Ways of presenting environmental elements in old cartographic records and their reliability

This article seeks to assess the reliability of the hydrographic type of environmental features depicted in old cartographic records up to the end of the 18th century

The Saccharomyces cerevisiae Srs2 Helicase Regulates Homologous Recombination through the Disassembly of Recombination Intermediates

Life on Earth relies on a set of instructions encoded within an organism’s genome that is passed along from one generation to the next. Inherent to this mechanism of propagation is the need to copy the genetic material before passing it along to the progeny. Errors in this process coupled with stochastic damage will inevitably lead to changes in these instructions and may result in a reduction of fitness or even death of an individual. Yet, these same changes are also responsible for the adaptation mandated by our dynamic environment. Thus, there exists a delicate balance between maintenance and alteration of genetic material that is embodied to a large part at the various intersections of DNA replication, recombination and repair. Homologous recombination (HR) has been well studied and found to play vital roles in many cellular processes from the repair of the harrowing double-stranded break, the restart of a stalled or collapsed replication fork, as well as proper chromosome segregation during meiosis, all with the goal of striking this delicate balance. And yet, while HR is incumbent for the fitness of an organism, if left unchecked this same process can become detrimental by preventing better suited DNA repair pathways, permanently arresting cell cycle progression and creating some of the very problems it was meant to address such as aneuploidy or cancer. Despite a wealth of knowledge, the precise regulatory mechanisms remain an active area of research as they provide likely targets to combat these persistent diseases. Motor proteins that translocate along DNA have been particularly compelling and elusive due to their transitory nature, as well as the inevitability of collisions with bound protein(s) or nucleic acid structures that are likely regulated intermediates in the process. The yeast Srs2 helicase/translocase has long been regarded as the prototypical “anti-recombinase” as it has been shown to dismantle the Rad51 presynaptic filament, but also displays contradictory pro-recombinase functions. In vivo studies of Srs2 have been hampered by its involvement in multiple bioprocesses beyond recombination, while bulk in vitro approaches often produce conflicting results. Recent single molecule imaging of these players has shed light onto their involvement in the regulation of the various stages of the canonical pathway of HR. The Greene laboratory has developed ssDNA curtains to study the pre-synaptic filament and shown that Rad51-ssDNA filaments can create bonafide D-loop intermediates that would be incapable of repair and thus represent a toxic intermediate. These structures persist far longer than the entire process of DSBR in vivo and led us to hypothesize that motor proteins would be a key regulatory element to dismantle improperly paired intermediates for redistribution of the bound proteins and reengagement of the homology search process. Here I extend the use of ssDNA curtains to study Srs2 as it assembles into multimeric complexes to perform long-range disruption of various pre- and post-synaptic filament assemblies that include replication protein A (RPA), Rad51, Rad52, and D-loops. For the first time, direct observation of Srs2 translocating over RPA filaments is provided and shows these proteins are efficiently removed by Srs2. By including Rad52 on the RPA filament, I offer a refined model of the contradictory pro- and anti-recombinase activities of Srs2 through its antagonism of the single-strand annealing pathway in favor of HR. Additionally, Srs2 was found to initiate Rad51 disruption at breaks in the continuity of the filament marked by the persistence of replication protein A (RPA), Rad52, or the presence of an improper D-loop intermediate, the latter of which is efficiently disrupted before continuing translocation. In contrast to the prevailing model, we demonstrate that direct interaction between Srs2 and Rad51 is not necessary for long-range Rad51 clearance. These findings offer insights into the dynamic regulation of crucial HR intermediates by Srs2 and demonstrate that sub-nuclear concentrations of these proteins may be a likely driver for their activities

