bluuebunny/crossref_metadata_2025 huggingface dataset:
Convergent Synthesis of the Potent P2Y Receptor Antagonist MG 50-3-1 Based on a Regioselective Ullmann Coupling Reaction
Authors: Baqi Younis , Müller Christa E.
Published: March 2012

MG 50-3-1 (3, trisodium 1-amino-4-{4-[4-chloro-6-(2-sulfophenylamino)-1,3,5-triazin-2-ylamino]-2-sulfophenylamino}-9,10-dioxo-9,10-dihydroanthracene 2-sulfonate) is the most potent and selective antagonist (IC50 4.6 nM) for “P2Y1-like” nucleotide-activated membrane receptors in guinea-pig taenia coli responsible for smooth muscle relaxation. Full characterization of the compound, however, e.g., at the human P2Y1 receptor, which is a novel potential target for antithrombotic drugs, as well as other P2 receptor subtypes, has been hampered due to difficulties in synthesizing the compound in sufficient quantity. MG 50-3-1 would be highly useful as a biological tool for detailed investigation of signal transduction in the gut. We have now developed a convenient, fast, mild, and efficient convergent synthesis of 3 based on retrosynthetic analysis. A new, regioselective Ullmann coupling reaction under microwave irradiation was successfully developed to obtain 1-amino-4-(4-amino-2-sulfophenylamino)-9,10-dioxo-9,10-dihydro­anthracene 2-sulfonate (8). Four different copper catalysts (Cu, CuCl, CuCl2, and CuSO4) were investigated at different pH values of sodium phosphate buffer, and in water in the absence or presence of base. Results showed that CuSO4 in water in the presence of triethylamine provided the best conditions for the regioselective Ullmann coupling reaction yielding the key intermediate compound 8. A new synthon (sodium 2-(4,6-dichloro-1,3,5-triazin-2-ylamino)benzenesulfonate, 13) which can easily be obtained on a gram scale was prepared, and 13 was successfully coupled with 8 yielding the target compound 3.
Oxidation of 2-Hydroxynevirapine, a Phenolic Metabolite of the Anti-HIV Drug Nevirapine: Evidence for an Unusual Pyridine Ring Contraction
Authors: Antunes Alexandra M. M. , Sidarus Muna , Novais David A. , Harjivan Shrika G. , Santos Pedro P. , Ferreira da Silva João L. , Beland Frederick A. , Marques M. Matilde
Published: March 2012

Nevirapine (NVP) is an anti-HIV drug associated with severe hepatotoxicity and skin rashes, which raises concerns about its chronic administration. There is increasing evidence that metabolic activation to reactive electrophiles capable of reacting with bionucleophiles is likely to be involved in the initiation of these toxic responses. Phase I NVP metabolism involves oxidation of the 4-methyl substituent and the formation of phenolic derivatives that are conceivably capable of undergoing further metabolic oxidation to electrophilic quinoid species prone to react with bionucleophiles. The covalent adducts thus formed might be at the genesis of toxic responses. As part of a program aimed at evaluating the possible contribution of quinoid derivatives of Phase I phenolic NVP metabolites to the toxic responses elicited by the parent drug, we have investigated the oxidation of 2-hydroxy-NVP with dipotassium nitroso-disulfonate (Frémy’s salt), mimicking the one-electron oxidation involved in enzyme-mediated metabolic oxidations. We report herein the isolation and full structural characterization of a 1H-pyrrole-2,5-dione derivative as a major product, stemming from an unusual pyridine ring contraction.
Submerged Fermentation of the Edible Mushroom Pleurotus ostreatus in a Batch Stirred Tank Bioreactor as a Promising Alternative for the Effective Production of Bioactive Metabolites
Authors: Papaspyridi Lefki-Maria , Aligiannis Nektarios , Topakas Evangelos , Christakopoulos Paul , Skaltsounis Alexandros-Leandros , Fokialakis Nikolas
Published: March 2012

The aim of this study was to investigate the potential of the submerged fermentation procedure in the production of bioactive metabolites of the common edible mushroom Pleurotus ostreatus. The biomass of the mushroom strain was produced by submerged fermentation in a batch stirred tank bioreactor and extracted by solvents of increasing polarity. The dichloromethane and methanol extract were fractioned by different techniques including Adsorption Chromatography and Fast Centrifugal Partition Chromatography (FCPC). The structures of pure compounds were elucidated with 1D/2D NMR-spectroscopic analyses, and chemical correlations combined with GC/MS and LC/MS experiments. Nineteen metabolites (e.g., fatty acids, phenolic metabolites, nucleotides and alkaloids) were isolated. Beyond the production of known metabolites, we report herein the production also of trans-3,4-dihydro-3,4,8-trihydroxynapthalen-1(2H)-one, indolo-3-carboxylic acid, 3-formylpyrrole and 4-hydroxybenzoic acid, that have pharmaceutical interest and are isolated for the first time from Pleurotus strains.This work indicates the great potential of the established bioprocess for the production of P. ostreatus mycelia with enhanced metabolic profile.
Phenolic Alkaloids from Menispermum dauricum Rhizome Protect against Brain Ischemia Injury via Regulation of GLT-1, EAAC1 and ROS Generation
Authors: Zhao Bo , Chen Yang , Sun Xi , Zhou Mei , Ding Jie , Zhan Jin-Jin , Guo Lian-Jun
Published: March 2012

