bluuebunny/crossref_metadata_2025 huggingface dataset:
Delayed Arterial Hemorrhage After Pancreaticoduodenectomy
Authors: Suzumura Kazuhiro , Kuroda Nobukazu , Kosaka Hisashi , Iimuro Yuji , Hirano Tadamichi , Fujimoto Jiro
Published: July 2014

Delayed arterial hemorrhage is a rare complication of pancreaticoduodenectomy that is associated with a high mortality and has no standard management. Between 2000 and 2011, 204 pancreaticoduodenectomies were performed, and there were 3 cases of delayed arterial hemorrhage. We reviewed the role of endoscopy, laparotomy, and interventional radiology the management of delayed hemorrhage. One patient presented with intraluminal bleeding and upper gastrointestinal endoscopy failed to identify the bleeding site. Two patients presented with bleeding from the drain tube. Laparotomy was performed in the patient with intraluminal bleeding and interventional radiology was employed for the other 2 patients. There was no hemorrhage-related mortality or rebleeding, but the patient who underwent laparotomy developed sepsis. Endoscopy may have no role in the initial management of delayed arterial hemorrhage after pancreaticoduodenectomy. Interventional radiology is less invasive compared with laparotomy, and may be considered as the first-line treatment for delayed arterial hemorrhage in pancreaticoduodenectomy patients.
Decreased Leakage Rate of Colonic Anastomoses by Tachosil Coating: An Experimental Study
Authors: Pommergaard Hans-Christian , Achiam Michael Patrick , Burcharth Jakob , Rosenberg Jacob
Published: July 2014

Colorectal anastomotic coating has been proposed as a means to lower the leakage rate. Prior to clinical testing, coating materials need thorough experimental evaluation to ensure safety and efficacy. The aim of this study was to evaluate Tachosil as an anastomotic coating agent. Technically insufficient colon anastomoses were created in 80 C57BL/6 mice, and in half of the animals the anastomoses were covered with Tachosil. The animals were examined for clinical signs of anastomotic leakage, and the breaking strength of the anastomoses was evaluated. The number of leakages was reduced by Tachosil coating (10/40 versus 20/40 in controls; P = 0.037). However, more cases of large bowel obstruction were found in the Tachosil group (12/40 versus 0/40 in controls; P < 0.0005). Breaking strength was comparable between the Tachosil and control groups (0.49 N versus 0.52 N, respectively; P = 0.423). Clinical studies are needed to clarify the efficacy of Tachosil anastomotic coating.
The Effectiveness of a Rapid-Access Flexible Sigmoidoscopy Clinic in a District Hospital
Authors: Sorelli Paolo G. , Iliadis Alex D. , Payne John G.
Published: July 2014

Historically rapid-access colorectal clinics have had high proportions of nonconforming referrals from primary care physicians, which calls into question the clinics' efficacy. We aim to determine the effectiveness of our rapid-access flexible sigmoidoscopy clinic, and the adherence to the referral guidelines for suspected bowel cancer by general practitioners. We performed a 3-month retrospective audit to evaluate (1) the proportion of patients seen within 2 weeks, (2) the appropriateness of referrals, (3) the proportion of patients with findings, and (4) the proportion of patients who had further tests. A total of 59 patients (19 male, 40 female; age 35–86 years) were included in the study. All were offered an appointment within 2 weeks. Forty-one cases (82%) were appropriate referrals. Twenty-eight patients (47%) had pathology at sigmoidoscopy. Cancer pick-up rate was 6%. Thirty-seven patients (74%) had further investigations. We determined that our rapid-access clinic for symptomatic patients has high diagnostic accuracy and that access to early investigation is being used appropriately by general practitioners. In the current climate of spending cuts and streamlining services, our study confirms we are meeting targets for delivery of our colorectal service. The majority of referrals under the 2-week rule are appropriate. Rapid access to early investigation is being used appropriately by general practitioners contrasting previous studies with high proportions of nonconforming referrals.
Parastomal Hernia Containing Stomach
Authors: Barber-Millet Sebastian , Pous Salvador , Navarro Vicente , Iserte Jose , García-Granero Eduardo
Published: July 2014

Parastomal hernia is the most common late stomal complication. Its appearance is usually asymptomatic. We report a parastomal hernia containing stomach. A 69-year-old patient with end colostomy arrived at the emergency room presenting with abdominal pain associated with vomiting and functioning stoma. She had a distended and painful abdomen without signs of peritoneal irritation and pericolostomic eventration in the left iliac fossa. X-ray visualized gastric fornix dilatation without dilated intestine bowels, and computed tomography showed parastomal incarcerated gastric herniation. Gastrografin (Bayer Australia Limited, New South Wales, Australia) was administered, showing no passage to duodenum. She underwent surgery, with stomal transposition and placement of onlay polypropylene mesh around the new stoma. Parastomal hernias are a frequent late complication of colostomy. Only four gastric parastomal hernia cases are reported in the literature. Three of these four cases required surgery. The placement of prosthetic mesh in the moment of stoma elaboration should be considered as a potential preventive measure.
Carcinoma Cecum Presenting as Right Gluteal Abscess Through Inferior Lumbar Triangle Pathway—Report of a Rare Case
Authors: Karthikeyan Vilvapathy Senguttuvan , Sistla Sarath Chandra , Ram Duvuru , Ali Sheik Manwar , Velayutham Sugi Subramaniam Raghavan , Vijayaraghavan Nandhagopal
Published: July 2014

