1,069 research outputs found
Phylogenetic Approach to the Study of Triatomines (Triatominae, Heteroptera) = Abordagem filogenética em Triatomíneos (Triatominae, Heteroptera)
Abstracts
Triatomines are insects belonging to the Hemiptera order, Heteroptera suborder, Reduviidae family and Triatominae subfamily. All members of this subfamily are hematophagous. Triatomines evolved from Reduviidae predators and they are probably polyphyletic in origin. The combination of anatomical, physiological and ethological factors observed in this group, as well as the plesiomorphic and apomorphic characters that differentiate the five tribes and fourteen triatomine genera reinforce the polyphiletic hypotesis. However if we consider the five groups of triatomines, the Rhodniini, Cavernicolini, Bolboderini, Linshcosteini and Alberproseniini tribes constitute monophyletic groups, while the Triatomini tribe is considered polyphyletic. The New World is the center of triatomine diversity and seems to be the point of group origin. Of approximately 137 triatomine species, 105 are only found in the Americas. It is now considered that triatomines represent a polyphyletic group defined according to their convergent apomorphic hematophagous characters, which have appeared several times in Reduviidae. This study revises the phylogeny of these vectors of Chagas\u27 disease, covering such topics as the origin of hematophagy in triatomines and ancestral proposal for the group.
Os triatomíneos são insetos pertencentes à ordem Hemiptera, subordem Heteroptera, família Reduviidae e subfamília Triatominae. Todos os membros desta subfamília são hematófagos. Os triatomíneos surgiram a partir de reduvídeos predadores e provavelmente têm origem polifilética. A combinação dos fatores anatômicos, fisiológicos e etológicos presentes no grupo, bem como os caracteres plésio e apomórficos que diferenciam as cinco tribos e os quatorze gêneros de triatomíneos reforçam a hipótese polifilética. As tribos Rhodniini, Cavernicolini, Bolboderini, Linshcosteini e Alberproseniini constituem grupos monofiléticos, per si, enquanto a tribo Triatomini é considerada polifilética. O Novo Mundo é claramente o centro de diversidade dos triatomíneos e possivelmente é a região de sua origem. Entre as aproximadamente 129 espécies desses insetos, 105 ocorrem somente nas Américas. Atualmente, os triatomíneos são considerados um grupo polifilético, definido com base em seus caracteres apomórficos convergentes relacionados à hematofagia. Acredita-se que este hábito alimentar tenha surgido várias vezes nos Reduviidae durante sua evolução. O presente trabalho faz uma revisão sobre a filogenia destes vetores da Doença de Chagas, aborda tópicos como a origem da hematofagia nos triatomíneos e ancestralidade proposta para o grupo
Technology and teaching in higher education: A simulation applied to the integration of concepts taught in postgraduate courses
Introducción: El objetivo de este trabajo fue implementar tecnologías de la información y la comunicación (TIC) a nivel de posgrado. En este caso particular se usó USINA, un simulador para la toma de decisiones diseñado por el Centro de Innovaciones en Tecnología y Pedagogía (CITEP), de la Universidad de Buenos Aires. Ésta permite trabajar con narraciones, estudio de casos y utilizar el “error” como método pedagógico. Métodos: 1) Diseñar una secuencia de pantallas para ser montadas en USINA utilizándola como herramienta de integración de conceptos en dos cursos de posgrado: Downstream Processing de proteínas (DSP) y Aplicaciones, Síntesis y Análisis de Péptidos Sintéticos (ASAP). 2) Aplicar una encuesta anónima para evaluar la eficiencia de USINA. 3) Realizar una clase presencial para intercambiar opiniones sobre la experiencia. Resultados y Discusión: En ambos cursos (DSP y ASAP) la experiencia resultó exitosa. El alumnado consideró que el uso de USINA permitió el andamiaje de conocimientos y la integración de conceptos al situarlo en el rol de experto. El uso de las TIC en los niveles educativos superiores sigue siendo una asignatura pendiente. A través de la experiencia aquí analizada, se abre la posibilidad de llevar esta herramienta a cursos de pregrado y con mayor número de estudiantesIntroduction: The aim of this work was to implement information and communication technologies (ICTs) at postgraduate level. In this particular case, USINA, a decision-making simulator designed by the Center for Innovation in Technology and Education (CITEP), of the University of Buenos Aires, was used. It allows working with stories, case studies and uses the "error" as a teaching method. Methods: 1) Design a sequence of screens to be mounted in the USINA platform to use it as a tool for the integration of concepts in two postgraduate courses: Protein Downstream Processing (DSP) and Applications, Synthesis and Analysis of Synthetic Peptides (ASAP). 2) Apply anonymous quiz to evaluate the efficiency of USINA. 3) Perform a class attendance to exchange opinions on the experience. Results: During both courses (DSP and ASAP) the experience was very successful. The students felt that the use of USINA enhanced learning and helped integrating concepts by situating them in the role of experts. Discussion: The use of ICTs in higher levels of education remains a pending issue. Through the experience here analyzed the possibility to bring this tool to undergraduate courses and more students is opene
Pretreatment of the cockroach cercal afferent/giant interneuron synapses with nicotinoids and neonicotinoids differently affects acetylcholine and nicotine-induced ganglionic depolarizations