Menispermum dauricum rhizome has been widely used in China to treat various cardiovascular and thrombosis disorders. Some studies have reported that the phenolic alkaloids of Menispermum dauricum rhizome (PAM) have protective effects against brain ischemia injury, but the mechanism of this action remains to be clarified. In the present study, we investigated the possible mechanisms of action of PAM on experimental brain ischemia injury. Oxygen and glucose deprivation (OGD) in rat primary cortical cultures and middle cerebral artery occlusion in rats were used to mimic ischemia-reperfusion injury, respectively. The results suggested that PAM protected rat primary cortical cultures against OGD-reoxygenation induced cytotoxicity. PAM decreased extracellular glutamate content and markedly prevented the effects induced by OGD on protein level of GLT-1 and EAAC1 glutamate transporters. In addition, it reduced intracellular ROS generation. In vivo, PAM significantly reduced cerebral infarct area and ameliorated neurological functional deficits at different time points. Our findings revealed that the possible mechanism of action of PAM protected against brain ischemia injury involves regulation of GLT-1, EAAC1 and ROS generation.
Separation and Identification of Highly Fluorescent Compounds Derived from trans-Resveratrol in the Leaves of Vitis vinifera Infected by Plasmopara viticola
Authors: Tříska Jan , Vrchotová Naděžda , Olejníčková Julie , Jílek Rudolf , Sotolář Radek
Published: March 2012

A method for identification of highly fluorescent compounds in vine leaves infected by Plasmopara viticola was developed using reversed phase liquid chromatography with simultaneous diode array and fluorometric detection. Fluorescent compounds were extracted from leaves with a methanol-water mixture (70:30). Separation by HPLC was performed using a C18 column and gradient elution with water-acetonitrile mixtures (20–80% of acetonitrile). The main unknown fluorescent compound was identified by line spectral comparison with a standard obtained by UV photoisomerization of trans-resveratrol glucoside, and its structure was confirmed by liquid chromatography-mass spectrometry. Identification and structural elucidation of the fluorescent compound in the leaves of Vitis vinifera allows early detection of Plasmopara viticola invasion.
Efficient Synthesis of β-Enaminones and β-Enaminoesters Catalyzed by Gold (I)/Silver (I) under Solvent-Free Conditions
Authors: Zhang Ming , Abdukader Ablimit , Fu Yong , Zhu Chengjian
Published: March 2012

An efficient method for the synthesis of β-enaminones and β-enaminoesters using a combination of [(PPh3)AuCl]/AgOTf as catalyst has been developed. The reaction between 1,3-dicarbonyl compounds and primary amines was carried out under solvent-free conditions with low catalyst loading in good to excellent yields at room temperature.
A New Method for Characterization of Natural Zeolites and Organic Nanostructure Using Atomic Force Microscopy
Authors: Fuoco Domenico
Published: March 2012

In order to study and develop an economical solution to environmental pollution in water, a wide variety of materials have been investigated. Natural zeolites emerge from that research as the best in class of this category. Zeolites are natural materials which are relatively abundant and non biodegradable, economical and serve to perform processes of environmental remediation. This paper contains a full description of a new method to characterize the superficial properties of natural zeolites of exotic provenience (Caribbean Islets) with atomic force microscopy (AFM). AFM works with the simplicity of the optical microscope and the high resolution typical of a transmission electron microscope (TEM). If the sample is conductive, structural information of mesoporous material is obtained using scanning and transmission electron microscopy (SEM and TEM), otherwise the sample has to be processed through the grafitation technique, but this procedure induces errors of topography. Therefore, the existing AFM method, to observe zeolite powders, is made in a liquid cell-head scanner. This work confirms that it is possible to use an ambient air-head scanner to obtain a new kind of microtopography. Once optimized, this new method will allow investigation of organic micelles, a very soft nanostructure of cetyltriammonium bromide (CTAB), upon an inorganic surface such as natural zeolites. The data also demonstrated some correlation between SEM microphotographies and AFM 3D images.
Enzyme Initiated Radical Polymerizations
Authors: Hollmann Frank , Arends Isabel W. C. E.
Published: March 2012

Biocatalysis is propagating into practically every area of organic chemistry, amongst them radical polymerizations. A review of the recent developments of this dynamic and quickly evolving area of research is presented together with a critical evaluation of its potential to yield novel polymers and/or environmentally more benign synthetic procedures.
The Influence of DEM Quality on Mapping Accuracy of Coniferous- and Deciduous-Dominated Forest Using TerraSAR‑X Images
Authors: Ortiz Sonia M. , Breidenbach Johannes , Knuth Ralf , Kändler Gerald
Published: March 2012

Climate change is a factor that largely contributes to the increase of forest areas affected by natural damages. Therefore, the development of methodologies for forest monitoring and rapid assessment of affected areas is required. Space-borne synthetic aperture radar (SAR) imagery with high resolution is now available for large-scale forest mapping and forest monitoring applications. However, a correct interpretation of SAR images requires an adequate preprocessing of the data consisting of orthorectification and radiometric calibration. The resolution and quality of the digital elevation model (DEM) used as reference is crucial for this purpose. Therefore, the primary aim of this study was to analyze the influence of the DEM quality used in the preprocessing of the SAR data on the mapping accuracy of forest types. In order to examine TerraSAR-X images to map forest dominated by deciduous and coniferous trees, High Resolution SpotLight images were acquired for two study sites in southern Germany. The SAR images were preprocessed with a Shuttle Radar Topography Mission (SRTM) DEM (resolution approximately 90 m), an airborne laser scanning (ALS) digital terrain model (DTM) (5 m resolution), and an ALS digital surface model (DSM) (5 m resolution). The orthorectification of the SAR images using high resolution ALS DEMs was found to be important for the reduction of errors in pixel location and to increase the classification accuracy of forest types. SAR images preprocessed with ALS DTMs resulted in the highest classification accuracies, with kappa coefficients of 0.49 and 0.41, respectively. SAR images preprocessed with ALS DTMs resulted in greater accuracy than those preprocessed with ALS DSMs in most cases. The classification accuracy of forest types using SAR images preprocessed with the SRTM DEM was fair, with kappa coefficients of 0.23 and 0.32, respectively.Analysis of the radar backscatter indicated that sample plots dominated by coniferous trees tended to have lower scattering coefficients than plots dominated by deciduous trees. Leaf-off images were only slightly better suited for the classification than leaf-on images. The combination of leaf-off and leaf-on improved the classification accuracy considerably since the backscatter changed between seasons, especially in deciduous-dominated forest.
Size Matters: Problems and Advantages Associated with Highly Miniaturized Sensors
Authors: Dahlin Andreas B.
Published: March 2012

