Horizontal biosedimentary gradients across the Sado estuary,W. Portugal

The topography of the Sado estuary, the second largest of Portugal, comprises the outer estuary inside the entrance channel and the inner estuary, on the inward side of which begins the tidal mudflats. The outer estuary subtidal area covers approximately 70 km² and presents a series of longitudinal intertidal sandbanks, separating a northern and a southern channel. A benthic survey was undertaken in the outer estuary during June 1986, in which superficial sediments and macrofauna were sampled at 133 locations. The environmental variables measured in the superficial sediments were the temperature, the granulometric structure, the silt, sand and the gravel content, and the total organic matter content. The primary macrofauna biological variables studied were the species composition, abundance and biomass, calculated on wet, dry and ash-free dry weight. The granulometry and the organic content of superficial sediments agreed with the transient and the residual currents velocity field, simulated in a 2-D hydrodynamic model previously elaborated for the outer estuary. The northern channel superficial sediments showed higher silt and total organic matter content, while the model also suggested lower transient and residual velocities, water flow and shear stress in this channel. The distribution patterns of the subtidal macrofauna were separated into two main groups of species, one comprising taxa essentially settled near the estuarine mouth and the other inwards. Biological primary variables also showed consistent patterns, comparable to other Portuguese estuaries. The major subtidal benthic biotopes were obtained through classification analysis and related to the prevailing hydrophysical and sedimentary conditions in the outer estuary.     

Morphological and temporal variation in early embryogenesis contributes to species divergence in Malawi cichlid fishes

The cichlid fishes comprise the largest extant vertebrate family and are the quintessential example of rapid “explosive” adaptive radiations and phenotypic diversification. Despite low genetic divergence, East African cichlids harbor a spectacular intra- and interspecific morphological diversity, including the hyper-variable, neural crest (NC)-derived traits such as coloration and craniofacial skeleton. Although the genetic and developmental basis of these phenotypes has been investigated, understanding of when, and specifically how early, in ontogeny species-specific differences emerge, remains limited. Since adult traits often originate during embryonic development, the processes of embryogenesis could serve as a potential source of species-specific variation. Consequently, we designed a staging system by which we compare the features of embryogenesis between three Malawi cichlid species—Astatotilapia calliptera, Tropheops sp. ‘mauve’ and Rhamphochromis sp. “chilingali”—representing a wide spectrum of variation in pigmentation and craniofacial morphologies. Our results showed fundamental differences in multiple aspects of embryogenesis that could underlie interspecific divergence in adult adaptive traits. First, we identified variation in the somite number and signatures of temporal variation, or heterochrony, in the rates of somite formation. The heterochrony was also evident within and between species throughout ontogeny, up to the juvenile stages. Finally, the identified interspecific differences in the development of pigmentation and craniofacial cartilages, present at the earliest stages of their overt formation, provide compelling evidence that the species-specific trajectories begin divergence during early embryogenesis, potentially during somitogenesis and NC development. Altogether, our results expand our understanding of fundamental cichlid biology and provide new insights into the developmental origins of vertebrate morphological diversity.     

Chemical composition and larvicidal activity of essential oils of three Artemisia species

Aedes aegypti L. (Diptera: Culicidae) is a vector for serious diseases in tropical regions. This pest is mainly controlled by commercial larvicides but the application of such products has led to environmental problems. Essential oils (EO) have been consistently reported as molecules with insecticidal activity and can be used to produce more environmentally friendly larvicides in the control of A. aegypti. In this study, the larvicidal effect of essential oils (EO) from the leaves of three Artemisia species was evaluated against A. aegypti. The oils were obtained from steam distillation and their chemical composition was determined by gas chromatography–mass spectrometry. The EO of Artemisia camphorata was the most active in the screening bioassay and presented LC₅₀ and LC₉₅ of 64.95 and 74.18 μg ml⁻¹, respectively. In addition, we found that germacrene D-4-ol was the constituent responsible for the toxicity of this EO. Artemisia camphorata EO and its major constituent, germacrene D-4-ol, are promising for the development of natural larvicides against A. aegypti.     

Plenty of rooftops with few neighbours occupied by young breeding Yellow-legged Gulls (Larus michahellis): Does this occur at the expense of their health condition?

