Revealing uncertainty in the status of biodiversity change

Biodiversity faces unprecedented threats from rapid global change1. Signals of biodiversity change come from time-series abundance datasets for thousands of species over large geographic and temporal scales. Analyses of these biodiversity datasets have pointed to varied trends in abundance, including increases and decreases. However, these analyses have not fully accounted for spatial, temporal and phylogenetic structures in the data. Here, using a new statistical framework, we show across ten high-profile biodiversity datasets2-11 that increases and decreases under existing approaches vanish once spatial, temporal and phylogenetic structures are accounted for. This is a consequence of existing approaches severely underestimating trend uncertainty and sometimes misestimating the trend direction. Under our revised average abundance trends that appropriately recognize uncertainty, we failed to observe a single increasing or decreasing trend at 95% credible intervals in our ten datasets. This emphasizes how little is known about biodiversity change across vast spatial and taxonomic scales. Despite this uncertainty at vast scales, we reveal improved local-scale prediction accuracy by accounting for spatial, temporal and phylogenetic structures. Improved prediction offers hope of estimating biodiversity change at policy-relevant scales, guiding adaptive conservation responses.

Drug metabolic enzyme genotype-phenotype discrepancy: High phenoconversion rate in patients treated with antidepressants

Cytochromes from the P450 family (CYP) play a central role in the primary metabolism of frequently prescribed antidepressants, potentially affecting their efficacy and tolerance. There are however important differences in the drug metabolic capacities of each individual resulting from a combination of intrinsic and environmental factors. This variability can present an important risk for patients and increases the difficulty of drug prescription in clinical practice. Pharmacogenetic studies have uncovered a number of alleles defining the intrinsic metabolizer status, however, additional factors affecting cytochrome activity can modify this activity and result in a phenoconversion. The present study investigates the discrepancy between the genetically predicted and actually measured activities for the six most important liver cytochromes (CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6 and CYP3A4) in a cohort of patients under antidepressant treatment, previously shown to have a high proportion of patients with low metabolizing activities. We now performed the genetic characterization of this cohort to determine the extent of the genetic versus environmental contribution in these decreased activities. For all enzyme tested, we observed an important rate of phenoconversion, affecting between 33 % and 65 % of the patients, as well as a significant (p < 1E-06) global reduction in the effective but not predicted activities of CYP2D6, CYP2C9 and CYP2C19 compared to the general population. Our results highlight the advantages of phenotyping versus genotyping as well as the increased risk of treatment failure or adverse effect occurrence in a polymedicated population.

Live fast, die young: Behavioural and physiological impacts of light pollution on a marine fish during larval recruitment

Artificial light at night (ALAN) is a recently acknowledged form of anthropogenic pollution of growing concern to the biology and ecology of exposed organisms. Though ALAN can have detrimental effects on physiology and behaviour, we have little understanding of how marine organisms in coastal areas may be impacted. Here, we investigated the effects of ALAN exposure on coral reef fish larvae during the critical recruitment stage, encompassing settlement, metamorphosis, and post-settlement survival. We found that larvae avoided illuminated settlement habitats, however those living under ALAN conditions for 10 days post-settlement experienced changes in swimming behaviour and higher susceptibility to nocturnal predation. Although ALAN-exposed fish grew faster and heavier than control fish, they also experienced significantly higher mortality rates by the end of the experimental period. This is the first study on the ecological impacts of ALAN during the early life history of marine fish.

Reactivity of shape-controlled crystals and metadynamics simulations locate the weak spots of alumina in water

The kinetic stability of any material in water relies on the presence of surface weak spots responsible for chemical weathering by hydrolysis. Being able to identify the atomistic nature of these sites and the first steps of transformation is therefore critical to master the decomposition processes. This is the challenge that we tackle here: combining experimental and modeling studies we investigate the stability of alumina in water. Exploring the reactivity of shape-controlled crystals, we identify experimentally a specific facet as the location of the weak spots. Using biased ab initio molecular dynamics, we recognize this weak spot as a surface exposed tetra-coordinated Al atom and further provide a detailed mechanism of the first steps of hydrolysis. This understanding is of great importance to heterogeneous catalysis where alumina is a major support. Furthermore, it paves the way to atomistic understanding of interfacial reactions, at the crossroad of a variety of fields of research.

