Parents' satisfaction with medical and social assistance provided to children with Down syndrome: experience in Estonia

OBJECTIVE: Parents of children with mental or physical disabilities have been assumed to live more stressful lives than other parents, and people with Down syndrome (DS) may get second-rate care because of their diagnosis. The aim of this work is to investigate the extent of parents' satisfaction with medical and social services in Estonia provided for the DS individuals and their families. METHODS: From 1999 to 2001, fifty-nine DS families answered questionnaires in which we inquired about their satisfaction with medical and social assistance. RESULTS: We found that satisfaction with the quality of the information about DS is low, and most of the parents are not satisfied with the social benefits and rehabilitation options. CONCLUSIONS: The DS families need more medical information about this syndrome.The medical staff has to learn more about how to deliver bad news and how to support parents. More work needs to be done in the area of rehabilitation options and social assistance.     

基于加权奇偶矢量的机载自主完好性监测算法

针对接收机自主完好性监测在卫星数少或多星同时发生故障下无法保证可用性的问题,结合实际机载多传感器配置,提出了一种基于陆基导航系统辅助的加权奇偶矢量机载自主完好性监测方法,利用陆基导航系统的斜距及卫星伪距观测信息建立联合监测系统的观测方程,并采用加权奇偶矢量法构建检验统计量实现对故障卫星的检测判别。仿真结果表明,该方法能及时准确地识别故障卫星,从而保证卫星导航系统的完好性及组合导航定位精度,具有重大的工程应用参考价值。     

A general nonlocal variable coefficient KdV equation with shifted parity and delayed time reversal

Nonlinear Dynamics - A general nonlocal time-dependent variable coefficient KdV (VCKdV) equation with shifted parity and delayed time reversal is derived from the nonlinear inviscid dissipative and...     

测定疲劳强度的双细节串联升降法

指定寿命下的疲劳强度是无法直接测定的,自从测定疲劳强度的小子样升降法被提出以后,这种方法被广泛地应用于测定材料疲劳强度的随机特征。本文提出一种用于疲劳强度测定的双细节串联试件,给出了一个新的升降法流程。试件两个细节的疲劳强度在统计上是相互独立的,一个细节的破坏不会影响另一个细节,当一个细节破坏后,另一个细节的疲劳试验仍可以继续进行。为验证方法的有效性,本文进行了一系列的数值模拟。同时,这种方法还被用于飞机结构模拟件的疲劳强度试验。数值模拟结果和实际试验过程均表明,串联双细节升降法可以显著地节约试验时间。     

Hopf Bifurcation in Viscous Incompressible Flow Down an Inclined Plane

We provide the Hopf bifurcation theorem, which guarantees the existence of time periodic solution bifurcating from the stationary flow down an inclined plane under certain assumptions on the eigenvalues of the problem obtained by linearization around the stationary flow. Since we reduce the problem to the fixed domain, the inhomogeneous terms of reduced equations and reduced boundary conditions contain the highest derivatives. To deal with these we apply the Lyapunov–Schmidt decomposition directly.     

Stability of a Liquid Film Flowing Down an Oscillating Inclined Surface

The stability of flow of a liquid film along an inclined plate subject to periodic oscillations under the action of the gravity force is investigated with allowance for the surface tension. An equation of the Orr-Sommerfeld type with time-periodic coefficients is used. A method for determining the eigenvalues of the linear stability problem is developed on the basis of Floquet theory, spectral representation of the variables, and multistep methods of integration of ordinary differential equations. The bifurcation spectrum of the resonance modes is investigated, and the amplification coefficients and phase velocities are calculated for the surface waves, Tollmien-Schlichting waves, and resonance waves. The influence of external parameters, namely, the inclination, the surface tension, and the layer thickness, on the resonance modes and the steady-state flow modes is studied.     

Stability Analysis of a Falling Film Flow Down a Plane with Sinusoidal Corrugations

The liquid viscous film falling down a vertical wall with sinusoidal relief is considered. The linear stability of steady-state flow with respect to time-periodic disturbances is studied using the Floquet theory. It is shown that in the case of applying corrugations the variation in the disturbance growth rate is proportional to the second power of their undulations. Depending on the relief parameters there exist two possibilities: the instability domain can expand or certain disturbances can be stabilized. The growth rates are obtained numerically and analytically in the approximation of low-amplitude corrugations. The development of waves from small disturbances is simulated within the framework of nonlinear equations and the formation of structures whose wavelength is significantly greater than the space relief period is found out.     

