bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrogen Production via Hydrolysis of Zn in a Hot Wall Flow Reactor
Authors: Abu Hamed Tareq , Davidson Jane H. , Stolzenburg Mark
Published: February 2009

Hydrolysis of Zn is investigated as the second step in a ZnO/Zn redox solar water splitting process. Zinc is evaporated and hydrolyzed in a hot wall flow tubular reactor. The design of the reactor was suggested by prior studies at ETH-Swiss Federal Institute in which simultaneous synthesis of hydrogen and zinc oxide nanoparticles was the goal. The influence of the reactor temperature and residence time on hydrogen conversion was measured for 1023 and 1073 K. Particle yield was measured in-situ using a scanning differential mobility sizer. Particle composition and morphology were characterized with X-ray diffraction and microscopy. In agreement with the prior work, hydrogen conversions of 87 to 96 percent at temperatures above zinc saturation are attributed primarily to hydrolysis of zinc(g) at the wall of the reactor.
A Material and Energy Flow Analysis of South Carolina: Past, Present, and Future
Authors: Russell James A. , Peters Wally H.
Published: February 2009

Material and energy flows and land use in North America have shifted dramatically in the last several decades and even more dramatically over the last few centuries. As concerns mount regarding the environmental, economic, and social costs of imported energy sources; feasibility studies of energy independence are one tool for guiding energy policy decisions. This paper reviews the changes in land use, material flows, and energy flows in South Carolina over the past 400 years; showing the shift from a near hunter gatherer society, to an export based agrarian society, to the current fossil fuel dependent society. These phases and their impacts are compared and an analysis is carried out to determine the feasibility of maintaining the current system without the input of materials or energy from outside the geographic borders of the state. Historical data is combined with geospatial data sets to determine levels and limits of energy use and availability. Results include an assessment of the feasibility of using biomass, solar thermal, and solar photovoltaic technologies to maintain the current levels of consumption.
Furthur Analysis of Accelerated Exposure Testing of Thin-Glass Mirror Matrix
Authors: Kennedy C. E. , Terwilliger K. , Jorgensen G. J.
Published: February 2009

Concentrating solar power (CSP) companies have deployed thin-glass mirrors produced by wet-silver processes on ∼1-mm-thick, relatively lightweight glass. These mirrors are bonded to metal substrates in commercial installations and have the confidence of the CSP industry. Initial hemispherical reflectance is ∼93%–96%, and the cost is ∼$16.1/m2–$43.0/m2. However, corrosion was observed in mirror elements of operational solar systems deployed outdoors for 2 years. National Renewable Energy Laboratory (NREL) Advanced Materials Team has been investigating this problem. First, it was noted that this corrosion is very similar to the corrosion bands and spots observed on small (45 mm × 67 mm) thin-glass mirrors laminated to metal substrates with several different types of adhesives and subjected to accelerated exposure testing (AET) at NREL. The corrosion appears as dark splotches in the center of the mirror, with a corresponding 5%–20% loss in reflectivity. Secondly, two significant changes in mirror manufacture have occurred in the wet-chemistry process because of environmental concerns. The first is the method of forming a copper-free reflective mirror, and the second is the use of lead-free paints. However, the copper-free process requires stringent quality control and the lead-free paints were developed for interior applications. A test matrix of 84 combinations of sample constructions (mirror type/back-protective paint/adhesive/substrate) was devised for AET as a designed experiment to identify the most-promising mirrors, paints, and adhesives for use with concentrator designs. Two types of accelerated exposure were used: an Atlas Ci5000 WeatherOmeter (CI5000) and a BlueM damp-heat chamber. Based on an analysis of variance (ANOVA), the various factors and interactions were modeled. These samples now have more than 36 months of accelerated exposure, and most samples have completed their test cycle. We will discuss the results of the final exposure testing of these mirror samples. Glass mirrors with copper back-layers and heavily leaded paints have been considered robust for outdoor use. However, the basic mirror composition of the new mirrors is radically different from that of historically durable solar mirrors, and the outdoor durability must be determined.
Thermal Transport From a Rotating Disk During Partially Confined Liquid Jet Impingement
Authors: Lallave Jorge , Rahman Muhammad M.
Published: February 2009

This paper presents a numerical study that characterizes the conjugate heat transfer results of a semi–confined liquid jet impingement on a uniformly heated spinning solid disk of finite thickness and radius. The model covers the entire fluid region including the impinging jet on a flat circular disk and flow spreading out downstream under the confined insulated wall that ultimately gets exposed to a free surface boundary condition. The solution is made under steady state and laminar conditions. The model examines how the heat transfer is affected by adding a secondary rotational flow under semi-confined jet impingement. The study considered various standard materials, namely aluminum, copper, silver, Constantan and silicon; covering a range of flow Reynolds number (220–900), under a broad rotational rate range from 0 to 750 rpm, or Ekman number (7.08×10−5 – ∞), nozzle to target spacing (β = 0.25 – 1.0), disk thicknesses to nozzle diameter ratio (b/dn = 0.25 – 1.67), Prandtl number (1.29 – 124.44) using ammonia (NH3), water (H2O), flouroinert (FC-77) and oil (MIL-7808) as working fluids and solid to fluid thermal conductivity ratio (36.91 – 2222). High thermal conductivity plate materials maintained more uniform and lower interface temperature distributions. Higher Reynolds number increased local heat transfer coefficient reducing the interface temperature difference over the entire wall. Rotational rate increases local heat transfer coefficient under most conditions. These findings are important for the design improvement and control of semi-confined liquid jet impingement under a secondary rotation induced motion.
Economic Optimization of a Combined Heat and Power System for an Office Building
Authors: Douglas M. E. , Wagner Timothy C. , Sahm Michael K. , Wepfer William J.
Published: February 2009

