Taxonomical Criteria Research Articles

Magnitude of terminological bias in international health services research: a disambiguation analysis in mental health.

Health services research (HSR) is affected by a widespread problem related to service terminology including non-commensurability (using different units of analysis for comparisons) and terminological unclarity due to ambiguity and vagueness of terms. The aim of this study was to identify the magnitude of the terminological bias in health and social services research and health economics by applying an international classification system. This study, that was part of the PECUNIA project, followed an ontoterminology approach (disambiguation of technical and scientific terms using a taxonomy and a glossary of terms). A listing of 56 types of health and social services relevant for mental health was compiled from a systematic review of the literature and feedback provided by 29 experts in six European countries. The disambiguation of terms was performed using an ontology-based classification of services (Description and Evaluation of Services and DirectoriEs - DESDE), and its glossary of terms. The analysis focused on the commensurability and the clarity of definitions according to the reference classification system. Interrater reliability was analysed using κ. The disambiguation revealed that only 13 terms (23%) of the 56 services selected were accurate. Six terms (11%) were confusing as they did not correspond to services as defined in the reference classification system (non-commensurability bias), 27 (48%) did not include a clear definition of the target population for which the service was intended, and the definition of types of services was unclear in 59% of the terms: 15 were ambiguous and 11 vague. The κ analyses were significant for agreements in unit of analysis and assignment of DESDE codes and very high in definition of target population. Service terminology is a source of systematic bias in health service research, and certainly in mental healthcare. The magnitude of the problem is substantial. This finding has major implications for the international comparability of resource use in health economics, quality and equality research. The approach presented in this paper contributes to minimise differentiation between services by taking into account key features such as target population, care setting, main activities and type and number of professionals among others. This approach also contributes to support financial incentives for effective health promotion and disease prevention. A detailed analysis of services in terms of cost measurement for economic evaluations reveals the necessity and usefulness of defining services using a coding system and taxonomical criteria rather than by 'text-based descriptions'.

Anisakis and Hysterothylacium species in Mediterranean and North-East Atlantic fishes commonly consumed in Spain: Epidemiological, molecular and morphometric discriminant analysis

The consumption of raw fish parasitized with larval ascaridoid nematodes of the family Anisakidae can cause anisakiasis, provoking gastrointestinal and/or allergic symptomatology. The main causative agents in the Anisakis genus are the sibling species Anisakis simplex sensu stricto (s.s.) and A. pegreffii of the A. simplex sensu lato (s.l.) complex. Larvae of A. simplex (s.l.) are frequently detected in fish commonly consumed in Spain, as are larvae of the genus Hysterothylacium of the family Raphidascarididae, associated with allergic reactions but not considered pathogenic. Reported here are the results of an epidemiological survey of ascaridoid larvae in three commonly consumed fish species in Spain, horse mackerel (Trachurus trachurus) (n = 52), blue whiting (Micromesistius poutassou) (n = 93) and anchovy (Engraulis encrasicolus) (n = 69), caught in the North-Eastern Atlantic, West Mediterranean and Adriatic Sea. The larvae found in the dissected fish were identified in the following order of abundance: A. simplex (s.l.) (n = 2003), Hysterothylacium aduncum (n = 422), H. fabri (n = 180) and A. physeteris (n = 15). Binomial regression analysis showed a correlation between A. simplex (s.l.) and Hysterothylacium larvae abundance and the host geographical location, the North-Eastern Atlantic being the area with the highest parasitation. Fish length and weight and Fulton's condition factor were correlated with A. simplex (s.l.) abundance only in horse mackerel. There was a significant presence of A. simplex (s.l.) and H. aduncum larvae in the musculature of North-Eastern Atlantic blue whiting, the most parasitized part being the anteroventral region, followed equally by the anterodorsal and central sections. The ITS rDNA of larvae of the sibling species A. simplex (s.s.) and A. pegreffii was identified by PCR-RFLP, and a binary logistic regression model was developed to study their morphometric differentiation. Anisakis simplex (s.s.) was detected in the North-Eastern Atlantic and A. pegreffii in all the areas studied. The morphometric analysis discriminated between the two species at the third and fourth larval stages (L3 and L4), the latter obtained by in vitro culture in RPMI-1640 medium. Two discriminant functions were obtained for the L3 and L4 larvae, the ventricle being a key parameter for specific differentiation in both stages, providing taxonomical criteria that could be used besides molecular identification. The present study reveals differences in the parasitation of the studied fish, including the distribution of larvae in the musculature, related to the host species and its geographical origin.

