salience at the extra-linguistic cognitive level. Human extralinguistic numerical abilities are phylogenetically ancient and are observed in non-human animal species, especially when counting salient animate entities such as social companions. Does the saliency of animacy influence the morphological encoding of Number in language processing? We designed an experiment to test the encoding of morphological Number in language processing in relation to animacy. In Italian, Gender and Number are mandatorily expressed in a fusional morpheme. In some nouns denoting animate referents, Gender encodes the sex of referents and is semantically interpretable. In some other animate nouns and in inanimate nouns, Gender is uninterpretable at the semantic level. We found that it is easier to inflect for Number nouns when the inflectional morpheme is interpretable with respect to a semantic feature related to animacy. We discuss the possibility that the primacy of animacy in counting is mirrored in morphological processing and that morphology is designed to easily express information that is salient from a cognitive point of view

    Plasmodium vivax-like genome sequences shed new insights into Plasmodium vivax biology and evolution

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    Although Plasmodium vivax is responsible for the majority of malaria infections outside Africa, little is known about its evolution and pathway to humans. Its closest genetic relative, P. vivax-like, was discovered in African great apes and is hypothesized to have given rise to P. vivax in humans. To unravel the evolutionary history and adaptation of P. vivax to different host environments, we generated using long- and short-read sequence technologies 2 new P. vivax-like reference genomes and 9 additional P. vivax-like genotypes. Analyses show that the genomes of P. vivax and P. vivax-like are highly similar and colinear within the core regions. Phylogenetic analyses clearly show that P. vivax-like parasites form a genetically distinct clade from P. vivax. Concerning the relative divergence dating, we show that the evolution of P. vivax in humans did not occur at the same time as the other agents of human malaria, thus suggesting that the transfer of Plasmodium parasites to humans happened several times independently over the history of the Homo genus. We further identify several key genes that exhibit signatures of positive selection exclusively in the human P. vivax parasites. Two of these genes have been identified to also be under positive selection in the other main human malaria agent, P. falciparum, thus suggesting their key role in the evolution of the ability of these parasites to infect humans or their anthropophilic vectors. Finally, we demonstrate that some gene families important for red blood cell (RBC) invasion (a key step of the life cycle of these parasites) have undergone lineage-specific evolution in the human parasite (e.g., reticulocyte-binding proteins [RBPs])

    Factors Affecting Fasting Urinary Calcium Excretion in Stone Former Patients on Different Dietary Calcium Intake

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    The effects of variable calcium content on daily and fasting urinary calcium and other lithogenic solutes excretion, on the bone turnover index (fasting hydroxyproline urinary excretion) and on the calciotropic hormones were studied in 312 stone former patients with an outpatient protocol and 15 stone former patients in an inpatient study. Furthermore in 60 of these patients, 30 while on a low calcium diet (LCD) and 30 on a free calcium home diet (FCD), the effects of an oral calcium load (OCL) on bone turnover index, calciotropic hormones and calcium excretion were evaluated. The results demonstrate that an LCD is effective in reducing daily calcium excretion. Fasting calcium excretion is apparently not affected by changes in dietary calcium content. On the other hand, LCD induces a marked increase in bone resorption, without apparent signs of increased parathyroid activity. This may explain the failure to reduce fasting urinary calcium excretion by the LCD. The OCL greatly reduced bone resorption rate, without any change in calciotropic hormones, especially in patients on LCD. In conclusion, the LCD induces a reduction in the lithogenic factors in the urine of stone formers, but induces a marked increase in bone resorption. The lack of any change in fasting urinary calcium excretion in conditions of different dietary calcium intake may be due to an opposite change in the intestinal and osseous components that affect this parameter, and is therefore of little value

    Swept-Source Optical Coherence Tomography Biometer as Screening Strategy for Macular Disease in Patients Scheduled for Cataract Surgery

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    The aim of this study was to assess the central macular imaging captured with an optical biometer based on full-eye-length Swept-Source OCT (SS-OCT) scan as a screening strategy for identifying macular diseases in patients scheduled for cataract surgery. 1,114 eyes of 749 consecutive patients underwent a biometrical examination with IOLMaster 700 SS-OCT technology (Carl Zeiss) and conventional Spectral-Domain OCT (SD-OCT) (Spectralis OCT, Heidelberg) device analysis on the same day. Seven examiners graded the scans individually in a full-masked mode. Twenty-five eyes were excluded for media opacities. Among the 1,089 included eyes, statistical analysis revealed a mean Kendall\u2019s Coefficient of 0.83 (range 0.76\u20130.89). A logistic regression model demonstrated a highly significant correlation (p < 0.001) between the coefficient of concordance and SD-OCT imaging. Intraobserver reproducibility was 0.89 (range 0.86\u20130.91). Optical biometer SS-OCT scans showed a mean sensitivity of 0.81 and a mean specificity of 0.84. The positive and negative predictive value detected was 0.78 and 0.86, respectively. In order to predict the risk of reduced visual recovery, especially in cases of retinal pathology, optical biometer with SS-OCT scan has proven to be a useful modality for detecting macular structural abnormalities in patients undergoing cataract surgery. Conventional SD-OCT remains mandatory to confirm the presumed diagnosis

    Memory In Children With Symptomatic Temporal Lobe Epilepsy.

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    In children with temporal lobe epilepsy (TLE), memory deficit is not so well understood as it is in adults. The aim of this study was to identify and describe memory deficits in children with symptomatic TLE, and to verify the influence of epilepsy variables on memory. We evaluated 25 children with TLE diagnosed on clinical, EEG and MRI findings. Twenty-five normal children were compared with the patients. All children underwent a neuropsychological assessment to estimate intellectual level, attention, visual perception, handedness, and memory processes (verbal and visual: short-term memory, learning, and delayed recall). The results allowed us to conclude: besides memory deficits, other neuropsychological disturbances may be found in children with TLE such as attention, even in the absence of overall cognitive deficit; the earlier onset of epilepsy, the worse verbal stimuli storage; mesial lesions correlate with impairment in memory storage stage while neocortical temporal lesions correlate with retrieval deficits.72184-
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