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E Smets

Publications and source records attributed to E Smets.

At least 19 recordsLinked to original sources
PubMed2006

The floral scales in Hellmuthia (Cyperaceae, Cyperoideae) and Paramapania (Cyperaceae, Mapanioideae): an ontogenetic study.

BACKGROUND AND AIMS: In 1976 the monotypic genus Hellmuthia was placed in the Hypolytreae s.l., but was subsequently ascribed to the Mapanioideae, tribe Chrysitricheae, mainly because of the presence in Hellmuthia of two lateral, mapanioid-like floral scales with ciliated keels, the anatomy of the nutlet, the embryo and the inflorescence. Recently, based on cladistic analyses and supported by pollen ontogenetic evidence, Hellmuthia was transferred to a Cyperaceae, tribe Cypereae, clade mainly consisting of Ficinia and Isolepis. In this study, the floral ontogeny in Hellmuthia was investigated and compared with the floral ontogeny in Paramapania, with special attention for the floral scales. METHODS: Freshly collected inflorescences of Hellmuthia membranacea and Paramapania parvibractea were investigated using scanning electron and light microscopy. KEY RESULTS: In the conical 'spikelet' in Hellmuthia, proximal bracts occur, each axillating an axis with empty glume-like structures, or a reduced spikelet. Hence, it is a reduced partial inflorescence. In Hellmuthia, the stamen primordia originate before the primordia of the perianth-gynoecium appear. Moreover, a third adaxially positioned 'floral scale' was observed for the first time. The position and relative time of appearance of the floral scales in Hellmuthia are typical for perianth parts in Cyperoideae. The basal position of Hellmuthia within a clade of species with usually perianthless flowers, allows the presence of rudiments of a perianth in Hellmuthia to be interpreted as a primitive state. Development of the lateral 'scales' in Paramapania follows a different pattern. Therefore, it was decided that the lateral 'scales' in Paramapania are different from the lateral perianth parts in Hellmuthia. The pollen grains in Hellmuthia are cyperoid, with one polar and five lateral apertures, of which the membrane is covered with sexinous bodies. The pollen surface is granulate and perforate with microspines. CONCLUSIONS: The floral ontogeny in Hellmuthia occurs according to the general cyperoid pattern. The lateral scales in Hellmuthia are perianth parts, and they are not homologous to the lateral 'scales' in Paramapania.

Cyperaceae↗
PubMed2005

Floral ontogeny in ficinia and isolepis (cyperaceae), with focus on the nature and origin of the gynophore.

BACKGROUND AND AIMS: The generic delimitations of Ficinia and Isolepis, sister genera in the Cypereae, are blurred. Typical Ficinia flowers have a lobed gynophore, which envelops the base of the nutlet, whereas in Isolepis the character is considered to be absent. Some former species of Isolepis, lacking the gynophore, were recently included in Ficinia. The floral ontogeny of representative taxa in Ficinia and Isolepis were investigated with the aim of evaluating the origin and nature of the gynophore in the Cypereae. METHODS: The spikelet and floral ontogeny in inflorescences collected in the field was investigated using scanning electron microscopy (SEM) and light microscopy (LM). KEY RESULTS: SEM images of Isolepis setacea and I. antarctica, Ficinia brevifolia, F. minutiflora, F. zeyheri and F. gracilis, and LM sections of F. radiata, show that the gynoecium in Ficinia is elevated above the flower receptacle by the development of a hypogynous stalk. From its apex, a (often three-)lobed cup is formed, which envelopes the basal part of the later nutlet. In developing flowers of I. antarctica, a rudimentary hypogynous stalk appears. In I. setacea, rudiments of a hypogynous stalk can be observed at maturity. In F. radiata and F. zeyheri, intralocular hairs are present in the micropylar zone. At the surface of developing gynoecia in flowers of F. gracilis, star-shaped cuticular structures appear which disappear again at maturity. CONCLUSIONS: The overall floral ontogeny of all species studied occurs following a typical scirpoid pattern, though no perianth primordia are formed. The gynophore in Ficinia originates as a hypogynous stalk, from which the typical gynophore lobes develop. The gynophore is not homologous with the perianth.

