4,473 research outputs found
Long-term quality of life after en-bloc vertebrectomy: 25 patients followed up for 9 years
AbstractObjectiveAssess quality-of-life results in patients who have undergone extensive curative surgery for spinal tumor and compare them to the general population in France.IntroductionLife expectancy is not the only criterion to assess the outcomes after massive tumor resections. Residual quality of life is also crucial. An indication for major surgery for spinal tumor should take the patient's long-term functional status into account, but the literature is limited on this question.Materials and methodsTwenty-five living patients from a group of 120 operated were assessed, all of whom were operated on by the same surgeon between 1984 and 2007. The mean follow-up was 9 years (range, 3–25 years). The mean age at surgery was 49 years. The patients completed different functional and quality-of-life questionnaires: the Oswestry Disability Index version 2 (ODI), the PROLO, the Karnofsky Index of performance status (KI), the Eastern Cooperative Oncology Group performance status (ECOG), the Short Form-36 Health Survey (SF-36), and the EuroQol-5 Dimensions (EQ5D). In addition, each patient was clinically and radiographically evaluated. Subgroups were identified considering the number of levels resected and histology. Their results on the SF-36 were compared with the results from the general population in France.ResultsThe mean PCS (physical component summary of the SF-36) was 52.4, the MCS (mental component summary, the psychological component of the SF-36) was 47.7, the ODI was 18.2, the PROLO was 7, the ECOG was 1, and the KI was 80%. The resections at three levels were associated with worse results in terms of quality of life, but overall, the results were similar to the French general population data for all categories of the SF-36.ConclusionAppropriate indications for massive spinal resection give good oncological and functional results. Although the expected life expectancy justifies this aggressive surgery, postoperative quality of life shows that it can also be successful on a functional level.Level of evidenceLevel IV; retrospective clinical study
Метод трехмерной триангуляции в задачах кластерного анализа
Представлен метод многомерного шкалирования на основе трехмерной триангуляции. Рассмотрена возможность качественного сохранения геометрической структуры множества объектов при отображении многомерного пространства в трехмерное. Приведены результаты применения метода для решения задачи кластеризации на примере периодической системы элементов Д.И. Менделеева. Экспериментально показано, что по критериям качества кластеризации предложенный метод более эффективен в сравнении с методами k-средних и нейронной сети Кохонена.Представлено метод багатовимірного шкалювання на основі тривимірної тріангуляції. Розглянуто можливість якісного збереження геометричної структури множини об’єктів при відображенні багатовимірного простору в тривимірне. Наведено результати застосування методу для вирішення задачі кластеризації на прикладі періодичної системи елементів Д.І. Менделєєва. Експериментально показано, що за критеріями якості кластеризації запропонований метод більш ефективний у порівнянні з методами k-середніх та нейронної мережі Кохонена.The method of multidimensional scaling on the basis of the 3-D triangulation is presented. The qualitative preservation possibility of geometrical structure of objects by multidimensional space mapping to three- dimensional space is considered. The results of application of the method for clustering problem of the Mendeleyev periodic table are presented. It is experimentally shown, that the presented method is more effective by criteria of clustering quality in comparison with the methods of k-averages and the Kohonen neural network
Discovery of Very High-Energy Gamma-Ray Radiation from the BL Lac 1ES 0806+524
The high-frequency-peaked BL-Lacertae object \objectname{1ES 0806+524}, at
redshift z=0.138, was observed in the very-high-energy (VHE) gamma-ray regime
by VERITAS between November 2006 and April 2008. These data encompass the two-,
and three-telescope commissioning phases, as well as observations with the full
four-telescope array. \objectname{1ES 0806+524} is detected with a statistical
significance of 6.3 standard deviations from 245 excess events. Little or no
measurable variability on monthly time scales is found. The photon spectrum for
the period November 2007 to April 2008 can be characterized by a power law with
photon index between
300 GeV and 700 GeV. The integral flux above 300 GeV is
which corresponds to 1.8% of the Crab Nebula flux. Non contemporaneous
multiwavelength observations are combined with the VHE data to produce a
broadband spectral energy distribution that can be reasonably described using a
synchrotron-self Compton model.Comment: 14 pages, 4 figures, accepted to APJ
VERITAS Upper Limit on the VHE Emission from the Radio Galaxy NGC 1275
The recent detection by the Fermi gamma-ray space telescope of high-energy
gamma-rays from the radio galaxy NGC 1275 makes the observation of the very
high energy (VHE: E > 100 GeV) part of its broadband spectrum particularly
interesting, especially for the understanding of active galactic nuclei (AGN)
with misaligned multi-structured jets. The radio galaxy NGC 1275 was recently
observed by VERITAS at energies above 100 GeV for about 8 hours. No VHE
gamma-ray emission was detected by VERITAS from NGC 1275. A 99% confidence
level upper limit of 2.1% of the Crab Nebula flux level is obtained at the
decorrelation energy of approximately 340 GeV, corresponding to 19% of the
power-law extrapolation of the Fermi Large Area Telescope (LAT) result.Comment: Accepted for publication in ApJ Letter
Towards a framework for critical citizenship education
