scholarly journals Post fire ground vegetation development over 25 years

2021 ◽  
Author(s):  
Lasma Freimane ◽  
◽  
Linda Caksa ◽  
Annija Karklina ◽  
Didzis Elferts ◽  
...  

Fire has been a part of natural disturbance regime in boreal and to some extent also hemiboreal forests, affecting soil and light conditions, seedbanks, trees and ground vegetation. The most significant factors affecting occurrence, severity and size of forest fires are anthropogenic, weather and the environment, all of which are changing due to human-caused climate change. This paper discusses medium term (25 years) vegetation development in five different biotopes after fire disturbance. Sample plots were established in Slitere Reserve (now National park) in north-western Latvia on areas affected by large fire in 1992. Data were collected in 1993, 2002 and 2017. The aim of the study was to characterize the regeneration and succession of ground vegetation after the fire. In 1993, species such as bog-rosemary (Andromeda polifolia), heather (Calluna vulgaris) and cloudberry (Rubus chamaemorus) were observed in the ground vegetation a year after the fire. In 2002 liverworts appeared, indicating that the bog has acquired more stable and wetter conditions, but in 2017, liverwort mosses were no longer present and the percentage cover of Rubus chamaemorus decreased significantly and Calluna vulgaris, sphagnum sp., and Betula pendula were present in large quantities in the bog. Comparing these studied years, it can be concluded that all these years the biotopes and species have continuously developed and are regenerating.

2007 ◽  
Vol 5 ◽  
pp. 127-132
Author(s):  
N.A. Vaganova

To detect damage to the underground pipeline, a mathematical model, allowing to take into account the most significant Factors affecting the distribution of temperature on the day surface. To implement this model, a software package has been developed and results of numerical calculations. With the help of these calculations, in particular, It is established that modern thermal imaging equipment has a principal possibility to determine an unauthorized frame in the main pipeline at a depth of two meters in clay soil.


2021 ◽  
Vol 10 (14) ◽  
pp. 3182
Author(s):  
Hiroaki Nakashima ◽  
Keigo Ito ◽  
Yoshito Katayama ◽  
Mikito Tsushima ◽  
Kei Ando ◽  
...  

The conus medullaris typically terminates at the L1 level; however, variations in its level and the factors associated with the conus medullaris level are unclear. We investigated the level of conus medullaris on magnetic resonance imaging in healthy volunteers. In total, 629 healthy adult volunteers (≥50 individuals of each sex and in each decade of age from 20 to 70) were enrolled. The level of the conus medullaris was assessed based on the T2-weighted sagittal magnetic resonance images, and factors affecting its level were investigated employing multivariate regression analysis including the participants’ background and radiographical parameters. L1 was the most common conus medullaris level. Participant height was significantly shorter in the caudally placed conus medullaris (p = 0.013). With respect to the radiographical parameters, pelvic incidence (p = 0.003), and pelvic tilt (p = 0.03) were significantly smaller in participants with a caudally placed conus medullaris. Multiple regression analysis showed that the pelvic incidence (p < 0.0001) and height (p < 0.0001) were significant factors affecting the conus medullaris level. These results indicated that the length of the spinal cord varies little among individuals and that skeletal differences affect the level of the conus medullaris.


Author(s):  
Mee Sun Lee ◽  
Sujin Shin ◽  
Eunmin Hong

The secondary traumatic stress (STS) of nurses caring for COVID-19 patients is expected to be high, and it can adversely affect patient care. The purpose of this study was to examine the degree of STS of nurses caring for COVID-19 patients, and we identified various factors that influence STS. This study followed a descriptive design. The data of 136 nurses who had provided direct care to COVID-19 patients from 5 September to 26 September 2020 were collected online. Hierarchical regression analysis was conducted to identify the factors influencing STS. Participants experienced moderate levels of STS. The regression model of Model 1 was statistically significant (F = 6.21, p < 0.001), and the significant factors influencing STS were the duration of care for patients with COVID-19 for more than 30 days (β = 0.28, p < 0.001) and working in an undesignated COVID-19 hospital (β = 0.21, p = 0.038). In Model 2, the factor influencing STS was the support of a friend in the category of social support (β = −0.21, p = 0.039). The nurses caring for COVID-19 patients are experiencing a persistent and moderate level of STS. This study can be used as basic data to treat and prevent STS.


