1,321 research outputs found
The underestimated role of pest pentatomid parasitoids in Southern South America.
Stink bugs are pests of economic importance of extensive crops (commodities) in the Neotropics, particularly in Southern South America. They are abundant, have a broad geographical distribution, and cause severe damage. Main species include the Neotropical brown-stink bug, Euschistus heros (F.), the red-banded stink bug, Piezodorus guildinii (Westwood), the Southern green stink bug, Nezara viridula (L.), the green-belly stink bugs, Dichelops furcatus (F.), and D. melacanthus (Dallas), and the brown-winged stink bug, Edessa meditabunda (F.). The management of these pest species on crops is complex because they can cause economic damage in low numbers, and it is difficult to control by the commonly used insecticides. Therefore, biological control appears as the most important tactic to be implemented in stink bug management programs. Among the many natural enemies present on the various agroecosystems, egg parasitoids (Hymenoptera) and parasitoids of adult stink bugs (Diptera and Hymenoptera) are the most promising groups to be exploited as biological control agents of pest species. Despite attempts in the past, implementation of biological control of stink bugs on major commodities in Southern South America still remains at a low level of adoption, and its high potential is, generally, underestimated. In this review article, we present extensive data from the literature on the two main groups of biological control agents referred above. Moreover, we discuss ways to promote biological control as the most important tactic to manage stink bugs in Southern South America. Keywords Heteroptera · Pentatomidae · Adult parasitoids · Egg parasitoids · Southern South Americ
Potentiodynamic current/potential characteristics of theoretical mechanisms related to the electrochemical formation and electroreduction of monolayer films on inert electrodes
The current/potential curves of various mechanisms related to the electrochemical formation and electroreduction of monolayer films on inert electrodes, involving a single surface covering species and two surface covering species are presented. The potential perturbation functions consist both of single either linear or triangular potential sweeps and of triangular modulated linear potential sweeps. A comparison of the theoretical Eli displays obtained with the different potential perturbation techniques is given for the various reaction pathways presented.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada
Driving the transition to a circular economic model: A systematic review on drivers and critical success factors in circular economy
The circular economy (CE) is arising as a novel economic system that is restorative by design. In light of its capability to boost sustainable economic development and to cope with environmental challenges, it has recently attracted increasing attention from academics, practitioners, policymakers, and intergovernmental organizations. Despite the wide speculation on this issue, the scientific literature lacks a wide-ranging, systematic, and updated identification and classification of the main drivers and Critical Success Factors of CE initiatives, which appears increasingly necessary to facilitate future scientific work, practical implementations, and policy guidelines. With this aim, this paper develops a systematic literature review by starting with over 400 manuscripts. A final set of 55 selected papers was selected for singling out and classifying drivers and Critical Success Factors in the CE context. The results may provide clear indications for further research, may help business organizations in evaluating CE initiatives, and may guide policy makers in developing and refining CE normative frameworks
Oases: robust de novo RNA-seq assembly across the dynamic range of expression levels
Motivation: High-throughput sequencing has made the analysis of new model organisms more affordable. Although assembling a new genome can still be costly and difficult, it is possible to use RNA-seq to sequence mRNA. In the absence of a known genome, it is necessary to assemble these sequences de novo, taking into account possible alternative isoforms and the dynamic range of expression values
Potentiodynamic current/potential characteristics of theoretical mechanisms related to the electrochemical formation and electroreduction of monolayer films on inert electrodes
The current/potential curves of various mechanisms related to the electrochemical formation and electroreduction of monolayer films on inert electrodes, involving a single surface covering species and two surface covering species are presented. The potential perturbation functions consist both of single either linear or triangular potential sweeps and of triangular modulated linear potential sweeps. A comparison of the theoretical Eli displays obtained with the different potential perturbation techniques is given for the various reaction pathways presented.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada
Representing and decomposing genomic structural variants as balanced integer flows on sequence graphs
The study of genomic variation has provided key insights into the functional
role of mutations. Predominantly, studies have focused on single nucleotide
variants (SNV), which are relatively easy to detect and can be described with
rich mathematical models. However, it has been observed that genomes are highly
plastic, and that whole regions can be moved, removed or duplicated in bulk.
These structural variants (SV) have been shown to have significant impact on
the phenotype, but their study has been held back by the combinatorial
complexity of the underlying models. We describe here a general model of
structural variation that encompasses both balanced rearrangements and
arbitrary copy-numbers variants (CNV). In this model, we show that the space of
possible evolutionary histories that explain the structural differences between
any two genomes can be sampled ergodically
Overwintering of Piezodorus guildinii (Heteroptera, Pentatomidae) populations.
