disequilibrium

不平衡
  • 文章类型: Journal Article
    眩晕,头晕,凝视不稳定和不平衡在MS(PwMS)患者中非常普遍,并且通常报道头部运动引起的头晕。前庭物理疗法(VPT)是一种专门的,这些问题的非侵入性和有效的治疗方法,但通常涉及到个人和碳成本的专家中心。使用可穿戴传感器跟踪头部运动和智能手机应用程序来交付和跟踪程序有可能改善MS的VPT。
    本研究调查了商用数字VPT系统(可穿戴式头部传感器,智能手机应用程序和临床医生软件)向PwMS提供VPT。采用治疗前/后设计,主要结果是系统可用性量表(SUS)。其他患者报告的结果是服务用户可接受性问卷(SUTAQ),患者能力量表(PEI)和头晕障碍量表(DHI)。物理结果测量包括Mini-BESTest(MB),修改后的动态步态指数(mDGI),步态速度(GS),运动过程中的动态视力(DVA)和头部运动学和症状。
    16个PwMS(14个女性),平均年龄44(±14)岁被纳入研究,12人完成VPT.坚持锻炼,数字测量为60%(±18.4)。SUS得分很高,为81(±14),SUTAQ得分也显示出系统的高度满意度和可接受性。MB的统计学显着改善(平均变化2.25;p=0.004),mDGI(中位数变化1.00;p=0.008),发现DVA(中位数变化-1.00;p=0.004)。头部频率随着头部运动过程中头晕强度的降低而显着改善(4次凝视稳定练习的平均变化为每分钟23次;p<0.05)。在DHI(p=0.07)和GS(p=0.15)中观察到非显著的改善。64.5%的随访是远程(视频或电话)进行的,在系统的推动下。
    这项研究对PwMS有两个主要结果和益处。首先,我们表明所使用的系统既可以接受,也可以被PwMS使用。其次,我们证明了一系列头晕的改善,平衡和步态指标与远程提供的护理。该系统有可能对MS理疗服务提供产生积极影响,并有可能提供有效的远程护理。
    UNASSIGNED: Vertigo, dizziness, gaze instability and disequilibrium are highly prevalent in people with MS (PwMS) and head movement induced dizziness is commonly reported. Vestibular physical therapy (VPT) is a specialised, non-invasive and effective therapy for these problems but usually involves travel for the person to a specialist center with both personal and carbon costs. The use of wearable sensors to track head movement and smartphone applications to deliver and track programs has potential to improve VPT in MS.
    UNASSIGNED: This study investigated the usability and effects of a commercially available digital VPT system (wearable head sensor, smartphone app and clinician software) to deliver VPT to PwMS. A pre/post treatment design was employed and the primary outcome was the System Usability Scale (SUS). Other patient reported outcomes were the Service User Acceptability Questionnaire (SUTAQ), the Patient Enablement Instrument (PEI) and the Dizziness Handicap Inventory (DHI). Physical outcomes measurements included Mini-BESTest (MB), Modified Dynamic Gait Index (mDGI), Gait Speed (GS), Dynamic Visual Acuity (DVA) and head kinematics and symptoms during exercise.
    UNASSIGNED: Sixteen PwMS (14 female), mean age 44(±14) years were recruited to the study and twelve completed VPT. Mean adherence to exercise, measured digitally was 60% (±18.4). SUS scores were high at 81 (±14) and SUTAQ scores also demonstrated high levels of satisfaction and acceptability of the system. Statistically significant improvements in MB (mean change 2.25; p = 0.004), mDGI (median change 1.00; p = 0.008), DVA (median change -1.00; p = 0.004) were found. Head frequencies significantly improved with concurrent decreased intensity of dizziness during head movements (mean change across 4 gaze stabilization exercises was 23 beats per minute; p < 0.05). Non-significant improvements were seen in DHI (p = 0.07) and GS (p = 0.15). 64.5% of follow up visits were conducted remotely (video or phone), facilitated by the system.
    UNASSIGNED: This study had two main outcomes and benefits for PwMS. Firstly, we showed that the system used was both acceptable and could be used by PwMS. Secondly, we demonstrated an improvement in a range of dizziness, balance and gait metrics with remotely delivered care. This system has the potential to positively impact on MS physiotherapy service provision with the potential to deliver effective remote care.
