scholarly journals What are the important landscape components for habitat selection of the ortolan bunting Emberiza hortulana in northern limit of range?

2015 ◽  
Vol 1 (1) ◽  
pp. 13-25 ◽  
Author(s):  
Jaanus Elts ◽  
Kunter Tätte ◽  
Riho Marja

AbstractOrtolan buntings Emberiza hotulana have undergone one of the most severe population declines of any European farmland bird over the last thirty years. The aim of this study was to find out which habitat features, including crop characteristics, ortolan bunting prefers in Estonia in breeding areas. This study compared currently occupied and unoccupied ortolan bunting territories. Occupied areas contained significantly more tall broadleaf trees, crop types, structural elements (trees, bushes, roads, overhead power lines and buildings) and spring wheat, but also had lower crop drilling densities. Ortolan bunting territories were best described by a logistic regression model containing six variables: amount of structural point elements, length of power lines, amount of tall broadleaf trees and number of different crops had a positive effect, whereas crop density and area of autumn-sown crops had a negative effect. Based on the findings of this study, the following conservation measures can be recommended: lower crop densities; spring rather than autumn-sown crops; small-field systems containing a variety of crops; scattered scrub preserved or planted; habitat patches of permanent grasslands, hedges and tall broadleaf trees retained within the agricultural landscape.

2018 ◽  
Vol 29 (1) ◽  
pp. 144-158 ◽  
Author(s):  
MARTIN ŠÁLEK ◽  
VÍT ZEMAN ◽  
RADOVAN VÁCLAV

SummaryEffective conservation measures for any bird species across their distribution ranges require detailed knowledge of landscape-specific differences in habitat associations. The Ortolan Bunting Emberiza hortulana is a farmland bird species, which experienced massive population declines during the recent decades and has become a conservation priority in many European countries. Thus, identification of the key habitat features is an important prerequisite for the conservation of the species. Here we investigate habitat associations of the Ortolan Bunting for the remaining breeding population of the species in the Czech Republic. This population is remarkable by its distribution in two markedly different environments – farmland and post-mining landscapes. The main objectives of this study were to identify habitat features associated with Ortolan Bunting occurrence within the two contrasting landscapes and at two spatial scales. Our results reveal a high degree of habitat plasticity by Ortolan Buntings in the Czech Republic which was revealed by the landscape- and scale- specific habitat associations. Habitat heterogeneity, in terms of compositional and configurational diversity, and the cover of bare ground were the most important predictors of Ortolan Bunting occurrence in both landscape types. In farmland, the species occurrence was positively associated with shrub and woody vegetation, poppy fields and set-asides, and negatively associated with grasslands, gardens/orchards, seedlings and urban habitats. In the post-mining landscape, the cover of herb vegetation and greater slope steepness and terrain ruggedness were most important habitat features. Ortolan Buntings in the post-mining landscape appear to avoid patches with a higher cover of shrub and woody vegetation, forests, seedlings and urban areas. We propose that conservation measures for Ortolan Buntings should focus on enhancing farmland habitat heterogeneity, but also on regulating the rate of succession in disturbed environments, such as post-mining landscapes.


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 302 ◽  
Author(s):  
Romualdas Kliukas ◽  
Arūnas Jaras ◽  
Ona Lukoševičienė

The current research paper is focused on the experimental investigation of features of chemical admixtures (superplasticizers C-3, ‘Dofen’ and formaldehyde resin ACF-3M) utilizing in reinforced spun concrete structures. For the sake of comparison, the results of studying the effects of chemical admixtures on physical and mechanical properties on vibrated and spun concrete are provided. As a separate part of spun concrete products, the supporting poles of overhead power lines are introduced. The results obtained indicate, that the positive effect of chemical admixtures for spun and vibrated concrete is most pronounced at an early age of concrete. The effective amount of chemical admixtures for spun concrete is 0.15% of cement mass when formaldehyde resin ACF-3M and 1% of cement mass when superplasticizers C-3 and ‘Dofen’ are used. Moreover, the brief review about the reinforced spun concrete members is provided.


