bluuebunny/crossref_metadata_2025 huggingface dataset:
Threshold‐based spraying decision programmes for the red spider mite Tetranychus marianae on eggplant
Authors: Reddy G. V. P. , Kikuchi R. , Bautista J. R.
Published: September 2012

The red spider mite, Tetranychus marianae McGregor (Acari: Tetranychidae), has been an important pest of eggplant Solanum melongena L. (Solanaceae) and other vegetables in the Mariana Islands. The damage due to T. marianae has been severe and caused huge economic losses. Because no threshold levels are available for T. marianae, many growers are applying up to 12 chemical applications per eggplant cropping period. This is not only expensive, but also results in lower yields because of extensive foliar damage and development of resistance in mites to chemicals. To diminish the calendar‐based chemical applications and to preclude damage to foliage and fruit quality, this study was undertaken for the development of a threshold level for optimum timing of chemical applications for T. marianae. In the direction of this aim, an attempt was made to generate different threshold levels by applying chemical spray (Sun‐spray 6E, 5 ml/l) within 12 h after reaching the threshold levels at 2, 4, 6, 8 and 10 mites/leaf, as well as current recommended calendar‐based sprays and non‐sprayed control in a replicated block design for the dry and wet seasons of 2010 at two locations (Yigo and Inaranjan) in Guam (USA). Based on T. marianae‐infested leaves, incidence of T. marianae and yield levels, the plots sprayed at 2 or 4 mites/leaf in the dry season and 2–8 mites/leaf during the wet season had significantly lower leaf damage and incidence of T. marianae compared with a greater number of mites/leaf in calendar‐based sprays and control plots. At the greater threshold levels, the mean yield was significantly reduced in comparison with the mean yield obtained when plots were sprayed at a threshold of 2–8 mites/leaf. Therefore, it is concluded that the optimum threshold chemical spray for T. marianae on eggplant is 4 mites/leaf during the dry season and 8 mites/leaf in the wet season.
Fusarium spp. are Responsible for Shoot Canker of Kumquat in China
Authors: Zhu Li , Chen Guo‐Qing , Zhao Xiao‐Long , Deng Chong‐Ling , Hyde Kevin D. , Li Hong‐Ye
Published: September 2012

Shoot and branch canker and tree decline of kumquat (Fortunella margarita cv. Guban) were recorded in Yangshuo County, Guilin City, in the Guangxi Zhuang Autonomous Region of China during 2008–2011. Fusarium oxysporum and a new Fusarium species within the Gibberella fujikuroi complex (Fusarium sp. GLB1) were isolated repeatedly from the infected shoots and branches. Species identifications were verified by their high translation elongation factor 1‐alpha (TEF1) sequence similarity with those of the species epitypes. Koch's postulates were fulfilled on kumquat (cv. Guban) and mandarin establishing pathogenicity. To our knowledge, this is the first report of Fusarium shoot canker disease caused by F. oxysporum and Fusarium sp. on kumquat.
Aggressiveness and Genetic Diversity of Hemileia vastatrix During an Epidemic in Colombia
Authors: Rozo Yomara , Escobar Carolina , Gaitán Álvaro , Cristancho Marco
Published: September 2012

Since 2008, Colombia has been experiencing an epidemic of the coffee rust Hemileia vastatrix. The altitude range of the disease has expanded, and nursery and young plants that were usually not attacked by the disease are now significantly affected. To determine whether this new epidemic has been caused by a new pathogenic isolate, the molecular diversity of the pathogen causing the epidemic in different regions of the country was assessed, using AFLP molecular markers on isolates collected from coffee fields prior and after the year 2008. We also evaluated the aggressiveness of isolates collected from diverse coffee‐producing areas and from different coffee genotypes. Isolates collected before and during the present epidemic were quite similar both genetically and with regard to their aggressiveness. Out of a total of 349 fragments amplified from 6 AFLP primer combinations, 48 (13.2%) were polymorphic and only 18 were unique among H. vastatrix isolates representative of pre‐2008 and post‐2008 epidemic populations. We conclude that the epidemic was caused by the excessive rainfall that has occurred in Colombia since 2006 and that extended to 2011 and not by the arrival of a new isolate of the pathogen or a change in virulence of the species present in the country.
How to Feel Global: The Modern, the Global and the World
Authors: Boehmer Elleke
Published: September 2012

Elleke Boehmer’s ‘How to Feel Global’ responds to the Oxford Handbook of Global Modernisms by exploring some of the variations and differences in the meaning of the global and the modern that are thrown up by bringing these terms into critical conjunction. In particular, the review examines the different conceptions of the world that underlie the Handbook’s readings of global modernism, and the contradiction that is produced when a close focus on modernity as capitalist expansion comes partially to occlude an attention to modernism as experimental form.
Peripheralizing Modernity: Global Modernism and Uneven Development.
Authors: Young Paul
Published: September 2012

This essay explores how global modernism might be understood to reveal the agency of the periphery in the creation of modernity, thus countering Eurocentric understandings of global history and exposing to view the exploitation, violence and uneven development that characterizes the modern world.
Are Services to Tennessee Children with Special Health Care Needs Comparable with National Achievement of MCHB Objectives?
Authors: Lutenbacher Melanie , Karp Sharon M. , Dietrich Mary S. , Sullivan Julie N.
Published: September 2012

Objective

We assessed experiences of families with children with special health care needs already engaged with Tennessee Children's Special Services or a family advocacy agency, family voices, and compared their experiences with national data to determine achievement of national maternal‐child health objectives.

