Geodesics on a supermanifold and projective equivalence of super connections

We investigate the concept of projective equivalence of connections in supergeometry. To this aim, we propose a definition for (super) geodesics on a supermanifold in which, as in the classical case, they are the projections of the integral curves of a vector field on the tangent bundle: the geodesic vector field associated with the connection. Our (super) geodesics possess the same properties as the in the classical case: there exists a unique (super) geodesic satisfying a given initial condition and when the connection is metric, our supergeodesics coincide with the trajectories of a free particle with unit mass. Moreover, using our definition, we are able to establish Weyl's characterization of projective equivalence in the super context: two torsion-free (super) connections define the same geodesics (up to reparametrizations) if and only if their difference tensor can be expressed by means of a (smooth, even, super) 1-form.Comment: 20 page

Geochemistry of the surface and ground waters of the upper bassin of the river Llobregat

In this work the main geochemical characteristics of the surface and ground waters of the Upper basin of the River Llobregat are described and, discussed. The water samples analysed reveal sharply contrasting characteristics. In both the Fonts del Llobregat and River Bastareny catchments, calcium bicarbonated waters with a low mineral content clearly predominate. However, in the catchment of the River Arija, although the waters of the upper course and the main tributaries are also calcium bicarbonated, it is worth noting that at the confluence with the River Llobregat calcium sulphated water is found. The catchment of the River Saldes shows a greater heterogeneity, with calcium bicarbonated, sodium chloridized and calcium sulphated waters, and thus at the confluence with the River Llobregat the water is sodium-calcium bicarbonated-sulphated. Principal components analysis enables us to arrive at a synthesis which clearly explains these characteristics. These results are fundamentally interpreted on the basis of the lithologies drained by the different watercourses.[es] En el presente estudio se presentan y discuten las principales características geoquímicas de las aguas superficiales y subterráneas de la Alta cuenca del río Llobregat hasta la entrada del río al embalse de La Baells. El conjunto de aguas analizadas presentan características muy contrastadas. Así, tanto en la subcuenca de las fuentes del Llobregat como en la del río Bastareny predominan las aguas bicarbonatadas cálcicas poco mineralizadas. En la subcuenca del río Arija, sí bien las aguas del curso alto y las de los principales afluentes también son bicarbonatadas cálcicas, destaca el hecho de que en la confluencia con el río Llobregat el agua es sulfatada cálcica. La subcuenca del río Saldes es la que presenta una mayor heterogeneidad, con aguas bicarbonatadas cálcicas, cloruradas sódicas y sulfatadas cálcicas, las cuales provocan que en la confluencia con el río Llobregat el agua sea bicarbonatada-sulfatada sódico-cálcica. El análisis de componentes principales ha permitido sintetizar estas características de forma muy clara. Los resultados se interpretan, esencialmente, a partir de las litologías drenadas por los distintos cursos de agua. [fr] Cette étude présente et discute des principales caractéristiques géochimiques des eaux superficielles et souterraines du haut-bassin du fleuve Llobregat (le point le plus en aval considéré se situe juste avant l'entrée du cours d'eau dans le lac de La Baells). L'ensemble des eaux analysées présente des caractéristiques très contrastées. Dans les sous-bassins des sources du Llobregat et du Bastareny prédominent des eaux bicarbonatées calciques peu minéralisées. Dans les sousbassin de la rivière Arija, sur son cours supérieur ainsi que ses principaux affluents, les eaux sont également bicarbonatées calciques, exceptées celles de la confluence avec le Llobregat qui sont sulfatées calciques. Le sous-bassin de la rivière Saldes est celui qui présente la plus grande hétérogénéité, avec des eaux bicarbonatées calciques, chlorurées sadiques et sulfatées calciques. Ces dernières sont responsables du fait qu'à la confluence avec la Llobregat les eaux soient bicarbonato-sulfato sodico-calciques. L'analyse en composantes principales a permis de discriminer nettement ces caractéristiques. Ces résultats sont essentiellement expliqués à partir de la lithologie des différents bassins versants drainés

Prilog istraživanju promjena na škrgama zebrice (Danio rerio) prilikom izloženosti dioksinu

