13 research outputs found

    Calcium orthophosphate-based biocomposites and hybrid biomaterials

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    Past and present trophic position and decadal changes in diet of Yellow-legged Gull in the Azores Archipelago, NE Atlantic

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    This study evaluates the trophic position of adult Yellow-legged Gulls Larus michahellis atlantis resident in the Azores archipelago in the past (1921–1928) and in the present (2009–2010), and analyses the decadal variation in the diet of breeding birds from the 1990s to the 2000s for three main colonies (Topo Islet, Baixo Islet and Mistério da Prainha). Using mixing models, we compared stable isotope signatures of nitrogen and carbon in adult breast feathers between birds from 1921 to 1928 (held in museum collections) and 2009 to 2010, jointly with both isotopic signatures of their main prey groups (fish, goose barnacles (Lepas anatifera), seabirds, mammals and refuse). The diet of breeding birds was analysed using pellets collected in 1989, 1995, 1996, 2004, 2009 and 2010. Stable isotopes analysis (SIA) results were in accordance with the results provided from the analysis of pellets, showing a relatively recent and significant change in the diet of adult gulls. In particular, SIA revealed a significant decrease in the trophic position of Yellow-legged Gulls in the Azores, over the last 89 years in response to the decrease in the consumption of seabirds and fish and, an increase in the consumption of marine invertebrates (goose barnacles) and refuse. The analysis of pellets confirmed the significant decrease in the fish ingested, whereas the ingestion of lower trophic level prey (i.e. goose barnacles, mammals and refuse) increased. Both methods reflect the feeding plasticity and opportunistic foraging behavior of this species, and are in accordance with patterns described for continental Europe.We acknowledge the support given by Fundação para a Ciência e Tecnologia, Portugal, to Patricia Pedro (SFRH/BD/ 40095/2007)

    Understanding credit card payment behavior among college students

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    College students remain a lucrative target market for credit card companies even after the advent of the Credit Card Act of 2009. Unfortunately, many students are not prepared to use credit responsibly or make payments in a timely manner. Numerous studies reveal risky student credit behaviors, lack of credit knowledge or irresponsible management of credit. However, there remains a need for more information on college students\u27 payment behaviors. This paper aims to explain credit card payment behavior among college students by segmenting college students into payment behavior groupings. Using an online survey, students provided their credit card payment activity and demographic characteristics. The results of this study shed light on different credit card payment behaviors by segmenting college students into four behavioral segments based on useful characteristics. Clear distinctions exist between segments who behave in responsible ways versus those who do not practice responsible behaviors. These segmentation results add to the understanding of Lyons (2004; Journal of Consumer Affairs 38 (1): 56-80) who determined a means of identifying Financially at Risk students (FAR) with payment behavior. Given potentially dangerous effects of targeted credit card marketing to college students, findings about payment behavior of college students will help policymakers, credit card companies and college administrators

    The ciliopathy-associated CPLANE proteins direct basal body recruitment of intraflagellar transport machinery

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    Cilia use microtubule-based intraflagellar transport (IFT) to organize intercellular signaling. Ciliopathies are a spectrum of human diseases resulting from defects in cilia structure or function. The mechanisms regulating the assembly of ciliary multiprotein complexes and the transport of these complexes to the base of cilia remain largely unknown. Combining proteomics, in vivo imaging and genetic analysis of proteins linked to planar cell polarity (Inturned, Fuzzy and Wdpcp), we identified and characterized a new genetic module, which we term CPLANE (ciliogenesis and planar polarity effector), and an extensive associated protein network. CPLANE proteins physically and functionally interact with the poorly understood ciliopathy-associated protein Jbts17 at basal bodies, where they act to recruit a specific subset of IFT-A proteins. In the absence of CPLANE, defective IFT-A particles enter the axoneme and IFT-B trafficking is severely perturbed. Accordingly, mutation of CPLANE genes elicits specific ciliopathy phenotypes in mouse models and is associated with ciliopathies in human patients.clos

    De novo mutations in <i>MSL3</i> cause an X-linked syndrome marked by impaired histone H4 lysine 16 acetylation

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    The etiological spectrum of ultra-rare developmental disorders remains to be fully defined. Chromatin regulatory mechanisms maintain cellular identity and function, where misregulation may lead to developmental defects. Here, we report pathogenic variations in MSL3, which encodes a member of the chromatin-associated male-specific lethal (MSL) complex responsible for bulk histone H4 lysine 16 acetylation (H4K16ac) in flies and mammals. These variants cause an X-linked syndrome affecting both sexes. Clinical features of the syndrome include global developmental delay, progressive gait disturbance, and recognizable facial dysmorphism. MSL3 mutations affect MSL complex assembly and activity, accompanied by a pronounced loss of H4K16ac levels in vivo. Patient-derived cells display global transcriptome alterations of pathways involved in morphogenesis and cell migration. Finally, we use histone deacetylase inhibitors to rebalance acetylation levels, alleviating some of the molecular and cellular phenotypes of patient cells. Taken together, we characterize a syndrome that allowed us to decipher the developmental importance of MSL3 in humans

    Радиационная стойкость нитевидных кристаллов SiGe, используемых для сенсоров физических величин

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    Приведены результаты исследования влияния облучения γ-квантами дозами до 1·10¹⁸ см⁻² и магнитного поля с индукцией до 14 Тл на электропроводность нитевидных кристаллов Si1-xGex в интервале температуры 4,2-300 К.Вивчено вплив опромінення γ-квантами (випромінювання Co⁶⁰) з дозами до 1·10¹⁸ см⁻² та магнітного поля з індукцією до 14 Тл на електропровідність ниткоподібних кристалів Si1-xGex (х = 0,03) з питомим опором 0,08,0,025 Ом·см в інтервалі температур 4,2 .300 К. Встановлено, що опір кристалів слабо змінюється в процесі опромінення дозами до 2·10¹⁷ см⁻², в той же час спостерігаються істотні зміни магнітоопору. На основі проведених досліджень запропоновано умови створення радіаційно стійких сенсорів деформації, дієздатних в умовах сильних магнітних полів.An influence of γ-irradiation (Co⁶⁰) with doze up to 1·10¹⁸ cm⁻² and magnetic field with induction up to 14 T on conduction of Si1-xGex (x = 0,03) whisker crystals with resistivity of 0,08-0,025 Ohm·cm in temperature range 4,2-300 K have been studied. It is shown that whisker crystals resistance faintly varies under irradiation with doze 2·10¹⁷ cm⁻², while their magnetoresistance substantially changes. The strain sensors stable to irradiation action operating in high magnetic fields on the base of the whiskers have been designed
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