The determination of a prime mover’s characteristics is important in ascertaining its suitability for combined heat and power (CHP) applications. By definition, its operation affects the operation of all heat recovery equipment downstream. The correct balance between component electrical efficiency and waste heat is needed if the electric power producing equipment is to be used in a CHP application in a cost effective manner. Understanding the relationship between electric efficiency and exhaust stream energy content for different prime movers systems is a first step in an overall CHP system optimization. The goals of this work are to determine the potential financial benefit of utilizing waste heat from various prime mover configurations as well as establish the relationship between the two types of energy generation and costs. An economic optimization was performed to determine the system with the lowest average product (electricity and thermal energy) generation cost. The prime mover system was required to meet the electrical load demand of a typical 9290 m2 (100,000 ft2) office building in New York, NY, USA. The composition of the most cost effective prime mover system, when considering both electrical and thermal energy generation, was shown to be a single microturbine. When comparing the electrical and thermal energy generation of all systems studied with product generation cost, the more cost effective systems had either high electrical efficiency with a low thermal energy generation or high amounts of waste heat with low electrical efficiency. Each installation site and load demand is unique. The results of this study, along with others, can be used to help determine a cost effective system for a particular application.
Gas Fired Test System for Stirling Engines
Authors: Lawler John P. , Lloyd Jimmy L.
Published: February 2009

Sandia National Laboratories in conjunction with Stirling Energy Systems (SES) has increased the capabilities of the National Solar Thermal Test Facility’s Engine Test Facility to include a gas fired burner for advance testing on the Kochums 4-95 Stirling engine. SES is using this engine in its current solar energy production system and is performing a redesign for manufacturability and reliability. The gas burner will aid in this task allowing a safe, controlled test environment. A burner was developed for the SES engine and tested at Arizona University. The gas and air controls were scavenged from an old gas fired Stirling engine test performed in the 1990s. Goals for the burner are to have the ability to do attended tests, but then have unattended tests. Due to equipment limitations, the gas and air control skid did not have these capabilities and was modified with newer equipment such as a PLC controller. Software to run the burner efficiently was developed and the system is prepared for testing a Stirling engine.
Transient Thermal Analysis of Cryogenic Liquid Hydrogen Tank With Active Circulation
Authors: Ho Son H. , Rahman Muhammad M.
Published: February 2009

This paper presents the transient analysis of fluid flow and heat transfer in a zero boil-off (ZBO) cryogenic storage tank of liquid hydrogen. The system includes a tank with cylindrical wall and oblate spheroidal top and bottom, a heat pipe located along the symmetric axis of the tank, and an active circulator. The heat pipe has a rounded evaporator section at its end. The active circulator is an assembly of a pump body, a suction tube for collecting fluid inside the tank, and a spray nozzle from which the fluid is discharged onto the evaporator section of the heat pipe, which is kept at a constant low temperature, where the heat is removed passively to the condenser section of the heat pipe located outside the tank and eventually to the ambient via a cryocooler. Whenever the maximum temperature inside the tank reaches the boiling point under the working pressure in the tank, the pump is activated to create a forced flow from the nozzle to cool off the heated fluid. After a preset period of time, the pump is shut down and standby until the maximum temperature reaches its threshold again and then the pump starts a new cycle. The transient simulations allow the visualization of flow field and temperature distribution, as well as the computation of maximum and mean temperatures of the fluid at various stages of the pump cycle.
Thermal Management Using Free Liquid Jet Impingement From a Slot Nozzle to a Curved Plate
Authors: Rahman Muhammad M. , Hernandez Cesar F.
Published: February 2009

The determination of a prime mover’s characteristics is important in ascertaining its suitability for combined heat and power (CHP) applications. By definition, its operation affects the operation of all heat recovery equipment downstream. The correct balance between component electrical efficiency and waste heat is needed if the electric power producing equipment is to be used in a CHP application in a cost effective manner. Understanding the relationship between electric efficiency and exhaust stream energy content for different prime movers systems is a first step in an overall CHP system optimization. The goals of this work are to determine the potential financial benefit of utilizing waste heat from various prime mover configurations as well as establish the relationship between the two types of energy generation and costs. An economic optimization was performed to determine the system with the lowest average product (electricity and thermal energy) generation cost. The prime mover system was required to meet the electrical load demand of a typical 9290 m2 (100,000 ft2) office building in New York, NY, USA. The composition of the most cost effective prime mover system, when considering both electrical and thermal energy generation, was shown to be a single microturbine. When comparing the electrical and thermal energy generation of all systems studied with product generation cost, the more cost effective systems had either high electrical efficiency with a low thermal energy generation or high amounts of waste heat with low electrical efficiency. Each installation site and load demand is unique. The results of this study, along with others, can be used to help determine a cost effective system for a particular application.
Numerical Simulation of Steady State Heat Transfer in a Microchannel With Obstruction
Authors: Injeti Phaninder , Rahman Muhammad M.
Published: February 2009

