193 research outputs found

    Production planning of biopharmaceutical manufacture.

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    Multiproduct manufacturing facilities running on a campaign basis are increasingly becoming the norm for biopharmaceuticals, owing to high risks of clinical failure, regulatory pressures and the increasing number of therapeutics in clinical evaluation. The need for such flexible plants and cost-effective manufacture pose significant challenges for planning and scheduling, which are compounded by long production lead times, intermediate product stability issues and the high cost - low volume nature of biopharmaceutical manufacture. Scheduling and planning decisions are often made in the presence of variable product titres, campaign durations, contamination rates and product demands. Hence this thesis applies mathematical programming techniques to the planning of biopharmaceutical manufacture in order to identify more optimal production plans under different manufacturing scenarios. A deterministic mixed integer linear programming (MILP) medium term planning model which explicitly accounts for upstream and downstream processing is presented. A multiscenario MILP model for the medium term planning of biopharmaceutical manufacture under uncertainty is presented and solved using an iterative solution procedure. An alternative stochastic formulation for the medium term planning of biomanufacture under uncertainty based on the principles of chance constrained programming is also presented. To help manage the risks of long term capacity planning in the biopharmaceutical industry, a goal programming extension is presented which accounts for multiple objectives including cost, risk and customer service level satisfaction. The model is applied to long term capacity analysis of a mix of contractors and owned biopharmaceutical manufacturing facilities. In the final sections of this thesis an example of a commercial application of this work is presented, followed by a discussion on related validation issues in the biopharmaceutical industry. The work in this thesis highlighted the benefits of applying mathematical programming techniques for production planning of biopharmaceutical manufacturing facilities, so as to enhance the biopharmaceutical industry's strategic and operational decision-making towards achieving more cost-effective manufacture

    New insights on the relative sea level change during Holocene along the coasts of Tunisia and western Libya from archaeological and geomorphological markers

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    New data of sea level changes for the Mediterranean region along the coasts of northern Africa are presented. Data are inferred from archaeological sites of Punic-Roman age located along the coast of Tunisia, between Tunis and Jerba island and along the western coast of Libya, between Sabratha and Leptis Magna. Data are based on precise measures of presently submerged archaeological markers that are good indicators of past sea-level elevation. Nineteen selected archaeological sites were studied in Tunisia and four in Libya, all aged between w2.0 and w1.5 ka BP. The functional elevations of significant archaeological markers were measured with respect to the sea level at the time of measurements, applying corrections for tide and atmospheric pressure values. The functional elevations of specific architectural parts of the sites were interpreted, related to sea level at the time of their construction providing data on the relative changes between land and sea. Observations were compared against sea level change predictions derived from the glacio-hydro-isostatic model associated with the Last Glacial cycle. The results indicate that local relative sea level change along the coast of Tunisia and Libya, has increased 0.2 O 0.5 m since the last w2 ka. Besides minor vertical tectonic movements of the land, the observed changes are produced by eustatic and glacio-hydro-isostatic variations acting in the Mediterranean basin since the end of the last glacial maximum

    Organisation et fonctionnement d’un Ă©cosystĂšme cĂŽtier du Maroc : la lagune de Khnifiss

