58 research outputs found

    Large Number Discrimination by Mosquitofish

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    Background: Recent studies have demonstrated that fish display rudimentary numerical abilities similar to those observed in mammals and birds. The mechanisms underlying the discrimination of small quantities (,4) were recently investigated while, to date, no study has examined the discrimination of large numerosities in fish. Methodology/Principal Findings: Subjects were trained to discriminate between two sets of small geometric figures using social reinforcement. In the first experiment mosquitofish were required to discriminate 4 from 8 objects with or without experimental control of the continuous variables that co-vary with number (area, space, density, total luminance). Results showed that fish can use the sole numerical information to compare quantities but that they preferentially use cumulative surface area as a proxy of the number when this information is available. A second experiment investigated the influence of the total number of elements to discriminate large quantities. Fish proved to be able to discriminate up to 100 vs. 200 objects, without showing any significant decrease in accuracy compared with the 4 vs. 8 discrimination. The third experiment investigated the influence of the ratio between the numerosities. Performance was found to decrease when decreasing the numerical distance. Fish were able to discriminate numbers when ratios were 1:2 or 2:3 but not when the ratio was 3:4. The performance of a sample of undergraduate students, tested non-verbally using the same sets of stimuli, largely overlapped that of fish

    A frameshift mutation in MOCOS is associated with familial renal syndrome (xanthinuria) in Tyrolean Grey cattle

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    [EN] Background: Renal syndromes are occasionally reported in domestic animals. Two identical twin Tyrolean Grey calves exhibited weight loss, skeletal abnormalities and delayed development associated with kidney abnormalities and formation of uroliths. These signs resembled inherited renal tubular dysplasia found in Japanese Black cattle which is associated with mutations in the claudin 16 gene. Despite demonstrating striking phenotypic similarities, no obvious presence of pathogenic variants of this candidate gene were found. Therefore further analysis was required to decipher the genetic etiology of the condition. Results: The family history of the cases suggested the possibility of an autosomal recessive inheritance. Homozygosity mapping combined with sequencing of the whole genome of one case detected two associated non-synonymous private coding variants: A homozygous missense variant in the uncharacterized KIAA2026 gene (g.39038055C > G; c.926C > G), located in a 15 Mb sized region of homozygosity on BTA 8; and a homozygous 1 bp deletion in the molybdenum cofactor sulfurase (MOCOS) gene (g.21222030delC; c.1881delG and c.1782delG), located in an 11 Mb region of homozygosity on BTA 24. Pathogenic variants in MOCOS have previously been associated with inherited metabolic syndromes and xanthinuria in different species including Japanese Black cattle. Genotyping of two additional clinically suspicious cases confirmed the association with the MOCOS variant, as both animals had a homozygous mutant genotype and did not show the variant KIAA2026 allele. The identified genomic deletion is predicted to be highly disruptive, creating a frameshift and premature termination of translation, resulting in severely truncated MOCOS proteins that lack two functionally essential domains. The variant MOCOS allele was absent from cattle of other breeds and approximately 4% carriers were detected among more than 1200 genotyped Tyrolean Grey cattle. Biochemical urolith analysis of one case revealed the presence of approximately 95% xanthine. Conclusions: The identified MOCOS loss of function variant is highly likely to cause the renal syndrome in the affected animals. The results suggest that the phenotypic features of the renal syndrome were related to an early onset form of xanthinuria, which is highly likely to lead to the progressive defects. The identification of the candidate causative mutation thus enables selection against this pathogenic variant in Tyrolean Grey cattleSIThis research received no specific grant from any funding agency in the public, commercial or non-profit sector

    Canine leishmaniosis in the Italian northeastern Alps: A survey to assess serological prevalence in dogs and distribution of phlebotomine sand flies in the Autonomous Province of Bolzano - South Tyrol, Italy

