The nervous system of Bothriomolus balticus (Proseriata) —a contribution to the knowledge of the orthogon in the Plathelminthes

Summary The nervous system (NS) of Bothriomolus balticus (Proseriata) was studied by the immunocytochemical (ICC) method with antisera to RFamide, SALMFamide and serotonin and with the histochemical GAIF method. The use of the ICC technique provided a much more precise morphological account of the nervous system than had previously been possible. The obtained data are discussed in connection with the comparative morphology of the nerve cords of the Plathelminthes. A similar position does not grant direct correspondence between nerve cords in the taxon Seriata. Marginal cords had probably an independent origin in the Monocelididae and Otoplanidae. The ventral (main) cords of B. balticus seem to correspond to the lateral (main) cords of the Monocelididae. It can be hypothesized that both: (1) a shift of the main cords accompanied by formation of new cords from the plexus and fusion of other cords and (2) a redistribution of nerve processes and perikarya between the cords, take part in the evolution of cords in the Plathelminthes. The first hypothesis seems to explain the difference in the position of main cords in proseriates, though, the second hypothesis might dominate, for example, in the Neorhabdocoela and the Neodermata. The correctness of the evolutionary analysis of the nerve cords in plathelminths can only be provided by neurons or neuron groups marking these structures.     

On the terms used to refer to ‘natural’ forests: a response to Veen et al.

The importance of harmonizing the group of terms used to indicate ‘natural’ forests is reported in several studies. In a recent paper the term virgin forest is proposed as a unifying concept for forests which are not influenced by man in their development. In response to that paper my aim is to clarify the terms virgin and old-growth. My response focuses on two points: the term virgin forest is generally used to indicate forests that have not been influenced by people even in the distant past, therefore something different from what described by the authors; the definition drawn up for the proposed term substantially overlaps with the definition of old-growth forest resulting from a long history of studies on this theme. I think that the overlap between the two analyzed terms can ultimately only increase the existing confusion on this group of forest terms.     

The phylogenetic relationships of the shags and cormorants: can sequence data resolve a disagreement between behavior and morphology?

Taxonomic arrangements for the cormorants and shags (Phalacrocoracidae) had varied greatly until two quite similar arrangements, one based on behavior and the other on osteological characters, became the basis for current thought on the evolutionary relationships of these birds. The terms cormorant and shag, which had previously been haphazardly applied to members of the group, became the vernacular terms for the two major subdivisions within this family. The two taxonomies differ in places, however, with the behavioral taxonomy placing several species within the shags and the osteological taxonomy and phylogeny grouping those species (as the marine cormorants) and placing them within the cormorants. In an attempt to resolve the differences in the relationships hypothesized by behavior and morphology, we sequenced three mitochondrial genes (12S, ATPase 6, and ATPase 8). Initial equally weighted parsimony trees differed slightly from our two weighted parsimony trees, one of which was also our maximum-likelihood tree. Many of the branches within our trees were well supported, but some sections of the phylogeny proved difficult to resolve with confidence. Our sequence trees differ substantially from the morphological phylogeny and show that neither the shags nor the cormorants are monophyletic, but form an intermingled group. Some of the groups supported by both the behavioral and the morphological taxonomies (e.g., the cliff shags, Stictocarbo) appear to be polyphyletic. Conversely, the monophyly of the blue-eyed shags, a traditional group that the osteological analysis had found to be paraphyletic, was supported by the sequence data. Until more taxa are sampled and a fully robust phylogeny is obtained, a conservative approach accepting a single genus, Phalacrocorax, for the shags and cormorants is recommended.     

Sick people and ‘trolls’: A contribution to the understanding of the dynamics of physician explanatory models

This paper describes and interprets a case in which the mutual influences of countertransference and physician explanatory model (EM) are identified, as are their roles in negotiating the clinical relationship and in clinical decision-making (assessment, diagnosis, treatment, expectations of outcome). The author argues that physicians' EMs do not derive exclusively from the official and professionally ideal biomedical model, but are shaped by situational, historical, and subjective influences. Patient-typing (e.g., the widespread distinction between sick people and trolls), together with its associated emotions (e.g., empathy and disdain, respectively), pervades medical education and practice, and often supersedes the biomedical model. Physicians' subjective responses to patients can affect biomedical diagnosis. Failed empathy can lead to missed diagnosis. Finally, the case study illustrates the validity and vitality of the ethnographic approach in clinical teaching and supervision, both in eliciting physicians' own complex EMs, and in facilitating the process of reinterpretation as well.     

