bluuebunny/crossref_metadata_2025 huggingface dataset:
Gadobenate dimeglumine‐enhanced liver MR imaging in cirrhotic patients: Quantitative and qualitative comparison of 1‐hour and 3‐hour delayed images
Authors: Jeong Woo Kyoung , Byun Jae Ho , Lee Seung Soo , Won Hyung Jin , Kim Kyoung Won , Shin Yong Moon , Kim Pyo Nyun , Lee Moon‐Gyu
Published: March 2011

Purpose:

To compare the image quality and diagnostic performance of 1‐ and 3‐h delayed‐phase MR images (DPIs) after gadobenate dimeglumine injection in detecting small hepatocellular carcinomas (HCCs) in cirrhotic patients.

Materials and Methods:

Relative enhancement of the liver (REliver) and HCC (REHCC) and liver‐to‐lesion contrast‐to‐noise ratio (CNR) of HCC were measured quantitatively on 1‐ and 3‐h DPIs in 65 patients with 88 HCCs. For qualitative analysis, two radiologists independently evaluated three image sets in 19 patients with 25 HCCs ≤2 cm and in 16 controls without HCCs: conventional liver MR without DPI (set A), adding 1‐h DPI (set B), and adding 3‐h DPI (set C), using a 5‐point scale for diagnosing small HCCs. Diagnostic performance for small HCCs was analyzed using the alternative free‐response receiver operating characteristic method.

Results:

Mean REliver (P = 0.013) and REHCC (P < 0.001) were significantly higher on 1‐h than on 3‐h DPI, whereas CNR was significantly higher on 3‐h than on 1‐h DPI (P = 0.001). Observer‐averaged figure of merit (FOM) was significantly higher for set C than for set A (0.942 versus 0.883; P = 0.013).

Conclusion:

In cirrhotic patients, 3‐h DPI provides a higher liver‐to‐lesion contrast and a better diagnostic performance for small HCCs than 1‐h DPI. J. Magn. Reson. Imaging 2011;33:889–897. © 2011 Wiley‐Liss, Inc.
Imaging of the wrist at 1.5 tesla using isotropic three‐dimensional fast spin echo cube
Authors: Stevens Kathryn J. , Wallace Charles G. , Chen Weitian , Rosenberg Jarrett K. , Gold Garry E.
Published: March 2011

Purpose:

To compare three‐dimensional fast spin echo Cube (3D‐FSE‐Cube) with conventional 2D‐FSE in MR imaging of the wrist.

Materials and Methods:

The wrists of 10 volunteers were imaged in a 1.5 Tesla MRI scanner using an eight‐channel wrist coil. The 3D‐FSE‐Cube images were acquired in the coronal plane with 0.5‐mm isotropic resolution. The 2D‐FSE images were acquired in both coronal and axial planes for comparison. An ROI was placed in fluid, cartilage, and muscle for SNR analysis. Comparable coronal and axial images were selected for each sequence, and paired images were randomized and graded for blurring, artifact, anatomic details, and overall image quality by three blinded musculoskeletal radiologists.

Results:

SNR of fluid, cartilage and muscle at prescribed locations were higher using 3D‐FSE‐Cube, without reaching statistical significance. Fluid–cartilage CNR was also higher with 3D‐FSE‐Cube, but not statistically significant. Blurring, artifact, anatomic details, and overall image quality were significantly better on coronal 3D‐FSE‐Cube images (P < 0.001), but significantly better on axial 2D‐FSE images compared with axial 3D‐FSE‐Cube reformats (P < 0.01).

Conclusion:

Isotropic data from 3D‐FSE‐Cube allows reformations in arbitrary scan planes, which may make multiple 2D acquisitions unnecessary, and improve depiction of complex wrist anatomy. However, axial reformations suffer from blurring, likely due to T2 decay during the long echo train, limiting overall image quality in this plane. J. Magn. Reson. Imaging 2011;33:908–915. © 2011 Wiley‐Liss, Inc.
Dynamic nuclear polarization system output volume reduction using inert fluids
Authors: Peterson Eric T. , Gordon Jeremy W. , Erickson Matthew G. , Fain Sean B. , Rowland Ian J.
Published: March 2011

Purpose:

To present a method for significantly increasing the concentration of a hyperpolarized compound produced by a commercial dynamic nuclear polarization (DNP) polarizer, enabling the polarization process to be more suitable for preclinical applications.

Materials and Methods:

Using a HyperSense DNP polarizer, we investigated the combined use of perfluorocarbon and water to warm and dissolve the hyperpolarized material from the polarization temperature of 1.4K to produce material at temperatures suitable for injection.

Results:

By replacing 75% of the water in the dissolution volume with a chemically and biologically inert liquid that is immiscible with water, the injection volume can be reduced 4‐fold. Rapid separation of the water and perfluorocarbon mixture enables the aqueous layer containing polarized material to be easily and rapidly collected.

