A COMPARISON OF CAVE MICROBIAL COMMUNITIES TO CAVE ROOSTING BAT MICROBIOTA IN EL MALPAIS NATIONAL MONUMENT, USA

The arrival of white-nose syndrome (WNS), a devastating fungal disease, has highlighted the need to better understand bat microbiota and how bats acquire their microbiota. To address this need, we investigated how bat microbiota compare to microbiota from the cave walls in two El Malpais National Monument caves. The external surfaces of six roosting bats from each cave, representing four different bat species, and their associated microbial mats were sampled. One to three air samples were taken in each cave. Samples were sequenced using Illumina MiSeq sequencing of the 16S rRNA gene for bacterial diversity and the ITS region for fungal diversity. Many bacterial and fungal operational taxonomic units (OTUs) were shared among the sample types. Within the bacterial OTUs, Actinobactria were highest overall in all samples, but were higher in bats than mats. The most prevalent actinobacterial genera recovered were Rhodococcus, Streptomyces, Arthrobacter, and Rubrobacter. SourceTracker suggested bat bacterial communities may originate from mat and air samples. Within the fungal OTUs, Ascomycota were highest overall in all samples, but higher in bats than mats. Prevalent fungal families included Cladosporiaceae, Pleosporaceae, Pseudeurotiaceae, Microascaceae, Leucosporidiaceae, and Mortierellaceae. A top fungal OTU recovered was a close relative of Pseudogymnoascus destructans, the cause of WNS. Our results shed light on a relatively understudied area that could have implications for understanding the source of potential natural defenses of bats, which could be important in predicting which western bats species are most vulnerable to WNS

Giant phonon anomalies in the pseudo-gap phase of TiOCl

We report infrared and Raman spectroscopy results of the spin-1/2 quantum magnet TiOCl. Giant anomalies are found in the temperature dependence of the phonon spectrum, which hint to unusual coupling of the electronic degrees of freedom to the lattice. These anomalies develop over a broad temperature interval, suggesting the presence of an extended fluctuation regime. This defines a pseudo-gap phase, characterized by a local spin-gap. Below 100 K a dimensionality cross-over leads to a dimerized ground state with a global spin-gap of about 2$\Delta_{spin}\approx$~430 K.Comment: 4 pages, 3 figures, for further information see http://www.peter-lemmens.d

Supersonic gas-liquid cleaning system

A system to perform cleaning and cleanliness verification is being developed to replace solvent flush methods using CFC 113 for fluid system components. The system is designed for two purposes: internal and external cleaning and verification. External cleaning is performed with the nozzle mounted at the end of a wand similar to a conventional pressure washer. Internal cleaning is performed with a variety of fixtures designed for specific applications. Internal cleaning includes tubes, pipes, flex hoses, and active fluid components such as valves and regulators. The system uses gas-liquid supersonic nozzles to generate high impingement velocities at the surface of the object to be cleaned. Compressed air or any inert gas may be used to provide the conveying medium for the liquid. The converging-diverging nozzles accelerate the gas-liquid mixture to supersonic velocities. The liquid being accelerated may be any solvent including water. This system may be used commercially to replace CFC and other solvent cleaning methods widely used to remove dust, dirt, flux, and lubricants. In addition, cleanliness verification can be performed without the solvents which are typically involved. This paper will present the technical details of the system, the results achieved during testing at KSC, and future applications for this system

Balanced Rotating Spray Tank and Pipe Cleaning and Cleanliness Verification System

A system for cleaning and verifying the cleanliness of the interior surfaces of hollow items, such as small bottles, tanks, pipes and tubes, employs a rotating spray head for supplying a gas-liquid cleaning mixture to the item's surface at a supersonic velocity. The spray head incorporates a plurality of nozzles having diverging cross sections so that the incoming gas-liquid mixture is first converged within the spray head and then diverged through the nozzles, thereby accelerating the mixture to a supersonic velocity. In the preferred embodiment, three nozzles are employed; one forwardly facing nozzle at the end of the spray head and two oppositely facing angled nozzles exiting on opposite sides of the spray head which balance each other, and therefore impart no net side load on the spray head. A drive mechanism is provided to rotate the spray head and at the same time move the head back and forth within the item to be cleaned. The drive mechanism acts on a long metal tube to which the spray head is fixed, and thus no moving parts are exposed to the interior surfaces of the items to be cleaned, thereby reducing the risk of contamination

La concentración de núcleos higroscópicos gigantes de sulfatos y cloruros en el aerosol atmosférico de Buenos Aires