Systematic bias and the phylogeny of Coleoptera—A response to Cai et al. (2022) following the responses to Cai et al. (2020)

Systematic bias is one of the major phylogenetic issues arising over the last two decades. Using methods designed to reduce compositional and rate heterogeneity, hence systematic bias, Cai and co-workers (2022) (= CEA22) reanalyzed the DNA sequence dataset for Coleoptera of Zhang et al. (2018) (= ZEA). CEA22 suggest that their phylogenetic results and major evolutionary hypotheses about the Coleoptera should be favoured over other recently published studies. Here, we discuss the methodology of CEA22 with particular attention to how their perfunctory reanalysis of ZEA obfuscates rather than illuminates beetle phylogeny. Similar to published rebuttals of an earlier study of theirs, we specifically find that many of their claims are misleading, unsupported, or false. Critically, CEA22 fail to establish the stated premise for their reanalysis. They fail to demonstrate how composition or rate heterogeneity supposedly impacted the phylogeny estimate of ZEA, let alone the results of other recent studies. Moreover, despite their claim of comprehensive sampling of Coleoptera, their dataset is neither the most diverse with respect to species and higher taxa included, nor anywhere near the largest in terms of sequence data and sampled loci. Although CEA22 does contribute additional fossils for calibration, those seeking the best available estimate for Coleoptera phylogeny and evolution based on molecular data are advised to look elsewhere.     

The phreatic aquifer of the ‘Plana de Castellón’ (Spain):relationships between animal assemblages and groundwater pollution

An applied groundwater study of the Plana de Castellón was performed to investigate possible impacts of pollutants on ecological characteristics of the aquifer. The area is illustrative for a western mediterranean coastal plain, densely populated, industrialized, and with intensive agricultural land-use. During one year, six wells in a subsection of the plain were monitored, simultaneously sampled for zoological and physicochemical analysis. Heavy metals and pesticides were not (or at very low levels) detected in the wells. Low correlations were found between physicochemical and biological data, but there were indications that organic pollution affects the abundance of the fauna. A logarithmic relationship between abundance and COD/BOD₅-ratio is postulated. Salinization, an important threat to the groundwater of the area, was clearly reflected in the chemistry of one of the wells. Probably, this process has important consequences for abundance and diversity of the fauna.     

Getting to the guts of the matter: The status and potential of ‘omics’ research of parasitic protists of the human gastrointestinal system

Parasitic protists are a major cause of diarrhoeal illnesses in humans globally. Collectively, enteric pathogens exceed all other forms of infectious disease, in terms of their estimated global prevalence and socioeconomic impact. They have a disproportionately high impact on children in impoverished communities, leading to acute (diarrhoea, vomiting, dehydration and death) and chronic disease (malabsorption, malnutrition, physical and cognitive stunting and predisposition to chronic, non-communicable disease) consequences. However, historically, investment in research and disease control measures has been disproportionately poor, leading to their current classification as neglected pathogens. A sound understanding of their biology is essential in underpinning detection, treatment and control efforts. One major tool in rapidly improving our knowledge of these parasites is the use of biological systems, including ‘omic’ technologies. In recent years, these tools have shown significant success when applied to enteric protists. This review summarises much of this knowledge and highlights the significant remaining knowledge gaps. A major focus of the present review was to provide a perspective on a way forward to address these gaps using advanced biotechnologies.     

First evidence of mitochondrial lensing in two species of the “Typhloplanoida” (Plathelminthes,Rhabdocoela): phylogenetic implications

 Based on electron-microscopical observations the light-sensing organs of Proxenetes deltoides and Ptychopera westbladi, representatives of the ”Typhloplanoida” Trigonostominae, are described. The photoreceptors in both species belong to the type of rhabdomeric pigment cup ocelli. P. deltoides has a single pigment cell and three sensory cells. P. westbladi possesses eyes made up of a single pigmented cup cell and a single sensory cell. The dioptric apparatus in the eyes of P. deltoides is formed by three proliferations of the cup cell containing giant mitochondria. In P. westbladi, the elements focalizing incoming light also consist of modified mitochondria which are arranged in the section of the cup cell covering the eye cavity. With regard to the new findings, mitochondrial lensing is hypothesized as an autapomorphy of a monophylum encompassing distinct taxa or all members of the free-living Rhabdocoela; the Neodermata also belong to this monophylum. Accepted: 21 March 1996     

Separating ‘Inquiry Questions’ and ‘Techniques’ to Help Learners Move between the How and the Why of Biology Practical Work

School science practical activities have been criticised for exposing learners to a series of phenomena disconnected from the conceptual frameworks needed to understand them. Such activities are successful in the ‘domain of observables’ but not the ‘domain of ideas’. Few resources exist for classroom teachers wishing to improve the effectiveness of practical activities in the domain of ideas. This report describes an action research project to develop a scaffold for biology practical lessons. This scaffold separates inquiry questions and the techniques needed to address them, and thus combines two approaches to scaffolding in a single tool (‘problematising’ and ‘reducing the degrees of freedom’). Analysis of the speech of 16–17 year olds in the study class (n = 23) was used to assess their engagement in the domain of ideas. Following the scaffold’s introduction, the learners were found to speak more about relevant ideas and concepts during practical activities. When the scaffold was partially faded, the learners continued to demonstrate engagement with the domain of ideas. The approach reported here would seem to have much potential for supporting learning from ‘minds-on’ biology practical work in a variety of contexts.     

