Acetalization of ketones on K-10 clay and rare earth exchanged HFAU-Y zeolites: A mild and facile procedure for the synthesis of dimethylacetals

Dimethylacetals of ketones; cyclohexanone, acetophenone, and benzophenone have been prepared by reacting ketones with methanol under mild reaction conditions. Large pore zeolites (H-Y and its rare earth metal, Ce3+, La3+, and RE3+ modified forms), and mesoporous clay (K-10 montmorillonite and its cerium exchanged counterpart) with regular pore structure, silica and silica-alumina have been used as catalysts. Clay catalysts are found to be much more active than zeolites, thanks to slightly bigger pore size. The nature of the pores of the solid acid catalysts determine acetalization efficiency of a particular catalyst. As evidenced by the reaction time studies, the catalyst decay is greater over the zeolites than over the clays. Carrying out the reaction with ketones of different molecular sizes it is shown that K-10 clays and rare earth exchanged H-Y zeolites are promising environmentally friendly catalysts for their use in the production fine chemicals.

Characterisation and Distribution of Amino Acids in the Mangrove Sediments of Kochi

Mangrove swamps are unique inter-tidal wetland ecosystems found in sheltered tropical and subtropical shores.Mangrove sediments can be considered as large reservoirs of amino acids,which exist in several different forms,like free amino acids in the sediment micropores,as amino acids,peptides or proteins bound to clay minerals or as amino acids,peptides or proteins bound to humic colloids.Inorder to assess survival conditions of organisms of mangroves,it is important to understand stability of amino acids in the sediments.The amounts of amino acids present in sediment represent a balance between its synthesis and destruction by microorganisms.Thus amino acid analysis offers more insight into the processes of diagenesis,which changes the nature and characteristics of organic matter deposition and decomposition.

Biochemical Studies on the Protective Effect of Taurine on Experimentally Induced Fulminat Hepatic Failure in Rats

Fulminant hepatic failure (FHF) is a dramatic and challenging syndrome in clinical medicine. Although an uncommon disorder, it is usually fatal and occurs in previously healthy person. While the causes of FHF remain unclear, viral hepatitis and drug-induced liver injury account for the majority of cases. Hepatitis E causes large-scale epidemics of hepatitis in the Indian subcontinent, involving hundreds of thousands of cases with high mortality. FHF is associated with several clinical features like jaundice, shrunken liver, easy bruising, low levels of serum proteins, fatigue, multi-organ failure etc and metabolic derangements like hypoglycemia, hyperlipidemia, hyponatremia, defective protein synthesis, reduced energy production, decreased rate of urea production etc. These disturbances are predominantly attributed to oxidative stress, membrane destabilization and osmolytic imbalances. The options available for these patients are quite minimal with liver transplantation being one of them. But the procedure is ridden with issues causing it to find less favor among the patients and the caregivers. Use of hepatoprotective and cytoprotective drugs, is being considered to be a more acceptable alternative as a strategy to enhance liver regeneration. In this regard use of taurine a naturally occurring amino acid that plays a crucial role in many physiological processes would prove to be effective. In the present study, hepatoprotective effect of taurine on a rat model of induced FHF was studied. Taurine supplementation has effectively counteracted the metabolic and structural aberrations in the liver caused by D-galactosamine intoxication.

Investigations on some amino acid based single crystals for nonlinear optical applications and amino acid capped nanocrystals

Organic crystals possess extremely large optical nonlinearity compared to inorganic crystals. Also organic compounds have the amenability for synthesis and scope for introducing desirable characteristics by inclusions. A wide variety of organic materials having electron donor and acceptor groups, generate high order of nonlinearity. In the present work, a new nonlinear optical crystal, L-citrulline oxalate (LCO) based on the aminoacid L-citrulline was grown using slow evaporation technique. Structural characterization was carried out by single crystal XRD. It crystallizes in the noncentrosymmetric, orthorhombic structure with space group P21 P21 P21. Functional groups present in the sample were identified by Fourier transform infra red (FTIR) and FT-Raman spectral analysis. On studying the FTIR and Raman spectra of the precursors L-citrulline and oxalic acid, used for growing L-citrulline oxalate crystal, it is found that the significant peaks of the precursors are present in the spectra of the L-citrulline oxalate crystal . This observation along with the presence of NH3 + group in the spectra of L-citrulline oxalate, confirms the formation of the charge transfer complex