There is no doubt that the recent advances in nanotechnology have made it possible to realize a great variety of new sensors with signal transduction mechanisms utilizing physical phenomena at the nanoscale. Some examples are conductivity measurements in nanowires, deflection of cantilevers and spectroscopy of plasmonic nanoparticles. The fact that these techniques are based on the special properties of nanostructural entities provides for extreme sensor miniaturization since a single structural unit often can be used as transducer. This review discusses the advantages and problems with such small sensors, with focus on biosensing applications and label-free real-time analysis of liquid samples. Many aspects of sensor design are considered, such as thermodynamic and diffusion aspects on binding kinetics as well as multiplexing and noise issues. Still, all issues discussed are generic in the sense that the conclusions apply to practically all types of surface sensitive techniques. As a counterweight to the current research trend, it is argued that in many real world applications, better performance is achieved if the active sensor is larger than that in typical nanosensors. Although there are certain specific sensing applications where nanoscale transducers are necessary, it is argued herein that this represents a relatively rare situation. Instead, it is suggested that sensing on the microscale often offers a good compromise between utilizing some possible advantages of miniaturization while avoiding the complications. This means that ensemble measurements on multiple nanoscale sensors are preferable instead of utilizing a single transducer entity.
Perch and Its Parasites as Heavy Metal Biomonitors in a Freshwater Environment: The Case Study of the Ružín Water Reservoir, Slovakia
Authors: Brázová Tímea , Torres Jordi , Eira Catarina , Hanzelová Vladimíra , Miklisová Dana , Šalamún Peter
Published: March 2012

Heavy metal concentrations were determined in 43 perches (Perca fluviatilis) and in two of its most common parasites, the acanthocephalan Acanthocephalus lucii and the cestode Proteocephalus percae, collected in the period 2009–2010 from Ružín, a seriously polluted water reservoir in Slovakia. Samples of muscle, liver, kidney, brain, male and female reproductive organs and adipose tissue of fish and both parasites were analyzed for As, Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn, by ICP-MS. Mean concentrations of individual heavy metals in all fish samples decreased in the order zinc > copper > manganese > mercury > arsenic > chromium > cadmium > nickel > lead. Zinc was found to be the dominant element and its antagonistic interaction with copper was confirmed. The kidney was a key target organ receiving the highest mean concentrations of all analyzed metals, but some metals showed specific affinity for particular tissues. In terms of human health, concentration of Hg in fish muscle, which exceeded more than two-times its maximum level admitted in foodstuffs in European countries, is of great importance and should be taken into account. Bioaccumulation factors (C[parasite]/C[fish tissue]) calculated for all elements indicated much higher detection skills of A. lucii and P. percae parasites than fish organs and hence, present results allow proposing both parasite models as useful tools to monitor aquatic environmental quality. Acanthocephalans, however, seem to be superior for heavy metal monitoring, also demonstrated under experimental conditions. Present results also indicate the decreasing heavy metal burden of the reservoir and its gradual recovery in the course of time.
Stereotyping Stigma: Undergraduate Health Students’ Perceptions at Handover
Authors: Doyle Kerrie Esme , Cruickshank Mary
Published: March 2012

The World Health Organization (WHO) has recognized that errors in communication are one of the leading causes of adverse patient outcomes. Consequently, the WHO developed the
High 5s Project
to review, among other variables, handover of patients between shifts, professionals, and organizations. Seven countries were involved in the initial project. Australia responded by using the ISOBAR (
I
dentify,
S
ituation,
O
bservations,
B
ackground,
A
greed plan, and
R
ead-back) tool as a template. However, none of the countries involved considered the social and emotional effects of handover on the staff or patients, although research has demonstrated that attitudes and values can be handed over from one nurse to another during this process. This article shows how the nurse who hands over care from one shift to the next can transfer stigma and labeling and offers suggestions for nurse educators and clinicians to apply national standards and core values to clinical practice and education.
Incompatible building materials within the stereotomic Avalos sculptures of the Valley of Fallen (Madrid, Spain)
Authors: García-Guinea J. , Almendros G. , Benavente D. , Correcher V. , Pérez-García A. , Recio-Vázquez L. , Sánchez-Moral S.
Published: March 2012

The examination of the recently open pit in top of head of the La Piety sculpture of Avalos confirms that the external outer of Black Limestone Calatorao (BLC) composite is made by slabs 20 cm thick joined with gypsum mortars without aggregates. The analyses of these mortars samples performed by optical microscopy (OM), X-ray diffraction (XRD) and Environmental Scanning Electron Microscopy with Energies Dispersive Spectrometry (ESEM-EDS) techniques show hydrous admixtures composed by portlandite, mirabilite, ettringite, thaumasite and gypsum, all of them are well-know dangerous phases for a suitable preservation of the architectural heritage. The huge stereotomic structures have open access to the raining waters reaching the internal core of the sculptures made by concrete with weathered alkali-feldspar aggregates providing sodium to the surrounding sulfated environment facilitating the formation of hydrous calcium and sodium sulfates such as ettringite and mirabilite which reduces the inter-grains adherence.
Algunas historias de los trabajadores. Las experiencias temporales y las identidades narrativas de los trabajadores
Authors: Castro Pericacho Carlos de
Published: March 2012