Conclusion:

The approach provides a significantly increased concentration of compound in a volume for injection that is more appropriate for small animal studies. This is demonstrated for 13C‐labeled pyruvic acid and 13C‐labeled succinate, but may be applied to the majority of nuclei and compounds hyperpolarized by the DNP method. J. Magn. Reson. Imaging 2011;33:1003–1008. © 2011 Wiley‐Liss, Inc.
Acute hemorrhagic leukoencephalitis with severe brainstem and spinal cord involvement: MRI features with neuropathological confirmation
Authors: Pinto Pedro S. , Taipa Ricardo , Moreira Bruno , Correia Carlos , Melo‐Pires Manuel
Published: March 2011

Acute hemorrhagic leukoencephalitis (AHLE) is a rare and fulminant demyelinating disease considered to be the most severe form of acute disseminated encephalomyelitis (ADEM). A 70‐year‐old man was admitted to our emergency department (ED) after 1 week of unspecific abdominal symptoms and moderate fever in the first 3 days. Within the ED he developed a rapid onset coma and flaccid tetraparesis. Cerebrospinal fluid (CSF) analysis showed mild polymorphonuclear pleocytosis and magnetic resonance imaging (MRI) revealed supratentorial focal white matter lesions and diffuse involvement of the medulla and spinal cord. A presumptive diagnosis of ADEM was made and the patient was treated with corticosteroids followed by intravenous immunoglobulin. His neurological state did not improve and the MRI on day 8 after admission showed an increased number of lesions, mainly in the brainstem, with hemorrhagic foci. The patient died the following day and pathological features confirmed the diagnosis of AHLE. This is a unique presentation of a rare disease with detailed MRI characteristics and pathological confirmation. Although this condition is usually fatal, early recognition and aggressive therapeutic management can facilitate survival. J. Magn. Reson. Imaging 2011;33:957–961. © 2011 Wiley‐Liss, Inc.
Automated brain extraction from T2‐weighted magnetic resonance images
Authors: Datta Sushmita , Narayana Ponnada A.
Published: March 2011

Purpose:

To develop and implement an automated and robust technique to extract brain from T2‐weighted images.

Materials and Methods:

Magnetic resonance imaging (MRI) was performed on 75 adult volunteers to acquire dual fast spin echo (FSE) images with fat‐saturation technique on a 3T Philips scanner. Histogram‐derived thresholds were derived directly from the original images followed by the application of regional labeling, regional connectivity, and mathematical morphological operations to extract brain from axial late‐echo FSE (T2‐weighted) images. The proposed technique was evaluated subjectively by an expert and quantitatively using Bland–Altman plot and Jaccard and Dice similarity measures.

Results:

Excellent agreement between the extracted brain volumes with the proposed technique and manual stripping by an expert was observed based on Bland–Altman plot and also as assessed by high similarity indices (Jaccard: 0.9825 ± 0.0045; Dice: 0.9912 ± 0.0023).

Conclusion:

Brain extraction using the proposed automated methodology is robust and the results are reproducible. J. Magn. Reson. Imaging 2011;33:822–829. © 2011 Wiley‐Liss, Inc.
Assessment of flow instabilities in the healthy aorta using flow‐sensitive MRI
Authors: Stalder Aurélien F. , Frydrychowicz Alex , Russe Max F. , Korvink Jan G. , Hennig Jürgen , Li Kuncheng , Markl Michael
Published: March 2011

Purpose:

To assess blood flow velocities and spatial distribution of aortic Reynolds numbers in vivo using flow‐sensitive magnetic resonance imaging (MRI) and probe for flow instabilities along the aorta based on an empirical model for physiological pulsatile blood flow.

Materials and Methods:

Thirty young healthy volunteers were examined by flow‐sensitive MRI at eight imaging planes distributed along the thoracic aorta. Flow, Womersley, Strouhal, Reynolds, and critical Reynolds numbers were calculated and used to assess the presence of flow instabilities.

Results:

The average peak Reynolds number was higher in the ascending (≈4500) and descending aorta (≈4200) than in the aortic arch (≈3400). According to the calculated critical Reynolds numbers, flow instabilities were prominent in the ascending (14/30 volunteers) and descending aorta (22/30 volunteers) but not in the aortic arch (3/30 volunteers). A significant difference (P < 0.05) in supracritical peak Reynolds numbers was observed between genders. The supracritical Reynolds number, indicating flow instabilities, significantly correlated (P < 0.05) with body weight (r = 0.34), aortic diameter (r = 0.48), and cardiac output (r = 0.53).

Conclusion:

Flow‐sensitive MRI was used to indirectly assess the presence of flow instabilities in vivo. The results in volunteers indicate the presence of flow instabilities in the young healthy aorta with a higher prevalence for men than women. J. Magn. Reson. Imaging 2011;33:839–846. © 2011 Wiley‐Liss, Inc.
T1 independent, T2* corrected chemical shift based fat–water separation with multi‐peak fat spectral modeling is an accurate and precise measure of hepatic steatosis
Authors: Hines Catherine D.G. , Frydrychowicz Alex , Hamilton Gavin , Tudorascu Dana L. , Vigen Karl K. , Yu Huanzhou , McKenzie Charles A. , Sirlin Claude B. , Brittain Jean H. , Reeder Scott B.
Published: March 2011

Purpose:

To determine the precision and accuracy of hepatic fat‐fraction measured with a chemical shift‐based MRI fat‐water separation method, using single‐voxel MR spectroscopy (MRS) as a reference standard.

Materials and Methods:

In 42 patients, two repeated measurements were made using a T1‐independent, T‐corrected chemical shift‐based fat‐water separation method with multi‐peak spectral modeling of fat, and T2‐corrected single voxel MR spectroscopy. Precision was assessed through calculation of Bland‐Altman plots and concordance correlation intervals. Accuracy was assessed through linear regression between MRI and MRS. Sensitivity and specificity of MRI fat‐fractions for diagnosis of steatosis using MRS as a reference standard were also calculated.

Results:

Statistical analysis demonstrated excellent precision of MRI and MRS fat‐fractions, indicated by 95% confidence intervals (units of absolute percent) of [−2.66%,2.64%] for single MRI ROI measurements, [−0.81%,0.80%] for averaged MRI ROI, and [−2.70%,2.87%] for single‐voxel MRS. Linear regression between MRI and MRS indicated that the MRI method is highly accurate. Sensitivity and specificity for detection of steatosis using averaged MRI ROI were 100% and 94%, respectively. The relationship between hepatic fat‐fraction and body mass index was examined.