An Efficient Multi-component Synthesis of 6-Amino-3-methyl-4-Aryl-2,4- dihydropyrano[2,3-c]Pyrazole-5-carbonitriles

Multi-component reactions are effective in building complex molecules in a single step in a minimum amount of time and with facile isolation procedures; they have high economy1–7 and thus have become a powerful synthetic strategy in recent years.8–10 The multicomponent protocols are even more attractive when carried out in aqueous medium. Water offers several benefits, including control over exothermicity, and the isolation of products can be carried out by single phase separation technique. Pyranopyrazoles are a biologically important class of heterocyclic compounds and in particular dihydropyrano[2,3-c]pyrazoles play an essential role in promoting biological activity and represent an interesting template in medicinal chemistry. Heterocyclic compounds bearing the 4-H pyran unit have received much attention in recent years as they constitute important precursors for promising drugs.11–13 Pyrano[2,3-c]pyrazoles exhibit analgesic,14 anti-cancer,15 anti-microbial and anti-inflammatory16 activity. Furthermore dihydropyrano[2,3-c]pyrazoles show molluscidal activity17,18 and are used in a screening kit for Chk 1 kinase inhibitor activity.19,20 They also find applications as pharmaceutical ingredients and bio-degradable agrochemicals.21–29 Junek and Aigner30 first reported the synthesis of pyrano[2,3-c]pyrazole derivatives from 3-methyl-1-phenylpyrazolin-5-one and tetracyanoethylene in the presence of triethylamine. Subsequently, a number of synthetic approaches such as the use of triethylamine,31 piperazine,32 piperidine,33 N-methylmorpholine in ethanol,34 microwave irradiation,35,36 solvent-free conditions,37–39 cyclodextrins (CDs),40 different bases in water,41 γ -alumina,42 and l-proline43 have been reported for the synthesis of 6-amino-4-alkyl/aryl-3-methyl- 2,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles. Recently, tetraethylammonium bromide (TEABr) has emerged as mild, water-tolerant, eco-friendly and inexpensive catalyst. To the best of our knowledge, quaternary ammonium salts, more specifically TEABr, have notbeen used as catalysts for the synthesis of pyrano[2,3-c]pyrazoles, and we decided to investigate the application of TEABr as a catalyst for the synthesis of a series of pyrazole-fused pyran derivatives via multi-component reactions

Matrix based Cryptographic Procedure for Efficient Image Encryption

In this paper we propose a cryptographic transformation based on matrix manipulations for image encryption. Substitution and diffusion operations, based on the matrix, facilitate fast conversion of plaintext and images into ciphertext and cipher images. The paper describes the encryption algorithm, discusses the simulation results and compares with results obtained from Advanced Encryption Standard (AES). It is shown that the proposed algorithm is capable of encrypting images eight times faster than AES.

Provenance, Isolation and Characterisation of Organic Matter in the Cochin Estuarine Sediment-“a Diagenetic Amino Acid Marker Scenario

