bluuebunny/crossref_metadata_2025 huggingface dataset:
Barriers and Facilitators to Effective Feedback: A Qualitative Analysis of Data From Multispecialty Resident Focus Groups
Authors: Reddy Shalini T. , Zegarek Matthew H. , Fromme H. Barrett , Ryan Michael S. , Schumann Sarah-Anne , Harris Ilene B.
Published: March 2015

Background

Despite the importance of feedback, the literature suggests that there is inadequate feedback in graduate medical education.

Objective

We explored barriers and facilitators that residents in anesthesiology, emergency medicine, obstetrics and gynecology, and surgery experience with giving and receiving feedback during their clinical training.

Methods

Residents from 3 geographically diverse teaching institutions were recruited to participate in focus groups in 2012. Open-ended questions prompted residents to describe their experiences with giving and receiving feedback, and discuss facilitators and barriers. Data were transcribed and analyzed using the constant comparative method associated with a grounded theory approach.

Results

A total of 19 residents participated in 1 of 3 focus groups. Five major themes related to feedback were identified: teacher factors, learner factors, feedback process, feedback content, and educational context. Unapproachable attendings, time pressures due to clinical work, and discomfort with giving negative feedback were cited as major barriers in the feedback process. Learner engagement in the process was a major facilitator in the feedback process.

Conclusions

Residents provided insights for improving the feedback process based on their dual roles as teachers and learners. Time pressures in the learning environment may be mitigated by efforts to improve the quality of teacher-learner relationships. Forms for collecting written feedback should be augmented by faculty development to ensure meaningful use. Efforts to improve residents' comfort with giving feedback and encouraging learners to engage in the feedback process may foster an environment conducive to increasing feedback.
Incidence of Lymphatic Metastasis to Neck Nodes Level IIb in Neck Dissection for Head and Neck Cancers: A Retrospective Study
Authors: Zahrani Faisal Al , Al-Qahtani Khalid , Alshahrani Mohammed , Almufargi Khamis , Alkhudhayri Abdullah , Obad Labeb , Islam Tahera
Published: March 2015

Introduction

Selective neck dissection (SND) is performed to prevent head and neck cancers metastasis. We tried to determine the incidence of level IIb lymph nodes metastasis and it is associations in head and neck cancers for selection of patients requiring SND.

Materials and methods

A retrospective study was conducted on 57 patients who underwent surgical removal of the head and neck tumor by 84 neck dissections. Fisher exact test was used to measure the association between positive IIb nodes and the other variables.

Results

Nine (15.8%) of 57 patients showed level IIb lymph nodes metastasis comprising 10.71% of the 84 neck dissections. Six (66.66%) were associated with oral cavity cancers, 8 (88.9%) with squamous cell carcinoma (SCC), 6 (66.66%) with T4 tumor. Five (55.6%) were N2b, and 7 (77.8%) were found in N+ necks. All (100%) positive IIb nodes were associated with metastatic level IIa. Significant associations were found betweenpositive IIbnodesand N2b (p= 0.005), clinically N+ necks (p = 0.005) and IIa (p < 0.01).

Conclusion

The incidence of level IIb nodes metastasis is high so they should be removed in any oral tumor, SCC, advanced staging, N+ necks or positive IIa lymph nodes metastasis.

How to cite this article

Al zahrani F, Al-Qahtani K, Alshahrani m, Almufargi K, Alkhudhayri A, Obad l, Islam T. Incidence of lymphatic metastasis to Neck Nodes level IIb in Neck Dissection for Head and Neck Cancers: A Retrospective Study. Int J Head Neck Surg 2014;5(3):99-103.
Acute Formic Acid Poisoning: A Case Series Analysis with Current Management Protocols and Review of Literature
Authors: Naik Sudhir M , Goutham MK , Bhat Ravishankar S , Bhat CR , Appaji Mohan , Chidananda KV , Devi Nongthomban Pinky , Joseph Sherry , Nayak Pooja
Published: March 2015

Background

Formic acid (FA) being pungent, odorless, easily available and consumed for suicidal purposes and the dilute form being colorless and odorless is consumed accidentally. Accidental ingestion is rare and deliberate self-harm is very painful and violent which has been a rare modality of committing suicide but for these areas where it is easily available.

Materials and methods

This a retrospective case series analysis study 14 patients with acute formic acid poisoning. There were 14 patients, with 3 females and 11 males. The average age was 35.5 years, with the average in males being 34.9 and 37.6 in females. Thirty milliliter were considered as cutoff range as diluted/undiluted FA below 30 ml were managed in our institution and 30 ml+ were referred to higher toxicology speciality care.

Results

Act of deliberate self-harm was seen in 11 cases (78.5%) and accidental ingestion in three cases (21.5%). All had orofacial burns, 4 had mild hematemesis and 3 severe hematemesis with impending renal complications. All the stabilized and referred cases were no further evaluated for follow-up. Facial burns and contracture needing cosmetic correction was seen in three cases, while corneal and lid scarring seen in two cases while a case of esophageal stricture with lower GIT and renal complications were seen in one case.

Conclusion

Formic acid poisoning is uncommon, and limited literature review is available with fewer protocols laid. So, immediate management of this corrosive poisoning with supportive measures reduces the mortality drastically. Serial upper gastrointestinal imaging diagnose stricture earlier and cosmetic reconstruction helps in facial scarring and contractures.

