The genus Leptospira encompass 22 species of spirochaetes, with ten pathogenic species that have been recorded in more than 160 mammals worldwide. In the last two decades, the numbers of records of these agents associated with bats have increased exponentially, particularly in America. Although order Chiroptera represents the second most diverse order of mammals in Mexico, and leptospirosis represents a human and veterinary problem in the country, few studies have been conducted to identify potential wildlife reservoirs. The aim of this study was to detect the presence and diversity of Leptospira sp. in communities of bats in an endemic state of leptospirosis in Mexico. During January to September 2016, 81 bats of ten species from three localities of Veracruz, Mexico, were collected with mist nets. Kidney samples were obtained from all specimens. For the detection of Leptospira sp., we amplified several genes using specific primers. Amplicons of the expected size were submitted to sequencing, and sequences recovered were compared with those of reference deposited in GenBank using the BLAST tool. To identify their phylogenetic position, we realized a reconstruction using maximum-likelihood (ML) method. Twenty-five samples from three bat species (Artibeus lituratus, Choeroniscus godmani and Desmodus rotundus) showed the presence of Leptospira DNA. Sequences recovered were close to Leptospira noguchii, Leptospira weilii and Leptospira interrogans. Our results include the first record of Leptospira in bats from Mexico and exhibit a high diversity of these pathogens circulating in the state. Due to the finding of a large number of positive wild animals, it is necessary to implement a surveillance system in populations of the positive bats as well as in related species, in order to understand their role as carriers of this bacterial genus.

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We obtain the thermodynamic properties for a non-interacting Bose gas constrained on multilayers modeled by a periodic Kronig-Penney delta potential in one direction and allowed to be free in the other two directions. We report Bose-Einstein condensation (BEC) critical temperatures, chemical potential, internal energy, specific heat, and entropy for different values of a dimensionless impenetrability P 0 between layers. The BEC critical temperature Tc coincides with the ideal gas BEC critical temperature T0 when P = 0 and rapidly goes to zero as P increases to infinity for any finite interlayer separation. The specific heat CV vs T for finite P and plane separation a exhibits one minimum and one or two maxima in addition to the BEC, for temperatures larger than Tc which highlights the effects due to particle confinement. Then we discuss a distinctive dimensional crossover of the system through the specific heat behavior driven by the magnitude of P . For T < Tc the crossover is revealed by the change in the slope of log CV (T ) and when T > Tc, it is evidenced by a broad minimum in CV (T ).

The critical BEC temperature Tc of a non interacting boson gas in a layered structure like those of cuprate superconductors is shown to have a minimum Tc,m, at a characteristic separation between planes am. It is shown that for a < am, Tc increases monotonically back up to the ideal Bose gas T0 suggesting that a reduction in the separation between planes, as happens when one increases the pressure in a cuprate, leads to an increase in the critical temperature. For finite plane separation and penetrability the specific heat as a function of temperature shows two novel crests connected by a ridge in addition to the well-known BEC peak at Tc associated with the 3D behavior of the gas. For completely impenetrable planes the model reduces to many disconnected infinite slabs for which just one hump survives becoming a peak only when the slab widths are infinite.Since London first suggested 1 that superfluidity in liquid 4 He might well be a manifestation of Bose-Einstein condensation (BEC) of the helium atoms before interatomic interactions are "switched on," BEC in layered systems began to be studied to understand helium films 2,3,4 . The discovery of high-T c superconductivity stimulated renewed interest in compounds with layered structures 5 in which a BEC mechanism seems to be an essential feature to explain high critical temperatures 6 . The so-called "Uemura plot" 7 of data from muon-spin relaxation (µSR), neutron and Raman scattering, and angle-resolved photoemission (ARPES) measurements exhibits T c vs Fermi temperatures T F ≡ E F /k B where E F the Fermi energy and k B the Boltzmann constant. Empirical T c s of many cuprates straddle a line parallel to the Uemura-plot diagonal line associated with the simple BEC formula T 0 ≃ 3.31 2 n 2/3 B /mk B ≃ 0.218T F corresponding to an ideal gas of bosons of mass m = 2m * and number density n B = n s /2 where m * is the individualcharge-carrier effective mass and n s their number density. The parallel line of data is shifted down from T 0 by a factor of 4-5. This has been judged 8 a "fundamental importance of the BEC concept in cuprates." In addition, the possibility of creating BECs or superfluidity of ultracold fermions 9 in optical lattices 10 , along with the expected observation of BEC of excitons (electron-hole pairs) in semiconductors 11 , have further revived theoretical and experimental 12,13 efforts to better understand the behavior of quantum gases in layered geometries.Most models based on layered structures 6,15 simulating quasi-2D high-T c superconductors, or other to study BEC 16,17,18 , rely on a single-boson hopping interaction term producing nearest-interlayer couplings in one spatial dimension while moving freely in the other two directions. The energy spectrum is typically of the form ǫ k = 2 (k 2 x + k 2 y )/2m + ǫ kz with ǫ kz = ( 2 /M a 2 )(1 − cos k z a) where a is the plane separation and the constant 2 /M a 2 is a measure of the bosonic Cooper pair hopping probability between planes. In the case of CuO 2 planes in cuprate superconductors a bos...

ZrO 2 . -Nanocrystalline ZrO 2 :Dy 3+ (crystallite sizes ranging from 20 to 50 nm) synthesized by the sol-gel method exhibits strong yellowish-white light emission under direct excitation at 350 nm. The host emission band is centered at ≈460 nm and the two strong Dy 3+ emission bands peak at 488 nm and 580 nm. The highest emission efficiency occurs at 0.5 mol% Dy2O3. It is concluded that nanocrystalline ZrO2:Dy 3+ (0.5%) is a promising phosphor candidate for white light applications. -(DIAZ-TORRES, L. A.; DE LA ROSA*, E.; SALAS, P.; ROMERO, V. H.; ANGELES-CHAVEZ, C.; J.

Mycoplasma ovis is a small, pleiotropic bacterium, which parasitizes the external surface of erythrocytes of several species of artiodactyl mammals, especially sheep and goats. We here report an outbreak of ovine mycoplasmosis in a sheep flock of a private ranch (Universidad Veracruzana) in Veracruz, Mexico. For the identification of Mycoplasma and other hemoparasitic bacterial agents, we stained blood smears with the DiffQuick® technique and additionally amplified several fragments of 16S rDNA gene. We detected the presence of morulas in erythrocytes from 30 sick female adult sheep, and found Mycoplasma ovis DNA in all of them. Furthermore, three of these animals also tested positive for Anaplasma ovis. Our findings represent the first record of M. ovis and A. ovis in an outbreak of hemolytic anemia in a sheep flock, leading to severe livestock loss in a ranch of Mexico. This study highlights the importance of establishing an active surveillance of both pathogens in the country.

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