Gaining atomistic level understanding of alumina/water interfaces is key to unraveling alumina decomposition processes. Here the authors combine the experimental synthesis of shape-controlled γ-Al₂O₃ samples with metadynamics simulations to identify the surface weak spots responsible for alumina decomposition.

Dihydroxyacetone conversion into lactic acid in an aqueous medium in the presence of metal salts: influence of the ionic thermodynamic equilibrium on the reaction performance

Different Lewis acid aluminium complexes catalyse the successive reactions to convert dihydroxyacetone into lactic acid in an aqueous medium.

Habitat selection by marine larvae in changing chemical environments

The replenishment and persistence of marine species is contingent on dispersing larvae locating suitable habitat and surviving to a reproductive stage. Pelagic larvae rely on environmental cues to make behavioural decisions with chemical information being important for habitat selection at settlement. We explored the sensory world of crustaceans and fishes focusing on the impact anthropogenic alterations (ocean acidification, red soil, pesticide) have on conspecific chemical signals used by larvae for habitat selection. Crustacean (Stenopus hispidus) and fish (Chromis viridis) larvae recognized their conspecifics via chemical signals under control conditions. In the presence of acidified water, red soil or pesticide, the ability of larvae to chemically recognize conspecific cues was altered. Our study highlights that recruitment potential on coral reefs may decrease due to anthropogenic stressors. If so, populations of fishes and crustaceans will continue their rapid decline; larval recruitment will not replace and sustain the adult populations on degraded reefs.

Singing in the Brain: Independence of Lyrics and Tunes

Why is vocal music the oldest and still the most popular form of music? Very possibly because vocal music involves an intimate combination of speech and music, two of the most specific, high-level skills of human beings. The issue we address is whether people listening to a song treat the linguistic and musical components separately or integrate them within a single percept. Event-related potentials were recorded while musicians listened to excerpts from operas sung a capella. Excerpts were ended by semantically congruous or incongruous words sung either in or out of key. Results clearly demonstrated the independence of lyrics and tunes, so that an additive model of semantic- and harmonic-violations processing predicted the data extremely well. These results are consistent with a modular organization of the human cognitive system and open new perspectives in the search for the similarities and differences between language and music processing.

From impulses to maladaptive actions: the insula is a neurobiological gate for the development of compulsive behavior

Impulsivity is an endophenotype of vulnerability for compulsive behaviors. However, the neural mechanisms whereby impulsivity facilitates the development of compulsive disorders, such as addiction or obsessive compulsive disorder, remain unknown. We first investigated, in rats, anatomical and functional correlates of impulsivity in the anterior insular (AI) cortex by measuring both the thickness of, and cellular plasticity markers in, the AI with magnetic resonance imaging and in situ hybridization of the immediate early gene zif268, respectively. We then investigated the influence of bilateral AI cortex lesions on the high impulsivity trait, as measured in the five-choice serial reaction time task (5-CSRTT), and the associated propensity to develop compulsivity as measured by high drinking levels in a schedule-induced polydipsia procedure (SIP). We demonstrate that the AI cortex causally contributes to individual vulnerability to impulsive-compulsive behavior in rats. Motor impulsivity, as measured by premature responses in the 5-CSRTT, was shown to correlate with the thinness of the anterior region of the insular cortex, in which highly impulsive (HI) rats expressed lower zif268 mRNA levels. Lesions of AI reduced impulsive behavior in HI rats, which were also highly susceptible to develop compulsive behavior as measured in a SIP procedure. AI lesions also attenuated both the development and the expression of SIP. This study thus identifies the AI as a novel neural substrate of maladaptive impulse control mechanisms that may facilitate the development of compulsive disorders.