Physiology of the parasitic association between maize and witchweed (Striga hermonthica): is ABA involved?

Striga hermonthica (Del.) Benth. is an obligate hemiparasiticangiosperm which can cause severe losses of yield in cerealcrops in the semi-arid tropics. The effects of this parasiteon the growth and stomatal conductance of three varieties ofmaize (Zea mays L.) during the first 6 weeks of the associationhave been studied. From 24 d after planting (DAP), infectedplants were significantly shorter than uninfected controls.When the plants were harvested 45 DAP, infected plants had fewerfully expanded leaves, less leaf biomass and less pseudo-stembiomass than uninfected controls. However, the parasitized plantshad more root biomass and hence a higher root:shoot ratio thanuninfected controls. The stomatal conductance of infected hostswas severely inhibited by comparison with that in uninfectedplants. The possibility that abscisic acid (ABA) may be involved inthe regulation of the parasitic association was investigated.ABA concentrations in leaf tissue of maize (cv. Cargimontana)and S. hermonthica were determined by radioimmunoassay. Whilethere was a difference between cultivars in the extent of theresponse, the concentrations of ABA were significantly higherin infected maize plants than in the uninfected controls. InS. hermonthica, leaf tissue ABA concentration was found to bean order of magnitude higher than in the host leaf tissue. Detachedleaves of S. hermonthica which were dehydrated at room temperatureuntil they had lost 10–20% of their fresh weight containedthree times the ABA concentration of control leaves. This suggeststhat leaves of S. hermonthica can synthesize or re-mobilizeABA in response to water deficit. It is not yet known whetherthis contributes to the higher concentration in infected hosts,but the results suggest that ABA has a role in this parasiticassociation. Key words: Striga hermonthica, abscisic acid, growth, parasitic angiosperm, stomatal conductance     

Wolbachia (Rickettsiales) infections and bee (Apoidea) barcoding: a response to Gerth et al.

In a recent Perspective, Gerth et al. (2011) expressed concern over how Wolbachia (Wolbachia pipientis Hertig) infections may affect the success of DNA barcoding efforts in bees. The potential and realized effects of endosymbiont-induced selective sweeps on host mitochondrial DNA diversity have been noted repeatedly – and rightly so – in the literature for some years. However, we are equally concerned with other misconceptions, including (a) presuming that a positive Wolbachia test indicates a stable infection, (b) presuming that Wolbachia-infected hosts cannot be identified with a single-locus barcode, and (c) inferring specific Wolbachia–mtDNA interactions based only on incomplete genotyping of Wolbachia strains. We address these issues in the context of the Gerth et al. (2011) survey of Wolbachia prevalence among the German bee fauna. We also clarify some of the context-dependent strengths and limitations of DNA barcoding when it is used as a research tool by taxonomists and ecologists.     

Assessing the contribution of products to the United Nations’ Sustainable Development Goals: a methodological proposal

Purpose

The 17 Sustainable Development Goals (SDGs) and their 169 targets pose the most important framework for sustainable development worldwide. However, the contributions of products and companies to the SDGs using social and environmental life cycle assessment (S-LCA; E-LCA) have not been thoroughly addressed in the scientific literature. The purpose of this research is therefore to identify product-related targets, derive suitable indicators and develop a social life cycle impact assessment (S-LCIA) method.

Methods

To systematically select product-related targets, two questions are developed. The questions ask whether a product (a) has a direct impact on the achievement of the target or (b) if the companies along the life cycle that produce or offer the product have a direct influence on the achievement of the respective target. Suitable indicators are derived and adapted from generally accepted frameworks such as the Global Indicator Framework (GIF-SDG). To develop an S-LCIA method, the targets are translated into conditions beneficial or damaging to the achievement of the target to estimate the socio-economic impact of the product using a scale from +1 to ?1. In cases where the targets remain vague, a systematic five-step approach to derive a quantifiable target involving five steps is applied.

Results and discussion

The main contribution of this paper is to propose a coherent method to measure the contribution of products to the targets. All 17 SDGs and 61 of the 169 targets (36%) were evaluated as product-related. For 57% of the product-related targets, indicators from the GIF-SDGs could at least partly be used after slight adaptations, while for the remaining 43% of the product-related targets, indicators were taken from other frameworks or sources or had to be added. In total, 45 indicators have been identified to be suitable for assessing the potential contribution of products to the 61 targets. To illustrate the systematic five-step approach to quantitatively assess the contribution of products to the targets, five types of contribution functions are presented in detail.

Conclusions

The presented method allows companies to analyse their impact and that of their products on the targets both within their own company and in the supply chain. As especially the latter is increasingly demanded by supply chain laws in different countries such as France, the Netherlands or the UK, the method fills an important research gap. However, future research to examine the proposed approach, the derived indicators and the impact assessment method is strongly encouraged.