How to cite this article

Bhat RS, Naik SM, Goutham MK, Bhat CR, Appaji M, Chidananda KV, Devi NP, Joseph S, Nayak P. Acute Formic Acid Poisoning: A Case Series Analysis with Current management Protocols and Review of Literature. Int J head Neck Surg 2014;5(3):104-107.
Physiotherapy on the Complications of Head and Neck Cancer: Retrospective Study
Authors: Tacani Rogerio Eduardo , Machado Aline Fernanda Perez , Goes João Carlos G Sampaio , Marx Angela Gonçalvez , Franceschini Juliana Pereira , Tacani Pascale Mutti
Published: March 2015

Introduction

Physiotherapy has an important role in cancer rehabilitation, particularly with the head and neck cancer patients, in an attempt to minimize the morbidities caused by the disease and its treatment.

Objective

To determine the role of physiotherapy treatment in morbidities of head and neck cancer, in a retrospective investigation, at one oncologic hospital.

Materials and methods

Retrospective study based on the analysis of medical records of 32 patients treated at the outpatient Physiotherapy department at the Brazilian Institute of Cancer Control (IBCC), from August 2008 to July 2010.

Results

Twenty-nine medical records were evaluated, 86.2% were males with cancer in the oral cavity (41.4%) that had radical neck dissection (69%) and radiotherapy (86.2%), evolving with lymphedema (89.7%), pain (82.8%), normotrophic scar (65.5%), tissue adherence (27.6%) and hypoesthesia (51.7%). The physiotherapeutic treatment included: manual lymphatic drainage (89.7%), transcutaneous electrical nerve stimulation (TENS; 51.7%), mechanical massage therapy (37.9%), stretching exercises (79.3%) and patient education (100%). The results showed a reduction of pain and lymphedema, increased normotrophic scars and normoesthesia, with an average of 19.3 ± 14.5 sessions and treatment discharge of 65.5%.

Conclusion

Physical therapy in morbidities of head and neck cancer was effective in reducing pain and lymphedema, combining manual lymphatic drainage, transcutaneous electrical nerve stimulation (TENS), mechanical massage therapy, stretching exercises and patient education, with an average of 19 sessions and discharge after treatment.

How to cite this article

Tacani RE, Machado AFP, Goes JCGS, Marx AG, Franceschini JP, Tacani PM. Physiotherapy on the Complications of Head and Neck Cancer: Retrospective Study. Int J Head Neck Surg 2014;5(3):112-118.
Paradigm Shift of Carotid Body Paraganglioma Surgical Technique from Caudocranial to Craniocaudal Dissection: Analysis of Recent Literature
Authors: Naik Sudhir , Halkud Rajshekar , Nanjundappa A , Biswas Siddharth , Shenoy Ashok M , Chavan Purshottam , Sidappa KT , Madhu SD
Published: March 2015

Background

The classical Shamblin's classification predicts only vascular morbidity without remarking on the neurological morbidity, while the neurological damage increase with vessel ligation and reconstruction. A modified Shamblin's classification described by Luna-ortiz with incorporation of the Hallett's zones of injury has been studied here.

Materials and methods

We present a case series analysis of carotid body paraganglioma managed in our institute. The study included 17 patients, 14 females and three males with a mean duration of presentation of 6.82 months. All were imaged with multislicer computed tomography angiography (CTA) and magnetic resonance angiography (MRA) for preoperative assessment and operated in the craniocaudal technique. The tumors were graded according to the modified Shamblin's criteria: grades I (2), II (13), IIIa (2), IIIb (0).

Results

All the preoperative assessment of grading matched with the intraoperative findings. External carotid artery (ECA) ligation was done in two cases, no internal carotid artery (ICA) ligation and reconstruction were done. Two cases of permanent damage to the 12th nerve, two vagal nerve weakness was seen. No stroke or mortality recorded. The tumor was confirmed on immunohistochemistry. The patients were followed up for 6 months to 5 years with a mean follow-up of 2.5 years.

Conclusion

Preoperative imaging assessment using multislicer computed tomography angiography (MSCTA) and MRA helps to measuring the circumferential vessel involvement in grade III tumors. So, a craniocaudal dissection with assessment of all the zones of injury reduced blood loss and minimized neurovascular complications.

How to cite this article

Halkud R, Shenoy AM, Nanjundappa A, Chavan P, Sidappa KT, Madhu SD, Biswas S, Naik SM. Paradigm Shift of Carotid Body Paraganglioma Surgical Technique from Caudocranial to Craniocaudal Dissection: Analysis of Recent Literature. Int J Head Neck Surg 2014;5(3):119-125.
Rosai-Dorfman Disease: A Rare Cause of Cervical Lymphadenopathy
Authors: Anand Adharsh , Lanjewar Kanchan , Ekhar Vipin Ram , Shelkar Ritesh N , Rane Sachin , Jain Suresh Kumar Tarachand
Published: March 2015

Rosai-Dorfman disease is also known as sinus histiocytosis with massive lymphadenopathy (SHML) is a rare clinico-pathological condition. It is a benign condition which causes significant cervical lymphadenopathy in children and young adults. The clinical presentation varies from isolated nodal involvement to significant extranodal manifestations. The clinical features are usually mild, but rarely life-threatening complications can occur in some individuals depending on the site of involvement. Here, we present two cases of Rosai-Dorfman disease, both diagnosed on fine needle aspiration cytology (FNAC) and histopathology and responded well to steroids. One of the patients had extranodal site involvement in the form of bilateral nasal mass which is very rare.

