Neuromuscular response of hip-spanning and low back muscles to medio-lateral foot center of pressure manipulation during gait

Background: Footwear-generated medio-lateral foot center of pressure manipulation has been shown to have potential positive effects on gait parameters of hip osteoarthritis patients, ultimately reducing maximum joint reaction forces. The objective of this study was to investigate effects of medio-lateral foot center of pressure manipulation on muscle activity of hip-spanning and back muscles during gait in bilateral hip osteoarthritis patients. Methods: Foot center of pressure was shifted along the medio-lateral foot axis using a foot-worn biomechanical device allowing controlled center of pressure manipulation. Sixteen female bilateral hip osteoarthritis patients underwent electromyography analysis while walking in the device set to three parasagittal configurations: neutral (control), medial, and lateral. Seven hip-spanning muscles (Gluteus Medius, Gluteus Maximus, Tensor Fascia Latae, Rectus Femoris, Semitendinosis, Biceps Femoris, Adductor Magnus) and one back muscle (Erector Spinae) were analyzed. Magnitude and temporal parameters were calculated. Results: The amplitude and temporal parameter varied significantly between foot center of pressure positions for 5 out of 8 muscles each for either the more or less symptomatic leg in at least one subphase of the gait cycle. Conclusion: Medio-lateral foot center of pressure manipulation significantly affects neuromuscular pattern of hip and back musculature during gait in female hip bilateral osteoarthritis patients.     

基于生态安全格局的国土空间生态修复关键区域识别——以贺州市为例

国土空间生态修复是落实生态文明建设战略的重要举措。科学识别国土空间生态修复关键区域,合理布局全域生态修复空间是当前国土空间规划面临的难点之一。以广西壮族自治区贺州市为例,从生态保护重要性、景观连通性、生态功能重要区域和自然保护区四个方面识别生态源地,运用电路理论提取生态廊道,构建生态安全格局。通过电流密度诊断生态廊道中的生态"夹点"和生态障碍点,判定生态廊道宽度,识别国土空间生态保护修复关键区域,制定生态修复的空间布局策略。研究结果表明：（1）市域生态源地面积3656.89 km²,呈"东西重,中部轻"的空间分布特征;生态廊道总长度639.50 km,以中部分布为主,关键生态廊道133.96 km。（2）市域生态"夹点"共16处,面积124.24 km²,主要分布在钟山县,亟待保护修复的生态"夹点"8处,面积45.02 km²,零散分布于市域;生态障碍点共32处,面积426.56 km²,主要分布在市域东部和南部,需优先保护修复的生态障碍点6处,面积166.05 km²,集中在平桂区。通过综合分析国土生态修复关键区域土地利用现状和空间分布特征,制定了分级分类的生态修复措施,以期进一步优化生态安全格局,为国土空间生态修复区域识别和国土空间生态修复规划编制提供参考。     

Host tree architecture mediates the effect of predators on herbivore survival

Abstract.  1. Vegetation structural complexity is an important factor influencing ecological interactions between different trophic levels. In order to investigate relationships between the architecture of trees, the presence of arthropod predators, and survival and parasitism of the autumnal moth Epirrita autumnata Borkhausen, two sets of experiments were conducted.
2. In one experiment, the architectural complexity of mountain birch was manipulated to separate the effects of plant structure and age. In the other experiment the trees were left intact, but chosen to represent varying degrees of natural complexity. Young autumnal moth larvae were placed on the trees and their survival was monitored during the larval period.
3. The larvae survived longer in more complex trees if predation by ants was prevented with a glue ring, whereas in control trees smaller canopy size improved survival times in one experiment. The density of ants observed in the trees was not affected by canopy size but spider density was higher on smaller trees. The effect of canopy structure on larval parasitism was weak; larger canopy size decreased parasitism only in one year. Until the fourth instar the larvae travelled shorter distances in trees with reduced branchiness than in trees with reduced foliage or control treatments. Canopy structure manipulation by pruning did not alter the quality of leaves as food for larvae.
4. The effect of canopy structure on herbivore survival may depend on natural enemy abundance and foraging strategy. In complex canopies herbivores are probably better able to escape predation by ambushing spiders but not by actively searching ants.     

