Floral scent evolution in the section Pseudophrys: pollinator-mediated selection or phylogenetic constraints?

Sexually deceptive orchid species from the Mediterranean genus Ophrys usually interact with one or a few pollinator species by means of specific floral scents. In this study, we investigated the respective role of pollinator-mediated selection and phylogenetic constraints in the evolution of floral scents in the section Pseudophrys. We built a phylogenetic tree of 19 Pseudophrys species based on three nuclear loci; we gathered a dataset on their pollination interactions from the literature and from our own field data; and we extracted and analysed their floral scents using solid phase microextraction and gas chromatography-mass spectrometry. We then quantified the phylogenetic signal carried by floral scents and investigated the link between plant-pollinator interactions and floral scent composition using phylogenetic comparative methods. We confirmed the monophyly of the section Pseudophrys and demonstrated the existence of three main clades within this section. We found that floral scent composition is affected by both phylogenetic relationships among Ophrys species and pollination interactions, with some compounds (especially fatty acid esters) carrying a significant phylogenetic signal and some (especially alkenes and alkadienes) generating dissimilarities between closely related Pseudophrys pollinated by different insects. Our results show that in the section Pseudophrys, floral scents are shaped both by pollinator-mediated selection and by phylogenetic constraints, but that the relative importance of these two evolutionary forces differ among compound classes, probably reflecting distinct selective pressures imposed upon behaviourally active and non-active compounds.

How to be a dioecious fig: Chemical mimicry between sexes matters only when both sexes flower synchronously.

In nursery pollination mutualisms, which are usually obligate interactions, olfactory attraction of pollinators by floral volatile organic compounds (VOCs) is the main step in guaranteeing partner encounter. However, mechanisms ensuring the evolutionary stability of dioecious fig-pollinator mutualisms, in which female fig trees engage in pollination by deceit resulting in zero reproductive success of pollinators that visit them, are poorly understood. In dioecious figs, individuals of each sex should be selected to produce odours that their pollinating wasps cannot distinguish, especially since pollinators have usually only one choice of a nursery during their lifetime. To test the hypothesis of intersexual chemical mimicry, VOCs emitted by pollen-receptive figs of seven dioecious species were compared using headspace collection and gas chromatography-mass spectrometry analysis. First, fig-flower scents varied significantly among species, allowing host-species recognition. Second, in species in which male and female figs are synchronous, intersexual VOC variation was not significant. However, in species where figs of both sexes flower asynchronously, intersexual variation of VOCs was detectable. Finally, with one exception, there was no sexual dimorphism in scent quantity. We show that there are two ways to use scent to be a dioecious fig based on differences in flowering synchrony between the sexes.

Positive effect of the yellow morph on female reproductive success in the flower colour polymorphic Iris lutescens (Iridaceae), a deceptive species.

The deceptive Iris lutescens (Iridaceae) shows a heritable and striking flower colour polymorphism, with both yellow- and purple-flowered individuals growing sympatrically. Deceptive species with flower colour polymorphism are mainly described in the family Orchidaceae and rarely found in other families. To explain the maintenance of flower colour polymorphism in I. lutescens, we investigated female reproductive success in natural populations of southern France, at both population and local scales (within populations). Female reproductive success was positively correlated with yellow morph frequency, at both the population scale and the local scale. Therefore, we failed to observe negative frequency-dependent selection (NFDS), a mechanism commonly invoked to explain flower colour polymorphism in deceptive plant species. Flower size and local flower density could also affect female reproductive success in natural populations. Pollinator behaviour could explain the positive effect of the yellow morph, and our results suggest that flower colour polymorphism might not persist in I. lutescens, but alternative explanations not linked to pollinator behaviour are discussed. In particular, NFDS, although an appealingly simple explanation previously demonstrated in orchids, may not always contribute to maintaining flower colour polymorphism, even in deceptive species.

Floral scent emitted by white and coloured morphs in orchids.

