Electron precipitation from the outer radiation belt during the St Patrick's Day storm 2015: observations, modelling, and validation

Recently, a model for medium energy (30–1000 keV) radiation belt‐driven electron precipitation (ApEEP) has been put forward for use in decadal to century‐long climate model runs as part of the Climate Modelling Intercomparison Project, phase 6 (CMIP6). The ApEEP model is based on directly observed precipitation data spanning 2002‐2012 from the constellation of low Earth orbiting Polar Operational Environmental Satellites (POES). Here we test the ApEEP model's ability using its magnetic local time variant, ApEEP_MLT, to accurately represent electron precipitation fluxes from the radiation belts during a large geomagnetic storm that occurred outside of the span of the development dataset. In a study of narrow band sub‐ionospheric VLF transmitter data collected during March 2015, continuous phase observations have been analyzed throughout the entire St. Patrick's Day geomagnetic storm period for the first time. Using phase data from the UK transmitter, call‐sign GVT (22.1 kHz), received in Reykjavik, Iceland, electron precipitation fluxes from L=2.8‐5.4 are calculated around magnetic local noon (12 MLT), and magnetic midnight (00 MLT). VLF‐inferred >30 keV fluxes are similar to the equivalent directly‐observed POES fluxes. The ApEEP_MLT >30 keV fluxes for L30 keV flux levels during a large geomagnetic storm, using three different techniques, indicates this flux forcing are appropriate for decadal climate simulations for which the ApEEP model was created

Predictors for distant metastasis in head and neck cancer, with emphasis on age

PURPOSE: Distant metastasis (DM) in patients with head and neck squamous cell carcinoma (HNSCC) is uncommon, but strongly deteriorates prognosis. Controversy exists regarding age as a predictor for the presence and development of DM. The aim of this study was to investigate age and other predictors for DM in HNSCC patients. METHODS: From 1413 patients diagnosed with a primary HNSCC between 1999 and 2010 in a tertiary referral centre, patient, disease and pathological characteristics were extracted from patient files. Uni- and multivariable Cox regression analyses were performed to identify risk factors for DM as primary outcome. RESULTS: DM occurred in 131 (9.3%) patients, of which 27 (1.9%) were diagnosed simultaneously with the primary tumour, 27 (1.9%) were diagnosed synchronous, and 77 (5.4%) were diagnosed metachronous. The most common site of DM was lung (51.1%), followed by bone (19.1%) and liver (11.5%). Multivariable analysis identified male gender (HR = 1.95, 95% CI 1.23-3.10) hypopharyngeal tumours (HR = 3.28, 95% CI 1.75-6.14), advanced T-stage (HR = 1.61, 95% CI 1.09-2.38), poor differentiation grade (HR = 2.49, 95% CI 1.07-5.78), regional lymph node metastasis (HR = 5.35, 95% CI 3.25-8.79) and extranodal extension of regional lymph nodes metastasis (HR = 3.06, 95% CI 1.39-6.72) as independent prognostic factors for the presence or development of DM. No relation with age was found. CONCLUSION: Age is not related to the presence or development of DM. This study emphasizes the importance of screening for DM, especially in males, patients with hypopharyngeal tumours, advanced T-stage, histopathological poor differentiation grade, regional lymph node metastasis and extranodal extension

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Experimental verification of asymmetrical short-term scintillation distribution model

The theory that tropospheric scintillation is associated with turbulence in clouds leads to an asymmetrical distribution of signal level fluctuations in decibels, in contrast to the commonly used symmetrical model. The asymmetry of measured signal fluctuations from Spino d'Adda is evaluated and it is found that the measured short-term distribution is in good agreement with the asymmetrical mode

Axial crosspolarization in reflector antennas due to asymmetric cross-polar feed patterns

\u3cp\u3eThe on-axis cross-polarisation of a reflector antenna illuminated by a feeding system with an asymmetric cross-polar radiation pattern is examined. A graph is presented from which the cross-polarisation discrimination (XPD) of the reflector antenna can be simply obtained.\u3c/p\u3

Development and validation of time-series synthesizers of rain attenuation for Ka-band and Q/V-band satellite communication systems

The aim of this paper is to present recent developments in terms of propagation time-series synthesizers, carried out in the framework of the ESA study 16865/03/NL/EC Development of propagation models for telecommunication satellite systems (ONERA Final Report RF 4/07757/DEMR, 2004). The paper is composed of three parts: a review of the initial requirements related to propagation time series for system performance simulation, a description of a collection of rain attenuation time-series synthesizers and of their related input parameters, and a comparative analysis of the output characteristics of these time-series synthesizers as compared with experimental data collected during the OLYMPUS and ITALSAT propagation experiments