Phylogenetic analysis of the genus <Emphasis Type="Italic">Argia</Emphasis> Rambur, 1842 (Odonata: Coenagrionidae), based on morphological characters of larvae and mitochondrial DNA sequences

The study of the evolutionary interrelationships among the species encompassed in the Neotropical genus Argia (Zygoptera: Coenagrionidae) has been neglected. The goal of this study is to infer the phylogenetic relationships among 36 species of Argia Rambur, 1842, using complementary data sets (i.e., larval morphology and mitochondrial DNA). The morphological data set comprises 76% of the larvae currently described for this genus and includes 97 morphological characters. From those, 47 characters have not been previously used in taxonomic studies involving dragonflies’ larvae. This is the first cladistic study based on larvae morphology for species within the suborder Zygoptera. Data partitions were analyzed individually, as well as total evidence, using parsimony and Bayesian inference as criteria for optimal-tree selection. The results support the monophyly of the North American species of Argia. This genus can be identified by the combination of eight synapomorphies, four of which are exclusively found in Argia. According to the optimal trees, the individual data sets (i.e., morphology and DNA sequences) have a high level of homoplasy, resulting in soft polytomies and low support for several nodes. The specific relationships of the terminal units differ between the phylogenies; nonetheless, there is historical congruence among them. Within Argia, five clades were consistently recovered. Most of those clades have been identified, at least in part, in previous phylogenetic and taxonomic studies. Indubitably, the morphological characters from larvae have historical signal useful for cladistic and taxonomic inference. Therefore, it should be a priority to pay more attention to this source of characters.     

The Burden of Provider-Initiated Preterm Birth and Associated Factors: Evidence from the Brazilian Multicenter Study on Preterm Birth (EMIP)

Background

About 15 million children are born under 37 weeks of gestation worldwide. Prematurity is the leading cause of neonatal deaths and short/long term morbidities, entailing consequences not only for the individual, but also their family, health agencies, facilities and all community. The provider-initiated preterm birth is currently one of the most important obstetric conditions related to preterm births, particularly in middle and high income countries, thus decreasing the need for therapeutic preterm birth is essential to reduce global prematurity. Therefore detailed knowledge on the factors associated with provider-initiated preterm birth is essential for the efforts to reduce preterm birth rates and its consequences. In this current analysis we aimed to assess the proportion of provider-initiated (pi-PTB) among preterm births in Brazil and identify associated factors.

Methods and Findings

This is an analysis of a multicenter cross-sectional study with a nested case-control component called Brazilian Multicenter Study on Preterm Birth (EMIP). EMIP was conducted in 20 referral obstetric hospitals located in the three most populated of the five Brazilian regions. We analysed data of women with pi-PTB, defined as childbirth occurring at less than 37 weeks, medically indicated for maternal/fetal compromise or both; and women with term birth, childbirth at or after 37 weeks. Maternal, sociodemographic, obstetric, prenatal care, delivery, and postnatal characteristics were assessed as possible factors associated with pi-PTB, compared to term births. The overall prevalence of preterm births was 12.3%. Of these, approximately one-third of cases were initiated by the provider. Hypertensive disorders, placental abruption, and diabetes were the main maternal conditions leading to pi-PTB. Caesarean section was the most common mode of delivery. Chronic hypertension (OR 7.47; 95%CI 4.02–13.88), preeclampsia/eclampsia/HELLP syndrome (OR 15.35; 6.57–35.88), multiple pregnancy (OR 12.49; 4.86–32.05), and chronic diabetes (OR 5.24; 2.68–10.25) were the most significant factors independently associated with pi-PTB.

Conclusions

pi-PTB is responsible for about one-third of all preterm births, requiring special attention. The decision-making process relative to the choice of provider-initiated birth is complex, and many factors should be elucidated to improve strategies for its prevention, including evidence-based guidelines on proper management of the corresponding clinical conditions.     

Sequential Thermochemical Hydrolysis of Corncobs and Enzymatic Saccharification of the Whole Slurry Followed by Fermentation of Solubilized Sugars to Ethanol with the Ethanologenic Strain <Emphasis Type="Italic">Escherichia coli</Emphasis> MS04

Interest in the use of corncobs as feedstock for bioethanol production is growing. This study assesses the feasibility of sequential thermochemical diluted sulfuric acid pretreatment of corncobs at moderate temperature to hydrolyze the hemicellulosic fraction, followed by enzymatic hydrolysis of the whole slurry, and fermentation of the obtained syrup. The total sugar concentration after enzymatic hydrolysis was 85.21 g/l, i.e., 86 % of the sugars were liberated from the polymeric fractions, together with a low amount of furfural (0.26 g/l) and 4.01 g/l of acetic acid. The syrups, which contained 36.3, 40.9, 4.47, and 1.84 g/l of xylose, glucose, arabinose, and mannose, respectively, were fermented (pH 7, 37 °C, 150 rpm) to ethanol with the metabolically engineered acetate-tolerant Escherichia coli strain MS04 under non-aerated conditions, producing 35 g/l of ethanol in 18 h (1.94 g_EtOH/l/h), i.e., a conversion yield greater than 80 % of the theoretical value based on total sugars was obtained. Hence, using the procedures developed in this study, 288 l of ethanol can be produced per metric ton of dry corncobs. Strain MS04 can ferment sugars in the presence of acetate, and the amount of furans generated during the sequential thermochemical and enzymatic hydrolysis was low; hence, the detoxification step was avoided. The residual salts, acetic acid, and solubilized lignin present in the syrup did not interfere with the production of ethanol by E. coli MS04 and the results show that this strain can metabolize mixtures of glucose and xylose simultaneously.     

