In Vitro Ketamine CYP3A Mediated Metabolism Study using Mammalian Liver S9 Fractions, cDNA Expressed Enzymes and Liquid Chromatography Tandem Mass Spectrometry

Ketamine is widely used in medicine in combination with several benzodiazepines including midazolam. The objectives of this study were to develop a novel HPLC-MS/SRM method capable of quantifying ketamine and norketamine using an isotopic dilution strategy in biological matrices and study the formation of norketamine, the principal metabolite of ketamine with and without the presence of midazolam, a well-known CYP3A substrate. The chromatographic separation was achieved using a Thermo Betasil Phenyl 100 x 2 mm column combined with an isocratic mobile phase composed of acetonitrile, methanol, water and formic acid (60:20:20:0.4) at a flow rate of 300 μL/min. The mass spectrometer was operating in selected reaction monitoring mode and the analytical range was set at 0.05–50 μM. The precision (%CV) and accuracy (%NOM) observed were ranging from 3.9–7.8 and 95.9.2–111.1% respectively. The initial rate of formation of norketamine was determined using various ketamine concentration and Km values of 18.4 μM, 13.8 μM and 30.8 μM for rat, dog and human liver S9 fractions were observed respectively. The metabolic stability of ketamine on liver S9 fractions was significantly higher in human (T1/2 = 159.4 min) compared with rat (T1/2 = 12.6 min) and dog (T1/2 = 7.3 min) liver S9 fractions. Moreover significantly lower IC50 and Ki values observed in human compared with rat and dog liver S9 fractions. Experiments with cDNA expressed CYP3A enzymes showed the formation of norketamine is mediated by CYP3A but results suggest an important contribution from others isoenzymes, most likely CYP2C particularly in rat.

Effect of Polymer Architecture on the Structural and Biophysical Properties of PEG-PLA Nanoparticles

Polymers made of poly(ethylene glycol) chains grafted to poly(lactic acid) chains (PEG-g-PLA) were used to produce stealth drug nanocarriers. A library of comb-like PEG-g-PLA polymers with different PEG grafting densities was prepared in order to obtain nanocarriers with dense PEG brushes at their surface, stability in suspension, and resistance to protein adsorption. The structural properties of nanoparticles (NPs) produced from these polymers by a surfactant-free method were assessed by DLS, zeta potential, and TEM and were found to be controlled by the amount of PEG present in the polymers. A critical transition from a solid NP structure to a soft particle with either a “micelle-like” or “polymer nano-aggregate” structure was observed when the PEG content was between 15 to 25% w/w. This structural transition was found to have a profound impact on the size of the NPs, their surface charge, their stability in suspension in presence of salts as well as on the binding of proteins to the surface of the NPs. The arrangement of the PEG-g-PLA chains at the surface of the NPs was investigated by 1H NMR and X-ray photoelectron spectroscopy (XPS). NMR results confirmed that the PEG chains were mostly segregated at the NP surface. Moreover, XPS and quantitative NMR allowed quantifying the PEG chain coverage density at the surface of the solid NPs. Concordance of the results between the two methods was found to be remarkable. Physical-chemical properties of the NPs such as resistance to aggregation in saline environment as well as anti-fouling efficacy were related to the PEG surface density and ultimately to polymer architecture. Resistance to protein adsorption was assessed by isothermal titration calorimetry (ITC) using lysozyme. The results indicate a correlation between PEG surface coverage and level of protein interactions. The results obtained lead us to propose such PEG-g-PLA polymers for nanomedecine development as an alternative to the predominant polyester-PEG diblock polymers.

Coastal Upwelling of the South Eastern Arabian Sea - An Integrated Approach

Upwelling regions occupies only a small portion of the global ocean surface. However it accounts for a large fraction of the oceanic primary production as well as fishery. Therefore understanding and quantifying the upwelling is of great importance for the marine resources management. Most of the coastal upwelling zones in the Arabian Sea are wind driven uniform systems. Mesoscale studies along the southwest coast of India have shown high spatial and temporal variability in the forcing mechanism and intensity of upwelling. There exists an equatorward component of wind stress as similar to the most upwelling zones along the eastern oceanic boundaries. Therefore an offshore component of surface Ekman transport is expected throughout the year. But several studies supported with in situ evidences have revealed that the process is purely recurring on seasonal basis. The explanation merely based on local wind forcing alone is not sufficient to support the observations. So, it is assumed that upwelling along the South Eastern Arabian Sea is an effect of basin wide wind forcing rather than local wind forcing. In the present study an integrated approach has been made to understand the process of upwelling of the South Eastern Arabian Sea. The latitudinal and seasonal variations (based on Sea Surface Temperature, wind forcing, Chlorophyll a and primary production), forcing mechanisms (local wind and remote forcing) and the factors influencing the system (Arabian Sea High Saline Water, Bay of Bengal water, runoff, coastal geomorphology) are addressed herewith.

