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PubMed2005

A neural-network technique to learn concepts from electroencephalograms.

A new technique is presented developed to learn multi-class concepts from clinical electroencephalograms (EEGs). A desired concept is represented as a neuronal computational model consisting of the input, hidden, and output neurons. In this model the hidden neurons learn independently to classify the EEG segments presented by spectral and statistical features. This technique has been applied to the EEG data recorded from 65 sleeping healthy newborns in order to learn a brain maturation concept of newborns aged between 35 and 51 weeks. The 39,399 and 19,670 segments from these data have been used for learning and testing the concept, respectively. As a result, the concept has correctly classified 80.1% of the testing segments or 87.7% of the 65 records.

Electroencephalography↗
PubMed2004

Folk concepts and intuitions: from philosophy to cognitive science.

Analytic philosophers have long used a priori methods to characterize folk concepts such as knowledge, belief and wrongness. Recently, researchers have begun to exploit social scientific methodologies to characterize such folk concepts. One line of work has explored folk intuitions with cases that are disputed within philosophy. A second approach, with potentially more radical implications, applies the methods of cross-cultural psychology to philosophical intuitions. Recent work in this area suggests that people in different cultures have systematically different intuitions surrounding folk concepts. A third strand of research explores the emergence and character of folk concepts in children. These approaches to characterizing folk concepts provide important resources that will supplement, and perhaps in some cases displace, a priori approaches.

Cognition↗
PubMed1997

Polysomnographic quantification of bioelectrical maturation in preterm and fullterm newborns at matched conceptional ages.

We analyzed the relationship between normal neonatal EEG features and gestational age and conceptional age, and evaluated the normal aspects of EEG maturation in preterm babies compared to term babies. We report 46 newborns, divided into two groups. Group I consisted of 11 newborns with gestational age between 30 and 32 weeks, followed with weekly polysomnograms until they reach 42 weeks' conceptional age. Group II (control) consisted of 35 newborns with gestational ages of 34 weeks (n = 5), 36 weeks (n = 10), 38 weeks (n = 10) and 40 weeks (n = 10) evaluated with one polysomnogram in their first 24-48 h of life. In each examination one 5 min epoch in REM and NREM sleep was analyzed to quantify the number of delta brushes, the presence of frontal and temporal sharp transients, the presence of delta frontal rhythmic activity, the grade of concordance between EEG patterns and sleep stages, the percent of interhemispheric synchrony and the duration of interburst interval. The age dependent variability of the EEG patterns was evaluated during the subsequent weeks with group comparisons at weeks 34, 36, 38 and 40. Our results show that the number of delta brushes and the duration of the interburst interval decrease as gestational and conceptional age increase. The percent of interhemispheric synchrony increases with gestational and conceptional age. The presence of frontal sharp transients and delta frontal rhythmic activity suggest that the newborn is fullterm. The presence of temporal sharp transients suggest a preterm newborn. The degree of concordance between behavioral sleep patterns and EEG was more helpful in recognizing sleep stages than in estimating gestational or conceptional age. Although the EEG patterns were comparable between the groups at the same age, analyses of the behavioral patterns of concordance in NREM sleep showed that newborns in Group I had a more immature behaviour than newborns in Group II. Our results also suggest that extrauterine life of preterm babies does not seem to accelerate EEG maturation but may influence the acquisition of behavioral patterns during NREM sleep.

Age Factors↗
PubMed2000

Delayed conception and active and passive smoking. The Avon Longitudinal Study of Pregnancy and Childhood Study Team.