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  • 文章类型: Journal Article
    头晕是门诊护理和急诊科最常见的主要投诉之一。这些症状可以代表广泛的实体。因此,任何治疗尝试都必须首先从确定病因开始。从目前的角度来看,我们特别关注前庭性偏头痛的诊断和治疗,这是常见的,并在临床上与各种其他诊断重叠。除了最近爆发的新型偏头痛疗法外,我们还讨论了前庭偏头痛的传统治疗方法。因为前庭偏头痛可以模仿,或者与之共存,各种其他前庭疾病,我们讨论了这些疾病中的几种,包括持续的姿势知觉头晕,良性阵发性位置性眩晕,脑震荡后综合征,梅尼埃病,和脑血管病因。我们讨论每个人的诊断,以及读者应该意识到的重叠和区分的临床特征。最后,最后,我们以证据为基础,以及关于管理的专家评论,特别强调前庭性偏头痛。
    Dizziness is one of the most common chief complaints in both the ambulatory care setting and the emergency department. These symptoms may be representative of a broad range of entities. Therefore, any attempt at treatment must first start with determining the etiology. In this current perspective, we focus specifically on the diagnosis of and treatment of vestibular migraine, which is common and overlaps clinically with a variety of other diagnoses. We discuss the traditional treatments for vestibular migraine in addition to the recent explosion of novel migraine therapeutics. Because vestibular migraine can mimic, or co-exist with, a variety of other vestibular diseases, we discuss several of these disorders including persistent postural-perceptual dizziness, benign paroxysmal positional vertigo, post-concussive syndrome, Ménière\'s disease, and cerebrovascular etiologies. We discuss the diagnosis of each, as well as overlapping and distinguishing clinical features of which the reader should be aware. Finally, we conclude with evidence based as well as expert commentary on management, with a particular emphasis on vestibular migraine.
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  • 文章类型: Journal Article
    由于缺乏标准化的术语,对头晕或眩晕患者的诊断评估变得复杂。症状描述的显著重叠,以及患者症状的主观性质。虽然头晕是一个不精确的术语,经常被患者用来描述失去平衡的感觉,在许多情况下,头晕可以根据症状分类为眩晕(虚假的运动或旋转感),不平衡(步态不稳定的不平衡),晕厥前(几乎昏厥或昏厥),或头晕(非特异性)。因此,当前的诊断范式集中在时机上,触发器,和相关症状,而不是头晕类型的主观描述。无论如何,这些因素使出现头晕或眩晕的患者选择适当的影像学诊断变得复杂.本文件通过使用可定义的临床变体的框架来帮助提供者进行这种选择。美国放射学会适当性标准是针对特定临床状况的循证指南,每年由多学科专家小组审查。指南的制定和修订过程支持对同行评审期刊的医学文献进行系统分析。既定的方法论原则,如建议评估分级,发展,评估或等级适用于评估证据。RAND/UCLA适当性方法用户手册提供了确定特定临床场景的成像和治疗程序适当性的方法。在那些缺乏同行评审文献或模棱两可的情况下,专家可能是制定建议的主要证据来源。
    Diagnostic evaluation of a patient with dizziness or vertigo is complicated by a lack of standardized nomenclature, significant overlap in symptom descriptions, and the subjective nature of the patient\'s symptoms. Although dizziness is an imprecise term often used by patients to describe a feeling of being off-balance, in many cases dizziness can be subcategorized based on symptomatology as vertigo (false sense of motion or spinning), disequilibrium (imbalance with gait instability), presyncope (nearly fainting or blacking out), or lightheadedness (nonspecific). As such, current diagnostic paradigms focus on timing, triggers, and associated symptoms rather than subjective descriptions of dizziness type. Regardless, these factors complicate the selection of appropriate diagnostic imaging in patients presenting with dizziness or vertigo. This document serves to aid providers in this selection by using a framework of definable clinical variants. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.
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  • 文章类型: Journal Article
    特发性外淋巴瘘(PLF)可能难以诊断,因为患者出现突发性感觉神经性听力损失(SSHL)和/或前庭症状而没有任何先前事件。在这种情况下,我们目前检测cochlin-tomoprotein(CTP)以确认特发性PLF的诊断,因为CTP仅在外淋巴液中检测到.在这项研究中,我们报告了5例明确诊断为特发性PLF的患者的临床过程,这些患者使用经耳道内窥镜手术(TEES)进行了PLF修复手术.