Calorimetry of hydrogen desorption from a-Si nanoparticles

The process of hydrogen desorption from amorphous silicon (a-Si) nanoparticles grown by plasma-enhanced chemical vapor deposition (PECVD) has been analyzed by differential scanning calorimetry (DSC), mass spectrometry, and infrared spectroscopy, with the aim of quantifying the energy exchanged. Two exothermic peaks centered at 330 and 410 C have been detected with energies per H atom of about 50 meV. This value has been compared with the results of theoretical calculations and is found to agree with the dissociation energy of Si-H groups of about 3.25 eV per H atom, provided that the formation energy per dangling bond in a-Si is about 1.15 eV. It is shown that this result is valid for a-Si:H films, too.

Development of a Fully Automated Image Analysis Method for High Density cDNA and array CGH Microarray Based Genomic Studies

In this thesis, different techniques for image analysis of high density microarrays have been investigated. Most of the existing image analysis techniques require prior knowledge of image specific parameters and direct user intervention for microarray image quantification. The objective of this research work was to develop of a fully automated image analysis method capable of accurately quantifying the intensity information from high density microarrays images. The method should be robust against noise and contaminations that commonly occur in different stages of microarray development.

Application of primary haemocyte culture of Penaeus monodon in the assessment of cytotoxicity and genotoxicity of heavy metals and pesticides

Lack of shrimp cell lines has hindered the study of pollutants which adversely affects shrimp health and its export value. In this context a primary haemocyte culture developed from Penaeus monodon was employed for assessing the cytotoxicity and genotoxicity of two heavy metal compounds, cadmium chloride and mercuric chloride and two organophosphate insecticides, malathion and monocrotophos. Using MTT assay 12 h IC50 values calculated were 31.09 16.27 mM and 5.52 1.16 mM for cadmium chloride and mercuric chloride and 59.94 52.30 mg l 1 and 186.76 77.00 mg l 1 for malathion and monocrotophos respectively. Employing Comet assay, DNA damage inflicted by these pollutants on haemocytes were evaluated and the pollutants induced DNA damage in >60% of the cells. The study suggested that haemocyte culture could be used as a tool for quantifying cytotoxicity and genotoxicity of aquaculture drugs, management chemicals and pollutants

Sustainable Solid Waste Management Through Ecological Footprint Analysis – A Solution To Kochi City, India

Kochi, the commercial capital of Kerala, South India and second most important city next to Mumbai on the Western coast is a land having a wide variety of residential environments. Due to rapid population growth, changing lifestyles, food habits and living standards, institutional weaknesses, improper choice of technology and public apathy, the present pattern of the city can be classified as that of haphazard growth with typical problems characteristics of unplanned urban development especially in the case of solid waste management. To have a better living condition for us and our future generations, we must know where we are now and how far we need to go. We, each individual must calculate how much nature we use and compare it to how much nature we have available. This can be achieved by applying the concept of ecological footprint. Ecological footprint analysis (EFA) is a quantitative tool that represents the ecological load imposed on earth by humans in spatial terms. The aim of applying EFA to Kochi city is to quantify the consumption and waste generation of a population and to compare it with the existing biocapacity. By quantifying the ecological footprint we can formulate strategies to reduce the footprint and there by having a sustainable living. The paper discusses the various footprint components of Kochi city and in detail analyses the waste footprint of the residential areas using waste footprint analyzer. An attempt is also made to suggest some waste foot print reduction strategies thereby making the city sustainable as far as solid waste management is concerned.

