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Internal energy storage

As continuous access to energy is necessary for survival, the level of energy stores has a strong effect on fitness and survival. Behaviors by which energy stores are acquired and built up are known as foraging, and this is a very common topic in animal behavior studies. It is especially important for flying organisms to finely tune the level of energy reserves they carry. While most animals will

Food hoarding

Many animals store food outside of their own bodies for later consumption, not only birds and mammals, but also invertebrates such as honeybees. I refer to such food storage as hoarding, to distinguish it from internal storage such as in fat deposits. There are two distinct food-hoarding strategies: larder hoarding (all food is stored in one or a few central larders) and scatter hoarding (storage

Evaluating the effect of vibration isolation mats on train-induced ground vibrations

In the present paper, the effectiveness of a vibration isolation mat for a railway slab track system is studied using a finite element model of the railway track. The finite elements are formulated in a moving frame of reference following the moving load at a particular speed. The rails are modeled using Bernoulli beams, whereas the track slab and an underlying supporting plate are modeled using K

Extending the visco-frictional branched modeling of filled rubbers to include coupling effects between rate and amplitude dependence

The traditional way to capture rate and amplitude dependence of filled rubbers is by a branched model containing elastic, viscous, and frictional branches, leading to a decoupling of the rate and amplitude dependence. In order to capture the experimentally observed phenomena with a steeper increasing dynamic modulus with frequency, for small amplitudes, a model by Besseling (1958) is revisited. In

Invertebrate vision

The extraordinary adaptability of invertebrates is in no small part due to their sense organs, and particularly their eyes, which help them to find food, locate mates, escape predators and migrate to new habitats. Even though most invertebrates do not see as sharply as we do, many see much better in dim light, can experience many more colours, can see polarised light and can clearly distinguish ex

Magnetic orientation in migratory songbirds

Migratory birds are well known to use information from the Earth’s magnetic field, stars and the sun for orientation and navigation. Here we give a historical overview of the research findings and techniques which have led to the current knowledge on how migratory songbirds use the Earth’s magnetic field for orientation. We discuss the functions and putative reception mechanisms of the magnetic in

Dynamic contrast-enhanced QSM for perfusion imaging : a systematic comparison of ΔR2*- and QSM-based contrast agent concentration time curves in blood and tissue

OBJECTIVE: In dynamic susceptibility contrast MRI (DSC-MRI), an arterial input function (AIF) is required to quantify perfusion. However, estimation of the concentration of contrast agent (CA) from magnitude MRI signal data is challenging. A reasonable alternative would be to quantify CA concentration using quantitative susceptibility mapping (QSM), as the CA alters the magnetic susceptibility in

A surrogate model for vibration transmission in layered soil

Ground vibration from traffic or construction work in cities is a known source of annoyance to inhabitants. However, vibration and re-radiated noise in buildings caused by exterior sources are seldom treated properly in the design process, which may be due to the lack of methodologies that can aid informed decision-making with respect to environmental vibration. To achieve efficient evaluation of

A surrogate model to describe uncertainties in wood floor modal frequencies

Wooden multi-story buildings have increased their market share in Europe over the last decades, mainly due to their relatively small carbon footprint and rapid onsite construction. Compared to more conventional heavy concrete buildings, wooden buildings are more sensitive to dynamic loads at low frequencies. Moreover, the dynamic response is generally more difficult to predict. This is, for exampl

Taking stock and moving forward in research on refugee entrepreneurship : A systematic review of the current field and future research directions

Problem: Refugee entrepreneurship has recently garnered a growing academic and political interest around the world. The rate of scientific publication has soared in the last few years due to the scholarly urgency on the topic following the ‘global refugee crises’. Nevertheless, the research field is currently underdeveloped with existing knowledge dispersed across various and often disconnected di

Association between added sugar intake and micronutrient dilution : a cross-sectional study in two adult Swedish populations

Background: The evidence on the impact of high sugar consumption on micronutrient dilution does not yet allow for the establishment of clear thresholds of consumption. To establish upper and lower limit intake thresholds for added sugar, more studies from different countries and multiple populations are needed. The aim of this study was to examine the association between the intakes of added sugar

Influence of uncertain parameters on modal properties of wood floors

The use of wood as load-bearing material in residential and office buildings has increased significantly in Europe over the last decades. Such buildings often have wooden floors built with boards supported by joists and/or beams. The modal properties of such floors are important regarding the floors’ dynamic response to walking and other usage as well as structure-borne vibration and re-radiated n

Amplitude and Phase Estimation for Absolute Calibration of Massive MIMO Front-Ends

Massive multiple-input multiple-output (MIMO) promises significantly higher performance relative to conventional multiuser systems. However, the promised gains of massive MIMO systems rely heavily on the accuracy of the absolute front-end calibration, as well as quality of channel estimates at the base station (BS). In this paper, we analyze user equipment-aided calibration mechanism to estimate t

Closed Form Characterization of Mutual Coupling in Uniform Linear Arrays

This paper proposes a pragmatic methodology to characterize mutual coupling in uniform linear arrays (ULAs). The classical coupling model used in the literature of multiple input multiple output (MIMO) antenna arrays is based on impedance parameters, resulting valid only for electromagnetically small antennas, e.g. short dipole. To test the robustness and accuracy of the proposed coupling model we

Uricemia in juvenile pigs model : Effect of nephrectomy and potassium oxonate

Uric acid is the end product of dietary and endogenous purine metabolism in humans and higher primates. In all lower mammalian species it is converted to allantoin by liver uricase. The aim of this study was to investigate the uric acid turnover in pig model after nephrectomy surgery, fructose-enriched diet and potassium oxonate application. The first experiment was performed using 4 intact contro

Green revolution

The Green Revolution in Asia from the early 1960s is defined as a process driven by governments in pursuit of self-sufficiency in food grains. The process was market-mediated and smallholder based and can be dated to the early 1960s with the Nobel Prize Laureate, Norman Borlaug’s research on high-yielding dwarf wheat in Mexico and later spread to rice and number of countries in South East and Sout

Combined microscopic and spectroscopic insights into the on-surface synthesis of graphene nanoribbons

Graphene nanoribbons (GNR) constitute a rapidly growing class of novel fascinating materials. Controlling the properties of GNR often implies controlling their atomic structure. In order to exert this control, a bottom-up approach for the growth of GNR is commonly used. Despite its great success, a lack of mechanistic understanding of the on-surface chemical processes remains one of the main chall