Is there an efficient trap or collection method for sampling Anopheles darlingi and other malaria vectors that can describe the essential parameters affecting transmission dynamics as effectively as human landing catches? - A Review

Distribution, abundance, feeding behaviour, host preference, parity status and human-biting and infection rates are among the medical entomological parameters evaluated when determining the vector capacity of mosquito species. To evaluate these parameters, mosquitoes must be collected using an appropriate method. Malaria is primarily transmitted by anthropophilic and synanthropic anophelines. Thus, collection methods must result in the identification of the anthropophilic species and efficiently evaluate the parameters involved in malaria transmission dynamics. Consequently, human landing catches would be the most appropriate method if not for their inherent risk. The choice of alternative anopheline collection methods, such as traps, must consider their effectiveness in reproducing the efficiency of human attraction. Collection methods lure mosquitoes by using a mixture of olfactory, visual and thermal cues. Here, we reviewed, classified and compared the efficiency of anopheline collection methods, with an emphasis on Neotropical anthropophilic species, especially Anopheles darlingi, in distinct malaria epidemiological conditions in Brazil.

Intracortical connectivity of layer VI pyramidal neurons in the somatosensory cortex of normal and barrelless mice.

In mice, barrels in layer IV of the somatosensory cortex correspond to the columnar representations of whisker follicles. In barrelless (BRL) mice, barrels are absent, but functionally, a columnar organization persists. Previously we characterized the aberrant geometry of thalamic projection of BRL mice using axonal reconstructions of individual neurons. Here we proceeded with the analysis of the intracortical projections from layer VI pyramidal neurons, to assess their contribution to the columnar organization. From series of tangential sections we reconstructed the axon collaterals of individual layer VI pyramidal neurons in the C2 barrel column that were labelled with biocytin [controls from normal (NOR) strain, 19 cells; BRL strain, nine cells]. Using six morphological parameters in a cluster analysis, we showed that layer VI neurons in NOR mice are distributed into four clusters distinguished by the radial and tangential extent of their intracortical projections. These clusters correlated with the cortical or subcortical projection of the main axon. In BRL mice, neurons were distributed within the same four clusters, but their projections to the granular and supragranular layers were significantly smaller and their tangential projection was less columnar than in NOR mice. However, in both strains the intracortical projections had a preference for the appropriate barrel column (C2), indicating that layer VI pyramidal cells could participate in the functional columnar organization of the barrel cortex. Correlative light and electron microscopy analyses provided morphometric data on the intracortical synaptic boutons and synapses of layer VI pyramidal neurons and revealed that projections to layer IV preferentially target excitatory dendritic spines and shafts.

Use and availability of scholarly journals in Catalan academic libraries

This paper presents the results of a survey of academics affiliated to the universities that are members of the Consortium of Academic Libraries of Catalonia (CBUC), and an analysis of the availability in the libraries of these universities, of the references cited in a sample of articles published by these academics. The results reflect the major importance that researchers assign to scholarly journals as the main source of scientific information. Most state that they use electronic journals either exclusively or in any case more than print journals, a preference that is higher among younger scholars. With regard to frequency of reading, four out of ten researchers state that they read journals virtually every day, while nine out of ten report that they do so at least once a week. Scholars claim that the obstacles they face when trying to download an article are related to the lack of subscriptions. However, the availability study showed that most of the articles cited in their publications are available at least at one of the CBUC libraries. Though most researchers keep a copy of the articles they consult, just over a third of them use some kind of reference management software.