Design and Sample

Using a descriptive/comparison design, Tennessee families engaged with the state or advocacy agency (n = 816) were compared with the 2005–2006 sample of the National Survey of Children with Special Health Care Needs (n = 40,840) and the Tennessee subsample (n = 794).

Measures

Primary data were obtained from a survey of families associated with either Tennessee agency. Secondary data analysis used raw data from the national survey.

Results

All families reported challenges related to time, finances, and family interactions. Most were satisfied with health care services received. Dental care was an issue for all families, but more so for the agencies' sample. Those families also reported more problems with continuous screenings of their affected child and less coordination of care than the national sample.

Conclusions

Examining the experiences of families with special needs children who receive services from state agencies in the national context contributes to improving family‐centered services and achieving Maternal‐Child Health Bureau objectives.
Effect of a Vascular Access Surveillance Program on Service Provision and Access Thrombosis
Authors: Jiang Simon , Stewart Glenn , Barnes Elizabeth , Jardine Meg , Razavian Mona , Gallagher Martin
Published: September 2012

Establishing and maintaining hemodialysis access are major challenges in dialysis patient care. The impact of implementing guideline recommendations around vascular access surveillance, which lacks strong evidence, is poorly understood. We report the results of a vascular access surveillance and early intervention program upon hemodialysis thrombosis rates for all patients hemodialyzing in a single center between January 2005 and March 2011. Data were derived from hospital records and the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA). Data were collected of 227 prevalent patients over the 6‐year period. Crude ultrasound and angiography intervention rates increased from 23 and 57 per 100 prevalent patients per quarter (/100 pts/qtr) to 31 and 83/100 pts/qtr, respectively, during the study. Crude thrombosis rates fell from 21 to 2/100 pts/qtr during the study. After adjustment for comorbidities, mean ultrasound use increased by 4.6% per quarter (95% CI: 2.4–6.9, p < 0.001), mean interventional angiography increased by 2.6% per quarter (95% CI: 1.1–4.2, p = 0.001), and the predicted mean of the number of thromboses decreased by 8.4% per quarter (95% CI: 5.6–11.1, p < 0.001). Implementation of a vascular access surveillance increases service utilization and is associated with a reduction in vascular access thrombosis.
Ty1 Gag Enhances the Stability and Nuclear Export of Ty1 mRNA
Authors: Checkley Mary Ann , Mitchell Jessica A. , Eizenstat Linda D. , Lockett Stephen J. , Garfinkel David J.
Published: September 2012

Retrotransposon and retroviral RNA delivery to particle assembly sites is essential for their replication. mRNA and Gag from the Ty1 retrotransposon colocalize in cytoplasmic foci, which are required for transposition and may be the sites for virus‐like particle (VLP) assembly. To determine which Ty1 components are required to form mRNA/Gag foci, localization studies were performed in a Ty1‐less strain expressing galactose‐inducible Ty1 plasmids (pGTy1) containing mutations in GAG or POL. Ty1 mRNA/Gag foci remained unaltered in mutants defective in Ty1 protease (PR) or deleted for POL. However, Ty1 mRNA containing a frameshift mutation (Ty1fs) that prevents the synthesis of all proteins accumulated in the nucleus. Ty1fs RNA showed a decrease in stability that was mediated by the cytoplasmic exosome, nonsense‐mediated decay (NMD) and the processing body. Localization of Ty1fs RNA remained unchanged in an nmd2Δ mutant. When Gag and Ty1fs mRNA were expressed independently, Gag provided in trans increased Ty1fs RNA level and restored localization of Ty1fs RNA in cytoplasmic foci. Endogenously expressed Gag also localized to the nuclear periphery independent of RNA export. These results suggest that Gag is required for Ty1 mRNA stability, efficient nuclear export and localization into cytoplasmic foci.
Evaluation of factors associated with prolonged hospital stay and outcome of febrile neutropenic patients receiving chemotherapy: 70 cases (1997–2010)
Authors: Britton B. M. , Kelleher M. E. , Gregor T. P. , Sorenmo K. U.
Published: September 2012

Febrile neutropenia (FN) is an important sequela in veterinary patients receiving chemotherapy. The purpose of this study was to identify factors associated with prolonged hospital stay and outcome in canine patients developingFNsecondary to chemotherapy administration. Medical records of 70 dogs treated forFNat the University of Pennsylvania from 1997 to 2010 were retrospectively evaluated. The mean interval between chemotherapy and hospitalization was 7 days. Two‐thirds of treated patients had lymphoma. The majority of patients (70%) received vincristine or doxorubicin prior to the development ofFN. Tachycardia at admission, complicating medical issues, G‐CSFuse and decreasing neutrophil count after admission were associated with prolonged hospital stay. Hypotension and G‐CSFuse were significantly associated with death in‐hospital. Mortality was 8.5%. Identification of factors associated with prolonged hospital stay and mortality in patients withFNmay enable the development of risk‐adapted treatment guidelines to minimize chemotherapy‐associated morbidity and mortality.
Effects of Core Flow Swirl on the Flow Characteristics of a Scalloped Forced Mixer
Authors: Lei Zhijun , Mahallati Ali , Cunningham Mark , Germain Patrick
Published: September 2012

