3,203 research outputs found

    The Dusty Starburst Nucleus of M33

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    We have thoroughly characterized the ultraviolet to near-infrared (0.15 - 2.2 micron) spectral energy distribution (SED) of the central parsec of the M33 nucleus through new infrared photometry and optical/near-infrared spectroscopy, combined with ultraviolet/optical observations from the literature and the HST archive. The SED shows evidence for a significant level of attenuation, which we model through a Monte Carlo radiative transfer code as a shell of clumpy Milky Way-type dust (tau_V ~ 2 +/- 1). The discovery of Milky Way-type dust (with a strong 2175 A bump) internal to the M33 nucleus is different from previous work which has found SMC-like dust (no bump) near starburst regions. The amount by which dust can be processed may be related to the mass and age of the starburst as well as the extent to which the dust can shield itself. Our starburst models include the effects of this dust and can fit the SED if the nucleus was the site of a moderate (~10^8 L_sun at 10 Myrs) episode of coeval star formation about 70 Myrs ago. This result is quite different from previous studies which resorted to multiple stellar populations (between 2 and 7) attenuated by either no or very little internal dust. The M33 nuclear starburst is remarkably similar to an older version (70 Myr versus 10 Myr) of the ultra-compact starburst in the center of the Milky Way.Comment: 29 pages, 9 embedded figures, ApJ, in pres

    Torsion pendulum facility for direct force measurements of LISA GRS related disturbances

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    A four mass torsion pendulum facility for testing of the LISA GRS is under development in Trento. With a LISA-like test mass suspended off-axis with respect to the pendulum fiber, the facility allows for a direct measurement of surface force disturbances arising in the GRS. We present here results with a prototype pendulum integrated with very large-gap sensors, which allows an estimate of the intrinsic pendulum noise floor in the absence of sensor related force noise. The apparatus has shown a torque noise near to its mechanical thermal noise limit, and would allow to place upper limits on GRS related disturbances with a best sensitivity of 300 fN/Hz^(1/2) at 1mHz, a factor 50 from the LISA goal. Also, we discuss the characterization of the gravity gradient noise, one environmental noise source that could limit the apparatus performances, and report on the status of development of the facility.Comment: Submitted to Proceedings of the 6th International LISA Symposium, AIP Conference Proceedings 200

    Combined sanger and ngs sequence analysis of the myostatin gene (mstn) in the Camelus dromedarius species

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    Different mutations have been identified in the myostatin gene (MSTN), some of which are responsible for protein inactivation and double muscling phenotype in mammals. So far, no extensive polymorphism survey has been carried out in Camelus dromedarius. We therefore performed a sequence analysis, adopting a combined strategy involving Sanger and next generation sequencing (NGS). Notably, 3.6 kb of the MSTN locus were Sanger sequenced in a population dataset including samples from Algeria (10), Tunisia (5), Egypt (9), Mauritania (5), Sudan (5) and Saudi Arabia (9). A further wholegenome dataset, including 7 C. dromedarius from Pakistan (1), Kenya (1), Saudi Arabia (3), Canary Islands (1) and Oman (1) were sequenced using the Illumina Hi-Seq 2000 technique at an average 15-fold coverage. Whole-genome NGS sequence data from 9 C. bactrianus and 7 C. ferus samples were also available for comparison. Overall, only four polymorphisms were detected, all of them were observed in intronic regions, corresponding to an average presence of one SNP per 1200 bps. Ten fixed sites were observed when comparing C. dromedarius MSTN sequences with those from C. bactrianus and C. ferus. The apparent low sequence diversity observed at the MSTN locus may reflect the peculiar evolutionary history of this species, with purifying selection and drift phenomena as the most likely acting forces.(Résumé d'auteur

    Supervivencia de una pequeña población trasladada de Procolobus kirkii en la isla de Pemba