Sustainable Solid Waste Management Solutions To Kochi City, India, Through The Environmental Management Tool Ecological Footprint Analysis

Solid waste management nowadays is an important environmental issue in country like India. Statistics show that there has been substantial increase in the solid waste generation especially in the urban areas. This trend can be ascribed to rapid population growth, changing lifestyles, food habits, and change in living standards, lack of financial resources, institutional weaknesses, improper choice of technology and public apathy towards municipal solid waste. Waste is directly related to the consumption of resources and dumping to the land. Ecological footprint analysis – an impact assessment environment management tool makes a relationship between two factors- the amount of land required to dispose per capita generated waste. Ecological footprint analysis is a quantitative tool that represents the ecological load imposed on the earth by humans in spatial terms. By quantifying the ecological footprint we can formulate strategies to reduce the footprint and there by having a sustainable living. In this paper, an attempt is made to explore the tool Ecological Footprint Analysis with special emphasis to waste generation. The paper also discusses and analyses the waste footprint of Kochi city,India. An attempt is also made to suggest strategies to reduce the waste footprint thereby making the city sustainable, greener and cleaner

Sustainable Development through the Environment Management Tool Ecological Footprint Analysis – A Study in Kochi City, India

In the past, natural resources were plentiful and people were scarce. But the situation is rapidly reversing. Our challenge is to find a way to balance human consumption and nature’s limited productivity in order to ensure that our communities are sustainable locally, regionally and globally. Kochi, the commercial capital of Kerala, South India and the second most important city next to Mumbai on the Western coast is a land having a wide variety of residential environments. Due to rapid population growth, changing lifestyles, food habits and living standards, institutional weaknesses, improper choice of technology and public apathy, the present pattern of the city can be classified as that of haphazard growth with typical problems characteristics of unplanned urban development. Ecological Footprint Analysis (EFA) is physical accounting method, developed by William Rees and M. Wackernagel, focusing on land appropriation using land as its “currency”. It provides a means for measuring and communicating human induced environmental impacts upon the planet. The aim of applying EFA to Kochi city is to quantify the consumption and waste generation of a population and to compare it with the existing biocapacity. By quantifying the ecological footprint we can formulate strategies to reduce the footprint and there by having a sustainable living. In this paper, an attempt is made to explore the tool Ecological Footprint Analysis and calculate and analyse the ecological footprint of the residential areas of Kochi city. The paper also discusses and analyses the waste footprint of the city. An attempt is also made to suggest strategies to reduce the footprint thereby making the city sustainable

Wirkung von Ernterückständen transgener Pflanzen auf die mikrobielle C- und N-Transformation in landwirtschaftlich genutzten Böden am Beispiel von Bt-Mais

In der vorliegenden Arbeit ging es um die Erarbeitung, Anwendung und Beurteilung von quantitativen Analysenverfahren / Methoden für ein Monitoring von durch Bt-Mais verursachbaren Umwelteffekten im Boden. Die Ausgangsthese besagte, dass sich transgene Maisstreu beim mikrobiellen Abbau anders verhält als konventionelle. Bezugnehmend auf die These wurden zwei Freilandversuche (Freilandmikrokosmenmethode nach Raubuch 1997 über 2 Jahre, Quantifizierung des Maisstreuabbaus mit Hilfe kleiner Bodensäulen über 1 Jahr) und zwei Inkubationsversuche im Labor (INK bei drei verschiedenen Temperaturen über 49 Tage und INK mit verschiedenen landwirtschaftlich genutzten Böden über 49 Tage mit jeweils kontinuierlicher Respirationsratenermittlung nach Isermeyer 1952) sowie Inhaltsstoffbestimmungen der Maisstreu durchgeführt. Für alle Untersuchungen wurde Streu der vier Maissorten Novelis (transgen, Monsanto 810), Nobilis (Isolinie von Novelis), Valmont (transgen, Bt 176, Fa. Syngenta) und Prelude (Isolinie von Valmont) eingesetzt. Nach Beendigung der Laborversuche sowie des Freilandversuches nach der Freilandmikrokosmenmethode wurden mikrobielle Messgrößen wie Adenylategehalt, Ergosterolgehalt, Cmik- und Nmik-Gehalt am Boden-Streu-Gemisch bestimmt. Der Einsatz der Isotopentechnik (Bestimmung von 13C/12C an gemahlenem Boden-Streu-Gemisch bzw. gefriergetrocknetem K2SO4 als Extrakt aus dem Boden-Streu-Gemisch) ermöglichte eine genaue Quantifizierung der abgebauten Maisstreu und brachte dadurch Aufschluss über das Abbauverhalten verschiedener Maissorten. Bezüglich der Ermittlung der mikrobiellen Messgrößen ergab sich für die transgene Sorte Novelis* stets eine durchschnittlich geringere pilzliche Biomasse. Langfristig ergaben sich bei der Kohlenstoff- und Stickstoffdynamik keine Trends hinsichtlich transgener bzw. konventioneller Maisstreu. Sowohl im Freilandversuch nach der Mikrokosmenmethode als auch in den Inkubationsversuchen trat das Phänomen der kurzzeitigen Respirationsratenerhöhung der Mikroorganismen nach Zugabe der transgenen Maissorten auf, welches nicht bei Zugabe der konventionellen Maisstreu auszumachen war. ______________________________

