这项研究部分由康涅狄格大学研究咨询委员会学院资助，该学院向鲁贝加大学提供大笔资助。K. 布尔吉奥在国家科学基金会NRT-IGE赠款#1545458支持M.鲁贝加。两位匿名评论者的深思熟虑的反馈大大改善了手稿。

这项工作不涉及任何活体动物的工作，因此不受动物护理审查。
1. 设置和材料（图1）
<ol><li>如果没有感兴趣的物种的扁平皮肤，请使用 Spaw 的协议29 从新鲜或冷冻标本中创建皮肤。将羽毛放入整齐、自然的位置，干燥，以便在进行测量之前获得恒定的重量。</li>
	<li>设置恒温热水浴池。 注意:这个设置相当高，所以它是最容易把热水浴在地板上。</li>
	<li>将一块透明丙烯酸玻璃（材料表）放在恒温热水浴的表面。玻璃允许热量传输到皮肤的底面，而不会弄湿标本。 注:本试验研究使用了一块丙烯酸玻璃（厚度0.125）。玻璃的厚度不会影响材料的发射率30（ 始终为 0.86），但会影响玻璃表面的绝对温度（即， 较厚的玻璃会导致较低的温度）。因此，所有测量都应使用厚度相同的丙烯酸玻璃片进行。</li>
	<li>将一块泡沫芯板（1 厚）放在丙烯酸玻璃上，在丙烯酸玻璃上放置一个圆形孔（直径 0.5）。 注:鸟的大小应引导孔的大小，因此不间断的羽毛接收热量从源头的大小。在这里，使用了一个直径为0.5的孔，因为这个大小足够大，足以实现足够的热量传输到标本，同时仍然足够小，以集中乳房羽毛带下的热量（所有鸟类除最小的鸟）。无论热开口大小如何，要为每只鸟获得可比和可复制的价值，请务必用相同大小的孔进行测量。</li>
	<li>将热像仪连接到摄像机最小对焦距离设置正上方的三脚架上。 注:这里使用FLIR SC655热像仪（680 px x 480 px 分辨率，±2 °C 或±2% 的读取精度，40 厘米的最小对焦距离）。其他摄像机的分辨率可能不同。</li>
	<li>通过将以下信息输入热像仪软件来校准摄像机:<ol>
<li>通过在泡沫上放置铝箔（朝上闪亮的一侧），在相机校准软件中将发射值设置为 1.0 来查找反射温度。拍摄热图像。铝箔表面的温度是反射温度，应与房间的环境温度相似。</li>
		<li>将发射值31 到 0.95 设置为 0.95。 注:1） 放射性是物体发射32 的相对热量，范围从 0 到 1。具有高发射值的物体会释放出大量的热量，而具有低发射值的物体会散射少量热量。此值表示羽毛的放电性。2） 此值 （0.95） 存在争议。科辛斯和鲍尔声称羽毛的放射值在0.90-0.95之间，但没有包括任何证据31。哈梅尔报告的价值为0.98，但他从冷冻标本中获得了这个值，所以它可能不准确33。尽管缺乏证据，但0.95发射率是热像文献中最常用的价值（科辛斯和鲍尔斯31证明了这一点）。</li>
		<li>确保房间的环境温度和湿度保持不变。这些值应在每次测量和更新相机校准软件之前进行测量。所有室内房间的温度和湿度都会有一定波动，因此在软件中记录这些值并更新这些值可减少测量误差。 注:这里，使用FLIR研究最大软件。此软件不会为所有图像保存数据，因此记录每个图像的所有这些值至关重要。</li>
	</ol>
</li>
</ol>2. 测量性能
<ol><li>将恒温热水浴设定为目标温度（40 °C 是大多数路人鸟类平均内部核心温度的代理）34。 注意:如果与休息核心温度较高（如蜂鸟34）或更低（如企鹅34或鼠34，35）的物种合作，则可能适合相应地调整热水浴。图3显示了热水浴的温度与丙烯酸玻璃表面温度之间的关系（例如，平底皮肤暴露在热源的实际温度）。<ol>
<li>从该协议中获得的结果（见 图5）表明，获得一系列温度的测量结果也有助于了解热性能差异。要实现此目的，请使用 30+55 °C 的 5 °C 增量遵循协议。</li>
	</ol></li>
	<li>在热像仪软件中，在散热的泡沫孔上画一个圆圈/椭圆。这使得在将皮肤放在泡沫上时能够可视化此区域，以确保测量平底皮肤上的正确区域。</li>
	<li>将扁平皮肤标本放在泡沫上，在孔上放置感兴趣的区域。 注:在这里，测量每只鸟的腹部区域，因为它不受身体的其他部位，如翅膀的阻碍，并位于中心位置足以不受到边缘的影响。皮肤在热孔上的位置会因实验问题而异。一般来说，建议将位置直接放置在羽毛道上，并尽可能远离皮肤边缘。放置皮肤时，请确保不要使羽毛变平或紊乱。如有必要，在放置皮肤后将其置于自然位置。</li>
	<li>等待 15 分钟，让皮肤适应热源。如果测量太早，羽毛大衣表面的温度值将太低。在这里，通过皮肤和羽毛的温度传输稳定在15分钟，所以等待超过15分钟不会产生人为的高结果。</li>
	<li>拍摄扁平皮肤的热图像。<ol>
<li>在拍摄热图像之前，将发射值设置为31 到 0.95。</li>
	</ol></li>
	<li>从泡沫中取出皮肤，并立即拍摄未在泡沫上平底皮肤的设置的热图像。这量化了丙烯酸玻璃表面的温度，并校准了热源区域与平底皮肤上的测量区域。<ol>
<li>在这里，使用的30 丙烯酸玻璃的放电性是0.86。在拍摄没有皮肤的照片之前，请务必在热像仪软件中记录这一点。 注:热水浴所显示的温度不一定是丙烯酸玻璃表面的温度（图3），因为它的热传导并不完美。使用玻璃的温度可以减少估计皮肤底面温度的错误，因此可以综合估计皮肤和羽毛会损失多少热量。</li>
	</ol></li>
	<li>将皮肤放回泡沫上，置于同一位置。重复步骤 2.502.6 共五次试验。<ol>
<li>要正确放置标本皮肤，请用一根指尖轻轻触摸目标测量区域的羽毛，然后取下手指并查看热图像。手指的剩余热量将在热图像上短暂可见。检查以确保采样区域位于软件中绘制的可见圆圈内，该圆圈表示热水浴中通过皮肤辐射的热量区域。如果不是，移动皮肤，直到它是。这个过程在 图2中得到了说明。 注:虽然新鲜皮肤（如果可用）可能更密切地代表活鸟皮肤的自然热性能，但这些测量使用干燥的皮肤可以在更大的标本池上产生可比的可重复结果。因此，所有测量都应使用干燥到恒定的重量的皮肤进行，或者使用标本的新鲜和干燥皮肤进行测量。</li>
	</ol></li>
</ol>3. 热图像数据收集
<ol><li>每个测量包括两个热图像:一个平底皮肤和一个丙烯酸玻璃。首先，打开丙烯酸玻璃的图像。将软件中绘制的圆圈与图像中可见的泡沫中的孔对齐。记录圆的中心温度值。 注意:有关从热图像中提取数据的更多详细信息，请参阅高级等人。<ol>
<li>确保校准具有正确值的相机。在记录温度值之前，将发射率设置为30 到 0.86，并设置环境温度和湿度以匹配实验室中的当前条件。</li>
	</ol>
</li>
	<li>打开平底皮肤的热图像。无需移动圆，即可记录圆中心的温度值。 注:由于圆圈未记录在图像中，因此必须校准圆圈的位置，并校准第 2.6 节中丙烯酸玻璃的图像。<ol>
<li>确保校准具有正确值的相机。将发射率31 到 0.95 设置，并确保在记录温度值之前，将环境温度和湿度设置为实验室中的当前条件。</li>
	</ol>
</li>
	<li>对于所有标本的所有测量，重复步骤 3.1-3.2。</li>
</ol>4. 热性能计算
<ol><li>从丙烯酸玻璃的温度中减去羽毛涂层表面的温度。此值表示羽毛涂层保留的热量。</li>
</ol>

