Intraseasonal variability of mixed layer depth in the tropical Indian Ocean

In this paper, we use an observational dataset built from Argo in situ profiles to describe the main large-scale patterns of intraseasonal mixed layer depth (MLD) variations in the Indian Ocean. An eddy permitting (0.25A degrees) regional ocean model that generally agrees well with those observed estimates is then used to investigate the mechanisms that drive MLD intraseasonal variations and to assess their potential impact on the related SST response. During summer, intraseasonal MLD variations in the Bay of Bengal and eastern equatorial Indian Ocean primarily respond to active/break convective phases of the summer monsoon. In the southern Arabian Sea, summer MLD variations are largely driven by seemingly-independent intraseasonal fluctuations of the Findlater jet intensity. During winter, the Madden-Julian Oscillation drives most of the intraseasonal MLD variability in the eastern equatorial Indian Ocean. Large winter MLD signals in northern Arabian Sea can, on the other hand, be related to advection of continental temperature anomalies from the northern end of the basin. In all the aforementioned regions, peak-to-peak MLD variations usually reach 10 m, but can exceed 20 m for the largest events. Buoyancy flux and wind stirring contribute to intraseasonal MLD fluctuations in roughly equal proportions, except for the Northern Arabian Sea in winter, where buoyancy fluxes dominate. A simple slab ocean analysis finally suggests that the impact of these MLD fluctuations on intraseasonal sea surface temperature variability is probably rather weak, because of the compensating effects of thermal capacity and sunlight penetration: a thin mixed-layer is more efficiently warmed at the surface by heat fluxes but loses more solar flux through its lower base.

Mindfulness-Based Cognitive Therapy for older people in a community setting: a mixed methods feasibility study

Rationale: In line with complex intervention development, this research takes a systematic approach to examining the feasibility and acceptability of delivering Mindfulness-Based Cognitive Therapy (MBCT) to older people who experience symptoms of depression. Methods: A mixed methods approach was adopted in line with recommendations made by the MRC Complex Intervention Development framework. Quantitative and qualitative methods were combined by administering questionnaires as well as conducting post intervention interviews. A number of trial feasibility factors were examined such as recruitment and attrition rates. Qualitative data was analysed using Braun and Clarke’s thematic analysis framework. Results: Nine participants started the MBCT intervention and six completed the 8-week programme. The results suggest that MBCT for older people is feasible and acceptable. Participants reported improved mindfulness skills. Participants responded positively to being asked to take part in research and appeared to particularly value the group delivery format of the intervention. Conclusions: MBCT is both feasible and acceptable for older people experiencing symptoms of depression. Further research is required with larger sample sizes to allow for more robust statistical exploration of outcome measures, including mechanisms of change.

