Effects of elevational range shift on the morphology and physiology of a carabid beetle invading the sub-Antarctic Kerguelen Islands.

Climatic changes can induce geographic expansion and altitudinal shifts in the distribution of invasive species by offering more thermally suitable habitats. At the remote sub-Antarctic Kerguelen Islands, the predatory insect Merizodus soledadinus (Coleoptera: Carabidae), introduced in 1913, rapidly invaded coastal habitats. More recent colonisation of higher elevation habitats by this species could be underlain by their increased thermal suitability as the area has warmed. This study compared the effect of elevational range shift on the morphology and physiology of adult M. soledadinus sampled along two altitudinal transects (from the foreshore to 250 m a.s.l.) and a horizontal lowland transect orthogonal to the seashore (400 m length). Although high inter-individual and inter-transect variations in the traits examined were present, we observed that body mass of males and females tended to decrease with elevation, and that triglyceride contents decreased with distance from the shore. Moreover, protein contents of females as well as those of 26 metabolites were influenced significantly by distance to the foreshore. These results suggest that future climate change at the Kerguelen Islands will further assist the colonisation of lowland inland and higher altitude habitats by this aggressively invasive predator, by making previously sub-optimal habitats progressively more suitable.

Distinct physiological, biochemical and morphometric adjustments in the malaria vectors Anopheles gambiae and A. coluzzii as means to survive dry season conditions in Burkina Faso.

Aestivation and dispersive migration are the two strategies evoked in the literature to explain the way in which malaria vectors Anopheles coluzzii and A. gambiae survive the harsh climatic conditions of the dry season in sub-Saharan Africa. However, the physiological mechanisms regulating these two strategies are unknown. In the present study, mosquito species were exposed to controlled environmental conditions mimicking the rainy and dry seasons of south western Burkina Faso. Survival strategies were studied through morphometric (wing length), ecophysiological (respiratory gas exchanges), biochemical (cuticular hydrocarbons composition) and molecular (AKH mRNA expression levels) parameters, variations of which are usually considered to be hallmarks of aestivation and dispersion mechanisms in various insects. Our results showed that ecophysiological and morphometric adjustments are made in both species to prevent water losses during the dry season. However, the usual metabolic rate modifications expected as signatures of aestivation and migration were not observed, highlighting specific and original physiological mechanisms sustaining survival in malaria mosquitoes during the dry season. Differences in epicuticular hydrocarbon composition and AKH levels of expression were found between the permanent and temporary A. coluzzii populations, illustrating the great phenotypic plasticity of this mosquito species. Altogether, our work underlines the diverse and complex pattern of changes occurring in the two mosquito species and at the population level to cope with the dry season and highlights potential targets of future control tools.

Comparative physiological plasticity to desiccation in distinct populations of the malarial mosquito Anopheles coluzzii.

BACKGROUND: In West Africa, populations of the malaria vector mosquito, Anopheles coluzzii, are seasonally exposed to strong desiccating conditions during the dry season. Their dynamics strictly follows the pace of the availability of suitable larval development sites (water collections). Accordingly, mosquitoes can reproduce all year long where permanent breeding is possible, or stop reproduction and virtually disappear at the onset of the dry season when surface water dries up, like observed in temporary habitats of dry savannah areas. This highlights the strong adaptive abilities of this mosquito species, which relies at least in part, upon physiological and molecular mechanisms of specific signatures. METHODS: Here, we analysed a range of physiological and molecular responses expressed by geographically different populations of An. coluzzii inhabiting permanent and temporary breeding sites from the north and the south-west of Burkina Faso. Four mosquito colonies, namely (i) Oursi, built from females breeding in permanent habitats of the north; (ii) Déou, from temporary northern habitats; (iii) Soumousso from south-western temporary breeding sites; and (iv) Bama, from permanent habitats of the same south-western zone, were reared in climatic chambers under contrasted environmental conditions, mimicking temperature, relative humidity and light regimen occurring in northern Burkina Faso. Female mosquitoes were analysed for the seasonal variation in their amounts of proteins, triglycerides and free-circulating metabolites. The expression level of genes coding for the adipokinetic (AKH-I) and the AKH/corazonin-related peptides (ACP) were also assessed and compared among populations and environmental conditions. RESULTS: Our analysis did not reveal an apparent pattern of physiological and molecular variations strictly correlated with either the larval ecotype or the geographical origin of the mosquitoes. However, specific distinct responses were observed among populations, suggesting that dry season survival may rely on more complex ecological parameters at a micro-habitat scale. Interestingly, the physiological and molecular data support the hypothesis that different aestivation abilities exist among populations of An. coluzzii inhabiting contrasted ecological settings. In particular, the striking metabotypes differentiation and the AKH mRNA expression level observed in females from temporary northern populations may suggest the existence of a "strong" aestivation strategy in these specimens. CONCLUSION: Our work provides insights into the physiological and molecular basis of dry and rainy season responses in An. coluzzii, and highlights the important diversity of the mechanisms involved. Such results represent key data for understanding the ecophysiological mechanisms underpinning the strong adaptive potential of this malaria vector species, which undoubtedly contributes to the spreading of mosquito distribution areas in space and time.