Shifting cultivation and forest resources in Nagaland, N.-E. India

Die vorliegende Studie befasst sich mit der Ressourcennachhaltigkeit der traditionellen, auf Wanderfeldbau beruhenden Subsistenzwirtschaft in zwei Dörfern (Hongphoy und Minyakshu) in Nagaland im Nordosten Indiens. Hierbei werden die Cerealien Produktion, der Feuerholz Konsum und auch die Folgen der intensivierten Bewirtschaftung (Forstdegradation und Bodenverarmung) im Hinblick auf das Bevölkerungswachstum diskutiert. Während das traditionelle System des Wanderfeldbaus (Jhum) seit Jahrzehnten die Bedürfnisse der ehemals kopfjagenden Stämme Nagalands erfüllte, ergab unsere Studie durch Interviews und Feldaufnahmen in 2004 und 2005, dass die steigende Nachfrage einer wachsenden Bevölkerung nach Cerealien und Feuerholz als wichtigste Ressourcen der Subsistenzwirtschaft zu einer verkürzten Brachezeit und letztlich der Degradation von Naturressourcen geführt hat: Pro Hektar Ernten sind reduziert und der Zuwachs der Holzvorräte auf den Feldern kann durch die verkürzten Bracheperioden nicht mehr die Feuerholz Nachfrage decken. Eine Nahrungsmittelknappheit wurde durch die Gegenüberstellung des Energiebedarfs einer Person und die jährlichen pro-Kopf Erntemengen und unter Berücksichtigung des Zukaufs von Reis reflektiert: In Hongphoy ergab dies ein Defizit auf Dorfebene von 130 Tonnen Reis, in Minyakshu von 480 Tonnen, die nicht durch Ernten gedeckt werden konnten. Diese Nahrungsmittelknappheit erweist sich vor allem vor dem Hintergrund eines Bevölkerungswachstums von 6.7% und marginalen Einkünften als problematisch. Für fünf verschiedene Waldformationen (zwei Brachewälder, zwei Dorfwälder und ein Naturwald) wurden die unterschiedliche Artenzusammensetzung (Diversität) und Bestandesvolumina durch Forstinventuren beschrieben. Der dem Bestandesvolumen der Brachewälder gegenübergestellte pro-Kopf Feuerholz Bedarf ergab ein jährliches Defizit von 1,81m³ in Hongphoy und 0.05m³ in Minyakshu. Der Unterschied dieses Defizits zwischen beiden Dörfern wurde in einer abweichenden Bestandesstruktur (Dominanz der N2 fixierenden Baumart Alnus nepalensis in den Brachewäldern Minyakshus) begründet. Über den erhobenen Feuerholzbedarf wurde ein theoretischer pro-Kopf Flächenbedarf an Brachewald errechnet, der nötig wäre um den gesamten Feuerholz Bedarf innerhalb des Wanderfeldbau Systems zu decken. Das daraus resultierende Defizit wurde mit den Feuerholzvolumina der Dorfwälder und des verbliebenen Naturwalds gegenüber gestellt. Hieraus ergibt sich die Bedeutung der Feuerholzernte und des Wanderfeldbau als Ursache für die fortschreitende Entwaldung und Forstdegradation in Nagaland. Mit Hilfe dieser Informationen und aktuellen Angaben zum Bevölkerungswachstum werden die Ergebnisse anhand einschlägiger Literatur diskutiert und letztendlich die Nachhaltigkeit und Tragfähigkeit des Wanderfeldbau Systems in dieser Region bestimmt. Mögliche Verbesserungsstrategien um der zunehmenden Ressourcendegradation zu begegnen, werden andiskutiert.