Piezodorus guildinii (Westwood) is a soybean pest that causes significant economic losses in the Americas. The variability of overwintering (diapause) traits was evaluated in populations of the Southwest (SW) (33°55′?34°17′S, 57°13′?57°46′W) during 2-year period (2011?2013) and of the Northwest (NW) (32°01′?33°02′S, 57°50′?57°24′W) during 1-year period (2014?2015) Regions of Uruguay. Samples were taken from different plant species (cultivated legumes, wild shrubs, and trees) and from overwintering sites (leaf litter and bark). Alfalfa, Medicago sativa L. was the main host, with a collection period of 10?11 months in the SW and 12 months in the NW. Cluster analysis for each sex was carried out to group the months according to the similarity in diapause traits of populations (body size, body lipid content, immature reproductive organs, and clear type of pronotum band and connexivum in females). Female diapause in the SWwas longer (beginning of autumn to end of winter) than that in the NW (mid-autumn to mid-winter). Male diapause was longer (mid-autumn o mid-winter) in SW1 (1st year) than in SW2 (2nd year) and NW (lateautumn to mid-winter). In both regions, male diapause was shorter than female. Differences were associated with maximum temperature at daylight hours ≤ 12.1, being necessary maximum temperatures below 23.8 °C for females and 19.2 °C for males to initiate diapause
Dynamic ageing of an oxygen-containing monolayer at platinum and gold electrodes in aqueous acid solutions
It is already well established that oxygen-containing species electrochemically formed in the monolayer range on Pt and Au electrodes in acid electrolytes undergo ageing processes which are easily evidenced by a potential shift of the corresponding electroreduction current peak observed under a cathodic linear potential sweep. During the ageing process the oxygen containing surface species undergoes a change into another one involving a more stable configuration but without any detectable change of the oxygen/surface metal atomic ratio. The ageing process takes place simultaneously with the electrosorption of oxygen and its contribution can be reasonably controlled during the electro° desorption process as is the case, for instance, when the surface species is allowed to stay under open circuit for a certain time after its electrochemical formation.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada
Pebble and Rock Band: Heuristic Resolution of Repeats and Scaffolding in the Velvet Short-Read de Novo Assembler
BACKGROUND: Despite the short length of their reads, micro-read sequencing technologies have shown their usefulness for de novo sequencing. However, especially in eukaryotic genomes, complex repeat patterns are an obstacle to large assemblies. PRINCIPAL FINDINGS: We present a novel heuristic algorithm, Pebble, which uses paired-end read information to resolve repeats and scaffold contigs to produce large-scale assemblies. In simulations, we can achieve weighted median scaffold lengths (N50) of above 1 Mbp in Bacteria and above 100 kbp in more complex organisms. Using real datasets we obtained a 96 kbp N50 in Pseudomonas syringae and a unique 147 kbp scaffold of a ferret BAC clone. We also present an efficient algorithm called Rock Band for the resolution of repeats in the case of mixed length assemblies, where different sequencing platforms are combined to obtain a cost-effective assembly. CONCLUSIONS: These algorithms extend the utility of short read only assemblies into large complex genomes. They have been implemented and made available within the open-source Velvet short-read de novo assembler
Cerulean: A hybrid assembly using high throughput short and long reads
Genome assembly using high throughput data with short reads, arguably,
remains an unresolvable task in repetitive genomes, since when the length of a
repeat exceeds the read length, it becomes difficult to unambiguously connect
the flanking regions. The emergence of third generation sequencing (Pacific
Biosciences) with long reads enables the opportunity to resolve complicated
repeats that could not be resolved by the short read data. However, these long
reads have high error rate and it is an uphill task to assemble the genome
without using additional high quality short reads. Recently, Koren et al. 2012
proposed an approach to use high quality short reads data to correct these long
reads and, thus, make the assembly from long reads possible. However, due to
the large size of both dataset (short and long reads), error-correction of
these long reads requires excessively high computational resources, even on
small bacterial genomes. In this work, instead of error correction of long
reads, we first assemble the short reads and later map these long reads on the
assembly graph to resolve repeats.
Contribution: We present a hybrid assembly approach that is both
computationally effective and produces high quality assemblies. Our algorithm
first operates with a simplified version of the assembly graph consisting only
of long contigs and gradually improves the assembly by adding smaller contigs
in each iteration. In contrast to the state-of-the-art long reads error
correction technique, which requires high computational resources and long
running time on a supercomputer even for bacterial genome datasets, our
software can produce comparable assembly using only a standard desktop in a
short running time.Comment: Peer-reviewed and presented as part of the 13th Workshop on
Algorithms in Bioinformatics (WABI2013
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