Fluctuations of tidewater glaciers in Hornsund Fjord (Southern Svalbard) since the beginning of the 20th century

Significant retreat of glaciers terminating in Hornsund Fjord (Southern Spitsbergen, Svalbard) has been observed during the 20th century and in the first decade of the 21st century. The objective of this paper is to present, as complete as possible, a record of front positions changes of 14 tidewater glaciers during this period and to distinguish the main factors influencing their fluctuations. Results are based on a GIS analysis of archival maps, field measurements, and aerial and satellite images. Accuracy was based on an assessment of seasonal fluctuations of a glacier's ice cliff position with respect to its minimum length in winter (November-December) and its maximum advance position in June or July.Morphometric features and the environmental setting of each glacier are also presented. The total area of the glacier cover in Hornsund Fjord in the period of 1899-2010 diminished approximately 172 km2, with an average areal retreat rate of 1.6 km2a-1. The recession rate increased from ~1 km2a-1 in first decades of the 20th century up to ~3 km2a-1 in years 2001-2010. The latest period was more thoroughly studied using optical satellite images acquired almost every year. The importance of glacier morphology and hypsometry, as well as fjord bathymetry and topography is analyzed. Large glacier systemswith low slopes terminating in deeper waters are retreating faster than small steep glaciers terminating in shallower water. A relation between mean annual air temperature and aerial retreat rate of tidewater glaciers was found for long time scales. A sudden temperature increase, known as the early 20th century warming in Svalbard, and an increase in temperatures during recent decades are well reflected in deglaciation rate. Influence of sea water temperatures on calving and retreat of glaciers was considered and is significant in short-time intervals of the last decade. Surge events are non-climatic factors which complicate the record. They are reflected in front advance or fast retreat due to a massive calving depending on the relation between ice thickness and water depth. Despite the influence of many factors, the response of tidewater glaciers to climate change is evident. The average linear retreat rate of all the tidewater glaciers in Hornsund amounted to ~70 ma-1 in 2001-2010 and was higher than the average retreat of other Svalbard tidewater glaciers (~45 ma-1). Thus, glaciers of this basin can be considered as more sensitive to climate than glaciers of other regions of the archipelago

Concept and First Results of Optical Navigational System

The paper presents a concept of the optical coastal navigational system. The task of the system is to provide information about object position in coastal areas based on optical information. The system is intended for Autonomous Underwater Vehicles that operate in GPS denied environments. In addition to the concept itself, the paper also outlines the first results achieved during the research on the system

Lignite biodegradation under conditions of acidic molasses fermentation

Lignite is difficult to degrade, thus stimulation of the autochthonous lignite microflora and introduction of additional microorganisms are required for lignite decomposition. Here, a packed bed reactor, filled with lignite samples from the Konin region (central Poland) was supplied continuously with M9 medium, supplemented with molasses (a by-product from the sugar industry), for 124 days to stimulate the autochthonous lignite microflora. Acidic fermentation of molasses was observed in the bioreactor. The simultaneous decomposition of lignite occurred under this acidic molasses fermentation condition. Our results show decay of free (non-bound) organic compounds during anaerobic lignite biodegradation. The concentrations of n-alkanes, n-alkanols, n-alkanoic acids, diterpenoids, triterpenoids and steroids present in non-biodegraded samples decreased significantly (some compounds to zero) during biodegradation. Interestingly, other compound classes like phenols, ketones and certain organic compounds increased. We interpret this phenomenon as a gradual decomposition of polymers, lignin and cellulose, present in the lignite. These changes resulted from microbial activity since they were not observed in pure solutions of short-chain fatty acids. The 16SrRNA profiling of the microbial community selected in the bioreactor revealed that the dominant bacteria belonged to the Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes, furthermore representatives of 16 other phyla were also found. All the known taxa of lignocellulolytic bacteria were represented in the microbial community. Synergistic relations between bacteria fermenting molasses and bacteria degrading lignite are assumed. The results confirm lignin degradation in acidic medium by bacteria under anaerobic conditions

