bluuebunny/crossref_metadata_2025 huggingface dataset:
Oceanic controls on the primary production of the northwest European continental shelf under recent past and potential future conditions
Authors: Holt J. , Butenschön M. , Wakelin S. L. , Artioli Y. , Allen J. I.
Published: August 2011

Abstract. In this paper we clearly demonstrate that changes in oceanic nutrients are a first order factor in determining changes in the primary production of the northwest European continental shelf on time scales of 5–10 yr. We present a series of coupled hydrodynamic ecosystem modelling simulations, using the POLCOMS-ERSEM system. These are forced by both re-analysis data and a coupled ocean-atmosphere general circulation model (OA-GCM) representative of possible conditions in 2080–2100 under an SRES A1B emissions scenario, along with the corresponding present day control. The OA-GCM forced simulations show a substantial reduction in surface nutrients in the open-ocean regions of the model domain, comparing future and present day time-slices. This arises from a large increase in oceanic stratification. Tracer transport experiments identify a substantial fraction of on-shelf water originates from the open-ocean region in the south of the domain, where this increase is largest, and indeed the on-shelf nutrient and primary production are reduced as this water is transported on shelf. This relationship is confirmed quantitatively by comparing changes in winter nitrate with total annual nitrate uptake. The reduction in primary production by the reduced nutrient transport is mitigated by on-shelf processes relating to temperature, stratification (length of growing season) and recycling. Regions less exposed to ocean-shelf exchange in this model (Celtic Sea, Irish Sea, English Channel, and southern North Sea) show a modest increase in primary production (of 5–10 %) compared with a decrease of 0–20 % in the outer shelf, central and northern North Sea. These findings are backed up by a boundary condition perturbation experiment and a simple mixing model.
Simulating the mid-Pliocene climate with the MIROC general circulation model: experimental design and initial results
Authors: Chan W.-L. , Abe-Ouchi A. , Ohgaito R.
Published: August 2011

Abstract. Recently, PlioMIP (Pliocene Model Intercomparison Project) was established to assess the ability of various climate models to simulate the mid-Pliocene warm period (MPWP), 3.29–2.97 million years ago. We use MIROC4m, a fully coupled atmosphere-ocean general circulation model (AOGCM), and its atmospheric component alone to simulate the MPWP, utilizing up-to-date data sets designated in PlioMIP as boundary conditions and adhering to the protocols outlined. In this paper, a brief description of the model is given, followed by an explanation of the experimental design and implementation of the boundary conditions, such as topography and sea surface temperature. Initial results show increases of approximately 10 °C in the zonal mean surface air temperature at high latitudes accompanied by a decrease in the equator-to-pole temperature gradient. Temperature in the tropical regions increase more in the AOGCM. However, warming of the AOGCM sea surface in parts of the northern North Atlantic Ocean and Nordic Seas is less than that suggested by proxy data. An investigation of the model-data discrepancies and further model intercomparison studies can lead to a better understanding of the mid-Pliocene climate and of its role in assessing future climate change.
Vertical profile of the specific surface area and density of the snow at Dome C and on a transect to Dumont D'Urville, Antarctica – albedo calculations and comparison to remote sensing products
Authors: Gallet J.-C. , Domine F. , Arnaud L. , Picard G. , Savarino J.
Published: August 2011

Abstract. The specific surface area (SSA) of snow determines in part the albedo of snow surfaces and the capacity of the snow to adsorb chemical species and catalyze reactions. Despite these crucial roles, almost no value of snow SSA are available for the largest permanent snow expanse on Earth, the Antarctic. We report the first extensive study of vertical profiles of snow SSA near Dome C (DC: 75°06' S, 123°20' E, 3233 m a.s.l.) on the Antarctic plateau, and at seven sites during the logistical traverse between Dome C and the French coastal base Dumont D'Urville (DDU: 66°40' S, 140°01' E) during the Austral summer 2008–2009. We used the DUFISSS system, which measures the IR reflectance of snow at 1310 nm with an integrating sphere. At DC, the mean SSA of the snow in the top 1 cm is 38 m2 kg−1, decreasing monotonically to 14 m2 kg−1 at a depth of 50 cm. Along the traverse, the snow SSA profile is similar to that at DC in the first 600 km from DC. Closer to DDU, the SSA of the top 5 cm is 23 m2 kg−1, decreasing to 19 m2 kg−1 at 50 cm depth. This difference is attributed to wind, which causes a rapid decrease of surface snow SSA, but forms hard windpacks whose SSA decrease more slowly with time. Since light-absorbing impurities are not concentrated enough to affect albedo, the vertical profiles of SSA and density were used to calculate the spectral albedo of the snow for several realistic illumination conditions, using the DISORT radiative transfer model. A preliminary comparison with MODIS data is presented and our calculations and MODIS data show similar trends.
Nietzsche's Value Conflict: Culture, Individual, Synthesis
Authors: Ward Joe
Published: August 2011

This article poses the question of what it is that Nietzsche values, arguing that we need a generic answer that makes sense of Nietzsche's admiration for both exceptional individuals and types of culture: what Nietzsche values are certain kinds of syntheses of the will to power, holding at diverse levels. These are syntheses endowed with a distinctive, “aristocratic” structure with a pathos of distance maintaining a separation between ruling and subjugated elements. But Nietzsche's valuing is also oriented by extrinsic criteria such as “agonistic” relations, subjugation of other syntheses, and the “exceptional” status of individuals; the determining of value must combine intrinsic and extrinsic factors. Conflict occurs within Nietzsche's values because the conditions that produce the most exceptional individuals are at odds with the conditions needed for flourishing cultures. I contend that the tenor of Nietzsche's late thinking suggests a way of resolving this tension through a willingness to give up on the exceptional status of individuals in favor of the advancement of flourishing cultures.
Nietzsche: Through the Lens of Purity
Authors: Duschinsky Robbie
Published: August 2011

