357 research outputs found
Public Relations Work to Increase Attainability Relating to EMail-Communication
The mere allotment of an e-mail address does in no way ensure answering quotas, which could be called sufficient to dependably hand out important information via roundmail. A loss of accessibility through e-mail addresses already provided by the university can be due to various technical problems and personal deficiencies of motivation. Students in particular often use external providers and are often also not on familiar terms with the use of consistent personal e-mail archives, POP-accounts, Web-Mail-Portals and the use of forewarding functions. Special email-courses are being offered within regular further training for staff and students
Self-organization in the olfactory system: one shot odor recognition in insects
We show in a model of spiking neurons that synaptic plasticity in the mushroom bodies in combination with the general fan-in, fan-out properties of the early processing layers of the olfactory system might be sufficient to account for its efficient recognition of odors. For a large variety of initial conditions the model system consistently finds a working solution without any fine-tuning, and is, therefore, inherently robust. We demonstrate that gain control through the known feedforward inhibition of lateral horn interneurons increases the capacity of the system but is not essential for its general function. We also predict an upper limit for the number of odor classes Drosophila can discriminate based on the number and connectivity of its olfactory neurons
Analyzing Childlessness
Childlessness has been on the rise in many European societies. In Germany, the UK, Austria, the Netherlands, and Switzerland, childlessness has increased starting with the 1950s cohorts. In these countries, about 20 % of the women born around 1965 will remain childless. In southern Europe and the former state-socialist countries of Central and Eastern Europe, the rise in levels of childlessness is a more recent phenomenon. Yet among younger cohorts in these countries, childlessness has reached levels of 15 % or higher. In this introductory chapter, we summarize the long-term trends in childlessness and discuss the differences between European countries in the prevalence of childlessness. We also outline the structure and the logic of this volume
Strategies of the honeybee Apis mellifera during visual search for vertical targets presented at various heights: a role for spatial attention?
When honeybees are presented with a colour discrimination task, they tend to choose swiftly and accurately when objects are presented in the ventral part of their frontal visual field. In contrast, poor performance is observed when objects appear in the dorsal part. Here we investigate if this asymmetry is caused by fixed search patterns or if bees can use alternative search mechanisms such as spatial attention, which allows flexible focusing on different areas of the visual field. We asked individual honeybees to choose an orange rewarded target among blue distractors. Target and distractors were presented in the ventral visual field, the dorsal field or both. Bees presented with targets in the ventral visual field consistently had the highest search efficiency, with rapid decisions, high accuracy and direct flight paths. In contrast, search performance for dorsally located targets was inaccurate and slow at the beginning of the test phase, but bees increased their search performance significantly after a few learning trials: they found the target faster, made fewer errors and flew in a straight line towards the target. However, bees needed thrice as long to improve the search for a dorsally located target when the target's position changed randomly between the ventral and the dorsal visual field. We propose that honeybees form expectations of the location of the target's appearance and adapt their search strategy accordingly. Different possible mechanisms of this behavioural adaptation are discussed.L.M. was recipient of a DOC-fFORTE fellowship of the Austrian
Academy of Science at the Department of Integrative Zoology,
University of Vienna. L.C. is supported by an ERC Advanced Grant
and a Royal Society Wolfson Research Merit Award
A performance characterization of quantum generative models
Quantum generative modeling is a growing area of interest for
industry-relevant applications. With the field still in its infancy, there are
many competing techniques. This work is an attempt to systematically compare a
broad range of these techniques to guide quantum computing practitioners when
deciding which models and techniques to use in their applications. We compare
fundamentally different architectural ansatzes of parametric quantum circuits
used for quantum generative modeling: 1. A continuous architecture, which
produces continuous-valued data samples, and 2. a discrete architecture, which
samples on a discrete grid. We compare the performance of different data
transformations: normalization by the min-max transform or by the probability
integral transform. We learn the underlying probability distribution of the
data sets via two popular training methods: 1. quantum circuit Born machines
(QCBM), and 2. quantum generative adversarial networks (QGAN). We study their
performance and trade-offs as the number of model parameters increases, with
the baseline of similarly trained classical neural networks. The study is
performed on six low-dimensional synthetic and two real financial data sets.
Our two key findings are that: 1. For all data sets, our quantum models require
similar or fewer parameters than their classical counterparts. In the extreme
case, the quantum models require two of orders of magnitude less parameters. 2.
We empirically find that a variant of the discrete architecture, which learns
the copula of the probability distribution, outperforms all other methods
Mechanisms, functions and ecology of colour vision in the honeybee.
