1,317 research outputs found
Successful pregnancy and delivery in a woman with panhypopituitarism
To The Editor: Pregnancy after a complete loss of hypophyseal function is rare. Lack of growth hormone (GH), adrenocorticotropin (ACTH) and thyroid-stimulating hormone (TSH) in childhood may result in malfunction of different organ systems, affecting fertility. Complete lack of ovarian stimulation by FSH and LH results in anovulation and ovarian atrophy. We present a patient with panhypopituitarism who has achieved pregnancy and delivered through in vitro fertilization (IVF) and embryo transfer (ET). This 35 year-old woman underwent four trans-sphenoidal hypophysectomies at 12, 13, 23 and 26 years of age, for recurrent neuroectodermal cysts (embryonic remnant). Her second operation was complicated by panhypopituitarism with severe diabetes insipidus, treated with adequate doses of hydrocortisone, L-thyroxine and desmopressin. At age 21, cyclic substitution therapy with estrogen and progesterone was given for primary amenorrhea. Two years later, GH therapy was added. At age 33, she requested fertility treatment. GH, cyclic estrogen, and progesterone therapy were stopped, and she underwent ovulation induction, with gonadotropins, followed by IVF and ET, resulting in a successful dichorionic twin pregnancy. She was followed regularly at a combined antenatal clinic. No changes in steroid, desmopressin, or thyroxine doses were required, and the antenatal period was uneventful. An elective caesarean section was performed at 37 weeks gestation, and healthy twin boys (weighing 3.0 and 3.14 kg) were delivered. Clinical course during puerperium was normal.Conception and uncomplicated pregnancy in patients with hypopituitiarism are rare [1,2]. Well-timed substitution of missing hormones enables normal physical development. Stimulation therapy with gonadotropins can induce adequate follicular maturation. IVF-ET may be a useful treatment for infertility in patients with hypopituitarism as it may reduce the incidence of multiple pregnancies associated with higher risk in GH deficient patients
Elementary School Experience with Comprehension Testing May Influence Metacomprehension Accuracy Among Seventh and Eighth Graders
We explored whether exposure to different kinds of comprehension tests during elementary years influenced metacomprehension accuracy among 7th and 8th graders. This research was conducted in a kindergarten through eighth grade charter school with an expeditionary learning curriculum. In literacy instruction, teachers emphasize reading for meaning and inference building, and they regularly assess deep comprehension with summarization, discussion, dialogic reasoning and prediction activities throughout the elementary years. The school recently expanded, doubling enrollments in 7th and 8th grades. Thus, approximately half of the students had long-term exposure to the curriculum and the other half did not. In Study 1, metacomprehension accuracy using the standard relative accuracy paradigm was significantly better for long-time students than for newcomers. In Study 2, all students engaged in delayed-keyword generation before judging their comprehension of texts. Metacomprehension accuracy was again significantly better for long-time students than for newcomers. Further, the superior monitoring accuracy led to more effective regulation of study, as seen in better decisions about which texts to restudy, that led, in turn, better comprehension. The results suggest the importance of early exposure to comprehension tests for developing skills in comprehension monitoring and self-regulated learning
Use of MMG signals for the control of powered orthotic devices: Development of a rectus femoris measurement protocol
Copyright © 2009 Rehabilitation Engineering and Assistive Technology Society (RESNA). This is an Author's Accepted Manuscript of an article published in Assistive Technology, 21(1), 1 - 12, 2009, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/10400430902945678.A test protocol is defined for the purpose of measuring rectus femoris mechanomyographic (MMG) signals. The protocol is specified in terms of the following: measurement equipment, signal processing requirements, human postural requirements, test rig, sensor placement, sensor dermal fixation, and test procedure. Preliminary tests of the statistical nature of rectus femoris MMG signals were performed, and Gaussianity was evaluated by means of a two-sided Kolmogorov-Smirnov test. For all 100 MMG data sets obtained from the testing of two volunteers, the null hypothesis of Gaussianity was rejected at the 1%, 5%, and 10%âsignificance levels. Most skewness values were found to be greater than 0.0, while all kurtosis values were found to be greater than 3.0. A statistical convergence analysis also performed on the same 100 MMG data sets suggested that 25 MMG acquisitions should prove sufficient to statistically characterize rectus femoris MMG. This conclusion is supported by the qualitative characteristics of the mean rectus femoris MMG power spectral densities obtained using 25 averages
Hostility, Race, and Glucose Metabolism in Nondiabetic Individuals