We have recently demonstrated that neonicotinoid insecticides were able to act as agonists of postsynaptic nicotinic acetylcholine receptors (nAChRs) expressed at the synapse between the cercal nerve XI and the giant interneurons, in the sixth abdominal ganglion. In this work, we demonstrated that nicotinoids such as nornicotine acted as an agonist of nicotinic acetylcholine receptors expressed at cercal afferent/giant interneurons while cotinine was a poor agonist. Indeed, nornicotine induced a ganglionic depolarization which was blocked by the nicotinic antagonist mecamylamine. In addition, we found that pretreatment of the sixth abdominal ganglion with 1 and 10 muM nornicotine and cotinine had no significant effect on acetylcholine and nicotine-induced depolarization. But pretreatment with 1 and 10 muM acetamiprid and imidacloprid had a strong effect. 1 and 10 muM acetamiprid completely blocked acetylcholine-induced depolarization, whereas imidacloprid had a partial effect. The present work therefore suggests, in agreement with previous studies, that nornicotine and cotinine bind to distinct cockroach postsynaptic nAChRs, whereas acetamiprid and imidacloprid have competitive effects with acetylcholine and nicotine on ganglionic depolarization
Fomite-mediated transmission as a sufficient pathway: a comparative analysis across three viral pathogens
Abstract
Background
Fomite mediated transmission can be an important pathway causing significant disease transmission in number of settings such as schools, daycare centers, and long-term care facilities. The importance of these pathways relative to other transmission pathways such as direct person-person or airborne will depend on the characteristics of the particular pathogen and the venue in which transmission occurs. Here we analyze fomite mediated transmission through a comparative analysis across multiple pathogens and venues.
Methods
We developed and analyzed a compartmental model that explicitly accounts for fomite transmission by including pathogen transfer between hands and surfaces. We consider two sub-types of fomite-mediated transmission: direct fomite (e.g., shedding onto fomites) and hand-fomite (e.g., shedding onto hands and then contacting fomites). We use this model to examine three pathogens with distinct environmental characteristics (influenza, rhinovirus, and norovirus) in four venue types. To parameterize the model for each pathogen we conducted a thorough literature search.
Results
Based on parameter estimates from the literature the reproductive number (
R
0
) for the fomite route for rhinovirus and norovirus is greater than 1 in nearly all venues considered, suggesting that this route can sustain transmission. For influenza, on the other hand,
R
0
for the fomite route is smaller suggesting many conditions in which the pathway may not sustain transmission. Additionally, the direct fomite route is more relevant than the hand-fomite route for influenza and rhinovirus, compared to norovirus. The relative importance of the hand-fomite vs. direct fomite route for norovirus is strongly dependent on the fraction of pathogens initially shed to hands. Sensitivity analysis stresses the need for accurate measurements of environmental inactivation rates, transfer efficiencies, and pathogen shedding.
Conclusions
Fomite-mediated transmission is an important pathway for the three pathogens examined. The effectiveness of environmental interventions differs significantly both by pathogen and venue. While fomite-based interventions may be able to lower
R
0
for fomites below 1 and interrupt transmission, rhinovirus and norovirus are so infectious (
R
0
>
>
1
) that single environmental interventions are unlikely to interrupt fomite transmission for these pathogens.https://deepblue.lib.umich.edu/bitstream/2027.42/146145/1/12879_2018_Article_3425.pd
On the Afterglow of the X-ray Flash of 2003 July 23: Photometric evdence for an Off-Axis Gamma-Ray burst with an Associated Supernova
Peer reviewe
Family physicians' views on participating in prevention of major depression. The predictD-EVAL qualitative study
Background The predictD intervention, a multicomponent intervention delivered by family physicians (FPs), reduced the incidence of major depression by 21% versus the control group and was cost-effective. A qualitative methodology was proposed to identify the mechanisms of action of these complex interventions. Purpose To seek the opinions of these FPs on the potential successful components of the predictD intervention for the primary prevention of depression in primary care and to identify areas for improvement. Method Qualitative study with FPs who delivered the predictD intervention at 35 urban primary care centres in seven Spanish cities. Face-to-face semi-structured interviews adopting a phenomenological approach. The data was triangulated by three investigators using thematic analysis and respondent validation was carried out. Results Sixty-seven FPs were interviewed and they indicated strategies used to perform the predictD intervention, including specific communication skills such as empathy and the activation of patient resources. They perceived barriers such as lack of time and facilitators such as prior acquaintance with patients. FPs recognized the positive consequences of the intervention for FPs, patients and the doctor-patient relationship. They also identified strategies for future versions and implementations of the predictD intervention. Conclusions The FPs who carried out the predictD intervention identified factors potentially associated with successful prevention using this program and others that could be improved. Their opinions about the predictD intervention will enable development of a more effective and acceptable version and its implementation in different primary health care settings