Las identidades de los trabajadores están vinculadas a la experiencia del tiempo, y su experiencia temporal ha sufrido importantes alteraciones debido a las transformaciones del mundo del trabajo de las últimas décadas. Este artículo defiende la hipótesis de que cada modelo de organización de los tiempos de trabajo da lugar a identidades narrativas distintas. Además este artículo se basa en la idea de que los trabajadores construyen sus identidades por medio de la configuración de una narración a través de la cual se combinan sus experiencias del tiempo interno y del tiempo externo. Para ello se propone analizar las identidades narrativas de tres grupos de trabajadores procedentes de diversos contextos laborales en los que los tiempos de trabajo se organizan de modo distinto.
Abrasive Waterjets—A Nontraditional Process for the Safe and Environmentally Friendly Demilitarization of Underwater High-Explosive Munitions
Authors: Miller Paul L.
Published: March 2012

AbstractHigh-pressure abrasive waterjets provide a nontraditional tool for the safe and environmentally friendly demilitarization of high-explosive munitions, whether the munition is on land or underwater. High-pressure waterjets have cut and demilitarized over two million
high-explosive items without incident, making it one of the safest and most environmentally friendly technologies for demilitarizing and recycling explosive munitions. This paper reviews the evolution of waterjet technology and discusses its applicability to underwater munitions.
Dispersion of Passive Tracers in the Baltic Sea Deep Water as Applied to Dumped Chemical Weapons
Authors: Zhurbas Victor , Paka Vadim
Published: March 2012

AbstractResults of modeling of the migration of chemical warfare agents (CWAs) and their decay products from the initial chemical weapons dump site are presented. The aim was to find idealized sediment redistribution schemes in deep basins of the Baltic Sea corresponding
to different wind conditions and to model the concentration of dissolved CWA in a continuous release scenario in the Bornholm dump site corresponding to real wind statistics.
Changes in Properties of Explosives Due to Prolonged Seawater Exposure
Authors: Pfeiffer Fritz
Published: March 2012

AbstractThe present paper gives a survey of problems encountered with changes in properties of energetic materials in sea-dumped military munitions.
Chemical Munitions Search and Assessment Project—Towards Creating Risk Assessment Tools for the Baltic Sea
Authors: Beldowski Jacek , Long Terrance P.
Published: March 2012

AbstractVast quantities of German chemical warfare agents (CWA) were stored in Wolgast, on the Baltic shore, at the end of World War II. Those munitions, together with others collected by allies after the war, were disposed in the Baltic Sea. Altogether, an estimated 50,000
tonnes of chemical weapons were sunk in the Baltic Sea. Official dumpsites are located in the Bornholm Deep, Gotland Deep, Little Belt, and Skagerrak. According to previous studies, several unofficial dumping sites exist on the transport routes from Wolgast to dumping areas and in the Gdańsk
Deep (cold war dump).In the years 2005‐2008, the interdisciplinary “Modeling of Environmental Risks related to sea-dumped Chemical Weapons” (MERCW) project performed mapping, (ca. 20% of dumping areas) and addressed some possible ecological risks in official dumpsites
in the Bornholm Deep, Gotland Deep, and Skagerrak. The Chemical Munitions Search and Assessment (CHEMSEA) project aims to fill the gaps in MERCW research (mapping using new techniques, sediment contamination study, corrosion estimation), observing temporal trends in the ecosystem (compare
present CWA and degradation products to that observed in MERCW), and extend this research to the largest unofficial dumpsite (Gdańsk Deep). Moreover, CHEMSEA will provide a number of guidelines for affected groups and stakeholders regarding operations in bottom areas contaminated with
CWA and assess the probability, range, and ecological consequences of CWA release from dumped munitions in the Baltic Sea. The results of the project will be shared with the Helsinki Commission and the project’s partners and associated partners. The CHEMSEA is planned for years 2011‐2014.
Munitions-Related Technology Demonstrations at Ordnance Reef (HI-06), Hawaii
Authors: Carton Geoffrey , King J. C. , Bowers R. Josh
Published: March 2012

AbstractDevelopment of methods and technologies to characterize sites with underwater military munitions (UWMM) and respond to UWMM where the risks posed to human health or the environment or explosive hazards are unacceptable is underway. Department of Defense Military Munitions
Sea Disposal Site Hawaii (HI-06), referred to locally as Ordnance Reef, is off Oahu’s leeward coast. This site has become the focal point for research on UWMM. Past studies found that the site presents no immediate danger to public safety. The location and water depth at this site present
advantages for UWMM research and development.Promising technologies demonstrated at Ordnance Reef (HI-06) include those for munitions recovery, at-sea demilitarization, nondestructive testing, and explosives detection. Studies on fate and transport of munitions-related compounds and corrosion
are ongoing.Among these technologies are the Remotely Operated Underwater Munitions Recovery System (ROUMRS) and the Explosive Hazard Demilitarization System (EHDS). Both are assemblages of commercial off-the-shelf components, and each is housed in a standard 6-m International Organization
for Standardization (ISO) shipping container and can be operated on a barge.ROUMRS consists of a remotely operated vehicle, manipulators, an interface between a precision GPS, and underwater navigation equipment used during recovery of UWMM. The system also transports recovered UWMM for
treatment. The EHDS consists of a portable X-ray unit to allow positive identification of recovered munitions, remotely operated wet band saws to cut recovered munitions to expose their explosive fill, and low-temperature ovens to treat the exposed explosives, making the remaining material
safe for recycling.
The Nearctic species ofTelmaturgus(Diptera: Dolichopodidae)
Authors: Runyon Justin B.
Published: March 2012