Effects of obstructions on the heat transfer in a microtube and a two-dimensional microchannel were investigated. The obstructions normally arise during the fabrication process on the inner surface of the microtube or microchannel. Various shapes and sizes of the obstruction were considered. The shapes that were modeled were rectangular, triangular, and semicircular obstructions. Calculations were done for incompressible flow of a Newtonian fluid with developing momentum and thermal boundary layers. Equations governing the conservation of mass, momentum and energy were solved for an isothermal condition at the wall. Comparison with no obstruction case was made. It was found that for microtubes, the local Nusselt number increases significantly at the obstruction whereas the average Nusselt number for the whole tube comes out somewhat lower. For two-dimensional microchannels, both local Nusselt number at the obstruction as well as average Nusselt number for the entire tube came out to be higher. The working fluids that were investigated were water and refrigerant R-134a. The results presented in the paper demonstrates that in microchannels and microtubes that are widely used in micro electro mechanical systems (MEMS), small defects in the fabrication process may lead to large changes in local as well as global performance of the device.
Spatial and Temporal Changes in Climatological Degree-Days in California
Authors: Lebassi B. , Gonza´lez J. E. , Bornstein R. , Fabris D.
Published: February 2009

Analysis of 35 years observed trends in summertime daily maximum and minimum temperatures in two non attainment California air basins showed coastal cooling and inland warming. To study the impact of these results on the energy consumption we analyzed the cooling/heating degree days (CDD/HDD) of California long term observed temperatures. In this research historical surface 2-m air temperature data analyses consist of long-term data records, from 273 locations in California, and the primary sources of such data include the cooperative network, first order National Weather Service stations, and military weather stations. Data were used from 273 cooperative stations with more than 100 stations in the northern Central Valley (CV) of California, each with 40 to 60 years of monthly average, minimum, and maximum temperature data records. About 100 of the stations are in the San Francisco Bay (SFB) and 30 of the stations are on the South Coast Air Basin (SoCAB) of California. Analysis of the CDD/HDD has been undertaken for California in general and in the SFB and SoCAB in particular, under regional climate change conditions. Regional climate fluctuations have larger effects on surface temperatures, which in turn affect the CDD and HDD. A closer look to the CDD reflects an asymmetric increase between the coast and inland regions of California during the last 35 years. In general coastal areas experienced historical decrease of CDD while inland regions experienced increase in CDD. This is attributed to the sea breeze flows, which suggest an increase of the cold marine air intrusion due to the increase of the regional sea breeze potential, which naturally ventilates the coastal areas.
Validation of Optical Modeling of Parabolic Trough Collectors by Flux Measurement
Authors: Schiricke Bjo¨rn , Pitz-Paal Robert , Lu¨pfert Eckhard , Neumann Andreas , Pottler Klaus , Pfa¨nder Markus , Riffelmann Klaus-Ju¨rgen
Published: February 2009

In order to optimize the solar field output of parabolic trough collectors (PTC) it is essential to study the influence of collector and absorber geometry on the optical performance. The optical ray-tracing model of PTC conceived for this purpose uses photogrammetrically measured concentrator geometry in commercial Monte Carlo ray tracing software. The model has been validated with measurements of a scanning flux measurement system, measuring the solar flux density distribution close to the focal line of the PTC. The tool uses fiber optics and a CCD-camera to scan the focal area of a PTC module. Since it is able to quantitatively detect spilled light with good spatial resolution it provides an evaluation of the optical efficiency of the PTC. For comparison of ray tracing predictions with measurements, both flux maps and collector geometry have been measured under identical conditions on the Eurotrough prototype collector at PSA. The validation of the model is provided by three methods: the comparison of measured intercept factors with corresponding simulations; comparison of measured flux density distributions with corresponding ray tracing predictions; and comparison of thermographically measured temperature distribution on the absorber surface with flux density distribution predicted for this surface. Examples of sensitivity studies performed with the validated model are shown.
Design and Analysis of Urban Building Integrated Photovoltaic System Simulation Software
Authors: Guragain Mandeep , Rapolu Kalyan , Singh Pritpal
Published: February 2009

A single comprehensive software package was developed for architects and building designers to optimize suitable location on various fac¸ades of urban buildings, where when photovoltaic modules were placed, would generate maximum energy. AutoCAD, the most widely used software by building architects, along with the ECOTECT, a building analysis tool, were used as primary tools in this software package. The process of solar analysis was automated with the help of customizing tools such as LISP, Visual Basic for Application and LUA scripts, creating a single plug-in for AutoCAD. The objective of this software package is to perform solar radiation analysis and obtain performance characteristics of the Building Integrated Photovoltaic (BIPV) system, taking into account shading and reflection from neighboring buildings, all within AutoCAD environment. In this project, we developed an urban building model in AutoCAD and performed the solar radiation analysis with the developed software tool. The performance characteristics were obtained and compared with the results from MATLAB model, previously presented [1]. The software package also incorporates provision to calculate energy from various commercially available solar modules.
Impact of Shape on Thermal Performance of Office Buildings in Kuwait
Authors: Al-Anzi Adnan , Seo Donghyun , Krarti Moncef
Published: February 2009

