The fourth-order single-switch improved super-boost converter with reduced input current ripple

This paper introduces a new single switch DC-DC fourth-order boost converter. The proposed converter is the improved version of an existing converter known as the super-boost converter. The improved super-boost ISP converter achieves a smaller input current ripple than the super-boost converter when the same parameters in passive components are used. Conversely, smaller components can be used to achieve the same input current ripple, which leads to a compact and cheaper design. A comparative evaluation showed a reduction of 37.3% of stored energy in inductors to comply with a required input current ripple in comparison with the super-boost converter for a particular design. Experimental results are provided to corroborate this benefit of the ISB proposed topology

TRY plant trait database – enhanced coverage and open access

Plant traits—the morphological, anatomical, physiological, biochemical and phenological characteristics of plants—determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits—almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

INITIAL TEST WELL CONDITIONING AT NOPAL I URANIUM DEPOSIT, SIERRA PENA BLANCA, CHIHUAHUA, MEXICO

Three test wells, PB-1, PB-2, and PB-3, were drilled at the Nopal I uranium deposit as part of a natural analogue study to evaluate radionuclide transport processes during March-April 2003. The initial pumping to condition the wells was completed during December 2003. The PB-1 well, drilled immediately adjacent to the Nopal I ore body, was continuously cored to a depth of 250 m, terminating 20 m below the top of the measured water level. The PB-2 and PB-3 wells, which were drilled on opposite sides of PB-1 at a radial distance of approximately 40 to 50 m outside of the remaining projected ore body, were also drilled to about 20 m below the top of the measured water level. Each test well was completed with 4-inch (10.2-cm) diameter PVC casing with a slotted liner below the water table. Initial conditioning of all three wells using a submersible pump at low pump rates [less than 1 gallon (3.8 1) per minute] resulted in measurable draw down and recoveries. The greatest drawdown ({approx}15 m) was observed in PB-2, whereas only minor (<1 m) drawdown occurred in PB-3. For PB-1 and PB-2, the water turbidity decreased as the wells were pumped and the pH values decreased, indicating that the contamination from the drilling fluid was reduced as the wells were conditioned. Test wells PB-1 and PB-2 showed increased inflow after several borehole volumes of fluid were removed, but their inflow rates remained less that the pumping rate. Test well PB-3 showed the smallest drawdown and least change in pH and conductivity during initial pumping and quickest recovery with a rise in measured water level after conditioning. The 195 gallons (750 l) of water pumped from PB-3 during conditioning was discharged through a household sponge. That sponge showed measurable gamma radiation, which decayed to background values in less than 12 hours. Preliminary interpretations include filtration of a radioisotope source with a short half-life or of a radioisotope that volatized as the sponge dried, such as Rn-222 and its short-lived daughters. No filtration was used during the pumping of PB-1 or PB-2

Body temperature predicts maximum microsatellite length in mammals

A long-standing mystery in genome evolution is why short tandem repeats vary so much in length and frequency. Here, we test the hypothesis that body temperature acts to influence the rate and nature of slippage-based mutations. Using the data from both 28 species where genome sequencing is advanced and 76 species from which marker loci have been published, we show that in mammals, maximum repeat number is inversely correlated with body temperature, with warmer-blooded species having shorter 'long' microsatellites. Our results support a model of microsatellite evolution in which maximum length is limited by a temperature-dependent stability threshold

A novel integrative approach elucidates fine-scale dispersal patchiness in marine populations

