The behavior of kinetic parameters in production of pectinase and xylanase by solid-state fermentation

AbstractSolid-state fermentation (SSF) is defined as the growth of microbes without a free-flowing aqueous phase. The feasibility of using a citrus peel for producing pectinase and xylanase via the SSF process by Aspergillus niger F3 was evaluated in a 2kg bioreactor. Different aeration conditions were tested to optimize the pectinase and xylanase production. The best air flow intensity was 1VkgM (volumetric air flow per kilogram of medium), which allowed a sufficient amount of O2 for the microorganism growth producing 265U/g and 65U/g pectinases and xylanases, respectively. A mathematical model was applied to determine the different kinetic parameters related to SSF. The specific growth rate and biomass oxygen yield decreased during fermentation, whereas an increase in the maintenance coefficient for the different employed carbon sources was concurrently observed

Biscay AGL. An observatory for state of the art operational oceanography at IEO. Derived products, sensor networks and future developments.

Since 1991, shelf and slope waters of the Southern Bay of Biscay are regularly sampled in a monthly hydrographical section north of Santander. From 2003, a deep hydrological standard section was included and on June 2007, an ocean-meteorological buoy was moored at the end of Santander Section (www.boya_agl.st.ieo.es). All of three are part of IEOOS (IEO Observing System). Biscay AGL is one observatory for the EU FixO3 project. The combination of these resources leads to a powerful tool, Biscay AGL, which is more than the combination of the AGL Buoy and the hydrographical samplings. This tool produces not only time series of several parameters at different time resolutions but also derived products, both real and delayed time. Derived products from this buoy include, annual cycles as well as anomalous values. In particular ones such as air-sea heat fluxes, salinity and water temperatures anomalies, sub inertial currents series, chlorophyll surface series, estimate of the mixed layer depth and wind and currents roses. Many sensor networks have been deployed to monitor marine environment, and more will follow in the future. Due to the large number of sensor manufacturers, integrating diverse sensors into observation systems is not straightforward. By defining standardized service interfaces it is possible to enable access to sensor networks and archived sensor data that can be discovered and accessed using standard protocols and application programming interfaces. Future developments include the deployment of a full sensor network as well as adding new devices to the Biscay AGL tool in order to achieve deeper knowledge of the ocean

Sensor Networks and derived products at Biscay AGL observatory. State of the art operational oceanography at IEO

Since 1991, shelf and slope waters of the Southern Bay of Biscay are regularly sampled in a monthly hydrographical section north of Santander, and on June 2007, an ocean meteorological buoy was moored at the end of Santander Section (www. boya_agl.st.ieo.es). Both are part of IEOOS (IEO Observing System). Biscay AGL is one observatory for the EU FixO3 project. Many sensor networks have been deployed to monitor marine environment, and more will follow in the future. Due to the large number of sensor technologies, integrating diverse sensors into observation systems is not straightforward. By defining standardized service interfaces (like those based on OGC standards) it is possible to enable access to sensor networks and archived sensor data that can be discovered and accessed using standard protocols and application programming interfaces, therefore complying with the requirements of the INSPIRE directive. Future developments include the deployment of a full sensor network as well as adding new devices to the Biscay AGL tool in order to achieve a deeper knowledge of the ocean. Biscay AGL is more than the combination of the AGL Buoy and the hydrographical samplings. This observatory produces not only time series of several parameters at different time resolutions but also derived products, both in real and in delayed time. Derived products from this buoy include annual cycles as well as anomalies of physical and biogeochemical magnitudes like air-sea heat fluxes, salinity and water temperatures, sub inertial currents, surface chlorophyll. Different products are derived from in-situ measurements at the AGL buoy like estimates of the mixed layer depth, wind and currents roses and wave intensity diagrams

