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Wyszukujesz frazę "variability" wg kryterium: Temat


Tytuł:
Overcoming problems associated with uncertainty of the environment by using foresight approach
Autorzy:
Ejdys, Joanna
Wydawca:
Kaunas University of Technology
Cytata wydawnicza:
Ejdys, J. (2013). Overcoming problems associated with uncertainty of the environment by using foresight approach. Enomics and Management. 18 (2), 331-339. https://doi.org/10.5755/j01.em.18.2.4062
Opis:
Diversity and variability of organization’s environment have a certain level of uncertainty about the future states. Uncertainty which is the central theme of strategic management is a key factor for managing organizations, determining the company's competitive position in a long time. Uncertainty means that the ability of managers to predict future states, requires the use of new instruments and methods. Such instruments include foresight. The article presents how organizations can overcome problems with variability and unpredictability of the environment in which they operate by using foresight approach. The basic features of foresight studies, which determine the usefulness in combating volatility and unpredictability of the environment include: use a variety of methods, ensuring diversity of sources of data, methods of obtaining them; socialization process of creating the future; continuity of the process of creating the future; taking account of the unprecedented events such as the wild card in the foresight study ensures that the organization is more aware of your surroundings and the strategic decision-making process is more resistant to future changes; the fact that the foresight research create a safe space. The results are placed in the distant future, which allows participants to be more open to co-operation, understanding their vision and the development of trust between the participants.
Joanna Ejdys
article
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
The relationship between blood pressure variability and outcome in acute ischemic stroke
Autorzy:
Gąsecki, Dariusz
Kowalczyk, Kamil
Wydawca:
Medical University of Gdańsk
Cytata wydawnicza:
Kowalczyk K, Gąsecki D. The relationship between blood pressure variability and outcome in acute ischemic stroke. Eur J Transl Clin Med. 2019;2(2):61-70. DOI: 10.31373/ejtcm/115986
Opis:
Stroke is the second most common cause of mortality. Ischemic stroke is approximately 10 times more common than haemorrhagic stroke. The strongest risk factor for ischemic stroke is hypertension, thus reduction of blood pressure decreases the risk of ischemic stroke. However, the prognostic importance of blood pressure after is unclear. The problem is even more complex considering blood pressure variability (BPV), i.e. continuous changes of blood pressure values. The aim of this review is to discuss the very short-term, short-term, mid-term, and long-term blood pressure variability in the context of clinical outcome in patients after acute ischemic stroke. Most of the studies have shown that increased BPV in ischemic stroke patients is associated with poorer prognosis, however in some of them there was not association between BPV and outcome.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
The results of an 18–year old beech trees (Fagus sylvatica L.) provenance trial in the Łobez Forest District
Autorzy:
Kowalkowski, Wojciech
Wydawca:
Instytut Badawczy Leśnictwa
Opis:
The experimental area is located in the Węgorzyno Forest Sub-District, Łobez Forest District. 29 Polish provenances of beech from their natural range were growth in a completely randomized block design with four replications. In 2010, after the end of the growing season, measurements were carried out on the experimental plot, including: determination of the survival rate and the diameter at breast height, and height of trees. Moreover, the total basal area and the total volume were calculated. Using ANOVA, statistically significant differences between provenances were apparent for four of the five traits measured; all except diameter at breast height. Provenances characterized by high values for the analyzed traits were considered the best adapted to the habitat conditions in the experimental plot, while provenances reaching low values were considered unsuitable for use under the conditions similar to those at the trial site location.
Przemysław Szmit
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Białowieża Forest: what it used to be, what it is now and what we want it to be in the future
Puszcza Białowieska; czym była, czym jest, czym ma być w przyszłości?