Conclusion:

Fat‐fraction measured with T1‐independent T‐corrected MRI and multi‐peak spectral modeling of fat is a highly precise and accurate method of quantifying hepatic steatosis. J. Magn. Reson. Imaging 2011;33:873–881. © 2011 Wiley‐Liss, Inc.
Reproducibility of flow and wall shear stress analysis using flow‐sensitive four‐dimensional MRI
Authors: Markl Michael , Wallis Wolf , Harloff Andreas
Published: March 2011

Purpose:

To systematically investigate the scan–rescan reproducibility and observer variability of flow‐sensitive four‐dimensional (4D) MRI in the aorta for the assessment of blood flow and global and segmental wall shear stress.

Materials and Methods:

ECG and respiration‐synchronized flow‐sensitive 4D MRI data (spatio‐temporal resolution = 1.7 × 2.0 × 2.2 mm3/40.8 ms) were acquired in 12 healthy volunteers. To analyze scan–rescan variability, flow‐sensitive 4D MRI was repeated in 10 volunteers during a second visit. Data analysis included calculation of time‐resolved and total flow, peak systolic velocity, and regional and global wall shear stress (WSS) in up to 24 analysis planes distributed along the aorta.

Results:

Scan–rescan, inter‐observer, and intra‐observer agreement was excellent for the calculation of total flow and peak systolic velocity (mean differences <5% of the average flow parameter). Global WSS demonstrated moderate agreement and increased variability regarding wall shear stress (scan‐rescan, inter‐observer, and intra‐observer agreement; mean differences <10% of the average WSS parameters). The segmental distribution of wall shear stress in the thoracic aorta could reliably be reproduced (r > 0.87; P < 0.001) for different observers and examinations.

Conclusion:

Flow‐sensitive 4D MRI‐based analysis of aortic blood flow can be performed with good reproducibility. Robustness of global and regional WSS quantification was limited, but spatio‐temporal WSS distributions could reliably be replicated. J. Magn. Reson. Imaging 2011;33:988–994. © 2011 Wiley‐Liss, Inc.
Decreased SH3BP2 inhibits osteoclast differentiation and function
Authors: Kawamoto Teruya , Fan Chun , Gaivin Robert J. , Levine Michael A. , Lietman Steven A.
Published: March 2011

Germline mutations in SH3BP2 gene have been identified in patients with cherubism, a skeletal disorder characterized by excessive osteoclastic bone resorption that is limited to the mandible and maxilla. We previously demonstrated that SH3BP2 overexpression in Raw264.7 cells increased RANKL‐induced osteoclastogenesis. Here, we examine the effect of decreased SH3BP2 on osteoclastogenesis. shRNA knockdown of SH3BP2 decreased PLCγ2 phosphorylation and NFATc1 expression, and reduced the expression of osteoclast‐specific genes. In BMMs knockdown of SH3BP2 led to reductions in both the number and the surface area of TRAP positive and multinucleated osteoclasts. Bone resorptive activity was also dramatically blocked by shRNA knockdown of SH3BP2. Similarly Sh3bp2(−/−) deficient mice BMMs formed smaller osteoclasts that stained less with TRAP than wild‐type mice. Taken together, this study demonstrates that SH3BP2 knockdown significantly decreases osteoclast differentiation and function. These results suggest that SH3BP2 plays a critical role in osteoclastogenesis and is a potential target for suppression of pathologic bone resorption. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1521–1527, 2011
Combining the evidence using stable weights
Authors: Kulinskaya Elena , Morgenthaler Stephan , Staudte Robert G.
Published: March 2011

In a meta‐analysis one seeks to combine the results of several studies in order to improve the accuracy of decisions. Here we compare by simulation four methods for combining estimates of the risk difference, namely the Cochran and Mantel–Haenszel (MH) methods, the inverse‐variance weights approach and a recent variance‐stabilized weights approach. Both the level and power of corresponding test statistics, as well as the coverage of related confidence intervals are compared over a wide range of sample size and parameter configurations.

We found that the inverse‐variance weights methodology is unreliable and is not recommended, while for equal risks, the Cochran test and the associated confidence intervals are the most reliable. Under alternatives of unequal risks, the coverage probabilities of the variance‐stabilized confidence intervals are almost uniformly more reliable than those based on other methods except when the average risk is small in which case the MH confidence intervals are preferable. Copyright © 2011 John Wiley & Sons, Ltd.
The impact of amount of bone resection on uncemented prosthesis failure in patients with a distal femoral tumor
Authors: Song Won Seok , Kong Chang‐Bae , Jeon Dae‐Geun , Cho Wan Hyeong , Kim Jung Ryul , Cho Yool , Lee Soo‐Yong
Published: March 2011

Background and Objectives

Previous reports on the correlation between the amount of bone resection and prosthetic failure might be confounded by variability in the amount of soft tissue resected and by the mode of prosthesis fixation.

Methods

We analyzed 117 patients who underwent intra‐articular resection and cementless modular tumor prosthetic reconstruction for a distal femoral tumor. Mean follow‐up duration was 95 months (range, 15–271 months). Associations between the prognostic variables and prosthesis survival were assessed. A receiver operating characteristic (ROC) curve was plotted for resection percentage to predict prosthetic failure.

Results

Prostheses were removed in 35 (30%) patients for; infection (17), local recurrence (5), loosening (7), stem fracture (4), or periprosthetic fracture (2). The 10‐year prosthetic survivals of the 117 implants were 65.2 ± 5.4%. A percentage bone resection (>40%) was found to be associated with mechanical prosthesis failure by multivariate analysis (P = 0.003). ROC curve analysis demonstrated that an optimal cut‐off point of 43% for resection percentage had a sensitivity of 95.9% and a specificity of 45.5% for predicting mechanical prosthesis failure.