Standard and Embedded Solitons in Nematic Optical Fibers

A model for a non-Kerr cylindrical nematic fiber is presented. We use the multiple scales method to show the possibility of constructing different kinds of wavepackets of transverse magnetic (TM) modes propagating through the fiber. This procedure allows us to generate different hierarchies of nonlinear partial differential equations (PDEs) which describe the propagation of optical pulses along the fiber. We go beyond the usual weakly nonlinear limit of a Kerr medium and derive an extended Nonlinear Schrodinger equation (eNLS) with a third order derivative nonlinearity, governing the dynamics for the amplitude of the wavepacket. In this derivation the dispersion, self-focussing and diffraction in the nematic are taken into account. Although the resulting nonlinear $PDE$ may be reduced to the modified Korteweg de Vries equation (mKdV), it also has additional complex solutions which include two-parameter families of bright and dark complex solitons. We show analytically that under certain conditions, the bright solitons are actually double embedded solitons. We explain why these solitons do not radiate at all, even though their wavenumbers are contained in the linear spectrum of the system. Finally, we close the paper by making comments on the advantages as well as the limitations of our approach, and on further generalizations of the model and method presented.Comment: "Physical Review E, in press

Research and operational products from the combination of a monthly hydrographic station and an oceanic buoy: The Biscay AGL fixed-point water column observatory.

Long term time series are an important tool for increasing the knowledge of ocean processes as well as for studying water masses variability in different time scales and changes and tendencies in marine ecosystems. Time series has been classically obtained by oceanographic ships that regularly cover standard sections and stations. From 1991, shelf and slope waters of the Southern Bay of Biscay are regularly sampled in a monthly hydrographic line north of Santander to a depth of 1000 m in early stages and for the whole water column down to 2580 m in recent times. Nearby, in June 2007, the IEO deployed an oceanic-meteorological buoy (AGL Buoy, 43º 50.67’N; 3º 46.20’W, and 40 km offshore, www.boya-agl.st.ieo.es). The long-term hydrographical record have allowed to define the seasonality, trends, and interannual variability at all levels, including the mixing layer and the main water masses North Atlantic Central Water and Mediterranean Water. The relation of these changes with high frequency surface conditions has been examined using the AGL buoy data from 2007 as well as satellite and reanalysis data. On that context and using that combination of sources, some products and quality controlled series of high interest and utility for scientific purposes have been developed and are offered hourly in the web page. Main products obtained are: SST and SSS anomalies, wave significant height character with respect to monthly average, and currents with respect to seasonal averages. Ocean-atmosphere heat fluxes (latent and sensible) are computed from the buoy atmospheric and oceanic measurements. Estimations of the mixed layer depth and bulk series at different water levels are provided in a monthly basis. Quality controlled series are provided for sea surface salinity, oxygen and chlorophyll data. Some sensors are particularly affected by biofouling, and monthly visits to the buoy permit to follow these sensors behaviour. Chlorophyll-fluorescence sensor is the main concern, but Dissolved Oxygen sensor is also problematic. Periods of realistic smooth variations present strong offset that is corrected based on the Winkler analysis of water samples. The incorporation of these observatories on larger scale research programs, as done in 2003 in the framework of the VACLAN and COVACLAN projects, is important in order to provide them with a larger spatial dimension and maximize its utility for process-oriented studies. In 2003, the Santander section was extended 90 miles offshore in the framework of a large-scale hydrographic and circulation monitoring program. Partnerships in a large EU project as FixO3 has provided tools for coordination, homogenization and data validation as well as improve the use of chemical-biological data.0,000

Accumulation of mutations in genes associated with sexual reproduction contributed to the domestication of a vegetatively propagated staple crop, enset

Enset (Ensete ventricosum (Welw.) Cheesman) is a drought tolerant, vegetatively propagated crop that was domesticated in Ethiopia. It is a staple food for more than 20 million people in Ethiopia. Despite its current importance and immense potential, enset is among the most genetically understudied and underexploited food crops. We collected 230 enset wild and cultivated accessions across the main enset producing regions in Ethiopia and applied amplified fragment length polymorphism (AFLP) and genotype by sequencing (GBS) analyses to these accessions. Wild and cultivated accessions were clearly separated from each other, with 89 genes found to harbour SNPs that separated wild from cultivated accessions. Among these, 17 genes are thought to be involved in flower initiation and seed development. Among cultivated accessions, differentiation was mostly associated with geographical location and with proximity to wild populations. Our results indicate that vegetative propagation of elite clones has favoured capacity for vegetative growth at the expense of capacity for sexual reproduction. This is consistent with previous reports that cultivated enset tends to produce non-viable seeds and flowers less frequently than wild enset.Kiflu Gebramicael Tesfamicael, Endale Gebre, Timothy J. March, Beata Sznajder, Diane E. Mather, and Carlos Marcelino Rodríguez Lópe

New developments on Biscay-AGL Observatory. From derived products to sensor networks.

