Assessment of two 'low-tech' genetic health care procedures performed by prenatal care providers in Washington state: implications for future policy development activities

Equity in health care demands that patients be treated fairly, impartially and with justice. Health care professionals and others have long been aware of the concept of equity, and the many inequities that exist in our health care system. As part of our analysis of postpartum data collected between 1993 and 1996 by the Washington Pregnancy Risk Assessment Monitoring System (PRAMS) from self-administered patient surveys, we explored equity as it pertains to two 'low-tech' prenatal genetic health care procedures: (1) whether or not prenatal care providers asked their patients about a family history of birth defects/genetic disorders, and (2) whether or not prenatal care providers talked to their patients about prenatal testing for birth defects/genetic disorders. Overall, about 80% of pregnant women reported that they had been asked about their family history of birth defects/genetic disorders, and about 85% said that their prenatal care provider(s) had talked to them about prenatal testing. Maternal characteristics associated with a lower likelihood of receiving these two low-tech genetic health care procedures appeared to be young maternal age, and low education and income levels, regardless of where women with these attributes received their prenatal care (e.g. community, migrant, health department or military health care clinics, private physicians, or health maintenance organizations).     

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     

Psychological distress and breast self-examination frequency in women at increased risk for hereditary or familial breast cancer

BACKGROUND: The Magnetic Resonance Imaging Screening study evaluates the efficacy and psychological impact of a surveillance program for women at increased risk for hereditary or familial breast cancer in the Netherlands. Surveillance consists of biannual physical examination, annual mammography, annual MRI and monthly breast self-examination (BSE). OBJECTIVE: To examine the association between psychological distress and reported BSE frequency. METHODS: Two months prior to surveillance demographics, BSE frequency, general distress (Hospital Anxiety and Depression Scale and the somatic scale of the Symptom Checklist-90) and breast cancer-specific distress (Impact of Event Scale) were assessed in 316 women (mean age 40.5 years, range 21-63 years). RESULTS: The majority (57%) reported performing monthly BSE. Ten percent reported never performing BSE, 20% less frequently than once a month and 13% at least once a week. Women below the age of 40 who examined their breasts more frequently than recommended (i.e. at least once a week) were shown to be significantly more distressed than the other women in the sample (p = 0.03). These women represented 15% of all the women below the age of 40 years in our study sample. CONCLUSION: Higher breast cancer-specific distress scores were observed among younger women who examined their breasts at least once a week. It is important for physicians to be aware of this hypervigilant behaviour, especially since it is correlated with breast cancer-specific distress.     

Risk factors for neonatal mortality in low-income population subgroups in Karachi, Pakistan

This paper assesses the risk factors for neonatal mortality (0-28 days of life) for full-term singleton live births. The study sample comprised 1,011 ever-married women who were residents of four multi-ethnic, multi-religious low-income areas of Karachi, Pakistan during 1995. The analysis sample was restricted to 4,488 live births to 912 women. Results showed that 4.8% (n = 217) of all births ended in death in the neonatal period, and 76% (n = 164) of these neonatal deaths occurred in the first week of life. While neonatal mortality rates had declined appreciably over time, a large proportion of neonatal deaths were clustered in a small group of women. The univariate analysis showed a statistically significant association between a number of maternal-level parameters (e.g., mother's age at birth, level of formal education, employment status, religious affiliation, and consanguinity) and child-level parameters (e.g., birth order, birth interval, survival status of the preceding child, sex of the neonate, year of death). At the multivariate level, consanguinity, birth order and year of death were found to be statistically significant risk factors for neonatal mortality analyses despite adjustment for death clustering. The study highlights the importance of inbreeding as a determinant of early offspring death, and points to the need for better understanding of why deaths are clustered in certain families. Given the widespread practice of close cousin marriages in Pakistan across all socio-economic groups, there is a need to validate the findings in less economically disadvantaged population subgroups within the country.     

