145 research outputs found
Genetic uniqueness and socio-cultural conservation values of the endangered Yakutian Cattle
At the local level the values of the cattle were more related to everyday livelihood strategies of single households and families, whereas the representatives of the republic, in line with the newspapers, highlighted the importance of the cattle for Sakha's food production and for national identity. Thus, individuals at different levels were in favour of conserving the cattle, but for different reasons. The local residents and experts were more concerned about developing economically sustainable cattle production, whereas the experts in Yakutsk were concerned about the conservation of genetic resources. The genetic studies have indicated that Yakutian Cattle show genetic distinctiveness and have genetic value for the maintenance of cattle diversity
Humanistic interpretation and machine learning
This paper investigates how unsupervised machine learning methods might make hermeneutic interpretive text analysis more objective in the social sciences. Through a close examination of the uses of topic modeling—a popular unsupervised approach in the social sciences—it argues that the primary way in which unsupervised learning supports interpretation is by allowing interpreters to discover unanticipated information in larger and more diverse corpora and by improving the transparency of the interpretive process. This view highlights that unsupervised modeling does not eliminate the researchers’ judgments from the process of producing evidence for social scientific theories. The paper shows this by distinguishing between two prevalent attitudes toward topic modeling, i.e., topic realism and topic instrumentalism. Under neither can modeling provide social scientific evidence without the researchers’ interpretive engagement with the original text materials. Thus the unsupervised text analysis cannot improve the objectivity of interpretation by alleviating the problem of underdetermination in interpretive debate. The paper argues that the sense in which unsupervised methods can improve objectivity is by providing researchers with the resources to justify to others that their interpretations are correct. This kind of objectivity seeks to reduce suspicions in collective debate that interpretations are the products of arbitrary processes influenced by the researchers’ idiosyncratic decisions or starting points. The paper discusses this view in relation to alternative approaches to formalizing interpretation and identifies several limitations on what unsupervised learning can be expected to achieve in terms of supporting interpretive work.This paper investigates how unsupervised machine learning methods might make hermeneutic interpretive text analysis more objective in the social sciences. Through a close examination of the uses of topic modeling—a popular unsupervised approach in the social sciences—it argues that the primary way in which unsupervised learning supports interpretation is by allowing interpreters to discover unanticipated information in larger and more diverse corpora and by improving the transparency of the interpretive process. This view highlights that unsupervised modeling does not eliminate the researchers’ judgments from the process of producing evidence for social scientific theories. The paper shows this by distinguishing between two prevalent attitudes toward topic modeling, i.e., topic realism and topic instrumentalism. Under neither can modeling provide social scientific evidence without the researchers’ interpretive engagement with the original text materials. Thus the unsupervised text analysis cannot improve the objectivity of interpretation by alleviating the problem of underdetermination in interpretive debate. The paper argues that the sense in which unsupervised methods can improve objectivity is by providing researchers with the resources to justify to others that their interpretations are correct. This kind of objectivity seeks to reduce suspicions in collective debate that interpretations are the products of arbitrary processes influenced by the researchers’ idiosyncratic decisions or starting points. The paper discusses this view in relation to alternative approaches to formalizing interpretation and identifies several limitations on what unsupervised learning can be expected to achieve in terms of supporting interpretive work.Peer reviewe
Fibonaccin luvut
Tiivistelmä. Tässä tutkielmassa tutustutaan Fibonaccin lukuihin. Tarkoituksena on antaa rekursiivinen määritelmä Fibonaccin luvuille sekä tutkia niitä lukuteorian näkökulmasta. Lisäksi tutkitaan Fibonaccin lukujen yhteyttä kultaiseen leikkaukseen ja Binet’n kaavaan. Tutkielman lopuksi todistetaan Zeckendorfin lause
Narkolepsiaan sairastuneiden lasten ja nuorten perheiden arki ja sopeutumisvalmennuskurssilta saatu tuki
Suomessa varauduttiin maailmanlaajuisesti levinneeseen sikainfluenssaan aloittamalla lokakuussa 2009 Pandemrix-rokotukset väestön suojaamiseksi. Helmikuussa 2010 diagnosoitiin ensimmäinen päiväaikaista nukahtelua aiheuttava narkolepsia lapsella, joka oli saanut Pandemrix-rokotuksen. Sosiaali- ja terveysministeriö antoi Kelalle tehtäväksi järjestää narkolepsiaan sairastuneille lapsille ja nuorille sopeutumisvalmennuskursseja. Kelan tutkimusosasto, Lapin yliopisto ja Suomen Mielenterveysseura toteuttivat tutkimuksen, jonka päätavoite oli selvittää, mitkä olivat sairastuneiden ja heidän perheidensä tarpeet ja odotukset sekä miten hyvin kurssit pystyivät vastaamaan niihin. Aineiston keruu toteutui kevään 2012 ja syksyn 2013 välisenä aikana. Narkolepsiaan liittyviä päiväaikaista nukahtelua, käyttäytymisen muutoksia ja keskittymisen vaikeuksia esiintyi lähes kaikilla tutkimukseen osallistuneilla