Search

BACKGROUND For children undergoing treatment of early onset scoliosis (EOS) using spine-based distraction, recently published research would suggest that total spine length (T1-S1) achieved after the initial lengthening procedure decreases with each subsequent lengthening. Our purpose was to evaluate the effect of rib-based distraction on spine growth in children with EOS. METHODS This was a retrospective multi-center review of 35 patients treated with rib-based distraction (minimum 5 y follow-up). Radiographs were analyzed at initial implantation and just before each subsequent lengthening. The primary outcome was T1-S1 height, which was also analyzed as: Change in T1-S1 height per lengthening procedure, percent of expected age-based T1-S1 growth per lengthening time interval, percent increase in T1-S1 height as compared with postimplantation total spine height, and percent of expected T1-S1 growth based upon patient age at time of lengthening procedure. RESULTS Thirty-five patients with a mean age of 2.6 years at initial surgery were studied. Diagnoses included congenital (n=18), syndromic (n=7), idiopathic (n=5), and neuromuscular (n=5). Major Cobb angle was 63.5 degrees and kyphosis was 40.5 degree. Four postoperative time periods were compared: L1 (preoperative first lengthening surgery), L2-L5 (preoperative second lengthening to preoperative fifth lengthening), L6-L10 (preoperative sixth lengthening to preoperative 10th lengthening), L11-L15 (preoperative 11th lengthening to preoperative 15th lengthening). Cobb angle stayed relatively constant for each lengthening period while maximum kyphosis increased. Total spine height was 19.9 cm pre-implantation, 22.1 cm postimplantation, and 28.0 cm by the 15th lengthening (P

The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) on the Lunar Reconnaissance Orbiter (LRO) characterizes the radiation environment to be experienced by humans during future lunar missions. CRaTER measures the effects of ionizing energy loss in matter due to penetrating solar energetic protons (SEP) and galactic cosmic rays (GCR), specifically in silicon solid-state detectors and after interactions with tissue-equivalent plastic (TEP), a synthetic analog of human tissue. The CRaTER investigation quantifies the linear energy transfer (LET) spectrum in these materials through direct measurements with the lunar space radiation environment, particularly the interactions of ions with energies above 10 MeV, which penetrate and are detected by CRaTER. Combined with models of radiation transport through materials, CRaTER LET measurements constrain models of the biological effects of ionizing radiation in the lunar environment as well as provide valuable information on radiation effects on electronic systems in deep space. In addition to these human exploration goals, CRaTER measurements also provide new insights on the spatial and temporal variability of the SEP and GCR populations and their interactions with the lunar surface. We present here an overview of the CRaTER science goals and investigation, including: an instrument description; observation strategies; instrument testing, characterization, and calibration; and data analysis, interpretation, and modeling plans., United States. National Aeronautics and Space Administration (contract NNG05EB92C)

Choices for today's electric ship propulsion systems include the asynchronous (i.e., induction) singly-fed or doubly-fed electric machine systems or the synchronous singly-fed electric machine systems with permanent magnets or DC field-windings (e.g., superconductor). Experts theorized that the variable-speed Brushless Wound-rotor [Synchronous] Doubly-fed Electric Machine System (BWRSDF), which can symmetrically motor or generate, provides higher efficiency, higher power density, higher torque density, and lower cost than any other electric machine system but only with the discovery of a practical brushless real time control solution for its known issues of instability and the multiphase slip-ring assembly that continually elude state-of-art control methods, such as Field Oriented Control (FOC). Comprising a dual-ported transformer circuit topology with the robust characteristics common to the advanced induction electric machine system, such as field weakening, practically unconstrained torque and power rating, etc., the fully electromagnetic core of the BWRSDF uses readily available technology and materials without the cost, safety and reliability issues of market volatile, rare-earth permanent magnets. A patented with patents pending Brushless and Sensorless Real Time Control (BSRTC) method provides the only available BWRSDF.

A new Brushless Real Time Control (RTC) method for electric motors or generators is an evolution in Sensor-less control. Very different from any derivative of Field Oriented Control (FOC), RTC uniquely eliminates all control uncertainty, including the extraneous shaft connected resolver for the specific purpose of measuring speed-position (i.e., Sensor-less). Although modified versions of RTC can be used for control of any type of electric machine, the variable speed Brushless Wound-rotor [Synchronous] Doubly-fed Electric Machine System (BWRSDF) with its symmetrical circuit topology best explains the attractive attributes of RTC but more importantly, the BWRSDF has been theorized by experts to provide the highest efficiency, highest power density, highest torque density, and lowest cost of any electric machine with practical solutions for known issues of instability and a multiphase slip-ring assembly that only RTC successfully provides. In addition, BWRSDF uses off-the-shelf technology and readily available materials without precious rare earth permanent magnets.