Exploring redox-driven self-assembly of mixed metal polyoxometalates

How can we control the experimental conditions towards the isolation of specific structures? Why do particular architectures form? These are some challenging questions that synthetic chemists try to answer, specifically within polyoxometalate (POM) chemistry, where there is still much unknown regarding the synthesis of novel molecular structures in a controlled and predictive manner. This work covers a wide range of POM chemistry, exploring the redox self-assembly of polyoxometalate clusters, using both “one-pot”, flow and hydrothermal conditions. For this purpose, different vanadium, molybdenum and tungsten reagents, heteroatoms, inorganic salts and reducing agents have been used. The template effect of lone-pair containing pyramidal heteroatoms has been investigated. Efforts to synthesize new POM clusters displaying pyramidal heteroanions (XO32-, where X= S, Se, Te, P) are reported. The reaction of molybdenum with vanadium in the presence of XO32- heteroatoms is explored, showing how via the cation and experimental control it is possible to direct the self-assembly process and to isolate isostructural compounds. A series of four isostructural (two new, namely {Mo11V7P} and {Mo11V7Te} and two already known, namely {Mo11V7Se} and {Mo11V7S} disordered egg-shaped Polyoxometalates have been reported. The compounds were characterized by X-ray structural analysis, TGA, UV-Vis, FT-IR, Elemental and Flame Atomic Absorption Spectroscopy (FAAS) analysis and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Cyclic Voltammetry measurements have been carried out in all four compounds showing the effect of the ionic density of the heteroatom on the potential. High-Resolution ESI-MS studies have revealed that the structures retain their integrity in solution. Efforts to synthesize new mixed-metal compounds led to isolation, structural, and electronic characterization of the theoretically predicted, but experimentally elusive δ-isomer of the Keggin polyoxometalate cluster anion, {H2W4V9O33(C6H13NO3)}, by the reaction of tungstate(VI) and vanadium(V) with triethanolammonium ions (TEAH), acting as a tripodal ligand grafted to the surface of the cluster. Control experiments (in the absence of the organic compound) have proven that the tripodal ligand plays crucial role on the formation of the isomer. The six vanadium metal centres, which consist the upper part of the cluster, are bonded to the “capping” TEA tripodal ligand. This metal-ligand bonding directs and stabilises the formation of the final product. The δ-Keggin species was characterized by single-crystal X-ray diffraction, FT-IR, UV-vis, NMR and ESI-MS spectrometry. Electronic structure and structure-stability correlations were evaluated by means of DFT calculations. The compounds exhibited photochromic properties by undergoing single-crystal-to-single-crystal (SC-SC) transformations and changing colour under light. Non-conventional synthetic approaches are also used for the synthesis of the POM clusters comparing the classical “one-pot” reaction conditions and exploring the synthetic parameters of the synthesis of POM compounds. Reactions under hydrothermal and flow conditions, where single crystals that depend on the solubility of the minerals under hot water and high pressure can be synthesized, resulted in the isolation of two isostructural compounds, namely, {Mo12V3Te5}. The compound isolated from a continuous processing method, crystallizes in a hexagonal crystal system, forming a 2D porous plane net, while the compound isolated using hard experimental conditions (high temperature and pressure) crystallizes in monoclinic system, resulting in a different packing configuration. Utilizing these alternative synthetic approaches, the most kinetically and thermodynamically compounds would possibly be isolated. These compounds were characterised by single-crystal X-ray diffraction, FT-IR and UV-vis spectroscopy. Finally, the redox-controlled driven oscillatory template exchange between phosphate (P) and vanadate (V) anions enclosed in an {M18O54(XO4)2} cluster is further investigated using UV-vis spectroscopy as a function of reaction time, showed that more than six complete oscillations interconverting the capsule species present in solution from {P2M18} to {V2M18} were possible, provided that a sufficient concentration of the TEA reducing agent was present in solution. In an effort to investigate the periodicity of the exchange of the phosphate and vanadate anions, time dependent Uv-vis measurements were performed for a period at a range of 170-550 hours. Different experimental conditions were also applied in order to investigate the role of the reducing agent, as well as the effect of other experimental variables on the oscillatory system.

Using an end-of-life care pathway in acute stroke: a mixed methods study of decision-making and care experiences

Background: The evidence base on end-of-life care in acute stroke is limited, particularly with regard to recognising dying and related decision-making. There is also limited evidence to support the use of end-of-life care pathways (standardised care plans) for patients who are dying after stroke. Aim: This study aimed to explore the clinical decision-making involved in placing patients on an end-of-life care pathway, evaluate predictors of care pathway use, and investigate the role of families in decision-making. The study also aimed to examine experiences of end-of-life care pathway use for stroke patients, their relatives and the multi-disciplinary health care team. Methods: A mixed methods design was adopted. Data were collected in four Scottish acute stroke units. Case-notes were identified prospectively from 100 consecutive stroke deaths and reviewed. Multivariate analysis was performed on case-note data. Semi-structured interviews were conducted with 17 relatives of stroke decedents and 23 healthcare professionals, using a modified grounded theory approach to collect and analyse data. The VOICES survey tool was also administered to the bereaved relatives and data were analysed using descriptive statistics and thematic analysis of free-text responses. Results: Relatives often played an important role in influencing aspects of end-of-life care, including decisions to use an end-of-life care pathway. Some relatives experienced enduring distress with their perceived responsibility for care decisions. Relatives felt unprepared for and were distressed by prolonged dying processes, which were often associated with severe dysphagia. Pro-active information-giving by staff was reported as supportive by relatives. Healthcare professionals generally avoided discussing place of care with families. Decisions to use an end-of-life care pathway were not predicted by patients’ demographic characteristics; decisions were generally made in consultation with families and the extended health care team, and were made within regular working hours. Conclusion: Distressing stroke-related issues were more prominent in participants’ accounts than concerns with the end-of-life care pathway used. Relatives sometimes perceived themselves as responsible for important clinical decisions. Witnessing prolonged dying processes was difficult for healthcare professionals and families, particularly in relation to the management of persistent major swallowing difficulties.