This paper provides a simplified analysis method to estimate the impact of building shape on energy efficiency of office buildings in Kuwait. The method is based on results obtained from a comprehensive whole building energy simulation analysis. The analysis takes into account several building shapes and forms including rectangular, L-shape, U-shape, and H-shape as well as building aspect ratios, window-to-wall-ratios, and glazing types. The simplified method is suitable for architects during preliminary design phase to assess the impact of shape on the energy efficiency of office buildings.
Interrelations Between Hourly and Daily Global and Diffuse Illuminance
Authors: Satyamurty V. V. , RaviKumar P.
Published: February 2009

In the present article, interrelations between hourly and daily global and diffuse solar illuminance have been developed. By examining a large database, 56 primary locations, of TMY2 [1], it has been found that the values of ratio of hourly global or diffuse illuminance to corresponding daily values, (rvt = Iv/Hv ; rvd = 1vd/Hvd), are very close to the corresponding values for global and diffuse solar radiation, rt = I/H; rd = Id/Hd). Thus, it has been proposed that the existing correlations for rt and rd be employed to calculate rvt and rvd. The performance of the existing correlations for rt and rd to predict rvt and rvd has been evaluated employing TMY2 data and data of 6 IDMP (International Daylight Measurement Programme) [2] locations. It has been found that the correlation for rt due to Collares-Pereira and Rabl [3] predicts rvt satisfactorily. Correlation due to Satyamurty and Lahiri [4] for rd predicts rvd satisfactorily after suitable modification.
Airflow Distribution and Microenvironment Evaluation of MP Task Conditioning System
Authors: Zheng Guozhong , Jing Youyin , Huang Hongxia , Shi Lijun
Published: February 2009

During recent years an increasing amount of attention has been paid to air distribution systems with which officer can individually condition the immediate environment of their workstations. Fanger suggested supplying ventilation air that is unmixed with room air, directly to the breathing zone of each occupant. Task conditioning aims to provide each occupant with personalized clean air direct to the breathing zone. Each occupant can control the environment at his/her workplace. Microenvironment of a typical office workplace consisting of movable panel (MP) task conditioning systems was studied by numerical simulation. MP task conditioning systems were operated while a conventional HVAC system supplied air through a diffuser located in the ceiling. Air was exhausted through a ducted ceiling-level grill. Numerical simulation of 3-D turbulent flow (k-ε closure) was separately conducted to study the influence of supply velocity, air blowing distance and size of MP supply outlet on microenvironment. Three task conditioning velocities, 0.6, 0.8 and 1.0m/s, three sizes 0.3×0.15, 0.3×0.1 and 0.25×0.08m and two air blowing distances were studied. In addition to analyzing temperature and velocity distribution, Draught Rating (DR) and Predicted Percentage of Dissatisfied (PPD) of the room and workstation were studied.
Investigation of Exergetic Efficiency and Thermodynamic Parameters of the Salihli Geothermal District Heating System
Authors: Ozgener Leyla , Ozgener Onder
Published: February 2009

This study investigates thermodynamic parameters and exergetic efficiency of the Salihli geothermal district heating system (SGDHS) in Manisa, Turkey for 2005/2006 heating season. The thermodynamic parameters considered are as follows: (i) fuel depletion rate, (ii) relative irreversibility, (iii) productivity lack, and (iv) exergetic factor. These parameters are determined for the system to assess and compare their individual performances. While the highest relative irreversibilities occur in the heat exchangers with the values of 44% for the SGDHS, exergetic efficiency of the system is found to be 60.3%.
Exergetic Performance Analysis of a Gas Turbine Cycle Integrated With Solid Oxide Fuel Cells
Authors: Granovskii Mikhail , Dincer Ibrahim , Rosen Marc A.
Published: February 2009

This paper deals with an exergetic performance analysis of a gas turbine cycle integrated with SOFCs with internal reforming. As the efficiency of a gas turbine cycle is mainly defined by the maximum temperature at the turbine inlet, this temperature is fixed at 1573 K for the analysis. In the cycle considered, the high-temperature gaseous flow from the turbine heats the input flows of natural gas and air, and is used to generate pressurized steam which is mixed with natural gas at the SOFC stack inlet to facilitate its conversion. The application of SOFCs provides the opportunity to reduce the exergy losses of the most irreversible process in the system: fuel combustion. Depending on the SOFC stack efficiency, the energy efficiency of the combined cycle reaches 70–80% which compares well to the efficiencies of 54–55% typical of conventional combined power generation cycles. Parametric studies are also undertaken to investigate how energy and exergy efficiencies of the integrated system change with variations in operating conditions. An increase in the efficiency of SOFCs is attained by increasing the fuel cell active area. Achieving the highest efficiency of the SOFC stack leads to a significant and non-proportional increase in the stack size and cost, and simultaneously to a decrease in steam generation, reducing the steam/methane ratio at the anode inlet and increasing the possibility of catalyst coking. Accounting for these factors, likely operating conditions of the SOFC stack in combination with a gas turbine cycle are presented.
Application of Genetic Algorithm (GA) Technique on Demand Estimation of Fossil Fuels in Turkey
Authors: Canyurt Olcay Ersel , O¨ztu¨rk Harun Kemal
Published: February 2009