2013 ◽  
Vol 34 (3) ◽  
pp. 159-169 ◽  
Author(s):  
Sevtap Cinan ◽  
Aslı Doğan

This research is new in its attempt to take future time orientation, morningness orientation, and prospective memory as measures of mental prospection, and to examine a three-factor model that assumes working memory, mental prospection, and cognitive insight are independent but related higher-order cognitive constructs by using confirmatory factor analysis (CFA). The three-factor model produced a good fit to the data. An alternative one-factor model was tested and rejected. The results suggest that working memory and cognitive insight are distinguishable, related constructs, and that both are distinct from, but negatively associated with, mental prospection. In addition, structural equation modeling (SEM) showed that working memory had a strong positive effect on cognitive insight and a moderate negative effect on mental prospection.


2020 ◽  
Vol 3 (2) ◽  
pp. 93-108
Author(s):  
Annisa Siti Fathonah ◽  
Dadang Hermawan

This study aims to determine and analyze how much influence the bank's internal factors such as Equity, Operational Costs per Operating Income (BOPO), Financing Deposit to Ratio (FDR), Non Performing Financing (NPF) as a mediator and external or macroeconomic factors namely inflation and Gross Domestic Product (GDP) on profitability represented by Return on Assets (ROA) at Bank Muamalat Indonesia for the period 2008-2018. The data used in this research are secondary data obtained from the publication of quarterly financial statements from 2008 to quarter 2 of 2018. The method that used in this research is path analysis with SPSS 20.0 as the analytical tool. The results of the study partially test the hypothesis (t-test), in substructure I shows that the capital variable has a significant negative effect on NPF, BOPO and inflation has a significant positive effect on NPF, FDR and GDP do not significantly influence NPF at Bank Muamalat Indonesia. In substructure II partially, Capital, BOPO, significant negative effect on ROA, FDR and NPF has a significant positive effect on ROA, Inflation and GDP does not significantly influence ROA while simultaneously significantly influencing ROA. Based on the sobel test, capital has a significant effect on ROA through NPF, BOPO has a significant effect on ROA through NPF, FDR has a significant effect on ROA through NPF, Inflation has a significant effect on ROA through NPF, while GDP has no significant effect on ROA through NPF.


2020 ◽  
Vol 2 (1) ◽  
pp. 60-79
Author(s):  
Wayan Arya Paramarta ◽  
Ni Putu Kurnia Darmayanti

The aims of this study was to explain the effect of employee engagement and work stress on job satisfaction and turnover intention at Aman Villas Nusa Dua-Bali. The type of data used in this study is qualitative and quantitative data, with data sources namely primary and secondary data. Data collection method is interview, distributing questionnaires to respondents and library research, while the data analysis technique used Smart PLS 3.2.8. The results of this study showed that employee engagement had a positive effect and significant on job satisfaction, work stress had a negative effect but not significant on job satisfaction, employee engagement had a negative effect and significant on turnover intention, work stress had a positive effect and significant on turnover intention, job satisfaction had a negative effect but not significant on turnover intention, employee engagement had a positive effect but not significant on turnover intention trough job satisfaction, work stress had a positive effect but not significant on turnover intention trough job satisfaction at Aman Villas Nusa Dua-Bali.


2019 ◽  
Vol 2 (3) ◽  
pp. 553-561
Author(s):  
Novian Hangga Prakosa ◽  
Fafurida Fafurida

The purposes of this research are to identify the influence of travel cost, income, distance, access, facilities, natural beautiness, and age on the number of individual visits to Curug Silawe and to estimate the economic value of Curug Silawe through individual travel cost method. The population in this study are tourists that visited Curug Silawe with sample of 98 respondents taken by the quota accidental sampling technique. The data collection method used are literature study and questionnaire. The analysis tool used are OLS linear regression and economic value estimation. The results showed the variables that influence the number of individual visits to Curug Silawe are income, distance and age. Income and age has a positive effect. While distance has a negative effect. The economic value of Curug Silawe reached IDR 1,109,930,140.48 per year. This value is obtained from consumer surplus obtained per individual per year of IDR 308,656.88. Tujuan dari penelitian ini adalah untuk mengidentifikasi pengaruh biaya perjalanan, pendapatan, jarak, akses, fasilitas, keindahan alam, dan usia pada jumlah kunjungan individu ke Curug Silawe dan untuk memperkirakan nilai ekonomi Curug Silawe melalui metode biaya perjalanan individu . Populasi dalam penelitian ini adalah wisatawan yang berkunjung ke Curug Silawe dengan sampel 98 responden yang diambil dengan teknik quota accidental sampling. Metode pengumpulan data yang digunakan adalah studi literatur dan kuesioner. Alat analisis yang digunakan adalah regresi linear OLS dan estimasi nilai ekonomi. Hasil penelitian menunjukkan variabel yang mempengaruhi jumlah kunjungan individu ke Curug Silawe adalah pendapatan, jarak dan usia. Penghasilan dan usia memiliki efek positif. Sedangkan jarak memiliki efek negatif. Nilai ekonomi Curug Silawe mencapai Rp1.109.930.140,48 per tahun. Nilai ini diperoleh dari surplus konsumen yang diperoleh per individu per tahun sebesar Rp308.656,88.