<ol>
	<li>Morris, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Feather+Postures+of+Birds+and+the+Problem+of+the+Origin+of+Social+Signals.">The Feather Postures of Birds and the Problem of the Origin of Social Signals.</a> Behaviour. 9, 75-111 (1956).</li><li>Wetmore, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> A Study of the Body Temperature of Birds. Smithsonian Miscellaneous Collections. 72 (12), (1921).</li><li>Hart, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seasonal+Acclimatization+in+Four+Species+of+Small+Wild+Birds.">Seasonal Acclimatization in Four Species of Small Wild Birds.</a> Physiological Zoology. 35 (3), 224-236 (1962).</li><li>Veghte, J. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermal+and+Metabolic+Responses+of+the+Gray+Jay+to+Cold+Stress.">Thermal and Metabolic Responses of the Gray Jay to Cold Stress.</a> Physiological Zoology. 37 (3), 316-328 (1964).</li><li>Brush, A. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Energetics,+Temperature+Regulation+and+Circulation+in+Resting,+Active+and+Defeathered+California+Quail,+Lophortyx+californicus.">Energetics, Temperature Regulation and Circulation in Resting, Active and Defeathered California Quail, Lophortyx californicus.</a> Comparative Biochemistry and Physiology. 15, 399-421 (1965).</li><li>Dawson, W. R., Carey, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seasonal+Acclimatization+to+Temperature+in+Cardueline+Finches.">Seasonal Acclimatization to Temperature in Cardueline Finches.</a> Journal of Comparative Physiology. 112, 317-333 (1976).</li><li>Cooper, S. J., Swanson, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seasonal+Acclimatization+of+Thermoregulation+in+The+Black-Capped+Chickadee.">Seasonal Acclimatization of Thermoregulation in The Black-Capped Chickadee.</a> The Condor. 96, 638-646 (1994).</li><li>Bush, N. G., Brown, M., Downs, C. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seasonal+Effects+on+Thermoregulatory+Responses+of+the+Rock+Kestrel,+Falco+rupicolis.">Seasonal Effects on Thermoregulatory Responses of the Rock Kestrel, Falco rupicolis.</a> Journal of Thermal Biology. 33, 404-412 (2008).</li><li>Nzama, S. N., Downs, C. T., Brown, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seasonal+Variation+in+the+Metabolism-Temperature+Relation+of+House+Sparrows+(Passer+domesticus)+in+KwaZulu-Natal,+South+Africa.">Seasonal Variation in the Metabolism-Temperature Relation of House Sparrows (Passer domesticus) in KwaZulu-Natal, South Africa.</a> Journal of Thermal Biology. 35, 100-104 (2010).</li><li>Noakes, M. J., Wolf, B. O., McKechnie, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seasonal+Metabolic+Acclimatization+Varies+in+Direction+and+Magnitude+among+Populations+of+an+Afrotropical+Passerine+Bird.">Seasonal Metabolic Acclimatization Varies in Direction and Magnitude among Populations of an Afrotropical Passerine Bird.</a> Physiological and Biochemical Zoology. 90 (2), 178-189 (2016).</li><li>Taylor, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermal+insulation+of+the+down+and+feathers+of+pygoscelid+penguin+chicks+and+the+unique+properties+of+penguin+feathers.">Thermal insulation of the down and feathers of pygoscelid penguin chicks and the unique properties of penguin feathers.</a> The Auk. 103 (1), 160-168 (1986).</li><li>Ward, J. M., Houston, D. C., Ruxton, G. D., McCafferty, D. J., Cook, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermal+resistance+of+chicken+(Gallus+domesticus)+plumage:+a+comparison+between+broiler+and+free-range+birds.">Thermal resistance of chicken (Gallus domesticus) plumage: a comparison between broiler and free-range birds.</a> British poultry science. 42 (5), 558-563 (2001).</li><li>Ward, J. M., Ruxton, G. D., Houston, D. C., McCafferty, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermal+consequences+of+turning+white+in+winter:+a+comparative+study+of+red+grouse+Lagopus+lagopus+scoticus+and+Scandinavian+willow+grouse+L.+l.+lagopus.">Thermal consequences of turning white in winter: a comparative study of red grouse Lagopus lagopus scoticus and Scandinavian willow grouse L. l. lagopus.</a> Wildlife Biology. 13 (2), 120-130 (2007).</li><li>Lucas, A. M., Stettenheim, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Avian Anatomy: Integument. , (1972).</li><li>Osv&#225;th, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+feathered+are+birds?+Environment+predicts+both+mass+and+density+of+body+feathers.">How feathered are birds? Environment predicts both mass and density of body feathers.</a> Functional Ecology. 32, 701-712 (2018).</li><li>Pap, P. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+phylogenetic+comparative+analysis+reveals+correlations+between+body+feather+structure+and+habitat.">A phylogenetic comparative analysis reveals correlations between body feather structure and habitat.</a> Functional Ecology. 31 (6), 1241-1251 (2017).</li><li>Caccamise, D. F., Weathers, W. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Winter+Nest+Microclimate+of+Monk+Parakeets.">Winter Nest Microclimate of Monk Parakeets.</a> The Wilson Bulletin. 89 (2), 346-349 (1977).</li><li>Broggi, J., Gamero, A., Hohtola, E., Orell, M., Nilsson, J. &. #. 1. 9. 7. ;. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interpopulation+variation+in+contour+feather+structure+is+environmentally+determined+in+great+tits.">Interpopulation variation in contour feather structure is environmentally determined in great tits.</a> PLoS ONE. 6 (9), 24942 (2011).</li><li>Howell, S. N. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Molt in North American Birds. , (2010).</li><li>Willoughby, E. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Unusual+Sequence+of+Molts+and+Plumages+in+Cassin's+and+Bachman's+Sparrows.">An Unusual Sequence of Molts and Plumages in Cassin's and Bachman's Sparrows.</a> The Condor. 88 (4), 461-472 (1986).</li><li>Wetmore, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Number+of+Contour+Feathers+in+Passeriform+and+Related+Birds.">The Number of Contour Feathers in Passeriform and Related Birds.</a> Auk. 53, 159-169 (1936).</li><li>Staebler, A. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Number+of+Contour+Feathers+in+the+English+Sparrow.">Number of Contour Feathers in the English Sparrow.</a> The Wilson Bulletin. 53 (2), 126-127 (1941).</li><li>Barnett, L. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seasonal+Changes+in+Temperature+Acclimatization+of+the+House+Sparrow,+Passer+domesticus.">Seasonal Changes in Temperature Acclimatization of the House Sparrow, Passer domesticus.</a> Comparative Biochemistry and Physiology. 33, 559-578 (1970).</li><li>Middleton, A. L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seasonal+Changes+in+Plumage+Structure+and+Body+Composition+of+the+American+Goldfinch,+Carduelis+tristis.">Seasonal Changes in Plumage Structure and Body Composition of the American Goldfinch, Carduelis tristis.</a> The Canadian Field-Naturalist. 100 (4), 545-549 (1986).</li><li>Lei, F. M., Qu, Y. H., Gan, Y. L., Gebauer, A., Kaiser, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+feather+microstructure+of+Passerine+sparrows+in+China.">The feather microstructure of Passerine sparrows in China.</a> Journal f&#252;r Ornithologie. 143 (2), 205-213 (2002).</li><li>D'alba, L., Carlsen, T. H., &#193;sgeirsson, &. #. 1. 9. 3. ;., Shawkey, M. D., J&#243;nsson, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Contributions+of+feather+microstructure+to+eider+down+insulation+properties.">Contributions of feather microstructure to eider down insulation properties.</a> Journal of Avian Biology. 48 (8), 1150-1157 (2017).</li><li>Gilbert, C., Robertson, G., Le Maho, Y., Naito, Y., Ancel, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Huddling+behavior+in+emperor+penguins:+dynamics+of+huddling.">Huddling behavior in emperor penguins: dynamics of huddling.</a> Physiology &amp; Behavior. 88, 479-488 (2006).</li><li>Kvadsheim, P. H., Folkow, L. P., Blix, A. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+device+for+measurement+of+the+thermal+conductivity+of+fur+and+blubber.">A new device for measurement of the thermal conductivity of fur and blubber.</a> Journal of thermal Biology. 19 (6), 431-435 (1994).</li><li>Spaw, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Combination Specimens a la Burke Museum. , 21-28 (1989).</li><li>Infrared Emissivity Table. ThermoWorks Available from: <a target="_blank" href="https://www.thermoworks.com/emissivity_table">https://www.thermoworks.com/emissivity_table</a> (2019)</li><li>Cossins, A. R., Bowler, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Temperature Biology of Animals. , (1987).</li><li>Hammel, H. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Infrared+Emissivities+of+Some+Arctic+Fauna.">Infrared Emissivities of Some Arctic Fauna.</a> Journal of Mammalogy. 37 (3), 375-378 (1956).</li><li>McNab, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Analysis+of+the+Body+Temperatures+of+Birds.">An Analysis of the Body Temperatures of Birds.</a> The Condor. 68 (1), 47-55 (1966).</li><li>Crawford, E. C., Lasiewski, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Oxygen+Consumption+and+Respiratory+Evaporation+of+the+Emu+and+Rhea.">Oxygen Consumption and Respiratory Evaporation of the Emu and Rhea.</a> The Condor. 70, 333-339 (1968).</li><li>Senior, R. A., Hill, J. K., Edwards, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ThermStats:+An+R+Package+for+Quantifying+Surface+Thermal+Heterogeneity+in+Assessments+of+Microclimates.">ThermStats: An R Package for Quantifying Surface Thermal Heterogeneity in Assessments of Microclimates.</a> Methods in Ecology and Evolution. 10, 1606-1614 (2019).</li><li>. FLIR Systems, Inc Available from: <a target="_blank" href="https://www.flir.com">https://www.flir.com</a> (2019)</li><li>McCafferty, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Applications+of+thermal+imaging+in+avian+science.">Applications of thermal imaging in avian science.</a> Ibis. 155 (1), 4-15 (2013).</li><li>Boonstra, R., Eadie, J. M., Krebs, C. J., Boutin, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Limitations+of+Far+Infrared+Thermal+Imaging+in+Locating+Birds.">Limitations of Far Infrared Thermal Imaging in Locating Birds.</a> Journal of Field Ornithology. 66 (2), 192-198 (1955).</li><li>Rodbard, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Weight+and+Body+Temperature.">Weight and Body Temperature.</a> Science. 111 (2887), 465-466 (1950).</li></ol>