Cyperaceae↗
PubMed2005

Floral ontogeny in Scirpus, Eriophorum and Dulichium (Cyperaceae), with special reference to the perianth.

BACKGROUND AND AIMS: Based on molecular phylogenetic analysis, it has been suggested recently that the Cyperaceae comprises only two subfamilies: the Mapanioideae and the Cyperoideae. In most flowers of the Cyperoideae, the whorl of inner stamens is reduced, resulting in tetracyclic flowers. In the more primitive (scirpoid) genera within the Cyperoideae, the perianth consists of two polysymmetric whorls, whereas the perianth parts in the more derived genera have been subject to modifications and/or reduction. Comparative studies of the many silky hairs of Eriophorum and of the eight bristles of Dulichium have given rise to much discussion about their homology. METHODS: The spikelet and floral ontogeny in freshly collected inflorescences was investigated using scanning electron microscopy. KEY RESULTS: Complete floral ontogenies are presented for Scirpus sylvaticus L., Eriophorum latifolium Hoppe and Dulichium arundinaceum (L.) Britton, with special reference to the perianth. The results in S. sylvaticus confirm the trimerous monocot-like organization of the flower. It is used as a model for floral development in Cyperoideae. In the early developmental stages, the androecium of E. latifolium is surrounded by a massive perigonial primordium, from which the many hair-like bristles originate. Consequently, the stamens develop among the hair primordia, more or less simultaneously. The hairs are arranged in whorls, which develop centripetally. The development of the perianth in D. arundinaceum starts with the formation of three initial perianth primordia opposite the stamens. Subsequently, two more abaxial bristle primordia, alternating with the stamens, originate simultaneously with the appearance of three adaxial bristle primordia in the zone where an adaxial inner perianth primordium is expected. CONCLUSIONS: The floral development in E. latifolium and D. arundinaceum can be considered as variations upon the scirpoid floral ontogenetic theme.

Cyperaceae↗
PubMed2004

Conflicting phylogenies of balsaminoid families and the polytomy in Ericales: combining data in a Bayesian framework.

The balsaminoid Ericales, namely Balsaminaceae, Marcgraviaceae, Tetrameristaceae, and Pellicieraceae have been confidently placed at the base of Ericales, but the relations among these families have been resolved differently in recent analyses. Sister to this basal group is a large polytomy comprising all other families of Ericales, which is associated with short internodes. Because there are more than 13 kb of sequences for a large sampling of representatives, a thorough examination of the available data with novel methods seemed in place. Because of its computational speed, Bayesian phylogenetics allows for the use of parameter-rich models that can accommodate differences in the evolutionary process between partitions in a simultaneous analysis. In addition, there are recently proposed Bayesian strategies of assessing incongruence between partitions. We have applied these methods to the current problems in Ericales phylogeny, taking into account reported pitfalls in Bayesian analysis such as model selection uncertainty. Based on our results we infer several, previously unresolved relationships in the order Ericales. In balsaminoid families, we find that the closest relatives of Balsaminaceae are Marcgraviaceae. In the Ericales polytomy, we find strong support for Pentaphylacaceae sensu APG II as the sister group of Maesaceae. In addition, Symplocaceae receive a position as sister to Theaceae and these families form a monophyletic group together with Styracaceae-Diapensiaceae. At the base of this clade are Actinidiaceae and Clethraceae. The positions of Ebenaceae and Lecythidaceae remain uncertain.

Balsaminaceae↗
PubMed2004

The distribution and phylogeny of aluminium accumulating plants in the Ericales.