Evaluation du stock de coquilles Saint-Jacques de la Baie de Seine et du Proche Extérieur. COMOR 32 (8-23 juillet 2002)

Scientific scallop surveys called COMOR are carried out in the bay of Seine since 1976. Results are used by fishermen’ associations and by fishing administration to lead management measures. In this report, the scientific results of the survey COMOR 32 realised in July 2002 are described. Abundance and growth indices for scallop, by age and area, are presented. During these surveys, data about most abundant benthic species are also collected since 1998. A first assessment with five years data is made here. A global descriptive analysis is undertaken about all the species present on scallops grounds. A special zoom is applied on both species whitch could be exploited (whelk Buccinum undatum and queen scallop Aequipecten opercularis) and three competitive species (starfish Asterias rubens, American slipper-limpet Crepidula fornicata and brittle star Ophiothrix fragilis)

A Mixed Discontinuous Galerkin Method for Incompressible Magnetohydrodynamics

We introduce and analyze a discontinuous Galerkin method for the numerical discretization of a stationary incompressible magnetohydrodynamics model problem. The fluid unknowns are discretized with inf-sup stable discontinuous P^3_{k}-P_{k-1} elements whereas the magnetic part of the equations is approximated by discontinuous P^3_{k}-P_{k+1} elements. We carry out a complete a-priori error analysis and prove that the energy norm error is convergent of order O(h^k) in the mesh size h. We also show that the method is able to correctly capture and resolve the strongest magnetic singularities in non-convex polyhedral domains. These results are verified in a series of numerical experiments.

Volatility Spillover and Multivariate Volatility Impulse Response Analysis of GFC News Events

This paper applies two measures to assess spillovers across markets: the Diebold Yilmaz (2012) Spillover Index and the Hafner and Herwartz (2006) analysis of multivariate GARCH models using volatility impulse response analysis. We use two sets of data, daily realized volatility estimates taken from the Oxford Man RV library, running from the beginning of 2000 to October 2016, for the S&P500 and the FTSE, plus ten years of daily returns series for the New York Stock Exchange Index and the FTSE 100 index, from 3 January 2005 to 31 January 2015. Both data sets capture both the Global Financial Crisis (GFC) and the subsequent European Sovereign Debt Crisis (ESDC). The spillover index captures the transmission of volatility to and from markets, plus net spillovers. The key difference between the measures is that the spillover index captures an average of spillovers over a period, whilst volatility impulse responses (VIRF) have to be calibrated to conditional volatility estimated at a particular point in time. The VIRF provide information about the impact of independent shocks on volatility. In the latter analysis, we explore the impact of three different shocks, the onset of the GFC, which we date as 9 August 2007 (GFC1). It took a year for the financial crisis to come to a head, but it did so on 15 September 2008, (GFC2). The third shock is 9 May 2010. Our modelling includes leverage and asymmetric effects undertaken in the context of a multivariate GARCH model, which are then analysed using both BEKK and diagonal BEKK (DBEKK) models. A key result is that the impact of negative shocks is larger, in terms of the effects on variances and covariances, but shorter in duration, in this case a difference between three and six months.

Analysis of maternal and child health policies in Malawi: The methodological perspective

The question of why most health policies do not achieve their intended results continues to receive a considerable attention in the literature. This is in the light of the recognized gap between policy as intent and policy as practice, which calls for substantial research work to understand the factors that improve policy implementation. Although there is substantial work that explains the reasons why policies achieve or fail to achieve their intended outcomes, there are limited case studies that illustrate how to analyze policies from the methodological perspective. In this article, we report and discuss how a mixed qualitative research method was applied for analyzing maternal and child health policies in Malawi. For the purposes of this article, we do not report research findings; instead we focus our dicussion on the methodology of the study and draw lessons for policy analysis research work. We base our disusssion on our experiences from a study in which we analyzed maternal and child health policies in Malawi over the period from 1964 to 2008. Noting the multifaceted nature of maternal and child health policies, we adopted a mixed qualitative research method, whereby a number of data collection methods were employed. This approach allowed for the capturing of different perspectives of maternal and child health policies in Malawi and for strengthening of the weaknesses of each method, especially in terms of data validity. This research suggested that the multidimensional nature of maternal and child health policies, like other health policies, calls for a combination of research designs as well as a variety of methods of data collection and analysis. In addition, we suggest that, as an emerging research field, health policy analysis will benefit more from case study designs because they provide rich experiences in the actual policy context.

