Iodouracil-mediated photocrosslinking of DNA to EcoRII restriction endonuclease in catalytic conditions

We used a XeCl excimer laser with 50 ns pulses, a frequency of 0.3 Hz and a wavelength of 308 mn in appropriate conditions for the photocrosslinking of EcoRII restriction endonuclease to a 14-mer DNA duplex, containing a 5-iodo-2′-deoxyuridine residue (IdU). IdU replaced the thymidine residue within the EcoRII recognition sequence 5′-CCT/AGG. The binding of EcoRII endonuclease to the IdU-containing DNA duplex was analyzed by gel retardation assay in the presence of Ca2+ or Mg2+ ions. Photocrosslinking of EcoRII to the IdU-containing DNA duplex occurred in a pre-reactive complex formed in the presence of Ca2+ ions. Photocrosslinking yields as a function of time and UV-laser light intensity were studied.We thank Professor Alexander Yu. Borisov for valuable discussions and Robin Rycroft for assistance in preparation of the manuscript. We are grateful to Professor Ashok Bhagwat for providing us with the pR224 plasmid containing the ecoRII gene. This study was supported by the Russian Foundation of Fundamental Investigation (project no. 01–04–48637).Peer reviewe

The micromorphology of glaciolacustrine varve sediments and their use for reconstructing palaeoglaciological and palaeoenvironmental change

Former glaciolacustrine systems are an important archive of palaeoglaciological, palaeoenvironmental and palaeoclimatic change. The annually laminated (varved) sediments that, under certain conditions, accumulate in former glacial lakes, offer a rare opportunity to reconstruct such changes (e.g. glacier advance and retreat cycles, glacier ablation trends, permafrost melt, nival events) at annual or even sub-annual temporal resolution. Data of this kind are desirable for their ability to guide and test numerical model simulations of glacier dynamics and palaeoclimatic change that occur over rapid time intervals, with implications for predicting future glacier response to climatic change, or the effects of weather and climate events on lake sedimentation. The most valuable records preserved in glaciolacustrine systems are continuous varved sequences formed in the distal parts of glacial lakes, where microscale lamination structures can accumulate relatively undisturbed. Technological advances, in the last few decades, have enabled improved characterisation of glaciolacustrine varve microfacies and the precise measurement of varve thickness at the micrometre scale. However, unlike in cognate fields (e.g. soil science), protocols for the robust and consistent description and interpretation of glaciolacustrine varve sediments are lacking. To fill this gap, and to provide a resource for future studies of glaciolacustrine varved sediments, this paper reviews the processes of sedimentation in glacial lake basins, and presents the defining microfacies characteristics of glacial varves using a descriptive protocol that uses consistent examination of grain size, sorting, structure, nature of contacts, development of plasmic fabrics and features such as dropgrains and intraclasts within individual laminations. These lamination types are then combined into lamination sets, whose structures can be interpreted as glaciolacustrine varves. Within this framework, we define five principal assemblages of glaciolacustrine varve microfacies which, if clearly identified in palaeoglaciolacustrine settings, enable more detailed palaeoenvironmental interpretations to be made. Finally, we discuss the utility and complexities of reconstructing the evolution of former glacial lake systems using varve microfacies and thickness datasets

En temmelig vill en: Kontroverser om laks, ca 1800-2009

Laksen har hatt stor betydning for det norske folk i lang tid. I dag forbindes laksen i stor grad med lakseoppdrett. Lakseoppdrett spiller en viktig økonomisk rolle, både lokalt og nasjonalt. Næringen bidrar vesentlig til sysselsetting og verdiskapning langs kysten, og er samtidig en av landets viktigste eksportnæringer. Forståelsen av hva en laks ”er” og kontroversene om den har utviklet seg over tid. Etter hvert som myndighetene har forsøkt å forvalte og regulere fisket og fisken, i takt med samfunnsutviklingen og nyetablerte praksiser knyttet til fiske og fangst, har nye problem oppstått. Oppdrettsnæringen har vært gjenstand for kritikk i offentligheten. De senere årene har kritikken dreid seg blant annet om rømming av oppdrettslaks og spredning av lakselus. Lakselus har negative konsekvenser både for oppdrettsnæringen og for vill laksefisk. Lakselusproblematikken involverer mange aktører, ofte med motstridende interesser. Jeg viser hvordan laks har vært gjenstand for konflikt i et historisk perspektiv. Oppgaven tar for seg ulike interesser som har vært involvert, og hvordan ulike interesser og forståelser har preget reguleringen og forvaltningen av lakseressursene. Gjennom laksens historie kan man ikke bare følge en næringspolitisk utvikling, men også en miljøpolitisk utvikling

