Exceptionally strong easterly wind burst stalling El Ni?o of 2014

Intraseasonal wind bursts in the tropical Pacific are believed to affect the evolution and diversity of El Niño events. In particular, the occurrence of two strong westerly wind bursts (WWBs) in early 2014 apparently pushed the ocean–atmosphere system toward a moderate to strong El Niño—potentially an extreme event according to some climate models. However, the event’s progression quickly stalled, and the warming remained very weak throughout the year. Here, we find that the occurrence of an unusually strong basin-wide easterly wind burst (EWB) in June was a key factor that impeded the El Niño development. It was shortly after this EWB that all major Niño indices fell rapidly to near-normal values; a modest growth resumed only later in the year. The easterly burst and the weakness of subsequent WWBs resulted in the persistence of two separate warming centers in the central and eastern equatorial Pacific, suppressing the positive Bjerknes feedback critical for El Niño. Experiments with a climate model with superimposed wind bursts support these conclusions, pointing to inherent limits in El Niño predictability. Furthermore, we show that the spatial structure of the easterly burst matches that of the observed decadal trend in wind stress in the tropical Pacific, suggesting potential links between intraseasonal wind bursts and decadal climate variations.El Niño, the warm phase of the El Niño–Southern Oscillation (ENSO), is characterized by anomalously warm water appearing in the central and eastern equatorial Pacific every 2–7 years, driven by tropical ocean–atmosphere interactions with far-reaching global impacts (recent reviews are in refs. 1–3). These interactions and El Niño development involve several important feedbacks, including the positive Bjerknes feedback [zonal wind relaxation leads to the reduction of the zonal sea surface temperature (SST) gradient and further wind relaxation] (4). Since the year 2000, there has been a shift in the observed properties of El Niño, including its magnitude, frequency, and spatial structure of temperature anomalies (5, 6). For example, El Niño events occurred more frequently than during the previous two decades, but all were weak, and none reached the extreme magnitude of the 1982 and 1997 events. Concurrently, the rise of global mean surface temperature has slowed down with the so-called global warming hiatus (7–9). The stalled development of the 2014 El Niño presents a showcase to explore the relevant connection and mechanisms of these changes.At the beginning of 2014, many in the scientific community anticipated that a moderate to strong El Niño could develop by the end of the year (10–14) (Fig. S1). In March, the National Oceanic and Atmospheric Administration (NOAA) Climate Prediction Center announced an “El Niño watch” based on predictions made by dynamical and statistical models (12), attracting attention of the general public. Admittedly, these predictions encompassed large uncertainties because of the stochastic nature of the tropical climate system (15–17). In May, the National Aeronautics and Space Administration (NASA) suggested that 2014 could potentially rival the strongest on-record event of 1997/19998 (Fig. 1B), while acknowledging the large existing uncertainty (14); their projection was supported by satellite observations of strong Kelvin waves evident in sea surface height (SSH) (Fig. 2C). The spread of spring forecast plumes from some climate models, for example that of the European Centre for Medium-Range Weather Forecasts (ECMWF), included the possibility of a failed El Niño (Fig. S1) but only as a low-probability outcome involving unusual instances of weather noise. The observed development fell near the limit of these forecast possibilities after June and July, and eventually, the 2014 warm event barely qualified as El Niño (Fig. 1A).Open in a separate windowFig. 