Unirationality of del Pezzo surfaces of degree two over finite fields

We prove that every del Pezzo surface of degree two over a finite field is unirational, building on the work of Manin and an extension by Salgado, Testa, and V\'arilly-Alvarado, who had proved this for all but three surfaces. Over general fields of characteristic not equal to two, we state sufficient conditions for a del Pezzo surface of degree two to be unirational.Comment: This is a short version (5 pages) of arXiv:1408.0269; the longer version contains more details and more general result

Reading Comprehension in L2 Italian: Connecting Psycholinguistic Research and Pedagogical Practice

This dissertation explores reading comprehension abilities with a special focus on language minority bilingual children (LMBC). This population is often found to display lower scores than their monolingual peers and this gap in performance can negatively affect their future educational experience. Our goal was to shed light on the origins of these comprehension difficulties. To do so, we carried out an experimental study that involved 109 pupils attending 4th and 5th grade of primary school. The participants were 61 language minority bilingual and 48 monolingual students. We assessed their performance in reading comprehension and in a series of linguistic and non-linguistic abilities that are considered potential predictors of reading comprehension, i.e., general cognitive abilities, decoding skills, receptive vocabulary, and receptive grammar. We conducted an analysis to determine which ones were the best predictors for the two groups. The outcomes highlighted that while monolingual students relied primarily on their vocabulary knowledge during reading comprehension, for LMBC grammar knowledge, speed during decoding, and general cognitive abilities were also influencing their performance. Moreover, using three Self-Paced Reading Tasks (SPRT), we explored on-line language processing to verify whether there were qualitative or quantitative differences between groups. The analysis of reading times revealed that both groups followed similar processing patterns, but monolinguals obtained significantly higher scores in terms of accuracy. These results seem to suggest that processing complex structures in Italian is cognitively more demanding for the LMBC. The last part of the project was dedicated to the implementation of pedagogical practices that focused on teaching grammar and practicing the ability to make inferences using methods that aimed to stimulate the pupils’ metalinguistic awareness instead of using abstract rules.Questa tesi esplora le abilità di comprensione della lettura con una particolare attenzione ai bambini bilingui con background migratorio. Questa popolazione mostra spesso punteggi più bassi rispetto ai loro coetanei monolingui e questa discrepanza nei risultati può influire negativamente sulla loro esperienza scolastica. Il nostro obiettivo è quello di fare luce sulle origini di queste difficoltà di comprensione. Per farlo, abbiamo condotto uno studio sperimentale che ha coinvolto 109 alunni frequentanti il quarto e quinto anno di scuola primaria. I partecipanti includevano 61 studenti bilingui con background migratorio e 48 studenti monolingui. Abbiamo valutato le loro capacità nella comprensione della lettura e in una serie di abilità linguistiche e non linguistiche considerate potenziali predittori della comprensione della lettura (abilità cognitive generali, abilità di decodifica, vocabolario recettivo e grammatica recettiva). Inoltre, abbiamo condotto un'analisi per determinare quali fossero i migliori predittori per i due gruppi. I risultati hanno evidenziato che, mentre gli studenti monolingui si affidavano principalmente alla loro conoscenza lessicale durante la comprensione della lettura, per i bilingui anche la conoscenza grammaticale, la velocità durante la decodifica e le abilità cognitive generali influenzavano i loro punteggi. Con tre Self-Paced Reading Tasks (SPRT), abbiamo esplorato le loro capacità di processing on-line per verificare se ci fossero differenze di tipo qualitativo o quantitativo tra i gruppi. L'analisi dei tempi di lettura ha rivelato che entrambi i gruppi hanno seguito strategie di processing simili, ma i monolingui hanno ottenuto punteggi significativamente più alti in termini di accuratezza. Questi risultati sembrano suggerire che l'elaborazione di strutture complesse in italiano richieda maggiori risorse cognitive per gli studenti bilingui. La parte finale del progetto è stata dedicata all'implementazione di pratiche pedagogiche incentrate sull'insegnamento della grammatica e sulla pratica dell'abilità di fare inferenze utilizzando metodi volti a stimolare la consapevolezza metalinguistica degli alunni invece di utilizzare regole astratte

On the arithmetic of a family of degree-two K3 surfaces

Let $\mathbb{P}$ denote the weighted projective space with weights $(1,1,1,3)$ over the rationals, with coordinates $x,y,z,$ and $w$; let $\mathcal{X}$ be the generic element of the family of surfaces in $\mathbb{P}$ given by \begin{equation*} X\colon w^2=x^6+y^6+z^6+tx^2y^2z^2. \end{equation*} The surface $\mathcal{X}$ is a K3 surface over the function field $\mathbb{Q}(t)$. In this paper, we explicitly compute the geometric Picard lattice of $\mathcal{X}$, together with its Galois module structure, as well as derive more results on the arithmetic of $\mathcal{X}$ and other elements of the family $X$.Comment: 20 pages; v2 with some all additions and clarifications suggested by the refere

The Cayley-Oguiso automorphism of positive entropy on a K3 surface

Recently Oguiso showed the existence of K3 surfaces that admit a fixed point free automorphism of positive entropy. The K3 surfaces used by Oguiso have a particular rank two Picard lattice. We show, using results of Beauville, that these surfaces are therefore determinantal quartic surfaces. Long ago, Cayley constructed an automorphism of such determinantal surfaces. We show that Cayley's automorphism coincides with Oguiso's free automorphism. We also exhibit an explicit example of a determinantal quartic whose Picard lattice has exactly rank two and for which we thus have an explicit description of the automorphism.Comment: 22 pages, 1 figure. We added several improvements, as well as a figure. A smaller pdf file with the figure in lower resolution (faster on most viewers) is available by downloading the source under "Other formats

