bluuebunny/crossref_metadata_2025 huggingface dataset:
Location Routing Approach for the Humanitarian Prepositioning Problem
Authors: Ukkusuri Satish V. , Yushimito Wilfredo F.
Published: January 2009

Events such as Hurricanes Katrina and Rita in 2005 have highlighted the need to understand network disruptions, in particular in the humanitarian supply chain. Humanitarian supply logistics cannot be improvised at the time of the emergency since little can be done after a disruption occurs. Therefore, special attention should be given to preparedness efforts and the design of the supply chain network. Inventory prepositioning is one of the strategies in the preparedness stage that enhances postdisaster response because it reduces the lead time needed to reach the affected destinations once a disaster has occurred. In this paper, the prepositioning of supplies for disasters is modeled as a facility location problem that accounts for the routing of vehicles and possible disruptions in the transportation network. The approach uses a combination of the most reliable path and an integer programming model to find the optimal location of supplies. The problem is solved on an example transportation network. The problem exploits a variant of the shortest-path problem and can be solved efficiently even for medium and large-scale transportation networks.
Maximal Dynamic Expected Flows Problem for Emergency Evacuation Planning
Authors: Miller-Hooks Elise , Sorrel Gabriel
Published: January 2009

In this paper, the maximal dynamic expected flows (MDEF) problem, which seeks the paths and associated flows that maximize the expected number of evacuees who successfully egress within a given time bound T, is defined. The MDEF problem is considered in a network, where arc traversal times and capacities are discrete random variables with time-varying distribution functions and capacities are assumed to be recaptured over time (i.e., the network is dynamic). A metaheuristic based on the principles of noisy genetic algorithms is proposed for its solution. Details of a novel approach (using an approximate likelihood measure) for overcoming the difficulties associated with computing state probabilities that require extremely small floating-point arithmetic are provided. Results from numerical experiments run on randomly generated networks with as many as 500 nodes are given. The results indicate that the proposed solution technique and approximate likelihood measure perform well. Solution of the proposed problem formulation results in robust evacuation paths that are likely to save the largest number of people before conditions become untenable.
Dynamic Shortest-Path Algorithm for Continuous Arc Travel Times
Authors: Hu Jian , Chan Yupo
Published: January 2009

To achieve the desired computational speed, existing algorithms for time-dependent (or dynamic) shortest-path problems call for the unrealistic aggregation of travel time as multiples of a given time increment. While the time increment can be varied between, say, peak and off-peak periods, it still has its obvious limitation on granularity. An improved solution algorithm is proposed for the all-to-one or one-to-all time-dependent versions of the problem. The algorithms are solidly founded on Bellman's principle of optimality and apply to continuous or real-value arc travel times (rather than the current practice of discrete-time specifications). The new algorithms are practical in computational speed, and they capture a more realistic metric for route choice. In this case, a relatively coarse time increment can be used throughout the analysis, yet it is compatible with any continuous or real-value arc travel times. To support these claims, computational results that consider various network sizes, densities, and numbers of time increments are provided. For future extensions, a non-first-in-first-out fastest-path and minimum-cost-path algorithm is proposed. A generalized cost (or disutility arc function) is defined to combine the two, on the basis of which route choices are made. For route-choice decisions, it is stipulated that adoption of such a disutility specification mandates a continuous valuation of arc time and cost. Instead of an all-to-one implementation, a one-to-all implementation is suggested under these circumstances. The latter approach, when complemented by the speed of algorithmic execution, facilitates real-world applications. It allows the driver to value incident delay and risks in route choice on a real-time basis.
Efficient Implementation of Improvement Procedures for Vehicle Routing with Time-Dependent Travel Times
Authors: Tang Hao
Published: January 2009

In this paper, efficient implementations of the classical improvement procedures for vehicle routing with time-dependent travel times are introduced. Specifically, the updating of tour-related variables (e.g., arrival and latest departure times) is incorporated in these implementations so that the computational complexity of solution approaches that use the improvement procedures can be significantly reduced. These implementation methods are applicable to several vehicle-routing improvement heuristics, including Or-opt, two-opt, one-shift, and CROSS exchanges. Numerical experiments were conducted to assess the effectiveness of the proposed implementations. Experimental results indicate that the computational complexity of the proposed efficient implementations for both single- and multitour improvement procedures is significantly reduced in comparison with the conventional implementations. The proposed efficient implementation schemes are especially useful for vehicle-routing applications in intelligent transportation systems in which the first-in-first-out property for link travel times is satisfied.
Combination of Multiple Ant Colony System and Simulated Annealing for the Multidepot Vehicle-Routing Problem with Time Windows
Authors: Ting Ching-Jung , Chen Chia-Ho
Published: January 2009

The vehicle-routing problem (VRP) is an important management problem in the field of physical distribution and logistics. In practice, the logistics system usually includes more than one depot, and the start of the service at each customer must be within a given time window. Hence, the multidepot vehicle-routing problem with time windows (MDVRPTW) is an important variant of the VRP. The MDVRPTW is a difficult combinatorial optimization problem due to the many complex constraints involved. The research presented in this paper proposes a multiple ant colony system (MACS) to solve the problem. In addition, two hybrid algorithms, which combine the strengths of MACS and simulated annealing, are developed to improve solution quality. The performance of the proposed algorithms is tested on several benchmark instances and compared with that of other algorithms in the literature. The results indicate that the proposed algorithms are effective in solving the MDVRPTW, and six new best solutions are found.
Outbreaks of Infectious Bursal Disease in Vaccinated and Unvaccinated Commercial Cockerel Farms in Bangladesh
Authors: Islam MT , Samad MA
Published: January 2009