Gluteal abscess commonly follows intramuscular injections with contaminated needles. Carcinoma cecum is known to present with pericolic abscess due to microperforations and may rupture intraperitoneally. Gluteal abscess secondary to perforated carcinoma cecum with pericolic abscess is extremely uncommon. A 50-year-old woman who was receiving intramuscular iron injections for anemia presented with a 10 × 10-cm abscess in the right gluteal region and a vague mass in the right iliac fossa. After investigations, a diagnosis of perforated carcinoma cecum with pericolic abscess tracking into the right gluteal region was made, and incision and drainage were done. Fine-needle aspiration cytology from the cecal growth revealed adenocarcinoma. Unfortunately, the patient was not willing to undergo definitive treatment. This case is being reported for its rarity and as an uncommon etiology for a common condition.
Single-Incision Laparoscopic Surgery for a Small-Intestinal Gastrointestinal Stromal Tumor: Report of a Case
Authors: Sakai Makoto , Wada Wataru , Kimura Shintaro , Okada Akiko , Hirakata Tomoko , Onozato Ryoichi , Saito Kana , Morohara Koji , Osawa Hidenobu , Katayama Kazuhisa , Yasuda Naokuni , Tanaka Shigebumi , Kuwano Hiroyuki
Published: July 2014

Our report concerns a 64-year-old man with a small-intestinal gastrointestinal stromal tumor (GIST), which was successfully treated with single-incision laparoscopic surgery (SILS). Small-bowel endoscopy detected a submucosal tumor located approximately 10 cm from the ligament of Treitz in the wall of the proximal jejunum. Contrast-enhanced computed tomography revealed a tumor (diameter, 4 cm) containing high- and low-density areas in the proximal jejunum. On 18F-fluorodeoxyglucose (FDG) positron-emission tomography (PET), the tumor demonstrated intense FDG uptake (maximum standard uptake value, 3.82), whereas it displayed high signal intensity on diffusion-weighted magnetic resonance images. No metastatic lesions were observed. The patient was diagnosed with a jejunal GIST. Wedge resection of the jejunum was performed using the SILS procedure. The tumor was histopathologically diagnosed as a low-grade malignant GIST. SILS is a useful resection technique for small-intestinal GIST.
An Extraordinary Case of Axillary Contracture: Trapped Healthy Skin and Its Adnexes Under Contracted Scar
Authors: Nisanci Mustafa , Sahin Ismail , Guzey Serbulent
Published: July 2014

Although striking improvements have been achieved in overall management of burn injury, postburn contractures are still an ongoing challenge to burn surgeons. Axillary adduction contracture is one of the most common types of these disabling postburn complications that usually result from suboptimal treatment after acute burns. An unusual and complicated case of axillary contracture in which the unburned, healthy axillary dome skin was trapped as a cystic mass under the scarred area was reconstructed by transfer of a big (17 × 13-cm) thoracodorsal artery perforator flap after contracture release. The result was satisfactory in terms of function and acceptable cosmetically. The underlying reasons for the inadequate treatment the patient received after surviving a severe electrical injury were discussed.
Risk Factors Associated With Sphincter-Preserving Resection in Patients With Low Rectal Cancer
Authors: Cong Zhi-Jie , Hu Liang-Hao , Xing Jun-Jie , Zhang Wei , Fu Chuan-Gang , Yu En-Da , Zhong Ming
Published: July 2014

Abdominoperineal resection (APR) and sphincter-preserving resection (SPR) are the two primary surgical options for rectal cancer. Retrospectively we collected rectal cancer patients for SPR and APR observation between 2005 and 2007. The patient-related, tumor-related, and surgery-related variables of the SPR and APR groups were analyzed by using logistic regression techniques. The mean distance from the anal verge (DAV) of cancer is significantly higher in SPR than that in APR (P < 0.001). In cancers with DAV <40 mm (SPR, 40 versus APR, 110), multivariate analysis shows that surgeon procedure volume (odds ratio [OR] = 0.244; 95% confidence interval [CI]: 0.077–0.772; P = 0.016) and neoadjuvant radiotherapy (OR = 0.031; 95% CI: 0.002–0.396; P = 0.008) are factors influencing SPR. In cancers with DAV ranging from 40 mm to 59 mm (SPR 190 versus APR 50), analysis shows that patient age (OR = 2.139; 95% CI: 1.124–4.069; P = 0.021), diabetes (OR = 2.657; 95% CI: 0.872–8.095; P = 0.086), and colorectal surgeon (OR = 0.122, 95% CI: 0.020–0.758; P = 0.024), are influencing factors for SPR. The local recurrence and disease-free survival reveal no significant difference. A significant difference exists in DAV, surgeon specialization, procedure volume, age, diabetes, and neoadjuvant radiotherapy between SPR and APR.
Surgical Interventions for Late Complications of Arteriovenous Fistulas
Authors: Belli Sedat , Yabanoglu Hakan , Aydogan Cem , Parlakgumus Alper , Yildirim Sedat , Haberal Mehmet
Published: July 2014

