320 research outputs found
Regional differences in the influence of the North Atlantic Oscillation on seasonal river runoff in Poland
In this paper, an analysis of monthly and seasonal runoff volumes in two stages of the North Atlantic
Oscillation are presented. The analysis embraced runoff at 146 profiles located on 96 Polish rivers during the
years 1951–2000. The changes in the runoff conditions of Polish rivers in the two NAO stages and their spatial
diversity were determined based on the differences between runoff observed in the years of exceptionally high
(NAODJFM > 2,0) and low (NAODJFM < –2,0) values of the winter NAO index. The results of the research indicate
that the influence of the North Atlantic Oscillation on the runoff of Polish rivers is diverse in terms of time and
space. A classification of rivers was made in terms of the similarity of deviations of their seasonal runoff between
the different NAODJFM stages. In the classification procedure use was made of Ward’s method of hierarchical
grouping. In this way, five classes of the river profiles under analysis were obtained. Environmental conditions
in the catchments and hydrological regime features clearly influence the regional differences in the impact of the
North Atlantic Oscillation on the flow of rivers
Stability of high and low flow periods on European rivers
The aim of this paper is to examine regional differences in the flow regime of European rivers. The
stability of a flow regime is defined as the regularity of high and low flow periods during a year (Corbus and
Stanescu, 2004). The first, second, and third maximum and minimum values of the mean monthly flows during
the year served as regime characteristics, i.e. descriptors of the regime phases. A series of monthly discharges
recorded during the years 1951–1990 at 510 stations on 369 European rivers were analysed. The coefficient
of stability used in the analysis enables an extension of classical hydrological regime analysis. The proposed
approach allows not only to establish the term of high and low flow periods of the river, but it also shows the
regularity (stability) of their occurrence.618319414Badania Fizjograficzn
Uncertainty of flow regime characteristics of rivers in Europe
The aim of the paper is to describe spatial differences in the uncertainty of features of the flow regimes
of rivers in Europe on the basis of measures whose methodological assumptions derive from Shannon’s information
entropy theory (1948). They included: the entropy of monthly flow volumes, the entropy of the flow
distribution over time, and the entropy of maximum and minimum monthly flows. An analysis was made of
monthly flow series for the years 1951–1990 from 510 gauging stations located on 369 rivers in Europe. It allowed
a quantitative determination of the degree of uncertainty of the four regime characteristics, indirectly establishing
the predictability, regularity and stability of their appearance and their spatial variability. In the procedure
of identification of spatial differences among rivers concerning the uncertainty of their flow regime features, use
was made of local indices of spatial dependence. On application of LISA (Local Indicators of Spatial Association)
based on Moran’s local Ii statistic, a typology of rivers was obtained in terms of the kind and statistical significance
of spatial associations involving the uncertainty of the flow regime variables in question
Effect of North Atlantic Oscillation on the hydrological conditions of Lake Morskie Oko (Carphatian Mountains)
The paper presents the effect of North Atlantic Oscillation of macroscale atmospheric circulation (NAO) on the hydrological conditions of Lake Morskie Oko located at an altitude of 1392.8 m a.s.l. in the highest range of the Carpathians. The paper applied detailed hydrometric information from the years 1971-2010 concerning water level fluctuations, water temperature, terms of the commencement and end of ice phenomena and ice cover, as well as meteorological data concerning air temperature and atmospheric precipitation, and monthly and seasonal NAO indices. The performed analysis suggests that the majority of analysed hydrological characteristics of Lake Morskie Oko was not prone to variability of NAO intensity in its various phases. The situation results from the local conditions, particularly responsible for the course of processes and phenomena in Lake Morskie Oko, simultaneously obscuring the effect of macroscale factor
INNOWACJE W REKRUTACJI
