Toward a script theory of guidance in computer-supported collaborative learning

This article presents an outline of a script theory of guidance for computer-supported collaborative learning (CSCL). With its four types of components of internal and external scripts (play, scene, role, and scriptlet) and seven principles, this theory addresses the question how CSCL practices are shaped by dynamically re-configured internal collaboration scripts of the participating learners. Furthermore, it explains how internal collaboration scripts develop through participation in CSCL practices. It emphasizes the importance of active application of subject matter knowledge in CSCL practices, and it prioritizes transactive over non-transactive forms of knowledge application in order to facilitate learning. Further, the theory explains how external collaboration scripts modify CSCL practices and how they influence the development of internal collaboration scripts. The principles specify an optimal scaffolding level for external collaboration scripts and allow for the formulation of hypotheses about the fading of external collaboration scripts. Finally, the article points towards conceptual challenges and future research questions

Influence of infertility diagnosis on pregnancy outcome in ART

Abstract Objective: To determine the influence of the infertility diagnosis on gestational age (GA) and birth weight (BW) of children conceived using assisted reproductive technology (ART). Design: Retrospective cohort. Setting: University-affiliated infertility clinic. Patients: Women with a singleton live birth following their first fresh ART cycle with autologous oocytes. Interventions: Patients were stratified into groups based on infertility diagnosis. GA and BW of their infants were compared. Main Outcome Measures: GA and BW of children conceived using ART. Results: 397 women were included. Average GA in the cohort was 38.7±2.3 weeks and average BW was 3301.5±633.8 grams. Maternal age, BMI, and parity were significantly different between groups. After controlling for these factors and stratifying by infertility diagnosis, there was no difference in GA or BW in infants conceived with ART. Conclusions: Contrary to previously reported data, there was no difference in GA or BW in infants conceived with ART when stratified by infertility diagnosis. Our results were not different from the national population; however GA was one week longer in our cohort than in the national ART database. These data suggest a difference exists between our cohort and the ART population at large. We propose that the main difference is our institution’s focus on single embryo transfer

Ovarian hyperstimulation syndrome: review and new classification criteria for reporting in clinical trials

STUDY QUESTION What is an objective approach that employs measurable and reproducible physiologic changes as the basis for the classification of ovarian hyperstimulation syndrome (OHSS) in order to facilitate more accurate reporting of incidence rates within and across clinical trials? SUMMARY ANSWER The OHSS flow diagram is an objective approach that will facilitate consistent capture, classification and reporting of OHSS within and across clinical trials. WHAT IS KNOWN ALREADY OHSS is a potentially life-threatening iatrogenic complication of the early luteal phase and/or early pregnancy after ovulation induction (OI) or ovarian stimulation (OS). The clinical picture of OHSS (the constellation of symptoms associated with each stage of the disease) is highly variable, hampering its appropriate classification in clinical trials. Although some degree of ovarian hyperstimulation is normal after stimulation, the point at which symptoms transition from those anticipated to those of a disease state is nebulous. STUDY DESIGN, SIZE, DURATION An OHSS working group, comprised of subject matter experts and clinical researchers who have significantly contributed to the field of fertility, was convened in April and November 2014. PARTICIPANTS/MATERIALS, SETTING, METHODS The OHSS working group was tasked with reaching a consensus on the definition and the classification of OHSS for reporting in clinical trials. The group engaged in targeted discussion regarding the scientific background of OHSS, the criteria proposed for the definition and the rationale for universal adoption. An agreement was reached after discussion with all members. MAIN RESULTS AND THE ROLE OF CHANCE One of the following conditions must be met prior to making the diagnosis of OHSS in the context of a clinical trial: (i) the subject has undergone OS (either controlled OS or OI) AND has received a trigger shot for final oocyte maturation (e.g. hCG, GnRH agonist [GnRHa] or kisspeptin) followed by either fresh transfer or segmentation (cryopreservation of embryos) or (ii) the subject has undergone OS or OI AND has a positive pregnancy test. All study patients who develop symptoms of OHSS should undergo a thorough examination. An OHSS flow diagram was designed to be implemented for all subjects with pelvic or abdominal complaints, such as lower abdominal discomfort or distention, nausea, vomiting and diarrhea, and/or for subjects suspected of having OHSS. The diagnosis of OHSS should be based on the flow diagram. LIMITATIONS, REASONS FOR CAUTION This classification system is primarily intended to address the needs of the clinical investigator undertaking clinical trials in the field of OS and may not be applicable for the use in clinical practice or with OHSS occurring under natural circumstances. WIDER IMPLICATIONS OF THE FINDINGS The proposed OHSS classification system will enable an accurate estimate of the incidence and severity of OHSS within and across clinical trials performed in women with infertility. STUDY FUNDING/COMPETING INTERESTS Financial support for the advisory group meetings was provided by Merck & Co., Inc., Kenilworth, NJ, USA. P.H. reports unrestricted research grants from MSD, Merck and Ferring, and honoraria for lectures from MSD, Merck and IBSA. S.M.N. reports that he has received fees and grant support from the following companies (in alphabetic order): Beckman Coulter, Besins, EMD Serono, Ferring Pharmaceuticals, Finox, MSD and Roche Diagnostics over the previous 5 years. P.D., C.C.C., J.L.F., H.M.F., and P.L. report no relationships that present a potential conflict of interest. B.C.T. reports: grants and honorarium from Merck Serono; unrestricted research grants, travel grants and honorarium, and participation in a company-sponsored speaker's bureau from Merck Sharp & Dohme; grants, travel grants, honoraria and advisory board membership from IBSA; travel grants from Ferring; and advisory board membership from Ovascience. L.B.S. reports current employment with Merck & Co, Inc., Kenilworth, NJ, USA, and owns stock in the company. K.G. and B.J.S. report prior employment with Merck & Co., Inc., Kenilworth, NJ, USA, and own stock in the company. All reported that competing interests are outside the submitted work. No other relationships or activities exist that could appear to have influenced the submitted work

