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51.
Victoria J. Bennett Vanessa S. Quinn Patrick A. Zollner 《Biodiversity and Conservation》2013,22(8):1783-1798
Site and wildlife managers globally are under increasing pressure to implement management strategies that address the negative implications of outdoor recreational activities on wildlife. For many rare and isolated species any anthropogenic activities that cause disturbance could potentially be detrimental to existing populations. Understanding how non-consumptive recreation can influence a species may therefore be critical to its preservation. We developed a novel approach to specifically address this need. Using a combination of field surveys and simulation modelling exercises, we (1) explored the responses of endangered Karner blue butterflies (Lycaeides melissa samuelis) to recreation, (2) assessed whether such responses influenced oviposition rate and/or host plant choice and (3) tested alternative management strategies that could alleviate the negative impacts of recreation. Our field surveys confirmed that Karner blues were sensitive to recreational disturbance. Butterflies flushed at similar speeds and distances from recreationists (2.2 m at 0.17 m/s), as they would from natural threats, such as predators (2.2 m at 0.19 m/s). Incorporating female response parameters into a simulation model revealed that regular disturbance could reduce egg laying potential and significantly restrict host plant choice, which in turn, could impact the butterfly’s population dynamics. However, we established that it was possible to effectively offset the implications of recreational disturbance using our simulation modelling approach. For example, extending Karner blue breeding habitat from trails and other public rights of way has the potential to alleviate such disturbance. Our study demonstrates that the potential impact of recreation on species of conservation concern should not be overlooked. 相似文献
52.
éva Borbély Zsófia Hajna Katalin Sándor László Kereskai István Tóth Erika Pintér Péter Nagy János Szolcsányi John Quinn Andreas Zimmer James Stewart Christopher Paige Alexandra Berger Zsuzsanna Helyes 《PloS one》2013,8(4)
Objective
Substance P, encoded by the Tac1 gene, is involved in neurogenic inflammation and hyperalgesia via neurokinin 1 (NK1) receptor activation. Its non-neuronal counterpart, hemokinin-1, which is derived from the Tac4 gene, is also a potent NK1 agonist. Although hemokinin-1 has been described as a tachykinin of distinct origin and function compared to SP, its role in inflammatory and pain processes has not yet been elucidated in such detail. In this study, we analysed the involvement of tachykinins derived from the Tac1 and Tac4 genes, as well as the NK1 receptor in chronic arthritis of the mouse.Methods
Complete Freund’s Adjuvant was injected intraplantarly and into the tail of Tac1−/−, Tac4−/−, Tacr1−/− (NK1 receptor deficient) and Tac1−/−/Tac4−/− mice. Paw volume was measured by plethysmometry and mechanosensitivity using dynamic plantar aesthesiometry over a time period of 21 days. Semiquantitative histopathological scoring and ELISA measurement of IL-1β concentrations of the tibiotarsal joints were performed.Results
Mechanical hyperalgesia was significantly reduced from day 11 in Tac4−/− and Tacr1−/− animals, while paw swelling was not altered in any strain. Inflammatory histopathological alterations (synovial swelling, leukocyte infiltration, cartilage destruction, bone damage) and IL-1β concentration in the joint homogenates were significantly smaller in Tac4−/− and Tac1−/−/Tac4−/− mice.Conclusions
Hemokinin-1, but not substance P increases inflammation and hyperalgesia in the late phase of adjuvant-induced arthritis. While NK1 receptors mediate its antihyperalgesic actions, the involvement of another receptor in histopathological changes and IL-1β production is suggested. 相似文献53.
54.
55.
Ammons MC Siemsen DW Nelson-Overton LK Quinn MT Gauss KA 《The Journal of biological chemistry》2007,282(24):17941-17952
56.