    五名患者最初接受了鼓室内地塞米松治疗SSHL,此时还进行了CTP测试(术前CTP测试).由于难治性听力损失和/或波动不平衡,使用TEES进行PLF修复手术以使用结缔组织和纤维蛋白胶密封椭圆形和圆形窗口。这些患者根据术前或术中CTP测试结果(阴性,<0.4ng/mL;中间体,0.4-<0.8ng/mL;阳性,>0.8ng/mL)。我们评估了术前和术中CTP值,通过放大的内窥镜视图发现术中手术结果,以及平均听力水平和前庭症状的术前和术后变化。
    3例患者术前和术中CTP值呈阳性和中等,一名患者的阳性和阴性,一名患者呈阴性和阳性。没有患者的术中发现与内耳和中耳之间的瘘管或外淋巴液渗漏一致。只有两名患者在术后听力略有恢复。四名患者术前抱怨不平衡,其中两人在术后有不平衡的解决。
    CTP试验阳性证实患者无明显术中发现PLF。CTP测试被认为比内镜下瘘确认更敏感。我们认为CTP检测结果是决定特发性PLF修复手术指征的重要指标。根据我们对这五个案例的经验,其中两个显示听力和前庭症状均得到改善。
    UNASSIGNED: An idiopathic perilymphatic fistula (PLF) can be difficult to diagnose because patients present with sudden sensorineural hearing loss (SSHL) and/or vestibular symptoms without any preceding events. In such cases, we currently test for cochlin-tomoprotein (CTP) to confirm the diagnosis of idiopathic PLF because CTP is only detected in the perilymph. In this study, we report the clinical course of five patients definitively diagnosed with idiopathic PLF who underwent PLF repair surgery using transcanal endoscopic ear surgery (TEES).
    UNASSIGNED: Five patients were initially treated with intratympanic dexamethasone for SSHL, at which time a CTP test was also performed (preoperative CTP test). Due to refractory hearing loss and/or fluctuating disequilibrium, PLF repair surgery using TEES was performed to seal the oval and round windows using connective tissue and fibrin glue. These patients were diagnosed with definite idiopathic PLF based on pre- or intra-operative CTP test results (negative, < 0.4 ng/mL; intermediate, 0.4-< 0.8 ng/mL; and positive, > 0.8 ng/mL). We evaluated pre- and intra-operative CTP values, intraoperative surgical findings via a magnified endoscopic view, and pre- and post-operative changes in averaged hearing level and vestibular symptoms.
    UNASSIGNED: Pre- and intra-operative CTP values were positive and intermediate in three patients, positive and negative in one patient, and negative and positive in one patient. None of the patients had intraoperative findings consistent with a fistula between the inner and middle ears or leakage of perilymph. Only two patients showed a slight postoperative recovery in hearing. Four patients complained of disequilibrium preoperatively, of whom two had resolution of disequilibrium postoperatively.
    UNASSIGNED: A positive CTP test confirms PLF in patients without obvious intraoperative findings. The CTP test is considered more sensitive than endoscopic fistula confirmation. We consider that CTP test results are important indicators to decide the surgical indication for idiopathic PLF repair surgery. In our experience with the five cases, two of them showed improvements in both hearing and vestibular symptoms.
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  • 文章类型: Journal Article
    Ubehebe峰的镁橄榄石带接触光环,死亡谷,美国由板状/杰克稻草橄榄石的外部区域和次等多面体橄榄石的内部区域组成。靠近侵入体的亚等多面体镁橄榄石晶体较小,而较远的板状镁橄榄石晶体较大。为了研究两种形态的形成,在CaO-MgO-SiO2-CO2-H2O系统的冷密封压力容器中进行了镁橄榄石生长实验。镁橄榄石沉淀遵循由三个反应组成的不平衡反应途径:[1]石英和白云石的板状镁橄榄石生长,[2]镁橄榄石从透闪石溶解生长,[3]从片状镁橄榄石溶解过程中生长出相应的多面体镁橄榄石。最初,石英与白云石反应,同时形成双晶板状镁橄榄石和透闪石。随着石英的反应,镁橄榄石通过透闪石溶解以较慢的速率继续沉淀。第二代镁橄榄石然后沉淀在一些板状镁橄榄石上,但具有不同的习性和tracht。一旦所有的透闪石反应消失,通过溶解片状镁橄榄石,亚定量多面体镁橄榄石的沉淀速度甚至更慢。杰克-稻草橄榄石的表格形态是孪生介导的单向生长的结果;双胞胎的丰度是由于在最初的高反应亲和力下快速成核和生长。双结是台阶的优先成核中心,因此,在{100}上,多面增长得到了增强。这种现象是双平面折返效应。Ubehebe峰内部接触中的副多面体镁橄榄石从板状镁橄榄石中重结晶并成熟。在外接触光环中,条件不利于重结晶和成熟,因此仍然存在发达的板状镁橄榄石。