Effect of mouse antisera targeting the Phlebotomus papatasi midgut chitinase PpChit1 on sandfly physiology and fitness

In sandflies, the absence of the peritrophic matrix (PM) affects the rate of blood digestion. Also, the kinetics of PM secretion varies according to species. We previously characterised PpChit1, a midgut-specific chitinase secreted in Phlebotomus papatasi (PPIS) that is involved in the maturation of the PM and showed that antibodies against PpChit1 reduce the chitinolytic activity in the midgut of several sandfly species. Here, sandflies were fed on red blood cells reconstituted with naïve or anti-PpChit1 sera and assessed for fitness parameters that included blood digestion, oviposition onset, number of eggs laid, egg bouts, average number of eggs per bout and survival. In PPIS, anti-PpChit1 led to a one-day delay in the onset of egg laying, with flies surviving three days longer compared to the control group. Anti-PpChit1 also had a negative effect on overall ability of flies to lay eggs, as several gravid females from all three species were unable to lay any eggs despite having lived longer than control flies. Whereas the longer survival might be associated with improved haeme scavenging ability by the PM, the inability of females to lay eggs is possibly linked to changes in PM permeability affecting nutrient absorption.

Prophylaxis with resin in wood ants

Animals may use plant compounds to defend themselves against parasites. Wood ants, Formica paralugubris, incorporate pieces of solidified conifer resin into their nests. This behaviour inhibits the growth of bacteria and fungi in nest material and protects the ants against some detrimental microorganisms. Here, we studied the resin-collecting behaviour of ants under field and laboratory conditions. First, we focused on an important assumption of the self-medication hypothesis, which is that the animals deliberately choose the active plant material. In field cafeteria tests, the ants indeed showed a strong preference for resin over twigs and stones, which are building materials commonly encountered in their environment. We detected seasonal variation in the choice of ants: the preference for resin over twigs was more pronounced in spring than in summer, whereas in autumn the ants collected twigs and resin at equal rates. Second, we found almost similar seasonal patterns when comparing the collecting rates of pieces of wood that had been impregnated with turpentine (a distillate of oleoresin) and untreated pieces of wood, which reveals that the preference for resin is based on odour cues. Third, we tested whether the collection of resin is prophylactic or therapeutic. We found that the relative collection rate of resin versus stones did not depend on an experimental infection with the entomopathogenic fungus Metarhizium anisopliae in laboratory colonies. Together, these results show that the ants deliberately choose the resin and suggest that resin collection is prophylactic rather than therapeutic.

Positive feedback in the transition from sexual reproduction to parthenogenesis.

Understanding how new phenotypes evolve is challenging because intermediate stages in transitions from ancestral to derived phenotypes often remain elusive. Here we describe and evaluate a new mechanism facilitating the transition from sexual reproduction to parthenogenesis. In many sexually reproducing species, a small proportion of unfertilized eggs can hatch spontaneously ('tychoparthenogenesis') and develop into females. Using an analytical model, we show that if females are mate-limited, tychoparthenogenesis can result in the loss of males through a positive feedback mechanism whereby tychoparthenogenesis generates female-biased sex ratios and increasing mate limitation. As a result, the strength of selection for tychoparthenogenesis increases in concert with the proportion of tychoparthenogenetic offspring in the sexual population. We then tested the hypothesis that mate limitation selects for tychoparthenogenesis and generates female-biased sex ratios, using data from natural populations of sexually reproducing Timema stick insects. Across 41 populations, both the tychoparthenogenesis rates and the proportions of females increased exponentially as the density of individuals decreased, consistent with the idea that low densities of individuals result in mate limitation and selection for reproductive insurance through tychoparthenogenesis. Our model and data from Timema populations provide evidence for a simple mechanism through which parthenogenesis can evolve rapidly in a sexual population.

Causal mechanisms underlying host specificity in bat ectoparasites.

In parasites, host specificity may result either from restricted dispersal capacity or from fixed coevolutionary host-parasite adaptations. Knowledge of those proximal mechanisms leading to particular host specificity is fundamental to understand host-parasite interactions and potential coevolution of parasites and hosts. The relative importance of these two mechanisms was quantified through infection and cross-infection experiments using mites and bats as a model. Monospecific pools of parasitic mites (Spinturnix myoti and S. andegavinus) were subjected either to individual bats belonging to their traditional, native bat host species, or to another substitute host species within the same bat genus (Myotis). The two parasite species reacted differently to these treatments. S. myoti exhibited a clear preference for, and had a higher fitness on, its native host, Myotis myotis. In contrast, S. andegavinus showed no host choice, although its fitness was higher on its native host M. daubentoni. The causal mechanisms mediating host specificity can apparently differ within closely related host-parasite systems.

