39 research outputs found
Detectable contributions of colloids to soil P and C content in arid and hyperarid region of the Atacama (Chile)
Atacama Desert is mainly known as the driest place on Earth where life has been developed under arid to hyper arid conditions since Oligocene-Miocene. Therefore, soils of Atacama contain fingerprints of past and present life which might be used as an analog to study the evolution of life under equivalent arid conditions, like Mars. In this study, we quantify the colloidal phosphorus and carbon distribution in the first 10 cm of soil profile along an altitudinal transect. Samples were taken along a transect in the region of Quebrada Aroma spanning from the arid Percordillera of the Andes (2720 m a.s.l.) towards the hyper arid core of the desert (1340 m a.s.l.). Water dispersible colloids (WDC) were separated and measured using the field-flow-field fractionation (FFF) method and subsequently their Corg and P content were characterized and quantified by detectors (DLS, ICP-MS, UV, OCD, fluorescence). Data was compared to total C, P and (available) Olsen-P also measured in the samples.
The Olsen-P (available-P) varied within the Aroma transect from ca. 2 to 8 mg P kg-1, but was not related to either altitude or depth in the upper soil (0-10 cm). Colloidal P contents ranged from <0.1 to 4 mg P kg-1 soil, with increasing trend from low to higher elevations. Thereby, suggesting an increasing proportion of the available P potential being present in the WDC fraction. The Colloidal Corg content of the Aroma transect did range from 65 to 90 (for sites 2020 to 1340m) and 110 mg Corg kg-1 soil WDC (2720 m). Colloidal Corg content as a function of the altitude showed a similar trend to the Corg content of the soils: the highest colloidal Corg content was found at 2720 m. The proportion of soil Corg within the colloidal fraction was up to 6% of the bulk soil organic matter (OM) content, as the OM content was intensively enriched in the colloidal fraction. Further quantification of phosphorus and carbon content in WDC in deeper part of soil is required to obtain a more comprehensive view of role of colloidal inputs and dynamics in the Atacama Desert
German Emigration and Remigration Panel Study (GERPS): Methodology and Data Manual of the Baseline Survey (Wave 1)
International migration between economically highly developed countries is a central component of global migration flows. Still, surprisingly little is known about the international mobility of the populations of these affluent societies. The aim of the German Emigration and Remigration Panel Study (GERPS) is to collect data to analyse the individual consequences of international migration as well as the consequences for the country of origin. GERPS is based on an origin-based multistage probability sample using the German population registers as a sampling frame. The realised net sample includes more than 11,000 persons who recently moved abroad from Germany and persons returning to Germany after having lived abroad. The study follows a multi-destination country design and allows comparative analyses of migrants and non-migrants who stayed in the country of origin. GERPS is a panel study with at least four waves during a period of at least 24 months. This documentation, however, presents the methodology and the data for the first wave providing the baseline survey. Detailed information is provided to invite external researchers to apply the new data infrastructure to their own research and to disseminate the innovative research design to construct migrant samples
German Emigration and Remigration Panel Study (GERPS): Methodology and Data Manual of the Baseline Survey (Wave 1)
International migration between economically highly developed countries is a central
component of global migration flows. Still, surprisingly little is known about the
international mobility of the populations of these affluent societies. The aim of the
German Emigration and Remigration Panel Study (GERPS) is to collect data to analyse the
individual consequences of international migration as well as the consequences for the
country of origin. GERPS is based on an origin-based multistage probability sample using
the German population registers as a sampling frame. The realised net sample includes
more than 11,000 persons who recently moved abroad from Germany and persons
returning to Germany after having lived abroad. The study follows a multi-destination
country design and allows comparative analyses of migrants and non-migrants who
stayed in the country of origin. GERPS is a panel study with at least four waves during a
period of at least 24 months. This documentation, however, presents the methodology
and the data for the first wave providing the baseline survey. Detailed information is
provided to invite external researchers to apply the new data infrastructure to their
own research and to disseminate the innovative research design to construct migrant
samples
Hyperacute Directional Hearing and Phonotactic Steering in the Cricket (Gryllus bimaculatus deGeer)
Background: Auditory mate or prey localisation is central to the lifestyle of many animals and requires precise directional hearing. However, when the incident angle of sound approaches 0u azimuth, interaural time and intensity differences gradually vanish. This poses a demanding challenge to animals especially when interaural distances are small. To cope with these limitations imposed by the laws of acoustics, crickets employ a frequency tuned peripheral hearing system. Although this enhances auditory directionality the actual precision of directional hearing and phonotactic steering has never been studied in the behaviourally important frontal range. Principal Findings: Here we analysed the directionality of phonotaxis in female crickets (Gryllus bimaculatus) walking on an open-loop trackball system by measuring their steering accuracy towards male calling song presented at frontal angles of incidence. Within the range of 630u, females reliably discriminated the side of acoustic stimulation, even when the sound source deviated by only 1u from the animal’s length axis. Moreover, for angles of sound incidence between 1u and 6u the females precisely walked towards the sound source. Measuring the tympanic membrane oscillations of the front leg ears with a laser vibrometer revealed between 0u and 30u a linear increasing function of interaural amplitude differences with a slope of 0.4 dB/u. Auditory nerve recordings closely reflected these bilateral differences in afferent response latency and intensity that provide the physiological basis for precise auditory steering