Conclusions

Infection is the major cause of prosthetic failure, and amount of bone resection is negatively correlated with implant longevity. J. Surg. Oncol. 2011;104:192–197. © 2011 Wiley‐Liss, Inc.
Fire, grazing history, lichen abundance, and winter distribution of caribou in Alaska's taiga
Authors: Collins William B. , Dale Bruce W. , Adams Layne G. , Mcelwain Darien E. , Joly Kyle
Published: March 2011

In the early 1990s the Nelchina Caribou (Rangifer tarandus) Herd (NCH) began a dramatic shift to its current winter range, migrating at least an additional 100 km beyond its historic range. We evaluated the impacts of fire and grazing history on lichen abundance and subsequent use and distribution by the NCH. Historic (prior to 1990) and current (2002) winter ranges of the NCH had similar vascular vegetation, lichen cover (P = 0.491), and fire histories (P = 0.535), but the former range had significantly less forage lichen biomass as a result of grazing by caribou. Biomass of forage lichens was twice as great overall (P = 0.031) and 4 times greater in caribou selected sites on the current range than in the historic range, greatly increasing availability to caribou. Caribou on the current range selected for stands with >20% lichen cover (P < 0.001), greater than 1,250 kg/ha (P < 0.001) forage lichen biomass and stands older than 80 yr postfire (P < 0.001). After fires, forage lichen cover and biomass seldom recovered sufficiently to attract caribou grazing until after ≥60 yr, and, as a group, primary forage lichen species did not reach maximum abundance until 180 yr postfire. Recovery following overgrazing can occur much more quickly because lichen cover, albeit mostly fragments, and organic substrates remain present. Our results provide benchmarks for wildlife managers assessing condition of caribou winter range and predicting effects of fires on lichen abundance and caribou distribution. Of our measurements of cover and biomass by species, densities and heights of trees, elevation, slope and aspect, only percentage cover by Cladonia amaurocraea, Cladina rangiferina, Flavocetraria cuculata, and lowbush cranberry (Vaccinium vitis‐idaea) were necessary for predicting caribou use of winter range. © 2011 The Wildlife Society
Genetic assessment of paternity and relatedness in a managed population of cougars
Authors: Onorato Dave , Desimone Rich , White Craig , Waits Lisette P.
Published: March 2011

Understanding the social dynamics of large carnivores is critical to effective conservation and management planning. We made the first attempt to delineate both paternity and relatedness for a population of cougar (Puma concolor) using microsatellite data. We analyzed a long‐term genetic dataset collected from a hunted population in the Garnet Mountains of western Montana. We assigned paternity for 62.5% of litters sampled using both exclusion and likelihood analyses. Attempts at reconstructing unsampled paternal genotypes resulted in delineating possible sires for 8 more litters. Sires were on average younger than reported for males involved in pairings assessed via field data in other cougar populations. Although most mating pairs were unrelated, 5 of 17 pairings involved cougars with levels of relatedness corresponding to half‐sibling and full‐sibling or parent offspring relationship (r = 0.215–0.575). Relatedness among adult and subadult males was higher than relatedness levels among adult and subadult females. Relatedness among males in the Garnet population differed from patterns hypothesized to occur under male‐biased dispersal theories for cougars. The long‐term impact of the turnover of resident cougars in hunted populations is still unclear and warrants additional research. Our results highlight the utility of monitoring cougar demographic parameters using a combination of genetic and field data that in turn may assist managers with determining cougar harvest quotas or strategies, harvest seasons, sustainable harvest, and the appropriate management level of cougar populations. © 2011 The Wildlife Society.
Effects of spatial disturbance on common loon nest site selection and territory success
Authors: Mccarthy Kyle P. , Destefano Stephen
Published: March 2011

The common loon (Gavia immer) breeds during the summer on northern lakes and water bodies that are also often desirable areas for aquatic recreation and human habitation. In northern New England, we assessed how the spatial nature of disturbance affects common loon nest site selection and territory success. We found through classification and regression analysis that distance to and density of disturbance factors can be used to classify observed nest site locations versus random points, suggesting that these factors affect loon nest site selection (model 1: Correct classification = 75%, null = 50%,K = 0.507,P < 0.001; model 2: Correct classification = 78%, null = 50%,K = 0.551,P < 0.001). However, in an exploratory analysis, we were unable to show a relation between spatial disturbance variables and breeding success (P = 0.595,R2 = 0.436), possibly because breeding success was so low during the breeding seasons of 2007–2008. We suggest that by selecting nest site locations that avoid disturbance factors, loons thereby limit the effect that disturbance will have on their breeding success. Still, disturbance may force loons to use sub‐optimal nesting habitat, limiting the available number of territories, and overall productivity. We advise that management efforts focus on limiting disturbance factors to allow breeding pairs access to the best nesting territories, relieving disturbance pressures that may force sub‐optimal nest placement. © 2011 The Wildlife Society
A population model to simulate northern bobwhite population dynamics in southern Texas
Authors: DeMaso Stephen J. , Grant William E. , Hernández Fidel , Brennan Leonard A. , Silvy Nova J. , Wu X. Ben , Bryant Fred C.
Published: March 2011