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    Abstract The Autonomous Province of Bolzano-South Tyrol (APB), located in the northernmost territory of the Italian eastern Alps, is still considered non-endemic for canine leishmaniosis (CanL) despite clinical cases being observed and a competent Leishmania infantum vector (Phlebotomus perniciosus) having been recorded since 2008. A serological survey of leishmaniosis among a randomly-selected subpopulation of registered owned dogs was carried in 2018, followed by entomological investigations performed in 2019 and driven by canine survey results. A total of 457 resident dogs from all over the APB territory were examined through IFAT for antibodies against L.infantum, of which 63 (13.8%) tested positive. Thirty-five seropositive cases (7.7%) were considered autochthonous to APB, i.e. dogs born and lived in the province, or imported dogs with no travel history in the past 5 years. Most of these animals showed an antibody titre at the threshold level of 1:40, suggesting a low degree of parasite transmission/contacts. In 2 autochthonous cases with moderately high IFAT titre, the infection was confirmed by nested-PCR in peripheral blood. Thirty-one georeferenced sites were monitored for sand flies by means of interception (sticky papers) and attraction (CDC miniature light traps) collection devices. Traps were set during summer approximately on monthly basis, and extended up to October for positive sites. Only 2 sites were found positive for a total of 317 phlebotomine specimens collected by sticky traps, which included a previously known P. perniciosus-endemic site near Bolzano town. Sergentomyia minuta was by far the most prevalent (98.1%) and the only recorded sand fly species in the most northerly Italian site ever investigated (Coldrano municipality in Venosta valley). For the first time, Leishmania serology and n-PCR positive dogs autochthonous to APB were identified, however the spread of sand flies competent for L. infantum transmission could not be demonstrated in several places where endemic seropositive cases were recorded. APB can be considered a territory of low CanL endemicity, however awareness and continuous monitoring are needed to detect changes in the epidemiological status of the zoonosis

    Effects of zinc transporters on Cryptococcus gattii virulence

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    Zinc is an essential nutrient for all living organisms because it is a co-factor of several important proteins. Furthermore, zinc may play an essential role in the infectiousness of microorganisms. Previously, we determined that functional zinc metabolism is associated with Cryptococcus gattii virulence. Here, we characterized the ZIP zinc transporters in this human pathogen. Transcriptional profiling revealed that zinc levels regulated the expression of the ZIP1, ZIP2 and ZIP3 genes, although only the C. gattii zinc transporter Zip1 was required for yeast growth under zinc-limiting conditions. To associate zinc uptake defects with virulence, the most studied cryptococcal virulence factors (i.e., capsule, melanin and growth at 37 °C) were assessed in ZIP mutant strains; however, no differences were detected in these classical virulence-associated traits among the mutant and WT strains. Interestingly, higher levels of reactive oxygen species were detected in the zip1Δ and in the zip1Δ zip2Δ double mutants. In line with these phenotypic alterations, the zip1Δ zip2Δ double mutant displayed attenuated virulence in a murine model of cryptococcosis. Together, these results indicate that adequate zinc uptake is necessary for cryptococcal fitness and virulence

    Laterality Enhances Numerical Skills in the Guppy, Poecilia reticulata

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    It has been hypothesized that cerebral lateralization can significantly enhance cognition and that this was one of the primary selective forces shaping its wide-spread evolution amongst vertebrate taxa. Here, we tested this hypothesis by examining the link between cerebral lateralization and numerical discrimination. Guppies, Poecilia reticulata, were sorted into left, right and non-lateralized groups using a standard mirror test and their numerical discrimination abilities tested in both natural shoal choice and abstract contexts. Our results show that strongly lateralized guppies have enhanced numerical abilities compared to non-lateralized guppies irrespective of context. These data provide further credence to the notion that cerebral lateralization can enhance cognitive efficiency

    Transcriptomic analysis reveals that mTOR pathway can be modulated in macrophage cells by the presence of cryptococcal cells

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    Cryptococcus neoformans and Cryptococcus gattii are the etiological agents of cryptococcosis, a high mortality disease. The development of such disease depends on the interaction of fungal cells with macrophages, in which they can reside and replicate. In order to dissect the molecular mechanisms by which cryptococcal cells modulate the activity of macrophages, a genome-scale comparative analysis of transcriptional changes in macrophages exposed to Cryptococcus spp. was conducted. Altered expression of nearly 40 genes was detected in macrophages exposed to cryptococcal cells. The major processes were associated with the mTOR pathway, whose associated genes exhibited decreased expression in macrophages incubated with cryptococcal cells. Phosphorylation of p70S6K and GSK-3β was also decreased in macrophages incubated with fungal cells. In this way, Cryptococci presence could drive the modulation of mTOR pathway in macrophages possibly to increase the survival of the pathogen

    Evidence for Two Numerical Systems That Are Similar in Humans and Guppies

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    Background: Humans and non-human animals share an approximate non-verbal system for representing and comparing numerosities that has no upper limit and for which accuracy is dependent on the numerical ratio. Current evidence indicates that the mechanism for keeping track of individual objects can also be used for numerical purposes; if so, its accuracy will be independent of numerical ratio, but its capacity is limited to the number of items that can be tracked, about four. There is, however, growing controversy as to whether two separate number systems are present in other vertebrate species. Methodology/Principal Findings: In this study, we compared the ability of undergraduate students and guppies to discriminate the same numerical ratios, both within and beyond the small number range. In both students and fish the performance was ratio-independent for the numbers 1–4, while it steadily increased with numerical distance when larger numbers were presented. Conclusions/Significance: Our results suggest that two distinct systems underlie quantity discrimination in both humans and fish, implying that the building blocks of uniquely human mathematical abilities may be evolutionarily ancient, datin