Biscay-AGL Observatory. Since 1991, shelf and slope waters of the Southern Bay of Biscay are regularly sampled in a monthly hydrographical section north of Santander to a maximum depth of 2500m, as part of the IEO Radiales program. On June 2007, an ocean-meteorological buoy (AGL) was moored at the end of Santander standard section, 22nm north at 2850m depth, to complete the ocean information with the ocean-atmosphere interaction. All of them are part of IEO Observing System (1). The integrated system of AGL and its nearest hydrographic station (2600m depth) is named Biscay-AGL observatory. It is also one station for the EU FixO3 project. Joint resources and systematic analysis lead to a powerful tool, which is much more than the combination of the AGL buoy and the hydrographical samplings. Data Access. All AGL buoy collected data are added to the local database sited at IEO-Santander in real-time and, after rutinary automatised quality controls, they are immediately available through its dedicated webpage (www.boya_agl.st.ieo.es). Monthly CTDO2 data from the hydrographic section are lab-calibrated in order to obtain acurated values of salinity, dissolved oxygen and density, and added to the long-term time series. Biscay-AGL data are quality controlled, flagged and formatted according internationally agreed standards (2, 3) and routinely sent to the IEO Datacenter. This added-value controlled data are incorporated to the IEO permanent archive and made freely available through the SeaDataNet infrastructure for data access and discovery. Derived products. Data acquired by Biscay-AGL may be displayed as timeseries as usual, but end-users are benefited by derived products which provide direct information. A recently developed software tool produces not only timeseries of several parameters at different time resolutions but also derived products, both real and delayed time. Derived products from this buoy include, but not only, annual cycles as well as anomalous values, air-sea heat fluxes, salinity and water temperature anomalies, subinertial currents series, chlorophyll surface series, estimations of the mixed layer depth and wind and currents roses. Sensor Web Enablement (SWE). Sensor Web infrastructures are setup to access real-time data observed by sensors. This system has been implemented in AGL buoy sensors in order to simplify the retrieved events and alerts triggered through sensors. All those functionalities of the Sensor Web are provided in an interoperable way, following the standards stablished by the Open Geospatial Consortium (OGC). By defining standardized service interfaces, these services hides the heterogeneity of the sensor network, its communication details, enabling the access to archived sensor data that can be discovered and accessed using standard protocols and application programming interfaces

Magnetic hyperthermia experiments with magnetic nanoparticles in clarified butter oil and paraffin: A thermodynamic analysis

In specific power absorption models for magnetic fluid hyperthermia (MFH) experiments, the magnetic relaxation time of nanoparticles (NPs) is known to be a fundamental descriptor of the heating mechanisms. The relaxation time is mainly determined by the interplay between the magnetic properties of NPs and the rheological properties of NPs’ environment. Although the role of magnetism in MFH has been extensively studied, the thermal properties of the NP medium and their changes during MFH experiments have been underrated so far. Herein, we show that ZnxFe3-xO4 NPs dispersed through different media with phase transition in the temperature range of experiment as clarified butter oil (CBO) and paraffin. These systems show nonlinear behavior of the heating rate within the temperature range of MFH experiments. For CBO, a fast increase at ~306 K is associated with changes in the viscosity (¿(T)) and specific heat (cp(T)) of the medium at its melting temperature. This increment in the heating rate takes place around 318 K for paraffin. The magnetic and morphological characterization of NPs together with the observed agglomeration of NPs above 306 and 318 K for CBO and paraffin, respectively, indicate that the fast increase in MFH curves could not be associated with the change in the magnetic relaxation mechanism, with Neél relaxation being dominant. In fact, successive experimental runs performed up to temperatures below and above the CBO and paraffin melting points resulted in different MFH curves due to agglomeration of NPs driven by magnetic field inhomogeneity during the experiments. Our results highlight the relevance of the thermodynamic properties of the system NP-medium for an accurate measurement of the heating efficiency for in vitro and in vivo environments, where the thermal properties are largely variable within the temperature window of MFH experiments