Is the social parasite Vespa dybowskii using chemical transparency to get her eggs accepted?

Both avian and insect cuckoos must trick their hosts into accepting foreign eggs. In birds this is achieved through egg mimicry. Within the hornets the only known social parasite is the rare Vespa dybowskii. We investigated how the V. dybowskii queen induces tens or hundreds of host workers to accept her eggs and offspring. Since hydrocarbons function as recognition cues in social insects, we investigated these compounds from the surface of eggs and workers of V. dybowskii, both host species (V. simillima and V. crabro) and an additional four non-host species. We found that chemical mimicry of the hosts’ colony odour and their eggs normally associated with wasps was not being employed by V. dybowskii. Chemical insignificance is also unlikely as the amounts of hydrocarbons extracted from parasite, host and non-host eggs were similar. Eggs of V. dybowskii may survive in part due to being chemically transparent, as methyl-branched compounds only represent a tiny proportion (<1%) of the parasites hydrocarbon profile but a large proportion (26–41%) in both host species. However, the functions of various hydrocarbon groups need to be investigated in the hornets before this new acceptance mechanism of parasite eggs and adults is understood.     

HIV aspartyl protease inhibitors as promising compounds against Candida albicans André Luis Souza dos Santos

Cells of Candida albicans (C. albicans) can invade humans and may lead to mucosal and skin infections or to deep-seated mycoses of almost all inner organs, especially in immunocompromised patients. In this context, both the host immune status and the ability of C. albicans to modulate the expression of its virulence factors are relevant aspects that drive the candidal susceptibility or resistance; in this last case, culminating in the establishment of successful infection known as candidiasis. C. albicans possesses a potent armamentarium consisting of several virulence molecules that help the fungal cells to escape of the host immune responses. There is no doubt that the secretion of aspartyl-type proteases, designated as Saps, are one of the major virulence attributes produced by C. albicans cells, since these hydrolytic enzymes participate in a wide range of fungal physiological processes as well as in different facets of the fungal-host interactions. For these reasons, Saps clearly hold promise as new potential drug targets. Corroborating this hypothesis, the introduction of new anti-human immunodeficiency virus drugs of the aspartyl protease inhibitor-type (HIV PIs) have emerged as new agents for the inhibition of Saps. The introduction of HIV PIs has revolutionized the treatment of HIV disease, reducing opportunistic infections, especially candidiasis. The attenuation of candidal infections in HIV-infected individuals might not solely have resulted from improved immunological status, but also as a result of direct inhibition of C. albicans Saps. In this article, we review updates on the beneficial effects of HIV PIs against the human fungal pathogen C. albicans, focusing on the effects of these compounds on Sap activity, growth behavior, morphological architecture, cellular differentiation, fungal adhesion to animal cells and abiotic materials, modulation of virulence factors, experimental candidiasis infection, and their synergistic actions with classical antifungal agents.     

Host dispersal as the driver of parasite genetic structure: a paradigm lost?

Understanding traits influencing the distribution of genetic diversity has major ecological and evolutionary implications for host–parasite interactions. The genetic structure of parasites is expected to conform to that of their hosts, because host dispersal is generally assumed to drive parasite dispersal. Here, we used a meta‐analysis to test this paradigm and determine whether traits related to host dispersal correctly predict the spatial co‐distribution of host and parasite genetic variation. We compiled data from empirical work on local adaptation and host–parasite population genetic structure from a wide range of taxonomic groups. We found that genetic differentiation was significantly lower in parasites than in hosts, suggesting that dispersal may often be higher for parasites. A significant correlation in the pairwise genetic differentiation of hosts and parasites was evident, but surprisingly weak. These results were largely explained by parasite reproductive mode, the proportion of free‐living stages in the parasite life cycle and the geographical extent of the study; variables related to host dispersal were poor predictors of genetic patterns. Our results do not dispel the paradigm that parasite population genetic structure depends on host dispersal. Rather, we highlight that alternative factors are also important in driving the co‐distribution of host and parasite genetic variation.     

On the tensions of universities as a social institution – developing a comparative sociology of higher education

This review of Natasha Warikoo’s timely and insightful intervention on the relationship between race, social mobility and elite university institutions argues that education has always presented a profoundly contested terrain for debates about race, racism and inclusion but that for too long those debates were confined to pre-eighteen education. The review argues that this study, with its revelatory, comparative U.S./U.K. lens, reveals the complex tensions, ambitions, achievements, identifications, anxieties, limits of diversity, and denials that shape the experiences and perspectives of those students who are part of the population of elite universities. It concludes that Warikoo’s work makes an original and important contribution to the emergent and much needed sociology of higher education.     