Nonlinear Stability Analysis of Thin Viscoelastic Film Flow Traveling Down along a Vertical Cylinder

This paper investigates the weakly nonlinear stability theoryof a thin viscoelastic liquid film flowing down along the outsidesurface of a vertical cylinder. The long-wave perturbation method isemployed to solve for generalized nonlinear kinematic equations withfree film interface. The normal mode approach is first used to computethe linear stability solution for the film flow. The method of multiplescales is then used to obtain the weak nonlinear dynamics of the filmflow for stability analysis. The modeling results indicate that both thesubcritical instability and supercritical stability conditions arepossible to occur in a viscoelastic film flow system. The degree ofinstability in the film flow is further intensified by the lateralcurvature of cylinder. This is somewhat different from that of theplanar flow. The modeling results also indicate that by increasing theviscoelastic effect and decreasing the radius of the cylinder the filmflow can become less stable as traveling down along the verticalcylinder.     

Hopf Bifurcation in Viscous Incompressible Flow Down an Inclined Plane: a Numerical Approach

In this article we investigate numerically a Hopf bifurcation phenomenon for a viscous incompressible flow down an inclined plane. This problem has been discussed by Nishida et al. who proved the existence of periodic solutions bifurcating from the steady flow. Using a computational methodology based on finite elements for the space discretization and on operator splitting for the time discretization, we have been able to reproduce the results predicted by Nishida et al.      

腕管综合征及其生物力学研究进展

腕管综合征(carpal tunnelsyndrome, CTS)是腕部正中神经受到卡压而引起的一种神经病症. 它所带来的高昂的社会和经济花费使得腕管综合征的研究应运而生, 并且在过去的10年里得到突飞猛进的发展. 常规的手术方式是将腕横韧带(transversecarpal ligament)切开, 以释放正中神经(mediannerve)所受到的压力. 本文不仅对腕管的解剖结构、腕管综合征的症状和发病机理、以及诊断和治疗等方面作了简要概述,还主要从以下几个方面探讨了近年来与腕管综合征相关的生物力学研究工作及其进展: (1)影响腕管内压力的因素,包括腕部姿势, 手指、肌腱或手掌所受外荷载的大小, 以及手工劳作的不同频率等; (2)腕管结构的稳定性研究, 如切开腕横韧带或腕骨间掌横韧带对腕刚度的影响, 以及从动力学角度分析腕管减压手术会导致的腕骨失稳现象; (3)腕管内容物(如肌腱、正中神经)的运动及内容物之间以及腕管内容物与腕横韧带之间的相互作用;(4)腕横韧带的延展实验, 如利用外荷载或移位搭接的方法拉长腕横韧带, 以达到降低腕管内压力的目的. 本文旨在加强人们对腕管综合征尤其是对与腕管综合征相关的生物力学研究进展的了解, 并从生物力学的观点提出利用有限元方法对腕管结构进行三维建模与分析将有可能成为腕管综合征进一步研究的一个重要发展方向.      

Epidemiology of Usher syndrome in Valencia and Spain

OBJECTIVE: To obtain epidemiological data on the prevalence of the different types of Usher syndrome (US) in Spain, since these data were missing; to estimate the proportion of sporadic cases among simplex families, and calculate the prevalence of the Usher syndrome in a homogeneous population from Eastern Spain (3,875,234 inhabitants) that is representative of the Spanish population. METHODS: Otological, ophthalmological and genetic studies were performed in 89 US patients from 46 families and subjected to statistical and segregation analysis. RESULTS: 41.6% of them suffered US type I, 46.1% type II, and in 12.3% the classification remains unclear. The estimated prevalence for the Province of Valencia was 4.2/100,000. There was a notable excess of male-only affected multiplex sibships in our sample that could be attributable to an X-linked inheritance. CONCLUSIONS: The number of families with USI type was similar to that of families with USII type. The estimated prevalence for the Province of Valencia is in agreement with other reports in which the estimate for the prevalence of US ranges from 1.8 to 6.2/100,000.     

Marfan syndrome in Europe

OBJECTIVES: Marfan syndrome (MFS) is a relatively frequent systemic connective tissue disorder with an important physical morbidity and mortality. The influences of MFS on physical problems, perception of severity, and impact on the quality of life and psychosocial well-being have been studied only limitedly. The aim of this study was to assess the association between the severity derived from the reported symptoms and subjectively experienced severity of MFS (expressed as a global judgment), with special emphasis regarding impact on relationships and pregnancies, psychosocial adjustment, and differences between the seven European countries. METHODS: A questionnaire designed specifically for this study and translated in each of the native languages was sent to 2,080 members of one of the patient support groups in Belgium, Denmark, France, Germany, The Netherlands, Switzerland, and the United Kingdom. 857 MFS patients of 13 years and older completed the questionnaire and were included in the data analysis. RESULTS: Physical impairments were scored by perception of severity of physical symptoms by the patients (physical severity perception score) and by their perception of the influence of MFS on their life (subjective severity score). Main discrepancy between physical severity perception and subjective severity score was the higher percentage of patients scoring in physical severity perception as severe (53.5%) compared to subjectively severe (26.5%). 61% of those who scored on the physical severity score as severely affected were designated as being mildly-moderately affected on subjective scoring. Both severity scores increased significantly with age. Two hundred-twenty women have carried 430 pregnancies (1.95 pregnancies/woman), with cardiovascular complications in 1.6%. Prenatal studies for MFS were rejected by 7.6% of MFS patients of 25 years and older, 33.6% were undecided, and 48.5% favored prenatal diagnosis for MFS if available. A positive general self-image was reported by 91.5% of patients. However, more than 90% stated that MFS had a negative influence on their sexual relationships, which they ascribed to negative perception of their body image. CONCLUSIONS: MFS has significant impact on daily life activities, but the majority of patients come to terms with their condition. Acceptance is mainly determined by subjective severity, and less by physical symptoms as reported by the patients themselves. It is important to stimulate a positive attitude towards MFS.     

