Influence of the river flow pulse on the maturity, resilience, and sustainability of tropical coastal ecosystems.

Coastal marine ecosystems have structural and functional features usually connected by the seasonal transfer of nutrients and organisms. These environments can utilize inter-ecosystem subsidies to increase resilience and maturity and support human activities like fishing. However, the importance of the connection and the role of the seasonal pulse of energy flows to enhance maturity are still poorly understood and reported. Our objective in this paper is to assess the effect of seasonal hydrological pulses on two tropical coastal interconnected ecosystems. Thus, we made four Ecopath models for estuarine and neritic environments considering the dry and rainy seasons, with a similar sampling design that allowed them to be compared. Our results provide evidence for the occurrence of the pulsed ecosystems since both environments seem driven by the river flow. Estuary presents more and more substantial differences (measured by ecosystem attributes) in both seasons because it is directly affected by river floods than the neritic environment. The neritic is affected indirectly by the movement of species from the estuary and by a weaker river flow. In the dry season, the differences between ecosystems are lower because the dry season trend to homogenize cycling, maturity, homeostasis, and resilience. We found that the seasonal river flow (pulse) forces the variability of biomass, flows, and ecosystem features, and this variance creates the required stability for both ecosystems. Still, these environments benefit through the exchange of components that relieve the pressures of predation on specific groups and maintain the energy flow necessary for the functioning of their trophic webs. The pulse by the rainfall favors connectivity and equalizes the two systems, increasing the connectivity between them and the exchange of subsidies that strengthens the trophic structures, contributing to the increase in maturity. In these ecosystems, seasonal changes become a key factor for exchanging flows that will promote sustainability, the accumulation of more biomass (growth), and the optimization of reserve energy (development) in both systems. This efficient joint strategy of perpetuation is what promotes resistance and resilience to these ecosystems, which together can reach different states of equilibrium, translated into maturity to withstand new environmental changes.

Intermediate-Range Casimir-Polder Interaction Probed by High-Order Slow Atom Diffraction.

At nanometer separation, the dominant interaction between an atom and a material surface is the fluctuation-induced Casimir-Polder potential. We demonstrate that slow atoms crossing a silicon nitride transmission nanograting are a remarkably sensitive probe for that potential. A 15% difference between nonretarded (van der Waals) and retarded Casimir-Polder potentials is discernible at distances smaller than 51 nm. We discuss the relative influence of various theoretical and experimental parameters on the potential in detail. Our work paves the way to high-precision measurement of the Casimir-Polder potential as a prerequisite for understanding fundamental physics and its relevance to applications in quantum-enhanced sensing.

Estuarization increases functional diversity of demersal fish assemblages in tropical coastal ecosystems.

This study assessed the influence of the seasonal fluctuation of abiotic conditions (wet v. dry season) on the functional diversity (FD) of tropical coastal fish assemblages. Sampling was carried out in three regions of north-east Brazil with contrasting coastlines (influenced by reef, lagoon and estuary). In each region, fishes were sampled from three depth strata (10, 20 and 30 m) and FD was estimated using an index based on key phenotypic and behavioural characteristics. All three regions had higher FD in the wet season at shallower depths, indicating the coexistence of species with low functional redundancy in sites subject to seasonal flushing of fresh water. Deeper sites had lower FD than shallower sites, although this difference was less pronounced for region 3, which is strongly affected by its proximity to the São Francisco estuary. The results broadly support the hypothesis that alterations in abiotic conditions in the wet season allow estuarine-adapted fishes with a different suite of functional traits to invade shallow coastal regions.

Intracranial Hypertension Is Painless!

