4,379 research outputs found

    Regional nanoindentation properties in different locations on the mouse tibia from C57BL/6 and Balb/C female mice

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    The local spatial heterogeneity of the material properties of the cortical and trabecular bone extracted from the mouse tibia is not well-known. Nevertheless, its characterization is fundamental to be able to study comprehensively the effect of interventions and to generate computational models to predict the bone strength preclinically. The goal of this study was to evaluate the nanoindentation properties of bone tissue extracted from two different mouse strains across the tibia length and in different sectors. Left tibiae were collected from four female mice, two C57BL/6, and two Balb/C mice. Nanoindentations with maximum 6 mN load were performed on different microstructures, regions along the axis of the tibiae, and sectors (379 in total). Reduced modulus (Er) and hardness (H) were computed for each indentation. Trabecular bone of Balb/C mice was 21% stiffer than that of C57BL/6 mice (20.8 Ā± 4.1 GPa vs. 16.5 Ā± 7.1 GPa). Moreover, the proximal regions of the bones were 13ā€“36% less stiff than the mid-shaft and distal regions of the same bones. No significant differences were found for the different sectors for Er and H for Balb/C mice. The bone in the medial sector was found to be 8ā€“14% harder and stiffer than the bone in the anterior or posterior sectors for C57BL/6 mice. In conclusion, this study showed that the nanoindentation properties of the mouse tibia are heterogeneous across the tibia length and the trabecular bone properties are different between Balb/C and C57BL/6 mice. These results will help the research community to identify regions where to characterize the mechanical properties of the bone during preclinical optimisation of treatments for skeletal diseases

    Constraining planet structure from stellar chemistry: the cases of CoRoT-7, Kepler-10, and Kepler-93

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    We explore the possibility that the stellar relative abundances of different species can be used to constrain the bulk abundances of known transiting rocky planets. We use high resolution spectra to derive stellar parameters and chemical abundances for Fe, Si, Mg, O, and C in three stars hosting low mass, rocky planets: CoRoT-7, Kepler-10, and Kepler-93. These planets follow the same line along the mass-radius diagram, pointing toward a similar composition. The derived abundance ratios are compared with the solar values. With a simple stoichiometric model, we estimate the iron mass fraction in each planet, assuming stellar composition. We show that in all cases, the iron mass fraction inferred from the mass-radius relationship seems to be in good agreement with the iron abundance derived from the host star's photospheric composition. The results suggest that stellar abundances can be used to add constraints on the composition of orbiting rocky planets.Comment: A&A Letters, in pres

    The CORALIE survey for southern extra-solar planets. X. A Hot Jupiter orbiting HD73256

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    Recent radial-velocity measurements obtained with the CORALIE spectrograph on the 1.2-m Euler Swiss telescope at La Silla unveil the presence of a new Jovian-mass Hot Jupiter around HD 73256. The 1.85-M_Jup planet moves on an extremely short-period (P=2.5486 d), quasi-circular orbit. The best Keplerian orbital solution is presented together with an unsuccessful photometric planetary-transit search performed with the SAT Danish telescope at La Silla. Over the time span of the observations, the photometric follow-up of the candidate has nevertheless revealed a P=14-d photometric periodicity corresponding to the rotational period of the star. This variation as well as the radial-velocity jitter around the Keplerian solution are shown to be related to the fair activity level known for HD 73256.Comment: 7 pages, 7 figures. Accepted in A&

    Biostimulant activity of azotobacter chroococcum and trichoderma harzianum in durum wheat under water and nitrogen deficiency

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    Biostimulants hold great potential for developing integrated sustainable agriculture systems. The rhizobacteria Azotobacter chroococcum strain 76A and the fungus Trichoderma harzianum strain T22, with demonstrated biostimulant activity in previous systems, were evaluated in Triticum durum cv Creso for their ability to enhance growth and tolerance to drought stress. Growth and drought tolerance were evaluated in conditions of low and high soil nitrogen, with two levels of water stress. T. harzianum increased plant growth (+16%) under control conditions and tolerance to moderate drought stress (+52%) under optimal fertilization, while A. chroococcum conferred a growth penalty (āˆ’28%) in well-watered conditions under suboptimal fertilization and increased tolerance only under extreme drought stress (+15%). This growth penalty was ameliorated by nitrogen fertilization. T. harzianum abundance was found to be positively correlated to extreme soil drying, whereas A. chroococcum-induced tolerance was dependent on soil nitrogen availability. These results indicate that while biostimulants may enhance growth and stress tolerance, nutrient availability soil and environmental conditions heavily influence these responses. These interactions should be considered when designing biostimulant products targeted to specific cultural conditions

    Imaging technologies in the differential diagnosis and follow-up of brown tumor in primary hyperparathyroidism: case report and review of the literature

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    Brown tumors are osteolytic lesions associated with hyperparathyroidism (HPT). They may involve various skeletal segments, but rarely the cranio-facial bones. We report a case of a young boy with a swelling of the jaw secondary to a brown tumor presenting as the first manifestation of primary HPT (PHPT). He was found to have brown tumor located in the skull, as well. Different imaging technologies were employed for the diagnosis and follow-up after parathyroidectomy. We enclose a review of the literature on the employment of such imaging technologies in the differential diagnosis of osteolytic lesions. A multidisciplinary approach comprising clinical, laboratory and imaging findings is essential for the differential diagnosis of brown tumor in PHPT

