Magnetic track array for efficient bead capture in microchannels

Magnetism-based microsystems, as those dedicated to immunoaffinity separations or (bio)chemical reactions, take benefit of the large surface area-to-volume ratio provided by the immobilized magnetic beads, thus increasing the sensitivity of the analysis. As the sensitivity is directly linked to the efficiency of the magnetic bead capture, this paper presents a simple method to enhance the capture in a microchannel. Considering a microchannel surrounded by two rectangular permanent magnets of different length (L m = 2, 5, 10mm) placed in attraction, it is shown that the amount of trapped beads is limited by the magnetic forces mainly located at the magnet edges. To overcome this limitation, a polyethylene terephthalate (PET) microchip with an integrated magnetic track array has been prototyped by laser photo-ablation. The magnetic force is therefore distributed all along the magnet length. It results in a multi-plug bead capture, observed by microscope imaging, with a magnetic force value locally enhanced. The relative amount of beads, and so the specific binding surface for further immunoassays, presents a significant increase of 300% for the largest magnets. The influence of the track geometry and relative permeability on the magnetic force was studied by numerical simulations, for the microchip operating with 2-mm-long magnet

A New Species of Cryptopone Emery (Hymenoptera: Formicidae: Ponerinae) from Brazil with Observations of this Genus and a Key for New World Species

The monophyly of Ponerinae was strongly supported by a detailed molecular phylogenetic study. Within the subfamily, substantial changes were yet done to the taxonomy of several genera, such as Cryptopone Emery, and after phylogenetic and morphological considerations, the genus Cryptopone was revived. Cryptopone is a moderately large genus of pantropical distribution, with 25 described species and subspecies, with its diversity centered mostly in East and Southeast Asia. In the New World, only four species were known until now, Cryptopone gilva (Roger), Cryptopone guianensis (Weber), Cryptopone holmgreni (Wheeler) and Cryptopone mirabilis (Mackay & Mackay). Since the Mackay and Mackay’s revision of 2010 of the genus Pachycondyla which included the species currently attributed to Cryptopone, no new species was added to Cryptopone genus in the New World. Recently an unidentified Cryptopone species was collected in the state of Rondônia, Brazil. The material here described was sampled by manual collection of soil in the Floresta Nacional do Jamari (FLONA Jamari). Four individuals belonging to the worker caste are hereafter described under the name of Cryptopone pauli sp. nov. Currently this ant is known only to a single locality in the state of Rondônia, Brazil. This is also the first record of this genus for that state. We present new records of Cryptopone for the Neotropical Region with some comments on its biology and an updated key to workers of the five species of Cryptopone currently known in the New World

Contrasting “Carrasco” and Forest Ant Communities in the Chapada Diamantina, Bahia, Brazil

This study contrasts the structure of ant communities of the “carrasco” (deciduous forest) and forest (semideciduous forest) remnants in the buffer zone of the Chapada Diamantina National Park, Bahia, Brazil. Our aim was to compare the richness, composition, vertical partitioning and guild organization at the level of leaf-litter, ground-surface and lower vegetation between the habitat types. Ants were sampled at six sites within each habitat by manual extraction in the leaf-litter, pitfall traps at ground level and baited pitfall traps on tree-trunks and shrubs 1.5 m above the soil surface. A total of 132 ant species was collected belonging to 34 genera and seven subfamilies. According to the analyses performed, the habitat types had equivalent species richness and a distinct species and functional composition at the vertical strata level. Furthermore, a greater vertical partitioning was observed in the forest ant community than in the carrasco ant community. The results indicated a distinct biogeographical association between the ant fauna of the two habitat types and suggested that ant communities in carrasco and forest remnants in the buffer zone of the Chapada Diamantina National Park are especially interesting for conservation and ecological research

Design of an Automated Dual IPCs 240 System for Asymmetric Power Flow Compensation in an AC Electric Network

In this paper, an automated dual IPCs 240 system for asymmetric power compensation, is designed from an analytical analysis of the power flow modes through the transmission line. Then, the ACL (automatic control logic) obtained consists of serial gates arrays of standard NAND/AND and OR operators.  It has been  implemented within Matlab/Simulink framework, and the simulation results obtained show the feasibility and great relevance of using the dual IPCs 240 technology, in power transmission networks  under normal and contingency conditions

Design of an Automated Dual IPCs 240 System for Asymmetric Power Flow Compensation in an AC Electric Network

In this paper, an automated dual IPCs 240 system for asymmetric power compensation is designed from an analytical analysis of the power flow modes through the transmission line. Then, the obtained ACL (Automatic Control Logic) consists of serial gates arrays of the standard NAND/AND and OR operators. It has been implemented within the Matlab/Simulink framework, and the obtained simulation results show the feasibility and great relevance of the dual IPCs 240 technology using, in power transmission networks under normal and contingency conditions

Learning robotic pyeloplasty without simulators: an assessment of the learning curve in the early robotic era

OBJECTIVE: To analyze our experience and learning curve for robotic pyeloplasty during this robotic procedure. METHODS: Ninety-nine patients underwent 100 consecutive procedures. Cases were divided into 4 groups of 25 consecutive procedures to analyze the learning curve. RESULTS: The median anastomosis times were 50.0, 36.8, 34.2 and 29.0 minutes (p=0.137) in the sequential groups, respectively. The median operative times were 144.6, 119.2, 114.5 and 94.6 minutes, with a significant difference between groups 1 and 2 (p=0.015), 1 and 3 (p=0.002), 1 and 4 (po0.001) and 2 and 4 (p=0.022). The mean hospital stay was 7.08, 4.76, 4.88 and 4.20 days, with a difference between groups 1 and 2 (po0.001), 1 and 3 (po0.001) and 1 and 4 (po0.001). Clinical and radiological improvements were observed in 98.9% of patients. One patient presented with recurrent obstruction. CONCLUSIONS: Our results demonstrate a high success rate with low complication rates. A significant decrease in hospital stay and surgical time was evident after 25 cases

Effects of Habitat Conversion on Ant Functional Groups: A Global Review

Conversion of natural to anthropogenic environments affects biodiversity, and the understanding of these impacts may be improved by assessing how different functional groups respond to such land conversion. We studied land conversion impacts on ant functional groups, as ants are ecologically important and respond well to various environmental changes. We hypothesized that conversion of natural to anthropogenic environments modifies the composition of functional groups, fostering generalist and opportunistic groups over specialist ones, with more responses of this type in tropical than in temperate regions. We recovered 412 papers from ISI Web of Science, of which we selected 17 studies, published between 1993 and 2018, that addressed our study’s question. We assessed whether each functional group responded positively or negatively to conversion of natural habitat into anthropogenic land uses and used Monte Carlo tests to assess significance. Ants were affected by natural habitat conversion into monoculture and polyculture and by the conversion of savannas and of tropical and subtropical forests. Land conversion affected six of the 13 functional groups assessed here. In the temperate zone, cryptic species, predators, subordinate Camponotini, cold-climate specialists and tropical-climate specialists were impaired, whereas hot-climate specialists were favored. In the tropics, land conversion negatively impacted fungus-growers and predators. In both climatic zones, several functional groups, mainly those with broad ecological niches, did not respond to land conversion. Our results corroborate that land conversion effects vary among ant functional groups and indicate that the ant fauna of temperate ecosystems may be more susceptible than that of tropical regions