This paper presents a detailed experimental investigation of the influence of core flow swirl on the mixing and performance of a scaled turbofan mixer with 12 scalloped lobes. Measurements were made downstream of the mixer in a coaxial wind tunnel. The core-to-bypass velocity ratio was set to 2:1, temperature ratio to 1.0, and pressure ratio to 1.03, giving a Reynolds number of 5.2 × 105, based on the core flow velocity and equivalent diameter. In the core flow, the background turbulence intensity was raised to 5% and the swirl angle was varied from 0 deg to 30 deg with five vane geometries. At low swirl angles, additional streamwise vortices were generated by the deformation of normal vortices due to the scalloped lobes. With increased core swirl, greater than 10 deg, the additional streamwise vortices were generated mainly due to radial velocity deflection, rather than stretching and deformation of normal vortices. At high swirl angles, stronger streamwise vortices and rapid interaction between various vortices promoted downstream mixing. Mixing was enhanced with minimal pressure and thrust losses for the inlet swirl angles less than 10 deg. However, the reversed flow downstream of the center body was a dominant contributor to the loss of thrust at the maximum core flow swirl angle of 30 deg.
Empirical Study of Simultaneously Low NOx and Soot Combustion With Diesel and Ethanol Fuels in Diesel Engine
Authors: Han Xiaoye , Xie Kelvin , Tjong Jimi , Zheng Ming
Published: September 2012

Diesel low temperature combustion (LTC) is capable of producing diesel-like efficiency while emitting ultra-low nitrogen oxides (NOx) and soot emissions. Previous work indicates that well-controlled single-shot injection with exhaust gas recirculation (EGR) is an operative way of achieving diesel LTC from low to mid engine loads. However, as the engine load is increased, demanding intake boost and injection pressure are necessary to suppress high soot emissions during the transition to LTC. The use of volatile fuels such as ethanol is deemed capable of promoting the cylinder charge homogeneity, which helps to overcome the high soot challenge and, thus, potentially expand the engine LTC load range. In this work, LTC investigations were carried out on a high compression ratio (18.2:1) engine. Engine tests were first conducted with diesel and LTC operation at 8 bar indicated mean effective pressure (IMEP) was enabled by sophisticated control of the injection pressure, injection timing, intake boost, and EGR application. The engine performance was characterized as the baseline, and the challenges were identified. Further tests were aimed to improve the engine performance against these baseline results. Experiments were, hence, conducted on the same engine with secondary ethanol port fuelling (PF). Single-shot diesel direct injection (DI) was applied close to top dead center (TDC) to ignite the ethanol and control the combustion phasing. The control sensitivity was studied through injection timing sweeps and EGR sweeps. Additional tests were performed to investigate the ethanol-to-diesel ratio effects on the mixture reactivity and the engine emissions. Engine load was also raised to 16.4 bar IMEP while keeping the simultaneously low NOx and soot emissions. Significant improvement of engine control and emissions was achieved by the DI+PF strategy.
A Journal Bearing With Variable Geometry for the Reduction of the Maximum Amplitude During Passage Through Resonance
Authors: Chasalevris Athanasios , Dohnal Fadi
Published: September 2012

A concept for a journal bearing with variable stiffness and damping properties is developed in order to decrease the vibration amplitude of a rotor-journal bearing system during passage through resonance. The introduction of an additional fluid film thickness in the bearing is proposed in this work in order to alter the dynamic properties in the bearing. The bearing ring is divided into two parts with the upper part being fixed with the housing and the lower part being flexibly mounted by a preloaded spring in parallel with a viscous damper. This allows relative motion between the two parts of the bearing ring. The relative motion introduces an additional fluid film zone in the bearing under the passive displacement of the lower part due to increased impedance forces that are developed in the lubricant film at resonance operation. The general concept is to change the system's damping and stiffness coefficients using this extra fluid film thickness only when the system passes through its critical speed in order to quench the vibration amplitude. For rotational speeds outside of the resonant regions, the bearing is considered to be fixed in order to behave as it was designed under the nominal loading operational conditions.
Effects of Charge Preheating Methods on the Combustion Phasing Limitations of an HCCI Engine With Negative Valve Overlap
Authors: Olesky Laura Manofsky , Vavra Jiri , Assanis Dennis , Babajimopoulos Aristotelis
Published: September 2012

Homogeneous charge compression ignition (HCCI) has the potential to reduce both fuel consumption and NOx emissions compared to normal spark-ignited (SI) combustion. For a relatively low compression ratio engine, high unburned temperatures are needed to initiate HCCI combustion, which is achieved with large amounts of internal residual or by heating the intake charge. The amount of residual in the combustion chamber is controlled by a recompression valve strategy, which relies on negative valve overlap (NVO) to trap residual gases in the cylinder. A single-cylinder research engine with fully-flexible valve actuation is used to explore the limits of HCCI combustion phasing at a load of ∼3 bar gross indicated mean effective pressure (IMEPg). This is done by performing two individual sweeps of (a) internal residual fraction (via NVO) and (b) intake air temperature to control combustion phasing. It is found that increasing both of these variables advances the phasing of HCCI combustion, which leads to increased NOx emissions and a higher ringing intensity. On the other hand, a reduction in these variables leads to greater emissions of CO and HC, as well as a decrease in combustion stability. A direct comparison of the two sweeps suggests that the points with elevated intake temperatures are more prone to ringing as combustion is advanced and less prone to instability and misfire as combustion is retarded. This behavior can be explained by compositional differences (air versus residual gas dilution) which lead to variations in burn rate and peak temperature. As a final study, two additional NVO sweeps are performed while holding intake temperature constant at 30 °C and 90 °C. Again, it is seen that for higher intake temperatures, combustion is more susceptible to ringing at advanced timings and more resistant to instability/misfire at retarded timings.
Degassing a vacuum system with in-situ UV radiation
Authors: Koebley Sean R. , Outlaw Ronald A. , Dellwo Randy R.
Published: September 2012