Stabilność posturalna w procesie starzenia

Studies on postural stability aim to develop methods to diagnose defects of upholding body balance, which would decrease the number of falls increasing with age. Posturography, both static and dynamic, assesses the stability of posture. A dynamic test of the ”maximal voluntary effort” sets the margin of erect posture stability. It is tantamount to Duncan’s test of functional range. This margin decreases with age at the expense of an increasing safety margin. Progressing posture instability is compensated by a forward tilting of the silhouette and an asymmetrical bear on lower limbs. As a sequel of defective balance control, old subjects develop a strategy of motion slowing. The strategy often does not bring expected results and may even hamper the dynamic balance control. During rehabilitation of body balance defects one should pay attention to the training of reaction velocity. Such a training may interrupt a ”vicious cycle” caused by motion slowing strategy and thus increase the quality of life of subjects in old age. Posturographic gear allows performing dynamic postural tests in a feedback manner, which is useful for the rehabilitation training. Patients may observe their center of gravity on a screen and translocate it in a defined manner with the control of accuracy. This is a sort of adoption of virtual reality, which may lead to the development of a virtual, but entirely safe sport, in which, however, physical exercise and its measurement are true.Celem badań nad stabilnością posturalną jest opracowanie metody diagnostycznej pozwalającej na wczesne wykrywanie zaburzeń równowagi, co zapobiegałoby wzrastającej z wiekiem liczbie przypadków utraty równowagi. Posturografia statyczna i dynamiczna są metodami oceny stabilności postawy człowieka. W ocenie dynamicznej „test maksymalnego pochylenia ciała” pozwala na wyznaczenie marginesu stabilności postawy stojącej. Jest on odpowiednikiem testu zasięgu funkcjonalnego Duncana. Margines ten w procesie starzenia stopniowo zmniejsza się kosztem zwiększenia marginesu bezpieczeństwa. Postępująca niestabilność jest kompensowana narastającym pochyleniem sylwetki do przodu oraz niesymetrycznym obciążaniem kończyn dolnych. W konsekwencji upośledzenia kontroli równowagi u ludzi w starszym wieku rozwija się strategia spowolnienia ruchowego. Strategia ta zazwyczaj nie przynosi oczekiwanych korzyści, a wręcz przeciwnie, utrudnia dynamiczną kontrolę równowagi. Dlatego w procesie rehabilitacji osób z ubytkiem równowagi należy zwrócić uwagę na trening szybkości reakcji. Pozwoli on na przełamanie zjawiska „błędnego koła” wywołanego strategią spowolnienia, a tym samym przyczyni się do podniesienia jakości życia osób w podeszłym wieku. Aparatura posturograficzna umożliwia wykonywanie dynamicznych zadań posturalnych w układzie sprzężenia zwrotnego, co można stosować w treningu rehabilitacyjnym. Pacjenci mogą obserwować na ekranie chwilowe położenie swojego środka ciężkości i przemieszczać go w określony sposób oraz kontrolować jego dokładność. Można w tym wypadku posłużyć się wirtualną rzeczywistością, co może prowadzić do powstania wirtualnego, całkowicie bezpiecznego sportu, gdzie prawdziwy jest wysiłek fizyczny i jego pomiar

Broken symmetry between RNA enantiomers in a crystal lattice

Explaining the origin of the homochirality of biolog-ical molecules requires a mechanism of disruptingthe natural equilibrium between enantiomers and am-plifying the initial imbalance to significant levels. Au-thors of existing models have sought an explanationin the parity-breaking weak nuclear force, in some se-lectively acting external factor, or in random fluctua-tions that subsequently became amplified by an auto-catalytic process. We have obtained crystals in whichL- and D-enantiomers of short RNA duplexes assem-ble in an asymmetric manner. These enantiomersmake different lattice contacts and have different ex-posures to water and metal ions present in the crys-tal. Apparently, asymmetry between enantiomers canarise upon their mutual interactions and then prop-agate via crystallization. Asymmetric racemic com-pounds are worth considering as possible factors insymmetry breaking and enantioenrichment that tookplace in the early biosphere