C ARBOHYDRATES and hydrocarbons are the prime sources of life everywhere. Without the energies locked in these compounds and their chemical derivatives, there is no life. To translate these technical terms into plain language, they mean food and fuel in their various forms. The more modernised a society becomes, the larger in volume and the more varied in quality anid composition are these basic ingredients of life, and the greater is the society's preoccupation with securing their ready supply. China is a case in point. Consciously or subconsciously, its leaders have recognised these facts by electing Tachai, the advanced agricultural commune, and Taching, the first major source of liquid energy, to serve as models in all spheres of development. For more than a decade, these two enterprises have been chosen as signposts to what modern China stands for. Tachai and Taching have also served as ideological symbols and as issues of practical politics. Where society is stagnant, the volume and composition of food and fuel can be treated as static. No such position exists where the population exceeds its resources, and where its growth exceeds past precedent. Here the search is on for ever new sources of carbohydrates and hydrocarbons and thus for the solution of exist'ing food and fuel problems. This is as true of the post-Mao era as it was during the lifetime of the great helmsman, even if the political language in which 'the issues are to be presented in future undergoes certain verbal changes.

Leaving aside the plantation enclaves, the problems of food and farming in Asia are centred on subsistence farming. This, in spite of recent improvements in farming techniques, remains subject to natural hazards, population pressure and risks which only those with ready access to land, labour, capital and know-how are able to face. By comparison, small cultivators, tenants and landless labourers suffer serious disadvantages. These can be reduced only as a result of reforms which bring security of tenure, transfers of land and a just system of land tax combined with public works programmes. Thus economic growth, coupled with social equilibrium and political stability, could be achieved.

June 1979 was a turning point for China. In the fast-moving world of today, one has to be careful in the use of catchphrases which can easily be invalidated when events of even greater import overtake them. Even so, the Second Session of the Fifth National People's Congress (NPC) may justly be regarded as a landmark in the brief post-Mao history of the People's Republic. Its significance pales, to be sure, when set against the T'ien An Men incident of April 1976, which gave the signal to the world that political and economic changes were in the making. Teng Hsiao-p'ing, deposed from all his posts as the main victim of that incident, emerged – fully rehabilitated – two years later as the chief architect of what can now legitimately be regarded as China's New Economic Policy. Of course, the foundation stone had been laid much earlier by the late Chou En-lai. Thus, as in the past, continuity and change were to live precariously side by side.

The Year of the Cockerel (starting in February 1981) seems a good time to reflect on China's record past, present and future. Officially, of course, the lunar cycle has been replaced by the secular calendar, but in the wide expanses of the Chinese countryside old traditional ways die hard. In the family circle, the beliefs of the ancestors are still respected and the days around the lunar New Year and the Spring festival are still celebrated, even though a day's work-points can be earned by those who prefer to attend the public functions on formal occasions. Of good intentions there were many at the start of the Year of the Cockerel one of the twelve animal symbols of old such as devotion to work and scholarship, industry and punctuality, bravery and generosity. Those interested in continuity and change could not but register certain similarities between the old virtues and the modern aims. Today, more than during most of the last twenty years, the old and the new intermingle. The decade preceding Mao's death is dismissed officially as a decade of unmitigated disaster, and approval of the early years following the revolution of 1949 knows no bounds. The outside observer may be forgiven if he remembers the praises and the condemnations of the recent past and allows his judgement to be swayed towards the middle ground. The so-called Cultural Revolution (now invariably put in quotation marks and no longer printed with capital letters) has been extended in the official records from May 1966 beyond the ninth Party congress (April 1969), when it was originally said to have ended, to October 1976 when the great helmsman was no longer in charge. Its excesses were at times even worse than the public records tell ; but there were also successes which are sometimes drowned nowadays by the accounts of individual horror and mass hysteria. Western admirers of the Maoist era will consider it unfair to be reminded of their past eulogies; but open critics of the last decade or so of Chinese history should beware of saying smugly: 'we told you so'. The reality of China yesterday, today and tomorrow is too complex to fill a canvas in mere black and white; there is an awful lot that is very much grey on grey, though those in search of a new credibility and respectability may not see it that way.