“Innovation” is a popular word today. Due to high rate of technological and societal changes, it has become necessary to constantly introduce new, or improve existing products and actions. Innovations are desirable in every aspect of organization functioning, including recruitment. Having the best, talented employees is very important for companies, which aspire to success. They undertake an effort at the stage of recruitment to hire such people. So, it is necessary to use the original methods of recruitment, which pay attention to potential employees and encourage them to work. The following elaboration is presenting the essence and targets of recruitment and innovation and their importance for organization success. The essential part describes the selected innovative methods of recruitment and examples of their use in practice.Popularnym dziś słowem jest „innowacja”. Ze względu na wysoką dynamikę zmian technicznych i społecznych konieczne stało się ciągłe wprowadzanie nowych lub udoskonalanie dotychczasowych produktów i działań. Innowacje są zatem pożądane w każdym aspekcie funkcjonowania organizacji, w tym także w rekrutacji. Firmom dążącym do sukcesu zależy na posiadaniu najlepszych, utalentowanych pracowników. Stąd też podejmują one starania na etapie naboru, aby tacy do nich trafili. W związku z tym potrzebne jest wykorzystywanie oryginalnych metod rekrutacyjnych, które zwrócą uwagę potencjalnych pracowników i zachęcą ich do podjęcia pracy. Poniższe opracowanie prezentuje istotę i cele rekrutacji oraz innowacji i jej znaczenie dla sukcesu organizacji. W zasadniczej części opisane zostały wybrane innowacyjne metody rekrutacyjne i przykłady ich wykorzystania w praktyce
Seasonal structure of water stages on lakes in Northern Poland
The paper presents the characteristics of hydrological periods in an average annual cycle in Polish lakes. The type of periods and their sequence determine the regime of water stages in lakes. The article applies the unsupervised approach of analysis of the pattern of water level fluctuations, where the identification of the regime is performed through grouping analytical parameters. Hydrological periods were designated by means of grouping elementary time units of the hydrological year (pentads) based on the similarity of their parameters, namely the distributions of water level frequencies. The analysis covered daily water stages in 33 lakes in Poland from the period from 1984 to 2013. Five types of hydrological periods were designated. The studied lakes differ in the number, type, and sequence of hydrological periods in an average annual cycle. The most abundant group of 19 lakes includes lakes with a 4-period temporal structure of water stages with the course of water stages in a year characteristic of this geographical zone. No spatial patterns occurred in terms of location of lakes from particular groups. This suggests the dominant role of local factors determining the seasonality of water stages
Contribution of transcription-coupled DNA repair to MMS-induced mutagenesis in E. coli strains deficient in functional AlkB protein.
In Escherichia coli the alkylating agent methyl methanesulfonate (MMS) induces defense systems (adaptive and SOS responses), DNA repair pathways, and mutagenesis. We have previously found that AlkB protein induced as part of the adaptive (Ada) response protects cells from the genotoxic and mutagenic activity of MMS. AlkB is a non-heme iron (II), alpha-ketoglutarate-dependent dioxygenase that oxidatively demethylates 1meA and 3meC lesions in DNA, with recovery of A and C. Here, we studied the impact of transcription-coupled DNA repair (TCR) on MMS-induced mutagenesis in E. coli strain deficient in functional AlkB protein. Measuring the decline in the frequency of MMS-induced argE3-->Arg(+) revertants under transient amino acid starvation (conditions for TCR induction), we have found a less effective TCR in the BS87 (alkB(-)) strain in comparison with the AB1157 (alkB(+)) counterpart. Mutation in the mfd gene encoding the transcription-repair coupling factor Mfd, resulted in weaker TCR in MMS-treated and starved AB1157 mfd-1 cells in comparison to AB1157 mfd(+), and no repair in BS87 mfd(-) cells. Determination of specificity of Arg(+) revertants allowed to conclude that MMS-induced 1meA and 3meC lesions, unrepaired in bacteria deficient in AlkB, are the source of mutations. These include AT-->TA transversions by supL suppressor formation (1meA) and GC-->AT transitions by supB or supE(oc) formation (3meC). The repair of these lesions is partly Mfd-dependent in the AB1157 mfd-1 and totally Mfd-dependent in the BS87 mfd-1 strain. The nucleotide sequence of the mfd-1 allele shows that the mutated Mfd-1 protein, deprived of the C-terminal translocase domain, is unable to initiate TCR. It strongly enhances the SOS response in the alkB(-)mfd(-) bacteria but not in the alkB(+)mfd(-) counterpart
Odpływ rzek w Polsce w różnych fazach oscylacji północnoatlantyckiej
Deviations of climatic elements from average levels, like those caused by changes in the atmosphe-
ric circulation, modify the conditions in which the river runoff forms. The river regime is controlled by both,
precipitation and air temperature, whose magnitudes show a significant dependence on the intensity of zonal
circulation. A simple indicator characterising the atmospheric circulation over the north Atlantic is the North
Atlantic Oscillation Index (henceforth, NAO). The North Atlantic Oscillation is considered a very important
climate-forming factor in Poland.