OBJECTIVE: To determine whether passive as well as active smoking by women or smoking by men is associated with delayed conception, after adjustment for confounding factors. DESIGN: Population study of couples expecting a baby. Logistic regression was performed to identify factors associated with delayed conception. SETTING: The Avon Health Authority area, United Kingdom. PATIENT(S): All couples expected to deliver between April 1991 and December 1992. INTERVENTION(S): Questionnaires administered early in pregnancy. MAIN OUTCOME MEASURE(S): Time taken to conceive, categorized as <6 months, 6-11 months, 1-3 years, and >3 years. RESULT(S): After correction for confounding factors, delayed conception was statistically significantly associated with both active smoking by the woman (odds ratio [OR] 1.23 [95% CI 0.98-1.49] for > 6 months and 1.54 [95% CI 1.19-2.01] for >12 months) and her exposure to passive smoking (OR 1.17 [95% CI 1.02-1.37] and 1.14 [95% CI 0.92-1.42]) compared with women with no exposure to tobacco smoke (referent). Heavy smoking by men was independently associated with delayed conception. In active smokers, the effect increased with the number of cigarettes. CONCLUSION(S): Smoking by men and passive and active smoking by women are associated with delayed conception.

Adult↗
PubMed2003

Conception, early pregnancy loss, and time to clinical pregnancy: a population-based prospective study.

OBJECTIVE: To examine rates of conception and pregnancy loss and their relations with time to clinical pregnancy and reproductive outcomes. DESIGN: A prospective observational study. SETTING: Population-based cohort in China. PATIENT(S): Five hundred eighteen healthy newly married women who intended to conceive. Upon stopping contraception, daily records of vaginal bleeding and daily first-morning urine specimens were obtained for < or =1 year or until a clinical pregnancy was achieved. Daily urinary hCG was assayed to detect early pregnancy loss (EPL). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Conception, pregnancy loss, and time to clinical pregnancy. RESULT(S): The conception rate per cycle was 40% over the first 12 months. Of the 618 detectable conceptions, 49 (7.9%) ended in clinical spontaneous abortion, and 152 (24.6%) in EPL. Early pregnancy loss was detected in 14% of all the cycles without clinically recognized pregnancy, but the frequencies were lower among women with delayed time to clinical pregnancy. Early pregnancy loss in the preceding cycle was associated with increased odds of conception (odds ratio [OR], 2.6; 95% confidence interval [CI], 1.8-3.9), clinical pregnancy (OR, 2.0; 95% CI, 1.3-3.0), and EPL (OR, 2.4; 95% CI, 1.4-4.2) but was not associated with spontaneous abortion, low birth weight, or preterm birth in the subsequent cycle. CONCLUSION(S): We demonstrated substantial EPL in the non-clinically pregnant cycles and a positive relation between EPL and subsequent fertility.

Abortion, Spontaneous↗
PubMed1983

Characteristics of donor semen and cervical mucus at the time of conception.

With freshly ejaculated semen from 15 donors, 1017 inseminations were performed in 247 women. One hundred conceptions were achieved. The degree of crystallization of the cervical mucus and the characteristics of the donor semen were examined at each insemination. One insemination only from one single ejaculate was performed in each cycle. This procedure made it possible to describe the quality of the cervical mucus and the sperm sample characteristics on each occasion of conception. The conception rate was significantly reduced (P less than 0.001) when the degree of crystallization of the cervical mucus was impaired. The conception rate was low when the sperm density was less than 20 million/ml, the percentage of abnormal sperm was above 50, and the degree of motility was graded 2 or less. The in vitro capillary sperm penetration test gave reliable information on the progressive motility of the sperm, showing a good correlation between penetration ability and conception rate.

Adult↗
PubMed1984

The periovulatory and luteal phase of conception cycles following in vitro fertilization and embryo transfer.

