Phylogenetic analyses of endoparasitic Acanthocephala based on mitochondrial genomes suggest secondary loss of sensory organs

The metazoan taxon Syndermata (Monogononta, Bdelloidea, Seisonidea, Acanthocephala) comprises species with vastly different lifestyles. The focus of this study is on the phylogeny within the syndermatan subtaxon Acanthocephala (thorny-headed worms, obligate endoparasites). In order to investigate the controversially discussed phylogenetic relationships of acanthocephalan subtaxa we have sequenced the mitochondrial (mt) genomes of Echinorhynchus truttae (Palaeacanthocephala), Paratenuisentis ambiguus (Eoacanthocephala), Macracanthorhynchus hirudinaceus (Archiacanthocephala), and Philodina citrina (Bdelloidea). In doing so, we present the largest molecular phylogenetic dataset so far for this question comprising all major subgroups of Acanthocephala. Alongside with publicly available mt genome data of four additional syndermatans as well as 18 other lophotrochozoan (spiralian) taxa and one outgroup representative, the derived protein-coding sequences were used for Maximum Likelihood as well as Bayesian phylogenetic analyses. We achieved entirely congruent results, whereupon monophyletic Archiacanthocephala represent the sister taxon of a clade comprising Eoacanthocephala and monophyletic Palaeacanthocephala (Echinorhynchida). This topology suggests the secondary loss of lateral sensory organs (sensory pores) within Palaeacanthocephala and is further in line with the emergence of apical sensory organs in the stem lineage of Archiacanthocephala.     

Characteristics of balance control in older persons who fall with injury – A prospective study

ObjectiveOlder adults who have recently fallen demonstrate increased postural sway compared with non-fallers. However, the differences in postural control between older adults who were seriously injured (SI) as a result of a fall, compared with those who fell but were not injured (NSI) and non-fallers (NFs), has not been investigated. The objective of the present study was to investigate the underlying postural control mechanisms related to injuries resulting from a fall.MethodsBoth traditional postural sway measures of foot center-of-pressure (CoP) displacements and fractal measures, the Stabilogram-Diffusion Analysis (SDA), were used to characterize the postural control. One hundred older adults aged 65–91 years were tested during narrow base upright stance in eyes closed condition; falls were monitored over a 1-year period.ResultsForty-nine older adults fell during the 1-year follow-up, 13 were seriously injured as a result of a fall (SI), 36 were not injured (NSI), and 49 were non-fallers (NFs); two passed away. The SDA showed significantly higher short-term diffusion coefficients and critical displacements in SI in the anterior–posterior direction compared with both NSI and NF. However, in the medio-lateral direction there were no statistically significant differences between groups. For the traditional measures of sway, the average anterior–posterior CoP range was also larger in SI individuals.ConclusionsThis work suggests that older fallers with a deterioration of anterior–posterior postural control may be at higher risk of serious injury following fall events.     

Behavioural response of the scyphozoan jellyfish Aurelia aurita (L.) upon contact with the predatory jellyfish Cyanea capillata (L.)

Underwater manipulative experiments were carried out in situ to investigate the sensibility of the jellyfish Amelia aurita (L.) to contact with the tentacles of Cyanea capillata (L), commonly known as a predator on A. aurita. Movements of individual medusae touched by tentacles of C. capillata and other objects were video‐recorded during SCUBA dives. The behavioural variable studied was change in swim pulse frequency. The results showed that A. aurita was highly susceptible to the tentacles of C. capillata and responded with an increased swim pulse frequency when touched at the umbrellar margin but not at the central exumbrella. Contact with other objects also induced a behavioural response in A. aurita.     

Cluster analysis of pressure pain threshold maps from the trapezius muscle

The aim of this study was to investigate and present a new mapping method to describe muscle pain sensitivity based on the assessment of pressure pain threshold (PPT) over the trapezius muscle. PPT data were recorded from 36 points in 20 healthy males using a standardised grid. Points were clustered using the K-means algorithm with a fixed initialisation procedure. The total number of clusters was determined on the basis of (1) R ² evaluation of the clustering outcome compared against a desired 95% reduction in variance criterion and (2) the number of empty clusters. A minimum of three clusters were found which fulfilled the criteria. The proposed method enables the identification of a relation between the muscle subdivisions and pressure pain sensitivity within the trapezius. Further, the cluster analysis will enable the study of differences in pain sensitivity distributions between patients and controls and quantify the effect of intervention (physical or pharmacological treatments).     