1.El Niño development in (A and C) 2014 and (B and D) 1997. (A and B) Evolution of the Niño3, Niño4, and Niño3.4 indices; the first two indices describe SST anomalies (in degrees Celsius) in the eastern and central equatorial Pacific, respectively, whereas the last index covers the region in between. (C and D) Variation in the zonal wind stress indices. These indices are obtained by averaging wind stress anomalies (in 10⁻² newtons per meter²) in the equatorial Pacific zonally and between 5 °S and 5 °N and then selecting negative (blue; easterly anomalies), positive (red; westerly anomalies), or full values (black) (Materials and Methods). The spatial averaging is intended to take into account both the magnitude and the fetch of the wind bursts. During 2014, two early year WWBs were followed by an exceptional EWB in June (highlighted by pink and blue, respectively). This easterly burst apparently led to a rapid decrease of the Niño indices (A). In contrast, the 1997 El Niño exhibited persistent westerly wind activity throughout the year. The graphs start on January 1.Open in a separate windowFig. 2.Spatiotemporal evolution of the 2014 El Niño. (A–D) Hovmöller diagrams for anomalies in (A) SST, (B) zonal wind stress, (C) SSH, and (D) surface zonal currents in the equatorial Pacific. Time goes downward. The SSH and surface velocity plots highlight the eastward propagating downwelling Kelvin waves, especially pronounced early in the year, and a strong upwelling Kelvin wave midyear. (E and F) El Niño development in 2014 (black line) compared with several historical (E) EP and (F) CP events. The diagrams show the position of the Warm Pool Eastern Edge (degrees of longitude) vs. the Niño3 SST (degrees Celsius) for different months of the year. The Warm Pool Eastern Edge is defined as the position of the 29 °C isotherm at the equator. Numbers indicate monthly averages (1, January; 2, February, etc.). The light vertical line marks the Dateline. In 2014, both the warm pool displacement and Niño3 SST anomalies were exceptionally large during May (month 5), were similar to those in 1997 and 1982 (the strongest events of the 20th century), and then, rapidly decreased by August (month 8).Open in a separate windowFig. S1.The El Niño spring forecasts of the Niño3.4 index from the European Centre for Medium-Range Weather Forecasts (ECMWF). Red lines show 50 ensemble members of the forecast plume initiated in March of 2014; the black dotted line indicates the observed Niño3.4 index. The observed development fell outside the forecast plume in June and July and remained beyond the typical forecast spread after that. Adapted from ref. 13.The question then arises as to which dynamic factors controlled the temporal and spatial development in the tropical Pacific in 2014. This warm event began with a rapid growth, such that, in early June, all major Niño indices (Materials and Methods) along the equator were nearly identical to those during the same time of 1997 (Fig. 1 A and B). A substantial warming also developed along the Peruvian coast (Fig. 3A). Then, the event’s progression slowed down or even reversed. By year end, the equatorial warming barely exceeded 1 °C, but the SST anomaly stretched uncharacteristically across the entire equatorial Pacific almost uniformly (Figs. 1A and ​and2A).2A). Accordingly, the major goal of this study is to investigate this unusual development, identify the main factors that impeded this event, and explore its broad implications.Open in a separate windowFig. 3.The June of 2014 EWB in satellite-based data. (A) The spatial structure of anomalies in surface winds (vectors; in meters per second) and SST (colors; in degrees Celsius) on June 12, 2014, when the burst was strongest. (B) Daily vs. weekly mean values of the zonal wind stress index (10⁻² newtons per meter²) for the period 1988–2014. The blue cross marks the peak value of the June of 2014 EWB. The wind stress index is defined as anomalous zonal wind stress averaged in the equatorial Pacific zonally and between 5 °S and 5 °N (Materials and Methods). Black circles are for the year 2014, red circles are for all El Niño years before 2014, and gray circles are for all other years (La Niña or neutral). Note that the June of 2014 EWB appears strongest in the satellite record for not only daily data but also, weekly averaged values, which confirms that the observations are robust.     