    Ontogeny of Numerical Abilities in Fish

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    Background: It has been hypothesised that human adults, infants, and non-human primates share two non-verbal systems for enumerating objects, one for representing precisely small quantities (up to 3–4 items) and one for representing approximately larger quantities. Recent studies exploiting fish’s spontaneous tendency to join the larger group showed that their ability in numerical discrimination closely resembles that of primates but little is known as to whether these capacities are innate or acquired. Methodology/Principal Findings: We used the spontaneous tendency to join the larger shoal to study the limits of the quantity discrimination of newborn and juvenile guppies. One-day old fish chose the larger shoal when the choice was between numbers in the small quantity range, 2 vs. 3 fish, but not when they had to choose between large numbers, 4 vs. 8 or 4 vs. 12, although the numerical ratio was larger in the latter case. To investigate the relative role of maturation and experience in large number discrimination, fish were raised in pairs (with no numerical experience) or in large social groups and tested at three ages. Forty-day old guppies from both treatments were able to discriminate 4 vs. 8 fish while at 20 days this was only observed in fish grown in groups. Control experiments showed that these capacities were maintained after guppies were prevented from using non numerical perceptual variables that co-vary with numerosity. Conclusions/Significance: Overall, our results suggest the ability of guppies to discriminate small numbers is innate and i

    Modeling and simulation in the production of a pharmaceutical company

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    Abweichender Titel laut Übersetzung der Verfasserin/des VerfassersDie Aktualität des Themas Simulation ist nach wie vor in vielen Bereichen unserer Gesellschaft gegeben. Gerade in Zeiten wirtschaftlicher Krisen, gilt es Ursachen-Wirkungsprinzipien auszuloten und möglichst gute Prognosen über Veränderungsmöglichkeiten und Optimierungsmaßnamen für Unternehmen und staatliche Systeme zu erstellen.Das zentrale Forschungsziel dieser Arbeit ist, einen Teil eines komplexen pharmazeutischen Produktionsprozess als Simulationsmodell abzubilden und anhand der Ergebnisse die Anwendbarkeit und den Nutzen für das Unternehmen aus pragmatischer Sicht abzuleiten. Nach der Aufarbeitung der wesentlichen wissenschaftlichen Grundlagen im Simulationsbereich, wird die Herstellung der Fraktion II-Paste simuliert. Die Fraktion II-Paste stellt ein aufwendig bereinigtes Proteinzwischenprodukt dar, welches aus menschlichem Blutplasma gewonnen wird und für andere Produkte der Octapharma als Grundlage dient.Im ersten Schritt wird über eine Situationsanalyse das Umfeld des Simulationsprojektes erörtert. Die daraus gewonnenen Erkenntnisse dienen als Basis für die Zielformulierung, den konzeptionellen Modellentwurf und die Planung der Experimente. In der darauf folgenden Modellentwicklung in AnyLogic werden iterativ die Schritte der Verifizierung und Validierung zur Überprüfung des Simulationsmodells, beziehungsweise zur Fehlerbehebung, verwendet. Nach einer abschließenden Gesamtmodellvalidierung ist die Richtigkeit und Gültigkeit für das erstellte Simulationsmodell sichergestellt.Aufbauend auf dem validierten Modell kann eine variantenreiche Simulation die verschiedenen Szenarien der Produktion durchspielen und so helfen, Optimierungen aufzufinden. Anhand des Simulationsmodells des Produktionsprozesses werden durch Experimente planerische und optimierungsrelevante Fragen beantwortet. Im letzten Schritt, der Interpretation, wird eine allgemeine Modellanalyse anhand des Simulationsmodells im definierten Gültigkeitsbereich durchgeführt und anhand der Experimente die prognostische und dynamische Gültigkeit diskutiert.Zusammenfassend kann gesagt werden, dass bei den hier gezeigten Ergebnissen für den Produktionsprozess das Modell nicht mit dem realen System verwechselt oder gar als gleichwertig angesehen werden darf. Die Brauchbarkeit für die Produktion in Pharmaunternehmen ist trotzdem eindeutig gegeben, als Ergebnis dieser Arbeit festgehalten und ausreichend analysiert worden.Um den maximalen Nutzen für das Unternehmen zu erreichen, ist es jedoch erforderlich nicht nur Teilbereiche, sondern die gesamte Produktionslandschaft in Simulationsmodellen abzubilden (besonders wenn die Produktionsprozesse nicht unabhängig von einander ablaufen!).16
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