Restricting the nonlinearity parameter in soil greenhouse gas flux calculation for more reliable flux estimates

The static chamber approach is often used for greenhouse gas (GHG) flux measurements, whereby the flux is deduced from the increase of species concentration after closing the chamber. Since this increase changes diffusion gradients between chamber air and soil air, a nonlinear increase is expected. Lateral gas flow and leakages also contribute to non linearity. Several models have been suggested to account for this non linearity, the most recent being the Hutchinson±Mosier regression model (HMR). However, the practical application of these models is challenging because the researcher needs to decide for each flux whether a nonlinear fit is appropriate or exaggerates flux estimates due to measurement artifacts. In the latter case, a flux estimate from the linear model is a more robust solution and introduces less arbitrary uncertainty to the data. We present the new, dynamic and reproducible flux calculation scheme, KAPPA.MAX, for an improved trade-off between bias and uncertainty (i.e. accuracy and precision). We develop a tool to simulate, visualise and optimise the flux calculation scheme for any specific static N2O chamber measurement system. The decision procedure and visualisation tools are implemented in a package for the R software. Finally, we demonstrate with this approach the performance of the applied flux calculation scheme for a measured flux dataset to estimate the actual bias and uncertainty. The KAPPA.MAX method effectively improved the decision between linear and nonlinear flux estimates reducing the bias at a minimal cost of uncertainty

Fast-paced city life? Tempo and mode of phenotypic changes in urban birds from Switzerland

Humans' large influence on the environment has constructed many new ecological niches, such as in urban areas. Phenotypic changes, including morphological ones related to human influence, are known from a small number of bird species. The amount of change in a given time period, that is, the rate of change, may vary. Rates of change (both evolutionary and through phenotypic plasticity) are reportedly rapid in human-influenced settings, although this is disputed. We present new data on changes in beak dimensions and rates of change over historical time periods in four urban bird species (Common Chaffinch, European Greenfinch, Eurasian Blackbird, House Sparrow) from three Swiss cities (Basel, Bern, Geneva). Our study shows that beak dimensions have changed little in most investigated urban bird populations over the past century. Only in Genevan Blackbirds there was evidence for an increase in beak length over the past 65 years; Bernese Chaffinches appear to be trending toward a decrease in beak width over the past 55 years. Rates of change in our sample in comparison with literature records showed that compared to populations less influenced by humans, urban evolutionary rates appear to be similar. Although in accordance with previous findings about other urban bird species, our study exemplifies the difficulty to find universal patterns in tempo and mode of phenotypic evolution in urban areas, even when considering the same taxa. Our data contribute to the expanding field of urban evolutionary biology, which is particularly important regarding the growing urban habitats worldwide

Climate effects of recycled fertilizers and biochar: emissions of nitrous oxide, methane and ammonia in a field experiment

Background Nitrogen (N) fertilizers are essential for crop production. Farmyard manure and slurry traditionally constitute about half of the total N inputs into crop production in Switzerland. Recycled fertilizers such as biogas slurry, liquid digestates and compost enable simultaneous energy production and closing of nutrient cycles. There is evidence that recycled fertilizers can help to increase N use efficiencies and to improve N supply in organic farming. Biochar amendment has shown a potential to mitigate soil greenhouse gas (GHG) emissions, in particular nitrous oxide (N2O) emissions. Here, we combine one of the liquid recycled fertilizer treatments with biochar. In a 2.5-years on-farm experiment, we quantify GHG emissions and further gaseous N-losses via ammonia (NH3) emissions

Multimodality evaluation of the pediatric brain: DTI and its competitors

The development of the human brain, from the fetal period until childhood, happens in a series of intertwined neurogenetical and histogenetical events that are influenced by environment. Neuronal proliferation and migration, cell aggregation, axonal ingrowth and outgrowth, dendritic arborisation, synaptic pruning and myelinisation contribute to the ‘plasticity of the developing brain'. These events taken together contribute to the establishment of adult-like neuroarchitecture required for normal brain function. With the advances in technology today, mostly due to the development of non-invasive neuroimaging tools, it is possible to analyze these structural events not only in anatomical space but also longitudinally in time. In this review we have highlighted current ‘state of the art' neuroimaging tools. Development of the new MRI acquisition sequences (DTI, CHARMED and phase imaging) provides valuable insight into the changes of the microstructural environment of the cortex and white matter. Development of MRI imaging tools dedicated for analysis of the acquired images (i) TBSS and ROI fiber tractography, (ii) new tissue segmentation techniques and (iii) morphometric analysis of the cortical mantle (cortical thickness and convolutions) allows the researchers to map the longitudinal changes in the macrostructure of the developing brain that go hand-in-hand with the acquisition of cognitive skills during childhood. Finally, the latest and the newest technologies, like connectom analysis and resting state fMRI connectivity analysis, today, for the first time provide the opportunity to study the developing brain through the prism of maturation of the systems and networks beyond individual anatomical areas. Combining these methods in the future and modeling the hierarchical organization of the brain might ultimately help to understand the mechanisms underlying complex brain structure function relationships of normal development and of developmental disorder