In remarks scattered across his corpus of writings, Nietzsche offers a fascinating analysis of the theme of purity. In this article I systematize these fragments into a genealogy and draw out conclusions relevant to philosophy and cultural criticism. Nietzsche argues that the Christian use of purity, as both an ideal and a means of achieving self-martyrdom of the will, has been retained in modern Western culture. He is generally quite skeptical of purity, considering it to be tightly associated with dominating and mediocratic social institutions. However, he also sees potential for purity to help bring about an escape from these systems of social control.
Delayed Urethral Obstruction After Uterine Torsion in a Pregnant Dog
Authors: Reynolds Debbie , Campbell Bonnie G.
Published: August 2011

A 4 yr old pregnant female shih tzu was presented with abdominal discomfort and bloody vulvar discharge. The nongravid uterine horn was reflected caudally over the trigone, obstructing urine outflow. A cesarian section and ovariohysterectomy were performed. Postoperatively, the hematuria and pollakiuria resolved. Seventeen days later, the pelvic urethra was completely obstructed by a soft tissue mass that was identified by rectal palpation, blocked catheterization attempts, contrast radiography, ultrasonography, and surgery. Management included temporary cystostomy tube and definitive prepubic urethrostomy. Histologic diagnosis was severe, multifocal, necrosuppurative urethritis with fibroplasia, fibrosis, and cellulitis, apparently secondary to ischemia. Delayed urethral obstruction is a potential complication of canine uterine torsion.
BAER Testing in a Dog with Bilateral External Ear Canal Atresia
Authors: Anwer Cona , Schwarz Tobias , Volk Susan W. , Vite Charles
Published: August 2011

A 3 yr old male castrated Labrador retriever presented for evaluation and treatment of bilateral atresia of the external ear canals. The owners reported that the dog could hear only loud and high-pitched noises. Computed tomography of the head revealed intact vertical and horizontal ear canals filled with debris and a debris-filled right tympanic bulla. Air- and bone-conducted brainstem auditory evoked response (BAER) testing revealed an elevated response threshold to air-conducted stimuli and greater amplitude waveforms evoked by bone-conducted stimuli. The ear canals were surgically corrected via lateral ear canal resection. BAER testing postoperatively revealed a decrease in the air-conducted BAER threshold. This case is an example of the use of bone-conducted BAER testing to aid in the diagnosis of conductive deafness, and in determining prognosis for normal hearing after surgical treatment of external ear canal atresia.
Multifocal Oligodendroglioma in Three Dogs
Authors: Koch Michael W. , Sánchez Melissa D. , Long Sam
Published: August 2011

This report describes the clinical, histopathologic, and imaging findings of multifocal oligodendrogliomas from three canine patients. Clinical history varied but included seizure activity and behavior changes. Neurologic examination abnormalities included ataxia, proprioceptive deficits, cranial nerve deficits, and changes in mentation. MRI in one patient revealed multifocal brain lesions; however, the MRI was normal in another one of the patients. Histopathologic evaluation identified multifocal neoplastic infiltrates in all three patients involving the cerebral cortex, brainstem, and spinal cord, with leptomeningeal extension in two of the three patients. All three patients were euthanized due to progression of their neurologic condition and/or complications due to aspiration pneumonia. Oligodendrogliomas should be considered a differential diagnosis for patients with multifocal brain disease.
Amlodipine-Induced Gingival Hyperplasia in a Great Dane
Authors: Pariser Marlene S. , Berdoulay Paul
Published: August 2011

A 3 yr old, 70 kg (154 lbs) female spayed Great Dane developed gingival hyperplasia after treatment of systemic hypertension with amlodipine 7.5 mg q 12 hr for 16 mo. Physical examination was unremarkable except for systemic hypertension and severe gingival hyperplasia. Amlodipine was replaced with hydralazine (0.72 mg/kg [0.32 mg/lb]). Nine months later, gingival hyperplasia was nearly resolved and hypertension was well controlled. Calcium channel blockers such as amlodipine are a rare cause of gingival hyperplasia in the canine patient. Recognition of this side effect is important because a full recovery can be achieved when the offending agent is removed.
Partial Resolution of Hypoplastic Trachea in Six English Bulldog Puppies with Bronchopneumonia
Authors: Clarke Dana L. , Holt David E. , King Lesley G.
Published: August 2011

Six English bulldog and nine nonbrachycephalic puppies with bronchopneumonia and radiographs were evaluated. Relative size of the trachea was measured by the tracheal diameter (TD) and the thoracic inlet distance (TI), expressed as a ratio (TD:TI). At diagnosis of bronchopneumonia, there was a significant difference between the median TD:TI of the bulldog puppies (0.07; range, 0.06–0.09) and that of the nonbrachycephalic puppies (0.14; range, 0.11–0.25; P=0.0004). At the same time, there was also a significant difference between the mean TD:TI of bulldog puppies (0.07±0.01) and that of nonbrachycephalic puppies (0.15±0.05; P=0.002). Follow-up radiographs showed significant increases in TD:TI ratio in all six bulldogs (median TD:TI = 0.14; range, 0.12–0.18; P=0.03 and mean TD:TI = 0.15±0.02; P=0.0007), whereas the ratio did not change significantly in the nonbrachycephalic control group (median TD:TI = 0.17; range, 0.14–0.22; P=0.10 and mean TD:TI = 0.18±0.03; P=0.06). Tracheal hypoplasia in some brachycephalic dogs might partially or completely resolve with growth to mature body size.
Concurrent Splenic and Right Atrial Mass at Presentation in Dogs with HSA: A Retrospective Study
Authors: Boston Sarah E. , Higginson Geraldine , Monteith Gabrielle
Published: August 2011