Reconstructing past ecological networks: the reconfiguration of seed-dispersal interactions after megafaunal extinction

The late Quaternary megafaunal extinction impacted ecological communities worldwide, and affected key ecological processes such as seed dispersal. The traits of several species of large-seeded plants are thought to have evolved in response to interactions with extinct megafauna, but how these extinctions affected the organization of interactions in seed-dispersal systems is poorly understood. Here, we combined ecological and paleontological data and network analyses to investigate how the structure of a species-rich seed-dispersal network could have changed from the Pleistocene to the present and examine the possible consequences of such changes. Our results indicate that the seed-dispersal network was organized into modules across the different time periods but has been reconfigured in different ways over time. The episode of megafaunal extinction and the arrival of humans changed how seed dispersers were distributed among network modules. However, the recent introduction of livestock into the seed-dispersal system partially restored the original network organization by strengthening the modular configuration. Moreover, after megafaunal extinctions, introduced species and some smaller native mammals became key components for the structure of the seed-dispersal network. We hypothesize that such changes in network structure affected both animal and plant assemblages, potentially contributing to the shaping of modern ecological communities. The ongoing extinction of key large vertebrates will lead to a variety of context-dependent rearranged ecological networks, most certainly affecting ecological and evolutionary processes.     

Induction of focal epithelial hyperplasia in tongue of young bk6-E6/E7 HPV16 transgenic mice

Squamous cell carcinoma (SCC) of the oral cavity is one of the most common neoplasms in the world. During the past 2 decades, the role of high-risk human papilloma virus (HR-HPV) has been studied and the data supporting HPV as a one of the causative agents in the development and progression of a sub-set of head and neck squamous cell carcinomas (HNSCC) has accumulated. In order to investigate the role of HR-HPV oncogene expression in early epithelial alterations in vivo, we produced transgenic mice expressing HPV16 early region genes from the promoter of the bovine keratin 6 gene (Tg[bK6-E6/E7]). In this article, we demonstrate that E6/E7 transgene was abundantly expressed and cellular proliferation was increased in the middle tongue epithelia of transgenic mice, and that in the same region young (27 weeks old) Tg[bK6-E6/E7] mice spontaneously developed histological alterations, mainly focal epithelial hyperplasia (FEH).     

AFLPs Reveal Different Population Genetic Structure under Contrasting Environments in the Marine Snail Nucella lapillus L.

Dispersal has received growing attention in marine ecology, particularly since evidence obtained with up-to-date techniques challenged the traditional view. The dogwhelk Nucella lapillus L., a sedentary gastropod with direct development, is a good example: dispersal was traditionally assumed to be limited until studies with microsatellites disputed this idea. To shed some light on this controversy, the genetic structure of dogwhelk populations in northwest Spain was investigated with highly polymorphic AFLP markers giving special attention to the influence of hydrodynamic stress. In agreement with the expectations for a poor disperser, our results show a significant genetic structure at regional (<200 km) and areal scales (<15 km). However, the spatial genetic structure varied with wave-exposure in the present case study: IBD was evident under sheltered conditions but absent from the exposed area where genetic differentiation was stronger. Our results provide evidence that differences in wave-exposure can exert a detectable influence on the genetic structure of coastal organisms, even in species without a planktonic larva.     

Inhibition of hydrolytic enzyme activities and plant pathogen growth by invertase inhibitors

The invertase inhibitory protein isolated from Cyphomandra betacea Sendt and Solanum tuberosum inhibited the invertase activity from different species, genera and even plant family. Furthermore, proteinaceous inhibitors are not invertase specific; fungal, bacterial and higher plant enzymes including polygalacturonase, pectinase, pectin lyase, alpha-L-arabinofuranosidase and beta-glucosidase are also shown to be inhibited. Both inhibitors exhibited an in vitro antibacterial action against phytopathogenics strains of Xanthomonas campestris pvar vesicatoria CECT 792, Pseudomonas solanacearum CECT 125, Pseudomonas corrugata CECT 124, Pseudomonas syringae and Erwinia carotovora var carotovora.     

Crystallization of human plasma apo-retinol-binding protein

Crystals of three forms of human plasma apo-retinol-binding protein have been obtained using the procedure described for the holoprotein. The apoprotein was prepared by a novel method, which uses hydrophobic interaction and immobilized dye chromatography. The three forms were separated by fast protein liquid chromatography. All of the crystals are isomorphous and diffract to 2.5 Å resolution. These crystals will be useful for studies of the mechanism of binding of retinol to its carrier using X-ray diffraction techniques.