Autorzy:
Szwagrzyk, Jerzy
Wydawca:
Instytut Badawczy Lesnictwa (Forest Research Institute), Sekocin Stary, Poland
Opis:
For many centuries, management of the Białowieża Forest has not focused on timber production. Therefore, despite hunting, grazing by domestic animals and sporadic cutting of valuable trees the forest has retained its natural character. After World War I, a small part of the Białowieża Forest was protected as a reserve that later became a national park, while the remainder was managed for timber. After World War II, the protection status of the Polish part of the Białowieża Forest was maintained with the national park at the center surrounded by managed stands. During the last few decades, the national park was enlarged and new reserves were established. However, the majority of the Białowieża Forest is still managed for timber. The forest management has been sustainable for decades and in the last few years logging has even been strongly reduced, to a level comparable with some national parks. In recent years the Białowieża Forest, like many areas in Central Europe, has been plagued by a high spruce mortality caused by bark beetles. In managed forests, cutting the infested spruces and removing them from the forest is a standard practice aimed at reducing the growth rate of the bark beetle population. This, however, raises the question of whether we expect the Białowieża Forest to remain a managed forest, in which case the fight against bark beetles would be justified, or whether we want it to be converted into a large national park? In the latter case, cutting trees to fight bark beetles would be inconsistent with the aim of conservation. Recent discussions concerning the Białowieża Forest have been dominated by two different ideologies for nature protection. The first approach aims at protecting nature to make it sustainable, beautiful and healthy. In the second approach, protecting nature is achieved by removing any direct human influence, even if the resulting natural environment does not meet our expectations.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Provenance experiment with spruce (Picea abies (L.) Karst. and Picea obovata (Ledeb.)) in the North of Russia (Arkhangelsk region)
Autorzy:
Prozherina, Nadezhda A.
Volkov, Alexey G.
Nakvasina, Elena N.
Wydawca:
The Committee on Forestry Sciences and Wood Technology of the Polish Academy of Sciences and the Forest Research Institute in Sekocin Stary
Opis:
This research presents the variability in the survival and growth for 27 provenances of spruce (Picea abies (L.) Karst. and Picea obovata (Ledeb.)). All the tests were carried out in Russia, Arkhangelsk region, 62º 54’ N, 40º 24’ E, in the northernmost site of the State Geographic Network, established in 1977. For the research on the spruce provenances, standard methods for studying the geographic variation of the main forest-forming species were used. Growth rates of provenances were correlated with their geographical coordinates and climatic characteristics. Data was expressed in standard deviation units to select the best in growth provenances. Despite the significant differences in the location of the original stands (up to 12º N and 37º E), variability in survival, height and diameter is low (coefficient of variation is 12.2–19.0%). Obtained data indicated that provenances’ growth is correlated on longitude of the location rather than on the latitude. Diameter and average height of provenances significantly depend on annual rainfall. The height of provenance is mostly dependent on the location of the initial habitats and their climatic characteristics. It is also related to the length of the growing season and the air temperature (annual average and in January). Groups of the provenances of the best and the worst growth were distinguished. The group of the best ones on the integral indicator (volume stand) includes provenances of the western origin represented by P. abies and its immediate hybrids – Karelia (3), Vologda (24), Leningrad (5), Pskov (7) and Moscow (29) Regions – and provenances of the eastern one represented by P. obovata – Komi (26) and Perm (38) Region. High plasticity of spruce (P. abies (L.) Karst. × P. obovata (Ledeb.)), growing within the Russian Plain, in sufficiently favourable conditions of middle taiga subzone (Arkhangelsk Region, Russia) was proved.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Population differences in morphological and anatomical traits of Pinus mugo Turra needles from the Polish part of the Tatra Mountains
Morfologiczne i anatomiczne zróżnicowanie populacji kosodrzewiny ( Pinus mugo Turra) z polskich Tatr wyrażone w cechach igieł
Autorzy:
Bączkiewicz, Alina
Czołpińska, Magdalena
Wawrzyniak, Piotr
Pawlaczyk, Ewa M.