How to cite this article

Ekhar VR, Shelkar RN, Rane S, Anand A, Lanjewar K, Jain SKT. Rosai-Dorfman Disease: A Rare Cause of Cervical Lymphadenopathy. Int J Head Neck Surg 2014;5(3): 152-154.
Novel Approach to Rhinosporidiosis
Authors: Aroor Rajeshwary , Gowda Madhukar Muniswamy , Bhat Vadisha Srinivas , Bhandary Satheesh Kumar
Published: March 2015

Rhinosporidiosis is a chronic enigmatic disease affecting mainly the upper aerodigestive tract and is notorious for frequent recurrences as high as 70%. Higher incidences of recurrence are mainly due to nonendoscopic excision with resultant residual disease leading to seedling of the disease.

Objectives

The aim of this study is to highlight the factors responsible for recurrence and to follow the clinical course to ensure against recurrence of rhinosporidiosis. External surgery in rhinosporidiosis should be avoided for the fear of implantation. With the advent of endoscopes and Lasers allow the surgeon to complete excision of the lesion with cauterization of the base.

Materials and methods

A retrospective study of thirty two cases of rhinosporidiosis presented to us over a period of 10 years from 2002 to 2012. Out of which 14 cases presented to us for the first time and 18 cases were recurrent cases. The commonest age group of presentation was between 20 and 30 years in patients presenting for the first time and in recurrent cases the commonest age of presentation was between 50 and 60 years of age. Majority of patients were males with male to female ratio of 9:1. All patients underwent endoscopic excision, electro cautery was used in 30 patients and Laser was used in 2 patients.

Results

Fourteen cases did not have any recurrence and in the 18 cases of recurrent cases three of them again had a recurrence where electro cautery was used to cauterize the base.

Conclusion

Endoscopic excision of rhinosporidiosis has a better result over nonendoscopic approaches with lesser recurrence rate. Our results show that use of endoscopes in patients who presented for the first time have a better results as the mucosa of recurrence patients have already been insulted due to previous surgeries.

How to cite this article

Aroor R, Gowda MM, Bhat VS, Bhandary SK. Novel Approach to Rhinosporidiosis. Int J Otorhinolaryngol Clin 2014;6(2):55-57.
Preauricular Sinus as Recurrent Postaural Abscess: A Rare Presentation
Authors: Malipatil Sharanabasappa Rudragouda
Published: March 2015

Preauricular sinus (PAS) is not uncommon congenital anomaly. It is usually asymptomatic and does not require any treatment. Patient presenting with discharge, recurrent infections and preauricular abscess will require management with antibiotics and surgical extirpation of the sinus tract. Here, it is a rare case report of PAS presenting as a recurrent postaural abscess.

How to cite this article

Malipatil SR. Preauricular Sinus as Recurrent Postaural Abscess: A Rare Presentation. Int J Otorhinolaryngol Clin 2014;6(2):84-86.
Doorwerking van WTO-recht in de Europese rechtsorde: het toenemende belang van de verdragsconforme interpretatie
Authors: van den Broek N.
Published: March 2015

Doorwerking van WTO-recht in de Europese rechtsorde: het toenemende belang van de verdragsconforme interpretatie

In een aantal recente zaken spreken het Hof van Justitie en een aantal advocaten-generaal zich wederom uit over de doorwerking van het recht van de Wereldhandelsorganisatie (WTO) in de Europese rechtsorde. Hoewel de deur voor ‘rechtstreeks effect’ gesloten blijft, is iedere Europese rechter onder het principe van de ‘verdragsconforme interpretatie’ verplicht om het Europees recht voor zover mogelijk uit te leggen in lijn met relevante regels van WTO-recht. Aldus bestaat er wel degelijk een mogelijkheid voor particuliere partijen om zich op het WTO-recht te beroepen en de rechter, althans de Europese, geeft daaraan steeds vaker (expliciet of impliciet) gehoor.

HvJ 14 april 2011, gevoegde zaken C-288/09 en C-289/09, BskyB and Pace/The Commissioners for Her Majesty’s Revenue & Customs, ECLI:EU:C:2011:248

HvJ 22 november 2012, gevoegde zaken C-320/11, C-330/11, C-382/11, en C-383/11, Digitalnet OOD, ECLI:EU:C:2012:745

HvJ 27 september 2007, zaak C-351/04, Ikea Wholesale Ltd./Commissioners of Customs & Excise, ECLI:EU:C:2007:547;

HvJ 27 juni 2013, gevoegde zaken C-457/11 tot en met C-460/11, VG Wort/Kyocera e.a., C-457/11 tot en met C-460/11, ECLI:EU:C:2013:426

HvJ 10 april 2014, zaak C-435/12, ACI Adam e.a., ECLI:EU:C:2014:254

HvJ 3 juni 2008, zaak C-308/06, Intertanko e.a./Secretary of State for Transport, ECLI:EU:C:2008:312

HvJ 13 januari 2015, gevoegde zaken C-404/12 P en C-405/12 P, Raad en Commissie/Stichting Natuur en Milieu en Pesticide Action Network Europe, ECLI:EU:C:2015:5

HvJ 13 januari 2015, gevoegde zaken C-401/12 P tot C-403/12 P, Raad e.a./Vereniging Milieudefensie en Stichting Stop Luchtverontreiniging Utrecht, ECLI:EU:C:2015:4

HvJ 9 september 2008, gevoegde zaken C-120/06 en C-121/06, Fabbrica italiana accumulatori motocarri Montecchio SpA (FIAMM) e.a./Raad en Commissie, ECLI:EU:C:2008:476

HvJ 14 juni 2012, zaak C-533/10, Compagnie international pour la vente à distance (CIVAD) SA/Receveur des douanes de Roubaix e.a., ECLI:EU:C:2012:347
Een lijdensweg die nog niet geëindigd is
Authors: Luijten E.A.A. , Meijer W.R.
Published: March 2015