Increasingly countries around the world are promoting forms of "critical" citizenship in the planned curricula of schools. However, the intended meaning behind this term varies markedly and can range from a set of creative and technical skills under the label "critical thinking" to a desire to encourage engagement, action and political emancipation, often labelled "critical pedagogy". This paper distinguishes these manifestations of the "critical" and, based on an analysis of the prevailing models of critical pedagogy and citizenship education, develops a conceptual framework for analysing and comparing the nature of critical citizenship
Is knife seizure imagery an effective crime deterrent? A multi-method study
The urgency to reduce knife carrying has been recognised by the police services in Scotland and has been addressed by the introduction of various initiatives to deter knife carrying and crime. One tactic includes the sharing of knife seizure images, where pictures of knives recovered by police are shared on media outlets, however, little research has explored whether this is an effective deterrent. The study sought to explore adults' views of the use of knife images as a deterrent to carrying knives utilising a multi-method approach: (1) a cross-sectional online survey (n= 553), and (2) individual, online semi-structured interviews with adults (n = 20). Fearful, worried and angry reactions towards the use of knife seizure images were expressed among adults and concern was raised that the use of such images may reinforce rather than deter knife carrying. Adults expressed concerns that the use of such images served to reinforce negative stereotypes and stigma within communities affected by high knife crime. The implications of these findings emphasise the limitations to the use of knife seizure images as a deterrent against knife carrying and the importance of community involvement in developing preventative and non-discriminatory approaches to tackling knife carrying throughout Scotland
Detection of Extended VHE Gamma Ray Emission from G106.3+2.7 with VERITAS
We report the detection of very-high-energy (VHE) gamma-ray emission from
supernova remnant (SNR) G106.3+2.7. Observations performed in 2008 with the
VERITAS atmospheric Cherenkov gamma-ray telescope resolve extended emission
overlapping the elongated radio SNR. The 7.3 sigma (pre-trials) detection has a
full angular extent of roughly 0.6deg by 0.4deg. Most notably, the centroid of
the VHE emission is centered near the peak of the coincident 12CO (J = 1-0)
emission, 0.4deg away from the pulsar PSR J2229+6114, situated at the northern
end of the SNR. Evidently the current-epoch particles from the pulsar wind
nebula are not participating in the gamma-ray production. The VHE energy
spectrum measured with VERITAS is well characterized by a power law dN/dE =
N_0(E/3 TeV)^{-G} with a differential index of G = 2.29 +/- 0.33stat +/-
0.30sys and a flux of N_0 = (1.15 +/- 0.27stat +/- 0.35sys)x 10^{-13} cm^{-2}
s^{-1} TeV^{-1}. The integral flux above 1 TeV corresponds to ~5 percent of the
steady Crab Nebula emission above the same energy. We describe the observations
and analysis of the object and briefly discuss the implications of the
detection in a multiwavelength context.Comment: 5 pages, 2 figure
Future Directions in the Molecular Breeding of Forage and Turf
Key points Molecular breeding of forage and turf plants and their endosymbionts has entered the post-genomic era with a large amount of structural genomics information and genomic resources available for key forage and turf species and relevant model systems. A primary future challenge is the conversion of this information into useful functional knowledge for the development of molecular breeding technologies and products that address a range of high impact outcome scenarios in forage and turf. High-throughput approaches for spatial and temporal analysis, from genome to phenome, and the respective data integration in a systems biology context will be critical for the establishment of stringent gene-function correlations. Translational genomics will permit results obtained using model systems to have major impact on the understanding of the molecular basis of plant processes and direct application to the molecular breeding of forage and turf plants. These developments will be enhanced through applications of transgenesis and functionally-associated genetic markers in forage and turf molecular breeding building on genomic and post-genomic discoveries in these target species
Evidence for long-term Gamma-ray and X-ray variability from the unidentified TeV source HESS J0632+057
HESS J0632+057 is one of only two unidentified very-high-energy gamma-ray
sources which appear to be point-like within experimental resolution. It is
possibly associated with the massive Be star MWC 148 and has been suggested to
resemble known TeV binary systems like LS I +61 303 or LS 5039. HESS J0632+057
was observed by VERITAS for 31 hours in 2006, 2008 and 2009. During these
observations, no significant signal in gamma rays with energies above 1 TeV was
detected from the direction of HESS J0632+057. A flux upper limit corresponding
to 1.1% of the flux of the Crab Nebula has been derived from the VERITAS data.
The non-detection by VERITAS excludes with a probability of 99.993% that HESS
J0632+057 is a steady gamma-ray emitter. Contemporaneous X-ray observations
with Swift XRT reveal a factor of 1.8+-0.4 higher flux in the 1-10 keV range
than earlier X-ray observations of HESS J0632+057. The variability in the
gamma-ray and X-ray fluxes supports interpretation of the ob ject as a
gamma-ray emitting binary.Comment: 8 pages, 3 figures, Accepted for publication in The Astrophysical
Journa
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