Use of real-time observations in an operational ocean data assimilation system: the Mediterranean case

Real-time observations are essential for operational forecasting that in turn can be used to predict changes of the state of the ocean and its associated biochemical fi elds. In addition, real-time observations are useful to detect changes in the past with the shortest delay, to standardize practices in data collection and to exchange data between remote regions of the ocean and seas. Th e drawback is that real-time observations could be less accurate than their delayed mode counterparts due to the time constraints for data dissemination. In situ real-time data are usually decimated to be transmitted in real time (loss of accuracy and resolution), whereas satellite data are corrected with approximate algorithms and less ancillary data. Delayed mode quality control analysis increases the value of the observational data set, fl agging outliers and producing climatological estimates of the state of the system. Th us real-time data, together with a modelling system and the climatological estimates, give the appropriate information for scientifi c studies and applications. Th e principles of operational science started to develop in the 1940s and 1950s, based on the combined use of real-time data and modelling systems that can extend the information from observations in space and time. Operational science is based on a sound knowledge of the dynamics and processes for the space/timescales of interest and operational meteorology and oceanography have started to implement these principles to weather and ocean forecasting activities. In the past 20 years, operational meteorology has become a reality with a network of in situ and satellite observations that has made the weather forecast capable of extending the theoretical limit of predictability of the atmosphere (only one-two days theoretically, now forecasts are useful for more than fi ve days on average). Today meteorological observations are mainly used in their assimilated form even if observations are still collected for specifi c process-oriented studies. Recently the meteorological re-analysis projects (Gibson et al., 1997; Kalnay et al., 1996) have released a wealth of data to be understood and analysed. Th ese data sets are coherent and approximately continuous (daily), fi lling the observational gaps in space and time with a dynamical interpolation scheme. Th e model and the real-time observations are fused in one best estimate of the state of the system by data-assimilation techniques that have been developed to a great degree of sophistication in recent years (Lorenc, 2002). Th e re-analysis data are now forming the basic reference data set to understand climate variability in the atmosphere and upper oceans. Ch20.indd 73Ch20.indd 733 3/7/07 9:58:01 AM Habwatch 734 Dynamical interpolation/extrapolation of observational data for operational forecasting in the ocean began to be investigated at the beginning of the 1980s and the fi rst successful forecasts were carried out in the open ocean (Robinson and Leslie, 1985). Th ese exercises required real-time data that were initially collected with rapid ship surveys realizing adaptive sampling schemes and collecting a combination of traditional recoverable and expendable instruments (CTD, XBTs). At the same time but in a totally independent way, shelf scale and coastal real-time data from moored and drifting sensors such as meteorological buoys and sea-level stations started to be used for shelf scale storm surge operational forecasting (Prandle, 2002). Operational oceanography is now building on this experience and considers real-time measurements from opportunity platforms and satellites in a manner very similar to operational meteorology. Th is chapter aims to show the use of real-time observations in a state-of-the-art ocean-predicting system realized in the Mediterranean. We discuss the pre-processing schemes required to properly assimilate the observations into an operational nowcasting/ forecasting system, elucidate the role and impact of diff erent observations in the assimilation system and show the use of real-time data to evaluate quality of the modelling system. We start with the description of the Mediterranean Forecasting System (MFS) real-time observing system and pre-processing quality control in Section 20.2, we then describe the modelling and assimilation system in relation to the impact of diff erent real-time observations in Section 20.3. In Section 20.4 we evaluate the consistency, quality and accuracy of the forecasting system using model-data intercomparison and Section 20.5 offers conclusion

Humerus shaft fracture complicated by radial nerve palsy: Is surgical exploration necessary?