Companies Active in Technology Parks and the Knowledge-Based Economy Paradigm

The main research aim of this paper is to identify the extent to which companies active in Poland’s technology parks are included in the knowledge-based economy paradigm. The article addresses the question of how such firms fit into the usual set of knowledge-based economy determinants. This question is accompanied by two basic assumptions that may be derived from research reports on economic development policies. First, the knowledge-based economy is a key segment of contemporary capitalism and it may thus be regarded as a pivotal factor of economic growth. Second, technology parks are potentially one of the basic tools to support the development of the knowledge-based economy. In this context, it is possible to hypothesize that technology parks agglomerate businesses that should be the vanguard of the knowledge-based economy. The article presents the results of surveys carried out among companies operating in Polish technology parks. The research focused on three issues: (1) the commitment of companies to R&B, (2) intellectual property rights, and (3) the introduction of product and processes innovations. The analysis of the presented data made it possible to develop a classification of the surveyed enterprises by their approach to the challenges of the knowledge-based economy. The research findings do not make it possible to unequivocally validate the hypothesis that companies active in technology parks play a key role in the development of the knowledge-based economy. In fact, about half of them remain outside the knowledge-based economy paradigm. In conclusion, the paper points to the need to redefine the role of Polish technology parks and their ways of operation.Celem artykułu jest weryfikacja stopnia dopasowania się firm-rezydentów polskich parków technologicznych do uwarunkowań gospodarki opartej na wiedzy. Tak postawionemu problemowi towarzyszą dwa podstawowe założenia, które można wywieść z literatury dotyczącej polityki rozwoju gospodarczego. Po pierwsze gospodarka oparta na wiedzy jest kluczowym sektorem współczesnego kapitalizmu, a tym samym obecnie traktowana jest jako zasadniczy czynnik wzrostu gospodarczego. Po drugie parki technologiczne potencjalnie stanowić mogą jedno z najbardziej podstawowych narzędzi polityki wspierania rozwoju gospodarki opartej na wiedzy. Można zatem postawić hipotezę, że w parkach technologicznych gromadzą się przedsiębiorstwa, które powinny stanowić awangardę ekonomii wiedzy. W artykule zaprezentowano wyniki badań kwestionariuszowych zrealizowanych wśród przedsiębiorstw działających w polskich parkach technologicznych. Badania te koncentrowały się na trzech kwestiach: (1) zaangażowania firm w działalność B+R, (2) zarządzania prawami własności intelektualnej oraz (3) wprowadzania na rynek innowacji produktowych i procesowych. Analiza przedstawionych danych pozwala opracować typologię firm biorących udział w badaniu uwzględniającą ich podejście do wyzwań stawianych przez gospodarkę wiedzy. Uzyskane wyniki nie pozwalają na jednoznacznie pozytywne rozstrzygnięcie hipotezy o wiodącej roli przedsiębiorstw w parkach technologicznych w gospodarce opartej na wiedzy. W podsumowaniu wskazano na potrzebę przedefiniowania funkcji i sposobów działania polskich parków technologicznych

Overview of Methods for Large-Scale RNA Synthesis

In recent years, it has become clear that RNA molecules are involved in almost all vital cellular processes and pathogenesis of human disorders. The functional diversity of RNA comes from its structural richness. Although composed of only four nucleotides, RNA molecules present a plethora of secondary and tertiary structures critical for intra and intermolecular contacts with other RNAs and ligands (proteins, small metabolites, etc.). In order to fully understand RNA function it is necessary to define its spatial structure. Crystallography, nuclear magnetic resonance and cryogenic electron microscopy have demonstrated considerable success in determining the structures of biologically important RNA molecules. However, these powerful methods require large amounts of sample. Despite their limitations, chemical synthesis and in vitro transcription are usually employed to obtain milligram quantities of RNA for structural studies, delivering simple and effective methods for large-scale production of homogenous samples. The aim of this paper is to provide an overview of methods for large-scale RNA synthesis with emphasis on chemical synthesis and in vitro transcription. We also present our own results of testing the efficiency of these approaches in order to adapt the material acquisition strategy depending on the desired RNA construct

Structure of Ty1 Internally Initiated RNA Influences Restriction Factor Expression

The long-terminal repeat retrotransposon Ty1 is the most abundant mobile genetic element in many Saccharomyces cerevisiae isolates. Ty1 retrotransposons contribute to the genetic diversity of host cells, but they can also act as an insertional mutagen and cause genetic instability. Interestingly, retrotransposition occurs at a low level despite a high level of Ty1 RNA, even though S. cerevisiae lacks the intrinsic defense mechanisms that other eukaryotes use to prevent transposon movement. p22 is a recently discovered Ty1 protein that inhibits retrotransposition in a dose-dependent manner. p22 is a truncated form of Gag encoded by internally initiated Ty1i RNA that contains two closely-spaced AUG codons. Mutations of either AUG codon compromise p22 translation. We found that both AUG codons were utilized and that translation efficiency depended on the Ty1i RNA structure. Structural features that stimulated p22 translation were context dependent and present only in Ty1i RNA. Destabilization of the 5′ untranslated region (5′ UTR) of Ty1i RNA decreased the p22 level, both in vitro and in vivo. Our data suggest that protein factors such as Gag could contribute to the stability and translational activity of Ty1i RNA through specific interactions with structural motifs in the RNA