Een lijdensweg die nog niet geëindigd is. Hof Den Haag 28 oktober 2014, ECLI:NL:GHDHA:2014:3858

De uitsluiting van twee wilsrechten die niet toepasselijk zijn, betekent volgens het Hof Den Haag niet dat het de bedoeling van de testateur was de twee wel toepasselijke wilsrechten uit te sluiten. Artikel 4:21 BW wordt geacht te zijn uitgesloten, artikel 4:22 BW wordt geacht niet te zijn uitgesloten. De auteurs zijn hier niet enthousiast over.
Media Ecology in Michel Serres's Philosophy of Communication
Authors: Barker Timothy ,   Philosophy Documentation Center
Published: March 2015

Throughout his philosophical project Michel Serres uses the etymological connections between words to reveal much larger experiential and philosophical links. One such connection is between the words ‘media’ and ‘milieu’. In this paper I show how Serres’ philosophy of communication can be used to think critically about the relationship between media and the environment. The paper provides an introduction to Serres’ mode of thought, focusing on his treatment of communication systems. It explores his articulation of noise, information, and thermodynamics and what this contributes to critical discussions of media ecology.
In Vitro Activity of Calcium Sulfate and Hydroxyapatite Antifungal Disks Loaded with Amphotericin B or Voriconazole in Consideration for Adjunctive Osteomyelitis Management
Authors: Karr Jeffrey C. , Lauretta Joseph
Published: March 2015

Background

Regarding antibiotic-loaded cements, there is an abundant amount of literature regarding the antibacterial in vitro inhibitory and clinical applications for the treatment of osteomyelitis. The opposite can be said about literature regarding in vitro antifungal-loaded cement drug delivery for the treatment of fungal osteomyelitis.

Methods

Aspergillus fumigatus and Candida (ATCC 1023ATCC, Manassas, Virginia) were plated on antibiotic/antifungal-free plates. Voriconazole- and amphotericin B–impregnated calcium sulfate and hydroxyapatite (HA) disks, calcium sulfate + HA control disks, and control polymethylmethacrylate disks were laid separately onto plates separately inoculated with Aspergillus and Candida spp. The zones of inhibition obtained were measured in millimeters at 24, 36, and 96 hours.

Results

Etest (bioMérieux, Marcy l'Etoile, France) results demonstrated susceptibility of Aspergillus and Candida to amphotericin B and voriconazole. The zone of inhibition data demonstrated that voriconazole and amphotericin B retained their antifungal activity when mixed into the calcium sulfate + HA bone void filler and eluted at biologically effective antifungal concentrations over 96 hours.

Conclusions

The calcium sulfate + HA bone void filler is a biocompatible ceramic carrier vehicle that can successfully deliver the antifungal drugs voriconazole and amphotericin B in the adjunctive treatment of fungal osteomyelitis. It is a reliable strategy in the local delivery of antifungal drugs to an area of osteomyelitis.
Ultrasound Diagnosis and Evaluation of Plantar Heel Pain
Authors: Argerakis Nicholas G. , Positano Rock G. , Positano Rock C. J. , Boccio Ashley K. , Adler Ronald S. , Saboeiro Gregory R. , Dines Joshua S.
Published: March 2015

Background

One of the most common causes of heel pain is plantar fasciitis; however, there are other pathologic disorders that can mimic the symptoms and clinical presentation of this disorder. The purpose of this study was to retrospectively review the prevalence of various pathologic disorders on ultrasound in patients with proximal plantar heel pain.

Methods

The medical records and diagnostic ultrasound reports of patients presenting with plantar heel pain between March 1, 2006, and March 31, 2007, were reviewed retrospectively, and the prevalence of various etiologies was collected. The inclusion criteria were based on their clinical presentation of plantar fasciitis or previous diagnosis of plantar fasciitis from an unknown source. Ultrasound evaluation was then performed to confirm the clinical diagnosis.

Results

We examined 175 feet of 143 patients (62 males and 81 females; age range, 16–79 years). Plantar fibromas were present in 90 feet (51%). Plantar fasciitis was diagnosed in 128 feet (73%). Coexistent plantar fibroma and plantar fascial thickening was found in 63 feet (36%). Of the 47 feet that were negative for plantar fasciitis on ultrasound, 27 (57%) revealed the presence of plantar fibroma.

Conclusions

Diagnostic ultrasound can effectively and safely identify the prevalence of various etiologies of heel pain. The high prevalence of plantar fibromas and plantar fascial tears cannot be determined by clinical examination alone, and, therefore, ultrasound evaluation should be performed for confirmation of diagnosis.
Radiographic Anatomy of the Foot and Ankle—Part 5
Authors: Christman Robert A.
Published: March 2015

Background

The normal radiographic anatomy of the foot and ankle, aside from my previous work, has been addressed only superficially or sparingly in the medical literature. This project correlates the detailed radiographic anatomy of the entire adult foot and ankle (two-dimensional) to osteology (three-dimensional).

Methods

Each bone's position was determined after meticulous examination and correlation to an articulated skeleton relative to the image receptor and direction of the x-ray beam, with correlation to the radiograph for confirmation.

Results

Images of each foot and distal leg bone (“front” and “back” perspectives) are presented alongside a corresponding radiographic image for comparison. The normal gross and radiographic anatomy is correlated and described for each radiographic positioning technique.