Economic values of growth and feed efficiency for fish farming in recirculating aquaculture system with density and nitrogen output limitations: a case study with African catfish (Clarias gariepinus)

In fish farming, economic values (EV) of breeding goal traits are lacking, even though they are key parameters when defining selection objectives. The aim of this study was to develop a bioeconomic model to estimate EV of 2 traits representing production performances in fish farming: the thermal growth coefficient (TGC) and the feed conversion ratio (FCR). This approach was applied to a farm producing African catfish (Clarias gariepinus) in a recirculating aquaculture system (RAS). In the RAS, 2 factors could limit production level: the nitrogen treatment capacity of the biofilter or the fish density in rearing tanks at harvest. Profit calculation includes revenue from fish sales, cost of juveniles, cost of feed, cost of waste water treatment, and fixed costs. In the reference scenario, profit was modeled to zero. EV were calculated as the difference in profit per kilogram of fish between the current population mean for both traits (µt) and the next generation of selective breeding (µt+Δt) for either TGC or FCR. EV of TGC and FCR were calculated for three generations of hypothetical selection on either TGC or FCR (respectively 6.8% and 7.6% improvement per generation). The results show that changes in TGC and FCR can affect both the number of fish that can be stocked (number of batches per year and number of fish per batch) and the factor limiting production. The EV of TGC and FCR vary and depend on the limiting factors. When dissolved NH3-N is the limiting factor for both µt and µt+Δt, increasing TGC decreases the number of fish that can be stocked but increases the number of batches that can be grown. As a result, profit remains constant and EVTGC is zero. Increasing FCR, however, increases the number of fish stocked and the ratio of fish produced per kilogram of feed consumed ("economic efficiency"). The EVFCR is 0.14 €/kg of fish, and profit per kilogram of fish increases by about 10%. When density is the limiting factor for both µt and µt+Δt, the number of fish stocked per batch is fixed; therefore, extra profit is obtained by increasing either TGC, which increases the annual number of batches, or by decreasing FCR, which decreases annual feed consumption. EVTGC is 0.03 €/kg of fish and EVFCR is 0.05-0.06 €/kg of fish. These results emphasize the importance of calculating economic values in the right context to develop efficient future breeding programs in aquaculture.

Co-activation of VTA DA and GABA neurons mediates nicotine reinforcement

Smoking is the most important preventable cause of mortality and morbidity worldwide. This nicotine addiction is mediated through the nicotinic acetylcholine receptor (nAChR), expressed on most neurons, and also many other organs in the body. Even within the ventral tegmental area (VTA), the key brain area responsible for the reinforcing properties of all drugs of abuse, nicotine acts on several different cell types and afferents. Identifying the precise action of nicotine on this microcircuit, in vivo, is important to understand reinforcement, and finally to develop efficient smoking cessation treatments. We used a novel lentiviral system to re-express exclusively high-affinity nAChRs on either dopaminergic (DAergic) or γ-aminobutyric acid-releasing (GABAergic) neurons, or both, in the VTA. Using in vivo electrophysiology, we show that, contrary to widely accepted models, the activation of GABA neurons in the VTA plays a crucial role in the control of nicotine-elicited DAergic activity. Our results demonstrate that both positive and negative motivational values are transmitted through the dopamine (DA) neuron, but that the concerted activity of DA and GABA systems is necessary for the reinforcing actions of nicotine through burst firing of DA neurons. This work identifies the GABAergic interneuron as a potential target for smoking cessation drug development.

AM1 Study of N-2-Acetylaminofluorene bonded to Deoxyguanosine at the Minor Adduct Site

We have computed the total energy as a function of six important torsion angles of the carcinogen N-2-acetylaminofluorene (AAF) bonded to thenitrogen N2 of deoxyguanosine using the semiempirical quantum mechanical method AM1. One global minimum and one local minimum are found separated by a modest barrier. We have computed the normal-mode frequencies of the relevant torsional motions and have determined the rate of conversion betweenthe two minima.