The pattern of periovulatory and luteal phase levels of serum estradiol (E2) and progesterone (P) were compared between 8 conception and 28 nonconception cycles of patients undergoing in vitro fertilization (IVF). Ten additional women served as control subjects and did not undergo follicular aspiration. Follicle growth was induced with an individualized Pergonal (human menopausal gonadotropin) regimen, and laparoscopy was performed 36 hours after human chorionic gonadotropin administration. The length of the luteal phase did not differ significantly among the three groups and was between 14 and 15 days in duration. When IVF conception cycles were compared with nonconception cycles, although no difference in the number of large follicles was observed (4.25 +/- 0.45 versus 3.6 +/- 0.25), the patterns of E2 and P differed significantly. Daily serum E2 levels tended to be higher in the periovulatory phase in conception cycles when compared with nonconception cycles, and were significantly (P less than 0.05) higher in the early, mid, and late luteal phases. Serum P levels were significantly higher (P less than 0.05) in conception cycles from the midluteal phase onward. A decline in both serum E2 and P in the midluteal phase in conception cycles suggested some degree of corpus luteum deficiency. It is suggested that high E2 levels in the periovulatory phase may be an indicator of better follicular development under human menopausal gonadotropin stimulation and that the deficiency observed in the late luteal phase is overcome with the establishment of pregnancy.

Adult↗
PubMed1997

Time to conception after orchidopexy: evidence for subfertility?

OBJECTIVE: To determine whether time to conception is increased among men who were formerly bilaterally or unilaterally cryptorchid compared with a group of matched control men. DESIGN: Retrospective cohort study. SETTING: Human volunteers in an academic research environment. PATIENT(S): Men who underwent orchidopexy between 1955 and 1971 at the Children's Hospital of Pittsburgh (n = 547) and a group of matched control men (n = 463) were surveyed by questionnaire. RESULT(S): Of the men who attempted paternity, the mean time to conception for the bilateral cases, unilateral cases, and control men was 33.90, 11.11, and 8.78 months, respectively. Kaplan-Meier survival analysis showed a significantly longer time to conception among bilateral cases compared with unilateral cases and controls, but not between unilateral cases and control men. Adjustment for confounders and covariates using a Cox Proportional Hazards model showed that former bilaterally cryptorchid men were 68% (95% CI = 55% to 81%) less likely than former unilaterally cryptorchid men or controls to conceive per month of unprotected intercourse. CONCLUSION(S): Time to conception was increased among former bilaterally cryptorchid men compared with both former unilaterally cryptorchid and control men. However, there were no significant differences in time to conception between the unilateral cryptorchid men and the control men.

Adult↗
PubMed1999

Preimplantation urinary hormone profiles and the probability of conception in healthy women.

OBJECTIVE: To examine hormonal predictors of conception in menstrual cycles from normal women. DESIGN: Longitudinal study. SETTING: Community. PATIENT(S): Two hundred fifteen healthy female volunteers with no known fertility problems who were trying to conceive. INTERVENTION(S): Participants recorded menstrual bleeding, sexual intercourse, and collected first morning urine specimens daily from when they stopped contraception until they became pregnant or for 6 months if no clinical pregnancy was achieved. Measurements were made of urinary LH and urinary metabolites of estrogen and progesterone. MAIN OUTCOME MEASURE(S): Conception was identified by a sensitive and specific immunoradiometric assay for urinary hCG. RESULT(S): Statistical analyses of 189 conception and 409 nonconception cycles controlled for sexual intercourse and interdependence of cycles from the same woman. Conception was more likely in cycles with lower baseline progesterone metabolite levels, higher ovulatory LH, and higher midluteal progesterone. Midluteal estrogen also was elevated in conception cycles when examined without adjusting for other hormone levels, but this finding did not persist after multivariate adjustment. CONCLUSIONS: Menstrual cycles in normal women vary in their hormonal quality in ways that are predictive of cycle fertility.

Adult↗
PubMed2001

Analysis of cow factors influencing conception rates after two timed breeding protocols.