Untersuchung zum Phosphorylierungsstatus der katalytischen Untereinheit der PKA mittels proteomischer Techniken

ZUSAMMENFASSUNG: Das Phosphorylierungsmuster eines Proteins ist kein statischer Zustand, sondern vielmehr ein dynamischer Status, den es in der modernen funktionellen (Phospho-) Proteomik und Analytik abzubilden gilt. Klassischerweise erfolgt der Nachweis der Proteinphosphorylierung auf Peptid-Ebene mittels MS/MS Sequenzierung. Diese Standardmethode der shotgun Phosphoproteomanalytik vernachlässigt jedoch wegen den in LC MS/MS Analysen oftmals schwer detektierbaren Phosphopeptiden gerade den variablen und oftmals nur geringen Phosphorylierungsgrad vieler Phosphorylierungsstellen (P-Stellen). Mittels phosphospezifischer Anreicherungsstrategien und MS/MS Sequenzierung konnten an der Modellkinase PKA-Cα nach rekombinanter Expression in E. coli insgesamt acht P-Stellen identifiziert werden. Der Phosphorylierungsgrad wurde in Kooperation mit Dr. J. Seidler über quantitative Signalintensitätsmessungen bestimmt und zeigte eine nahezu vollständige Phosphorylierung von pS10, pS139, pT197 und pS338, während der Phosphorylierungsgrad für pS34, pS53, pS65 und pS259 zwischen <5 und 45 % variierte. Neben der Quantifizierung der P-Stellen wurde auch das Auftreten und die Verteilung definierter Phosphoformen der PKA-Cα untersucht und deren Abhängigkeit von der primären Aminosäureabfolge, dem Auftreten von zusätzlichen Modifikationen sowie den gewählten Expressions- und Reinigungsbedingungen aufgezeigt. Endogene, aus Säugergewebe isolierte PKA-Cα wies nur eine einzige Phosphoform mit den P-Stellen pT197 und pS338 auf. Auch in vitro autophosphorylierte rekombinante PKA-Cα, die zuvor dephosphoryliert worden war, wies eine zweifach modifizierte Phosphoform auf. Im Vergleich zum endogenen Protein ließ sich dieses Protein an S10 und S338 exzessiv phosphorylieren, wohingegen an T197 keine Autophosphorylierung nachzuweisen war. Das Ausbleiben weiterer Phosphorylierungen stellt in Frage, ob die Hyperphosphorylierung in E. coli ausschließlich auf Autophosphorylierungsprozessen beruht, was anhand einer nicht phosphorylierten, katalytisch inaktiven Variante von PKA-Cα (PKA-Cα K72H) vermutet wurde. Im Hinblick auf die funktionellen P-Stellen pT197 und pS338 erfordert diese Entdeckung sowie der unabhängige Nachweis, dass zellfrei exprimierte PKA-Cα nur an S338 phosphoryliert ist, eine Modifizierung des sequenziellen Vorhersagemodells, wonach die Phosphorylierung an T197 eine zwingende Voraussetzung für die nachfolgende Phosphorylierung an S338 ist. Ferner konnte über phosphomimetische Mutagenese die Funktionalität der Phosphorylierung an S53 innerhalb der glycinreichen Schleife der PKA-Cα und somit ein potenzieller Weg zur Regulation der enzymatischen Aktivität gezeigt werden. Ein weiterer möglicher upstream Regulator von PKA-Cα ist die Proteinphosphatase 5, die in der Lage war, die bislang als phosphatasestabil beschriebene P Stelle pT197 in vitro zu dephosphorylieren. Die vorliegende Arbeit zeigt, dass der Phosphorylierungszustand eines Proteins von zahlreichen internen und externen Faktoren abhängt – eine Tatsache, die gerade für rekombinante Proteine, insbesondere enzymatisch aktive Kinasen, oft vernachlässigt wurde. Daher müssen auch in der shotgun Phosphoproteomanalytik P-Stellen nicht mehr nur identifiziert und quantifiziert werden, sondern die resultierenden Proteinphosphoformen differenziert auch in ihrem physiologischen Kontext beschrieben werden.

