Ecomorphological diversification of the Late Palaeozoic Palaeodictyopterida reveals different larval strategies and amphibious lifestyle in adults

This work is licensed under a Creative Commons Attribution 4.0 International License.The Late Palaeozoic insect superorder Palaeodictyopterida exhibits a remarkable disparity of larval ecomorphotypes, enabling these animals to occupy diverse ecological niches. The widely accepted hypothesis presumed that their immature stages only occupied terrestrial habitats, although authors more than a century ago hypothesized they had specializations for amphibious or even aquatic life histories. Here, we show that different species had a disparity of semiaquatic or aquatic specializations in larvae and even the supposed retention of abdominal tracheal gills by some adults. While a majority of mature larvae in Palaeodictyoptera lack unambiguous lateral tracheal gills, some recently discovered early instars had terminal appendages with prominent lateral lamellae like in living damselflies, allowing support in locomotion along with respiratory function. These results demonstrate that some species of Palaeodictyopterida had aquatic or semiaquatic larvae during at least a brief period of their post-embryonic development. The retention of functional gills or gill sockets by adults indicates their amphibious lifestyle and habitats tightly connected with a water environment as is analogously known for some modern Ephemeroptera or Plecoptera. Our study refutes an entirely terrestrial lifestyle for all representatives of the early diverging pterygote group of Palaeodictyopterida, a greatly varied and diverse lineage which probably encompassed many different biologies and life histories

Objawy dysfunkcji czaszkowo- żuchwowej lub bruksizmu wśród studentów

Wstęp. Współcześnie odnotowuje się wyraźny wzrost częstości występowania zaburzeń czynnościowych układu stomatognatycznego. Ma to zapewne związek ze wrastająca potrzebą dbałości o swoje zdrowie, ale także może wynikać z rzeczywistego wzrostu częstości występowania tej patologii. Duża aktualność problematyki skłoniła autorów do podjęcia badań własnych. Cel pracy. Celem badań była ocena częstości występowanie objawów bruksizmu wśród studentów krakowskich uczelni wyż-szych. Materiał i metody. Grupę badaną stanowiło 277 osób (172 kobie-ty i 105 mężczyzn) w wieku 19 - 29 lat, studentów krakowskich uczelni. Wykorzystano autorską ankietę oraz przeprowadzono krótkie badanie fizykalne. Wyniki i wnioski. Najczęściej odczuwaną dolegliwością wśród badanych był ból głowy. Zgłaszało go 80% respondentów, następnie zaburzony tor ruchu odwodzenia żuchwy, który rejestrowano u 78% badanych, trzaski w stawie skroniowo- żuchwowym, które podawało 50% badanych: obecność starć zębów i brak symetrii napięcia mięśni żwaczy , które stwierdzano z jednakową częstością u 38% badanych. Szumy uszne dotyczyły 22,74% badanych. Zaburzony tor odwodzenia żuchwy występował u 77,98% chorych z dysfuncją narządu żucia . Wnioski. Jednym z wiodących , choć niecharakterystycznych objawów dysfuncji narządu żucia jest ból. Chorym z zaburzeniami układu stomatognatycznego towarzyszyć mogą różnorodne objawy otologiczne występujące w dużym przedziale częstości.Introduction. Nowadays, there is a clear increase in the incidence of functional disorders of the stomatognathic system. This is probably related to the growing need to care for your health, but it also may result from a real increase in the incidence of this pathology. High relevance of the issues, prompted the authors to undertake their own research. Aim of the study. The aim of the study was to assess the frequency of the occurrence of bruxism symptoms among students of Krakow’s universities. Material and methods. The study group consisted of 277 people (172 women and 105 men) aged 19 – 29 who were students of Krakow’s universities. An original questionnaire was used and a short physical examination was carried out. Results and conclusions. The most frequently felt ailment among the subjects was headache. It was reported by 80% of respondents, followed by a disturbed mandibular movement pathway, which was recorded in 78% of respondents, cracks in the temporo-mandibular joint, which were given by 50% of subjects: presence of tooth clashes and lack of symmetry of masseter muscles, which were found at the same frequency in 38 % of respondents. Tinnitus related to 22.74% of the subjects. A disturbed mandibu-lar disorder pathway occurred in 77.98% of patients with masticatory system dysfunction