Dispersal is one of the main determining factors of population structure. In the marine habitat, well-connected populations with large numbers of reproducing individuals are common but even so population structure can exist on a small-scale. Variation in dispersal patterns between populations or over time is often associated to geographic distance or changing oceanographic barriers. Consequently, detecting structure and variation in dispersal on a fine-scale within marine populations still remains a challenge. Here we propose and use a novel approach of combining a clustering model, early-life history trait information from fish otoliths, spatial coordinates and genetic markers to detect very fine-scale dispersal patterns. We collected 1573 individuals (946 adults and 627 juveniles) of the black-faced blenny across a small-scale (2 km) coastline as well as at a larger-scale area (<50 kms). A total of 178 single nucleotide polymorphism markers were used to evaluate relatedness patterns within this well-connected population. In our clustering models we categorized SHORT-range dispersers to be potential local recruits based on their high relatedness within and low relatedness towards other spatial clusters. Local retention and/or dispersal of this potential local recruitment varied across the 2 km coastline with higher frequency of SHORT-range dispersers towards the southwest of the area for adults. An inverse pattern was found for juveniles, showing an increase of SHORT-range dispersers towards the northeast. As we rule out selective movement and mortality from one year to the next, this pattern reveals a complex but not full genetic mixing, and variability in coastal circulation is most likely the main driver of this fine-scale chaotic genetic patchiness within this otherwise homogeneous population. When focusing on the patterns within one recruitment season, we found large differences in temperatures (from approx. 17 °C to 25 °C) as well as pelagic larval duration (PLD) for juveniles from the beginning of the season and the end of the season. We were able to detect fine-scale differences in LONG-range juvenile dispersers, representing distant migrants, depending on whether they were born at the beginning of the season with a longer PLD, or at the end of the reproductive season. The ability to detect such fine-scale dispersal patchiness will aid in our understanding of the underlying mechanisms of population structuring and chaotic patchiness in a wide range of species even with high potential dispersal abilities

Strategies for the development of research in teaching

El presente capítulo recopila los aspectos relevantes que se toman de las propuestas de los miembros del grupo del área de Ciencias Económico Administrativa del Proyecto Innova Cesal, enfatizando la forma como las mismas abordan la investigación en la docencia. Se inicia con la presentación de referentes teóricos que se tomaron como base para el diseño de las estrategias, y a continuación se les describe de manera breve. En la mayoría de los casos la descripción se tomó de los documentos originales y sólo en algunos de ellos se hicieron ajustes para disminuir su extensión. Al final de cada estrategia se presenta una síntesis de la intervención educativa y la referencia del reporte de la experiencia completa

Validation of data association for monocular SLAM

Background and Aims: The virulence of Enterococcus faecalis is associated with three proteins involved in biofilm production: Ace, Agg, and Esp. Isolates also vary with respect to drug resistance. The present study investigated four characteristics of clinical isolates of E. faecalis recovered from three hospitals in Mexico, including biofilm production, the presence of biofilm-related genes, antibiotic susceptibility, and clonal diversity. Methods: We studied 109 clinical isolates. Biofilm formation was investigated using crystal violet and the safranin method with biofilm index correction. The presence of ace, agg, and esp genes was determined by PCR. Susceptibility to antibiotics was determined by the broth microdilution method and clonal relatedness was determined by pulsed-field gel electrophoresis (PFGE). Results: Using the crystal violet method, 4.6% (5/109) of isolates were high biofilm producers, 48% (52/109) were moderate producers, 20% (39/109) were low producers, and 11% (12/109) were nonproducers. The agg gene was present in 44% (48/109), the ace gene in 39% (43/109), and the esp gene in 33% (36/109). The esp gene was associated with biofilm production (p <0.001), whereas the ace gene correlated with tetracycline resistance (p <0.01). The biofilm index was associated with the presence of both esp plus agg in glucose medium (p= 0.006). Clinical isolates showed high resistance to tetracycline and ciprofloxacin. Also, 2% of isolates were resistant to linezolid and there was no vancomycin resistance. PFGE revealed 109 different restriction patterns. Conclusions: The presence of the esp and agg gene was associated with biofilm production, whereas the presence of the ace gene correlated with tetracycline resistance. Overall, a moderate resistance to antibiotics was detected and there was no clonal relatedness among isolates. " 2013 IMSS.",,,,,,"10.1016/j.arcmed.2013.07.003",,,"http://hdl.handle.net/20.500.12104/45683","http://www.scopus.com/inward/record.url?eid=2-s2.0-84885120455&partnerID=40&md5=cec8fe93f53a4b1e4385ab3b9c5f14f1",,,,,,"6",,"Archives of Medical Research",,"42