Photon-stimulated desorption (PSD) from a high-powered ultraviolet source was investigated as a technique to degas a vacuum system. A stainless steel vacuum system was pumped down from atmosphere with different time doses of 185 nm light, and the resulting outgassing rates were compared to that of a control pumpdown without UV assistance. PSD was found to provide a factor of 2 advantage in pumpdown pressure after only 30 min of UV exposure, with no additional advantage observed for longer irradiation times. Specifically, an outgassing rate of 3 × 10−10 Torr L s−1 cm−2 was reached 3 h sooner in pumpdowns with UV assistance compared to those without UV, while a rate of 1.2 × 10−10 Torr L s−1 cm−2 was reached 16 h sooner in UV runs. The authors calculated that about 22 monolayers of water were desorbed after 30 min of UV exposure. The results indicate that PSD by a 40 W 185 nm UV source can serve as a nonthermal technique to significantly speed the pumpdown of a vacuum system from atmosphere after only 30 min.
Measured dose rate constant from oncology patients administered 18F for positron emission tomography
Authors: Quinn Brian , Holahan Brian , Aime Jean , Humm John , Germain Jean St. , Dauer Lawrence T.
Published: September 2012

Purpose:

Patient exposure rate measurements verify published patient dose rate data and characterize dose rates near 2‐18‐fluorodeoxyglucose (18F‐FDG) patients. A specific dose rate constant based on patient exposure rate measurements is a convenient quantity that can be applied to the desired distance, injection activity, and time postinjection to obtain an accurate calculation of cumulative external radiation dose. This study reports exposure rates measured at various locations near positron emission tomography (PET) 18F‐FDG patients prior to PET scanning. These measurements are normalized for the amount of administered activity, measurement distance, and time postinjection and are compared with other published data.

Methods:

Exposure rates were measured using a calibrated ionization chamber at various body locations from 152 adult oncology patients postvoid after a mean uptake time of 76 min following injection with a mean activity of 490 MBq18F‐FDG. Data were obtained at nine measurement locations for each patient: three near the head, four near the chest, and two near the feet.

Results:

On contact with, 30 cm superior to and 30 cm lateral to the head, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.482 (0.511), 0.135 (0.155), and 0.193 (0.223)μSv/MBq h, respectively. On contact with, 30 cm anterior to, 30 cm lateral to and 1 m anterior to the chest, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.623 (0.709), 0.254 (0.283), 0.190 (0.218), and 0.067 (0.081) μSv/MBq h respectively. 30 cm inferior and 30 cm lateral to the feet, the mean (75th percentile) dose rates per unit injected activity at 60 min postinjection were 0.024 (0.022) and 0.039 (0.044) μSv/MBq h, respectively.

Conclusions:

The measurements for this study support the use of 0.092μSv m2/MBq h as a reasonable representation of the dose rate anterior from the chest of patients immediately following injection. This value can then be reliably scaled to the desired time and distance for planning and staff dose evaluation purposes. At distances closer than 1 m, a distance‐specific dose rate constant of 0.367 μSv/MBq h at 30 cm is recommended for accurate calculations. An accurate patient‐specific dose rate constant that accounts for patient‐specific variables (e.g., distribution and attenuation) will allow an accurate evaluation of the dose rate from a patient injected with an isotope rather than simply utilizing a physical constant.
Measurement of joint kinematics using a conventional clinical single‐perspective flat‐panel radiography system
Authors: Seslija Petar , Teeter Matthew G. , Yuan Xunhua , Naudie Douglas D. R. , Bourne Robert B. , MacDonald Steven J. , Peters Terry M. , Holdsworth David W.
Published: September 2012

Purpose:

The ability to accurately measure joint kinematics is an important tool in studying both normal joint function and pathologies associated with injury and disease. The purpose of this study is to evaluate the efficacy, accuracy, precision, and clinical safety of measuring 3D joint motion using a conventional flat‐panel radiography system prior to its application in anin vivo study.

Methods:

An automated, image‐based tracking algorithm was implemented to measure the three‐dimensional pose of a sparse object from a two‐dimensional radiographic projection. The algorithm was tested to determine its efficiency and failure rate, defined as the number of image frames where automated tracking failed, or required user intervention. The accuracy and precision of measuring three‐dimensional motion were assessed using a robotic controlled, tibiofemoral knee phantom programmed to mimic a subject with a total knee replacement performing a stair ascent activity. Accuracy was assessed by comparing the measurements of the single‐plane radiographic tracking technique to those of an optical tracking system, and quantified by the measurement discrepancy between the two systems using the Bland–Altman technique. Precision was assessed through a series of repeated measurements of the tibiofemoral kinematics, and was quantified using the across‐trial deviations of the repeated kinematic measurements. The safety of the imaging procedure was assessed by measuring the effective dose of ionizing radiation associated with the x‐ray exposures, and analyzing its relative risk to a human subject.

