A characterization of Hermitian varieties as codewords

It is known that the Hermitian varieties are codewords in the code defined by the points and hyperplanes of the projective spaces $PG(r,q^2)$. In finite geometry, also quasi-Hermitian varieties are defined. These are sets of points of $PG(r,q^2)$ of the same size as a non-singular Hermitian variety of $PG(r,q^2)$, having the same intersection sizes with the hyperplanes of $PG(r,q^2)$. In the planar case, this reduces to the definition of a unital. A famous result of Blokhuis, Brouwer, and Wilbrink states that every unital in the code of the points and lines of $PG(2,q^2)$ is a Hermitian curve. We prove a similar result for the quasi-Hermitian varieties in $PG(3,q^2)$, $q=p^{h}$, as well as in $PG(r,q^2)$, $q=p$ prime, or $q=p^2$, $p$ prime, and $r\geq 4$

Measurements of Pilot Time Delay as Influenced by Controller Characteristics and Vehicles Time Delays

A study to measure and compare pilot time delay when using a space shuttle rotational hand controller and a more conventional control stick was conducted at NASA Ames Research Center's Dryden Flight Research Facility. The space shuttle controller has a palm pivot in the pitch axis. The more conventional controller used was a general-purpose engineering simulator stick that has a pivot length between that of a typical aircraft center stick and a sidestick. Measurements of the pilot's effective time delay were obtained through a first-order, closed-loop, compensatory tracking task in pitch. The tasks were implemented through a space shuttle cockpit simulator and a critical task tester device. The study consisted of 450 data runs with four test pilots and one nonpilot, and used three control stick configurations and two system delays. Results showed that the heavier conventional stick had the lowest pilot effective time delays associated with it, whereas the shuttle and light conventional sticks each had similar higher pilot time delay characteristics. It was also determined that each control stick showed an increase in pilot time delay when the total system delay was increased

On permutation trinomials of type x2ps+r+xps+r+λxr

We determine all permutation trinomials of type x(2ps+r) + x(ps+r) + lambda x(r) over the finite field F-pt when (2p(s) + r)(4) < p(t). This partially extends a previous result by Bhattacharya and Sarkar in the case p = 2, r = 1. (C) 2017 Elsevier Inc. All rights reserved

Non-minimum tensor rank Gabidulin codes

The tensor rank of some Gabidulin codes of small dimension is investigated. In particular, we determine the tensor rank of any rank metric code equivalent to an 8-dimensional Fq-linear generalized Gabidulin code in Fq4×4. This shows that such a code is never minimum tensor rank. In this way, we detect the first infinite family of Gabidulin codes which are not minimum tensor rank

A new family of maximum scattered linear sets in PG(1,q^6)

We generalize the example of linear set presented by the last two authors in "Vertex properties of maximum scattered linear sets of PG(1; qn)" (2019) to a more general family, proving that such linear sets are maximum scattered when q is odd and, apart from a special case, they are new. This solves an open problem posed in "Vertex properties of maximum scattered linear sets of PG(1; qn)" (2019). As a consequence of Sheekey's results in "A new family of linear maximum rank distance codes" (2016), this family yields to new MRD-codes with parameters (6; 6; q; 5)

Complete (k,3)-arcs from quartic curves

Complete (Formula presented.) -arcs in projective planes over finite fields are the geometric counterpart of linear non-extendible Near MDS codes of length (Formula presented.) and dimension (Formula presented.). A class of infinite families of complete (Formula presented.) -arcs in (Formula presented.) is constructed, for (Formula presented.) a power of an odd prime (Formula presented.). The order of magnitude of (Formula presented.) is smaller than (Formula presented.). This property significantly distinguishes the complete (Formula presented.) -arcs of this paper from the previously known infinite families, whose size differs from (Formula presented.) by at most (Formula presented.)