Chapter 10 - Industry
This chapter provides an update to developments on mitigation in the industry sector since the IPCC (Intergovernmental Panel on Climate Change) Fourth Assessment Report (AR4) (IPCC, 2007), but has much wider coverage. Industrial activities create all the physical products (e.g., cars, agricultural equipment, fertilizers, textiles, etc.) whose use delivers the final services that satisfy current human needs. Compared to the industry chapter in AR4, this chapter analyzes industrial activities over the whole supply chain, from extraction of primary materials (e.g., ores) or recycling (of waste materials), through product manufacturing, to the demand for the products and their services. It includes a discussion of trends in activity and emissions, options for mitigation (technology, practices, and behavioural aspects), estimates of the mitigation potentials of some of these options and related costs, co-benefits, risks and barriers to their deployment, as well as industry-specific policy instruments. Findings of integrated models (long-term mitigation pathways) are also presented and discussed from the sector perspective. In addition, at the end of the chapter, the hierarchy in waste management and mitigation opportunities are synthesized, covering key waste-related issues that appear across all chapters in the Working Group III contribution to the IPCC Fifth Assessment Report (AR5)
Effects of temperature on survival, moulting, and expression of neuropeptide and mTOR signalling genes in juvenile Dungeness crab (Metacarcinus magister)
Mechanistic target of rapamymcin (mTOR) is a highly conserved protein kinase that controls cellular protein synthesis and energy homeostasis. We hypothesize that mTOR integrates intrinsic signals (moulting hormones) and extrinsic signals (thermal stress) to regulate moulting and growth in decapod crustaceans. The effects of temperature on survival, moulting and mRNA levels of mTOR signalling genes (Mm-Rheb, Mm-mTOR, Mm-AMPKα, Mm-S6K and Mm-AKT) and neuropeptides (Mm-CHH and Mm-MIH) were quantified in juvenile Metacarcinus magister. Crabs at different moult stages (12, 19 or 26 days postmoult) were transferred from ambient temperature (∼15°C) to temperatures between 5 and 30°C for up to 14 days. Survival was 97–100% from 5 to 20°C, but none survived at 25 or 30°C. Moult stage progression accelerated from 5 to 15°C, but did not accelerate further at 20°C. In eyestalk ganglia, Mm-Rheb, Mm-AMPKα and Mm-AKT mRNA levels decreased with increasing temperatures. Mm-MIH and Mm-CHH mRNA levels were lowest in the eyestalk ganglia of mid-premoult animals at 20°C. In the Y-organ, Mm-Rheb mRNA levels decreased with increasing temperature and increased during premoult, and were positively correlated with haemolymph ecdysteroid titre. In the heart, moult stage had no effect on mTOR signalling gene mRNA levels; only Mm-Rheb, Mm-S6K and Mm-mTOR mRNA levels were higher in intermoult animals at 10°C. These data suggest that temperature compensation of neuropeptide and mTOR signalling gene expression in the eyestalk ganglia and Y-organ contributes to regulate moulting in the 10 to 20°C range. The limited warm compensation in the heart may contribute to mortality at temperatures above 20°C
Longitudinal analysis of palatal volume in unilateral cleft lip and palate children
Cleft lip and/or palate are among the most frequent congenital craniofacial defects, which every year affect one in 500-700 newborn worldwide (1,2). The aim of this study was to analyze the effect of orthopaedic and surgical treatments on the palatal size and shape of patients with unilateral cleft lip and palate (UCLP). Ninetysix palatal casts from 32 neonatal patients, attending the Fundacion Clinica de Noel (Colombia) were analyzed through a stereophotogrammetric system. The analysis was carried out before (mean age 10.5 days, SD 4.8) and after (mean age 83.3 days, SD 6.6) orthopaedic treatment (performed with acrylic plates) and after cheiloplasty (mean age 317.1 days, SD 44.2). Volumes of the greater and the minor alveolar segments were evaluated through a new measurement protocol. Intra and inter operator repeatability was evaluated using paired Student\u2019s t test. In order to investigate differences between alveolar segments and time, volume measurements were compared with a repeated two-way analysis of variance (ANOVA). No significant differences between repetitions, both intra and inter operator, were found (p>0.05). Random errors explained 3.7% of the sample variance. On the other hand, significant differences in volume measurements were found both in alveolar segment and time (p<0.01). Before orthopaedic treatment, the smaller palatal segment had a mean volume of 0.52 cm3 (SD 0.23), and the greater of 0.9 cm3 (SD 0.40); after orthopaedic treatment, the mean volumes were 0.58 cm3 (SD 0.25), and 1.09 cm3 (SD 0.43). After surgery, mean values of 0.73 cm3 (SD 0.28) and 1.31 cm3 (SD 0.52) were measured. Results suggest that a three-dimensional stereophotogrammetric system is a repeatable and reliable method to evaluate palatal casts of patients with UCLP. Obtained data offer a preliminary quantitative information about the changes occurring in maxillary arches of UCLP patients after orthopaedic treatment and surgery. Further investigation is required to increase the frequency of evaluations and the number of patients
- …