Diagnostics of the tropical tropopause layer from in-situ observations and CCM data

A suite of diagnostics is applied to in-situ aircraft measurements and one Chemistry-Climate Model (CCM) data to characterize the vertical structure of the Tropical Tropopause Layer (TTL). The diagnostics are based on vertical tracer profiles and relative vertical tracer gradients, using tropopause-referenced coordinates, and tracer-tracer relationships in the tropical Upper Troposphere/Lower Stratosphere (UT/LS). Observations were obtained during four tropical campaigns performed from 1999 to 2006 with the research aircraft Geophysica and have been compared to the output of the ECHAM5/MESSy CCM. The model vertical resolution in the TTL (~500 m) allows for appropriate comparison with high-resolution aircraft observations and the diagnostics used highlight common TTL features between the model and the observational data. The analysis of the vertical profiles of water vapour, ozone, and nitrous oxide, in both the observations and the model, shows that concentration mixing ratios exhibit a strong gradient change across the tropical tropopause, due to the role of this latter as a transport barrier and that transition between the tropospheric and stratospheric regimes occurs within a finite layer. The use of relative vertical ozone and carbon monoxide gradients, in addition to the vertical profiles, helps to highlight the region where this transition occurs and allows to give an estimate of its thickness. The analysis of the CO-O3 and H2O-O3 scatter plots and of the Probability Distribution Function (PDF) of the H2O-O3 pair completes this picture as it allows to better distinguish tropospheric and stratospheric regimes that can be identified by their different chemical composition. The joint analysis and comparison of observed and modelled data allows to state that the model can represent the background TTL structure and its seasonal variability rather accurately. The model estimate of the thickness of the interface region between tropospheric and stratospheric regimes agrees well with average values inferred from observations. On the other hand, the measurements can be influenced by regional scale variability, local transport processes as well as deep convection, that can not be captured by the model

Diagnostics of the tropical tropopause layer from in-situ observations and CCM data

A suite of diagnostics is applied to in-situ aircraft measurements and one Chemistry-Climate Model (CCM) data to characterize the vertical structure of the Tropical Tropopause Layer (TTL). The diagnostics are based on the vertical tracers profiles, relative vertical tracers gradients, and tracer-tracer relationships in the tropical Upper Troposphere/Lower Stratosphere (UT/LS), using tropopause coordinates. Observations come from the four tropical campaigns performed from 1998 to 2006 with the research aircraft Geophysica and have been directly compared to the output of the ECHAM5/MESSy CCM. The model vertical resolution in the TTL allows for appropriate comparison with high-resolution aircraft observations and the diagnostics used highlight common TTL features between the model and the observational data. The analysis of the vertical profiles of water vapour, ozone, and nitrous oxide, in both the observations and the model, shows that concentration mixing ratios exhibit a strong gradient change across the tropical tropopause, due to the role of this latter as a transport barrier and that transition between the tropospheric and stratospheric regimes occurs within a finite layer. The use of relative vertical ozone gradients, in addition to the vertical profiles, helps to highlight the region where this transition occurs and allows to give an estimate of its thickness. The analysis of the CO-O3 and H2O-O3 scatter plots and of the Probability Distribution Function (PDF) of the H2O-O3 pair completes this picture as it allows to better distinguish tropospheric and stratospheric regimes that can be identified, first, by their differing chemical composition. The joint analysis and comparison of observed and modelled data allows us to evaluate the capability of the model in reproducing the observed vertical structure of the TTL and its variability, and also to assess whether observations from particular regions on a monthly timescale can be representative of the fine scale mean structure of the Tropical Tropopause Layer

Ovarian stimulation and liver dysfunction: Is a clinical relationship possible? A case of hepatic failure after repeated cycles of ovarian stimulation

