Search for Rare Particles with the MACRO Detector

We report on the search for Rare Particles (Magnetic Monopoles, Nuclearites, Weakly Interacting Massive Particles and Lightly Ionizing Particles) with the MACRO detector. For magnetic monopoles (the main goal of the experiment) our limit is about 0.4 times the Parker bound for monopole velocities between 10^{-4} and 10^{-1}

Seroprotein Patterns in the Bufo marinus Complex

The systematic relationships of the large species of neotropical toads of the Bufo marinus complex have not been defined since the studies of Lutz (1925). On the basis of recent contributions (Lutz and Kloss, 1952; Cochran, 1955; and Vellard, 1959) the following fundamental taxonomic units can be recognized: 1) an Amazonian population extending north to Mexico, corresponding to Bufo m. marinus (Linnaeus) with some subspecies bordering its range, as B. marinus poeppigii (Tschudi); 2) a well-defined eastern form, Bufo ictericus Spix, from the humid coastal Brasilian realm; 3) a central, latitudinally widespread giant form, Bufo paracnemis Lutz, adapted to the dry and open uplands or catingas; 4) two closely related southern and southeastern forms, Bufo arenarum Hensel extending from Matto Grosso and Rio Grande do Sul to the paragonian meseta of Rio Negro, and Bufo ruf us Garman in the Brasilian states of Matto Grosso and Minas Gerais (see Fig. 1). The specific interrelation of B. arenarum and B. rufus have not been studied. Bufo ictericus and B. paracnemis were formerly described as geographical forms of B. marinus (Müller, 1927; Mertens, 1930; Müller and Hellmich, 1936; Lutz and Kloss, 1952) but their specific status was recently re-evaluated (Cochran, 1955). Bufo paracnemis appears to be sympatric with B. arenarum, B. rufus and B. ictericus. B. ictericus is probably sympatric with B. arenarum and B. rufus. Recent studies (Buzzati-Traverso and Rechnitzer, 1953; Lanza and Antonini, 1955; Dessauer and Fox, 1956; Boyden and Paulsen, 1957; Zweig and Crenshaw, 1957; Van Sande and Kar- cher, 1960), indicate the value of biophysical tests in elucidating the relationship of closely related species. The studies here reported are an attempt to check independently the status of the species of the Bufo marinus complex by an electrophoretic analysis of the seroproteins.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Seroprotein Patterns in the Bufo marinus Complex

The systematic relationships of the large species of neotropical toads of the Bufo marinus complex have not been defined since the studies of Lutz (1925). On the basis of recent contributions (Lutz and Kloss, 1952; Cochran, 1955; and Vellard, 1959) the following fundamental taxonomic units can be recognized: 1) an Amazonian population extending north to Mexico, corresponding to Bufo m. marinus (Linnaeus) with some subspecies bordering its range, as B. marinus poeppigii (Tschudi); 2) a well-defined eastern form, Bufo ictericus Spix, from the humid coastal Brasilian realm; 3) a central, latitudinally widespread giant form, Bufo paracnemis Lutz, adapted to the dry and open uplands or catingas; 4) two closely related southern and southeastern forms, Bufo arenarum Hensel extending from Matto Grosso and Rio Grande do Sul to the paragonian meseta of Rio Negro, and Bufo ruf us Garman in the Brasilian states of Matto Grosso and Minas Gerais (see Fig. 1). The specific interrelation of B. arenarum and B. rufus have not been studied. Bufo ictericus and B. paracnemis were formerly described as geographical forms of B. marinus (Müller, 1927; Mertens, 1930; Müller and Hellmich, 1936; Lutz and Kloss, 1952) but their specific status was recently re-evaluated (Cochran, 1955). Bufo paracnemis appears to be sympatric with B. arenarum, B. rufus and B. ictericus. B. ictericus is probably sympatric with B. arenarum and B. rufus. Recent studies (Buzzati-Traverso and Rechnitzer, 1953; Lanza and Antonini, 1955; Dessauer and Fox, 1956; Boyden and Paulsen, 1957; Zweig and Crenshaw, 1957; Van Sande and Kar- cher, 1960), indicate the value of biophysical tests in elucidating the relationship of closely related species. The studies here reported are an attempt to check independently the status of the species of the Bufo marinus complex by an electrophoretic analysis of the seroproteins.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Seroprotein Patterns in the Bufo marinus Complex

The systematic relationships of the large species of neotropical toads of the Bufo marinus complex have not been defined since the studies of Lutz (1925). On the basis of recent contributions (Lutz and Kloss, 1952; Cochran, 1955; and Vellard, 1959) the following fundamental taxonomic units can be recognized: 1) an Amazonian population extending north to Mexico, corresponding to Bufo m. marinus (Linnaeus) with some subspecies bordering its range, as B. marinus poeppigii (Tschudi); 2) a well-defined eastern form, Bufo ictericus Spix, from the humid coastal Brasilian realm; 3) a central, latitudinally widespread giant form, Bufo paracnemis Lutz, adapted to the dry and open uplands or catingas; 4) two closely related southern and southeastern forms, Bufo arenarum Hensel extending from Matto Grosso and Rio Grande do Sul to the paragonian meseta of Rio Negro, and Bufo ruf us Garman in the Brasilian states of Matto Grosso and Minas Gerais (see Fig. 1). The specific interrelation of B. arenarum and B. rufus have not been studied. Bufo ictericus and B. paracnemis were formerly described as geographical forms of B. marinus (Müller, 1927; Mertens, 1930; Müller and Hellmich, 1936; Lutz and Kloss, 1952) but their specific status was recently re-evaluated (Cochran, 1955). Bufo paracnemis appears to be sympatric with B. arenarum, B. rufus and B. ictericus. B. ictericus is probably sympatric with B. arenarum and B. rufus. Recent studies (Buzzati-Traverso and Rechnitzer, 1953; Lanza and Antonini, 1955; Dessauer and Fox, 1956; Boyden and Paulsen, 1957; Zweig and Crenshaw, 1957; Van Sande and Kar- cher, 1960), indicate the value of biophysical tests in elucidating the relationship of closely related species. The studies here reported are an attempt to check independently the status of the species of the Bufo marinus complex by an electrophoretic analysis of the seroproteins.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Neutrinos from supernovae: experimental status and perspectives

