5,520 research outputs found
On the impact of the Bimodal Oscillating System (BiOS) on the biogeochemistry and biology of the Adriatic and Ionian Seas (Eastern Mediterranean)
Analysis of 20-year time-series of the vertically averaged salinity and nutrient data in the Southern Adriatic shows that the two parameters are subject to strong decadal variability. In addition, it is documented that nutrient and salinity variations are out of phase. Nutrients in the Ionian and in the Adriatic vary in parallel except that generally the nutrient content in the Adriatic is lower than in the Ionian, a fact that has been attributed to primary producer consumption following the winter convective mixing. As shown earlier, North Ionian Gyre (NIG) changes its circulation sense on a decadal scale due to the Bimodal Oscillating System, i.e. the feedback mechanism between the Adriatic and Ionian. Cyclonic circulation causes a downwelling of the nitracline along the borders of the NIG and a decrease in the nutrient content of the water flowing into the Adriatic across the Otranto Strait, and vice versa. In addition, the highly oligotrophic central area of the Ionian shows annual blooms only during cyclonic NIG circulation. Inversion of the sense of the NIG results in the advection of Modified Atlantic Water or of the Levantine/Eastern Mediterranean waters in the Adriatic. Here, we show that the presence of allochtonous organisms from Atlantic/Western Mediterranean and Eastern Mediterranean/temperate zone in the Adriatic are concurrent with the anticyclonic and cyclonic circulations of the NIG, respectively. On the basis of the results presented, a revision of the theory of Adriatic ingressions formulated in the early 1950s is proposed
Prostate Multiparametric MRI: Common Pitfalls in Primary Diagnosis and How to Avoid Them
Abstract
Purpose of Review
To provide the radiologist with basic knowledge about normal and abnormal findings in the prostatic mp-MRI, taking a look at the possible diagnostic pitfalls commonly seen in daily clinical practice, allowing him to recognize and consequently avoid them.
Recent Findings
Prostate mp-MRI has now become commonly used in most diagnostic imaging centers, as a precise, accurate and above all non-invasive tool, useful in the diagnosis, staging and follow-up of prostate diseases, first of all prostatic carcinoma. For this reason, it is important to take into account the existence of numerous possible anatomic and pathologic processes which can mimick or masquerade as prostate cancer.
Summary
Through the combination of anatomical (T2WI) and functional sequences (DWI/ADC and DCE), the mp-MRI of the prostate provides all the information necessary for a correct classification of patients with prostate disease, cancer in particular. It is not uncommon, however, for the radiologist to make errors in the interpretation of imaging due to conditions, pathological or otherwise, that mimic prostate cancer and that, consequently, affect the diagnostic/therapeutic process of patients. The strategy, and what this pictorial review aims at, is to learn to recognize the potential pitfalls of the prostatic mp-MRI and avoid them
Endoscopic ultrasound-guided fine-needle aspiration vs fine-needle biopsy for the diagnosis of pancreatic neuroendocrine tumors
Background and study aims Endoscopic ultrasoundguided fine-needle aspiration (EUS-FNA) as a method of obtaining preoperative diagnosis of pancreatic neuroendocrine tumors (PanNETs) has been reported in several series.
Fine-needle biopsies (FNB) are increasingly employed to obtain core specimens during EUS. However, the differences in
efficacy between these sampling methods in the diagnosis
of PanNETs still needs to be defined.
Patients and methods Over a 13-year period, all patients
who underwent EUS-guided tissue sampling of suspicious
pancreatic lesions with clinical, endoscopic and pathologic
details were entered into an electronic database. Lesions
underwent EUS-FNA or FNB sampling, or a combination of
the two. The accuracy and safety of different EUS-guided
sampling methods for confirmed PanNETs were investigated.
Results A total of 91 patients (M/F: 42/49, median age: 57
years), who underwent 102 EUS procedures had a final diagnosis of PanNET. Both EUS-guided sampling modalities
were used in 28 procedures, EUS-FNA alone was used in 61
cases, while EUS-FNB alone in 13 cases. Diagnostic yield of
EUS-FNA and EUS-FNB alone, including the inadequate specimens, was 77.5 % (95 %CI: 68.9 – 86.2%) and 85.4 % (95 %
CI: 74.6 – 96.2 %), respectively. The combination of both
sampling modalities established the diagnosis in 96.4 % of
cases (27/28) (95 %CI: 89.6 – 100%), significantly superior
to EUS-FNA alone (P = 0.023). Diagnostic sensitivity among
the adequate samples for EUS-FNA, EUS-FNB and for the
combination of the two methods was 88.4 % (95 %CI:
80.9 – 96.0 %), 94.3% (95 %CI: 86.6 – 100%) and 100% (95%
CI: 100 – 100 %). There was one reported complication, a
post-FNA bleeding, treated conservatively.
Conclusions EUS-FNB improves diagnostic sensitivity and
confers additional information to cytological assessment
of PanNETs
El taller de arqueologĂa definido por sus integrantes
El taller de ArqueologĂa del Museo "Alte Brown", de Bernal, fuĂ© creado en abril de 1987 y depende de la Municipalidad de Quilmes. A principios de 1988 ingresa un nuevo grupo, estableciĂ©ndose dos niveles los que se fusionarán en Ăşnico nivel, para 1989.
Objetivos del taller:
Una permanente consideraciĂłn de las metas y objetivos personales de cada miembro del grupo del Taller, ha permitido resumir estos objetivos en dos grupos;
a) Objetivos iniciales:
De las encuestas realizadas al iniciarse las reuniones surgieron las siguientes inquietudes:
- Asistir a clases y conferencias sobre historia y arqueologĂa.
