Neurotoxic action of permethrin in Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae) female ticks. Morphological and cytochemical evaluation of the central nervous system

Studies on the molecular bases of the neurotoxic action of acaricides are found in the literature; but there are no studies of this action on the nervous system of ticks at the cellular level. The present study describes the morphological and cytochemical changes in the synganglion of Rhipicephalus sanguineus semi-engorged females exposed to different concentrations of permethrin, a pyrethroid with recognized neurotoxic action. Permethrin induced the degeneration of the synganglion through a process of apoptosis involving autophagy, characterized by the condensation and margination of the chromatin, formation of blebs in the nuclear envelope and fragmentation of the nucleus, loss of shape of neural cells and integrity of cellular membrane, cytoplasmic shrinkage, and lower levels of acid phosphatase in the nervous tissue as the concentration of permethrin increased. This study provided further evidence of the neurotoxic action of permethrin, which impairs the metabolism of R. sanguineus nervous systems, and consequently the physiology of other systems, dependent on the neural control. These results provide cytochemical and histological confirmation of the neurotoxic action of permethrin, previously inferred from molecular and tick behavioral evidence. © 2013 Elsevier B.V.

The management of cover plant residues for cotton cropped in a no-tillage system

The cutting of plant residue in no-tillage systems under certain environmental conditions becomes necessary to adequately establish and grow crops. This study aims to assess the effect on the yield of different methods of managing millet plant residue in cotton plantations. The study was conducted during the agricultural years 2006/07 and 2007/08, and the treatments included no-mechanical-treatment tillage and the use of a rotary shredder, crimper-roller, and mechanical disintegrator for millet plants before sowing the cotton. Evaluations were performed for the residue fragmentation, emergence speed, percent of soil cover during the cycle and yield of the cotton crop. The emergence speed was faster in the management with the rotary shredder. In 2006/07, the no-tillage treatment showed a rate of loss for soil cover that was 46 percent greater than the disintegrator treatment. The rotary shredder and the disintegrator yielded greater soil coverage during the cultivation cycle, and the yield was highly correlated with the soil cover at 75 days after emergence. The management of the millet residue affected the cotton plants for the two-year study period.

How population loss through habitat boundaries determines the dynamics of a predator-prey system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

System size and energy dependence of near-side dihadron correlations

Two-particle azimuthal (Delta phi) and pseudorapidity (Delta eta) correlations using a trigger particle with large transverse momentum (p(T)) in d+Au, Cu+Cu, and Au+Au collisions at root s(NN) = 62.4 GeV and 200 GeV from the STAR experiment at the Relativistic Heavy Ion Collider are presented. The near-side correlation is separated into a jet-like component, narrow in both Delta phi and Delta eta, and the ridge, narrow in Delta phi but broad in Delta eta. Both components are studied as a function of collision centrality, and the jet-like correlation is studied as a function of the trigger and associated p(T). The behavior of the jet-like component is remarkably consistent for different collision systems, suggesting it is produced by fragmentation. The width of the jet-like correlation is found to increase with the system size. The ridge, previously observed in Au+Au collisions at root s(NN) = 200 GeV, is also found in Cu+Cu collisions and in collisions at root s(NN) = 62.4 GeV, but is found to be substantially smaller at root s(NN) = 62.4 GeV than at root s(NN) = 200 GeV for the same average number of participants (< N-part >). Measurements of the ridge are compared to models.

Mating system parameters at hierarchical levels of fruits, individuals and populations in the Brazilian insect-pollinated tropical tree, Tabebuia roseo-alba (Bignoniaceae)

For many tree species, mating system analyses have indicated potential variations in the selfing rate and paternity correlation among fruits within individuals, among individuals within populations, among populations, and from one flowering event to another. In this study, we used eight microsatellite markers to investigate mating systems at two hierarchical levels (fruits within individuals and individuals within populations) for the insect pollinated Neotropical tree Tabebuia roseo-alba. We found that T. roseo-alba has a mixed mating system with predominantly outcrossed mating. The outcrossing rates at the population level were similar across two T. roseo-alba populations; however, the rates varied considerably among individuals within populations. The correlated paternity results at different hierarchical levels showed that there is a high probability of shared paternal parentage when comparing seeds within fruits and among fruits within plants and full-sibs occur in much higher proportion within fruits than among fruits. Significant levels of fixation index were found in both populations and biparental inbreeding is believed to be the main cause of the observed inbreeding. The number of pollen donors contributing to mating was low. Furthermore, open-pollinated seeds varied according to relatedness, including half-sibs, full-sibs, self-sibs and self- half-sibs. In both populations, the effective population size within a family (seed-tree and its offspring) was lower than expected for panmictic populations. Thus, seeds for ex situ conservation genetics, progeny tests and reforestation must be collected from a large number of seed-trees to guarantee an adequate effective population in the sample.