Our aim was to determine the most effective surgical treatment for arteriovenous fistula (AVF) complications after all other methods of salvage have failed. We evaluated 110 patients for 139 complications that occurred after the initial AVF placement and for whom surgical intervention was the last hope for retaining fistula access. Vascular steal syndrome and venous hypertension were the most common complications seen in our patients. The anastomoses of 17 of the vascular steal syndrome cases were narrowed either by stitches or by a polytetrafluoroethylene graft. The second most performed revision surgery was excision of the aneurysm and repair with primary suturing, followed by excision of the aneurysm and interposition grafting. Successful surgical outcomes were achieved in 111 of 139 procedures after revision surgery without constructing a new AVF. AVF salvage surgery is of paramount importance in order to increase the patency rate, which prolongs survival and increases the patient's quality of life.
Short-Term Outcomes of Simultaneous Laparoscopic Colectomy and Hepatectomy for Primary Colorectal Cancer With Synchronous Liver Metastases
Authors: Inoue Akira , Uemura Mamoru , Yamamoto Hirofumi , Hiraki Masayuki , Naito Atsushi , Ogino Takayuki , Nonaka Ryoji , Nishimura Junichi , Wada Hiroshi , Hata Taishi , Takemasa Ichiro , Eguchi Hidetoshi , Mizushima Tsunekazu , Nagano Hiroaki , Doki Yuichiro , Mori Masaki
Published: July 2014

Although simultaneous resection of primary colorectal cancer and synchronous liver metastases is reported to be safe and effective, the feasibility of a laparoscopic approach remains controversial. This study evaluated the safety, feasibility, and short-term outcomes of simultaneous laparoscopic surgery for primary colorectal cancer with synchronous liver metastases. From September 2008 to December 2013, 10 patients underwent simultaneous laparoscopic resection of primary colorectal cancer and synchronous liver metastases with curative intent at our institute. The median operative time was 452 minutes, and the median estimated blood loss was 245 mL. Median times to discharge from the hospital and adjuvant chemotherapy were 13.5 and 44 postoperative days, respectively. Negative resection margins were achieved in all cases, with no postoperative mortality or major morbidity. Simultaneous laparoscopic colectomy and hepatectomy for primary colorectal cancer with synchronous liver metastases appears feasible with low morbidity and favorable outcomes.
Laparoscopic Repair of a Diaphragmatic Hernia Associated with Radiofrequency Ablation for Hepatocellular Carcinoma: Lessons from a Case and the Review of the Literature
Authors: Nomura Ryohei , Tokumura Hiromi , Furihata Makoto
Published: July 2014

We describe the case of a patient with a diaphragmatic hernia associated with radiofrequency ablation for hepatocellular carcinoma who was successfully treated by laparoscopic surgery. A 62-year-old man with a long history of hepatitis C-induced liver cirrhosis was admitted to our institution because of recurrent postprandial periumbilical pain. Eight years earlier, he had undergone radiofrequency ablation for hepatocellular carcinoma at hepatic segment VIII. Computed tomography, gastrografin enema examination revealed transverse colon obstruction because of a diaphragmatic hernia. We diagnosed diaphragmatic hernia associated with the prior radiofrequency ablation treatment. The patient underwent laparoscopic repair of the diaphragmatic hernia. Though the patient experienced the recurrence once, relaparoscopic treatment has improved the patient's conditions. Thus, diaphragmatic hernia can develop as a complication of radiofrequency ablation treatment. A laparoscopic approach is safe, feasible, and minimally invasive, even in patients with cirrhosis who develop iatrogenic diaphragmatic hernia as a complication of radiofrequency ablation treatment.
ULTRAPRO Hernia System Versus Lichtenstein Repair in Treatment of Primary Inguinal Hernias: A Prospective Randomized Controlled Study
Authors: Karateke Faruk , Ozyazici Sefa , Menekse Ebru , Özdogan Hatice , Kunt Mevlüt , Bozkurt Hilmi , Bali İlhan , Özdogan Mehmet
Published: July 2014

The Lichtenstein repair has been recommended as the gold standard for inguinal hernia repair. However, postoperative discomfort still constitutes a concern and an area for improvement. New mesh materials have been continuously introduced to achieve this goal. The goal of the present study was to investigate the outcomes of ULTRAPRO Hernia System (UHS) compared with Lichtenstein mesh repair. A total of 99 male patients with primary unilateral inguinal hernia were included in the study during the period of September 2010–January 2012. Patients with body mass index >30, comorbid diseases, and anesthetic risk of ASA-III and ASA-IV were excluded. The patients were randomly allocated to operation with the Lichtenstein technique (group L) or UHS. Demographics, operative and postoperative/recovery data, and short- and medium-term outcomes of the patients were recorded. A total of 50 patients in group L and 49 patients in group UHS were analyzed. The median follow-up time for the study was 33 months. There were no significant differences regarding demographics, complications, and rehabilitation between the groups. Overall, there was a prolonged operation time in the UHS group compared with the L group (UHS: 53.7 ± 5.7 minutes; L: 44.5 ± 5.5 minutes; P < 0.001). UHS may provide results similar to those for the Lichtenstein technique in open repair of inguinal hernias regarding perioperative course, complications, recovery, and recurrence rates. However, because of reduced costs and the lack of need for the exploration of the preperitoneal space, we conclude that the Lichtenstein technique should be recommended as the first choice.
Remote sensing of subsurface fractures in the Otway Basin, South Australia
Authors: Bailey Adam , King Rosalind , Holford Simon , Sage Joshua , Backe Guillaume , Hand Martin
Published: July 2014