Cochin estuarine system is among the most productive aquatic environment along the Southwest coast of India, exhibits unique ecological features and possess greater socioeconomic relevance. Serious investigations carried out during the past decades on the hydro biogeochemical variables pointed out variations in the health and ecological functioning of this ecosystem. Characterisation of organic matter in the estuary has been attempted in many investigations. But detailed studies covering the degradation state of organic matter using molecular level approach is not attempted. The thesis entitled Provenance, Isolation and Characterisation of Organic Matter in the Cochin Estuarine Sediment-“ A Diagenetic Amino Acid Marker Scenario” is an integrated approach to evaluate the source, quantity, quality, and degradation state of the organic matter in the surface sediments of Cochin estuarine system with the combined application of bulk and molecular level tools. Sediment and water samples from nine stations situated at Cochin estuary were collected in five seasonal sampling campaigns, for the biogeochemical assessment and their distribution pattern of sedimentary organic matter. The sampling seasons were described and abbreviated as follows: April- 2009 (pre monsoon: PRM09), August-2009 (monsoon: MON09), January-2010 (post monsoon: POM09), April-2010 (pre monsoon: PRM10) and September- 2012 (monsoon: MON12). In order to evaluate the general environmental conditions of the estuary, water samples were analysed for water quality parameters, chlorophyll pigments and nutrients by standard methods. Investigations suggested the fact that hydrographical variables and nutrients in Cochin estuary supports diverse species of flora and fauna. Moreover the sedimentary variables such as pH, Eh, texture, TOC, fractions of nitrogen and phosphorous were determined to assess the general geochemical setting as well as redox status. The periodically fluctuating oxic/ anoxic conditions and texture serve as the most significant variables controlling other variables of the aquatic environment. The organic matter in estuary comprise of a complex mixture of autochthonous as well as allochthonous materials. Autochthonous input is limited or enhanced by the nutrient elements like N and P (in their various fractions), used as a tool to evaluate their bioavailability. Bulk parameter approach like biochemical composition, stoichiometric elemental ratios and stable carbon isotope ratio was also employed to assess the quality and quantity of sedimentary organic matter in the study area. Molecular level charactersation of free sugars and amino acids were carried out by liquid chromatographic techniques. Carbohydrates are the products of primary production and their occurrence in sediments as free sugars can provide information on the estuarine productivity. Amino acid biogeochemistry provided implications on the system productivity, nature of organic matter as well as degradation status of the sedimentary organic matter in the study area. The predominance of carbohydrates over protein indicated faster mineralisation of proteinaceous organic matter in sediments and the estuary behaves as a detrital trap for the accumulation of aged organic matter. The higher lipid content and LPD/CHO ratio pointed towards the better food quality that supports benthic fauna and better accumulation of lipid compounds in the sedimentary environment. Allochthonous addition of carbohydrates via terrestrial run off was responsible for the lower PRT/CHO ratio estimated in thesediments and the lower ratios also denoted a detrital heterotrophic environment. Biopolymeric carbon and the algal contribution to BPC provided important information on the better understanding the trophic state of the estuarine system and the higher values of chlorophyll-a to phaeophytin ratio indicated deposition of phytoplankton to sediment at a rapid rate. The estimated TOC/TN ratios implied the combined input of both terrestrial and autochthonous organic matter to sedimentsAmong the free sugars, depleted levels of glucose in sediments in most of the stations and abundance of mannose at station S5 was observed during the present investigation. Among aldohexoses, concentration of galactose was found to be higher in most of the stationsRelative abundance of AAs in the estuarine sediments based on seasons followed the trend: PRM09-Leucine > Phenylalanine > Argine > Lysine, MON09-Lysine > Aspartic acid > Histidine > Tyrosine > Phenylalanine, POM09-Lysine > Histadine > Phenyalanine > Leucine > Methionine > Serine > Proline > Aspartic acid, PRM10-Valine > Aspartic acid > Histidine > Phenylalanine > Serine > Proline, MON12-Lysine > Phenylalanine > Aspartic acid > Histidine > Valine > Tyrsine > MethionineThe classification of study area into three zones based on salinity was employed in the present study for the sake of simplicity and generalized interpretations. The distribution of AAs in the three zones followed the trend: Fresh water zone (S1, S2):- Phenylalanine > Lysine > Aspartic acid > Methionine > Valine ῀ Leucine > Proline > Histidine > Glycine > Serine > Glutamic acid > Tyrosine > Arginine > Alanine > Threonine > Cysteine > Isoleucine. Estuarine zone (S3, S4, S5, S6):- Lysine > Aspartic acid > Phenylalanine > Leucine > Valine > Histidine > Methionine > Tyrosine > Serine > Glutamic acid > Proline > Glycine > Arginine > Alanine > Isoleucine > Cysteine > Threonine. Riverine /Industrial zone (S7, S8, S9):- Phenylalanine > Lysine > Aspartic acid > Histidine > Serine > Arginine > Tyrosine > Leucine > Methionine > Glutamic acid > Alanine > Glycine > Cysteine > Proline > Isoleucine > Threonine > Valine. The abundance of AAs like glutamic acid, aspartic acid, isoleucine, valine, tyrosine, and phenylalanine in sediments of the study area indicated freshly derived organic matter.