Results:

The automated tracking algorithm displayed a failure rate of 2% and achieved an average computational throughput of 8 image frames/s. Mean differences between the radiographic and optical measurements for translations and rotations were less than 0.08 mm and 0.07° in‐plane, and 0.24 mm and 0.6° out‐of‐plane. The repeatability of kinematics measurements performed using the radiographic tracking technique was better than ±0.09 mm and 0.12° in‐plane, and ±0.70 mm and ±0.07° out‐of‐plane. The effective dose associated with the imaging protocol used was 15μSv for 10 s of radiographic cine acquisition.

Conclusions:

This study demonstrates the ability to accurately measure knee‐joint kinematics using a single‐plane radiographic measurement technique. The measurement technique can be easily implemented at most clinical centers equipped with a modern‐day radiographic x‐ray system. The dose of ionizing radiation associated with the image acquisition represents a minimal risk to any subjects undergoing the examination.
Evaluation of the Gafchromic® EBT2 film for the dosimetry of radiosurgical beams
Authors: Lárraga‐Gutiérrez José M. , García‐Hernández Diana , García‐Garduño Olivia A. , Galván de la Cruz Olga O. , Ballesteros‐Zebadúa Paola , Esparza‐Moreno Karina P.
Published: September 2012

Purpose:

Radiosurgery uses small fields and high‐radiation doses to treat intra‐ and extracranial lesions in a single session. The lack of a lateral electronic equilibrium and the presence of high‐dose gradients in these fields are challenges for adequate measurements. The availability of radiation detectors with the high spatial resolution required is restricted to only a few. Stereotactic diodes and EBT radiochromic films have been demonstrated to be good detectors for small‐beam dosimetry. Because the stereotactic diode is the standard measurement for the dosimetry of radiosurgical beams, the goal of this work was to perform measurements with the radiochromic film Gafchromic® EBT2 and compare its results with a stereotactic diode.

Methods:

Total scatter factors, tissue maximum, and off‐axis ratios from a 6 MV small photon beams were measured using EBT2 radiochromic film in a water phantom. The film‐measured data were evaluated by comparing it with the data measured with a stereotactic field diode (IBA‐Dosimetry).

Results:

The film and diode measurements had excellent agreement. The differences between the detectors were less than or equal to 2.0% for the tissue maximum and the off‐axis ratios. However, for the total scatter factors, there were significant differences, up to 4.9% (relative to the reference field), for field sizes less than 1.0 cm.

Conclusions:

This work found that the Gafchromic® EBT2 film is adequate for small photon beam measurements, particularly for tissue maximum and off‐axis ratios. However, careful attention must be taken when measuring output factors of small beams below 1.0 cm due to the filmˈs energy dependence. The measurement differences may be attributable to the filmˈs active layer composition because EBT2 incorporates higher Z elements (i.e., bromide and potassium), hence revealing a potential energy dependence for the dosimetry of small photon beams.
Germ Cell Migration Across Sertoli Cell Tight Junctions
Authors: Smith Benjamin E. , Braun Robert E.
Published: September 2012

Observing Sperm Factories

The blood-testis barrier creates a permissive microenvironment for germ cell differentiation and protects meiotic germ cells from autoimmunity. To become sperm, large cysts of germline progenitors must cross the blood-testis barrier without causing damage.
Smith and Braun
(p.
798
, published online 20 September) show that somatic Sertoli cells, the gate-keepers of the blood-testis barrier, manage this task by building a network of compartments bounded by old and new tight junctions. Intercellular bridges, which connect germ cells within cysts, span the transient compartments by passing through vertical strands at tricellular junctions. Only after the formation of a new blood-testis barrier are old tight junctions removed and germ cells released.
Pitted Terrain on Vesta and Implications for the Presence of Volatiles
Authors: Denevi B. W. , Blewett D. T. , Buczkowski D. L. , Capaccioni F. , Capria M. T. , De Sanctis M. C. , Garry W. B. , Gaskell R. W. , Le Corre L. , Li J.-Y. , Marchi S. , McCoy T. J. , Nathues A. , O’Brien D. P. , Petro N. E. , Pieters C. M. , Preusker F. , Raymond C. A. , Reddy V. , Russell C. T. , Schenk P. , Scully J. E. C. , Sunshine J. M. , Tosi F. , Williams D. A. , Wyrick D.
Published: September 2012

Vesta to the Core

Vesta is one of the largest bodies in the main asteroid belt. Unlike most other asteroids, which are fragments of once larger bodies, Vesta is thought to have survived as a protoplanet since its formation at the beginning of the solar system (see the Perspective by
Binzel
, published online 20 September). Based on data obtained with the Gamma Ray and Neutron Detector aboard the Dawn spacecraft,

Prettyman
et al.

(p.
242
, published online 20 September) show that Vesta's reputed volatile-poor regolith contains substantial amounts of hydrogen delivered by carbonaceous chondrite impactors. Observations of pitted terrain on Vesta obtained by Dawn's Framing Camera and analyzed by

Denevi
et al.

(p.
246
, published online 20 September), provide evidence for degassing of volatiles and hence the presence of hydrated materials. Finally, paleomagnetic studies by

Fu
et al.