作者没有什么可透露的。

本文为可重复、标准化的鸟类平底皮肤标本热成像测量提供了协议。这种方法使得比较羽毛大衣在物种之间、物种内部、可比个体之间以及个体身体的不同位置之间的热性能，所有这些都无需破坏标本。
必要材料和设备的提供可能是这种方法的局限性。虽然热像仪正迅速变得更加容易获得和负担得起，研究级热像仪仍然花费数万美元37。然而，热像仪可用于...

羽毛是鸟类的决定性特征，具有多种功能，其中最关键的是绝缘1。鸟类的平均核心温度是任何脊椎动物群中最高的，而羽毛使它们免受环境温度变化的隔热是能量平衡的重要组成部分，尤其是在寒冷的环境中。尽管羽毛很重要，但大多数关于鸟类热条件变化的文献都集中在对温度变化的代谢反应上，而不是羽毛作为绝缘体的功能，如绝缘3、4、5、6、7、8、9、10（详情请参阅Ward等人）。11，12，13。然而，羽毛本身可能因时间、个体和物种而异。
此处介绍的方法可用于仅量化羽毛大衣的整体热值。它消除活鸟的混淆因素，如行为热调节1 和不同数量的绝缘脂肪。更广泛地测量羽毛大衣的热性能是必要的，以提高对羽毛如何促进绝缘的理解，以及在整个鸟类的生命历史和年度周期中，这些物种之间和物种内部是如何变化的。
羽毛通过在皮肤和羽毛之间以及羽毛内部捕获空气来隔离鸟类，它们为热量损失创造了物理屏障。羽毛由中央羽毛轴组成，称为拉奇，投影称为 barbs14。巴布是小，二次投影的酒吧，与相邻的酒吧联锁在一起，"拉链"羽毛，并给它的结构。此外，羽绒羽毛缺乏中央拉奇，几乎没有巴布，因此在皮肤上形成松散的，绝缘的巴布质量14。羽毛大衣因物种15、16、17、18和可比个体2、19、20、21、22、23、24而异。然而，关于羽毛数量的变化、鸟类上不同种类羽毛的相对丰度或刺/栏杆数量的变化如何影响羽毛大衣的整体热性能，几乎没有定量信息。先前的研究重点是确定特定物种11、12、13的绝缘和导热的单一平均值。
众所周知，羽毛大衣因物种而异。例如，大多数鸟类的皮肤区域各不一，羽毛从这些区域生长，或不长出，分别称为斑马和紫杉。pterylae（有时称为"羽毛带"）的位置因物种而异，并具有一定的分类特征14的价值。然而，一些鸟类（即老鼠和企鹅）已经失去了这种腺病，并有一个统一分布的羽毛在整个身体14。此外，不同的物种，特别是那些居住在不同环境，有不同的比例的羽毛类型15。例如，生活在较冷气候中的鸟类比生活在温暖环境中的物种拥有更多的羽绒羽毛15和轮廓羽毛，其羽毛的羽状部分大于16。
某些类型的羽毛的微观结构也可能对25、26物种的绝缘产生影响。雷等人比较了许多中国路人麻雀轮廓羽毛的微观结构，发现栖息在较冷环境中的物种在每个轮廓羽毛中羽状棒的比例较高，球状体较长，节点密度较高，节点较大，比居住在温暖环境中的物种多。D'alba等人比较了普通羽毛（索马特里亚·莫利西玛）和灰鹅（安瑟安瑟）羽绒羽毛的微观结构，并描述了这些差异如何影响羽毛的凝聚力和羽毛捕获空气的能力。关于羽毛变化如何影响不同物种羽毛涂层整体热性能的定量比较数据有限（有关更多详细信息，请参阅泰勒和沃德等人）。11，13.
在一个物种中，羽毛大衣的热性能可能会有所不同。有些物种，如僧鹦鹉（米约普西塔莫纳丘斯）17，栖息在非常大和多样化的地理范围。这些不同环境造成的不同热应力可能会影响区域内鸟类的羽毛外衣，但目前没有关于这一主题的数据。此外，布罗吉等人比较了北半球的两个大山雀（帕鲁斯主要L.）种群。他们表明，北方人口较多的轮廓羽毛比南方人口更密集，但更短，比例更小。然而，当两种种群的鸟类在同一地点饲养时，这些差异消失了。
此外，Broggi等人将这些发现解释为对不同热条件的塑料反应，但他们没有测量这些不同羽绒大衣的绝缘值。研究结果还表明，轮廓羽毛密度比轮廓羽毛中羽毛中羽毛的比例更重要，但布罗吉等人认为，北方种群可能因缺乏足够的营养而无法产生最佳的羽毛。对这些羽绒服整体热性能的定量测量将进一步理解羽毛差异的重要性。
随着时间的推移，个别鸟类的羽毛外衣会有所不同。每年至少一次，所有的鸟都会剥落（替换所有的羽毛）19。随着一年的流逝，羽毛变得磨损2，20和少无数18，21，22，23。有些鸟每年的毛绒不止一次，每年给它们多件不同的羽毛大衣19件。米德尔顿显示，美国金雀（脊柱三叶草），每年软糖两次，有较高的羽毛数量和羽绒羽毛的比例，在他们的基本羽毛在冬季几个月比他们在夏季的替代羽毛24。羽毛大衣的这些年度差异可能使鸟类在寒冷时期被动地保存更多的热量，或在温暖的季节被动地散发更多的热量，但是没有研究能最终证明这一点。
虽然鸟类在行为上调节行为1，27，并可以适应不同的热条件3，4，5，6，7，8，9，10，26，羽毛发挥重要的作用，在热调节提供恒定的绝缘层。这里描述的方法旨在通过隔离羽毛来回答有关羽毛涂层及其在被动热调节中的作用的问题（即活鸟在不改变其行为或新陈代谢的情况下保留多少热量？虽然主动和生理热调节在生态上很重要，但了解羽毛本身如何帮助绝缘以及它们如何影响主动行为和生理温度调节的需求也很重要。
先前的研究已经建立了量化动物皮毛11、12、13、28的导热性和保温方法。这里介绍的方法是"保护热板"方法11，12，13，28的扩展。但是，此处描述的方法使用热像仪而不是热电偶测量羽毛涂层外边界的温度。防护热板方法对通过皮毛的能量流动给出了非常精确的估计，但它需要构建一个多材料热板，对热电偶和热电瓶的使用有所熟悉，并且必须切成小块的毛皮的破坏性使用。然后对这些部件进行润滑，以消除样品和热板设备之间的空气。除了少数缺乏阿普特里亚（例如企鹅）的鸟类外，从鸟皮上切出小方块对于比较而言是有问题的，因为切口的位置对实际附着在（和过度）皮肤上的羽毛数量有很大影响。这个问题因ptyerlae14的存在、大小和位置的差异而加剧。
此外，虽然博物馆标本可能是评估鸟类绝缘变化的潜在丰富资源，但一般来说，在科学收藏中，切割和润滑皮肤标本的许可是无法实现的。此外，从野外采集的用于保护热板测量的标本随后不能用作博物馆标本。这里介绍的方法不同于保护热板方法，因为它可以与整个干燥的鸟皮一起使用，无需 1） 要求销毁标本，2） 润滑皮肤底面。它使用热像仪，这是越来越实惠（虽然仍然相对昂贵），精确，并用于活鸟测量热关系。
这种方法不会像保护热板方法那样直接测量通过皮肤和羽毛的能量流（因此热电导率或绝缘值）。相反，它使用热像仪测量羽毛大衣外边界的温度。由此产生的值表示通过皮肤、羽毛和空气被动地损失的热量的综合测量（与下面的热源相比）。标本作为扁平皮肤准备，并使用上述技术测量，可以存储在收藏品中，并无限期地为未来的研究提供价值。这种方法提供了一种标准化、可比性和相对简单的方法来测量任何平皮标本中的羽绒外衣热性能，这在特定的相互比较和内部比较中特别有用。

