The metrology system of the VLTI instrument GRAVITY

The VLTI instrument GRAVITY combines the beams from four telescopes and provides phase-referenced imaging as well as precision-astrometry of order 10 microarcseconds by observing two celestial objects in dual-field mode. Their angular separation can be determined from their differential OPD (dOPD) when the internal dOPDs in the interferometer are known. Here, we present the general overview of the novel metrology system which performs these measurements. The metrology consists of a three-beam laser system and a homodyne detection scheme for three-beam interference using phase-shifting interferometry in combination with lock-in amplifiers. Via this approach the metrology system measures dOPDs on a nanometer-level.Comment: 9 pages, 5 figure

The GRAVITY instrument software / High-level software

GRAVITY is the four-beam, near- infrared, AO-assisted, fringe tracking, astrometric and imaging instrument for the Very Large Telescope Interferometer (VLTI). It is requiring the development of one of the most complex instrument software systems ever built for an ESO instrument. Apart from its many interfaces and interdependencies, one of the most challenging aspects is the overall performance and stability of this complex system. The three infrared detectors and the fast reflective memory network (RMN) recorder contribute a total data rate of up to 20 MiB/s accumulating to a maximum of 250 GiB of data per night. The detectors, the two instrument Local Control Units (LCUs) as well as the five LCUs running applications under TAC (Tools for Advanced Control) architecture, are interconnected with fast Ethernet, RMN fibers and dedicated fiber connections as well as signals for the time synchronization. Here we give a simplified overview of all subsystems of GRAVITY and their interfaces and discuss two examples of high-level applications during observations: the acquisition procedure and the gathering and merging of data to the final FITS file.Comment: 8 pages, 7 figures, published in Proc. SPIE 9146, Optical and Infrared Interferometry IV, 91462

Smoking Determinants in Turkish University Students

The aim was to explore the prevalence and the correlates of smoking in a group of Turkish university students. A sample of 1,870 students (21.2 ± 2.0 years old) completed the Beck Depression Inventory, Beck Hopelessness Scale, Anxiety Sensitivity Index, 20-item Toronto Alexithymia Scale. Smoking was highly prevalent (35.9%) in this sample. Male gender (OR = 2.72, CI 2.15–3.44), and parental smoking (OR = 1.41, CI 1.13–1.78) were factors associated with increased likelihood of smoking. Higher depressive symptoms and hopelessness levels were significantly related to smoking behavior. Smoking behavior might initiate as a mild and transient habit and unfortunately could become more serious and lead to an actual dependence. The results of this study show that it is necessary to pay attention to levels of depression and hopelessness, as well as parental influence

Multiple star systems in the Orion nebula

This is the author accepted manuscript. The final fersion is available from EDP Sciences via the DOI in this record.This work presents an interferometric study of the massive-binary fraction in the Orion Trapezium cluster with the recently comissioned GRAVITY instrument. We observed a total of 16 stars of mainly OB spectral type. We find three previously unknown companions for θ1 Ori B, θ2 Ori B, and θ2 Ori C. We determined a separation for the previously suspected companion of NU Ori. We confirm four companions for θ1 Ori A, θ1 Ori C, θ1 Ori D, and θ2 Ori A, all with substantially improved astrometry and photometric mass estimates. We refined the orbit of the eccentric high-mass binary θ1 Ori C and we are able to derive a new orbit for θ1 Ori D. We find a system mass of 21.7 M⊙ and a period of 53 days. Together with other previously detected companions seen in spectroscopy or direct imaging, eleven of the 16 high-mass stars are multiple systems. We obtain a total number of 22 companions with separations up to 600 AU. The companion fraction of the early B and O stars in our sample is about two, significantly higher than in earlier studies of mostly OB associations. The separation distribution hints toward a bimodality. Such a bimodality has been previously found in A stars, but rarely in OB binaries, which up to this point have been assumed to be mostly compact with a tail of wider companions. We also do not find a substantial population of equal-mass binaries. The observed distribution of mass ratios declines steeply with mass, and like the direct star counts, indicates that our companions follow a standard power law initial mass function. Again, this is in contrast to earlier findings of flat mass ratio distributions in OB associations. We excluded collision as a dominant formation mechanism but find no clear preference for core accretion or competitive accretion.Marie Skłodowska-Curie Grant AgreementFCT-PortugalERC Starting Gran

Does solitary- and organ-confined metastasectomy really improve survival in advanced urologic malignancies?