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    A survey to evaluate the distribution of Procolobus kirkii on Pemba island (Tanzania) was conducted, 20 years after they had been translocated from Zanzibar in the Ngezi forest park. A team of both expert and trained observers, guided by the authors, censused 68.3 linear km of forest, corresponding to an estimated area of 3.5 km2 (63.6%) of the protected Ngezi forested area of 5.5 km2. Nineteen groups of Cercopithecus aethiops were observed, with a total of 166 animals and an estimated density of 47.43 individuals per km2, and only one troop of Procolobus kirkii. Supplemented by interviewing the local people we obtained an estimate of 15–30 P. kirkii, including a small troop outside the protected area. This small population survived but did not increase, possibly due to adverse relations with humans.Se realizó un estudio para evaluar la distribución de Procolobus kirkii en la isla de Pemba (Tanzania), veinte años después de que fuera trasladada desde Zanzíbar al Parque Ngezi. Un equipo de observadores expertos y entrenados, guiados por los autores, efectuó un censo a lo largo de 68,3 km lineales de bosque, correspondiente a un área estimada de 3,5 km2 (63,6%) del área protegida del bosque de Ngezi de 5,5 km2. Se observaron 19 grupos de Cercopithecus aethiops, con un total de 166 animales y una densidad estimada de 47,43 individuos/km2, y sólo un grupo de Procolobus kirkii. Complementando los datos con entrevistas a la población local se obtuvo una estimación de 15–30 ejemplares de P. kirkii, incluyendo un pequeño grupo localizado fuera del área protegida. Este pequeño grupo sobrevivía pero no se incrementaba en número, posiblemente debido a las relaciones adversas con los humanos

    Small optic suspensions for Advanced LIGO input optics and other precision optical experiments

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    We report on the design and performance of small optic suspensions developed to suppress seismic motion of out-of-cavity optics in the Input Optics subsystem of the Advanced LIGO interferometric gravitational wave detector. These compact single stage suspensions provide isolation in all six degrees of freedom of the optic, local sensing and actuation in three of them, and passive damping for the other three

    Emergence of a non trivial fluctuating phase in the XY model on regular networks

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    We study an XY-rotor model on regular one dimensional lattices by varying the number of neighbours. The parameter 2γ12\ge\gamma\ge1 is defined. γ=2\gamma=2 corresponds to mean field and γ=1\gamma=1 to nearest neighbours coupling. We find that for γ<1.5\gamma<1.5 the system does not exhibit a phase transition, while for γ>1.5\gamma > 1.5 the mean field second order transition is recovered. For the critical value γ=γc=1.5\gamma=\gamma_c=1.5, the systems can be in a non trivial fluctuating phase for whichthe magnetisation shows important fluctuations in a given temperature range, implying an infinite susceptibility. For all values of γ\gamma the magnetisation is computed analytically in the low temperatures range and the magnetised versus non-magnetised state which depends on the value of γ\gamma is recovered, confirming the critical value γc=1.5\gamma_{c}=1.5

    Translating proteomic into functional data: An high mobility group A1 (HMGA1) proteomic signature has prognostic value in breast cancer

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    Cancer is a very heterogeneous disease, and biological variability adds a further level of complexity, thus limiting the ability to identify new genes involved in cancer development. Oncogenes whose expression levels control cell aggressiveness are very useful for developing cellular models that permit differential expression screenings in isogenic contexts. HMGA1 protein has this unique property because it is a master regulator in breast cancer cells that control the transition from a nontumorigenic epithelial-like phenotype toward a highly aggressive mesenchymal-like one. The proteins extracted from HMGA1-silenced and control MDA-MB-231 cells were analyzed using label-free shotgun mass spectrometry. The differentially expressed proteins were cross-referenced with DNA microarray data obtained using the same cellular model and the overlapping genes were filtered for factors linked to poor prognosis in breast cancer gene expression meta-data sets, resulting in an HMGA1 protein signature composed of 21 members (HRS, HMGA1 reduced signature). This signature had a prognostic value (overall survival, relapse-free survival, and distant metastasis-free survival) in breast cancer. qRT-PCR, Western blot, and immunohistochemistry analyses validated the link of three members of this signature (KIFC1, LRRC59, and TRIP13) with HMGA1 expression levels both in vitro and in vivo and wound healing assays demonstrated that these three proteins are involved in modulating tumor cell motility. Combining proteomic and genomic data with the aid of bioinformatic tools, our results highlight the potential involvement in neoplastic transformation of a restricted list of factors with an as-yet-unexplored role in cancer. These factors are druggable targets that could be exploited for the development of new, targeted therapeutic approaches in triple-negative breast cancer

