Metatranscriptomic analysis of larvae guts from field-collected and laboratory-reared Spodoptera frugiperda from the South American subtropical region

This is the first study to report a high-throughput approach integrating gene expression data from Spodoptera frugiperda guts and their associated metatranscriptomes. Our datasets provide information on the potential effects of environmental conditions on the expression profile of S. frugiperda larval guts, their associated metatranscriptome, and putative interactions between them.Fil: Mccarthy, Cristina Beryl. Universidad Nacional de La Plata. Centro Regional de Estudios Genómicos; Argentina. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cabrera, Natalia Alina. Universidad Nacional de La Plata. Centro Regional de Estudios Genómicos; ArgentinaFil: Virla, Eduardo Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucuman. Planta Piloto de Procesos Industriales Microbiologicos; Argentin

E-commerce adoption by European firms: a cross-country multilevel analysis

E-commerce has been recognized as a new form of commerce and a fresh way to identify, target, and retain customers. However, firms are often uncertain about investing in the online channel as there is no guarantee this will result in consumers engaging in online transactions. The studies on e-commerce adoption usually distinguish the following three dimensions: environmental, technological, and organizational (Rodríguez-Ardura & Meseguer-Artola, 2010; Zhu, Kraemer, & Xu, 2003). There are few purely virtual firms, and the traditional channel and multichannels continue to be the predominant types of retail channels used by firms (Zhu, Kraemer, & Xu, 2006; Li, Troutt, Brandyberry, & Wang, 2011). This is due to the many obstacles faced by firms adopting e-commerce; more specifically, they must overcome important technical, cognitive, socio-political, economic, legal, managerial, financial, and cultural challenges (Zhu, Kraemer, & Xu, 2003; Molla & Licker, 2005; Kshetri, 2007). Given the heterogeneity of contexts, the factors constraining the adoption of ecommerce are not the same across firms and countries (digital divide). In light of this, our focus will be on firms that have not yet taken the decision to adopt e-commerce due to a set of restraints, and on analyzing the differences within- and between-countries. The research question to be answered is: What are the inhibitors of e-commerce adoption in each EU country? An analysis is made of the overall attitudes towards e-commerce adoption in European firms, linking specific deterrents of e-commerce adoption (e.g., higher delivery costs or the nature of business) and the following retailer characteristics: size, type of product, retail channels, and respondent’s position in the firm and engagement in distance selling. To explore the overall attitude towards e-commerce adoption, we propose a conceptual model that combines a two-level structure: the individual level, which models the attitudes towards barriers that prevent adoption of the online channel within each country; and the country level that highlights the similarities (and differences) between EU countries. The statistical model combines factorial and regression components. This model was estimated by the maximum likelihood method using the MPlus 6.12. CFI is 0.989, TLI is 0.984, and RMSEA is 0.034; therefore, model fit is excellent (Hu & Bentler, 1999). Results show that aspects such as firm size and the job position of respondents do not influence the attitudes toward e-commerce adoption. Three covariates point to theiv aversion to e-commerce: telesales/call center retailing, direct retail channels, and selling non-food products.A adoção do comércio eletrónico tem vindo a ser reconhecida como uma nova forma de retalho, bem como uma forma inovadora de identificar, adquirir e reter clientes. As empresas têm tendência a enfrentar a incerteza no momento de decidir se irão ou não investir num canal na Internet, dado que são necessários recursos internos e a oferta de um serviço que faça os clientes quererem efetuar novas compras pela Internet. Os estudos nesta área focam-se principalmente em três dimensões: organizacional, tecnológica e contextual (Rodríguez-Ardura & Meseguer-Artola, 2010; Zhu, Kraemer, & Xu, 2003). São poucas as firmas que usam apenas canais virtuais para vender produtos/serviços/informações, sendo o retalho tradicional e o multicanal os canais mais utilizados pelos retalhistas (Zhu, Kraemer, & Xu, 2006; Li, Troutt, Brandyberry, & Wang, 2011). Em consequência, a adoção de comércio eletrónico enfrenta vários obstáculos, nomeadamente técnicos, cognitivos, sociopolíticos, económicos, legais, financiais, culturais e organizacionais (Zhu, Kraemer, & Xu, 2003; Molla & Licker, 2005; Kshetri, 2007). Tendo em consideração a heterogeneidade contextual, torna-se evidente que os fatores que dificultam a adoção do comércio eletrónico não são os mesmos em diferentes empresas ou países, o que origina um fosso digital a nível global. Assim sendo, o nosso foco ao longo desta dissertação será em empresas que ainda não adotaram o comércio eletrónico, considerando os diferentes inibidores no momento da tomada de decisão pelos gestores, bem como as diferenças que existem em cada países e entre países da União Europeia. A questão principal a ser respondida será: Quais os fatores que inibem a adoção do comércio eletrónico em cada país europeu? Considerando esta questão basilar, irão ser analisadas as atitudes das empresas europeias perante a adoção de comércio eletrónico, cruzando impedimentos específicos à adoção de e-comércio (como por exemplo, os elevados custos associados à entrega ou a natureza do negócio) com características específicas dos retalhistas (covariáveis): dimensão da empresa, tipo de produto transacionado, os canais de venda, a posição dos entrevistados na empresa, bem como se estão já ou não a exportar produtos ou serviços. Para explorar estas atitudes das empresas europeias perante a adoção de comércio eletrónico, foi proposto um modelo conceptual que combina uma estrutura em dois níveis: a nível individual, o modelo analisa as atitudes em cada país relacionada com as barreiras associadas à adoção do comércio eletrónico; e ao nível do país, onde são identificadas as diferenças e as semelhanças entre os paísesii europeus. O modelo estatístico combina uma componente fatorial e uma componente de regressão. Para além disso, foi estimado usando o método de máxima verosimilhança, recorrendo ao software MPlus 6.12. Como o CFI é 0,989, o TLI é 0,984 e o RMSEA é 0,034, podemos concluir que o ajuste do modelo é excelente (Hu & Bentler, 1999). Os resultados revelam que aspetos como a dimensão da empresa e a posição dos entrevistados não influenciam as atitudes em relação à adoção do comércio eletrónico. Contudo, são três as covariáveis identificadas como tendo aversão à adoção do ecomércio: as empresas que usam as televendas, as empresas que usam o call center como canal de vendas e os retalhistas que optam pelas vendas diretas (comércio tradicional), bem como as que vendem produtos não alimentares