    The forsterite zone of the Ubehebe Peak contact aureole, Death Valley, USA consists of an outer zone of tabular/jack-straw olivine and an inner zone of subequant polyhedral olivine. Subequant polyhedral forsterite crystals close to the intrusion are small and tabular forsterite crystals farther away are larger. To investigate the formation of the two morphologies, forsterite growth experiments were conducted in cold seal pressure vessels in the CaO-MgO-SiO2-CO2-H2O system. Forsterite precipitation follows a disequilibrium reaction pathway made of three reactions: [1] tabular forsterite growth from quartz and dolomite, [2] forsterite growth from tremolite dissolution, and [3] subequant polyhedral forsterite growth from tabular forsterite dissolution. Initially, quartz reacts with dolomite to simultaneously form twinned tabular forsterite and tremolite. As quartz reacts away, forsterite precipitation continues at a slower rate through tremolite dissolution. A second generation of forsterite then precipitates on top of some tabular forsterite but has different habit and tracht. Once all the tremolite reacts away, subequant polyhedral forsterite precipitation continues at an even slower rate through dissolution of tabular forsterite. The tabular morphology of jack-straw olivine is a consequence of twin-mediated unidirectional growth; the abundance of twins being due to rapid nucleation and growth at initially high reaction affinities. Twin junctions are preferential nucleation centers for steps, so faceted growth is enhanced on {100}. This phenomenon is the twin plane re-entrant effect. Subequant polyhedral forsterite in the Ubehebe Peak inner contact aureole recrystallized and ripened from tabular forsterite. In the outer contact aureole, conditions were not conducive to recrystallization and ripening so well-developed tabular forsterite persists.
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  • 文章类型: Case Reports
    小脑共济失调,智力迟钝,不平衡综合征(CAMRQ)是一种遗传和临床异质性疾病,具有四种所述亚型。小脑共济失调的常染色体隐性综合征,智力迟钝,不平衡4型(CAMRQ4)是由ATP8A2基因突变引起的。我们报道了一个8岁男孩患有舞蹈症,低张力,没有能力抬头和严重的智力低下。有四足动物的运动,也是。脑部MRI显示call体肥大,弥漫性白质减少,广泛的延迟髓鞘形成和脑室增宽。Trio全外显子组测序揭示了ATP8A2基因中的复合杂合性,该基因由已知的变体c.1756C>T组成(p。Arg586*)从母亲和一个新的变体c.691_701delCTGATGAAGTT(p。Leu231fs)继承自父亲。在大约50名患者中发现了CAMRQ4型。据我们所知,这是首例有这些基因变异的CAMRQ4患者.临床表现严重。
    Cerebellar ataxia, mental retardation, and disequilibrium syndrome (CAMRQ) is a genetically and clinically heterogeneous disorder with four described subtypes. Autosomal recessive syndrome of cerebellar ataxia, mental retardation, and disequilibrium type 4 (CAMRQ4) is caused by mutations in the ATP8A2 gene. We report an 8-year-old boy with choreoathetosis, hypotonia, without the ability to keep his head up and profound mental retardation. There was quadrupedal locomotion, as well. MRI of the brain revealed a hypotrophy of the corpus callosum, diffuse white matter reduction, widespread delayed myelination and ventriculomegaly. Trio whole-exome sequencing revealed compound heterozygosity in the ATP8A2 gene consisting of a known variant c.1756C>T (p.Arg586*) inherited from the mother and a novel variant c.691_701delCTGATGAAGTT (p.Leu231fs) inherited from the father. CAMRQ type 4 has been found in about 50 patients. To the best of our knowledge, this is the first reported patient with CAMRQ4 with these gene variants. The clinical presentation is severe.