Fractures of the humerus shaft often are complicated by radial nerve palsy. Controversy still exists in the treatment that includes clinical observation and eventually late surgical exploration or early surgical exploration. Algorithms have been proposed to provide recommendations with regard to management of the injuries. However, advantages and disadvantages are associated with each of these algorithms. The aim of this study was to analyze the indications of each treatment options and facilitate the surgeon in choosing the conduct for each lesion, proposing our own algorithm

Selenium and Other Trace Elements in the Etiology of Parkinson's Disease: A Systematic Review and Meta-Analysis of Case-Control Studies

Background: Parkinson's disease (PD) is the most common neurodegenerative disease after Alzheimer's dementia. Whereas the exact etiology of PD remains unknown, risk of developing PD seems to be related to a combination of genetic and environmental factors. This also includes abnormal exposure to trace elements of nutritional and toxicological interest. Objectives: In this systematic review and meta-Analysis, we summarized the results of case-control studies comparing levels of selenium, copper, iron, and zinc in PD patients and controls in either blood (whole blood, serum/plasma) or cerebrospinal fluid (CSF). Methods: We performed a systematic PubMed search selecting studies reporting trace element levels in different specimens of patients and controls. We performed a meta-Analysis using a random-effect model to compute the weighted mean differences (WMD) and corresponding 95% CI of selenium, copper, iron, and zinc levels in the blood or CSF of patients and their matched controls. Results: We retrieved 56 papers reporting data for selenium (cases/controls: 588/721), copper (2,190/2,522), iron (2,956/3,469), and zinc (1,798/1,913) contents in CSF and blood. Cases showed considerably higher levels of selenium in CSF compared with controls (+51.6%; WMD 5.49; 95% CI 2.82 to 8.15), while levels in serum were similar (-0.2%; WMD-0.22; 95% CI-8.05 to 7.62). For copper, cases showed slightly higher levels in CSF and slightly lower concentrations in serum (+4.5%; WMD 1.87; 95% CI-3.59 to 7.33, and-4.5%; WMD-42.79; 95% CI-134.35 to 48.76, respectively). A slight increase was also found for CSF iron-levels (+9.5%; WMD 9.92; 1.23 to 18.61), while levels were-decreased in serum/plasma (-5.7%; WMD-58.19; 95% CI-106.49 to-9.89) and whole blood (-10.8%; WMD-95.69; 95% CI-157.73 to-33.65). Conversely, for zinc cases exhibited lower levels both in CSF (-10.8%; WMD-7.34; 95% CI-14.82 to 0.14) and serum/plasma (-7.5%; WMD-79.93; 95% CI-143.80 to-16.06). A longer duration of the disease tends to be associated with overall lower trace element levels in either CSF or blood. Conclusions: Due to the study findings and the greater relevance of the CSF compartment compared with the circulating peripheral ones, this meta-Analysis suggests that overexposure in the central nervous system to selenium, and possibly to copper and iron, may be a risk factor of the disease, while zinc might have a protective-effect

Selenium and other trace elements in the etiology of Parkinson’s disease: a systematic review and meta-analysis of case-control studies

.INTRODUCTION Parkinson’s disease (PD) is a neurodegenerative illness recognised as the most common neurological disorder after Alzheimer’s dementia. Whereas the exact PD etiology remains unknown, risk of developing PD seems to be related to an interrelation of genetic and environmental factors, including also altered exposure to trace elements. In this systematic review and meta-analysis, we updated and summarized the results of epidemiologic case-control studies comparing levels of selenium, copper, iron and zinc in PD patients with healthy subjects in either blood (as whole blood, serum or plasma) and cerebrospinal fluid (CSF). MATERIALS AND METHODS We performed a systematic PubMed search and we included in our assessment only studies reporting demographic and disease-related characteristics, as well as trace element levels in different specimens (whole blood, serum/plasma and CSF). We then performed a meta-analysis of mean differences of trace element levels between cases and controls, using a random-effect model computing the weighted mean differences (WMD) and corresponding 95% confidence intervals (CI) to assess the association between serum/plasma, whole blood, CSF and selenium, copper, iron and zinc with Parkinson’s disease. RESULTS We retrieved 55 papers reporting data for selenium (588 cases and 721 controls), copper (2190 and 2522), iron (2843 and 3434), and zinc (1798 and 1913). Cases showed higher levels of selenium in CSF compared with controls (WMD=5.49; 95%CI 2.82 to 8.15), while levels in serum were similar (WMD=-0.22; -8.05 to 7.62). For copper cases showed higher levels in CSF and lower in serum compared to controls (WMD=1.87; -3.59 to 7.33, and -42.79, -134.35 to 48.76 respectively). Same results were found for iron in CSF (WMD=6.54; -1.97 to 15.04) and in serum/plasma (WMD=-58.19; -106.49 to -9.89 and whole blood (WMD=-95.69; 157.73 to -33.65). On the converse, cases had lower levels of zinc both in CSF (WMD=-7.34; -14.82 to 0.14) and serum/plasma (WMD=-79.93; -143.80 to -16.06). CONCLUSIONS Results of this systematic review and meta-analysis suggests that overexposure to environmental selenium, copper and iron may be risk factors for PD onset or progression. Alternatively, some variation in levels of these trace elements may occur as a consequence of the disease. Considering the burden of PD in the world population, further investigation of trace element exposure in this disease is therefore warranted, especially to plan possible prevention measures