Neural modelling of the semantic predictability gain under challenging listening conditions

When speech intelligibility is reduced, listeners exploit constraints posed by semantic context to facilitate comprehension. The left angular gyrus (AG) has been argued to drive this semantic predictability gain. Taking a network perspective, we ask how the connectivity within language‐specific and domain‐general networks flexibly adapts to the predictability and intelligibility of speech. During continuous functional magnetic resonance imaging (fMRI), participants repeated sentences, which varied in semantic predictability of the final word and in acoustic intelligibility. At the neural level, highly predictable sentences led to stronger activation of left‐hemispheric semantic regions including subregions of the AG (PGa, PGp) and posterior middle temporal gyrus when speech became more intelligible. The behavioural predictability gain of single participants mapped onto the same regions but was complemented by increased activity in frontal and medial regions. Effective connectivity from PGa to PGp increased for more intelligible sentences. In contrast, inhibitory influence from pre‐supplementary motor area to left insula was strongest when predictability and intelligibility of sentences were either lowest or highest. This interactive effect was negatively correlated with the behavioural predictability gain. Together, these results suggest that successful comprehension in noisy listening conditions relies on an interplay of semantic regions and concurrent inhibition of cognitive control regions when semantic cues are available.     

飞秒激光微小切口基质透镜取出术基质切削可预测性研究

目的：比较飞秒激光微小切口基质透镜取出术(SMILE)术后角膜基质实际切削量与术前预测量间差别,评估SMILE基质切削的可预测性与精确性。

方法：前瞻性研究。选取2019-01/07在云南大学附属医院行SMILE术近视矫正患者113例220眼,术前,术后1、3mo行常规检查,包括视力、非接触式眼压、等值球镜度(SE)、角膜平均曲率、角膜前表面球面系数、Pentacam眼前节分析。随机选取研究对象中102眼于术前及术后3mo运用A超角膜测厚仪测量角膜中央厚度(CCT)。术后实际切削量为术前角膜最薄点厚度与术后角膜最薄点厚度的差值,误差量为术前预计切削量与术后实际切削量的差值。观察切削误差大小,并对误差量与术前各生理参数进行相关性分析。

结果：SMILE术后效果良好,术后1、3mo角膜形态和视力相对稳定。A超角膜厚度测厚仪测量数据与Pentacam眼前节分析系统中角膜最薄点数据一致性较好。术前预计切削量101.36±18.91μm,术后1、3mo实际切削量88.89±18.69、84.95±18.64μm比较有差异(F=334.65,P<0.01),术后1、3mo时切削误差量为12.59±9.78、16.50±9.21μm,两者间比较有差异(t=-8.370,P<0.01)。术后1、3mo切削误差量均只与术前SE具有相关性(r=0.299,P<0.01; r=0.305,P<0.01)。术后1、3mo SE与同时间点切削误差量具有相关性(r=-0.275,P<0.01; r=-0.306,P<0.01),随着切削量误差增加,术后等值球镜向负镜度偏移。

结论：SMILE术后角膜基质实际切削量小于术前预测切削量,随着术前屈光度增大,预测切削误差亦增大; 随着误差量增大,术后屈光度逐渐呈负向偏移,但此误差在术后早期并未影响目标视力。     

Failure of explicit movement control in patients with functional motor symptoms

Functional neurological symptoms are one of the most common conditions observed in neurological practice, but understanding of their underlying neurobiology is poor. Historic psychological models, based on the concept of conversion of emotional trauma into physical symptoms, have not been implemented neurobiologically, and are not generally supported by epidemiological studies. In contrast, there are robust clinical procedures that positively distinguish between organic and functional motor signs that rely primarily on distracting attention away from movement or accessing it covertly. We aimed to investigate the neurobiological principles underpinning these techniques and implications for understanding functional symptoms. We assessed 11 patients with functional motor symptoms and 11 healthy controls in three experimental set‐ups, where voluntary movements were made either with full explicit control or could additionally be influenced automatically by factors of which participants were much less aware (one‐back reaching, visuomotor transformation, and precued reaction time with variable predictive value of the precue). Patients specifically failed in those tasks where preplanning of movement could occur and under conditions of increasing certainty regarding the movement to be performed. However, they implicitly learned to adapt to a visuomotor transformation as well as healthy controls. We propose that when the movement to be performed can be preplanned or is highly predicted, patients with functional motor symptoms shift to an explicit attentive mode of processing that impairs kinematics of movement control, but movement becomes normal when such processes cannot be employed (e.g., during unexpected movement or implicit motor adaptation). © 2013 Movement Disorder Society     

MEL-80治疗近视的准分子激光上皮下角膜磨镶术效果评价

目的评价使用蔡司MEL-80准分子激光治疗仪施行准分子激光上皮下角膜磨镶术（1aser-assisted subepithe-lial keratomileusis，LASEK）治疗近视和近视散光的预测性、有效性、安全性和稳定性。方法回顾性分析使用MEL-80准分子激光治疗系统行LASEK治疗近视和近视散光的连续性病例76例（150眼），于术后第1天、第1、第3、第6和第12个月定期随访，检查裸眼视力，以显然主觉验光检查术后屈光状态及最佳矫正视力。结果术后第10天、第1、第3、第6和第12个月时，裸眼视力平均值分别为4．91±0．15、4．97±0．26、5．05±0．37、5．12±0、20、4．96±0．24。预测性：术前屈光度等效球镜值为（-6．25±1．25）D，术后第3、第6和第12个月分别降到（＋0．12±0．42）D、（-0．03±0．23）D、（-0．15±0．36）D，术后第3、第6和第12个月屈光度变化量在＋0．50D以内的比例分别为94．6％、96．0％、97．3％。术后第3、第6和第12个月离焦等效球镜值在±0．50D内的眼数分别为88．0％、96．0％、96．6％。有效性：术后第3个月，24．0％的眼裸眼视力（uncor-rected visual acuity,UCVA）≥5．1，94．6％的眼UCVA≥5．0，97.3％的眼UCVA≥4．9。术后第6个月，36．0％的眼UCVA≥5．1．96．0％的眼UCVA≥5．0，98．6％的眼UCVA≥4．9。术后第12个月，38．0％的眼UCVA≥5．1，98．0％的眼UCVA≥5．0，98．6％的眼UCVA≥4．9。安全性：术后第3、第6、第12个月，均无任何一眼最佳矫正视力（best spectacle corrected vision acuity，BSCVA）下降2行以上；分别有34．6％、34．6％和30．0％的眼BSCVA提高1行；16．0％、17．3％和14．6％的眼BSCVA提高2行。稳定性：术后第3、第6、第12个月显然验光值等效球镜平均值变化小于1．00D。结论使用MEL-80的LASEK治疗近视和近视散光有良好的预测性、有效性、安全性和稳定性。     