The objective of this retrospective study was to evaluate the presence of concurrent splenic and cardiac hemangiosarcoma (HSA). Dogs were divided into two groups: group 1 included 23 dogs with splenic HSA, and group 2 included 31 dogs with a cardiac HSA. All dogs were fully assessed for metastasis with thoracic radiography, abdominal and/or cardiac ultrasound, and/or postmortem examination. Two dogs (8.7%) in group 1 had a concurrent cardiac mass. Neither of these dogs had pericardial effusion, and both were golden retrievers. Thirteen of the dogs in group 1 presented with a hemoabdomen. Concurrent intra-abdominal metastasis was noted in seven dogs. In group 2, 9/31 (29%) of the dogs had a concurrent splenic HSA, and 13/31 (42%) of the dogs had evidence of metastasis to another site. There was a significant association between age and the presence of nonsplenic metastasis (odds ratio, 0.457). The rate of concurrent right atrial mass detected by cardiac ultrasound in dogs with splenic HSA was 8.7%, which is less than previously reported. For dogs with right atrial HSA, the risk of metastasis to nonsplenic sites decreases with age.
Relación del origen de eyecciones coronales de masa a partir de la formación de manchas en el disco visible del Sol
Authors: Guerrero Maribel S
Published: August 2011

En esta investigación se estudió la cantidad de eyecciones coronales de masa que se produjeron en la misma fecha de la formación de regiones activas en el disco visible del Sol, durante los dos últimos periodos mínimos de actividad solar. Así mismo de la base de datos de este trabajo de investigación se construyó un catálogo. Correlacionando la coincidencia estadística de estos eventos se ha encontrado una relación de la actividad solar desde la fotosfera con las manchas solares, hasta la formación de Eyecciones coronales de masa, como era de esperar. Y con el análisis de los datos de todo el año 2005 y medio año del 2006 de la formación de 165 regiones activas observadas en el disco visible del Sol, se hace notable la cantidad de regiones activas y no el tamaño de éstas, para la relación en la secuencia de eventos fotosfericos. Para los mismos años se encontraron 701 manchas formadas y se contaron 445 CME producidas. De lo que podemos concluir estadísticamente, que existe la correlación buscada entre ambos fenómenos, en una proporción mayor a 60%; respecto a la cantidad total de manchas para los años antes mencionados. Palabras clave: Eyecciones Coronales de Masa; Regiones activas; Disco visible; Actividad solar; Correlación; Fotosfera; Manchas solares; Filamentos; Prominencias; Corona solar DOI: http://dx.doi.org/10.5377/rct.v0i4.524 Revista Ciencia y Tecnología, No. 4, Segunda época, Junio 2009: 15-19
Base de datos de eventos solares observados desde la Plaza del Sol del Parque Arqueológico de Copán Ruinas
Authors: De Carías María Cristina Pineda , Véliz Santos Vito
Published: August 2011

El objetivo principal de este trabajo ha sido diseñar y conformar una base de datos a partir del uso del material fotográfico recolectado entre 1998 y 2008 por nosotros, como Grupo de Arqueoastronomía del Observatorio Astronómico Centroamericano de Suyapa de la Universidad Nacional Autónoma de Honduras. En este trabajo describimos las características de la base de datos relacional que contiene 2,467 fotografías y 8 tablas de atributos con fechas y lugares desde donde se realizaron las observaciones de las salidas y puestas del Sol, o para diferentes horas del día para conocer el tamaño y la dirección de las sombras de la Estela D, reloj solar del Parque Arqueológico de Copán Ruinas. La utilización del software de dominio público Picasa3 en combinación con hojas de cálculo de Excel facilita que cualquier usuario, en especial de la comunidad de investigadores y personas estudiosas de la Arqueoastronomía, aproveche esta información para comprender cómo se realizaban las observaciones astronómicas en Copán Ruinas o para generar nuevas líneas de investigación en Arqueoastronomía. Palabras clave: Arqueoastronomía; observaciones solares; Parque Arqueológico Copán Ruinas; base de datos. DOI: http://dx.doi.org/10.5377/rct.v0i4.525 Revista Ciencia y Tecnología, No. 4, Segunda época, Junio 2009: 20-35
Relación de agujeros negros súper masivos con propiedades globales de las galaxias que los albergan
Authors: Rosales Yvelice Soraya Castillo
Published: August 2011