Status and Potential of Smallholder Livestock Production Systems in Xishuangbanna, southern P.R. China

With Chinas rapid economic development during the last decades, the national demand for livestock products has quadrupled within the last 20 years. Most of that increase in demand has been answered by subsidized industrialized production systems, while million of smallholders, which still provide the larger share of livestock products in the country, have been neglected. Fostering those systems would help China to lower its strong urban migration streams, enhance the livelihood of poorer rural population and provide environmentally save livestock products which have a good chance to satisfy customers demand for ecological food. Despite their importance, China’s smallholder livestock keepers have not yet gained appropriate attention from governmental authorities and researchers. However, profound analysis of those systems is required so that adequate support can lead to a better resource utilization and productivity in the sector. To this aim, this pilot study analyzes smallholder livestock production systems in Xishuangbanna, located in southern China. The area is bordered by Lao and Myanmar and geographically counts as tropical region. Its climate is characterized by dry and temperate winters and hot summers with monsoon rains from May to October. While the regionis plain, at about 500 m asl above sea level in the south, outliers of the Himalaya mountains reach out into the north of Xishuangbanna, where the highest peak reaches 2400 m asl. Except of one larger city, Jinghong, Xishuangbanna mainly is covered by tropical rainforest, areas under agricultural cultivation and villages. The major income is generated through inner-Chinese tourism and agricultural production. Intensive rubber plantations are distinctive for the lowland plains while small-scaled traditional farms are scattered in the mountane regions. In order to determine the current state and possible future chances of smallholder livestock production in that region, this study analyzed the current status of the smallholder livestock sector in the Naban River National Nature Reserve (NRNNR), an area which is largely representative for the whole prefecture. It covers an area of about 50square kilometer and reaches from 470 up to 2400 m asl. About 5500 habitants of different ethnic origin are situated in 24 villages. All data have been collected between October 2007 and May 2010. Three major objectives have been addressed in the study: 1. Classifying existing pig production systems and exploring respective pathways for development 2. Quantifying the performance of pig breeding systemsto identify bottlenecks for production 3. Analyzing past and current buffalo utilization to determine the chances and opportunities of buffalo keeping in the future In order to classify the different pig production s ystems, a baseline survey (n=204, stratified cluster sampling) was carried out to gain data about livestock species, numbers, management practices, cultivated plant species and field sizes as well associo-economic characteristics. Sampling included two clusters at village level (altitude, ethnic affiliation), resulting in 13 clusters of which 13-17 farms were interviewed respectively. Categorical Principal Component Analysis (CatPCA) and a two-step clustering algorithm have been applied to identify determining farm characteristics and assort recorded households into classes of livestock production types. The variables keep_sow_yes/no, TLU_pig, TLU_buffalo, size_of_corn_fields, altitude_class, size_of_tea_plantationand size_of_rubber_fieldhave been found to be major determinants for the characterization of the recorded farms. All farms have extensive or semi-intensive livestock production, pigs and buffaloes are predominant livestock species while chicken and aquaculture are available but play subordinate roles for livelihoods. All pig raisers rely on a single local breed, which is known as Small Ear Pig (SMEP) in the region. Three major production systemshave been identified: Livestock-corn based LB; 41%), rubber based (RB; 39%) and pig based (PB;20%) systems. RB farms earn high income from rubber and fatten 1.9 ±1.80 pigs per household (HH), often using purchased pig feed at markets. PB farms own similar sized rubber plantations and raise 4.7 ±2.77 pigs per HH, with fodder mainly being cultivated and collected in theforest. LB farms grow corn, rice and tea and keep 4.6 ±3.32 pigs per HH, also fed with collected and cultivated fodder. Only 29% of all pigs were marketed (LB: 20%; RB: 42%; PB: 25%), average annual mortality was 4.0 ±4.52 pigs per farm (LB: 4.6 ±3.68; RB: 1.9 ±2.14; PB: 7.1 ±10.82). Pig feed mainly consists of banana pseudo stem, corn and rice hives and is prepared in batches about two to three times per week. Such fodder might be sufficient in energy content but lacks appropriate content of protein. Pigs therefore suffer from malnutrition, which becomes most critical in the time before harvest season around October. Farmers reported high occurrences of gastrointestinal parasites in carcasses and often pig stables were wet and filled with manure. Deficits in nutritional and hygienic management are major limits for development and should be the first issues addressed to improve productivity. SME pork was found to be known and referred by local customers in town and by richer lowland farmers. However, high prices and lacking availability of SME pork at local wet-markets were the reasons which limited purchase. If major management constraints are overcome, pig breeders (PB and LB farms) could increase the share of marketed pigs for town markets and provide fatteners to richer RB farmers. RB farmers are interested in fattening pigs for home consumption but do not show any motivation for commercial pig raising. To