Caracterización morfogenética de cuatro cultivares de Avena spp.

El objetivo fue estudiar la dinámica de morfogénesis en cuatro cultivares de Avena spp., a los efectos de determinar variabilidad genética en el filocrono y definir el momento donde se maximice la acumulación de lámina viva. El trabajo se realizó, en condiciones de invernáculo, durante la temporada de crecimiento 2011. Se evaluaron cuatro cultivares de avena con características morfofisiológicas contrastantes, dos cvs. de avena blanca (Avena sativa L.), Carlota y Máxima y dos cvs. de avena amarilla (Avena byzantina K. Koch), Aurora y Milagros. La siembra se realizó en tubos de PVC, con 10 repeticiones. Sobre cada planta, se marcaron cuatro macollos con cable de diferente color y se registró, cada siete días, número de hojas y longitud de lámina viva y se estimaron las tasas de aparición de hoja (TAH) y de acumulación de lámina viva y lámina senescente. La relación entre las variables número de hojas por macollo y los grados días fue descripta mediante un modelo lineal. Los resultados indicaron que la tasa de aparición de hojas y el filocrono (1/TAH) difirió (p<0,05) entre cultivares, siendo la amplitud en el rango de valores encontrado de 0,0071 a 0,0092 hoja ºCd-1, ó 141 a 109 ºCd hoja-1 . La senescencia foliar presentó un incremento lineal y variable entre cultivares (0,0504 a 0,0778 cm por macollo por cada incremento en los grados días). La longitud acumulada máxima neta de lámina se registró, en los cvs. de A. sativa, alrededor de los 1205 y 1135 ºCd en Carlota y Máxima, respectivamente. Mientras que, en los cvs. de A. byzantina, estos valores fueron de alrededor de 1110 y 1193 ºCd en Aurora y Milagros, respectivamente. Para lograr esta acumulación, considerando una temperatura media del aire de 14 ºC, deberían transcurrir entre 79 y 86 días desde la emergencia del cultivo. Se encontraron diferencias intra e interespecíficas en las variables morfogenéticas estudiadas, aunque en general las diferencias intraespecíficas fueron mayores que entre especies

Precision tests of the Standard Model with leptonic and semileptonic kaon decays

We present a global analysis of leptonic and semileptonic kaon decays data, including all recent results by BNL-E865, KLOE, KTeV, ISTRA+, and NA48. Experimental results are critically reviewed and combined, taking into account theoretical (both analytical and numerical) constraints on the semileptonic kaon form factors. This analysis leads to a very accurate determination of Vus and allows us to perform several stringent tests of the Standard Model.We present a global analysis of leptonic and semileptonic kaon decays data, including all recent results by BNL-E865, KLOE, KTeV, ISTRA+, and NA48. Experimental results are critically reviewed and combined, taking into account theoretical (both analytical and numerical) constraints on the semileptonic kaon form factors. This analysis leads to a very accurate determination of Vus and allows us to perform several stringent tests of the Standard Model

Search for heavy neutral lepton production in K+ decays

A search for heavy neutral lepton production in K + decays using a data sample collected with a minimum bias trigger by the NA62 experiment at CERN in 2015 is reported. Upper limits at the 10−7 to 10−6 level are established on the elements of the extended neutrino mixing matrix |Ue4| 2 and |Uμ4| 2 for heavy neutral lepton mass in the ranges 170–448 MeV/c2 and 250–373 MeV/c2, respectively. This improves on the previous limits from HNL production searches over the whole mass range considered for |Ue4|2 and above 300 MeV/c2 for |Uμ4|2

A Probe into the Reform of Public Calligraphy Course in Chinese Colleges and Universities

中国书法是中国传统文化中的瑰宝，它既是一门艺术，又有着深厚的文化内涵。我国普通高校开设公共书法教学是与目前倡导的素质教育，培养创新型人才，提倡人的全面和谐发展的高等教育理念相一致的。加强高校公共书法教育，是全面推进素质教育的有效途径之一，也是提高当代大学生人文素质的重要手段。它对促进大学生人格完善、创造力培养以及民族文化的传承等有着不可低估的作用。本文主要针对我国普通高等院校公共书法教学现状进行分析，并由此比较借鉴日本高校中实施书法教学的成功经验提出对我国高校公共书法教学改革的具体建议和措施，设计并实践一种具备学科视野的、以学生为主体的公共书法教学的新模式。论文共分为五部分。引言扼要介绍论文写...Chinese calligraphy is a treasure of Chinese traditional culture. It not only is an art, but also has profound culture contents. Opening the public calligraphy course to the university students is in accordance with the concept that advocated by the current quality- oriented education, which aims to cultivate the students’ creative talent and comprehensive development. This paper concentrates on a...学位：文学硕士院系专业：艺术教育学院美术系_美术学学号：20042201