The distribution of aluminium (Al) accumulation in the Ericales is surveyed, based on semi-quantitative tests of 114 species and literature data. Al accumulation mainly characterises the families Diapensiaceae, Pentaphylacaceae, Symplocaceae, Ternstroemiaceae, and Theaceae. Al accumulation is consistently present or absent in most families examined, but the character appears to be more variable in a few taxa (e.g., Lecythidaceae, Myrsinaceae). Although the interfamilial relationships within the Ericales require further research, the ability to accumulate high levels of Al appears to show considerable taxonomic significance. While the majority of Al accumulating Ericales includes woody, tropical plants, the feature is remarkably present in several herbaceous Diapensiaceae, which have a distribution in cold to temperate areas. The association of different mycorrhizae types with plant roots is suggested to play a role in the exclusion of high Al levels from the shoot.

Aluminum↗
PubMed2004

Are patients with chronic low back pain or chronic neck pain fatigued?

OBJECTIVES: The objectives of this study were the following: to determine if fatigue is present in chronic low back pain (LBP) and chronic neck pain patients to a greater extent than in controls (nonpatients); to determine which variables are associated with the presence of fatigue; and to determine which of the above chronic pain patient (CPP) groups is more fatigued. To the authors' knowledge, this is the first such study in the literature. DESIGN: Totals of 175 chronic LBP and 33 chronic neck pain patients completed the Multidimensional Fatigue Inventory (MFI), Neuropathic Pain Scale (NPS), and Beck Depression Inventory rating scales on admission. In addition, an information tool was completed on each CPP and contained the following information: demographics, primary and secondary pain diagnoses, DSM-IV psychiatric diagnoses assigned, pain location, pain precipitating event, type of injury, years in pain, number of surgeries, types of surgery, type of pain pattern, opioids consumed per day in morphine equivalents, workers' compensation status, and whether, according to the clinical examination, the pain did or did not have a neuropathic component. Scores on the MFI were then compared with published norms for controls (nonpatients) via chi-squared tests. Bivariate analyses were conducted between the MFI subscales and the variables selected for analysis. Pearson correlations, analyses of variance, and t-tests were used to test for relationships between MFI scale scores and the appropriate variables. In the next step of the analysis, stepwise regression analyses were used to predict each of the MFI subscale scores using the variables that were found to be significantly (P < 0.05) related to fatigue by the preceding analysis. In the final analysis, the variables that were significant predictors of the fatigue subscales were controlled for as covariates in an analysis of variance in order to determine if chronic LBP patients had scores on the MFI subscales that were significantly different from those of chronic neck pain patients. SETTING: Multidisciplinary pain facility. PATIENTS: Chronic LBP and chronic neck pain patients. RESULTS: Chronic LBP and chronic neck pain patients were found to be significantly more fatigued than controls (nonpatients). Most of the MFI subscale scores could be predicted by four major variables: presence of neuropathic pain, female gender, presence of depression, and total number of DSM-IV diagnoses. Chronic LBP patients were as fatigued as chronic neck pain patients. CONCLUSIONS: The complaint of fatigue appears to be a significant problem for chronic LBP and chronic neck pain patients. This complaint may be associated with neuropathic pain, female gender, and psychiatric comorbidities.

Chronic Disease↗
PubMed2003

The remarkable genus Coptosapelta (Rubiaceae): pollen and orbicule morphology and systematic implications.

The pollen morphology and distribution of orbicules were investigated in ten species of the genus Coptosapelta (Rubiaceae) using light, scanning electron and transmission electron microscopy. In general, Coptosapelta pollen is three- to five-pororate and suboblate to oblate-spheroidal. The sexine ornamentation varies from psilate to reticulate, and the pollen-wall stratification lacks columellae. 'Droplets' are observed on the inner nexine surface. Distinct orbicules are found in five species. Orbicules are often lobed and appear to be aggregated and embedded in the tapetal remnants of the locule wall. Ultrastructurally, a single, flattened core is frequently observed. Coptosapelta has a unique pollen type within Rubiaceae and does not resemble possibly related genera. Pollen characteristics provide additional evidence supporting earlier findings that Coptosapelta represents an isolated lineage in Rubiaceae.

Asia, Southeastern↗
PubMed2001

Modern pollen studies in the territory of Sagalassos (Southwest Turkey) and their use in the interpretation of a Late Holocene pollen diagram.

