Chesapeake Bay wave climate : Thimble Shoal light wave station, report and summary of wave observations, October 8, 1990 through August 22, 1991 and Chesapeake light tower - VIMS Star gage test measurements and evaluation, July, August, October 1991

This report also presents a description of a directional wave gaging system, known as a Star gage, that is designed for long-term, low-maintenance operation both within and immediately outside the Chesapeake Bay entrance area. This development was prompted by our dependence to date on the single-point, PUV-type directional wave gage described below. While ideally suited for short-term investigative studies at different sites, the PUV directional wave gage requires field service visits at monthly intervals to maintain adequate performance and uninterrupted operation. A prototype Star gage system was constructed and field tested to evaluate its potential use as a long-term and eventual real-time wave gage for the Virginia coastal environment. A test deployment of the VIMS Star gage, a 4-element pressure sensor array utilizing a star configuration (Goda, 1985) was conducted at the Chesapeake Light Tower (CLT, Fig. 1) located approximately 14 nautical miles east of the bay entrance. Results of these tests are reported in Section VII

Validation of a Predictive Model for Survival in Patients With Advanced Cancer: Secondary Analysis of RTOG 9714.

BackgroundThe objective of this study was to validate a simple predictive model for survival of patients with advanced cancer.MethodsPrevious studies with training and validation datasets developed a model predicting survival of patients referred for palliative radiotherapy using three readily available factors: primary cancer site, site of metastases and Karnofsky performance score (KPS). This predictive model was used in the current study, where each factor was assigned a value proportional to its prognostic weight and the sum of the weighted scores for each patient was survival prediction score (SPS). Patients were also classified according to their number of risk factors (NRF). Three risk groups were established. The Radiation Therapy and Oncology Group (RTOG) 9714 data was used to provide an additional external validation set comprised of patients treated among multiple institutions with appropriate statistical tests.ResultsThe RTOG external validation set comprised of 908 patients treated at 66 different radiation facilities from 1998 to 2002. The SPS method classified all patients into the low-risk group. Based on the NRF, two distinct risk groups with significantly different survival estimates were identified. The ability to predict survival was similar to that of the training and previous validation datasets for both the SPS and NRF methods.ConclusionsThe three variable NRF model is preferred because of its relative simplicity

Spawning rings of exceptional points out of Dirac cones

The Dirac cone underlies many unique electronic properties of graphene and topological insulators, and its band structure--two conical bands touching at a single point--has also been realized for photons in waveguide arrays, atoms in optical lattices, and through accidental degeneracy. Deformations of the Dirac cone often reveal intriguing properties; an example is the quantum Hall effect, where a constant magnetic field breaks the Dirac cone into isolated Landau levels. A seemingly unrelated phenomenon is the exceptional point, also known as the parity-time symmetry breaking point, where two resonances coincide in both their positions and widths. Exceptional points lead to counter-intuitive phenomena such as loss-induced transparency, unidirectional transmission or reflection, and lasers with reversed pump dependence or single-mode operation. These two fields of research are in fact connected: here we discover the ability of a Dirac cone to evolve into a ring of exceptional points, which we call an "exceptional ring." We experimentally demonstrate this concept in a photonic crystal slab. Angle-resolved reflection measurements of the photonic crystal slab reveal that the peaks of reflectivity follow the conical band structure of a Dirac cone from accidental degeneracy, whereas the complex eigenvalues of the system are deformed into a two-dimensional flat band enclosed by an exceptional ring. This deformation arises from the dissimilar radiation rates of dipole and quadrupole resonances, which play a role analogous to the loss and gain in parity-time symmetric systems. Our results indicate that the radiation that exists in any open system can fundamentally alter its physical properties in ways previously expected only in the presence of material loss and gain

Impact of KRAS mutation status on the efficacy of immunotherapy in lung cancer brain metastases

Immune checkpoint inhibitors (ICIs) have resulted in improved outcomes in non-small cell lung cancer (NSCLC) patients. However, data demonstrating the efficacy of ICIs in NSCLC brain metastases (NSCLCBM) is limited. We analyzed overall survival (OS) in patients with NSCLCBM treated with ICIs within 90 days of NSCLCBM diagnosis (ICI-90) and compared them to patients who never received ICIs (no-ICI). We reviewed 800 patients with LCBM who were diagnosed between 2010 and 2019 at a major tertiary care institution, 97% of whom received stereotactic radiosurgery (SRS) for local treatment of BM. OS from BM was compared between the ICI-90 and no-ICI groups using the Log-Rank test and Cox proportional-hazards model. Additionally, the impact of KRAS mutational status on the efficacy of ICI was investigated. After accounting for known prognostic factors, ICI-90 in addition to SRS led to significantly improved OS compared to no-ICI (12.5 months vs 9.1, p \u3c 0.001). In the 109 patients who had both a known PD-L1 expression and KRAS status, 80.4% of patients with KRAS mutation had PD-L1 expression vs 61.9% in wild-type KRAS patients (p = 0.04). In patients without a KRAS mutation, there was no difference in OS between the ICI-90 vs no-ICI cohort with a one-year survival of 60.2% vs 54.8% (p = 0.84). However, in patients with a KRAS mutation, ICI-90 led to a one-year survival of 60.4% vs 34.1% (p = 0.004). Patients with NSCLCBM who received ICI-90 had improved OS compared to no-ICI patients. Additionally, this benefit appears to be observed primarily in patients with KRAS mutations that may drive the overall benefit, which should be taken into account in the development of future trials

