The Experts below are selected from a list of 85014 Experts worldwide ranked by ideXlab platform
Nanette Verboven - One of the best experts on this subject based on the ideXlab platform.
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Is the evaporative water loss of Knot Calidris canutus higher in tropical than in temperate climates
Ibis, 2008Co-Authors: Nanette VerbovenAbstract:To test whether Knot Calidris canutus wintering in the tropics suffer higher rates of water loss through evaporation than do Knot wintering at temperate latitudes, we tried to develop a physically realistic model to predict evaporative heat loss from air temperature, wind and humidity. In separate experiments, involving respirometry and double-labelled water, we tried to estimate relevant parameters, In both sets of experiments, we were able to show significant effects of air temperature on evaporative water loss only, Knot which were able to eat and drink had an evaporative water loss three times that of postabsorptive Knot unable to drink when in a metabolic chamber. Water turnover rates of Knot feeding on bivalves under simulated field conditions were high and did not correlate with predicted evaporative water loss. Over 32 experimental bird-days, the average contribution of predicted evaporative water loss to daily water turnover was 20%. A comparison of predicted evaporative water loss in the north-temperate Dutch Wadden Sea and in the tropical Bane d'Arguin in Mauritania in midwinter showed that Knot wintering in the tropics may need only marginally more water for evaporative cooling than Knot wintering in the Dutch Wadden Sea. Knot foraging on intertidal invertebrates are able to maintain high water turnover rates with little need to drink seawater.
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is the evaporative water loss of Knot calidris canutus higher in tropical than in temperate climates
Ibis, 2008Co-Authors: Nanette VerbovenAbstract:To test whether Knot Calidris canutus wintering in the tropics suffer higher rates of water loss through evaporation than do Knot wintering at temperate latitudes, we tried to develop a physically realistic model to predict evaporative heat loss from air temperature, wind and humidity. In separate experiments, involving respirometry and double-labelled water, we tried to estimate relevant parameters, In both sets of experiments, we were able to show significant effects of air temperature on evaporative water loss only, Knot which were able to eat and drink had an evaporative water loss three times that of postabsorptive Knot unable to drink when in a metabolic chamber. Water turnover rates of Knot feeding on bivalves under simulated field conditions were high and did not correlate with predicted evaporative water loss. Over 32 experimental bird-days, the average contribution of predicted evaporative water loss to daily water turnover was 20%. A comparison of predicted evaporative water loss in the north-temperate Dutch Wadden Sea and in the tropical Bane d'Arguin in Mauritania in midwinter showed that Knot wintering in the tropics may need only marginally more water for evaporative cooling than Knot wintering in the Dutch Wadden Sea. Knot foraging on intertidal invertebrates are able to maintain high water turnover rates with little need to drink seawater. [KEYWORDS: STANDARD OPERATIVE TEMPERATURE, AVIAN METABOLIC-RATE, HEAT-STRESSED BIRDS, BANC-DARGUIN, ENERGY, WIND, SALT, THERMOREGULATION, MAURITANIA, PIGEONS]
Hujun Shen - One of the best experts on this subject based on the ideXlab platform.
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Folding mechanisms of Trefoil Knot proteins studied by molecular dynamics simulations and Go-model.
Advances in Experimental Medicine and Biology, 2014Co-Authors: Xue Wu, Peijun Xu, Jinguang Wang, Yong Xu, Ting Fu, Depeng Zhang, Meixia Zhao, Hujun ShenAbstract:Most proteins need to avoid the complex topologies when folding into the native structures, but some proteins with nontrivial topologies have been found in nature. Here we used protein unfolding simulations under high temperature and all-atom Gō-model to investigate the folding mechanisms for two trefoil Knot proteins. Results show that, the contacts in β-sheet are important to the formation of Knot protein, and if these contacts disappeared, the Knot protein would be easy to untie. In the Gō-model simulations, the folding processes of the two Knot proteins are similar. The compact structures of the two Knot proteins with the native contacts in β-sheet are formed in transition state, and the intermediate state has loose C-terminal. This model also reveals the detailed folding mechanisms for the two proteins.
Sungmo Kang - One of the best experts on this subject based on the ideXlab platform.