2016 ◽  
Vol 25 (2) ◽  
pp. 213 ◽  
Author(s):  
Kajar Köster ◽  
Frank Berninger ◽  
Jussi Heinonsalo ◽  
Aki Lindén ◽  
Egle Köster ◽  
...  

In boreal forest ecosystems fire, fungi and bacteria, and their interactions, have a pronounced effect on soil carbon dynamics. In this study we measured enzymatic activities, litter decomposition rates, carbon stocks and fungal and microbial biomasses in a boreal subarctic coniferous forest on a four age classes of non-stand replacing fire chronosequence (2, 42, 60 and 152 years after the fire). The results show that microbial activity recovered slowly after fire and the decomposition of new litter was affected by the disturbance. The percent mass loss of Scots pine litter increased with time from the last fire. Slow litter decomposition during the first post-fire years accelerates soil organic matter accumulation that is essential for the recovery of soil biological activities. Fire reduced the enzymatic activity across all the enzyme types measured. Carbon-degrading, chitin-degrading and phosphorus-dissolving enzymes showed different responses with the time elapsed since the fire disturbance. Microbial and enzymatic activity took decades before recovering to the levels observed in old forest stands. Our study demonstrates that slower post-fire litter decomposition has a pronounced impact on the recovery of soil organic matter following forest fires in northern boreal coniferous forests.


2021 ◽  
Vol 10 (15) ◽  
pp. 3207
Author(s):  
Iwona Strzelecka ◽  
Małgorzata Biedrzycka ◽  
Filip Franciszek Karuga ◽  
Bartosz Szmyd ◽  
Katarzyna Batarowicz ◽  
...  

Hypoplastic left heart syndrome (HLHS) and single ventricle (SV) remain a significant cause of cardiac deaths occurring in the first week of life. Their pathogenesis and seasonal frequency are still unknown. Therefore, we attempt to look at the genesis of the HLHS and SV in the context of territorial distribution as well as seasonality. A total of 193 fetuses diagnosed with HLHS and 92 with SV were selected. The frequency was analyzed depending on the year, calendar month, quarter and season (fall-winter vs. spring-summer). The spatial distribution of HLHS and SV in Poland was analyzed. We observed a statistically significant overrepresentation of HLHS formation frequency in March: 27 (14.00%) in comparison to a monthly median of 15 (IQR: 13.75–16.25; p = 0.039), as well as a significantly higher frequency of HLHS in 2007−2009: 65 cases (33.68%) in comparison to the annual mean of 13.79 ± 6.36 (p < 0.001). We noted a higher frequency of SV among parous with the last menstrual period reported in the fall/winter season of 58 vs. 34 in the spring/summer season (p = 0.014). The performed analysis also revealed significant SV overrepresentation in 2008: 11 cases (12.00%) in comparison to the annual mean of 6.57 ± 2.71 (p = 0.016). Every single case of HLHS was observed when the concentration of benzo(a)pyrene and/or PM10 exceeded the acceptable/target level. Our research indicates that both the season and the level of pollution are significant factors affecting the health of parous women and their offspring. The reason why HLHS and SV develop more frequently at certain times of the year remains unclear, therefore research on this topic should be continued, as well as on the effects of PM10 and benzo(a)pyrene exposure.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sucheta Agarwal ◽  
Veland Ramadani ◽  
Leo-Paul Dana ◽  
Vivek Agrawal ◽  
Jitendra Kumar Dixit

