A strategic development model for the role of the biomedical physicist in the education of healthcare professionals in Europe

This is the third of a series of articles targeted at biomedical physicists providing educational services to other healthcare professions, whether in a university faculty of medicine/health sciences or otherwise (e.g., faculty of science, hospital-based medical physics department). The first paper identified the past and present role of the biomedical physicist in the education of the healthcare professions and highlighted issues of concern. The second paper reported the results of a comprehensive SWOT (strengths, weaknesses, opportunities, threats) audit of that role. In this paper we present a strategy for the development of the role based on the outcomes of the SWOT audit. The research methods adopted focus on the importance of strategic planning at all levels in the provision of educational services. The analytical process used in the study was a pragmatic blend of the various theoretical frameworks described in the literature on strategic planning research as adapted for use in academic role development. Important results included identification of the core competences of the biomedical physicist in this context; specification of benchmarking schemes based on experiences of other biomedical disciplines; formulation of detailed mission and vision statements; gap analysis for the role. The paper concludes with a set of strategies and specific actions for gap reduction.     

Medical physics in radiotherapy: The importance of preserving clinical responsibilities and expanding the profession's role in research,education, and quality control

Medical physicists have long had an integral role in radiotherapy. In recent decades, medical physicists have slowly but surely stepped back from direct clinical responsibilities in planning radiotherapy treatments while medical dosimetrists have assumed more responsibility. In this article, I argue against this gradual withdrawal from routine therapy planning. It is essential that physicists be involved, at least to some extent, in treatment planning and clinical dosimetry for each and every patient; otherwise, physicists can no longer be considered clinical specialists. More importantly, this withdrawal could negatively impact treatment quality and patient safety. Medical physicists must have a sound understanding of human anatomy and physiology in order to be competent partners to radiation oncologists. In addition, they must possess a thorough knowledge of the physics of radiation as it interacts with body tissues, and also understand the limitations of the algorithms used in radiotherapy. Medical physicists should also take the lead in evaluating emerging challenges in quality and safety of radiotherapy. In this sense, the input of physicists in clinical audits and risk assessment is crucial. The way forward is to proactively take the necessary steps to maintain and advance our important role in clinical medicine.     

棉花生育时期及蕾铃发生发育模拟模型研究

通过定量分析南京、安阳、保定和石河子4个试验点2002年不同播期3个品种(早熟品种中棉所36号、中早熟品种中棉所35号、中熟品种中棉所41号)的生育时期与环境因子之间的动态关系,建立了基于生理发育时间(DPT)的棉花生育期、果枝出现时间及其蕾铃发育阶段的模拟模型.模型的热效应计算考虑了不同棉区昼夜温较差对棉花发育速率的影响以及薄膜覆盖的增温效应,在模型中引入了果枝始节系数(I_FIN)、日照时数因子(F_SH)和果枝节位光照系数(I_FBR).利用不同年份、生态区、基因型的试验资料对模型进行了测试检验.结果表明,不同条件下模拟值与观测值的符合度较好.不同生育时期的模拟值与观测值的根均方差(RMSE)从播种到出苗、出苗到现蕾、开花到吐絮及播种到吐絮分别为0.9、2.2、17和2.1d,平均2.1d;棉株各果节点从现蕾到开花日期的模拟值与观测值的RMSE为1.8～3.7d,从开花到吐絮日期的RMSE值为4.6～5.8d.     

A general model for effects of temperature on ectotherm ontogenetic growth and development

The temperature size rule (TSR) is the tendency for ectotherms to develop faster but mature at smaller body sizes at higher temperatures. It can be explained by a simple model in which the rate of growth or biomass accumulation and the rate of development have different temperature dependence. The model accounts for both TSR and the less frequently observed reverse-TSR, predicts the fraction of energy allocated to maintenance and synthesis over the course of development, and also predicts that less total energy is expended when developing at warmer temperatures for TSR and vice versa for reverse-TSR. It has important implications for effects of climate change on ectothermic animals.     