The sympycnine genusTelmaturgusMik is reviewed for the Nearctic region, and includes three species:Telmaturgus parvus(Van Duzee),Telmaturgus robinsonisp. nov., andTelmaturgus vockerothisp. nov.Species ofTelmaturguscan be recognized by the reduced number of dorsocentral setae (three pairs in Nearctic species) and the projecting lower face of females. Examination of the holotype ofT. parvusreveals that the widespread species previously thought to beT. parvusisT. robinsoni. A key to species and comments on the taxonomic history and ecology of the genus are provided.
Physical activity and brain plasticity in late adulthood: a conceptual and comprehensive review
Authors: Erickson Kirk I. , Miller Destiny L. , Weinstein Andrea M. , Akl Stephanie L. , Banducci Sarah
Published: March 2012

A growing body of evidence from neuroscience, epidemiology, and kinesiology suggests that physical activity is effective as both a prevention and treatment for cognitive problems throughout the lifespan. Given the expected increase in the proportion of older adults in most countries over the next 40 years, physical activity could be a low-cost and relatively accessible method for maintaining cognitive function throughout later life. Despite the emerging recognition of physical activity as a powerful method to enhance brain health, there is continued confusion from both the public and scientific communities about what the extant research has discovered about the potential for physical activity to improve neurocognitive health and which questions remain unanswered. In this review, we outline four overarching themes that provide a conceptual structure for understanding the questions that have been asked and have been addressed, as well as those that have yet to be answered. These themes are descriptive, mechanistic, applied, and moderating questions. We conclude from our review that descriptive questions have been the first and most thoroughly studied, but we have much yet to learn about the underlying mechanisms, application, and moderating factors that explain how and to what extent physical activity improves brain health.
Small-Volume Hypertonic Saline/Pentastarch Improves Ileal Mucosal Microcirculation in Experimental Peritonitis
Authors: Assadi Abdelnasser , Desebbe Olivier , Rimmelé Thomas , Florence Arnal , Goudable Joëlle , Chassard Dominique , Allaouchiche Bernard
Published: March 2012

We compared the effects of hypertonic saline 7.2%/6% hydroxyethyl starch (HSS-HES) and isotonic saline 0.9%/6% hydroxyethyl starch (ISS-HES) on ileal microcirculatory blood flow (MBF) at the initial phase of septic shock. Pigs were anesthetized and mechanically ventilated. Catheters were inserted into right atrium, pulmonary artery, carotid artery, and portal vein for hemodynamic measurements and for blood sampling. Ileal mucosal and muscularis MBF was continuously measured by laser Doppler flowmetry (LDF). Septic shock was obtained 240 min after induction of fecal peritonitis; then animals were randomized to receive 10 mL.kg-1 during 10 min of either HSS-HES or ISS-HES. Systemic and microcirculatory blood flow as well as systemic metabolism were assessed. Fecal peritonitis promoted a hypodynamic septic shock, with significant reduction of mean arterial pressure (MAP) and cardiac index (CI). Ileal mucosal MBF (-34%) and ileal muscularis MBF (-54%) significantly diminished from baseline. Contrary to ISS-HES group, mucosal MBF significantly augmented after HSS-HES (+192% at min 150 post-shock) despite low blood pressure. There was weak correlation with CI (r²= 0.2, P = 0.01) . Muscularis MBF didn’t change. HSS-HES-treated animals had a significantly higher osmolarity and sodium concentration than ISS-HES group. Other variables did not change. Small-volume resuscitation with HSS-HES, but not ISS-HES, improved ileal microcirculatory impairment in experimental peritonitis model of septic shock even when MAP was low. This beneficial microcirculatory effect could be valuable in the management of early severe sepsis.
Can advance of first lambing induced by melatonin implants influence the next lambing time in Sarda breed sheep?
Authors: Carcangiu Vincenzo , Mura Maria Consuelo , Bini Pier Paolo , Vacca Giuseppe Massimo , Daga Cinzia , Luridiana Sebastiano
Published: March 2012

Carcangiu, V., Mura, M. C., Bini, P. P., Vacca, G. M., Daga, C. and Luridiana, S. 2012. Can advance of first lambing induced by melatonin implants influence the next lambing time in Sarda breed sheep? Can. J. Anim. Sci. 92: 67–71. In adult sheep, exogenously administered melatonin from continuous slow-release implants has been shown to advance the onset of the breeding season by mimicking the stimulatory effect of short days. The aim of this study was to verify if treatment with one or two melatonin implants was effective in advancing the first conception in Sarda ewe lambs, and if this advance would also be seen in the second lambing too. In the first year, 600 ewe lambs were randomly assigned to groups M, M+M and C, each with 200 animals. On Jun. 30, group M received a single implant while group M+M received two implants. Group C was untreated. On Aug. 04, 25 rams were introduced in the groups and removed after 70 d. From these 600 animals the 420 head that lambed prior to Mar. 12 were chosen for the second year. These ewes were subdivided into two groups T1 (ewes who lambed between 2007 Jan. 01 and Feb. 10) and T2 (ewes which lambed between 2007 Feb. 11 and Mar. 12). Both in T1 and T2 the distribution of the animals in M, M+M and C group was maintained. In the first year, the treated animals lambed earlier (P<0.05) and showed higher numbers of lambed ewes at Feb. 10 (P<0.01) and at March 12 (P<0.05) compared with untreated control animals. The animals that showed an advance in the period of their first conception, also showed, in the second breeding year, an advance in the lambing time (P<0.001). This study provides evidence that the advance of first conception, obtained with melatonin treatment also influenced the reproductive activity in the following breeding season.
Animal-related factors associated with piglet mortality in a bedded, group-farrowing system
Authors: Li Y. Z. , Anderson J. E. , Johnston L. J.
Published: March 2012