Understanding import diversification: an empirical analysis

This paper analyzes import diversification in an aggregated perspective -- Using a dataset for 60 countries covering the period 1995-2010, we study the main determinants of import diversification -- We expect to contribute to the current literature, taking into account that there have been few empirical studies addressing import diversification and more specifically, at the cross-country level -- We take into account variables classified into four categories: Structural factors, macroeconomic factors, international trade factors and political factors -- We find robust evidence that total factor productivity (TFP), capital stock, real Exchange rates and terms of trade are key drivers of import diversification -- On the other hand, domestic consumption and trade openness exert an effect leading to import concentration -- We interpret this finding, taking into account the theoretical framework provided by the international trade and growth theories

Train scheduling and rolling stock assignment in high speed trains

The Train Timetabling Problem (TTP) has been widely studied for freight and passenger rail systems. A lesser effort has been devoted to the study of high-speed rail systems. A modeling issue that has to be addressed is to model departure time choice of passengers on railway services. Passengers who use these systems attempt to travel at predetermined hours due to their daily life necessities (e.g., commuter trips). We incorporate all these features into TTP focusing on high-speed railway systems. We propose a Rail Scheduling and Rolling Stock (RSch-RS) model for timetable planning of high-speed railway systems. This model is composed of two essential elements: i) an infrastructure model for representing the railway network: it includes capacity constraints of the rail network and the Rolling-Stock constraints; and ii) a demand model that defines how the passengers choose the departure time. The resulting model is a mixed-integer programming model which objective function attempts to maximize the profit for the rail operator

Agreement of Mixed Venous Carbon Dioxide Tension (PvCO2) and Transcutaneous Carbon Dioxide (PtCO2) Measurements in Ventilated Infants

Background: Noninvasive transcutaneous carbon dioxide monitoring has been shown to be accurate in infants and children, limited data are available to show the usefulness and limitations of partial transcutaneous carbon dioxide tension (PtCO2) value. Objectives: The current study prospectively determines the effectiveness and accuracy of PtCO2 measurements in newborns. Materials and Methods: Venous blood gas sampling and monitoring of the PtCO2 level (TCM TOSCA, Radiometer) were done simultaneously. All measurements are performed on mechanically ventilated infants. Partial venous carbon dioxide tension (PvCO2) values divided into three groups according to hypocapnia (Group 1: < 4.68 kPa), normocapnia (Group 2: 4.68–7.33 kPa), hypercapnia (Group 3: > 7.33 kPa) and then PvCO2 and PtCO2 data within each group were compared separately. Results: A total of 168 measurements of each PvCO2 and PtCO2 data were compared in three separated groups simultaneously (13 in Group 1, 118 in Group 2, and 37 in Group 3). A bias of more than ± 0.7 kPa was considered unacceptable. PtCO2 was related to PvCO2 with acceptable results between the two measurements in hypocapnia (mean difference 0.20 ± 0.19 kPa) and normocapnia (0.002 ± 0.30 kPa) groups. On the other hand in hypercapnia group PtCO2 values were statistically significant (P < 0.001) and lower than PvCO2 data (mean difference 0.81 ± 1.19 kPa) Conclusions: PtCO2 measurements have generally good agreement with PvCO2 in hypocapnic and normocapnic intubated infants but there are some limitations especially with high level of CO2 tension. Monitoring of PtCO2 is generally a useful non-invasive indicator of PvCO2 in hypocapnic and normocapnic infants.

The meaning of implied volatility in pricing stock options traded in options markets

Ph.D. in the Faculty of Business Administration

Simultaneous estimation of the nutritional contribution of fish meal, soy protein isolate and corn gluten to the growth of Pacific white shrimp (Litopenaeus vannamei) using dual stable isotope analysis