- Efectuar o colaborar en tareas afines o propias del arqueĂłlogo.
- BĂşsqueda de informaciĂłn histĂłrica (sobre Egipto particularmente).
- Conocer sobre métodos de análisis e interpretación.
b) Objetivos actuales:
Hoy los objetivos pueden resumirse en:
- Adquirir nociones sobre mĂ©todos y tĂ©cnicas en ArqueologĂa.
- Ampliar nuestro panorama de la ArqueologĂa Argentina.
- Concientizar (nos) de la importancia del Rescate y ProtecciĂłn del patrimonio arqueolĂłgico.Facultad de Ciencias Naturales y Muse
Validation of Androgen Receptor loss as a risk factor for the development of brain metastases from ovarian cancers
Abstract Background Central nervous system (CNS) spreading from epithelial ovarian carcinoma (EOC) is an uncommon but increasing phenomenon. We previously reported in a small series of 11 patients a correlation between Androgen Receptor (AR) loss and localization to CNS. Aims of this study were: to confirm a predictive role of AR loss in an independent validation cohort; to evaluate if AR status impacts on EOC survival. Results We collected an additional 29 cases and 19 controls as validation cohort. In this independent cohort at univariate analysis, cases exhibited lower expression of AR, considered both as continuous (p <  0.001) and as discrete variable (10% cut-off: p <  0.003; Immunoreactive score: p <  0.001). AR negative EOC showed an odds ratio (OR) = 8.33 for CNS dissemination compared with AR positive EOC. Kaplan-Meier curves of the combined dataset, combining data of new validation cohort with the previously published cohort, showed that AR <  10% significantly correlates with worse outcomes (p = 0.005 for Progression Free Survival (PFS) and p = 0.002 for brain PFS (bPFS) respectively). Comparison of AR expression between primary tissue and paired brain metastases in the combined dataset did not show any statistically significant difference. Conclusions We confirmed AR loss as predictive role for CNS involvement from EOC in an independent cohort of cases and controls. Early assessment of AR status could improve clinical management and patients’ prognosis
Operational experience, improvements, and performance of the CDF Run II silicon vertex detector
The Collider Detector at Fermilab (CDF) pursues a broad physics program at
Fermilab's Tevatron collider. Between Run II commissioning in early 2001 and
the end of operations in September 2011, the Tevatron delivered 12 fb-1 of
integrated luminosity of p-pbar collisions at sqrt(s)=1.96 TeV. Many physics
analyses undertaken by CDF require heavy flavor tagging with large charged
particle tracking acceptance. To realize these goals, in 2001 CDF installed
eight layers of silicon microstrip detectors around its interaction region.
These detectors were designed for 2--5 years of operation, radiation doses up
to 2 Mrad (0.02 Gy), and were expected to be replaced in 2004. The sensors were
not replaced, and the Tevatron run was extended for several years beyond its
design, exposing the sensors and electronics to much higher radiation doses
than anticipated. In this paper we describe the operational challenges
encountered over the past 10 years of running the CDF silicon detectors, the
preventive measures undertaken, and the improvements made along the way to
ensure their optimal performance for collecting high quality physics data. In
addition, we describe the quantities and methods used to monitor radiation
damage in the sensors for optimal performance and summarize the detector
performance quantities important to CDF's physics program, including vertex
resolution, heavy flavor tagging, and silicon vertex trigger performance.Comment: Preprint accepted for publication in Nuclear Instruments and Methods
A (07/31/2013
Inclusive Search for Anomalous Production of High-pT Like-Sign Lepton Pairs in Proton-Antiproton Collisions at sqrt{s}=1.8 TeV
We report on a search for anomalous production of events with at least two
charged, isolated, like-sign leptons with pT > 11 GeV/c using a 107 pb^-1
sample of 1.8 TeV ppbar collisions collected by the CDF detector. We define a
signal region containing low background from Standard Model processes. To avoid
bias, we fix the final cuts before examining the event yield in the signal
region using control regions to test the Monte Carlo predictions. We observe no
events in the signal region, consistent with an expectation of
0.63^(+0.84)_(-0.07) events. We present 95% confidence level limits on new
physics processes in both a signature-based context as well as within a
representative minimal supergravity (tanbeta = 3) model.Comment: 15 pages, 4 figures. Minor textual changes, cosmetic improvements to
figures and updated and expanded reference
Measurement of the Helicity Fractions of W Bosons from Top Quark Decays Using Fully Reconstructed top-antitop Events with CDF II
We present a measurement of the fractions F_0 and F_+ of longitudinally
polarized and right-handed W bosons in top quark decays using data collected
with the CDF II detector. The data set used in the analysis corresponds to an
integrated luminosity of approximately 318 pb -1. We select ttbar candidate
events with one lepton, at least four jets, and missing transverse energy. Our
helicity measurement uses the decay angle theta*, which is defined as the angle
between the momentum of the charged lepton in the W boson rest frame and the W
momentum in the top quark rest frame. The cos(theta*) distribution in the data
is determined by full kinematic reconstruction of the ttbar candidates. We find
F_0 = 0.85 +0.15 -0.22 (stat) +- 0.06 (syst) and F_+ = 0.05 +0.11 -0.05 (stat)
+- 0.03 (syst), which is consistent with the standard model prediction. We set
an upper limit on the fraction of right-handed W bosons of F_+ < 0.26 at the
95% confidence level.Comment: 11 pages, 2 figures, submitted to Phys. Rev.
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