Chronic exposure to soil salinity in terrestrial species: Does plasticity and underlying physiology differ among specialized ground-dwelling spiders?

In salt marshes, the alternation of low and high tides entails rapid shifts of submersion and aerial exposure for terrestrial communities. In these intertidal environments, terrestrial species have to deal with an osmotic loss in body water content and an increase in sodium chloride concentration when salt load increases. In salt marshes, spiders represent an abundant arthropod group, whose physiological ecology in response to variations of soil salinity must be further investigated. In this study, we compared the effect of salinity on the survival and physiology of three species of Lycosidae; two salt marsh species (Arctosa fulvolineata and Pardosa purbeckensis) and one forest species (P. saltans). Spiders were individually exposed at three salinity conditions (0‰, 35‰ and 70‰) and survival, changes in body water content, hemolymph ions (Na(+), Ca(2+), Mg(2+), K(+); ICP-MS technique) and metabolites (mainly amino acids, polyols, sugars; LC and GC techniques) were assessed. The survival of the forest species P. saltans was very quickly hampered at moderate and high salinities. In this spider, variations of hemolymph ions and metabolites revealed a quick loss of physiological homeostasis and a rapid salt-induced dehydration of the specimens. Conversely, high survival durations were measured in the two salt-marsh spiders, and more particularly in A. fulvolineata. In both P. purbeckensis and A. fulvolineata, the proportion of Na(+), Ca(2+), Mg(2+), K(+) remained constant at the three experimental conditions. Accumulation of hemolymph Na(+) and amino acids (mainly glutamine and proline) demonstrated stronger osmoregulatory capacities in these salt-marsh resident spiders. To conclude, even if phylogenetically close (belonging to the same, monophyletic, family), we found different physiological capacities to cope with salt load among the three tested spider species. Nevertheless, physiological responses to salinity were highly consistent with the realized ecological niches of the spiders.

Monitoring Dry Season Persistence of Anopheles gambiae s.l. Populations in a Contained Semi-Field System in Southwestern Burkina Faso, West Africa.

To gain insight into the dry season survival strategies of Anopheles gambiae s.l., a new contained semi-field system was developed and used for the first time in Burkina Faso, West Africa. The system consisted of a screened greenhouse within which the local environment was reproduced, including all ecological requirements for mosquito development cycle completion. The system was seeded with the progenies of female Anopheles gambiae, Anopheles coluzzii, and Anopheles arabiensis collected in the vicinity of the greenhouse during the rainy season. After successful establishment in the semi-field system, mosquito populations were monitored over a 1-yr period by regular surveys of larval and adult specimens. We provided evidence for the persistence of adult mosquitoes throughout the dry season, in the absence of any suitable larval development site. During the hot and dry periods, adult insects were observed in artificial shelters (clay pots, building blocks, and dark corners). The mosquito population rapidly built up with the return of the rainy season in the area, when artificial breeding sites were refilled in the enclosure. However, only An. coluzzii and, later, An. arabiensis were detected in the subsequent rainy season, whereas no An. gambiae specimen was found. Our findings suggest that An. coluzzii and An. arabiensis may be able to aestivate throughout the dry season in Southwestern Burkina Faso, whereas An. gambiae might adopt a different dry-season survival strategy, such as long-distance re-colonization from distant locations. These results may have important implications for malaria control through targeted vector control interventions.

Combining two-dimensional gel electrophoresis and metabolomic data in support of dry-season survival in the two main species of the malarial mosquito Anopheles gambiae.