Changes in amino acid enantiomers and microbial performance in soils from a subtropical mountain oasis in Oman abandoned for different periods

An important feature of maintaining the agricultural stability in millennia-old mountain oases of northern Oman is the temporary abandonment of terraces. To analyse the effects of a fallow period on soil microbial performance, i.e. microbial activity and microbial biomass, samples of eight terrace soils abandoned for different periods were collected in situ, assigned to four fallow age classes and incubated for 30 days in the laboratory after rewetting. The younger fallow age classes of 1 and 5 years were based on the records of the farmers’ recollections, the two older fallow age classes of 10–20 and 25–60 years according to the increase in the D -to- L ratio of valine and leucine enantiomers. The increase in these two ratios was in agreement with that of the D -to- L ratio of lysine. The strongest relationship was observed between the increase in the D -to- L ratio of lysine and the decrease in soil microbial biomass C. However, the most stringent coherence between the increase in fallow age and soil properties was revealed by the decreases in cumulative respiration and net N mineralisation rates with decreasing availability of substrate to soil microorganisms. During the 30-day incubation following rewetting, relative changes in microbial activity (respiration and net N mineralisation) and microbial biomass (C and N)indices were similar in the eight terrace soils on a fallow age-class-specific level, indicating that the same basic processes occurred in all of the sandy terrace soils investigated.

Synthesis of N-amino compounds and C2 symmetric N-amino compounds and transformation into aziridines using olefins

Aziridine, Stickstoffanaloga der Epoxide, können regio- und stereoselektive Ringöffnungsreaktionen eingehen, wodurch ihnen als „building blocks“ in der Organischen Synthese eine große Bedeutung zukommt. In dieser Arbeit wurden unterschiedliche N-Aminoverbindungen synthetisiert sowie die Anwendungsmöglichkeit dieser Hydrazinderivate als Stickstoffquellen in Aziridinierungen von Olefinen untersucht. In der vorliegenden Dissertation wurde eine neue Methode zur Darstellung von N-Aminosuccinimid entwickelt und die Einsatzmöglichkeit als Stickstoffquelle in Aziridinierungsreaktionen in einer Reihe von Umsetzungen mit funktionalisierten ebenso wie mit nicht-funktionalisierten Olefinen demonstriert. Die ableitbaren Aziridine wurden hierbei in Ausbeuten von bis zu 80 % erhalten. In der Aziridinierungsreaktion von N-Aminosuccinimid mit 4,7-Dihydro-2-isopropyl-1,3-dioxepin resultieren bicyclische Aziridinierungsprodukte, die als endo/exo-Isomere in einem 1:1-Verhältnis anfallen. Es ist in dieser Arbeit gelungen, die Isomere in guten Ausbeuten zu erhalten, sie säulenchromatographisch zu trennen und ihre Konfiguration im festen Zustand mittels Kristallstrukturanalyse eindeutig zu bestimmen. Enantiomerenangereicherte Olefine, wie z. B. in 2-Position alkylsubstituierte 5-Methyl-4H-1,3-dioxine mit Enantiomerenüberschüssen von 92% ee liefern in der Aziridinierung mit N-Aminosuccinimid und Iodosylbenzol ein 4-Methyl-1,3-oxazolidin-4-carbaldehydderivat in einer zweistufigen Reaktion- der Aziridinierung und einer Umlagerung- ein 4-Methyl-1,3-oxazolidin-4-carbaldehydderivat. Für die Diastereoselektivität des Aziridinierungsschrittes wurde 65 % de bestimmt. In einer neuen Synthese über zwei Stufen ausgehend von (+)-3,4-Dimethoxysuccinanhydrid konnte ein chiraler Stickstoffüberträger - (+)-N-Amino-3,4-dimethoxysuccinimid - in Ausbeuten bis zu 86 % synthetisiert. Die Umsetzung dieser optisch aktiven Stickstoffquelle mit einer Vielzahl prochiraler Alkene führt zu diastereomeren Aziridinen in Ausbeuten bis zu 65% und Diastereoselektivitäten von bis zu 66% de. Anhand ausgewählter Verbindungen konnten die Absolutkonfigurationen der Reaktionsprodukte mittels Kristallstrukturanalyse eindeutig geklärt werden.

