4,900 research outputs found
Government and Self-Government of Science - Constitutional Safeguards of Scientific Research and Teaching
Reproducing the assembly of massive galaxies within the hierarchical cosmogony
In order to gain insight into the physical mechanisms leading to the
formation of stars and their assembly in galaxies, we compare the predictions
of the MOdel for the Rise of GAlaxies aNd Active nuclei (MORGANA) to the
properties of K- and 850 micron-selected galaxies (such as number counts,
redshift distributions and luminosity functions) by combining MORGANA with the
spectrophotometric model GRASIL. We find that it is possible to reproduce the
K- and 850 micron-band datasets at the same time and with a standard Salpeter
IMF, and ascribe this success to our improved modeling of cooling in DM halos.
We then predict that massively star-forming discs are common at z~2 and
dominate the star-formation rate, but most of them merge with other galaxies
within ~100 Myr. Our preferred model produces an overabundance of bright
galaxies at z<1; this overabundance might be connected to the build-up of the
diffuse stellar component in galaxy clusters, as suggested by Monaco et al.
(2006), but a naive implementation of the mechanism suggested in that paper
does not produce a sufficient slow-down of the evolution of these objects.
Moreover, our model over-predicts the number of 10^{10}-10^{11} M_sun galaxies
at z~1; this is a common behavior of theoretical models as shown by Fontana et
al. (2006). These findings show that, while the overall build-up of the stellar
mass is correctly reproduced by galaxy formation models, the ``downsizing''
trend of galaxies is not fully reproduced yet. This hints to some missing
feedback mechanism in order to reproduce at the same time the formation of both
the massive and the small galaxies.Comment: 14 pages; 11 figures; accepted for publication by MNRA
In-out versus out-in technique for ACL reconstruction. a prospective clinical and radiological comparison
Background: Several studies have recently shown better restoration of normal knee kinematics and improvement of rotator knee stability after reconstruction with higher femoral tunnel obliquity. The aim of this study is to evaluate tunnel obliquity, length, and posterior wall blowout in single-bundle anterior cruciate ligament (ACL) reconstruction, comparing the transtibial (TT) technique and the out–in (OI) technique. Materials and methods: Forty consecutive patients operated on for ACL reconstruction with hamstrings were randomly divided into two groups: group A underwent a TT technique, while group B underwent an OI technique. At mean follow-up of 10 months, clinical results and obliquity, length, and posterior wall blowout of femoral tunnels in sagittal and coronal planes using computed tomography (CT) scan were assessed. Results: In sagittal plane, femoral tunnel obliquity was 38.6 ± 10.2° in group A and 36.6 ± 11.8° in group B (p = 0.63). In coronal plane, femoral tunnel obliquity was 57.8 ± 5.8° in group A and 35.8 ± 8.2° in group B (p = 0.009). Mean tunnel length was 40.3 ± 1.2 mm in group A and 32.9 ± 2.3 mm in group B (p = 0.01). No cases of posterior wall compromise were observed in any patient of either group. Clinical results were not significantly different between the two groups. Conclusions: The OI technique provides greater obliquity of the femoral tunnel in coronal plane, along with satisfactory length of the tunnel and lack of posterior wall compromise. Level of evidence: II, prospective study
Extra-articular tenodesis combined with an anterior cruciate ligament reconstruction in acute anterior cruciate ligament tear in elite female football players
PURPOSE: The growing popularity of elite soccer among female participants has led to increased incidents of anterior cruciate ligament (ACL) ruptures. Many authors underline a positive glide after ACL reconstruction (ACLR), especially in women. In fact, an isolated intra-articular ACLR may be inadequate to control rotational instability after a combined injury of the ACL and the peripheral structures of the knee. Extra-articular procedures are sometimes used in primary cases displaying excessive antero-lateral rotatory instability. The purpose of this case series was to report subjective and objective outcomes after combined ACL and lateral extra-articular tenodesis (LET) with a minimum 4-year follow-up in a selected high-risk population of elite female football players.