Infectious bursal disease (IBD) is a contagious viral disease has been reported in young broiler and layer chickens from Bangladesh. This communication report the outbreaks of IBD on two vaccinated (Gumboro D78Â®, Intervet) and one unvaccinated commercial cockerel farms which were diagnosed on clinico-pathological findings and assessment of ELISA antibody titre. The outbreaks of IBD occurred on two vaccinated farms in cockerels of 29 to 31 days (Farm 1) and 30 to 33 days (Farm 2), whereas 19 to 22 days old in unvaccinated (Farm 3) birds. It caused 39.38% (Farm 1) and 75.0% (Farm 2) mortality in vaccinated and 29.20% (Farm 3) in unvaccinated cockerel farms. Clinical investigation showed rapid onset, dullness, depression, anorexia, whitish loose diarrhoea, soiling and pasting of the vent, ruffled feathers, trembling and finally prostration and death due to dehydration. Necropsy examination revealed dehydrated carcasses, enlargement and oedematous swelling of bursa Fabricius and some cases yellowish, haemorrhagic, yellowish and caseous exudate in the bursa. Skeletal muscles especially thigh muscles showed haemorrhages in some birds. The IBD ELISA antibody titre of both the vaccinated and the unvaccinated moribund cockerels showed at vulnerable state and the mean antibody titre of vaccinated farm 1 had 161 Â± 59.22 and vaccinated farm 2 had 57.82 Â± 14.85, whereas unvaccinated farms had 194 Â± 90.35. The occurrence of IBD outbreaks in both the vaccinated and unvaccinated birds indicate not only vaccination failure but also defective control strategies, which resulted heavy economic loss (85.05%) in the three cockerel farms. Therefore, a sound control strategy requires monitoring of maternal derived antibody with correct vaccination policy as well as good biosecurity principles to control IBD in Bangladesh.Key words: Outbreaks, infectious bursal disease, cockerels, vaccination failure DOI = 10.3329/bjvm.v1i1.1912 Bangl. J. Vet. Med. (2003). 1 (1) : 21 - 24 Â
Clinical and Haematobiochemical Studies on Experimentally Induced Chronic Babesiosis in Splenectomized Adult Dogs
Authors: Hossain MA , Yamato O , Yamasaki M , Maede Y
Published: January 2009

The pathogenicity of the carrier Babesia gibsoni organism was studied in the experimentally inoculated carrier blood into the three susceptible splenectomized adult dogs during the period between 2000 to 2002. The pathogenic effect was assessed on clinical pictures and haematobiochemical changes. All the three experimentally infected dogs showed signs of depression, anorexia and anaemia (pale visible mucous membrane) at 2 years of post-infection. Haematological effects included macrocytic normochromic anemia with polychromasia, anisocytosis and a marked increased in nucleated erythrocytes. Biochemical changes included significant (p < 0.05) increase in mean total serum protein (8.27 Â± 2.37), serum bilirubin (1.02 Â± 0.11), total serum iron (279 Â± 142.03) in comparison to control healthy dogs. It may be concluded from this study that the chronic canine babesiosis caused by B. gibsoni is highly pathogenic associated with anaemia and haematobiochemical alteration. Key words: Haematobiochemical changes chronic babesiosis, experimentally induced, splenectomized dog DOI = 10.3329/bjvm.v1i1.1919 Bangl. J. Vet. Med. (2003). 1(1) : 53 - 56
Evaluation of Nutritional Status of Common Vetch (Vicia sativa) on Growing Rats
Authors: Islam MR , Bari ASM , Rahman MH , Rahman MM
Published: January 2009

Anti-nutritional effect of common vetch (Vicia sativa) was evaluated in 12 growing long-Evans rats of either sex, divided into three groups (A, B & C), each consisting of 4 rats during the period from September 1999 to April 2000.Â  Rats of group A fed with commercial poultry pellet feed (Quality Feeds Ltd., Dhaka), group B fed vetch supplemented ration and group C fed with ration contained vetch and methionine for a period of 43 days. Results showed that the body weight gain was significantly (p < 0.01) lowerÂ  in rats fed with vetch supplemented (183.75 Â± 11.09 g) in comparison to control (221.25 Â± 22.87 g) and vetch + methionine supplemented (246.25 Â± 2.5 g) diets. On proportional weight basis, gut length was significantly (p < 0.01) higher in rats fed vetch supplemented diet (167.08 Â± 12.72 cm) than those of vetch + methionine supplemented (106.63 Â±Â  4.12 cm) and control (123.53 Â± 19.85 cm) groups. Addition of methionine in the vetch diet resulted in a significant (p < 0.01) increases in pancreatic weight on wet weight basis. The apparent digestibility of nitrogen was found to be increased in case of rats fed vetch supplemented diet than those of control and vetch + methionine supplemented diet. Key words: Anti-nutritional effect, common vetch, growing rat DOI = 10.3329/bjvm.v1i1.1920 Bangl. J. Vet. Med. (2003). 1(1) : 57 - 61
“Flash” Solvent-free Synthesis of Triazoles Using a Supported Catalyst
Authors: Jlalia Ibtissem , Meganem Faouzi , Herscovici Jean , Girard Christian
Published: January 2009