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  • 文章类型: Journal Article
    假定中枢神经系统功能障碍会导致肌痛性脑脊髓炎(ME)(最初称为“慢性疲劳综合征”)患者的衰弱症状。重复经颅磁刺激(rTMS)是一种新开发的神经调节程序,已被建议促进皮质神经活动。
    这项研究纳入了30名ME患者(7名男性和23名女性),平均年龄为39±12岁,他接受了左背外侧前额叶皮层和左脑主要运动区的rTMS治疗。限制日常生活活动的表现状态得分(0-9),在10分钟的站立试验中,直立不耐受(OI),神经不平衡被诊断为双脚并拢眼睛不稳定站立,神经性疼痛或纤维肌痛,比较两组治疗前后肌无力情况。
    治疗后,在20例患者(67%)中,表现状况评分或日常生活活动受限指数降低≥2分,观察到了良好的效果.12名患者中有10名(83%)的OI无法完成10分钟的站立测试,17例患者中有15例(88%)的不平衡得到解决。10名患者中有7名(70%)的神经性疼痛或纤维肌痛减弱。在四名患者中,有两名(50%)患者的握力<10kg的肌肉无力得到解决。所有研究患者均未遇到不良反应。
    用rTMS治疗可有效缓解各种症状,尤其是OI和不平衡,并改善ME患者的日常生活活动。
    UNASSIGNED: Central nervous system dysfunction has been postulated to cause debilitating symptoms in patients with myalgic encephalomyelitis (ME) (originally called \"chronic fatigue syndrome\"). Repetitive transcranial magnetic stimulation (rTMS) is a newly developed neuromodulatory procedure and has been suggested to facilitate the cortical neural activity.
    UNASSIGNED: This study enrolled 30 patients with ME (7 men and 23 women) with a mean age of 39 ± 12 years, who received rTMS treatment of both the left dorsolateral prefrontal cortex and the left primary motor area in the brain. The performance status score (0-9) for restricting activities of daily living, orthostatic intolerance (OI) during a 10-min standing test, neurologic disequilibrium diagnosed as unstable standing with their feet together and eyes closed, neuropathic pain or fibromyalgia, and muscle weakness were compared before and after treatment.
    UNASSIGNED: After therapy, favorable effects were observed with a decrease in performance status score or index for restriction of activities of daily living of ≥ 2 points in 20 patients (67%). OI with the inability to complete the 10-min standing test was resolved in 10 (83%) out of 12 patients, and disequilibrium was resolved in 15 (88%) out of 17 patients. Neuropathic pain or fibromyalgia was attenuated in seven (70%) out of 10 patients. Muscle weakness with grip power of < 10 kg was resolved in two (50%) out of four patients. No untoward effects were encountered in all the study patients.
    UNASSIGNED: The treatment with rTMS is effective in alleviating various symptoms, especially OI and disequilibrium, and in improving the activities of daily living in patients with ME.
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  • 文章类型: Journal Article
    外淋巴瘘(PLF),内耳的充满流体的空间和中耳的充满空气的空间之间的异常连通,是前庭和听觉症状的重要原因。这是22例PLF修复手术的回顾性研究。根据我们的手术适应症选择。我们分析了这22例患者的特点,并评估了PLF修复手术治疗前庭和听觉症状的疗效。先前事件的病例在手术前的间隔时间明显缩短。PLF修复手术后前庭症状的恢复非常迅速,82%的病例在一周内表现出明显改善,即使在慢性病例中。尽管在研究中明显没有对照组,前庭症状的显著改善和头晕障碍量表(DHI)评分的显著降低表明,观察到的获益可归因于手术干预.Further,及时手术显示听力改善,在后期手术中也有一些好处。使用外淋巴特异性蛋白Cochlin-tocoprotein(CTP)作为诊断生物标志物,我们可以证明PLF可能是这些患者的不平衡和相关听觉障碍的原因.提出了一个新的假设,即许多PLF患者经历的慢性不平衡是由于囊的活动性增强而不是内淋巴积水。使用我们开发的手术适应症,需要进一步的研究来充分阐明PLF的症状和治疗效果。
    Perilymph Fistula (PLF), abnormal communication between the fluid-filled space of the inner ear and the air-filled space of the middle ear, is a significant cause of vestibular and auditory symptoms. This is a retrospective study of 22 cases treated with PLF repair surgery, selected based on our surgical indication. We analyzed the characteristics of these 22 cases and evaluated the efficacy of PLF repair surgery in treating vestibular and auditory symptoms. Cases with antecedent events had significantly shorter intervals before surgery. The postoperative recovery from vestibular symptoms following PLF repair surgery was strikingly rapid, with 82% of cases demonstrating marked improvement within a week, even in chronic cases. Despite the notable absence of a control group in the study, the marked improvements in vestibular symptoms and substantial reductions in Dizziness Handicap Inventory (DHI) scores suggest that the observed benefits are attributable to the surgical intervention. Further, timely surgery showed improvements in hearing, with some benefits also seen in late-stage surgeries. Using the perilymph-specific protein Cochlin-tomoprotein (CTP) as a diagnostic biomarker, we could prove that PLF could be responsible for disequilibrium and related auditory disturbances in these patients. A new hypothesis is proposed that the chronic disequilibrium experienced by many PLF patients is due to enhanced mobility of the utricle and not to endolymphatic hydrops. Further research is needed to fully elucidate PLF\'s symptoms and treatment efficacy using the surgical indication we developed.
