251 research outputs found
Development of neutron activation for investigation of water clarification
Student supported: 1 Student AssistantThe applicability of power spectral density techniques, Fourier series analysis, and linear regression to the mathematical modeling of river water temperature is demonstrated. Consideration is also given to the problem of estimating thermal inputs to rivers from man-made sources such as electrical power plants. First, power spectral density techniques are used in the time-series analysis of water temperature records which were taken from the Missouri River. Two spectral ranges are then studied from the standpoint of their applicability to (1) mathematical model building and (2) detection and identification of cyclic thermal inputs. Next, a Fourier regression fit to the time-series data is used to show that normal random variates having zero mean are obtained when the regression curve is extracted from the data. A 60-day prediction of daily-average water temperature is then made using a model which is based upon a polynomial regression fit to the fluctuating amplitudes of significant Fourier components. A final predictive model, which is based on the above analysis methods,is proposed.Project # A-026 -MO Agreement # 14-31-0001-302
Relatively Complete Verification of Probabilistic Programs: An Expressive Language for Expectation-Based Reasoning
We study a syntax for specifying quantitative “assertions” - functions mapping program states to numbers - for probabilistic program verification. We prove that our syntax is expressive in the following sense: Given any probabilistic program C, if a function f is expressible in our syntax, then the function mapping each initial state σ to the expected value of f evaluated in the final states reached after termination C on σ (also called the weakest preexpectation wp[C](f)) is also expressible in our syntax. As a consequence, we obtain a relatively complete verification system for verifying expected values and probabilities in the sense of Cook: Apart from a single reasoning step about the inequality of two functions given as syntactic expressions in our language, given f, g, and C, we can check whether g ≤ wp[C](f)
Early and Later Perceptions and Reactions to the COVID-19 Pandemic in Germany: On Predictors of Behavioral Responses and Guideline Adherence During the Restrictions
In March 2020, the German government enacted measures on movement restrictions and social distancing due to the COVID-19 pandemic. As this situation was previously unknown, it raised numerous questions about people’s perceptions of and behavioral responses to these new policies. In this context, we were specifically interested in people’s trust in official information, predictors for self-prepping behavior and health behavior to protect oneself and others, and determinants for adherence to social distancing guidelines. To explore these questions, we conducted three studies in which a total of 1,368 participants were surveyed (Study 1 N=377, March 2020; Study 2 N=461, April 2020; Study 3 N=530, April 2021) across Germany between March 2020 and April 2021. Results showed striking differences in the level of trust in official statistics (depending on the source). Furthermore, all three studies showed congruent findings regarding the influence of different factors on the respective behavioral responses. Trust in official statistics predicted behavioral responses in all three studies. However, it did not influence adherence to social distancing guidelines in 2020, but in 2021. Furthermore, adherence to social distancing guidelines was associated with higher acceptance rates of the measures and being older. Being female and less right-wing orientated were positively associated with guidelines adherence only in the studies from 2020. This year, political orientation moderated the association between acceptance of the measures and guideline adherence. This investigation is one of the first to examine perceptions and reactions during the COVID-19 pandemic in Germany across 1year and provides insights into important dimensions that need to be considered when communicating with the public
First HARPSpol discoveries of magnetic fields in massive stars
In the framework of the Magnetism in Massive Stars (MiMeS) project, a
HARPSpol Large Program at the 3.6m-ESO telescope has recently started to
collect high-resolution spectropolarimetric data of a large number of Southern
massive OB stars in the field of the Galaxy and in many young clusters and
associations. In this Letter, we report on the first discoveries of magnetic
fields in two massive stars with HARPSpol - HD 130807 and HD 122451, and
confirm the presence of a magnetic field at the surface of HD 105382 that was
previously observed with a low spectral resolution device. The longitudinal
magnetic field measurements are strongly varying for HD 130807 from -100
G to 700 G. Those of HD 122451 and HD 105382 are less variable with
values ranging from -40 to -80 G, and from -300 to -600 G,
respectively. The discovery and confirmation of three new magnetic massive
stars, including at least two He-weak stars, is an important contribution to
one of the MiMeS objectives: the understanding of origin of magnetic fields in
massive stars and their impacts on stellar structure and evolution.Comment: 4 pages, 2 figures, accepted for publication in A&A Lette
Aberrant DNA Methylation characterizes a subtype of juvenile myelomonocytic leukemia (JMML) with poor outcome
Implementing Diversity Training Targeting Faculty Microaggressions and Inclusion: Practical Insights and Initial Findings
Despite the importance of faculty diversity training for advancing an inclusive society, little research examines whether participation improves inclusion perceptions and belongingness. Integrating training and diversity education literature concepts, this study examines the effectiveness of training targeting microaggressions in six STEM (Science, Technology, Engineering, Mathematics) oriented departments at a research-intensive university. Reactions data collected at the end of face-to-face training suggested that participation generally increased inclusion understanding. Self-assessments on inclusion concepts collected from 45% of participants before and three weeks after training suggest participation increases perceptions of the importance of inclusion, microaggression allyship awareness, inclusive behaviors, and organizational identification. Compared to white men, women and minorities reported a greater increase in satisfaction with their department affiliation. While self-assessment results are exploratory and have limitations, analysis suggests that diversity training may enhance knowledge of microaggressions, allyship, inclusive behaviors, and belongingness perceptions. We provide insights for evaluating and implementing diversity training interventions
Multisite spectroscopic seismic study of the beta Cep star V2052 Oph: inhibition of mixing by its magnetic field
We used extensive ground-based multisite and archival spectroscopy to derive
observational constraints for a seismic modelling of the magnetic beta Cep star
V2052 Ophiuchi. The line-profile variability is dominated by a radial mode
(f_1=7.14846 d^{-1}) and by rotational modulation (P_rot=3.638833 d). Two
non-radial low-amplitude modes (f_2=7.75603 d^{-1} and f_3=6.82308 d^{-1}) are
also detected. The four periodicities that we found are the same as the ones
discovered from a companion multisite photometric campaign (Handler et al.