Modelling the Galactic Bar Using Red Clump Giants

The color-magnitude diagrams of $\sim 7 \times 10^5$ stars obtained for 12 fields across the Galactic bulge with the OGLE project reveal a well-defined population of bulge red clump giants. We find that the distributions of the apparent magnitudes of the red clump stars are systematically fainter when moving towards lower galactic $l$ fields. The most plausible explanation of this distinct trend is that the Galactic bulge is a bar, whose nearest end lies at positive galactic longitude. We model this Galactic bar by fitting for all fields the observed luminosity functions in the red clump region of the color-magnitude diagram. We find that almost regardless of the analytical function used to describe the 3-D stars distribution of the Galactic bar, the resulting models have the major axis inclined to the line of sight by $20-30\deg$, with axis ratios corresponding to $x_0:y_0:z_0=3.5:1.5:1$. This puts a strong constraint on the possible range of the Galactic bar models. Gravitational microlensing can provide us with additional constrains on the structure of the Galactic bar.Comment: submitted to the New Astronomy, 27 pages, 11 figures; also available at ftp://www.astro.princeton.edu/stanek/Barmodel and through WWW at http://www.astro.princeton.edu/~library/prep.htm

New high precision orbital and physical parameters of the double-lined low-mass spectroscopic binary BY Draconis

We present the most precise to date orbital and physical parameters of the well known short period (P=5.975 d), eccentric (e=0.3) double-lined spectroscopic binary BY Draconis, a prototype of a class of late-type, active, spotted flare stars. We calculate the full spectroscopic/astrometric orbital solution by combining our precise radial velocities (RVs) and the archival astrometric measurements from the Palomar Testbed Interferometer (PTI). The RVs were derived based on the high resolution echelle spectra taken between 2004 and 2008 with the Keck I/HIRES, Shane/CAT/HamSpec and TNG/SARG telescopes/spectrographs using our novel iodine-cell technique for double-lined binary stars. The RVs and available PTI astrometric data spanning over 8 years allow us to reach 0.2-0.5% level of precision in M sin3(i) and the parallax but the geometry of the orbit (i=154 deg) hampers the absolute mass precision to 3.3%, which is still an order of magnitude better than for previous studies. We compare our results with a set of Yonsei-Yale theoretical stellar isochrones and conclude that BY Dra is probably a main sequence system more metal-rich than the Sun. Using the orbital inclination and the available rotational velocities of the components, we also conclude that the rotational axes of the components are likely misaligned with the orbital angular momentum. Given BY Dra's main sequence status, late spectral type and the relatively short orbital period, its high orbital eccentricity and probable spin-orbit misalignment are not in agreement with the tidal theory. This disagreement may possibly be explained by smaller rotational velocities of the components and the presence of a substellar mass companion to BY Dra AB.Comment: 10 pages, 7 figures, 4 tables, to appear in MNRA

Mapping the meaning of "difference' in Europe: A social topography of prejudice

This paper draws on original empirical research to investigate popular understandings of prejudice in two national contexts: Poland and the United Kingdom. The paper demonstrates how common-sense meanings of prejudice are inflected by the specific histories and geographies of each place: framed in terms of ‘distance’ (Poland) and ‘proximity’ (United Kingdom), respectively. Yet, by treating these national contexts as nodes and linking them analytically the paper also exposes a connectedness in these definitions which brings into relief the common processes that produce prejudice. The paper then explores how inter-linkages between the United Kingdom and Poland within the wider context of the European Union are producing – and circulating through the emerging international currency of ‘political correctness’ – a common critique of equality legislation and a belief that popular concerns about the way national contexts are perceived to be changing as a consequence of super mobility and super diversity are being silenced. This raises a real risk that in the context of European austerity and associated levels of socioeconomic insecurity, negative attitudes and conservative values may begin to be represented as popular normative standards which transcend national contexts to justify harsher political responses towards minorities. As such, the paper concludes by making a case for prejudice reduction strategies to receive much greater priority in both national and European contexts