355 research outputs found
Improving Face-to-Face Communication Skills using Active Video Watching
Although communication skills are widely recognized as crucial for effective
software development teams, many graduates lack such skills, which are difficult to teach. We
adopt the active video watching (AVW) approach to teach face-to-face communication skills to
second-year software engineering project course. We conducted an experiment with
AVW-Space, an online platform which supports video-based learning. The participants
watched and commented on tutorial videos first, and later on provided videos of meetings. In the
last phase, the participants commented on the recording of their own team meeting. We found
that students who commented and rated others’ comments increased their conceptual
understanding of face-to-face communication skills
Multiwavelength study of the high-latitude cloud L1642: chain of star formation
L1642 is one of the two high galactic latitude (|b| > 30deg) clouds confirmed
to have active star formation. We examine the properties of this cloud,
especially the large-scale structure, dust properties, and compact sources in
different stages of star formation. We present high-resolution far-infrared and
submm observations with the Herschel and AKARI satellites and mm observations
with the AzTEC/ASTE telescope, which we combined with archive data from near-
and mid-infrared (2MASS, WISE) to mm observations (Planck). The Herschel
observations, combined with other data, show a sequence of objects from a cold
clump to young stellar objects at different evolutionary stages. Source B-3
(2MASS J04351455-1414468) appears to be a YSO forming inside the L1642 cloud,
instead of a foreground brown dwarf, as previously classified. Herschel data
reveal striation in the diffuse dust emission around L1642. The western region
shows striation towards NE and has a steeper column density gradient on its
southern side. The densest central region has a bow-shock like structure
showing compression from the west and a filamentary tail extending towards
east. The differences suggest that these may be spatially distinct structures,
aligned only in projection. We derive values of the dust emission cross-section
per H nucleon for different regions of the cloud. Modified black-body fits to
the spectral energy distribution of Herschel and Planck data give emissivity
spectral index beta values 1.8-2.0 for the different regions. The compact
sources have lower beta values and show an anticorrelation between T and beta.
Markov chain Monte Carlo calculations demonstrate the strong anticorrelation
between beta and T errors and the importance of mm Planck data in constraining
the estimates. L1642 reveals a more complex structure and sequence of star
formation than previously known.Comment: 22 pages, 18 figures, accepted to Astronomy & Astrophysics; abstract
shortened and figures reduced for astrop
Matching dust emission structures and magnetic field in high-latitude cloud L1642 : comparing Herschel and Planck maps
The nearby cloud L1642 is one of only two known very high latitude (b| > 30 deg) clouds actively forming stars. It is a rare example of star formation in isolated conditions, and can reveal important details of star formation in general, e.g. of the effect of magnetic fields. We compareHerschel dust emission structures and magnetic field orientation revealed byPlanck polarization maps in L1642. The high-resolution (similar to 20 arcsec)Herschel data reveal a complex structure including a dense, compressed central clump, and low-density striations. ThePlanck polarization data (at 10 arcmin resolution) reveal an ordered magnetic field pervading the cloud and aligned with the surrounding striations. There is a complex interplay between the cloud structure and large-scale magnetic field. This suggests that the magnetic field is closely linked to the formation and evolution of the cloud. CO rotational emission confirms that the striations are connected with the main clumps and likely to contain material either falling into or flowing out of the clumps. There is a clear transition from aligned to perpendicular structures approximately at a column density ofN(H) = 1.6 x 10(21) cm(-2). Comparing theHerschel maps with thePlanck polarization maps shows the close connection between the magnetic field and cloud structure even in the finest details of the cloud.Peer reviewe
Investigating human audio-visual object perception with a combination of hypothesis-generating and hypothesis-testing fMRI analysis tools
