Nuclear fusions contribute to polyploidization of the gigantic nuclei in the chalazal endosperm of Arabidopsis

Somatic polyploidization is recognized as a means to increase gene expression levels in highly active metabolic cells. The most common mechanisms are endoreplication, endomitosis and cell fusion. In animals and plants the nuclei of multinucleate cells are usually prevented from fusing. Here, we report that the nuclei from the syncytial cyst of the chalazal endosperm of Arabidopsis thaliana (L.) Heynh. are polyploid with some intermediate ploidy levels that cannot be attributed to endoreplication, suggesting nuclear fusion. Analysis of isolated nuclei, together with fluorescent in situ hybridization (FISH), revealed that nuclei from the chalazal endosperm are two or three times bigger than the nuclei from the peripheral endosperm and have a corresponding increase in ploidy. Together with the consistent observation of adjoined nuclei, we propose that nuclear fusion contributes, at least in part, to the process of polyploidization in the chalazal endosperm. Confocal analysis of intact seeds further suggested that free nuclei from the peripheral endosperm get incorporated into the chalazal cyst and likely participate in nuclear fusion

Рецензія на монографію І.С. Чекмана «Нанофармакологія»

Рецензія на монографію І.С. Чекмана «Нанофармакологія» К.: Задруга, 2011. – 424 с

Klimaat onderzoek bij het Nederlands Instituut voor Onderzoek der Zee

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Statistical analysis of simple repeats in the human genome

The human genome contains repetitive DNA at different level of sequence length, number and dispersion. Highly repetitive DNA is particularly rich in homo-- and di--nucleotide repeats, while middle repetitive DNA is rich of families of interspersed, mobile elements hundreds of base pairs (bp) long, among which the Alu families. A link between homo- and di-polymeric tracts and mobile elements has been recently highlighted. In particular, the mobility of Alu repeats, which form 10% of the human genome, has been correlated with the length of poly(A) tracts located at one end of the Alu. These tracts have a rigid and non-bendable structure and have an inhibitory effect on nucleosomes, which normally compact the DNA. We performed a statistical analysis of the genome-wide distribution of lengths and inter--tract separations of poly(X) and poly(XY) tracts in the human genome. Our study shows that in humans the length distributions of these sequences reflect the dynamics of their expansion and DNA replication. By means of general tools from linguistics, we show that the latter play the role of highly-significant content-bearing terms in the DNA text. Furthermore, we find that such tracts are positioned in a non-random fashion, with an apparent periodicity of 150 bases. This allows us to extend the link between repetitive, highly mobile elements such as Alus and low-complexity words in human DNA. More precisely, we show that Alus are sources of poly(X) tracts, which in turn affect in a subtle way the combination and diversification of gene expression and the fixation of multigene families

Perancangan Sekolah Tinggi Psikologi Di Manado (Penerapan Prinsip Zen Dalam Desain)

Psikologi merupakan ilmu dengan potensi penerapan yang baik dalam berbagai bidang terapan, terkait dengan fungsinya untuk mendalami sifat dan perilaku manusia. Potensi ilmu psikologi ini sangat bermanfaat untuk menanggapi kondisi masyarakat yang pada daerah yang sedang berkembang. Dengan penerapan yang tepat, ilmu psikologi dapat dimanfaatkan untuk mengoptimalkan kualitas sumber daya manusia suatu daerah. Melihat prospek ini, maka dirasa sangat tepat untuk mengembangkan pemahaman terhadap psikologi melalui fasilitas pembelajaran yang memadai. Secara nasional, fasilitas pendidikan psikologi di Indonesia terbilang menunjang secara kuantitas maupun kualitas. Namun secara lokal, tepatnya di Provinsi Sulawesi Utara, masih belum tersedia fasilitas pendidikan ilmu psikologi yang cukup. Ini dibuktikan dengan ketersediaan fasilitas pendidikan psikologi yang hanya terdapat pada 2 universitas, masing-masing di Manado dan Tondano. Melihat permasalahan tersebut maka dibutuhkan adanya solusi berupa pengadaan tambahan fasilitas pendidikan psikologi di kota Manado. Solusi ini hadir dalam bentuk perancangan obyek “Sekolah Tinggi Psikologi di Manado”. Pengadaan fasilitas ini untuk menunjang perkembangan ilmu psikologi di Manado, dimana diharapkan dengan adanya objek ini dapat meningkatkan antusiasme masyarakat Manado untuk mempelajari tentang psikologi serta penerapannya dalam berbagai aspek kehidupan sehari-hari. Perancangan Sekolah Tinggi Ilmu Psikologi ini akan dilakukan dengan pendekatan tema “Penerapan Prinsip Zen dalam Disain” berupa pemaknaan prinsip estetika Zen dalam rancangan arsitektural. Lewat pemaknaan tema serta berbagai analisa aspek perancangan diharapkan dapat mengoptimalkan pemahaman personal dan terutama dalam kaitannya dengan fungsi belajar-mengajar bagi pengguna objek

