Developmental plasticity of the stress response in female but not in male guppies

To survive, animals must respond appropriately to stress. Stress responses are costly, so early-life experiences with potential stressors could adaptively tailor adult stress responses to local conditions. However, how multiple stressors influence the development of the stress response remains unclear, as is the role of sex. Trinidadian guppies (Poecilia reticulata) are small fish with extensive life-history differences between the sexes and population variation in predation pressure and social density. We investigated how sex and early-life experience influence hormonal stress responses by manipulating conspecific density and perceived predation risk during development. In adults, we sampled cortisol twice to measure initial release and change over time in response to a recurring stressor. The sexes differed considerably in their physiological stress response. Males released more cortisol for their body mass than females and did not reduce cortisol release over time. By contrast, all females, except those reared at high density together with predation cues, reduced cortisol release over time. Cortisol responses of males were thus less dynamic in response to current circumstances and early-life experiences than females, consistent with life-history differences between the sexes. Our study underscores the importance of early-life experiences, interacting ecological factors and sex differences in the organization of the stress response

Edge detection in static and dynamic environments using robot swarms

<b>Table S2</b>: Estimates and standard error of fixed parameters and their interactions for the GLMM with response variable cortisol concentration per gram of body mass per hour (ng/g/h) during phase 1. Estimates are given on the scale of the “inverse” link (1/x), and negative estimate values thus represent an increase in cortisol concentration. The model estimates represent the difference between the level of a factor (identified in parenthesis) with the reference levels. As our factors each contain two levels, the estimates represent the difference between the two groups. The reference levels were no-predator cues for predation, high density, and females. Housing group was included as random effect in the model. Significant p values (p < 0.05) are shown in bold

Gene Expression Profiling Reveals New Aspects of PIK3CA Mutation in ERalpha-Positive Breast Cancer: Major Implication of the Wnt Signaling Pathway

BACKGROUND: The PI3K/AKT pathway plays a pivotal role in breast cancer development and maintenance. PIK3CA, encoding the PI3K catalytic subunit, is the oncogene exhibiting a high frequency of gain-of-function mutations leading to PI3K/AKT pathway activation in breast cancer. PIK3CA mutations have been observed in 30% to 40% of ERα-positive breast tumors. However the physiopathological role of PIK3CA mutations in breast tumorigenesis remains largely unclear. METHODOLOGY/PRINCIPAL FINDINGS: To identify relevant downstream target genes and signaling activated by aberrant PI3K/AKT pathway in breast tumors, we first analyzed gene expression with a pangenomic oligonucleotide microarray in a series of 43 ERα-positive tumors with and without PIK3CA mutations. Genes of interest were then investigated in 249 ERα-positive breast tumors by real-time quantitative RT-PCR. A robust collection of 19 genes was found to be differently expressed in PIK3CA-mutated tumors. PIK3CA mutations were associated with over-expression of several genes involved in the Wnt signaling pathway (WNT5A, TCF7L2, MSX2, TNFRSF11B), regulation of gene transcription (SEC14L2, MSX2, TFAP2B, NRIP3) and metal ion binding (CYP4Z1, CYP4Z2P, SLC40A1, LTF, LIMCH1). CONCLUSION/SIGNIFICANCE: This new gene set should help to understand the behavior of PIK3CA-mutated cancers and detailed knowledge of Wnt signaling activation could lead to novel therapeutic strategies

Wohnungsmarkt im Kanton Basel-Stadt: Leerstände und Neubauten: eine empirische Untersuchung der Wohnungsmarktsituation im Kanton Basel-Stadt in den Jahren 2001-2007 und 2008/2009