Conclusions

Foundational knowledge is provided that future researchers can use as a baseline (“normal”) and that students and practitioners can use for comparison when interpreting radiographs and distinguishing abnormal findings. The results of the original project, owing to its broad scope, have been divided into five parts: the lower leg, the greater tarsus, the lesser tarsus, the metatarsals, and the phalanges (the focus of this article).
Entrapment of the Superficial Peroneal Nerve
Authors: Tzika Maria , Paraskevas George , Natsis Konstantinos
Published: March 2015

Entrapment of the superficial peroneal nerve is an uncommon neuropathy that may occur because of mechanical compression of the nerve, usually at its exit from the crural fascia. The symptoms include sensory alterations over the distribution area of the superficial peroneal nerve. Clinical examination, electrophysiologic findings, and imaging techniques can establish the diagnosis. Variations in the superficial peroneal sensory innervation over the dorsum of the foot may lead to variable results during neurologic examination and variable symptomatology in patients with nerve entrapment or lesions. Knowledge of the nerve's anatomy at the lower leg, foot, and ankle is of essential significance for the neurologist and surgeon intervening in the area.
Severe Chronic Heel Pain in a Diabetic Patient with Plantar Fasciitis Successfully Treated Through Transcranial Direct Current Stimulation
Authors: Mohomad Al Sawah , Mohammad Rimawi , Chusid Eileen , Trepal Michael , Battaglia Fortunato
Published: March 2015

Background

Recently, transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique, was proposed as a suitable method for the treatment of several chronic pain syndromes. We describe a case of severe heel pain in a diabetic patient with plantar fasciitis successfully treated with tDCS.

Methods

The present study investigated whether tDCS treatment could reduce pain and pain-related anxiety in a 65-year-old diabetic man affected by treatment-resistant right heel pain due to plantar fasciitis. The patient underwent five tDCS treatment sessions on 5 consecutive days. Each session consisted of 20-min anodal tDCS over the left primary motor cortex leg area.

Results

The neurostimulation protocol induced a decrease in pain intensity and pain-related anxiety that outlasted the stimulation (1 week). Furthermore, the patient stopped the intake of opioid medication.

Conclusions

Therapeutic neuromodulation with tDCS may represent an alternative option for treating severe lower-extremity pain.
A Rare Presentation of Foot Pain
Authors: George David A. , Ray Pinak S. , Livingstone Julian
Published: March 2015

In this case report, we discuss a rare tarsal coalition occurring bilaterally between the navicular and the medial cuneiform in a 15-year-old girl and highlight the management of such cases.
Red, Exophytic Nodule of the Plantar Foot
Authors: Kober Mary-Margaret , Alapati Usha , Khachemoune Amor
Published: March 2015

Pyogenic granulomas are benign vascular tumors characterized histologically by a lobular proliferation of capillaries. We report an unusual presentation of a pyogenic granuloma in an elderly patient with a bleeding red nodule on the plantar surface of the foot. Nodular exophytic plantar foot lesions often present a diagnostic challenge, as the differential diagnosis includes benign and malignant entities ranging from eccrine poroma and pyogenic granuloma to Kaposi's sarcoma and amelanotic melanoma. This case highlights the need for an adequate biopsy technique to confirm the diagnosis and guide management.
Bovine F1Fo ATP synthase monomers bend the lipid bilayer in 2D membrane crystals
Authors: Jiko Chimari , Davies Karen M , Shinzawa-Itoh Kyoko , Tani Kazutoshi , Maeda Shintaro , Mills Deryck J , Tsukihara Tomitake , Fujiyoshi Yoshinori , Kühlbrandt Werner , Gerle Christoph
Published: March 2015

We have used a combination of electron cryo-tomography, subtomogram averaging, and electron crystallographic image processing to analyse the structure of intact bovine F1Fo ATP synthase in 2D membrane crystals. ATPase assays and mass spectrometry analysis of the 2D crystals confirmed that the enzyme complex was complete and active. The structure of the matrix-exposed region was determined at 24 Å resolution by subtomogram averaging and repositioned into the tomographic volume to reveal the crystal packing. F1Fo ATP synthase complexes are inclined by 16° relative to the crystal plane, resulting in a zigzag topology of the membrane and indicating that monomeric bovine heart F1Fo ATP synthase by itself is sufficient to deform lipid bilayers. This local membrane curvature is likely to be instrumental in the formation of ATP synthase dimers and dimer rows, and thus for the shaping of mitochondrial cristae.
An open source Bayesian Monte Carlo isotope mixing model with applications in Earth surface processes
Authors: Arendt Carli A. , Aciego Sarah M. , Hetland Eric A.
Published: March 2015

The implementation of isotopic tracers as constraints on source contributions has become increasingly relevant to understanding Earth surface processes. Interpretation of these isotopic tracers has become more accessible with the development of Bayesian Monte Carlo (BMC) mixing models, which allow uncertainty in mixing end‐members and provide methodology for systems with multicomponent mixing. This study presents an open source multiple isotope BMC mixing model that is applicable to Earth surface environments with sources exhibiting distinct end‐member isotopic signatures. Our model is first applied to new δ18O and δD measurements from the Athabasca Glacier, which showed expected seasonal melt evolution trends and vigorously assessed the statistical relevance of the resulting fraction estimations. To highlight the broad applicability of our model to a variety of Earth surface environments and relevant isotopic systems, we expand our model to two additional case studies: deriving melt sources from δ18O, δD, and 222Rn measurements of Greenland Ice Sheet bulk water samples and assessing nutrient sources from ɛNd and 87Sr/86Sr measurements of Hawaiian soil cores. The model produces results for the Greenland Ice Sheet and Hawaiian soil data sets that are consistent with the originally published fractional contribution estimates. The advantage of this method is that it quantifies the error induced by variability in the end‐member compositions, unrealized by the models previously applied to the above case studies. Results from all three case studies demonstrate the broad applicability of this statistical BMC isotopic mixing model for estimating source contribution fractions in a variety of Earth surface systems.
High‐resolution magnetic signature of active hydrothermal systems in the back‐arc spreading region of the southern Mariana Trough
Authors: Fujii Masakazu , Okino Kyoko , Honsho Chie , Dyment Jerome , Szitkar Florent , Mochizuki Nobutatsu , Asada Miho
Published: March 2015