    WASP-117b: a 10-day-period Saturn in an eccentric and misaligned orbit

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    We report the discovery of WASP-117b, the first planet with a period beyond 10 days found by the WASP survey. The planet has a mass of Mp=0.2755Ā±0.0089ā€‰MJM_p= 0.2755 \pm 0.0089 \, M_{J}, a radius of Rp=1.021āˆ’0.065+0.076ā€‰RJR_p= 1.021_{-0.065}^{+0.076}\, R_{J} and is in an eccentric (e=0.302Ā±0.023 e= 0.302 \pm 0.023 ), 10.02165Ā±0.00055 10.02165 \pm 0.00055 ~d orbit around a main-sequence F9 star. The host star's brightness (V=10.15 mag) makes WASP-117 a good target for follow-up observations, and with a periastron planetary equilibrium temperature of Teq=1225āˆ’39+36T_{eq}= 1225_{-39}^{+36} K and a low planetary mean density (Ļp=0.259āˆ’0.048+0.054ā€‰ĻJ\rho_p= 0.259_{-0.048}^{+0.054} \, \rho_{J}) it is one of the best targets for transmission spectroscopy among planets with periods around 10 days. From a measurement of the Rossiter-McLaughlin effect, we infer a projected angle between the planetary orbit and stellar spin axes of Ī²=āˆ’44Ā±11\beta = -44 \pm 11 deg, and we further derive an orbital obliquity of Ļˆ=69.6āˆ’4.1+4.7\psi = 69.6 ^{+4.7}_{-4.1} deg. Owing to the large orbital separation, tidal forces causing orbital circularization and realignment of the planetary orbit with the stellar plane are weak, having had little impact on the planetary orbit over the system lifetime. WASP-117b joins a small sample of transiting giant planets with well characterized orbits at periods above ~8 days.Comment: To appear in A&

    Diet and Plastic Ingestion in the Blackmouth Catshark Galeus melastomus, Rafinesque 1810, in Italian Waters

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    Simple Summary The blackmouth catshark has a habitat range that spans from the Norwegian seas to Senegal and throughout the Mediterranean Sea, and it is one of the most common sharks in Italian waters. The aim of this work is to investigate, through the analyses of the stomach contents of five populations from the Tyrrhenian and Ionian Seas, the diet of blackmouth catsharks. The analyses showed that the most frequent items were Osteichthyes of the family Myctophidae, except for one population, in which the most common items were Cephalopods and Crustacean of the Decapods order. Plastic debris was also found in all populations analysed and classified by colour and shape. This study ought to increase the knowledge of the feeding ecology of the blackmouth catshark, thus improving the meagre literature about Tyrrhenian and Ionian waters. Galeus melastomus is the most common Pentanchidae in the Mediterranean Sea. A scavenger and opportunistic feeder, and despite the wide distribution, little is known about its feeding habits in Italian waters. The main purpose of this study was to investigate the diet of the blackmouth catshark by analysing the stomach contents. The specimens analysed were obtained from five populations of the Tyrrhenian and of the Ionian Seas, collected from a depth between 40 and 700 m. A total of 259 stomachs were analysed. The stomach contents were grouped into macro-categories and identified to the lowest taxonomic level possible. Crustaceans such as Parapenaeus longirostris, the Cephalopods Heteroteuthis dispar and Onychoteuthis banksii, and Osteichthyes, mostly Myctophidae, were identified. Plastic debris was also found among the stomach contents and classified according to its colour and shape. Osteichthyes represent the most abundant item (44%), above all the Myctophidae family, except for the catshark population from Tuscany, in which the most frequent species were Cephalopods, such as Abralia veranyi and Heteroteuthis dispar. Differences in the plastic debris contents were also observed between the Tuscany population and other populations. These could be explained as a probable consequence of the different depths at which the blackmouth catshark populations were sampled

    A Genome-Wide Screening and SNPs-to-Genes Approach to Identify Novel Genetic Risk Factors Associated with Frontotemporal Dementia

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    Frontotemporal dementia (FTD) is the second most prevalent form of early onset dementia after Alzheimerā€™s disease (AD). We performed a case-control association study in an Italian FTD cohort (n = 530) followed by the novel SNPs-to-genes approach and functional annotation analysis. We identified two novel potential loci for FTD. Suggestive SNPs reached p-values ~10-7 and OR > 2.5 (2p16.3) and 1.5 (17q25.3). Suggestive alleles at 17q25.3 identified a disease-associated haplotype causing decreased expression of -cis genes such as RFNG and AATK involved in neuronal genesis and differentiation, and axon outgrowth, respectively. We replicated this locus through the SNPs-to-genes approach. Our functional annotation analysis indicated significant enrichment for functions of the brain (neuronal genesis, differentiation and maturation), the synapse (neurotransmission and synapse plasticity), and elements of the immune system, the latter supporting our recent international FTD-GWAS. This is the largest genome-wide study in Italian FTD to date. Although our results are not conclusive, we set the basis for future replication studies and identification of susceptible molecular mechanisms involved in FTD pathogenesis
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