Pouvoir attractif des reines de la fourmi d 'Argentine, Iridomyrmex humilis (Mayr). Rôle de la polygynie et du statut physiologique des reines

The fecundity of queens of Iridomyrmex humilis (Mayr) as mesaured by an oviposition test in isolation was correlated with their weight, The relative attractiveness of queens to workers was not correlated with either their weight or fecundity. Comparison of these results with those on other ant species show that queens of I. humilis have a relatively low level of attractiveness. This low attractiveness may result from the high number of queens per nest in I .humilis. This hypothesis is supported by the comparison of the attractiveness of queens in experimental monogynous and polygynous colonies which showed that queens in monogynous colonies have a higher attractiveness to workers. As a consequence of their higher attractiveness, queens in monogynous colonies probably receive more food. This may partially explain the higher weight and fecundity of queens in monogynous colonies. These results are dicussed with regard to some implications of polygyny

Molecular and physiological characterisation of lonotropic receptors in the sacculus in drosophila

Chemosensation is the detection of chemical signals in the environment that enable an animal to make informed decisions about food choice, mate preference or predator detection. Dissecting the molecular and neural mechanisms by which animals detect chemical cues is an important goal towards understanding how they interact with the environment. An attractive system to dissect the mechanisms of chemosensation is the olfactory system. One of the most-investigated olfactory systems is that of Drosophila melanogaster, a model organism that is amenable to a powerful combination of genetic and physiological analyses. Embedded within the antennal olfactory organ of Drosophila is an unusual sensory structure called the sacculus. The sacculus is comprised of three distinct chambers, each lined with several sensilla housing two to three neurons. Previous morphological, anatomical and surgical studies of sacculus neurons have implicated sacculus neurons in chemosensation, hygrosensation and/or thermosensation. While a subset of sacculus neurons have been physiologically characterised as temperature sensors, the role of this organ has remained largely mysterious, due to its inaccessibility to peripheral electrophysiological analysis. Recently a new family of olfactory receptors, the lonotropic Receptors (IRs), was identified. Five IRs are expressed in sacculus neurons providing the first selective molecular markers for these cells. In this thesis I describe the molecular, physiological and anatomical characterisation of these neurons. Genetic labelling of specific populations of sacculus neurons with anatomical (CD8:GFP) reporters has identified neurons in sacculus chambers I and II express IR40a+IR93a together with their co- receptor IR25a, while neurons in chamber III express IR64a with its co-receptor IR8a. Both these sets of neurons project to two distinct glomeruli in the antennal lobe; IR40a neurons project to the column and arm, IR64a neurons project to DC4 and DP1m. Through a live optical imaging screen I showed that these neurons are indeed olfactory and IR64a neurons recognise acidic ligands, while IR40a neurons recognise amine ligands. IR40a and IR64a neurons are in fact composed of anatomically and physiologically distinct subpopulations, strongly implying the existence of other factors that define their functional properties. My thesis identifies the sacculus as a specialised olfactory organ capable of detecting acids and bases, which are of widespread importance to insects. The data from my thesis along with data from other labs show the sacculus is composed of different populations of olfactory sensory neurons and thermosensory neurons. Comparative genomic analysis of sacculus IRs across insects reveals them to be among the most conserved of this receptor repertoire, suggesting that the sacculus represents an evolutionarily ancient insect olfactory acid-base sensor. - La détection des produits chimiques se trouvant dans l'environnement (perception chimiosensorielle) permet à un animal de choisir sa nourriture, son partenaire ou encore d'identifier ses prédateurs. Décortiquer les mécanismes moléculaires et neuronaux grâce auxquels les animaux détectent ces signaux chimiques permet de comprendre comment ces animaux interagissent avec leur environnement. Un système intéressant pour décortiquer ces mécanismes de perception chimiosensorielle est le système olfactif, de la drosophile (Drosophila melanogaster), aussi appelée mouche du vinaigre. C'est un animal modèle très utile grâce à la combinaison d'outils génétiques puissants et d'analyses physiologiques facilement réalisables. Dans l'antenne de la drosophile, qui est l'organe olfactif principal de cet animal, se