With or Without Sugar? (A)glycosylation of Therapeutic Antibodies

Antibodies and antibody-based drugs are currently the fastest-growing class of therapeutics. Over the last three decades, more than 30 therapeutic monoclonal antibodies and derivatives thereof have been approved for and successfully applied in diverse indication areas including cancer, organ transplants, autoimmune/inflammatory disorders, and cardiovascular disease. The isotype of choice for antibody therapeutics is human IgG, whose Fc region contains a ubiquitous asparagine residue (N₂₉₇) that acts as an acceptor site for N-linked glycans. The nature of these glycans can decisively influence the therapeutic performance of a recombinant antibody, and their absence or modification can lead to the loss of Fc effector functions, greater immunogenicity, and unfavorable pharmacokinetic profiles. However, recent studies have shown that aglycosylated antibodies can be genetically engineered to display novel or enhanced effector functions and that favorable pharmacokinetic properties can be preserved. Furthermore, the ability to produce aglycosylated antibodies in lower eukaryotes and bacteria offers the potential to broaden and simplify the production platforms and avoid the problem of antibody heterogeneity, which occurs when mammalian cells are used for production. In this review, we discuss the importance of Fc glycosylation focusing on the use of aglycosylated and glyco-engineered antibodies as therapeutic proteins.     

eScience and the need for data standards in the life sciences: in pursuit of objectivity rather than truth

Referring to European history of natural sciences as an example, I discuss the relation between development of standards and the emergence of new epistemic virtues. I distinguish standards relating to scientific argumentation from standards relating to data production. The former are based on truth-seeking epistemic virtues and use criteria of logical coherence and empirical grounding. They are important for the justification of an explanatory hypothesis. Data and metadata standards, on the other hand, concern the data record itself and all steps and actions taken during data production and are based on virtues of objectivity. In the second part I focus on data and metadata standards and argue that, in order to meet the requirements of eScience, the specification of the currently popular minimum information checklists should be complemented to cover four aspects: (i) content standards, which increase reproducibility and operational transparency of data production, (ii) concept standards, which increase the semantic transparency of the terms used in data records, (iii) nomenclatural standards, which provide stable and unambiguous links between the terms used and their underlying definitions or their real referents, and (iv) format standards, which increase compatibility and computer-parsability of data records. I discuss the role of scientific terminology for standardizing data and the need for using semantically standardized and formalized data-reporting languages in the form of controlled vocabularies and ontologies for establishing content standards for data in the life sciences. Finally I comment on the necessity of community participation in the development and application of standards and in making data openly available.     

Effects of ocean acidification on growth and physiology of Ulva lactuca (Chlorophyta) in a rockpool‐scenario

Rising atmospheric CO₂‐concentrations will have severe consequences for a variety of biological processes. We investigated the responses of the green alga Ulva lactuca (Linnaeus) to rising CO₂‐concentrations in a rockpool scenario. U. lactuca was cultured under aeration with air containing either preindustrial pCO₂ (280 μatm) or the pCO₂ predicted by the end of the 21st century (700 μatm) for 31 days. We addressed the following question: Will elevated CO₂‐concentrations affect photosynthesis (net photosynthesis, maximum relative electron transport rate (rETR(max)), maximum quantum yield (Fv/Fm), pigment composition) and growth of U. lactuca in rockpools with limited water exchange? Two phases of the experiment were distinguished: In the initial phase (day 1–4) the Seawater Carbonate System (SWCS) of the culture medium could be adjusted to the selected atmospheric pCO₂ condition by continuous aeration with target pCO₂ values. In the second phase (day 4–31) the SWCS was largely determined by the metabolism of the growing U. lactuca biomass. In the initial phase, Fv/Fm and rETR(max) were only slightly elevated at high CO₂‐concentrations, whereas growth was significantly enhanced. After 31 days the Chl a content of the thalli was significantly lower under future conditions and the photosynthesis of thalli grown under preindustrial conditions was not dependent on external carbonic anhydrase. Biomass increased significantly at high CO₂‐concentrations. At low CO₂‐concentrations most adult thalli disintegrated between day 14 and 21, whereas at high CO₂‐concentrations most thalli remained integer until day 31. Thallus disintegration at low CO₂‐concentrations was mirrored by a drastic decline in seawater dissolved inorganic carbon and HCO₃^?. Accordingly, the SWCS differed significantly between the treatments. Our results indicated a slight enhancement of photosynthetic performance and significantly elevated growth of U. lactuca at future CO₂‐concentrations. The accelerated thallus disintegration at high CO₂‐concentrations under conditions of limited water exchange indicates additional CO₂ effects on the life cycle of U. lactuca when living in rockpools.