Partiendo del trabajo de Tesis de Maestría de Castillo Rosales, Y.S., que incluyó una exhaustiva revisión bibliográfica de revistas profesionales de astronomía y astrofísica (“papers”) que se refieren a agujeros negros súper masivos (en adelante, ANSs) y a varias propiedades de las galaxias que los albergan; se han seleccionado diez publicaciones que se consideraron representativas en cuanto a datos y a correlaciones significativas entre las masas de agujeros negros centrales y las propiedades globales de las galaxias anfitrionas. Tomando los datos de estas diez publicaciones, se seleccionaron 11 propiedades relevantes, que fueron agrupadas en tres tipos de tablas: galaxias elípticas, galaxias de disco y galaxias peculiares (peculiares incluye galaxias activas, irregulares y fusiones de galaxias). La muestra final es de 144 galaxias. En total se recopilaron 1,453 datos. Además se elaboraron nueve gráficos de correlaciones entre las masas de agujero negro súper masivo central de las galaxias de la muestra, con las nueve siguientes propiedades de las galaxias: dispersión central de velocidades, luminosidad del bulbo, radio de influencia del ANS, radio efectivo del bulbo, masa del esferoide, relación masaluminosidad total, corrimiento al rojo, distancia al centro de la Galaxia, y luminosidad en lejano infrarrojo. Con ayuda de los gráficos de correlaciones elaborados se hizo un análisis comparativo entre estas correlaciones y las correlaciones que arrojan cinco modelos teóricos recientes de formación y evolución de galaxias. Los resultados parecen apoyar las teorías de formación de galaxias a partir de halos de materia oscura, que posteriormente formarían galaxias de disco, cuyos agujeros negros centrales serían los motores del crecimiento galáctico, a tasas de acreción moderadas. Palabras clave: agujero negro súper masivo (ANS); correlación; galaxia; dispersión de velocidades; evolución; formación. DOI: http://dx.doi.org/10.5377/rct.v0i4.526 Revista Ciencia y Tecnología, No. 4, Segunda época, Junio 2009: 36-66
Análisis del comportamiento espectroscópico de largo período de las estrellas Be
Authors: Zavala Ligia Del Carmen Aréas
Published: August 2011

Las estrellas Be son objetos tempranos con líneas en emisión que muestran variabilidad espectroscópica en diversas escalas de tiempo asociadas con diferentes fenómenos que tienen lugar en sus envolturas extendidas. La complejidad de estos objetos hace que aún estén en debate las condiciones físicas y dinámicas del material circumestelar que los rodea. Con el fin de aportar información acerca de la estructura y evolución de las envolturas extendidas de las estrellas Be, analizamos las variaciones espectroscópicas de dos objetos Be, 48 Lib y 66 Oph, cuya compleja fenomenología resulta difícil de ser explicada por los modelos de envoltura existentes. Para nuestro análisis utilizamos material recopilado de la literatura y espectros obtenidos en CASLEO. Estudiamos, en particular, el comportamiento de la línea H del hidrógeno, cuyo perfil resulta sensible a los cambios físicos ocurridos en la envoltura. Describimos, para ambos objetos, las variaciones temporales cíclicas de largo período de los valores medidos de velocidades radiales, anchos equivalentes e intensidades del ala roja y el ala violeta del perfil de H. En lo que respecta a 48 Lib, completamos el análisis del material espectroscópico que ya había sido publicado por Áreas y Cidale en 2006, agregando nuevos datos. Para 66 Oph observamos que la intensidad de la emisión en la línea Há comienza a decaer en 1996 indicando una dilución de la envoltura y el comienzo de un fase B normal. Cabe destacar la importancia de continuar con un seguimiento temporal de este objeto para detectar el inicio de una nueva fase de actividad estelar. Palabras Clave: estrellas variables; envoltura circumestelar; línea de emisión DOI: http://dx.doi.org/10.5377/rct.v0i4.529 Revista Ciencia y Tecnología, No. 4, Segunda época, Junio 2009: 90-98
Vibro‐Acoustic Simulation of Aluminium Foam Parts Using MultiScale Techniques
Authors: Karas Lukasz , Jalics Karoly , Priebsch Hans‐Herwig
Published: August 2011

A special approach is required when applying common simulation techniques (e.g. finite elements methods) for vibro‐acoustic analysis (natural and force vibrations, mode shapes) to cellular metals. While models using average values for Young's module and for the material density are not sufficiently precise – especially when the material is strongly inhomogeneous, in contrast, simulation using precise microstructure information is not time efficient. Therefore, the main challenge is to map the material microstructure information to the vibro‐acoustic simulation model with acceptable efficiency. In this paper, a multiscale technique with representative volume elements is used for this purpose. The results from this approach are validated for a truck oil pan made from closed‐cell aluminium foam with strong variations in the microstructure. The investigations show that with more detailed microstructure information the simulation precision can be improved significantly. The simulation results for the natural frequencies show a good agreement (to within 5%) with the values from experiment.
Defects in Cu(In,Ga)Se2 Chalcopyrite Semiconductors: A Comparative Study of Material Properties, Defect States, and Photovoltaic Performance
Authors: Cao Qing , Gunawan Oki , Copel Matthew , Reuter Kathleen B. , Chey S. Jay , Deline Vaughn R. , Mitzi David B.
Published: August 2011

Understanding defects in Cu(In,Ga)(Se,S)2 (CIGS), especially correlating changes in the film formation process with differences in material properties, photovoltaic (PV) device performance, and defect levels extracted from admittance spectroscopy, is a critical but challenging undertaking due to the complex nature of this polycrystalline compound semiconductor. Here we present a systematic comparative study wherein varying defect density levels in CIGS films were intentionally induced by growing CIGS grains using different selenium activity levels. Material characterization results by techniques including X‐ray diffraction, scanning electron microscopy, transmission electron microscopy, secondary ion mass spectrometry, X‐ray photoelectron spectroscopy, and medium energy ion scattering indicate that this process variation, although not significantly affecting CIGS grain structure, crystal orientation, or bulk composition, leads to enhanced formation of a defective chalcopyrite layer with high density of indium or gallium at copper antisite defects ((In, Ga)Cu) near the CIGS surface, for CIGS films grown with insufficient selenium supply. This defective layer or the film growth conditions associated with it is further linked with observed current‐voltage characteristics, including rollover and crossover behavior, and a defect state at around 110 meV (generally denoted as the N1 defect) commonly observed in admittance spectroscopy. The impact of the (In, Ga)Cu defects on device PV performance is also established.
The 11‐item workplace organizational policies and practices questionnaire (OPP‐11): examination of its construct validity, factor structure, and predictive validity in injured workers with upper‐limb disorders
Authors: Tang Kenneth , MacDermid Joy C. , Amick Benjamin C. , Beaton Dorcas E.
Published: August 2011

Background

Reliable and valid measurement of workplace organizational policies and practices (OPPs) is needed to evaluate their influences on the prevention and management of occupational injuries.