Polymorphism of floral signals, such as colour and odour, is widespread in flowering plants and often considered to be adaptive, reflecting various pollinator preferences for particular floral traits. Several authors have recently hypothesized that particular associations exist between floral colour and scent, which would result from shared biochemistry between these two floral traits. In this study, we compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of three different orchid species, including two food-deceptive species (Orchis mascula and Orchis simia) and a food-rewarding species (Anacamptis coriophora fragrans). We found clear interspecific differences in floral odours. As expected from their pollination strategy, the two deceptive orchids showed high inter-individual variation of floral volatiles, whereas the food-rewarding A. c. fragrans showed low variation of floral scent. Floral volatiles did not differ overall between white- and coloured-flowered morphs in O. mascula and A. c. fragrans, while O. simia exhibited different volatile profiles between the two colour morphs. However, a detailed analysis restricted to benzenoid compounds (which are associated with the production of floral anthocyanin pigments) showed that white inflorescences emitted more volatiles of the shikimic pathway than coloured ones, both for O. mascula and O. simia. These results are consistent with the current hypothesis that shared biochemistry creates pleiotropic links between floral colour and scent. Whether intraspecific variation of floral signals actually affects pollinator attraction and influences the reproductive success of these orchids remains to be determined.

Rare white-flowered morphs increase the reproductive success of common purple morphs in a food-deceptive orchid.

How floral colour polymorphism can be maintained in evolutionary time is still debated. In rewardless orchids, it is unknown whether rare white-flowered morphs differ in scent chemistry from pigmented morphs, and whether such intraspecific variation in floral signals may have an impact on reproductive success. We compared the chemical composition of floral volatiles emitted by white- and purple-flowered morphs of Orchis mascula, and recorded the fruit set of both colour morphs. We also used white ping-pong balls to mimic white-flowered morphs in field bioassays. We found that colour polymorphism was not associated with floral odour polymorphism. Surprisingly, when populations of purple-flowered plants included a few white-flowered individuals, the fruit set of the purple morph increased significantly (from 6 to 27%), while that of the white morph remained low. We obtained the same fourfold increase in fruit set when using ping-pong balls as visual lures, demonstrating the association between colour variation and fruit set, and the key role of visual signals in pollinator attraction. Our results are incompatible with negative frequency-dependent selection, a hypothesis invoked to explain colour polymorphism in other rewardless orchids. We propose several hypotheses to explain the maintenance of white morphs in O. mascula.

First Report of Sclerotinia Stem Rot of Chickpea Caused by Sclerotinia sclerotiorum in North Dakota and Washington.

Chickpea (Cicer arietinum L.) is cultivated as a rotational crop in the cereal-based production system in the U.S. Pacific Northwest (PNW) and its production is expanding to other northern tier states. During July 2005, symptoms of Sclerotinia stem rot were observed on chickpea cv. Dwelley and Dylan in fields near Spangle, WA and Carrington, ND, respectively, with disease incidence of approximately ≤1% in affected areas at both locations. Symptoms included stem whitening, wilting, and stem breakage. Occasionally, white fluffy mycelium was observed; however, production of sclerotia on infected plants was rarely observed. Sclerotinia sclerotiorum was isolated from diseased stems collected from both states. The isolates produced a ring of sclerotia near the edge of potato dextrose agar (PDA) plates in 7 days and produced neither conidia nor other fruiting bodies in culture after 30 days. PCR amplification of the rDNA internal transcribed spacer region from two representative isolates and subsequent digestion with restriction enzymes, Mbo I and Taq I, produced identical banding patterns to previously identified isolates of S. sclerotiorum from pea from the PNW (2). Chickpea cvs. Dwelley and Spanish White (eight plants of each) were inoculated by fastening mycelial agar plugs from an actively growing colony on PDA onto the stems with Parafilm. Symptoms of stem whitening were observed as early as 2 days after inoculation, and the lesions extended upward and downward from the inoculation site. Wilting and stem breakage were also observed. Control inoculations of four plants of each cultivar with PDA plugs without mycelium produced no visible symptoms. S. sclerotiorum was consistently reisolated from inoculated plants but not from control plants. Chickpea had been grown in the PNW for more than 20 years without any reported incidence of Sclerotinia stem rot although the disease has been reported from Arizona (3) and Asian countries (1). This is likely because of the upright growth habit of the chickpea plant coupled with relatively dry conditions late in the growing season. Previous chickpea cultivars were very susceptible to Ascochyta blight, an early-season disease of chickpea in the PNW that reduced chickpea stands and canopy coverage. Current cultivars possess much improved resistance to Ascochyta blight, allowing greater vegetative growth to occur and creating microenvironmental conditions conducive to Sclerotinia stem rot. In North Dakota, where humid conditions prevail late in the growing season, symptoms of Sclerotinia stem rot had been observed in previous years but had not been documented because of a recent history of chickpea cultivation there. To our knowledge, this is the first report of confirmed Sclerotinia stem rot of chickpea in North Dakota and Washington. References: (1) G. J. Boland and R. Hall. Can. J. Plant Pathol. 16:93, 1994. (2) I. Jimenez-Hidalgo et al. Phytopathology (Abstr.) 94(suppl.):S47, 2004. (3) M. E. Matheron and M. Porchas. Plant Dis. 84:1250, 2000.