Gonera, Patrycja
Buczkowska-Chmielewska, Katarzyna
Wydawca:
Instytut Badawczy Leśnictwa (Forest Research Institute), Sękocin Stary, Poland
Opis:
The main aim of this study was to describe the variation between the populations of the dwarf mountain pine Pinus mugo Turra based on the morphological and anatomical traits of their needles, and to investigate the relationship between the observed variation and environmental conditions (altitude and substrate).Two-year-old needles were collected from 180 individuals of six populations of P. mugo growing in the Tatra Mts. Two populations were classified as dense, located at 1360–1450 m altitude, and the remaining four formed loose clusters and were situated at 1500–1650 m altitude. Four of the populations are growing on granite and two on a limestone substrate. The natural variation of 10 morpho-anatomical and 3 synthetic needle traits was measured. In addition to descriptive statistics, the analyses of variance (ANOVA) with a Tukey test and principal component analysis were computed. We also estimated Pearson correlation coefficients for the examined needle traits and altitude as well as substrate. Our results indicate that the P. mugo populations differ significantly with regard to the investigated traits for which the Trzydniowiański Wierch population was the most distinct. The observed pattern of variability is largely caused by differences in stomatal traits and these features are positive correlated with altitude. Additionally, populations growing on granite have larger values for most of the examined traits compared to populations growing on limestone.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Analysis of heart rate variability during head-up tilt-test in patients with vasovagal syncope
Autorzy:
Budrejko, Szymon
Kozłowski, Dariusz
Chmielecka, Monika
Raczak, Grzegorz
Kempa, Maciej
Wydawca:
Gdański Uniwersytet Medyczny
Cytata wydawnicza:
Budrejko S, Kempa M, Chmielecka M, Kozłowski D, Raczak G. Analysis of Heart Rate Variability During Head‐Up Tilt‐Test in Patients with Vasovagal Syncope. Eur J Transl Clin Med 2018;1(1):24‐36.DOI: 10.31373/ejtcm/92837
Opis:
Introduction: Syncope is defined as transient loss of consciousness, due to decrease in brain perfusion. The most frequent mechanism is vasovagal syncope. In many patients, the cause of syncope remains unspecified, despite an extensive diagnostic work-up. Tilt-test (TT) is an acknowledged diagnostic tool for syncope. Currently, the so-called Italian protocol of TT is most widely used. Vasovagal syncope is caused by impaired circulatory regulation in response to orthostatic stress. One of the available tools to examine the influence of the nervous system on the circulation is the analysis of heart rate variability (HRV). Despite numerous publications concerning HRV parameters and autonomic regulation in patients with syncope, direct comparisons and metaanalysis of the results is impossible, due to variability of TT protocols and study group specifications. Aim of the study: As there is no uniform model of HRV during TT, we aimed to analyze HRV parameters during TT (performed according to the Italian protocol) in patients with vasovagal syncope, in order to determine the possible application of HRV measurements in clinical practice in that group of patients. Detailed objectives were: (1) analysis and comparison of HRV in patients with and without the history of syncope; (2) analysis of HRV changes in consecutive stages of TT; (3) identification of possible HRV differences between patients with positive and negative TT results. Material and methods: Patients between 18 and 50 years of age were qualified for the study, if they had a history of at least 2 incidents of syncope or presyncope within the preceeding 6 months, and if signs and symptoms indicated the vasovagal mechanism. The study group included 150 patients: 100 consecutive patients with a postive TT result (POS), and 50 consecutive patients with a negative TT result (NEG). The control group (CG) comprised 50 volunteers with no history of syncope nor presyncope, matched according to age and sex to the study group. In all patients a TT was performed according to the Italian protocol, with paced breathing at a rate of 15/min. Time-domain (meanRR, SDNN, RMSSD, pNN50) and frequency-domain (abs_LF, abs_HF, rel_LF, rel_HF, norm_LF, norm_HF, LF/HF) HRV parameters were analyzed and compared at different stages of TT in the study groups as specified above. Results: 100 patients at the age of 18-44 years were included in the POS group, 50 patients at the age of 18-39 years in the NEG group, and 50 volunteers at the age of 20-39 in the CG. Volunteers in the control group developed unexpectedly high percentage of positive TT (14 patients). For consistency of analysis, the CG was thus subdivided according to the result of the TT into CG_POS (positive result of TT) – 14 patients, and CG_ NEG (negative result of TT) – 36 patients. Based on HRV analaysis, no significant differences in HRV values were noted between patients with a history of syncope and positive or negative result of TT. Upright tilt resulted in HRV changes of the same direction and value in syncopal patients in the POS and NEG goup, as well as in patients in the CG_NEG group. Conclusion: HRV values and changes of those values at subsequent stages of TT were not different between syncopal patients with postive or negative TT result, or negative TT control group. The Italian protocol of TT may be associated with a surprisingly high percentage of false positive results.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Innovazioni fraseologiche nei titoli della stampa italiana: una classificazione dei motivi delle innovazioni fraseologiche
Autorzy:
Gadacz, Joanna
Golda, Paweł
Wydawca:
Wydawnictwo Uniwersytetu Śląskiego
Cytata wydawnicza:
Gadacz, J., & Golda, P. (2020). Innovazioni fraseologiche nei titoli della stampa italiana: una classificazione dei motivi delle innovazioni fraseologiche. NEOPHILOLOGICA, 32, 280-302. DOI: http://doi.org/10.31261/NEO.2020.32.15.