OBJECTIVEâ The present study was designed to determine whether hostility is differentially related to measures of glucose metabolism in African-Americans and Caucasians. RESEARCH DESIGN AND METHODSâ The relationship of hostility, as measured by a subset of the Cook-Medley hostility scale (CMHOST) inventory items, to various parameters of glucose metabolism were examined in a young, healthy sample of male and female African-American and Caucasian volunteers. Fasting blood samples were collected during an inpatient admission, at which time the CMHOST was also administered. RESULTSâ In the entire sample, the CMHOST was found to be significantly correlated with fasting glucose and insulin sensitivity, as measured by the homeostatic model assessment (HOMA). However, the relationship of hostility to these parameters of glucose metabolism was different in African-American and Caucasian subjects. Hostility was significantly related to fasting glucose in African-Americans and to insulin sensitivity and fasting insulin in Caucasian subjects. The relationship of hostility to insulin sensitivity and fasting insulin was partially dependent on BMI in Caucasians, but the relationship of hostility to fasting glucose was unrelated to BMI in African-Americans. CONCLUSIONSâ Our data suggest that the relationship of hostility to measures of glucose metabolism is mediated differently in these two ethnic groups. Therefore, hostility seems to be part of a constellation of risk-related behaviors related to BMI in Caucasians but independently related to fasting glucose in African-Americans
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Improving conservation practice with principles and tools from systems thinking and evaluation
Achieving nature conservation goals require grappling with âwickedâ problems. These intractable problems arise from the complexity and dynamism of the socialâecological systems in which they are embedded. To enhance their ability to address these problems, conservation professionals are increasingly looking to the transdisciplines of systems thinking and evaluation, which provide philosophies, theories, methods, tools and approaches that show promise for addressing intractable problems in a variety of other sectors. These transdisciplines come together especially around praxis, i.e., the process by which a theory or idea is enacted, embodied or realized. We present a review and synthesis of the learnings about praxis that have emerged from The Silwood Group, a consortium of conservation professionals, professional evaluators, and complexity and systems thinkers. The Silwood Group believes that for conservation activities to achieve ambitious goals, we should benefit nature without compromising the well-being of people, and that framing a praxis for conservation in the context of socialâecological systems will provide the greatest potential for positive impact. The learnings are presented as four key principles of a âpraxis for effective conservationâ. The four principles are: (1) attend to the whole with humility; (2) engage constructively with the values, cultures, politics, and histories of stakeholders; (3) learn through evaluative, systemic enquiry, and (4) exercise wisdom in judgement and action. We also provide descriptions and references for tools and methods to support such praxis and discuss how the thinking and approaches used by conservation professionals can be transformed to achieve greater effectiveness
Radiation damage in the LHCb vertex locator
The LHCb Vertex Locator (VELO) is a silicon strip detector designed to reconstruct charged particle trajectories and vertices produced at the LHCb interaction region. During the first two years of data collection, the 84 VELO sensors have been exposed to a range of fluences up to a maximum value of approximately 45 Ă 1012 1 MeV neutron equivalent (1 MeV neq). At the operational sensor temperature of approximately â7 °C, the average rate of sensor current increase is 18 ÎŒA per fbâ1, in excellent agreement with predictions. The silicon effective bandgap has been determined using current versus temperature scan data after irradiation, with an average value of Eg = 1.16±0.03±0.04 eV obtained. The first observation of n+-on-n sensor type inversion at the LHC has been made, occurring at a fluence of around 15 Ă 1012 of 1 MeV neq. The only n+-on-p sensors in use at the LHC have also been studied. With an initial fluence of approximately 3 Ă 1012 1 MeV neq, a decrease in the Effective Depletion Voltage (EDV) of around 25 V is observed. Following this initial decrease, the EDV increases at a comparable rate to the type inverted n+-on-n type sensors, with rates of (1.43±0.16) Ă 10â12 V/ 1 MeV neq and (1.35±0.25) Ă 10â12 V/ 1 MeV neq measured for n+-on-p and n+-on-n type sensors, respectively. A reduction in the charge collection efficiency due to an unexpected effect involving the second metal layer readout lines is observed
Genotype, Childhood Maltreatment, and Their Interaction in the Etiology of Adult Antisocial Behaviors