<table>
	<tbody>
		<tr>
			<td>Aluminum Foil</td>
			<td>Reynolds Wrap</td>
			<td>109000831</td>
			<td>30 square ft.; this exact model need not be used.</td>
		</tr>
		<tr>
			<td>Foam Core Board</td>
			<td>Foamular</td>
			<td>20WE</td>
			<td>1 in. x 4 ft. x 8 ft; this exact model need no be used.</td>
		</tr>
		<tr>
			<td>General Purpose Water Bath</td>
			<td>PolyScience</td>
			<td>WB02</td>
			<td>Ambiet +5 &#176;C to 100 &#176;C; &#177;.01 &#176;C</td>
		</tr>
		<tr>
			<td>PDF Data logger</td>
			<td>Elitech</td>
			<td>RC-51H</td>
			<td>Built in temperature and humidity sensor</td>
		</tr>
		<tr>
			<td>Plexiglass</td>
			<td>AdirOffice</td>
			<td>1212-3-C</td>
			<td>Acrylic glass; 12 in. x 12 in. x 1/8 in.; this exact model need not be used.</td>
		</tr>
		<tr>
			<td>Thermal Image Analysis Software</td>
			<td>FLIR</td>
			<td>ResearchIR Max v4.40.7.26 (64-bit)</td>
			<td>Allows collection of precise, quantitative thermal data</td>
		</tr>
		<tr>
			<td>Thermal Imaging Camera</td>
			<td>FLIR</td>
			<td>SC655</td>
			<td>680x480-pixel resolution, &#177;2 &#176;C or &#177;2% accuracy, 40 cm minimum focusing distance</td>
		</tr>
		<tr>
			<td>Tripod</td>
			<td>The Audubon Shop</td>
			<td>The Birder Tripod with Manfrotto 700RC2 Rapid Release Head</td>
			<td>65&#34; maximum height; this exact model need not be used.</td>
		</tr>
	</tbody>
</table>

using a thermal camera to measure heat loss through bird feather coats

羽毛对鸟类的绝缘至关重要，因此对热调节的成本也至关重要。关于各种生态环境下鸟类热调节的能量成本，有丰富的文献。然而，很少有研究将羽毛单独描述为热调节。先前的几项研究已经建立了测量动物毛皮绝缘值的方法，但它们需要破坏性的取样方法，这对鸟类来说是个问题，因为鸟类的羽毛在皮肤上分布不均匀。需要更多信息，包括1）羽毛对热调节的贡献在物种之间和物种内部的变化，2）羽毛大衣在空间和时间上的变化。这里报道的是一种使用干燥的全皮肤标本快速直接测量羽毛大衣和皮肤的热性能的方法，无需破坏皮肤标本。这种方法分离和测量羽毛涂层的热梯度的方式，测量热损失和代谢成本的活鸟，使用行为和生理策略来热调节，不能。该方法采用热像仪，可快速收集定量热数据，通过皮肤测量来自稳定来源的热损失。此协议可以很容易地应用于各种研究问题，适用于任何鸟类分类，并且不需要破坏皮肤标本。最后，它将通过简化和加速收集定量数据，进一步理解被动热调节在鸟类中的重要性。

图 4 和 图5中介绍了在6个温度下测量的5个物种中每个物种中一个个体的代表性结果。这些结果表明，皮肤位置的微小变化可能导致高达 1.7 °C 的读数变化。 图 4 显示了对调查员的培训如何提高测量的可重复性。例如，同一个单个家麻雀（路人家居）被一个缺乏经验的调查员在一个目标温度下测量了五次（?...

Watch this Scientific Journal Video about Using a Thermal Camera to Measure Heat Loss Through Bird Feather Coats at JoVE.com

Using a Thermal Camera to Measure Heat Loss Through Bird Feather Coats

该协议描述了通过平底鸟类标本使用热像仪和热水浴进行热传播的量化。该方法允许使用干平皮标本获取有关羽毛大衣跨物种热性能的定量比较数据。

使用热像仪测量通过鸟羽毛大衣的热损失

Feathers are essential to insulation, and therefore to the cost of thermoregulation,&#160;in birds. There is robust literature on the energetic cost of ...

using-a-thermal-camera-to-measure-heat-loss-through-bird-feather-coats

Research

JoVE Journal

Biology

3.4K 次观看.  University of Connecticut. 该协议描述了通过平底鸟类标本使用热像仪和热水浴进行热传播的量化。该方法允许使用干平皮标本获取有关羽毛大衣跨物种热性能的定量比较数据。

视频: Using a Thermal Camera to Measure Heat Loss Through Bird Feather Coats

Transformation of Plasmid DNA into E. coli Using the Heat Shock Method

Transformation of plasmid DNA into E. coli using the heat shock method is a basic technique of molecular biology. It consists of inserting a foreign plasmid or ligation product into bacteria. This video protocol describes the traditional method of transformation using commercially available chemically competent bacteria from Genlantis. After a short incubation in ice, a mixture of chemically competent bacteria and DNA is placed at 42&deg;C for 45 seconds (heat shock) and then placed back in ice. SOC media is added and the transformed cells are incubated at 37&deg;C for 30 min with agitation. To be assured of isolating colonies irrespective of transformation efficiency, two quantities of transformed bacteria are plated. This traditional protocol can be used successfully to transform most commercially available competent bacteria. The turbocells from Genlantis can also be used in a novel 3-minute transformation protocol, described in the instruction manual.

