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International Journal of Primatology - The selection of sleeping sites and sleeping trees in nonhuman primates is related to social and ecological factors. We investigate the role of body...  相似文献   
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The rat optic nerve is a useful model for stem cell regeneration research. Direct injection into the rat optic nerve allows delivery into the central nervous system in a minimally-invasive surgery without bone removal. This technique describes an approach to visualization and direct injection of the optic nerve following minor fascial dissection from the orbital ridge, using a conjunctival traction suture to gently pull the eye down and out. Representative examples of an injected optic nerve show successful injection of dyed beads.  相似文献   
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Zusammenfassung Die Feinstruktur der Maxillarnephridien von Scutigerella immaculata Newport mit ihren drei Abschnitten Sacculus, Tubulus und Ausführgang wurde untersucht. Die Zellen des Sacculus sind typische Podocyten, an denen eine Ultrafiltration ablaufen kann. Möglicherweise wird die Filtration durch einen den Sacculus umgebenden Muskel unterstützt. Die Zellen des Tubulus zeigen basale Einfaltungen und im proximalen Teil auch Mikrovilli. Sowohl im Tubulus als auch im Ausführgang, dessen Zellen ebenfalls basale Einfaltungen aufweisen, werden Reabsorptionsprozesse vermutet.
The fine structure of the maxillary kidney of the garden centipede, Scutigerella immaculata Newport (Symphyla, Myriapoda)
Summary The fine structure of the maxillary kidney of Scutigerella immaculata Newport (Symphyla) has been investigated. It may be compared with segmental organs of other Arthropoda having an end-sac which forms a primary urine by ultrafiltration. The filtration may be supported by a muscle surrounding the end-sac. The tubular part of the nephridium and the efferent duct show structures which may be involved in reabsorption.
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Zusammenfassung Am Präanalsegment von Scutigerella befindet sich ein Paar Trichobothrien, das komplizierter gebaut ist als entsprechende Sinnesorgane anderer Arthropoden. Die distalen Fortsätze von sechzehn Sinneszellen stehen mit der Gelenkmembran des nach allen Seiten beweglichen Sinneshaares in Verbindung. Aus ihrer Anordnung kann geschlossen werden, daß Scutigerella mit Hilfe des Trichobothriums mindestens acht verschiedene Richtungen unterscheiden kann. Der adäquate Reiz für die Trichobothrien dürften Luftbewegungen sein.
Sense organs of symphyla (Myriapoda)I. Ultrastructure of the trichobothrium of Scutigerella immaculata newport
Summary One pair of trichobothria is situated on the lateral portions of the preanal segment of Scutigerella. They are rather complicated compared to similar organs of other Arthroods. The distal portions of 16 sense cells are connected to the elastic membrane of the sense hair which can be turned in every direction. From the arrangement of the distal parts of the sense cells it may be concluded that Scutigerella can distinguish at least eight different directions. Probably movements of the air are the adequate stimulus for the trichobothrium.
Für technische Mitarbeit danke ich Frl. M. Genehr und Fr. G. Schröer, für die Anfertigung der Zeichnung Fr. C. St. Friedemann.  相似文献   
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Regulation of phosphate uptake was studied in HeLa cell lines after transfection with DNA encoding the human 5-HT1A receptor. Phosphate uptake was saturable and greater than 90% sodium-dependent, with Vmax approximately 30-35% without changing Km. Treatment with 5-HT or the 5-HT1A-specific agonist 8-OH-2-(di-n-propylamino)1,2,3,4-tetrahydronaphthalene increased Vmax approximately 40% without affecting Km. This effect was blocked by pretreatment with the 5-HT1 antagonists, methiothepine and spiperone, or pertussis toxin. Surprisingly, the stimulation was not secondary to an inhibition of adenylyl cyclase because 5-HT stimulated phosphate uptake approximately 20% in the presence of 1 mM 8-Br-cAMP. Rather, the primary pathway linked to the stimulation of phosphate uptake involved activation of protein kinase C because (i) 5-HT measurably activated protein kinase C in these cells, (ii) activators of protein kinase C (phorbol esters and diacylglycerol analogues) stimulated phosphate uptake in these cells (iii) the half-maximal doses for 5-HT-induced phosphatidylinositol hydrolysis and stimulation of phosphate uptake were virtually equivalent, and both effects were equally sensitive to pertussis toxin, and (iv) the stimulation was markedly attenuated in cells made deficient in protein kinase C. These results demonstrate that the stimulation of phosphatidylinositol hydrolysis by the 5-HT1A receptor can generate physiologically measurable effects on cellular transport and suggest that such accessory pathways may play a prominent role in signal transduction.  相似文献   
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Industrial ecology (IE) methodologies, such as input/output or material flow analysis and life cycle assessment (LCA), are often used for the environmental evaluation of circular economy strategies. Up to now, an approach that utilizes these methods in a systematic, integrated framework for a holistic assessment of a geographic region's sustainable circular economy potential has been lacking. The approach developed in this study (IE4CE approach) combines IE methodologies to determine the environmental impact mitigation potential of circular economy strategies for a defined geographic region. The approach foresees five steps. First, input/output analysis helps identify sectors with high environmental impacts. Second, a refined analysis is conducted using material flow and LCA. In step 3, circular strategies are used for scenario design and evaluated in step 4. In step 5, the assessment results are compiled and compared across sectors. The approach was applied to a case study of Switzerland, analyzing 8 sectors and more than 30 scenarios in depth. Carbon capture and storage (CCS) from waste incineration, biogas and cement production, food waste prevention in households, hospitality and production, and the increased recycling of plastics had the highest mitigation potential. Most of the scenarios do not influence each other. One exception is the CCS scenarios: waste avoidance scenarios decrease the reduction potential of CCS. A combination of scenarios from different sectors, including their impact on the CCS scenario potential, led to an environmental impact mitigation potential of 11.9 Mt CO2-eq for 2050, which equals 14% of Switzerland's current consumption-based impacts.  相似文献   
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What can the stable isotope values of human and animal faeces tell us? This often under-appreciated waste product is gaining recognition across a variety of disciplines. Faecal isotopes provide a means of monitoring diet, resource partitioning, landscape use, tracking nutrient inputs and cycling, and reconstructing past climate and environment. Here, we review what faeces are composed of, their temporal resolution, and how these factors may be impacted by digestive physiology and efficiency. As faeces are often used to explore diet, we clarify how isotopic offsets between diet and faeces can be calculated, as well as some differences among commonly used calculations that can lead to confusion. Generally, faecal carbon isotope (δ13C) values are lower than those of the diet, while faecal nitrogen isotope values (δ15N) values are higher than in the diet. However, there is considerable variability both within and among species. We explore the role of study design and how limitations stemming from a variety of factors can affect both the reliability and interpretability of faecal isotope data sets. Finally, we summarise the various ways in which faecal isotopes have been applied to date and provide some suggestions for future research. Despite remaining challenges, faecal isotope data are poised to continue to contribute meaningfully to a variety of fields.  相似文献   
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