Teaching, motivation, and well-being during COVID-19 from the perspective of university students and lecturers

This initial report gives an overview of some preliminary results. Please note that due to the explorative nature of some analyses, the significant tests should only be used to aid interpretation. We recommend focusing to the effect sizes presented when interpreting the results (see Wasserstein & Lazar, 2016). The interim report starts by describing the demographic data of our student and university teacher sample. Following that, some general findings on students’ and lecturers’ general life satisfaction and well-being are presented. Well-being is measured by self-reports of perceived stress which is compared to ratings of a norm sample (Fliege et al., 2005). In the paragraph on teaching, students’ and university lecturers’ attitudes towards e-learning are presented. Moreover, an overview on the choice of communication channels is provided along with the type of course (seminar, lecture, etc.). Additionally, the student perceived interaction between students and lecturers during online teaching is discussed. Following this, lecturer behavior concerning the support of students’ basic psychological needs is presented, as well as the teachers’ and students’ motivation and well-being during classes. To conclude the interim report, the descriptive data on perceived support from the university and peers from the perspective of lecturers is presented

Realidad social y práctica artística : el arte como una manera de evidenciar la realidad social y de crear vínculos artístico-sociales para intervenirla

Nos encontramos en un contexto social acotado, interconectado virtualmente, globalizado, en el cual podemos apreciar como se suceden los hechos en todo el mundo y de que manera se combinan las culturas en un proceso de mixturación constante. El arte, la religión, las costumbres, los pensamientos, parecen no solo ir cambiando sino también mezclándose. Nos volvemos sujetos pluriculturales, tomamos algo de aquí y algo de allá y al mismo tiempo no profundizamos raíces. Transitamos por el mundo en una red virtual que nos permite relacionarnos, superficialmente, con el mundo entero. Somos nómades virtuales, como tales, somos sujetos “radicantes” (Bourriaud, 2009, a), inquietos, queremos saber de todo un poco, podemos hacer nuestra cualquier lucha y movernos en cualquier campo, porque nuestras raíces son horizontales, rizomáticas, se van arraigando a las diferentes inquietudes que vamos desarrollado en el transcurso de la vida. No nos anclamos a una sola causa, a una sola manera de hacer las cosas o a un único pensamiento. Nos vamos retroalimentado uno del otro, de nuestras anécdotas, de nuestro conocimiento, de nuestras experiencias. Estamos en constante intercambio. La hibridación es la regla. El conocimiento no es vertical sino horizontal y experimental. Por ende, nuestro arte deviene en una pluralidad de sentidos, en un diálogo abierto e inclusivo, de ida y vuelta, no se cierra ni se agota en la forma sino que genera contenido constante, se vuelve una experiencia compartida y polivalente. Al artista radicante “… Nada le es más ajeno que un pensamiento disciplinario, que un pensamiento de la médium specificity- idea por lo demás sedentaria, que se reduce a cultivar su campo.” ( Bourriaud, 2009, b. pág. 60.) El arte radicante abandona las exclusividades disciplinarias. El Arte nos da la posibilidad de transitar varios caminos, de crear nuevas estructuras, de entrelazar el conocimiento y la acción. Nos permite borrar fronteras y crear nuevas sendas, de atar nuevos lazos de pensar nuevas formas de caminar. Es extensa, amplia, generosa, inagotable. Y en mi libertad para crear, me propongo alzar la voz y mostrar la realidad que transito, de manera tangible, cercana, apropiable y con urgencia de ser atravesada, intervenida, reconstruida, transformada.Fil: Hüppi, Nadia Jesica. Universidad Nacional de Córdoba. Facultad de Artes. Departamento Académico de Artes Visuales; Argentina