notes: PMCID: PMC4035557types: Journal Article© The Author(s) 2014.This is an open access article that is freely available in ORE or from Springerlink.com. Please cite the published version available at: http://link.springer.com/article/10.1007%2Fs00359-014-0915-1Research in the honeybee has laid the foundations for our understanding of insect colour vision. The trichromatic colour vision of honeybees shares fundamental properties with primate and human colour perception, such as colour constancy, colour opponency, segregation of colour and brightness coding. Laborious efforts to reconstruct the colour vision pathway in the honeybee have provided detailed descriptions of neural connectivity and the properties of photoreceptors and interneurons in the optic lobes of the bee brain. The modelling of colour perception advanced with the establishment of colour discrimination models that were based on experimental data, the Colour-Opponent Coding and Receptor Noise-Limited models, which are important tools for the quantitative assessment of bee colour vision and colour-guided behaviours. Major insights into the visual ecology of bees have been gained combining behavioural experiments and quantitative modelling, and asking how bee vision has influenced the evolution of flower colours and patterns. Recently research has focussed on the discrimination and categorisation of coloured patterns, colourful scenes and various other groupings of coloured stimuli, highlighting the bees' behavioural flexibility. The identification of perceptual mechanisms remains of fundamental importance for the interpretation of their learning strategies and performance in diverse experimental tasks.Biotechnology and Biological Sciences Research Council (BBSRC
Applying quality improvement methods to neglected conditions: Development of the South Asia Burn Registry (SABR)
Objective: South Asia has the highest mortality rate from burns in the world. Application of quality improvement methods to burn care can help identify health system gaps. Our overall aim is to introduce a sustainable hospital-based burn registry for resource-constrained settings to assess health outcomes of burn injury patients presenting to dedicated burn injury centers in South Asia.Results: The South Asia Burn Registry (SABR) is implemented through collaborative approach in selected burn centers in Bangladesh and Pakistan. Th registry collects data on burn injury events, the care provided, and the functional status of patients at discharge from burn centers. It covers the entire spectrum of care provision for burn injury patients from the actual event through their discharge from the healthcare system. SABR investigates locally relevant contextual factors associated with burn injury and health-system requirements for burn patients receiving emergency and inpatient care in resource-constrained settings. It also explores factors associated with burn injury and care provision. SABR will inform better prevention and management efforts in South Asia and help to address healthcare needs of burn injury patients
Dance Type and Flight Parameters Are Associated with Different Mushroom Body Neural Activities in Worker Honeybee Brains
Background: Honeybee foragers can transmit the information concerning the location of food sources to their nestmates using dance communication. We previously used a novel immediate early gene, termed kakusei, to demonstrate that the neural activity of a specific mushroom body (MB) neuron subtype is preferentially enhanced in the forager brain. The sensory information related to this MB neuron activity, however, remained unclear. Methodology/Principal Findings: Here, we used kakusei to analyze the relationship between MB neuron activity and types of foraging behavior. The number of kakusei-positive MB neurons was higher in the round dancers that had flown a short distance than in the waggle dancers that had flown a long distance. Furthermore, the amount of kakusei transcript in the MBs inversely related to the waggle-phase duration of the waggle dance, which correlates with the flight distance. Using a narrow tunnel whose inside was vertically or axially lined, we manipulated the pattern of visual input, which is received by the foragers during flight, and analysed kakusei expression. The amount of kakusei transcript in the MBs was related to the foraging frequency but not to the tunnel pattern. In contrast, the number of kakusei-positive MB neurons was affected by the tunnel patterns, but not related to foraging frequency. Conclusions/Significance: These results suggest that the MB neuron activity depends on the foraging frequency, whereas the number of active MB neurons is related to the pattern of visual input received during foraging flight. Our results sugges
A Combined Perceptual, Physico-Chemical, and Imaging Approach to ‘Odour-Distances’ Suggests a Categorizing Function of the Drosophila Antennal Lobe
How do physico-chemical stimulus features, perception, and physiology relate? Given the multi-layered and parallel architecture of brains, the question specifically is where physiological activity patterns correspond to stimulus features and/or perception. Perceived distances between six odour pairs are defined behaviourally from four independent odour recognition tasks. We find that, in register with the physico-chemical distances of these odours, perceived distances for 3-octanol and n-amylacetate are consistently smallest in all four tasks, while the other five odour pairs are about equally distinct. Optical imaging in the antennal lobe, using a calcium sensor transgenically expressed in only first-order sensory or only second-order olfactory projection neurons, reveals that 3-octanol and n-amylacetate are distinctly represented in sensory neurons, but appear merged in projection neurons. These results may suggest that within-antennal lobe processing funnels sensory signals into behaviourally meaningful categories, in register with the physico-chemical relatedness of the odours
Mobilization and hematopoietic stem cell collection in poor mobilizing patients with lymphoma: final results of the german OPTIMOB study
<jats:p>Introduction: Successful mobilization and collection of peripheral hematopoietic stem cells (HSCs) are necessary for lymphoma patients eligible for myeloablative chemotherapy with subsequent autologous stem cell transplantation (ASCT). Albeit G-CSF alone or combined with chemotherapy is well-established methods for HSC mobilization, up to 40% of the patients fail to mobilize (poor mobilizer, PM). Plerixafor (PLX) is commonly used in PM patients resulting in increased migration of HSCs into peripheral blood and thus improves the collection outcome. Methods: The prospective, multicenter, open-label, non-interventional OPTIMOB study assessed mobilization and collection parameter of patients with lymphoma or multiple myeloma to get deep insights in the treatment of those patients in clinical routine focusing on PM patients. PM was defined as follows: (1) no achievement of ≥20 CD34+ progenitor cells/µL before first apheresis, (2) PLX administration at any time point during the observational period, (3) reduction of the initially planned CD34+ progenitor cell yield as necessity due to failed mobilization or HSC collection, and (4) no performance of apheresis due to low CD34+ progenitor level. Primary objective of the study was to assess mobilization success by the proportion of PM patients achieving &amp;gt;2 × 106 CD34+ progenitor cells/kg body weight on the first day of apheresis. Here, the data of the lymphoma cohort are presented. Results: Out of 238 patients with lymphoma documented in the study, 32% were classified as PM. 87% of them received PLX. Demographic data revealed no obvious differences between PM and good mobilizing (GM) patients. All patients were treated highly individualized prior to mobilization. Majority of all PM patients were able to undergo apheresis (95%) and reached their individual requested CD34+ progenitor cell target (72%). 57% of the PM patients achieved &amp;gt;2.0 × 106 CD34+ progenitor cells/kg body weight on day 1 of apheresis and nearby 70% of them underwent ASCT. Median time to engraftment was similar in PM and GM patients of the lymphoma cohort. Conclusions: Majority of PM patients with lymphoma were successfully mobilized and underwent ASCT. Most of them received PLX during the study. </jats:p>
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