A new insight into the Stygofauna Mundi: assembling a global dataset for aquatic fauna in subterranean environments

The potential of subterranean environments as models to address major evolutionary and ecological questions has been highlighted in the literature. They represent partially isolated, discrete units offering several replicates of the same evolutionary processes. Species occurrence data of these environments is abundant, although sparse in the literature or gathered in databases established according to regional, taxonomical, or ecological criteria. We here present a newly assembled dataset consisting of records of aquatic animals in all types of caves or wells from all over the world. Literature sources were gathered from Google Scholar by independently searching for each metazoan phylum/arthropod order, as well as the key words “cave”, “groundwater”, “well”, or “stygobite”, in English, Galician, Spanish, Portuguese, Catalonian, French, Italian, Hungarian, Greek, German, Polish, Russian, and Serbo-Croatian. The relevance of each source was confirmed after checking the title and the abstract. For each selected source, we examined its reference list in order to identify studies that were not published in journals indexed in the databases we searched. From the 6852 selected references, we manually extracted all records that concerned either occurrence of a species in a given geographical area or occurrence of any taxon in a particular cave or well. occurrence of a species in a given geographical area or occurrence of any taxon in a particular cave or well. Records were classified as primary or secondary, depending on whether they provided new information or referred to already publish records, allowing us to identify redundant information in posterior analyses. Information for each access point was organized in as a gazetteer, including synonym names, geographical, ecological, and geological information. Following this strategy, we have obtained 48,800 records (32,769, primary) from 1957 references checked so far. Most records are amongst fish and crustaceans. In contrast, few data exist for other groups that are comparatively diverse outside caves, such as Nematoda. Relevant information will be included in World Register of Marine Cave Species (Fig. 1).

Production of hemolysin BL by Bacillus cereus group isolates of dairy origin is associated with whole-genome phylogenetic clade.

BackgroundBacillus cereus group isolates that produce diarrheal or emetic toxins are frequently isolated from raw milk and, in spore form, can survive pasteurization. Several species within the B. cereus group are closely related and cannot be reliably differentiated by established taxonomical criteria. While B. cereus is traditionally recognized as the principal causative agent of foodborne disease in this group, there is a need to better understand the distribution and expression of different toxin and virulence genes among B. cereus group food isolates to facilitate reliable characterization that allows for assessment of the likelihood of a given isolate to cause a foodborne disease.ResultsWe performed whole genome sequencing of 22 B. cereus group dairy isolates, which represented considerable genetic diversity not covered by other isolates characterized to date. Maximum likelihood analysis of these genomes along with 47 reference genomes representing eight validly published species revealed nine phylogenetic clades. Three of these clades were represented by a single species (B. toyonensis –clade V, B. weihenstephanensis – clade VI, B. cytotoxicus - VII), one by two dairy-associated isolates (clade II; representing a putative new species), one by two species (B. mycoides, B. pseudomycoides – clade I) and four by three species (B. cereus, B. thuringiensis, B. anthracis – clades III-a, b, c and IV). Homologues of genes encoding a principal diarrheal enterotoxin (hemolysin BL) were distributed across all, except the B. cytotoxicus clade. Using a lateral flow immunoassay, hemolysin BL was detected in 13 out of 18 isolates that carried hblACD genes. Isolates from clade III-c (which included B. cereus and B. thuringiensis) consistently did not carry hblACD and did not produce hemolysin BL. Isolates from clade IV (B. cereus, B. thuringiensis) consistently carried hblACD and produced hemolysin BL. Compared to others, clade IV was significantly (p = 0.0001) more likely to produce this toxin. Isolates from clade VI (B. weihenstephanensis) carried hblACD homologues, but did not produce hemolysin BL, possibly due to amino acid substitutions in different toxin-encoding genes.ConclusionsOur results demonstrate that production of diarrheal enterotoxin hemolysin BL is neither inclusive nor exclusive to B. cereus sensu stricto, and that phylogenetic classification of isolates may be better than taxonomic identification for assessment of B. cereus group isolates risk for causing a diarrheal foodborne disease.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-2883-z) contains supplementary material, which is available to authorized users.