Gas-phase fragmentation and conformation of the sugar-modified antisense oligonucleotide tcDNA

Tricyclo-DNA (tcDNA) is a sugar- and backbone-modified analogue of DNA that is currently tested as antisense oligonucleotide for the treatment of Duchenne muscular dystrophy. The name tricyclo-DNA is derived from the modified sugar-moiety: the deoxyribose is extended to a three-membered ring system. This modification is designed to limit the flexibility of the structure, thus giving rise to entropically stabilized hybrid duplexes formed between tcDNA and complementary DNA or RNA oligonucleotides. While the structural modifications increase the biostability of the therapeutic agent, they also render the oligonucleotide inaccessible to enzyme-based sequencing methods. Tandem mass spectrometry constitutes an alternative sequencing technique for partially and fully modified oligonucleotides. For reliable sequencing, the fragmentation mechanism of the structure in question must be understood. Therefore, the presented work evaluates the effect of the modified sugar-moiety on the gas-phase dissociation of single stranded tcDNA. Moreover, our experiments reflect the exceptional gas-phase stability of hybrid duplexes that is most noticeable in the formation of truncated duplex ions upon collision-induced dissociation. The stability of the duplex arises from the modified sugar-moiety, as the rigid structure of the tcDNA single strand minimizes the change of the entropy for the annealing. Moreover, the tc-modification gives rise to extended conformations of the nucleic acids in the gas-phase, which was studied by ion mobility spectrometry-mass spectrometry.

Dithiothreitol triggers photooxidative stress and fragmentation of the large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase in intact pea chloroplasts

In intact chloroplasts isolated from mature pea leaves (Pisum sativum L.), the large subunit (LSU) of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) was rapidly fragmented into several products upon illumination in the presence of 1 mM dithiothreitol (DTT). Very similar effects on LSU stability could be observed when illuminated chloroplasts were poisoned with cyanide which, like DTT, inhibits important plastid antioxidant enzymes, or when a light-dependent hydroxyl radical-producing system was added to the incubation medium. Moreover, DTT-stimulated light degradation of LSU was markedly delayed in the presence of scavengers of active oxygen species (AOS). It is therefore suggested that light degradation of LSU in the presence of DTT is mainly due to inhibition of the chloroplast antioxidant defense system and the subsequent accumulation of AOS in intact organelles. When chloroplasts were isolated from nonsenescent or senescent leaves, LSU remained very stable upon incubation without DTT, indicating that the antioxidant system was still functional in the isolated chloroplasts during leaf ageing. Our data support the notion that AOS might be important for the degradation of Rubisco in vivo under oxidative stress.

Resistance to DNA fragmentation and chromatin condensation in mice lacking the DNA fragmentation factor 45

The DNA fragmentation factor 45 (DFF45) is a subunit of a heterodimeric nuclease complex critical for the induction of DNA fragmentation in vitro. To understand the in vivo role of DFF45 in programmed cell death, we generated DFF45 mutant mice. DNA fragmentation activity is completely abolished in cell extracts from DFF45 mutant tissues. In response to apoptotic stimuli, splenocytes, thymocytes, and granulocytes from DFF45 mutant mice are resistant to DNA fragmentation, and splenocytes and thymocytes are also resistant to chromatin condensation. Nevertheless, development of the immune system in the DFF45 mutant mice is normal. These results demonstrate that DFF45 is critical for the induction of DNA fragmentation and chromatin condensation in vivo, but is not required for normal immune system development.

Evidence-Based Practice in the Juvenile Justice System: Balancing Clinical Expertise with Best Available Research and Client Variables

Each year, thousands of adolescents are processed through the juvenile justice system -- a system that is complicated, expensive, and inadequately addressing the needs of the youth in its care. While there is extensive literature available in support of interventions for youthful offenders that are clinically superior to current care and more cost-effective than the existing structure, there is a gap between research and practice that is preventing their implementation. The use of Evidence-Based Practice in Psychology (EBPP) as defined by the American Psychological Association is presented as one method to bridge this gap. This paper identifies and discusses each of five barriers to effective use of EBPP: cost, fragmentation of the mental health system, historical and systemic variables, research methodology, and clinician variables. These barriers are first defined and then illustrated using examples from the author's experience working in the juvenile justice field. Finally, recommendations for the field are presented.