(p.
238
) on a meteorite originating from Vesta suggest that magnetic fields existed on the surface of the asteroid 3.7 billion years ago, supporting the past existence of a magnetic core dynamo.
Genomic Variation in Seven Khoe-San Groups Reveals Adaptation and Complex African History
Authors: Schlebusch Carina M. , Skoglund Pontus , Sjödin Per , Gattepaille Lucie M. , Hernandez Dena , Jay Flora , Li Sen , De Jongh Michael , Singleton Andrew , Blum Michael G. B. , Soodyall Himla , Jakobsson Mattias
Published: September 2012

African Origins

Humans originated in Africa and then spread across the globe. The high genetic diversity found in sub-Saharan Africa is consistent with this view, but the relationships among and within African populations have been less well explored.

Schlebusch
et al.

(p.
374
, published online 20 September) genotyped 220 individuals from 11 populations representing groups from Southern Africa to determine their relationships and history. The data suggest that modern-day human populations arose from a complex blend of mixing between groups and genetic stratification.
A Golden Spike for Planetary Science
Authors: Binzel Richard P.
Published: September 2012

The progression from astronomical observation to geochemical analysis epitomizes advancements in planetary exploration.
Apathy and executive functions: insights from brain damage involving the anterior cingulate cortex
Authors: Njomboro Progress , Deb Shoumitro , Humphreys Glyn W
Published: September 2012

Patients with anterior cingulate cortex (ACC) lesions present an opportunity for understanding apathy's disputed neuropsychiatric features, as well as its associated neurocognitive phenotype. In this case report, two male patients (patient A and patient B) with lesions involving the ACC bilaterally were assessed for apathy, depressive symptoms, executive functioning, and also tested on the Iowa Gambling Task (IGT). Twenty neurologically intact controls also provided normative scores on the IGT. Patient A and patient B had high scores for apathy and low depressive symptoms scores. Patient A had relatively intact performance on standard executive function tests, but patient B had significant impairments. Both patients were significantly impaired on the IGT. Our findings suggest that executive function deficits are not crucial for the presence of apathy symptoms. These findings not only shed light on the relationship between apathy and executive function deficits, but also have important implications for patient care and rehabilitation.
Cerebrotendinous xanthomatosis: a rare disorder with a rare presentation
Authors: Agrawal N K , Garg Sunny
Published: September 2012

A young man was brought for mental retardation, frequent non-bloody diarrhoea and swellings at ankles and elbow. He became bed-ridden due to cataract, mental retardation and pain in the back and lower limb. There were repeated pathological fractures and vitamin D deficiency without renal dysfunction. There were low low-density lipoprotein and triglyceride levels. MRI of the brain revealed hypointense lesions in cerebellar white matter, heterogenous hyperintensity in dentate nucleus and adjacent white matter, right basal ganglia and in the periventricular region with diffuse cerebral atrophy. T1-weighted MRI (ankle region) revealed bilaterally thickened and irregular achilles tendons with hyperintense masses surrounded by patchy hypointensities. A similar xanthomatous lesion (cholestanol deposits) was also present in the sacral region. Vitamin D and calcium supplementation and chenodeoxycholic acid therapy improved pain at lower limbs and body weight. Cerebrotendinous xanthomatosis is a rare autosomal-recessive familial mutation of the sterol 27 hydroxylase causing lipid metabolic disease.
Hodgkin's lymphoma presents as an inguinal abscess: a case report and literature review
Authors: Telfah Muwaffaq Mezeil
Published: September 2012

Lymphadenitis with suppuration is a rare presentation of Hodgkin's lymphoma with few cases reported in the literature. We report two cases of Hodgkin's lymphoma in two male members of the same family. They presented initially with clinical features suggesting infective inguinal lymphadenitis and then the picture was indistinguishable from inguinal abscess. The diagnosis was made after drainage of the pus and excision of the involved lymph node. The histopathology of the excised lymph node showed Hodgkin's lymphoma—nodular sclerosis for both brothers. After careful staging of both patients, the disease found to be localised to the inguinal group of lymph nodes. The patients referred to the haematologist for chemotherapy and they recovered after treatment.
Young stroke due to vascular anomaly from neurofibromatosis type 1
Authors: Krishnaswami Vachagan , Gilmore James , Vahidassr Djamil
Published: September 2012

Aetiology of stroke in young is often different to that of an older person. In nearly half of these cases no cause is established. Every effort should be explored to establish a cause as treatment varies accordingly and the prognosis with rehabilitation is favourable when compared with older people. We present a case of pontine infarct in a 43-year-old man due to vascular ectasia associated with neurofibromatosis type 1. Following the stroke, the patient went through intensive rehabilitation where he had a good functional outcome.
A patient with tuberculous peritonitis with very high serum CA 125: Figure 1
Authors: Seo Bong Soo , Hwang In Kyeom , Ra Ji Eun , Kim Yong Sung
Published: September 2012

An 88-year-old woman presented with abdominal pain and distension. Serum cancer antigen 125 (CA 125) level was very high; however, abdominal CT reveals ascites without definite mass. Ascites analysis revealed a lymphocytic exudate with high adenosine deaminase enzyme level, negative stains for bacteria and negative PCR forMycobacterium tuberculosis. Presumptive diagnosis for tuberculous peritonitis was made and antituberculous therapy resulted in the resolution of ascites and normalisation of CA 125.
A likely diagnosis of Crohn's disease in a 95-year-old woman
Authors: Parmar Kishan R , Patel Ekta , McCann Peter
Published: September 2012