Screening of filamentous fungi for lipase production: Hypocrea pseudokoningii a new producer with a high biotechnological potential

Filamentous fungi isolated from soil samples were screened for extracellular lipase production. The best producer was Hypocrea pseudokoningii identified by taxonomical criteria, and by rDNA sequencing of the variable internal transcribed spacers (ITS I and II) and the intervening 5.8S gene. The fungus was grown in a complex medium supplemented with 1% Tween 80 and 0.2% yeast extract, for 4 days. The optimum pH for extracellular and intracellular lipases was 7.0 and 8.0, respectively. Both enzymes exhibited maximum activity at 40°C. Extracellular and intracellular lipase activities were highly stable in the pH range 3.0–8.0 at room temperature. The intracellular lipase was thermostable up to 60°C, for 15 min and the extracellular, for 107 min, at the same temperature. The intracellular lipase was stimulated by silver ions. Extracellular lipase was stable in organic solvents, such as DMSO, alcohols, acetone, and acetonitrile, for 24 hours. Lipase activity increased around 80% when detergents were added to the enzymatic assay, such as Tween 80, Triton X-100, and SDS.

APHID-INDUCED GALLS ON PISTACIA IN THE NATURAL MEDITERRANEAN FOREST OF ISRAEL: WHICH, WHERE, AND HOW MANY?

ABSTRACT Fifteen species of aphids belonging to the subfamily Fordinae (Pemphigidae, Homoptera) induce galls on wild Pistacia (Anacardiaceae) trees in Israel. In this paper I provide a summary of research on the distribution and abundance of the Fordinae in Israel, and indicate the principal ecological factors that may affect their geographical and genetical differentiation. The distribution of the Fordinae galls is primarily restricted by the ranges of their host trees, P. palaestina (8 galling species), P. atlantica (6), and P. lentiscus (1). Within these ranges, abundance of each galling species on individual trees depends on the location of the secondary host plants, on the ability of aphid spring migrants to recognize their primary host, and perhaps on genetical properties of the individual tree. Limited migratory ability of the aphids may result in genetic differentiation of geographical populations considered conspecific by morphological (taxonomical) criteria.

The Pleistocene Glyptodontidae Gray, 1869 (Xenarthra: Cingulata) of Colombia and some considerations about the South American Glyptodontinae

Until recently, one well-characterized Pleistocene genus of the subfamily Glyptodontinae (Glyptodon ca. 1.08-0.0011 My) was recognized in South America. In recent times, some authors have demonstrated, through the re-analysis of material originally classified as Glyptodon Owen and Hoplophorus Lund, the presence of a second species belonging to the North American glyptodontine Glyptotherium Osborn (ca. 58-12 ky BP), currently known from in Venezuela and Brazil. This situation implies the need for a new study, with modern taxonomical criteria, of those materials belonging to the Glyptodontinae, particularly in those territories where the knowledge of these taxa is scarce. Presented here is a new analysis of the Pleistocene Glyptodontidae from Colombia, including some taxonomic and paleobiogeographic remarks. The results show that the only reported Glyptodontidae specimens in Colombia belong to Glyptodon sp. In turn, the evidence suggests that only one single species of Glyptotherium is present in South America, currently assigned to Glyptotherium cf. Gl. cylindricum. However, a more accurate analysis is necessary to confirm or refute this taxonomic identification. To date, Glyptotherium present has been found only in an area parallel to the Caribbean Sea and the Atlantic Ocean (northern Venezuela and eastern Brazil), up to 20°S, and is always linked to lowlands. This geographic distribution agrees with the proposition of an eastern corridor during the Great American Biotic Interchange. Below this latitude, the only recorded glyptodontine corresponds to Glyptodon, which is also recorded in a strip parallel to the Cordillera de Los Andes reaching Colombia and Venezuela. Taking into account this distribution, the presence of this genus in Central America cannot be discarded.