Implementation Feasibility of a Digital Nervous System for the Construction Industry: For Efficient and Effective Information Management across the Project Lifecycle

The construction industry has long been considered as highly fragmented and non-collaborative industry. This fragmentation sprouted from complex and unstructured traditional coordination processes and information exchanges amongst all parties involved in a construction project. This nature coupled with risk and uncertainty has pushed clients and their supply chain to search for new ways of improving their business process to deliver better quality and high performing product. This research will closely investigate the need to implement a Digital Nervous System (DNS), analogous to a biological nervous system, on the flow and management of digital information across the project lifecycle. This will be through direct examination of the key processes and information produced in a construction project and how a DNS can provide a well-integrated flow of digital information throughout the project lifecycle. This research will also investigate how a DNS can create a tight digital feedback loop that enables the organisation to sense, react and adapt to changing project conditions. A Digital Nervous System is a digital infrastructure that provides a well-integrated flow of digital information to the right part of the organisation at the right time. It provides the organisation with the relevant and up-to-date information it needs, for critical project issues, to aid in near real-time decision-making. Previous literature review and survey questionnaires were used in this research to collect and analyse data about information management problems of the industry – e.g. disruption and discontinuity of digital information flow due to interoperability issues, disintegration/fragmentation of the adopted digital solutions and paper-based transactions. Results analysis revealed efficient and effective information management requires the creation and implementation of a DNS.

Intelligent Decision-Making System Frameworks for a Digital Plan of Work: A Theoretical Investigation for the Construction Industry

The construction industry is characterised by fragmentation and suffers from lack of collaboration, often adopting adversarial working practices to achieve deliverables. For the UK Government and construction industry, BIM is a game changer aiming to rectify this fragmentation and promote collaboration. However it has become clear that there is an essential need to have better controls and definitions of both data deliverables and data classification. Traditional methods and techniques for collating and inputting data have shown to be time consuming and provide little to improve or add value to the overall task of improving deliverables. Hence arose the need in the industry to develop a Digital Plan of Work (DPoW) toolkit that would aid the decision making process, providing the required control over the project workflows and data deliverables, and enabling better collaboration through transparency of need and delivery. The specification for the existing Digital Plan of Work (DPoW) was to be, an industry standard method of describing geometric, requirements and data deliveries at key stages of the project cycle, with the addition of a structured and standardised information classification system. However surveys and interviews conducted within this research indicate that the current DPoW resembles a digitised version of the pre-existing plans of work and does not push towards the data enriched decision-making abilities that advancements in technology now offer. A Digital Framework is not simply the digitisation of current or historic standard methods and procedures, it is a new intelligent driven digital system that uses new tools, processes, procedures and work flows to eradicate waste and increase efficiency. In addition to reporting on conducted surveys above, this research paper will present a theoretical investigation into usage of Intelligent Decision Support Systems within a digital plan of work framework. Furthermore this paper will present findings on the suitability to utilise advancements in intelligent decision-making system frameworks and Artificial Intelligence for a UK BIM Framework. This should form the foundations of decision-making for projects implemented at BIM level 2. The gap identified in this paper is that the current digital toolkit does not incorporate the intelligent characteristics available in other industries through advancements in technology and collation of vast amounts of data that a digital plan of work framework could have access to and begin to develop, learn and adapt for decision-making through the live interaction of project stakeholders.

Floral structure, breeding system and fruit-set in the threatened sub-shrub Tetratheca juncea Smith (Tremandraceae)