Inactivation of Omi/HtrA2 protease leads to the deregulation of mitochondrial Mulan E3 ubiquitin ligase and increased mitophagy

Omi/HtrA2 is a nuclear encoded mitochondrial serine protease with dual and opposite functions that depend entirely on its subcellular localization. During apoptosis, Omi/HtrA2 is released into the cytoplasm where it participates in cell death. While confined in the inter-membrane space of the mitochondria, Omi/HtrA2 has a pro-survival function that may involve the regulation of protein quality control (PQC) and mitochondrial homeostasis. Loss of Omi/HtrA2's protease activity causes the neuromuscular disorder of the mnd2 (motor neuron degeneration 2) mutant mice. These mice develop multiple defects including neurodegeneration with parkinsonian features. Loss of Omi/HtrA2 in non-neuronal tissues has also been shown to cause premature aging. The normal function of Omi/HtrA2 in the mitochondria and how its deregulation causes neurodegeneration or premature aging are unknown. Here we report that the mitochondrial Mulan E3 ubiquitin ligase is a specific substrate of Omi/HtrA2. During exposure to H₂O₂, Omi/HtrA2 degrades Mulan, and this regulation is lost in cells that carry the inactive protease. Furthermore, we show accumulation of Mulan protein in various tissues of mnd2 mice as well as in Omi/HtrA2(−/−) mouse embryonic fibroblasts (MEFs). This causes a significant decrease of mitofusin 2 (Mfn2) protein, and increased mitophagy. Our work describes a new stress-signaling pathway that is initiated in the mitochondria and involves the regulation of Mulan by Omi/HtrA2 protease. Deregulation of this pathway, as it occurs in mnd2 mutant mice, causes mitochondrial dysfunction and mitophagy, and could be responsible for the motor neuron disease and the premature aging phenotype observed in these animals.     

开放式腹膜前间隙修补术与Lichtenstein修补术治疗腹股沟疝的比较

目的：比较腹股沟疝采用Lichtenstein 修补术和开放式腹膜前间隙修补术的临床效果和安全性。方法：将我院普外科收治的 132例腹股沟疝患者随机分为两组,每组66 例。一组患者采用Lichtenstein 修补术进行治疗,另外一组患者采用开放式腹膜前间 隙修补术进行治疗,对比两组平均手术时间、平均术中出血量、平均术后下床时间、平均术后住院时间、平均术后恢复时间;对比 两组患者术后各种并发症的发生情况和1 年内复发情况。结果：腹膜前间隙组平均手术时间、平均术后下床时间、平均术后住院 时间、平均术后恢复时间略短于Lichtenstein 组,平均术中出血量略少于Lichtenstein 组,但差异无统计学意义(P＞0.05);腹膜前间 隙组患者各种并发症发生率及术后1 年内复发率明显低于Lichtenstein 组,差异具有统计学意义(P＜0.05)。结论：腹股沟疝采用开 放式腹膜前间隙修补术和Lichtenstein 修补术治疗的临床效果均较好,但开放式腹膜前间隙修补术的并发症发生率和1 年内复发 率更低,临床优势更明显。     

Design of multispecific protein sequences using probabilistic graphical modeling

In nature, proteins partake in numerous protein– protein interactions that mediate their functions. Moreover, proteins have been shown to be physically stable in multiple structures, induced by cellular conditions, small ligands, or covalent modifications. Understanding how protein sequences achieve this structural promiscuity at the atomic level is a fundamental step in the drug design pipeline and a critical question in protein physics. One way to investigate this subject is to computationally predict protein sequences that are compatible with multiple states, i.e., multiple target structures or binding to distinct partners. The goal of engineering such proteins has been termed multispecific protein design. We develop a novel computational framework to efficiently and accurately perform multispecific protein design. This framework utilizes recent advances in probabilistic graphical modeling to predict sequences with low energies in multiple target states. Furthermore, it is also geared to specifically yield positional amino acid probability profiles compatible with these target states. Such profiles can be used as input to randomly bias high‐throughput experimental sequence screening techniques, such as phage display, thus providing an alternative avenue for elucidating the multispecificity of natural proteins and the synthesis of novel proteins with specific functionalities. We prove the utility of such multispecific design techniques in better recovering amino acid sequence diversities similar to those resulting from millions of years of evolution. We then compare the approaches of prediction of low energy ensembles and of amino acid profiles and demonstrate their complementarity in providing more robust predictions for protein design. Proteins 2010. © 2009 Wiley‐Liss, Inc.     