The analysis embraced monthly, seasonal and annual runoff of Polish rivers taking into consideration
Hurrell’s winter NAO index from the years 1951–2000. The analysed flow series came from 141 profiles loca-
ted on 86 Polish rivers. The selected rivers are distributed evenly throughout Poland and represent a diversity
of environmental conditions (Fig. 1).
The aim of the present research was to examine the extent to which the North Atlantic Oscillation affects
the runoff of Polish rivers: its seasonal structure and spatial variability. Differences were calculated between
the monthly, seasonal and annual runoff observed in the years with exceptionally high (NAODJFM > 2) and
low (NAODJFM < –2) values of the winter NAO index and their statistical significance was determined. Also
calculated were monthly, seasonal and annual deviations of runoff in the years with high NAODJFM indices
from that in the years with their low values (assuming the runoff in the years with low NAODJFM indices to
be 100%).
The research results have confirmed a strong effect of the North Atlantic Oscillation on the runoff volume
of the Polish rivers. In the winter months – January, February and March, the most statistically significant
positive relations can be observed on rivers in the north-east and north of the country. The river runoff in those
regions in a positive NAO stage is then more than 200% higher than in a negative stage. In the spring months,
in April hold for the runoff of rivers in north-eastern Poland and the middle parts of the Oder and Warta basins,
and in May, rivers of almost the entire country with the exception of the east and south-east. In those areas stre-
amflow in a negative NAO stage is more than 50% higher in a positive NAO stage. The obtained results show
that the North Atlantic Oscillation has the greatest effect on streamflow in the winter-spring months, i.e. in the
period when the most abundant water resources are being formed in Poland. Hence, in a positive NAO stage,
one might expect a considerable buildup of the water resources in the winter months, mostly in the north-east,
and their marked dwindling almost throughout the entire country in spring.A6112914
Zróżnicowanie reżimu odpływu rzek w północno-zachodniej Polsce
This paper seeks to identify features of the flow regime of rivers in north–western Poland in terms
of runoff, structure, as well as temporal and spatial variability. The analysis was performed on the basis of
hydrometric data of the Institute of Meteorology and Water Management from the years 1951–2010 coming
from 46 gauging stations located on 33 rivers. The research embraced coastal rivers and lakeland tributaries of
the Oder, Noteć and Vistula. In hydrological terms, this area is characterised by wide differences in flow conditions,
as indicated by both, very great and very low water abundance. As a result, those rivers have different
regime features, and on the basis of regularities in their flow variability they can be classified into 3 varieties
of the nival hydrological regime. The rivers in this area display exceptional differences in total runoff, from
the lowest values in the entire country (under 100 mm, the upper Noteć basin), to very high, the highest in the
lowland part of Poland (over 300, and in the case of the Radunia even over 400 mm). They also show wide
differences in their groundwater flow and its contribution to total runoff. For many coastal rivers this figure
exceeds 80%, the highest in the country. Another of their characteristics is the lowest variability of discharges,
especially annual ones. Also notable are the distinctly greater water abundance, higher groundwater flow and
its share in total runoff, as well as lower variability of yearly discharges of streams in the eastern part of the
coastal region than in its western area
Identyfikacja cech reżimu odpływu rzek w Polsce na różnych poziomach grupowania
The paper presents the characteristics of the river regime types in Poland which were obtained by
applying the unsupervised approach to the regime based on the results of clustering rivers with respect to the
values of the 12 monthly flow coefficients in the average annual cycle. In the paper were used daily flow values
from the period 1971–2010 for 516 gauges located on 280 Polish rivers.On three clustering levels, 5, 9 and
12 varieties of river runoff regimes were identified and detailed. The paper also presents the spatial distribution
of rivers that represent these variants
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