Modern pollen precipitation studies were carried out on a regional scale in the territory of the classical city of Sagalassos (Southwest Turkey). 57 moss cushions and 7 soil samples from different vegetation types were analysed palynologically. The resulting pollen spectra were grouped into 14 vegetation groups, which were examined using discriminant analysis and principal components analysis. These numerical procedures are applied to display the structure in the data set in a comprehensive way. Some of the modern spectra groups seem to be well-defined, whereas others are difficult to distinguish from each other. After the relationships between the modern pollen spectra had been analysed, the fossil data from a core from the marsh of Gravgaz were added to the data set so that any similarities between fossil and modern spectra could be seen. A joint principal components analysis of the modern and fossil pollen spectra revealed that the pollen spectra from the earliest (ca. 2600-2500 BP; Cal. 830-590 BC till 790-520 BC) and the latest (starting at ca. 1300 BP; Cal. 660-780 AD) pollen assemblage zones have modern counterparts. On the other hand, the pollen spectra from the pollen assemblage zone dominated by Artemisia (ca. 2500-2300 BP; Cal. 790-520 BC till 410-210 BC) and from the pollen assemblage zone that indicated the practice of arboriculture (ca. 2300-1300 BP; Cal. 410-210 BC till 660-780 AD) have no close modern analogues, although individual tabulated pollen percentages revealed some similarities with some modern spectra groups.

Journal Article↗
PubMed2001

The potential role of orbicules as a vector of allergens.

BACKGROUND: In the locules of anthers of flowering plants, tiny (1.5-2 microm) granules of sporopollenin may occur next to the pollen grains. Those granules, called orbicules, mostly occur on the radial and innermost tangential wall of secretory tapetum cells. METHODS: We have investigated the presence of orbicules in 15 important European allergenic species with scanning electron microscopy (SEM). RESULTS: Orbicules were present in all species investigated of the families Betulaceae, Chenopodiaceae, Fagaceae, Poaceae, Polygonaceae, and Urticaceae. However, in the Asteraceae and Oleaceae species studied, orbicules were lacking. In all Chenopodiaceae, Poaceae, and Urticaceae species, orbicules were attached to the pollen exine. These observations indicate the possibility of the dispersal of orbicules into the atmosphere during anthesis. CONCLUSIONS: The hypothesis of the potential role of orbicules as possible important vectors of allergens is put forward, based on the comparison of our results with recent literature about the evidence of allergenic activity in the smaller micronic atmospheric aerosol fraction. Our results provide evidence that an in-depth investigation of the sites of allergens across the whole anther is required. We suggest that allergen researchers apply immunoelectron microscopy on whole anthers to determine whether orbicules possess allergens.

Allergens↗
PubMed2001

Participants in HIV clinical trials in Europe.

In recent years an increasing number of antiretrovirals have become available. In order to define the optimal treatment regimens an increasing number of clinical trials are needed. Our objective was to study the profile of participants in HIV clinical trials in Europe and learn from their experience and views. Between August 1996 and September 1997, self-administered anonymous questionnaires were distributed to people with HIV infection at inpatient and outpatient clinics in 11 European countries. One thousand three hundred and sixty-six people completed the questionnaire (50% response rate). Four hundred and twenty (31%) of the respondents reported that they had previously participated in at least one HIV clinical trial. The percentage of people who had taken part in a clinical trial varied widely between the different centres, from 12% in Athens to 61% in Antwerp and Brussels. A significantly higher participation rate was observed in the northern and central part of Europe compared with the south (respectively 40% vs 18%) and also among people with a higher income. Most people (92%) stated that they were 'well' or 'very well' informed prior to enrolment in the trial. However, 4% reported that they had not given written approval and 22% felt that they were pushed into participating. Only 21% stated that they were informed about the outcome of the study on its completion. The most important reason for non-participation (37% of the non-participants) was because a clinical trial had never been proposed. In conclusion, a majority of people with HIV infection in European HIV treatment reference centres were willing to participate in clinical trials. HIV clinical trials in Europe should adhere more strictly to universal ethical standards.