热休克法转化到大肠杆菌质粒DNA

Transformation of plasmid DNA into E. coli using the heat shock method is a basic technique of molecular biology. It consists of inserting a foreign ...

科研

生物学

A Behavioral Assay to Measure Responsiveness of Zebrafish to Changes in Light Intensities 

The optokinetic reflex (OKR) is a basic visual reflex exhibited by most vertebrates and plays an important role in stabilizing the eye relative to the visual scene. However, the OKR requires that an animal detect moving stripes and it is possible that fish that fail to exhibit an OKR may not be completely blind. One zebrafish mutant, the no optokinetic response c (nrc) has no OKR under any light conditions tested and was reported to be completely blind. Previously, we have shown that OFF-ganglion cell activity can be recorded in these mutants. To determine whether mutant fish with no OKR such as the nrc mutant can detect simple light increments and decrements we developed the visual motor behavioral assay (VMR). In this assay, single zebrafish larvae are placed in each well of a 96-well plate allowing the simultaneous monitoring of larvae using an automated video-tracking system. The locomotor responses of each larva to 30 minutes light ON and 30 minutes light OFF were recorded and quantified. WT fish have a brief spike of motor activity upon lights ON, known as the startle response, followed by return to lower-than baseline activity, called a freeze. WT fish also sharply increase their locomotor activity immediately following lights OFF and only gradually (over several minutes) return to baseline locomotor activity. The nrc mutants respond similarly to light OFF as WT fish, but exhibit a slight reduction in their average activity as compared to WT fish. Motor activity in response to light ON in nrc mutants is delayed and sluggish. There is a slow rise time of the nrc mutant response to light ON as compared to WT light ON response. The results indicate that nrc fish are not completely blind. Because teleosts can detect light through non-retinal tissues, we confirmed that the immediate behavioral responses to light-intensity changes require intact eyes by using the chokh (chk) mutants, which completely lack eyes from the earliest stages of development. In our VMR assay, the chk mutants exhibit no startle response to either light ON or OFF, showing that the lateral eyes mediate this behavior. The VMR assay described here complements the well-established OKR assay, which does not test the ability of zebrafish larvae to respond to changes in light intensities. Additionally, the automation of the VMR assay lends itself to high-throughput screening for defects in light-intensity driven visual responses.

A Behavioral Assay to Measure Responsiveness of Zebrafish to Changes in Light Intensities

We developed the Visual-Motor Response to quantitate the motor output of larval zebrafish in response to light increments and decrements. We also examined zebrafish vision mutants, including the no optokinetic response (nrc) mutants, which were thought to be completely blind when tested by another vision assay, the optokinetic reflex.

斑马鱼的响应行为的检测，以测量光强的变化

The optokinetic reflex (OKR) is a basic visual reflex exhibited by most vertebrates and plays an important role in stabilizing the eye relative to the ...

Rapid PCR Thermocycling using Microscale Thermal Convection

Many molecular biology assays depend in some way on the polymerase chain reaction (PCR) to amplify an initially dilute target DNA sample to a detectable concentration level. But the design of conventional PCR thermocycling hardware, predominantly based on massive metal heating blocks whose temperature is regulated by thermoelectric heaters, severely limits the achievable reaction speed1. Considerable electrical power is also required to repeatedly heat and cool the reagent mixture, limiting the ability to deploy these instruments in a portable format.
Thermal convection has emerged as a promising alternative thermocycling approach that has the potential to overcome these limitations2-9. Convective flows are an everyday occurrence in a diverse array of settings ranging from the Earth's atmosphere, oceans, and interior, to decorative and colorful lava lamps. Fluid motion is initiated in the same way in each case: a buoyancy driven instability arises when a confined volume of fluid is subjected to a spatial temperature gradient. These same phenomena offer an attractive way to perform PCR thermocycling. By applying a static temperature gradient across an appropriately designed reactor geometry, a continuous circulatory flow can be established that will repeatedly transport PCR reagents through temperature zones associated with the denaturing, annealing, and extension stages of the reaction (Figure 1). Thermocycling can therefore be actuated in a pseudo-isothermal manner by simply holding two opposing surfaces at fixed temperatures, completely eliminating the need to repeatedly heat and cool the instrument.
One of the main challenges facing design of convective thermocyclers is the need to precisely control the spatial velocity and temperature distributions within the reactor to ensure that the reagents sequentially occupy the correct temperature zones for a sufficient period of time10,11. Here we describe results of our efforts to probe the full 3-D velocity and temperature distributions in microscale convective thermocyclers12. Unexpectedly, we have discovered a subset of complex flow trajectories that are highly favorable for PCR due to a synergistic combination of (1) continuous exchange among flow paths that provides an enhanced opportunity for reagents to sample the full range of optimal temperature profiles, and (2) increased time spent within the extension temperature zone the rate limiting step of PCR. Extremely rapid DNA amplification times (under 10 min) are achievable in reactors designed to generate these flows.

We describe a novel method to perform DNA replication via the polymerase chain reaction (PCR). Thermal convection is harnessed to continuously shuttle reagents between denaturing, annealing, and extension conditions by maintaining opposing surfaces of the reactor at constant temperature. This inherently simple design promises to make rapid PCR more accessible.

快速PCR热循环利用微型热对流

Many molecular biology assays depend in some way on the polymerase chain reaction (PCR) to amplify an initially dilute target DNA sample to a detectable ...