The main objective of the present study is to investigate Turkey’s fossil fuels demand, projection and supplies by giving the structure of the Turkish industry and Turkish economic conditions. This present study develops several scenarios to analyze fossil fuels; such as, coal, oil and natural gas consumption and make future projections based on Genetic Algorithm (GA) notion, and examines the effect of the design parameters on the fossil fuels utilization values. The models developed in the nonlinear form are applied to the coal, oil and natural gas demand of Turkey. Several Genetic Algorithm Demand Estimation Models (GA-DEM) are developed to estimate the future coal, oil and natural gas demand values based on population, Gross National Product (GNP), import, export figures. It may be concluded that the proposed models can be used as an alternative solution and estimation techniques for the future fossil fuel utilization values of any country. Oil is the most important fuel in Turkey, contributing 43% of the Total Primary Energy Supply (TPES), followed by coal (almost 30% of TPES) and natural gas (11.8%). In the study, coil, oil and natural gas consumption of Turkey are projected. Estimation shows that the coal, oil and natural gas consumption values may increase 2.82, 1.73 and 4.83 times from 2000 to 2020.
Exergetic Optimization of Generated Electric Power Split in a Heat Pump Coupled Poly-Generation System
Authors: Kilkis Birol I. , Kilkis Siir
Published: February 2009

This study analyzes environmental, energy, and economical benefits of a ground source heat pump coupled poly-generation system by incorporating exergy into the energy efficiency analysis. Two additional terms, namely the rational exergy efficiency and the coefficient of performance were introduced to the primary energy savings equation in the European Union Directive 2004/8/EC. Based on the new equation, an optimization algorithm was developed, which can quantify the environmental, energy and economy benefits of any poly-generation system in a broader extent and scope. This algorithm was used to investigate the factors affecting the optimum split of the power generated by a poly-generation system between the heat pump and the customer. A base system was analyzed, which consists of a ground-source heat pump (GSHP) and a combined heat and power (CHP) system. Results show that any increase in the split in favor of the heat pump boosts the primary energy savings potential and thus CO2 emissions reducing potential while the pay-back period of the system is reduced. When all the constraints, including electricity and fuel costs in the energy market are taken into account, a one-to-three split seems to be optimal for many practical applications. It is concluded that benefits of CHP may be enhanced by GSHP coupling pending a careful exergy balance analysis between the resource supply and the application demand. This paper provides the fundamentals of the algorithm and discusses that a win-win-win situation among the environment, energy, and economy is feasible, most importantly, from the global warming perspective.
A New Metric for Net-Zero Carbon Buildings
Authors: Kilkis Siir
Published: February 2009

In this study a new carbon equivalency metric was developed in order to quantify the compound carbon emissions that buildings are responsible in the built environment. This metric first analyses the rationale about the management of exergy balance among supply and demand involved in satisfying building power and energy loads. Then using the degree of the rationale found, direct carbon emissions from the building and avoidable secondary carbon emissions that the building is responsible due to exergy mismatches are calculated. Based on this metric a net-zero carbon building definition was introduced and its advantages for quantifying the actual impact of buildings on global sustainability were discussed in comparison to net-zero energy building and carbon neutral building concepts. A case study for an example net-zero energy building is presented, which reveals that the new carbon equivalency metric can indicate whether the building is actually environmentally neutral or not. Results show that the example building has negative impact on environment and global sustainability in terms of carbon emissions even though it is rated a net-zero building. This paper also discusses that although another new net-zero exergy building definition may reduce the shortcomings of the net-zero building definition, only the net-zero carbon building metric may accurately rate the environmental impact of buildings. Beyond carbon emissions from buildings, the same metric can be used for any variety of greenhouse emissions and sectors.
In Bad Taste: Evidence for the Oral Origins of Moral Disgust
Authors: Chapman H. A. , Kim D. A. , Susskind J. M. , Anderson A. K.
Published: February 2009

In common parlance, moral transgressions “leave a bad taste in the mouth.” This metaphor implies a link between moral disgust and more primitive forms of disgust related to toxicity and disease, yet convincing evidence for this relationship is still lacking. We tested directly the primitive oral origins of moral disgust by searching for similarity in the facial motor activity evoked by gustatory distaste (elicited by unpleasant tastes), basic disgust (elicited by photographs of contaminants), and moral disgust (elicited by unfair treatment in an economic game). We found that all three states evoked activation of the levator labii muscle region of the face, characteristic of an oralnasal rejection response. These results suggest that immorality elicits the same disgust as disease vectors and bad tastes.
Mutations in FUS, an RNA Processing Protein, Cause Familial Amyotrophic Lateral Sclerosis Type 6
Authors: Vance Caroline , Rogelj Boris , Hortobágyi Tibor , De Vos Kurt J. , Nishimura Agnes Lumi , Sreedharan Jemeen , Hu Xun , Smith Bradley , Ruddy Deborah , Wright Paul , Ganesalingam Jeban , Williams Kelly L. , Tripathi Vineeta , Al-Saraj Safa , Al-Chalabi Ammar , Leigh P. Nigel , Blair Ian P. , Nicholson Garth , de Belleroche Jackie , Gallo Jean-Marc , Miller Christopher C. , Shaw Christopher E.
Published: February 2009