[Propause survey: profile of patients treated with progestins in perimenopause]. / Enquête propause: profil de patientes traitées par progestatif en périménopause.

UNLABELLED: Progestins are widely used in France for treatment of perimenopause. OBJECTIVES: To evaluate the real use of progestins in daily practice. MATERIAL AND METHODS: A transverse epidemiological survey conducted between May and June 1998, by 284 gynecologists representative of French private practitioner gynecologists, who selected the first 4 patients treated with progestins for perimenopause. RESULTS: For 887 observations collected, the most frequent indications of prescription were: functional disorders of perimenopause (57%), mastalgia (47%), premenstruel syndrome (38%), endometrial pathology (29%) and ovulation inhibition (28%). Multiple reasons were present in 81% of patients: when progestin was prescribed more than 10 days per cycle, breast pathologies were the most frequent indication and the length of treatment was more than one year; when progestin was prescribed 10 days per cycle, isolated menstrual irregularities (without breast or endometrium pathology) predominated and the length of treatment was one year or less. The most widely used progestin classes were pregnanes and norpregnanes; there was an estrogene co-prescription in 17% of cases, more frequently in women with perimenopause disorders. CONCLUSION: We found the following pattern for progestin prescription in perimenopause: 10-day prescription for one-third of the women, 11 to 15 days for one-third, and 20 days per cycle for one-third. We thus observe some differences with recommended use. This difference is observed either with the initial prescription or with symptom-related dose adaptation.

[The antigonadrotropic activity of chlormadinone acetate in reproductive women]. / Activité antigonadotrope de l'acétate de chlormadinone chez la femme en période d'activité génitale.

INTRODUCTION: Progesterone modulates pulsatile secretion of LH throughout the normal menstrual cycle in women. This effect is observed essentially at hypothalamic level via progesterone receptors, with a decline in frequency of GnRH cyclic secretion. It was observed that when several nor-progesterone and nor-testosterone derived progestins were administered, the antigonadotropic function of the hypothalamic-pituitary-ovarian axis was inhibited. OBJECTIVE: Determine chlormadinone acetate's antigonadotropic activity when administered according to two schemes: from the day 5 to day 25 (L5) and from day 8 to day 25 (L8) of the menstrual cycle. PATIENTS AND METHODS: Randomized monocentric study carried out in twenty normally cycling healthy women included in two parallel groups and receiving 10 mg of chlormadinone acetate once a day, either from day 5 to day 25, or from day 8 to day 25 of the menstrual cycle. Hormonal dosages were determined with blood samplings performed each day from day 5 to day 25 of each menstrual cycle for estradiol, FSH and LH and from day 14 to day 25 of each cycle for progesterone. RESULTS: Sixteen women in group L5 and 14 in group L8 were kept for per protocol analysis. At the first cycle of treatment a decline in LH peak amplitude was observed in all women (16/16) of the L5 group and in 12 women out of 14 in the L8 group. For all women under treatment, graphs show a decrease in progesterone secretion parallel to decline in LH secretory peak amplitude as well as significant decline in estradiol secretion. Clinical tolerance was good. DISCUSSION AND CONCLUSION: Chlormadinone acetate induces anti-gonadotropic activity which is similar to other nor-progesterone and nor-testosterone derived progestins. This activity is shown at first cycle when the drug is used from day 5; when the drug is used from day 8, cycle 2 or 3 must be waited for in order to obtain the same result.

[Ultrasound diagnosis in trauma: elbow and hand]. / Sonographie beim Trauma: Ellenbogen und Hand.

