Vulnerability assessment of a large electrical grid by new graph theory approach

In previous research a novel methodology to assess structural vulnerability was proposed and applied in IEEE test system and high voltage transmission networks of 94 buses, by using graph theory to investigate various risk scenarios that can trigger cascading failures. In this paper we validate the application of this methodology in larger networks by applying a case study on the transmission network 230 and 400 kV of Mexico. The events of cascading failures are simulated through two elimination strategies: by deliberate attacks on critical nodes or by random errors. Iterations are performed by running successive N-1 contingencies on a network that is constantly changing its structure with the elimination of each node. The power flows are not necessary and only the calculation of the graph statistical parameter geodesic vulnerability is required. This reduces the computation time and leads to a comparative analysis of structural vulnerability

Comportamiento de la actividad enzimática de gamma glutamil transferasa en líquido ruminal bovino sometido a métodos térmicos, físicos y químicos

In order to determine the effect of treatments using centrifugation, thawing and the addition of magnesium salts on activity in rumen fluid (LR) of gamma glutamyl transferase (GGT) cattle, 2 samples (100 mL each) of LR were extracted from mature, fistulated Holstein cows (620 ± 14 Kg 7 years old). Samples were stored frozen and then divided equally and subjected to sequential treatments of thawing [room temperature (LRDC) or water bath (LRCal)], centrifugation [9.000 rpm x 10 min (LRDC+C and LRCal+C)], and the addition of salt and Mg [MgSO4 or MgCl2]. The data were compared with fresh rumen fluid (LRF) extracted from the same cows. The activity of the gamma glutamil transferase (GGT) was measured on all samples by applying the colorimetric method using a spectrophotometric kit (Biosystems®). The means of treatments were compared using a t test, which revealed that samples of lr with the addition of MgCl2 had significantly greater in vitro activity (p < 0.01) than samples from the control group or from those treated with MgSO4. A decrease in enzyme activity was also observed when the samples were placed in a centrifuge, as compared to other treatments. We conclude that the Mg++ positively affects GGT enzyme activity in vitro in contrast to the physical effect of the spin treatment. Although both thermal treatments increased enzyme activity, there were no significant differences with respect to fresh rumen fluid.El proyecto “Comportamiento de la actividad enzimática de gamma glutamil transferasa en líquido ruminal bovino sometido a métodos térmicos, físicos y químicos”, desarrollado en el 2012 por el grupo de investigación “Nutrición, Toxicología y Reproducción” (Grupontra), de la Universidad Cooperativa de Colombia, sede Bucaramanga, fue conducido para determinar el efecto de tratamientos de descongelamiento, centrifugación y adición de sales de magnesio sobre la actividad en líquido ruminal (LR) de la enzima gamma glutamil transferasa (GGT) de bovinos fistulados. Se extrajeron 2 muestras de 100 ml de LR de vacas Holstein fistuladas (620±14 kg 7 años de edad). Las muestras se almacenaron en congelación y posteriormente se dividieron en partes iguales y fueron sometidas a tratamientos secuenciales de descongelación [temperatura ambiente (LRDC) o baño de María (LRCal)], centrifugación [9.000 rpm x 10 min (LRDC+C y LRCal+C)] y adición de sal de Mg [MgSO4 o MgCl2]; los datos se compararon con líquido ruminal fresco (LRF) extraído de las mismas vacas. Sobre todas las muestras se midió la actividad de la GGT por el método colorimétrico utilizando un kit espectrofotométrico. Los promedios de los tratamientos se compararon por medio de una prueba t, la cual reveló que las muestras de LR con adición de MgCl2 presentaron significativamente (p < 0,01) mayor actividad in vitro que las muestras del tratamiento control o con MgSO4. Adicionalmente se observó una disminución en la actividad enzimática del LR que se centrifugó, frente a los demás tratamientos. Se concluye que la adición de MgCl2 afecta positivamente la actividad de la enzima GGT in vitro, al contrario del efecto generado por el tratamiento físico de centrifugación. Aunque ambos tratamientos térmicos originaron aumentos en la actividad enzimática, no mostraron diferencias estadísticamente significativas con respecto al líquido ruminal fresco