trouve une structure appelée sacculus. Celui-ci est composé de trois chambres distinctes, chacune comprenant plusieurs sensilles à l'intérieur desquelles se trouvent deux à trois neurones. De précédentes études morphologiques et anatomiques des ces neurones ont déterminé qu'ils sont impliqués dans la perception des odeurs, de l'humidité et de la température. Malgré ceci, la fonction principale de cet organe reste largement inconnue, principalement car il est inaccessible aux analyses électrophysiologiques. Récemment, une nouvelle famille de soixante-six récepteurs olfactifs, nommés Récepteurs lonotropiques (IRs), a été découverte chez la drosophile. Cinq IRs sont exprimés dans les neurones du sacculus. Pour la première fois, une sélection de marqueurs moléculaires est disponible pour l'étude de ces cellules. Dans cette thèse, les caractéristiques moléculaires, physiologiques et anatomiques des neurones du sacculus sont décrites. Ces populations de neurones situés dans le sacculus ont été marquées avec des gènes rapporteurs (CD8:GFP). Ceci a montré que les récepteurs IR40a et IR93a sont exprimés ensemble avec le co-récepteur IR25a dans les chambres I et II, tandis que les neurones de la chambre III expriment IR64a avec son co-récepteur IR8a. Ces deux groupes de neurones projettent vers deux glomérules distincts du lobe antennaire : les neurones IR40a projettent vers la column et le arm, alors que les neurones IR64a projettent vers DC4 et DP1m. Un screen d'imagerie optique a démontré que ces neurones sont en effet des neurones olfactifs, et que les neurones IR64a reconnaissent des ligands acides, tandis que les neurones IR40a reconnaissent des ligands aminés. De plus, les neurones IR40a et IR64a sont séparés en sous-populations distinctes anatomiquement et physiologiquement, et d'autres facteurs permettant de définir leurs propriétés fonctionnelles sont probablement impliqués. Cette thèse identifie ainsi le sacculus comme un organe olfactif spécialisé capable de détecter des acides et amines, lesquels sont très importants pour les insectes. Toutes les données collectées durant cette thèse, combinées aux données d'autres laboratoires, montrent que le sacculus est composé de différentes populations de neurones olfactifs et thermosenseurs. Ces IRs sont très conservés parmi les insectes, suggérant que le sacculus représente révolution d'un ancien détecteur olfactif d'acides et de bases chez l'insecte. - Tous les animaux sont capables de percevoir les signaux chimiques dans leur environnement, comme les odeurs ou le goût, via différents organes. L'odorat est le sens qui permet de percevoir les odeurs, et il est implique des neurones olfactifs qui se trouvent dans le nez des mammifères ou les antennes des insectes. La capacité d'un neurone olfactif à détecter une molécule odorante dépend des types de récepteurs olfactifs qu'il exprime. Il existe deux grandes familles de récepteurs qui perçoivent les odeurs : les Récepteurs Olfactifs, ORs, et Récepteurs lonotropiques IRs, qui détectent différents types d'odeurs avec différents mécanismes. Lorsqu'un récepteur reconnaît une molécule odorante, il convertit ce signal en un signal électrique qui est ensuite transmis au centre olfactif dans le cerveau. La drosophile (Drosophila melanogaster), aussi appelée mouche du vinaigre, est utilisée comme animal modèle pour étudier l'odorat, parce que son génome entier a été séquencé et que ses gènes sont facilement manipulables. De plus, l'anatomie du système olfactif de la mouche est similaire à celui des mammifères, malgré qu'il possède moins de neurones, ce qui le rend moins complexe. Ma thèse a pour objectif d'étudier les Récepteurs lonotropiques dans un organe spécifique, appelé le sacculus, situé dans les antennes. Les neurones du sacculus exprimant des IRs envoient leurs projections au centre olfactif du cerveau, suggérant que ces neurones perçoivent les odeurs. Une technique d'imagerie optique a été utilisée sur le cerveau de mouches vivantes afin de mesurer la réponse des neurones du le sacculus à différentes odeurs. J'ai démontré que ces récepteurs détectent des acides et des amines, qui sont très importants pour les insectes. Par exemple, les acides se retrouvent dans les fruits mûrs sur lesquels les mouches vont se nourrir, s'accoupler et poser leurs oeufs, et les amines sont souvent produites par des bactéries pouvant être nuisible pour la mouche. La principale découverte de ma thèse est donc l'identification du sacculus comme un organe capable de détecter deux des principales odeurs importantes pour la mouche. Ces récepteurs sont aussi présents dans d'autres insectes où ils jouent peut-être des rôles différents. Les acides et les amines se retrouvent aussi dans les excrétions (comme la sueur ou l'urine) de beaucoup de mammifères, qui pourraient potentiellement être dangereux pour la mouche, mais qui attirent les moustiques se nourrissant de leur sang.