The nutritional contribution of the dietary nitrogen, carbon and total dry matter supplied by fish meal (FM), soy protein isolate (SP) and corn gluten (CG) to the growth of Pacific white shrimp Litopenaeus vannamei was assessed by means of isotopic analyses. As SP and CG are ingredients derived from plants having different photosynthetic pathways which imprint specific carbon isotope values to plant tissues, their isotopic values were contrasting. FM is isotopically different to these plant meals with regards to both, carbon and nitrogen. Such natural isotopic differences were used to design experimental diets having contrasting isotopic signatures. Seven isoproteic (36% crude protein), isoenergetic (4.7 kcal g−1) diets were formulated; three diets consisted in isotopic controls manufactured with only one main ingredient supplying dietary nitrogen and carbon: 100% FM (diet 100F), 100% SP (diet 100S) and 100% CG (diet 100G). Four more diets were formulated with varying mixtures of these three ingredients, one included 33% of each ingredient on a dietary nitrogen basis (diet 33FSG) and the other three included a proportion 50:25:25 for each of the three ingredients (diets 50FSG, 50SGF and 50GFS). At the end of the bioassay there were no significant differences in growth rate in shrimps fed on the four mixed diets and diet 100F (k=0.215–0.224). Growth rates were significantly lower (k=0.163–0.201) in shrimps grown on diets containing only plant meals. Carbon and nitrogen stable isotope values (δ13C and δ15N) were measured in experimental diets and shrimp muscle tissue and results were incorporated into a three-source, two-isotope mixing model. The relative contributions of dietary nitrogen, carbon and total dry matter from FM, SP and CG to growth were statistically similar to the proportions established in most of the diets after correcting for the apparent digestibility coefficients of the ingredients. Dietary nitrogen available in diet 33FSG was incorporated in muscle tissue at proportions representing 24, 35 and 41% of the respective ingredients. Diet 50GSF contributed significantly higher amounts of dietary nitrogen from CG than from FM. When the level of dietary nitrogen derived from FM was increased in diet 50FSG, nutrient contributions were more comparable to the available dietary proportions as there was an incorporation of 44, 29 and 27% from FM, SP and CG, respectively. Nutritional contributions from SP were very consistent to the dietary proportions established in the experimental diets.

Tribes under threat : the collective behavior of firms during the stock market crisis

Due to their unpredictable behavior, stock markets are examples of complex systems. Yet, the dominant analysis of these markets as- sumes simple stochastic variations, eventually tainted by short-lived memory. This paper proposes an alternative strategy, based on a stochastic geometry defining a robust index of the structural dynamics of the markets and based on notions of topology defining a new coef- ficient that identifies the structural changes occurring on the S&P500 set of stocks. The results demonstrate the consistency of the random hypothesis as applied to normal periods but they also show its in- adequacy as to the analysis of periods of turbulence, for which the emergence of collective behavior of sectoral clusters of firms is mea- sured. This behavior is identified as a meta-routine.

A importância dos módulos logísticos do SIG na reorganização logistica e financeira do Exército

No âmbito do plano curricular do Mestrado em Administração Militar (AdMil) procedemos á realização do presente Trabalho de Investigação Aplicada (TIA) intitulado de “A importância dos módulos logísticos do SIG na reorganização logística e financeira do Exército”. É de referir que este assunto é de total interesse porque se enquadra no objetivo estratégico do Exército (OEPB10) que visa incrementar a gestão de recursos apoiada em sistemas de informação publicados na Diretiva de Planeamento do Exército para o biénio 2015 e 2016. O objetivo geral desta investigação é explicar se as funcionalidades do módulo MM do SIG respondem às necessidades do Exército. Pretendemos também identificar se o processo de compras logístico é utilizado em pleno, determinar se é possível fazer uma análise das compras já efetuadas e em curso, determinar se o Exército em SIG consegue gerir as suas existências em quantidade e valor, identificar se existe gestão de necessidades de reabastecimento das U/E/O em SIG e expor as vantagens e inconvenientes da sua utilização, descrever as vantagens da migração dos dados para a aplicação SIG de outras aplicações usadas para a gestão de stocks. O módulo MM do SIG integra a administração de materiais, planeamento, controlo dos materiais, compras, recebimentos de mercadorias, administração de stocks e verificação de faturas. A presente investigação trata-se de um estudo de caso, para tal recorremos ao método hipotético-dedutivo e aplicámos um estudo exploratório/descritivo. Nesta investigação procedeu-se à recolha de informação através de inquéritos por entrevista e por questionário, tendo sido selecionado consequentemente um método misto (qualitativo e quantitativo). Após a análise e discussão dos resultados concluímos que as funcionalidades do módulo MM do SIG implementado no Exército não respondem na totalidade às necessidades do Exército, em determinadas classes de abastecimento no âmbito das existências. Assim é de salientar que do antecedente foram implementadas as ferramentas MM compras centrais e locais, e desde o ano de 2014, têm sido implementados em sistema a gestão dos combustíveis e neste momento o fardamento. Acrescentamos que o módulo MM está integrado e como tal há necessidade de resolver vários problemas considerados externos, nomeadamente a agilização do processo da catalogação, a descentralização das compras que leva a que as U/E/O recorram maioritariamente à utilização de NNA genéricos, não possibilitando a gestão dos materiais em sistema SIG, o que resulta posteriormente numa apresentação incorreta da conta 3 das existências no balanço.