The OpenMolcas Web: A Community-Driven Approach to Advancing Computational Chemistry
The developments of the open-source OpenMolcas chemistry software environment since spring 2020 are described, with a focus on novel functionalities accessible in the stable branch of the package or via interfaces with other packages. These developments span a wide range of topics in computational chemistry and are presented in thematic sections: electronic structure theory, electronic spectroscopy simulations, analytic gradients and molecular structure optimizations, ab initio molecular dynamics, and other new features. This report offers an overview of the chemical phenomena and processes OpenMolcas can address, while showing that OpenMolcas is an attractive platform for state-of-the-art atomistic computer simulations
Grand Challenges in global eye health: a global prioritisation process using Delphi method
Background
We undertook a Grand Challenges in Global Eye Health prioritisation exercise to identify the key issues that must be addressed to improve eye health in the context of an ageing population, to eliminate persistent inequities in health-care access, and to mitigate widespread resource limitations.
Methods
Drawing on methods used in previous Grand Challenges studies, we used a multi-step recruitment strategy to assemble a diverse panel of individuals from a range of disciplines relevant to global eye health from all regions globally to participate in a three-round, online, Delphi-like, prioritisation process to nominate and rank challenges in global eye health. Through this process, we developed both global and regional priority lists.
Findings
Between Sept 1 and Dec 12, 2019, 470 individuals complete round 1 of the process, of whom 336 completed all three rounds (round 2 between Feb 26 and March 18, 2020, and round 3 between April 2 and April 25, 2020) 156 (46%) of 336 were women, 180 (54%) were men. The proportion of participants who worked in each region ranged from 104 (31%) in sub-Saharan Africa to 21 (6%) in central Europe, eastern Europe, and in central Asia. Of 85 unique challenges identified after round 1, 16 challenges were prioritised at the global level; six focused on detection and treatment of conditions (cataract, refractive error, glaucoma, diabetic retinopathy, services for children and screening for early detection), two focused on addressing shortages in human resource capacity, five on other health service and policy factors (including strengthening policies, integration, health information systems, and budget allocation), and three on improving access to care and promoting equity.
Interpretation
This list of Grand Challenges serves as a starting point for immediate action by funders to guide investment in research and innovation in eye health. It challenges researchers, clinicians, and policy makers to build collaborations to address specific challenge
Visualization and Clustering of Tagged Music Data
Abstract. The process of assigning keywords to a special group of objects is often called tagging and becomes an important character of community based networks like Flickr, YouTube or Last.fm. This kind of user generated content can be used to define a similarity measure for those objects. The usage of Emergent-Self-Organizing-Maps (ESOM) and U-Map techniques to visualize and cluster this sort of tagged data to discover emergent structures in collections of music is reported. An item is described by the feature vector of the most frequently used tags. A meaningful similarity measure for the resulting vectors needs to be defined by removing redundancies and adjusting the variances. In this work we present the principles and first examples of the resulting U-Maps.
Zips : mining compressing sequential patterns in streams
We propose a streaming algorithm, based on the minimal description length (MDL) principle, for extracting non-redundant sequential patterns. For static databases, the MDL-based approach that selects patterns based on their capacity to compress data rather than their frequency, was shown to be remarkably effective for extracting meaningful patterns and solving the redundancy issue in frequent itemset and sequence mining. The existing MDL-based algorithms, however, either start from a seed set of frequent patterns, or require multiple passes through the data. As such, the existing approaches scale poorly and are unsuitable for large datasets. Therefore, our main contribution is the proposal of a new, streaming algorithm, called Zips, that does not require a seed set of patterns and requires only one scan over the data. For Zips, we extended the Lempel-Ziv (LZ) compression algorithm in three ways: first, whereas LZ assigns codes uniformly as it builds up its dictionary while scanning the input, Zips assigns codewords according to the usage of the dictionary words; more heaviliy used words get shorter code-lengths. Secondly, Zips exploits also non-consecutive occurences of dictionary words for compression. And, third, the well-known space-saving algorithm is used to evict unpromising words from the dictionary. Experiments on one synthetic and two real-world large-scale datasets show that our approach extracts meaningful compressing patterns with similar quality to the state-of-the-art multi-pass algorithms proposed for static databases of sequences. Moreover, our approach scales linearly with the size of data streams while all the existing algorithms do not