Maternal demographic and clinical variables do not predict intrauterine contraception placement: Evidence for postplacental intrauterine contraception placement

Objective: Determine if specific demographic and clinical variables are associated with intra-uterine contraception (IUC) placement by eight weeks postpartum. Methods: This retrospective cohort study included all patients who delivered at Dartmouth-Hitchcock Medical Center (DHMC) (July-December 2008) who identified IUC as their preferred postpartum contraceptive method. Medical records of patients identified from the birth log were reviewed for preferred contraception, demographics, medical, obstetric, and social histories, as well as payer status. Chi-squared analysis was performed for categorical variables, and Mann-Whitney U test was used for continuous variables. Nonparametric continuous variables were categorized for regression modeling. Results: 224 (34%) patients who delivered identified IUC as their preferred method of postpartum contraception. Of these, 94 (49.7%) women had an IUC placed by 8 weeks postpartum. In univariate analyses comparing those who received an IUC versus those patients who did not, only mean interdelivery interval in months (39.7 vs. 35.5, p=0.027) and mean gravidity (2.3 vs. 2.8, p=0.036) were statistically significant. In multivariate regression modeling, no variables were significantly associated with IUC placement. Conclusions: While statically significant interdelivery interval and gravidity are not likely to be clinically significant. Multivariate modeling failed to identify a model associated with IUC placement suggesting that postpartum IUC placement is not well predicted by patient variables. Lack of identifying factors may support offering postplacental IUC placement to all patients who indicate IUC as their preferred contraceptive method

Spatially resolved X-ray spectroscopy and modeling of the nonthermal emission of the PWN in G0.9+0.1

We performed a spatially resolved spectral X-ray study of the pulsar wind nebula (PWN) in the supernova remnant G0.9+0.1. Furthermore we modeled its nonthermal emission in the X-ray and very high energy (VHE, E > 100 GeV) gamma-ray regime. Using Chandra ACIS-S3 data, we investigated the east-west dependence of the spectral properties of G0.9+0.1 by calculating hardness ratios. We analyzed the EPIC-MOS and EPIC-pn data of two on-axis observations of the XMM-Newton telescope and extracted spectra of four annulus-shaped regions, centered on the region of brightest emission of the source. A radially symmetric leptonic model was applied in order to reproduce the observed X-ray emission of the inner part of the PWN. Using the optimized model parameter values obtained from the X-ray analysis, we then compared the modeled inverse Compton (IC) radiation with the published H.E.S.S. gamma-ray data. The spectral index within the four annuli increases with growing distance to the pulsar, whereas the surface brightness drops. With the adopted model we are able to reproduce the characteristics of the X-ray spectra. The model results for the VHE gamma radiation, however, strongly deviate from the H.E.S.S. data.Comment: 8 pages, 7 figures, accepted for publication in Astronomy & Astrophysic

The influence of fetal sex on patterns of change in anti-Mullerian hormone during pregnancy

Maternal anti-mullerian hormone declines sharply between 13-15 weeks, likely as a result of feto-placental signaling. Fetal AMH levels are known to be widely disparate after the first trimester, with high levels in male and absent levels in female. However, it is unclear as to whether differing fetal AMH levels influence the pattern of change of maternal AMH. Our objective was to examine AMH throughout gestation to determine if the maternal concentration varies according to the gender of the fetus

Testing Thermo-acoustic Sound Generation in Water with Proton and Laser Beams

Experiments were performed at a proton accelerator and an infrared laser acility to investigate the sound generation caused by the energy deposition of pulsed particle and laser beams in water. The beams with an energy range of 1 PeV to 400 PeV per proton beam spill and up to 10 EeV for the laser pulse were dumped into a water volume and the resulting acoustic signals were recorded with pressure sensitive sensors. Measurements were performed at varying pulse energies, sensor positions, beam diameters and temperatures. The data is well described by simulations based on the thermo-acoustic model. This implies that the primary mechanism for sound generation by the energy deposition of particles propagating in water is the local heating of the media giving rise to an expansion or contraction of the medium resulting in a pressure pulse with bipolar shape. A possible application of this effect would be the acoustical detection of neutrinos with energies greater than 1 EeV.Comment: 5 pages, 2 figures, to appear in the proceedings of the 1st International ARENA Workshop, May 17-19th, 2005, DESY Zeuthe