lapsilla ja nuorilla. Muistin ja oppimisen vaikeuksia sekä katapleksiaa oli yli puolella ja harha-aistimuksia noin kolmanneksella. Käyttäytymisen ja mielialan muutokset vaikuttivat koko perheen arkeen. Vanhemmat olivat huolissaan nuoren tulevaisuudesta, omien auttamiskeinojensa riittävyydestä, sisarusten voinnista ja omasta jaksamisestaan. Perheillä oli runsaasti psykososiaalisen tuen tarpeita. Perheiden odotukset painottuivat vertaistuen saamiseen, ja kurssit vastasivat näihin odotuksiin. Enemmistö koki saaneensa jonkin verran etäisyyttä arkisiin huoliin, tukea tunteiden käsittelyyn ja sairastuneen vahvuuksien tunnistamiseen. Asiantuntijatiedon ja ammatillisen psykososiaalisen tuen tarpeeseen kurssit eivät vastanneet. Sopeutumisvalmennuskurssien toimeenpanossa ilmeni useita kehittämisen kohteita. Kurssien tavoitteiden tarkentaminen, asiantuntijatiedon vahvistaminen, yksilöllisten työmenetelmien valinnan mahdollisuus, ennakkoinformaation lisääminen sekä Kelan ja palveluntuottajan välisen yhteistyön vahvistaminen mahdollistavat kuntoutujalähtöisiin tarpeisiin vastaamisen
Radio-to-UV monitoring of AO 0235+164 by the WEBT and Swift during the 2006--2007 outburst
The blazar AO 0235+164 was claimed to show a quasi-periodic behaviour in the
radio and optical bands. Moreover, an extra emission component contributing to
the UV and soft X-ray flux was detected, whose nature is not yet clear. A
predicted optical outburst was observed in late 2006/early 2007. We here
present the radio-to-optical WEBT light curves during the outburst, together
with UV data acquired by Swift in the same period. We found the optical
outburst to be as strong as the big outbursts of the past: starting from late
September 2006, a brightness increase of 5 mag led to the outburst peak in
February 19-21, 2007. We also observed an outburst at mm and then at cm
wavelengths, with an increasing time delay going toward lower frequencies
during the rising phase. Cross-correlation analysis indicates that the 1 mm and
37 GHz flux variations lagged behind the R-band ones by about 3 weeks and 2
months, respectively. These short time delays suggest that the corresponding
jet emitting regions are only slightly separated and/or misaligned. In
contrast, during the outburst decreasing phase the flux faded contemporaneously
at all cm wavelengths. This abrupt change in the emission behaviour may suggest
the presence of some shutdown mechanism of intrinsic or geometric nature. The
behaviour of the UV flux closely follows the optical and near-IR one. By
separating the synchrotron and extra component contributions to the UV flux, we
found that they correlate, which suggests that the two emissions have a common
origin.Comment: 9 pages, 7 figures, in press for Astronomy and Astrophysic
Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution
The larger number of models of asteroid shapes and their rotational states
derived by the lightcurve inversion give us better insight into both the nature
of individual objects and the whole asteroid population. With a larger
statistical sample we can study the physical properties of asteroid
populations, such as main-belt asteroids or individual asteroid families, in
more detail. Shape models can also be used in combination with other types of
observational data (IR, adaptive optics images, stellar occultations), e.g., to
determine sizes and thermal properties. We use all available photometric data
of asteroids to derive their physical models by the lightcurve inversion method
and compare the observed pole latitude distributions of all asteroids with
known convex shape models with the simulated pole latitude distributions. We
used classical dense photometric lightcurves from several sources and
sparse-in-time photometry from the U.S. Naval Observatory in Flagstaff,
Catalina Sky Survey, and La Palma surveys (IAU codes 689, 703, 950) in the
lightcurve inversion method to determine asteroid convex models and their
rotational states. We also extended a simple dynamical model for the spin
evolution of asteroids used in our previous paper. We present 119 new asteroid
models derived from combined dense and sparse-in-time photometry. We discuss
the reliability of asteroid shape models derived only from Catalina Sky Survey
data (IAU code 703) and present 20 such models. By using different values for a
scaling parameter cYORP (corresponds to the magnitude of the YORP momentum) in
the dynamical model for the spin evolution and by comparing synthetics and
observed pole-latitude distributions, we were able to constrain the typical
values of the cYORP parameter as between 0.05 and 0.6.Comment: Accepted for publication in A&A, January 15, 201
WEBT and XMM-Newton observations of 3C 454.3 during the post-outburst phase. Detection of the little and big blue bumps
The blazar 3C 454.3 underwent an unprecedented optical outburst in spring
2005. This was first followed by a mm and then by a cm radio outburst, which
peaked in February 2006. We report on follow-up observations by the WEBT to
study the multiwavelength emission in the post-outburst phase. XMM-Newton
observations on July and December 2006 added information on the X-ray and UV
fluxes. The source was in a faint state. The radio flux at the higher
frequencies showed a fast decreasing trend, which represents the tail of the
big radio outburst. It was followed by a quiescent state, common at all radio
frequencies. In contrast, moderate activity characterized the NIR and optical
light curves, with a progressive increase of the variability amplitude with
increasing wavelength. We ascribe this redder-when-brighter behaviour to the
presence of a "little blue bump" due to line emission from the broad line
region, which is clearly visible in the source SED during faint states.
