Comparison of vapour pressure deficit patterns during cucumber cultivation in a traditional high PE tunnel greenhouse and a tunnel greenhouse equipped with a heat accumulator

Plant productivity in protected cultivation is highly influenced by air temperature and humidity. The conditions relating to the moisture content of the air in protected plant cultivation are preferably defined by vapour pressure deficit (VPD), which describes the difference between the maximal and actual water vapour pressure (kPa). VPD is widely used as the parameter describing the climate conditions favourable for the development of fungal diseases and for highlighting conditions unfavourable for plant development. In protected cultivation, both the air temperature and the humidity are influenced by heating systems, and one such system is a heat accumulator, which may store the excessive heat produced during the day by converting the solar energy inside the plastic tunnel, and using it when plant heating is required. The tunnel equipped with a heat accumulator maintained an optimal level of humidity for a longer period, and significantly reduced the time of excessive air humidity. The longest time with an optimal VPD was recorded in August in a tunnel with an accumulator – 30.5% of total time vs. 22.3% of time for control tunnel. The highest difference of total time where the VPD was too low (below 0.2 kPa) was recorded in July – 12.4% of time in a tunnel with an accumulator vs. 39.1% of time for control tunnel. The highest difference of total time with an excessive VPD (over 1.4 kPa) was recorded in May – 12.1% of time in a tunnel with an accumulator vs. 17.9% of time for control tunnel. However, a situation beneficial for plant growth occurred every month during the investigated season

Morphological and Physiological Responses of Strawberry Plants to Water Stress

The most of previous studies have been focused on the effect of water stress on plant yielding. However, the conditions in which plants grow from the moment of planting might affect their morphology and physiological response. The aim of this study was to examine the effect of water deficiency on growth and plant physiological response of strawberry (Fragaria x ananassa Duch. cv. ‘Salut’) under greenhouse conditions. The plants were grown in plastic containers filled with peat substratum. Water stress was imposed by reducing the irrigation according to substratum moisture readings. Water stressed plants had the lowest values of water potential and showed strong decrease in gas exchange rate. Also, biomass and leaf area were the lowest in this group of plants. No differences in the length of root system were observed between control and water stressed plants. The lack of water in growing medium resulted also in a decrease of density and reduction of dimensions of stomata on plant leaves. These changes contribute to optimizing the use of assimilates and water use efficiency in periods when water availability is decreased

Untranslated regions of diverse plant viral RNAs vary greatly in translation enhancement efficiency

Background: Whole plants or plant cell cultures can serve as low cost bioreactors to produce massive amounts of a specific protein for pharmacological or industrial use. To maximize protein expression, translation of mRNA must be optimized. Many plant viral RNAs harbor extremely efficient translation enhancers. However, few of these different translation elements have been compared side-by-side. Thus, it is unclear which are the most efficient translation enhancers. Here, we compare the effects of untranslated regions (UTRs) containing translation elements from six plant viruses on translation in wheat germ extract and in monocotyledenous and dicotyledenous plant cells.Results: The highest expressing uncapped mRNAs contained viral UTRs harboring Barley yellow dwarf virus (BYDV)-like cap-independent translation elements (BTEs). The BYDV BTE conferred the most efficient translation of a luciferase reporter in wheat germ extract and oat protoplasts, while uncapped mRNA containing the BTE from Tobacco necrosis virus-D translated most efficiently in tobacco cells. Capped mRNA containing the Tobacco mosaic virus omega sequence was the most efficient mRNA in tobacco cells. UTRs from Satellite tobacco necrosis virus, Tomato bushy stunt virus, and Crucifer-infecting tobamovirus (crTMV) did not stimulate translation efficiently. mRNA with the crTMV 5′ UTR was unstable in tobacco protoplasts.Conclusions: BTEs confer the highest levels of translation of uncapped mRNAs in vitro and in vivo, while the capped omega sequence is most efficient in tobacco cells. These results provide a basis for understanding mechanisms of translation enhancement, and for maximizing protein synthesis in cell-free systems, transgenic plants, or in viral expression vectors

Cation-dependent folding of 30 cap-independent translation elements facilitates interaction of a 17-nucleotide conserved sequence with eIF4G

The 3\u27-untranslated regions of many plant viral RNAs contain cap-independent translation elements (CITEs) that drive translation initiation at the 5\u27-end of the mRNA. The barley yellow dwarf virus-like CITE (BTE) stimulates translation by binding the eIF4G subunit of translation initiation factor eIF4F with high affinity. To understand this interaction, we characterized the dynamic structural properties of the BTE, mapped the eIF4G-binding sites on the BTE and identified a region of eIF4G that is crucial for BTE binding. BTE folding involves cooperative uptake of magnesium ions and is driven primarily by charge neutralization. Footprinting experiments revealed that functional eIF4G fragments protect the highly conserved stem-loop I and a downstream bulge. The BTE forms a functional structure in the absence of protein, and the loop that base pairs the 5\u27-untranslated region (5\u27-UTR) remains solventaccessible at high eIF4G concentrations. The region in eIF4G between the eIF4E-binding site and the MIF4G region is required for BTE binding and translation. The data support the model in which the eIF4F complex binds directly to the BTE which base pairs simultaneously to the 5\u27-UTR, allowing eIF4F to recruit the 40S ribosomal subunit to the 5\u27-end

Administracja, zarządzanie i handel zagraniczny w warunkach integracji. Materiały konferencyjne - Handel Zagraniczny

Ze wstępu: "Obrady w sekcji H - „Handel zagraniczny” - prowadzone w ramach Międzynarodowej Konferencji Naukowej „Administracja, zarządzanie i handel zagraniczny w warunkach integracj i” dotyczyły szeroko rozumianej wymiany handlowej i współpracy gospodarczej Polski z innymi krajami, zarówno z punktu widzenia gospodarki, jak i poszczególnych przedsiębiorstw. Prezentowane w naszej sekcji referaty dotyczyły w głównej mierze problematyki ujednolicania polskich przepisów w zakresie prowadzenia działalności w szeroko pojętym handlu zagranicznym w celu dostosowania ich do regulacji obowiązujących w Unii Europejskiej."(...