Determining science teachers’ ideas about the science process skills: a case study

AbstractThe aim of this study is to investigate science teachers’ ideas about the science process skills (SPS) using qualitative analysis. This study was carried out at the first term of 2008- 2009 academic year. A case study research methodology was used. The sample of this study consisted of 10 science teachers (ST), who has been working at Giresun center elementary schools in Turkey. A semi-structured interview procedure was used to collect data. The collected data were analyzed with Nvivo 8 program. The results indicate that the majority of sample have not had widespread theoretical knowledge on SPS

The Fourteenth Data Release of the Sloan Digital Sky Survey: First Spectroscopic Data from the extended Baryon Oscillation Spectroscopic Survey and from the second phase of the Apache Point Observatory Galactic Evolution Experiment

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) has been in operation since July 2014. This paper describes the second data release from this phase, and the fourteenth from SDSS overall (making this, Data Release Fourteen or DR14). This release makes public data taken by SDSS-IV in its first two years of operation (July 2014-2016). Like all previous SDSS releases, DR14 is cumulative, including the most recent reductions and calibrations of all data taken by SDSS since the first phase began operations in 2000. New in DR14 is the first public release of data from the extended Baryon Oscillation Spectroscopic Survey (eBOSS); the first data from the second phase of the Apache Point Observatory (APO) Galactic Evolution Experiment (APOGEE-2), including stellar parameter estimates from an innovative data driven machine learning algorithm known as "The Cannon"; and almost twice as many data cubes from the Mapping Nearby Galaxies at APO (MaNGA) survey as were in the previous release (N = 2812 in total). This paper describes the location and format of the publicly available data from SDSS-IV surveys. We provide references to the important technical papers describing how these data have been taken (both targeting and observation details) and processed for scientific use. The SDSS website (www.sdss.org) has been updated for this release, and provides links to data downloads, as well as tutorials and examples of data use. SDSS-IV is planning to continue to collect astronomical data until 2020, and will be followed by SDSS-V.Comment: SDSS-IV collaboration alphabetical author data release paper. DR14 happened on 31st July 2017. 19 pages, 5 figures. Accepted by ApJS on 28th Nov 2017 (this is the "post-print" and "post-proofs" version; minor corrections only from v1, and most of errors found in proofs corrected

Manipulating the alpha level cannot cure significance testing

We argue that making accept/reject decisions on scientific hypotheses, including a recent call for changing the canonical alpha level from p = 0.05 to p = 0.005, is deleterious for the finding of new discoveries and the progress of science. Given that blanket and variable alpha levels both are problematic, it is sensible to dispense with significance testing altogether. There are alternatives that address study design and sample size much more directly than significance testing does; but none of the statistical tools should be taken as the new magic method giving clear-cut mechanical answers. Inference should not be based on single studies at all, but on cumulative evidence from multiple independent studies. When evaluating the strength of the evidence, we should consider, for example, auxiliary assumptions, the strength of the experimental design, and implications for applications. To boil all this down to a binary decision based on a p-value threshold of 0.05, 0.01, 0.005, or anything else, is not acceptable

SELNET clinical practice guidelines for bone sarcoma

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context

The Canadian VirusSeq Data Portal & Duotang: open resources for SARS-CoV-2 viral sequences and genomic epidemiology