INTRODUCTION: Headache is usually considered a key symptom of intracranial hypertension (ICHT). However, there are no published experimental data to support the concept that increased intracranial pressure (ICP) is painful in humans. MATERIALS AND METHODS: This prospective study was performed in 16 patients with suspected normal-pressure hydrocephalus, necessitating a lumbar infusion test with measurement of cerebrospinal fluid (CSF) hydrodynamics. During the test, ICP was increased from baseline to a plateau. Headache was scored on a visual analog scale (VAS) (0 = no pain, 10 = very severe pain) at baseline ICP and when ICP plateaued. RESULTS: At baseline, mean ICP was 11 ± 3.6 mmHg and VAS was 0. At plateau, mean ICP was 28 ± 9.5 mmHg and VAS was 0. There was a significant increase in ICP (p <0.001), but no increase in headache intensity (VAS). An acute (20-min) moderate increase in ICP was not accompanied by a headache. DISCUSSION: We demonstrate that an acute, isolated increase in CSF pressure does not produce a headache. To occur, a headache needs activation of the pain-sensitive structures (dura and venous sinuses) or central activation of the cerebral nociceptive structures. This peripheral or central activation does not occur with an isolated increase in CSF pressure.

Peripheral late reactivation of a previously typical monofocal Baló's concentric sclerosis lesion.

We report a 41-year-old woman with rapidly progressive left hemiparesis, revealing an inflammatory reactivation of a previously known parietal Baló's concentric sclerosis lesion. The first attack occurred five years before. After a slow recovery following high-dose steroid infusions the patient stabilized. Because of recurrent ataxia and left hemiparesis a new magnetic resonance imaging was performed showing an extension of the initial lesion with a peripheral gadolinium enhancement on T1-weighted images. Such a reactivation pattern of an isolated Baló's concentric sclerosis lesion, occurring some years later, is described for the first time.

An individual rehabilitation program: evaluation by Parkinsonian patients and their physiotherapists.

OBJECTIVES: The purpose of this work was to study the feasibility of an individual Parkinson disease (PD) rehabilitation program based on each patient's prevalent symptoms and to determine the effects of this program on patient's quality of life as well as the level of patient's and physiotherapist's satisfaction with the program. PATIENTS AND METHODS: In association with physiotherapists with expertise in PD, a physical medicine and rehabilitation physician, we elaborated a physical therapy program based on the core areas for physical therapy in PD: transfers; posture; balance and falls; physical capacity and inactivity. Within this program, we selected exercises tailored to each patient's main impairment and proposed this selection to their local physiotherapist for three months. Quality of life was evaluated with PDQ-39 at baseline and after three months of the individualized physical therapy program. We built an anonymous satisfaction questionnaire for patients and physiotherapists that was filled out at the end of the program. RESULTS: One hundred and three individuals with moderately advanced but clinically stable idiopathic PD were included. Significant improvement was found for the emotional well-being, bodily discomfort and stigma domain (P ≤ 0.05). No significant improvement was found for the other PDQ-39 domains. The mean global satisfaction figures for this program were 6.0 ± 2.4 and 7.2 ± 2.1 for patients and physiotherapists respectively. Most of the patients felt improved by the physiotherapy program and especially for transfer, balance, gait, and mobility. CONCLUSION: Our study found evidence of the potential benefits of a patient-tailored physiotherapy program. Such a program was feasible and had a favorable impact on patients' quality of life and on physiotherapists' practices for PD patients. Specific physiotherapy may be effective to limit physical mobility impairment. Our results also pointed out that physiotherapy may be efficient to confine the negative impact of social isolation, pain and emotional reactions. Such a program should be associated with a therapeutic education intervention such as encouraging patients to perform physical therapy exercises alone.

Bilateral Wada test: amobarbital or propofol?

PURPOSE: The Wada test is still the gold standard procedure to predict language and memory deficits before temporal lobe epilepsy surgery. As amobarbital was no longer available, our aim was to validate propofol as an alternative. METHOD: We retrospectively studied 47 patients who underwent a bilateral intracarotid procedure, performed with amobarbital (18), or propofol (29), between 2000 and 2010 during the preoperative evaluation of temporal lobe epilepsy. RESULTS: The number of patients experiencing an adverse event (mostly transient disturbance of consciousness or benign ocular symptoms) during both injections did not differ significantly between amobarbital and propofol. Hemispheric dominance was successfully determined in 96.5% patients with propofol vs. 94.4% with amobarbital for language, and in 72.4% under propofol vs. 77.7% under amobarbital for memory with no significant difference between groups. CONCLUSION: Propofol can be used for the Wada test with an efficacy and safety comparable to amobarbital.