ACTG-HIV symptoms changes in patients switched to RPV/FTC/TDF due to previous intolerance to CART. Interim analysis of the PRO-STR study.

INTRODUCTION Tolerability and convenience are crucial aspects for the long-term success of combined antiretroviral therapy (cART). The aim of this study was to investigate the impact in routine clinical practice of switching to the single tablet regimen (STR) RPV/FTC/TDF in patients with intolerance to previous cART, in terms of patients' well-being, assessed by several validated measures. METHODS Prospective, multicenter study. Adult HIV-infected patients with viral load under 1.000 copies/mL while receiving a stable ART for at least the last three months and switched to RPV/FTC/TDF due to intolerance of previous regimen, were included. Analyses were performed by ITT. Presence/magnitude of symptoms (ACTG-HIV Symptom Index), quality of life (EQ-5D, EUROQoL & MOS-HIV), adherence (SMAQ), preference of treatment and perceived ease of medication (ESTAR) through 48 weeks were performed. RESULTS Interim analysis of 125 patients with 16 weeks of follow up was performed. 100 (80%) were male, mean age 46 years. Mean CD4 at baseline was 629.5±307.29 and 123 (98.4%) had viral load <50 copies/mL; 15% were HCV co-infected. Ninety two (73.6%) patients switched from a NNRTI (84.8% from EFV/FTC/TDF) and 33 (26.4%) from a PI/r. The most frequent reasons for switching were psychiatric disorders (51.2%), CNS adverse events (40.8%), gastrointestinal (19.2%) and metabolic disorders (19.2%). At the time of this analysis (week 16), four patients (3.2%) discontinued treatment: one due to adverse events, two virologic failures and one with no data. A total of 104 patients (83.2%) were virologically suppressed (<50 copies/mL). The average degree of discomfort in the ACTG-HIV Symptom Index significantly decreased from baseline (21±15.55) to week 4 (10.89±12.36) & week 16 (10.81±12.62), p<0.001. In all the patients, quality of life tools showed a significant benefit in well-being of the patients (Table 1). Adherence to therapy significantly and progressively increased (SMAQ) from baseline (54.4%) to week 4 (68%), p<0.001 and to week 16 (72.0%), p<0.001. CONCLUSIONS Switching to RPV/FTC/TDF from another ARV regimen due to toxicity, significantly improved the quality of life of HIV-infected patients, both in mental and physical components, and improved adherence to therapy while maintaining a good immune and virological response.

