scholarly journals Influence of initial light intensity and deer browsing on Taxus baccata saplings: a six years field study

Dendrobiology ◽  
2013 ◽  
pp. 93-99 ◽  
Author(s):  
Grzegorz Iszkuło ◽  
Kinga Nowak-Dyjeta ◽  
Maciej Sękiewicz
2005 ◽  
Vol 156 (12) ◽  
pp. 487-495 ◽  
Author(s):  
Milan Saniga ◽  
Peter Jaloviar

The study analysed a 15-years experiment focusing on the effect of silvicultural treatment (increment thinning) and red deer browsing on the structure and regeneration processes of common yew (Taxus baccata L.) on a series of four permanent experimental plots in the Nature Reserve Pavelcovo. The reserve Pavelcovo is an age-differentiated natural forest with a typical two-layer structure. The fragmented upper layer is formed of common beech, silver fir, sycamore, Norway maple,Wych elm, common ash and European larch. The lower layer,which is relatively continuous, is formed primarily of common yew. Concerning forest typology, a major part of the reserve was classified to Fagetum tiliosum. The analysis of the effect of the thinning from above with negative selection confirmed a significant increment of yew crown diameters. Concerning the damage on yews with DBH over 2 cm by red deer browsing, a positive correlation was observed: with the increasing breastheight diameter, the share of yew trees damaged by barking increased. Red deer at the present counts becomes a serious factor disturbing natural regeneration processes of yew and causing its gradual decline in the forest ecosystems under investigation. The analysis of the efficiency of a thinning from above on the improvement of ecological conditions for seed germination, establishment, survival and growth of yew seedlings showed that in case of a continuous lower layer, the amount of the transmitted light is insufficient and is one of the principal causes of the auto-reduction of this tree species. A better survival of yew would require an intervention into the lower yew layer mainly through a sanitary selection.


Author(s):  
C.V.L. Powell

The overall fine structure of the eye in Placopecten is similar to that of other scallops. The optic tentacle consists of an outer columnar epithelium which is modified into a pigmented iris and a cornea (Fig. 1). This capsule encloses the cellular lens, retina, reflecting argentea and the pigmented tapetum. The retina is divided into two parts (Fig. 2). The distal retina functions in the detection of movement and the proximal retina monitors environmental light intensity. The purpose of the present study is to describe the ultrastructure of the retina as a preliminary observation on eye development. This is also the first known presentation of scanning electron microscope studies of the eye of the scallop.


Author(s):  
C. S. Bricker ◽  
S. R. Barnum ◽  
B. Huang ◽  
J. G. Jaworskl

Cyanobacteria are Gram negative prokaryotes that are capable of oxygenic photosynthesis. Although there are many similarities between eukaryotes and cyanobacteria in electron transfer and phosphorylation during photosynthesis, there are two features of the photosynthetic apparatus in cyanobacteria which distinguishes them from plants. Cyanobacteria contain phycobiliproteins organized in phycobilisomes on the surface of photosynthetic membrane. Another difference is in the organization of the photosynthetic membranes. Instead of stacked thylakolds within a chloroplast envelope membrane, as seen In eukaryotes, IntracytopIasmlc membranes generally are arranged in three to six concentric layers. Environmental factors such as temperature, nutrition and light fluency can significantly affect the physiology and morphology of cells. The effect of light Intensity shifts on the ultrastructure of Internal membrane in Anabaena variabilis grown under controlled environmental conditions was examined. Since a major constituent of cyanobacterial thylakolds are lipids, the fatty acid content also was measured and correlated with uItrastructural changes. The regulation of fatty acid synthesis in cyanobacteria ultimately can be studied if the fatty acid content can be manipulated.


2018 ◽  
Vol 32 (4) ◽  
pp. 182-190 ◽  
Author(s):  
Kenta Matsumura ◽  
Koichi Shimizu ◽  
Peter Rolfe ◽  
Masanori Kakimoto ◽  
Takehiro Yamakoshi

Abstract. Pulse volume (PV) and its related measures, such as modified normalized pulse volume (mNPV), direct-current component (DC), and pulse rate (PR), derived from the finger-photoplethysmogram (FPPG), are useful psychophysiological measures. Although considerable uncertainties exist in finger-photoplethysmography, little is known about the extent of the adverse effects on the measures. In this study, we therefore examined the inter-method reliability of each index across sensor positions and light intensities, which are major disturbance factors of FPPG. From the tips of the index fingers of 12 participants in a resting state, three simultaneous FPPGs having overlapping optical paths were recorded, with their light intensity being changed in three steps. The analysis revealed that the minimum values of three coefficients of Cronbach’s α for ln PV, ln mNPV, ln DC, and PR across positions were .948, .850, .922, and 1.000, respectively, and that those across intensities were .774, .985, .485, and .998, respectively. These findings suggest that ln mNPV and PR can be used for psychophysiological studies irrespective of minor differences in sensor attachment positions and light source intensity, whereas and ln DC can also be used for such studies but under the condition of light intensity being fixed.


Author(s):  
Martin Bettschart ◽  
Marcel Herrmann ◽  
Benjamin M. Wolf ◽  
Veronika Brandstätter

Abstract. Explicit motives are well-studied in the field of personality and motivation psychology. However, the statistical overlap of different explicit motive measures is only moderate. As a consequence, the Unified Motive Scales (UMS; Schönbrodt & Gerstenberg, 2012 ) were developed to improve the measurement of explicit motives. The present longitudinal field study examined the predictive validity of the UMS achievement motive subscale. Applicants of a police department ( n = 168, Mage = 25.11, 53 females and 115 males) completed the UMS and their performance in the selection process was assessed. As expected, UMS achievement predicted success in the selection process. The findings provide first evidence for the predictive validity of UMS achievement in an applied setting.


2018 ◽  
Vol 17 (1) ◽  
pp. 33-41 ◽  
Author(s):  
Jing Jiang ◽  
Ang Gao ◽  
Baiyin Yang

Abstract. This study uses implicit voice theory to examine the influence of employees’ critical thinking and leaders’ inspirational motivation on employees’ voice behavior via voice efficacy. The results of a pretest of 302 employees using critical thinking questionnaires and a field study of 273 dyads of supervisors and their subordinates revealed that both employees’ critical thinking and leaders’ inspirational motivation had a positive effect on employees’ voice and that voice efficacy mediates the relationships among employees’ critical thinking, leaders’ inspirational motivation, and employees’ voice. Implications for research and practice are discussed.


1999 ◽  
Author(s):  
Tara K. Macdonald ◽  
Mark P. Zanna ◽  
Geoffrey T. Fong ◽  
Alanna M. Martineau

2010 ◽  
Author(s):  
Shuhua Sun ◽  
Zhaoli Song ◽  
Vivien Kim Geok Lim ◽  
Don J. Q. Chen ◽  
Xian Li

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