Spatial population structure of the Neotropical tiger catfish Pseudoplatystoma metaense: skull and otolith shape variation.

Using geometric morphometrics, the skull and otolith of tiger catfish Pseudoplatystoma metaense were analysed to identify population structure in tributaries of the Apure River (i.e. the Sarare, Caparo, Guanare, Portuguesa and San Carlos Rivers) in the Orinoco basin, Venezuela. The analyses show uniformity in skull and otolith shapes of P. metaense within and among four tributaries, with only the Caparo River showing significant differences. Within the Apure basin, the stock of P. metaense was differentiated through spawning, refuge and nursery areas. This study concludes that populations of P. metaense from each major tributary in the Orinoco basin should be considered as part of a metapopulation system for management purposes. Human disturbances in the catchment have directly reduced the spawning areas available to this species, decreased the total biomass and changed the spatial distribution of spawning areas.

Functional neuroimaging of migraine.

This review summarizes the history of migraine imaging and key findings of studies on functional neuroimaging in migraine and describes how these data have changed our view of the disorder. Functional neuroimaging during migraine attacks and also interictally has initiated the description of "the migraine brain". These studies have led to the demonstration of cortical spreading depression in migraine with aura, the crucial role for the brainstem during migraine attacks, and cortical hypersensitivity in migraineurs modulated by the trigeminal pathway, explaining sensory sensitization such as photophobia and osmophobia.

[Ovarian drilling by fertiloscopy: feasibility, results and predictive values]. / Drilling ovarien par fertiloscopie : faisabilité, résultats et valeurs prédictives.

OBJECTIVES: The aims of this study were to assess the effectiveness of the ovarian drilling, compare the techniques by fertiloscopy or by laparoscopy, and search for prognostic factors of success. PATIENTS AND METHODS: This retrospective study focused on 154 ovarian drilling carried out between June 1998 and December 2010 where the drilling has been proposed after failure of the clomifene and before stimulation by FSH among PCOS patients. RESULTS: The post-drilling ovulation rate is 62%. The spontaneous on-going pregnancy rate is 31% and the total pregnancy rate scalable including secondary stimulation is 58%. No significant difference was found between laparoscopy and the fertiloscopy. The peroperative complications in fertiloscopy were more frequent but without consequences and 20% of the fertiloscopy had to be converted to laparoscopy, half of them for complications and half of them for technical difficulties. The only found preoperative predictors of success are an euthyroidy that increases the chances of pregnancy in general (including the side stimulation) and a lower FSH levels. However, it appears that the chances of pregnancy in FSH stimulation are dramatically decreased if the drilling did not induce ovulation versus the cases where it induced ovulation but no pregnancy (28.8% versus 58.1%, P<0.003). DISCUSSION AND CONCLUSION: Fertiloscopy results are comparable with those of laparoscopy, which suggests an advantage to this technique in terms of cost, comfort, and length of hospital stay. No usable in practice patient selection criteria could be highlighted. The study suggests that the absence of ovulation after drilling may be a direct indication for IVF.

Effect of slope and footwear on running economy and kinematics.

Lower energy cost of running (Cr) has been reported when wearing minimal (MS) vs traditional shoes (TS) on level terrain, but the effect of slope on this difference is unknown. The aim of this study was to compare Cr, physiological, and kinematic variables from running in MS and TS on different slope conditions. Fourteen men (23.4 ± 4.4 years; 177.5 ± 5.2 cm; 69.5 ± 5.3 kg) ran 14 5-min trials in a randomized sequence at 10 km/h on a treadmill. Subjects ran once wearing MS and once wearing TS on seven slopes, from -8% to +8%. We found that Cr increased with slope gradient (P < 0.01) and was on average 1.3% lower in MS than TS (P < 0.01). However, slope did not influence the Cr difference between MS and TS. In MS, contact times were lower (P < 0.01), flight times (P = 0.01) and step frequencies (P = 0.02) were greater at most slope gradients, and plantar-foot angles - and often ankle plantar-flexion (P = 0.01) - were greater (P < 0.01). The 1.3% difference between footwear identified here most likely stemmed from the difference in shoe mass considering that the Cr difference was independent of slope gradient and that the between-footwear kinematic alterations with slope provided limited explanations.