New method to option pricing for the general black-scholes model—An actuarial approach

Using physical probability measure of price process and the principle of fair premium, the results of Mogens Bladt and Hina Hviid Rydberg are generalized. In two cases of paying intermediate divisends and no intermediate dividends, the Black-Scholes model is generalized to the case where the risk-less asset (bond or bank account) earns a time-dependent interest rate and risk asset (stock) has time-dependent the continuously compounding expected rate of return, volatility. In these cases the accurate pricing formula and put-call parity of European option are obtained. The general approach of option pricing is given for the general Black-Scholes of the risk asset (stock) has the continuously compounding expected rate of return, volatility. The accurate pricing formula and put-call parity of European option on a stock whose price process is driven by general Ornstein-Uhlenback (O-U) process are given by actuarial approach. Foundation items: the National Natural Science Foundation of China (69972036); the Natural Science Foundation of Henan Education Committee (1999110010) Biography: YAN Hai-feng (1964∼), Associate Professor, Doctor (E-mail: yhaif@263.net)     

Coherent structure of Alice–Bob modified Korteweg de-Vries equation

To describe two-place events, Alice–Bob systems have been established by means of the shifted parity and delayed time reversal in the preprint arXiv:1603.03975v2 [nlin.SI], (2016). In this paper, we mainly study exact solutions of the integrable Alice–Bob modified Korteweg de-Vries (AB-mKdV) system. The general Nth Darboux transformation for the AB-mKdV equation is constructed. By using the Darboux transformation, some types of shifted parity and time reversal symmetry breaking solutions including one-soliton, two-soliton, and rogue wave solutions are explicitly obtained. In addition to the similar solutions of the mKdV equation (group invariant solutions), there are abundant new localized structures for the AB-mKdV systems.     

Screening for alpha-thalassemia-1 heterozygotes in expecting couples by the combination of a simple erythrocyte osmotic fragility test and a PCR-based method

OBJECTIVE: To develop a simple method for the prospective identification of couples at risk of homozygous alpha-thalassemia-1 (Hb Bart's hydrops fetalis) in pregnancy. METHODS: Antenatal care (ANC) women and their husbands were analyzed using a simple erythrocyte osmotic fragility (EOF) test and a PCR-based method for the detection of the mutation leading to alpha-thalassemia-1 of the Southeast Asian type (SEA). RESULTS: Heterozygosity for the alpha-thalassemia-1 (SEA) deletion was found to correlate with an EOF value <60%. For a prospective screening, ANC women and their husbands are analyzed with the EOF test and only those having a value <60% were further checked by PCR. Of 2,769 cases analyzed during a 6-month period, 24 couples in which both partners are heterozygotes could be identified for genetic counseling and prenatal diagnosis. The application of the EOF test decreased the workload for PCR by approximately 80%. CONCLUSION: Prospective screening for alpha-thalassemia-1 (SEA) heterozygotes in northern Thailand is becoming easier to realize by the combination of EOF test and PCR.     

Glycogen storage disease type II: birth prevalence agrees with predicted genotype frequency

OBJECTIVES: To compare the overall birth prevalence of diagnosed glycogen storage disease type II (GSD II) with the predicted frequency based on mutation screening, in order to determine whether GSD II is an underdiagnosed condition, and to analyze which medical disciplines recognize GSD II. METHODS: Retrospective data on all enzymatic diagnoses of GSD II were collected from diagnostic labs throughout the Netherlands, covering the period from January 1, 1972 to December 31, 1996. Age-specific diagnostic incidence rates were calculated for the entire study period. By adding together the diagnostic incidences for all age groups, we calculated the birth prevalence of diagnosed GSD II and compared these figures with the predicted frequency based on mutation screening in a random sample from the general population. The medical specialization of the referring clinicians was also recorded. RESULTS: GSD II was diagnosed in 154 individuals, including 11 prenatal diagnoses. The birth prevalences of the various phenotypes were 1/101,000 (infantile form), 1/720,000 (juvenile form) and 1/53,000 (adult form). The birth prevalence of the adult and infantile phenotype together was 1/35,000. Eighty-two percent of the patients were diagnosed in university hospitals. Of the patients with infantile GSD II, 71% were diagnosed by a pediatrician, whereas most patients with adult GSD II were diagnosed by a neurologist (80%). CONCLUSIONS: There is no evidence for the underdiagnosis of GSD II in the Netherlands, as the calculated birth prevalences of the disease are consistent with previous predictions based on mutation screening in a random sample of newborns. The worldwide birth prevalence of the disease may well be higher than 1 in 100,000. GSD II is mainly diagnosed in university hospitals.     