    Thermal gradient-induced forces on geodetic reference masses for LISA

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    The low frequency sensitivity of space-borne gravitational wave observatories will depend critically on the geodetic purity of the trajectories of orbiting test masses. Fluctuations in the temperature difference across the enclosure surrounding the free-falling test mass can produce noisy forces through several processes, including the radiometric effect, radiation pressure, and outgassing. We present here a detailed experimental investigation of thermal gradient-induced forces for the LISA gravitational wave mission and the LISA Pathfinder, employing high resolution torsion pendulum measurements of the torque on a LISA-like test mass suspended inside a prototype of the LISA gravitational reference sensor that will surround the test mass in orbit. The measurement campaign, accompanied by numerical simulations of the radiometric and radiation pressure effects, allows a more accurate and representative characterization of thermal-gradient forces in the specific geometry and environment relevant to LISA free-fall. The pressure dependence of the measured torques allows clear identification of the radiometric effect, in quantitative agreement with the model developed. In the limit of zero gas pressure, the measurements are most likely dominated by outgassing, but at a low level that does not threaten the LISA sensitivity goals.Comment: 21 pages, 16 figures, submitted to Physical Review

    Trans-arterial radioembolization in intermediate-advanced hepatocellular carcinoma: systematic review and meta-analyses.

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    Published onlineJournal ArticleThis is the final version of the article. Available from Impact Journals via the DOI in this record.Trans-arterial radioembolization (TARE) is a recognized, although not explicitly recommended, experimental therapy for unresectable hepatocellular carcinoma (HCC).A systematic literature review was performed to identify published studies on the use of TARE in intermediate and advanced stages HCC exploring the efficacy and safety of this innovative treatment.Twenty-one studies reporting data on overall survival (OS) and time to progression (TTP), were included in a meta-analysis. The pooled post-TARE OS was 63% (95% CI: 56-70%) and 27% (95% CI: 21-33%) at 1- and 3-years respectively in intermediate stage HCC, whereas OS was 37% (95% CI: 26-50%) and 13% (95% CI: 9-18%) at the same time intervals in patients with sufficient liver function (Child-Pugh A-B7) but with an advanced HCC because of the presence of portal vein thrombosis. When an intermediate and advanced case-mix was considered, OS was 58% (95% CI: 48-67%) and 17% (95% CI: 12-23%) at 1- and 3-years respectively. As for TTP, only four studies reported data: the observed progression probability was 56% (95% CI: 41-70%) and 73% (95% CI: 56-87%) at 1 and 2 years respectively. The safety analysis, focused on the risk of liver decompensation after TARE, revealed a great variability, from 0-1% to more than 36% events, influenced by the number of procedures, patient Child-Pugh stage and treatment duration.Evidence supporting the use of radioembolization in HCC is mainly based on retrospective and prospective cohort studies. Based on this evidence, until the results of the ongoing randomized trials become available, radioembolization appears to be a viable treatment option for intermediate-advanced stage HCC.The present study was funded by ASBM Srl through an unrestricted grant to CERGAS, Bocconi University, Via Roentgen 1, 20136 Milan, Italy

    ANALISI DELL’INDICE DI INTERAZIONE BAMBINO-PETS IN FATTORIA ZOOANTROPOLOGICA: STUDIO PILOTA

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    INTRODUZIONE - La didattica applicata alla zooantropologia prevede un’attuazione in campo educativo e pedagogico dei principi zooantropologici; essa si prefigge un duplice obiettivo: di ridurre il gap relazionale tra animali e giovani generazioni e di recuperare i contenuti e le valenze della relazione, al fine dell’utilizzo pedagogico ed educativo. Nasce un nuovo modello educativo che pone al centro delle strutture pedagogiche l’animale, non più come oggetto da sfruttare, ma come soggetto che aiuti il bambino nella sua crescita educativa (1,2). In quest’ottica generale, la Fattoria Zooantropologica sembra essere un buon sistema in grado di permettere la “fruizione” da parte di bambini e\o soggetti con disabilità di questo modello relazionale e di consentire, altresì, attività e terapie assistite con gli animali (3,4). La Fattoria Zooantropologica offre l’opportunità di attivare la relazione reciproca in un ambiente nuovo, attraente e confortevole tra il fruitore e l’animale che giova di un habitat naturale e familiare. L’esperienza diretta permette ai bambini di usare tutti i loro sensi per imparare: più i bambini vedono, toccano, odorano, sentono, gustano, più imparano (5,6). Partendo da questi presupposti, lo studio si è posto l’obiettivo di effettuare una valutazione del gradimento delle differenti specie animali, attraverso l’analisi degli indici di interazione dei bambini rispetto agli animali presenti in fattoria, al fine di fornire delle linee guida nella scelta del pet in relazione ad una amplificazione delle risposte cognitive ed emozionali del bambino
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