UPAYA MENINGKATKAN HASIL BELAJAR GEOGRAFI SISWA MELALUI MODEL PEMBELAJARAN KOOPERATIF TEAM ASSISTED INDIVIDUALIZATION (TAI) PADA MATERI PERAIRAN LAUT KELAS X SMA N.1 T.JAWA T.A. 2011/2012

Penelitian ini bertujuan untuk mengetahui peningkatan : (1) Aktivitas belajar geografi yang dilihat dari ranah afektif dan psikomotorik siswa pada materi perairan laut dengan menggunakan model pembelajaran kooperatif Team Assisted Individualization. (2) Hasil belajar geografi siswa pada materi perairan laut dengan menggunakan model pembelajaran Numbered Heads Together di SMA Negeri I Tanah Jawa, Kelas X-4 Semester 2 T.A 2011/2012. Penelitian ini merupakan penelitian tindakan kelas (PTK) dengan subjek penelitian kelas X-4 yang berjumlah 40 siswa. Penelitian ini dilaksanakan dalam dua siklus. Teknik pengumpulan data yang digunakan adalah teknik komunikasi tidak langsung dan teknik analisis data yang digunakan adalah analisis deskriptif. Hasil penelitian menunjukkan bahwa: (1) Aktivitas belajar siswa dengan menggunakan model Team Assisted Individualization pada materi perairan laut dari ranah afektif meningkat dengan rata-rata 38,36% (46,97% pada siklus I menjadi 85,33% pada siklus II). 2) Aktivitas belajar siswa dengan menggunakan model Team Assisted Individualization pada materi perairan laut dari ranah psikomotorik meningkat dengan rata-rata 40,31% (41,72% pada siklus I menjadi 82,03% pada siklus II). 3) Hasil belajar siswa pada materi perairan laut dengan menggunakan model Team Assisted Individualization juga meningkat, sebesar 20% (67,50% pada siklus I menjadi 87,50% pada siklus II). Dari data-data yang dihasilkan menunjukkan bahwa penerapan model pembelajaran Team Assisted Individualization dapat meningkatkan aktivitas belajar siswa dan hasil belajar siswa di SMA Negeri 1 Tanah Jawa. Penelitian ini juga menunjukkan adanya hubungan antara peningkatan aktivitas belajar siswa dengan ketuntasan hasil belajar

ASUHAN KEPERAWATAN DENGAN RESIKO INFEKSI PADA KLIEN POST SECTIO CAESAREA DI RUMAH SAKIT IBU DAN ANAK KIRANA SIDOARJO

Sayatan pada dinding uterus dan dinding depan abdomen menimbulkan luka bekas operasi Sectio Caesarea. Hal ini menyebabkan terputusnya jaringan dan kerusakan sel. Yang dapat beresiko infeksi apabila luka tidak dirawat dengan benar akan terjadi infeksi. Tujuan peneliti adalah untuk melakukan asuhan keperawatan dengan masalah resiko infeksi pada klien post Sectio Caesarea. Desain penelitian ini menggunakan metode studi kasus dengan subyek yang digunakan adalah 2 klien dengan masalah keperawatan dan diagnosis yang sama yaitu Resiko infeksi pada klien post Sectio Caesarea di Rumah Sakit Ibu dan Anak Kirana Sidoarjo, metode pengumpulan data dimulai dari tahap pengkajian, diagnosa keperawatan, merencanakan tindakan keperawatan, melaksanakan tindakan keperawatan, dan mengevaluasi Hasil penelitian setelah dilakukan asuhan keperawatan selama 3 x 24 jam pada Ny A dan Ny I dapat teratasi klien tidak terlihat tanda-tanda infeksi, tidak terdapat peradangan dan kemerahan disekitar luka. kesimpulan dari peneliti ini setelah dilakukan tindakan asuhan keperawatan selama 3 x 24 jam pada Ny A dan Ny I tidak terlihat tanda-tanda infeksi saat di Rumah Sakit. Saran peneliti sebelum keluar rumah sakit adalah memberikan bekal pendidikan dan kesehatan kepada Ny A dan Ny I tentang perawatan luka yang benar saat dirumah dan cara menjaga nutrisi agar luka cepat kering

Woman Religious Rights’ Discrimination in King Mongkuts’ Era: an Anthropology Research with Feminist Approach in Novel Anna and the King written by Elizabeth Hand

The aim of the research is to reveal women oppression by men which happened in Siam Palace. This condition makes the life aspects in Siam unbalanced, especially those related to religion. Siamese women have different rights in religion, where women got the lower right.This study uses an anthropology and feminism approach, so this study will be more comprehensive. The result showed that there is treatment differentiation between men and women, especially in religious system

Rationalizability of field extensions

In this paper we generalize the definition of rationalizability for square roots of polynomials introduced by M. Besier and the first author to field extensions. We then show that the rationalizability of a set of field extensions is equivalent to the rationalizability of the compositum of the field extensions, providing a new strategy to prove rationalizability of sets of square roots of polynomials.Comment: The proof of the main theorem was not correct in full generality. The new main theorem is now less general. All the applications to physics still hold. Few side results added and exposition improved. 13 pages. Comments are welcome