Propagation and amplification of tide at the northeastern coast of the Antarctic peninsula: an observational study

The amplification and propagation of the tide at the northeastern coast of the Antarctic Peninsula was studied by analysis of instantaneous sea levels measured at the tidal station of Base Esperanza,at the northern end of the Antarctic Peninsula (63゜22.46\u27S, 56゜59.33\u27W) ,at the northeastern coast of Marambio Island (Seymour Island,64゜14.11\u27S, 56゜34.51\u27W) and near Base Matienzo,Larsen nunatak (64゜54.23\u27S, 60゜2.60\u27W) at the edge of the Larsen ice-shelf. By means of harmonic analysis the amplitudes and phases of the most energetic ten tidal constituents were obtained.The tidal regime was typified by means of the factor F and a preponderantly semidiurnal mixed tide was obtained. Signi ficant southward amplification was observed in the amplitudes of semidiurnal constituents,and a less evident amplification was obtained in diurnal ones.Consequently,slightly southward diminution in factor F,from 0.75 (Esperanza) to 0.6 (Matienzo),was found.Bothsouthward amplification in amplitudes and northward propagation of the main tidal constituents obtained from numerical global models show good agreement with the present observations

In Vitro Permeation Screening of a New Formulation of Thiocolchicoside Containing Various Enhancers

Thiocolchicoside, a muscle relaxant agent with anti-inflammatory and analgesic actions, also is used topically for the treatment of muscular spasms and for rheumatologic, orthopedic, and traumatologic disorders. In this study, thiocolchicoside was formulated to use as foam to avoid contact with the afflicted area during the spreading phase. To enhance drug penetration, various enhancers were added to the base formulation. The tested enhancers were ethoxyethylendiglycol (Transcutol), highly purified phosphatidylcholine (Lipoid S20), capsaicin, propylene glycol dipelargonate (DPPG), and glycolysed ethoxylated glycerides (Labrafil M1944 CS). The transdermal absorption of the tested formulations containing enhancers, in comparison with base formulation, was evaluated in vitro through rat skin using standard Franz diffusion cells. Base formulation was found to have a higher permeation profile than the simple aqueous and hydroalcoholic solutions of the drug, meaning that the base formulation by itself enhances the drug permeation. Among the tested formulations, only the formulation containing DPPG/ethanol was found to be statistically different, showing an enhancement factor of 3.58. In the same experimental session, Muscoril ointment, the commercially available pharmaceutical product containing the same thiocolchicoside concentration (0.25%), also was tested. The formulation containing DPPG/ethanol showed a 4.86 times increase of permeability constant in comparison with Muscoril ointment. The formulation containing DPPG/ethanol as an enhancer could be a good candidate for a new topical foam, considering its good characteristics of permeability and compliance

HIRDLS Science Meeting Oxford (20 Sep 2006) Presentations

Selection of presentations given at the HIRDLS Science Meeting Oxford on the 20th September 2006

Assessment of upper tropospheric and stratospheric water vapor and ozone in reanalyses as part of S-RIP

Reanalysis data sets are widely used to understand atmospheric processes and past variability, and are often used to stand in as “observations” for comparisons with climate model output. Because of the central role of water vapor (WV) and ozone (O3) in climate change, it is important to understand how accurately and consistently these species are represented in existing global reanalyses. In this paper, we present the results of WV and O3 intercomparisons that have been performed as part of the SPARC (Stratosphere–troposphere Processes and their Role in Climate) Reanalysis Intercomparison Project (S-RIP). The comparisons cover a range of timescales and evaluate both inter-reanalysis and observation-reanalysis differences. We also provide a systematic documentation of the treatment of WV and O3 in current reanalyses to aid future research and guide the interpretation of differences amongst reanalysis fields. The assimilation of total column ozone (TCO) observations in newer reanalyses results in realistic representations of TCO in reanalyses except when data coverage is lacking, such as during polar night. The vertical distribution of ozone is also relatively well represented in the stratosphere in reanalyses, particularly given the relatively weak constraints on ozone vertical structure provided by most assimilated observations and the simplistic representations of ozone photochemical processes in most of the reanalysis forecast models. However, significant biases in the vertical distribution of ozone are found in the upper troposphere and lower stratosphere in all reanalyses

Iron overload alters the energy metabolism in patients with myelodysplastic syndromes: results from the multicenter FISM BIOFER study

Myelodysplastic syndromes (MDS) are hematological malignancies characterized by ineffective hematopoiesis and increased apoptosis in the bone marrow, which cause peripheral cytopenia. Mitochondria are key regulators of apoptosis and a site of iron accumulation that favors reactive oxygen species (ROS) production with detrimental effects on cell survival. Although the energy metabolism could represent an attractive therapeutic target, it was poorly investigated in MDS. The purpose of the study was to analyze how the presence of myelodysplastic hematopoiesis, iron overload and chelation impact on mitochondrial metabolism. We compared energy balance, OxPhos activity and efficiency, lactic dehydrogenase activity and lipid peroxidation in mononuclear cells (MNCs), isolated from 38 MDS patients and 79 healthy controls. Our data show that ATP/AMP ratio is reduced during aging and even more in MDS due to a decreased OxPhos activity associated with an increment of lipid peroxidation. Moreover, the lactate fermentation enhancement was observed in MDS and elderly subjects, probably as an attempt to restore the energy balance. The biochemical alterations of MNCs from MDS patients have been partially restored by the in vitro iron chelation, while only slight effects were observed in the age-matched control samples. By contrast, the addition of iron chelators on MNCs from young healthy subjects determined a decrement in the OxPhos efficiency and an increment of lactate fermentation and lipid peroxidation. In summary, MDS-MNCs display an altered energy metabolism associated with increased oxidative stress, due to iron accumulation. This condition could be partially restored by iron chelatio