In vitro anthelmintic activity of the essential oils of Zanthoxylum zanthoxyloides and Newbouldia laevis against Strongyloides ratti.

The need for new anthelmintic with no chemical residues is becoming urgent. In a program aiming at the evaluation of plant as sources of new active molecules, the anthelmintic activities of the essential oils (EOs) obtained from either Zanthoxylum zanthoxyloides seeds or Newbouldia laevis leaves were evaluated against Strongyloides ratti by analyzing the results of two in vitro bioassays. These two plants and their tested parts were retained after an ethnopharmacology survey that confirmed their use by small-scale farmers for treatment of small ruminants affected by digestive helminths. The plants were harvested in Benin, and their EO were obtained by hydrodistillation. The EO yield of extraction was 0.65% (w/w) of for Z. zanthoxyloides seeds and 0.05% (w/w) for N. laevis. The chemical compositions of the two EOs were analyzed by gas chromatography coupled with mass spectrometry. The major constituents of the EO from Z. zanthoxyloides consisted of the following compounds: γ-terpinene (18 %), undecane (15 %), valencene (8.3 %), decanal (8.3 %), and 3-carene (6.7 %). In contrast, the major constituents of the EO from N. laevis leaves consisted of the following compounds: ß-caryophyllene (36 %) and eugenol (5.8 %). An egg-hatching inhibition (EHI) assay was developed and a larval migration inhibition assay was used on S. ratti to examine the effects of the EOs and to evidence their inhibitory concentrations (IC(50) and IC(90)) values on this nematode. Furthermore, the toxicity of the two EOs on Vero cell line was evaluated. When tested on S. ratti egg hatching, the two EOs resulted in similar IC(50) values (19.5 and 18.2 µg/ml for Z. zanthoxyloides and N. laevis, respectively), which were about sevenfold higher than that of the control (thiabendazole, IC(50) = 2.5 µg/ml). Larval migration was inhibited at similar concentrations for: Z. zanthoxyloides (IC(50) = 46 µg/ml), N. laevis (IC(50) = 51 µg/ml), and the control [levamisole (IC(50) = 36 µg/ml)]. No cytotoxicity was found on Vero cells because both EOs had IC(50) values higher than 50 µg/ml. Therefore, we have concluded that the EOs from two plants, used in folk medicine, may contain compounds with anthelmintic activity and could be used as improved traditional medicines or, at least, as food additives in a combined treatment for the control of helminth infections.

Involvement of tannins and flavonoids in the in vitro effects of Newbouldia laevis and Zanthoxylum zanthoxyloïdes extracts on the exsheathment of third-stage infective larvae of gastrointestinal nematodes.

The present study aimed at examining the possible role of tannins and flavonoids on the in vitro anthelmintic properties of the extracts of two plants from the southern area of Western Africa, i.e. Newbouldia laevis and Zanthoxylum zanthoxyloïdes. Extracts of the two plants were prepared by use of acetone/water (70/30) and their anthelmintic activity was measured by use of the larval exsheathment inhibition assay (LEIA) applied on the abomasal species, Haemonchus contortus and the intestinal species Trichostrongylus colubriformis. Three concentrations of extracts were evaluated to examine the possible dose effect. In addition, the possible involvement of tannins and flavonoids was examined by comparing the levels of inhibition of larval exsheathment obtained with the same extracts, after of not addition of PVPP which forms complexes with these compounds. The results indicate significant effects with both plants and both nematode species. In the range of concentrations examined, the results were dose-dependent for N. laevis extracts but not for Z. zanthoxyloïdes because the three doses applied provoked a similar highly significant inhibition whatever the tested dose. The use of PVPP indicated for both plant and nematode species, that tannins and flavonoids are involved partly in the effect but that some other biochemical compounds were also involved in both plants.