Naturally occurring fractures were remotely detected in a 3‐D seismic volume from the Penola Trough in South Australia's Otway Basin and validated through an integrated approach. Identified in image logs are 508 fractures and 523 stress indicators, showing maximum horizontal stress orientation in the Penola Trough is 127°N. Two fracture types were identified: (1) 268 electrically conductive (potentially open to fluid flow) fractures with mean NW‐SE strikes and (2) 239 electrically resistive (closed to fluid flow) fractures with mean E‐W strikes. Core from Jacaranda Ridge‐1 shows that open fractures are rarer than what image logs indicate, due to the presence of fracture‐filling siderite, an electrically conductive cement which may cause fractures to appear hydraulically conductive in image logs. The majority of fractures detected is favorably oriented for reactivation under in situ stresses, although it is demonstrated that fracture fills primarily control which fractures are open. Seismic attributes calculated from the 3‐D Balnaves/Haselgrove survey are mapped to the Pretty Hill Formation to enhance observations of structural fabrics, showing linear discontinuities likely representing faults and fractures. Discontinuity orientations are consistent with natural fracture orientations identified in image logs, striking E‐W and NW‐SE, limited to zones around larger faults. However, it is unlikely that a large proportion of these fractures are open given observations of core and image logs, limiting possible fracture connectivity and therefore significant secondary permeability in the Penola Trough. The integrated methodology presented herein provides an effective workflow for remote detection of subsurface fractures and determining if electrically conductive fractures are also hydraulically conductive.
Quantifying uncertainty sources in the gridded data of sea surface CO2 partial pressure
Authors: Wang Guizhi , Dai Minhan , Shen Samuel S. P. , Bai Yan , Xu Yi
Published: July 2014

The bulk uncertainty in the gridded sea surface pCO2 data is crucial in assessing the reliability of the CO2 flux estimated from measurements of air‐sea pCO2 difference, because atmospheric pCO2 are relatively homogeneous and well defined. The bulk uncertainty results from three different sources: analytical error (Em), spatial variance (
), and the bias from undersampling (
). Common uncertainty quantification by standard deviation may mix up the different sources of uncertainty. We have established a simple procedure to determine these three sources of uncertainty using remote sensing‐derived and field‐measured pCO2 data. Em is constrained by the analytical method and data reduction procedures.
is derived from the remotely sensed pCO2 field.
is determined by spatial variance and the effective number of observations, considering, for the first time, the geometric bias introduced by pCO2 sampling. This approach is applied to 1° × 1° gridded pCO2 data collected from the East China Sea. We demonstrate that the spatial distribution of these biases is uneven and that none of them follow the same spatial trend as the standard deviation.
contributes the most to the uncertainty in gridded pCO2 data over those grid boxes with good sampling coverage, while
dominates the total uncertainty in the grid boxes with poor sampling coverage. Application of this procedure to other parts of the global ocean will help to better define the inherent spatial variability of the pCO2 field and thus better interpolate and/or extrapolate pCO2 data, and eventually better constrain air‐sea CO2 fluxes.
Resonant ocean current responses driven by coastal winds near the critical latitude
Authors: Kim Sung Yong , Crawford Greg
Published: July 2014

The currents forced by wind stress near the critical latitude (30°N or 30°S) appear enhanced as a result of the combination of natural modes of ocean currents (e.g., near‐inertial motions) and diurnal land/sea breeze‐driven currents. Here we assess the wind‐current transfer function, derived from observations of coastal surface currents and surface winds off the U.S. West Coast (32°N to 47°N), as a function of the latitude (alongshore direction) and frequency. We compare the transfer functions at the diurnal frequency derived from observations and two analytical models (e.g., the Ekman model and a near‐surface averaged Ekman model). The amplitude of the data‐derived transfer function decreases with increasing distance from the critical latitude, and its argument varies nearly within the range estimated from two analytical models. Our results confirm that the resonant wind‐current responses near the critical latitude are 8 to 12 times stronger than the purely diurnal land/sea breeze‐forced currents in other latitudes.
Acoustic Green's function extraction from ambient noise in a coastal ocean environment
Authors: Brown Michael G. , Godin Oleg A. , Williams Neil J. , Zabotin Nikolay A. , Zabotina Liudmila , Banker Geoffrey J.
Published: July 2014

We report on the results of an underwater acoustic field experiment conducted in December 2012 on the continental shelf off the Florida Keys in water of approximately 100 m depth. Ambient noise was recorded concurrently on three moored near‐bottom instruments with horizontal separations of approximately 5 km, 10 km, and 15 km. We focus in this letter on instrument pairs with 5 km and 10 km separations. Consistent with theoretical predictions, coherent sums of many realizations of cross correlations of ambient noise records at two measurement locations are shown to yield approximations to deterministic acoustic Green's functions that describe propagation between those two locations. The results presented demonstrate the feasibility of extracting information suitable for use in tomographic inversions from measurements of underwater acoustic ambient noise.
Radon emanation from brittle fracturing in granites under upper crustal conditions
Authors: Nicolas Aurélien , Girault Frédéric , Schubnel Alexandre , Pili Éric , Passelègue François , Fortin Jérôme , Deldicque Damien
Published: July 2014