Mediante el método de impacto sobre gelatinas sensibilizadas se determinaron en 26 oportunidades, durante el verano 1972-73, las concentraciones de partículas de sulfatos y de cloruros presentes en el aerosol atmosférico de la ciudad de Buenos Aires. Salvo para partículas iguales o mayores que 6 micrones o gotas iguales o mayores que 11 micrones de radio, para las que se encontraron concentraciones del mismo orden, los valores de concentración de partículas de cloruros prevalecen sobre los de sulfatos de manera muy marcada. Las concentraciones mayores de partículas de cloruros se obtuvieron para tamaños comprendidos entre 0,6 y menores que 2 micrones de radio (gotas de solución saturada entre 1,2 y menores que 3,5 micrones). Los valores de concentración son muy variables para ambas especies de partículas, pero el rango en que varían las concentraciones de cloruros es mucho mayor y llega hasta tres órdenes de magnitud.By means of impact methods on sensitized gelatin it has been determined on twenty-six occasions during the summer of 1972-73 the concentration of chloride and sulfate giant particles present in the atmospheric aerosol of the Buenos Aires City. Except for those particles that are equal to or greater than 6 microns or droplets equal to or greater than 11 microns in radius, for which it has been found concentrations of the same order, the concentration values of chloride particles prevail over those of sulfates remarkably. The greatest concentrations of chloride particles were obtained for sizes between 0,6 and 2 microns of radius (droplets of saturated solutions within 1,2 and less than 3,5 microns). The concentration values for both sorts of particles are greatly variable but the range in which chloride concentrations changes is by far larger and reaches three orders of magnitude.Asociación Argentina de Geofísicos y Geodesta

Aspectos actuales en los estudios de la física de nubes

Diversas reacciones químicas entre gases de la atmósfera dan por resultado partículas sólidas solubles. Son de especial interés las que originan partículas de nitrato a partir del NO y el y las que dan lugar a partículas de sulfatos solubles. Estas últimas difieren según que las reacciones sucedan en la tropósfera, en el interior de gotas de nubes o en la estratósfera. El origen común para todas las reacciones que conducen a la formación de partículas de sulfatos es la oxidación del SO₂ a SO₃ sea por la acción del C (oxígeno atómico), del C₃, y en el interior de las gotas de nubes por la presencia de iones de metales pesados y NH₃ que catalizan la transformación de SO₃ en SO₄. La concentración de partículas de hielo en algunas nubes cuyo tope está por encima del nivel de 0°C es varios órdenes superior a la que podría esperarse considerando la de los núcleos de congelación a la temperatura del tope. Para explicar este hecho se sugiere varios mecanismos productores de partículas secundarias de hielo; a) fractura mecánica de los cristales frágiles; b) desprendimierto de astillas durante el crecimiento escarchado de las partículas; c) ruptura y fragmentación de gotas sobrenfriadas que congelan. Algunas especies de bacterias que se desarrollan en lechos de rojas en descomposición o en el plankton marino, son capaces de actuar como núcleos de congelación e temperaturas tan altas como -1,3°C. Probablemente esas bacterias reducen la resistencia de las plantas a las heladas. Son alentadoras las experiencias de protección de algunas cosechas realizadas empleando bactericidas. El crecimiento de gotas por coelescencia puede tratarse a través de tres modeles: continuo, estocástico y cuasiestocástico. En todos se hace use de la Punción ” núcleo de colección K (a₁,a₂) = K (a₁+a₂)² Ec (u₁-u₂). Se plantea la conveniencia de utilizar otros núcleos para el caso de que las gotas que coalescen sean del mismo tamaño.Asociación Argentina de Geofísicos y Geodesta

Magneto-optical evidence of double exchange in a percolating lattice

Substituting $Eu$ by $Ca$ in ferromagnetic $EuB_6$ leads to a percolation limited magnetic ordering. We present and discuss magneto-optical data of the $Eu_{1-x}Ca_{x}B_6$ series, based on measurements of the reflectivity $R(\omega)$ from the far infrared up to the ultraviolet, as a function of temperature and magnetic field. Via the Kramers-Kronig transformation of $R(\omega)$ we extract the complete absorption spectra of samples with different values of $x$. The change of the spectral weight in the Drude component by increasing the magnetic field agrees with a scenario based on the double exchange model, and suggests a crossover from a ferromagnetic metal to a ferromagnetic Anderson insulator upon increasing $Ca$-content at low temperatures.Comment: 10 pages, 3 figure