Efficacy of Nordic walking in obesity management.

The effects of a Nordic walking (NW) program compared to those of a walking (W) program on physiological and perceptual variables in obese middle-aged women were investigated. Subjects (n=12 NW group, n=11 W group) trained over 12 weeks 3 times.week (-1). Body mass, body mass index (BMI), body fat, heart rate (HR), resting blood pressure, peak oxygen consumption (V˙O (2peak)) were measured before and after the training period. Moreover, HR, rating of perceived exertion (RPE) and adherence were recorded during all training sessions. After the training period body mass, body fat and diastolic blood pressure decreased in both groups (P<0.05) whereas V˙O (2peak) increased in the NW group (+3.7 ml.min (-1).kg (-1); P=0.005). During the training sessions, mean HR (P=0.021), HR at preferred walking speed (P=0.020) and % of time at high intensity (P=0.031) were higher in NW than in the W group. Finally, RPE was not influenced by the modality of exercise and NW group showed a higher rate of adherence (91±19% vs. 81±29%; P=0.011). To conclude, NW activity in obese women allows an increase in exercise intensity and adherence to a training program without increasing the perception of effort leading to enhanced aerobic capacity.

Optimal design of a microcavity organic laser device under electrical pumping.

The quality factor of microcavity organic lasers, designed for operation under electric pumping, has been numerically investigated. The microcavity structure consists of an organic light emitting diode set in between multilayer dielectric mirrors centered for an emission at 620 nm. In order to optimize the quality factor, different parameters have been studied: the impact of high and low index materials used for the multilayer mirrors, the role of a spacer inserted in between the mirrors to obtain an extended cavity, and the effect of an absorbing electrode made of metallic or transparent conductive oxide layer. The results of our different optimizations have shown a quality factor (Q) as high as 15,000.

A PET study of photophobia during spontaneous migraine attacks.

BACKGROUND: Photophobia is an abnormal sensitivity to light experienced by migraineurs during attacks. The pathophysiology of photophobia is poorly understood. Nevertheless, 2 facts appear to have a link with photophobia: visual cortex hyperexcitability on the one hand and interactions between visual pathway and trigeminal nociception on the other. METHODS: We used H(2)(15)O PET to study photophobia induced by continuous luminous stimulation covering the whole visual field in 8 migraineurs during spontaneous migraine attacks, after headache relief by sumatriptan and during attack-free interval. The intensity of the luminous stimulation provoking photophobia with subsequent headache enhancement was specifically determined for each patient. RESULTS: We found that low luminous stimulation (median of 240 Cd/m(2)) activated the visual cortex during migraine attacks and after headache relief but not during the attack-free interval. The visual cortex activation was statistically stronger during migraine headache than after pain relief. CONCLUSION: These findings suggest that ictal photophobia is linked with a visual cortex hyperexcitability. The mechanism of this cortical hyperexcitability could not be explained only by trigeminal nociception because it persisted after headache relief. We hypothesize that modulation of cortical excitability during migraine attack could be under brainstem nuclei control.

Fish and aquatic habitat conservation in South America: a continental overview with emphasis on neotropical systems.

Fish conservation in South America is a pressing issue. The biodiversity of fishes, just as with all other groups of plants and animals, is far from fully known. Continuing habitat loss may result in biodiversity losses before full species diversity is known. In this review, the main river basins of South America (Magdalena, Orinoco, Amazon and Paraná-La Plata system), together with key aquatic habitats (mangrove-fringed estuaries of the tropical humid, tropical semi-arid and subtropical regions) are analysed in terms of their characteristics and main concerns. Habitat loss was the main concern identified for all South American ecosystems. It may be caused by damming of rivers, deforestation, water pollution, mining, poor agricultural practice or inadequate management practice. Habitat loss has a direct consequence, which is a decrease in the availability of living resources, a serious social and economic issue, especially for South American nations which are all developing countries. The introduction of exotic species and overfishing were also identified as widespread across the continent and its main freshwater, coastal and marine ecosystems. Finally, suggestions are made to find ways to overcome these problems. The main suggestion is a change of paradigm and a new design for conservation actions, starting with integrated research and aiming at the co-ordinated and harmonized management of the main transboundary waters of the continent. The actions would be focused on habitat conservation and social rescue of the less well-off populations of indigenous and non-indigenous peoples. Energy and freshwater demands will also have to be rescaled in order to control habitat loss.