The role of metastasectomy on survival in advanced/urologic malignancies still remains unclear. Renal cell carcinoma (RCC) is the most common solid tumor within the kidney. 25-30 % of patients have metastases at manifestation. Urothelial carcinoma (UC) consists of bladder carcinoma, upper urinary tract urothelial cell carcinoma and urethral carcinoma. Bladder cancer is the ninth most common cancer worldwide. Half of patients with muscle invasive bladder cancer have lymph node or distant metastases. In metastatic disease first-line treatment is multi-agent platinum-based systemic chemotherapy. Testicular cancer is the most common cancer in men between the age of 15 and 35. Testicular tumors represent excellent oncologic outcomes. Prostate cancer is the most common solid tumor in Europe. Surgical resection of metastases can be considered as a treatment choice in advanced/metastatic urologic malignancies to improve survival rates, particularly in RCC and UC. Metastasectomy can be suggested in conjunction with effective chemotherapy if complete resection is possible. Solitary metastasectomy can represent better survival rates compared to multiple metastasectomy even if multiple metastases confined to single organ. Site of metastases is one of the main determinants of successful metastasectomy such as lung metastasectomy in urothelial cell carcinoma and liver metastasectomy in RCC may lead to better oncologic outcomes. Due to the lack of the relevant data it is not possible to make an evidence-based recommendation on the role of metastasectomy for solitary-/organ-confined metastases of prostate cancer, testicular cancer and penile cancer

Minimal Invasive Management of Small Renal Masses: State of Art and New Trends

With the widespread use of abdominal imaging modalities such as ultrasound (US), computerized tomography (CT) and magnetic resonance imaging (MRI), there has been a pronounced increase in the incidence of renal tumors especially clinically localized, small < 2 cm ones. Moreover the final pathology of these lesions is benign up to 30%. The development of ablation techniques (radiofrequency ablation, cryoablation, high-intensity focused ultrasound and microwave ablation) with continuous innovations such as refinement of probes and real-time imaging capabilities has pioneered the great interest in these techniques, especially for the treatment of T1 renal malignancies. RFA and CA have similar cancer specific survival, disease-free survival, recurrence free survival and overall survival rates compared to nephrectomy. MWA and HIFU remain still experimental due to low patient volume and insufficient clinical experience. Minimal invasive techniques can be a feasible treatment alternative for patients who have high surgical and anesthetic risk with multiple comorbidities, have multiple tumors due to a systemic disease like VHL or do not want to undergo extirpative surgery. Especially elderly patients can be good candidates for these procedures with their relatively short life expectance and impaired performance status

Which Patients Should Undergo Immediate or Deferred Cystectomy in Non-Muscle Invazive Bladder Cancer? Evaluation of Selection Criteria

Bladder cancer is the most common malignancy of the urinary tract in Europe. 70% of all muscle invasive is bladder cancer (MIBC) at the time of diagnosis whereas remaining 30% is non-muscle invasive bladder cancer (NMIBC). NMIBC patients with low-risk can be treated with complete transurethral resection of bladder tumor (TUR-BT) and perioperative single-dose adjuvant chemotherapeutic instillation; whilst TUR-BT and bacille calmette guerin (or mitomycin) treatment are usually used in patient management with high-risk tumor. Radical cystectomy may be the choice of treatment in high-risk NMIBC. Although radical cystectomy is the definitive treatment of MIBC, its role and timing in NMIBC is still remains unclear. Early and deferred cystectomy refers two different cystectomy concepts in NMIBC without a definitive time threshold. Early cystectomy defines cystectomy in a short time span following pathologic diagnosis, whereas cystectomy performed after bladder-sparing surgery is a deferred cystectomy. Despite the difference between these studies in regard to design and outcomes, most of the conducted studies have shown immediate cystectomy to be superior to deferred cystectomy with favorable survival rates. According to previous studies and a meta-analysis, depth of invasion in lamina propria and presence of carcinoma in situ have shown to be the most significant factors supporting immediate cystectomy. Increased knowledge and surgical experience, the advantages of robotic surgery as well as orthotopic urinary diversions being used more common are some factors which may encourage clinicians and patients in decision making for an early cystectomy with functional and aesthetic advantages

Cystectomy and urinary diversion improves health-related quality of life in female patients with non-malignant urologic diseases

Objective: To evaluate the health related quality of life (QoL) in female patients with non-malignant diseases after cystectomy and ileal conduit and to assess postoperative complication