Models are important tools that can help managers and researchers understand the population dynamics of a species and how different habitat or population management scenarios impact that species. We used radio‐telemetry data from northern bobwhites (Colinus virginianus) in southern Texas from 2000 to 2005 to develop a stochastic simulation model for bobwhite populations. Our model is based on difference equations, with stochastic variables drawn from normal and Weibull distributions. We simulated bobwhite populations to 100 yr and evaluated our model by comparing results with independent estimates of 4 population parameters (spring and fall density, finite rate of increase in the fall population [λ], and winter juv:ad age ratios). Using a quasi‐extinction criterion of ≤40 birds (density = ≤0.05 birds/ha), probability of persistence to 100 yr was 88.3% (106 of 120 simulations) for the spring population and 96.7% (116 of 120 simulations) for the fall population. Using a less restrictive quasi‐extinction criteria (≤14 birds), probability of persistence was 93.3% (112 of 120 simulations) for the spring population and 98.3% (118 of 120 simulations) for the fall population. Simulated population parameters were similar to independent estimates for 4 of 4 population parameters. Winter age ratios differed between our model ($\overline {x} = 4.98$juv:ad,n = 120, SE = 0.32) and empirical age ratios from harvested bobwhites on our study area ($\overline {x} = 2.85$juv:ad,n = 25, SE = 0.24). However, when we corrected harvest age ratios for bias in juvenile harvest ($\overline {x} = 3.85$juv:ad,n = 25, SE = 0.32) simulated and empirical estimates were similar. Our model appears to be a reliable predictor of bobwhite populations in the southern Texas. Our simulation results indicate that bobwhite hunters and managers can expect excellent bobwhite hunting (fall populations ≥2.2 birds per ha) in about one of 10 yr. © 2011 The Wildlife Society
Bias associated with baited camera sites for assessing population characteristics of deer
Authors: Mccoy J. Clint , Ditchkoff Stephen S. , Steury Todd D.
Published: March 2011

Camera surveys often involve placing bait in front of the camera to capture animals more frequently, which could introduce biases in parameter estimates. From September 2008 to March 2009, we monitored cameras placed at random, along game trails, and at feed stations to determine if camera placement influenced measures of population demographics in a herd of white‐tailed deer (Odocoileus virginianus). There was no time period in which cameras placed at feed stations provided sex ratio and recruitment estimates similar to those acquired from randomly placed cameras. Trail‐based camera surveys provided population estimates similar to those from random sites and may provide a feasible alternative to using baited camera stations. © 2011 The Wildlife Society.
Effect of great‐horned owl trapping on chick survival in piping plovers
Authors: Catlin Daniel H. , Felio Joy H. , Fraser James D.
Published: March 2011

We studied the effect of great‐horned owl (Bubo virginianus) removal on piping plover (Charadrius melodus) hatchling survival on Missouri River sandbars (2008–2009). Owl removal increased daily survival of piping plover chicks in 2008 (β = 2.03, 95% CI: 0.04–4.02), but this effect decreased with increasing age of the chick (β = −0.42, 95% CI: −0.81 to −0.03). Results for 2009 were similar in direction but not significant. Survival was higher in 2008 than in 2009, regardless of owl capture, indicating that even if owl capture consistently were effective at increasing survival, overall survival resulting from trapping may vary annually. Owl trapping was a successful means to raise chick survival on the Missouri River in ≥1 year and could be used at other sites experiencing depressed chick survival due to avian predators. © 2011 The Wildlife Society.
Habitat selection by mountain plovers in shortgrass steppe
Authors: Augustine David J.
Published: March 2011

Much of the breeding range for the mountain plover (Charadrius montanus) occurs in shortgrass steppe and mixed‐grass prairie in the western Great Plains of North America. Studies of mountain plovers in shortgrass steppe during the 1970s and 1990s were focused in Weld County, Colorado, which was considered a key breeding area for the species. These studies, however, did not include habitats influenced by black‐tailed prairie dogs (Cynomys ludovicianus) or prescribed fire. The role of these 2 rangeland disturbance processes has increased substantially over the past 15 years. During 2008–2009, I used radial distance point count surveys to estimate mountain plover densities early in the nesting season in 4 habitats on public lands in Weld County, Colorado. All 4 habitats were grazed by cattle during the growing season at moderate stocking rates but had different additional disturbances consisting of 1) dormant‐season prescribed burns, 2) active black‐tailed prairie dog colonies, 3) black‐tailed prairie dog colonies affected by epizootic plague in the past 1–2 years, and 4) rangeland with no recent history of fire or prairie dogs. Mountain plover densities were similar on active black‐tailed prairie dog colonies (${\rm {\bar {X}}}$ = 6.8 birds/km2, 95% CI = 4.3–10.6) and prescribed burns (${\rm {\bar {X}}}$ = 5.6 birds/km2, 95% CI = 3.5–9.1). In contrast, no plovers were detected at randomly selected rangeland sites grazed by cattle but lacking recent disturbance by prairie dogs or fire, even though survey effort was highest for this rangeland habitat. Mountain plover densities were intermediate (2.0 birds/km2, 95% CI = 0.8–5.0) on sites where black‐tailed prairie dogs had recently been extirpated by plague. These findings suggest that prescribed burns and active black‐tailed prairie dog colonies may enhance breeding habitat for mountain plovers in shortgrass steppe and illustrate the potential for suppressed or altered disturbance processes to influence habitat availability for declining wildlife species. © 2011 The Wildlife Society.
Development of kinetic models for acid‐catalyzed methyl acetate formation reaction: Effect of catalyst concentration and water inhibition
Authors: Ganesh B. , Rani K. Yamuna , Satyavathi B. , Venkateswarlu Ch.
Published: March 2011