Radon‐222, a radioactive gas naturally produced in the Earth's crust, informs us about the migration of fluids and is sometimes considered as a potential earthquake precursor. Here we investigate the effects of mechanical and thermal damage on the radon emanation from various granites representative of the upper crust. Radon concentration measurements performed under triaxial stress and pore fluid pressure show that mechanical damage resulting from cycles of differential stress intensifies radon release up to 170 ± 22% when the sample ruptures. This radon peak is transient and results from the connection of isolated micropores to the permeable network rather than new crack surface creation per se. Heating to 850°C shows that thermal fracturing irreversibly decreases emanation by 59–97% due to the amorphization of biotites hosting radon sources. This study, and the developed protocols, shed light on the relation between radon emanation of crustal rocks, deformation, and pressure‐temperature conditions.
Statistical relationship between large‐scale upward field‐aligned currents and electron precipitation
Authors: Korth Haje , Zhang Yongliang , Anderson Brian J. , Sotirelis Thomas , Waters Colin L.
Published: July 2014

Simultaneous observations of Birkeland currents by the constellation of Iridium satellites and N2 Lyman‐Birge‐Hopfield (LBH) auroral emissions measured by the Global Ultraviolet Imager (GUVI) onboard the Thermosphere, Ionosphere, and Mesosphere Energetics and Dynamics (TIMED) satellite are used to establish relationships between large‐scale upward field‐aligned currents and electron precipitation during stable current configurations. The electron precipitation was inferred from GUVI data using a statistical relationship between LBH intensity and electron energy flux. LBH emissions with >5% contribution from protons, identified by Lyman‐alpha intensity, were excluded from the analysis. The Birkeland currents were derived with a spatial resolution of 3° in latitude and 2 h in local time. For southward interplanetary magnetic field (IMF), the electron precipitation occurred primarily within and near large‐scale upward currents. The correspondence was less evident for northward IMF, presumably because the spatial variability is large compared to the areas of interest so that the number of events identified is smaller and the derived statistical distributions are less reliable. At dusk, the correlation between upward current and precipitation was especially high, where a larger fraction of the electron precipitation is accelerated downward by a field‐aligned potential difference. Unaccelerated electron precipitation dominated in the morning sector, presumably induced by scattering of eastward‐drifting energetic electrons into the loss cone through interaction with whistler‐mode waves (diffuse precipitation) rather than by field‐aligned acceleration. In the upward Region 1 on the dayside, where the electron precipitation is almost exclusively due to field‐aligned acceleration, a quadratic relationship between current density and electron energy flux was observed, implying a linear current‐voltage relationship in this region. Current density and electron energy flux in the regions of the large‐scale upward currents from pre‐midnight through dawn to noon are essentially uncorrelated, consistent with diffuse electron precipitation dominating the incident energy flux.
Properties of dust particles near Saturn inferred from voltage pulses induced by dust impacts on Cassini spacecraft
Authors: Ye S.‐Y. , Gurnett D. A. , Kurth W. S. , Averkamp T. F. , Kempf S. , Hsu H.‐W. , Srama R. , Grün E.
Published: July 2014

The Cassini Radio and Plasma Wave Science (RPWS) instrument can detect dust particles when voltage pulses induced by the dust impacts are observed in the wideband receiver. The size of the voltage pulse is proportional to the mass of the impacting dust particle. For the first time, the dust impacts signals measured by dipole and monopole electric antennas are compared, from which the effective impact area of the spacecraft is estimated to be 4 m2. In the monopole mode, the polarity of the dust impact signal is determined by the spacecraft potential and the location of the impact (on the spacecraft body or the antenna), which can be used to statistically infer the charge state of the spacecraft. It is shown that the differential number density of the dust particles near Saturn can be characterized as a power law dn/dr ∝ rμ, where μ ~ − 4 and r is the particle size. No peak is observed in the size distribution, contrary to the narrow size distribution found by previous studies. The RPWS cumulative dust density is compared with the Cosmic Dust Analyzer High Rate Detector measurement. The differences between the two instruments are within the range of uncertainty estimated for RPWS measurement. The RPWS onboard dust recorder and counter data are used to map the dust density and spacecraft charging state within Saturn's magnetosphere.
Active faulting in apparently stable peninsular India: Rift inversion and a Holocene‐age great earthquake on the Tapti Fault
Authors: Copley Alex , Mitra Supriyo , Sloan R. Alastair , Gaonkar Sharad , Reynolds Kirsty
Published: July 2014

We present observations of active faulting within peninsular India, far from the surrounding plate boundaries. Offset alluvial fan surfaces indicate one or more magnitude 7.6–8.4 thrust‐faulting earthquakes on the Tapti Fault (Maharashtra, western India) during the Holocene. The high ratio of fault displacement to length on the alluvial fan offsets implies high stress‐drop faulting, as has been observed elsewhere in the peninsula. The along‐strike extent of the fan offsets is similar to the thickness of the seismogenic layer, suggesting a roughly equidimensional fault rupture. The subsiding footwall of the fault is likely to have been responsible for altering the continental‐scale drainage pattern in central India and creating the large west flowing catchment of the Tapti river. A preexisting sedimentary basin in the uplifting hanging wall implies that the Tapti Fault was active as a normal fault during the Mesozoic and has been reactivated as a thrust, highlighting the role of preexisting structures in determining the rheology and deformation of the lithosphere. The slip sense of faults and earthquakes in India suggests that deformation south of the Ganges foreland basin is driven by the compressive force transmitted between India and the Tibetan Plateau. The along‐strike continuation of faulting to the east of the Holocene ruptures we have studied represents a significant seismic hazard in central India.
Simulated tomographic reconstruction of ocean current profiles in a bottom‐limited sound channel
Authors: Taniguchi Naokazu , Huang Chen‐Fen
Published: July 2014

