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1.
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.  相似文献   

2.
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.  相似文献   

3.
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.  相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
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.  相似文献   

7.
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.  相似文献   

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11.
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  相似文献   

12.
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.  相似文献   

13.
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.

  相似文献   

14.
The damage on the surface of a mole fossil humerus from the early Pleistocene site of Sima del Elefante (Atapuerca, Burgos, Spain) has been recently interpreted as bite marks of the extinct shrew Beremendia fissidens. The present work considers this attribution not evident, and it stresses some doubts on the feasibility of a shrew leaving bite marks on a bone using its incisors, as well as the physical and ethological inconsistencies that it would imply.  相似文献   

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Although phylogenetic studies are increasingly utilizing multi-locus datasets, a review of GenBank data for the Gastropoda indicates a strong bias towards a few short gene fragments (most commonly COI, LSU rRNA, and SSU rRNA). This is particularly the case for the Rissooidea, one of the largest and most taxonomically difficult gastropod superfamilies. Here we analyze fragments of these three genes from 90 species to determine whether they can well resolve higher relationships within this superfamily, whether structurally aligned sequence datasets increase phylogenetic signal, and whether the inclusion of highly variable regions introduces noise. We also used the resulting phylogenetic data in combination with morphological/anatomical evidence to re-evaluate the taxonomic status of ‘hydrobioid’ family-level groups.Our results indicate that all three of the alignment strategies that were used resulted in phylogenies having similar signal levels. However, there was a slight advantage to using structural alignment for inferring family-level relationships. Moreover, the set of ‘standard’ gastropod genes supported recognition of many previously recognized families and provides new insight into the systematics of several problematic groups. However, some family-group taxa were unresolved and the relationships among families were also poorly supported, suggesting a need for more extensive sampling and inclusion of additional genes.  相似文献   

17.
Strains T5K1 and AV446 isolated from apple cider vinegars during a submerged vinegar production in two separate vinegar facilities showed 94% 16S rRNA gene similarity to its closest neighbors Komagataeibacter maltaceti LMG 1529T and Gluconacetobacter entanii LTH 4560T. Further phylogenetic and phenotypic characterizations indicated that the isolates belonged to a novel species of the Komagataeibacter genus. Comparison based on 16S–23S rRNA gene ITS sequences and concatenated partial sequences of the housekeeping genes dnaK, groEL and rpoB, grouped both strains to a single phylogenetic cluster well separated from the other species of the Komagataeibacter genus. Average nucleotide identity of T5K1 and AV446 draft genome sequences compared to other Komagataeibacter type strains was below 94% and at the same time, in-silico DNA–DNA hybridization was below 70%. Both strains on the other hand showed approximately 98% (average nucleotide identity) and 87% (in silico DNA–DNA hybridization) similarity to each other. Strains T5K1 and AV446 can be differentiated from other Komagataeibacter type strains based on their ability to produce 2-keto-d-gluconic acid and at the same time inability to produce 5-keto-d-gluconic acid. Furthermore, strains of the new species do not grow on Asai medium supplemented with d-glucose or d-mannitol. The growth is also absent (T5K1) or weak (AV446) on Hoyer–Frateur medium supplemented with afore mentioned sugars. Both strains produce cellulose. In addition, draft genome analysis revealed that strains T5K1 and AV446 possess genes involved in the synthesis of acetan-like extracellular heteropolysaccharide. We propose the name Komagataeibacter pomaceti sp. nov. for the new species with LMG 30150T [= CCM 8723T = ZIM B1029T] as the type strain. Data collected in this study and in a previous study also revealed that Komagataeibacter kombuchae is a later heterotypic synonym of Komagataeibacter hansenii.  相似文献   

18.
Flavobacterium arborescens (Frankland and Frankland) Bergey et al. IFO 3750 (ATCC 4358) is a Gram-positive, coryneform bacterium and the only available reference strain of the species. The cell wall peptidoglycan of the organism possesses alanine, glycine, lysine, glutamic acid plus 3-hydroxyglutamic acid, and homoserine at a ratio of 1:3:1:1:1, and a possible peptidoglycan structure is the B1 type described by Schleifer and Kandler. Cell wall sugars are galactose, mannose, and 6-deoxy-l-talose, but not rhamnose. Major menaquinones are unsaturated MK-11 and MK-12. These findings and other taxonomic properties suggest that F. arborescens should be reclassified in the genusMicrobacterium (Orla-Jensen) Collins et al., asMicrobacterium arborescens comb. nov., nom. rev.  相似文献   

19.
X-ray mammography is the gold standard for diagnosis of lesions within the female breast. It is also recognized as the technique of choice for breast cancer screening in women over 50-years-old. Notwithstanding these important roles it has shortcomings in terms of limited sensitivity and specificity, especially in younger women. This paper describes the concept of a combined optical density and Doppler ultrasound method proposed initially as a supplement to mammography. A specially devised tissue compressor is also described. Results obtained using test phantoms and initial clinical studies are presented. Neovascularization at the advancing front of neoplastic lesions is believed to underlie detection of lesions by both telediaphanography and Doppler ultrasound.  相似文献   

20.
We tend to think that the difficulties in bioethics spring from the novel and alarming issues that arise due to discoveries in the new biosciences and biotechnologies. But many of the crucial difficulties in bioethics arise from the assumption we make about ethics. This paper offers a brief overview of bioethics, and relates ethical 'principlism' to 'ethical fundamentalism.' It then reviews some alternative approaches that have emerged during the second phase of bioethics and argues for a neo-Aristotelian approach. Misconceptions about ethical principles and ethical reasoning not only distort our views of the business of bioethics, but they also prevent us from facing up to the formidable problems posed by ethical pluralism in so-called liberal societies.  相似文献   

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