scholarly journals Short-toed snake eagles Circaetus gallicus (Gmelin, 1788) (Aves: Accipitridae) approaching a water barrier show reverse direction of migration

2016 ◽  
Vol 83 (4) ◽  
pp. 543-548 ◽  
Author(s):  
N. Agostini ◽  
M. Gustin ◽  
M. Panuccio
Author(s):  
Z.L. Wang ◽  
J. Bentley ◽  
R.E. Clausing ◽  
L. Heatherly ◽  
L.L. Horton

It has been found that the abrasion of diamond-on-diamond depends on the crystal orientation. For a {100} face, the friction coefficient for sliding along <011> is much higher than that along <001>. For a {111} face, the abrasion along <11> is different from that in the reverse direction <>. To interpret these effects, a microcleavage mechanism was proposed in which the {100} and {111} surfaces were assumed to be composed of square-based pyramids and trigonal protrusions, respectively. Reflection electron microscopy (REM) has been applied to image the microstructures of these diamond surfaces.{111} surfaces of synthetic diamond:The synthetic diamonds used in this study were obtained from the De Beers Company. They are in the as-grown condition with grain sizes of 0.5-1 mm without chemical treatment or mechanical polishing. By selecting a strong reflected beam in the reflection high-energy electron diffraction (RHEED) pattern, the dark-field REM image of the surface is formed (Fig. 1).


1998 ◽  
Author(s):  
William G. Szymczak ◽  
Charles E. Higdon
Keyword(s):  

2020 ◽  
Vol 3 (1) ◽  
pp. 8-13
Author(s):  
Moch. Munir ◽  
Amiruddin Kade ◽  
Muslimin Muslimin

This study aims to determine the relations between metacognitive to science process skills on grade VIII students MTs Negeri 3 Parigi. This research is descriptive, the approach used is a quantitative approach, manifested in the form of numbers analyzed by statistics and the results are described. The population is students of MTs Negeri 3 Parigi Academic Year 2017-2018 with a population of three classes, with a sample of 30 students. The instrument used is a metacognitive questionnaire consisting of 50 questions and an essay about science process skills 6 questions test. The result of the prerequisite test of the research result is all metacognitive indicators of normal and linear distributed and based on the regression feasibility test show that all data is feasible for regression test. The result of the regression test and test of determination to obtain a value which is not significant. Based on the results of the research analysis it can be concluded that the relationship of each metacognitive indicator to science process skills was not significant even there were metacognitive indicators that reverse direction significantly. The magnitude of the relationship of each metacognitive indicator with science process skills maximum 15.3%.  


Author(s):  
Sabina Perrino

From a country of emigrants, Italy has recently become a receiver of migrants. These new, reverse direction migratory flows have triggered strong reactions by Italians, such as nativist discourses about national culture and identity and aggressive, exclusionary, anti-immigration politics. This chapter explores how everyday Italian discursive practices—joke-telling, in particular—operate in relation to these politics, at times totally or partially excluding migrants while simultaneously creating intimate spaces of inclusion for Italians. By codeswitching, for example, from standardized Italian into their local code during joke-telling performances that feature migrants, Northern Italian speech participants address audiences who are presumed to “share” this code while enacting exclusionary stances. This chapter also demonstrates that dichotomies such as exclusion/inclusion are inadequate analytical tools, and it proposes more processual approaches to participation.


1961 ◽  
Vol 201 (5) ◽  
pp. 873-880 ◽  
Author(s):  
T. Hoshiko ◽  
Nick Sperelakis

In frog ventricular strips bathed in Ca-free Ringer's solution containing 6–30 mm/liter Mg and treated with conditioning current pulses, propagation became impaired. An exaggerated foot, or prepotential, was consistently more prominent when the conditioned strip was stimulated from one end than from the other. Occasionally a prepotential in isolation alternated with a prepotential plus action potential response. After further treatment with current pulses, propagation failed in the direction of negative current flow. Thresholds of impaled cells were identical. Bidirectional propagation was restored in Ringer's solution. Conditioning pulses of reversed polarity induced unidirectional propagation in the reverse direction. Propagation in frog sartorius muscle was not blocked under similar conditions. Prepotentials and unidirectional propagation may be explained by junctional transmission from cell to cell.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2761
Author(s):  
Leszek Resner ◽  
Sandra Paszkiewicz

With wind turbines increasing in size, installed at greater distances from the mainland, and greater depths, submarine cables are facing new challenges. Materials and technologies used so far for the production of submarine cables with lead, aluminium, or copper sheaths make them unsuitable or even obsolete for modern solutions such as floating wind farms. The article discusses types of submarine cables, their construction, working conditions, and operational factors, with emphasis placed on the role of the radial water barrier. The focus has been placed on dry and semi-dry designs. The article is also devoted to a discussion regarding directions of further development, possible materials, and constructions that may appear in the future. Current research and results regarding the use of multi-layer coatings with the use of thermoplastic block copolymers for the layer with high moisture absorption are also presented.


Author(s):  
Bruna Rage Baldone Lara ◽  
Paulo Sérgio de Andrade ◽  
Mario Guimarães Junior ◽  
Marali Vilela Dias ◽  
Lizzy Ayra Pereira Alcântara

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Juan Carlos Serrani-Yarce ◽  
Luis Escamilla-Trevino ◽  
Jaime Barros ◽  
Lina Gallego-Giraldo ◽  
Yunqiao Pu ◽  
...  

Abstract Background Hydroxycinnamoyl CoA: shikimate hydroxycinnamoyl transferase (HCT) is a central enzyme of the so-called “esters” pathway to monolignols. As originally envisioned, HCT functions twice in this pathway, to form coumaroyl shikimate and then, in the “reverse” direction, to convert caffeoyl shikimate to caffeoyl CoA. The discovery of a caffeoyl shikimate esterase (CSE) that forms caffeic acid directly from caffeoyl shikimate calls into question the need for the reverse HCT reaction in lignin biosynthesis. Loss of function of HCT gives severe growth phenotypes in several dicot plants, but less so in some monocots, questioning whether this enzyme, and therefore the shikimate shunt, plays the same role in both monocots and dicots. The model grass Brachypodium distachyon has two HCT genes, but lacks a classical CSE gene. This study was therefore conducted to evaluate the utility of HCT as a target for lignin modification in a species with an “incomplete” shikimate shunt. Results The kinetic properties of recombinant B. distachyon HCTs were compared with those from Arabidopsis thaliana, Medicago truncatula, and Panicum virgatum (switchgrass) for both the forward and reverse reactions. Along with two M. truncatula HCTs, B. distachyon HCT2 had the least kinetically unfavorable reverse HCT reaction, and this enzyme is induced when HCT1 is down-regulated. Down regulation of B. distachyon HCT1, or co-down-regulation of HCT1 and HCT2, by RNA interference led to reduced lignin levels, with only modest changes in lignin composition and molecular weight. Conclusions Down-regulation of HCT1, or co-down-regulation of both HCT genes, in B. distachyon results in less extensive changes in lignin content/composition and cell wall structure than observed following HCT down-regulation in dicots, with little negative impact on biomass yield. Nevertheless, HCT down-regulation leads to significant improvements in biomass saccharification efficiency, making this gene a preferred target for biotechnological improvement of grasses for bioprocessing.


Sign in / Sign up

Export Citation Format

Share Document