Genetic Diversity in Old Portuguese Durum Wheat Cultivars Assessed by Retrotransposon-Based Markers

Retrotransposon-based markers, such as the inter-retrotransposon-amplified polymorphism (IRAP) and the retrotransposon microsatellite-amplified polymorphism (REMAP) are highly informative, multilocus, and reveal insertional polymorphisms among plant individuals. These markers have been used for evolutionary studies, genetic diversity assessment, DNA fingerprinting, genetic mapping linkage, and for the detection of genetic rearrangements induced by polyploidization. In this study, we used IRAP and REMAP markers to assess the genetic diversity among 51 old Portuguese durum wheat cultivars belonging to 27 botanical varieties and to define their genetic relationships. Five IRAP and four REMAP primer combinations were used. IRAP markers revealed 66.3% of polymorphism and an average of 18.4 bands per primer combination which ranged in size from 450 to 3,100 bp. The REMAP technique allowed the detection of 86.36% of inter-cultivar polymorphism and an average of 11 bands per primer combination. The molecular weight of the REMAP bands ranged from 250 to 2,750 bp. The durum wheat cultivars analyzed here belong to 27 botanical varieties of the subspecies Triticum turgidum subsp. turgidum L. [syn. T. turgidum] and Triticum turgidum L. subsp. durum [syn. T. durum] (Desf.) Husn.. Our results showed that the genetic variability assessed by both the IRAP and REMAP markers did not allow the clustering of the durum wheat cultivars according to their taxonomical criteria (subspecies or botanical variety) or homonymy. Nonetheless, these markers were useful for the assessment of genetic diversity at the individual level, for the definition of genetic relationships among cultivars, and for estimation of the genetic structure of the Old collection under analysis. The achieved data could be valuable for future experiments of DNA fingerprinting, genetic improvement, and germplasm conservation in wheat.

The oogonial aperture of Oedogonium decipiens var. decipiens (Oedogoniales, Chlorophyta) and its systematic significance

According to traditional taxonomical criteria, the fertilization aperture in the genus Oedogonium has been classified into pore or circumcision type. To contribute with information useful to clarify the systematics of the Oedogoniales, we have studied the oogonial aperture in O. decipiens var. decipiens showing a circumcision in median position. The aperture mechanism and associated structures (line of weakness and thin layer) are similar to those previously described in O. cardiacum. The type and position of the aperture in mature oogonia was also studied in other seven Oedogonium species. In all the analyzed species, the fertilization aperture occurs along the line of weakness, but they would differ only in the opening degree of this line. Therefore, the types of oogonial aperture would not be so different as to discriminate groups of species belonging to the genus Oedogonium, in agreement with a previous molecular phylogenetic study of this group of algae.

Oral viral infections of adults

The field of virology has advanced greatly over the past two decades, mainly because of the introduction of sophisticated molecular tools, such as monoclonal antibodies, polymerase chain reaction (PCR)-based amplification, DNA sequencing, DNA and protein microarray chip assays, and rapid diagnostic tests. These technologies have been the driving force in the identification of viral bodies, proteins and nucleic acids in body fluids and tissue samples, and in determining the host response to viral infections. The 5th (2007) edition of Fields Virology provides an indepth description of viral methodology and medical virology, and is an important source of reference for this review (118). Viruses replicate only when present within eukaryotic (animals, plants, protists and fungi) or prokaryotic (bacteria and archaea) cells, not on their own. The extracellular virion particle ranges in size from 20 to 300 nm and consists of either DNA or RNA contained within a protective protein capsid. Some viruses have an additional envelope comprising a lipid bilayer derived from the outer cellular membrane, the internal nuclear membrane, or the endoplasmic reticulum membrane of the infected cell. Taxonomically, viruses are classified according to the presence of DNA or RNA, single-stranded or double-stranded nucleic acid, and an enveloped or nonenveloped nucleocapsid. Additional taxonomical criteria include mode of replication, type of host, capsid shape, immunological properties and disease association. The host recognizes and reacts to the infecting virus by innate and adaptive immune responses. Important cells of the innate immune system include macrophages, dendritic cells and natural killer cells. Viruses activate inflammatory cell types to release antiviral cytokines and cytotoxic agents, and to induce lymphocyte-mediated adaptive immunity. A significant cytokine release is stimulated through activation of the tumor necrosis factor-a receptor ⁄ nuclear factor-jB ⁄ extracellular signal-regulated kinase pathway (49). Virally derived proteins, which are presented by major histocompatibility complex molecules on the surface of infected cells, serve as epitopes for specific host immune cells. Nonenveloped viruses are mainly controlled by the humoral adaptive immunity. Enveloped viruses are controlled by the cellular immunity through the action of natural killer cells and cytotoxic CD8 T lymphocytes. After recognizing viral surface antigens on infected cells, cytotoxic T lymphocytes inhibit virus replication by cytolytic killing and by releasing interferons, chemokines, tumor necrosis factor-a or other pro-inflammatory mediators. Viral disease may be a direct result of cell destruction or a secondary consequence of host immune reactions against viral proteins. Proinflammatory cytokines play important roles in the antiviral immune response, but interleukin-1b, interleukin-6 and tumor necrosis factor-a cytokines can also contribute to disease manifestation. The host usually performs a delicate balancing act between promoting antiviral cytokine responses and limiting the amount of tissue damage. To counteract the immune attack, viruses employ sophisticated immunoevasive strategies to suppress antiviral host responses. For example, some viruses produce proteins that alter the major histocompatibility complex and hence the exposure of viral proteins on the surface of infected cells. Viruses may encode viral homologs of host cytokines and decoy receptors capable of binding and neutralizing host-derived cytokines. A rapid rate of mutation in critical viral genes can help viruses avoid the adaptive host defense. Other viral gene products inhibit apoptosis, which facilitates a prolonged state of replication of infected cells and spread of the virus. Viral diseases of the oral mucosa and the perioral region are often encountered in dental practice, but have received only limited research interest. Viruses are important ulcerogenic and tumorigenic agents of the human mouth. The finding of an abundance of mammalian viruses in periodontitis lesions may suggest a role for viruses in more oral diseases than