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that is familial in 10% of cases. We have identified a missense mutation in the gene encoding fused in sarcoma (FUS) in a British kindred, linked to ALS6. In a survey of 197 familial ALS index cases, we identified two further missense mutations in eight families. Postmortem analysis of three cases with FUS mutations showed FUS-immunoreactive cytoplasmic inclusions and predominantly lower motor neuron degeneration. Cellular expression studies revealed aberrant localization of mutant FUS protein. FUS is involved in the regulation of transcription and RNA splicing and transport, and it has functional homology to another ALS gene,
TARDBP
, which suggests that a common mechanism may underlie motor neuron degeneration.
Mutations in the
FUS/TLS
Gene on Chromosome 16 Cause Familial Amyotrophic Lateral Sclerosis
Authors: Kwiatkowski T. J. , Bosco D. A. , LeClerc A. L. , Tamrazian E. , Vanderburg C. R. , Russ C. , Davis A. , Gilchrist J. , Kasarskis E. J. , Munsat T. , Valdmanis P. , Rouleau G. A. , Hosler B. A. , Cortelli P. , de Jong P. J. , Yoshinaga Y. , Haines J. L. , Pericak-Vance M. A. , Yan J. , Ticozzi N. , Siddique T. , McKenna-Yasek D. , Sapp P. C. , Horvitz H. R. , Landers J. E. , Brown R. H.
Published: February 2009

Amyotrophic lateral sclerosis (ALS) is a fatal degenerative motor neuron disorder. Ten percent of cases are inherited; most involve unidentified genes. We report here 13 mutations in the
fused in sarcoma/translated in liposarcoma
(
FUS/TLS
) gene on chromosome 16 that were specific for familial ALS. The FUS/TLS protein binds to RNA, functions in diverse processes, and is normally located predominantly in the nucleus. In contrast, the mutant forms of
FUS/TLS
accumulated in the cytoplasm of neurons, a pathology that is similar to that of the gene
TAR DNA-binding protein 43
(
TDP43
), whose mutations also cause ALS. Neuronal cytoplasmic protein aggregation and defective RNA metabolism thus appear to be common pathogenic mechanisms involved in ALS and possibly in other neurodegenerative disorders.
Antagonistic Actions of Msx1 and Osr2 Pattern Mammalian Teeth into a Single Row
Authors: Zhang Zunyi , Lan Yu , Chai Yang , Jiang Rulang
Published: February 2009

Mammals have single-rowed dentitions, whereas many nonmammalian vertebrates have teeth in multiple rows. Neither the molecular mechanism regulating iterative tooth initiation nor that restricting mammalian tooth development in one row is known. We found that mice lacking the transcription factor odd-skipped related-2 (Osr2) develop supernumerary teeth lingual to their molars because of expansion of the odontogenic field. Osr2 was expressed in a lingual-to-buccal gradient and restricted expression of bone morphogenetic protein 4 (Bmp4), an essential odontogenic signal, in the developing tooth mesenchyme. Expansion of odontogenic field in
Osr2
-deficient mice required Msx1, a feedback activator of
Bmp4
expression. These findings suggest that the Bmp4-Msx1 pathway propagates mesenchymal activation for sequential tooth induction and that spatial modulation of this pathway provides a mechanism for patterning vertebrate dentition.
Meropenem-Clavulanate Is Effective Against Extensively Drug-Resistant
Mycobacterium tuberculosis
Authors: Hugonnet Jean-Emmanuel , Tremblay Lee W. , Boshoff Helena I. , Barry Clifton E. , Blanchard John S.
Published: February 2009

β-lactam antibiotics are ineffective against
Mycobacterium tuberculosis
, being rapidly hydrolyzed by the chromosomally encoded
blaC
gene product. The carbapenem class of β-lactams are very poor substrates for BlaC, allowing us to determine the three-dimensional structure of the covalent BlaC-meropenem covalent complex at 1.8 angstrom resolution. When meropenem was combined with the β-lactamase inhibitor clavulanate, potent activity against laboratory strains of
M. tuberculosis
was observed [minimum inhibitory concentration (MIC
meropenem
) less than 1 microgram per milliliter], and sterilization of aerobically grown cultures was observed within 14 days. In addition, this combination exhibited inhibitory activity against anaerobically grown cultures that mimic the “persistent” state and inhibited the growth of 13 extensively drug-resistant strains of
M. tuberculosis
at the same levels seen for drug-susceptible strains. Meropenem and clavulanate are Food and Drug Administration–approved drugs and could potentially be used to treat patients with currently untreatable disease.
Early Hominin Foot Morphology Based on 1.5-Million-Year-Old Footprints from Ileret, Kenya
Authors: Bennett Matthew R. , Harris John W.K. , Richmond Brian G. , Braun David R. , Mbua Emma , Kiura Purity , Olago Daniel , Kibunjia Mzalendo , Omuombo Christine , Behrensmeyer Anna K. , Huddart David , Gonzalez Silvia
Published: February 2009

Hominin footprints offer evidence about gait and foot shape, but their scarcity, combined with an inadequate hominin fossil record, hampers research on the evolution of the human gait. Here, we report hominin footprints in two sedimentary layers dated at 1.51 to 1.53 million years ago (Ma) at Ileret, Kenya, providing the oldest evidence of an essentially modern human–like foot anatomy, with a relatively adducted hallux, medial longitudinal arch, and medial weight transfer before push-off. The size of the Ileret footprints is consistent with stature and body mass estimates for
Homo ergaster/erectus
, and these prints are also morphologically distinct from the 3.75-million-year-old footprints at Laetoli, Tanzania. The Ileret prints show that by 1.5 Ma, hominins had evolved an essentially modern human foot function and style of bipedal locomotion.
Seeing the Fermi Surface in Real Space by Nanoscale Electron Focusing
Authors: Weismann Alexander , Wenderoth Martin , Lounis Samir , Zahn Peter , Quaas Norbert , Ulbrich Rainer G. , Dederichs Peter H. , Blügel Stefan
Published: February 2009

