Efecto del nivel de proteína en el crecimiento de Goodea atripinnis (Pisces: Goodeidae)

Background. Goodea atripinnis is an omnivorous fish that is only found in the state of Aguascalientes. Its population is being drastically reduced and its survival is considered to be threatened. To avoid its extinction, ex situ breeding programs are being implemented. To implement these programs, however, it is necessary to have feeding plans that allow the nutritional needs of this species to be met. Goals. To evaluate the effects of different protein levels in the diet (25, 30, 35, 40 and 45 % PC) on the growth of G. atripinnis. Methods. A randomized complete-block design with five treatments (protein levels) and 3 aquariums per treatment was used, each aquarium containing 20 fish. The experiment lasted 150 days. Daily feed intake and changes in weight and length of each fish were recorded every 15 days. Results. We found differences in final weight and total weight gain (p <0.05) depended on protein levels. Both the growth rate and the total food intake increased with higher levels of protein. As a result, the feed conversion rate, protein efficiency, and Fulton (K) body condition factor improved. The Gompertz model showed that high protein levels increased standard weight and that the inflection point occurred at the same weight. Conclusions. With higher protein levels, the standard weight is reached at an earlier age, leading to greater development of the fish.  Antecedentes. Goodea atripinnis es un pez omnívoro que sólo se localiza en el estado de Aguascalientes y su población se encuentra en estatus de amenaza. Para evitar su extinción se están implementando programas de reproducción ex situ; sin embargo, para lograrlo es necesario contar con planes de alimentación que permitan satisfacer las necesidades nutricionales de la especie. Objetivos. Evaluar los efectos de 5 niveles de proteína (25, 30, 35, 40 y 45% PC) en la dieta, velocidad de crecimiento y parámetros productivos de G. atripinnis. Métodos. Se utilizó un diseño de bloques al azar con 5 tratamientos (niveles de proteína) y 3 acuarios por tratamiento, cada uno contenía 20 peces (peso medio: 0.47 ± 0.02 g). El experimento duró 150 días, durante los cuales se registraron el consumo de alimento diariamente y los cambios en peso y longitud de cada pez cada 15 días. Resultados. Se encontraron diferencias en peso final y ganancia de peso total (p <0.05) entre los niveles de proteína. Tanto la tasa de crecimiento como la ingesta total de alimento aumentaron con el nivel alto de proteína. La tasa de conversión de alimento, la eficiencia proteínica y el factor de condición corporal de Fulton (K) mejoraron. El modelo de Gompertz mostró que los altos niveles de proteína aumentaron el peso estándar y que el punto de inflexión se produce en el mismo peso. Conclusiones. Con los niveles altos de proteína el peso estándar se alcanza a una edad más temprana y permite un mayor desarrollo de los peces

Results from the Super Cryogenic Dark Matter Search (SuperCDMS) experiment at Soudan

We report the result of a blinded search for Weakly Interacting Massive Particles (WIMPs) using the majority of the SuperCDMS Soudan dataset. With an exposure of 1690 kg days, a single candidate event is observed, consistent with expected backgrounds. This analysis (combined with previous Ge results) sets an upper limit on the spin-independent WIMP--nucleon cross section of $1.4 \times 10^{-44}$ ($1.0 \times 10^{-44}$) cm$^2$ at 46 GeV/$c^2$. These results set the strongest limits for WIMP--germanium-nucleus interactions for masses $>$12 GeV/$c^2$

Energy loss due to defect formation from 206Pb recoils in SuperCDMS germanium detectors

The Super Cryogenic Dark Matter Search experiment at the Soudan Underground Laboratory studied energy loss associated with defect formation in germanium crystals at mK temperatures using in situ 210Pb sources. We examine the spectrum of 206Pb nuclear recoils near its expected 103 keV endpoint energy and determine an energy loss of (6:08 ± 0:18)%, which we attribute to defect formation. From this result and using TRIM simulations, we extract the first experimentally determined average displacement threshold energy of 19.7+0.6−0.5 eV for germanium. This has implications for the analysis thresholds of future germanium-based dark matter searches

Gene expression profile of cervical and skin tissues from human papillomavirus type 16 E6 transgenic mice