小麦发育过程及生育期机理模型的研究I.建模的基本设想与模型的描述

将小麦发育的温度效应曲线化,以发育生理生态过程为基础,利用作物生理发育时间(Physiological Development Time,简称PDT)为尺度,提出系统地预测小麦顶端发育阶段和物候生育期的模拟模型.预测的顶端发育阶段包括单棱期、二棱期、小花原基分化期、雌雄蕊原基分化期、药隔期、四分体期、抽穗期.物候发育阶段包括种子萌发、出苗期、分蘖期、越冬期、返青期、拔节期、孕穗期、抽穗期、开花期、灌浆期、成熟期.模型中用来描述特定品种发育遗传差异的参数有温度敏感性、生理春化时间、光周期敏感性和基本早熟性,分别体现了不同品种小麦在热效应、春化作用、光周期反应以及最早开花时间这四方面的遗传特性,共同决定了不同品种到达各发育阶段的生理发育时间     

Influence of femoral chordotonal organ afferences on ecdysis and on the development of motor programmes in locust larvae

ABSTRACT. The receptor apodemes of the femoral chordotonal organs of hind legs of locust larvae were crossed. This reverses the sign of the chordotonal organ afferences. Animals were operated during the second, third and fourth instars and some could be reared to adults with the receptor apodeme remaining crossed. During walking, the animals did not habituate to the incorrect afference, but those operated at the beginning of the third instar altered their walking programme to some extent. The results from animals operated during the second instar and the first 2 days of the third instar were ambiguous. The jumping generator is not affected by the incorrect afference.     

Antibody variable region interactions with Protein A: implications for the development of generic purification processes

In this paper, a wide range of antibodies from various subclasses and subfamilies are employed to evaluate the creation of generic separation processes using Protein A chromatography. The reasons for elution pH differences amongst several IgG1s, IgG2s, antibody fragments, and Fc-fusion proteins during Protein A chromatography are investigated using several complimentary techniques. The results indicate that variable region interactions play a major role in determining elution pH for VH3 subfamily antibodies while using traditional protein A chromatographic materials. On the other hand, experiments with a resin which employs a ligand consisting solely of B domain of Protein A indicate that variable region interactions can be mitigated, enabling the use of a single elution pH for a range of antibodies. Finally, the moderation of elution conditions associated with this engineered ligand are shown to minimize problems associated with low pH induced aggregation. It is expected that the findings reported in this paper will facilitate faster process development cycle times for this important class of human therapeutics.     

临床医学专业学位研究生培养模式的实践与探索

针对当前临床医学专业学位研究生生源多样化、复杂化的现状,从当前临床医学专业学位研究生培养模式存在的问题出发,以青岛大学医学院附属医院培养临床专业学位研究生为例,以应用型医学人才为目标,探讨了一种有效的临床医学专业学位研究生培养模式,模式包括设置科学合理的课程体系、建立并实施临床医学专业学位研究生临床技能培训及考核体系、临床医学专业学位研究生非专业素质教育培训体系,对提高临床医学专业学位研究生临床技能、执业素质及未来临床工作适应力有积极作用。     

A systems model and computer simulation of the green rice leafhopper populations in control programmes

A simulation model of the green rice leafhopper-spiders system was presented. The validity of this model for simulation purpose was tested by comparing the calculated values with observed ones (Fig. 4). The effectiveness of various control measures against leafhoppers was evaluated by computer simulations. The computer simulation demonstrated that the wrong use of selective insecticide, contrary to expectation, brought an increase in the pest density, i. e., that the egg densities of leafhoppers in the 2nd and 3rd generations are increased by the insecticidal application in February, while they are decreased by the July application (Table 2). To obtain satisfactory control by sterile-male release, 320,000 sterile-male per square kilometer should be released even in the combined use with insecticides (Fig. 5). The escape of leafhoppers from predation by spiders was demonstrated by the simulation. It is suggested that spiders are able to suppress the leafhopper populations at a low density when there is a very favorable balance between spiders and leafhoppers, and this condition may be realized by sophisticated use of selective insecticides (Fig. 6). Factors and/or processes which have to be involved in a more improved systems model are discussed.     

A stochastic development fraction model for predicting the development of the nematode parasite of sheep, Haemonchus contortus from egg to infective larvae under the influence of temperature

1. 1 Regression models for predicting the minimum, the median and the maximum period of development of the parasite H. contortus from egg to the infective stage of constant temperature were described.

2. 2. Simulations were used to study the development of the parasite to the infective stage.

3. 3. Further, an analytic Stochastic Development Fraction Model was used to reproduce the development of the parasite obtained by simulations.

4. 4. The Stochastic Development Fraction Model was compared with the Deterministic Development Fraction Model to expose its potentials for predicting the development of parasites on pasture where varying temperature prevail.