Ten months after the PRC's State Statistical Bureau (SSB) published -for the first time in two decades - a reasonably comprehensive set of national economic data (XINHUA, 27 June 1979), these were amended, up-dated and supplemented in an even fuller statement, issued by the SSB at the end of April (and early in May) 1980 and covering the results of the national plan for 1979. As on the previous occasion, most of the items published were given in such a way as to facilitate comparisons with the information available for the year prior to the first plan (1952) and the year in which it was completed (1957). Whilst the data for the early years fall short in part, particularly in the agricultural sector, of being perfect, the years 1952 and 1957 nevertheless serve as useful landmarks on China's long, and often winding, path from the past to the present. Thus the China-watcher now has a dossier of economic and social data from official sources against which he can check his own estimates and those made - in the absence of official statistical documentation - by various national and international agencies concerning themselves with the successes and shortcomings of the PRC since its inception in 1949. Where he is not satisfied with the newly published information, he must, of course, reserve the right to ask questions even where no answer may be given for some time to come.

Economics of Change in Less Developed Countries. David Colman and Frederick Nixson, Oxford: Philip Allan. 1978. 309pp. £10.50. £5.25 pb. Development and the Problems of Village Nutrition. Sue Schofield, London: Croom Helm. 1979. 174pp. £8.95. Food Commodities. Bernhard Davies, London: Heinemann. 1978. 346pp. £4.90 pb. The Political Economy of Food. Edited by Vilho Harle, Farnborough, England: Saxon House. 1978. 438pp. £11.50. To Feed this World: the challenge and the strategy. Sterling Wortman and Ralph W Cummings Jr. Baltimore: John Hopkins University Press. 1978. 440pp. $6.95 pb. Food and Population: priorities in decisionmaking. Edited by T Dams, the late K E Hunt and G J Tyler, Farnborough, England: Saxon House. 1978. 192pp. £8.50. Agricultural Development and the Rural Poor. Edited by Guy Hunter, London: Overseas Development Institute. 1978. 113pp. £1.50. Rural Asia: challenge and opportunity. Supplementary Papers, Vols I‐IV. Manila: Asian Development Bank. 1978. 430pp. Rural Development: learning fr...

“Living standards have improved, but levels are low and not even.” These words are contained in an appraisal by two senior members of the State Statistical Bureau of the People's Republic of China, which seems to be the first detailed account in years, written for the benefit of foreigners who are interested in the well-being of the people of China. Other, briefer statements have been available lately, but none of such authenticity. In this respect, December 1978 can be taken as the point of departure: since then, not only have major political and economic changes occurred, but the non-Chinese world has been allowed to participate in these changes and to take account of their successes and failures. Even the language in which official reports are made astonishes. Admittedly, reforms had preceded the third plenary session of the 11th Central Committee of the Chinese Communist Party held in December 1978. The plenum was the occasion when China's policies underwent a dramatic shift from Hua Guofeng's doctrinal concept to a more “pragmatic” approach, with problems being tackled as they arose. Strategy and tactics were revised, following a re-evaluation of major political events, organizational change at the highest political level, a reassessment of Mao's role in the history of the People's Republic and the revision of economic targets. A stable future seemed to be guaranteed by the election of Hu Yaobang to the Politbureau and – a little later – the appointment of Zhao Ziyang as premier in overall charge of modernization, as Deng Xiaoping interpreted this concept. Within a few months Hua Guofeng's modernization projects suffered some drastic amendments and his 10-year Plan in particular was abandoned. In its place, the plenum considered the “eight-character charter” of readjustment, reform, consolidation and improvement. In the countryside, which still provides work and a home for the largest number of men and women, agriculture was given the highest priority - but this time in earnest and not, as during the previous two decades, merely as a slogan.

T HE uninitiated may be forgiven if they are somewhat confused by widely differing accounts of the world food situation. Following the crop failures of 1965, an apocalyptic picture of hunger, disease and death was conveyed to a public which had grown used to believing in the almighty power of industrial growth. Yet, a few years later, an image of imminent abundance was portrayed when the first promising results of technical progress led to premature euphoria, expressed in such terms as ' miracle crops ' and ' the green revolution '. A few years later still, the beginning of the last quarter of our century gave rise, once again, to gloom and despondency. The World Food Conference, held last November in Rome, was hailed by Sayed Ahmed Marei, its Secretary General (and Egypt's former Minister of Agrarian Reform), as a 'watershed of history'. Dr. Waldheim had warned that increased food production depended 'not on a torrent of words and resolutions but on adopting new and tangible objectives', but his advice remained unheeded. In a year during which more than enough had already been written and spoken at conferences on the world's population, raw materials and fuel resources, some 360 pages of documentation 1 were handed to a thousand delegates of national governments. Also briefed was the international fraternity which fed public opinion during the twelve days when the world, in the words of the United Nations information services, 'faced one of the gravest crises in its history'. Yet, a few months later, reports of rising food stocks, falling demand and declining prices on the world commodity markets seemed to call in question some of what had been said so recently. Thus there is ground to pause and ponder about orders of magnitude and their likely significance in days to come, when the irrelevancies of a grandiose public relations exercise will have given way to consideration of the more lasting aspects of the world food situation. The organisers of the food conference were right in advising its preparatory committee to distinguish between the food shortages of the immediate future and the long-term problems caused by insufficient