A solvent-free synthesis of 1,4-disubstituted-1,2,3-triazoles using neat azides and alkynes and a copper(I) polymer supported catalyst (Amberlyst® A21•CuI) is presented herein. As it provides the products in high yields and purities within minutes, this method thus being characterized as a "flash" synthesis, and was exemplified through the synthesis of a 24-compound library on a small scale.
Biological and Pharmacological Activities of Squalene and Related Compounds: Potential Uses in Cosmetic Dermatology
Authors: Huang Zih-Rou , Lin Yin-Ku , Fang Jia-You
Published: January 2009

Squalene is a triterpene that is an intermediate in the cholesterol biosynthesis pathway. It was so named because of its occurrence in shark liver oil, which contains large quantities and is considered its richest source. However, it is widely distributed in nature, with reasonable amounts found in olive oil, palm oil, wheat-germ oil, amaranth oil, and rice bran oil. Squalene, the main component of skin surface polyunsaturated lipids, shows some advantages for the skin as an emollient and antioxidant, and for hydration and its antitumor activities. It is also used as a material in topically applied vehicles such as lipid emulsions and nanostructured lipid carriers (NLCs). Substances related to squalene, including β-carotene, coenzyme Q10 (ubiquinone) and vitamins A, E, and K, are also included in this review article to introduce their benefits to skin physiology. We summarize investigations performed in previous reports from both in vitro and in vivo models.
Rubiacordone A: A New Anthraquinone Glycoside from the Roots of Rubia cordifolia
Authors: Li Xiang , Liu Zhi , Chen Yun , Wang Li-Juan , Zheng Yi-Nan , Sun Guang-Zhi , Ruan Chang-Chun
Published: January 2009

A new anthraquinone, Rubiacordone A (1) (6-acetoxy-1-hydroxy-2-methylanthraquinone-3-O-α-L-rhamnopyranoside), was isolated together with the known anthraquinone, 1-acetoxy-6-hydroxy-2-methylanthraquinone-3-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside] (2), from the dried roots of Rubia cordifolia. Their structures were elucidated on the basis of extensive 1D and 2D-NMR, as well as HRESI-MS spectroscopic analysis. Metabolites 1 and 2 showed considerable antimicrobial activity against Gram-positive bacteria.
Antiosteoporotic Activity of Anthraquinones from Morinda officinalis on Osteoblasts and Osteoclasts
Authors: Wu Yan-Bin , Zheng Cheng-Jian , Qin Lu-Ping , Sun Lian-Na , Han Ting , Jiao Lei , Zhang Qiao-Yan , Wu Jin-Zhong
Published: January 2009

Bioactivity-guided fractionation led to the successful isolation of antiosteoporotic components, i.e. physicion (1), rubiadin-1-methyl ether (2), 2-hydroxy-1-methoxy- anthraquinone (3), 1,2-dihydroxy-3-methylanthraquinone (4), 1,3,8-trihydroxy-2-methoxy- anthraquinone (5), 2-hydroxymethyl-3-hydroxyanthraquinone (6), 2-methoxyanthraquinone (7) and scopoletin (8) from an ethanolic extract of the roots of Morinda officinalis. Compounds 4-8 are isolated for the first time from M. officinalis. Among them, compounds 2 and 3 promoted osteoblast proliferation, while compounds 4, 5 increased osteoblast ALP activity. All of the isolated compounds inhibited osteoclast TRAP activity and bone resorption, and the inhibitory effects on osteoclastic bone resorption of compounds 1 and 5 were stronger than that of other compounds. Taken together, antiosteoporotic activity of M. officinalis and its anthraquinones suggest therapeutic potential against osteoporosis.
Observation of a Large Landslide on La Reunion Island Using Differential Sar Interferometry (JERS and Radarsat) and Correlation of Optical (Spot5 and Aerial) Images
Authors: Delacourt Christophe , Raucoules Daniel , Le Mouélic Stéphane , Carnec Claudie , Feurer Denis , Allemand Pascal , Cruchet Marc
Published: January 2009

Slope instabilities are one of the most important geo-hazards in terms of socio-economic costs. The island of La Réunion (Indian Ocean) is affected by constant slope movements and huge landslides due to a combination of rough topography, wet tropical climate and its specific geological context. We show that remote sensing techniques (Differential SAR Interferometry and correlation of optical images) provide complementary means to characterize landslides on a regional scale. The vegetation cover generally hampers the analysis of C–band interferograms. We used JERS-1 images to show that the L-band can be used to overcome the loss of coherence observed in Radarsat C-band interferograms. Image correlation was applied to optical airborne and SPOT 5 sensors images. The two techniques were applied to a landslide near the town of Hellbourg in order to assess their performance for detecting and quantifying the ground motion associated to this landslide. They allowed the mapping of the unstable areas. Ground displacement of about 0.5 m yr-1 was measured.
Reduction of Non-Specific Protein Adsorption Using Poly(ethylene) Glycol (PEG) Modified Polyacrylate Hydrogels In Immunoassays for Staphylococcal Enterotoxin B Detection
Authors: Charles Paul T. , Stubbs Veronte R. , Soto Carissa M. , Martin Brett D. , White Brandy J. , Taitt Chris R.
Published: January 2009