UNESCO Regional Network for Microbiology and Allied Activities in Southeast Asia: A model training and research network in microbiology for development

The Regional Network for Microbiology in Southeast Asia is one of the programmes for regional cooperation in the basis sciences established by UNESCO in collaboration with the government of Japan through a funds-in-trust agreement, in 1974. Up to 1991, the network has organized 50 scientific activities and 945 young microbiologists have received training in microbiology. The nature of the programme's activities has become more specific recently and concerns microbial resources and use of biotechnology to conserve the environment.     

A mathematical model of breast cancer development, local treatment and recurrence

Cancer development is a stepwise process through which normal somatic cells acquire mutations which enable them to escape their normal function in the tissue and become self-sufficient in survival. The number of mutations depends on the patient's age, genetic susceptibility and on the exposure of the patient to carcinogens throughout their life. It is believed that in every malignancy 4-6 crucial similar mutations have to occur on cancer-related genes. These genes are classified as oncogenes and tumour suppressor genes (TSGs) which gain or lose their function respectively, after they have received one mutative hit or both of their alleles have been knocked out. With the acquisition of each of the necessary mutations the transformed cell gains a selective advantage over normal cells, and the mutation will spread throughout the tissue via clonal expansion. We present a simplified model of this mutation and expansion process, in which we assume that the loss of two TSGs is sufficient to give rise to a cancer. Our mathematical model of the stepwise development of breast cancer verifies the idea that the normal mutation rate in genes is only sufficient to give rise to a tumour within a clinically observable time if a high number of breast stem cells and TSGs exist or genetic instability is involved as a driving force of the mutation pathway. Furthermore, our model shows that if a mutation occurred in stem cells pre-puberty, and formed a field of cells with this mutation through clonal formation of the breast, it is most likely that a tumour will arise from within this area. We then apply different treatment strategies, namely surgery and adjuvant external beam radiotherapy and targeted intraoperative radiotherapy (TARGIT) and use the model to identify different sources of local recurrence and analyse their prevention.     

A mathematical model of epiphyseal development: hypothesis of growth pattern of the secondary ossification centre

This paper introduces a ‘hypothesis about the growth pattern of the secondary ossification centre (SOC)’, whereby two phases are assumed. First, the formation of cartilage canals as an event essential for the development of the SOC. Second, once the canals are merged in the central zone of the epiphysis, molecular factors are released (primarily Runx2 and MMP9) spreading and causing hypertrophy of adjacent cells. In addition, there are two important molecular factors in the epiphysis: PTHrP and Ihh. The first one inhibits chondrocyte hypertrophy and the second helps the cell proliferation. Between these factors, there is negative feedback, which generates a highly localised and stable pattern over time. From a mathematical point of view, this pattern is similar to the patterns of Turing. The spread of Runx2 hypertrophies the cells from the centre to the periphery of the epiphysis until found with high levels of PTHrP to inhibit hypertrophy. This mechanism produces the epiphyseal bone-plate. Moreover, the hypertrophy is inhibited when the cells sense low shear stress and high pressure levels that maintain the articular cartilage structure. To test this hypothesis, we solve a system of coupled partial differential equations using the finite element method and we have obtained spatio-temporal patterns of the growth process of the SOC. The model is in qualitative agreement with experimental results previously reported by other authors. Thus, we conclude that this model can be used as a methodological basis to present a complete mathematical model of the whole epiphyseal development.     

国际基因工程机器大赛对本科生综合能力培养模式的探索

华东理工大学生物工程学院从高水平专业比赛出发,以学生的兴趣为切入点,依托强大的科研和教学基地,构建具有"生物创客"精神的人才培养体系和创新实践能力培养体系.充分发挥学生主观能动性,提升了生物工程类相关专业本科生的科研素养和综合能力.对传统的高校教育模式进行了有效探索,满足了生命科学飞速发展时期对创新型人才的迫切需求.     

A model for the evolution of developmental arrest in male orangutans

Male Sumatran orangutans (Pongo abelii) may delay for many years the acquisition of the full array of secondary sexual traits, including their characteristic cheek flanges. Such flexible developmental arrest is unique among male primates. Among male Bornean orangutans (Pongo pygmaeus) such long delays appear less common. Here, we develop a simple model to identify the conditions under which developmental arrest can be adaptive. We show that the baseline strategy (i.e., males are not susceptible to arrest) cannot be invaded by the flexible strategy (i.e., males can arrest their development when the conditions are unfavorable) when the potential for high‐ranking unflanged or flanged males to monopolize sexual access to females is low. In contrast, at high monopolization potential, the flexible strategy is the evolutionarily stable strategy. We also derive the proportion of flanged males in the population for each combination of monopolization values. This model concurs with field data that found a different monopolization potential between Bornean and Sumatran flanged males and a lower proportion of flanged males in the population in Sumatran orangutans. Pronounced developmental arrest is linked to very low adult mortality, which explains why it is so limited in its taxonomic distribution. Am J Phys Anthropol 2012. © 2012 Wiley Periodicals, Inc.     