Impact of Multi-altimeter Sea Level Assimilation in the Mediterranean Forecasting Model

In this paper we analyze the impact of multi-satellite altimeter observations assimilation in a high-resolution Mediterranean model. Four different altimeter missions (Jason-1, Envisat, Topex/Poseidon interleaved and Geosat Follow-On) are used over a 7-month period [September 2004, March 2005] to study the impact of the assimilation of one to four satellites on the analyses quality. The study highlights three important results. First, it shows the positive impact of the altimeter data on the analyses. The corrected fields capture missing structures of the circulation and eddies are modified in shape, position and intensity with respect to the model simulation. Secondly, the study demonstrates the improvement in the analyses induced by each satellite. The impact of the addition of a second satellite is almost equivalent to the improvement given by the introduction of the first satellite: the second satellite data brings a 12% reduction of the root mean square of the differences between analyses and observations for the Sea Level Anomaly (SLA). The third and fourth satellite also significantly improve the rms, with more than 3% reduction for each of them. Finally, it is shown that Envisat and Geosat Follow-On additions to J1 impact the analyses more than the addition of Topex/Poseidon suggesting that the across track spatial resolution is still one of the important aspects of a multi-mission satellite observing system. This result could support the concept of multi-mission altimetric monitoring done by complementary horizontal resolution satellite orbits

New in vitro cellular model for molecular studies of retinitis pigmentosa

Retinitis pigmentosa (RP) is an inherited form of retinal degeneration characterized by primary rod photoreceptor cell death followed by cone loss. Mutations in several genes linked to the disease cause increased levels of cyclic guanosine monophosphate (cGMP) and calcium ion influxes. The purpose of this project was to develop a new in vitro photoreceptor degeneration model for molecular studies of RP. 661W cells were genetically modified to stably express the neural retina leucine zipper (NRL) transcription factor. One clone (661W-A11) was selected based on the expression of Nrl target genes. 661W-A11 showed a significant increase in expression of rod-specific genes but not of cone-specific genes, compared with 661W cells. Zaprinast was used to inhibit phosphodiesterase 6 (PDE6) activity to mimic photoreceptor degeneration in vitro. The activation of cell death pathways resulting from PDE6 inhibition was confirmed by detection of decreased viability and increased intracellular cGMP and calcium, as well as activation of protein kinase G (PKG) and calpains. In this new in vitro system, we validated the effects of previously published neuroprotective drugs. The 661W-A11 cells may serve as a new model for molecular studies of RP and for high-throughput drug screening

A Nested Atlantic-Mediterranean Sea General Circulation Model for Operational Forecasting.

Abstract. A new numerical general circulation ocean model for the Mediterranean Sea has been implemented nested within an Atlantic general circulation model within the framework of the Marine Environment and Security for the European Area project (MERSEA, Desaubies, 2006). A 4-year twin experiment was carried out from January 2004 to December 2007 with two different models to evaluate the impact on the Mediterranean Sea circulation of open lateral boundary conditions in the Atlantic Ocean. One model considers a closed lateral boundary in a large Atlantic box and the other is nested in the same box in a global ocean circulation model. Impact was observed comparing the two simulations with independent observations: ARGO for temperature and salinity profiles and tide gauges and along-track satellite observations for the sea surface height. The improvement in the nested Atlantic-Mediterranean model with respect to the closed one is particularly evident in the salinity characteristics of the Modified Atlantic Water and in the Mediterranean sea level seasonal variability

Kesuburan Perairan Ditinjau dari Kandungan Klorofil-a Fitoplankton : Studi Kasus di Sungai Wedung, Demak