The Fermi surface that characterizes the electronic band structure of crystalline solids can be difficult to image experimentally in a way that reveals local variations. We show that Fermi surfaces can be imaged in real space with a low-temperature scanning tunneling microscope when subsurface point scatterers are present: in this case, cobalt impurities under a copper surface. Even the very simple Fermi surface of copper causes strongly anisotropic propagation characteristics of bulk electrons that are confined in beamlike paths on the nanoscale. The induced charge density oscillations on the nearby surface can be used for mapping buried defects and interfaces and some of their properties.
Making German Evolution: Translation and Tragedy
Authors: Nyhart Lynn K.
Published: February 2009

The Tragic Sense of Life
. Ernst Haeckel and the Struggle over Evolutionary Thought.
By Robert J. Richards
. University of Chicago Press, Chicago, 2008. 579 pp. $39, £27. ISBN 9780226712147.

H. G. Bronn, Ernst Haeckel, and the Origins of German Darwinism
. A Study in Translation and Transformation.
By Sander Gliboff
. MIT Press, Cambridge, MA, 2008. 271 pp. $35, £22.95. ISBN 9780262072939.

Richards and Gliboff offer contrasting perspectives on Ernst Haeckel and evolutionary thought in 19th-century Germany.
Evidence of Prior Exposure to Human Bocavirus as Determined by a Retrospective Serological Study of 404 Serum Samples from Adults in the United States
Authors: Cecchini Sylvain , Negrete Alejandro , Virag Tamas , Graham Barney S. , Cohen Jeffrey I. , Kotin Robert M.
Published: February 2009

Recently, molecular screening for pathogenic agents has identified a partial genome of a novel parvovirus, called human bocavirus (HBoV). The presence of this newly described parvovirus correlated with upper and lower respiratory tract infections in children. Lower respiratory tract infections are a leading cause of hospital admission in children, and the etiological agent has not been identified in up to 39% of these cases. Using baculovirus expression vectors (BEVs) and an insect cell system, we produced virus-like particles (VLPs) of HBoV. The engineered BEVs express the HBoV capsid proteins stoichiometrically from a single open reading frame. Three capsid proteins assemble into the VLP rather than two proteins predicted from the HBoV genome sequence. The denatured capsid proteins VP1, VP2, and VP3 resolve on silver-stained sodium dodecyl sulfate-polyacrylamide gels as three bands with apparent molecular masses of 72 kDa, 68 kDa, and 62 kDa, respectively. VP2 apparently initiates at a GCT codon (alanine) 273 nucleotides downstream from the VP1 start site and 114 nucleotides upstream from the VP3 initiation site. We characterized the stable capsids using physical, biochemical, and serological techniques. We found that the density of the VLP is 1.32 g/cm
3
and is consistent with an icosahedral symmetry with approximately a 25-nm diameter. Rabbit antiserum against the capsid of HBoV, which did not cross-react with adeno-associated virus type 2, was used to develop enzyme-linked immunosorbent assays (ELISAs) for anti-HBoV antibodies in human serum. Using ELISA, we tested 404 human serum samples and established a range of antibody titers in a large U.S. adult population sample.
Genotyping of Clinical Varicella-Zoster Virus Isolates Collected in China
Authors: Liu Jingjing , Wang Mingli , Gan Lin , Yang Sen , Chen Jason
Published: February 2009

Varicella-zoster virus (VZV) is genetically stable; and various schemes for the genotyping of VZV based on restriction fragment length polymorphisms (RFLPs), PCR, and sequencing have been developed. At least three major genotypes have been recognized among VZV isolates or clinical samples from different locations around the world; however, few data were available for viral isolates from China. In the current study, a collection of 19 VZV isolates from patients with zoster or varicella in the middle eastern region of China was examined for genetic variations. RFLP analysis of DNA fragments of open reading frames (ORFs) 38, 54, and 62 showed that all 19 isolates were PstI and BglI positive and SmaI negative, and this may represent the major restriction pattern of wild-type VZV strains in China. Further analysis of the R5 variable-repeat region in those strains revealed that 9 (47.4%) were type R5A, while the remaining 10 strains (52.6%) were type R5B. On the basis of the sequencing data for ORFs 1, 21, 22, and 54, all 19 Chinese strains could be grouped into genotype J or J1. A novel in-frame 3-nucleotide insertion (CGG) in ORF1 was found in 4 (21%) of the 19 isolates. Additionally three new nucleotide substitutions were detected in two of the isolates. A varicella isolate from the United States, strain MLS, was included in this study as a control for American wild-type VZV, and was found to be type M1, which represents one of the minor genotypes in North America.
Development and Validation of a Microsphere-Based Luminex Assay for Rapid Identification of Clinically Relevant Aspergilli
Authors: Etienne Kizee A. , Kano Rui , Balajee S. Arunmozhi
Published: February 2009