Copper content in soil at different distances from road edge national roads no 3 near Nowe Miasteczko

W artykule przedstawiono wyniki koncentracji w glebie miedzi całkowitej oraz potencjalnie dostępnej dla roślin w różnych odległościach od krawędzi jezdni przy drodze krajowej nr 3 w okolicy Nowego Miasteczka. Wyniki porównano z obowiązującymi w Polsce normami. Zawartość miedzi form ogólnych wynosiła od 6 do 135 mg∙kg-1, zaś form potencjalnie dostępnych dla roślin od 5-80 mg∙kg-1. Największe stężenia miedzi stwierdzono tuż przy krawędzi jezdni, niższe stężenia miedzi stwierdzono w glebach położonych dalej od drogi. Porównując wartość miedzi z Rozporządzeniem Ministra Środowiska z 9 września 2002 r. w sprawie standardów jakości gleby oraz standardów jakości ziemi stwierdza się, że nie zostały przekroczone wartości graniczne dla gruntów grupy B.This paper presents the results of the copper concentration in the soil forms approaching high-lighted the general and potentially available to plants at different distances from the edge of the roadway at the national road No. 3 in the area of Nowe Miasteczko. The results were compared with the Polish standards. The total Cu content ranged of 6-135 mg∙kg-1, and Cu potentially available to plant of 5-80 mg∙kg-1. The highest copper concentration was achieved right at the edge of the road. Lower copper concentrations were obtained in soil localized farther from the road. Comparing the value of copper to the Regulation of the Minister of Environmental of 9 September 2002 on standards for soil quality and land quality standards states that Cu concentrations did not exceed the limit values for soil group B and C

Effects of COVID-19 on First-Year Undergraduate Research in Physical Geography

Having confirmed that including research in first-year undergraduate teaching can actually help students understand the research process, link research with concepts, and improve both their academic and professional skills, we intended to evaluate how this experiential learning component fared during the COVID-19 challenge. For a first-year three-credit physical geography class, we have included a First Year Research Experience (FYRE) project for six iterations. A cluster analysis grouped students’ perceptions obtained from survey questions into five categories, from high to low. The results showed an overall improvement in perception of the FYRE during the pandemic, driven primarily by soft-skill development related to time management and self-motivation. Students were also able to better connect the research project with the theoretical content of the course. Components of the FYRE that suffered during the pandemic include engaging with course instructors and completing the oral presentation phase of the research. Soft-skill development continued through the second year of the pandemic, although students’ dissatisfaction with continued restrictions on in-person contact was evident

Concetration of zinc at different distances from edge of road example national roads no 3 near Nowe Miasteczko

W artykule przedstawiono wyniki zawartości cynku form zbliżonych do ogólnych oraz potencjalnie dostępnych dla roślin w różnych odległościach od krawędzi jezdni przy drodze krajowej nr 3 w okolicy Nowego Miasteczka. Celem pracy było określenie zawartości cynku w glebie oraz ocena ilości w odniesieniu do obowiązujących norm.The results of zinc forms similar to the general and potentially available to plants at different distances, ranging from the edge of the road at the national road No. 3 in the area of Nowe Miasteczko. The aim of this study was determine the zinc content in the soil and evaluate the amount in relation to the standards

from a degree-day

Accumulation at the equilibrium-line altitude of glaciers inferre