Studies of siblings have focused mainly on their competitive interactions and to a lesser extent on their cooperation. However, competition and cooperation are at opposite ends on a continuum of possible interactions and the nature of these interactions may be flexible with ecological factors tipping the balance toward competition in some environments and cooperation in others. Here we show tha...

We describe and demonstrate an architecture for active acoustic metamaterials whose effective material parameters can be tuned independently over a wide range of values, including negative material parameters. The approach is demonstrated experimentally through the design and measurement of two types of unit cells that generate metamaterials in which either the effective density or bulk modulus...

The problem of constructing a model of an extended charged particle within the context of general relativity has a long and distinguished history. The distinctive feature of these models is that, in some way or another, they require the presence of negative mass in order to maintain stability against Coulomb's repulsion. Typically, the particle contains a core of negative mass surrounded by a p...

BACKGROUND Conflicting results exist about the short-and long-term effects of breastfeeding on bone mineral content (BMC) and bone mineral density (BMD). We conducted a systematic review to assess the relationship between method of infant feeding and bone mass in children, adolescents and adults. METHODS The literature review was concluded in September 2014 in MEDLINE, Web of Science and LILA...

Surface-enhanced laser desorption/ionization timeof-flight mass spectrometry (SELDI or SELDI-TOF MS) has yielded predictive protein profiles for a number of clinically relevant diseases. Yet, rather than identifying specific proteins, such studies have provided diagnostic information solely based on “black box” predictors that look at differential patterns of mass spectrometry peaks. This paper...

In this paper we describe the predictions for the smoothed weak lensing shear and aperture-mass of two simple analytical models of the density field: the minimal tree-model and the stellar model. Both models give identical results for the statistics of the 3-d density contrast smoothed over spherical cells and only differ by the detailed angular dependence of the many-body density correlations....

Background: Ageing of population worldwide will be responsible for a major increase of the incidence of osteoporosis in elderly. For the individual, osteoporotic fractures result in great disability as well as loss of quality of life and also represent an enormous burden for healthcare systems. This study was conducted to determine the prevalence of osteoporosis and it's association with serum ...

At a time when uninhibited speculation about negative tension – and by implication negative mass density – world branes has become commonplace, it seems worthwhile to call attention to the risk involved in sacrificing traditional energy positivity postulates such as are required for the classical vacuum stability theorem of Hawking and Ellis. As well as recapitulating the technical content of t...

The effect of negative ions on the charging of dust particles in a plasma is investigated experimentally. A plasma containing a very low percentage of electrons is formed in a single-ended Q machine when SF6 is admitted into the vacuum system. The relatively cold Q machine electrons Te 0.2 eV readily attach to SF6 molecules to form SF6 − negative ions. Calculations of the dust charge indicate t...

In self-similar fragmentations with a negative index, fragments split even faster as their mass is smaller, so that the fragmentation runs away and some mass is reduced to dust. Our purpose is to investigate the regularity of this formation of dust. Let M(t) denote the mass of dust at time t.We give some sufficient and some necessary conditions for the measure dM to be absolutely continuous. In...