Hydrodynamics of Ebrié lagoon as revealed by a chemical and isotopic study

To determine the origin and the circulation of waters in the different areas of the Ebrié lagoon (Ivory Coast), ionic concentrations (K⁺ Cl^-) and isotopic (¹⁸O) measurements were performed. Sixty stations were sampled. Chemical and isotopic analyses were made thrice during a hydrological cycle: in May 1986, at the end of the great dry season; in October 1986, during the maximum of rainfall, in December 1987, after the Comoe river peak flow. From a hydrodynamical point of view, the results reported in this work indicate that the lagoon comprises four distinctive areas. The first is filled with freshwater all the year round and is characterized by an weak isotopic enrichment (these waters are of continental origin and annually renewed); the second corresponds to oligohaline waters highly enriched in¹⁸O (waters essentially of continental origin and poorly renewed); the third area is constituted of a mixture of waters of continental and oceanic origins. The latter group can be separated into two subgroups: a group completely renewed by oceanic water during the dry season and another group totally renewed by freshwater during the rainy and flood seasons.     

Campylobacter Infection as a Trigger for Guillain-Barré Syndrome in Egypt

Background

Most studies of Campylobacter infection triggering Guillain-Barré Syndrome (GBS) are conducted in western nations were Campylobacter infection and immunity is relatively rare. In this study, we explored Campylobacter infections, Campylobacter serotypes, autoantibodies to gangliosides, and GBS in Egypt, a country where Campylobacter exposure is common.

Methods

GBS cases (n = 133) were compared to age- and hospital-matched patient controls (n = 374). A nerve conduction study was performed on cases and a clinical history, serum sample, and stool specimen obtained for all subjects.

Results

Most (63.3%) cases were demyelinating type; median age four years. Cases were more likely than controls to have diarrhea (29.5% vs. 22.5%, Adjusted Odds Ratio (ORa) = 1.69, P = 0.03), to have higher geometric mean IgM anti-Campylobacter antibody titers (8.18 vs. 7.25 P<0.001), and to produce antiganglioside antibodies (e.g., anti-Gd1a, 35.3 vs. 11.5, ORa = 4.39, P<0.0001). Of 26 Penner:Lior Campylobacter serotypes isolated, only one (41:27, C. jejuni, P = 0.02) was associated with GBS.

Conclusions

Unlike results from western nations, data suggested that GBS cases were primarily in the young and cases and many controls had a history of infection to a variety of Campylobacter serotypes. Still, the higher rates of diarrhea and greater antibody production against Campylobacter and gangliosides in GBS patients were consistent with findings from western countries.     

Is there such thing as a parasite free lunch? The direct and indirect consequences of eating invasive prey

As the number of invasive species increases globally, more and more native predators are reported to shift their diet toward invasive prey. The consequences of such diet shifts for the health of populations of native predators are poorly studied, but diet shifts are expected to have important parasitological and immunological consequences, ultimately affecting predator fitness. We reviewed evidence that diet shifts from native to invasive prey can alter parasite exposure directly and also indirectly affect immune functions via changes in condition and contaminant exposure. We highlight relevant conceptual and methodological tools that should be used for the design of experiments aimed at exploring important links between invasive prey and parasitism, contaminants and fitness of their native predators.     

Does pulsatile urea excretion serve as a social signal in the gulf toadfish Opsanus beta?

This study evaluated the hypothesis that the pulsatile excretion of urea by toadfish could serve as a social signal. In the first experiment, physiological parameters were measured in pairs of dominant and subordinate toadfish. Subordinate toadfish had elevated concentrations of circulating plasma cortisol, an effect maintained even after cannulation. In the second experiment, one fish of a pair was injected with 14C-urea, and the occurrence of urea pulses during social encounters was documented. Social status did not influence the order of pulsing, that is, whether a dominant or subordinate fish pulsed first during a social encounter. However, in seven out of eight pairs, both toadfish pulsed within 2 h of each other, indicating some form of communication between fish. In the third and final experiment, the response of toadfish to urea (natural or synthetic) was observed. There was a tendency for toadfish to avoid synthetic urea but there was no apparent behavioural response to water containing toadfish urea. Pulsing events do not appear to play an integral role during social encounters as previously hypothesised, but the close timing of pulses in toadfish pairs suggests some transfer of information.     