Adult↗
PubMed2001

Pollen development of Rondeletia odorata (Rubiaceae).

Pollen wall ontogeny of RONDELETIA: odorata was studied with transmission electron microscopy (TEM) and scanning electron microscopy (SEM) from tetrad stage until maturity. The ontogenetic sequence of wall development in RONDELETIA: follows, to some extent, the basic scheme in the angiosperms, i.e., development starts centripetally with the pro-columellae in a plasmalemma surface coating (primexine) at the early tetrad stage when the microspores are still enveloped by callose, until intine formation in young pollen grains. The main ontogenetical features of Rondeletia odorata pollen are (1) the very thin irregular foot layer, (2) development of a continuous layer of radially oriented membranous granular material under the thick endexine, (3) initiation of intine before first mitosis with characteristic radial plasmalemma invaginations, and (4) a strong stretching force upon engorgement just prior to dehiscence, which leads to reduction in thickness of all wall layers. The possible function of Golgi vesicles in the considerable increase in surface area of the plasmalemma at intine initiation is discussed. The endocingulum observed on acetolyzed and sectioned mature grains is explained ultrastructurally.

Journal Article↗
PubMed2001

Ritonavir/saquinavir plus one nucleoside reverse transcriptase inhibitor (NRTI) versus indinavir plus two NRTIs in protease inhibitor-naive HIV-1-infected adults (IRIS study).

OBJECTIVES: To compare the efficacy, tolerability and safety of a ritonavir 400 mg/saquinavir hard gel fomulation 400 mg twice daily versus an indinavir 800 mg once every 8 h containing first-line protease inhibitor (PI) treatment regimen. METHODS: Open, randomized, multicentre clinical trial. PI-naive patients received either ritonavir/saquinavir and one nucleoside reverse transcriptase inhibitor (NRTI) or indinavir and two NRTIs. Intention-to-treat (ITT) and on-treatment (OT) analyses were performed. RESULTS: The baseline characteristics of the study participants were similar in both arms, 67 patients (37%) were naive to antiretroviral treatment. The proportion of patients who achieved a plasma viral load below the level of detection of 400 copies/ml at week 48 was 43% (39/90) in the ritonavir/saquinavir arm and 63% (57/90) in the indinavir arm (P=0.005, I

Acquired Immunodeficiency Syndrome↗
PubMed2000

Morphology and ultrastructure of orbicules in the subfamily Ixoroideae (Rubiaceae).

Orbicules were studied in 43 species belonging to 32 genera of the five tribes of the Ixoroideae (Rubiaceae). The orbicules were investigated with scanning electron microscopy (SEM), light microscopy (LM), and transmission electron microscopy (TEM). Orbicules are present in all species investigated of the tribes Pavetteae, Octotropideae and Coffeeae. In the tribes Gardenieae and Aulacocalyceae orbicules were found in some species, while they were absent in others. 15 species out of 11 genera lack orbicules. Three orbicule types (III, V, and VI) could be distinguished, mainly on the basis of general morphological and ultrastructural variations. Orbicules that belong to type III (0.50-1.29µm) have perforations in their wall, a regular or irregular shape and two or three electron transparent cores. This orbicule type, exclusively found in all Pavetteae species investigated, can be divided into two subtypes. Orbicules of subtype IIIa are present in all genera related to Ixora, and orbicules of subtype IIIb in those genera related to Tarenna. Orbicules of type V (0.97-1.86µm) are present in Himalrandia tetrasperma (Aulacocalyceae), and in all Octotropideae genera investigated, except Feretia. Complexes of more than three individual orbicules characterize this type. They are irregularly shaped and have many perforations as well as sporopollenin granules on the orbicule wall. In all species investigated of tribe Coffeeae, type VI orbicules (0.56-1.60µm) are present. These orbicules are characterized by their embedded position towards the tapetal membrane, their aggregated form and by the presence of perforations as well as sporopollenin granules on their orbicule wall. In the tribe Gardenieae different types of orbicule were found (V, VI and orbicules that cannot be classified in our typology). Our results suggest that orbicule characters in the Ixoroideae may be systematically useful on tribal level.

