Function, regulation and pathological roles of the Gab/DOS docking proteins

Since their discovery a little more than a decade ago, the docking proteins of the Gab/DOS family have emerged as important signalling elements in metazoans. Gab/DOS proteins integrate and amplify signals from a wide variety of sources including growth factor, cytokine and antigen receptors as well as cell adhesion molecules. They also contribute to signal diversification by channelling the information from activated receptors into signalling pathways with distinct biological functions. Recent approaches in protein biochemistry and systems biology have revealed that Gab proteins are subject to complex regulation by feed-forward and feedback phosphorylation events as well as protein-protein interactions. Thus, Gab/DOS docking proteins are at the centre of entire signalling subsystems and fulfil an important if not essential role in many physiological processes. Furthermore, aberrant signalling by Gab proteins has been increasingly linked to human diseases from various forms of neoplasia to Alzheimer's disease

The impact of resource dependence of the mechanisms of life on the spatial population dynamics of an in silico microbial community

Biodiversity has a critical impact on ecosystem functionality and stability, and thus the current biodiversity crisis has motivated many studies of the mechanisms that sustain biodiversity, a notable example being non-transitive or cyclic competition. We therefore extend existing microscopic models of communities with cyclic competition by incorporating resource dependence in demographic processes, characteristics of natural systems often oversimplified or overlooked by modellers. The spatially explicit nature of our individual-based model of three interacting species results in the formation of stable spatial structures, which have significant effects on community functioning, in agreement with experimental observations of pattern formation in microbial communities. Published by AIP Publishing

Physical activity increases bone mass during growth

BACKGROUND: The incidence of fragility fractures has increased during the last half of the 1990's. One important determinant of fractures is the bone mineral content (BMC) or bone mineral density (BMD), the amount of mineralised bone. If we could increase peak bone mass (the highest value of BMC reached during life) and/or decrease the age-related bone loss, we could possibly improve the skeletal resistance to fracture. OBJECTIVE: This review evaluates the importance of exercise as a strategy to improve peak bone mass, including some aspects of nutrition. DESIGN: PUBLICATIONS WITHIN THE FIELD WERE SEARCHED THROUGH MEDLINE (PUBMED) USING THE SEARCH WORDS: exercise, physical activity, bone mass, bone mineral content, bone mineral density, BMC, BMD, skeletal structure and nutrition. We included studies dealing with exercise during growth and young adolescence. We preferably based our inferences on randomised controlled trials (RCT), which provide the highest level of evidence. RESULTS: Exercise during growth increases peak bone mass. Moderate intensity exercise intervention programs are beneficial for the skeletal development during growth. Adequate nutrition must accompany the exercise to achieve the most beneficial skeletal effects by exercise. CONCLUSION: Exercise during growth seems to enhance the building of a stronger skeleton through a higher peak bone mass and a larger bone size

Constraining Dark Energy and Cosmological Transition Redshift with Type Ia Supernovae

The property of dark energy and the physical reason for acceleration of the present universe are two of the most difficult problems in modern cosmology. The dark energy contributes about two-thirds of the critical density of the present universe from the observations of type-Ia supernova (SNe Ia) and anisotropy of cosmic microwave background (CMB).The SN Ia observations also suggest that the universe expanded from a deceleration to an acceleration phase at some redshift, implying the existence of a nearly uniform component of dark energy with negative pressure. We use the ``gold'' sample containing 157 SNe Ia and two recent well-measured additions, SNe Ia 1994ae and 1998aq to explore the properties of dark energy and the transition redshift. For a flat universe with the cosmological constant, we measure $\Omega_{M}=0.28_{-0.05}^{+0.04}$, which is consistent with Riess et al. The transition redshift is $z_{T}=0.60_{-0.08}^{+0.06}$. We also discuss several dark energy models that define the $w(z)$ of the parameterized equation of state of dark energy including one parameter and two parameters ($w(z)$ being the ratio of the pressure to energy density). Our calculations show that the accurately calculated transition redshift varies from $z_{T}=0.29_{-0.06}^{+0.07}$ to $z_{T}=0.60_{-0.08}^{+0.06}$ across these models. We also calculate the minimum redshift $z_{c}$ at which the current observations need the universe to accelerate.Comment: 16 pages, 5 figures, 1 tabl

Probing the cosmic acceleration history and the properties of dark energy from the ESSENCE supernova data with a model independent method

