Dormancy and germination: making every seed count in restoration

From 50 to 90% of wild plant species worldwide produce seeds that are dormant upon maturity, with specific dormancy traits driven by species' occurrence geography, growth form, and genetic factors. While dormancy is a beneficial adaptation for intact natural systems, it can limit plant recruitment in restoration scenarios because seeds may take several seasons to lose dormancy and consequently show low or erratic germination. During this time, seed predation, weed competition, soil erosion, and seed viability loss can lead to plant re‐establishment failure. Understanding and considering seed dormancy and germination traits in restoration planning are thus critical to ensuring effective seed management and seed use efficiency. There are five known dormancy classes (physiological, physical, combinational, morphological, and morphophysiological), each requiring specific cues to alleviate dormancy and enable germination. The dormancy status of a seed can be determined through a series of simple steps that account for initial seed quality and assess germination across a range of environmental conditions. In this article, we outline the steps of the dormancy classification process and the various corresponding methodologies for ex situ dormancy alleviation. We also highlight the importance of record‐keeping and reporting of seed accession information (e.g. geographic coordinates of the seed collection location, cleaning and quality information, storage conditions, and dormancy testing data) to ensure that these factors are adequately considered in restoration planning.     

Separating distinct structures of multiple macromolecular assemblies from cryo-EM projections

Single particle analysis for structure determination in cryo-electron microscopy is traditionally applied to samples purified to near homogeneity as current reconstruction algorithms are not designed to handle heterogeneous mixtures of structures from many distinct macromolecular complexes. We extend on long established methods and demonstrate that relating two-dimensional projection images by their common lines in a graphical framework is sufficient for partitioning distinct protein and multiprotein complexes within the same data set. The feasibility of this approach is first demonstrated on a large set of synthetic reprojections from 35 unique macromolecular structures spanning a mass range of hundreds to thousands of kilodaltons. We then apply our algorithm on cryo-EM data collected from a mixture of five protein complexes and use existing methods to solve multiple three-dimensional structures ab initio. Incorporating methods to sort single particle cryo-EM data from extremely heterogeneous mixtures will alleviate the need for stringent purification and pave the way toward investigation of samples containing many unique structures.     

Molecular Targets for the Testing of COVID‐19

The pandemic outbreaks of coronavirus disease 2019 (COVID‐19), caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), spread all over the world in a short period of time. Efficient identification of the infection by SARS‐CoV‐2 has been one of the most important tasks to facilitate all the following counter measurements in dealing with the infectious disease. In Taiwan, a COVID‐19 Open Science Platform adheres to the spirit of open science: sharing sources, data, and methods to promote progress in academic research while corroborating findings from various disciplines has established in mid‐February 2020, for collaborative research in support of the development of detection methods, therapeutics, and a vaccine for COVID‐19. Research priorities include infection control, epidemiology, clinical characterization and management, detection methods (including viral RNA detection, viral antigen detection, and serum antibody detection), therapeutics (neutralizing antibody and small molecule drugs), vaccines, and SARS‐CoV‐2 pathogenesis. In addition, research on social ethics and the law are included to take full account of the impact of the COVID‐19 virus.     

个体化精准运动为核心的整体康复方案对冠心病介入治疗术后患者整体功能再提高的临床研究*

目的: 探讨个体化精准运动为核心的整体康复方案对冠心病介入治疗术后患者整体功能再提高的作用。方法: 选择2016 年6 月至2019 年12 月间在北京康复医院临床诊断为冠心病稳定性心绞痛患者20 例,随机分为对照组（n=10）和运动组（n=10）。全部患者择期行冠状动脉介入治疗,术后对照组患者仅进行除运动康复之外的常规治疗指导;运动组患者进行12周个体化运动为核心的心脏康复,介入前、介入后2周、康复后12周分别评估患者标准化症状限制性极限运动的心肺运动试验（CPET）指标、心脏超声、6 min步行距离（6MWD）等。结果: 所有患者均安全无并发症完成症状限制性CPET,运动组患者完成12周全程运动康复治疗。组间比较显示,介入前和介入后2周,对照组和运动组患者CPET指标以及左心室射血分数、6MWD等均无明显差异（P>0.05）。康复12周后,运动组患者无氧阈（ml/min、ml/（min·kg））、峰值摄氧量（ml/（min·kg））、氧脉搏（ml/beat）和6MWD较对照组明显升高,差异有统计学意义（P<0.05）。组内比较显示,康复治疗12周后,运动组患者无氧阈（ml/min、ml/（min·kg）、%pred）、峰值摄氧量（ml/min、ml/（min·kg）、%pred）、峰值氧脉搏（ml/beat）和6MWD均较介入前明显改善,差异有统计学意义（P<0.05）;而且与介入后2周比较,无氧阈（ml/（min·kg））和峰值摄氧量（ml/（min·kg））均明显升高,差异有统计学意义（P<0.05）。对照组患者在康复12周后无氧阈（ml/min）和峰值氧脉搏（ml/beat）较介入前改善,差异有统计学意义（P<0.05）,但CPET指标与介入后2周比较无明显差异。结论: 冠状动脉介入术后进行个体化运动康复为核心的整体管理可进一步提高冠心病稳定性心绞痛患者运动心肺功能和运动耐力。运动康复是介入术后患者二级预防的重要内容,需要大量推广。     

