O-GlcNAcase contributes to cognitive function in Drosophila

Contains fulltext : 219183.pdf (publisher's version ) (Open Access

High spatial resolution and high contrast optical speckle imaging with FASTCAM at the ORM

In this paper, we present an original observational approach, which combines, for the first time, traditional speckle imaging with image post-processing to obtain in the optical domain diffraction-limited images with high contrast (1e-5) within 0.5 to 2 arcseconds around a bright star. The post-processing step is based on wavelet filtering an has analogy with edge enhancement and high-pass filtering. Our I-band on-sky results with the 2.5-m Nordic Telescope (NOT) and the lucky imaging instrument FASTCAM show that we are able to detect L-type brown dwarf companions around a solar-type star with a contrast DI~12 at 2" and with no use of any coronographic capability, which greatly simplifies the instrumental and hardware approach. This object has been detected from the ground in J and H bands so far only with AO-assisted 8-10 m class telescopes (Gemini, Keck), although more recently detected with small-class telescopes in the K band. Discussing the advantage and disadvantage of the optical regime for the detection of faint intrinsic fluxes close to bright stars, we develop some perspectives for other fields, including the study of dense cores in globular clusters. To the best of our knowledge this is the first time that high contrast considerations are included in optical speckle imaging approach.Comment: Proceedings of SPIE conference - Ground-based and Airborne Instrumentation for Astronomy III (Conference 7735), San Diego 201

Discovery of a wide companion near the deuterium burning mass limit in the Upper Scorpius association

We present the discovery of a companion near the deuterium burning mass limit located at a very wide distance, at an angular separation of 4.6+/-0.1 arcsec (projected distance of ~ 670 AU) from UScoCTIO108, a brown dwarf of the very young Upper Scorpius association. Optical and near-infrared photometry and spectroscopy confirm the cool nature of both objects, with spectral types of M7 and M9.5, respectively, and that they are bona fide members of the association, showing low gravity and features of youth. Their masses, estimated from the comparison of their bolometric luminosities and theoretical models for the age range of the association, are 60+/-20 and 14^{+2}_{-8} MJup, respectively. The existence of this object around a brown dwarf at this wide orbit suggests that the companion is unlikely to have formed in a disk based on current planet formation models. Because this system is rather weakly bound, they did not probably form through dynamical ejection of stellar embryos.Comment: 10 pages, including 4 figures and 2 table

Synthesis of acetogenin analogues. Asymmetric transfer hydrogenation coupled with dynamic kinetic resolution of α-amido-β-keto Ester

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Atsetogeniinid on huvitav grupp looduslikke ühendeid, millel on leitud selektiivne tsütotoksilisus vähirakkude vastu. Kuigi atsetogeniine on juba mõnda aega uuritud, ei ole nende struktuuri ja bioloogilise toime suhe veel selge. Oluline on uurida ka atsetogeniinide sünteesimisvõimalusi, panustades nii nende erinevate struktuuride paremale kättesaadavusele, kuna taimeekstraktid sisaldavad atsetogeniine vähestes kogustes ja tihti mitut erinevat atsetogeniini struktuuri korraga. Antud uurimistöös sünteesiti kuus atsetogeniini analoogi ja hinnati nende bioloogilist toimet mudelvähirakuliinil. Väljatöötatud sünteesirada saab kohandada igale sünteesitud analoogile, mis erinevad üksteisest ühe keskse ühiku poolest. Seega saab analoogi erinevad struktuurielemendid eraldi valmis sünteesida ja lõpp-ühendiks kokku panna alles viimastes etappides. Sünteesi juures pöörati erilist tähelepanu aatomite ruumilisele asetusele struktuuris ehk stereokeemiale, millel on tihti väga oluline mõju ühendi bioloogilisele toimele. Neli ühte tüüpi analoogi mõjutasid rakukasvu üksteisega võrreldaval määral, kuigi ei viinud nii palju mudelvähirakke rakusurmani kui looduslikud atsetogeniinid; kaks teist tüüpi analoogi avaldasid rakukasvule vähem mõju. Uurimistöö teine osa käsitleb võrreldes esimese teemaga suhteliselt väikeste ühendite, aminohappe derivaatide, sünteesi. Selliseid ühendeid saab edukalt kasutada keerukamate molekulide sünteesil. Töös keskenduti aminohappe derivaatide sünteesivõimalusele asümmeetrilise vesiniku ülekande teel läbi dünaamilise kineetilise lahutamise, mis andis kõrgeid saagiseid. Reaktsiooni käigus liideti aminohappe derivaadi eellasele üks vesiniku aatom kõrge stereoselektiivsusega. Vesiniku aatom pärines ühelt teiselt reaktsioonis osalevalt orgaaniliselt ühendilt, mitte gaasiliselt vesinikult nagu sarnaste reaktsioonide puhul tihti kasutatakse. Leitud meetod võimaldab reaktsiooni läbi viia toatemperatuuril ja õhukeskkonnas, vältides gaasilise vesiniku ja kõrgete rõhkude kasutamist.Acetogenins are an interesting group of natural compounds, which can exhibit selective cytotoxicity towards tumorous cell-tissue. Although acetogenins have been studied for a while now, the relationship between their structure and bioactivity has not been fully elucidated. In this work six analogues of acetogenins were synthesized and their bioactivity was assessed in a model tumorous cell line. The developed synthetic route can be adjusted for all of the analogues synthesized – this approach allows units of the compound to be prepared separately, and joined together in later stages to form the end-compound. The spatial arrangement of the atoms in the structure, called stereochemistry, was also under scrutiny during the synthesis. The three-dimensional positioning within the structure can often be very important for the bioactivity. Four of the synthesized analogues, similar in type, retained bioactivity in model tumour cells causing cell death, although being less active than their natural counterparts. Two other synthesized analogues exhibited negligible bioactivity in the tested cell-line. The second part of the presented work discusses the synthesis of amino acid like derivates. These relatively small, yet important molecules can be used as ‘building blocks’ in the synthesis of more complex molecules. The study entailed the synthesis of these derivates via asymmetric transfer of a hydrogen atom coupled with dynamic kinetic resolution, giving high yields. During the reaction one hydrogen atom was added to the starting material with high stereoselectivity, noting that the hydrogen atom originated from another organic compound in the reaction mixture and not from hydrogen gas. The developed method permits the reaction to be run at room temperature and in air atmosphere, omitting the use of high pressures and hydrogen gas, often used for similar transformations