High‐resolution vector magnetic measurements were performed on five hydrothermal vent fields of the back‐arc spreading region of the southern Mariana Trough using Shinkai 6500, a deep‐sea manned submersible. A new 3‐D forward scheme was applied that exploits the surrounding bathymetry and varying altitudes of the submersible to estimate absolute crustal magnetization. The results revealed that magnetic‐anomaly‐derived absolute magnetizations show a reasonable correlation with natural remanent magnetizations of rock samples collected from the seafloor of the same region. The distribution of magnetic‐anomaly‐derived absolute magnetization suggests that all five andesite‐hosted hydrothermal fields are associated with a lack of magnetization, as is generally observed at basalt‐hosted hydrothermal sites. Furthermore, both the Pika and Urashima sites were found to have their own distinct low‐magnetization zones, which could not be distinguished in magnetic anomaly data collected at higher altitudes by autonomous underwater vehicle due to their limited extension. The spatial extent of the resulting low magnetization is approximately 10 times wider at off‐axis sites than at on‐axis sites, possibly reflecting larger accumulations of nonmagnetic sulfides, stockwork zones, and/or alteration zones at the off‐axis sites.
Improving representation of convective transport for scale‐aware parameterization: 1. Convection and cloud properties simulated with spectral bin and bulk microphysics
Authors: Fan Jiwen , Liu Yi‐Chin , Xu Kuan‐Man , North Kirk , Collis Scott , Dong Xiquan , Zhang Guang J. , Chen Qian , Kollias Pavlos , Ghan Steven J.
Published: March 2015

The ultimate goal of this study is to improve the representation of convective transport by cumulus parameterization for mesoscale and climate models. As Part 1 of the study, we perform extensive evaluations of cloud‐resolving simulations of a squall line and mesoscale convective complexes in midlatitude continent and tropical regions using the Weather Research and Forecasting model with spectral bin microphysics (SBM) and with two double‐moment bulk microphysics schemes: a modified Morrison (MOR) and Milbrandt and Yau (MY2). Compared to observations, in general, SBM gives better simulations of precipitation and vertical velocity of convective cores than MOR and MY2 and therefore will be used for analysis of scale dependence of eddy transport in Part 2. The common features of the simulations for all convective systems are (1) the model tends to overestimate convection intensity in the middle and upper troposphere, but SBM can alleviate much of the overestimation and reproduce the observed convection intensity well; (2) the model greatly overestimates Ze in convective cores, especially for the weak updraft velocity; and (3) the model performs better for midlatitude convective systems than the tropical system. The modeled mass fluxes of the midlatitude systems are not sensitive to microphysics schemes but are very sensitive for the tropical case indicating strong microphysics modification to convection. Cloud microphysical measurements of rain, snow, and graupel in convective cores will be critically important to further elucidate issues within cloud microphysics schemes.
A multisite analysis of temporal random errors in soil CO2 efflux
Authors: Cueva Alejandro , Bahn Michael , Litvak Marcy , Pumpanen Jukka , Vargas Rodrigo
Published: March 2015

An important component of the terrestrial carbon balance is the efflux of CO2 from soils to the atmosphere, which is strongly influenced by changes in soil moisture and temperature. Continuous measurements of soil CO2 efflux are available around the world, and there is a need to develop and improve analyses to better quantify the precision of the measurements. We focused on random errors in measurements, which are caused by unknown and unpredictable changes such as fluctuating environmental conditions. We used the CO2 gradient flux method with two different algorithms to study the temporal variation of soil CO2 efflux and associated random errors at four different ecosystems with wide ranges in mean annual temperature, soil moisture, and soil CO2 efflux. Our results show that random errors were better explained by a double‐exponential distribution, had a mean value close to zero, were nonheteroscedastic, and were independent of soil moisture conditions. Random errors increased with the magnitude of soil CO2 efflux and scale isometrically (scaling exponent ≈ 1) within and across all sites, with a single relation common to all data. This isometric scaling is unaffected by ecosystem type, soil moisture conditions, and soil CO2 efflux range (maximum and minimum values within an ecosystem). These results suggest larger uncertainty under extreme events that increase soil CO2 efflux rates. The accumulated annual uncertainty due to random errors varied between ±0.38 and ±2.39%. These results provide insights on the scalability of the sensitivity of soil CO2 efflux to changing weather conditions across ecosystems.
Anthropogenic and climatic influences on carbon fluxes from eastern North America to the Atlantic Ocean: A process‐based modeling study
Authors: Tian Hanqin , Yang Qichun , Najjar Raymond G. , Ren Wei , Friedrichs Marjorie A. M. , Hopkinson Charles S. , Pan Shufen
Published: March 2015

