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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Chronic cluster headache: a French clinical descriptive study.

BACKGROUND: Cluster headache (CH) is a relatively rare disease and episodic CH is more frequent than chronic CH. Few studies have described the characteristics of patients with chronic CH. METHODS: This was a descriptive study carried out by eight tertiary care specialist headache centres in France participating in the Observatory of Migraine and Headaches (OMH). From 2002 to 2005, OMH collected data from 2074 patients with CH, of whom 316 had chronic CH. From January to June 2005, 113 patients with chronic CH were interviewed using standardised questionnaires during a consultation. RESULTS: The male to female ratio was 4.65:1. Median age was 42 years. The majority of patients were smokers or former smokers (87%). 46% had primary chronic CH (chronic at onset) and 54% secondary chronic CH (evolving from episodic CH). Most patients had unilateral pain during attacks and 7% had sometimes bilateral pain during an attack. 48% reported a persisting painful state between attacks. Symptoms anteceding pain onset (mainly discomfort/diffuse pain, exhaustion, mood disorders) and auras were reported by 55% and 20% of patients, respectively. The functional impact of chronic CH was estimated as severe by 74% of patients, and 75.7% suffered from anxiety, as assessed by the Hospital Anxiety and Depression scale. There was no substantial difference in clinical presentation between primary and secondary CH. DISCUSSION: This study confirms the existence of auras and interictal signs and symptoms in patients with chronic CH, and male sex and smoking as CH risk factors. Primary and secondary chronic CH appear equally prevalent. Male sex does not appear to favour the shift from episodic to chronic CH.

Amazonian plants from Peru used by Quechua and Mestizo to treat malaria with evaluation of their activity.

Indigenous Quechua and Mestizo populations from distinct areas in Loreto, Peru, were interviewed about traditional medication for the treatment of malaria. An ethnographic survey concerning the native theory of illness aetiology in the specific case of malaria permitted the elaboration of an efficient ethnopharmacological enquiry. The survey took place on three main zones corresponding to villages on the Napo and the Pastaza rivers (for the Quechua), and in the surroundings of Iquitos (for the Mestizos) and led to the collection of 14 plants. Serial extractions in hexane, dichloromethane, and methanol were performed on the different parts of the plants collected. The extracts were then tested for antiplasmodial activity in vitro. Seven plants displayed antiplasmodial activity (IC(50) from 2 to 25 microg/mL) and usually low cytotoxicity, indicating their antiplasmodial specificity. The results give scientific validation to the traditional medical knowledge of Quechua and Mestizo populations from Loreto and confirm a source of potentially active plants.

Molluscicidal activity against Bulinus truncatus of Croton campestris.

The bark of Croton campestris provided three furano-clerodane named, respectively, velamone, velamolone acetate and velamolone. Fractions containing these diterpenoids were investigated for their molluscicidal activity against Bulinus truncatus, one of the aquatic snail vectors of schistosomiasis. A dichloromethanic extract of root barks, rich in furano-clerodane and molluscicidal at 20ppm was promising as natural molluscicide. Enriched fraction with velamone gave 80% mortality from 25ppm, while its LD(100) was at 50ppm. The LD(80) was ca. at 45ppm, while LD(100) was at 60ppm for the enriched fraction containing velamolone acetate. The velamolone-enriched fraction was less efficient and gave a mortality of 90% at 90ppm. The pure compounds, velamone and velamolone acetate were active at 100% at 3 and 6ppm, respectively. Velamolone showed a molluscicidal activity at 20ppm.

[Treatment of cluster headache]. / Traitement des céphalées trigémino-vasculaires: nouveautés et perspectives.

Remarkable therapeutic improvements have come forward recently for trigemino-autonomic cephalalgias. Attack treatment in cluster headache is based on sumatriptan and oxygen. Non-vasoconstrictive treatments are opening a new post-triptan era but are not yet applicable. Prophylactic treatment of cluster headache is based on verapamil and lithium. The efficacy of anti-epileptic drugs in cluster headache remains to be demonstrated. Surgical treatment aimed at the parasympathetic pathways and at the trigeminal nerve demonstrates a high rate of recurrence and adverse events and questions about the relevance of a "peripheral" target in cluster headache. The efficacy of continuous hypothalamic stimulation in patients with intractable headache constitutes a breakthrough, but must be demonstrated at a larger scale and the benefice/risk ratio must be carefully evaluated. Indomethacin still remains the gold standard in paroxysmal hemicrania treatment. Until recently SUNCT was considered an intractable condition. However there are some reports of complete relief with lamotrigine, topiramate and gabapentin.

[Positron emission tomographic studies of migraine]. / Tomographie par émission de positons dans la migraine.

Due to technical constraints and randomness of migraine attacks, studies using PET are scarce. Nevertheless, these studies have given new insights into migraine pathogenesis. One of the main facts revealed by PET studies is that posterior cerebral hypoperfusion accompanying migraine auras could also be present in migraine attacks without aura. This hypoperfusion is probably due to an increase of intrinsic vasoconstrictive tone in the cerebral circulation. Using PET within 6 hours after the onset of a spontaneous migraine attack, significant activations of brainstem (midbrain and pons) and of hypothalamus, persisting after headache relief by sumatriptan have been shown. These structures could play the role of migraine attack generators, modulating intrinsic vascular tone and central pain transmission.