Observations biologiques sur la fourmiPlagiolepis grassei Le Masne Passera parasite social dePlagiolepis pygmæa Latr. (Hym. Formicidae)

Résumé Plagiolepis grassei est une Fourmi «parasite social» incapable de survivre de façon autonome, hôte obligatoire dePlagiolepis pygmæa.Les reines et les ouvrièresP. grassei ont un comportement très pacifique et accueillent sans difficulté des individus de leur propre espèce ou de l'espèce hôte.Les ufs (0,34 mm de long en moyenne) sont pondus au printemps.La chronologie de l'apparition des castes est la suivante: au début de l'été, éclosion des sexués des 2 sexes issus du couvain hivernant, lui-même résultant des ufs les derniers pondus l'année précédente; puis apparition de sexués des 2 sexes originaires du couvain de l'année (ufs les premiers pondus); enfin éclosion des ouvrières provenant d'ufs de l'année. L'apparition des sexués avant les ouvrières est un cas unique chez les Fourmis.Il y a production dans les mêmes colonies de sexués mâles et femelles.Expérimentalement, il y a envol des sexués etretour des femelles désailées dans leur nid d'origine. Ceci, joint au massacre des reinesP. grassei par les coloniesP. pygmæa lors des tentatives d'adoption, nous fait pencher vers une multiplication des sociétés par bouturage.

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Summary Plagiolepis grassei, a social parasitic ant is unable to survive autonomously; it is a compulsory host ofPlagiolepis pygmæa.ThePlagiolepis grassei queens and workers behave pacifically and receive without any difficulty individuals of their own species or of the hostspecies.Their eggs (0,34 mm average long) are laid in springtime.The chronology of the apparition of the castes is as follow: in early summer the winged males and females hatch out of the wintry brood resulting itself from the last eggs laid the year before; then the winged males and females appear which hatch out of the brood of the year (the first laid eggs); lastly the workers hatch from the eggs laid in the year.The apparition of winged males and females before the worker's is a unique case among ants.There is a production of winged males and females in the same colonies.In the experience, there is a mating flight of the alates andreturn of the wingless queens into their nests of origin. This added to the slaughter of the queens ofP. grassei by theP. pygmæa colonies during the attempt of adoption makes us incline towards a multiplication of the societies through slips.

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Zusammenfassung Plagiolepis grassei ist eine soziale Schmarotzerameise, sie ist unfähig, auf eine autonome Weise Zu überleben, und sie ist der verbindliche Gast vonPlagiolepis pygmæa.Die Königinnen und die Arbeiterinnen vonP. grassei haben ein ganz friedliches Verhalten und nehmen ohne Schwierigkeiten Einzelne ihrer eigenen Spezies oder der Gastspezies.Die Eier (durchschnittliche Länge: 0,34 mm.) werden im Frühling gelegt.Die Chronologie in der Erscheinung der Kasten ist folgende: am Anfang des Sommers schlüpfen die Geschlechtstiere, Weibchen und Männchen, aus der mit den im vorigen Jahr gelegten. Eiern gebildeten Winterbrut; dann Erscheinung von Geschlechtstieren; Weibchen und Männchen, aus der Brut des Jahres (erst gelegte Eier); schliesslich schlüpfen die Arbeiterinnen aus der Brut des Jahres aus.Die Erscheinung der Geschlechtstiere vor den Arbeiterinnen ist ein einzelner Fall bei den Ameisen.Eine Produktion von Geschlechtstieren, Weibchen und Männchen, findet in derselben Kolonie statt.Im Verlauf des Versuchs beobachtet man einen Schwarmflug der Geschlechtstiere unddie Rückkehr der flügellosen Königinnen in das Stammnest. Dieses, nebst dem Gemetzel derP. grassei Königinnen von denP. pygmæa Kolonien während der Aufnahmeversuche lässt uns an eine Vermehrung der Ameisenstaaten durch Stecklinge denken.

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Cette note constitue une partie d'une thèse qui sera présentée devant la Faculté des Sciences de Toulouse (Laboratoire d'Entomologie) en vue d'obtenir le doctorat ès Sciences Naturelles.     