Tomographic reconstruction of the vertical current profile in a bottom‐limited sound channel requires solving a difficult ray identification problem. An approach to deal with this problem is a ray group method in which received arrival pulses are divided into several ray groups according to the characteristics of the arrival patterns. The method is validated using numerically simulated reciprocal acoustic transmission in a synthetic ocean in the Luzon Strait, where the Kuroshio Current has speeds as high as 1.2 m/s, for both narrowband and broadband signals. Four ray groups are found for the synthetic data; these are chosen based on arrival time. The differential travel time is determined by pairing up the reciprocal arrival peaks and then averaging the differential travel times within the selected time windows. Compared with the narrowband case, the estimated broadband differential travel time is more consistent with that computed from the current magnitude in the synthetic ocean. The vertical current profile is reconstructed from the broadband differential travel times by a generalized Tikhonov regularization approach. The data weighting matrix includes observation error in picking and pairing travel times and model parameter error due to path length uncertainty. The time series of the reconstructed current agrees with the synthetic ocean current; the fractional residual variance is 0.013 for the surface layer and 0.01 for the entire water column. The ray group method mitigates the ray identification problem in the bottom‐limited environment and could offer valuable data regarding the range‐integrated current velocity.
Intraseasonal to interannual variability of the Atlantic meridional overturning circulation from eddy‐resolving simulations and observations
Authors: Xu Xiaobiao , Chassignet Eric P. , Johns William E. , Schmitz William J. , Metzger E. Joseph
Published: July 2014

Results from two 1/12° eddy‐resolving simulations, together with data‐based transport estimates at 26.5°N and 41°N, are used to investigate the temporal variability of the Atlantic meridional overturning circulation (AMOC) during 2004–2012. There is a good agreement between the model and the observation for all components of the AMOC at 26.5°N, whereas the agreement at 41°N is primarily due to the Ekman transport. We found that (1) both observations and model results exhibit higher AMOC variability on seasonal and shorter time scales than on interannual and longer time scales; (2) on intraseasonal and interannual time scales, the AMOC variability is often coherent over a wide latitudinal range, but lacks an overall consistent coherent pattern over the entire North Atlantic; and (3) on seasonal time scales, the AMOC variability exhibits two distinct coherent regimes north and south of 20°N, due to different wind stress variability in the tropics and subtropics. The high AMOC variability south of 20°N in the tropical Atlantic comes primarily from the Ekman transport of the near‐surface water, and is modulated to some extent by the transport of the Antarctic Intermediate water below the thermocline. These results highlight the importance of the surface wind in driving the AMOC variability.
Aerosol radiative forcing from the 2010 Eyjafjallajökull volcanic eruptions
Authors: Flanner M. G. , Gardner A. S. , Eckhardt S. , Stohl A. , Perket J.
Published: July 2014

Although the 2010 volcanic eruptions of Eyjafjallajökull did not exert a large climate forcing, several features of their emissions favored weaker aerosol cooling or stronger warming than commonly attributed to volcanic events. These features include a high ratio of fine ash to SO2, occurrence near reflective surfaces exposed to strong insolation, and the production of very little stratospheric sulfate. We derive plausible ranges of optical properties and top‐of‐atmosphere direct radiative forcing for aerosol emissions from these events and find that shortwave cooling from sulfate was largely offset by warming from ash deposition to cryospheric surfaces and longwave warming from atmospheric ash and sulfate. Shortwave forcing from atmospheric ash was slightly negative in the global mean under central estimates of optical properties, though this forcing term was uniquely sensitive to the simulated distribution of clouds. The forcing components sum to near climate‐neutral global mean 2010 instantaneous (−1.9 mWm−2) and effective (−0.5 mWm−2) radiative forcing, where the latter is elevated by high efficacy of snow‐deposited ash. Ranges in net instantaneous (−7.3 to +2.8 mWm−2) and effective (−7.2 to +4.9 mWm−2) forcing derived from sensitivity studies are dominated by uncertainty in ash shortwave absorptivity. Forcing from airborne ash decayed quickly, while sulfate forcing persisted for several weeks and ash deposits continued to darken snow and sea ice surfaces for months following the eruption. Despite small global forcing, monthly averaged net forcing exceeded 1 Wm−2 in some regions. These findings indicate that ash can be an important component of climate forcing from high‐latitude volcanic eruptions and in some circumstances may exceed sulfate forcing.
Biased self‐perceptions of social competence and engagement in physical and relational aggression: The moderating role of peer status and sex
Authors: McQuade Julia D. , Achufusi Adaora K. , Shoulberg Erin K. , Murray‐Close Dianna
Published: July 2014

This study sought to expand on prior research suggesting that children low in peer status who either over‐ or underestimate their social competence relative to others' reports are more likely to be aggressive (White and Kistner [2011]. Journal of Abnormal Child Psychology, 39, 645–656). The curvilinear associations between social competence bias and two forms of aggression (physical and relational) were examined in a sample of 4th through 6th graders (n = 183); moderation by both sex and peer status (peer preference and popularity) also were tested. Social competence bias was operationally defined as the residual difference between child and teacher ratings of the child's social competence. Aggression and peer status were measured using peer nomination procedures. There was a significant curvilinear association between social competence bias and physical aggression moderated by both types of peer status. For low peer status children greater underestimation and overestimation of social competence was associated with higher physical aggression. The curvilinear association between social competence bias and relational aggression was moderated by both peer status and sex. Popular boys had higher rates of relational aggression when they had accurate, rather than biased, self‐perceptions of social competence. However, for very highly preferred girls, a more extreme positive bias was associated with an exponential increase in relational aggression. Results are discussed in terms of implications for aggression theory and intervention. Aggr. Behav. 40:512–525, 2014. © 2014 Wiley Periodicals, Inc.
Tetradentate Platinum Complexes for Efficient and Stable Excimer‐Based White OLEDs
Authors: Fleetham Tyler , Huang Liang , Li Jian
Published: July 2014

