scholarly journals Diet, energy storage, and reproductive condition in a bioindicator species across beaches with different levels of human disturbance

2020 ◽  
Vol 117 ◽  
pp. 106636 ◽  
Author(s):  
Mustafa R. Gül ◽  
Blaine D. Griffen
The Condor ◽  
2005 ◽  
Vol 107 (1) ◽  
pp. 178-181 ◽  
Author(s):  
Nicolaas V. Webb ◽  
Daniel T. Blumstein

Abstract Many studies have demonstrated that birds behave differently in areas with different levels of human disturbance. Studies frequently characterize sites as having an overall level of human disturbance, and compare how birds respond at sites with high and low levels of disturbance. Doing so assumes that disturbance has a fairly constant effect on animals throughout a site. We measured the distance at which individual Western Gulls (Larus occidentalis) moved away from an approaching observer along a stretch of beach on both sides of the Santa Monica Pier, a heavily visited tourist attraction in southern California. We found that these flight initiation distances decreased in areas where more people visited the beach, and specifically in a small area near the pier. We found that flight initiation distance changed very rapidly within a short distance from the pier. Our results indicate that anthropogenic features may leave a “behavioral footprint.” Identifying the scale of such behavioral footprints should be an important goal of studies that seek to reduce anthropogenic impacts on birds. La Variación del Disturbio Humano Afecta Diferencialmente la Percepción del Riesgo de Depredación en Gaviotas Larus occidentalis Resumen. Muchos estudios han demostrado que las aves se comportan de modo diferente en áreas con distintos niveles de disturbio humano. Los estudios frecuentemente caracterizan sitios con base en su nivel general de disturbio y comparan las respuestas de las aves entre lugares con niveles altos y bajos de disturbio. Al hacer esto, se supone que el disturbio tiene un efecto aproximadamente constante sobre los animales a través de un sitio dado. En este estudio medimos la distancia a la cual gaviotas de la especie Larus occidentalis se desplazaron alejándose de un observador a lo largo de un tramo de playa en ambos lados del embarcadero de Santa Monica, una atracción turística muy visitada ubicada en el sur de California. Encontramos que las distancias al observador a las que las aves iniciaron el vuelo disminuyeron en áreas donde más personas visitaron la playa, y específicamente en un área cercana al embarcadero. Las distancias a las que las gaviotas iniciaron el vuelo cambiaron muy rá pidamente en una distancia muy corta desde el puerto, hasta alcanzar una distancia constante. Nuestros resultados indican que las estructuras antropogénicas podrian dejar una “huella comportamental”. Identificar la escala de dichas huellas debería ser un objetivo importante de estudios que tengan como fin reducir el impacto antrópico sobre las aves.


2020 ◽  
Vol 173 ◽  
pp. 03004
Author(s):  
Darío Benavides ◽  
Paúl Arévalo ◽  
Luis G. Gonzalez ◽  
José A. Aguado

The importance of energy storage systems is increasing in microgrids energy management. In this study, an analysis is carried out for different types of energy storage technologies commonly used in the energy storage systems of a microgrid, such as: lead acid batteries, lithium ion batteries, redox vanadium flux batteries and supercapacitors. In this work, it is analyzed the process of charging and discharging (slow and fast) in these systems, the calculation of energy efficiency, performance and energy supplied under different load levels, in its normal operating conditions and installed power capacity is developed. The results allow us to choose the optimal conditions of charge and discharge at different levels of reference power, analyzing the strengths and weaknesses of the characteristics of each storage system within a microgrid.


2012 ◽  
Vol 1 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Genadijs Zaleskis ◽  
Viesturs Brazis ◽  
Leonards Latkovskis

Abstract The paper presents configuration of the traction drive test bench with energy storage system, calculation of the scale factors, estimation of the energy storage system size and Matlab simulation results of the bench operation in a braking mode at different levels of the supercapacitor initial voltage.


2018 ◽  
Vol 8 (22) ◽  
pp. 11309-11321
Author(s):  
Cecilia Bessega ◽  
Carolina Pometti ◽  
Ramiro Pablo López ◽  
Daniel Larrea-Alcázar ◽  
Reneé H. Fortunato ◽  
...  

2018 ◽  
Vol 38 (2) ◽  
Author(s):  
王美娜 WANG Meina ◽  
卢训令 LU Xunling ◽  
崔洋 CUI Yang ◽  
王梦茹 WANG Mengru ◽  
丁圣彦 DING Shengyan

2019 ◽  
Vol 88 (2) ◽  
Author(s):  
Run Liu ◽  
Zhaohui Zhang ◽  
Jiachen Shen ◽  
Zhihui Wang

The diversity of bryophytes in karst sinkholes has received little attention, and these habitats probably play a crucial role as refugia. In this study, bryophyte diversity affected by different levels of human disturbance in five karst sinkholes was compared. A total of 132 species of bryophytes (17 liverworts and 115 mosses) that belong to 64 genera and 30 families were recorded. The richness of the bryophytes in the natural sinkholes was significantly higher than that of the bryophytes in the sinkholes affected by tourism and used as farmland. Canonical correspondence analysis showed that soil moisture is one of the most important factors that affect the abundance of bryophyte distribution in the five sinkholes. Human activities, including agriculture, animal husbandry, and tourism development, reduce the bryophyte coverage of sinkholes and lead to soil moisture loss. Therefore, effective protection of karst sinkholes is required to maintain their original value for biodiversity conservation.


Author(s):  
J. E. Doherty ◽  
A. F. Giamei ◽  
B. H. Kear ◽  
C. W. Steinke

Recently we have been investigating a class of nickel-base superalloys which possess substantial room temperature ductility. This improvement in ductility is directly related to improvements in grain boundary strength due to increased boundary cohesion through control of detrimental impurities and improved boundary shear strength by controlled grain boundary micros true tures.For these investigations an experimental nickel-base superalloy was doped with different levels of sulphur impurity. The micros tructure after a heat treatment of 1360°C for 2 hr, 1200°C for 16 hr consists of coherent precipitates of γ’ Ni3(Al,X) in a nickel solid solution matrix.


Author(s):  
M. Kraemer ◽  
J. Foucrier ◽  
J. Vassy ◽  
M.T. Chalumeau

Some authors using immunofluorescent techniques had already suggested that some hepatocytes are able to synthetize several plasma proteins. In vitro studies on normal cells or on cells issued of murine hepatomas raise the same conclusion. These works could be indications of an hepatocyte functionnal non-specialization, meanwhile the authors never give direct topographic proofs suitable with this hypothesis.The use of immunoenzymatic techniques after obtention of monospecific antisera had seemed to us useful to bring forward a better knowledge of this problem. We have studied three carrier proteins (transferrin = Tf, hemopexin = Hx, albumin = Alb) operating at different levels in iron metabolism by demonstrating and localizing the adult rat hepatocytes involved in their synthesis.Immunological, histological and ultrastructural methods have been described in a previous work.


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