Optical evidence for a spin-filter effect in the charge transport of Eu0.6Ca0.4B6Eu_{0.6}Ca_{0.4}B_{6}

We have measured the optical reflectivity $R(\omega)$ of $Eu_{0.6}Ca_{0.4}B_{6}$ as a function of temperature between 1.5 and 300 $K$ and in external magnetic fields up to 7 $T$. The slope at the onset of the plasma edge feature in $R(\omega)$ increases with decreasing temperature and increasing field but the plasma edge itself does not exhibit the remarkable blue shift that is observed in the binary compound $EuB_{6}$. The analysis of the magnetic field dependence of the low temperature optical conductivity spectrum confirms the previously observed exponential decrease of the electrical resistivity upon increasing, field-induced bulk magnetization at constant temperature. In addition, the individual exponential magnetization dependences of the plasma frequency and scattering rate are extracted from the optical data.Comment: submitted to Phys. Rev. Let

Evaluation of carcass and meat traits of Muscovy duck fed with black soldier fly partially defatted meal

The aim of this study was to evaluate the carcass characteristics and breast meat quality in Muscovy duck (Cairina moschata domestica) fed different inclusion levels of a partially defatted black soldier fly larva (BSF) meal. A total of 256 Muscovy ducklings (average live weight, LW: 71.32\ub12.70 g) were reared from day 3 to day 48 and randomly allotted in 32 pens (8 replicates/treatment). Four different diets were formulated with increasing substitution level of corn gluten meal with BSF larva meal (0, 3, 6 and 9%; BSF0, BSF3, BSF6 and BSF9, respectively) and divided in 3 feeding phases: starter (1-14 days), grower (14-35 days) and finisher (35-48 days). At day 48, 2 animals/replicate were slaughtered and dissected to determine their carcass yields. The weights of spleen, bursa of Fabricius, liver, heart and abdominal fat were recorded. Breast and thigh muscles were then excised from 16 ducks/treatment and weighted. Ultimate pH (pHu) and L*, a*, b* colour values were then measured on breast muscle. The collected data were tested by means of oneway ANOVA evaluating the effect of dietary BSF inclusion level by polynomial contrasts. Significance was declared at P<0.05. The inclusion of BSF did not affect final LW (2,515.68\ub192.42 g on average). Hot and cold carcass weights showed a quadratic response (P<0.05) to increasing BSF larva meal, with a minimum corresponding to BSF6; however, refrigeration losses were not affected by treatments. Weight of spleen, bursa of Fabricius, liver and heart did not differ among treatments. The weight of abdominal fat showed a quadratic response to increasing BSF meal with a minimum corresponding to BSF6 group (P<0.05). Breast and thigh yields, pHu and L*, a*, b* colour values did not differ among groups. With the exception of BSF6, the inclusion of BSF meal did not affect meat traits and carcass characteristics, confirming the potential use of BSF meal in Muscovy duck diets

Apparent digestibility of insect protein meals for rainbow trout

Insect meals are considered to be promising future ingredients for aquaculture feeds. In past feeding trials in rainbow trout, insect meals were included in diets only on the basis of their nutrients content and energy density without taking into account their biological availability due to the lack of their digestible values. Apparent digestibility (ADC) provides good indication of the bioavailability of nutrients and energy thus providing rational basis for the correct inclusion of feedstuffs. The aim of this research was to assess, in an in vivo trial on rainbow trout, the ADC of five full fat insect meals: one Tenebrio molitor (TM), two Hermetia illucens obtained through two different process (HI1 and HI2), one Musca domestica (MD), and one Alphitobius diaperinus (AD). Fish were fed a high-quality reference diet (R) and test diets obtained mixing the R diet with each of the test ingredients at a ratio of 70:30. Diets contained 1% celite as inert marker. Fish were fed to visual satiety twice a day and faecal samples collected using a continuous automatic device. Faeces were freeze dried and frozen (-20 \ub0C) until analyses. The ADC of dry matter, crude protein and ether extract of each insect meal diet were calculated. ADC for dry matter varied between 70.07 (HI1) and 80.85 (TM). ADC for protein was above 84% in all treatments and resulted the highest in MD, TM and AD treatments. Ether extract apparent digestibility significantly differed among diets with the highest value reported for TM treatment. All treatments reported values higher than 96%. Observed differences could be due to the insect species and meal treatment but in general, tested insect meals were highly digestible for rainbow trout. The results from this research could be useful to optimize the diet formulation