Preparation of Quality Inositol Pyrophosphates

Myo-inositol is present in nature either unmodified or in more complex phosphorylated derivates. Of the latest, the two most abundant in eukaryotic cells are inositol pentakisphosphate (IP5) and inositol hexakisphosphate (phytic acid or IP6). IP5 and IP6 are the precursors of inositol pyrophosphate molecules that contain one or more pyrophosphate bonds1. Phosphorylation of IP6 generates diphoshoinositolpentakisphosphate (IP7 or PP-IP5) and bisdiphoshoinositoltetrakisphosphate (IP8 or (PP)2-IP4). Inositol pyrophosphates have been isolated from all eukaryotic organisms so far studied. In addition, the two distinct classes of enzymes responsible for inositol pyrophosphate synthesis are highly conserved throughout evolution2-4.
The IP6 kinases (IP6Ks) posses an enormous catalytic flexibility, converting IP5 and IP6 to PP-IP4 and IP7 respectively and subsequently, by using these products as substrates, promote the generation of more complex molecules5,6. Recently, a second class of pyrophosphate generating enzymes was identified in the form of the yeast protein VIP1 (also referred as PP-IP5K), which is able to convert IP6 to IP7 and IP87,8.
Inositol pyrophosphates regulate many disparate cellular processes such as insulin secretion9, telomere length10,11, chemotaxis12, vesicular trafficking13, phosphate homeostasis14 and HIV-1 gag release15. Two mechanisms of actions have been proposed for this class of molecules. They can affect cellular function by allosterically interacting with specific proteins like AKT16. Alternatively, the pyrophosphate group can donate a phosphate to pre-phosphorylated proteins17. The enormous potential of this research field is hampered by the absence of a commercial source of inositol pyrophosphates, which is preventing many scientists from studying these molecules and this new post-translational modification. The methods currently available to isolate inositol pyrophosphates require sophisticated chromatographic apparatus18,19. These procedures use acidic conditions that might lead to inositol pyrophosphate degradation20 and thus to poor recovery. Furthermore, the cumbersome post-column desalting procedures restrict their use to specialized laboratories.
In this study we describe an undemanding method for the generation, isolation and purification of the products of the IP6-kinase and PP-IP5-kinases reactions. This method was possible by the ability of polyacrylamide gel electrophoresis (PAGE) to resolve highly phosphorylated inositol polyphosphates20. Following IP6K1 and PP-IP5K enzymatic reactions using IP6 as the substrate, PAGE was used to separate the generated inositol pyrophosphates that were subsequently eluted in water.

Inositol pyrophosphates play an important role in human pathologies such cancer, diabetes and obesity; however, the exact mechanism of action is a matter of dispute. The lack of commercially available inositol pyrophosphates renders detailed studies problematic. Here we describe a simple protocol to produce and isolate milligrams of inositol pyrophosphates.

编制质量肌醇Pyrophosphates

Myo-inositol is present in nature either unmodified or in more complex phosphorylated derivates. Of the latest, the two most abundant in eukaryotic cells ...

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

RNA interference by feeding worms bacteria expressing dsRNAs has been a useful tool to assess gene function in C. elegans. While this strategy works well when a small number of genes are targeted for knockdown, large scale feeding screens show variable knockdown efficiencies, which limits their utility. We have deconstructed previously published RNAi knockdown protocols and found that the primary source of the reduced knockdown can be attributed to the loss of dsRNA-encoding plasmids from the bacteria fed to the animals. Based on these observations, we have developed a dsRNA feeding protocol that greatly reduces or eliminates plasmid loss to achieve efficient, high throughput knockdown. We demonstrate that this protocol will produce robust, reproducible knock down of C. elegans genes in multiple tissue types, including neurons, and will permit efficient knockdown in large scale screens. This protocol uses a commercially available dsRNA feeding library and describes all steps needed to duplicate the library and perform dsRNA screens. The protocol does not require the use of any sophisticated equipment, and can therefore be performed by any C. elegans lab.

Large-scale Gene Knockdown in C. elegans Using dsRNA Feeding Libraries to Generate Robust Loss-of-function Phenotypes

While dsRNA feeding in C. elegans is a powerful tool to assess gene function, current protocols for large scale feeding screens result in variable knockdown efficiencies. We describe an improved protocol for performing large scale RNAi feeding screens that results in highly efficacious and reproducible knockdown of gene expression.

在大规模的基因敲除<em&gt; C。线虫</em&gt;使用双链RNA料库产生失去功能的鲁棒表型

RNA interference by feeding worms bacteria expressing dsRNAs has been a useful tool to assess gene function in C. elegans. While this strategy works well ...

Quantitative Immunofluorescence Assay to Measure the Variation in Protein Levels at Centrosomes

Centrosomes are small but important organelles that serve as the poles of mitotic spindle to maintain genomic integrity or assemble primary cilia to facilitate sensory functions in cells. The level of a protein may be regulated differently at centrosomes than at other .cellular locations, and the variation in the centrosomal level of several proteins at different points of the cell cycle appears to be crucial for the proper regulation of centriole assembly. We developed a quantitative fluorescence microscopy assay that measures relative changes in the level of a protein at centrosomes in fixed cells from different samples, such as at different phases of the cell cycle or after treatment with various reagents. The principle of this assay lies in measuring the background corrected fluorescent intensity corresponding to a protein at a small region, and normalize that measurement against the same for another protein that does not vary under the chosen experimental condition. Utilizing this assay in combination with BrdU pulse and chase strategy to study unperturbed cell cycles, we have quantitatively validated our recent observation that the centrosomal pool of VDAC3 is regulated at centrosomes during the cell cycle, likely by proteasome-mediated degradation specifically at centrosomes.

Here, a novel quantitative fluorescence assay is developed to measure changes in the level of a protein specifically at centrosomes by normalizing that protein&#8217;s fluorescence intensity to that of an appropriate internal standard.

定量免疫检测，以衡量在中心体的变异蛋白水平

Centrosomes are small but important organelles that serve as the poles of mitotic spindle to maintain genomic integrity or assemble primary cilia to ...