Max试验验证症状限制心肺运动试验为最大极限运动进一步临床研究*

目的: 验证临床受试者所完成的心肺运动试验（CPET）为最大极限运动,进一步设计完善Max试验验证CPET结果客观定量功能评估的准确性及以某特定指标的特定数值作为停止运动的标准是否可行。方法: 选择2017年9月至2019年1月在阜外医院签署知情同意书后进行CPET和Max试验受试者216例。其中正常受试者41例,因CPET峰值呼吸交换率（RER）≤1.10,或运动中心率和血压不上升,对CPET极限运动结果存在质疑的临床患者175例进行研究。其中60例已初步报告,本研究进一步扩大研究。Max试验方法：完成CPET测试后,先蹬车≥60 r/min,再施加130%峰值功率的恒定功率,鼓励受试者运动至不能坚持的极限状态。计算分析Max试验30 s的最大心率和最大摄氧量、及其与峰值心率和峰值摄氧量之间的差值和百分差值。百分差值=（Max值-峰值值）/Max值× 100%。评测标准：①若心率和摄氧量任一指标的差值百分比≤-10%（Max测试的数值低于CPET峰值数据）则定义Max试验操作失败,否则为成功;2若心率和摄氧量的差值百分比均在-10%~10%,则Max试验操作成功,证明CPET数据为极限运动,CPET 峰值相关数据较为准确;③若心率和摄氧量差值任一指标差值百分比≥10%时,则Max试验操作成功,证明CPET结果为非极限运动。结果: 病例组峰值摄氧量（L/min、ml/（min·kg）、%pred）、无氧阈（L/min、ml/（min·kg）、%pred）、峰值氧脉搏（ml/beat、%pred）、峰值RER、峰值收缩压（mmHg）、峰值运动负荷（W/min）、峰值心率（bpm）、摄氧有效性峰值平台（OUEP）（比值、%pred）低于正常组,二氧化碳通气有效性平均90 s最低值（Lowest Ve/VCO₂）（比值、%pred）、二氧化碳通气效率斜率（Ve/VCO₂ Slope）（比值、%pred）高于正常组（P<0.05）。所有正常组与病例组均安全无任何事件完成CPET和Max试验。216例受试者中,Max试验成功198例（91.7%）,其中证明CPET为极限运动182例,为非极限运动16例;失败18例（8.3%）。结论: 在临床检查中,若对CPET结果是否为最大极限存在质疑,利用Max试验可验证CPET是否为极限运动。Max试验方法安全可行,值得进一步深入研究和临床推广应用。     

Knowledge and attitudes regarding genetic testing among Jordanians: An approach towards genomic medicine

BackgroundThe twenty first century can be called the genomic era referring to the rapid development of genetics, and the beginning of genomic medicine. An initial step towards genomic medicine is to evaluate the knowledge and attitude towards genetic testing among different populations. The aims of this study were to assess the genetic knowledge and attitude towards genetic testing among the Jordanian population and patients with immune diseases. In addition, we evaluated the association between knowledge, attitude and several demographic factors of the population.MethodsThis study was performed using an online questionnaire that was distributed to respondents from different regions of Jordan.ResultsA total of 1149 participants were recruited from the Jordanian population. Overall factual genetic knowledge of the participants was good (65.4%), with education level, working or studying in a health-related field and household average monthly income being significant predictors of factual knowledge scores (P = 0.03, P < 0.001 and P < 0.001, respectively). However, factual knowledge results revealed that scores of questions related to diseases were significantly higher than scores of gene-related scientific facts (P < 0.01). Participants of our study reported to have low perceived knowledge on medical uses (39.5%) and social consequences (23.9%) of genetic testing. Regarding the participants’ attitudes, favorable attitudes towards genetic testing were prevailing (91.5%). Favorable attitudes were more prominent among higher educated participants, and participants with higher scores of factual knowledge.ConclusionDespite the fact that our Jordanian-based study revealed a good level of genetic knowledge as well as a favorable attitude towards genetic testing, we realized an imbalance of knowledge between gene-related scientific facts and disease-related concepts as well as between factual and perceived genetic knowledge, which indicates the necessity of increasing the awareness about genetic testing in order to ensure that individuals can take informed decisions that help in the employment of personalized medicine.     