Liver damage induced by ovarian stimulation has been demonstrated in some cases reported in the literature. However, there has never been a fruitful debate on this topic. The present manuscript tried to fill this gap. We reported a case of a 35-year-old nulliparous woman admitted to our obstetric emergency room for severe pre-eclampsia. She had been subjected to four cycles of controlled ovarian stimulation for intrauterine insemination. At 32 weeks of gestation, she developed severe pre-eclampsia, which led to HELLP syndrome complicated by fatal liver failure. The etiological link between ovarian stimulation and HELLP syndrome is intriguing. Further investigations are needed to understand whether repeated ovarian stimulation may represent a risk factor in pre-eclamptic patients. © 2013. The Korean Society for Reproductive Medicine

The critical pregnant patient: a field of competence not only obstetric

Abstract: the pregnancy status may confound the normal diagnostic workup in the critical patient because the gynecologist usually evaluates the patient from the obstetrical point of view whereas the non-specialist physician tends to consider other medical conditions. In these critical cases, the teamwork is fundamental because the different knowledge in various fields of medicine can be integrated for a diagnosis more fast and accurat

Ovarian stimulation and liver dysfunction: Is a clinical relationship possible? A case of hepatic failure after repeated cycles of ovarian stimulation

Liver damage induced by ovarian stimulation has been demonstrated in some cases reported in the literature. However, there has never been a fruitful debate on this topic. The present manuscript tried to fill this gap. We reported a case of a 35-year-old nulliparous woman admitted to our obstetric emergency room for severe pre-eclampsia. She had been subjected to four cycles of controlled ovarian stimulation for intrauterine insemination. At 32 weeks of gestation, she developed severe pre-eclampsia, which led to HELLP syndrome complicated by fatal liver failure. The etiological link between ovarian stimulation and HELLP syndrome is intriguing. Further investigations are needed to understand whether repeated ovarian stimulation may represent a risk factor in pre-eclamptic patients

The critical pregnant patient: A field of competence not only obstetric

Abstract: the pregnancy status may confound the normal diagnostic workup in the critical patient because the gynecologist usually evaluates the patient from the obstetrical point of view whereas the non-specialist physician tends to consider other medical conditions. In these critical cases, the teamwork is fundamental because the different knowledge in various fields of medicine can be integrated for a diagnosis more fast and accurat

The Prevention of Gestational Diabetes

Abstract The negative impact of the gestational diabetes on the maternal and fetal health is well known and this impact is closely related to gestational age at which the diagnosis is done. Therefore, the use of therapeutic options able to prevent or delay the gestational diabetes occurrence has a positive impact on maternal and neonatal outcomes. a non-pharmacological option and have a positive impact on insulin resistance although they do not seem to prevent the gestational diabetes onset.The preconceptional use of metformin in women with polycystic ovary syndrome protects the pancreatic beta cell reserve preventing or delaying the occurrence of gestational diabetes. However, there are also doubts on the drug safety in pregnancy since it completely crosses the placenta.From this point of view, the inositol could represent an excellent alternative.Its role as insulin sensitizing agent is well documented on improving both the hormonal and reproductive parameters. However, the studies on its preconc

Northern winter stratospheric temperature and ozone responses to ENSO inferred from an ensemble of Chemistry Climate Models

The connection between the El Ni˜no Southern Oscillation (ENSO) and the Northern polar stratosphere has been established from observations and atmospheric modeling. Here a systematic inter-comparison of the sensitivity of the modeled stratosphere to ENSO in Chemistry Climate Models (CCMs) is reported. This work uses results from a number of the CCMs included in the 2006 ozone assessment. In the lower stratosphere, the mean of all model simulations reports a warming of the polar vortex during strong ENSO events in February–March, consistent with but smaller than the estimate from satellite observations and ERA40 reanalysis. The anomalous warming is associated with an anomalous dynamical increase of column ozone north of 70� N that is accompanied by coherent column ozone decrease in the Tropics, in agreement with that deduced from the NIWA column ozone database, implying an increased residual circulation in the mean of all model simulations during ENSO. The spread in the model responses is partly due to the large internal stratospheric variability and it is shown that it crucially depends on the representation of the tropospheric ENSO teleconnection in the models