Zarządzanie i handel zagraniczny w małych i średnich przedsiębiorstwach w warunkach integracji europejskiej: materiały z konferencji

Z przedmowy: "Integracja europejska to proces łączenia, scalania się odrębnych ekonomicznie, społecznie, kulturowo gospodarek europejskich krajów. Proces integracji prowadzi do istotnych przekształceń w sferze gospodarki, strategiach organizacji i funkcjonowania przedsiębiorstw, handlu międzynarodowym, działalności marketingowej, strukturach organizacyjnych i mechanizmach ekonomicznych przedsiębiorstw i instytucji działających w krajach integrujących się. Proces integracji to w praktyce proces dostosowywania się struktur gospodarczych; tworzenia związków kooperacyjno-produkcyjnych; powstawania trwałych więzi ekonomicznych między przedsiębiorstwami integrujących się krajów a więc proces kształtowania jednolitego obszaru gospodarczego z odrębnych a często także wzajemnie konkurencyjnych krajów, gospodarek, regionów, gałęzi, branż. Proces międzynarodowej integracji gospodarczej to w dużej mierze proces tworzenia komplementamości przedsiębiorstw i instytucji, komplementamości międzygałęziowej i wewnątrz gałęziowej, w produkcji i wymianie jak też kształtowanie niezbędnej infrastruktury technicznej i ekonomicznej umożliwiającej tworzenie sytemu trwałych powiązań gospodarczych między poszczególnymi krajami."(...

Review article Prevalence and clinical specificity of fatigue symptoms in chronic fatigue syndrome, multiple sclerosis, and myasthenia gravis

This article provides a critical review of the psychological and related literature on fatigue resulting in both mental and physical experiences. On one hand, prolonged severe fatigue is a prominent disabling symptom in various diseases of different aetiology – psychiatric (e.g. depression), somatic (e.g. some infections) and neurologic (e.g. multiple sclerosis, myasthenia gravis). For instance, fatigue is a main symptom of myasthenia that leads to pathological skeletal muscle weakness. Furthermore, 40 to 90 per cent of individuals suffering from multiple sclerosis confirm they have experienced fatigue, which impairs their cognitive functioning. In both multiple sclerosis and myasthenia, fatigue has not only a physical but also a psychological dimension. On the other hand, fatigue can be seen as an isolated set of symptoms of unknown origin called the chronic fatigue syndrome (CFS). The development of the concept, diagnostic criteria and some strategies of coping with CFS are presented. Various somatic disorders, as well as subjective cognitive and emotional complaints, are common and well documented in patients with CFS. The most typical include depression, as well as problems with concentration of attention, decision-making and reasoning in complex situations. However, general intellectual abilities and higher order cognitive skills are intact. Directions for future research are outlined

Evaluation of the head cabbage inbreed lines for the breeding for the drought stress resistance.

Dwanaście linii wsobnych kapusty głowiastej białej otrzymanych w Pracowni Genetyki i Hodowli Roślin Warzywnych, Zakład Hodowli Roślin Ogrodniczych Instytutu Ogrodnictwa-PIB zostało poddanych ocenie pod względem cech morfologicznych i agro-ekonomicznych, dynamice wzrostu systemu korzeniowego, intensywności fotosyntezy oraz transpiracji mających wpływ na ich odporność na stres suszy. Badania prowadzono w warunkach kontrolowanych w fazie wiązania główek jak również w fazie dojrzałości zbiorczej na polu doświadczalnym. Wszystkie linie wsobne odznaczały się wysoką wartością hodowlaną oraz wyrównaniem, były również silnie zróżnicowane pod względem badanych cech. Linie wsobne kapusty różniły się pod względem reakcji na stres suszy. Genotypy o silnej dynamice rozwoju systemu korzeniowego, mniejszych liściach oraz kompaktowym pokroju roślin, które odznaczały się silniejszym ograniczeniem fotosyntezy oraz transpiracji w warunkach stresu suszy, mogą być wykorzystywane do hodowli odpornościowej. Wysoki poziom zróżnicowania linii wsobnych umożliwia uzyskanie efektu heterozji przy tworzeniu nowych eksperymentalnych mieszańców F1 lepiej przystosowanych do niekorzystnych warunków środowiska w tym na stres niedoboru wody.Twelve head cabbage inbred lines obtained at the Research Institute of Horticulture, Department of Genetics and Breeding, Skierniewice, Poland were evaluated in respect to the morphological and agro economical characters, dynamic of the root development, photosynthesis and transpiration activity affecting their resistance for the drought stress. Cabbage lines were highly diversified in respect to their characters with desired morphological traits. Different reactions for drought stress between the lines was recorded in controlled conditions and at the field. Lines with high dynamics of root development, smaller leaf size, compact shape of plant, with stronger transpiration and photosynthesis reaction with be probably less susceptible to drought stress. High level of diversity of cabbage inbred lines  reflects their  potential for the breeding of the new F1 cultivars with better adaptation for the abiotic stresses in the future