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    La lagune de Khnifiss, situĂ©e au sud du Maroc, est une rĂ©serve biologique d’intĂ©rĂȘt mondial pour l’avifaune. Des Ă©tudes pluridisciplinaires portant sur la physico-chimie des eaux, la biologie, la sĂ©dimentologie et les courants ont Ă©tĂ© rĂ©alisĂ©es par l’INRH dans la lagune en septembre 1998 et fĂ©vrier 2001. Les rĂ©sultats du courant obtenus montrent que la circulation des eaux Ă  l’intĂ©rieur de la lagune est gĂ©rĂ©e par un courant alternatif et bidirectionnel : les courants du jusant sont plus importants que ceux du flot et varient Ă©galement en fonction du rythme de la marĂ©e vive-eau/morte-eau. Ce mode de circulation des eaux attribue Ă  la lagune une richesse en Ă©lĂ©ments azotĂ©s et phosphatĂ©s, surtout en pĂ©riode de vive-eau. La biomasse chlorophyllienne, assez importante dans la lagune, est causĂ©e par la richesse du milieu en Ă©lĂ©ments nutritifs et le phĂ©nomĂšne d’upwelling qui se manifeste en Ă©tĂ© et au printemps dans la zone sud du Maroc. Ces Ă©tudes ont montrĂ© que la lagune de Khnifiss est un milieu propice Ă  la conchyliculture. NĂ©anmoins, l’installation de tout projet aquacole dans le site devra tenir compte de sa capacitĂ© trophique et de son Ă©quilibre Ă©cologique.The Moroccan coastal marine area has several zones that are targets for exploitation but must simultaneously be protected. Lagoons are considered to be among the most productive natural systems in the world, but they are also vulnerable systems due to natural and human constraints. Lagoons can also be a target of economic expansion. This is why an understanding about the state of these ecosystems is important in order to proceed with rational use of the resource. The Khnifiss lagoon, situated on the South Atlantic coast of Morocco, is a potential site for aquaculture and tourism if planned with an ecological awareness. The large surface area and high biological production for the avifauna qualify it to be among the four protected sites by the RAMSAR convention for humid zone conservation (lagoons of Khnifiss and Moulay Bousselham, lakes of Sidi Boughaba and Afennourir). The objective of this work was to complete previous studies and to estimate the nutritive richness of the Khnifiss lagoon. To understand the spatio-temporal variability in the water currents, and the physico-chemical and biological and characteristics of this lagoon, two surveys were organized in September 1998 and February 2001.The Khnifiss lagoon (20 km long and 65 km2 surface area) is situated between Tantan and Tarfaya (28°02'54'' N, 12°13'66'' W). It opens up into the Atlantic ocean by a narrow inlet called ''Foum Agouitir'', about 100 m wide. The lagoon continues upstream beyond a salt marsh, called "Sebkha Tazra". Physical, chemical and biological variables were monitored: temperature and salinity; dissolved oxygen, nitrates and phosphates; chlorophyll a. The current (direction and intensity) and the sediment were also studied. Samples were collected four times from the surface and bottom waters during spring tide (ST), neap tide (NT), low tide (LT) and high tide (HT) during two seasons (September 1998 and February 2001). Seven hydrological stations were sampled, representing the lagoon system and one reference station in a neighbouring zone (HrĂ©f), which represents the marine zone of the lagoon. Temperature and salinity were measured with a multi-sensor probe. The chemical analyses were carried out according to methods suggested by AMINOT & CHAUSSEPIED (1983). Thirty (30) sediment samples were also collected. Currents were measured at two fixed points by two current-meters.Based on the hydrological characteristics of the lagoon, especially temperature, salinity, water circulation and the nature of sediment, three zones were identified :1. Zone I (downstream from the lagoon) was dominated by the ocean’s influence and included the HrĂ©f, H1 and H2 stations. Maximum depths varied from 2.5 to 6.6 m, depending on the tide and location. The concentrations of the different hydrological parameters were controlled by the plug effect of the oceanic environment. The most important current in the lagoon was recorded in this zone in the spring tide (ST: 110 cm.s-1). The sediment was coarse and important water - sediment exchange was caused by the strong current recorded in this zone.2. Zone II (middle of the lagoon) was a transition zone with an intermediate oceanic influence. It was situated between the H3 and H5 stations. The size of the inlet and the important exchanges governed by currents caused by strong tides resulted in concentrations of the various parameters being similar to those in Zone I. Depths varied from 2.64 to 8.7 m. Waters were more saline during the LT and NT periods (36-41 practical salinity unit, or psu). The current decreased relative to that is zone I (56 cm.s-1 in September 1998 and 78 cm.s-1 in February 2001). In this zone the current moved preferentially towards the right strand at high tide and toward the left strand at low tide.3. Zone III (upstream in the lagoon) covered a different biotope compared to the first two zones. The waters were less deep (2.64 to 5.3 m) and included the stations H6, H7 and the upper part of the lagoon. This zone was characterized by a very low oceanic influence. Water temperature and salinity were higher, 24-26°C and 41-44 psu respectively, during the LT and NT periods.On the basis of the hydrological zonation, the conjunction of the climate descriptors (moderate wind, rare precipitation, absence of storms, moderate air temperature) of the lagoon and the strong hydrodynamic influence in the lagoon suggest that the Knifiss lagoon is a relatively unconfined ecosystem. The hydrodynamics of this lagoon permit a fast water renewal rate and insure a good environmental quality. In addition, studies carried out on the healthiness of this lagoon demonstrated not only a healthy environment, but also healthy shellfish. This diagnosis seemed to be related to the geographical location and important rates of water exchange. However, the absence of continental freshwater sources leads to an important increase in salinity and temperature at the level of the upstream zone (zone III). Zone III therefore cannot be considered for shellfish breeding.On the basis of the biological zones: With respect to the bathymetry of the lagoon (depths varied from 2.5 to 8.7 m), shellfish, in contrast to fish, require less water depth. Therefore, it is sufficient to search for a less turbulent zone, which offers sufficient planktonic food for the shellfish growth. In the Khnifiss lagoon, the taxonomy of the phytoplankton has not been yet studied. However, BENNOUNA (1999) demonstrated that the phytoplankton community was dominated by dinoflagellates and diatoms in the Oualidia and Sidi Moussa lagoons. RHARBI (2000) found that picophytoplankton were the principal breeding food source of oysters and clams in Oualidia lagoon. The source of shellfish for breeding is located in the neighbouring upwelling marine waters. Development projects planned for the lagoon must include an awareness programme for fishermen about the role that moderate and responsible shellfish breeding programs can play in the preservation and reconstitution of the marine resource as well as in the improvement of their incomes