Methods

Injured workers (n = 614) attending an upper‐limb specialty clinic operated by the Workplace Safety & Insurance Board of Ontario were recruited for a 1‐year study. The OPP‐11, completed at baseline, was examined for scaling properties (floor/ceiling effects, internal consistency, and item‐convergent/discriminant validity), construct validity, and factor structure. Predictive validity for longitudinal work disability was examined using multivariable logistic regressions.

Results

Strong scaling properties were observed for the OPP‐11. High internal consistency (Cronbach's alpha = 0.80–0.90) and expected associations with comparator constructs were evident. A 4‐domain structure (fit statistics: CFI = 0.98, TLI = 0.97, and RMSEA = 0.06) was supported. Higher OPP‐11 predicted more favorable 12‐month work disability outcomes, after adjusting for demographic and health attributes.

Conclusions

The OPP‐11 is valid for use in upper‐limb disorders. Expanding the ergonomic practices domain could be considered. Am. J. Ind. Med. 54:834–846, 2011. © 2011 Wiley Periodicals, Inc.
Comparing the risk factors associated with serious versus and less serious work‐related injuries in ontario between 1991 and 2006
Authors: Smith Peter , Hogg‐Johnson Sheilah , Mustard Cameron , Chen Cynthia , Tompa Emile
Published: August 2011

Background

The objective of this study was to examine and compare the demographic and labor market risks for more serious and less serious work‐related injuries and illnesses.

Methods

Secondary analysis of accepted workers' compensation claims in Ontario, combined with labor force estimates for the period 1991 to 2006. Serious injuries and illnesses were claims resulting in wage replacement. Less serious injuries and illnesses were claims only requiring health care. Regression models examined the relationship between demographic and labor market characteristics (age, gender, industry, job tenure, and unemployment) and claim type.

Results

Relative risk estimates for serious and less serious claims were not concordant across age, gender and industry employment groups. For example, while the mining and utilities and the construction industry had an increased probability of reporting NLTCs, they had a decreased probability of reporting LTCs.

Conclusions

The risk for serious and less serious work‐related injury and illness claims differ by demographic and labor market groups. The use of composite measures that combine wage‐replacement and health care only claims should be considered when using compensation data for surveillance and primary prevention targeting strategies. Am. J. Ind. Med. 55:84–91, 2012. © 2011 Wiley Periodicals, Inc.
Indexing disease progression at study entry with individuals at‐risk for Huntington disease
Authors: Zhang Ying , Long Jeffrey D. , Mills James A. , Warner John H. , Lu Wenjing , Paulsen Jane S. ,   the PREDICT‐HD Investigators and Coordinators of the Huntington Study Group
Published: August 2011

The identification of clinical and biological markers of disease in persons at risk for Huntington disease (HD) has increased in efforts to better quantify and characterize the epoch of prodrome prior to clinical diagnosis. Such efforts are critical in the design and implementation of clinical trials for HD so that interventions can occur at a time most likely to increase neuronal survival and maximize daily functioning. A prime consideration in the examination of prodromal individuals is their proximity to diagnosis. It is necessary to quantify proximity so that individual differences in key marker variables can be properly interpreted. We take a data‐driven approach to develop an index that can be viewed as a proxy for time to HD diagnosis known as the CAG‐Age Product Scaled or CAPS. CAPS is an observed utility variable computed for all genetically at‐risk individuals based on age at study entry and CAG repeat length. Results of a longitudinal receiver operating characteristic (ROC) analysis showed that CAPS had a relatively strong ability to predict individuals who became diagnosed, especially in the first 2 years. Bootstrap validation provided evidence that CAPS computed on a new sample from the same population could have similar discriminatory power. Cutoffs for the empirical CAPS distribution can be used to create a classification for mutation‐positive individuals (Low–Med–High), which is, useful for comparison with the naturally occurring mutation‐negative Control group. The classification is an improvement over the one currently in use as it is based on observed data rather than model‐based estimated values. © 2011 Wiley‐Liss, Inc.
Optimization of base‐catalyzed ethyl ester production from palm oil
Authors: Shahla Sanaz , Ngoh Gek Cheng , Yusoff Rozita
Published: August 2011

Plant‐based ethyl esters can be used directly as biodiesel or as a bio‐resource for other industries such as lubricant and detergents. In this work, production of ethyl ester from chemical transesterification of palm oil with ethanol using sodium ethoxide as catalyst has been optimized by Box‐Behnken design and response surface methodology. Catalyst concentration was found to be the most significant parameter affecting the conversion rate of the reaction. The interaction of temperature and molar ratio of ethanol to palm oil had minor effect on the conversion rate. A reduced cubic model was developed to navigate the design space. It was predicted by the model at optimum reaction conditions, that is 1.2 wt% of sodium ethoxide and 12:1 molar ratio of ethanol to oil at 25 °C, that as high as 98% ethyl ester can be achieved. It was then verified experimentally that close to 100% conversion rate is achievable under these optimum conditions. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Orthology prediction methods: A quality assessment using curated protein families
Authors: Trachana Kalliopi , Larsson Tomas A. , Powell Sean , Chen Wei‐Hua , Doerks Tobias , Muller Jean , Bork Peer
Published: August 2011