In dry savannahs of West-Africa, the malarial mosquitoes of the Anopheles gambiae sensu stricto complex annually survive the harsh desiccating conditions of the dry season. However, the physiological and biochemical mechanisms underlying how these mosquitoes survive such desiccating conditions are still undefined, and controversial. In this context, we provide the first work examining both proteomic and metabolomic changes in the two molecular forms of A. gambiae s.s (M and S forms) experimentally exposed to the rainy and dry season conditions as they experience in the field. Protein abundances of the mosquitoes were measured using a two-dimensional fluorescence difference gel electrophoresis (2D DIGE) coupled with a matrix-assisted laser desorption/ionisation-time of flight (MALDI-TOF) and tandem mass spectrometry (MS) for protein identification. These assays were conducted by Applied Biomics (http://www.appliedbiomics.com, Applied Biomics, Inc. Hayward, CA, USA), and the mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium (http://proteomecentral.proteomexchange.org) via the PRIDE partner repository with the dataset identifier PXD000294. The metabolomic analysis was conducted using both Acquity UPLC(®) system (for amino acid identification), and a gas-chromatography-mass spectrometry platform (for sugars identification). Metabolomic fingerprintings were assessed in the University of Rennes 1, UMR CNRS 6553 EcoBio (France). A detailed interpretation of the obtained data can be found in Hidalgo et al. (2014) [1] (Journal of Insect Physiology (2014)).

[Ten-year evolution in non-small-cell lung cancer according to sex. Results of the KBP-2010-CPHG study by the College of General Hospital Respiratory Physicians]. / Évolution en 10ans du cancer bronchique non à petites cellules en fonction du sexe. Résultats de l'étude KBP-2010-CPHG du Collège des pneumologues des hôpitaux généraux.

INTRODUCTION: Comparison by sex and presenting features between 2000 and 2010 of the characteristics of new cases of non-small-cell lung cancer (NSCLC). METHODS: Observational KBP-2010-CPHG study similar to KBP-2000-CPHG. Both studies were promoted by the French College of General Hospital Respiratory Physicians (CPHG). KBP-2010-CPHG collected data for 6083 NSCLC diagnosed between January 1st and December 31st, 2010, and followed in the respiratory departments of 119 French general hospitals. RESULTS: In 2010, 24.4 % of the patients were women (16 % in 2000, p<0.0001). Compared to men, women were more commonly non-smokers (34.2 vs 4.7 %) or lighter consumers (37.2 vs 43.7 pack per years) (p<0.0001). Their tumours (mostly adenocarcinoma: 64.6 vs 48.7 %, p<0.0001) were more frequently diagnosed at stage IV (62.4 vs 56.9 %, p=0.0008). EGFR mutation research was more frequently performed (48.5 vs 31.0 %, p<0.0001) and positive (20.6 vs 5.2 %, p<0.0001) in women than men. Their treatment more frequently included targeted therapy (13.4 vs 5.7 %, p<0.0001). Compared to 2000, the percentage of non-smokers increased in men (4.7 vs 2.5 %, p<0.0001) while remaining stable in women (36.1 vs 34.2 %, p=0.32). The percentage of adenocarcinomas increased, particularly in men (48.7 vs 31.5 %, p<0.0001). CONCLUSIONS: The percentage of women with NSCLC has increased in 10years in France. In 2010, the main gender differences persist, but have decreased with the increasing proportion of non-smokers and adenocarcinomas in men. Various hypotheses to explain these changes are discussed.

Novel insights into the metabolic and biochemical underpinnings assisting dry-season survival in female malaria mosquitoes of the Anopheles gambiae complex.

The mechanisms by which Anopheles gambiae mosquitoes survive the desiccating conditions of the dry season in Africa and are able to readily transmit malaria soon after the rains start remain largely unknown. The desiccation tolerance and resistance of female An. gambiae M and S reared in contrasting environmental conditions reflecting the onset of dry season ("ods") and the rainy season ("rs") was determined by monitoring their survival and body water loss in response to low relative humidity. Furthermore, we investigated the degree to which the physiology of 1-h and 24-h-old females is altered at "ods" by examining and comparing their quantitative metabotypes and proteotypes with conspecifics exposed to "rs" conditions. Results showed that distinct biochemical rearrangements occurred soon after emergence in female mosquitoes that enhance survival and limit water loss under dry conditions. In particular, three amino acids (phenylalanine, tyrosine, and valine) playing a pivotal role in cuticle permeability decreased significantly from the 1-h to 24-h-old females, regardless of the experimental conditions. However, these amino acids were present in higher amounts in 1-h-old female An. gambiae M reared under "ods" whereas no such seasonal difference was reported in S ones. Together with the 1.28- to 2.84-fold increased expression of cuticular proteins 70 and 117, our data suggests that cuticle composition, rigidity and permeability were adjusted at "ods". Increased expression of enzymes involved in glycogenolytic and proteolytic processes were found in both forms at "ods". Moreover, 1-h-old S forms were characterised by elevated amounts of glycogen phosphorylase, isocitrate dehydrogenase, and citrate synthase, suggesting an increase of energetic demand in these females at "ods".

