978 research outputs found
Numerical Assessment of Infragravity Swash Response to Offshore Wave Frequency Spread Variability
We use a numerical model, already validated for this purpose, to simulate the effect of wave frequency spread on wave transformation and swash amplitudes. Simulations are performed for planar beach slope cases and for offshore wave spectra whose frequency spread changes over realistic values. Results indicate that frequency spread, under normally approaching waves, affects swash amplitudes. For moderately dissipative conditions, the significant infragravity swash increases for increasing values of the offshore frequency spread. The opposite occurs under extremely dissipative conditions. The numerical analysis suggests that this inverted pattern is driven by the effect that different distributions of incoming long?wave energy have on low?frequency wave propagation and dissipation. In fact, with large frequency spreads, wave groups force relatively short subharmonic waves that are strongly enhanced in the shoaling zone. This process leads to an infragravity swash increase for increasing frequency spread under moderately dissipative conditions in which low?frequency energy dissipation in shallow water is negligible or small. However, under extremely dissipative conditions, the significant low?frequency energy dissipation associated with large frequency spreads overturns the strong energy growth in the shoaling zone eventually yielding an infragravity swash decrease for increasing frequency spread.This work has been funded under (1) the RETOS INVESTIGACION 2014 (Grant BIA2014-59718-R) program of the Spanish Ministry of Economy and Competitiveness and (2) the NEPTUNE 2 project, L. R. 7/2007 by Regione Autonoma della Sardegna
Coherent control of laserinduced breakdown
We demonstrate coherent control of laser-induced optical breakdown in Ar and Xe with a femtosecond timescale pulse train. By using a genetic algorithm to set the relative phases of seven optical sidebands that span two octaves of bandwidth, we enhance or suppress the probability of breakdown, vary the onset time of the spark, and to some extent, vary the position of the spark and the timing of the laser-produced shock wave
Quiescience as a mechanism for cyclical hypoxia and acidosis
Tumour tissue characteristically experiences fluctuations in substrate supply. This unstable microenvironment drives constitutive metabolic changes within cellular populations and, ultimately, leads to a more aggressive phenotype. Previously, variations in substrate levels were assumed to occur through oscillations in the hĂŠmodynamics of nearby and distant blood vessels. In this paper we examine an alternative hypothesis, that cycles of metabolite concentrations are also driven by cycles of cellular quiescence and proliferation. Using a mathematical modelling approach, we show that the interdependence between cell cycle and the microenvironment will induce typical cycles with the period of order hours in tumour acidity and oxygenation. As a corollary, this means that the standard assumption of metabolites entering diffusive equilibrium around the tumour is not valid; instead temporal dynamics must be considered
The 2016 Kumamoto Earthquakes: Cascading Geological Hazards and Compounding Risks
A sequence of two strike-slip earthquakes occurred on April 14 and 16, 2016 in the intraplate region of Kyushu Island, Japan, apart from subduction zones, and caused significant damage and disruption to the Kumamoto region. The analyses of regional seismic catalog and available strong motion recordings reveal striking characteristics of the events, such as migrating seismicity, earthquake surface rupture, and major foreshock-mainshock earthquake sequences. To gain valuable lessons from the events, a UK Earthquake Engineering Field Investigation Team (EEFIT) was dispatched to Kumamoto, and earthquake damage surveys were conducted to relate observed earthquake characteristics to building and infrastructure damage caused by the earthquakes. The lessons learnt from the reconnaissance mission have important implications on current seismic design practice regarding the required seismic resistance of structures under multiple shocks and the seismic design of infrastructure subject to large ground deformation. The observations also highlight the consequences of cascading geological hazards on community resilience. To share the gathered damage data widely, geo-tagged photos are organized using Google Earth and the kmz file is made publicly available.The work is funded by the EPSRC grant (EP/I01778X/1) for the Earthquake Engineering Field Investigation Team (EEFIT). The financial supports for industrial members (GC, LH, LK, and RM) are provided by Arup, Mott MacDonald, and Willis
NK cell receptors in anti-tumor and healthy tissue protection: Mechanisms and therapeutic advances
natural killer (NK) cells are integral to the innate immune system, renowned for their ability to target and eliminate cancer cells without the need for antigen presentation, sparing normal tissues. these cells are crucial in cancer immunosurveillance due to their diverse array of activating and inhibitory receptors that modulate their cytotoxic activity. however, the tumor microenvironment can suppress NK cell function through various mechanisms. over recent decades, research has focused on overcoming these tumor escape mechanisms. Initially, efforts concentrated on enhancing T cell activity, leading to impressive results with immunotherapeutic approaches aimed at boosting T cell responses. nevertheless, a substantial number of patients do not benefit from these treatments and continue to seek effective alternatives. In this context, NK cells present a promising avenue for developing new treatments, given their potent cytotoxic capabilities, safety profile, and activity against T cell- resistant tumors, such as those lacking HLA-I expression. recent advancements in immunotherapy include strategies to restore and amplify NK cell activity through immune checkpoint inhibitors, cytokines, adoptive NK cell therapy, and CAR-NK cell technology. this review provides a comprehensive overview of NK cell receptors, the tumor escape mechanisms that hinder NK cell function, and the evolving field of NK cell-based cancer immunotherapy, highlighting ongoing efforts to develop more effective and targeted cancer treatment strategies
Fast Rossi-alpha Measurements of Plutonium using Organic Scintillators
In this work, Rossi-alpha measurements were simultaneously performed with a
He-based detection system and an organic scintillator-based detection
system. The assembly is 15 kg of plutonium (93 wt Pu) reflected by
copper and moderated by lead. The goal of Rossi-alpha measurements is to
estimate the prompt neutron decay constant, alpha. Simulations estimate
= 0.624 and = 52.3 2.5 ns for the measured
assembly. The organic scintillator system estimated = 47.4 2.0
ns, having a 9.37 error (though the 1.09 standard deviation confidence
intervals overlapped). The He system estimated = 37 s. The
known slowing down time of the He system is 35-40 s, which means the
slowing down time dominates and obscures the prompt neutron decay constant.