Three PEG molecules (PEG-methacrylate, -diacrylate and -dimethacrylate) were incorporated into galactose-based polyacrylate hydrogels and their relative abilities to reduce non-specific protein adsorption in immunoassays were determined. Highly crosslinked hydrogels containing amine-terminated functionalities were formed and used to covalently attach antibodies specific for staphylococcal enterotoxin B (SEB). Patterned arrays of immobilized antibodies in the PEG-modified hydrogels were created with a PDMS template containing micro-channels for use in sandwich immunoassays to detect SEB. Different concentrations of the toxin were applied to the hydrogel arrays, followed with a Cy3-labeled tracer antibody specific for the two toxins. Fluorescence laser scanning confocal microscopy of the tracer molecules provided both qualitative and quantitative measurements on the detection sensitivity and the reduction in non-specific binding as a result of PEG incorporation. Results showed the PEG-modified hydrogel significantly reduced non-specific protein binding with a detection limit for SEB of 1 ng/mL. Fluorescence signals showed a 10-fold decrease in the non-specific binding and a 6-fold increase in specific binding of SEB.
Applications of Nanomaterials in Electrogenerated Chemiluminescence Biosensors
Authors: Qi Honglan , Peng Yage , Gao Qiang , Zhang Chengxiao
Published: January 2009

Electrogenerated chemiluminescence (also called electrochemiluminescence and abbreviated ECL) involves the generation of species at electrode surfaces that then undergo electron-transfer reactions to form excited states that emit light. ECL biosensor, combining advantages offered by the selectivity of the biological recognition elements and the sensitivity of ECL technique, is a powerful device for ultrasensitive biomolecule detection and quantification. Nanomaterials are of considerable interest in the biosensor field owing to their unique physical and chemical properties, which have led to novel biosensors that have exhibited high sensitivity and stability. Nanomaterials including nanoparticles and nanotubes, prepared from metals, semiconductor, carbon or polymeric species, have been widely investigated for their ability to enhance the efficiencies of ECL biosensors, such as taking as modification electrode materials, or as carrier of ECL labels and ECL-emitting species. Particularly useful application of nanomaterials in ECL biosensors with emphasis on the years 2004-2008 is reviewed. Remarks on application of nanomaterials in ECL biosensors are also surveyed.
Transplantation of Mesenchymal Stem Cells Improves Atrioventricular Conduction in a Rat Model of Complete Atrioventricular Block
Authors: Yokokawa Miki , Ohnishi Shunsuke , Ishibashi-Ueda Hatsue , Obata Hiroaki , Otani Kentaro , Miyahara Yoshinori , Tanaka Koichi , Shimizu Wataru , Nakazawa Kazuo , Kangawa Kenji , Kamakura Shiro , Kitamura Soichiro , Nagaya Noritoshi
Published: January 2009

Mesenchymal stem cells (MSCs) are multipotent cells that differentiate into a variety of lineages including myocytes and vascular endothelial cells. However, little information is available regarding the therapeutic potential of MSCs in patients with atrioventricular block (AVB). We investigated whether local implantation of MSCs improves AV conduction in a rat model of complete AVB. Complete AVB was achieved by injection of ethanol into the AV nodal region of Lewis rats. Five days after ethanol injection, 2 × 106of MSCs (MSC group) or vehicle (Control group) were injected into the AV nodal region. Animals were monitored by electrocardiograms for 14 days, and physiological and histological examinations were performed. The 1:1 AV conduction was recovered in 5 of 15 rats (33%) in the MSC group during the follow-up period, whereas no improvement was observed in the control group. MSC transplantation significantly decreased collagen deposition in the AV node, which was associated with a marked decrease in transforming growth factor-β1 expression. In vitro experiments demonstrated that MSCs secreted a large amount of antifibrotic factors such as hepatocyte growth factor and interleukin-10, and MSC conditioned medium inhibited the growth of adult cardiac fibroblasts. In addition, local injection of MSC conditioned medium recovered AV conduction in 2 of 15 rats (13%). MSC transplantation improved AV conduction in a rat model of complete AVB, at least in part through antifibrotic paracrine effects.
Functional Assessment of the Quality of Human Hepatocyte Preparations for Cell Transplantation
Authors: Donato María Teresa , Lahoz Agustín , Montero Sandra , Bonora Ana , Pareja Eugenia , Mir José , Castell José V. , Gómez-Lechón María José
Published: January 2009

Hepatocyte transplantation is an alternative therapy to orthotopic liver transplantation for the treatment of liver diseases. Good quality freshly isolated or cryopreserved human hepatocytes are needed for clinical transplantation. However, isolation, cryopreservation, and thawing processes can seriously impair hepatocyte viability and functionality. The aim of the present study was to develop a fast and sensitive procedure to estimate the quality of hepatocyte preparations prior to clinical cell infusion. To this end, cell viability, attachment efficiency, and metabolic competence (urea synthesis and drug-metabolizing P450 activities) were selected as objective criteria. Viability of hepatocyte suspension was estimated by trypan blue staining. DNA content of attached cells 50 min after hepatocyte platting to fibronectin/collagen-coated dishes was quantified to estimate adherence capacity. Urea production was determined after incubating hepatocyte suspensions with 2 mM ClNH4for 30 min. The cytochrome P450 function was assayed by a 30-min incubation of hepatocyte suspension with a cocktail mixture containing selective substrates for seven individual P450 activities (CYP1A2, 2A6, 2C9, 2C19, 2D6, 2E1, and 3A4). The assay can be applied to both freshly isolated and cryopreserved hepatocyte suspensions, and the results are available within 1 h, which could help to make short-term decisions: 1) to assess the suitability for cell transplantation of a preparation of freshly isolated hepatocytes or a particular batch of thawed cells, or 2) to estimate the convenience of banking a particular cell preparation.
Aflatoxigenic fungi and aflatoxin B1 in commercial pet food in Brazil
Authors: Campos S. , Keller L. , Cavaglieri L. , Krüger C. , Fernández Juri M. , Dalcero A. , Magnoli C. , Rosa C.
Published: January 2009

