Letter from a Canadian Supporter to Geraldine Ferraro

Letter from a Canadian supporter to Geraldine Ferraro. Letter has handwritten notes.https://ir.lawnet.fordham.edu/vice_presidential_campaign_correspondence_1984_international/1221/thumbnail.jp

What is the best spatial distribution to model base station density? A deep dive into two european mobile networks

This paper studies the base station (BS) spatial distributions across different scenarios in urban, rural, and coastal zones, based on real BS deployment data sets obtained from two European countries (i.e., Italy and Croatia). Basically, this paper takes into account different representative statistical distributions to characterize the probability density function of the BS spatial density, including Poisson, generalized Pareto, Weibull, lognormal, and \alpha -Stable. Based on a thorough comparison with real data sets, our results clearly assess that the \alpha -Stable distribution is the most accurate one among the other candidates in urban scenarios. This finding is confirmed across different sample area sizes, operators, and cellular technologies (GSM/UMTS/LTE). On the other hand, the lognormal and Weibull distributions tend to fit better the real ones in rural and coastal scenarios. We believe that the results of this paper can be exploited to derive fruitful guidelines for BS deployment in a cellular network design, providing various network performance metrics, such as coverage probability, transmission success probability, throughput, and delay

A population of faint low surface brightness galaxies in the Perseus cluster core

We present the detection of 89 low surface brightness (LSB), and thus low stellar density galaxy candidates in the Perseus cluster core, of the kind named ‘ultra-diffuse galaxies’, with mean effective V-band surface brightnesses 24.8-27.1 mag arcsec−2, total V-band magnitudes −11.8 to −15.5 mag, and half-light radii 0.7-4.1 kpc. The candidates have been identified in a deep mosaic covering 0.3 square degrees, based on wide-field imaging data obtained with the William Herschel Telescope. We find that the LSB galaxy population is depleted in the cluster centre and only very few LSB candidates have half-light radii larger than 3 kpc. This appears consistent with an estimate of their tidal radius, which does not reach beyond the stellar extent even if we assume a high dark matter content (M/L = 100). In fact, three of our candidates seem to be associated with tidal streams, which points to their current disruption. Given that published data on faint LSB candidates in the Coma cluster – with its comparable central density to Perseus – show the same dearth of large objects in the core region, we conclude that these cannot survive the strong tides in the centres of massive clusters

Accounting for Individual Differences in Bradley-Terry Models by Means of Recursive Partitioning

The preference scaling of a group of subjects may not be homogeneous, but different groups of subjects with certain characteristics may show different preference scalings, each of which can be derived from paired comparisons by means of the Bradley-Terry model. Usually, either different models are fit in predefined subsets of the sample, or the effects of subject covariates are explicitly specified in a parametric model. In both cases, categorical covariates can be employed directly to distinguish between the different groups, while numeric covariates are typically discretized prior to modeling. Here, a semi-parametric approach for recursive partitioning of Bradley-Terry models is introduced as a means for identifying groups of subjects with homogeneous preference scalings in a data-driven way. In this approach, the covariates that -- in main effects or interactions -- distinguish between groups of subjects with different preference orderings, are detected automatically from the set of candidate covariates. One main advantage of this approach is that sensible partitions in numeric covariates are also detected automatically

Achievements and problems in the implementation of microcutting technology for clonaI rubber rootstock propagation

Microcutting is one of in vitro plant propagation methods and has been developed for rubber (Hevea brasiliensis) by using axillary buds from young seedlings as explant sources. There are some constraints to implement microcutting technology in mass propagation of Hevea such as high level of contamination, low proliferation rate, poor rooting, and difficulty in acclimatization process. Achievements and problems in the implementation this technique in Indonesia will be reported in this paper. Around 19.000 explants from 89 genotypes have been introduced in primary culture for almost 3 years (2006-2008), 40% of them loss during this stage due to contamination and no response of the explants. All healthy and good response explants had been transferred to multiplication phase. The multiplication rate was 1.3 to 1.6 per month for the best genotypes. In 2007 and 2008, around 6.000 new shoots had been introduced to conditioning phase, 80% of them have continued to rooting phase. These two stages produced about 4.000 plantlets which were then acclimatized to ex vitro conditions on different media and micro-environments. The suitable medium for vitroplants acclimatization was a mix of cocopeat, soil, sand and dung manure. Better growth and survival rate were achieved when the vitroplants were cultured inside a closed plastic tunnel placed under tree canopies. The survival rate of vitroplants, 1.5 month after weaning, has increased to 60% but still fluctuated and only 15% in average after 6 months. The survived plants with good root systems were then transferred to a shading nursery. Vitroplants and GT 1 seedlings were planted in the field for 7 months before budded with scions of PB 260 clone. All rootstocks from vitroplants and GT 1 seedlings were successfully budded with scions of PB 260. At present, budded and unbudded vitroplants are being planted in the field. (Résumé d'auteur

Cross-comparison of MRCGP & MRCP(UK) in a database linkage study of 2,284 candidates taking both examinations: assessment of validity and differential performance by ethnicity.

MRCGP and MRCP(UK) are the main entry qualifications for UK doctors entering general [family] practice or hospital [internal] medicine. The performance of MRCP(UK) candidates who subsequently take MRCGP allows validation of each assessment. In the UK, underperformance of ethnic minority doctors taking MRCGP has had a high political profile, with a Judicial Review in the High Court in April 2014 for alleged racial discrimination. Although the legal challenge was dismissed, substantial performance differences between white and BME (Black and Minority Ethnic) doctors undoubtedly exist. Understanding ethnic differences can be helped by comparing the performance of doctors who take both MRCGP and MRCP(UK)

New quasars behind the Magellanic Clouds. Spectroscopic confirmation of near-infrared selected candidates

Context. Quasi-stellar objects (quasars) located behind nearby galaxies provide an excellent absolute reference system for astrometric studies, but they are difficult to identify because of fore- and background contamination. Deep wide-field, high angular resolution surveys spanning the entire area of nearby galaxies are needed to obtain a complete census of such quasars. Aims. We embarked on a program to expand the quasar reference system behind the Large and the Small Magellanic Clouds, the Magellanic Bridge, and the Magellanic Stream that connects the Clouds with the Milky Way. Methods. Hundreds of quasar candidates were selected based on their near-infrared colors and variability properties from the ongoing public ESO VISTA Magellanic Clouds survey. A subset of 49 objects was followed up with optical spectroscopy. Results. We confirmed the quasar nature of 37 objects (34 new identifications): four are low redshift objects, three are probably stars, and the remaining three lack prominent spectral features for a secure classification. The bona fide quasars, identified from their broad emisison lines, are located as follows: 10 behind the LMC, 13 behind the SMC, and 14 behind the Bridge. The quasars span a redshift range from z ~ 0.5 to z ~ 4.1. Conclusions. Upon completion the VMC survey is expected to yield a total of ~1500 quasars with Y< 19.32 mag, J< 19.09 mag, and Ks< 18.04 mag