Review of Kaon Physics at CERN and in Europe

The Kaon physics program at CERN and in Europe will be presented. I will first give a short review of recent results form the NA48/2 and NA62 experiments, with special emphasis to the measurement of RK , the ratio of Kaon leptonic decays rates, K → eν and K → μν, using the full minimum bias data sample collected in 2007-2008. The main subject of the talk will be the study of the highly suppressed decay K → πνν. While its rate can be predicted with minimal theoretical uncertainty in the Standard Model (BR ∼ 8 × 10−11), the smallness of BR and the challenging experimental signature make it very difficult to measure. The branching ratio for this decay is thus a sensitive probe of the flavour sector of the SM. The aim of NA62 is the measurement of the K → πνν BR with ∼ 10% precision in two years of data taking. This will require the observation of 10K decays in the experiment's fiducial volume, as well as the use of high-performance systems for precision tracking, particle identification, and photon vetoing. These aspects of the experiment will also allow NA62 to carry out a rich program of searches for lepton flavour and/or number violating K decays. Data taking will start in October 2014. The physics prospects and the status of the construction and commissioning of the NA62 experiment will be presented. In the last part of the talk I will report on Kaon physics results and prospects from other experiments at CERN (e.g. LHCb) and in Europe (e.g. KLOE and KLOE-2) and briefly mention the status in US

Measurement of the very rare K+→π+ννˉK^+ \to \pi^+ \nu \bar\nu decay

The decay K+→π+νν¯ , with a very precisely predicted branching ratio of less than 10−10 , is among the best processes to reveal indirect effects of new physics. The NA62 experiment at CERN SPS is designed to study the K+→π+νν¯ decay and to measure its branching ratio using a decay-in-flight technique. NA62 took data in 2016, 2017 and 2018, reaching the sensitivity of the Standard Model for the K+→π+νν¯ decay by the analysis of the 2016 and 2017 data, and providing the most precise measurement of the branching ratio to date by the analysis of the 2018 data. This measurement is also used to set limits on BR(K+→π+X ), where X is a scalar or pseudo-scalar particle. The final result of the BR(K+→π+νν¯ ) measurement and its interpretation in terms of the K+→π+X decay from the analysis of the full 2016-2018 data set is presented, and future plans and prospects are reviewed

Study of the rare decay K±→π±γγK^{\pm} → \pi^{\pm}γγ in the NA48/2 and NA62 experiments at CERN

A sample of about 300 K ! rare decays with a background contamination below 10% has been collected by the NA48/2 and NA62 experiments at CERN during low intensity runs with minimum bias trigger conguration. The measurements of the decay spectrum and rate provide a crucial test of the Chiral Perturbation Theory (ChPT) describing weak processes at low energ

The NA62 experiment at CERN

The rare decays K -> pivv̄ are excellent processes to make tests of new physics at the highest scale complementary to LHC thanks to their theoretically cleanness. The NA62 experiment at CERN SPS aims to collect of the order of 100 events in two years of data taking for the decay K^+ -> pi^+vv̄, keeping the background at the level of 10%. Part of the experimental apparatus has been commissioned during a technical run in 2012. The diverse and innovative experimental techniques will be explained and some preliminary results obtained during the 2014 pilot run will be reviewed.The rare decays K → πvv̄ are excellent processes to make tests of new physics at the highest scale complementary to LHC thanks to their theoretically cleanness. The NA62 experiment at CERN SPS aims to collect of the order of 100 events in two years of data taking for the decay K+ → π+vv̄, keeping the background at the level of 10%. Part of the experimental apparatus has been commissioned during a technical run in 2012. The diverse and innovative experimental techniques will be explained and some preliminary results obtained during the 2014 pilot run will be reviewed

Precision measurement of the form factors of the charged kaon semileptonic decays K±→πl3±K^\pm \rightarrow \pi^\pm_{l3}

The NA48/2 experiment has presented a final result of the charged kaon semileptonic decays form factors measurement based on 4.28 million $K^{\pm}\rightarrow \pi^0 e^{\pm}\nu$ (K$_{e3}$) and 2.91 million $K^{\pm}\rightarrow \pi^0 \mu^{\pm}\nu$ (K$_{\mu 3}$) selected decays, collected in 2004. The result is competitive with other measurements in (K$_{\mu 3}$) mode and has a smallest uncertainty for (K$_{e3}$), that leads to the most precise combined (K$_{\it{l}3}$) result and allows to reduce the form factor uncertainty on the extraction of |V$_{US}$|.The NA48/2 experiment has presented a final result of the charged kaon semileptonic decays form factors measurement based on 4.28 million $K^{\pm}\rightarrow \pi^0 e^{\pm}\nu$ (K$_{e3}$) and 2.91 million $K^{\pm}\rightarrow \pi^0 \mu^{\pm}\nu$ (K$_{\mu 3}$) selected decays, collected in 2004. The result is competitive with other measurements in (K$_{\mu 3}$) mode and has a smallest uncertainty for (K$_{e3}$), that leads to the most precise combined (K$_{\it{l}3}$) result and allows to reduce the form factor uncertainty on the extraction of |V$_{US}$|