METHODS: Between January 2007 and December 2010, 16 elite Italian female football players were included in the study. All patients underwent the same surgical technique: anatomical ACLR with autogenous semitendinosus and gracilis tendons. After the intra-articular reconstruction was performed, an additional extra-articular MacIntosh modified Coker-Arnold procedure was carried out. Patients were assessed pre- and post-operatively with the subjective and objective International Knee Documentation Committee (IKDC) evaluation form, Tegner activity scale (TAS) and Lysholm score. Joint laxity was assessed with KT-1000 by measuring the side-to-side (S/S) differences in displacement at manual maximum (mm) testing.
RESULTS: At a mean follow-up of 72.6 ± 8.1 months, two independent examiners reviewed all players. All of the patients had a fully recovered range of motion. Lachman test was negative in all patients (100 %). The evaluation of joint laxity and clinical evaluation showed a statistically significant improvement. No patients experienced complication or a re-rupture.
DISCUSSION: The rationale of combining extra-articular procedures with ACLR is to restrict the internal rotation of the reconstructed knee, taking advantage of its long lever arm and thus providing more stability in the rotational axis and preventing the ACL graft from undergoing further excessive strain.
CONCLUSIONS: The combination of an LET with ACLR in elite female football players demonstrated excellent results in terms of subjective scales, post-operative residual laxity and re-rupture rate with no complication, and a complete return to sport activity
Can the outside-in half-tunnel technique reduce femoral tunnel widening in anterior cruciate ligament reconstruction? A CT study
There are different techniques for drilling the femoral tunnel in the anterior cruciate ligament reconstruction (ACLR), but their influence in the bone tunnel enlargement in unknown. The purpose of this study was to compare two different surgical techniques for evaluating femoral tunnel enlargement in ACLR. The hypothesis was that tunnel placement using the outside-in technique leads to less tunnel enlargement compared to the transtibial technique.
METHODS:
Forty-four patients treated for ACLR between March 2013 and March 2014 were prospectively enrolled in this study. According to the surgical technique, subjects were assigned to Group A (Out-in) or Group B (Transtibial). All patients underwent CT examination in order to evaluate the femoral tunnel enlargement at four different levels. Moreover, all patients were evaluated with the Lachman test and pivot shift test, and the KT1000 arthrometer was used to measure the anterior laxity of the knee. A subjective evaluation was performed using the 2000 International Knee Documentation Committee Subjective Knee score, Lysholm knee score and Tegner activity scale. All patients were assessed after 24 months of follow-up.
RESULTS:
At the final follow-up, there were statistically significant differences (p 0.05).
CONCLUSIONS:
In ACLR with a suspension system, the outside-in technique leads to less enlargement of the femoral tunnel lower than the transtibial technique.
KEYWORDS:
Anterior cruciate ligament reconstruction; CT imaging; Drilling technique; Femoral tunnel enlargement
PMID: 28389757 DOI: 10.1007/s00590-017-1950-8
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All N = (8, 0) AdS3 solutions in 10 and 11 dimensions
International audienceWe classify AdS solutions preserving = (8, 0) supersymmetry in ten and eleven dimensions and find the local form of each of them. These include the AdS×S solution of [1] and the embeddings of AdS into AdS×S, AdS×S, AdS/ℤ×S and its IIA reduction within AdS. More interestingly we find solutions preserving the superconformal algebras on certain squashings of the 7-sphere. These solutions asymptote to AdS×S and are promising candidates for holographic duals to defects in Chern-Simons matter theories
CXCR4 pos circulating progenitor cells coexpressing monocytic and endothelial markers correlating with fibrotic clinical features are present in the peripheral blood of patients affected by systemic sclerosis
There is still controversy regarding the role of circulating endothelial and
progenitor cells (CECs/CEPs) in the pathogenesis of systemic sclerosis (SSc).