Metabolomic and ecdysteroid variations in Anopheles gambiae s.l. mosquitoes exposed to the stressful conditions of the dry season in Burkina Faso, West Africa.

This study explored the metabolic adjustments prompted by a switch between the rainy and dry season conditions in the African malaria mosquitoes Anopheles gambiae (M and S molecular forms) and Anopheles arabiensis. Mosquitoes were reared in contrasted experimental conditions reflecting environmental variation in Burkina Faso. Thirty-five metabolites (including sugars, polyols, and amino acids) were monitored in newly emerged males and females, and their ecdysteroid titers were determined. Metabolomic signatures were remarkably similar across species, when specimens of same age and sex were reared under identical experimental conditions. In males and females, amino acids (including glycine, leucine, phenylanine, serine, threonine, and valine) were accumulated in 1-h-old mosquitoes, then decreased 24 h after emergence, probably reflecting adult maturation and the amino acid-consuming process of cuticle sclerotisation. In turn, elevated amounts of alanine and proline in 24-h-old mosquitoes may assist the development of flight ability. Lower concentration of tricarboxylic acid cycle intermediates and isoleucine characterized older females reared under dry season conditions, suggesting metabolic and reproduction depression. In all cases, ecdysteroid concentration was much higher in males than in females, with significant seasonal variation in males. This might reflect a unique role of these hormones in shaping reproductive strategies and population demography in the An. gambiae s.l. species complex, further contributing to local adaptation in a highly fluctuating environment.

Comparison of preservative-free ketotifen fumarate and preserved olopatadine hydrochloride eye drops in the treatment of moderate to severe seasonal allergic conjunctivitis.

PURPOSE: To compare preservative-free ketotifen 0.025% ophthalmic solution to olopatadine 0.1% ophthalmic solution in with the treatment of seasonal allergic conjunctivitis (SAC) in clinical practice. METHODS: This was a comparative, randomised, investigator-masked, pilot clinical study in adult patients with documented history of SAC and presenting with moderate to severe itching and conjunctival hyperemia. Eligible patients initiated either ketotifen or olopatadine treatment at a dose of one drop twice daily for 28days. The resolution of ocular signs and symptoms was assessed on day 7 and day 28. Itching was also assessed within 15minutes following the first instillation (day 0). Conjunctival impression cytology was performed at each visit to assess the evolution of ICAM-1 expression (day 0, 7 and 28). RESULTS: Seventy-five patients were randomised (ketotifen: 38 patients; olopatadine: 37 patients). At day 28, the composite score for primary criteria (itching, tearing, and conjunctival hyperemia) improved from 6.8±1.2 to 0.9±1.0 in the Ketotifen group, without statistically significant difference between treatment groups (P=0.67). There was no relevant difference between treatment groups in other efficacy parameters, except a trend for a more rapid resolution of conjunctival hyperemia in the Ketotifen group. Both drugs were well tolerated, with a trend for a better tolerability reported by patients on ketotifen compared to those on olopatadine at day 7 (P=0.054). CONCLUSIONS: A rapid and comparable improvement in SAC was achieved after 28days of treatment with both preservative-free ketotifen and preserved olopatadine ophthalmic solutions, with a slightly better ocular tolerance with unpreserved ketotifen 0.025% eye drops.

Seasonal changes in the cold hardiness of the two-spotted spider mite females (Acari: Tetranychidae).

The twospotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae) is an important agricultural pest. Population dynamics and pest outbreaks highly depend on the overwintering success of the mite specimens; therefore, it is necessary to assess winter survival dynamics of this pest. Seasonal changes in supercooling point (SCP) and acute cold tolerance (2-h exposure at -5, -10, -15, -20, -23, or -25°C) were assessed in field-collected females during the winter in 2010-2011 in Iran. The SCP values varied from a minimum of -30.5°C (January 2011) to a maximum of -12.6°C (April 2011). Significant differences were recorded in the SCP distribution patterns between autumn- and winter-sampled females, depicting the acquisition of cold hardiness over the winter. The mean ambient air temperature was the lowest in January (4°C), when the females showed the highest supercooling ability. Correlated patterns between monthly temperatures and acute cold tolerance also were found. At -20°C, the survival of the mites was very low (10%) when they were sampled in October 2010; whereas it was high (97.5%) in January 2011, before decreasing to 5% in April 2011. The present data show that T. urticae females are chill tolerant and capable of adjusting their cold tolerance over the winter season. Acute cold tolerance (-15 and -20°C) and SCP represent valuable metrics that can be used for predicting the seasonal changes of the cold hardiness of T. urticae females.

Preventive antioxidant responses to extreme oxygen level fluctuation in a subterranean crustacean.

The principal aim of this work was to explore the responses of the groundwater crustacean Niphargus rhenorhodanensis to oxidative stress caused by short- and long-term drastic variations in oxygen level. To this end, we investigated thiobarbituric acid reactive substances (TBARS) levels and anti-oxidative enzyme (SOD and GPx) activities during 24 h anoxia and post-anoxia recovery, and during 10 days of severe hypoxia and post-hypoxia recovery. We observed a decrease in TBARS amounts during recovery from severe hypoxia. Parallel to these results, we observed an overactivation of SOD activity after a 24 h anoxic stress. GPx activity measured at the end of anoxia or severe hypoxia and in the early hours of post-stress recovery also showed an overactivation compared to the control group. We can hypothesize that this overproduction of GPx corresponded to an anticipatory mechanism coping with the overproduction of reactive oxygen species (ROS) during the recovery phase in subterranean animals. This response could be considered as a major asset for life in alternately normoxic and hypoxic conditions, and therefore in extreme biotopes such as groundwaters.

Thermal tolerance breadths among groundwater crustaceans living in a thermally constant environment.

The climate variability hypothesis assumes that the thermal tolerance breadth of a species is primarily determined by temperature variations experienced in its environment. If so, aquatic invertebrates living in thermally buffered environments would be expected to exhibit narrow thermal tolerance breadths (stenothermy). We tested this prediction by studying the thermal physiology of three isopods (Asellidae, Proasellus) colonizing groundwater habitats characterized by an annual temperature amplitude of less than 1°C. The species responses to temperature variation were assessed in the laboratory using five physiological variables: survival, locomotor activity, aerobic respiration, immune defense and concentrations of total free amino acids and sugars. The three species exhibited contrasted thermal physiologies, although all variables were not equally informative. In accordance with the climate variability hypothesis, two species were extremely sensitive even to moderate changes in temperature (2°C) below and above their habitat temperature. In contrast, the third species exhibited a surprisingly high thermal tolerance breadth (11°C). Differences in response to temperature variation among Proasellus species indicated that their thermal physiology was not solely shaped by the current temperature seasonality in their natural habitats. More particularly, recent gene flow among populations living in thermally constant yet contrasted habitats might explain the occurrence of eurytherm species in thermally buffered environments.

Metabolic fingerprinting of the responses to salinity in the invasive ground beetle Merizodus soledadinus at the Kerguelen Islands.

Salinity is an abiotic factor that may impact survival and fitness of terrestrial insects in coastal environments. Meanwhile, some terrestrial arthropods can survive in hypersaline environments, and counterbalance osmotic stress by intra- and extracellular buildups of organic osmolytes. The ground beetle Merizodus soledadinus originates from South America and it is distributed in forests and riparian zones, where salinity levels are considerably low. This species has been introduced at the Kerguelen Islands a century ago, where it colonized coastal areas (tide drift lines), and must thus withstand salinity variations due to tide, spray, and organic matter deposited therein. In the present study, we addressed the physiological plasticity of M. soledadinus to saline conditions, by monitoring body water content and survival in adults experimentally subjected to different salinities. We also investigated possible metabolic adjustments involved at three contrasted salinity levels (0‰, 35‰, 70‰) at 4 and 8°C. We hypothesized that this invasive ground beetle can withstand a broad range of salinity conditions thanks to the plastic accumulation of compatible solutes. The study revealed a progressive drop in body water content in individuals exposed to 35‰ and 70‰, as opposed to the controls. Metabolic fingerprints showed compatible solute (erythritol, alanine, glycine and proline) accumulation at medium and high salinity conditions (35‰ and 70‰). We concluded that the osmo-induced accumulation of amino acids and polyols was likely to modulate the ground beetles' body water balance on medium saline substrates, thus enhancing their survival ability.