    Low-temperature rate constants for rotational excitation and de-excitation of C3 (X 1∑g +) by collisions with He (1S)

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    The low-temperature rotational (de-) excitation of C3 (X 1∑g 1) by collisions with He (1S) is studied using an ab initio potential energy surface (PES). This PES has been calculated using the single- and double-excitation coupled-cluster approach with noniterative perturbational treatment of triple excitations [CCSD(T)] and the augmented correlation-consistent triple-ζ basis set (aug-cc-pVTZ) with bond functions. This PES is then incorporated in full close-coupling quantum scattering calculations for collision energies between 0.1 and 50 cm -1 in order to deduce the rate constants for rotational levels of C3 up to j = 10, covering the temperature range 5-15 K. © 2008. The American Astronomical Society. All rights reserved.The Agencia Española de CooperaciĂłn Internacional (project A/8083/07, CSIC-UniversitĂ© Tunis El Manar) and the Spanish Ministerio de EducaciĂłn y Ciencia (project AYA 2005-00702) are thanked for ïŹnancial supportPeer Reviewe

    Kyste neurentĂ©rique intra dural extra mĂ©dullaire: Ă  propos d’un cas

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    Le kyste neurentĂ©rique (KNE) est une malformation congĂ©nitale rare du systĂšme nerveux central (SNC) entrant dans le cadre des notochordodysraphies. Nous rapportons un nouveau cas de KNE de localisation intra durale extra mĂ©dullaire chez un patient de 16 ans, admis dans un tableau de compression mĂ©dullaire cervicale haut Ă©voluant depuis 4 mois. L’imagerie a objectivĂ© une lĂ©sion kystique prĂ© mĂ©dullaire en regardde C1-C2-C3. Le patient a bĂ©nĂ©ficiĂ© d’une Ă©vacuation kystique et l’histologie avait conclu Ă  un kyste neurentĂ©rique. L’évolution Ă©tait marquĂ©e par le dĂ©cĂšs du patient par des complications neurovĂ©gĂ©tatives graves. MalgrĂ© sa bĂ©nignitĂ© histologique, le kyste neurentĂ©rique de localisation cervicale haute peut se compliquer de troubles neurovĂ©gĂ©tatifs parfois imprĂ©visibles pouvant aboutir Ă  une Ă©volution dramatique