Im Allgemeinen ist Basels Baubestand alt, aufgrund der Sanierungstätigkeit aber relativ gut erhalten. Meist entspricht das Konzept der Wohnung jedoch kaum mehr den heutigen Erwartungen. Der Trend geht heute hin zu grossen offenen Wohnungen, die hell sind und eine moderne Ausstattung aufweisen. Ein zentrales Forschungsinteresse dieses Artikels war die Erhebung des Leerwohnungsbestandes. Es konnte aufgezeigt werden, dass der Leerwohnungsanteil 2001-2007 ziemlich konstant bei 1.4% lag. Dieser Anteil war im schweizerischen Vergleich hoch. 2008 und schliesslich 2009 ist der Anteil an leeren Wohnungen aber deutlich gesunken. Aktuell liegt er bei 0.9%, so tief wie seit über zehn Jahren nicht mehr. Auffallend ist aber die hohe Zahl an leer stehenden Wohnungen, die weniger als drei Zimmer aufweisen. Das geht Hand in Hand mit der Annahme, dass die Ansprüche an Qualität und Fläche hoch sind: die kleinen und kleinsten Wohnungen vermögen diesen offenbar nicht mehr zu entsprechen. Der zweite Schwerpunkt lag bei der Neubautätigkeit im Kanton Basel-Stadt. Auf Grund seiner knappen Landressourcen gibt es im Kanton Basel-Stadt nur noch sehr wenige freie Bauflächen. Daher werden bevorzugt still gelegte Industrieareale als Alternativen genutzt. Der Anteil an neuen Wohnungen auf dem Markt ist seit 2001 noch klein, doch ist allgemein ein Anstieg der Neubautätigkeit zu verzeichnen. Bei den Neubauprojekten im Stadtkanton fällt auf, dass sie schon fast regelmässig über die Stadt verteilt realisiert werden. Es ist praktisch überall in der Stadt ein zentrales Grossprojekt mit geplanten modernen Wohn- und Arbeitsstandorten zu finden. Aktuell sind einige Neubauprojekte im Bau, die in Kürze für den Basler Wohnungsmarkt zahlreiche zusätzliche neue Wohneinheiten mit dem heute gewünschten Standard bringen werden. Zusammenfassend kann gesagt werden, dass Basel einiges für die Wohnsituation im Kanton unternimmt. Einiges wurde schon erreicht, vieles ist noch in Planung und im Bau, doch wurden zahlreiche Projekte lanciert und begonnen, welche die Wohnungssituation in Basel nachhaltig verbessern werden. Die Aktionsprogramme der Basler Regierung haben zum Ziel, den Kanton Basel-Stadt langfristig als attraktiven Wohnstandort zu fördern. Gezielte Quartiersaufwertung, viele Neubauprojekte und Werbekampagnen für das Stadtwohnen haben u.a. in den letzten zehn Jahren zu einer Stabilisierung der Bevölkerungszahlen geführt

Early environment and the development of social behaviours in the Trinidadian guppy, Poecilia reticulata

One of the many advantages of group living is the swift transfer of information between group members. Social learning – learning from others – offers a quick and economical way to acquire information about the local environment and is considered adaptive under a wide range of circumstances. However, social information can be unreliable or quickly become outdated in rapidly changing environments. Thus flexibility in the utilization of social learning, depending on the associated costs and benefits, would be expected to be advantageous in most situations. Early environment plays a major role in shaping the morphological, physiological or behavioural phenotype of an animal, and conditions and experiences during early life can potentially prepare (or program) a developing individual for the environment it will encounter when adult. In this project we examined whether social behaviours such as grouping and social learning could be influenced by early life conditions and to what extent. For this purpose, we used two different strains of the guppy (domestic and wild-origin), Poecilia reticulata, a popular study system in behavioural and evolutionary ecology with well-described social behaviour. Overall, we found evidence for consistency and heritability in grouping behaviour, but although grouping tendencies were (to some extent) correlated with social learning propensities, we found no evidence for consistency and heritability in social learning. Furthermore, we saw that early environmental conditions and experiences play a major role in shaping the behavioural phenotype of an individual. We found that both cues about the value of social information and context cues like predation risk and population density in early life, can influence an individual’s reliance on social information later in life. Moreover, as males and females differ significantly in their strategies to maximise fitness and survival, these early life cues can affect the behaviour of the two sexes in different ways

Early environment and the development of social behaviours in the Trinidadian guppy, Poecilia reticulata

One of the many advantages of group living is the swift transfer of information between group members. Social learning – learning from others – offers a quick and economical way to acquire information about the local environment and is considered adaptive under a wide range of circumstances. However, social information can be unreliable or quickly become outdated in rapidly changing environments. Thus flexibility in the utilization of social learning, depending on the associated costs and benefits, would be expected to be advantageous in most situations. Early environment plays a major role in shaping the morphological, physiological or behavioural phenotype of an animal, and conditions and experiences during early life can potentially prepare (or program) a developing individual for the environment it will encounter when adult. In this project we examined whether social behaviours such as grouping and social learning could be influenced by early life conditions and to what extent. For this purpose, we used two different strains of the guppy (domestic and wild-origin), Poecilia reticulata, a popular study system in behavioural and evolutionary ecology with well-described social behaviour. Overall, we found evidence for consistency and heritability in grouping behaviour, but although grouping tendencies were (to some extent) correlated with social learning propensities, we found no evidence for consistency and heritability in social learning. Furthermore, we saw that early environmental conditions and experiences play a major role in shaping the behavioural phenotype of an individual. We found that both cues about the value of social information and context cues like predation risk and population density in early life, can influence an individual’s reliance on social information later in life. Moreover, as males and females differ significantly in their strategies to maximise fitness and survival, these early life cues can affect the behaviour of the two sexes in different ways

Dynamic interactions among people, livestock, and savanna: ecosystems under climate change

A poster prepared for the ILRI Annual Program Meeting (APM) 2010, held at ILRI campus, Addis Ababa, Ethiopia, April 14-17, 201

Dataset from Developmental plasticity of the stress response in female but not in male guppies

Data of cortisol collection experiment on fish reared in a 2x2 design manipulating early life experience of predation and density

Dataset from Developmental plasticity of the stress response in female but not in male guppies

Data of cortisol collection experiment on fish reared in a 2x2 design manipulating early life experience of predation and density