The aims of this study were to determine the aflatoxigenic mycoflora and the incidence of aflatoxin B1 in commercial
samples of ready dog food. This in turn demonstrated the ability of the Aspergillus flavus and Aspergillus parasiticus
strains to produce aflatoxin B1. 180 samples (standard, premium and super premium) were collected. Aspergillus
was the prevalent genera followed by Penicillium and Fusarium. A. flavus and A. parasiticus were the prevalent
species. All A. flavus and A. parasiticus strains from super premium samples were able to produce aflatoxin B1,
whereas toxigenic strains isolated from standard and premium samples varied from 80 to 100%. A high percentage
of ready pet food contaminated by toxigenic species from section Flavi was found and aflatoxin B1 levels were
detected. The fungal counts from the three kinds of feed did not exceed the proposed value (1×104 cfu/g) and none
of the samples exceeded the aflatoxin B1 recommended level (20 ng/g). The presence of A. flavus and A. parasiticus
with aflatoxigenic ability could be a potential risk for production of AFB1 in feedstuffs when environmental storage
conditions are not adequate.
Occurrence of aflatoxin M1 in traditional cheese consumed in Esfahan, Iran
Authors: Rahimi E. , Karim G. , Shakerian A.
Published: January 2009

Aflatoxin M1 (AFM1) was determined by enzyme linked immunosorbent assay in 88 samples of traditional cheese
consumed in Esfahan city of Iran. In 47 of 88 samples (53.4%), the presence of AFM1 was detected in concentrations
between 82 ng/kg and 1254 ng/kg. The mean level of AFM1 of positive samples was 412 ng/kg. AFM1 in 28 (31.8%)
samples was higher than the maximum tolerance limit (250 ng/kg) accepted by some countries. Statistical analysis
showed that there were no significant differences (P>0.05) between the mean concentrations of AFM1 in cheese
samples of spring, summer, autumn and winter. However, the mean concentration of AFM1 in cheese samples
from spring and summer was significantly lower than autumn and winter (P=0.05). It can be concluded that the
high occurrence of AFM1 in cheese is probably due to the presence of aflatoxin in the feed and cheese milk. This
condition should be considered as a probable hazard for human health.
El islamismo en el mundo árabe. Interpretaciones de algunas trayectorias políticas
Authors: Desrues Thierry
Published: January 2009

Desde los atentados del 11 de septiembre, se observa una renovada tendencia a analizar lo que ocurre en el mundo árabe a partir de las referencias religiosas que aparecen en los discursos de los actores sociales y políticos. Se buscan las pruebas de una relación entre lo que dicen el Corán y sus exégesis posteriores con los comportamientos de los violentos. Estos últimos son asimilados sin más a los islamistas, con la deriva frecuente hacia generalizaciones abusivas que engloban al conjunto de los musulmanes. Para superar este tipo de cuestionamientos, que poco pueden aportar al conocimiento de las lógicas sociales y la política del mundo árabe, en este artículo analizamos algunos aspectos significativos del islamismo. Presentamos algunos elementos de definición de lo que es el islamismo, y abordamos dos cuestiones centrales, a saber: la compatibilidad de la agenda islamista con los principios de la democracia liberal, y la concepción del papel que se le reserva a la mujer. Asimismo, tras exponer las distintas tesis que dominan las interpretaciones sobre el islamismo y su futuro, aportamos algunas reflexiones sobre la necesidad de recuperar la metodología de las ciencias sociales para analizar la situación política y social en el mundo árabe.
De las armas a la desmovilización. El poder paramilitar en Colombia
Authors: Álvaro Rodríguez Miriam
Published: January 2009

Este trabajo analiza la cooptación del ámbito local por los grupos armados paramilitares en Colombia desde el gobierno presidido por Belisario Betancur (1980-1984) hasta la presidencia de Álvaro Uribe (2002-2006). Esta investigación examina cómo los grupos paramilitares llegaron a establecer su poder en el gobierno local colombiano consolidándose como actor hegemónico en determinados departamentos. El problema planteado se estudia bajo una perspectiva histórica con ayuda de la disciplina sociológica. Se propone un marco teórico que describe y analiza las oportunidades y limitaciones políticas de estos actores armados para llevar a cabo su movilización, desarrollo y consolidación de sus actividades en un marco de acción caracterizado por la presencia del conflicto armado interno.
La lógica de los trabajadores. Un estudio sobre la racionalidad, la autonomía y la coherencia de las prácticas y los significados de los trabajadores
Authors: León Medina Francisco José
Published: January 2009

En parte de la literatura reciente sobre sociología del trabajo y de las organizaciones, el reconocimiento del papel de los obreros como agentes ha venido de la mano de una concepción de la subjetividad de los trabajadores como un “efecto” contradictorio e inconsistente de las relaciones de poder. Frente a esta concepción, y a partir del análisis de dieciocho entrevistas realizadas a trabajadores de una multinacional automovilística de Barcelona, se pondrá de manifiesto en este artículo el carácter innovador, autónomo, lógico y coherente del conjunto de los significados que guían las acciones cotidianas de los trabajadores. En el caso analizado, los trabajadores guían sus acciones cotidianas bajo la idea de la necesidad de respetar un código ético de comportamiento compuesto por una serie de principios morales bien trabados. Las acciones de compromiso y resistencia, que algunos autores presentan como contradictorias, aparecen aquí como acciones coherentes con una serie de principios éticos, y por tanto, como racionalmente ajustadas a valores.
La fragua de un oficio. Consideraciones en torno a Sociologie de l´Algerie de Pierre Bourdieu
Authors: Marqués Perales Ildefonso
Published: January 2009