A nutritional model of late embryonic vitamin A deficiency produces defects in organogenesis at a high penetrance and reveals new roles for the vitamin in skeletal development

Vitamin A plays an essential role in vertebrate embryogenesis. In the present study, pregnant vitamin A-deficient (VAD) rats were maintained during early pregnancy on the short half-life vitamin A metabolite, all-trans retinoic acid (atRA), in an amount sufficient to support normal development to E10.5, with a higher level of atRA (250 μg atRA/g diet) provided from embryonic day (E) 8.5-10.5 to prevent mid-gestational resorption. When limiting amounts of atRA (1.5 or 12 μg/g diet) were provided after E10.5, a highly reproducible and penetrant state of late fetal vitamin A deficiency (late VAD) was induced in the organs of developing fetuses. In addition, late VAD fetuses displayed both anteriorization of cervical regions and novel posteriorization events at the thoracic and sacral levels of the skeleton, and showed sternal and pelvic malformations not previously observed in early VAD or genetic models. The expression of several Hox genes (Hoxd3 and Hoxb4) was altered in late VAD embryos, with a reduction in Hoxd3 noted as early as 1 day after instituting deficiency. All late VAD-induced malformations were prevented by the addition of retinol starting at E10.5, whereas provision of a high level of atRA throughout pregnancy improved but could not completely rescue the development of all organ systems. This work defines a nutritional model in which vitamin A deficiency can be induced during fetal development, and reveals new functions for the vitamin in the development of the axial and appendicular skeleton.     

The recombinant limb as a model for the study of limb patterning, and its application to muscle development

The recombinant limb is a model system that has proved fruitful for analyzing epithelial-mesenchymal interactions and understanding the functional properties of the components of the limb bud. Here we present an overview of some of the insights obtained through the use of this technique. Among these are the understanding that fore or hind limb identity is inherent to the limb bud mesoderm, that the apical ectodermal ridge (AER) is a permissive signaling center and that the limb bud ectoderm plays a central role in the control of dorsoventral polarity. Recombinant limb studies have also allowed the identification of the affected tissue component in several limb mutants. More recently this model has been applied to the study of regulation of gene expressions related to patterning. In this report we use recombinant limbs to analyze pattering of the Pax3 expressing limb muscle cell lineage in the early stages of limb development. In recombinant limbs made without the zone of polarizing activity (ZPA), myoblasts appear intermingled with other mesodermal cells at the beginning of the recombinant limb development. Rapidly thereafter, the muscle precursors segregate and organize around the central forming chondrogenic core of the recombinant. Although this segregation is reminiscent of that occurring during normal development, the myoblasts in the recombinant fail to proliferate appropriately and also fail to migrate distally. Consequently, the muscle pattern in the recombinant limb is defective indicating that normal patterning cues are absent. However, recombinant limbs polarized with a ZPA exhibited a larger mass of muscle cells and a more normal morphogenesis, supporting a role for this signaling center in limb muscle development. Finally, we have ruled out host somite contributions to recombinant limbs by grafting chick recombinant limbs to quail hosts. This initial report demonstrates the value of the recombinant limb model system for dissecting the environmental cues required for normal muscle limb patterning. Received: 31 August 1998 / Accepted: 29 September 1998     

A murine model for the assessment of placental and fetal development in teratogenicity studies

During normal pregnancy in the mouse, maternal serum levels of the analogues to human schwangerschaftsprotein-1 and alpha-fetoprotein correlate significantly with the growth of the placenta and fetus respectively. This relationship has been utilized in the analysis of the effect of sodium selenite on placental and fetal growth in mice. Moderate doses of sodium selenite did not affect the growth of the placenta and fetus significantly, whereas high doses of selenite resulted in a large percentage of abortions. The protein markers were found to be useful in the prediction of placental and fetal growth, and they are suggested to be of general use in the study of the impact of teratogenic substances, since they reflect the status of the fetoplacental mass during gestation.