Laboratory and telescope demonstration of the TP3-WFS for the adaptive optics segment of AOLI

AOLI (Adaptive Optics Lucky Imager) is a state-of-art instrument that combines adaptive optics (AO) and lucky imaging (LI) with the objective of obtaining diffraction limited images in visible wavelength at mid- and big-size ground-based telescopes. The key innovation of AOLI is the development and use of the new TP3-WFS (Two Pupil Plane PositionsWavefront Sensor). The TP3-WFS, working in visible band, represents an advance over classical wavefront sensors such as the Shack-Hartmann WFS (SH-WFS) because it can theoretically use fainter natural reference stars, which would ultimately provide better sky coverages to AO instruments using this newer sensor. This paper describes the software, algorithms and procedures that enabled AOLI to become the first astronomical instrument performing real-time adaptive optics corrections in a telescope with this new type of WFS, including the first control-related results at the William Herschel Telescope (WHT)This work was supported by the Spanish Ministry of Economy under the projects AYA2011-29024, ESP2014-56869-C2-2-P, ESP2015-69020-C2-2-R and DPI2015-66458-C2-2-R, by project 15345/PI/10 from the Fundación Séneca, by the Spanish Ministry of Education under the grant FPU12/05573, by project ST/K002368/1 from the Science and Technology Facilities Council and by ERDF funds from the European Commission. The results presented in this paper are based on observations made with the William Herschel Telescope operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. Special thanks go to Lara Monteagudo and Marcos Pellejero for their timely contributions

PENGARUH KUALITAS PRODUK DAN HARGA TERHADAP MINAT BELI KONSUMEN PADA QUBICLE COFFEE PALEMBANG

Penelitian ini bertujuan untuk mengetahui pengaruh kualitas produk dan harga terhadap minat beli konusmen pada Qubicle Coffee Palembang baik secara parsial maupun simultan. Analisis data dilakukan dengan metode regresi linear berganda yang diolah dengan menggunakan aplikasi SPSS versi 22 for windows. Data dikumpulkan dengan menggunakan kuesioner. Teknik pengambilan sampel pada penelitian ini menggunakan metode non probability sampling yaitu teknik accidental sampling, sehingga didapatkan sampel pada penelitian ini sebanyak 37 responden yaitu konsumen pada Qubicle Coffee Palembang. Berdasarkan hasil penelitian analisis koefisien determinasi (R2) besarnya pengaruh kualitas produk dan harga terhadap minat beli konsumen adalah sebanyak 53,8% dan sisanya sebesar 46,2% dipengaruhi oleh hal lainnya yang tidak dibahas dalam penelitian ini. Berdasarkan hasil uji t secara parsial kualitas produk berpengaruh secara positif terhadap minat beli konsumen, sedangkan secara parsial harga berpengaruh secara positif terhadap minat beli konsumen. Berdasarkan hasil uji F secara simultan kualitas produk dan harga secara signifikan berpengaruh terhadap minat beli konsumen pada Qubicle Coffee Palembang