Effects of tubers of the Jerusalem artichoke (Helianthus tuberosus) and potatoes (Solanum tuberosum) on the intestinal microbiota of pigs and evaluation of a procedure for quantification of microbial mass in pig faeces

Die Mikrobiota im Gastrointestinaltrakt (GIT) spielt eine bedeutende Rolle beim Fermentationsprozess im Bezug auf die Nährstoffversorgung sowie die Gesundheit des Darms und des gesamten Organismus. Inulin und resistente Stärke (RS) konnten als präbiotisch wirksame Substanzen identifiziert werden und sind jeweils auch in den Knollen der Topinamburpflanze (Helianthus tuberosus) und in Kartoffeln (Solanum tuberosum) enthalten. Da sie ebenfalls energiereiche Futtermittel für Schweine sind, war es das Ziel der ersten beiden Studien, die Auswirkungen der Aufnahme von Topinamburknollen und Kartoffeln auf die intestinale Mikrobiota und Parameter des Immunsystems bei Endmastschweinen zu bestimmen. In der dritten Studie wurde die mikrobielle Biomasse quantitativ mit einem Verfahren zur Isolation von Bakterien in einer Flüssigkeit durch Hochgeschwindigkeits-Zentrifugation erfasst und der bakteriell gebundene Stickstoff (MP-N) mit dem bakteriellen und endogenem Kotstickstoff (BEDN) verglichen. Im ersten Versuch wurden 72 Endmastschweine in einem Freilandhaltungssystem in eine Kontroll- (CT), die mit Kraftfutter entsprechend des Bedarfs der Tiere für ein Leistungsniveau von 700 g täglichem Lebendmassezuwachs versorgt wurde, und eine Versuchsvariante (ET) aufgeteilt. In der Versuchsvariante erhielten die Tiere nur 70% der Kraftfuttermenge der Kontrollvariante, hatten aber Zugang zu einer abgeteilten Fläche, auf der Topinamburknollen angebaut waren. Die freie Aufnahme von Topinamburknollen wurde auf 1•24 kg Trockenmasse (TM)/Tag bestimmt, entsprechend einer Inulinaufnahme von durchschnittlich 800 g/Tag. Während sich die Wachstumsleistung in der Kontrollvariante auf 0•642 ± 0•014 kg/Tag belief, war sie in der Versuchsvariante mit 0•765 ± 0•015 kg/Tag (P=0•000) höher. Die freie Verfügbarkeit von Inulin und Fructo-oligosacchariden (FOS) im GIT der Schweine erhöhte die Keimzahlen der anaeroben Bakterien (P=0•000), Laktobazillen (P=0•046) und Hefen (P=0•000) signifikant und verringerte das Vorkommen von Clostridium perfringens im Schweinekot erheblich von lg 5•24 ± 0•17 kolonie-bildende Einheiten pro g Frischmasse (KbE/ g FM) in der Kontrollvariante auf lg 0•96 ± 0•20 KbE/ g FM in der Versuchsvariante (P=0•000). C-reaktives Protein (CRP) und Antikörper gegen Lipopolysaccharide (LPS) von Escherichia coli J5 ließen keine Unterschiede zwischen den Fütterungsvarianten erkennen. In der zweiten Untersuchung wurden 58 Endmastschweine einer Kontrollvariante (CT), die bedarfsgerecht mit einer Kraftfuttermischung für ein Leistungsniveau von 700 g Tageszunahmen gefüttert wurde, und zwei Versuchsvarianten zugeteilt. Die Versuchsvarianten erhielten eine Menge von 1•2 kg TM gedämpften Kartoffeln (potato treatment, PT) oder gedämpften und einsilierten Kartoffeln (silage treatment, ST) pro Tag und nur 46% bzw. 43% der Menge des Kraftfutters der Kontrollvariante. Die Wachstumsleistung und Schlachtkörperzusammensetzung ließen keine signifikanten Unterschiede zwischen den Varianten erkennen. Im PT und ST waren gegenüber dem CT im Kot der pH-Wert sowie die Gehalte von TM, Neutral-Detergenz-Faser (NDF), unverdautem Futterstickstoff (UDN) und teilweise von Säure-Detergenz-Faser (ADF) signifikant niedriger (P=0•000) und die von Ammonium (NH4) und Ammoniumstickstoff (NH4-N) signifikant höher (P=0•000). Das hohe Angebot von hitzebehandelten Kartoffeln führte zu einer erheblichen Verringerung von E. coli (P=0•000), C. perfringens (P=0•000) und Immunoglobulin A gegen LPS von E. coli J5 (P=0•001). Darüber hinaus waren in der ersten Versuchsperiode im ST die aeroben und anaeroben Gesamtkeimzahlen sowie die Laktobazillen und Hefen gegenüber dem PT signifikant erhöht. Die Unterschiede in der Mikrobiota zwischen der Kontroll- und Versuchsvarianten weisen auf die positiven Auswirkungen von Topinamburknollen und hitzebehandelten Kartoffeln auf die Mikrobiota im hinteren Darmabschnitt hin. Das Ziel der dritten Untersuchung war die Modifizierung des Verfahrens zur Isolation von Bakterien in einer Flüssigkeit mittels verschiedener Zentrifugationsschritte, um ein mikrobielles Pellet (MP) zu erhalten, welches die quantitative Abtrennung und Erfassung der Bakterien in Schweinekot ermöglicht. Zusätzlich wurde der BEDN Anteil sowie die Gehalte der Aminozucker Galactosamin, Glucosamin, Mannosamin und Muraminsäure im Kot und im MP bestimmt. Die untersuchten Kotproben stammten von Schweinen eines Phosphor (P) Stoffwechselversuch. Zehn männlich-kastrierte Schweine mit einem durchschnittlichen Lebendgewicht von 51•1 ± 8•5 kg wurden einzeln in Stoffwechselkäfigen gehalten. Die Tiere wurden fünf Fütterungsvarianten zugeteilt, die dem Bedarf der Tiere für ein Leistungsniveau von 700 g Tageszunahmen entsprachen, in den Rationen 2 bis 5 jedoch eine P-Gehalt unter dem Tagesbedarf der Tiere aufwiesen und in den Rationen 3 bis 5 mit abgestuften Gehalten von 50, 100 sowie 200 mg/kg einer experimentellen Phytase ergänz waren. Die Absenkung des P Gehaltes im Futter verringerte den Asche- (P=0•024) und Trockenmassegehalt im Kot (P=0•017) sowie die P Konzentration im MP (P=0•000) signifikant. Die mikrobielle Biomasse im Kot wurde durch die Wiegung des MP auf durchschnittlich 467 g/kg TM bestimmt. Der Stickstoffgehalt im Kot betrug im Mittel 46•1 g/kg TM und der in die Bakterienmasse eingebaute Stickstoffanteil 27•1 g/kg TM bzw. 58% vom Gesamtstickstoffgehalt im Kot. Die BEDN Fraktion wurde auf 73% am Kotstickstoff bestimmt. Der P-Gehalt im Kot sowie der N Gehalt im MP mit durchschnittlichen 10•4 und 57•9 g/kg TM lagen im Bereich von Literaturangaben. Die P Gehalte im MP schwankten in Abhängigkeit von der Zugabe von Phytase signifikant (P=0•000) von 1•8 bis 4•8 g/kg TM. Die Aminozucker wiesen keine signifikanten unterschiede zwischen Fütterungsvarianten auf und lagen im Bereich von Werten von Rinderkot. Ergebnisse weisen darauf hin, dass die angewandte Methode zur direkten Quantifizierung der mikrobiellen Biomasse geeignet ist.