A series of tetradentate platinum complexes that exhibit both efficient monomer and excimer emission are synthesized. Via small modifications to the cyclometalating ligands, both the monomer and excimer emission energy can be separately tuned. Devices employing all of the developed emitters demonstrate impressively high external quantum efficiencies (EQEs) within the range of 22% to 27% for concentrations between 2% and 16%. The halogen‐free design of the complexes also enables the fabrication of single, doped, white organic light‐emitting diodes (OLEDs) with long operational lifetimes. A balanced white device employing the complex Pt2O2, achieves a device operational lifetime to 80% of the initial luminance estimated at over 200 h at 1000 cd m–2, while also achieving 12.5% peak EQE for a warm white light with a color rendering index of 80. Furthermore, a highly doped device exhibiting nearly exclusive excimer emission showed an impressive operational lifetime, which is estimated at more than 400 h for 1000 cd m‐2.
Integration of Self‐Assembled Epitaxial BiFeO3–CoFe2O4 Multiferroic Nanocomposites on Silicon Substrates
Authors: Kim Dong Hun , Aimon Nicolas M. , Sun Xue Yin , Kornblum Lior , Walker Fred. J. , Ahn Charles. H. , Ross Caroline A.
Published: July 2014

Perovskite‐spinel epitaxial nanocomposite thin films are commonly grown on single crystal perovskite substrates, but integration onto a Si substrate can greatly increase their usefulness in devices. Epitaxial BiFeO3–CoFe2O4 nanocomposites consisting of CoFe2O4 pillars in a BiFeO3 matrix are grown on (001) Si with two types of buffer layers: molecular beam epitaxy (MBE)‐grown SrTiO3‐coated Si and pulsed‐laser‐deposited (PLD) Sr(Ti0.65Fe0.35)O3/CeO2/yttria‐stabilized ZrO2/Si. The nanocomposite grows with the same crystallographic orientation and morphology as that observed on single crystal SrTiO3 when the buffered Si substrates are smooth, but roughness of the Sr(Ti0.65Fe0.35)O3 promoted additional CoFe2O4 pillar orientations with 45° rotation. The nanocomposites on MBE‐buffered Si show very high magnetic anisotropy resulting from magnetoelastic effects, whereas the hysteresis of nanocomposites on PLD‐buffered Si can be understood as a combination of the hysteresis of the Sr(Ti0.65Fe0.35)O3 film and the CoFe2O4 pillars.
Boron Nitride Nanosheets for Metal Protection
Authors: Li Lu Hua , Xing Tan , Chen Ying , Jones Rob
Published: July 2014

Although the high impermeability of graphene makes it an excellent barrier to inhibit metal oxidation and corrosion, graphene can form a galvanic cell with the underlying metal that promotes corrosion of the metal in the long term. Boron nitride (BN) nanosheets which have a similar impermeability could be a better choice as protective barrier, because they are more thermally and chemically stable than graphene and, more importantly, do not cause galvanic corrosion due to their electrical insulation. In this study, the performance of commercially available BN nanosheets grown by chemical vapor deposition as a protective coating on metal has been investigated. The heating of the copper foil covered with the BN nanosheet at 250 °C in air over 100 h results in dramatically less oxidation than the bare copper foil heated for 2 h under the same conditions. The electrochemical analyses reveal that the BN nanosheet coating can increase open circuit potential and possibly reduce oxidation of the underlying copper foil in sodium chloride solution. These results indicate that BN nanosheets are a good candidate for oxidation and corrosion protection, although conductive atomic force microscopy analyses show that the effectiveness of the protection relies on the quality of BN nanosheets.
Synthesis, Characterization, and Thermal Properties of Organic–Inorganic Hybrids Based on Gelatin and Organomodified Silicones
Authors: Wojciechowska Patrycja , Pietras Przemysław , Maciejewski Hieronim
Published: July 2014

The synthesis of organic–inorganic hybrids is an interesting approach as it offers the possibility of combining the advantages of organic polymer (elasticity, formability) and inorganic material (hardness, strength, high chemical resistance, and thermal stability). Gelatin–siloxane hybrid materials were prepared in the reaction of gelatin and organomodified silicones containing epoxy‐ and both epoxy‐ as well as fluoroalkyl groups. The hybrids obtained were characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, and scanning electron microscopic analysis. Thermal properties of the samples were evaluated by means of thermogravimetric analysis and differential scanning calorimetric measurements, showing the influence of type and amount of organosilicon compound on thermal properties of the hybrid materials. The samples obtained with siloxane containing fluoroalkyl groups as well as with mixed siloxanes revealed higher thermal stability than unmodified gelatin. Glass transition temperatures of the hybrids occurred at lower values than for gelatin, exhibiting the plasticizing effect of the applied siloxanes. Enthalpy values of the hybrids decreased, indicating the changes in the helical structure of gelatin caused by the introduction of siloxane.
The Crucial Influence of Fullerene Phases on Photogeneration in Organic Bulk Heterojunction Solar Cells
Authors: Zusan Andreas , Vandewal Koen , Allendorf Benedikt , Hansen Nis Hauke , Pflaum Jens , Salleo Alberto , Dyakonov Vladimir , Deibel Carsten
Published: July 2014