Supported noble metal catalysts in the catalytic wet air oxidation of industrial wastewaters and sewage sludges

This paper reviews some catalytic wet air oxidation (CWAO) investigations of industrial wastewaters over platinum and ruthenium catalysts supported on TiO2 and ZrO2 formulated to be active and resistant to leaching, with particular focus on the stability of the catalyst. Catalyst recycling experiments were performed in batch reactors and long-term stability tests were conducted in trickle-bed reactors. The catalyst did not leach upon treatment of Kraft bleaching plant and olive oil mill effluents, and could be either recycled or used for long periods of time in continuous reactors. Conversely, these catalysts were rapidly leached when used to treat effluents from the production of polymeric membranes containing N,N-dimethylformamide. The intermediate formation of amines, such as dimethylamine and methylamine with a high complexing capacity for the metal, was shown to be responsible for the metal leaching. These heterogeneous catalysts also deactivated upon CWAO of sewage sludges due to the adsorption of the solid organic matter. Pre-sonication of the sludge to disintegrate the flocs and improve solubility was inefficient.

Naloxone-responsive acute dystonia and parkinsonism following general anaesthesia

Various movement disorders such as dystonia may acutely develop during or at emergence from general anaesthesia in patients with or without pre-existing Parkinson disease. These movements are triggered by a variety of drugs including propofol, sevoflurane, anti-emetics, antipsychotics and opioids. The postulated mechanism involves an imbalance between dopaminergic and cholinergic neurotransmitters in the basal ganglia. We report an acute, severe and generalised dystonic reaction in an otherwise healthy woman at emergence from general anaesthesia, dramatically reversed by the administration of naloxone, pointing to a potential role of the fentanyl and morphine that the patient had received. Recent literature on the mechanisms of abnormal movements induced by opioids are discussed. The severity of the reaction with usual doses of opioids, in a patient with no prior history of parkinsonism, led to further investigation that demonstrated the possibility of an enhanced susceptibility to opioids, involving a genetically determined abnormal function of glycoproteine-P and catechol-O-methyltransferase.

[Self-medication amongst illegal Latino-American immigrants: necessary or inapropriate]

Self-medication is well known risk in Latin America. This situation can partly be explain by the difficult access to doctors and poorly regulated drug sales. Illegal Latino-American immigrants import their practice of self-medication and their drugs with them. The economic advantage of this practice makes it popular and confronts medical practitioners to question the benefice/risk of such behavior. Taking the particular situation of illegal Latino-American immigrants, this review discusses the necessity of abording systematically the question of self-medication during a medical consultation.

Targeted in vivo expression of nicotinic acetylcholine receptors in mouse brain using lentiviral expression vectors

Nicotinic acetylcholine receptors (nAChRs) in the brain exhibit diverse functional properties and ubiquitous distribution. Yet, except for providing a receptor for the exogenously applied nicotine of tobacco products, their role in the normal functioning of the brain has remained elusive. We have used a lentiviral expression vector to re-express the beta2 subunit specifically in the ventral tegmental area (VTA) of beta2-/- mice. The viral vector efficiently expresses beta2- subunit protein leading to new nAChR-binding sites. VTA neurons transduced by the lentiviral vector are responsive to intravenous nicotine when analyzed using in vivo electrophysiology. Nicotine-induced dopamine release from the nucleus accumbens (NuAcc) was also restored in re-expressing beta2-/- mice. Intra-VTA injection of nicotine was found to be reinforcing in both wild-type and beta2-subunit re-expressing beta2-/- mice, but not in beta2-/- mice. Furthermore, in the absence of applied nicotine, the spontaneous slow exploratory behavior of the mice was restored, whereas fast navigation did not change. This latter behavioral analysis suggests a role for beta2* nAChR, specifically expressed in the VTA, in mammalian cognitive function.

Genetic dissociation of two behaviors associated with nicotine addiction: beta-2 containing nicotinic receptors are involved in nicotine reinforcement but not in withdrawal syndrome

RATIONALE

Nicotine addiction is characterized by two distinct behaviors, chronic compulsive self-administration and the induction of a withdrawal syndrome upon cessation of nicotine consumption.

OBJECTIVE

To examine if these two processes rely on beta2-containing nicotinic receptors--beta2*nAChRs--we analyzed the behavior of mice lacking these receptors in the two situations.

RESULTS

First, we showed that, in contrast to wild-type (WT) mice, beta2-knockout (beta2-/-) mice exhibit no intra-ventral tegmental area (VTA) nicotine self-administration, whereas their ability to self-administer morphine is intact. However, beta2-/- mice showed some sensitivity to locomotor effects of nicotine, implying an effect of the drug on other nicotinic subtypes. Then, we observed that beta2-/- mice exhibited a normal nicotine withdrawal syndrome, i.e., increased levels of rearing and jumping upon precipitated withdrawal. Thus, the beta2*nAChRs are not involved in the behaviors induced by cessation of nicotine consumption.