Crohn's disease (CD) has a bimodal distribution in incidence, with a second peak in the elderly. However, its diagnosis in the elderly is difficult due to a wider range of more common differential diagnoses such as diverticulitis, ischaemic colitis and colorectal cancer. We report a likely case of CD in a 95-year-old woman. She presented with diarrhoea and rectal bleeding and was found to have multiple pleomorphic ulcers with a patchy cobblestone mucosa on sigmoidoscopy. Histopathology demonstrated focal ulceration, altered crypt architecture and adjacent neutrophil polymorph infiltration with no granolomata or features of malignancy. The patient passed away after steroid treatment was started. This case is a reminder that CD can present in the elderly and highlights the challenging diagnosis and high mortality of CD-related hospitalisation in the elderly. When considering management, attention should be given to comorbid disease, age-related changes in pharmacokinetics and patients social circumstances.
Tachycardia-induced cardiomyopathy
Authors: Nakatani Bruno Tsutomu , Minicucci Marcos Ferreira , Okoshi Katashi , Politi Okoshi Marina
Published: September 2012

Tachycardia-induced cardiomyopathy (TIC) is an important cause of heart failure as it is potentially reversible after ventricular rate control. A 66-year-old hypertensive woman presented with a 15-day history of tachycardia, dyspnoea and oedema. ECG revealed atrial fibrillation with ventricular frequency of 130 beats per minute (bpm). Echocardiogram showed dilated left ventricle (LV) with 0.39 ejection fraction. Angiography revealed non-obstructed coronary arteries. Heart rate and cardiac failure were controlled with amiodarone, digoxine, captopril, metoprolol and furosemide. During follow-up, despite drug dose optimisation, the patient kept complaining of tachycardia and dyspnoea with a ventricular rate between 108 and 120 bpm. Medical staff suspected she was not taking her medicines properly. Two months later, the patient was asymptomatic and had converted to sinus rhythm (heart rate of 76 bpm). Echocardiogram showed normal LV size and function. Patient's diagnosis was TIC. Although rare, TIC should be considered in all cases of systolic dysfunction associated with tachyarrhythmia.
Lipomatous hypertrophy of interatrial septum: Figure 1
Authors: Lampropoulos Konstantinos M , Kotsas Dimitrios , Iliopoulos Themistoklis
Published: September 2012

Lipomatous hypertrophy of the interatrial septum is being increasingly recognised and should be considered as part of the differential diagnosis for any cardiac tumour. We present the case of a 65-year-old male patient who presented at the emergency department complaining of palpitations. Transthoracic and transoesophageal echocardiography detected a lipomatous membrane separating the dilated left atrium from the right atrium. Diagnosis was confirmed by MRI. In such cases, the opinion of a specialist echocardiologist would help to avoid a misdiagnosis and unnecessary intervention.
Rosai Dorfman disease: appearances can be deceptive
Authors: Rajasekharan Chandrasekharan , Ratheesh Narayanan Santhanavally , Nandinidevi Rajan , Parvathy Rajasekharan
Published: September 2012

A 14-year-old boy was referred to us with a history of progressive painless massive symmetrical cervical lymphadenopathy, provisionally diagnosed as lymphoma. Multiple biopsies were needed, and confirmed the diagnosis of Rosai Dorfman disease (RDD), which is a very rare benign condition. Sinus histiocytosis with massive lymphadenopathy, also known as RDD, manifests as bulky lymphadenopathy in children and young adults. Extranodal sites such as the skin, upper airways, gastrointestinal tract and central nervous system can be involved. There is a characteristic pattern of lymphoid proliferation with a thick fibrous capsule, distention of lymphoid sinuses, accumulation of plasma cells and proliferation of large, often atypical, histiocytes showing emperipolesis is characteristic. The disease is considered to be benign and usually self-limited. We emphasise the need for doing a repeat lymphnode biopsy even if the prior histopathology is suggestive of reactive lypmhnode hyperplasia in every case of persisting lymphadenopathy.
Successful deep anterior lamellar keratoplasty following multiple failed limbal transplantations for chronic ocular burns
Authors: Toor Gurpal Singh , Basu Sayan , MacNeil Sheila , Sangwan Virender S
Published: September 2012

A 9-year-old girl with severe unilateral ocular surface disease due to limbal stem cell deficiency following chemical injury underwent autologous cultivated limbal epithelial transplantation (CLET) twice in her right eye that failed to improve the condition of the ocular surface. On both occasions, limbal biopsies were obtained from the unaffected left eye. Since further attempts at CLET were not considered to be safe, deep anterior lamellar keratoplasty (DALK) was performed instead. DALK was complicated by postoperative Descemet's membrane detachment, which was successfully treated. Two years post-DALK the patient had a clear graft, stable ocular surface and visual acuity of 20/80. The mechanism by which CLET allows a patient to repopulate the ocular surface is as yet unknown. This case highlights that although clinically little had changed following two failed CLET surgeries, some subclinical improvement must have taken place for a DALK to remain successful after 2 years.
Traumatic pulmonary arteriovenous fistula may be misdiagnosed with residual shunt after patent foramen ovale closure
Authors: Roshanali Farideh , Mandegar Mohammad Hossein , Oraii Saeed
Published: September 2012