This study determined cell changes in the gills of zebrafish (Danio rerio, Hamilton, 1822) as a result of a dietary supply of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). 50 zebrafish were divided into five groups, one control group and four experimental ones. The experimental groups were supplied 10, 40, 100 and 270 ng/day/fish TCDD, respectively. Structural, ultrastructural and morphometric studies of the fish gill were carried out, indicating that, in low concentrations, fish gills presented hyperemia with progressive erosion of the endothelium of the capillaries resulting in edema and microhaemorrhages. In the non-respiratory gill, in those groups with low concentrations, it could be observed that the chloride cells presented hypertrophy as a result of dilatation of the intracellular canal and swelling of the microvilli, losing their activity in the degradation of chemical substances (according to some authors) in those groups with a higher concentration. Mucous cells presented hyperplasia and hypertrophy. The sensory buds were not directly affected, but, due to the presence of interstitial edema, swelling of the supporting cells occurred without the involvement of the neurosensory cells. We concluded that dioxins affect the gills to a greater or lesser extent depending on their concentration in the fish’s diet, which alters their functionality.Ovim istraživanjem utvrđene su promjene na stanicama škrga zebrice (Danio rerio, Hamilton, 1822) kao rezultat hranjena 2,3,7,8 tetraklorodibenzo p-dioksinom (TCDD). Pedeset jedinki zebrice podijeljeno je u pet grupa, jednu kontrolnu grupu i četiri eksperimentalne. Eksperimentalnim grupama davano je 10, 40, 100 i 270 ng/riba/dan TCDD. Provedena su strukturalna, ultrastrukturalna i morfološka istraživanja škrga ribe, ukazujući da su škrge riba pokazivale hiperemiju s progresivnom erozijom endotel kapilara koja je rezultirala edemima i mikrokrvarenjima. Kod grupa kojima je dana manja koncentracija, u škrgama koje ne služe za disanje može se primijetiti da kloridne stanice pokazuju hipertrofiju kao posljedicu dilatacije međustaničnog kanala i oticanje mikroresica kojima se smanjuje aktivnost tijekom razgradnje kemijskih tvari (prema mišljenjima nekih autora) u onim grupama koje su bile izložene većim koncentracijama. Mukozne stanice pokazuju hiperplaziju i hipertrofiju. Osjetni pupoljci nisu bili izravno pogođeni, ali, zbog prisutnosti intersticijskog edema, oticanja potpornih stanica bez uključivanja neurosenzornih stanica. Zaključak je da dioksini utječu na škrge u većoj ili manjoj mjeri ovisno o njihovoj koncentraciji u ishrani ribe, što mijenja njihovu funkcionalnost

Prilog istraživanju promjena na škrgama zebrice (Danio rerio) prilikom izloženosti dioksinu

This study determined cell changes in the gills of zebrafish (Danio rerio, Hamilton, 1822) as a result of a dietary supply of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). 50 zebrafish were divided into five groups, one control group and four experimental ones. The experimental groups were supplied 10, 40, 100 and 270 ng/day/fish TCDD, respectively. Structural, ultrastructural and morphometric studies of the fish gill were carried out, indicating that, in low concentrations, fish gills presented hyperemia with progressive erosion of the endothelium of the capillaries resulting in edema and microhaemorrhages. In the non-respiratory gill, in those groups with low concentrations, it could be observed that the chloride cells presented hypertrophy as a result of dilatation of the intracellular canal and swelling of the microvilli, losing their activity in the degradation of chemical substances (according to some authors) in those groups with a higher concentration. Mucous cells presented hyperplasia and hypertrophy. The sensory buds were not directly affected, but, due to the presence of interstitial edema, swelling of the supporting cells occurred without the involvement of the neurosensory cells. We concluded that dioxins affect the gills to a greater or lesser extent depending on their concentration in the fish’s diet, which alters their functionality.Ovim istraživanjem utvrđene su promjene na stanicama škrga zebrice (Danio rerio, Hamilton, 1822) kao rezultat hranjena 2,3,7,8 tetraklorodibenzo p-dioksinom (TCDD). Pedeset jedinki zebrice podijeljeno je u pet grupa, jednu kontrolnu grupu i četiri eksperimentalne. Eksperimentalnim grupama davano je 10, 40, 100 i 270 ng/riba/dan TCDD. Provedena su strukturalna, ultrastrukturalna i morfološka istraživanja škrga ribe, ukazujući da su škrge riba pokazivale hiperemiju s progresivnom erozijom endotel kapilara koja je rezultirala edemima i mikrokrvarenjima. Kod grupa kojima je dana manja koncentracija, u škrgama koje ne služe za disanje može se primijetiti da kloridne stanice pokazuju hipertrofiju kao posljedicu dilatacije međustaničnog kanala i oticanje mikroresica kojima se smanjuje aktivnost tijekom razgradnje kemijskih tvari (prema mišljenjima nekih autora) u onim grupama koje su bile izložene većim koncentracijama. Mukozne stanice pokazuju hiperplaziju i hipertrofiju. Osjetni pupoljci nisu bili izravno pogođeni, ali, zbog prisutnosti intersticijskog edema, oticanja potpornih stanica bez uključivanja neurosenzornih stanica. Zaključak je da dioksini utječu na škrge u većoj ili manjoj mjeri ovisno o njihovoj koncentraciji u ishrani ribe, što mijenja njihovu funkcionalnost