Attitudes of Israeli Muslims at risk of genetic disorders towards pregnancy termination

OBJECTIVES: (1) To examine attitudes towards termination of pregnancy (TOP) among high-risk and non-high-risk (for cystic fibrosis) Arab-Muslims, and (2) to examine the effect of an intervention, which among other things related explicitly to TOP. METHODS: The study comprised three groups: (1) an intervention group at high risk for CF, which received community genetic counseling; (2) a control group at high risk for CF, and (3) a control group from the general population. The latter two groups were exposed to minimal intervention. Attitudes were measured two or three times during a 1-year period (for the control and intervention groups, respectively). RESULTS: Predictors of an affected fetus being considered a legitimate cause for TOP were religiosity, familiarity with an affected child, and benefits of the test. Predictors of individuals (hypothetically) choosing abortion in the case of an affected fetus were education and age. No change occurred in the attitudes of participants (either experimental or control groups) in the course of 1 year. CONCLUSIONS: Other possible intervention options are discussed, and specifically, the advantages of using opinion leaders such as clergy and medical staff.     

Age at postnatal diagnosis of down syndrome in the northern Netherlands for the period 1981-2000

BACKGROUND: In live-born children with Down syndrome it may be very difficult for the clinician or midwife assisting at the delivery to recognise Down syndrome in newborn babies due to varying physical appearances. Meanwhile more and more therapeutical interventions become available that should start early in life. We were interested in the age at the postnatal diagnosis of Down syndrome, and found no literature on the subject. METHODS: We studied the age at the diagnosis of Down syndrome for live-born babies born in the period of 1981-2000 and registered by the European Registration of Congenital Anomalies in the northern part of The Netherlands. RESULTS: For 289 children, data on the age at the postnatal diagnosis were available, in 70.8% of whom there was suspicion of DS on the day of birth. In 1.7% of the cases, the diagnosis was made after 1 year. Place of birth and the specialty of the health worker assisting at the delivery were associated with age at diagnosis. When the child was delivered at hospital, 96.4% of the Down syndrome cases had been diagnosed within 1 month compared to 81.3% following home delivery. CONCLUSION: In some cases of Down syndrome in live-born babies, the diagnosis is made only after months or a year. The diagnosis was made faster in babies born in hospital compared to those born at home.     

Community-based program for the diagnosis and prevention of genetic disorders in Cuba. Twenty years of experience

The author's experience of 20 years as director of the medical genetic services program in Cuba is presented. The setting of the infrastructure for equipment and the training of personnel for the medical genetic program began in 1981 in the city of Havana, and was progressively extended to cover the whole country in 1988. Between 1982 and 2002, 2.8 million pregnant women were tested for sickle cell carrier status, 96,000 carriers and 4,786 couples at risk were detected and offered genetic counseling and prenatal diagnosis. In the same period, the combination of maternal serum alpha-fetoprotein screening and fetal ultrasound led to the prenatal diagnosis of anomalies in several thousand fetuses. The accessibility to legal abortion, and the autonomous decisions by the majority of couples to terminate abnormal pregnancies reduced the prevalence of neural tube defects and sickle cell disease at birth by 90 and 65%, respectively, by 2002. In the span of approximately 20 years, 22,690 pregnant women at risk received prenatal chromosomal diagnosis. Newborn screening for phenylketonuria and congenital hypothyroidism was established. Genetic counseling was offered to every detected person or family at risk for genetic conditions. The network of medical genetic services established in the country received a very positive acceptance by the population. A very successful connection with the primary health care level was established.     