Cartilage matrix mechanical function is largely determined by interactions between the collagen fibrillar network and the proteoglycan gel. Although the molecular physics of these matrix constituents have been characterized and modern imaging methods are capable of localized measurement of molecular densities and orientation distributions, theoretical tools for using this information for prediction of cartilage mechanical behavior are lacking. We introduce a means to model collagen network contributions to cartilage mechanics based upon accessible microstructural information (fibril density and orientation distributions) and which self-consistently follows changes in microstructural geometry with matrix deformations. The interplay between the molecular physics of the collagen network and the proteoglycan gel is scaled up to determine matrix material properties, with features such as collagen fibril pre-stress in free-swelling cartilage emerging naturally and without introduction of ad hoc parameters. Methods are developed for theoretical treatment of the collagen network as a continuum-like distribution of fibrils, such that mechanical analysis of the network may be simplified by consideration of the spherical harmonic components of functions of the fibril orientation, strain, and stress distributions. Expressions for the collagen network contributions to matrix stress and stiffness tensors are derived, illustrating that only spherical harmonic components of orders 0 and 2 contribute to the stress, while orders 0, 2, and 4 contribute to the stiffness. Depth- and compression-dependent equilibrium mechanical properties of cartilage matrix are modeled, and advantages of the approach are illustrated by exploration of orientation and strain distributions of collagen fibrils in compressed cartilage. Results highlight collagen-proteoglycan interactions, especially for very small physiological strains where experimental data are relatively sparse. These methods for determining matrix mechanical properties from measurable quantities at the microscale (composition, structure, and molecular physics) may be useful for investigating cartilage structure-function relationships relevant to load-bearing, injury, and repair. 相似文献
57.
S. J. Oyler-McCance F. A. Ransler L. K. Berkman T. W. Quinn 《Conservation Genetics》2007,8(6):1339-1353
For management purposes, the range of naturally occurring trumpeter swans (Cygnus buccinator) has been divided into two populations, the Pacific Coast Population (PP) and the Rocky Mountain Population (RMP). Little
is known about the distribution of genetic variation across the species’ range despite increasing pressure to make difficult
management decisions regarding the two populations and flocks within them. To address this issue, we used rapidly evolving
genetic markers (mitochondrial DNA sequence and 17 nuclear microsatellite loci) to elucidate the underlying genetic structure
of the species. Data from both markers revealed a significant difference between the PP and RMP with the Yukon Territory as
a likely area of overlap. Additionally, we found that the two populations have somewhat similar levels of genetic diversity
(PP is slightly higher) suggesting that the PP underwent a population bottleneck similar to a well-documented one in the RMP.
Both genetic structure and diversity results reveal that the Tri-State flock, a suspected unique, non-migratory flock, is
not genetically different from the Canadian flock of the RMP and need not be treated as a unique population from a genetic
standpoint. Finally, trumpeter swans appear to have much lower mitochondrial DNA variability than other waterfowl studied
thus far which may suggest a previous, species-wide bottleneck. 相似文献
58.
Nishikawa K Biewener AA Aerts P Ahn AN Chiel HJ Daley MA Daniel TL Full RJ Hale ME Hedrick TL Lappin AK Nichols TR Quinn RD Satterlie RA Szymik B 《Integrative and comparative biology》2007,47(1):16-54
Neuromechanics seeks to understand how muscles, sense organs,motor pattern generators, and brain interact to produce coordinatedmovement, not only in complex terrain but also when confrontedwith unexpected perturbations. Applications of neuromechanicsinclude ameliorating human health problems (including prosthesisdesign and restoration of movement following brain or spinalcord injury), as well as the design, actuation and control ofmobile robots. In animals, coordinated movement emerges fromthe interplay among descending output from the central nervoussystem, sensory input from body and environment, muscle dynamics,and the emergent dynamics of the whole animal. The inevitablecoupling between neural information processing and the emergentmechanical behavior of animals is a central theme of neuromechanics.Fundamentally, motor control involves a series of transformationsof information, from brain and spinal cord to muscles to body,and back to brain. The control problem revolves around the specifictransfer functions that describe each transformation. The transferfunctions depend on the rules of organization and operationthat determine the dynamic behavior of each subsystem (i.e.,central processing, force generation, emergent dynamics, andsensory processing). In this review, we (1) consider the contributionsof muscles, (2) sensory processing, and (3) central networksto motor control, (4) provide examples to illustrate the interplayamong brain, muscles, sense organs and the environment in thecontrol of movement, and (5) describe advances in both roboticsand neuromechanics that have emerged from application of biologicalprinciples in robotic design. Taken together, these studiesdemonstrate that (1) intrinsic properties of muscle contributeto dynamic stability and control of movement, particularly immediatelyafter perturbations; (2) proprioceptive feedback reinforcesthese intrinsic self-stabilizing properties of muscle; (3) controlsystems must contend with inevitable time delays that can simplifyor complicate control; and (4) like most animals under a varietyof circumstances, some robots use a trial and error processto tune central feedforward control to emergent body dynamics. 相似文献
59.