Using a sequential Boolean gating strategy based on a 4-color flow cytometric
protocol, an increased number of CD31(pos)/CD184(pos)(CXCR4)/CD34(pos)/CD45(pos)
and CD31(pos)/CD117(pos) (c-kit-R) /CD34(pos)/ CD45(pos) hematopoietic
circulating progenitor cells (HCPCs) was detected in SSc patients compared with
healthy subjects. In SSc, no circulating mature and progenitor endothelial cells
were observed, while an enhanced generation of erythroid progenitor cells was
found to be correlated with the presence of CD117+ HCPCs. The presence of freshly
detected CXCR4posHCPC was correlated either to the in vitro cultured
spindle-shaped endothelial like cells (SELC) with an endo/myelomonocytic profile
or to SDF-1 and VEGF serum level. These data are related to more fibrotic
clinical features of the disease, thus supporting a possible role of these cells
in fibrosis
The economic performance of urban gardening in three European cities – examples from Ljubljana, Milan and London
Urban gardening is not a new phenomenon but it has received considerably more practical and academic interest
in recent years. Studies on economic aspects such as crop yields, inputs and outputs of production, productivity,
gross margins and the contribution to home economics are rare, especially in Europe. While urban gardening
plays an important role in the Global South, its role in Western Europe for food productivity and home eco-
nomics is currently under-researched. The aim of this study is to analyse European urban gardeners\u2019 economic
performance and self-sufficiency on a household level, as well as to reach a better understanding of their con-
tribution to food self-provision and food security in the metropolitan areas. In a study carried out in 2014 with
on-site personal and with online questionnaires participated 180 urban gardeners from three case study cities
(Ljubljana, Milan, and London). Results from the economic analysis showed that although for most urban gar-
deners, profit is not their main motivation, the economic calculation shows that productivity in small urban plots
can be comparable to market garden production. Urban gardeners are saving money, especially when, compared
to retail prices for regular produce or organic produce, their input is included in the gross margin calculation. We
conclude that, in the case-study cities, the self-provisional potential of urban gardeners\u2019 households to ade-
quately cover the annual vegetable need of five-a-day servings can be met under three conditions: (1) sufficient
garden size; (2) increased area productivity, and (3) sufficient labour-hour inputs
Identification of murine phosphodiesterase 5A isoforms and their functional characterization in HL-1 cardiac cell line
Phosphodiesterase 5A (PDE5A) specifically degrades the ubiquitous second messenger cGMP and experimental and clinical data highlight its important role in cardiac diseases. To address PDE5A role in cardiac physiology, three splice variants of the PDE5A were cloned for the first time from mouse cDNA library (mPde5a1, mPde5a2 and mPde5a3). The predicted amino acidic sequences of the three murine isoforms are different in the N-terminal regulatory domain. mPDE5A isoforms were transfected in HEK293T cells and they showed high affinity for cGMP and similar sensitivity to sildenafil inhibition. RT-PCR analysis showed that mPde5a1, mPde5a2 and mPde5a3 had differential tissue distribution. In the adult heart, mPde5a1 and mPde5a2 were expressed at different levels whereas mPde5a3 was undetectable. Overexpression of mPDE5As induced an increase of HL-1 number cells which progress into cell cycle. mPDE5A1 and mPDE5A3 overexpression increased the number of polyploid and binucleated cells, mPDE5A3 widened HL-1 areas and modulated hypertrophic markers more efficiently respect to the other mPDE5A isoforms. Moreover, mPDE5A isoforms had differential subcellular localization: mPDE5A1 was mainly localized in the cytoplasm, mPDE5A2 and mPDE5A3 were also nuclear localized. These results demonstrate for the first time the existence of three PDE5A isoforms in mouse and highlight their potential role in the induction of hypertrophy. This article is protected by copyright. All rights reserved
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