Biodiversidad, morfometría y alimentación de los cangrejos del género Callinectes (Decapoda: Portunidae) en Santiago de Cuba

On the basis of fishery intensity and proximity to river mouth, a total of 257 swimming Callinectes crabs were collected from March 2007 to April 2008 in eight localities. Captures were made with hanging nets, to a maximal depth of 1.5 m, establishing a top time of 2 hr. The genus was widely distributed, and it is represented at least by four species: C. sapidus, C. similis, C. rathbunae and C. larvatus, the last two not included in the last list of Cuban crustaceans (Crustacea: Decapoda). The size and shape of the gonopods were very useful as taxonomical criteria, considering the prevalence of males. The most abundant species were C. sapidus (47.08%), and C. similis (30.35%). C rathbunae, which was identified at 75% (6) of the localities, showed a better distribution, followed by C. sapidus, which appears in the 63% (5). Sex rate (R(s)) by species (male:female) was 6.20 for C. rathbunae, 3.58 for C. similis, 1.40 for C. larvatus and 0.40 for C. sapidus. The most abundant species had a lower R value. Morphometrical analysis and weight allowed us to know the average carapace width (CW) and weight (W). C. sapidus had an average CW = 110.57 mm (DS 21.55, n = 121) and W = 84.46 g (SD 43.25, n = 121); C. rathbunae a CW = 115.50 mm (DS 14.94, n = 36) and W = 140.44 g (DS 55.02, n = 36); C. larvatus a CW = 76.04 mm (DS 10.88, n = 22) and W = 31.70 g (DS 14.67, n = 22); and C. similis had the minimal parameter values, with a CW = 59.77 mm (DS 14.09, n = 78) and W = 13.80 g (DS 10.00, n = 78). These are the first records of the coastal crabs in the area. All values are lower than in previous reports. The largest individuals (CW>140 mm: C. rathbunae and C. sapidus) were captured in localities with adequate environmental characteristics. The stomach content suggests nine dietary categories, mainly fishes and macroalgae. The genus Callinectes has a diversified trophic spectrum. These crabs eat the available food, but they have a preference for the most abundant items.

Erythropsidinium (Gymnodiniales, Dinophyceae) in the Pacific Ocean, a unique dinoflagellate with an ocelloid and a piston

The distribution and morphology of the dinoflagellate Erythropsidinium (= Erythropsis) was studied in the vicinity of the Kuroshio and Oyashio Currents, the Philippine, Celebes, Sulu and South China Seas, western and central equatorial and southeast Pacific Ocean. Ninety-four specimens were observed, most of them collected from depths of less than 90 m. The highest abundance (15 cells L −1) was recorded in the north Philippine Sea in May (32°N, 138°E, 30-m depth). Twenty-four specimens were found in a station in the offshore Perú-Chile Current (31°52′S, 91°24′W). The transition regions between open warm waters and productive currents or upwellings seem to favour the abundance of Erythropsidinium. Specimens with duplicate pistons, with two protuberant ocelloids, and specimens with a piston that attains up to 20 times the body length are illustrated for the first time. All the specimens have been ascribed to the type species, Erythropsidinium agile, until stable taxonomical criteria are established for the species diagnosis. Despite the complexity of its organelles, the ocelloid and piston, the competitiveness of Erythropsidinium in the pelagic ecosystem seems to be low.