2012) and known in the literature. Using the photometric constraints on the
degrees l of the pulsation modes, we show that both f_2 and f_3 are prograde
modes with (l,m)=(4,2) or (4,3). These results allowed us to deduce ranges for
the mass (M \in [8.2,9.6] M_o) and central hydrogen abundance (X_c \in
[0.25,0.32]) of V2052 Oph, to identify the radial orders n_1=1, n_2=-3 and
n_3=-2, and to derive an equatorial rotation velocity v_eq \in [71,75] km
s^{-1}. The model parameters are in full agreement with the effective
temperature and surface gravity deduced from spectroscopy. Only models with no
or mild core overshooting (alpha_ov \in [0,0.15] local pressure scale heights)
can account for the observed properties. Such a low overshooting is opposite to
our previous modelling results for the non-magnetic beta Cep star theta Oph
having very similar parameters, except for a slower surface rotation rate. We
discuss whether this result can be explained by the presence of a magnetic
field in V2052 Oph that inhibits mixing in its interior.Comment: 12 pages, 6 figures and 5 tables; accepted for publication in MNRAS
on 2012 August 1
Host-associated Genetic Import in Campylobacter jejuni
C. jejuni genomes have a host signature that enables attribution of isolates to animal sources
ISOGAL: A deep survey of the obscured inner Milky Way with ISO at 7 and 15 micron and with DENIS in the near-infrared
The ISOGAL project is an infrared survey of specific regions sampling the
Galactic Plane selected to provide information on Galactic structure,stellar
populations,stellar mass-loss and the recent star formation history of the
inner disk and Bulge of the Galaxy. ISOGAL combines 7 and 15 micron ISOCAM
observations - with a resolution of 6'' at worst - with DENIS IJKs data to
determine the nature of the sources and theinterstellar extinction. We have
observed about 16 square degrees with a sensitivity approaching 10-20mJy,
detecting ~10^5 sources,mostly AGB stars,red giants and young stars. The main
features of the ISOGAL survey and the observations are summarized in this
paper,together with a brief discussion of data processing and quality. The
primary ISOGAL products are described briefly (a full description is given in
Schuller et al. 2003, astro-ph/0304309): viz. the images and theISOGAL-DENIS
five-wavelength point source catalogue. The main scientific results already
derived or in progress are summarized. These include astrometrically calibrated
7 and 15um images,determining structures of resolved sources; identification
and properties of interstellar dark clouds; quantification of the infrared
extinction law and source dereddening; analysis of red giant and (especially)
AGB stellar populations in the central Bulge,determining luminosity,presence of
circumstellar dust and mass--loss rate,and source classification,supplemented
in some cases by ISO/CVF spectroscopy; detection of young stellar objects of
diverse types,especially in the inner Bulge with information about the present
and recent star formation rate; identification of foreground sources with
mid-IR excess. These results are the subject of about 25 refereed papers
published or in preparation.Comment: A&A in press. 19 pages,10 Ps figures; problems with figures fixe
CONCERTO: High-fidelity simulation of millimeter line emissions of galaxies and [CII] intensity mapping
The intensity mapping of the [CII] 158-μm line redshifted to the submillimeter window is a promising probe of the za>4 star formation and its spatial distribution into large-scale structures. To prepare the first-generation experiments (e.g., CONCERTO), we need realistic simulations of the submillimeter extragalactic sky in spectroscopy. We present a new version of the simulated infrared dusty extragalactic sky (SIDES) model including the main submillimeter lines around 1 mm (CO, [CII], [CI]). This approach successfully reproduces the observed line luminosity functions. We then use our simulation to generate CONCERTO-like cubes (125-305 GHz) and forecast the power spectra of the fluctuations caused by the various astrophysical components at those frequencies. Depending on our assumptions on the relation between the star formation rate and [CII] luminosity, and the star formation history, our predictions of the za∼6 [CII] power spectrum vary by two orders of magnitude. This highlights how uncertain the predictions are and how important future measurements will be to improve our understanding of this early epoch. SIDES can reproduce the CO shot noise recently measured at a4;100 GHz by the millimeter-wavelength intensity mapping experiment (mmIME). Finally, we compare the contribution of the different astrophysical components at various redshifts to the power spectra. The continuum is by far the brightest, by a factor of three to 100, depending on the frequency. At 300 GHz, the CO foreground power spectrum is higher than the [CII] one for our base scenario. At lower frequencies, the contrast between [CII] and extragalactic foregrounds is even worse. Masking the known galaxies from deep surveys should allow us to reduce the foregrounds to 20% of the [CII] power spectrum up to z∼ 6.5. However, this masking method will not be sufficient at higher redshifts. The code and the products of our simulation are released publicly, and can be used for both intensity mapping experiments and submillimeter continuum and line surveys
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