Li, Y. Z., Anderson, J. E. and Johnston, L. J. 2012. Animal-related factors associated with piglet mortality in a bedded, group-farrowing system. Can. J. Anim. Sci. 92: 11–20. To understand pre-weaning mortality of piglets in a bedded, group-farrowing system, associations with sow parity, mortality of piglets during the first 24 h after birth, farrowing behavior, cross-fostering, birth weight and gender of piglets were investigated. Sows (n=169, parity 1 to 10) from eight contemporary groups were evaluated. Litter size at birth, dead piglets from birth to weaning, and individual weight of piglets at birth and weaning (27±2.6 d) were recorded. Behavior of 46 focal sows during farrowing was video-recorded. Piglet mortality within litter increased (P<0.001) with increasing parity. Piglets that died before weaning were lighter (P<0.001) at birth than weaned piglets. Mortality of pigs during the first 24 h postpartum was correlated positively with pre-weaning mortality within litter (R2=0.34; P<0.001). Farrowing behaviors were not associated with piglet mortality, and were not different among sows of different parities, or between sows with and without 24 h piglet mortality. Gender of piglets and cross-fostering did not affect piglet mortality. Results indicate that parity, 24 h mortality, and birth weight of piglets were the major animal-related factors associated with piglet mortality in the loose farrowing system studied.
Bioperformance evaluation of various summer pasture and winter feeding strategies for cow-calf production
Authors: Legesse Getahun , Small Julie A. , Scott Shannon L. , Kebreab Ermias , Crow Gary H. , Block Hushton C. , Robins Clayton D. , Khakbazan Mohammad , Mccaughey W. Paul
Published: March 2012

Legesse, G., Small, J. A., Scott, S. L., Kebreab, E., Crow, G. H., Block, H. C., Robins, C. D., Khakbazan, M. and McCaughey, W. P. 2012. Bioperformance evaluation of various summer pasture and winter feeding strategies for cow-calf production. Can. J. Anim. Sci. 92: 89–102. Bioperformance of two summer pasture and four winter feeding cow-calf production strategies in the western Canadian Parkland was evaluated. Diet composition and animal data were collected over 5 production years. Each production year began with fixed-time artificial insemination (TAI) of cows and turnout of cow-calf pairs (n=288 yr−1 including 76 primiparous replacement cows) assigned to either alfalfa-grass (AG, n=9 paddocks) or grass (G, n=9 paddocks) pastures until weaning. Post-weaning, pregnant cows (n=240 yr−1) were assigned to either extended-grazing (EG, n=120) of dormant regrowth of perennial pastures and swathed annual crops, or one of three diets fed in a drylot (DL): hay (HY, n=40), straw/barley (SB, n=40; 70% oat straw:30% steam-rolled barley grain DM), and silage/straw (SS, n=40; 40% barley silage:60% oat straw DM). Common diets were used for all treatment groups between the weaning and winter feeding period, as well as between the pre-calving and summer grazing period. Cow and calf body weight (BW) gains were higher (P<0.05) for AG than G pasture until the third production year and the advantage diminished as the carrying capacity declined. The latter may be attributed to a lack of spring/summer moisture. Further, G pastures required more nitrogen fertilizer to achieve the same level of bioperformance as that of AG pastures in years 4 and 5. Cows in the EG treatment maintained BW better than those in the DL treatment (especially those cows receiving the SS diet) except in year 5 (P<0.05) in which drought resulted in lower body weights for cows in the EG treatment. On all treatments, cows maintained BCS that supported reproductive function; however, fertility to TAI was lowest (P<0.05) in years 4 and 5. Cows in the DL group had a 1.8 times greater risk of being culled before turnout and as a result lower (P<0.05) rates of calf survival to weaning. In conclusion, AG pastures and EG are important alternatives to further develop for cow-calf production in western Canada.
Chloride leaching in two Ontario soils: Measurement and prediction using HYDRUS-1D
Authors: Saso J. K. , Parkin G. W. , Drury C. F. , Lauzon J. D. , Reynolds W. D.
Published: March 2012

Saso, J. K., Parkin, G. W., Drury, C. F., Lauzon, J. D. and Reynolds, W. D. 2012. Chloride leaching in two Ontario soils: Measurement and prediction using HYDRUS-1D. Can. J. Soil Sci. 92: 285–296. Deterministic numerical modelling can often be used to complement and extend field results, and to provide extra insight into the mechanisms of water and solute movement within the profile of agricultural soils. Chloride leaching and near-surface soil water content in a Guelph loam and a Maryhill loam cropped to corn (Zea mays L.) were measured over a 12-mo period (October 2007 to September 2008) and simulated using the HYDRUS-1D numerical model (version 4.12). Field measurements and prediction indicated that over 70% of the applied chloride (Cl) was lost to deep drainage (below 80 cm depth) during the winter months (November 2007 to April 2008) in both soils. Normalized root mean square error (NRMSE) values for HYDRUS-1D estimates of near-surface (0- to 30-cm depth interval) soil water content over the growing season (April to September, 2008) were 28% for Guelph loam and 42% for Maryhill loam. The NRMSE value for estimated versus measured Cl mass remaining in the soil profile (0–80 cm depth interval) over the winter months was 17% for both soils. It was concluded that the HYDRUS-1D model can provide reasonable predictions of near-surface soil water content and profile leaching losses of tracer solutes. Further work is required, however, to determine if the predictive ability of HYDRUS-1D might be improved by incorporating the effects of freeze-thaw cycles on soil hydraulic properties and solute leaching. Further study is also required to establish the model's ability to simulate the leaching behaviour of reactive solutes, such as nitrate, in agricultural soils.
Fractal characteristics of synthetic soil for cut slope revegetation in the Purple soil area of China
Authors: Ai Yingwei , Chen Zhaoqiong , Guo Peijun , Zeng Lixia , Liu Hao , Da Zhujun , Li Wei
Published: March 2012