Previous studies demonstrated that overexpression of the type-1 insulin-like growth factor (IGF) receptor (IGF-1R) in skeletal myogenic cell lines increased proliferation and differentiation responses to IGF. However, it was unclear if such manipulations in primary, untransformed skeletal myogenic cells would result in modulation of these responses, which may be more stringently regulated in primary cells than in myogenic cell lines. In this study, low passage untransformed fetal bovine myogenic cultures were infected with a replication-deficient retroviral expression vector (LISN) coding for the human IGF-1R or with a control retroviral vector (LNL6). Bovine myogenic cultures infected with the LISN vector (Bov-LISN) displayed ten times more IGF-1Rs than controls (Bov-LNL6). Bov-LISN myogenic cultures exhibited elevated rates of IGF-I-stimulated proliferation and increased rates of terminal differentiation which were reduced to control levels by the anti-human IGF-1R antibody αIR3. These findings indicate overexpression of the IGF-1R can enhance IGF sensitivity and thereby modify the proliferation and differentiation behavior of untransformed low passage myoblasts. Such manipulations may be useful to increase muscle mass in clinical or agricultural applications. © 1996 Wiley-Liss, Inc. 相似文献
60.
Susan E. Damon Kathleen L. Haugk Roger S. Birnbaum Lebris S. Quinn 《Journal of cellular physiology》1998,175(1):109-120
Recent studies have indicated that the insulin-like growth factors (IGFs) stimulate skeletal myoblast proliferation and differentiation. However, the question of whether IGFs are required for myoblast differentiation has not been resolved. To address this issue directly, we used a retroviral vector (LBP4SN) to develop a subline of mouse C2 myoblasts (C2-BP4) that constitutively overexpress IGF binding protein-4 (IGFBP-4). A control C2 myoblast subline (C2-LNL6) was also developed by using the LNL6 control retroviral vector. C2-BP4 myoblasts expressed sixfold higher levels of IGFBP-4 protein than C2-LNL6 myoblasts. 125I-IGF-I cross linking indicated that IGFBP-4 overexpression reduced IGF access to the type-1 IGF receptor tenfold. At low plating densities, myoblast proliferation was inhibited, and myoblast differentiation was abolished in C2-BP4 cultures compared with C2-LNL6 cultures. At high plating densities in which nuclear numbers were equal in the two sets of cultures, C2-BP4 myoblast differentiation was inhibited completely. Differentiation was restored in C2-BP4 cells by treatment with high levels of exogenous IGF-I or with des(1–3)IGF-I, an analog of IGF-I with reduced affinity for IGFBPs. These findings confirm the hypothesis that positive differentiation signals from the IGFs are necessary for C2 myoblast differentiation, and they suggest that the present model of myogenic differentiation, which involves only negative external control of differentiation by mitogens, may be incomplete. J. Cell. Physiol. 175:109–120, 1998. © 1998 Wiley-Liss, Inc. 相似文献