Early embryonic requirement for nucleoporin Nup35/NPP-19 in nuclear assembly

11 pages, 8 figures, 3 tables.-- PMID: 19146848 [PubMed].-- Available online Dec 30, 2008.Supporting information (Suppl. figs S1-S5, movies S1-S6) available at: http://dx.doi.org/10.1016/j.ydbio.2008.12.024Nuclear pore complexes (NPCs) are gateways for transport between the nucleus and cytoplasm of eukaryotic cells and play crucial roles in regulation of gene expression. NPCs are composed of multiple copies of not, vert, similar 30 different nucleoporins (nups) that display both ubiquitous and cell type specific functions during development. Vertebrate Nup35 (also known as Nup53) was previously described to interact with Nup93, Nup155 and Nup205 and to be required for nuclear envelope (NE) assembly in vitro. Here, we report the first in vivo characterization of a Nup35 mutation, npp-19(tm2886), and its temperature-dependent effects on Caenorhabditis elegans embryogenesis. At restrictive temperature, npp-19(tm2886) embryos exhibit chromosome missegregation, nuclear morphology defects and die around mid-gastrulation. Depletion of Nup35/NPP-19 inhibits NE localization of Nup155/NPP-8, NPC assembly and nuclear lamina formation. Consequently, nuclear envelope function, including nucleo-cytoplasmic transport, is impaired. In contrast, recruitment of Nup107/NPP-5, LEM-2 and nuclear membranes to the chromatin surface is Nup35/NPP-19-independent, suggesting an uncoupling of nuclear membrane targeting and NPC assembly in the absence of Nup35/NPP-19. We propose that Nup35/NPP-19 has an evolutionary conserved role in NE formation and function, and that this role is particularly critical during the rapid cell divisions of early embryogenesis.This work was funded by grants from the Spanish Ministry of Science and Education (RYC-2003-001521, BFU-2004-01096, BFU-2007-60116) to PA. In addition, we wish to acknowledge Fundación Ramón Areces for a fellowship to ER and Junta de Andalucía for institutional support.Peer reviewe

Parametric decomposition of the multi-phase transport models

Багатоетапні транспортні моделі займають особливе місце серед задач математичного програмуванні. При деталізованому підході до їх розв’язання, з описом елементарних актів управлінської діяльності, виникає проблема пошуку екстремуму алгоритмічної функції на безлічі алгоритмічних обмежень в умовах високої розмірності простору змінних. В таких випадках має сенс застосовувати параметричну декомпозицію, пов'язану з проблемами негладкої оптимізації опуклих функцій багатоетапних транспортних моделей. У статті розглянуто застосування алгоритму найшвидшого спуску для розв’язання таких задач.Flighted transport models occupy a special place among the problems of mathematical programming. With granular approach to their solution, describing the elementary acts of administrative activity, there arises the problem of the extremum of algorithmic functions on the set of algorithmic restrictions in the conditions of high dimensionality of the space of variables. Given that multi-stage transportation problem has a block structure with a small number of links, it makes sense to use such decomposition schemes that lead to the problem of minimizing nonsmooth convex piecewise-linear function of the related parameters, relevant constraints of the problem in a binder. The most promising and appropriate for solving such problems is the approximate analytical description of the object of management and development of approaches for solving the problem of finding an extremum algorithmic functions on the set of algorithmic constraints in high dimensional space of the variables of the problem and the limited time calculations. In such cases, it makes sense to use a parametric

Impacts environnementaux de systèmes contrastés de pompage d’eau souterraine, évalués par la méthode d’analyse de cycle de vie : contribution à l’étude du Nexus eau-énergie

International audienceMost studies on the environmental performance of irrigation have focused on the water–food–energy nexus, i.e. relationships betweenfood production, water consu mption and energy. However, water and energy are not the only relevant indicators of the environmentalperformance of irrigation systems. Life cycle assessment (LCA) is a holistic method that is well suited to comprehensive assessment. Thispaper aims at using LCA to assess the environmental impacts of contrasted groundwater pumping systems in semi-arid central Tunisia.In line with previous studies, our results confirm that for groundwater pumping, energy has the highest environmentalimpacts on human health, the ecosystem and resource depletion. Our work also highlights that along with pump efficiency,the type of power source must be considered when ranking pumping systems based on environmental performance. Indeed, diesel-powered pumping systems are more harmful than electric pumps when electricity is generated from naturalgas and diesel-powered pump efficiency is low. However, the diesel pumping system becomes the best option when electricityis derived from coal and diesel-powered pump efficiency exceeds 12%.Finally, water depletion has been shown of great importance in this study, and ongoing LCA improvements should facilitatea more comprehensive picture of these site-specific impacts