The objective of this study was to determine cow factors that influence conception rates after timed artificial insemination (TAI) on a commercial dairy farm. In Trial 1, 197 cows were synchronized by an administration of 25 mg of dinoprost between Days 48 and 54 post partum and again 14 days later. Cows were inseminated 66 and 90 hours after the second treatment. In Trial 2, 186 cows were treated with an Ovsynch protocol consisting of an administration of 0.02 mg of buserelin between Days 62 and 68 post partum, a treatment with 0.75 mg of tiaprost 7 days later and a second treatment with buserelin 48 h later. Cows were bred 16 to 20 hours after the last treatment. Cows with abnormal vaginal discharge at the time of insemination were excluded from AI. Lactation number, milk yield, fat and protein content of milk, signs of endometritis at an examination 14 to 20 days post partum and month of breeding were included as potential factors influencing conception on TAI. Conception rates after timed breeding were 32.0% and 30.6% in Trials 1 and 2, respectively. Logistic regression revealed that neither milk production parameters nor endometritis at post partum examination influenced conception rates in either of the two timed breeding protocols. Only parity showed an effect (P=0.012) in Trial 2. Primiparous cows were more likely to conceive after timed breeding than older cows (43.5 vs. 23.1%). An effect of parity, however, was not observed in Trial 1. It can be concluded that neither milk production nor endometritis at an examination 14 to 20 days post partum influence conception rates after TAI if cows with abnormal vulval discharge at the designated time of AI are excluded from breeding.

Animals↗
PubMed2002

Effect of preparing and loading multiple insemination guns on conception rate in two large commercial dairy herds.

In large herds, inseminators frequently thaw multiple straws of semen and prepare several insemination guns at once. The aim of this study was to measure the effect of breeding order, the order that thawed straws are used, on conception rate in commercial dairy herds. A single professional inseminator, utilizing semen from five suppliers, performed 2629 inseminations over 30 months. Up to four straws were thawed at one time with the restriction that straws were used within 20 min of thawing. Straws were thawed per supplier's recommendations, with 66.4% of the straws pocket thawed and the remainder warm-water thawed. Conception was determined by a pregnancy check at 42 days. Data were modeled by multiple logistic regression analysis, which included herd, breeding order, lactation number, times bred, month bred and year bred. Breeding order had no significant effect on the probability of conception: Cows 1-4 achieved adjusted conception rates of 0.36, 0.41, 0.37, and 0.39, respectively. Odds ratios (and 95% confidence intervals) were 1.00 (1.00-1.00), 1.22 (0.99-1.49), 1.04 (0.82-1.32), and 1.12 (0.86-1.45), respectively. Associated laboratory studies, which evaluated the effect of post-thaw holding time on percentage of sperm with progressive motility, found mean values at 20 min holding time to be largely unchanged from mean values at 5 min. Thawing temperatures were 6, and 35 degrees C and holding temperatures were 6, 22, and 35 degrees C. The length of the trial and the wide use of semen from multiple suppliers with differing thawing methods suggests that under similar conditions, a careful and experienced inseminator can thaw multiple straws of semen and prepare insemination guns sufficient to breed up to four cows within 20 min, without an adverse effect on conception.

Animals↗
PubMed1999

Plasma GH, IGF-I, and conception rate in cattle treated with low doses of recombinant bovine GH.

Blood and uterine concentrations of GH and insulin-like growth factor (IGF)-I are correlated with improved fertility in cattle. We tested incremental doses of a 14-d sustained release recombinant bovine GH (rbGH) to increase blood GH and IGF-I (Experiments 1 and 2). Conception rate after administration of an optimized rbGH dose was also tested (Experiment 3). In Experiment 1, lactating Holstein cows (n = 18) were randomly assigned to receive 0 (n = 5), 100 (n = 5), 200 (n = 5), or 500 (n = 3) mg sc rbGH. Increasing the doses of rbGH was associated with increased serum concentrations of GH and IGF-I. The 100- and 200-mg doses caused an IGF-I release that was below and above, respectively, the perceived optimum response. Therefore, Experiment 2 was designed to test a rbGH dose (167 mg), which was intermediate to the doses tested in Experiment 1. Lactating and nonlactating postpartum beef cows were treated with 0 (n = 9) or 167 (n = 9) mg rbGH at insemination. Plasma concentrations of GH and IGF-I were greater in rbGH-treated cows than in controls. Lactating cows had initial IGF-I concentrations that were lower than nonlactating cows. The 167-mg dose of rbGH increased plasma IGF-I concentrations in lactating cows to the levels of those of nonlactating cows. In Experiment 3, cows and heifers were administered either 0 or 167 mg rbGH at insemination. The conception rate for rbGH-treated and control cows was 54.4 and 49.5% (n = 617), and 46.0 and 46.3% for heifers (n = 1123), respectively. Herd (P<0.01) and parity (P<0.01) affected conception rate, but conception rates for rbGH and control cattle were similar. In summary, low doses of rbGH increased blood GH and restored blood IGF-I concentrations in lactating cows to those of nonlactating cows, but the conception rate in cows and heifers was not affected by administration of 14-d sustained-release rbGH at insemination.