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PRIMITIVE/SEIFERT KnotS WHICH ARE NOT TWISTED TORUS Knot POSITION
2016Co-Authors: Sungmo KangAbstract:Abstract. The twisted torus Knots and the primitive/Seifert Knots both lie on a genus 2 Heegaard surface of S3. In [5], J. Dean used the twisted torus Knots to provide an abundance of examples of primitive/Seifert Knots. Also he showed that not all twisted torus Knots are primitive/Seifert Knots. In this paper, we study the other inclusion. In other words, it shows that not all primitive/Seifert Knots are twisted torus Knot position. In fact, we give infinitely many primitive/Seifert Knots that are not twisted torus Knot posi-tion. 1
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primitive seifert Knots which are not twisted torus Knot position
Honam Mathematical Journal, 2013Co-Authors: Sungmo KangAbstract:The twisted torus Knots and the primitive/Seifert Knots both lie on a genus 2 Heegaard surface of S3. In [5], J. Dean used the twisted torus Knots to provide an abundance of examples of primitive/Seifert Knots. Also he showed that not all twisted torus Knots are primitive/Seifert Knots. In this paper, we study the other inclusion. In other words, it shows that not all primitive/Seifert Knots are twisted torus Knot position. In fact, we give infinitely many primitive/Seifert Knots that are not twisted torus Knot position.
Zoltan Szabo - One of the best experts on this subject based on the ideXlab platform.
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Knot floer homology and rational surgeries
Algebraic & Geometric Topology, 2010Co-Authors: Peter Ozsvath, Zoltan SzaboAbstract:Let $K$ be a rationally null-homologous Knot in a three-manifold $Y$. We construct a version of Knot Floer homology in this context, including a description of the Floer homology of a three-manifold obtained as Morse surgery on the Knot $K$. As an application, we express the Heegaard Floer homology of rational surgeries on $Y$ along a null-homologous Knot $K$ in terms of the filtered homotopy type of the Knot invariant for $K$. This has applications to Dehn surgery problems for Knots in $S^3$. In a different direction, we use the techniques developed here to calculate the Heegaard Floer homology of an arbitrary Seifert fibered three-manifold.
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Knot floer homology and rational surgeries
Algebraic & Geometric Topology, 2010Co-Authors: Peter Ozsvath, Zoltan SzaboAbstract:Let K be a rationally null-homologous Knot in a three-manifold Y. We construct a version of Knot Floer homology in this context, including a description of the Floer homology of a three-manifold obtained as Morse surgery on the Knot K. As an application, we express the Heegaard Floer homology of rational surgeries on Y along a null-homologous Knot K in terms of the filtered homotopy type of the Knot invariant for K. This has applications to Dehn surgery problems for Knots in S3. In a different direction, we use the techniques developed here to calculate the Heegaard Floer homology of an arbitrary Seifert fibered three-manifold with even first Betti number.
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heegaard floer homology and alternating Knots
Geometry & Topology, 2003Co-Authors: Peter Ozsvath, Zoltan SzaboAbstract:In an earlier paper, we introduced a Knot invariant for a null-homologous Knot K in an oriented three-manifold Y, which is closely related to the Heegaard Floer homology of Y. In this paper we investigate some properties of these Knot homology groups for Knots in the three-sphere. We give a combinatorial description for the generators of the chain complex and their gradings. With the help of this description, we determine the Knot homology for alternating Knots, showing that in this special case, it depends only on the signature and the Alexander polynomial of the Knot (generalizing a result of Rasmussen for two-bridge Knots). Applications include new restrictions on the Alexander polynomial of alternating Knots.
Tiziana Pandolfini - One of the best experts on this subject based on the ideXlab platform.
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plant cystine Knot peptides pharmacological perspectives
British Journal of Clinical Pharmacology, 2017Co-Authors: Barbara Molesini, Davide Treggiari, Andrea Dalbeni, Pietro Minuz, Tiziana PandolfiniAbstract:Cystine-Knot miniproteins are a class of 30-50 amino acid long peptides widespread in eukaryotic organisms. Due to their very peculiar three-dimensional structure, they exhibit high resistance to heat and peptidase attack. The cystine-Knot peptides are well represented in several plant species including medicinal herbs and crops. The pharmacological interest in plant cystine-Knot peptides derives from their broad biological activities, mainly cytotoxic, antimicrobial and peptidase inhibitory and in the possibility to engineer them to incorporate pharmacophoric information for oral delivery or disease biomonitoring. The mechanisms of action of plant cystine-Knot peptides are still largely unknown, although the capacity to interfere with plasma membranes seems a feature common to several cystine-Knot peptides. In some cases, such as potato carboxypetidase inhibitor (PCI) and tomato cystine-Knot miniproteins (TCMPs), the cystine-Knot peptides target human growth factor receptors either by acting as growth factor antagonist or by altering their signal transduction pathway. The possibility to identify specific molecular targets of plant cystine-Knot peptides in human cells opens novel possibilities for the pharmacological use of these peptides besides their use as scaffold to develop stable disease molecular markers and therapeutic agents.