The increasing number of sequenced genomes has prompted the development of several automated orthology prediction methods. Tests to evaluate the accuracy of predictions and to explore biases caused by biological and technical factors are therefore required. We used 70 manually curated families to analyze the performance of five public methods in Metazoa. We analyzed the strengths and weaknesses of the methods and quantified the impact of biological and technical challenges. From the latter part of the analysis, genome annotation emerged as the largest single influencer, affecting up to 30% of the performance. Generally, most methods did well in assigning orthologous group but they failed to assign the exact number of genes for half of the groups. The publicly available benchmark set (http://eggnog.embl.de/orthobench/) should facilitate the improvement of current orthology assignment protocols, which is of utmost importance for many fields of biology and should be tackled by a broad scientific community.
Determination of deferiprone in urine and serum using a terbium‐sensitized luminescence method
Authors: Manzoori Jamshid L. , Amjadi Mohammad , Soleymani Jafar , Tamizi Elnaz , Rezamand Azim , Jouyban Abolghasem
Published: August 2011

Optimized conditions, validation and practical applications of a new, rapid and specific fluorometric method for the determination of deferiprone (DFP) in urine and serum samples are reported. The proposed method, which is based on the formation of a luminescent complex with Tb3+ ion, is evaluated in terms of linearity, accuracy, precision, stability, recovery and limits of detection (LOD) and quantification (LOQ). Under optimum conditions (pH 7.5, [Tb3+] = 3 × 10–4 mol/L, temperature 0 °C and excitation wavelength 295 nm), the relative intensities at 545 nm are linear, with the concentration of DFP in the range 0.072–13 mmol/L for urine and serum samples. The LOD and LOQ, respectively, are calculated to be 0.014 and 0.045 mmol/L for urine and 0.022 and 0.072 mmol/L for serum samples. The intra‐day and inter‐day values for the precision and accuracy of the proposed method are all < 5%, and the recovery of the method is in the range 97.1–103.8%. The method was applied to human urine and serum samples collected from patients receiving DFP. The results indicated that the method can be successfully applied to the determination of DFP in human urine and serum samples collected for clinical or biopharmaceutical investigations in which simple, rapid, cheap and specific determination methods facilitate and speed up the analytical procedure. Copyright © 2011 John Wiley & Sons, Ltd.
Food‐grade gene expression in lactic acid bacteria
Authors: Peterbauer Clemens , Maischberger Thomas , Haltrich Dietmar
Published: August 2011

In the 1990s, significant efforts were invested in the research and development of food‐grade expression systems in lactic acid bacteria (LAB). At this time, Lactococcus lactis in particular was demonstrated to be an ideal cell factory for the food‐grade production of recombinant proteins. Steady progress has since been made in research on LAB, including Lactococcus, Lactobacillus and Streptococcus, in the areas of recombinant enzyme production, industrial food fermentation, and gene and metabolic pathway regulation. Over the past decade, this work has also led to new approaches on chromosomal integration vectors and host/vector systems. These newly constructed food‐grade gene expression systems were designed with specific attention to self‐cloning strategies, food‐grade selection markers, plasmid replication and chromosomal gene replacements. In this review, we discuss some well‐characterized chromosomal integration and food‐grade host/vector systems used in LAB, with a special focus on sustainability, stability and overall safety, and give some attractive examples of protein expression that are based on these systems.
Intramolecular CH···O Hydrogen‐bond mediated stabilization of a Cis‐DPro imide‐bond in a stereocontrolled heterochiral model peptide
Authors: Bhadbhade Mohan M. , Kishore Raghuvansh
Published: August 2011

The X‐ray diffraction analysis of a stereocontrolled heterochiral designed model peptide Boc‐DPro‐Thr‐OMe (1) revealed the existence of an unusual folded molecular structure, stabilized via an effective unconventional CH…O type intramolecular hydrogen‐bond, encompassing a noncovalent 12‐membered ring‐motif. Together with an uncommon type a disposition of the urethane moiety, the tightly folded topology is compounded with a cis‐DPro imide‐bond. The overall conformation is suggested to be the reminiscent of specific type VI β‐turn structures, hitherto, characterized across the Aaa‐cis‐Pro peptide‐bonds in globular proteins and polypeptides. The 13C NMR spectrum of 1 in an apolar CDCl3 environment revealed the presence of approximately an equal population of cis and trans isomers unexpectedly, analogous to Pro side‐chain, the 13C NMR chemical‐shifts of Thr Cβ‐resonance is observed to be sensitive toward cis‐trans isomerization. In conjunction with solid‐state FT‐IR spectral data, we established that a network of complex intermolecular hydrogen‐bonds stabilize a self‐complementary noncovalent helical hexagonal self‐assembly and crystallographic supramolecular aggregate. The results incline us to highlight that the stabilization of cis‐DPro peptide‐bond in crystalline state may be driven by the favorable energy of formation of an unconventional weak CH…O intramolecular hydrogen‐bond. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 73–82, 2012.
Comparison of solution conformations and stabilities of modified helix 69 rRNA analogs from bacteria and human
Authors: Sumita Minako , Jiang Jun , SantaLucia John , Chow Christine S.
Published: August 2011