Este artículo analiza los contenidos de la primera obra del antropólogo y sociólogo francés Pierre Bourdieu: Sociologie de l’Algérie. No obstante, se estudiarán contemplando también las relaciones del autor con otros intelectuales durante los años que van de 1955 a 1958, años en los que escribió este libro. Mantengo que sólo podemos comprender esta obra si nos ayudamos de una sociología que examine la relación entre intelectuales radicados en Argelia al comienzo de la Guerra de Independencia. Únicamente si analizamos las probables influencias del joven Bourdieu podremos entender sus elecciones y rechazos teóricos y políticos. Al final del texto, se pondrá una serie de objeciones al autor confrontando su investigación con otras publicadas en la misma época.
Family‐based association of YWHAH in psychotic bipolar disorder
Authors: Grover Deepak , Verma Ranjana , Goes Fernando S. , Mahon Pamela L. Belmonte , Gershon Elliot S. , McMahon Francis J. , Potash James B.
Published: January 2009

YWHAH is a positional and functional candidate gene for both schizophrenia and bipolar disorder (BP). This gene has been previously shown to be associated with both disorders, and the chromosome location (22q12.3) has been repeatedly implicated in linkage studies for these disorders. It codes for the η subtype of the 14‐3‐3 protein family, is expressed mainly in brain, and is involved in HPA axis regulation. We investigated the association of YWHAH with BP in a large sample, consisting of 1211 subjects from 318 nuclear families including 554 affected offspring. We tested for association with the standard BP phenotype as well as subtypes defined by psychotic and mood‐incongruent features. We genotyped five tag SNPs and the (GCCTGCA)n polymorphic locus present in this gene. Using a family‐based association test, we found that rs2246704 was associated with BP (OR 1.31, P = 0.03) and psychotic BP (OR = 1.66, P = 0.002). The polymorphic repeat and two other SNPs were also modestly associated with psychotic BP. We have provided additional evidence for association of variants in YWHAH with major mental illness. Additional association analyses of larger sample sets will be required to clarify the role of YWHAH in schizophrenia and BP. The use of clinical sub‐phenotypes such as psychotic features or other potential schizophrenia/BP overlap variables including cognitive abnormalities and poor functioning might shed further light on the potential subtypes of illness most closely associated with genetic variation in YWHAH. © 2009 Wiley‐Liss, Inc.
Determinants of outcome after colorectal resection within an enhanced recovery programme
Authors: Hendry P O , Hausel J , Nygren J , Lassen K , Dejong C H C , Ljungqvist O , Fearon K C H
Published: January 2009

Background

Postoperative outcomes were studied in relation to adverse nutritional risk (body mass index (BMI) below 20 kg/m2), advanced age (80 years or more) and co-morbidity (American Society of Anesthesiologists (ASA) grade III–IV) in patients undergoing colorectal resection within an enhanced recovery after surgery programme.

Methods

Outcomes were audited prospectively in 1035 patients. Morbidity and mortality were compared with those predicted using the Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity, and a multivariable model was used to determine independent predictors of outcome.

Results

Postoperative morbidity was lower than predicted (observed to expected 0·68; P < 0·001). Independent predictors of delayed mobilization were ASA III–IV (P < 0·001) and advanced age (P = 0·025). Prolonged hospital stay was related to advanced age (P = 0·002), ASA III–IV (P < 0·001), male sex (P = 0·037) and rectal surgery (P < 0·001). Morbidity was related to ASA III–IV (P = 0·004), male sex (P = 0·023) and rectal surgery (P = 0·002). None of the factors predicted 30-day mortality.

Conclusion

Age and nutritional status were not independent determinants of morbidity or mortality. Pre-existing co-morbidity was an independent predictor of several outcomes.
Electrical stimulation induces propagated colonic contractions in an experimental model
Authors: Aellen S , Wiesel P H , Gardaz J-P , Schlageter V , Bertschi M , Virag N , Givel J-C
Published: January 2009

Background

Direct colonic electrical stimulation may prove to be a treatment option for specific motility disorders such as chronic constipation. The aim of this study was to provoke colonic contractions using electrical stimulation delivered from a battery-operated device.

Methods

Electrodes were inserted into the caecal seromuscular layer of eight anaesthetized pigs. Contractions were induced by a neurostimulator (Medtronic 3625). Caecal motility was measured simultaneously by video image analysis, manometry and a technique assessing colonic transit.

Results

Caecal contractions were generated using 8–10 V amplitude, 1000 µs pulse width, 120 Hz frequency for 10–30 s, with an intensity of 7–15 mA. The maximal contraction strength was observed after 20–25 s. Electrical stimulation was followed by a relaxation phase of 1·5–2 min during which contractions propagated orally and aborally over at least 10 cm. Spontaneous and stimulated caecal motility values were significantly different for both intraluminal pressure (mean(s.d.) 332(124) and 463(187) mmHg respectively; P < 0·001, 42 experiments) and movement of contents (1·6(0·9) and 3·9(2·8) mm; P < 0·001, 40 experiments).

Conclusion

Electrical stimulation modulated caecal motility, and provoked localized and propagated colonic contractions.
Randomized clinical trial of a modified Seldinger technique for open central venous cannulation for implantable access devices
Authors: Knebel P , Fischer L , Huesing J , Hennes R , Büchler M W , Seiler C M
Published: January 2009

Introduction

Totally implantable access ports (TIAPs) are often used for patients who need permanent venous access. The primary success rate using direct open insertion is about 80 per cent, so rescue strategies are needed. This study compared the primary success rates of standard open insertion and a modified Seldinger technique.