A feasibility study on using inkjet technology, micropumps, and MEMs as fuel injectors for bipropellant rocket engines

Control over drop size distributions, injection rates, and geometrical distribution of fuel and oxidizer sprays in bi-propellant rocket engines has the potential to produce more efficient, more stable, less polluting rocket engines. This control also offers the potential of an engine that can be throttled, working efficiently over a wide range of output thrusts. Inkjet printing technologies, MEMS fuel atomizers, and piezoelectric injectors similar in concept to those used in diesel engines are considered for their potential to yield a new, more active injection scheme for a rocket engine. Inkjets are found to be unable to pump at sufficient pressures, and have possibly dangerous failure modes. Active injection is found to be feasible if high pressure drop along the injector plate are used. A conceptual design is presented and its basic behavior assessed

The robustness of poverty profiles reconsidered

Poverty measures and profiles are used increasingly to guide antipoverty policies in low-income countries. An essential element in these analyses is the specification of a poverty line. However, there are many different methods for setting poverty lines, and different methods can yield strikingly different results, with correspondingly different policy implications. Using recent household survey data from Mozambique, this paper explores the differences that occur using the most common poverty line methodologies, the Food Energy Intake (FEI) and the Cost of Basic Needs (CBN) methods, over different levels of geographic specificity. We find that regional and provincial rankings of Foster, Greer, and Thorbecke poverty indices are not robust to the method of poverty line determination, but that the characteristics of the poor are reasonably similar under all methods. The FEI poverty lines often yield counterintuitive results, whereas the family of CBN poverty lines was more robust. Food consumption patterns of the poor show a high degree of substitution among basic staples from one region to another, which is consistent with observed differences in relative food prices, indicating that CBN poverty lines that allow for regional variation in the food consumption bundle may be most appropriate in these settings.Poverty. ,Household surveys Mozambique. ,Food consumption Mathematical models. ,

Activation of effector immune cells promotes tumor stochastic extinction: A homotopy analysis approach

In this article we provide homotopy solutions of a cancer nonlinear model describing the dynamics of tumor cells in interaction with healthy and effector immune cells. We apply a semi-analytic technique for solving strongly nonlinear systems - the Step Homotopy Analysis Method (SHAM). This algorithm, based on a modification of the standard homotopy analysis method (HAM), allows to obtain a one-parameter family of explicit series solutions. By using the homotopy solutions, we first investigate the dynamical effect of the activation of the effector immune cells in the deterministic dynamics, showing that an increased activation makes the system to enter into chaotic dynamics via a period-doubling bifurcation scenario. Then, by adding demographic stochasticity into the homotopy solutions, we show, as a difference from the deterministic dynamics, that an increased activation of the immune cells facilitates cancer clearance involving tumor cells extinction and healthy cells persistence. Our results highlight the importance of therapies activating the effector immune cells at early stages of cancer progression