The reaction kinetics of reversible liquid‐phase esterification of acetic acid with methanol is investigated in the temperature range 26–50°C using sulfuric acid catalyst. The main goal of this work is to study the effect of catalyst concentration and sensitivity to the presence of water on the rate expression of this industrially important reaction. Experiments are conducted in an isothermal batch reactor and a second‐order kinetic model is used to correlate the experimental data, which are found to fit well with the assumed kinetic model in terms of the concentrations of reactants and products. Furthermore, an activity‐based kinetic model is also developed employing the UNIQUAC (universal quasi‐chemical equation) model to compute the activities. It is observed that the rate constant is influenced by the concentration of catalyst, and the reaction rate increased with an increase in the catalyst concentration. It is also observed that the catalyst activity is slightly inhibited by the water present in the reaction mixture. The performance of the proposed models is compared with that of other models reported in the literature, and it is found that the proposed models outperformed all the other models reported in the literature. © 2011 Wiley Peiodicals, Inc. Int J Chem Kinet 43: 263–277, 2011
Science for improving the monitoring and assessment of dryland degradation
Authors: Winslow M. D. , Vogt J. V. , Thomas R. J. , Sommer S. , Martius C. , Akhtar‐Schuster M.
Published: March 2011

The United Nations Convention to Combat Desertification (UNCCD) commissioned its First Scientific Conference in 2009 to deliberate on ways to improve the global monitoring and assessment of dryland degradation to support decision‐making in land and water management. The papers included in this issue of Land Degradation & Development elaborate the reasoning behind the 11 recommendations that emerged from the Conference and were formally submitted to the UNCCD. These papers argue for a more holistic, harmonised and integrated approach to dryland monitoring and assessment, and describe scientific and institutional approaches for achieving this goal. A central challenge is to integrate human/social with environmental observations in accordance with the Convention's view that the interactions and tradeoffs between human development needs and land condition must be considered. A global monitoring and assessment regime should be established to gather and analyse relevant data on a routine basis, allowing locally‐relevant indicators to be aggregated into meaningful classes appropriate to different decision‐making levels. The underlying forces that cause changes in land condition should also be monitored and assessed so that remedial actions can target the true causes of dryland degradation, including social, economic, policy, institutional and knowledge drivers that have often been overlooked in the past. Monitoring and assessment should hybridise differing types of knowledge generated by different stakeholders in order to strengthen collective capacities to combat dryland degradation. An independent scientific advisory mechanism should be created to advise the UNCCD about the results emerging from the monitoring and assessment regime in order to improve decision‐making. Copyright © 2011 John Wiley & Sons, Ltd.
Porphyrin–Polymer Networks, Worms, and Nanorods: pH‐triggerable Hierarchical Self‐assembly
Authors: Ruthard Christian , Schmidt Manfred , Gröhn Franziska
Published: March 2011

In this study, we present a novel, multifaceted pH‐triggerable system of self‐organized hierarchical nanostructures. The system consists of meso‐tetrakis(4‐sulfonatophenyl)porphyrin (TPPS) and poly(2‐vinylpyridine) cylindrical brushes (PVP brushes) and can yield polymer–porphyrin networks, porphyrin loaded polymer brushes and pure porphyrin nanorods. In addition, the polymer influences the pKa and the mutual TPPS stacking geometry. Structures were characterized by AFM, dynamic light scattering using an IR laser, UV–Vis spectroscopy and small‐angle neutron scattering (SANS). Supramolecular composite porphyrin structures that can be switched through external triggers have potential in photodynamic tumor therapy (PDT) and for nanoelectronics.

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Guaiane‐type sesquiterpenoid glucosides from Gardenia jasminoides Ellis
Authors: Yu Yang , Gao Hao , Dai Yi , Xiao Gao‐Keng , Zhu Hua‐Jie , Yao Xin‐Sheng
Published: March 2011

Two new guaiane‐type sesquiterpenoid glucosides (1 and 2) were isolated from the fruit of Gardenia jasminoides Ellis. Their structures were elucidated to be (1R,7R,10S)‐11‐O‐β‐D‐glucopyranosyl‐4‐guaien‐3‐one (1) and (1R,7R,10S)‐7‐hydroxy‐11‐O‐β‐D‐glucopyranosyl‐4‐guaien‐3‐one (2) by one‐ and two‐dimensional NMR techniques (1H NMR, 13C NMR, HSQC, HMBC and NOESY), MS, CD spectrometry and chemical methods. Copyright © 2011 John Wiley & Sons, Ltd.
1H, 13C, 15N NMR coordination shifts in Fe(II), Ru(II) and Os(II) cationic complexes with 2,2′:6′,2″‐terpyridine
Authors: Pazderski Leszek , Pawlak Tomasz , Sitkowski Jerzy , Kozerski Lech , Szlyk Edward
Published: March 2011

1H, 13C and 15N NMR studies of iron(II), ruthenium(II) and osmium(II) bis‐chelated cationic complexes with 2,2′:6′,2″‐terpyridine ([M(terpy)2]2+; M = Fe, Ru, Os) were performed. Significant shielding of nitrogen‐adjacent H(6) and deshielding of H(3′), H(4′) protons were observed, both effects being mostly expressed for Fe(II) compounds. The metal‐bonded nitrogens were shielded, this effect being much larger for the outer N(1), N(1″) than the inner N(1′) atoms, and enhanced in the Fe(II) → Ru(II) → Os(II) series. Copyright © 2011 John Wiley & Sons, Ltd.
Complete 13C NMR assignments for ent‐kaurane diterpenoids from Sideritis species
Authors: Halfon Belkıs , Ceyhan Gören Ahmet , Ertaş Abdülselam , Topçu Gülaçtı
Published: March 2011

In this work, the detailed NMR studies and full 13C NMR assignments for five diterpenoids isolated from Sideritis caesarea and Sideritis athoa are described. The assignments are based on a combination of 1D and 2D NMR techniques including 1H, 13C, 1H1H COSY, gHSQC [1J(C,H)] and gHMBCδC [nJ(C,H) (n = 2 and 3)] and NOESY experiments. Copyright © 2011 John Wiley & Sons, Ltd.
Molecular cloning and expression analysis of the Mitogen‐activating protein kinase 1 (MAPK1) gene and protein during ovarian development of the giant tiger shrimp Penaeus monodon
Authors: Ponza Pattareeya , Yocawibun Patchari , Sittikankaew Kanchana , Hiransuchalert Rachanimuk , Yamano Keisuke , Klinbunga Sirawut
Published: March 2011