I discuss the state of the art in the search for neutrinos from galactic stellar collapses and the future perspectives of this field. The implications for the neutrino physics of a high statistics supernova neutrino burst detection by the network of detectors operating around the world are also reviewed.Comment: 19 pages, 12 figures. Extended version of talk given at IInd International Workshop on Matter, Anti-Matter and Dark Matter, Trento (Italy), 29-30 October 2001. A reduced version will appear in Int. J. of Mod. Phys.

Commissioning of the MEG II tracker system

The MEG experiment at the Paul Scherrer Institut (PSI) represents the state of the art in the search for the charged Lepton Flavour Violating (cLFV) $\mu^+ \rightarrow e^+ \gamma$ decay. With the phase 1, MEG set the new world best upper limit on the \mbox{BR}(\mu^+ \rightarrow e^+ \gamma) < 4.2 \times 10^{-13} (90% C.L.). With the phase 2, MEG II, the experiment aims at reaching a sensitivity enhancement of about one order of magnitude compared to the previous MEG result. The new Cylindrical Drift CHamber (CDCH) is a key detector for MEG II. CDCH is a low-mass single volume detector with high granularity: 9 layers of 192 drift cells, few mm wide, defined by $\sim 12000$ wires in a stereo configuration for longitudinal hit localization. The filling gas mixture is Helium:Isobutane (90:10). The total radiation length is $1.5 \times 10^{-3}$ \mbox{X}_0, thus minimizing the Multiple Coulomb Scattering (MCS) contribution and allowing for a single-hit resolution $< 120$ $\mu$m and an angular and momentum resolutions of 6 mrad and 90 keV/c respectively. This article presents the CDCH commissioning activities at PSI after the wiring phase at INFN Lecce and the assembly phase at INFN Pisa. The endcaps preparation, HV tests and conditioning of the chamber are described, aiming at reaching the final stable working point. The integration into the MEG II experimental apparatus is described, in view of the first data taking with cosmic rays and $\mu^+$ beam during the 2018 and 2019 engineering runs. The first gas gain results are also shown. A full engineering run with all the upgraded detectors and the complete DAQ electronics is expected to start in 2020, followed by three years of physics data taking.Comment: 10 pages, 12 figures, 1 table, proceeding at INSTR'20 conference, accepted for publication in JINS

Electroferogramas de proteínas séricas en el género bufo

La utilidad del estudio electroforético de las proteínas séricas, para investigaciones sobre afinidad sistemática, ya subrayada por varios autores y por nosotros en otra comunicación, resalta por la presente contribución, que tiene por objeto las relaciones de afinidad entre diversas de las especies de Bufo que viven en la Argentina, y en particular entre las poblaciones de Bufo arenarum Hensel, especie predominante, distribuida sobre una área geográfica extensa.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Facultad de Ciencias Naturales y Muse

Single-hit resolution measurement with MEG II drift chamber prototypes

Drift chambers operated with helium-based gas mixtures represent a common solution for tracking charged particles keeping the material budget in the sensitive volume to a minimum. The drawback of this solution is the worsening of the spatial resolution due to primary ionisation fluctuations, which is a limiting factor for high granularity drift chambers like the MEG II tracker. We report on the measurements performed on three different prototypes of the MEG II drift chamber aimed at determining the achievable single-hit resolution. The prototypes were operated with helium/isobutane gas mixtures and exposed to cosmic rays, electron beams and radioactive sources. Direct measurements of the single hit resolution performed with an external tracker returned a value of 110 $\mu$m, consistent with the values obtained with indirect measurements performed with the other prototypes.Comment: 18 pages, 18 figure

Diferencias entre Leptodactylus ocellatus y Leptodactylus chaquensis reveladas por vía electroforética en suero

Se presentan en este trabajo datos comparativos obtenidos por electroforesis en papel, en muestras homogéneas del mismo sexo (machos), del mismo período del año (15 Julio- 15 Agosto, 1959), y en las mismas condiciones ambientales; muestras pertenecientes a las dos especies en que parece dividirse en la Argentina el conjunto poblacional de Leptodactylus ocellatus (L), anfibio de amplia distribución neotropical.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Trabajo publicado en Actas y trabajos del Primer Congreso Sudamericano de Zoología, tomo IV, Universidad Nacional de La Plata, 1960.Facultad de Ciencias Naturales y Muse

Diferencias entre Leptodactylus ocellatus y Leptodactylus chaquensis reveladas por vía electroforética en suero

Se presentan en este trabajo datos comparativos obtenidos por electroforesis en papel, en muestras homogéneas del mismo sexo (machos), del mismo período del año (15 Julio- 15 Agosto, 1959), y en las mismas condiciones ambientales; muestras pertenecientes a las dos especies en que parece dividirse en la Argentina el conjunto poblacional de Leptodactylus ocellatus (L), anfibio de amplia distribución neotropical.Material digitalizado en SEDICI gracias a la colaboración del Dr. Jorge Williams (FCNM-UNLP).Trabajo publicado en Actas y trabajos del Primer Congreso Sudamericano de Zoología, tomo IV, Universidad Nacional de La Plata, 1960.Facultad de Ciencias Naturales y Muse