CONCLUSION

Taken together, the present data demonstrated a genetic dissociation of two distinct behavioral patterns associated with nicotine addiction. They further suggested that independent molecular mechanisms underlie these two aspects, offering the possibility of controlling them separately.

[Mesenteric hematoma: Unusual complication of a long term oral anticoagulation therapy]

Authors report a case of a 77 years old man who developed a small bowel mesenteric hematoma as consequence of an unusual complication from a long term oral anticoagulation treatment. Computed tomoangiography helpfully suggests diagnosis of a mesenteric hematoma and refuts an organic cause as vascular anomalies, by an equivalent method to conventional angiography, noninvasely. In our case report, patient's deterioration justified an emergency surgery corroborating medical imager findings. Authors review the rare cases previously reported.

[Suspected non-accidental trauma in children: pseudofracture of the parietal bone]

We reported the case of a three month old child who was suspected of abuse syndrome because of a possible parietal bone fracture during radiographic investigation. At autopsy, the parietal bone abnormalities were not fractures, but proved to be unossified membranous strips. A review of the literature about normal variants of parietal suture on roentgenograms was made to avoid the diagnosis of non-accidental trauma in children, especially in live children where autopsy cannot be made.

[Social inequalities and health: experiences of a mobile health care unit in Geneva]

Health care professionals are in contact with patients of all social horizons. Healthcare professionals come into contact with patients from all social backgrounds. Low socio-economic status is a well-known determinant of morbidity and mortality. A mobile community health care unit ("Umsco") was created in Geneva in 1996 with the aim of providing health care to very low-income patients who aren't catered for by the traditional healthcare system in Switzerland. The Mobile Unit's patients are mainly female South American illegal immigrants, but also the city' homeless. This article explains how the Unit functions on a day-to-day basis. We describe socio-demographic characteristics of the patients and their main presenting complaints. We also discuss how health care professionals in general can adapt to the specific needs of socially deprived and vulnerable patients.

Nicotine reinforcement and cognition restored by targeted expression of nicotinic receptors

Worldwide, 100 million people are expected to die this century from the consequences of nicotine addiction, but nicotine is also known to enhance cognitive performance. Identifying the molecular mechanisms involved in nicotine reinforcement and cognition is a priority and requires the development of new in vivo experimental paradigms. The ventral tegmental area (VTA) of the midbrain is thought to mediate the reinforcement properties of many drugs of abuse. Here we specifically re-expressed the beta2-subunit of the nicotinic acetylcholine receptor (nAChR) by stereotaxically injecting a lentiviral vector into the VTA of mice carrying beta2-subunit deletions. We demonstrate the efficient re-expression of electrophysiologically responsive, ligand-binding nicotinic acetylcholine receptors in dopamine-containing neurons of the VTA, together with the recovery of nicotine-elicited dopamine release and nicotine self-administration. We also quantified exploratory behaviours of the mice, and showed that beta2-subunit re-expression restored slow exploratory behaviour (a measure of cognitive function) to wild-type levels, but did not affect fast navigation behaviour. We thus demonstrate the sufficient role of the VTA in both nicotine reinforcement and endogenous cholinergic regulation of cognitive functions.

[MR imaging in the evaluation of blunt pancreatic trauma]

Pancreatic injuries caused by blunt trauma are unusual but associated with a high morbidity and a high mortality because of a delay in diagnosis. Clinical and laboratory findings are non-specific. Accurate grading of blunt pancreatic injury with identification of pancreatic duct disruption helps to define practical treatment guidelines. Computed tomography does not allow direct visualization of the pancreatic duct and may result in low accuracy for the detection of ductal injury. Endoscopic retrograde pancreatography is the "gold standard" but invasive (3-5% complication rate, mainly pancreatitis) and may not be possible in up to 30% of patients, or requested after surgery. Endoscopic retrograde pancreatography may be used as a therapeutic modality (stenting of the main pancreatic duct). Magnetic resonance cholangiopancreatography is non invasive and preliminary results are promising. Magnetic resonance cholangiopancreatography detects pseudocysts, has multiplanar capability and complemented with conventional MR imaging allows evaluation of the pancreatic parenchyma.