Ai, Y., Chen, Z., Guo, P., Zeng, L., Liu, H., Da, Z. and Li, W. 2012. Fractal characteristics of synthetic soil for cut slope revegetation in the Purple soil area of China. Can. J. Soil Sci. 92: 277–284. Revegetation of the cut slopes formed during railroad construction can reduce potential hazards, improve the quality of the environment, and beautify the landscape along the railways. Artificial backfill soil is required to anchor the plant roots and satisfy the plant's moisture and nutritional demands on the bare rock face. The soil particle size distribution (PSD), fertility and stability of the reconstructed topsoils are affected by the soil type used as a backfill. In this study, a fractal method was used to characterize the PSD. The relationships between the fractal dimension of the PSD and selected soil properties, including soil moisture, bulk density, and organic carbon are discussed. Various soil samples were obtained from four different land-use environments in the purple soil area in southwest, China: a cut slope reconstructed from rock fragments (RF), a cut slope reconstructed with agricultural soil (AS), a naturally developed slope (NS), and a cropland used for growing Vicia faba (CL). Analysis of the soil samples revealed that: (1) from CL to RF, the sand content increased from 59.6 to 83.9%; (2) the fractal dimension of PSD ranged from 2.605 for RF to 2.725 for CL, being the greater the sand content and the lower the fractal dimension; (3) there existed marked linear relationships between the fractal dimensions and selected physicochemical properties of the soils. Therefore, the fractal dimension of PSD can be a useful parameter with which to monitor the structural deterioration and nutrient loss of the synthetic soils used for the revegetation of a cut slope.
Biochar enhances seedling growth and alters root symbioses and properties of sub-boreal forest soils
Authors: Robertson Susan J. , Rutherford P. Michael , López-Gutiérrez Juan C. , Massicotte Hugues B.
Published: March 2012

Robertson, S. J., Rutherford, P. M., López-Gutiérrez, J. C. and Massicotte, H. B. 2012. Biochar enhances seedling growth and alters root symbioses and properties of sub-boreal forest soils. Can. J. Soil Sci. 92: 329–340. Biochar application may enhance soil properties, improve plant productivity, and increase long-term carbon storage, but impacts of biochar on plant-microbe symbioses mediating plant nutrient uptake in temperate or boreal soils are not well known. We planted lodgepole pine (Pinus contorta var. latifolia) or sitka alder (Alnus viridis ssp. sinuata) seeds in pots containing field-collected forest soils (from central British Columbia) amended with 0, 5, or 10% (dry mass basis) biochar with and without urea fertilizer (150 mg N kg−1). Pine seedlings were harvested at 4 mo and roots were assessed for abundance and diversity of ectomycorrhizal (ECM) morphotypes using light microscopy and DNA sequencing. Biochar raised soil pH, exchangeable cations and cation exchange capacity in some treatments in both soils. Pine had greater biomass in biochar+fertilizer treatments compared to control and fertilizer-only treatments; this corresponded in part to an increase in abundance of some ECMs. Alder seedlings were harvested at 2, 3 and 4 mo to measure N fixation in root nodules using acetylene reductase assay (ARA). Alder seedlings had greater shoot biomass when grown in biochar-amended soils compared with unamended control. Although mean ARA rates (at 4 mo) were greater in biochar-amended soils compared with controls, the data showed great variation and differences were not statistically significant (P>0.05). This study showed that biochar addition can enhance soil properties and the early growth of pine and alder in some sub-boreal forest soils; small changes in ECM abundances may be expected.
Urea fertilizer forms affect grain corn yield and nitrogen use efficiency
Authors: Gagnon Bernard , Ziadi Noura , Grant Cynthia
Published: March 2012

Gagnon, B., Ziadi, N. and Grant, C. 2012. Urea fertilizer forms affect grain corn yield and nitrogen use efficiency. Can. J. Soil Sci. 92: 341–351. Controlled-release urea may be a good management strategy to increase the efficiency of N fertilizers. In a 3-yr study (2008–2010) conducted on a clay soil near Quebec City, Canada, we compared the effect of polymer-coated urea (PCU), nitrification inhibitor urea (NIU), dry urea and urea ammonium nitrate 32% (UAN) on corn yield, plant N accumulation and soil NO3-N remaining at harvest. Corn was fertilized with urea and PCU at 50, 100 and 150 kg N ha−1 in addition to an unfertilized control (0 N), and NIU and UAN at 150 kg N ha−1. Urea, PCU, and NIU were pre-plant broadcast whereas UAN was side-banded at the six-leaf stage of corn. Response to N fertilization occurred in all years, but the magnitude of the response varied with years. In wet years (2008 and 2009), PCU and NIU resulted in higher grain yield than urea, but the increase was greater for PCU (+0.8 to 1.6 Mg ha−1) than for NIU (+0.3 to 0.6 Mg ha−1). In a dry year (2010), no significant difference was found between urea, PCU and NIU. Yields and apparent N recovery were comparable for PCU and UAN except in the dry year, when plant N accumulation was much higher for the UAN treatment. At harvest, soil NO3-N was increased by PCU in all years. Economic analysis revealed that despite 30% higher cost, PCU gave comparable net returns at equivalent N rate than UAN in wet years. We conclude that controlled-release urea, particularly PCU, would be an additional option to farmers instead of sidedressed UAN application for fertilizing corn grown in eastern Canada.
Tendencias de las relaciones sociales e interpersonales de los nativos digitales y jóvenes en la web 2.0
Authors: Núñez-Gómez Patricia , García Guardia Maria Luisa , Hermida Ayala Lourdes Ainhoa
Published: March 2012