Gulls, as largely flexible opportunistic individuals, have been increasingly breeding in many cities around the world, but it is still unclear whether urban habitats are of equal or higher quality than traditional natural habitats or represent an ecological trap with immediate reproductive benefits but longer-term detrimental consequences to health. Here we present a study of breeding parameters (nest density, egg dimensions, clutch size, hatching success and adult body condition) and physiological parameters (erythrocyte sedimentation rate, heterophil/lymphocyte ratio, haemoglobin concentration and measurements of oxidative stress) as indicators of the general health condition of Yellow-legged Gull Larus michahellis adults and chicks from natural and urban colonies. Yellow-legged Gulls in the largest urban area (Porto) laid smaller eggs and clutches, showed a significantly lower occurrence of inflammatory processes in chicks, and showed a slower early chick growth than in the natural colony of Deserta. This suggests that urban gulls might be facing important trade-offs between the advantages of breeding in lower density urban colonies, with fewer intraspecific interactions and a lower disease transmission probability, and the disadvantages of having an anthropogenic diet usually lower in nutritional value.     

Selection of synthetic proteins to modulate the human frataxin function

Frataxin is a kinetic activator of the mitochondrial supercomplex for iron-sulfur cluster assembly. Low frataxin expression or a decrease in its functionality results in Friedreich's Ataxia (FRDA). With the aim of creating new molecular tools to study this metabolic pathway, and ultimately, to explore new therapeutic strategies, we have investigated the possibility of obtaining small proteins exhibiting a high affinity for frataxin. In this study, we applied the ribosome display approach, using human frataxin as the target. We focused on Affi_224, one of the proteins that we were able to select after five rounds of selection. We have studied the interaction between both proteins and discussed some applications of this specific molecular tutor, concerning the modulation of the supercomplex activity. Affi_224 and frataxin showed a K_D value in the nanomolar range, as judged by surface plasmon resonance analysis. Most likely, it binds to the frataxin acidic ridge, as suggested by the analysis of chemical shift perturbations (nuclear magnetic resonance) and computational simulations. Affi_224 was able to increase Cys NFS1 desulfurase activation exerted by the FRDA frataxin variant G130V. Importantly, Affi_224 interacts with frataxin in a human cellular model. Our results suggest quaternary addition may be a new tool to modulate frataxin function in vivo. Nevertheless, more functional experiments under physiological conditions should be carried out to evaluate Affi_224 effectiveness in FRDA cell models.     

Monocarbonyl Analogs of Curcumin with Potential to Treat Colorectal Cancer

Curcumin has a plethora of biological properties, making this compound potentially effective in the treatment of several diseases, including cancer. However, curcumin clinical use is compromised by its poor pharmacokinetics, being crucial to find novel analogs with better pharmacokinetic and pharmacological properties. Here, we aimed to evaluate the stability, bioavailability and pharmacokinetic profiles of monocarbonyl analogs of curcumin. A small library of monocarbonyl analogs of curcumin 1a–q was synthesized. Lipophilicity and stability in physiological conditions were both assessed by HPLC-UV, while two different methods assessed the electrophilic character of each compound monitored by NMR and by UV-spectroscopy. The potential therapeutic effect of the analogs 1a–q was evaluated in human colon carcinoma cells and toxicity in immortalized hepatocytes. Our results showed that the curcumin analog 1e is a promising agent against colorectal cancer, with improved stability and efficacy/safety profile.     

Casearia Essential Oil: An Updated Review on the Chemistry and Pharmacological Activities

Casearia species are found in the America, Africa, Asia, and Australia and present pharmacological activities, besides their traditional uses. Here, we reviewed the chemical composition, content, pharmacological activities, and toxicity of the essential oils (EOs) from Casearia species. The EO physical parameters and leaf botanical characteristics were also described. The bioactivities of the EOs from the leaves and their components include cytotoxicity, anti-inflammatory, antiulcer, antimicrobial, antidiabetic, antioxidant, antifungal, and antiviral activities. The main components associated with these activities are the α-zingiberene, (E)-caryophyllene, germacrene D, bicyclogermacrene, spathulenol, α-humulene, β-acoradiene, and δ-cadinene. Data on the toxicity of these EOs are scarce in the literature. Casearia sylvestris Sw. is the most studied species, presenting more significant pharmacological potential. The chemical variability of EOs components was also investigated for this species. Caseria EOs have relevant pharmacological potential and must be further investigated and exploited.     

Evaluation of Probiotic Properties of Novel Brazilian Lactiplantibacillus plantarum Strains

Probiotics and Antimicrobial Proteins - Beneficial effects of Lactiplantibacillus plantarum strains have been widely reported. Knowing that the effects of probiotic bacteria are strain-dependent,...