The EEG in acute ischaemic cerebrovascular disease

The electroencephalogram (EEG) is a neurophysiological technique with high temporal resolution and sensibility in the evaluation of brain function in real time. Besides this, EEG is the gold standard for the identification of epileptogenesis and ictogenesis biomarkers. Epileptic seizures and Cerebrovascular disease are two of the most frequent neurological disorders imposing important mutual challenges. Furthermore, in recent years, stroke care has evolved remarkably and, facing a new paradigm of acute standard of care (centred on multidisciplinary Stroke Units), epileptic seizures (as stroke complications) deserve to be rethought. The EEG is an essential neurophysiological exam in the evaluation of patients with epileptic seizures, status epilepticus and/or epilepsy, both for diagnosis and classification, as well as for the establishment of a correct treatment or outcome prediction. Furthermore, EEG has been previously used in cerebrovascular disease with different purposes. However, its clinical usefulness in the differential diagnosis of transient neurological symptoms, specifically in the differentiation between a transient ischaemic attack and some epileptic seizures, and also in the diagnosis or prediction of post-stroke seizures or in post-stroke prognosis prediction, remains uncertain. In this work, we aim to use the clinical model of acute ischaemic cerebrovascular disease to study the value of EEG in the differential diagnosis of transient neurological symptoms, in the diagnosis and prediction of post-stroke seizures and epilepsy, as well as to analyse if electroencephalographic abnormalities and/or epileptic seizures are independent predictors of an anterior circulation ischaemic stroke outcome. Furthermore, since the gold standard of acute stroke care (namely intravenous alteplase treatment) is associated with a reduction of mortality and incapacity of treated patients with possible consequences in post-stroke seizure frequency, but a pro-convulsive and an epileptogenic effect of alteplase has also been described, we aim to test the hypothesis that ischaemic stroke patients treated with intravenous alteplase have a different frequency of epileptic (clinic and/or electroencephalographic) manifestations compared to non-treated patients. Different research methodologies were used in this thesis. A systematic review and meta-analysis of observational studies was performed to evaluate both the frequency of post-stroke (ictal and interictal) epileptiform activity in the EEG, and the quality of studies about this subject. Furthermore, different types of observational studies (including clinical case report, case series and cohort studies) were completed to answer relevant clinical questions. We performed a prospective longitudinal study of possible transient ischaemic attacks (TIA) patients evaluated at a tertiary centre during 36 months, with 1-3 months follow-up and also of acute anterior circulation ischaemic stroke patients, consecutively admitted to a Stroke Unit over 24 months and followed-up for one year. In both studies, patients underwent standardized clinical, diagnostic and neurophysiological assessment. A short duration (≤60 minutes) video-EEG protocol with an extended montage including 64 EEG, two electrooculogram, one electrocardiogram and at least one electromyogram channel was established. Different electroencephalographic investigation technics including visual, back-average and quantitative analysis were used in the clinical workup of patients with possible and definite, transient and established, cerebrovascular disease as tools for the differential diagnosis and for brain functional assessment, concerning not only epileptic manifestations detection and prediction but also to search for predictors of ischaemic stroke functional outcome and vital prognosis. Although epileptic seizures were the most frequent defined final diagnosis (n=13; 16.3%) in our series of 80 patients with difficult-to-diagnose transient neurological symptoms, visual inspection of EEG supported this diagnosis only in 7.5% (n=6) of patients with possible TIA. Moreover, the majority (n=6; 53.8%) of patients with the final diagnosis of epileptic seizures did not have interictal epileptiform activity in an early EEG. Furthermore, early focal slow wave activity, the most frequent EEG abnormality in this patient’s series, did not distinguished between TIA and seizure patients. Our systematic review and random-effects meta-analysis showed that the pooled frequency of post-stroke ictal and interictal epileptiform activity was 7% (95%CI: 3%-12%) and 8% (95%CI: 4%-13%) respectively. Only 2 out of 17 included studies (11.7%) attained the maximum quality score. Moreover, no study exclusively enrolled ischaemic stroke patients, highlighting the need for higher quality studies in the evaluation of epileptiform activity frequency in this type of cerebrovascular disease. Furthermore, due to detection bias, it was not possible to correlate clinical and electrographic seizures. In our prospective cohort of 151 anterior circulation acute stroke patients, we identified different post-stroke, clinical and electroencephalographic, epileptic manifestations including 22.7% (5/22) of acute symptomatic seizures that were exclusively electrographic and therefore could not otherwise be recognised. Furthermore, only EEG back-average analysis allowed the diagnosis of cortical myoclonus during intravenous alteplase perfusion in one clinical vignette included in this work and the recognition of epilepsia partialis continua as a chronic complication of this stroke type in 1.7% of patients. This original work also showed that studied clinical and EEG epileptic manifestations were not significantly different between intravenous alteplase treated and non-treated patients. This thesis work established which abnormalities of an early EEG after acute stroke (background activity asymmetry and the presence of interictal epileptiform activity) are independent predictors of epilepsy in the year after (even when adjusted for clinical and imaging stroke severity). Besides this, early (within the first 72h) post-stroke EEG features, extracted from visual (background activity diffuse slowing and asymmetry) and quantitative (such as delta-theta to alpha-beta ratio and alfa relative power) analysis were recognized as independent predictors of death or functional dependency, at hospital discharge and at 12 months after stroke. Furthermore, outcome models that incorporate delta-theta to alpha-beta ratio or alpha relative power were better than models based exclusively on clinical and imaging-related ischaemic stroke severity at hospital admission. Additionally, post-stroke acute symptomatic seizures and epilepsy were independently associated to death and to an unfavourable outcome 1 year after an acute anterior circulation ischaemic stroke, respectively. Globally, these research projects have shown the value of EEG in the current paradigm of stroke patient’s care. Furthermore, they expand the knowledge both about the EEG role as a complementary neurophysiological tool in general Neurology and about different aspects of the diagnosis and outcome of two of the most prevalent neurological disorders, Cerebrovascular Diseases and Epilepsy, in particular. Beyond the value of specific results, with this work several other research questions about EEG and seizures in ischaemic cerebrovascular disease emerge. Therefore, new possibilities of future research, ideally multicentric, clinical or translational arise