Using plusTipTracker Software to Measure Microtubule Dynamics in Xenopus laevis Growth Cones

Microtubule (MT) plus-end-tracking proteins (+TIPs) localize to the growing plus-ends of MTs and regulate MT dynamics1,2. One of the most well-known and widely-utilized +TIPs for analyzing MT dynamics is the End-Binding protein, EB1, which binds all growing MT plus-ends, and thus, is a marker for MT polymerization1. Many studies of EB1 behavior within growth cones have used time-consuming and biased computer-assisted, hand-tracking methods to analyze individual MTs1-3. Our approach is to quantify global parameters of MT dynamics using the software package, plusTipTracker4, following the acquisition of high-resolution, live images of tagged EB1 in cultured embryonic growth cones5. This software is a MATLAB-based, open-source, user-friendly package that combines automated detection, tracking, visualization, and analysis for movies of fluorescently-labeled +TIPs. Here, we present the protocol for using plusTipTracker for the analysis of fluorescently-labeled +TIP comets in cultured Xenopus laevis growth cones. However, this software can also be used to characterize MT dynamics in various cell types6-8.

Using plusTipTracker Software to Measure Microtubule Dynamics in Xenopus laevis Growth Cones

The MATLAB-based, open source software package, plusTipTracker, can be used to analyze image series of fluorescently-labeled +TIPs to quantify microtubule dynamics.

使用plusTipTracker软件测量微管动力学<em&gt;非洲爪蟾</em&gt;生长锥

Microtubule (MT) plus-end-tracking proteins (+TIPs) localize to the growing plus-ends of MTs and regulate MT dynamics1,2. One of the most well-known and ...

A New Technique for Quantitative Analysis of Hair Loss in Mice Using Grayscale Analysis

Alopecia is a common form of hair loss which can occur in many different conditions, including male-pattern hair loss, polycystic ovarian syndrome, and alopecia areata. Alopecia can also occur as a side effect of chemotherapy in cancer patients. In this study, our goal was to develop a consistent and reliable method to quantify hair loss in mice, which will allow investigators to accurately assess and compare new therapeutic approaches for these various forms of alopecia. The method utilizes a standard gel imager to obtain and process images of mice, measuring the light absorption, which occurs in rough proportion to the amount of black (or gray) hair on the mouse. Data that has been quantified in this fashion can then be analyzed using standard statistical techniques (i.e., ANOVA, T-test). This methodology was tested in mouse models of chemotherapy-induced alopecia, alopecia areata and alopecia from waxing. In this report, the detailed protocol is presented for performing these measurements, including validation data from C57BL/6 and C3H/HeJ strains of mice. This new technique offers a number of advantages, including relative simplicity of application, reliance on equipment which is readily available in most research laboratories, and applying an objective, quantitative assessment which is more robust than subjective evaluations. Improvements in quantification of hair growth in mice will improve study of alopecia models and facilitate evaluation of promising new therapies in preclinical studies.

Alopecia is a common form of hair loss which can occur in many different conditions, including as a side-effect of chemotherapy. We have developed a method to quantify hair loss in mice, utilizing a standard gel imager to perform a grayscale analysis, to facilitate study of promising new alopecia therapies.

新技术脱发的定量分析小鼠使用灰度分析

Alopecia is a common form of hair loss which can occur in many different conditions, including male-pattern hair loss, polycystic ovarian syndrome, and ...

In Vitro Assay to Measure Phosphatidylethanolamine Methyltransferase Activity

Phosphatidylethanolamine methyltransferases are biosynthetic enzymes that catalyze the transfer of one or more methyl group(s) from S-adenosyl-L-methionine onto phosphatidylethanolamine, monomethyl-phosphatidylethanolamine, or dimethyl-phosphatidylethanolamine to give either monomethyl-phosphatidylethanolamine, dimethyl-phosphatidylethanolamine or phosphatidylcholine. These enzymes are ubiquitous in animal cells, fungi, and are also found in approximately 10% of bacteria. They fulfill various important functions in cell physiology beyond their direct role in lipid metabolism such as in insulin resistance, diabetes, atherosclerosis, cell growth, or virulence. The present manuscript reports on a simple cell-free enzymatic assay that measures the transfer of tritiated methyl group(s) from S-[Methyl-3H]adenosyl-L-methionine onto phosphatidylethanolamine using whole cell extracts as an enzyme source. The resulting methylated forms of phosphatidylethanolamine are hydrophobic and thus, can be separated from water soluble S-[Methyl-3H]adenosyl-L-methionine by organic extraction. This assay can potentially be applied to any other cell types and used to test inhibitors/drugs specific to a phosphatidylethanolamine methyltransferase of interest without the need to purify the enzyme.

In Vitro Assay to Measure Phosphatidylethanolamine Methyltransferase Activity

The present report describes an in vitro enzymatic assay to measure phosphatidylethanolamine methyltransferase activity using Leishmania cell extracts. This assay is based on the transfer of a radioactive methyl group from S-[Methyl-3H]adenosyl-L-methionine onto endogenous phosphatidylethanolamine.

体外试验来测量磷脂酰乙醇胺甲基转移酶活

Phosphatidylethanolamine methyltransferases are biosynthetic enzymes that catalyze the transfer of one or more methyl group(s) from ...

Using Microfluidic Devices to Measure Lifespan and Cellular Phenotypes in Single Budding Yeast Cells

Budding yeast Saccharomyces cerevisiae is an important model organism in aging research. Genetic studies have revealed many genes with conserved effects on the lifespan across species. However, the molecular causes of aging and death remain elusive. To gain a systematic understanding of the molecular mechanisms underlying yeast aging, we need high-throughput methods to measure lifespan and to quantify various cellular and molecular phenotypes in single cells. Previously, we developed microfluidic devices to track budding yeast mother cells throughout their lifespan while flushing away newborn daughter cells. This article presents a method for preparing microfluidic chips and for setting up microfluidic experiments. Multiple channels can be used to simultaneously track cells under different conditions or from different yeast strains. A typical setup can track hundreds of cells per channel and allow for high-resolution microscope imaging throughout the lifespan of the cells. Our method also allows detailed characterization of the lifespan, molecular markers, cell morphology, and the cell cycle dynamics of single cells. In addition, our microfluidic device is able to trap a significant amount of fresh mother cells that can be identified by downstream image analysis, making it possible to measure the lifespan with higher accuracy.

This article presents a protocol optimized for the production of microfluidic chips and the setup of microfluidic experiments to measure the lifespan and cellular phenotypes of single yeast cells.

使用微流体装置来衡量寿命和细胞表型单芽殖酵母细胞

Budding yeast Saccharomyces cerevisiae is an important model organism in aging research. Genetic studies have revealed many genes with conserved effects ...

使用热像仪测量通过鸟羽毛大衣的热损失

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