El desarrollo evolutivo de la Red hacia una Red Universal Digital conlleva una modificación de las conductas, usos y competencias de los internautas. Han surgido nuevas formas de acceso, gestión y diseño de la información, las cuales están generando conductas distintas a la hora de gestionar dicha información y en el seno de las relaciones sociales. Son los llamados “nativos digitales” los que hacen una mayor utilización de este tipo de recursos y servicios nuevos. El objeto de la investigación presente es la evaluación y análisis de las conductas y competencias sociocomunicativas que los “nativos digitales” y jóvenes desarrollan en la Red. Esta fase del proyecto es meramente cualitativa por lo que siempre se habla de tendencias. Los resultados muestran una clara diferencia entre dos grupos: los “nativos digitales” (jóvenes de 14 a 17 años), y los “inmigrantes digitales” (jóvenes de 18 a 35 años) respecto a su comportamiento en la red.
Record-breaking ozone loss in the Arctic winter 2010/2011: comparison with 1996/1997
Authors: Kuttippurath J. , Godin-Beekmann S. , Lefèvre F. , Nikulin G. , Santee M. L. , Froidevaux L.
Published: March 2012

Abstract. We present a detailed discussion of the chemical and dynamical processes in the Arctic winters 1996/1997 and 2010/2011 with high resolution chemical transport model (CTM) simulations and space-based observations. In the Arctic winter 2010/2011, the lower stratospheric minimum temperatures were below 195 K for a record period, from December to mid-April, and a strong and stable vortex was present during that period. Analyses with the Mimosa-Chim CTM simulations show that the chemical ozone loss started by early January and progressed slowly to 1 ppmv (parts per million by volume) by late February. The loss intensified by early March and reached a record maximum of ~2.4 ppmv in the late March–early April period over a broad altitude range of 450–550 K. This coincides with elevated ozone loss rates of 2–4 ppbv sh−1 (parts per billion by volume/sunlit hour) and a contribution of about 40% from the ClO–ClO cycle and about 35–40% from the ClO-BrO cycle in late February and March, and about 30–50% from the HOx cycle in April. We also estimate a loss of around 0.7–1.2 ppmv contributed (75%) by the NOx cycle at 550–700 K. The ozone loss estimated in the partial column range of 350–550 K also exhibits a record value of ~148 DU (Dobson Unit). This is the largest ozone loss ever estimated in the Arctic and is consistent with the remarkable chlorine activation and strong denitrification (40–50%) during the winter, as the modeled ClO shows ~1.8 ppbv in early January and ~1 ppbv in March at 450–550 K. These model results are in excellent agreement with those found from the Aura Microwave Limb Sounder observations. Our analyses also show that the ozone loss in 2010/2011 is close to that found in some Antarctic winters, for the first time in the observed history. Though the winter 1996/1997 was also very cold in March–April, the temperatures were higher in December–February, and, therefore, chlorine activation was moderate and ozone loss was average with about 1.2 ppmv at 475–550 K or 42 DU at 350–550 K, as diagnosed from the model simulations and measurements.
Response of Nodularia spumigena to pCO2 – Part I: Growth, production and nitrogen cycling
Authors: Wannicke N. , Endres S. , Engel A. , Grossart H.-P. , Nausch M. , Unger J. , Voss M.
Published: March 2012

Abstract. Heterocystous cyanobacteria of the genus Nodularia form extensive blooms in the Baltic Sea contributing substantially to the total annual primary production. Moreover, they dispense a large fraction of new nitrogen to the ecosystem, when inorganic nitrogen concentration in summer is low. Thus, it is of great ecological importance to know how Nodularia will react to future environmental changes, in particular to increasing carbon dioxide (CO2) concentrations and what consequences there might arise for cycling of organic matter in the ocean. Here, we determined carbon (C) and dinitrogen (N2) fixation rates, growth, elemental stoichiometry of particulate organic matter and nitrogen turnover during batch growth of the heterocystous cyanobacterium Nodularia spumigena under glacial (180 ppm), present (380 ppm), and future (780 ppm) CO2 concentrations. Our results demonstrate an overall stimulating effect of rising pCO2 on C and N2 fixation, as well as on cell growth. An increase in pCO2 resulted in an elevation in growth rate, C and N2 fixation by 23%, 36% and 25%, respectively (180 ppm vs. 380 ppm) and by 27%, 2% and 4%, respectively (380 ppm vs. 780 ppm). Additionally, elevation in the carbon and nitrogen to phosphorus quota of the particulate biomass formed (POC:POP and PON:POP) was observed at high pCO2. Our findings suggest that rising pCO2 stimulates the growth of heterocystous diazotrophic cyanobacteria, in a similar way as reported for non-heterocystous diazotrophs. Implications for biogeochemical cycling and food web dynamics, as well as ecological and socio-economical aspects in the Baltic Sea are discussed.