[Gastric necrosis from acute dilatation without underlying psychiatric disorder]

Acute gastric dilatation with necrosis is a rare and severe complication associated with anorexia nervosa, bulimia, and psychogenic polyphagia. The Authors report an unusual case without underlying psychiatric context. Gastric necrosis was suspected based on imaging findings (plain radiograph and computed tomography). The detection of these imaging signs in an appropriate clinical setting, even without underlying psychiatric context, is important to avoid any delay in diagnosis and reduce mortality.

Partial thrombosis of an idiopathic azygos vein aneurysm

Aneurysms of the azygos vein are often asymptomatic, detected on a chest radiograph simulating paratracheal mass. When the aneurysm is totally thrombosed, it is impossible to distinguish it from another cause of mediastinal mass. A case is presented in which partial thrombosis of the aneurysm and communication with the superior vena cava led to a diagnosis on angiography and CT.

[Congenital absence of a cervical spine pedicle: misdiagnosis in a context of trauma]

Absence of a cervical spine pedicle is an exceptional congenital anomaly with a characteristic radiographic triad: i) absence of pedicle producing a pseudo-enlargement of the homolateral foramen, ii) dysplastic aspect with posterior displacement of the homolateral facets and lamina, and iii) defect or absence of the homolateral transverse process. It is particularly important to recognize this radiographic picture in order to avoid misdiagnosis, e.g. unilateral fracture-displacement of the facet joints in a context of acute trauma, as occurred in our case, or pathological enlargement of the foramen (neurofibroma) without trauma. We describe the radiographic presentation of this congenital anomaly, stressing the importance of a homolateral oblique view and the usefulness of computed tomography for correct diagnosis.

[Radiologic appearance of epiploic appendages and their complications]

A wide spectrum of pathologic processes can involve epiploic appendages, and primary epiploic appendagitis is the most frequent. Pathologic processes are today more frequently identified with the increased use of radiological assessment (ultrasound and computed tomography) of patients presenting with acute abdominal pain. Recognition of specific imaging abnormalities of complications enables the radiologist to make the diagnosis, thus allowing appropriate treatment.

Caractérisation des incidentalomes surrénaliens découverts sur tomodensitométrie, revue générale

The detection of an incidentaloma at abdominal Computed Tomography (CT), except CT features that permit a specific diagnosis (hemorrhage, myelolipoma or cyst), become a problem to differentiate adenomas from "non adenomas" (primary or secondary malignancy) incidentalomas. A density of ten Hounsfield units or less with a nonenhanced CT is a feature of benign incidentaloma (essentially lipid-rich adrenal adenomas). There are two limitations of this characterization: incidentalomas initially detected at enhanced CT and lipid-poor adrenal adenomas. The relative enhancement washout on enhanced CT, by using a threshold of 50% washout, permit then to characterized as adenomas or "non adenomas" incidentalomas on a 10-minute-delayed enhanced CT. Limitations of this characterization are only for benign pheochromocytomas and atypical adrenal cortical carcinomas.

[Iatrogenic renal perforation during percutaneous angioplasty]

Percutaneous transluminal angioplasty is recommended as the first choice of therapy for renal artery stenosis. However, morbidity and mortality are significant. Among hemorrhagic complications, renal perforation is unusual. A case is reported, caused by the use of an angled hydrophilic guidewire, in which the diagnosis has been made by computed tomography angiography with typically perirenal hematoma and extravasation of contrast material corresponding to the perforation. This complication has been successfully treated with conservative measures.

[Isolated dissection of the superior mesenteric artery]

Isolated spontaneous dissection of the superior mesenteric artery is uncommon. We report a case complicated by arterial rupture and discuss diagnostic imaging work-up. Diagnosis is usually made by conventional arteriography. But, dissection can also be diagnosed noninvasively by computed tomography angiography and ultrasound.