A short-term mineral amendment impacts the mineral weathering bacterial communities in an acidic forest soil

Mineral amendment (i.e. calcium, phosphorous, potassium and/or magnesium) is a management practice used in forestry to improve nutrient availability and recover soil fertility, especially in nutrient-poor forest ecosystems. However, whether this amendment can lead to modifications of the soil characteristics and an improvement in tree growth, and its impact on the soil bacterial communities, especially the mineral weathering bacterial communities, remains poorly documented. In this study, we investigated the short-term impact of a mineral amendment on the taxonomic and functional structure of the mineral weathering bacterial communities. To do this, a plantation of four-year old oak (Quercus petraea) trees amended with or without dolomite [CaMg(CO₃)₂] was established in the experimental forest site of Breuil-Chenue, which is characterized by an acidic soil and a low availability of calcium and magnesium. Three years after amendment, soil samples were used to isolate bacteria as well as to determine the soil characteristics and the metabolic potentials of these soil microbial communities. Based on a bioassay for quantifying the solubilisation of inorganic phosphorous, we demonstrate that the bacterial isolates coming from the non-amended bulk soil were significantly more efficient than those from the amended bulk soil. No difference was observed between the bacterial isolates coming from the amended and non-amended rhizospheres. Notably, the taxonomic analyses revealed a dominance of bacterial isolates belonging to the Burkholderia genus in both samples. Overall, our results suggest that the bioavailability of nutritive cations into soil impacts the distribution and the efficacy of mineral weathering bacterial communities coming from the soil but not those coming from the rhizosphere.     

微咸水灌溉条件下施用不同改良剂对盐渍化土壤盐分离子分布的影响--测试文章

利用5种不同的土壤改良剂,对矿化度在2～3 g·L^-1的微咸水灌溉棉田土壤进行改良效果研究。结果表明：五种改良剂均降低土壤pH值和总盐含量,并能有效控制土体Na⁺、Ca²⁺、SO₄^2-、HCO₃^-积累;其中,磷石膏能显著降低土体Na⁺、Ca²⁺、SO₄^2-总含量（P＜0.05）,DS1997能显著降低土体Na⁺、HCO₃^-总含量（P＜0.05）,酸碱平衡剂显著降低土体Ca²⁺、SO₄^2-总含量（P＜0.05）,禾康改良剂有效控制土体SO₄^2-、HCO₃^-含量;改良剂对土体中Cl^-改良效果不显著（P＞0.05）。研究得出：微咸水灌溉导致土壤pH值升高和含盐量增加,造成土壤盐分的积累;土壤改良剂可有效减少微咸水灌溉引起的盐分积累,改善土壤理化特性和盐分离子分布。     

Corrective loops involved in fast aiming movements: effect of task and environment

In daily living, we continuously interact with our environment. This environment is rarely stable and living beings show remarkable adaptive capacities. When we reach for an object, it is necessary to localize the position of this object with respect to our own body before programming an adequate arm movement. If the target remains stable, the programmed movement brings the hand near the target. However, what happens when the target suddenly jumps to another position in space? The aim of this work was to investigate how rapid aiming movements are corrected when the target is displaced close to movement onset. Our results reveal that rapid movements can be modified and that the efficiency of trajectory amendments vary according to task (directional or direction/amplitude pointings) and environment (structured or darkness). We were most interested in the specific role played by peripheral and/or central feedback information (efferent copy) in the control of aiming movements. The results suggest that the two types of loops are complementary in movement regulation. However, their predominance varies according to the nature of the task at hand.     

参考桩钉修正曲面断层片垂直向的测量值*

背景：牙周病的诊断和治疗过程中常需测量牙槽骨高度和牙根长度,用曲面断层片对其进行定量测量的可靠性一直存在争议。 目的：验证用参考桩钉修正曲面断层片垂直向测量值的可行性。 方法：采用20例正畸患者的寄存模,在模型中的磨牙区、双尖牙区、尖牙区和切牙区嵌入5.00 mm钢珠作为测量对象,并在与钢珠相应的位置放置10.0 mm桩钉作参照物。拍摄模型的曲面断层片,测量钢珠影像垂直径,用桩钉校准和修正测量结果,比较钢珠影像测量值和真实值的差异。 结果与结论：用单一部位的参照物和1组参照物的平均值来校准,不同区域和不同桩钉放置方法测量结果的失真率不同,部分区域的失真率≥5%。在测量区域相应的部位放置完全垂直于牙合 平面的参考桩钉来修正测量值,可提高各区域测量结果的准确性,其失真率皆<1%,修正后的结果不受参照物的影响。而用贴在模型牙槽骨表面的参考桩钉来修正测量值,所得结果不理想。     