    Cavernome intramedullaire: a propos d’un cas

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    Le cavernome intramĂ©dullaire, malformation vasculaire rare, reprĂ©sente environ 5 Ă  12 % des malformations vasculaires spinales et 3 % des malformations vasculaires intra-durales. Il peut ĂȘtre longtemps asymptomatique ou se manifester par une altĂ©ration brutale ou progressive des fonctions mĂ©dullaires. Le diagnostic repose sur l’imagerie par rĂ©sonance magnĂ©tique (IRM) mĂ©dullaire et l’anatomopathologie. La chirurgie reprĂ©sente l’essentiel de la prise en charge, nĂ©anmoins elle n’est pas dĂ©nudĂ©e de complications. Nous rapportons un cas de cavernome intramĂ©dullaire chez une patiente de 24 ans, admise dans un tableau de compression mĂ©dullaire dorsale lente avec une paraparĂ©sie Ă©voluant depuis 2 ans. L’IRM mĂ©dullaire a objectivĂ© une lĂ©sion intramĂ©dullaire en regard deT7-T8. La patiente a bĂ©nĂ©ficiĂ© d’une exĂ©rĂšse totale de la tumeur et l’histologie a confirmĂ© le cavernome intramĂ©dullaire. L’évolution a Ă©tĂ© marquĂ©e par une aggravation partielle du dĂ©ficit moteur. A travers cette observation, les auteurs discutent les aspects cliniques, radiologiques ainsi que la prise en charge de cette pathologie rare.Mots clĂ©s: Cavernome, intramĂ©dullaire, malformation vasculair

    Nouvelle approche géologique et géodinamique du Complexe Hydrothermal de Moulay Yacoub, bordure septentrionale du Sillon Sud Rifain

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    As ĂĄguas termais de Moulay Yacoub surgem em formaçÔes miocĂ©nicas do Sulco Sul do Rife. SĂŁo caracterizadas por forte mineralização, relacionada com a natureza do seu local de armazenamento e circulação em reservatĂłrios de litologias variadas. Apresentam duas fĂĄcies quĂ­micas principais: uma Cl-Na, pouco diluĂ­da, e outra, Cl-Ca-Mg, dominada por ĂĄguas imaturas. A comparção geoquĂ­mica e geotermomĂ©trica com outras fontes regionais sugere uma origem mais profunda que o reservatĂłrio liĂĄssico. A recente descoberta de extrusĂ”es de blocos de calcĂĄrio liĂĄssico, de magmatitos paleozĂłicos, de metassedimentos e de grandes massas de doleritos triĂĄssicos, sugere a existĂȘncia de formaçÔes permeĂĄveis sob a cobertura margosa do MiocĂ©nico. Os acidentes profundos NE-SW, associados a um cavalgamento cego, sugerem uma relação estreita entre estas ĂĄguas termais e as extrusĂ”es do soco ante-neogĂ©nicos. Durante a sua passagem para a superfĂ­cie, as ĂĄguas termais de Moulay Yacoub terĂŁo sido diluĂ­das atravĂ©s de misturas ocorridas principalmente no reservatĂłrio liĂĄssico

    Target repurposing for neglected diseases

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    Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Future Science for personal use, not for redistribution. The definitive version was published in Future Medicinal Chemistry 3 (2011): 1307-1315, doi:10.4155/fmc.11.92.Infectious diseases are an enormous burden to global health, and since drug discovery is costly, those infectious diseases that affect the developing world are often not pursued by commercial drug discovery efforts. Therefore, pragmatic means by which new therapeutics can be discovered are needed. One such approach is target repurposing, where pathogen targets are matched with homologous human targets that have been pursued for drug discovery for other indications. In many cases, the medicinal chemistry, structural biology, and biochemistry knowledge around these human targets can be directly repurposed to launch and accelerate new drug discovery efforts against the pathogen targets. This article describes the overarching strategy of target repurposing as a tool for initiating and prosecuting neglected disease drug discovery programs, highlighting this approach with three case studies.Support from the National Institutes of Health (R01 AI082577) is gratefully acknowledged.2012-08-0
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