A Luminex-based assay for the rapid identification of
Aspergillus
species was designed, optimized, and validated with 131 clinical isolates of
Aspergillus fumigatus
,
A. flavus
,
A. niger
,
A. terreus
,
A. ustus
, and
A. versicolor
. The six species-specific probes were directed toward the internal transcribed spacer 1 (ITS-1) region and tested in a multiplex format with results generated within 6 h. Species identifications generated by the
Aspergillus
Luminex assay were 100% concordant with results from comparative sequence analyses of the ITS-1 region and showed excellent specificity. The
Aspergillus
Luminex assay is a rapid, relatively simple method that may prove to be a useful diagnostic tool for rapid
Aspergillus
identification in clinical laboratory settings.
Suitability of Simple Human Immunodeficiency Virus Rapid Tests in Clinical Trials in Community-Based Clinic Settings
Authors: Everett Dean B. , Baisley Kathy , Changalucha John , Vallely Andrew , Watson-Jones Deborah , Cook Claire , Knight Louise , Ross David A. , Mugeye Kokugonza , McCormack Sheena , Lacey Charles J. , Jentsch Ute , Hayes Richard J.
Published: February 2009

The suitability and accuracy of using simple human immunodeficiency virus (HIV) rapid (SR) tests in community-based clinics in northwest Tanzania were determined to assess eligibility for participation in clinical trials. The HIV rapid and ELISA test results for 789 women aged 16 to 54 who were screened for two clinical trials of HIV prevention were compared. Women were offered voluntary HIV counseling and testing (VCT) at screening; those who accepted were tested with the Abbott Determine and Trinity Biotech Capillus SR tests in parallel. The results were confirmed by two parallel HIV enzyme-linked immunosorbent assay (ELISA) tests (Abbott Murex HIV Ag/Ab combination and Vironostika Uniform II HIV Ag/Ab) to determine eligibility. Positive samples for any of the four assays were confirmed by a line immunoassay and p24 testing. The parallel SR tests had high concordance (96.2%) with the parallel ELISA algorithm. The sensitivities of the SR tests were 98.6% for Capillus (95% confidence interval [CI], 95.1 to 99.8%), 99.3% for Determine (95% CI, 96.2 to 100%), and 98.6% for the parallel SR (95% CI, 95.1 to 99.8%). The specificities were 99.7% for Capillus (95% CI, 98.9 to 100%), 99.7% for Determine (95% CI, 98.9 to 100%), and 100% for the parallel SR (95% CI, 99.4 to 100%). SR tests are suitable for use in community-based clinical research settings to assess eligibility both for trial participation and for the provision of on-site VCT services.
Evaluation of a Rapid Fluorescent Staining Method for Detection of Mycobacteria in Clinical Specimens
Authors: Hendry Cindy , Dionne Kim , Hedgepeth Annie , Carroll Karen , Parrish Nicole
Published: February 2009

Rapid detection of mycobacterial disease is essential. Using multiple specimen types and concentrations of mycobacteria, we compared two commercial auramine O stains. The more rapid stain permitted consistent acid-fast bacillus quantitation and exhibited less debris staining, and the staining procedure required less time (∼2 min) to perform. These results suggest that the rapid stain may be more cost-effective and efficient for use in clinical laboratories.
Suppression of Tetherin-Restricting Activity upon Human Immunodeficiency Virus Type 1 Particle Release Correlates with Localization of Vpu in the
trans
-Golgi Network
Authors: Dubé Mathieu , Roy Bibhuti Bhusan , Guiot-Guillain Pierre , Mercier Johanne , Binette Julie , Leung Grace , Cohen Éric A.
Published: February 2009

Vpu promotes the efficient release of human immunodeficiency virus type 1 (HIV-1) by overcoming the activity of tetherin, a host cell restriction factor that retains assembled virions at the cell surface. In this study, we analyzed the intracellular localization and trafficking of subtype B Vpu in HIV-1-producing human cells. We found that mutations of conserved positively charged residues (R30 and K31) within the putative overlapping tyrosine- and dileucine-based sorting motifs of the Vpu hinge region affected both the accumulation of the protein in the
trans
-Golgi network (TGN) and its efficient delivery to late endosomal degradative compartments. A functional characterization of this mutant revealed that the mislocalization of Vpu from the TGN correlated with an attenuation of HIV-1 release. Interestingly, clathrin light chain small interfering RNA-directed disruption of Vpu trafficking from the TGN to the endosomal system slightly stimulated Vpu-mediated HIV-1 release and completely restored the activity of the Vpu R30A,K31A mutant. An analysis of the C-terminal deletion mutants of Vpu identified an additional determinant in the second helical structure of the protein, which regulated TGN retention/localization, and further revealed the functional importance of Vpu localization in the TGN. Finally, we show that a large fraction of Vpu colocalizes with tetherin in the TGN and provide evidence that the degree of Vpu colocalization with tetherin in the TGN is important for efficient HIV-1 release. Taken together, our results reveal that Vpu traffics between the TGN and the endosomal system and suggest that the proper distribution of Vpu in the TGN is critical to overcome the restricting activity of tetherin on HIV-1 release.
CD4 T Cells Mediate Killing during Persistent Gammaherpesvirus 68 Infection
Authors: Stuller Kathleen A. , Flaño Emilio
Published: February 2009

CD4 T cells are critical for the control of gammaherpesvirus persistence, but their direct effector mechanisms of virus control in vivo are still poorly understood. In this study, we use murine gammaherpesvirus 68 (γHV68) in in vitro and in vivo cytotoxicity assays to show CD4-dependent killing of γHV68-loaded cells in mice persistently infected with γHV68. Our results underscore the cytotoxic capacity of CD4 T cells during γHV68 persistence.