Physiological and perceptual responses to Nordic walking in obese middle-aged women in comparison with the normal walk.

This study aimed to compare physiological and perceptual responses to Nordic walking (NW) in obese women to those of walking (W), and to assess if these responses were modified by a learning period of NW technique. Eleven middle-aged obese women completed exercise trials (5 min each) at 4 km/h, inclinations of -5, 0 and +5%, with and without poles. Ventilation (V(E)) oxygen consumption V(O)(2) energy cost (EC), heart rate (HR), rating of perceived exertion (RPE) and cycle length were measured before and after a 4-week learning period (12 sessions). V(E), V(O)(2), EC, HR and cycle length were significantly higher (P < 0.001) during NW trials than W trials. RPE was significantly diminished (pole x inclination interaction, P = 0.031) when using NW poles compared to W uphill. Significant pole x inclination interactions were observed for V(O)(2) (P = 0.022) and EC (P = 0.022), whereas significant pole x time interaction was found for EC (P = 0.043) and RPE (P = 0.039). Our results confirmed that use of NW poles increased physiological responses at a given speed but decreased RPE in comparison with W during inclined level. Moreover, this is the first study showing that a learning period of NW technique permitted to enhance the difference between EC with NW poles versus the W condition and to decrease the RPE when using NW poles. Thus, although it requires a specific learning of the technique, the NW might be considered like an attractive physical activity with an important public health application.

Neuronal in vitro models for the estimation of acute systemic toxicity.

The objective of the EU funded integrated project "ACuteTox" is to develop a strategy in which general cytotoxicity, together with organ-specific endpoints and biokinetic features, are taken into consideration in the in vitro prediction of oral acute systemic toxicity. With regard to the nervous system, the effects of 23 reference chemicals were tested with approximately 50 endpoints, using a neuronal cell line, primary neuronal cell cultures, brain slices and aggregated brain cell cultures. Comparison of the in vitro neurotoxicity data with general cytotoxicity data generated in a non-neuronal cell line and with in vivo data such as acute human lethal blood concentration, revealed that GABA(A) receptor function, acetylcholine esterase activity, cell membrane potential, glucose uptake, total RNA expression and altered gene expression of NF-H, GFAP, MBP, HSP32 and caspase-3 were the best endpoints to use for further testing with 36 additional chemicals. The results of the second analysis showed that no single neuronal endpoint could give a perfect improvement in the in vitro-in vivo correlation, indicating that several specific endpoints need to be analysed and combined with biokinetic data to obtain the best correlation with in vivo acute toxicity.

Posterior cerebral hypoperfusion in migraine without aura.

In cerebral blood flow studies, migraine aura is characterized by a posterior cortical hypoperfusion. In contrast, only rare and mild changes in brain perfusion have been demonstrated in migraine without aura, suggesting two different haemodynamic patterns in migraine with and without aura. Our aim was to study hypoperfusion with positron emission tomography (PET) as early as possible during spontaneous migraine without aura attacks. We used H(2) (15)O PET to investigate seven patients (six female, one male) with migraine without aura (International Classification of Headache Diseases-II code 1.1) in three situations: during the headache phase, after headache relief following sumatriptan injection, and during an attack-free interval. Statistical analysis was performed with SPM2. Within 4 h after the attack onset, significant relative bilateral posterior cortical hypoperfusion was found and persisted after headache relief following sumatriptan injection. A posterior cortical hypoperfusion demonstrated in migraine without aura could suggest a common pathogenesis in migraine with and without aura. The significance of relative posterior hypoperfusion in migraine without aura is discussed according to the current knowledge of migraine pathogenesis.