Purpose The ascent of women enterprising community (WEC) in a couple of decades draws the attention of various government and non-government bodies. Literature has mentioned various studies that focus on the factors affecting the success or failure of women entrepreneurs (WEs), but understanding of the ranking of the factors depending on the experiences of different WEs is needed. This study aims to identify the significant factors essential for the growth of WEC. Design/methodology/approach This study examines the factors through interview of 33 WEs having different entrepreneurial experiences (less than 1 year, more than 1 year but less than 10 years and more than 10 years of experiences) from different regions of Uttar Pradesh, India, and with the help of analytical hierarchical process, ranks the factors affecting the sustainable growth of WEs. Findings Through analysis, significant factors have been identified such as determination, education, entrepreneurial resilience, personal satisfaction and provide employment, and these factors have been analysed according to the different experiences of WEs. An investigation of ranking these factors of WEC, especially in the emerging nations, can assist policymakers in designing projects that improve the mindfulness associated with women enterprise and define the compelling methodologies. Practical implications The growth of the WEC is significantly affected by gender orientation ways of thinking as driven by entrepreneurship models. Originality/value This study gives a direction to policymakers by emphasizing on significant factors of various stages of enterprise development for the encouragement of WEs in the emerging economies.


2014 ◽  
Vol 14 (7) ◽  
pp. 1663-1676 ◽  
Author(s):  
M. Brazdova ◽  
J. Riha

Abstract. In this paper a model for the estimation of the number of potential fatalities is proposed based on data from 19 past floods in central Europe. First, the factors contributing to human losses during river floods are listed and assigned to the main risk factors: hazard – exposure – vulnerability. The order of significance of individual factors has been compiled by pairwise comparison based on experience with real flood events. A comparison with factors used in existing models for the estimation of fatalities during floods shows good agreement with the significant factors identified in this study. The most significant factors affecting the number of human losses in floods have been aggregated into three groups and subjected to correlation analysis. A close-fitting regression dependence is proposed for the estimation of loss of life and calibrated using data from selected real floods in central Europe. The application of the proposed model for the estimation of fatalities due to river floods is shown via a flood risk assessment for the locality of Krnov in the Czech Republic.


Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1499
Author(s):  
Patricio G. Riofrío ◽  
Fernando Antunes ◽  
José Ferreira ◽  
António Castanhola Batista ◽  
Carlos Capela

This work is focused on understanding the significant factors affecting the fatigue strength of laser-welded butt joints in thin high-strength low-alloy (HSLA) steel. The effects of the weld profile, imperfections, hardness, and residual stresses were considered to explain the results found in the S-N curves of four welded series. The results showed acceptable fatigue strength although the welded series presented multiple-imperfections. The analysis of fatigue behavior at low stress levels through the stress-concentrating effect explained the influence of each factor on the S-N curves of the welded series. The fatigue limits of the welded series predicted through the stress-concentrating effect and by the relationship proposed by Murakami showed good agreement with the experimental results.


Author(s):  
Sabah Abdullah Alsomali  ,   Amira AbdulAziz Alghamdi

The current study focused on the definition of electronic training and the importance of electronic training in the health organizations. The study main objective was to study the most significant factors that are affecting the electronic training application in the health organizations. The researcher used both a descriptive and analytical methods in her study. A questionnaire was used as a tool for data collection; the questionnaire was divided into two sections. The first section contained questions about general information that included: sex – age- qualification – experience in years – computer skills. The second section dealt with questions related to the study hypothesis. This section consists of four parts as follows: The first part included 11 statements about the reality of the electronic training in the health organizations in the present, which is considered the dependent variable in this study. The second part consists of 15 statements; the third part consists of 13 statements. The fourth part consists of 8 statements. These parts addressed the most significant factors that affected the implementation of the electronic training in the health organizations. These were the independent variables of the study. The questionnaire was distributed to a study sample of (368) employee in the hospital. A (200) questionnaire were collected on a rate of 54%. The Results of the study showed that the infrastructure for the Information technology and the government's tends towards the digital society were the most important factors that primarily affect the possibility of applying the electronic training in the health organizations. The main recommendations of the study were: the need for a support from the high and senior management in the king Abdul Aziz University hospital to adopt the electronic application of the electronic training and manage the resistance of change that many organization faces. The necessity of the electronic training for all the staff on computers skills. Finally, the importance of having a unit for the technical support king Abdul Aziz University hospital.


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