First description of Candida nivariensis in Brazil: antifungal susceptibility profile and potential virulence attributes

This study evaluated the antifungal susceptibility profile and the production of potential virulence attributes in a clinical strain of Candida nivariensis for the first time in Brazil, as identified by sequencing the internal transcribed spacer (ITS)1-5.8S-ITS2 region and D1/D2 domains of the 28S of the rDNA. For comparative purposes, tests were also performed with reference strains. All strains presented low planktonic minimal inhibitory concentrations (PMICs) to amphotericin B (AMB), caspofungin (CAS), and voriconazole. However, our strain showed elevated planktonic MICs to posaconazole (POS) and itraconazole, in addition to fluconazole resistance. Adherence to inert surfaces was conducted onto glass and polystyrene. The biofilm formation and antifungal susceptibility on biofilm-growing cells were evaluated by crystal violet staining and a XTT reduction assay. All fungal strains were able to bind both tested surfaces and form biofilm, with a binding preference to polystyrene (p < 0.001). AMB promoted significant reductions (≈50%) in biofilm production by our C. nivariensis strain using both methodologies. This reduction was also observed for CAS and POS, but only in the XTT assay. All strains were excellent protease producers and moderate phytase producers, but lipases were not detected. This study reinforces the pathogenic potential of C. nivariensis and its possible resistance profile to the azolic drugs generally used for candidiasis management.

Mg/Ca and Sr/Ca ratios of ostracod valves from living species of Lake Geneva

The Mg/Ca and Sr/Ca ratios of living ostracods belonging to 15 different species and sampled monthly over a one year-cycle at five sites (2, 5, 13, 33, and 70 m water depths) in western Lake Geneva (Switzerland) are compared to the oxygen and carbon isotope compositions measured on the same samples as well as to the temperature and chemical composition of the water (δ18OH2O, δ13CDIC, Mg/CaH2O, and Sr/CaH2O) at the time of ostracod calcification. The results indicate that trace element incorporation varied at the species level, mainly because of the ecological and biological differences between the different species (life-cycle, (micro-)habitat preference, biomineralisation processes) and the control thereof on trace element incorporation of the ostracods. In littoral zones, the Mg/Ca and Sr/Ca of ostracod valves increase as temperature and Mg/Ca and Sr/Ca of water increase during spring and summer, hence reflecting mainly seasonal variations. However, given that for Lake Geneva the Mg/Ca and Sr/Ca of water also vary with temperature, it is not possible to distinguish the effects of temperature from those of changes in chemical composition of water on the trace element content in ostracod valves. Results support that both water temperature and water Mg/Ca and Sr/Ca ratios control the final trace element content of Cyprididae valves. In contrast, the trace element content of species living in deeper zones of the basin is influenced by variations in the chemical composition of the pore water for the infaunal species. Trace element content measured for these specimens cannot, therefore, be used to reconstruct the compositions of the water lake bottom. In addition, incorporation of Mg and Sr into the shell differs from one family, sub-family, or even species to the other. This suggests that the distinctive Mg and Sr partition coefcients for the analysed taxa result from different valve calcification strategies that may be phylogenetic.

Patients' and physicians' preferences for type 2 diabetes mellitus treatments in Spain and Portugal: a discrete choice experiment.