determine the productivity of input factors in pig production, eproductive performance, feed quality and quantity as well as weight development of pigs under current management were recorded. The data collection included a progeny history survey covering 184 sows and 437 farrows, bi-weekly weighing of 114 pigs during a 16-months time-span on 21 farms (10 LB and 11 PB) as well as the daily recording of feed quality and quantity given to a defined number of pigs on the same 21 farms. Feed samples of all recorded ingredients were analyzed for their respective nutrient content. Since no literature values on thedigestibility of banana pseudo stem – which is a major ingredient of traditional pig feed in NRNNR – were found, a cross-sectional digestibility trial with 2x4 pigs has been conducted on a station in the research area. With the aid of PRY Herd Life Model, all data have been utilized to determine thesystems’ current (Status Quo = SQ) output and the productivity of the input factor “feed” in terms of saleable life weight per kg DM feed intake and monetary value of output per kg DM feed intake.Two improvement scenarios were simulated, assuming 1) that farmers adopt a culling managementthat generates the highest output per unit input (Scenario 1; SC I) and 2) that through improved feeding, selected parameters of reproduction are improved by 30% (SC II). Daily weight gain averaged 55 ± 56 g per day between day 200 and 600. The average feed energy content of traditional feed mix was 14.92 MJ ME. Age at first farrowing averaged 14.5 ± 4.34 months, subsequent inter-farrowing interval was 11.4 ± 2.73 months. Littersize was 5.8 piglets and weaning age was 4.3 ± 0.99 months. 18% of piglets died before weaning. Simulating pig production at actualstatus, it has been show that monetary returns on inputs (ROI) is negative (1:0.67), but improved (1:1.2) when culling management was optimized so that highest output is gained per unit feed input. If in addition better feeding, controlled mating and better resale prices at fixed dates were simulated, ROI further increased to 1:2.45, 1:2.69, 1:2.7 and 1:3.15 for four respective grower groups. Those findings show the potential of pork production, if basic measures of improvement are applied. Futureexploration of the environment, including climate, market-season and culture is required before implementing the recommended measures to ensure a sustainable development of a more effective and resource conserving pork production in the future. The two studies have shown that the production of local SME pigs plays an important role in traditional farms in NRNNR but basic constraints are limiting their productivity. However, relatively easy approaches are sufficient for reaching a notable improvement. Also there is a demand for more SME pork on local markets and, if basic constraints have been overcome, pig farmers could turn into more commercial producers and provide pork to local markets. By that, environmentally safe meat can be offered to sensitive consumers while farmers increase their income and lower the risk of external shocks through a more diverse income generating strategy. Buffaloes have been found to be the second important livestock species on NRNNR farms. While they have been a core resource of mixed smallholderfarms in the past, the expansion of rubber tree plantations and agricultural mechanization are reasons for decreased swamp buffalo numbers today. The third study seeks to predict future utilization of buffaloes on different farm types in NRNNR by analyzing the dynamics of its buffalo population and land use changes over time and calculating labor which is required for keeping buffaloes in view of the traction power which can be utilized for field preparation. The use of buffaloes for field work and the recent development of the egional buffalo population were analyzed through interviews with 184 farmers in 2007/2008 and discussions with 62 buffalo keepers in 2009. While pig based farms (PB; n=37) have abandoned buffalo keeping, 11% of the rubber based farms (RB; n=71) and 100% of the livestock-corn based farms (LB; n=76) kept buffaloes in 2008. Herd size was 2.5 ±1.80 (n=84) buffaloes in early 2008 and 2.2 ±1.69 (n=62) in 2009. Field work on own land was the main reason forkeeping buffaloes (87.3%), but lending work buffaloes to neighbors (79.0%) was also important. Other purposes were transport of goods (16.1%), buffalo trade (11.3%) and meat consumption(6.4%). Buffalo care required 6.2 ±3.00 working hours daily, while annual working time of abuffalo was 294 ±216.6 hours. The area ploughed with buffaloes remained constant during the past 10 years despite an expansion of land cropped per farm. Further rapid replacement of buffaloes by tractors is expected in the near future. While the work economy is drastically improved by the use of tractors, buffaloes still can provide cheap work force and serve as buffer for economic shocks on poorer farms. Especially poor farms, which lack alternative assets that could quickly be liquidizedin times of urgent need for cash, should not abandon buffalo keeping. Livestock has been found to be a major part of small mixed farms in NRNNR. The general productivity was low in both analyzed species, buffaloes and pigs. Productivity of pigs can be improved through basic adjustments in feeding, reproductive and hygienic management, and with external support pig production could further be commercialized to provide pork and weaners to local markets and fattening farms. Buffalo production is relatively time intensive, and only will be of importance in the future to very poor farms and such farms that cultivate very small terraces on steep slopes. These should be encouraged to further keep buffaloes. With such measures, livestock production in NRNNR has good chances to stay competitive in the future.