A survey of partial differential equations in geometric design

YesComputer aided geometric design is an area where the improvement of surface generation techniques is an everlasting demand since faster and more accurate geometric models are required. Traditional methods for generating surfaces were initially mainly based upon interpolation algorithms. Recently, partial differential equations (PDE) were introduced as a valuable tool for geometric modelling since they offer a number of features from which these areas can benefit. This work summarises the uses given to PDE surfaces as a surface generation technique togethe

Quaternionic Salkowski Curves and Quaternionic Similar Curves

In this paper, we give the definitions and characterizations of quaternionic Salkowski, quaternionic anti-Salkowski and quaternionic similar curves in the Euclidean spaces E^3 and E^4. We obtain relationships between these curves and some special quaternionic curves such as quaternionic slant helices and quaternionic B2-slant helices.Comment: 17 page

Draft Genome Sequence of Xylella fastidiosa subsp. Fastidiosa Strain IVIA5235, Isolated from Prunus avium in Mallorca Island, Spain

We report the complete annotated genome sequence of the plant-pathogenic bacterium Xylella fastidiosa subsp. fastidiosa strain IVIA5235. This strain was recovered from a cherry tree in Mallorca, Spain

Informe sobre les característiques sociodemogràfiques, clíniques i els factors pronòstics dels pacients amb el diagnòstic de COVID-19 a Catalunya: resum executiu

Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Característiques sociodemogràfiques; Característiques clíniques; Factors pronòstics; PacientsCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Características sociodemográficas; Características clínicas; Factores pronósticos; PacientesCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Sociodemographic characteristics; Clinical features; Prognostic factors; PatientsInforme que descriu quines són les característiques de les persones afectades per la COVID-19 i quins són els factors que condicionen el seu pitjor pronòstic. Aquests factors són importants actualment, per exemple, per a definir el grup considerat vulnerable i al que s’ha de protegir amb l’ús de les mesures de confinament/distanciament físic que s’estan implementant per part dels governs

On the computation of zone and double zone diagrams

Classical objects in computational geometry are defined by explicit relations. Several years ago the pioneering works of T. Asano, J. Matousek and T. Tokuyama introduced "implicit computational geometry", in which the geometric objects are defined by implicit relations involving sets. An important member in this family is called "a zone diagram". The implicit nature of zone diagrams implies, as already observed in the original works, that their computation is a challenging task. In a continuous setting this task has been addressed (briefly) only by these authors in the Euclidean plane with point sites. We discuss the possibility to compute zone diagrams in a wide class of spaces and also shed new light on their computation in the original setting. The class of spaces, which is introduced here, includes, in particular, Euclidean spheres and finite dimensional strictly convex normed spaces. Sites of a general form are allowed and it is shown that a generalization of the iterative method suggested by Asano, Matousek and Tokuyama converges to a double zone diagram, another implicit geometric object whose existence is known in general. Occasionally a zone diagram can be obtained from this procedure. The actual (approximate) computation of the iterations is based on a simple algorithm which enables the approximate computation of Voronoi diagrams in a general setting. Our analysis also yields a few byproducts of independent interest, such as certain topological properties of Voronoi cells (e.g., that in the considered setting their boundaries cannot be "fat").Comment: Very slight improvements (mainly correction of a few typos); add DOI; Ref [51] points to a freely available computer application which implements the algorithms; to appear in Discrete & Computational Geometry (available online