A new artificial neural network tracking technique for particle image velocimetry

 The analysis of Particle Image Velocimetry (PIV) data requires effective algorithms to track efficiently the particles suspended in the fluid flow. The artificial neural network algorithm method described here presents a new approach to solve this problem. Contrary to the classic cross correlation method, this new method does not require a large number of particles per frame, it can handle flows with large velocity gradients, and is suited for tracking images with multiple exposures as well as tracking through consecutive images. The algorithm was tested on synthetic and available experimental data to provide a thorough performance analysis. Received: 28 May 1996/Accepted: 25 December 1996     

NEW METHOD TO OPTION PRICING FOR THE GENERAL BLACK-SCHOLES MODEL-AN ACTUARIAL APPROACH

IntroductionRobertMerton[1] startedcontinuous_timefinancialmodelingwithhisexplicitdynamicprogrammingsolutionforoptimalportfolioandconsumptionpolices.Thissetsthestageforhis1973generalequilibriummodelofsecurityprices,anothermilestone .Hismajorcontributionwashisarbitrage_basedproofoftheoptionpricingformulaintroducedbyFisherBlackandMyronScholesin 1973[2 ] ,andhiscontinualdevelopmentofthatapproachtoderivativepricing .Darrelluffie[3 ] derivedtheBlack_ScholesFormulaintraditionaloptionpricingmetho…     

Influence of Permeability Heterogeneity on Miscible CO<Subscript>2</Subscript> Flooding Efficiency in Sandstone Reservoirs: An Experimental Investigation

In this study, we systematically investigate the effect of core-scale heterogeneity on the performance of miscible CO₂ flooding under various injection modes (secondary and tertiary). Manufactured heterogeneous core plugs are used to simulate vertical and horizontal heterogeneity that may be present in a reservoir. A sample with vertical heterogeneity (i.e. a layered sample) is constructed using two axially cut half plugs each with a distinctly different permeability value. In these samples, the permeability ratio (PR) defines the ratio between the permeabilities of adjacent half plugs. Horizontal heterogeneity (i.e. a composite sample) is introduced by stacking two or three short cylindrical core segments each with a different permeability value. Our special sample construction techniques have also enabled us to investigate the effect of permeability ratio and crossflow in layered samples and axial arrangement of core segments in composite samples on the ultimate recovery of the floods. Core flooding experiments are conducted with an n-Decane–brine–CO₂ system at a pore pressure of 17.2 MPa and a temperature of 343 K. At this temperature, the minimum miscibility pressure of CO₂ with n-Decane is 12.6–12.7 MPa so it is expected that at 17.2 MPa CO₂ is fully miscible with n-Decane. The results obtained for both the composite and layered samples indicate that CO₂ injection would achieve the highest recovery factor (RF) when performed under the secondary mode (e.g. layered: 79.00%, composite: 89.83%) compared with the tertiary mode (e.g. layered: 73.2%, composite: 86.2%). This may be attributed to the effect of water shielding which impedes the access of the injected CO₂ to the residual oil under the tertiary injection mode. It is also found that the oil recovery from a layered sample decreases noticeably with an increase in the PR as higher PR makes the displacement more uneven due to CO₂ channelling. The RFs of 93.4, 87.89, 77.9 and 69.8% correspond to PRs of 1, 2.5, 5, and 12.5, respectively. In addition, for the layered samples, crossflow was found to have an important role during the recovery process; however, due to excessive channelling, this effect tends to diminish as PR increases. Compared with the layered heterogeneity, the effect of composite heterogeneity on the RF seems to be very subtle as the RF is found to be almost independent from the permeability sequence along the length of a composite sample. This outcome may have been caused by the small diameter of the plugs resulting in invariable 1-D floods.     