Perairan Sungai Wedung merupakan ekosistem pesisir yang banyak dimanfaatkan untuk berbagai kegiatan manusia. Hal tersebut tentunya berpengaruh terhadap kesuburan perairan Sungai Wedung. Kesuburan di perairan tersebut dipengaruhi oleh plankton, faktor kimia, fisika dan juga kandungan Klorofil-A. Pengukuran kandungan klorofil-a fitoplankton merupakan salah satu alat pengukuran kesuburan suatu perairan. Klorofil-a fitoplankton adalah suatu pigmen aktif dalam sel tumbuhan yang mempunyai peran penting dalam berlangsungnya proses fotosintesis perairan. Penelitian dilakukan pada bulan April – Mei 2013 di Sungai Wedung, Demak bertujuan untuk mengetahui aktivitas manusia terhadap sebaran klorofil-a, keterkaitan antara klorofil-a dan kelimpahan fitoplankton dan tingkat kesuburan perairan berdasarkan kandungan klorofil-a fitoplankton. Metode yang digunakan adalah metode studi kasus dengan teknik pengambilan sampel menggunakan metode “Sample Survey Method”. Hasil penelitian menunjukkan bahwa hasil analisis data klorofil menggunakan metode anova tersarang (nested anova) diperoleh nilai P untuk stasiun cukup besar sehingga tidak memberikan perbedaan yang nyata pada taraf kepercayaan 95 %. Akan tetapi perbedaan akan nyata pada taraf 90%. Hubungan antara klorofil-a dengan kelimpahan fitoplankton secara linear menunjukkan nilai keeratan yang tinggi dengan nilai koefisien korelasi sebesar 0,93 dan koefisien determinasi sebesar 0,8633 dimana 86% klorofil-a dipengaruhi oleh kelimpahan fitoplankton. Berdasarkan nilai rata-rata klorofil-a yang diperoleh sebesar 1,039863 mg/l dapat disimpulkan bahwa perairan Sungai Wedung tergolong kedalam perairan yang bersifat oligotrofik

Humic acid formation in artificial soils amended with compost at different stages of organic matter evolution

A composting process was conducted under optimal conditions for 150 d, obtaining three biomasses at different levels of maturity: raw material (RM), fresh compost obtained after 11 d of composting (FC), and evolved compost (EC) obtained after 150 d of composting. During the composting process, HAs were extracted and fully characterized by mass balance, DRIFT, and 1H and 13C-nuclear magnetic resonance spectroscopy. Each compost sample was incubated for 180 d in an artificial soil, after which HA extraction was repeated and characterized. To compare composts containing different amounts of labile organic matter (OM), an equal amount of unhydrolyzable OM was added to the soils. Our results indicated that compost HAs consist of a biologically and chemically stable fraction (i.e., the unhydrolyzable HA [U-HA]) and a labile fraction, whose relative contents depended on the composting duration. Humic acid from more EC contained a higher amount of recalcitrant fraction (aromatic carbon) and a lesser amount of labile fraction (aliphatic carbon) than HA from RM and FC. These results suggest that the humification process during composting preserves the more recalcitrant fraction of the compost-alkali soluble/acid insoluble fraction (HA-fraction). Incubation of composts in soil showed that due to the higher labile fraction content, HAs from raw material were more degraded than those from EC. The abundance of labile carbon of soil amended with less-evolved compost (RM and FC) allowed the more recalcitrant fractions of U-HA to be more preserved than in EC. These results suggest that less-evolved compost could contribute more than well evolved compost to the stable soil OM. Copyrigh

A nested Atlantic-Mediterranean Sea general circulation model for operational forecasting

A new numerical general circulation ocean model for the Mediterranean Sea has been implemented nested within an Atlantic general circulation model within the framework of the Marine Environment and Security for the European Area project (MERSEA, Desaubies, 2006). A 4- year twin experiment was carried out from January 2004 to December 2007 with two different models to evaluate the impact on the Mediterranean Sea circulation of open lateral boundary conditions in the Atlantic Ocean. One model considers a closed lateral boundary in a large Atlantic box and the other is nested in the same box in a global ocean circulation model. Impact was observed comparing the two simulations with independent observations: ARGO for temperature and salinity profiles and tide gauges and along-track satellite observations for the sea surface height. The improvement in the nested Atlantic-Mediterranean model with respect to the closed one is particularly evident in the salinity characteristics of the Modified Atlantic Water and in the Mediterranean sea level seasonal variability