An experimental and numerical study of particle nucleation and growth during low-pressure thermal decomposition of silane

Abstract This paper discusses an experimental and numerical study of the nucleation and growth of particles during low-pressure (∼1:0 Torr) thermal decomposition of silane (SiH 4 ). A Particle Beam Mass Spectrometer was used to measure particle size distributions in a parallel-plate showerhead-type semiconductor reactor. An aerosol dynamics moment-type formulation coupled with a chemically reacting uid ow model was used to predict particle concentration, size, and transport in the reactor. Particle nucleation kinetics via a sequence of chemical clustering reactions among silicon hydride molecular clusters, growth by heterogeneous chemical reactions on particle surfaces and coagulation, and transport by convection, di usion, and thermophoresis were included in the model. The e ect of pressure, temperature, ow residence time, carrier gas, and silane concentration were examined under conditions typically used for low-pressure (∼1 Torr) thermal chemical vapor deposition of polysilicon. The numerical simulations predict that several pathways involving linear and polycyclic silicon hydride molecules result in formation of particle "nuclei," which subsequently grow by heterogeneous reactions on the particle surfaces. The model is in good agreement with observations for the pressure and temperature at which particle formation begins, particle sizes and growth rates, and relative particle concentrations at various process conditions. A simpliÿed, computationally inexpensive, quasi-coupled modeling approach is suggested as an engineering tool for process equipment design and contamination control during low-pressure thermal silicon deposition.

The Glial Regenerative Response to Central Nervous System Injury Is Enabled by Pros-Notch and Pros-NFκB Feedback

Organisms are structurally robust, as cells accommodate changes preserving structural integrity and function. The molecular mechanisms underlying structural robustness and plasticity are poorly understood, but can be investigated by probing how cells respond to injury. Injury to the CNS induces proliferation of enwrapping glia, leading to axonal re-enwrapment and partial functional recovery. This glial regenerative response is found across species, and may reflect a common underlying genetic mechanism. Here, we show that injury to the Drosophila larval CNS induces glial proliferation, and we uncover a gene network controlling this response. It consists of the mutual maintenance between the cell cycle inhibitor Prospero (Pros) and the cell cycle activators Notch and NFκB. Together they maintain glia in the brink of dividing, they enable glial proliferation following injury, and subsequently they exert negative feedback on cell division restoring cell cycle arrest. Pros also promotes glial differentiation, resolving vacuolization, enabling debris clearance and axonal enwrapment. Disruption of this gene network prevents repair and induces tumourigenesis. Using wound area measurements across genotypes and time-lapse recordings we show that when glial proliferation and glial differentiation are abolished, both the size of the glial wound and neuropile vacuolization increase. When glial proliferation and differentiation are enabled, glial wound size decreases and injury-induced apoptosis and vacuolization are prevented. The uncovered gene network promotes regeneration of the glial lesion and neuropile repair. In the unharmed animal, it is most likely a homeostatic mechanism for structural robustness. This gene network may be of relevance to mammalian glia to promote repair upon CNS injury or disease

Targeted Therapy After Brain Radiotherapy for BRAF-Mutated Melanoma With Extensive Ependymal Disease With Prolonged Survival: Case Report and Review of the Literature

Melanoma brain metastasis with ependymal spread/metastases is uncommon. These cases are frequently classified together with leptomeningeal disease. However, the commonalities and differences in the underlying pathophysiology and clinical outcomes between these two types of spread are not clear. Very few reports on long term outcome and durable central nervous system (CNS) disease control have been reported in the literature. Here, we report a case of a 45 year-old Caucasian lady with BRAF-V600E mutant metastatic melanoma to the brain who had whole brain radiotherapy followed by two Gamma knife radiosurgery treatments for localized disease progression. She then developed extensive ependymal disease progression with no evidence of leptomeningeal spread. She was treated with a repeat course of whole brain radiotherapy and maintained on BRAF and MEK inhibitors with durable CNS disease control for more than a year. This study reviews the management of BRAF-V600E mutant melanoma with ependymal involvement. Management using radiation therapy with maintenance targeted therapy seems to be a reasonable approach to this challenging disease