Tipificación en Gutierrezia (Asteraceae, Astereae)

During the course of the revision of the South American species of Gutierrezia, we have detected names that require typification. After the analysis of the protologues and the herbarium specimens, we designated eight lectotypes and one neotype for nine names of the Gutierrezia genus and we assigned the category of holotype to one specimen. A detailed discussion is provided for each case.Durante el transcurso de la revisión de las especies sudamericanas de Gutierrezia, hemos podido hallar nombres que requieren tipificación. Luego del análisis de los protologos y especímenes de herbario, hemos designado ocho lectótipos y un neótipo para nueve nombres del género Gutierrezia. Además, se asignó la categoría de hólotipo a un especimen. Se provee una discusión detallada para cada nombre

Metastatic Uterine Leiomyosarcoma in the Upper Buccal Gingiva Misdiagnosed as an Epulis

Uterine leiomyosarcoma (LMS) is a rare tumor constituting 1% of all uterine malignancies. This sarcoma demonstrates an aggressive growth pattern with an high rate of recurrence with hematologic dissemination; the most common sites are lung, liver, and peritoneal cavity, head and neck district being rarely interested. Only other four cases of metastasis in the oral cavity have been previously described. The treatment of choice is surgery and the use of adjuvant chemotherapy and radiation has limited impact on clinical outcome. In case of metastases, surgical excision can be performed considering extent of disease, number and type of distant lesions, disease free interval from the initial diagnosis to the time of metastases, and expected life span. We illustrate a case of uterine LMS metastasis in the upper buccal gingiva that occurred during chemotherapy in a 63-year-old woman that underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy for a diagnosis of LMS staged as pT2bN0 and that developed lung metastases eight months after primary treatment. Surgical excision of the oral mass (previously misdiagnosed as epulis at a dental center) and contemporary reconstruction with pedicled temporalis muscle flap was performed in order to improve quality of life. Even if resection was achieved in free margins, "local" relapse was observed 5 months after surgery

The impact of different energy policy options on feedstock price and land demand for maize silage: the case of biogas in Lombardy

The growing demand of maize silage for biogas production in Northern Italy has triggered an intense debate concerning land rents, maize prices and their possible negative consequences on important agri-food chains. The aim of this work is to quantify the extent to which the rapid spread of biogas raised the maize price at regional level, increasing the demand of land for energy crops. For this purpose we applied a partial-equilibrium framework simulating the agricultural sector and the biogas industry in Lombardy, under two alternative schemes of subsidization policy. Results show that policy measures implemented in 2013 \u2013 reducing the average subsidy per kWh \u2013 may contribute to enforce the complementarity of the sector with agri-food chains, decreasing the competition between energy and non-energy uses. Compared to the old scheme, maize demand for biogas would decrease , lessening the market clearing price (as well as feed opportunity cost for livestock sector) and reducing land demand for energy purposes

Analytical and numerical seismic assessment of heritage masonry towers

Abstract The new Italian building code, published in 2018 [MIT in NTC 2018: D.M. del Ministero delle Infrastrutture e dei trasporti del 17/01/2018. Aggiornamento delle Norme Tecniche per le Costruzioni (in Italian), 2018], explicitly refers to the Italian “Guidelines for the assessment and mitigation of the seismic risk of the cultural heritage” [PCM in DPCM 2011: Direttiva del Presidente del Consiglio dei Ministri per valutazione e riduzione del rischio sismico del patrimonio culturale con riferimento alle norme tecniche per le costruzioni, G.U. n. 47 (in Italian), 2011] as a reliable source of guidance that can be employed for the vulnerability assessment of heritage buildings under seismic loads. According to these guidelines, three evaluation levels are introduced to analyse and assess the seismic capacity of historic masonry structures, namely: (1) simplified global static analyses; (2) kinematic analyses based on local collapse mechanisms, (3) detailed global analyses. Because of the complexity and the large variety of existing masonry typologies, which makes it particularly problematic to adopt a unique procedure for all existing structures, the guidelines provide different simplified analysis approaches for different structural configurations, e.g. churches, palaces, towers. Among the existing typologies of masonry structures there considered, this work aims to deepen validity, effectiveness and scope of application of the Italian guidelines with respect to heritage masonry towers. The three evaluation levels proposed by the guidelines are here compared by discussing the seismic risk assessment of a representative masonry tower: the Cugnanesi tower located in San Gimignano (Italy). The results show that global failure modes due to local stress concentrations cannot be identified if only simplified static and kinematic analyses are performed. Detailed global analyses are in fact generally needed for a reliable prediction of the seismic performance of such structures.</jats:p