Human Adenovirus Type 52: a Type 41 in Disguise?

Recently, Jones et al. described a new human adenovirus (HAdV) (3) and claimed it to be a “new type” and even a “new species”: “human adenovirus 52 or HAdV-52 of species G.” We dispute both claims. By virus neutralization (VN), they showed it to be different from its phylogenetically closest relative, simian adenovirus 1. Surprisingly, they failed to provide additional VN data corroborating their claim of a novel serotype. Consequently, the new adenovirus may later, on the basis of VN data, prove to be a known serotype, e.g., HAdV-40 or HAdV-41. In their attempts to show that the virus was sufficiently distinct from HAdV-40 and HAdV-41 to be considered a new type, they embarked on phylogenetic analyses. These viruses were accepted as separate serotypes by the ICTV (1) on the basis of differences in their DNAs and their antigenic distances as measured by VN (1, 2), complying with the definition of serotypes (or “types”) as follows. Adenovirus serotypes are differentiated on the basis of neutralization assays. A serotype is defined as one which either exhibits no cross-reaction with others, or shows a homologous/heterologous titer ratio greater than 16 (in both directions). For homologous/heterologous titer ratios of 8 or 16, a serotype assignment is made if either the viral haemagglutinins are unrelated (as shown by lack of cross-reaction in haemagglutination-inhibition tests), or if substantial biophysical, biochemical or phylogenetic differences exist (1). Jones et al. also claim that the new adenovirus belongs to a novel species, named “G.” They argue that the phylogenetic distance between “HAdV-52” and HAdV-40 and HAdV-41 is “at least as great as those differentiating the other HAdV species.” This species designation would also be unprecedented. The phylogenetic distance between HAdV-40 and HAdV-41 is also at least as great as those differentiating other HAdV species, and also these two adenoviruses are not considered different species (1). In summary, according to current taxonomical criteria and the data presented, the newly identified adenovirus should not be considered a novel serotype, let alone a novel species.

Assessing business model concepts with taxonomical research criteria

PurposeThe purpose of this paper is to synthesize taxonomical criteria that can be used for assessing research constructs and assess current business model conceptualizations. The paper attempts to show how the criticism plaguing current business model conceptualizations could be removed with future conceptual development against these taxonomical criteria.Design/methodology/approachThe paper synthesizes taxonomical criteria and assesses current business model conceptualizations.FindingsThe results of the paper revealed that the current business model concepts comply poorly with the taxonomical criteria. The assessment of taxonomical compliance in this paper exposed major opportunities for enhancements in the existing conceptualizations of business model.Research limitations/implicationsThe findings of the paper outline novel avenues for future research in developing more coherent and rigorous business model conceptualizations.Practical implicationsThe practical implications of the paper are that current conceptualizations of a business model are at best incommensurate and at worst even misleading. This paper presents criteria that may be used in guiding the necessary caution and careful deliberation when practical application of the current business model conceptualizations is enforced.Originality/valueThe paper is original in that it establishes the taxonomical criteria, which may be used in research seeking to develop more sound and rigorous business model conceptualizations. To advance this new field the paper concludes that the taxonomical criteria can aid in the future research endeavors to design relevant business model conceptualizations.

A chloroplast genealogy of myrmecophyticMacarangaspecies (Euphorbiaceae) in Southeast Asia reveals hybridization, vicariance and long‐distance dispersals