Effect of environmental conditions on the N uptake route of soil microorganisms and adaption of a method to determine amino acid oxidase in soil

Soil microorganisms have evolved two possible mechanisms for their uptake of organic N: the direct route and the mobilization-immobilization-turnover (MIT) route. In the direct route, simple organic molecules are taken up via various mechanisms directly into the cell. In the MIT route, the deamination occurs outside the cell and all N is mineralized to NH4+ before assimilation. A better understanding of the mechanisms controlling the different uptake routes of soil microorganisms under different environmental conditions is crucial for understanding mineralization processes of organic material in soil. For the first experiment we incubated soil samples from the long term trial in Bad Lauchstädt with corn residues with different C to N ratios and inorganic N for 21 days at 20 °C. Under the assumption that all added amino acids were taken up or mineralized, the direct uptake route was more important in soil amended with corn residues with a wide C to N ratio. After 21 days of incubation the direct uptake of added amino acids increased in the order addition of corn residue with a: “C to N ratio of 40 & (NH4)2SO4 and no addition (control)” (69% and 68%, respectively) < “C to N ratio of 20” (73%) < “C to N ratio of 40” (95%). In all treatments the proportion of the added amino acids that were mineralized increased with time, indicating that the MIT route became more important over time. To investigate the effects of soil depth on the N uptake route of soil microorganisms (experiment II), soil samples in two soil depths (0-5 cm; 30-40 cm) were incubated with corn residues with different C to N ratios and inorganic N for 21 days at 20 °C and 60% (WHC). The addition of corn residue resulted in a marked increase of protease activity in both depths due to the induction from the added substrate. Addition of corn residue with a wide C to N ratio resulted in a significantly greater part of the direct uptake (97% and 94%) than without the addition of residues (85% and 80%) or addition of residue with a small C to N ratio (90% and 84%) or inorganic N (91% and 79% in the surface soil and subsoil, respectively), suggesting that under conditions of sufficient mineralizable N (C to N ratio of 20) or increased concentrations of NH4+, the enzyme system involved in the direct uptake is slightly repressed. Substrate additions resulted in an initially significantly higher increase of the direct uptake in the surface soil than in the subsoil. As a large proportion of the organic N input into soil is in form of proteinaceous material, the deamination of amino acids is a key reaction of the MIT route. Therefore the enzyme amino acid oxidase contribute to the extracellular N mineralization in soil. The objective of experiment III was to adapt a method to determine amino acid oxidase in soil. The detection via synthetic fluorescent Lucifer Yellow derivatives of the amino acid lysine is possible in soil. However, it was not possible to find the substrate concentration at which the reaction rate is independent of substrate concentration and therefore we were not able to develop a valid soil enzyme assay.