Nonlinear Stability Analysis of Thin Viscoelastic Film Flowing Down on the Inner Surface of a Rotating Vertical Cylinder

This paper investigates the stability of thin viscoelastic liquid film flowing down on the inner surface of a rotating vertical cylinder by means of the long wave perturbation. After proving the insufficiency of the linear model in characterization of certain flow behaviors, a generalized nonlinear kinematic model is then derived to represent the physical system. This model is solved through the following procedure. In the first step, the normal mode method is used to characterize the linear behaviors. The amplitude growth rates and the threshold conditions are characterized subsequently and summarized as the by-products of the linear solutions. In the second step, a nonlinear film flow model is solved by using the method of multiple scales to characterize flow behaviors at various states of sub-critical stability, sub-critical instability, supercritical stability, and supercritical explosion. The modeling results indicate that with the increase in the rotation speed Ω and the radius of cylinder R, the film flow system will be more stable.     

Triple Test Screening for Down Syndrome: Looking Back on a False-Positive Result and Having or Not Having a Triple Test in Subsequent Pregnancies

Objectives: It was the main aim of the present retrospective study carried out in Flanders to evaluate how women with a false-positive triple test result look back on their experience and decision making and how many of them make use of the triple test in subsequent pregnancies. Methods: All 508 women tested in the Centre for Human Genetics in Leuven in 1995 who had a positive triple test result followed by a normal amniocentesis outcome were invited to participate in a mailed questionnaire study with open and multiple choice questions in 1998. The response rate was 68%. Results: The answers to the multiple choice question assessing how they look back on their initial expectations regarding the exact meaning of the triple test revealed that less than one half reported that it concerned the identification of 'a higher risk of carrying a child with Down syndrome (DS)'. Reporting correct initial expectations was significantly associated with a higher education level. The same holds for indecisiveness regarding pregnancy termination should the amniocentesis have detected a fetus with DS. As expected, a large majority of the women reported a high level of distress or worry after the communication of the positive triple test result. Overall the findings show that retrospectively most women had the feeling that the decision to have amniocentesis was their own decision rather than a professional's. Of the subgroup with one or more subsequent pregnancies 70% had another triple test. Conclusions: The overall results of this study clearly reveal a need for a systematic approach aimed at better informing and counselling pregnant women about the implications and limitations of the triple test. Notwithstanding the reported high level of distress caused by a positive triple test result, a large majority of the women with subsequent pregnancies had another triple test; they represent a clearly higher percentage than in another recent study. Copyright 2001 S. Karger AG, Basel     

A cytogenetic register of down syndrome in Lebanon

OBJECTIVES: To provide data on the cytogenetics and epidemiology of Down syndrome in our community. METHODS: All cases of Down syndrome diagnosed cytogenetically were entered over a period of 5 years together with data regarding age at referral, parental ages and parity. RESULTS: A total of 280 cases were entered. In postnatal cases, the mean maternal age was 32.19 years and 41.5% of mothers were over 35 years. Only 47.3% of Down syndrome children were diagnosed at less than 1 month of age. The male to female sex ratio of 1.66 is significantly more elevated than that reported in larger registers. CONCLUSIONS: Because of problems inherent to Lebanon, this register does not have a high level of ascertainment, however it appears that the emphasis in a potential prevention programme should be placed on education, information and family planning.     

猪生殖与呼吸综合征病毒TaqMan荧光定量RT-PCR检测方法的建立

根据GenBank登录的PRRSV保守基因序列设计合成了引物和探针,并对其进行了筛选;对荧光定量PCR的反应条件进行了优化,建立了TaqMan荧光定量RT-PCR检测方法。同时用建立的检测方法对组织病料进行了检测,并与常规RT-PCR做了对比。结果显示,所建立的TaqMan荧光定量RT-PCR方法灵敏度可达5.0×100拷贝/μL,比常规RT-PCR灵敏度高100倍。用该方法对东莞、增城、湛江等地的猪血清和多种组织样品进行了检测。结果,该方法与常规RT-PCR检测方法的阳性符合率为100%。用该方法对3份不同的组织样品进行了重复检测,结果表明,该方法具有良好的重复性,可满足当前PRRS的诊断需要。