Subsequently, the organic scintillator system should be used for assemblies
with alpha much less than 35 s.Comment: PHYSOR 2020: Transition to a Scalable Nuclear Future Cambridge,
United Kingdom, March 29th-April 2nd, 202
Experimental Study of Dispersion and Modulational Instability of Surface Gravity Waves on Constant Vorticity Currents
This paper examines experimentally the dispersion and stability of weakly nonlinear waves on opposing linearly vertically sheared current profiles (with constant vorticity). Measurements are compared against predictions from the unidirectional (1D + 1) constant vorticity nonlinear Schrödinger equation (the vor-NLSE) derived by Thomas et al. (Phys. Fluids, vol. 24, no. 12, 2012, 127102). The shear rate is negative in opposing currents when the magnitude of the current in the laboratory reference frame is negative (i.e. opposing the direction of wave propagation) and reduces with depth, as is most commonly encountered in nature. Compared to a uniform current with the same surface velocity, negative shear has the effect of increasing wavelength and enhancing stability. In experiments with a regular low-steepness wave, the dispersion relationship between wavelength and frequency is examined on five opposing current profiles with shear rates from 0 to â0.87 sâ1. For all current profiles, the linear constant vorticity dispersion relation predicts the wavenumber to within the 95 % confidence bounds associated with estimates of shear rate and surface current velocity. The effect of shear on modulational instability was determined by the spectral evolution of a carrier wave seeded with spectral sidebands on opposing current profiles with shear rates between 0 and â0.48 sâ1. Numerical solutions of the vor-NLSE are consistently found to predict sideband growth to within two standard deviations across repeated experiments, performing considerably better than its uniform-current NLSE counterpart. Similarly, the amplification of experimental wave envelopes is predicted well by numerical solutions of the vor-NLSE, and significantly over-predicted by the uniform-current NLSE
Quantum interferometry with three-dimensional geometry
Quantum interferometry uses quantum resources to improve phase estimation
with respect to classical methods. Here we propose and theoretically
investigate a new quantum interferometric scheme based on three-dimensional
waveguide devices. These can be implemented by femtosecond laser waveguide
writing, recently adopted for quantum applications. In particular, multiarm
interferometers include "tritter" and "quarter" as basic elements,
corresponding to the generalization of a beam splitter to a 3- and 4-port
splitter, respectively. By injecting Fock states in the input ports of such
interferometers, fringe patterns characterized by nonclassical visibilities are
expected. This enables outperforming the quantum Fisher information obtained
with classical fields in phase estimation. We also discuss the possibility of
achieving the simultaneous estimation of more than one optical phase. This
approach is expected to open new perspectives to quantum enhanced sensing and
metrology performed in integrated photonic.Comment: 7 pages (+4 Supplementary Information), 5 figure
Primitive neuroectodermal tumor of the cervix: a case report
<p>Abstract</p> <p>Introduction</p> <p>Peripheral primitive neuroectodermal tumor of the cervix uteri is extremely rare. Between 1987 and 2010, there were only nine cases reported in the English literature, with considerably different management policies.</p> <p>Case presentation</p> <p>A 45-year-old Iranian woman presented to our facility with a primitive neuroectodermal tumor of the cervix uteri. Her clinical stage IB2 tumor was treated successfully with chemotherapy. Our patient underwent radical hysterectomy. There was no trace of the tumor after four years of follow-up.</p> <p>Conclusions</p> <p>According to current knowledge, primitive neuroectodermal tumors belong to the Ewing's sarcoma family, and the improvement of treatment outcome in our patient was due to dose-intensive neoadjuvant chemotherapy, surgery and consolidation chemotherapy in accordance with the protocol for bony Ewing's sarcoma.</p
The landscape of combining immune checkpoint inhibitors with novel Therapies: Secret alliances against breast cancer
this review focuses on the immune checkpoint inhibitors (ICIs) in the context of breast cancer (BC) management. these innovative treatments, by targeting proteins expressed on both tumor and immune cells, aim to overcome tumor-induced immune suppression and reactivate the immune system. the potential of this approach is the subject of numerous clinical studies. here, we explore the key studies and emerging therapies related to ICIs providing a detailed analysis of their specific and combined use in BC treatment
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