高频电刀质量检测规范技术要求探讨

目的：探讨《高频电刀质量检测技术规范（试行）》部分技术要求的合理性。方法：针对在用设备的检测不合格率偏高,结合设备原理探讨《高频电刀质量检测技术规范（试行）》的部分条款及技术要求的合理性。结果：《高频电刀质量检测技术规范（试行）》测试方法和要求存在不完善之处。结论：建议对规范进行修改,并提出修改建议以利于测试工作的正常进行。     

Image interpretation by radiographers in South Africa: A systematic review

Purpose

To determine the current knowledge on the accuracy, experiences, influence of training, and potential impact on patient management of image interpretation/reporting by South African diagnostic radiographers.

平衡施肥及土壤改良剂对连作条件下三七生长与产量的影响

目的:探求三七连作障碍的解决途径。方法:采用间隔3年的三七连作土进行盆栽试验,比较大、中、微量元素配合施用和施用甘蔗渣、粉煤灰、糖泥、牛粪、发酵烟杆、沸石、玉米杆等改良剂,对三七出苗率、存苗率、植株生长和产量影响。结果:间隔3年的三七连作土中全氮、全磷、碱解氮、有效磷等成分的含量较新土大幅度增加,速效钾含量及土壤钾素与氮素养分间比例则是大幅降低,有效铜、有效锌和有效硼等微量元素比较缺乏。三七连作土采用"低氮+钙镁磷+高钾+石灰+微肥"的平衡施肥方式可显著提高连作条件下三七的存苗率,促进三七植株生长,并显著提高三七单株生物量和总产量。使用甘蔗渣做土壤改良剂也可显著缓解三七连作土的连作障碍效应,提高连作三七的存苗率,促进三七植株生长,增加三七总产量;同对照相比(不施改良剂),其存苗率增加31.6%,三七地下部分总产量增加19.5%。使用粉煤灰做土壤改良剂对缓解三七连作土的连作障碍效应也有一定效果,其他土壤改良剂效果较差。结论:连作土连作三七时应采用"调酸(施用石灰)、减氮(低氮)、保磷(钙镁磷)、增钾(高钾)和补充微量元素"的平衡施肥方法,并增施甘蔗渣作为土壤改良剂。     

戒毒人员药物渴求度调查问卷的修订

目的：修订戒毒人员药物渴求问卷,为测定药物渴求程度提供有效的测量工具;方法：通过专题访谈等技术,对原问卷题项进行重新审查与筛选,运用探索性因素分析重构了新问卷的理论模型,运用验证性因素分析验证了模型的合理性。结果：修订后的问卷包含29个项目,5个维度。问卷的内部一致性系数在0．807-0．936之间,总问卷及各因子的分半信度为均在0．8以上。验证性因素分析证实问卷具有良好的结构效度;吸毒行为变量与问卷各维度之间的高度相关证实问卷具有良好的区分效度。结论：修订后戒毒人员药物渴求度问卷结构清晰,信效度良好。     

Adaptive Group Sequential Test for Clinical Trials with Changing Patient Population

In clinical trials, a standard group sequential test with a fixed number of planned interim analyses is usually considered to assess the effect of a test treatment under study. The standard group sequential test is statistically valid under the assumption that the patient population remains unchanged from one interim analysis to another. In practice, however, this assumption is often not met because the trial may be modified after the review of the clinical data at interim. As a result, the original patient population may have changed to a similar but different patient population. In this paper, we consider changes in patient population related to some covariates of an on-going trial through a linear regression model. Under this model, we can make inference on the original target population based on additional data from the changed populations. A new group sequential test procedure that accounts for the effect of population changes is proposed. A simulation was performed to evaluate the performance of the proposed method. The results indicate that the type I error rate of the proposed test procedure is well preserved, while the type I error rate of the standard group sequential test is inflated as the population changes. Statistical powers of the proposed group sequential test are also presented.