The conjugated polymer, poly(2,5‐bis(3‐hexadecylthiophen‐2‐yl)thieno[3,2‐b]thiophene) (pBTTT‐C16), allows a systematic tuning of the blend morphology by varying the acceptor type and fraction, making it a well‐suited structural model for studying the fundamental processes in organic bulk heterojunction solar cells. To analyze the role of intercalated and pure fullerene domains on charge carrier photogeneration, time delayed collection field (TDCF) measurements and Fourier‐transform photocurrent spectroscopy (FTPS) are performed on pBTTT‐C16:[6,6]‐phenyl‐C61‐butyric acid methyl ester (PC61BM) solar cells with various stoichiometries. A weak influence of excess photon energy on photogeneration along with a photogeneration having a weaker field dependence at increasing fullerene loading is found. The findings are assigned to a dissociation via thermalized charge transfer (CT) states supported by an enhanced electron delocalization along spatially extended PC61BM nanophases that form in addition to a bimolecular crystal (BMC) for PC61BM rich blends. The highly efficient transfer of charge carriers from the BMC into the pure domains are studied further by TDCF measurements performed on non‐intercalated pBTTT‐C16:bisPC61BM blends. They reveal a field dependent charge generation similar to the 1:4 PC61BM blend, demonstrating that the presence of pure acceptor phases is the major driving force for an efficient, field independent CT dissociation.
Impact of separator's solid‐phase ion conductivity parameter on convection battery performance and modeling
Authors: Hilton Ramsey , Gordon Michael , Dornbusch Donald , Suppes Galen J.
Published: July 2014

A solid‐phase ion conductivity parameter has been added to the separator of a porous electrode theory description of a convection battery performance to increase the accuracy of this model. With the addition of the ion conductivity parameter, the variances between the model and experimental data have been reduced by 80–85% in both the convection cell and the diffusion cell. The parameter is fundamentally consistent with solid‐phase mechanisms by which ions can transport through separators in parallel with liquid‐phase transport, and the improved modeling results substantiate the importance of solid or surface ion transport mechanisms at high current fluxes. Modeling was supplemented with dimensionless analysis to lump fundamental parameters that are inherently coupled in the underlying equations. From this analysis, a global parameter has been developed describing the ratio of convective charge transfer to diffusive charge transfer that characterizes the transition from diffusive to convective cell behavior. © 2014 American Institute of Chemical Engineers AIChE J, 60: 3784–3791, 2014
Evaluation of a community‐based participatory farmworker eye health intervention in the “black dirt” region of New York State
Authors: Earle‐Richardson Giulia , Wyckoff Lynae , Carrasquillo Marilyn , Scribani Melissa , Jenkins Paul , May John
Published: July 2014

Background

Eye irritation is a constant hazard for migrant and seasonal farmworkers, but there are few studies of the problem or how to address it. Researchers evaluated the effect of a community‐based participatory eye health intervention on farmworker eye symptoms in the Hudson Valley, NY.

Methods

A randomized pre‐post intervention with 2, 4‐week follow‐up periods was implemented with a sample of 97 farmworkers. Five eye symptoms were measured, along with utilization of protective eyewear and eye drops.

Results

Leading baseline eye symptoms were redness (49%), blurred vision (43%), itching (43%), and eye pain (29%). Significant reductions in eye pain (P = 0.009), and non‐significant reductions in redness were observed for the intervention group while controls experienced increases in both.

Conclusions

The intervention was effective in significantly reducing eye pain, and to a lesser extent, redness. Future eyewear promotion programs should offer a range of eye wear, tailor offerings to local climate and tasks, evaluate eyewear durability, and include eye drops. Am. J. Ind. Med. 57:1053–1063, 2014. © 2014 Wiley Periodicals, Inc.
Health and disease: Exploring the relation between parasitic infections, child nutrition status, and markets
Authors: Tanner Susan ,   TAPS Bolivia Study Team
Published: July 2014

Research in bioarchaeology and among living people provides insight into the biological and biocultural consequences of subsistence, political, and economic transitions. Central to this effort is examining infectious disease, such as diarrheal disease, respiratory infections, and parasitic infections because they are an important source of nutritional and energetic stress in both past and current groups. Although infection may not always result in overt disease, frequent exposure results in biological stress with a negative effect on child growth and, by extension, health. The goal of this article is to examine the association between a common class of infectious disease, soil‐transmitted helminth worms, and nutritional status among youth living in communities that vary with respect to their distance from a commercial center. In 2007, anthropometric measurements and parasitological surveys were collected for 338 2–14‐year‐old children and adolescents living in lowland Bolivia as part of the Tsimane' Amazonian Panel Study. Associations between the presence of helminth infections and markers of both short‐ and long‐term nutritional status were overall weak. Youth living in communities distant from the commercial center were more likely to be positive for multiple parasite species than youth in near communities, but youth in mid‐distance communities had lower infection rates. This article demonstrates the challenge of identifying associations between nutritional and disease stress when individual and household factors are nested in a larger context of socioeconomic and environmental change. Increased collaboration between bioarchaeology and human biology should continue to examine the connections between stress and disease across time. Am J Phys Anthropol 155:221–228, 2014. © 2014 Wiley Periodicals, Inc.