Opis:
The purpose of this study is to investigate the phenomenon of phraseological innovations in the titles of the articles in one of the Italian newspapers La Stampa. In the first part of the article, key terms such as the phraseological norm and the phraseological innovation have been defined, taking into account various terms related to this process. Then, some innovation classifications have been presented. Finally, the analytical part describes 91 titles that are examples of innovations.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Effects of HRV biofeedback training on recovery, stress management, reaction time and concentration in competitive rowing – preliminary study
Autorzy:
Kozłowski, Dariusz
Myszka, Zuzanna
Basta, Piotr
Wolff, Maria
Cytata wydawnicza:
Myszka Z, Wolff M, Basta P, Kozłowski D. Effects of HRV biofeedback training on recovery, stress management, reaction time and concentration in competitive rowing – preliminary study. Eur J Transl Clin Med. 2025;8(1):32-44
Opis:
Background: Our aim was to determine the effect of HRV biofeedback (HRVB) training on psychophysiological factors, e.g. reaction time, stress management and concentration during the starting period in competitive rowing. Material and methods: 12 senior national team rowers aged 20-40 (both men and women) were assigned to an experimental (n = 6) and a control (n = 6) group. The experimental group performed HRVB training for 4 weeks, for 20 minutes, twice a day. The control group did not perform any respiratory training. Parameters such as reaction time, resting breathing rate, concentration, subjective stress and heart rate variability were evaluated during the pre-test, post-test and post-post test phases. Results: We noted an improvement in reaction time in the experimental group after HRVB training (pre-test 63.8 sec to post-post test 58.8 sec) and no significant statistical differences in the control group, as well as a statistically significant reduction in resting respiratory rate frequency in the experimental group in comparison to the control group in the post-test (p = 0.0398). Other analyses did not exceed the threshold for statistical significance. Conclusions: Our results suggest that HRVB training may reduce the resting respiratory rate in the experimental group and may improve the reaction time of rowers.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł
Tytuł:
Exploring the relationship between fetal growth restriction and heart rate variability parameters
Autorzy:
Lakhno, Igor Victorovich
Wydawca:
Medical University of Gdańsk
Cytata wydawnicza:
Lakhno I V. Exploring the relationship between fetal growth restriction and heart rate variability parameters. Eur J Transl Clin Med. 2025;8(2):9-16
Opis:
Background: Fetal growth restriction (FGR) is a multifactorial disturbance of fetal nutrition with short- and long- -term consequences (e.g. autonomic malfunction and delayed neurological maturation). Fetal heart rate variability (HRV) is critically dependent on autonomic regulation. This study focused on identifying a correlation between neonatal biometry and HRV variables. Material and methods: This was a descriptive cross-sectional study of 48 women at 22-36 weeks of pregnancy. The fetal cardiac signals were obtained from the maternal abdominal wall via non-invasive fetal electrocardiography (NI-FECG). The stress index (SI) was selected for evaluation among all linear HRV variables. Cardiotocographic parameters (short-term variation (STV) and long-term variation (LTV)) were determined, along with cardiographic: AC (acceleration capacity) and DC (deceleration capacity). Results: FGR was detected in 9 women. The fetal growth was appropriate in 31 patients. 8 patients were excluded from the study. The detected variables of HRV in FGR were different, however statistical significance was impossible to determine (small number of cases). A strong linear correlation was detected between all the HRV variables: AC, DC, SI, STV, and LTV. Whereas, AC and DC had significant correlation with the 1-minute Apgar score. Multivariate regression analysis showed a statistically significant correlation of SI with the gestational age at birth. Conclusions: SI could be of use in the advancement of conventional FGR management and has potential for further research.
Dostawca treści:
Repozytorium Centrum Otwartej Nauki
Artykuł

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