Methods

This randomized trial recruited 164 patients scheduled for primary implantation of a TIAP and compared two interventions. The primary endpoint was the success rate of the implantation technique.

Results

The primary success rates were similar: 66 (80 per cent) of 82 patients who had standard open insertion versus 69 (84 per cent) of 82 patients undergoing the modified Seldinger method (P = 0·686). A logistic mixed regression analysis including treatment group, age, Karnofsky index, body mass index and surgeon's experience showed no advantage for the Seldinger method: odds ratio 1·30 (95 per cent confidence interval 0·62 to 2·70). TIAPs were eventually implanted successfully in 163 (99·4 per cent) of 164 patients. In 11 patients randomized to standard surgery, the Seldinger method was a successful rescue strategy.

Conclusion

The primary success rate was similar for both open insertion methods. The modified Seldinger method is useful if standard open insertion fails. Registration number: ISRCTN 52368201 (http://www.controlled-trials.com).
Composite abdominosacral resection for recurrent rectal cancer
Authors: Sagar P M , Gonsalves S , Heath R M , Phillips N , Chalmers A G
Published: January 2009

Background

En bloc resection of the tumour and adjacent involved organs offers the only realistic curative option for patients with locally recurrent rectal cancer. This study assessed outcomes of composite resection for recurrent tumours involving the sacrum.

Methods

A consecutive series of patients underwent composite abdominosacral resection (abdominal mobilization and stoma construction followed by sacral division and tumour retrieval) for recurrent rectal cancer between 2001 and 2007. Patients were staged with preoperative computed tomography, magnetic resonance imaging and positron emission tomography. Data were collected prospectively.

Results

Forty patients (28 men; median age 59 (range 31–77) years) underwent surgery with sacral division at the S2/3 interface in 13, S3/4 level in 20 and S4/5 level in seven patients. One patient died and 24 had complications. An R0 resection was achieved in 20 patients and conferred benefit in disease-free interval over an R1 resection. The mean disease-free interval was 55·6 (95 per cent confidence interval (c.i.) 40·0 to 71·3) months for R0 and 32·2 (95 per cent c.i. 19·7 to 44·7) months for R1 resection (P = 0·048).

Conclusion

Composite abdominosacral resection of locally recurrent rectal cancer is an effective treatment for a difficult clinical scenario.
Laparoscopic management of insulinomas
Authors: Isla A , Arbuckle J D , Kekis P B , Lim A , Jackson J E , Todd J F , Lynn J
Published: January 2009

Background

Conventional surgical management of insulinomas involves an open technique. The laparoscopic approach has advantages in terms of improved postoperative pain and recovery time. This retrospective study evaluated the laparoscopic management of pancreatic insulinomas.

Methods

Between December 2000 and March 2007, 23 patients were referred for consideration of laparoscopic insulinoma resection. Two patients were not deemed appropriate for the laparoscopic approach and were managed with open surgery. All surgery was performed by one experienced pancreatic surgeon. Laparoscopic intraoperative ultrasonography was not available for the first six procedures, but was used thereafter.

Results

Twenty-one patients (five men and 16 women, median age 46 (range 22–70) years) had a successful resection. All had single tumours, five in the head, nine in the body and seven in the tail of the pancreas. One conversion to open operation was performed in a patient with an insulinoma in the head of the pancreas who had dense adhesions resulting from pancreatitis. Three patients developed a postoperative pancreatic fistula. There has been no recurrence of symptoms in any patient.

Conclusion

Laparoscopic management of insulinomas is feasible and safe. Laparoscopic intraoperative ultrasonography is a promising adjunct to the procedure, even after accurate preoperative localization.
Intravenous fluid therapy
Authors: Lassen K
Published: January 2009

Management guidelines
Non-operative management of rectal cancer after neoadjuvant chemoradiation
Authors: Habr-Gama A , Perez R O
Published: January 2009

A problem of patient selection
Feasibility of complex coronary intervention in combination with percutaneous aortic valve implantation in patients with aortic stenosis using percutaneous left ventricular assist device (TandemHeart®)
Authors: Piazza Nicolo , Serruys Patrick W. , de Jaegere Peter
Published: January 2009

Coronary atherosclerosis is a common finding in patients with severe aortic stenosis. Indeed, aortic stenosis is associated with risk factors similar those of coronary atherosclerosis such as older age, hypertension, diabetes, hypercholesterolemia and smoking. In light of the evolution of percutaneous aortic valve implantation (PAVI) and ongoing improvements in techniques of PCI, a combined approach using PCI and PAVI can be proposed for patients with complex coronary artery and aortic valve disease. This report describes the feasibility of the combination of percutaneous coronary intervention and percutaneous aortic valve implantation with peripheral left ventricular assist device (TandemHeart) support in 3 elderly patients with complex coronary altery disease and aortic stenosis considered too high risk for conventional surgical therapy. © 2009 Wiley‐Liss, Inc.
Use of Tetradentate Monoanionic Ligands for Stabilizing Reactive Metal Complexes
Authors: Chomitz Wayne A. , Arnold John
Published: January 2009

Ligand scaffolding: The chemist's ability to choose from a wide range of supporting ligands is an important factor in designing new metal complexes. The introduction of new ligand scaffolds with different donor types and coordination numbers allows for the expansion of reaction chemistry at metal centers. This article surveys the use of the tetradentate monoanionic (TMDA) ligands (shown here) with main‐group, transition‐metal, and f‐block elements.