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  • 文章类型: Journal Article
    在未来几年和几十年中,有望提供外星生命(过去或现在)的潜在生物特征,无论是在我们自己的太阳系内,来自系外行星的大气层,或以其他方式。每一个这样的潜在生物特征,我们的不确定性程度将是第一个问题。我们真的确定了外星生命吗?我们有多确定?本文考虑了未考虑的替代解释问题。我们强调,阐明我们的不确定性需要评估我们探索相关可能性空间的程度。有人认为,对于最可能想到的潜在生物特征,我们目前还没有非常彻底地探索相关的可能性空间。这不仅严重限制了我们对外星生命的探测有合理信心的情况,这也对量化我们不确定性程度的任何尝试构成了重大挑战。讨论使我们得出以下建议:当特别涉及到外星生命探测主张时,天体生物学界应该遵循政府间气候变化专门委员会(IPCC)采用的不确定性评估方法。
    Potential biosignatures that offer the promise of extraterrestrial life (past or present) are to be expected in the coming years and decades, whether from within our own solar system, from an exoplanet atmosphere, or otherwise. With each such potential biosignature, the degree of our uncertainty will be the first question asked. Have we really identified extraterrestrial life? How sure are we? This paper considers the problem of unconceived alternative explanations. We stress that articulating our uncertainty requires an assessment of the extent to which we have explored the relevant possibility space. It is argued that, for most conceivable potential biosignatures, we currently have not explored the relevant possibility space very thoroughly at all. Not only does this severely limit the circumstances in which we could reasonably be confident in our detection of extraterrestrial life, it also poses a significant challenge to any attempt to quantify our degree of uncertainty. The discussion leads us to the following recommendation: when it comes specifically to an extraterrestrial life-detection claim, the astrobiology community should follow the uncertainty assessment approach adopted by the Intergovernmental Panel on Climate Change (IPCC).
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  • 文章类型: Journal Article
    背景:在植物水分关系研究中,黎明前叶水势(Φpd)通常用作土壤水势(Φ土壤)的代表,没有测试夜间蒸腾作用可以忽略不计的基本假设,并且已经过了足够的时间来建立静水平衡。这项研究的目的是测试田间种植的葡萄树的假设pd=土。
    结果:在华盛顿东南部干旱的一个葡萄园中,对30种不同品种的酿酒葡萄进行了田间试验,美国,两年了.在几个干燥周期中,多次测量了每个采样植物下的Wpd和土壤体积含水量(θv)。结果表明,在湿土(Φ土>-0.14MPa或相对可提取水含量,θe>0.36),对于所有30个品种,pd均显着低于土。在干燥土壤条件下(Φ土壤<-0.14MPa或θe<0.36),Φpd与Φ土壤更好地排列。品种之间存在差异,但是这些多年来并不一致。
    结论:这些结果表明,对于葡萄藤的湿土,无法将葡萄藤用作土壤的代表,而Wpd=^土壤假设可能适用于干土。
    BACKGROUND: In plant water relations research, predawn leaf water potential (Ψpd) is often used as a proxy for soil water potential (Ψsoil), without testing the underlying assumptions that nighttime transpiration is negligible and that enough time has passed for a hydrostatic equilibrium to be established. The goal of this research was to test the assumption Ψpd = Ψsoil for field-grown grapevines.
    RESULTS: A field trial was conducted with 30 different cultivars of wine grapes grown in a single vineyard in arid southeastern Washington, USA, for two years. The Ψpd and the volumetric soil water content (θv) under each sampled plant were measured multiple times during several dry-down cycles. The results show that in wet soil (Ψsoil >  - 0.14 MPa or relative extractable water content, θe > 0.36), Ψpd was significantly lower than Ψsoil for all 30 cultivars. Under dry soil conditions (Ψsoil <  - 0.14 MPa or θe < 0.36) Ψpd lined up better with Ψsoil. There were differences between cultivars, but these were not consistent over the years.
    CONCLUSIONS: These results suggest that for wet soils Ψpd of grapevines cannot be used as a proxy for Ψsoil, while the Ψpd = Ψsoil assumption may hold for dry soils.
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