Large-scale vortical structure,supported by small-scale turbulent motions. Helicity as a cause for inverse energy cascade

In this article we demonstrate that turbulent stress contributions which depend on the rotation of the frame of reference (and therefore are system dependent) give rise to the inverse energy cascade, and thus introduce an ordering in the structure of turbulence.We first demonstrate that a non-rotating Boussinesq fluid subject to an artificial force that is not invariant under parity changes of the orthogonal group has a destabilizing effect in the B'enard problem. This destabilization is due to helicity and the stability regimes are divided into two regions: (1) If the helicitys is below a threshold values ^*, then long and very short wavelength disturbances at Rayleigh numbers Ra > Ra^crit are stable whereas those with intermediate wavelengths are unstable. (2) If the helicitys >s _* then all disturbances are unstable.For a rotating turbulent Boussinesq fluid we derive the most simple rotation dependent expression for the stress divergence and demonstrate that it leads quantitatively to a similar helicity dependent force. In the B6nard problem it gives rise to an analogous division of the stability/instability regime as obtained for non-rotating fluids subject to the artificial helicity dependent force.     

The reactions of general practitioners, nurses and midwives in Flanders concerning breast cancer risks in a high-risk situation

OBJECTIVE: To investigate the reactions of general practitioners (GPs), nurses and midwives concerning the cancer risks in a high-risk family. METHODS: Questionnaires were sent to 356 GPs, 881 nurses and 119 midwives. RESULTS: The response rate was 60% for GPs, 58% for midwives and 33% for nurses. The breast cancer risk of an unaffected patient from a high-risk family as well as the risk of her daughter were mostly (>80%) correctly evaluated as increased. The percentage answering 'increased risk' dropped to 40% for the daughters of the patient's brother. Half of the GPs and nurses/midwives explicitly mentioned that a predictive DNA test was available. Less than one third would recommend such a test for a young child. Reluctance was also observed regarding prophylactic mastectomy. CONCLUSION: These results should be taken into account in genetic education initiatives for GPs, nurses and midwives.     

The Differential System Method for the Identification of Transmissivity and Storativity

The differential system (DS) method for the identification of transmissivity and storativity is applied to a confined isotropic aquifer in transient conditions. The data that are required for the identification are the piezometric heads and the source terms, together with the value of transmissivity at a single point only, which is the only parameter value needed a priori. In particular, no a priori knowledge of storativity is needed and, moreover, the identification of transmissivity does not depend upon storativity. The DS method yields the internode transmissivities necessary for the conservative finite differences models in a natural way, because it identifies transmissivities along the internodal segments, so that a well-known formula can be applied that bypasses the difficulty of finding an equivalent cell transmissivity and an averaging scheme. In addition, the DS method takes into account several different flows all over the aquifer, so that the identified parameters are to a certain degree global andflow independent. Moreover, the method allows for a piecemeal identification of the parameters, thus keeping away from the regions where wells are pumping so that a two-dimensional model can be used throughout. We test the applicability of the DS method with noisy data by means of numerical synthetic examples and compare the identified internode transmissivities with the reference values. We use the identified parameters to forecast the behaviour of the aquifer under different exploitation and boundary conditions and we compare the forecast piezometric heads, their gradients and the associated fluxes with those computed with the reference parameters.     

The statistical convergence of aerosol deposition measurements

 The spatial distribution of deposited aerosol particles shows substantial statistical variation. This variation is especially important for sampling techniques having a high spatial resolution, such as laser-based methods, or for experiments involving a small sample size (few identical locations measured) or a short duration. This paper develops a criterion to ensure adequate statistical convergence in deposition measurements. The time evolution of statistical variations is modeled using standard Poisson statistics; this model provides a bound on measurement uncertainties. The model is compared to experimental measurements of the spatial variation of deposition. Numerical simulations are used to examine the effects of aerosol polydispersity on statistical convergence. Both the experiments and the numerics show excellent agreement with the model. Received: 17 July 1996 / Accepted: 17 October 1996