The helix 69 (H69) region of the large subunit (28S) ribosomal RNA (rRNA) of Homo sapiens contains five pseudouridine (Ψ) residues out of 19 total nucleotides, three of which are highly conserved. In this study, the effects of this abundant modified nucleotide on the structure and stability of H69 were compared with those of uridine in double‐stranded (stem) regions. These results were compared with previous hairpin (stem plus single‐stranded loop) studies to understand the contributions of the loop sequences to H69 structure and stability. The role of a loop nucleotide substitution from an A in bacteria (position 1918 in Escherichia coli 23S rRNA) to a G in eukaryotes (position 3734 in H. sapiens 28S rRNA) was examined. Thermodynamic parameters for the duplex RNAs were obtained through UV melting studies, and differences in the modified and unmodified RNA structures were examined by circular dichroism spectroscopy. The overall folded structure of human H69 appears to be similar to the bacterial RNA, consistent with the idea that ribosome structure and function are highly conserved; however, our results reveal subtle differences in structure and stability between the bacterial and human H69 RNAs in both the stem and loop regions. These findings may be significant with respect to H69 as a potential drug target site. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 94–106, 2012.
Controlling the dimensions of amyloid fibrils: Toward homogenous components for bionanotechnology
Authors: Domigan Laura J. , Healy Jackie P. , Meade Susie J. , Blaikie Richard J. , Gerrard Juliet A.
Published: August 2011

Amyloid fibrils have been recognized as having potential in a variety of bionanotechnological applications. However, realization of these applications is constrained by a lack of control over morphology and alignment, both crucial for potential end uses. This article focuses on the use of growth and storage conditions to control the length of amyloid fibrils formed from bovine insulin, with length distributions constructed from transmission electron microscopy (TEM) images. Growth temperature, pH, protein concentration, and storage conditions were examined and were seen to offer a range of conditions that favor different length distribution. The use of amyloid fibrils as nanowires is one area where control of fibril dimensions is desirable, for experimental setup and endpoint applications. The conductive properties of fibrils formed from bovine insulin are presented, with these insulin fibrils being shown to have high resistivity in their unmodified state, with current values in the nanoamp range. These low current values can be increased via modification, or the fibrils used in their native state in applications where low current values are desirable. These findings, coupled with the ability to predict and select for various insulin amyloid fibril dimensions, enhances their utility as nanomaterials. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 123–133, 2012.
Transient hydrogen bonding in uniformly 13C,15N‐Labeled Carbohydrates in Water
Authors: Norris Scott E. , Landström Jens , Weintraub Andrej , Bull Thomas E. , Widmalm Göran , Freedberg Darón I.
Published: August 2011

We report NMR studies of transient hydrogen bonding in a polysaccharide (PS) dissolved in water without cosolvent at ambient temperature. The PS portion of the Escherichia coli O142 lipopolysaccharide is comprised of repeating pentasaccharide units of GalNAc (N‐acetyl galactosamine), GlcNAc (N‐acetyl glucosamine), and rhamnose in a 3:1:1 ratio, respectively. A 105‐ns molecular dynamics (MD) simulation on one pentasaccharide repeat unit predicts transient inter‐residue hydrogen bonds from the GalNAc NH groups in the PS. To investigate these predictions experimentally, the PS was uniformly 13C,15N enriched and the NH, carbonyl, C2, C4, and methyl resonances of the GalNAc and GlcNAc residues assigned using through‐bond triple‐resonance NMR experiments. Temperature dependence of amide NH chemical shifts and one‐bond NH J couplings support that NH groups on two of the GalNAc residues are donors in transient hydrogen bonds. The remaining GalNAc and GlcNAc NHs do not appear to be donors from either temperature‐dependent chemical shifts or one‐bond NH J couplings. These results substantiate the presence of weak or partial hydrogen bonds in carbohydrates, and that MD simulations of repeating units in PSs provide insight into overall PS structure and dynamics. Published 2011 Wiley Periodicals, Inc. Biopolymers 97: 145–154, 2012.
Quantitative analysis of the fermentative metabolism of glycerol in Escherichia coli
Authors: Cintolesi Angela , Clomburg James M. , Rigou Venetia , Zygourakis Kyriacos , Gonzalez Ramon
Published: August 2011

Availability, low price, and high degree of reduction have made glycerol a highly attractive and exploited carbon source for the production of fuels and reduced chemicals. Here we report the quantitative analysis of the fermentative metabolism of glycerol in Escherichia coli through the use of kinetic modeling and metabolic control analysis (MCA) to gain a better understanding of glycerol fermentation and identify key targets for genetic manipulation that could enhance product synthesis. The kinetics of glycerol fermentation in a batch culture was simulated using a dynamic model consisting of mass balances for glycerol, ethanol, biomass, and 11 intracellular metabolites, along with the corresponding kinetic expressions for the metabolism of each species. The model was then used to calculate metabolic control coefficients and elucidate the control structure of the pathways involved in glycerol utilization and ethanol synthesis. The calculated flux control coefficients indicate that the glycolytic flux during glycerol fermentation is almost exclusively controlled by the enzymes glycerol dehydrogenase (encoded by gldA) and dihydroxyacetone kinase (DHAK) (encoded by dhaKLM). In agreement with the MCA findings, overexpression of gldA and dhaKLM led to significant increase in glycerol utilization and ethanol synthesis fluxes. Moreover, overexpression of other enzymes involved in the pathways that mediate glycerol utilization and its conversion to ethanol had no significant impact on glycerol utilization and ethanol synthesis, further validating the MCA predictions. These findings were then applied as a means of increasing the production of ethanol: overexpression of glycerol dehyrdogenase and DHAK enabled the production of 20 g/L ethanol from crude glycerol, a by‐product of biodiesel production, indicating the potential for industrial scale conversion of waste glycerol to ethanol under anaerobic conditions. Biotechnol. Bioeng. 2012;109: 187–198. © 2011 Wiley Periodicals, Inc.
Synthesis of FAEEs from glycerol in engineered Saccharomyces cerevisiae using endogenously produced ethanol by heterologous expression of an unspecific bacterial acyltransferase
Authors: Yu Kyung Ok , Jung Ju , Kim Seung Wook , Park Chul Hwan , Han Sung Ok
Published: August 2011