Tetratheca juncea Smith (Tremandraceae) has undergone a range contraction of approx. 50 km in the last 100 years and is now listed as a vulnerable sub-shrub restricted to the central and north coast regions of New South Wales, Australia. There are approx. 250 populations in a 110 km north-south distribution and populations are usually small with fewer than 50 plants/clumps. The reproductive ecology of the species was studied to determine why seed-set is reportedly rare. Flowers are bisexual, odourless and nectarless. Flowers are presented dependentally and there are eight stamens recurved around the pistil. Anthers are poricidal, contain viable pollen and basally contain a deep-red tapetal fluid that is slightly oily. Thus flowers are presented for buzz pollinators, although none were observed at flowers during our study. The species was found to be facultatively xenogamous with only one in 50 glasshouse flowers setting seed autogamously, i.e. without pollinator assistance. Field studies revealed fertile fruit in 24 populations but production varied significantly across sites from exceedingly low (0.6 fruits per plant clump) to low (17 fruits per plant clump). Fruit-set ranged from 0 to 65%, suggesting that pollen vectors exist or that autogamy levels in the field are variable and higher than glasshouse results. Fruit production did not vary with population size, although in three of the five populations in the south-west region more than twice as much fruit was produced as in populations elsewhere. A moderately strong relationship between foliage volume and fruit : flower ratios suggests that bigger plants may be more attractive than smaller plants to pollinators. A review of Tetratheca pollination ecology revealed that several species are poorly fecund and pollinators are rare. The habitat requirements for Tetratheca, a genus of many rare and threatened species, is discussed. (C) 2003 Annals of Botany Company.

Genetic effects of chronic habitat fragmentation on tree species: the case of Sorbus aucuparia in a deforested Scottish landscape

Sustainable forest restoration and management practices require a thorough understanding of the influence that habitat fragmentation has on the processes shaping genetic variation and its distribution in tree populations. We quantified genetic variation at isozyme markers and chloroplast DNA (cpDNA), analysed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in severely fragmented populations of Sorbus aucuparia (Rosaceae) in a single catchment (Moffat) in southern Scotland. Remnants maintain surprisingly high levels of gene diversity (H-E) for isozymes (H-E = 0.195) and cpDNA markers (H-E = 0.490). Estimates are very similar to those from non-fragmented populations in continental Europe, even though the latter were sampled over a much larger spatial scale. Overall, no genetic bottleneck or departures from random mating were detected in the Moffat fragments. However, genetic differentiation among remnants was detected for both types of marker (isozymes Theta(n) = 0.043, cpDNA Theta(c) = 0.131; G-test, P-value < 0.001). In this self-incompatible, insect-pollinated, bird-dispersed tree species, the estimated ratio of pollen flow to seed flow between fragments is close to 1 (r = 1.36). Reduced pollen-mediated gene flow is a likely consequence of habitat fragmentation, but effective seed dispersal by birds is probably helping to maintain high levels of genetic diversity within remnants and reduce genetic differentiation between them.

The effects of habitat fragmentation due to forestry plantation establishment on the demography and genetic variation of a marsupial carnivore, Antechinus agilis

We conducted a demographic and genetic study to investigate the effects of fragmentation due to the establishment of an exotic softwood plantation on populations of a small marsupial carnivore, the agile antechinus (Antechinus agilis), and the factors influencing the persistence of those populations in the fragmented habitat. The first aspect of the study was a descriptive analysis of patch occupancy and population size, in which we found a patch occupancy rate of 70% among 23 sites in the fragmented habitat compared to 100% among 48 sites with the same habitat characteristics in unfragmented habitat. Mark-recapture analyses yielded most-likely population size estimates of between 3 and 85 among the 16 occupied patches in the fragmented habitat. Hierarchical partitioning and model selection were used to identify geographic and habitat-related characteristics that influence patch occupancy and population size. Patch occupancy was primarily influenced by geographic isolation and habitat quality (vegetation basal area). The variance in population size among occupied sites was influenced primarily by forest type (dominant Eucalyptus species) and, to a lesser extent, by patch area and topographic context (gully sites had larger populations). A comparison of the sex ratios between the samples from the two habitat contexts revealed a significant deficiency of males in the fragmented habitat. We hypothesise that this is due to male-biased dispersal in an environment with increased dispersal-associated mortality. The population size and sex ratio data were incorporated into a simulation study to estimate the proportion of genetic diversity that would have been lost over the known timescale since fragmentation if the patch populations had been totally isolated. The observed difference in genetic diversity (gene diversity and allelic richness at microsatellite and mitochondrial markers) between 16 fragmented and 12 unfragmented sites was extremely low and inconsistent with the isolation of the patch populations. Our results show that although the remnant habitat patches comprise approximately 2% of the study area, they can support non-isolated populations. However, the distribution of agile antechinus populations in the fragmented system is dependent on habitat quality and patch connectivity. (C) 2004 Elsevier Ltd. All rights reserved.