The magnitude, spatiotemporal patterns, and controls of carbon flux from land to the ocean remain uncertain. Here we applied a process‐based land model with explicit representation of carbon processes in streams and rivers to examine how changes in climate, land conversion, management practices, atmospheric CO2, and nitrogen deposition affected carbon fluxes from eastern North America to the Atlantic Ocean, specifically the Gulf of Maine (GOM), Middle Atlantic Bight (MAB), and South Atlantic Bight (SAB). Our simulation results indicate that the mean annual fluxes (±1 standard deviation) of dissolved organic carbon (DOC), particulate organic carbon (POC), and dissolved inorganic carbon (DIC) in the past three decades (1980–2008) were 2.37 ± 0.60, 1.06 ± 0.20, and 3.57 ± 0.72 Tg C yr−1, respectively. Carbon export demonstrated substantial spatial and temporal variability. For the region as a whole, the model simulates a significant decrease in riverine DIC fluxes from 1901 to 2008, whereas there were no significant trends in DOC or POC fluxes. In the SAB, however, there were significant declines in the fluxes of all three forms of carbon, and in the MAB subregion, DIC and POC fluxes declined significantly. The only significant trend in the GOM subregion was an increase in DIC flux. Climate variability was the primary cause of interannual variability in carbon export. Land conversion from cropland to forest was the primary factor contributing to decreases in all forms of C export, while nitrogen deposition and fertilizer use, as well as atmospheric CO2 increases, tended to increase DOC, POC, and DIC fluxes.
Modeling methane emissions from arctic lakes: Model development and site‐level study
Authors: Tan Zeli , Zhuang Qianlai , Walter Anthony Katey
Published: March 2015

To date, methane emissions from lakes in the pan‐arctic region are poorly quantified. In order to investigate the response of methane emissions from this region to global warming, a process‐based climate‐sensitive lake biogeochemical model was developed. The processes of methane production, oxidation, and transport were modeled within a one‐dimensional sediment and water column. The sizes of 14C‐enriched and 14C‐depleted carbon pools were explicitly parameterized. The model was validated using observational data from five lakes located in Siberia and Alaska, representing a large variety of environmental conditions in the arctic. The model simulations agreed well with the measured water temperature and dissolved CH4 concentration (mean error less than 1°C and 0.2 μM, respectively). The modeled CH4 fluxes were consistent with observations in these lakes. We found that bubbling‐rate‐controlling nitrogen (N2) stripping was the most important factor in determining CH4 fraction in bubbles. Lake depth and ice cover thickness in shallow waters were also controlling factors. This study demonstrated that the thawing of Pleistocene‐aged organic‐rich yedoma can fuel sediment methanogenesis by supplying a large quantity of labile organic carbon. Observations and modeling results both confirmed that methane emission rate at thermokarst margins of yedoma lakes was much larger (up to 538 mg CH4 m−2 d−1) than that at nonthermokarst zones in the same lakes and a nonyedoma, nonthermokarst lake (less than 42 mg CH4 m−2 d−1). The seasonal variability of methane emissions can be explained primarily by energy input and organic carbon availability.
Progressive shoaling of the equatorial Pacific thermocline over the last eight glacial periods
Authors: Regoli Fabienne , de Garidel‐Thoron Thibault , Tachikawa Kazuyo , Jian Zhiming , Ye Liming , Droxler André W. , Lenoir Guillaume , Crucifix Michel , Barbarin Nicolas , Beaufort Luc
Published: March 2015

The depth of equatorial Pacific thermocline is diagnostic of the main modes of tropical climates. Past estimates of Pacific thermocline dynamics have been reconstructed either for the Last Glacial Maximum or on longer timescales at low resolution. Here we document a new high‐resolution set of reconstructed past sea surface and subsurface waters temperatures from the southwestern subequatorial Pacific, core MD05‐2930, in the Gulf of Papua, over the last 800 ka. We used two morphotypes of Globigerinoides ruber known to live at different water depths to reconstruct past stratification. We estimated calcification temperature of each morphotypes by Mg/Ca paleothermometry. Our subequatorial Pacific thermocline paleotemperature record indicates a response of the thermocline to both direct orbital forcing and glacial‐interglacial changes. Our stratification record shows a systematic shallower glacial thermocline, whereas sea surface temperatures are characterized by precessional forcing. The record is indicative of a progressive long‐term shoaling of the thermocline during the glacial stages during the late Pleistocene. The shoaling of the subequatorial Pacific thermocline is consistent with regional estimates. An enhanced South Pacific shallow overturning wind‐driven circulation could have driven this progressive shoaling. We speculate that this late Pleistocene glacial shoaling of the thermocline could be related to an increase in the amplitude of the obliquity.
The thinning of subcontinental lithosphere: The roles of plume impact and metasomatic weakening
Authors: Wang Hongliang , van Hunen Jeroen , Pearson D. Graham
Published: March 2015

Geologically rapid (tens of Myr) partial removal of thick continental lithosphere is evident beneath Precambrian terranes, such as North China Craton, southern Africa, and the North Atlantic Craton, and has been linked with thermomechanical erosion by mantle plumes. We performed numerical experiments with realistic viscosities to test this hypothesis and constrain the most important parameters that influence cratonic lithosphere erosion. Our models indicate that the thermomechanical erosion by a plume impact on typical Archean lithospheric mantle is unlikely to be more effective than long‐term erosion from normal plate‐mantle interaction. Therefore, unmodified cratonic roots that have been stable for billions of years will not be significantly disrupted by the erosion of a plume event. However, the buoyancy and strength of highly depleted continental roots can be modified by fluid‐melt metasomatism, and our models show that this is essential for the thinning of originally stable continental roots. The long‐term but punctuated history of metasomatic enrichment beneath ancient continents makes this mode of weakening very likely. The effect of the plume impact is to speed up the erosion significantly and help the removal of the lithospheric root to occur within tens of Myr if affected by metasomatic weakening.
Small shear modulus of cubic CaSiO3 perovskite
Authors: Kawai Kenji , Tsuchiya Taku
Published: March 2015