<p>Abstract</p> <p>Background</p> <p>Although K14E6 transgenic mice develop spontaneous tumors of the skin epithelium, no spontaneous reproductive tract malignancies arise, unless the transgenic mice were treated chronically with 17β-estradiol. These findings suggest that E6 performs critical functions in normal adult cervix and skin, highlighting the need to define E6-controlled transcriptional programs in these tissues.</p> <p>Methods</p> <p>We evaluated the expression profile of 14,000 genes in skin or cervix from young K14E6 transgenic mice compared with nontransgenic. To identify differentially expressed genes a linear model was implemented using R and the LIMMA package. Two criteria were used to select the set of relevant genes. First a set of genes with a Log-odds ≥ 3 were selected. Then, a hierarchical search of genes was based on Log Fold Changes.</p> <p>Results</p> <p>Microarray analysis identified a total of 676 and 1154 genes that were significantly up and down-regulated, respectively, in skin from K14E6 transgenic mice. On the other hand, in the cervix from K14E6 transgenic mice we found that only 97 and 252 genes were significantly up and down-regulated, respectively. One of the most affected processes in the skin from K14E6 transgenic mice was the cell cycle. We also found that skin from transgenic mice showed down-regulation of pro-apoptotic genes and genes related to the immune response. In the cervix of K14E6 transgenic mice, we could not find affected any gene related to the cell cycle and apoptosis pathways but did observe alterations in the expression of immune response genes. Pathways such as angiogenesis, cell junction and epidermis development, also were altered in their gene expression profiles in both tissues.</p> <p>Conclusion</p> <p>Expression of the HPV16 E6 oncoprotein in our model alters expression of genes that fell into several functional groups providing insights into pathways by which E6 deregulate cell cycle progression, apoptosis, the host resistance to infection and immune function, providing new opportunities for early diagnostic markers and therapeutic drug targets.</p

Energy loss due to defect formation from \u3csup\u3e206\u3c/sup\u3ePb recoils in SuperCDMS germanium detectors

The Super Cryogenic Dark Matter Search experiment (SuperCDMS) at the Soudan Underground Laboratory studied energy loss associated with Frenkel defect formation in germanium crystals at mK temperatures using in situ 210Pb sources. We examine the spectrum of 206Pb nuclear recoils near its expected 103 keV endpoint energy and determine an energy loss of (6.08±0.18) %, which we attribute to defect formation. From this result and using TRIM simulations, we extract the first experimentally determined average displacement threshold energy of (19.7+0.6−0.5) eV for germanium. This has implications for the analysis thresholds of future germanium-based dark matter searches

New Results from the Search for Low-Mass Weakly Interacting Massive Particles with the CDMS Low Ionization Threshold Experiment

The CDMS low ionization threshold experiment (CDMSlite) uses cryogenic germanium detectors operated at a relatively high bias voltage to amplify the phonon signal in the search for weakly interacting massive particles (WIMPs). Results are presented from the second CDMSlite run with an exposure of 70 kg day, which reached an energy threshold for electron recoils as low as 56 eV. A fiducialization cut reduces backgrounds below those previously reported by CDMSlite. New parameter space for the WIMP-nucleon spin-independent cross section is excluded for WIMP masses between 1.6 and 5.5  GeV/c[superscript 2].National Science Foundation (U.S.)United States. Dept. of EnergyFermi National Accelerator Laboratory (Visiting Scholar Award 13-S-04

Production Rate Measurement of Tritium and Other Cosmogenic Isotopes in Germanium with CDMSlite

Future direct searches for low-mass dark matter particles with germanium detectors, such as SuperCDMS SNOLAB, are expected to be limited by backgrounds from radioactive isotopes activated by cosmogenic radiation inside the germanium. There are limited experimental data available to constrain production rates and a large spread of theoretical predictions. We examine the calculation of expected production rates, and analyze data from the second run of the CDMS low ionization threshold experiment (CDMSlite) to estimate the rates for several isotopes. We model the measured CDMSlite spectrum and fit for contributions from tritium and other isotopes. Using the knowledge of the detector history, these results are converted to cosmogenic production rates at sea level. The production rates in atoms/(kg · day) are 74  ±  9 for 3H, 1.5  ±  0.7 for 55Fe, 17  ±  5 for 65Zn, and 30  ±  18 for 68Ge

Search for low-mass dark matter with CDMSlite using a profile likelihood fit

The Cryogenic Dark Matter Search low ionization threshold experiment (CDMSlite) searches for interactions between dark matter particles and germanium nuclei in cryogenic detectors. The experiment has achieved a low energy threshold with improved sensitivity to low-mass (/c2) dark matter particles. We present an analysis of the final CDMSlite data set, taken with a different detector than was used for the two previous CDMSlite data sets. This analysis includes a data salting method to protect against bias, improved noise discrimination, background modeling, and the use of profile likelihood methods to search for a dark matter signal in the presence of backgrounds. We achieve an energy threshold of 70 eV and significantly improve the sensitivity for dark matter particles with masses between 2.5 and 10 GeV/c2 compared to previous analyses. We set an upper limit on the dark matter-nucleon scattering cross section in germanium of 5.4×10−42 cm2 at 5 GeV/c2, a factor of ∼2.5 improvement over the previous CDMSlite result