Internal contamination by actinides after wounding: a robust rodent model for assessment of local and distant actinide retention.

Internal contamination by actinides following wounding may occur in nuclear fuel industry workers or subsequent to terrorist activities, causing dissemination of radioactive elements. Contamination by alpha particle emitting actinides can result in pathological effects, either local or distant from the site of entry. The objective of the present study was to develop a robust experimental approach in the rat for short- and long- term actinide contamination following wounding by incision of the skin and muscles of the hind limb. Anesthetized rats were contaminated with Mixed OXide (MOX, uranium, plutonium oxides containing 7.1% plutonium) or plutonium nitrate (Pu nitrate) following wounding by deep incision of the hind leg. Actinide excretion and tissue levels were measured as well as histological changes from 2 h to 3 mo. Humid swabs were used for rapid evaluation of contamination levels and proved to be an initial guide for contamination levels. Although the activity transferred from wound to blood is higher after contamination with a moderately soluble form of plutonium (nitrate), at 7 d most of the MOX (98%) or Pu nitrate (87%) was retained at the wound site. Rapid actinide retention in liver and bone was observed within 24 h, which increased up to 3 mo. After MOX contamination, a more rapid initial urinary excretion of americium was observed compared with plutonium. At 3 mo, around 95% of activity remained at the wound site, and excretion of Pu and Am was extremely low. This experimental approach could be applied to other situations involving contamination following wounding including rupture of the dermal, vascular, and muscle barriers.

Metabolic effects of CO(2) anaesthesia in Drosophila melanogaster.

Immobilization of insects is necessary for various experimental purposes, and CO(2) exposure remains the most popular anaesthetic method in entomological research. A number of negative side effects of CO(2) anaesthesia have been reported, but CO(2) probably brings about metabolic modifications that are poorly known. In this work, we used GC/MS-based metabolic fingerprinting to assess the effect of CO(2) anaesthesia in Drosophila melanogaster adults. We analysed metabolic variation of flies submitted to acute CO(2) exposure and assessed the temporal metabolic changes during short- and long-term recovery. We found that D. melanogaster metabotypes were significantly affected by the anaesthetic treatment. Metabolic changes caused by acute CO(2) exposure were still manifested after 14 h of recovery. However, we found no evidence of metabolic alterations when a long recovery period was allowed (more than 24 h). This study points to some metabolic pathways altered during CO(2) anaesthesia (e.g. energetic metabolism). Evidence of short-term metabolic changes indicates that CO(2) anaesthesia should be used with utmost caution in physiological studies when a short recovery is allowed. In spite of this, CO(2) treatment seems to be an acceptable anaesthetic method provided that a long recovery period is allowed (more than 24 h).

Habitat phenotyping of two sub-Antarctic flies by metabolic fingerprinting: evidence for a species outside its home?

Metabolic fingerprinting can elucidate rearrangements of metabolic networks in organisms exposed to various environmental conditions. Maintenance of organismal performance occurs by alterations in metabolic fluxes and pathways, resulting in habitat-specific metabolic signatures. Several insects of sub-Antarctic Islands, including the wingless flies Anatalanta aptera and Calycopteryx moseleyi, are exposed to saline organic matter accumulated along littoral margins. However, C. moseleyi has long been considered restricted to a habitat of lower salinity, the Kerguelen cabbage. High C. moseleyi densities identified in saline decaying seaweeds are intriguing, and may involve osmoregulatory adjustments including accumulation of osmoprotectants. In the present work, we examined quantitative metabotypes (metabolic phenotypes) among wild C. moseleyi individuals from seaweeds versus non-saline Kerguelen cabbages. They were compared to metabotypes from wild A. aptera, a common fly on seaweed. Statistical procedures designed to magnify between-class differences failed to clearly separate C. moseleyi metabotypes from cabbage and seaweed, despite contrasted morphotypes, diets, and salinities. A. aptera exhibited higher glycerol, inositol, trehalose, and other osmoprotectants concentrations that may enhance its performance under saline environments. Seaweed may represent a secondary niche in C. moseleyi, promoted by the marked reduction in Kerguelen cabbage frequency subsequent to climate change, and herbivorous pressures caused by rabbit invasion.