Primate multisensory object perception involves distributed brain regions. To investigate the network character of these regions of the human brain, we applied data-driven group spatial independent component analysis (ICA) to a functional magnetic resonance imaging (fMRI) data set acquired during a passive audio-visual (AV) experiment with common object stimuli. We labeled three group-level independent component (IC) maps as auditory (A), visual (V), and AV, based on their spatial layouts and activation time courses. The overlap between these IC maps served as definition of a distributed network of multisensory candidate regions including superior temporal, ventral occipito-temporal, posterior parietal and prefrontal regions. During an independent second fMRI experiment, we explicitly tested their involvement in AV integration. Activations in nine out of these twelve regions met the max-criterion (A < AV > V) for multisensory integration. Comparison of this approach with a general linear model-based region-of-interest definition revealed its complementary value for multisensory neuroimaging. In conclusion, we estimated functional networks of uni- and multisensory functional connectivity from one dataset and validated their functional roles in an independent dataset. These findings demonstrate the particular value of ICA for multisensory neuroimaging research and using independent datasets to test hypotheses generated from a data-driven analysis
Bacterial species associated with interdigital phlegmon outbreaks in Finnish dairy herds
Background: Severe outbreaks of bovine interdigital phlegmon (IP) have occurred recently in several free stall dairy
herds in Finland. We studied the aetiology of IP in such herds, and the association of bacterial species with the
various stages of IP and herds of various morbidity of IP. Nineteen free stall dairy herds with IP outbreaks and three
control herds were visited and bacteriological samples collected from cows suffering from IP (n = 106), other hoof
diseases (n = 58), and control cows (n = 64). The herds were divided into high morbidity (morbidity ≥50%) and
moderate morbidity groups (9–33%) based on morbidity during the first two months of the outbreak.
Results: F. necrophorum subspecies necrophorum was clearly associated with IP in general, and T. pyogenes was
associated with the healing stage of IP. Six other major hoof pathogens were detected; Dichelobacter nodosus,
Porphyromonas levii, Prevotella melaninogenica, Treponema spp. and Trueperella pyogenes. Most of the samples of
acute IP (66.7%) harboured both F. necrophorum and D. nodosus. We found differences between moderate
morbidity and high morbidity herds. D. nodosus was more common in IP lesion in high than in moderate morbidity
herds.
Conclusions: Our result confirms that F. necrophorum subspecies necrophorum is the main pathogen in IP, but also
T. pyogenes is associated with the healing stage of IP. Our results suggest that D. nodosus may play a role in the
severity of the outbreak of IP, but further research is needed to establish other bacteriological factors behind these
severe outbreaks
Preclinical animal research on therapy dosimetry with dual isotopes
Preclinical research into radionuclide therapies based on radiation dosimetry will enable the use of any LET-equivalent radionuclide. Radiation dose and dose rate have significant influence on dose effects in the tumour depending on its radiation sensitivity, possibilities for repair of sublethal damage, and repopulation during or after the therapy. Models for radiation response of preclinical tumour models after peptide receptor radionuclide therapy based on the linear quadratic model are presented. The accuracy of the radiation dose is very important for observation of dose-effects. Uncertainties in the radiation dose estimation arise from incomplete assay of the kinetics, low accuracy in volume measurements and absorbed dose S-values for stylized models instead of the actual animal geometry. Normal dose uncertainties in the order of 20% might easily make the difference between seeing a dose-effect or missing it altogether. This is true for the theoretical case of a homogeneous tumour type behaving in vivo in the same way as its cells do in vitro. Heterogeneity of tumours induces variations in clonogenic cell density, radiation sensitivity, repopulation capacity and repair kinetics. The influence of these aspects are analysed within the linear quadratic model for tumour response to radionuclide therapy. Preclinical tumour models tend to be less heterogenic than the clinical conditions they should represent. The results of various preclinical radionuclide therapy experiments for peptide receptor radionuclide therapy are compared to the outcome of theoretical models and the influence of increased heterogeneity is analysed when the results of preclinical research is transferred to the clinic. When the radiation dose and radiobiology of the tumour response is known well enough it may be possible to leave the current phenomenological approach in preclinical radionuclide therapy and start basing these experiments on radiation dose. Then the use of a gamma ray-emitting radionuclides for a chemically comparable beta-particle-emitting paired isotope for therapy evaluation would be feasible