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Supporting ligand design has played a vital role in the development of coordination and organometallic chemistry. A myriad of ligands with varying charge, donor‐type, and denticity have been explored in this realm. A ligand type that has garnered recent attention involves a tetradentate monoanionic (TDMA) framework. TDMA ligands have been used with p‐, d‐, and f‐block elements to form an array of interesting new complexes with applications ranging from bioinorganic chemistry to catalysis. Complexes incorporating TDMA ligands have been shown to stabilize reactive low‐valent and cationic species. Functionalized β‐diiminato and TACN derivatives as well as tripodal ligands featuring both hard σ‐donors as well as “mixed‐donors” are covered in this review. The synthetic challenges associated with the implementation of each ligand set are discussed.
Towards Allosteric Receptors: Adjustment of the Rotation Barrier of 2,2′‐Bipyridine Derivatives
Authors: Zahn Stefan , Reckien Werner , Kirchner Barbara , Staats Holger , Matthey Jens , Lützen Arne
Published: January 2009

What a difference! The energy differences between anti and syn conformers as well as the energy barrier for the rotation around the aryl–aryl bond of a number of 2,2′‐bipyridine molecules were examined by quantum‐chemical methods. The energy differences were found to be governed by the substituents directly attached to the bipyridine and their ability to form intramolecular hydrogen bonds.

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Quantum‐chemical calculations at the BP86/TZVP level of theory were performed to determine the energy differences between the syn and the anti conformers, as well as the energy barrier for the rotation of the aryl–aryl bond of 2,2′‐bipyridine molecules and a number of disubstituted derivatives. Substitutents with hydrogen‐bond donor (or electron acceptor) functions or hydrogen‐bond acceptors (or electron donors) are generally found to have large effects on the difference and the barrier. Substitution with a hydrogen‐bond donor (or an electron acceptor) at position 6 and 6′ leads to a decrease owing to a charge transfer from the pyridine nitrogen lone pair to the donor, which is caused by the formation of weak intramolecular hydrogen bonds and/or dipolar interactions, respectively. Conversely, substitution at position 4 and 4′ causes an increase in the energy barrier. Substitution with a hydrogen‐bond acceptor (or an electron donor) shows the opposite behavior, which can be explained by the weak intramolecular interactions. Interestingly, even very weak CH hydrogen‐bond donors (electron acceptors) such as methyl groups have a significant influence. This indicates the importance of such weak interactions for the structure and energetics of supramolecular systems. The energy differences are mainly governed by the substituents directly attached to the bipyridine core as the introduction of sterically demanding groups in the periphery hardly influences the barriers or energy differences of the conformers. These findings are important for the design of heterotropic positive cooperative allosteric receptors with 2,2′‐bipyridines as the allosteric centre.
Ti‐Catalyzed Barbier‐Type Allylations and Related Reactions
Authors: Estévez Rosa E. , Justicia José , Bazdi Btissam , Fuentes Noelia , Paradas Miguel , Choquesillo‐Lazarte Duane , García‐Ruiz Juan M. , Robles Rafael , Gansäuer Andreas , Cuerva Juan M. , Oltra J. Enrique
Published: January 2009

Versatility of titanium: Titanocene(III) complexes catalyze Barbier‐type allylations, intramolecular crotylations (cyclizations), and prenylations of a wide range of aldehydes and ketones. These reactions take place at RT under mild conditions compatible with many functional groups; provide good yields of open‐chain and cyclic homoallylic alcohols, including heterocyclic derivatives; and can be conducted enantioselectively by using enantiomerically pure titanium catalysts.

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Titanocene(III) complexes, easily generated in situ from commercial TiIV precursors, catalyze Barbier‐type allylations, intramolecular crotylations (cyclizations), and prenylations of a wide range of aldehydes and ketones. The reaction displays surprising and unprecedented mechanistic subtleties. In cyclizations a fast and irreversible addition of an allyl radical to a TiIII‐coordinated carbonyl group seems to occur. Intermolecular additions to conjugated aldehydes proceed through a coupling of a TiIV‐bound ketyl radical with an allyl radical. Reactions of ketones with allylic halides take place by the classical addition of an allylic organometallic reagent. The radical coupling processes enable transformations such as the highly regioselective α‐prenylation that are otherwise difficult to achieve. The mild reaction conditions and the possibility to employ titanocene complexes in only catalytic quantities are highly attractive features of our protocol. These unusual properties have been taken advantage of for the straightforward synthesis of the natural products rosiridol, shikalkin, and 12‐hydroxysqualene.
The effect of mismatch in current‐versusvoltage‐mode resistive grids
Authors: Shi Bertram E.
Published: January 2009

Resistive grids are commonly used in neuromorphic very large‐scale integration (VLSI) designs for image smoothing and signal aggregation. Because mismatch is inevitable in VLSI chips, one reason that resistive grids are attractive is that their output is robust to mismatch in the component values. Here, we examine relative sensitivity of different resistive grid designs that differ depending upon whether the input and output are represented by current or voltage. Our analysis reveals that a mixed‐mode design, where the input is represented by current but the output is represented by voltage, is less sensitive to mismatch when the amount of smoothing is large. On the other hand, when little smoothing is desired, pure voltage‐mode and current‐mode designs are preferred. From the point of view of mismatch sensitivity, there is little difference between the two pure‐mode designs. Our analysis also reveals that the difference in mismatch sensitivity is due to the vertical resistors, which are the most sensitive to mismatch in all the three designs studied. Copyright © 2008 John Wiley & Sons, Ltd.