Scientific production on the Mantel-Haenszel procedure as a way of detecting DIF

Resumen tomado de la publicaci??n

Two isomeric reaction products: hydrogen-bonded sheets in methyl 4-(5-amino-3-phenyl-1H-pyrazol-1-yl)-3-nitrobenzoate and hydrogen-bonded chains of edge-fused rings in methyl 3-nitro-4-[(5-phenyl-1H-pyrazol-3-yl)amino] benzoate

In methyl 4-(5-amino-3-phenyl-1H-pyrazol-1-yl)-3-nitrobenzoate, C17H14N4O4, the molecules are linked into complex sheets by a combination of N-H center dot center dot center dot N, N-H center dot center dot center dot O and C - H center dot center dot center dot O hydrogen bonds. In the isomeric methyl 3-nitro-4-[(5-phenyl- 1H-pyrazol-3-yl)amino] benzoate, molecules exhibit a polarized molecular-electronic structure and are linked into chains of edge-fused rings by a combination of N-H center dot center dot center dot O and C - H center dot center dot center dot O hydrogen bonds.

The mutual agreement procedure and arbitration of double taxation disputes

It is in the interest of most states to eliminate double taxation (i.e. the payment of the same tax in two jurisdictions) of transnational commercial enterprises. Because such disputes involve, on the one hand, the state imposition of taxes, a right universally asserted by all states, and private entities on the other, taxation disputes between such parties are not, on their face, easily susceptible to arbitration. This article analyzes two dispute settlement procedures-the OECD First Model Tax Convention and a similar EU Convention-with the exclusive focus on disputes relating to the imposition of double taxation. It will look at the ways in which state roles may vary under these procedures from assisting in the negotiation process to taking a part similar to, but with important differences from, diplomatic protection on behalf of an affected enterprise. The article will examine the situations under which the settlement procedure is required and/or available, how the procedures are triggered, the obligations and parts played by the parties, the means by which the disputes are resolved (from negotiations to tribunals) and the limitations of the procedures. Are they “taxpayer friendly”? As a result the reader may draw comparisons between the two procedures. Finally, the article will look at the proposed OECD Arbitration Clause which is intended to be incorporated into Article 25 of the OECD Model Tax Convention as well as how these mechanisms relate and/or conflict with bilateral tax treaties and the GATS.

Normalization procedure for the Baptista Depression Scale - Adult Version (EBADEP-A): transferring of norms

Regarding the standardization of psychological assessment instruments, that is, the construction of referential interpretations of a test, we can find different procedures performed both by Classical Test Theory (CTT) and the Theory of Item Response (IRT). Especially in this case (IRT), we can admit one test as a default, so to use its standardization and transfer the cut-off point to another instrument. Based on this information, the present study aimed to provide a cutoff score for the Baptista Depression Scale - Adult Version (EBADEP-A) through procedures of norms-transfer based on the Center for Epidemiologic Studies – Depression Scale (CES-D). The EBADEP-A presented good distribution and ability to discriminate depressive symptoms, and the sample, consisting of Brazilian College students, received a cutoff score of 32 points. It is emphasized that this is an exploratory and preliminary study, and it is suggested further analyzes to be performed with clinical samples for which results can be corroborated or confronted.