Ultrasonography with high-frequency transducers nowadays plays an important role in diagnosing post-traumatic complaints of the elbow and hand tissue in children as well as in adults. We see it as an addition to clinical examination, standard X-ray, and other radiological methods. As a noninvasive procedure we can investigate post-traumatic changes and postoperative pain, detect foreign bodies, and also use it for postoperative metal removal. The possibility of imaging cartilage structures with ultrasound also enables us to diagnose post-traumatic injuries in children's elbows such as supracondylar fractures, epiphysiolyses, and fractures of the epicondyles.

Monitoring of quality of life in congestive heart failure populations.

The health care system has traditionally focused on treating disease at the point of failure, such as life-saving surgery or intensive medical therapy. As demographics shift more to an aging population, management of health-related quality of life and life-restricting disease becomes more necessary. Prominent among such diseases is congestive heart failure, which must be addressed as a major chronic health condition with its consequent effect on quality of life. This paper examines the methods of monitoring the quality of life in congestive heart failure. Particular attention is paid to congestive heart failure-related questionnaires to derive lifestyle information directly from patients. Comparison is made with general quality of life instruments. Most commonly, these questionnaires are applied to small populations in limited situations. New technology, such as the Internet, has greatly expanded the breadth and depth of health monitors by tracking status directly in patients' homes. This promises new levels of population management for heart disease. (c)2001 by CHF, Inc.

Essential and alternative prey in a ponerine ant: variations according to the colony life cycle.

We studied the prey specialization of Plectroctena minor, a ponerine ant known to capture mostly millipedes. We compared the prey spectrum of the hunting workers from large colonies with that of the founding queens. The hunting workers captured all kinds of tested prey, but hunted mostly millipedes. Founding queens, which avoided relatively large prey, including the millipedes tested, captured mostly isopods under experimental conditions. We also verified that the presence of millipedes in the diet of the larvae of large colonies was necessary for the production of winged females and strongly enhanced the production of workers, permitting us to assert that P. minor is a predatory species specialized in the capture of millipedes. In contrast, the presence of millipedes had no impact on the production of males. We thus assert that millipedes constitute the 'essential prey' of P. minor, while other arthropod taxa are therefore 'alternative prey'.

Extracting noun phrases for all of MEDLINE.

A natural language parser that could extract noun phrases for all medical texts would be of great utility in analyzing content for information retrieval. We discuss the extraction of noun phrases from MEDLINE, using a general parser not tuned specifically for any medical domain. The noun phrase extractor is made up of three modules: tokenization; part-of-speech tagging; noun phrase identification. Using our program, we extracted noun phrases from the entire MEDLINE collection, encompassing 9.3 million abstracts. Over 270 million noun phrases were generated, of which 45 million were unique. The quality of these phrases was evaluated by examining all phrases from a sample collection of abstracts. The precision and recall of the phrases from our general parser compared favorably with those from three other parsers we had previously evaluated. We are continuing to improve our parser and evaluate our claim that a generic parser can effectively extract all the different phrases across the entire medical literature.

Spatio-temporal learning by the ant ectatomma ruidum

We tested, under field and laboratory conditions, whether the neotropical ant Ectatomma ruidum Roger can learn several associations between temporal and spatial changes in the daily pattern of food availability. Honey was shuffled between two or three feeding sites following a fixed daily schedule. Foragers learnt to associate particular sites with the specific times at which food was available, individually marked ants being observed on the correct sites at the correct times. Some ants anticipated the time of food delivery by approximately 30 min, and it was not necessary for them to be rewarded at the first stage of the sequence of food collection to continue their search for honey according to the correct schedule of reward. Ants also followed the same schedule when no honey was supplied at each stage of the sequence, and they stayed at the expected unrewarded site for a period equivalent to the reward period of the corresponding training phase, indicating that they had learnt when and for how long the food was available. Thus, ants rely on their spatio-temporal memory rather than on local cues coming from the honey source to guide them.

Pharmacokinetics of once-daily dosing of gentamicin in neonates.