miR-Q: a novel quantitative RT-PCR approach for the expression profiling of small RNA molecules such as miRNAs in a complex sample
<p>Abstract</p> <p>Background</p> <p>MicroRNAs (miRNAs) are small endogenous non-coding interfering RNA molecules regarded as major regulators in eukaryotic gene expression. Different methods are employed for miRNA expression profiling. For a better understanding of their role in essential biological processes, convenient methods for differential miRNA expression analysis are required.</p> <p>Results</p> <p>Here, we present the miR-Q assay as a highly sensitive quantitative reverse transcription PCR (qRT-PCR) for expression analysis of small RNAs such as miRNA molecules. It shows a high dynamic range of 6 to 8 orders of magnitude comprising a sensitivity of up to 0.2 fM miRNA, which corresponds to single copies per cell. There is nearly no cross reaction among closely-related miRNA family members, which points to the high specificity of the assays. Using this approach, we quantified the expression of let-7b in different human cell lines as well as miR-145 and miR-21 expression in porcine intestinal samples.</p> <p>Conclusion</p> <p>miR-Q is a cost-effective and highly specific approach, which neither requires the use of fluorochromic probes, nor Locked Nucleic Acid (LNA)-modified oligonucleotides. Moreover, it provides a remarkable increase in specificity and simplified detection of small RNAs.</p
Boundary triplets for skew-symmetric operators and the generation of strongly continuous semigroups
We give a self-contained and streamlined exposition of a generation theorem
for C0-semigroups based on the method of boundary triplets. We apply this
theorem to port-Hamiltonian systems where we discuss recent results appearing
in stability and control theory. We give detailed proofs and require only a
basic knowledge of operator and semigroup theory.Comment: 19 page
Gas phase Elemental abundances in Molecular cloudS (GEMS) : II. On the quest for the sulphur reservoir in molecular clouds: the H2S case
Context. Sulphur is one of the most abundant elements in the Universe. Surprisingly, sulphuretted molecules are not as abundant as expected in the interstellar medium and the identity of the main sulphur reservoir is still an open question.Aims. Our goal is to investigate the H2S chemistry in dark clouds, as this stable molecule is a potential sulphur reservoir.Methods. Using millimeter observations of CS, SO, H2S, and their isotopologues, we determine the physical conditions and H2S abundances along the cores TMC 1-C, TMC 1-CP, and Barnard 1b. The gas-grain model NAUTILUS is used to model the sulphur chemistry and explore the impact of photo-desorption and chemical desorption on the H2S abundance.Results. Our modeling shows that chemical desorption is the main source of gas-phase H2S in dark cores. The measured H2S abundance can only be fitted if we assume that the chemical desorption rate decreases by more than a factor of 10 when n(H) > 2 x 10(4). This change in the desorption rate is consistent with the formation of thick H2O and CO ice mantles on grain surfaces. The observed SO and H2S abundances are in good agreement with our predictions adopting an undepleted value of the sulphur abundance. However, the CS abundance is overestimated by a factor of 5-10. Along the three cores, atomic S is predicted to be the main sulphur reservoir.Conclusions. The gaseous H2S abundance is well reproduced, assuming undepleted sulphur abundance and chemical desorption as the main source of H2S. The behavior of the observed H2S abundance suggests a changing desorption efficiency, which would probe the snowline in these cold cores. Our model, however, highly overestimates the observed gas-phase CS abundance. Given the uncertainty in the sulphur chemistry, we can only conclude that our data are consistent with a cosmic elemental S abundance with an uncertainty of a factor of 10.Peer reviewe
A representation of all solutions of the control algebraic Riccati equation for infinite-dimensional systems
- …