Macaranga (Euphorbiaceae) includes about 280 species with a palaeotropic distribution. The genus not only comprises some of the most prominent pioneer tree species in Southeast Asian lowland dipterocarp forests, it also exhibits a substantial radiation of ant-plants (myrmecophytes). Obligate ant-plant mutualisms are formed by about 30 Macaranga species and 13 ant species of the genera Crematogaster or Camponotus. To improve our understanding of the co-evolution of the ants and their host plants, we aim at reconstructing comparative organellar phylogeographies of both partners across their distributional range. Preliminary evidence indicated that chloroplast DNA introgression among closely related Macaranga species might occur. We therefore constructed a comprehensive chloroplast genealogy based on DNA sequence data from the noncoding ccmp2, ccmp6, and atpB-rbcL regions for 144 individuals from 41 Macaranga species, covering all major evolutionary lineages within the three sections that contain myrmecophytes. A total of 88 chloroplast haplotypes were identified, and grouped into a statistical parsimony network that clearly distinguished sections and well-defined subsectional groups. Within these groups, the arrangement of haplotypes followed geographical rather than taxonomical criteria. Thus, up to six chloroplast haplotypes were found within single species, and up to seven species shared a single haplotype. The spatial distribution of the chloroplast types revealed several dispersals between the Malay Peninsula and Borneo, and a deep split between Sabah and the remainder of Borneo. Our large-scale chloroplast genealogy highlights the complex history of migration, hybridization, and speciation in the myrmecophytes of the genus Macaranga. It will serve as a guideline for adequate sampling and data interpretation in phylogeographic studies of individual Macaranga species and species groups.

Analysis of the fruit surfaces in Bupleurum L. (Umbelliferae) with SEM

20 Bupleurum L. taxa were investigated for micromorphological typology of the fruit surfaces with SEM. Considerably different types of sculpturing at species and subspecies level and similarities between related taxa were observed. A dichotomic key was prepared using the diagnostic surface patterns. Reticulate (sect. Bupleurum), rugose (sect. Aristata Godron subsect. Aristata) and rugulose-colliculate-verrucate (subsect. Juncea Briq.) types of surface structures were distinguished. Micromorphological characteristics may be valuable additional taxonomical criteria for the delimitation of infrageneric groups of species.

Taxonomic Identification of Foraminifera Using Ribosomal DNA Sequences

Taxonomic Identification of Foraminifera Using Ribosomal DNA Sequences

Cladistic analysis and a comparison between taxonomical criteria in the classification of nematodes

Abstract Nematodes are characterized by an exceedingly high degree of structural homogeneity, their species having adopted the most various conditions of life without undergoing conspicuous morphological changes. For this reason, the systematic study of the phylum is particularly difficult and the classification of nematodes is still in a state of great instability. The present classification of nematodes has been almost entirely constructed with the traditional taxonomical criteria of the evolutionary school, based on the overall similarities of the species rather than on their phylogenetic relationship. Only recently have some taxonomists begun to study selected taxa of nematodes on phylogenetic bases, using the cladistic analysis of Hennig. In order to compare the different criteria and their effects on the classification of nematodes, a taxonomical study recently conducted by the present author on the superfamily Ac‐tinolaimoidea is discussed and analyzed.

Phylogeny of some Fusarium species, as determined by large-subunit rRNA sequence comparison.

Fifty-two strains from eight species of Fusarium were analyzed by rapid rRNA sequencing. Two highly variable stretches (138 and 214 nucleotides) of the 5' end of the 28S-like rRNA molecule were sequenced. Such stretches permit evaluation of the divergence between closely related species and even between varieties within a species. The phylogenetic tree computed from the number of nucleotide differences shows seven Fusarium species to be more closely related to one another than the eighth species, F. nivale, is to them. On the basis of these data, we discuss both the phylogenetic value of taxonomical criteria and the impact of our findings on the demarcation of the genus Fusarium. We conclude that this method is suitable for establishing a precise phylogeny between closely related species within a genus.

Some cultural and physiological aspects of methane-utilizing bacteria.

A number of different methane-utilizing bacteria are described and compared with isolates of other investigators. The strains can be divided into three groups based on pigmentation, cell morphology and internal membrane structures. The oxidation of hydrocarbons, alcohols, aldehydes, fatty acids, methyl ethers and sugar phosphates by these bacteria was studied. There was much similarity between strains within the same group. Differences between groups as regards oxidative properties could be detected, but these were mainly quantitative and could not be used as taxonomical criteria. In addition, the inhibition of methane oxidation by metabolites and enzyme inhibitors was investigated. Formaldehyde proved to be the most active of the organic compounds tested. Iodoacetic acid inhibited both methane and methanol oxidation at concentrations of 0.03 M or above. Of the inorganic compounds, KCN completely suppressed methane oxidation at 5 times 10(-4) M and to more than 90% at 5 times 10(-5) M.