In a prospective, randomized trial of once-daily versus twice-daily intravenous or intramuscular dosing with gentamicin, 11 neonates received 5.0 mg/kg once daily and 15 received 2.5 mg/kg twice daily for 2 ro 3 days. The once-daily intravenous dosing group and the twice-daily intravenous or intramuscular dosing group, respectively, had mean steady-state gentamicin peak concentrations of 10.7 versus 6.6 micrograms/ml (p < 0.05), 6-hour postdosing concentrations of 4.7 versus 2.8 micrograms/ml (p < 0.05), trough concentrations of 1.7 versus 1.7 micrograms/ml, elimination half-life of 8.8 versus 5.4 hours (p < 0.05), and volume of distribution at steady state of 0.67 versus 0.46 L/kg. No nephrotoxic effects were identified in any group. Once-daily gentamicin therapy with 5.0 mg/kg in neonates achieves peak serum levels that are more suitable for optimal bacterial killing than those which traditional regimens achieve. Similar trough levels suggest that even larger doses and longer dosing intervals may be ideal in term neonates.

[Value of ultrasound of the support and locomotor system--with special reference to radiation exposure and cost reduction]. / Stellenwert der Sonographie am Stütz- und Bewegungsapparat--unter besonderer Berücksichtigung von Strahlenbelastung und Kostenreduktion.

In recent years, ultrasonic assessment of the locomotory system has become established both as a screening method in patients with chronic disorders and for evaluating acute injuries. Thanks to technical improvements to the equipment (use of high-frequency probes up to 20 MHz), ever smaller structures can be visualized. Ultrasonography can be carried out immediately following the clinical- and possibly radiological-assessment, by one and the same investigator, and requires little extra time. A bilateral examination in particular permits good evaluation of the extent of an injury and, with appropriate experience and good-quality equipment, an accurate assessment of the anatomical topography. Ultrasonography should now be used as the primary imaging method in the diagnosis of injuries to the following parts of the locomotory system, thus helping to minimize the number of expensive, and more invasive, diagnostic procedures: muscles and tendons, peri-articular soft tissue (in particular shoulder, knee and elbow joints), detection of intra-articular effusions, collections of fluid and, where applicable, ultrasonically guided puncture. In numerous other problems, too (postoperative complications, foreign bodies, fractures, osteomyelitis, soft tissue inflammation, etc.), ultrasound can deliver the first information. In this way, expensive diagnostic techniques can be reserved for special cases only, thus reducing costs. Furthermore, used as an adjunctive method, ultrasonography can reduce the number of diagnostic and follow-up X-rays in the case of injuries to the AC joint, shoulder dislocations, Hill-Sachs lesions, fractures in children, and for the detection of foreign bodies, again reducing radiation exposure and overall costs.

[Ultrasound fracture diagnosis--an experimental study]. / Die sonographische Frakturdiagnostik--eine experimentelle Studie.

Thanks to the increasing use of ultrasonography in the diagnostic evaluation of the musculoskeletal system, and the development of high-resolution ultrasonic transducers with ever better image quality, as well as the greater general trend towards non-invasive techniques, the use of ultrasonography in the diagnosis and follow-up of fractures would appear to make good sense. The aim of the present experimental study was, therefore, to identify the typical acoustic pattern of fractures and areas of bone impression and defects, while taking account of possible sources of error due to artefacts. Experiments were carried out on cadaver bones immersed in a water bath, using 7.5 and 10 MHz linear transducers. Depending on its size, the bony defect is represented by an interruption of the cortical echo, or a dorsal band of echoes limited to the fracture zone. Of interest is the fact that fractures and bony defects are not represented as such when the transducer is directed parallel to the line of the fracture or the impression area. Particular attention needs to be paid to the numerous artefacts occurring at the margins of the fracture. In summary, it may be noted that using resolution transducers under standardised experimental examination conditions, cortical interruptions of not less than 1 mm can be identified.

Information retrieval in digital libraries: bringing search to the net.

A digital library enables users to interact effectively with information distributed across a network. These network information systems support search and display of items from organized collections. In the historical evolution of digital libraries, the mechanisms for retrieval of scientific literature have been particularly important. Grand visions in 1960 led first to the development of text search, from bibliographic databases to full-text retrieval. Next, research prototypes catalyzed the rise of document search, from multimedia browsing across local-area networks to distributed search on the Internet. By 2010, the visions will be realized, with concept search enabling semantic retrieval across large collections.