BACKGROUND: Maltreatment by an adult or caregiver during childhood is a prevalent and important predictor of antisocial behaviors in adulthood. A functional promoter polymorphism in the monoamine oxidase A (MAOA) gene has been implicated as a moderating factor in the relationship between childhood maltreatment and antisocial behaviors. Although there have been numerous attempts at replicating this observation, results remain inconclusive. METHODS: We examined this gene-environment interaction hypothesis in a sample of 3356 white and 960 black men (aged 24-34) participating in the National Longitudinal Study of Adolescent Health. RESULTS: Primary analysis indicated that childhood maltreatment was a significant risk factor for later behaviors that violate rules and the rights of others (p .05). Power analyses indicated that these results were not due to insufficient statistical power. CONCLUSIONS: We could not confirm the hypothesis that MAOA genotype moderates the relationship between childhood maltreatment and adult antisocial behaviors
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Depression, Stressful Life Events, and the Impact of Variation in the Serotonin Transporter: Findings from the National Longitudinal Study of Adolescent to Adult Health (Add Health)
BackgroundThe low transcriptionally efficient short-allele of the 5HTTLPR serotonin transporter polymorphism has been implicated to moderate the relationship between the experience of stressful life events (SLEs) and depression. Despite numerous attempts at replicating this observation, results remain inconclusive.MethodsWe examined this relationship in young-adult Non-Hispanic white males and females between the ages of 22 and 26 (n = 4724) participating in the National Longitudinal Study of Adolescent to Adult Health (Add Health) with follow-up information every six years since 1995.ResultsLinear and logistic regression models, corrected for multiple testing, indicated that carriers of one or more of the S-alleles were more sensitive to stress than those with two L-alleles and at a higher risk for depression. This relationship behaved in a dose-response manner such that the risk for depression was greatest among those who reported experiencing higher numbers of SLEs. In post-hoc analyses we were not able to replicate an interaction effect for suicide ideation but did find suggestive evidence that the effects of SLEs and 5HTTLPR on suicide ideation differed for males and females. There were no effects of childhood maltreatment.DiscussionOur results provide partial support for the original hypothesis that 5-HTTLPR genotype interacts with the experience of stressful life events in the etiology of depression during young adulthood. However, even with this large sample, and a carefully constructed a priori analysis plan, the results were still not definitive. For the purposes of replication, characterizing the 5HTTLPR in other large data sets with extensive environmental and depression measures is needed
Precision luminosity measurements at LHCb
Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy âs. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for âs = 2.76, 7 and 8 TeV (proton-proton collisions) and for âsNN = 5 TeV (proton-lead collisions). Both the "van der Meer scan" and "beam-gas imaging" luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves significantly the consistency of the results. For proton-proton interactions at âs = 8 TeV a relative precision of the luminosity calibration of 1.47% is obtained using van der Meer scans and 1.43% using beam-gas imaging, resulting in a combined precision of 1.12%. Applying the calibration to the full data set determines the luminosity with a precision of 1.16%. This represents the most precise luminosity measurement achieved so far at a bunched-beam hadron collider
Performance of the LHCb vertex locator
The Vertex Locator (VELO) is a silicon microstrip detector that surrounds the proton-proton interaction region in the LHCb experiment. The performance of the detector during the first years of its physics operation is reviewed. The system is operated in vacuum, uses a bi-phase CO2 cooling system, and the sensors are moved to 7 mm from the LHC beam for physics data taking. The performance and stability of these characteristic features of the detector are described, and details of the material budget are given. The calibration of the timing and the data processing algorithms that are implemented in FPGAs are described. The system performance is fully characterised. The sensors have a signal to noise ratio of approximately 20 and a best hit resolution of 4 ÎŒm is achieved at the optimal track angle. The typical detector occupancy for minimum bias events in standard operating conditions in 2011 is around 0.5%, and the detector has less than 1% of faulty strips. The proximity of the detector to the beam means that the inner regions of the n+-on-n sensors have undergone space-charge sign inversion due to radiation damage. The VELO performance parameters that drive the experiment's physics sensitivity are also given. The track finding efficiency of the VELO is typically above 98% and the modules have been aligned to a precision of 1 ÎŒm for translations in the plane transverse to the beam. A primary vertex resolution of 13 ÎŒm in the transverse plane and 71 ÎŒm along the beam axis is achieved for vertices with 25 tracks. An impact parameter resolution of less than 35 ÎŒm is achieved for particles with transverse momentum greater than 1 GeV/c
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