Photon beam energy dependent single-arc volumetric modulated arc optimization

PurposeThe purpose of this work was to present a new single-arc mixed photon (6&18MV) VMAT (SAMP) optimization framework that concurrently optimizes for two photon energies with corresponding partial arc lengths.Methods and materialsOwing to simultaneous optimization of energy dependent intensity maps and corresponding arc locations, the proposed model poses nonlinearity. Unique relaxation constraints based on McCormick approximations were introduced for linearization. Energy dependent intensity maps were then decomposed to generate apertures. Feasibility of the proposed framework was tested on a sample of ten prostate cancer cases with lateral separation ranging from 34 cm (case no.1) to 52 cm (case no.6). The SAMP plans were compared against single energy (6MV) VMAT (SE) plans through dose volume histograms (DVHs) and radiobiological parameters including normal tissue complication probability (NTCP) and equivalent uniform dose (EUD).ResultsThe contribution of higher energy photon beam optimized by the algorithm demonstrated an increase for cases with a lateral separation >40 cm. SAMP–VMAT notably improved bladder and rectum sparing in large size cases. Compared to single energy, SAMP–VMAT plans reduced bladder and rectum NTCP in cases with large lateral separation. With the exception of one case, SAMP–VMAT either improved or maintained femoral heads compared to SE–VMAT. SAMP–VMAT reduced the nontarget tissue integral dose in all ten cases.ConclusionsA single-arc VMAT optimization framework comprising mixed photon energy partial arcs was presented. Overall results underline the feasibility and potential of the proposed approach for improving OAR sparing in large size patients without compromising the target homogeneity and coverage.     

Somatic embryogenesis and in vitro plant regeneration of Bacopa monnieri (Linn.) Wettst., a potential medicinal water hyssop plant

Bacopa monnieri (Linn.) Wettst. commonly known as waterhyssop, Brahmi plant, traditionally used for memory enhancement, nerve tonic, epilepsy, central nervous system (CNS), antidepressant, anxiety, blood pressure and antioxidant activities. Due to pharmaceutical demands its lost natural habitat. At this juncture we describe a resourceful protocol for micropropagation of water hyssop plant. Surface sterilized leaf and nodal explants were inoculated on basal MS semi-solid medium added with PGRs; auxins, cytokinins. Highest calli formation from leaf explants was obtained on NAA (2.5 mg⁻¹) and showed (94.22%) accompanied via 2,4-D showed (2.5 mg⁻¹; 82.43%), maximum calli formation in nodal explants was obtained on 2,4-D showed (2.5 mg⁻¹; 71.14%) followed by NAA (2.5 mg⁻¹) showed (62.15%), in internodes explants uppermost calli formation was obtained from 2,4-D showed (2.5 mg⁻¹; 65.21%) followed by NAA (2.5 mg⁻¹) showed (52.14%). The maximum somatic embryogenic callus, calli induction and formation (84%) was observed on 2,4-D + KIN (2.0 + 1.5 mg⁻¹) amended solid medium. Uppermost shoot formation was observed in combination of IAA + BAP (1.0 + 1.0 mg⁻¹) showed (78.54%) shoot formation followed by IBA (2.0 mg⁻¹) alone showed (75.37%). The maximum shoot elongation was noticed from NAA + BAP (3.0 + 3.0 mg⁻¹) with 21.21 cm followed by NAA (2.0 mg⁻¹) showed (15.22 cm) although, chief root formation was obtained from IBA (2.0 mg⁻¹) with 83.75% root formation along higher number of roots (47.43%) per shoot. Followed by IAA (2.0 mg⁻¹) showed root induction (73.43%) and no of roots (38.54%) per shoot. In hardening under pot condition plants survivability (100%) was observed under glass house conditions, the present in vitro PTC techniques is extremely significant to gratifying its natural conservation.     

News from the BSC No. 8

Abstract

In the 8th and following issues of News from the Biological Stain Commission (BSC), under the heading of Regulatory affairs, the BSC's International Affairs Committee will present information from a meeting held in Ghent, Belgium on 15–18 June 2009 concerning the progress achieved by the International Standards Organization Committee ISO/TC 212 Clinical Laboratory Testing and in Vitro Diagnostic Test Systems since the last meeting held in Vancouver, Canada in 2008. A note on the meaning and significance of E numbers found on the labels of foodstuffs and beverages sold for human consumption concludes this edition of News from the Biological Stain Commission.