Isolation and characterization of genes and/or proteins differentially expressed in ovaries are necessary for understanding ovarian development in the giant tiger shrimp (Penaeus monodon). In this study, the full‐length cDNA of P. monodon mitogen‐activating protein kinase 1 (PmMAPK1) was characterized. PmMAPK1 was 1,398 bp in length containing an open reading frame of 1,098 bp that corresponded to a polypeptide of 365 amino acids. PmMAPK1 was more abundantly expressed in ovaries than in testes of P. monodon. Quantitative real‐time PCR revealed differential expression levels of PmMAPK1 mRNA during ovarian development of intact broodstock, where it peaked in early cortical rod (stage III) ovaries (P < 0.05) and slightly decreased afterwards (P > 0.05). Likewise, the expression level of PmMAPK1 in early cortical rod and mature (IV) ovaries was significantly greater than that in previtellogenic (I) and vitellogenic (II) ovaries of eyestalk‐ablated broodstock (P < 0.05). The PmMAPK1 transcript was localized in ooplasm of previtellogenic oocytes. In intact broodstock, the expression of the PmMAPK1 protein was clearly increased from previtellogenic ovaries in subsequent stages of ovarian development (P < 0.05). In contrast, the level of ovarian PmMAPK1 protein was comparable during oogenesis in eyestalk‐ablated broodstock (P > 0.05). The PmMAPK1 protein was localized in ooplasm of previtellogenic and vitellogenic oocytes. It was also detected around the nuclear membrane of early cortical rod oocytes in both intact and eyestalk‐ablated broodstock. Results indicated that PmMAPK1 gene products seem to play functional roles in the development and maturation of oocytes/ovaries in P. monodon. Mol. Reprod. Dev. 78:347–360, 2011. © 2011 Wiley‐Liss, Inc.
Activation of cumulus cell SMAD2/3 and epidermal growth factor receptor pathways are involved in porcine oocyte–cumulus cell expansion and steroidogenesis
Authors: Nagyova Eva , Camaioni Antonella , Scsukova Sona , Mlynarcikova Alzbeta , Prochazka Radek , Nemcova Lucie , Salustri Antonietta
Published: March 2011

Several lines of evidence suggest that in mice the activation of SMAD2/3 signaling by oocyte secreted factors, together with epidermal growth factor receptor (EGFR) activation, is essential to induce cumulus expansion. Here we show that inhibition of EGFR kinase in follicle stimulating hormone (FSH)‐stimulated porcine oocyte–cumulus cell complex (OCCs) strongly decreases hyaluronan (HA) synthesis and its retention in the matrix, as well as progesterone synthesis. Although porcine cumulus cells undergo expansion independently of oocytes, we use biochemical and gene expression analyses to show that they do require activation of SMAD2/3 for optimal stimulation of HA synthesis and proteins involved in the organization of this polymer in the expanded matrix. Furthermore, FSH‐induced progesterone synthesis by porcine cumulus cells was increased by blocking SMAD2/3 activation. In conclusion, these results support the hypothesis that an FSH–EGF autocrine loop is active in porcine OCCs, and provide the first evidence that the SMAD2/3 signaling pathway is induced by paracrine/autocrine factors in porcine cumulus cells and is involved in the control of both cumulus expansion and steroidogenesis. Mol. Reprod. Dev. 78:391–402, 2011. © 2011 Wiley‐Liss, Inc.
Cost reduction techniques for the design of non‐linear flapping wing structures
Authors: Stanford Bret K. , Beran Philip S.
Published: March 2011

This work details a computational framework for gradient‐based optimization of a non‐linear flapping wing structure with a large number of design variables, where analytical sensitivities of the unsteady finite element system are computed using the adjoint method. Two techniques are used to reduce the large computational cost of this structural design process. The first projects the finite element system onto a reduced basis of POD modes. The second uses a monolithic time formulation with spectral elements, and can be used to compute only the desired time‐periodic response. Results are given in terms of the trade‐off between accuracy and computational efficiency of these methods for both system response and adjoint computations, for a variety of mesh/time step refinements, degrees of non‐linearity (i.e. weakly or strongly non‐linear), and harmonic content. The work concludes with the structural design of a flapping wing: the elastic deformation at the wingtip is minimized through the flapping stroke by varying the thickness of each finite element. Significant improvements in computational cost are obtained at little expense to the accuracy of the results obtained via design optimization. Published in 2011 by John Wiley & Sons, Ltd.
Comparison of solution strategies for multibody dynamics equations
Authors: Mariti L. , Belfiore N. P. , Pennestrì E. , Valentini P. P.
Published: March 2011

In the last decades, several different formalisms have been proposed in the literature in order to simulate the dynamics of multibody systems. First, the choice of the coordinates leads to very different formalisms. The set of constraint equations appears very different in complexity or in size depending on whether either relative, natural or reference point Cartesian coordinates are adopted. Second, once such a choice has been made, different solution strategies can be followed. It seems that formalisms based on redundant coordinates are often used in commercial software, whereas those based on a minimum number of coordinates are usually preferred in real‐time computations.