脑出血并发应激性溃疡出血患者的预见性护理

目的：探讨脑出血并发应激性溃疡出血患者预见性护理的临床效果。方法：回顾性分析23例脑出血并发应激性溃疡出血患者的临床资料。结果：23例患者通过积极治疗和预见性护理等措施，显效11例，有效9例，无效2例，总有效率86．9％。结论：脑出血患者并发应激性溃疡出血具有一定的诱因及临床先兆，对高血压脑出血并发应激性溃疡患者进行早期治疗及预见性护理，能有效地防止脑出血患者应激性溃疡的发生和发展，促进疾病的康复。     

急性应激障碍能否预测创伤后应激障碍

灾难后心理创伤是临床心理学领域和精神医学领域的研究热点,灾难后急性应激障碍(ASD)和创伤后应激障碍(PTSD)之间的关系日益受到关注。本文对ASD预测PTSD的文献进行了分析,回顾了ASD诊断预测PTSD存在的一些问题,并综述了ASD各种症状(分离、再体验、回避、唤起水平增高症状)对PTSD的预测作用,以及认知模式和叙事特点等因素对PTSD的预测作用。总之,作者认为,以ASD诊断和ASD各种症状预测PTSD存在局限性。     

The roles of the cerebellum and basal ganglia in timing and error prediction

Recent evidence that the cerebellum and the basal ganglia are activated during the performance of cognitive and attention tasks challenges the prevailing view of their primary function in motor control. The specific roles of the basal ganglia and the cerebellum in cognition, however, have been difficult to identify. At least three functional hypotheses regarding their roles have been proposed. The first hypothesis suggests that their main function is to switch attentional set. The second hypothesis states that they provide error signals regarding stimuli or rewards. The third hypothesis is that they operate as an internal timing system, providing a precise representation of temporal information. Using functional magnetic resonance imaging, we tested these three hypotheses using a task-switching experiment with a 2 x 2 factorial design varying timing (random relative to fixed) and task order (unpredictable relative to predictable). This design allowed us to test whether switching between tasks, timing irregularity and/or task order unpredictability activate the basal ganglia and/or the cerebellum. We show that the cerebellum is primarily activated with timing irregularity while the anterior striatum is activated with task order unpredictability, supporting their distinctive roles in two forms of readjustment. Task order unpredictability alone, independent of reward delivery, is sufficient to induce striatal activation. In addition, activation of the cerebellum and basal ganglia were not specific to switching attention because these regions were both activated during switching between tasks and during the simultaneous maintenance of two tasks without switching between them.     

对《伤寒论》预后诊断思想方法的研究

为提高临床诊断疾病的准确性和对治疗效果的判定,作者认真研读《伤寒论》对疾病病证的传变和预测疾病生死愈危,并对其方法进行了深入地研究,对现实临床实践具有重要的指导意义。     

Individual predictability of repeated spinal anaesthesia with plain 0.5% bupivacaine

To evaluate the individual predictability of spinal anaesthesia, 10 patients (3 women and 7 men) scheduled for control cystoscopy were studied twice within 9 months. Lumbar puncture was performed in the midline at the L2/3 interspace with the patient in the sitting position using plain 0.5% bupivacaine at 37 degrees C. A non-parametric Spearman test showed that, on the basis of the first block, the predictability of the cephalad analgesic spread of the second anaesthesia was high up to 60 min after injection. Thereafter the predictability decreased. The predictability of the motor blockade was generally low. Six patients obtained complete motor blockade twice; the remaining four, once.