Animals↗
PubMed2001

Censoring in survival analysis: a simulation study of the effect of milk yield on conception.

Survival-analysis methods often are used to analyze data from dairy herds where the outcome of interest is the interval from calving to conception. The purpose of this study was to determine whether an association between milk yield and culling biases the estimation of the effect of milk yield on conception. This was done by simulating four different scenarios modeling dairy-cattle milk yield and reproductive performance with known relationships among study factors. Cox's proportional-hazards model was used to analyze the effect of milk yield on days open under the following four scenarios: (1) no association between milk yield and culling or between milk yield and conception; (2) association between milk yield and culling only; (3) association between milk yield and conception only; (4) associations between milk yield and both culling and conception. The analyses also were repeated for data sets with an association between milk yield and culling, but with probabilities of culling ranging from 0.01 to 0.4. An effect of milk production on culling appeared to cause a small increase in the parameter estimates for the association of milk yield and days open - particularly when the probability of culling was high. The effect of high milk production on median days open (as estimated by survival functions) changed by 2 to 4 days when an association between milk yield and culling was programmed in the simulated data sets.

Animals↗
PubMed2003

Parents' contributions to the narrative identity of offspring of donor-assisted conception.

Donated sperm, eggs, and embryos are an increasing feature of assisted reproduction; people conceived in this way have different genetic and social histories. Although most offspring of donor-assisted conception are ignorant of their genetic history, recipient parents must negotiate increasing demand for full disclosure to offspring. This paper illustrates some of the reasons parents give for not telling their children, underlines the experience of many parents of being uncertain of how to go about telling, presents information from some parents who have endeavoured to be open with their children about conception from very early childhood, and discusses implications for the narrative identity of offspring of donor-assisted conception. Recipient parents (n=55) and offspring (12) from Australia; Canada, US, England, and Argentina were interviewed and subsequently consulted about the development of their narrative accounts and the way in which these have been interpreted. Parental narratives were found to be located along a continuum, broadly encompassing: (1). Parents who intend to exclude donor-assisted conception from the narratives they construct for their children, (2). parents who are uncertain about what they want to do, or confused about the best way to disclose and discuss donor conception with their children and (3). those have incorporated the donor in their children's narratives from the beginning. From interviews with offspring and on the basis of human rights issues and the increasing salience of genetic knowledge, it is concluded that disclosure to offspring before adolescence should be encouraged.

Access to Information↗
PubMed2000

Revisiting the concept of 'vulnerability'.

The terms 'vulnerable' and 'vulnerability' are used more and more frequently in the areas of both social science research into and prevention of HIV/AIDS, but certain difficulties arise when it comes to applying this concept to actual situations at the heart of which individuals or groups are more exposed to HIV. The concept of vulnerability must thus be clarified to reinforce its heuristic capacity and political and practical relevancy. The first part of this paper is devoted to presenting a heuristic matrix of vulnerability, used in previous research among people living with HIV/AIDS (PWHAs) and to extracting three levels of intelligibility, that is to say, first the social trajectory level, then the level on which two or more trajectories intersect, and finally that of the social context. Each of the elements belonging to these three levels must be described both objectively and subjectively. The identity construction processes are then proposed as particular observation and 'gelling' points for these various levels taken as a whole. In the second part of the paper, we have reviewed how the concept of 'vulnerability' has been defined and used in other fields, notably disaster, famine, and mental health, paying special attention to the crucial points in the debates that are raging in these fields. We have also shed light on a few concepts that are frequently associated with vulnerability, such as victimization, insecurity, and risk. In the third part, we have summarized our approach to vulnerability as a relevant concept for elucidating risk-taking processes and designing intervention programmes. The importance of analysing the inter-individual differences, the variability in time and the relational dimension of all social vulnerability has been stressed.