Starvation resistance and effects of diet on energy reserves in a predatory ground beetle (Merizodus soledadinus; Carabidae) invading the Kerguelen Islands.

The relationship between nutritional requirements and the availability or quality of food is a prime parameter in determining the geographical expansion of invasive insects. At the sub-Antarctic Kerguelen Islands, the invasive ground beetle Merizodus soledadinus becomes the main invertebrate predator when it colonizes new habitats, leading to the local extinction of native fly species. Such changes in the structure of prey communities may alter the energy management (storage and expenditure) of this predator. In this species, we monitored survival and body mass during food deprivation, in addition to evaluating the effects of two distinct diets (maggots versus enchytraeids) on the consumption and restoration of body reserves (sugars and triglycerides). We found that adults can starve for more than 60 days, and feed every 3.76 days on average when food is available. We recorded higher predation rates on maggots, associated with steeper body mass variations, compared to enchytraeids. Sugars and triglycerides were significantly consumed during food deprivation and restored after refeeding, but varied similarly among individuals supplied on the distinct diets. Other parameters may determine the food preferences observed, such as salt content in prey tissues, because M. soledadinus mainly feeds in hypersaline foreshore habitats, and may limit the consumption of osmotic conformers.

Plasma levels and systemic safety of 0.1% unpreserved timolol maleate gel, 0.5% timolol aqueous solution and 0.5% timolol maleate gel.

PURPOSE: To compare systemic absorption of three formulations of timolol eye drops: 0.1% timolol maleate gel, 0.5% timolol aqueous solution, and 0.5% timolol maleate gel. METHODS: This was a double cross-over phase I study. Cross-over 1: two weeks of 0.1% timolol gel once daily, followed by a 3-week wash-out period and then two weeks of 0.5% timolol aqueous solution twice a day (group 1) or the reverse (group 2). Cross-over 2: two weeks of 0.1% timolol gel once daily, followed by a 3-week wash-out period, and then two weeks of 0.5% timolol gel once daily (group 3) or the reverse (group 4). Subjects underwent tonometry, blood sampling, and heart rate and blood pressure assessments (during bicycle exercise and head-up tilt tests) before and after instillation at the beginning and end of each treatment period. RESULTS: Forty-three healthy volunteers were randomized: 11 subjects in groups 1, 2, and 3, and 10 subjects in group 4. Areas under the concentration-time curve (AUC) values after administration of timolol 0.5% formulations were 15- to 38-fold higher than those seen after administration of timolol 0.1% gel. Maximum timolol concentrations after instillation of 0.1% gel are reduced by almost 90% compared to concentrations obtained after both 0.5% aqueous solution and 0.5% gel instillation. The AUC between 0 and 12 h post-administration were also reduced by up to 93 to 98%. CONCLUSIONS: After treatment with a timolol 0.1% gel formulation, systemic concentrations found were considerably lower than after administration of timolol 0.5% gel or in aqueous solution.

Metabolic rate and oxidative stress in insects exposed to low temperature thermal fluctuations.

Fluctuating temperatures are a predominant feature of the natural environment but their effects on ectotherm physiology are not well-understood. The warm periods of fluctuating thermal regimes (FTRs) provide opportunities for repair leading to increased survival, but there are also indications of negative effects of warm exposure. In this study, we examined respiration and oxidative stress in adult Alphitobius diaperinus exposed to FTRs and to constant low temperatures. We hypothesized that cold exposure will cause oxidative stress and that FTRs would reduce the amount of chill injuries, via activation of the antioxidant system. We measured V˙CO2, activities of super oxide dismutase (SOD), amounts of total (GSHt) and oxidized glutathione (GSSG) during cold and warm periods of FTRs. Increased severity of cold exposure caused a decrease in the glutathione pool. SOD levels increased during the recovery period in the more severe FTR. The antioxidant response was sufficient to counter the reactive oxygen species production, as the GSH:GSSG ratio increased. We conclude that cold stress causes oxidative damage in these beetles, and that a warm recovery period activates the antioxidant system allowing repair of cold-induced damage, leading to the increased survival previously noted in beetles exposed to fluctuating versus constant temperatures.