In this paper, with reference to models with redundant absolute coordinates, the problem of coordinate reduction will be discussed and a group of 11 different methods will be compared on the basis of their computational efficiency. In particular, methods based on constraint orthogonalization and on the use of pseudoinverse matrices have been selected, together with other methods based on least‐squares block solution. The methods have been implemented on three different test cases. The main purpose is to provide hints and guidelines on the choice and availability of solution strategies during simulation of moderate size multibody systems. Copyright © 2011 John Wiley & Sons, Ltd.
H2 filter design for discrete‐time Markov jump linear systems with partly unknown transition probabilities
Authors: Shen Mouquan , Yang Guang‐Hong
Published: March 2011

The H2 filter design problem for discrete‐time Markov jump linear systems with partly unknown transition probabilities is addressed in this paper. The so‐called partly unknown transition probabilities cover two cases: one is that some unknown elements have known lower and upper bounds, the other is that some unknown elements have no information available. By employing Finsler's lemma and linear matrix inequality (LMI) technique, sufficient conditions are developed in the LMI setting to design an H2 filter such that the filtering error system is mean‐square stable and at the same time satisfies a prescribed H2 performance index. Numerical examples are presented to illustrate the effectiveness of the developed theoretical results. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis of mesoporous silica and its modification of bismaleimide/cyanate ester resin with improved thermal and dielectric properties
Authors: Hu Jiang‐tao , Gu Aijuan , Liang Guozheng , Zhuo Dongxian , Yuan Li
Published: March 2011

A novel method is proposed to synthesize new mesoporous silica containing amine groups (MPSA), and it was further employed to modify bismaleimide‐dialllyl bisphenol (BD)/cyanate ester (CE) resin to form novel MPSA/BD/CE hybrids; in addition, the typical properties of MPSA/BD/CE were systematically investigated. Results show that these hybrids have very low dielectric constant and loss as well as good thermal properties. Compared with BD/CE resin, all hybrids have not only decreased dielectric constant and loss but also similar dependence of dielectric properties on frequency over the whole frequency from 10 to 106 Hz. Specifically, with the addition of MPSA to BD/CE resin, the dielectric constant reduces from 3.5 to 3.0, and the dielectric loss is only 85% of that of BD/CE resin. Note that all hybrids show better thermal resistance (reflected by higher glass transition temperature, decreased maximum degradation rate, and higher char yield at 800°C) than BD/CE resin. All these differences in macro‐properties are attributed to the different structure between MPSA/BD/CE hybrids and BD/CE resin. Copyright © 2011 John Wiley & Sons, Ltd.
The responses of preosteoblasts to collagen/hyaluronic acid polyelectrolyte multilayer coating on titanium
Authors: Li Xiaojun , Luo Qiaojie , Huang Ying , Li Xiaodong , Zhang Feng , Zhao Shifang
Published: March 2011

The purpose of this study was to investigate the effect of Collagen/hyaluronic acid (Col/HA) polyelectrolyte multilayer (PEM) coating on the behaviors and function of pre‐osteoblastic cells. Col/HA PEM coating was fabricated on acid etched Ti disc via layer‐by‐layer technique. The formation and properties of Col/HA PEM coating were investigated using scanning electron microscope (SEM), contact angle and quartz crystal microbalance (QCM). Moreover, mouse preosteoblasts were used to evaluate the effect of Col/HA PEM coating on cell behaviors and function. The results of in vitro evaluations showed that the Col/HA PEM coating could accelerate the proliferation and differentiation of preosteoblasts cells. Copyright © 2011 John Wiley & Sons, Ltd.
Diffusion energies of oxygen diffusing into polystyrene (PS)/poly (N‐isopropylacrylamide) composites
Authors: Yargı Ö. , Ugur Ş. , Pekcan Ö.
Published: March 2011

Diffusion coefficient of oxygen penetrating into polystyrene (PS) latex/poly (N‐isopropylacrylamide) (PNIPAM) microgel composite films were measured using Fluorescence technique. Three different (5, 15, and 40 wt%) PS content films were prepared from PS/PNIPAM mixtures. Diffusivity of PS/PNIPAM composite films were studied by diffusion measurements which were performed over the temperature range of 24–70°C. Pyrene was used as the fluorescent probe. The diffusion coefficients (D) of oxygen were determined using the Stern–Volmer fluorescence quenching method combined with Fickian transport and were computed as a function of temperature for each PS content film. The results showed that D values were strongly dependent on both temperature and PS content in the film. Diffusion energies were measured and found to be dependent on the composition of the composite films. Copyright © 2011 John Wiley & Sons, Ltd.
The effect of chemically reactive type flame retardant additives on flammability of PES toughened epoxy resin and carbon fiber‐reinforced composites
Authors: Biswas Bhaskar , Kandola Baljinder K.
Published: March 2011

The effect of different concentrations (4 and 8 wt%) of chemically reactive type flame retardant (FR) chemicals on the thermal stability and flammability of an aerospace grade epoxy resin has been studied by thermal analysis, limiting oxygen index, UL‐94, and cone calorimetry. Chemically reactive flame retardant term implies that they interact with the polymer during some part of the pyrolysis and fire chemistries. Flame retardants included (i) phosphorous‐ and nitrogen‐containing, active in condensed phase, (ii) intumescent chemicals, active in condensed phase and also known as char promoters, (iii) organophosphates, active primarily in condensed phase, but in some polymers known to have also shown vapor phase activity, (iv) halogen‐containing, active in vapor phase. During curing process some of the flame retardants settled on the bottom of the resin plaque, affecting the flammability results. All FRs reduced the flammability of the resin, the extent of which depended upon the FR type, concentration of flame retardant elements in the formulation and the type of fire testing performed. With selective FRs, carbon fiber‐reinforced composites have also been fabricated and tested for their fire and mechanical performance. FR chemicals decreased the flammability of composites up to 50% without affecting their mechanical properties. Copyright © 2011 John Wiley & Sons, Ltd.