Moreover, the data from the XMM-Newton OM reveal a rise of the SED in the UV,
suggesting the existence of a "big blue bump" due to thermal emission from the
accretion disc. The X-ray spectra are well fitted with a power-law model with
photoelectric absorption, possibly larger than the Galactic one. However, the
comparison with previous X-ray observations would imply that the amount of
absorbing matter is variable. Alternatively, the intrinsic X-ray spectrum
presents a curvature, which may depend on the X-ray brightness. In this case,
two scenarios are possible.Comment: 9 pages, 7 figures, accepted for publication in A&
Characterization of the Pore Structure of Functionalized Calcium Carbonate Tablets by Terahertz Time-Domain Spectroscopy and X-Ray Computed Microtomography
Novel excipients are entering the market to enhance the bioavailability of drug particles by having a high porosity and, thus, providing a rapid liquid uptake and disintegration to accelerate subsequent drug dissolution. One example of such a novel excipient is functionalized calcium carbonate, which enables the manufacture of compacts with a bimodal pore size distribution consisting of larger interparticle and fine intraparticle pores. Five sets of functionalized calcium carbonate tablets with a target porosity of 45%-65% were prepared in 5% steps and characterized using terahertz time-domain spectroscopy and X-ray computed microtomography. Terahertz time-domain spectroscopy was used to derive the porosity using effective medium approximations, that is, the traditional and an anisotropic Bruggeman model. The anisotropic Bruggeman model yields the better correlation with the nominal porosity (R = 0.995) and it provided additional information about the shape and orientation of the pores within the powder compact. The spheroidal (ellipsoids of revolution) shaped pores have a preferred orientation perpendicular to the compaction direction causing an anisotropic behavior of the dielectric porous medium. The results from X-ray computed microtomography confirmed the nonspherical shape and the orientation of the pores, and it further revealed that the anisotropic behavior is mainly caused by the interparticle pores. The information from both techniques provides a detailed insight into the pore structure of pharmaceutical tablets. This is of great interest to study the impact of tablet microstructure on the disintegration and dissolution performance.Drs Markl and Zeitler would like to acknowledge the U.K. Engineering and Physical Sciences Research Council for funding (EP/L019922/1)
A theory of moving form perception: Synergy between masking, perceptual grouping, and motion computation in retinotopic and non-retinotopic representations
Because object and self-motion are ubiquitous in natural viewing conditions,
understanding how the human visual system achieves a relatively clear perception
for moving objects is a fundamental problem in visual perception. Several
studies have shown that the visible persistence of a briefly presented
stationary stimulus is approximately 120 ms under normal viewing conditions.
Based on this duration of visible persistence, we would expect moving objects to
appear highly blurred. However, in human vision, objects in motion typically
appear relatively sharp and clear. We suggest that clarity of form in dynamic
viewing is achieved by a synergy between masking, perceptual grouping, and
motion computation across retinotopic and non-retinotopic representations. We
also argue that dissociations observed in masking are essential to create and
maintain this synergy
Anatomical and Physiological Plasticity in Leymus chinensis (Poaceae) along Large-Scale Longitudinal Gradient in Northeast China
Although it has been widely accepted that global changes will pose the most important constrains to plant survival and distribution, our knowledge of the adaptive mechanism for plant with large-scale environmental changes (e.g. drought and high temperature) remains limited.An experiment was conducted to examine anatomical and physiological plasticity in Leymus chinensis along a large-scale geographical gradient from 115° to 124°E in northeast China. Ten sites selected for plant sampling at the gradient have approximately theoretical radiation, but differ in precipitation and elevation. The significantly increasing in leaf thickness, leaf mass per area, vessel and vascular diameters, and decreasing in stoma density and stoma index exhibited more obvious xerophil-liked traits for the species from the moist meadow grassland sites in contrast to that from the dry steppe and desert sites. Significant increase in proline and soluble sugar accumulation, K(+)/Na(+) for the species with the increasing of stresses along the gradient showed that osmotic adjustment was enhanced.Obvious xerophytic anatomical traits and stronger osmotic adjustment in stress conditions suggested that the plants have much more anatomical and physiological flexibilities than those in non-stress habitats along the large-scale gradient
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