Microsatellite Analysis Characterizes Burkina Faso as a Genetic Contact Zone Between Sahelian and Djallonké Sheep

A total of 123 sheep belonging to the Djallonké, Mossi, and Burkina-Sahel breeds, along with 41 Spanish Xalda sheep were genotyped for 27 microsatellites. The pair Djallonké-Mossi had the highest between breeds molecular coancestry. Admixture analysis informed on the parental role of the Burkina-Sahel and Djallonké breeds. The Mossi breed was a hybrid population nearer to the Djallonké breed. Only half of the Mossi individuals were correctly assigned to their breed. The Burkina-Sahel and Djallonké breeds can be considered ancestrally different genetic entities. Differentiation between the Djallonké and Mossi breeds may be due to introgression of Sahelian sheep.     

Use of koji prepared with a high citric acid producing mutant of Aspergillus usamii as a raw material for Saké brewing

There is a possibility of developing a new kind of saké in which the refreshing sour taste of citric acid is introduced. In this study, we bred a new mutant of Aspergillus usamii mut. shiro-usamii that produced much citric acid. The koji prepared with the mutant contained about 20 mg of citric acid per gram of dry koji, twice that of the koji of the parental strain. The activities of a-amylase, glucoamylase, and acidic protease in the koji prepared with the mutant were 82%, 94%, and 95%, respectively, those of the parental strain. Using this koji with the mutant, saké was produced. The levels of citric acid and isoamyl acetate were 5.1 and 1.4 times, respectively, those of saké prepared with koji of A. oryzae. Sensory tests indicated that saké made with koji with the mutant was refreshingly sour, with a good aroma.     

Cluster analysis as a method for evaluation of genetic similarity in specific host — parasite interaction (Lactuca sativa — Bremia lactucae)

Summary In gene-for-gene systems, specificity of hostparasite interactions is most often estimated qualitatively using the symbols +, –, (i.e. susceptibility and/or resistance). In large sets (interaction patterns) it becomes impossible to analyze numerous data by mere comparison. This is overcome by application of cluster analysis. In our experiments the methods in question were used to estimate the data obtained in a study on interactions between more than 220 Lactuca sativa cultivars and 12 Bremia lactucae physiological races (isolates) of Czechoslovak origin. The matrix of similarity coefficients was analyzed by hierarchical clustering. Similarity and/or dissimilarity of host R-genotypes was graphically expressed using the method of two principal components. The results obtained are related to genetic constitution of race specific resistance of the host and the possibility of predicting effective resistance sources.     

Guillain-Barré syndrome as a cause of acute flaccid paralysis in Iraqi children: a result of 15 years of nation-wide study

Background

Guillain-Barré syndrome (GBS) is the most common cause of acute flaccid paralysis (AFP) in the post-poliomyelitis eradication era. This is the first study done to identify the epidemiology, clinical features, and outcome of GBS in Iraqi children over 15 years.

Methods

The surveillance database about AFP cases?<?15 years reported during January 1997-December 2011 was used.

Results

GBS represented 52.5% of AFP cases, with an incidence of 1.33 case/100,000 population?<?15 years/year. There was a higher incidence in the Southern provinces, age group 1–4 years, males, and outside the capital city of province, with no significant seasonal variations (p?=?.22). Survival probability after the 1 year of onset for those with respiratory muscle involvement was .76 (95% CI: .60-.86), versus .97 (95% Cl: .96-.98) for those who did not develop it (p?<?.001); and .97 (95% CI: .96-.98) for those living inside the capital city, versus .94 (.93-.95) for those living outside (p?=?.001). Cumulative incidence of residual paralysis for patients living inside the capital city was .21 (95% CI: .18-.24), versus .27 (95% CI: .25-.29) for those living outside (p?<?.001).

Conclusions

The incidence, age and gender distribution, and seasonality of GBS among Iraqi children is similar to those reported from other previous studies. It is the most important cause of AFP, especially in those between the age of 1 to 4 years living in rural areas.

     

Old drugs as lead compounds for a new disease? Binding analysis of SARS coronavirus main proteinase with HIV, psychotic and parasite drugs

The SARS-associated coronavirus (SARS-CoV) main proteinase is a key enzyme in viral polyprotein processing. To allow structure-based design of drugs directed at SARS-CoV main proteinase, we predicted its binding pockets and affinities with existing HIV, psychotic and parasite drugs (lopinavir, ritonavir, niclosamide and promazine), which show signs of inhibiting the replication of SARS-CoV. Our results suggest that these drugs and another two HIV inhibitors (PNU and UC2) could be used as templates for designing SARS-CoV proteinase inhibitors.     

Environmental change as a driver of diversification in temporary aquatic habitats: does the genetic structure of extant fairy shrimp populations reflect historic aridification?

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