Validez del supuesto de neutralidad del horizonte de tiempo en el CAPM y la metodología del rango reescalado: aplicación a Colombia

La existencia de memoria de largo plazo en las series financieras implica que los retornos de un activo hoy pueden tener incidencia sobre los retornos futuros, incluso más allá del corto plazo. En presencia de dicha memoria el horizonte de inversión elegido puede resultar en diferentes condiciones de riesgo para el inversionista. Peters (1989 y 1992), Mandelbrot (1972), León y Vivas (2010), entre otros, encuentran evidencia de dependencia de largo plazo de las series de tiempo financieras y muestran sus principales implicaciones. Este documento se ocupa de extender el análisis al uso del supuesto de neutralidad del horizonte de tiempo en el CAPM, estimando el efecto cuantitativo de la existencia de dependencia de largo plazo en este modelo según lo desarrollado por Greene y Fieltz (1980). Los resultados para una muestra de acciones colombianas y estadounidenses muestran que la distribución de la medida del riesgo sistémico en el modelo, el beta, es estadísticamente diferente cuando se incorpora el efecto de dependencia de largo plazo; por lo tanto, los retornos esperados de estas acciones cambian. En el mercado colombiano se observa una sobreestimación del beta cuando no se realiza el ajuste propuesto, mientras que en las acciones estadounidenses analizadas el beta sin el ajuste se encuentra subestimado. En cuanto a los retornos esperados, estos son sobrevalorados al no tener en cuenta el ajuste por dependencia de largo plazo, tanto en las acciones colombianas como en las estadounidenses.

Mortalidad por trauma cardiaco penetrante en un hospital de Bogotá, Colombia : análisis de factores asociados

Objetivó: Caracterizar los pacientes con heridas cardiacas penetrantes grado II a VI, describir las características del trauma, tratamiento quirúrgico, evolución clínica e identificar los factores asociados a un desenlace. Metodología: Se diseñó un estudio de asociación en 308 pacientes que ingresaron a cirugía con diagnóstico de herida penetrante de corazón entre enero de 1999 y octubre de 2009. Se excluyeron 68 casos. La serie analizada incluyó 240 pacientes con heridas cardiacas. Se analizaron variables demográficas, clínicas, quirúrgicas y de evolución, tabulados en EXCEL® y analizados en SPSS 20®. Resultados: El promedio de edad fue 27.8 años, principalmente hombres (96%), lesiones por arma cortopunzante 93% y un 7% por proyectil arma de fuego. El estado hemodinámico al ingreso (según Ivatury) fue normal 44%; Shock profundo 34%; Agónicos 18% y 3% fatales. El 67% (n=161) presentaron taponamiento cardiaco. Los grados de lesión cardiaca según la clasificación OIS-AAST fueron: grado II 33%, grado III 13%, grado IV 29%, grado V 22% y grado VI 3%. La ventana pericárdica fue el método diagnóstico confirmatorio de lesión en 63% y las incisiones de abordaje quirúrgico fueron la esternotomía 63% y la toracotomía anterolateral 35%. La mortalidad fue 15% (n=36). Las diferencias en mortalidad entre el estado hemodinámico al inicio de cirugía, mecanismo de lesión y grado de herida, demostraron ser estadísticamente significativas (valor de p<0.001). Conclusiones: El estado hemodinámico y las heridas por arma de fuego son factores asociados a mortalidad. La ventana pericárdica subxifoidea favorece la preferencia y buenos resultados de la esternotomía como vía de abordaje quirúrgico.