With a model independent method the expansion history $H(z)$, the deceleration parameter $q(z)$ of the universe and the equation of state $w(z)$ for the dark energy are reconstructed directly from the 192 Sne Ia data points, which contain the new ESSENCE Sne Ia data and the high redshift Sne Ia data. We find that the evolving properties of $q(z)$ and $w(z)$ reconstructed from the 192 Sne Ia data seem to be weaker than that obtained from the Gold set, but stronger than that from the SNLS set. With a combination of the 192 Sne Ia and BAO data, a tight constraint on $\Omega_{m0}$ is obtained. At the $1\sigma$ confidence level $\Omega_{m0}=0.278^{+0.024}_{-0.023}$, which is highly consistent with that from the Gold+BAO and SNLS+BAO.Comment: 11 pages, 5 figures, to appear in JCA

Federalisation and education in Nepal: contemporary reflections on working through change

This paper presents reflections from recent research on the opportunities and barriers for education in Nepal in the context of federalisation. Public administration of services including education is subject to major reorganisation as a national priority. By 2019, new structures of local governance will be established, presenting an opportunity for improved coordination of education, health and social work at regional and municipality levels. Drawing on interviews with academic, school based and NGO stakeholders, findings offer a contemporary commentary on processes, power and possibilities to improve educational inclusion and progress towards the Sustainable Development Goal 4: Quality Education

Constraints on Dark Energy Models from Weak Gravity Conjecture

We study the constraints on the dark energy model with constant equation of state parameter $w=p/\rho$ and the holographic dark energy model by using the weak gravity conjecture. The combination of weak gravity conjecture and the observational data gives $w<-0.7$ at the $3\sigma$ confidence level. The holographic dark energy model realized by a scalar field is in swampland.Comment: 4 two column pages, 3 figures, accepted by Chin. Phys. Let

Self-control, goal interference, and the binge-watching experience: An event reconstruction study

High-speed internet connections and online streaming services gave rise to the possibility to binge-watch multiple television shows in one sitting. Binge-watching can be characterized as a problematic behavior but also as an enjoyable way to engage with television shows. This study investigates whether self-control explains the valence of binge-watching experiences as measured using the event reconstruction method. The study tests whether lower levels of trait self-control predict higher levels of negative affect and lower levels of positive affect during binge-watching. Additionally, the study tests whether these relationships are mediated by situational aspects of self-control (plans, goal interference, or automaticity). Regression analyses show that participants with higher trait self-control report lower levels of tiredness, boredom, guilt, and sadness when binge-watching compared to less self-controlled participants. These associations are partly explained by binge-watching interfering less with higher order goals for highly self-controlled participants. Lower levels of trait self-control are also associated with a stronger increase in happiness on initiating binge-watching and increased feelings of guilt after binge-watching. Overall, the study suggests that binge-watching is particularly pleasant when it does not interfere with other goals, which is more likely the case for individuals with high trait self-control

No evidence for Dark Energy Metamorphosis ?

Recent attempts to fit Type Ia supernova data by modeling the dark energy density as a truncated Taylor series have suggested the possibility of metamorphosis, i.e., a rapidly evolving equation of state parameter, w_DE(z). However, we show that fits using that parametrization have significant problems: evolution of w_DE(z) is both favoured and in some sense forced, and the equation of state parameter blows up or diverges in large regions of the parameter space. To further elucidate these problems we have simulated sets of supernova data in a Lambda-universe to show that the suggested ``evidence'' for metamorphosis is also common for w_DE=-1.Comment: 12 pages, 5 figures, Minor revisions to match version accepted in Journal of Cosmology and Astroparticle Physic

Genetic algorithms and the analysis of SnIa data

The Genetic Algorithm is a heuristic that can be used to produce model independent solutions to an optimization problem, thus making it ideal for use in cosmology and more specifically in the analysis of type Ia supernovae data. In this work we use the Genetic Algorithms (GA) in order to derive a null test on the spatially flat cosmological constant model $\Lambda$CDM. This is done in two steps: first, we apply the GA to the Constitution SNIa data in order to acquire a model independent reconstruction of the expansion history of the Universe $H(z)$ and second, we use the reconstructed $H(z)$ in conjunction with the Om statistic, which is constant only for the $\Lambda$CDM model, to derive our constraints. We find that while $\Lambda$CDM is consistent with the data at the $2\sigma$ level, some deviations from $\Lambda$CDM model at low redshifts can be accommodated.Comment: 11 pages, 7 figures, to be published in the proceedings of the 14th Conference on Recent Developments in Gravity (NEB-14), Ioannina, Greece, 8-11 June 201