Biosensors and molecular imaging

The increase in the understanding of the physical and functional properties of the biological material, from the cellular level down to single molecules, owes its success to the development of suitable high-sensitivity platforms to image the biomaterial and analyze its response to specific stimuli. Imaging has indeed reached molecular capabilities, thanks to optical or magnetic markers [1], to the atomic force microscopy (AFM) in surface reconstruction [2], and is nearing success in three-dimensional (3-D) reconstruction thanks to X-ray holography [3].     

Population Structure of Osmunda regalis in Relation to Environment and Vegetation: An Example in the Mediterranean Area

The structure of 42 natural populations of the endangered fern Osmunda regalis was studied at the southern limit of its European distribution. The aims were to i) investigate the population structures and status of the species; ii) test which local habitat and population characteristics correlate with the different population structures in the Mediterranean area; iii) evaluate which habitat types are suitable to support viable populations. The structure of populations is determined by the attribution of different stages of development of the sporophyte. This study documented the life-stage structure of O. regalis using an original classification of life stages that may be applicable to other fern populations with similar morphology. Using statistical analyses we distinguished: i) dynamic populations, which are characterized by a large proportion of sporelings and vegetative adults and are associated with streams and nemoral species; ii) stable populations, with a higher proportion of generative adults, growing prevalently in habitats rich in hygrophilous grasses and shrubs, with lower tree cover; iii) senile populations, with a relatively higher proportion of senescent individuals and with marked rejuvenation dominated by vegetative adults, which are prevalently located in spring swamps. The proportion of senescent stage individuals is positively correlated with the mean geographic distance between populations. Spring swamps, with populations that provide a clear example of remnant dynamics, are the habitat with the most stable conditions for O. regalis in the Mediterranean area.     

A wavelet-based ECG delineation algorithm for 32-bit integer online processing

Background  

Since the first well-known electrocardiogram (ECG) delineator based on Wavelet Transform (WT) presented by Li et al. in 1995, a significant research effort has been devoted to the exploitation of this promising method. Its ability to reliably delineate the major waveform components (mono- or bi-phasic P wave, QRS, and mono- or bi-phasic T wave) would make it a suitable candidate for efficient online processing of ambulatory ECG signals. Unfortunately, previous implementations of this method adopt non-linear operators such as root mean square (RMS) or floating point algebra, which are computationally demanding.     

Recent outbreaks of downy mildew on grape ivy (Parthenocissus tricuspidata, Vitaceae) in Germany are caused by a new species of Plasmopara

Plasmopara viticola is one of the most destructive pathogens in grape production and was introduced from North America to Europe more than a century ago. The pathogen is thought to affect a broad range of hosts in the Vitaceae, including the genera Vitis and Parthenocissus. However, the latter has not previously been reported as a host in Germany. Here, it is shown on the basis of phylogenetic and morphological data that recent outbreaks of downy mildew on Parthenocissus tricuspidata in the Stuttgart area of Southern Germany are not caused by Plasmopara viticola, but by an undescribed species introduced here as Plasmopara muralis. The new species has rapidly spread in the Stuttgart area throughout the past 2 years and poses a potential threat to ornamental vines grown as wall cover should its spread not be controlled.     

Performance prediction of deep learning applications training in GPU as a service systems

Cluster Computing - Data analysts predict that the GPU as a service (GPUaaS) market will grow to support 3D models, animated video processing, gaming, and deep learning model training. The main...     

From dusk till dawn: camera traps reveal the diel patterns of flower feeding by hawkmoths

1. Diel rhythms of foraging activity by animal flower visitors can reflect niche partitioning and are considered an important component of selection on floral traits. However, it has been notoriously difficult to obtain objective information on the patterns of flower visitation by crepuscular and nocturnal insects. 2. Motion-activated cameras were used for field-based studies of hawkmoth foraging behaviour on six African plant species. 3. The results showed that short-tongued hawkmoth species forage mainly around dusk and then sporadically throughout the night, whereas long-tongued hawkmoth species feed consistently throughout the night, with a peak shortly before midnight. 4. These results provide the first quantitative estimates of diel patterns of interactions between multiple hawkmoth and plant species and, when combined with qualitative reports from other studies, suggest that differences in diel activity between the two main hawkmoth functional groups (short- and long-tongued) are consistent across the Old and New Worlds.     

Hydrogen peroxide: a metabolic by-product or a common mediator of ageing signals?

The reactive oxygen species that are generated by mitochondrial respiration, including hydrogen peroxide (H2O2), are potent inducers of oxidative damage and mediators of ageing. It is not clear, however, whether oxidative stress is the result of a genetic programme or the by-product of physiological processes. Recent findings demonstrate that a fraction of mitochondrial H2O2, produced by a specialized enzyme as a signalling molecule in the pathway of apoptosis, induces intracellular oxidative stress and accelerates ageing. We propose that genes that control H2O2 production are selected determinants of lifespan.     

Effect of positive charges in the structural interaction of crabrolin isoforms with lipopolysaccharide

Antimicrobial peptides (AMPs) appear as chemical compounds of increasing interest for their role in killing bacteria and, more recently, for their ability to bind endotoxin (lipopolysaccharide, LPS) that is released during bacterial infection and that may lead to septic shock. This dual role in the mechanism of action can further be enhanced in a synergistic way when two or more AMPs are combined together. Not all AMPs are able to bind LPS, suggesting that several modes of binding to the bacterial surface may exist. Here we analyze a natural AMP, crabrolin, and two mutated forms, one with increased positive charge (Crabrolin Plus) and the other with null charge (Crabrolin Minus), and compare their binding abilities to LPS. While Crabrolin WT as well Crabrolin Minus do not show binding to LPS, the mutated Crabrolin Plus exhibits binding and forms a well defined structure in the presence of LPS. The results strengthen the importance of positive charges for the binding to LPS and suggest the mutated form with increased positive charge as a promising candidate for antimicrobial and antiseptic activity.