OBJECTIVE To assess Spanish and Portuguese patients' and physicians' preferences regarding type 2 diabetes mellitus (T2DM) treatments and the monthly willingness to pay (WTP) to gain benefits or avoid side effects. METHODS An observational, multicenter, exploratory study focused on routine clinical practice in Spain and Portugal. Physicians were recruited from multiple hospitals and outpatient clinics, while patients were recruited from eleven centers operating in the public health care system in different autonomous communities in Spain and Portugal. Preferences were measured via a discrete choice experiment by rating multiple T2DM medication attributes. Data were analyzed using the conditional logit model. RESULTS Three-hundred and thirty (n=330) patients (49.7% female; mean age 62.4 [SD: 10.3] years, mean T2DM duration 13.9 [8.2] years, mean body mass index 32.5 [6.8] kg/m(2), 41.8% received oral + injected medication, 40.3% received oral, and 17.6% injected treatments) and 221 physicians from Spain and Portugal (62% female; mean age 41.9 [SD: 10.5] years, 33.5% endocrinologists, 66.5% primary-care doctors) participated. Patients valued avoiding a gain in bodyweight of 3 kg/6 months (WTP: €68.14 [95% confidence interval: 54.55-85.08]) the most, followed by avoiding one hypoglycemic event/month (WTP: €54.80 [23.29-82.26]). Physicians valued avoiding one hypoglycemia/week (WTP: €287.18 [95% confidence interval: 160.31-1,387.21]) the most, followed by avoiding a 3 kg/6 months gain in bodyweight and decreasing cardiovascular risk (WTP: €166.87 [88.63-843.09] and €154.30 [98.13-434.19], respectively). Physicians and patients were willing to pay €125.92 (73.30-622.75) and €24.28 (18.41-30.31), respectively, to avoid a 1% increase in glycated hemoglobin, and €143.30 (73.39-543.62) and €42.74 (23.89-61.77) to avoid nausea. CONCLUSION Both patients and physicians in Spain and Portugal are willing to pay for the health benefits associated with improved diabetes treatment, the most important being to avoid hypoglycemia and gaining weight. Decreased cardiovascular risk and weight reduction became the third most valued attributes for physicians and patients, respectively.

Application of the european customer satisfaction index to postal services. Structural equation models versus partial least squars

Customer satisfaction and retention are key issues for organizations in today’s competitive market place. As such, much research and revenue has been invested in developing accurate ways of assessing consumer satisfaction at both the macro (national) and micro (organizational) level, facilitating comparisons in performance both within and between industries. Since the instigation of the national customer satisfaction indices (CSI), partial least squares (PLS) has been used to estimate the CSI models in preference to structural equation models (SEM) because they do not rely on strict assumptions about the data. However, this choice was based upon some misconceptions about the use of SEM’s and does not take into consideration more recent advances in SEM, including estimation methods that are robust to non-normality and missing data. In this paper, both SEM and PLS approaches were compared by evaluating perceptions of the Isle of Man Post Office Products and Customer service using a CSI format. The new robust SEM procedures were found to be advantageous over PLS. Product quality was found to be the only driver of customer satisfaction, while image and satisfaction were the only predictors of loyalty, thus arguing for the specificity of postal services

Division of labour and worker size polymorphism in ant colonies: the impact of social and genetic factors

Division of labour among workers is central to the organisation and ecological success of insect societies. If there is a genetic component to worker size, morphology or task preference, an increase in colony genetic diversity arising from the presence of multiple breeders per colony might improve division of labour. We studied the genetic basis of worker size and task preference in Formica selysi, an ant species that shows natural variation in the number of mates per queen and the number of queens per colony. Worker size had a heritable component in colonies headed by a doubly mated queen (h(2)=0.26) and differed significantly among matrilines in multiple-queen colonies. However, higher levels of genetic diversity did not result in more polymorphic workers across single- or multiple-queen colonies. In addition, workers from multiple-queen colonies were consistently smaller and less polymorphic than workers from single-queen colonies. The relationship between task, body size and genetic lineage appeared to be complex. Foragers were significantly larger than brood-tenders, which may provide energetic or ergonomic advantages to the colony. Task specialisation was also often associated with genetic lineage. However, genetic lineage and body size were often correlated with task independently of each other, suggesting that the allocation of workers to tasks is modulated by multiple factors. Overall, these results indicate that an increase in colony genetic diversity does not increase worker size polymorphism but might improve colony homeostasis.