1985 ◽  
Vol 110 (3) ◽  
pp. 329-337 ◽  
Author(s):  
G. A. Schuiling ◽  
H. Moes ◽  
T. R. Koiter

Abstract. The effect of pretreatment in vivo with oestradiol benzoate on in vitro secretion of LH and FSH was studied in long-term ovariectomized (OVX) rats both at the end of a 5-day continuous in vivo pretreatment with LRH and 4-days after cessation of such LRH pretreatment. Rats were on day 0 sc implanted with osmotic minipumps which released LRH at the rate of 250 ng/h. Control rats were implanted with a piece of silicone elastomer with the dimensions of a minipump. On days 2 and 4 the rats were injected with either 3 μg EB or with oil. On day 5 part of the rats were decapitated and the in vitro autonomous (i.e. non-LRH-stimulated) and 'supra-maximally' LRHstimulated release of LH and FSH was studied using a perifusion system. From other rats the minipumps were removed on day 5 and perifusion was performed on day 9. On the 5th day of the in vivo LRH pretreatment the pituitary LH/FSH stores were partially depleted; the pituitaries of the EB-treated rats more so than those of the oil-injected rats. EB alone had no significant effect on the content of the pituitary LH- and FSH stores. On day 9, i.e. 4 days after removal of the minipumps, the pituitary LH and FSH contents had increased in both the oil- and the EB injected rats, but had not yet recovered to control values. In rats not subjected to the 5-days pretreatment with LRH EB had a positive effect on the supra-maximally LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. EB had no effect on the non-stimulated secretion of FSH. After 5 days of in vivo pretreatment with LRH only, the in vitro non-stimulated and supra-maximally LRH-stimulated secretion of both LH and FSH were strongly impaired, the effect correlating well with the LRH-induced depletion of the pituitary LH/FSH stores. In such LRH-pretreated rats EB had on day 5 a negative effect on the (already depressed) LRH-stimulated secretion of LH (not on that of FSH). EB had no effect on the non-stimulated LH/FSH secretion. It could be demonstrated that the negative effect of the combined LRH/EB pretreatment was mainly due to the depressing effect of this treatment on the pituitary LH and FSH stores: the effect of oestradiol on the pituitary LRH-responsiveness (release as related to pituitary gonadotrophin content) remained positive. In LRH-pretreated rats, however, this positive effect of EB was smaller than in rats not pretreated with LRH. Four days after removal of the minipumps there was again a positive effect of EB on the LRH-stimulated secretion of LH and FSH as well as on the non-stimulated secretion of LH. The positive effect of EB on the pituitary LRH-responsiveness was as strong as in rats which had not been exposed to exogenous LRH. The non-stimulated secretion of FSH was again not affected by EB. The results demonstrate that the effect of EB on the oestrogen-sensitive components of gonadotrophin secretion consists of two components: an effect on the pituitary LRH-responsiveness proper, and an effect on the pituitary LH/FSH stores. The magnitude of the effect of EB on the LRH-responsiveness is LRH dependent: it is very weak (almost zero) in LRH-pretreated rats, but strong in rats not exposed to LRH as well as in rats of which the LRH-pretreatment was stopped 4 days previously. Similarly, the effect of EB on the pituitary LH and FSH stores is LRH-dependent: in the absence of LRH, EB has no influence on the contents of these stores, but EB can potentiate the depleting effect of LRH on the LH/FSH-stores. Also this effect disappear after cessation of the LRH-pretreatment.


2016 ◽  
Vol 2016 (4) ◽  
pp. 23-25
Author(s):  
A.V. Krasnozhon ◽  
◽  
R.O. Buinyi ◽  
I.V. Pentegov ◽  
◽  
...  

2018 ◽  
Vol 3 (3) ◽  
pp. 11-17 ◽  
Author(s):  
Aleksandr L. KULIKOV ◽  
◽  
Anton A. LOSKUTOV ◽  
Pavel S. PELEVIN ◽  
◽  
...  

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