Tuning DO:DM Ratios Modulates MHC Class II Immunopeptidomes

Major histocompatibility complex class II (MHC-II) antigen presentation underlies a wide range of immune responses in health and disease. However, how MHC-II antigen presentation is regulated by the peptide-loading catalyst HLA-DM (DM), its associated modulator, HLA-DO (DO), is incompletely understood. This is due largely to technical limitations: model antigen-presenting cell (APC) systems that express these MHC-II peptidome regulators at physiologically variable levels have not been described. Likewise, computational prediction tools that account for DO and DM activities are not presently available. To address these gaps, we created a panel of single MHC-II allele, HLA-DR4-expressing APC lines that cover a wide range of DO:DM ratio states. Using a combined immunopeptidomic and proteomic discovery strategy, we measured the effects DO:DM ratios have on peptide presentation by surveying over 10,000 unique DR4-presented peptides. The resulting data provide insight into peptide characteristics that influence their presentation with increasing DO:DM ratios. These include DM sensitivity, peptide abundance, binding affinity and motif, peptide length, and choice of binding register along the source protein. These findings have implications for designing improved HLA-II prediction algorithms and research strategies for dissecting the variety of functions that different APCs serve in the body.     

Resident and transient coyotes exhibit differential patterns of movement behavior across heterogeneous landscapes in the southeastern United States

Coyotes (Canis latrans) are a highly adaptable canid species whose behavioral plasticity has allowed them to persist in a wide array of habitats throughout North America. As generalists, coyotes can alter movement patterns and change territorial strategies between residency (high site fidelity) and transiency (low site fidelity) to maximize fitness. Uncertainty remains about resident and transient coyote movement patterns and habitat use because research has reached conflicting conclusions regarding patterns of habitat use by both groups. We quantified effects of habitat on resident and transient coyote movement behavior using first passage time (FPT) analysis, which assesses recursive movement along an individual''s movement path to delineate where they exhibit area‐restricted search (ARS) behaviors relative to habitat attributes. We quantified monthly movement rates for 171 coyotes (76 residents and 53 transients) and then used estimated FPT values in generalized linear mixed models to quantify monthly habitat use for resident and transient coyotes. Transients had greater movement rates than residents across all months except January. Resident FPT values were positively correlated with agricultural land cover during fall and winter, but negatively correlated with agriculture during spring. Resident FPT values were also negatively correlated with developed habitats during May–August, deciduous land cover during June–August, and wetlands during September–January except November. FPT values of transient coyotes were positively correlated with developed areas throughout much of the year and near wetlands during July–September. Transient FPT values were negatively correlated with agriculture during all months except June and July. High FPT values (ARS behavior) of residents and transients were generally correlated with greater densities of edge habitat. Although we observed high individual variation in space use, our study found substantive differences in habitat use between residents and transients, providing further evidence that complexity and plasticity of coyote habitat use is influenced by territorial strategy.     

异色瓢虫法国种群对豆蚜的捕食效应

异色瓢虫Harmonia axyridis(Pallas)的法国种群具有飞行能力较低的特点,在生物防治方面可能更具利用价值。为了使其更好的在田间应用,本文进行了异色瓢虫的法国种群各龄幼虫及雌、雄成虫对豆蚜的捕食功能比较研究。结果表明:各龄幼虫及雌、雄成虫对豆蚜捕食功能反应符合Holling II模型,检验各圆盘方程理论值和实测值拟合较好。同一虫态在不同空间水平对蚜虫的捕食能力有显著差异,在广口瓶处理中(较大空间),1～4龄幼虫及雌、雄成虫的最大理论捕食量分别为4.51、83.33、111.12、166.67、190及200头;不同虫期及成虫的瞬间攻击率a为3龄>4龄>雄虫>雌虫>2龄>1龄,且1龄的处理时间Th最长(0.2225);在培养皿处理中(较小空间),1～4龄幼虫及雌、雄成虫的最大理论捕食量分别为6.17、19.23、45.45、100、142.86、111.11头,不同虫期的瞬间攻击率a为2龄>3龄>雄虫>4龄>1龄>雌虫,且4龄的处理时间Th最长(0.1624)。