Search results for "current"

No Reservations Required: Achieving Fairness between Wi-Fi and NR-U with Self-Deferral Only

2021

Wireless technologies coexisting in unlicensed bands should receive a fair share of the available channel resources, even when they use different access methods. We consider the problem of coexistence between Wi-Fi and New Radio Unlicensed (NR-U) nodes, which employ, respectively, a random and scheduled access scheme. The latter typically resorts to reservation signals (RSs), which allow keeping the control of the channel until the start of the next synchronized slot. This mechanism, although effective for increasing the channel access opportunities of scheduled-based nodes, is also a waste of channel resources. We investigate alternative solutions, based on self-deferral only. We built ana…

Role of Cytoreductive surgery in recurrent ovarian cancer

2010

Ovarian cancer is the leading cause of death from gynecologic malignancy in western countries, primarily because over 60% of patients with ovarian cancer will experience disease recurrence. Primary cytoreductive surgery and combination chemotherapy are the cornerstones of the initial treatment for epithelial ovarian cancer. The management of recurrent ovarian cancer is less clear than that of primary disease. The management of recurrent ovarian cancer is largely based on systemic chemotherapy, with surgery being offered only in selected individuals. Despite this, the benefits of surgery has been shown in a meta-analysis by Bristow et al. where the survival is influenced by the completeness …

Laparoscopic surgical management of localized recurrent ovarian cancer: a single-institution experience

2014

Background: Optimally, secondary cytoreduction is acknowledged as a valid option in terms of oncologic outcome for patients with platinum-sensitive recurrent ovarian cancer. In cases of localized relapse, a laparoscopic approach has been attempted at various institutions, but studies on its role for this subset of patients still are limited. This report describes the authors' experience using laparoscopic secondary cytoreduction for patients with localized recurrent ovarian cancer. The results from a retrospective analysis of a prospective case series are reported. Methods: Between October 2011 and May 2013, 29 patients with localized recurrent ovarian cancer were selected for a laparoscopi…

Electron Emission of Pt: Experimental Study and Comparison With Models in the Multipactor Energy Range

2016

Experimental data of secondary emission yield (SEY) and electron emission spectra of Pt under electron irradiation for normal incidence and primary energies lower than 1 keV are presented. Several relevant magnitudes, as total SEY, elastic backscattering probability, secondary emission spectrum, and backscattering coefficient, are given for different primary energies. These magnitudes are compared with theoretical or semiempirical formulas commonly used in the related literature.

Modeling Transit Flow Through Port Gates and Connecting Channel in Baltic Sea—Liepaja Port—Liepaja Lake System

2021

This study investigates a water transport features by extending Copernicus Marine Environment Service (CMEMS) to the Liepaja coast-port-channel-lake system with a two-way nested model. The Liepaja lake and Liepaja port are connected by Trade channel. The Liepaja port has three gates—the openings in wave breakers connecting the port aquatory with the Baltic sea. Each of gates has a corresponding dredged channel for securing the navigation. A hydrodynamic model is set up to study the flow and water level in this system. The area of the port gates, port and Trade channel are resolved by 33 m grid. The model results are verified against currents and sea level observations inside/outside port, T…

Psychometric properties of the Finnish version of the Young Person's Clinical Outcomes in Routine Evaluation (YP-CORE) questionnaire.

2017

An increasing need exists for suitable measures to evaluate treatment outcome in adolescents. YP-CORE is a pan-theoretical brief questionnaire developed for this purpose, but it lacks studies in different cultures or languages.To explore the acceptability, factor structure, reliability, validity, and sensitivity to change of the Finnish translation of YP-CORE.The study was conducted at the Department of Adolescent Psychiatry, Helsinki University Central Hospital. A Finnish translation was prepared by a team of professionals and adolescents. A clinical sample of 104 patients was asked to complete the form together with BDI-21 and BAI, and 92 of them filled the forms again after a 3-month tre…

Relativistic multipole operators for semileptonic weak and electromagnetic nuclear reactions.

1989

We discuss multipole operators that arise in a relativistic analysis ofsemileptonic weak and electromagnetic interactions with nuclei. Thesesingle-particle operators are evaluated between relativistic nucleon boundstates that are solutions to the Dirac equation with potentials of the formproduced by the sigma-..omega.. model. The reduced matrix elements aregiven in terms of easily programmable radial integrals and can be applied to anumber of reactions such as elastic and inelastic electron scattering, realphoton processes, ..beta.. decay, and charged lepton capture as well as moreexotic interactions such as charged and neutral current neutrino reactions. Asa specific example, we calculate …

Effects of low-gamma tACS on primary motor cortex in implicit motor learning

2019

Abstract In the primary motor cortex (M1), rhythmic activity in the gamma frequency band has been found during movement planning, onset and execution. Although the role of high-gamma oscillatory activity in M1 is well established, the contribution of low-gamma activity is still unexplored. In this study, transcranial alternating current stimulation (tACS) was used with the aim to specifically modulate low-gamma frequency band in M1, during an implicit motor learning task. A 40 Hz-tACS was applied over the left M1 while participants performed a serial reaction time task (SRTT) using their right hand. The task required the repetitive execution of sequential movements in response to sequences …

Functional Role of Cerebellar Gamma Frequency in Motor Sequences Learning: a tACS Study

2021

Although the role of the cerebellum in motor sequences learning is widely established, the specific function of its gamma oscillatory activity still remains unclear. In the present study, gamma (50 Hz)—or delta (1 Hz)—transcranial alternating current stimulation (tACS) was applied to the right cerebellar cortex while participants performed an implicit serial reaction time task (SRTT) with their right hand. The task required the execution of motor sequences simultaneously with the presentation of a series of visual stimuli. The same sequence was repeated across multiple task blocks (from blocks 2 to 5 and from blocks 7 to 8), whereas in other blocks, new/pseudorandom sequences were reproduce…

2018

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that allows the modulation of cortical excitability as well as neuroplastic reorganization using a weak constant current applied through the skull on the cerebral cortex. TDCS has been found to improve motor performance in general and motor learning in particular. However, these effects have been reported almost exclusively for unimanual motor tasks such as serial reaction time tasks, adaptation tasks, or visuo-motor tracking. Despite the importance of bimanual actions in most activities of daily living, only few studies have investigated the effects of tDCS on bimanual motor skills. The objectives …