从威尼斯到北京——《心·跳》展的历程和对神话的拆解

威尼斯双年展一直是艺术界的权力制高点;去拆解威尼斯神话是为打破文化上的"一神论";《心·跳》展的策划始末和在境外的矛盾协调;回国后的《心·跳—北京》展在策划理念和作品实施上的转换;艺术对于人、对于时代的意义。

Effect of heartbeat perception on heartbeat evoked potential waves

Objective Early researches found that different heartbeat perceivers have different heartbeat evoked potential （HEP）waves.Two tasks were considered in our experiments to get more details about the differences between good and poor heartbeat perceivers at attention and resting state.Methods Thirty channels of electroencephalogram（EEG）were recorded in 22 subjects,who had been subdivided into good and poor heartbeat perceivers by mental tracking task. Principal component analysis（PCA）was applied to remove cardiac field artifact（CFA）from the HEP.Results（1）The good heart-beat perceivers showed difference between attention and resting state in the windows from 250 ms to 450 ms after R wave at C3 location and from 100 ms to 300 ms after R wave at C4 location;（2）The difference waveforms between good and poor heartbeat perceivers was a positive waveform at FZ from 220 ms to 340 ms after R wave,which was more significant in attention state.Conclusion Attention state had more effect on the HEPs of good heartbeat perceivers than that of poor heartbeat perceivers;and perception ability influenced HEPs more strongly in the attention state than in the resting state.

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An Enhanced Hadoop Heartbeat Mechanism for MapReduce Task Scheduler Using Dynamic Calibration

MapReduce is a popular program- ming model for processing large-scale datasets in a distributed environment and is a funda- mental component of current cloud comput- ing and big data applications. In this paper, a heartbeat mechanism for MapReduce Task Scheduler using Dynamic Calibration （HMTS- DC） is proposed to address the unbalanced node computation capacity problem in a het- erogeneous MapReduce environment. HMTS- DC uses two mechanisms to dynamically adapt and balance tasks assigned to each com- pute node： 1） using heartbeat to dynamically estimate the capacity of the compute nodes, and 2） using data locality of replicated data blocks to reduce data transfer between nodes. With the first mechanism, based on the heart- beats received during the early state of the job, the task scheduler can dynamically estimate the computational capacity of each node. Us- ing the second mechanism, unprocessed Tasks local to each compute node are reassigned and reserved to allow nodes with greater capacities to reserve more local tasks than their weaker counterparts. Experimental results show that HMTS-DC performs better than Hadoop and Dynamic Data Placement Strategy （DDP） in a dynamic environment. Furthermore, an en- hanced HMTS-DC （EHMTS-DC） is proposed bv incorporatin historical data. In contrastto the ＂slow start＂ property of HMTS-DC, EHMTS-DC relies on the historical computation capacity of the slave machines. The experimental results show that EHMTS-DC outperforms HMTS-DC in a dynamic environment.

Repetitive narrow QRS tachycardia in a 61-year-old female patient with recent palpitations

A 61-year-old female patient suffering from recent onset palpitations and dyspnea on exertion with hypertension and mitral valve prolapse in her past history came to our outpatient department. Echocardiography revealed a mild mitral valve prolapse, slightly decreased left ventricular （LV） function （LV ejection fraction： 51%） and a mild mitral regurgitation.

Comparison of plasma NSE, protein S-100b and EEG changes in traditional arrested-heart procedures and on-pump beating-heart procedures

Objective: To assess the cerebral injury in on-pump beating-heart procedures under mild hypothermia in comparison with traditional on-pump arrested-heart procedures under moderate hypothermia. Methods: Forty patients, 20 with congenital heart disease (CHD) and 20 of rheumatic heart disease (RHD) , were divided into 2 groups: Control group (group A, n =20) including 10 patients suffering from CHD as group Al and the left 10 from RHD as group A2; and experiment group (group B, n =20) which consisting of group B1 (10 with CHD) and group B2 (10 of RHD). The patients in group A underwent traditional arrested-heart procedures, and those in group B were operated on with beating-heart procedures. Arterial blood samples were collected at preoperation (time A) , 20 min after cardiopul-monary bypass (CPB) starting (time B) , 1 h after CPB (time C) and 24 h postoperation (time D) respectively. Plasma contents of neuron-specific enolase (NSE) and protein S-100b were measured with sensitive ELISA. All the patients received echoencephalography (EEG) before and 1 week after operation. Results: The plasma contents of protein S-lOOb were increased very significantly at time B, C and D in comparison with those at time A (P<0.01) , and that of patients in group Al was significantly higher than that in group B at time B (P < 0. 05 ). There was no significant difference at other time points. At time B, the plasma contents of NSE were significantly higher in group A than in group B, and in group Al and Bl than in group A2 and B2. What's more, at time B, the former fell back to their pre-operative levels, but the latter remained still higher levels than the preoperative ones ( P < 0.01). No significant difference was found in the abnormality rates of postoperative EEG between 2 groups. Conclusion: The perioperative plasma contents of NSE and protein S-100b are not significantly higher in group B than in group A. On-pump beating-heart procedures do not make more serious cerebral dysfunction than the traditional arrested-heart procedures.

Aortic and mitral valve replacement with retrograde perfusion in the beating heart

Objective To estimate the value of aortic valves and combined mitral valve replacement with retrograde perfusion in beating hearts.Methods Continuous retrograde coronary sinus perfusion with beating hearts was used in 83 patients undergoing aortic valve or aortic valve combined with mitral valve replacement,without application of cardioplegia.After aortic valve replacement,the retrograde perfusion wes changed to antegrade perfusion for mitral valve replacement or correction of the other deformities(group A).Cold blood cardioplegia solution(15℃)was infused at intervals in 20 cases(group B).The following parameters were tested:lactate,ET,CTn-T and MDA in blood;myocardial ultra-structure;and cardiac rhythm and cardiac output (co).Results All biochemical values increased after cardiopulmonary bypass(P ＜ 0.05 - 0.01).Empty and beating heart sinus rhythm was maintained in group A.Myocardial ultrastructure did not change significantly.The pump was stopped smoothly as the surgical procedure finished.No postoperative low cardiac output syndrome or arrhythmia was observed.Eight-one patients recovered smoothly,two died from renal failure or infective shock.When the pump stopped,all patients in group B were supported by 5 - 10 μg· kg-1· min-1 dopamine.Transient pacing was used in 9 patients.One patient died from low cardiac output syndrome.Conclusion This method is a good myocardial protection which simulates physiologic status.It is applicable to aortic valve and combined mitral valve replacement of patients with large heart or heart failure and long time aortic cross-clamping.Ideal clinical effect can be achieved.

Surge Control of a Centrifugal Compression System by Using a Bouncing Ball

The purpose of this study is to suppress the fluctuations of surge by a simple passive control method. A bouncing ball system with different weight of the balls was tested. As a result, the bouncing ball system suppressed mild surge without the deterioration of the performance characteristics, and moved the initiation point of surge toward the lower flow rate when the steel ball of 15mm outer diameter was used. The present system was effective to suppress the surge and to widen the stable operating range of a centrifugal compressor when the ball was chosen appropriately.