Explaining coexistence of nitrogen fixing and non-fixing rhizobia in legume-rhizobia mutualism using mathematical modeling

In the mutualism established between legumes and soil bacteria known as rhizobia, bacteria from soil infect plants roots and reproduce inside root nodules where they fix atmospheric N2 for plant nutrition, receiving carbohydrates in exchange. Host-plant sanctions against non N2 fixing, cheating bacterial symbionts have been proposed to act in the legume-Rhizobium symbiosis, to preserve the mutualistic relationship. Sanctions include decreased rhizobial survival in nodules occupied by cheating rhizobia. Previously, a simple population model experimentally based showed that the coexistence of fixing and cheating rhizobia strains commonly found in field conditions is possible, and that the inclusion of sanctions leads to the extinction of cheating strains in soil. Here, we extend the previous model to include other factors that could complicate the sanction scenario, like horizontal transmission of symbiotic plasmids, turning non-nodulating strains into nodulating rhizobia, and competition between fixing and cheating strains for nodulation. In agreement with previous results, we show that plant populations persist even in the presence of cheating rhizobia without incorporating any sanction against the cheater populations in the model, under the realistic assumption that plants can at least get some amount of fixed N2 from the effectively mutualistic rhizobia occupying some nodules. Inclusion of plant sanctions leads to the unrealistic extinction of cheater strains in soil. Our results agree with increasing experimental evidence and theoretical work showing that mutualisms can persist in presence of cheating partners.Fil: Moyano, Gabriel Eduardo. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Marco, Diana Elizabeth. Universidad Nacional de Córdoba. Facultad de Cs.exactas Físicas y Naturales. Departamento de Matemáticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Knopoff, Damián Alejandro. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomia y Física. Sección Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; ArgentinaFil: Torres, German Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Modelado e Innovación Tecnológica. Universidad Nacional del Nordeste. Facultad de Ciencias Exactas Naturales y Agrimensura. Instituto de Modelado e Innovación Tecnológica; ArgentinaFil: Turner, Cristina Vilma. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentin

Improving Web user experience with document activity sparklines

The temporal dimension of the web has been mostly ignoredwhen designing user interfaces for both searching and document browsing.The dynamic nature of the web is invisible to the typical user despitethe fact that most web documents and sites change at a very rapid pace.In this paper we present and describe visual extensions applied to bothindividual web sites and search engines, that capture content activityover time. This idea is implemented with a prototype that processespublicly available web feeds to generate activity profiles and enhancesselected web sites using sparklines. These proposals bring a temporalperspective to the users browsing experience