The COVID-19 pandemic led to a large global effort to sequence SARS-CoV-2 genomes from patient samples to track viral evolution and inform public health response. Millions of SARS-CoV-2 genome sequences have been deposited in global public repositories. The Canadian COVID-19 Genomics Network (CanCOGeN - VirusSeq), a consortium tasked with coordinating expanded sequencing of SARS-CoV-2 genomes across Canada early in the pandemic, created the Canadian VirusSeq Data Portal, with associated data pipelines and procedures, to support these efforts. The goal of VirusSeq was to allow open access to Canadian SARS-CoV-2 genomic sequences and enhanced, standardized contextual data that were unavailable in other repositories and that meet FAIR standards (Findable, Accessible, Interoperable and Reusable). The Portal data submission pipeline contains data quality checking procedures and appropriate acknowledgement of data generators that encourages collaboration. Here we also highlight Duotang, a web platform that presents genomic epidemiology and modeling analyses on circulating and emerging SARS-CoV-2 variants in Canada. Duotang presents dynamic changes in variant composition of SARS-CoV-2 in Canada and by province, estimates variant growth, and displays complementary interactive visualizations, with a text overview of the current situation. The VirusSeq Data Portal and Duotang resources, alongside additional analyses and resources computed from the Portal (COVID-MVP, CoVizu), are all open-source and freely available. Together, they provide an updated picture of SARS-CoV-2 evolution to spur scientific discussions, inform public discourse, and support communication with and within public health authorities. They also serve as a framework for other jurisdictions interested in open, collaborative sequence data sharing and analyses

The Fifteenth Data Release of the Sloan Digital Sky Surveys: First Release of MaNGA-derived Quantities, Data Visualization Tools, and Stellar Library

Twenty years have passed since first light for the Sloan Digital Sky Survey (SDSS). Here, we release data taken by the fourth phase of SDSS (SDSS-IV) across its first three years of operation (2014 July–2017 July). This is the third data release for SDSS-IV, and the 15th from SDSS (Data Release Fifteen; DR15). New data come from MaNGA—we release 4824 data cubes, as well as the first stellar spectra in the MaNGA Stellar Library (MaStar), the first set of survey-supported analysis products (e.g., stellar and gas kinematics, emission-line and other maps) from the MaNGA Data Analysis Pipeline, and a new data visualization and access tool we call "Marvin." The next data release, DR16, will include new data from both APOGEE-2 and eBOSS; those surveys release no new data here, but we document updates and corrections to their data processing pipelines. The release is cumulative; it also includes the most recent reductions and calibrations of all data taken by SDSS since first light. In this paper, we describe the location and format of the data and tools and cite technical references describing how it was obtained and processed. The SDSS website (www.sdss.org) has also been updated, providing links to data downloads, tutorials, and examples of data use. Although SDSS-IV will continue to collect astronomical data until 2020, and will be followed by SDSS-V (2020–2025), we end this paper by describing plans to ensure the sustainability of the SDSS data archive for many years beyond the collection of data

Sloan Digital Sky Survey IV: Mapping the Milky Way, Nearby Galaxies, and the Distant Universe

We describe the Sloan Digital Sky Survey IV (SDSS-IV), a project encompassing three major spectroscopic programs. The Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) is observing hundreds of thousands of Milky Way stars at high resolution and high signal-to-noise ratios in the near-infrared. The Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey is obtaining spatially resolved spectroscopy for thousands of nearby galaxies (median $z\sim 0.03$). The extended Baryon Oscillation Spectroscopic Survey (eBOSS) is mapping the galaxy, quasar, and neutral gas distributions between $z\sim 0.6$ and 3.5 to constrain cosmology using baryon acoustic oscillations, redshift space distortions, and the shape of the power spectrum. Within eBOSS, we are conducting two major subprograms: the SPectroscopic IDentification of eROSITA Sources (SPIDERS), investigating X-ray AGNs and galaxies in X-ray clusters, and the Time Domain Spectroscopic Survey (TDSS), obtaining spectra of variable sources. All programs use the 2.5 m Sloan Foundation Telescope at the Apache Point Observatory; observations there began in Summer 2014. APOGEE-2 also operates a second near-infrared spectrograph at the 2.5 m du Pont Telescope at Las Campanas Observatory, with observations beginning in early 2017. Observations at both facilities are scheduled to continue through 2020. In keeping with previous SDSS policy, SDSS-IV provides regularly scheduled public data releases; the first one, Data Release 13, was made available in 2016 July