The high price of petroleum‐based diesel fuel has led to the development of alternative fuels, such as ethanol. Saccharomyces cerevisiae was metabolically engineered to utilize glycerol as a substrate for ethanol production. For the synthesis of fatty acid ethyl esters (FAEEs) by engineered S. cerevisiae that utilize glycerol as substrate, heterologous expression of an unspecific acyltransferase from Acinetobacter baylyi with glycerol utilizing genes was established. As a result, the engineered YPH499 (pGcyaDak, pGupWs‐DgaTCas) strain produced 0.24 g/L FAEEs using endogenous ethanol produced from glycerol. And this study also demonstrated the possibility of increasing FAEE production by enhancing ethanol production by minimizing the synthesis of glycerol. The overall FAEE production in strain YPH499 fps1Δ gpd2Δ (pGcyaDak, pGupWs‐DgaTCas) was 2.1‐fold more than in YPH499 (pGcyaDak, pGupWs‐DgaTCas), with approximately 0.52 g/L FAEEs produced, while nearly 17 g/L of glycerol was consumed. These results clearly indicated that FAEEs were synthesized in engineered S. cerevisiae by esterifying exogenous fatty acids with endogenously produced ethanol from glycerol. This microbial system acts as a platform in applying metabolic engineering that allows the production of FAEEs from cheap and abundant substrates specifically glycerol through the use of endogenous bioethanol. Biotechnol. Bioeng. 2012;109: 110–115. © 2011 Wiley Periodicals, Inc.
Putting cells under pressure: A simple and efficient way to enhance the productivity of medium‐chain‐length polyhydroxyalkanoate in processes with Pseudomonas putida KT2440
Authors: Follonier Stéphanie , Henes Bernhard , Panke Sven , Zinn Manfred
Published: August 2011

The success of bioprocess implementation relies on the ability to achieve high volumetric productivities and requires working with high‐cell‐density cultivations. Elevated atmospheric pressure might constitute a promising tool for enhancing the oxygen transfer rate (OTR), the major growth‐limiting factor for such cultivations. However, elevated pressure and its effects on the cellular environment also represent a potential source of stress for bacteria and may have negative effects on product formation. In order to determine whether elevated pressure can be applied for enhancing productivity in the case of medium‐chain‐length polyhydroxyalkanoate (mcl‐PHA) production by Pseudomonas putida KT2440, the impact of a pressure of 7 bar on the cell physiology was assessed. It was established that cell growth was not inhibited by this pressure if dissolved oxygen tension (DOT) and dissolved carbon dioxide tension (DCT) were kept below ∼30 and ∼90 mg L−1, respectively. Remarkably, a little increase of mcl‐PHA volumetric productivity was observed under elevated pressure. Furthermore, the effect of DCT, which can reach substantial levels during high‐cell‐density processes run under elevated pressure, was investigated on cell physiology. A negative effect on product formation could be dismissed since no significant reduction of mcl‐PHA content occurred up to a DCT of ∼540 mg L−1. However, specific growth rate exhibited a significant decrease, indicating that successful high‐cell‐density processes under elevated pressure would be restricted to chemostats with low dilution rates and fed‐batches with a small growth rate imposed during the final part. This study revealed that elevated pressure is an adequate and efficient way to enhance OTR and mcl‐PHA productivity. We estimate that the oxygen provided to the culture broth under elevated pressure would be sufficient to triple mcl‐PHA productivity in our chemostat system from 3.4 (at 1 bar) to 11 g L−1 h−1 (at 3.2 bar). Biotechnol. Bioeng. 2012; 109:451–461. © 2011 Wiley Periodicals, Inc.
Self-expanding metallic stents for large bowel obstruction
Authors: Mackay C D , Craig W , Hussey J K , Loudon M A
Published: August 2011

Background

Self-expanding metallic stents (SEMS) may relieve colonic obstruction as definitive therapy or as a bridge to elective surgery.

Methods

This was a retrospective longitudinal cohort study of patients undergoing insertion of SEMS for large bowel obstruction at one institution. Scrutiny of the radiology department's coding system allowed identification of all patients undergoing colonic stent insertion between 2002 and 2008. Data were extracted from patient case notes and investigation reports.

Results

Eighty-two patients with a median age of 75 (interquartile range (i.q.r.) 43–94) years underwent stent insertion, 71 for palliation and 11 as a bridge to surgery. Obstruction was due to malignant disease in 67 patients and had a benign cause in 15. Median survival in the palliative setting was 103 (i.q.r. 44–317) days. Complications occurred in 43 patients, of whom 22 underwent unplanned surgery. High-grade obstruction (relative risk (RR) 2·05; P = 0·055) and benign disease (RR 3·45; P < 0·001) were associated with risk of adverse events.

Conclusion

SEMS should not be used for large bowel obstruction with benign pathology.