Ca‐perovskite (CaPv) is considered to be one of the most abundant minerals in the Earth's lower mantle (LM). Furthermore, previous static calculations and mean‐field theory suggest that it has a much larger shear modulus than bridgmanite (MgPv). In this study, the elasticity of cubic CaPv was reinvestigated using the density functional constant‐temperature first principles molecular dynamics method under the correct conditions to simulate its elasticity. Our new results clearly demonstrate that cubic CaPv has comparable bulk and slightly smaller shear moduli than Fe‐bearing MgPv. This is because the boundary condition for the supercell used in this study allows for the rotational phonon motion of SiO6 octahedra under strain, which predominantly affects the decrease in C11 and C44. Acoustic wave velocities determined from the elastic moduli indicate that cubic CaPv has slower velocities and larger densities than Fe‐bearing MgPv and preliminary reference Earth model in the LM. This suggests that if CaPv‐rich material exists, it can accumulate in the lowermost LM and produce a seismically low‐velocity anomaly.
The interhemispheric and F region dynamo currents revisited with the Swarm constellation
Authors: Lühr Hermann , Kervalishvili Guram , Michaelis Ingo , Rauberg Jan , Ritter Patricia , Park Jaeheung , Merayo Jose M. G. , Brauer Peter
Published: March 2015

Based on magnetic field data sampled by the Swarm satellite constellation it is possible for the first time to determine uniquely F region currents at low latitudes. Initial results are presented from the first 200 days of formation flight (17 April to 5 November 2014). Detailed results have been obtained for interhemispheric field‐aligned currents connecting the solar quiet day magnetic variation (Sq) current systems in the two hemispheres. We obtain prominent currents from the Southern (winter) Hemisphere to the Northern around noon. Weaker currents in opposite direction are observed during morning and evening hours. Furthermore, we could confirm the existence of vertical currents above the dip equator, downward around noon and upward around sunset. For both current systems we present and discuss longitudinal variations.
ACN9 and alcohol dependence: Family‐based association analysis in multiplex alcohol dependence families
Authors: Hill Shirley Y. , Jones Bobby L. , Zezza Nicholas , Stiffler Scott
Published: March 2015

A previous genome‐wide linkage study of alcohol dependence (AD) in the Pittsburgh‐based multiplex family study found suggestive evidence for linkage on Chromosome 7q, a region in which the ACN9 gene is located. Using the same two generation Pittsburgh family data in which linkage was found, data for a third generation was added. The expanded sample included 133 pedigrees with 995 individuals. Finer mapping was undertaken using six SNPs extending from rs1917939 to rs13475 with minor allele frequency (MAF) ≥0.15 and pair‐wise linkage disequilibrium (LD) of r2 <0.8 using the HapMap CEU population. Binary affection status, visual, and auditory P300 data were tested for family‐based association. Family‐based analyses found all six SNPs associated with affected status. Three SNPs are located upstream of the gene, two SNPs are within intron 1 and one is in Exon 4. FBAT P‐values for the six SNPs ranged between 0.05 and 0.0005. Haplotype analysis revealed one four‐SNP block formed by rs10499934, rs7794886, rs12056091, and rs13475 with an overall significant association at P = 0.0008. Analysis of visual P300 amplitude data, a known endophenotype of alcohol dependence risk, revealed a significant association for SNPs within intron 1 and exon 4 under a dominant model of transmission. Family‐based association analysis shows the ACN9 gene significantly associated with alcohol dependence and P300 amplitude variation. The potential importance of the ACN9 gene for AD risk may be related to its role in gluconeogenesis which may be involved in the regulation of alcohol metabolism. © 2015 Wiley Periodicals, Inc.
Psychopathological manifestations of joint hypermobility and joint hypermobility syndrome/ Ehlers–Danlos syndrome, hypermobility type: The link between connective tissue and psychological distress revised
Authors: Sinibaldi Lorenzo , Ursini Gianluca , Castori Marco
Published: March 2015

Psychological distress is a known feature of generalized joint hypermobility (gJHM), as well as of its most common syndromic presentation, namely Ehlers–Danlos syndrome, hypermobility type (a.k.a. joint hypermobility syndrome — JHS/EDS‐HT), and significantly contributes to the quality of life of affected individuals. Most published articles dealt with the link between gJHM (or JHS/EDS‐HT) and anxiety‐related conditions, and a novel generation of studies is emerging aimed at investigating the psychopathologic background of such an association. In this paper, literature review was carried out with a semi‐systematic approach spanning the entire spectrum of psychopathological findings in gJHM and JHS/EDS‐HT. Interestingly, in addition to the confirmation of a tight link between anxiety and gJHM, preliminary connections with depression, attention deficit (and hyperactivity) disorder, autism spectrum disorders, and obsessive–compulsive personality disorder were also found. Few papers investigated the relationship with schizophrenia with contrasting results. The mind–body connections hypothesized on the basis of available data were discussed with focus on somatotype, presumed psychopathology, and involvement of the extracellular matrix in the central nervous system. The hypothesis of positive Beighton score and alteration of interoceptive/proprioceptive/body awareness as possible endophenotypes in families with symptomatic gJHM or JHS/EDS‐HT is also suggested. Concluding remarks addressed the implications of the psychopathological features of gJHM and JHS/EDS‐HT in clinical practice. © 2015 Wiley Periodicals, Inc.