Journal Article↗
PubMed2000

Pollen morphological survey of Pentas (Rubiaceae-Rubioideae) and its closest allies.

Pollen descriptions, based on LM and SEM observations, are provided for the Pentas complex, an African alliance within the Hedyotideae-Spermacoceae alliance, which includes the genera Pentas, Otomeria, Batopedina, Parapentas, and Chamaepentas. The close relationship among these genera is confirmed by pollen morphological data. The observed variation in pollen character states agrees well with the existing genera and subgenera. The combination of small spheroidal pollen grains with narrow, acute endocolpi, and a small apocolpium index distinguishes Batopedina from Otomeria and Pentas. Parapentas differs from Batopedina in having broad endocolpi with vague ends.Two of the three subgenera of Otomeria, Neotomeria and Volubilis, are supported by pollen data. Pollen of the subgenus Otomeria, however, is less differentiated and is similar to pollen of Pentas subgenus Pentas. The exact relationship between the genera Otomeria and Pentas remains unclear, and molecular data are needed to interpret the observed morphological variation. Chamaepentas has pollen that is nearly identical to that of the Pentas subgenus Chamaepentadoides and of the subgenus Megapentas, i.e. large spheroidal pollen grains with three, medium-length colpi and endocolpi with acute ends. Pollen morphology provides additional support for a close affinity between Pentas subgenus Phyllopentas and Pentas subgenus Vignaldiopsis.

Journal Article↗
PubMed2000

'I don't have any energy': The experience of fatigue in young adult survivors of childhood cancer.

Although it is speculated that fatigue occurs equally in adults, children and adolescents with cancer, little research exists to substantiate this view. Evidence that fatigue continues after treatment is limited in both the adult and paediatric oncology literature. Due to the current lack of knowledge, more information on the phenomenology of fatigue of childhood cancer survivors is desirable. Therefore a study was conducted to explore the concept of fatigue from a survivor's perspective. A semi-structured interview was conducted with a purposeful sample of 35 long-term survivors of childhood cancer who reported feeling extremely fatigued. The topics which were covered during the interview included the nature, onset and pattern of fatigue, sleep rest pattern, what helps with fatigue and what does not help, and the impact of fatigue on their daily life. Most survivors who were diagnosed with cancer in their adolescence identified fatigue as a significant side-effect of the treatment. The majority of survivors who were toddlers or preschooler at the time of cancer treatment mentioned that, as far as they could recall, they had suffered from fatigue their entire life. The course of fatigue during the day differed among the survivors, although the majority reported to be fatigued when waking up in the morning. None of the survivors reported sleep problems. Many survivors slept 9 hours or more. Fatigue was defined by all respondents as having a negative impact on their daily lives. Findings revealed that fatigue is a serious problem for some young adult survivors of childhood cancer and affects many aspects of quality of life.

Journal Article↗
PubMed2000

Wood anatomy of Elaeagnaceae, with comments on vestured pits, helical thickenings, and systematic relationships.

The secondary xylem of Elaeagnus, Hippophae, and Shepherdia is described and illustrated in detail. Shrubs and small trees of Elaeagnaceae have ring-porous or semi-ring-porous wood with simple perforation plates, vascular tracheids, fiber-tracheids, diffuse or rarely paratracheal axial parenchyma, and uni- or biseriate rays in Hippophae and Shepherdia, but wider rays in Elaeagnus. Walls of vessel elements, especially narrow ones, tracheids, or fiber-tracheids sometimes show helical thickenings; in a few instances these intergrade with small bud-like protrusions associated with pits. Scanning electron microscopy illustrates that small to vestigial vestures are present in all species studied, although nonvestured pits are also common. The analogous nature of vestures and helical thickenings is considered. Comparative wood anatomy suggests a rather isolated position of the family Elaeagnaceae; affinities with Rhamnaceae, Proteaceae, and Thymelaeaceae are discussed.

Journal Article↗