Climate fluctuations and the spring invasion of the North Sea by Calanus finmarchicus

The population of Calanus finmarchicus in the North Sea is replenished each spring by invasion from an overwintering stock located beyond the shelf edge. A combincation of field observations, statistical analysis of Continuous Plankton Recorder (CPR) data, and particle tracking model simulations, was used to investigate the processes involved in the cross-shelf invasion. The results showed that the main source of overwintering animals entering the North Sea in the spring is at depths of greater than 600m in the Faroe Shetland Channel, where concentrations of up to 620m -3 are found in association with the overflow of Norwegian Sea Deep Water (NSDW) across the Iceland Scotland Ridge. The input of this water mass to the Faroe Shetland Channel, and hence the supply of overwintering C. finmarchicus, has declined since the late 1960s due to changes in convective processes in the Greenland Sea. Beginning in February, animals start to emerge from the overwintering state and migrate to the surface waters, where their transport into the North Sea is mainly determined by the incidence of north-westerly winds that have declined since the 1960s. Together, these two factors explain a high proportion of the 30-year trends in spring abundance in the North Sea as measured by the CPR survey. Both the regional winds and the NSDW overflow are connected to the North Atlantic Oscillation Index (NAO), which is an atmospheric climate index, but with different time scales of response. Thus, interannual fluctuations in the NAO can cause immediate changes in the incidence of north-westerly winds without leading to corresponding changes in C. finmarchicus abundance in the North Sea, because the NSDW overflow responds over longer (decadal) time scales

Jump landing performance in footballers

Dieen, J.H. van [Promotor]Kingma, I. [Copromotor

Life histories of the copepods Pseudocalanus minutus, P. acuspes (Calanoida) and Oithona similis (Cyclopoida) in the Arctic Kongsfjorden (Svalbard)

The year-round variation in abundance and stage-specific (vertical) distribution of Pseudocalanus minutus and Oithona similis was studied in the Arctic Kongsfjorden, Svalbard. Maxima of vertically integrated abundance were found in November with 111,297 ind m−2 for P. minutus and 704,633 ind m−2 for O. similis. Minimum abundances comprised 1,088 ind m−2 and 4,483 ind m−2 in June for P. minutus and O. similis, respectively. The congener P. acuspes only occurred in low numbers (15–213 ind m−2), and successful reproduction was debatable. Reproduction of P. minutus took place in May/June, and stage distribution revealed a 1-year life cycle with copepodids CIII, CIV, and CV as the overwintering stages. Oithona similis exhibited two main reproductive peaks in June and August/September, respectively. Moreover, it reproduced more or less continuously throughout the whole year with all stages occurring during the entire sampling period, suggesting two generations per year. Both species migrated towards greater depth in November, but O. similis preferred to stay longer in the upper 100 m as compared to Pseudocalanus. The reproduction of the two species in Kongsfjorden seemed to be linked to phytoplankton dynamics