Przemiany środowiskowe związane z antropopresją w ujściowym odcinku Warty

This article is an attempt at presenting environmental changes within the Warta valley during the last 250 years on the basis of existing archives, i.e. historical sources and old hydrographic hand-drawn maps, compiled in 1773 and 1786. Correlation with a modern map illustrates how much the hydrographic network and water conditions has changed in this area. The area under discussion by the author covers the valley of the lower Warta river from the mouth of Noteć river to the mouth of the Warta into the Odra river. First of all, an attempt was mode to reconstruct the initial environmental conditions. The greatest changes were connected with river regulation work in the Warta valley, including irrigation channels and discharge ditches draining the water from swampy valleys parts. These field works were for the most part of valley carried out towards the end of the 18-th century and the early part of the 19-th century. In this period the changes of hydrographic conditions were greatest. The present hydrographic pattern in the Warta Valley is artificial regulated with strengthened nearly straight line banks. This works provided for its stability, whereas in its other segments of Warta river often changed its course creating new meanders or arms. The dominance of drainage works in this area, liquidation of wet areas and river patterns made this terrain periodically dry, completely different than in the middle Ages. The Warta also lost its significance as a water route, and its water are polluted. In the Warta valley also the transformation of relief is caused by the development of transport routes, building the flood dam and another type of anthropogenic forms. In area under consideration as a result of human activity, practically all physiographic elements were changed – waters, swamps, relief, soils and topoclimate

Listy do pani B.

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Rural Revitalization in Appalachian Ohio

Over the last 100 years, the population of the United States of American has dramatically shifted from being heavily centered around rural communities to large urban center, all in thanks to changing standards of living, technological revolutions, and work opportunities. With this shift came the decline of small towns across the nation, leaving lasting and systemic socio-economic disparities between urban areas and their rural counterparts. Most of these disparities manifest as lower educational attainment and, in conjunction with that, a lowered household income. As the globe enters a new era that is dominated by remote work opportunities, more rural communities now have an unprecedented opportunity to positively change the narrative. This project explores the possibilities for rural towns to reinvent themselves through asset-based community development. Specifically, this project has examined multiple rural communities within the State of Ohio that have previously diversified or are attempting to diversify their economies by focusing on tourism and recreation; especially ones that have historically hosted agriculture, natural resources, manufacturing, or other such services. The purpose of this is to examine the variety of strategies used by these communities and their peers to make tourism and recreational activities compatible economic opportunities. Additionally, the goal is to recognize the continued preservation of their unique identities and atmosphere as they vary in not only location, but regional identities and purpose. Focusing specifically on rural Ohio prevents harsh overgeneralization as many of these communities have a unique cultural background. By communicating and sharing the challenges and opportunities capitalized up by these communities, others looking for alternative pathways to find economic reinvestment may use this document as a guide.No embargoAcademic Major: City and Regional Plannin

Rola i znaczenie Warty w dawnym Poznaniu

In this article an attempt has been made to demonstrate the role and significance of the Warta river in the spatial organisation of Poznań, its defence system and its economic role. Water from the Warta and its tributaries was both one of the basic raw materials and an energy producer, via water mills, in the manufacturing processes of workshops or groups of craftsmen (tanners, shoe makers, wood workers, beer brewers) along its banks. While in the Middle Ages the river pattern of Poznań played an important role in the development of the city area, in the middle of the 17th century its significance began to gradually decline, ultimately disappearing. The Warta lost its significance as a water route. Its waters are polluted and it seems that the city has turned away from it.647694Badania Fizjograficzn

„Opłaty półkowe” z punktu widzenia ekonomicznej analizy prawa

Celem niniejszego artykułu jest przedstawienie tzw. opłat półkowych, o których mowa w art. 15 ust. 1 pkt 4 ustawy o zwalczaniu nieuczciwej konkurencji, z perspektywy ekonomicznej analizy prawa. Artykuł wskazuje na konieczność pogłębionej interpretacji prawa z uwzględnieniem całościowym relacji biznesowych pomiędzy dostawcami a sieciami handlowymi. Artykuł prezentuje współczesny model współpracy pomiędzy dostawcami i sieciami detalicznymi jako wertykalnie zintegrowanych kanałów marketingowych (kanałów dystrybucji), w którym strony muszą uzgadniać kluczowe parametry współpracy, takiej jak: warunki logistyczne, warunki i metody promocji produktów, asortyment, terminy wprowadzenia nowych produktów i wiele innych. Artykuł przedstawia biznesową i ekonomiczną perspektywę tzw. opłat półkowych w przekonaniu, że jakiekolwiek formalistyczne podejście do zachowań biznesowych, bez uwzględnienia „myślenia ekonomicznego”, może prowadzić do nieprawidłowości w funkcjonowaniu konkurencji, a w konsekwencji negatywnie wpływać na konsumentów