Crime↗
PubMed2003

Stress relief after infertility treatment--spontaneous conception, adoption and psychological counselling.

OBJECTIVE: In this study, we sought to evaluate characteristics of couples with spontaneous conceptions after treatment with assisted reproductive technologies (ART). STUDY DESIGN: Data from 254 couples who underwent 1127 therapy cycles between November 1987 and February 1997, were analyzed. Chi-Square (chi(2)) test and Student's t-test were used. P<0.05 was considered significant. RESULTS: Spontaneous pregnancies occurred in 14% of all treated couples. Psychological counselling only was performed in 21% but was observed significantly more frequently among patients without later spontaneous conception. Ten percent of all treated couples applied for adoption. The miscarriage rate was significantly higher in the group of treatment dependent pregnancies compared to the group of patients with later spontaneous conception (27% versus 9%). The spontaneous conception rate differed significantly depending on women's age and normal semen analysis. CONCLUSION: Appearance of spontaneous conception after ART-procedures should be taken into account in the first patient's interview. Depending on women's age and andrological parameters, treatment-success will differ. The positive impact of psychological counselling for stress relief during and after therapy should also be noted, even though a statistically significant impact could not be demonstrated in the present study. Adoption should be discussed as an alternative to overcome infertility.

Abortion, Spontaneous↗
PubMed1998

An analysis of the concept of countertransference.

A knowledge of countertransference is a necessary step in using it therapeutically in the nurse-patient relationship. However, this concept, which has its roots in psychoanalytic theory, has been applied to nurses and nursing situations in an unhelpful and ambiguous manner. In fact, the term is often used to denigrate nurses without providing clarity as to what the components of countertransference are and how they might be understood and used therapeutically. As such, it is necessary to delineate the meaning of countertransference in its entirely as a concept suitable for nursing practice. Positive countertransference, negative countertransference, and empathy are the composite parts of the concept of countertransference. Through concept analysis, by using methods outlined by Rodgers (1989), Journal of Advanced Nursing, 14, 330-335, it is suggested that countertransference is an inescapable factor in the nurse-patient relationship. Furthermore, a comprehensive analysis of the concept of countertransference will assist nurses in recognizing it when it occurs and may enhance the use of the understanding gained to the benefit of the nurse-patient relationship.

Adult↗
PubMed1996

Improving health care, Part 4: Concepts for improving any clinical process.

BACKGROUND: One promising method for streamlining the generation of "good ideas" is to formulate what are sometimes called change concepts-general notions or approaches to change found useful in developing specific ideas for changes that lead to improvement. For example, in current efforts to reduce health care costs by discounting provider charges, the underlying generic concept is "reducing health care costs," and the specific idea is "discounting provider charges." Short-term gains in health care cost reduction can occur by pursuing discounts. After some time, however, limits to such reduction in costs are experienced. Persevering and continuing to travel down the "discounting provider charges" path is less likely to produce further substantial improvement than returning to the basic concept of "reducing health care costs." THE HIP REPLACEMENT CASE: An interdisciplinary team aiming to reduce costs while improving quality of care for patients in need of hip joint replacement generated ideas for changing "what's done (process) to get better results." After team members wrote down their improvement ideas, they deduced the underlying change concepts and used them to generate even more ideas for improvement. Such change concepts include reordering the sequence of steps (preadmission physical therapy "certification"), eliminating failures at hand-offs between steps (transfer of information from physician's office to hospital), and eliminating a step (epidural pain control). CONCLUSION: Learning about making change, encouraging change, managing the change within and across organizations, and learning from the changes tested will characterize the sustainable, thriving health systems of the future.

Group Processes↗