We report the case of a 48-year-old woman with a history of transient ischaemic attacks (TIA). The patient was diagnosed with a large patent foramen ovale (PFO), for which she underwent percutaneous PFO closure. Two years postprocedurally, the patient suffered frequent TIA and assessment showed the displacement of the device. The device was surgically removed, and the septum was repaired with a pericardial patch. Afterward, however, the patient experienced repeat TIA. It was discovered that the patient had a pulmonary arteriovenous fistula (PAVF), and a diagnosis of a trauma was made. The PAVF was later coil embolised. This case illustrates the importance of evaluating PFO closure patients for the associated causes of right-to-left shunting.
Giant tuberculoma in an adolescent: atypical form of tuberculosis
Authors: Mascarenhas Maria Inês , Pacheco Susana , Silvestre Catarina , Felix Francisco , Brito Maria João , Correia Paula
Published: September 2012

A tuberculoma is a rare form of presentation of tuberculosis (TB) in children. We describe the case of a 13-year-old girl, with 3 weeks of progressive tiredness and asthenia and a 48 h fever and cough. Physical examination revealed diminished pulmonary sounds in the left lower hemithorax. A chest radiograph showed an oval hypotransparency image in this location. The TB skin test was anergic and sputum was negative for acid-fast bacilli (AFB). The thoracic CT revealed a cystic mass in the left lower half hemithorax, compressing the adjacent pulmonary lobe, with double non-calcificated membrane. The exeresis of the pulmonary mass was performed and the anatomopathological study revealed a tuberculoma with AFB. TB treatment was established with a favourable clinical and radiological evolution. TB is a prevalent disease around the world. In this case, due to the mass dimensions and adjacent-organ compression, surgery was essential for a favourable clinical evolution.
Dental avulsion due to direct laryngoscopy during the induction of general anaesthesia and avulsed teeth in nasopharynx
Authors: Ozer Ayse B , Erhan Omer L , Demirel Ismail , Keles Erol
Published: September 2012

General anaesthesia was induced to a 32-year-old female patient. During direct laryngoscopy, the four upper front incisors were avulsed and fell into the patient's oral cavity without fracture. After endotracheal intubation, her oral cavity was searched laryngoscopically but the teeth were not found. Radiological findings of her chest and abdomen obtained by the C-armed x-ray device and endoscopic findings of the oesophagus were normal. Her head and neck imaging revealed a radiopaque lesion in the nasopharyngeal area. Later, the nasopharyngeal area was examined endoscopically and the teeth were removed following adenoidectomy. We emphasise that preoperative evaluation is essential for dental injuries, and patients with a risk of dental injury must be detected before surgery. The localisation of the broken teeth must be identified and removed, and one must keep in mind that the dental fragments can travel to the nasopharynx.
Bickerstaff's brainstem encephalitis associated with ulcerative colitis
Authors: Yamamoto Miyuki , Inokuchi Ryota , Nakamura Kensuke , Yahagi Naoki
Published: September 2012

A 25-year-old Japanese man showed symptoms of common cold and digestive problems for 1 month. He later developed hypoesthesia ascending from the lower extremities and consulted the emergency outpatient department with the chief complaint of generalised dysesthesia. Because of a history of ulcerative colitis, his condition was initially treated as acute aggravation of the disease; however, after admission, his consciousness level gradually deteriorated. Physical findings showed weakened tendon reflexes, and anti-GQ1b antibodies were strongly positive in the cerebrospinal fluid. Therefore, the patient was diagnosed with Bickerstaff's brainstem encephalitis (BBE). Plasmapheresis was performed 8 times, resulting in an improvement of the symptoms; the patient was discharged 1 month later.Campylobacterinfections are the main cause of BBE, and its incidence is high among patients with ulcerative colitis. Therefore, in cases where patients with ulcerative colitis develop disturbance in consciousness, BBE should be included in the differential diagnosis.
International Atomic Energy Agency study with referring physicians on patient radiation exposure and its tracking: a prospective survey using a web-based questionnaire
Authors: Rehani Madan M , Berris Theocharis
Published: September 2012

Objectives

To assess the following themes among referring physicians: (A) importance of acquiring information about previous diagnostic exposures; (B) knowledge about radiation doses involved, familiarity with radiation units and, age-related radiosensitivity; (C) opinion on whether patients should be provided information about radiation dose and (D) self-assessment of appropriateness of referrals.

Design

A prospective survey using a web-based questionnaire.

Setting

International survey among referring physicians.

Participants

Referring physicians from 28 countries.

Main outcome measures

Knowledge, opinion and practice of the four themes of the survey.

Results

All 728 responses from 28 countries (52.3% from developed and 47.7% from developing countries) indicated that while the vast majority (71.7%) of physicians feel that being aware of history of CT scans would always or mostly lead them to a better decision on referring patients for CT scans, only 43.4% often enquire about it. The majority of referring physicians (60.5%) stated that having a system that provides quick information about patient exposure history would be useful. The knowledge about radiation doses involved is poor, as only one-third (34.7%) of respondents chose the correct option of the number of chest x-rays with equivalence of a CT scan. In total, 70.9% of physicians stated that they do not feel uncomfortable when patients ask about radiation risk from CT scans they prescribe. Most physicians (85.6%) assessed that they have rarely prescribed CT scans of no clinical use in patient management.

Conclusions

This first ever multinational survey among referring physicians from 28 countries indicates support for a system that provides radiation exposure history of the patient, demonstrates poor knowledge about radiation doses, supports radiation risk communication with patients and mandatory provisions for justification of a CT examination.