So little detailed information on the Chinese economy is available, even in the present relatively relaxed atmosphere, that readers of The China Quarterly may well be interested to hear about the attempt of Mr G. Hidasi, an East European “China-oriented economist,” to give his own account on the basis of data available to him. Mr Hidasi published his findings last year in the journal sponsored by the Academy of Sciences in Budapest.1 In his paper, he not only gives his assessment of China's economic performance from 1952 to 1970, but even ventures to guess what things will be like by the end of 1975: a unique undertaking for a foreigner who does not seem to have been in direct contact with Chinese economic reality. Like many other commentators, Mr Hidasi admits to suffering from a lack of data on targets planned and results achieved and he does not claim to have had any access to information other than that generally available to those interested in Chinese affairs. Nor does he say which of the internationally available sources, such as, for instance, the American Congressional reports or the volumes published under the auspices of the American Social Science Research Council, he has consulted. Indeed, the lack of a list of sources used somewhat weakens the author's otherwise interesting and complex “correlation calculations.” Nevertheless, they certainly merit a close examination and a comparison with communist and non-communist compilations of a similar kind.

Dr. W. Klatt is an economic expert on Communist Affairs who contributes frequently to China Quarterly.

The writer on Chinese economic affairs may be forgiven for recalling an incident from early schooldays when the headmaster, introducing his pupils to The Odyssey, mused about its author: “Nobody, he said, knows for certain whether Homer ever lived; what is known, though, is that he was blind.” Turning to China, the student of contemporary affairs is similarly uncertain of his facts. He is facing the most populous, yet one of the industrially least advanced and statistically least well documented countries in the world. At the same time, China not only succeeded within two decades in developing its own nuclear striking force, but at the end of this short period of development it launched its first earth satellite. We are thus confronted with an entirely new situation, the study of which requires certain adjustments of the techniques of analysis usually applied. Today's “China-watchers” find themselves where 20 years ago the analysts of the Soviet scene were when they had to guess Stalin's intentions and successes on the strength of misleading indices related to unknown starting dates.

Torsional deformities of the femur and/or tibia often go unrecognized in adolescents and adults who present with anterior knee pain, and patellar maltracking or instability. While open and arthroscopic surgical techniques have evolved to address these problems, unrecognized torsion may compromise the outcomes of these procedures. We collected a group of 16 consecutive patients (23 knees), with mean age of 17, who had undergone knee surgery before torsion was recognized and subsequently treated by means of rotational osteotomy of the tibia and/or femur. By follow-up questionnaire, we sought to determine the role of rotational correction at mean 59-month follow-up. We reasoned that, by correcting torsional alignment, we might be able to optimize long-term outcomes and avert repeated knee surgery. Knee pain was significantly improved after torsional treatment (mean 8.6 pre-op vs. 3.3 post-op, p

The Radiation Belt Storm Probes (RBSP)-Energetic Particle, Composition, and Thermal Plasma (ECT) suite contains an innovative complement of particle instruments to ensure the highest quality measurements ever made in the inner magnetosphere and radiation belts. The coordinated RBSP-ECT particle measurements, analyzed in combination with fields and waves observations and state-of-the-art theory and modeling, are necessary for understanding the acceleration, global distribution, and variability of radiation belt electrons and ions, key science objectives of NASA’s Living With a Star program and the Van Allen Probes mission. The RBSP-ECT suite consists of three highly-coordinated instruments: the Magnetic Electron Ion Spectrometer (MagEIS), the Helium Oxygen Proton Electron (HOPE) sensor, and the Relativistic Electron Proton Telescope (REPT). Collectively they cover, continuously, the full electron and ion spectra from one eV to 10’s of MeV with sufficient energy resolution, pitch angle coverage and resolution, and with composition measurements in the critical energy range up to 50 keV and also from a few to 50 MeV/nucleon. All three instruments are based on measurement techniques proven in the radiation belts. The instruments use those proven techniques along with innovative new designs, optimized for operation in the most extreme conditions in order to provide unambiguous separation of ions and electrons and clean energy responses even in the presence of extreme penetrating background environments. The design, fabrication and operation of ECT spaceflight instrumentation in the harsh radiation belt environment ensure that particle measurements have the fidelity needed for closure in answering key mission science questions. ECT instrument details are provided in companion papers in this same issue. In this paper, we describe the science objectives of the RBSP-ECT instrument suite on the Van Allen Probe spacecraft within the context of the overall mission objectives, indicate how the characteristics of the instruments satisfy the requirements to achieve these objectives, provide information about science data collection and dissemination, and conclude with a description of some early mission results.