bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Eocene to middle Miocene cooling and aridification of East Antarctica
Authors: Passchier S. , Bohaty S. M. , Jiménez‐Espejo F. , Pross J. , Röhl U. , van de Flierdt T. , Escutia C. , Brinkhuis H.
Published: March 2013

Few high‐latitude terrestrial records document the timing and nature of the Cenozoic “Greenhouse” to “Icehouse” transition. Here we exploit the bulk geochemistry of marine siliciclastic sediments from drill cores on Antarctica's continental margin to extract a unique semiquantitative temperature and precipitation record for Eocene to mid‐Miocene (~54–13 Ma). Alkaline elements are strongly enriched in the detrital mineral fraction in fine‐grained siliciclastic marine sediments and only occur as trace metals in the biogenic fraction. Hence, terrestrial climofunctions similar to the chemical index of alteration (CIA) can be applied to the alkaline major element geochemistry of marine sediments on continental margins in order to reconstruct changes in precipitation and temperature. We validate this approach by comparison with published paleotemperature and precipitation records derived from fossil wood, leaves, and pollen and find remarkable agreement, despite uncertainties in the calibrations of the different proxies. A long‐term cooling on the order of ≥8°C is observed between the Early Eocene Climatic Optimum (~54–52 Ma) and the middle Miocene (~15–13 Ma) with the onset of transient cooling episodes in the middle Eocene at ~46–45 Ma. High‐latitude stratigraphic records currently exhibit insufficient temporal resolution to reconstruct continental aridity and inferred ice‐sheet development during the middle to late Eocene (~45–37 Ma). However, we find an abrupt aridification of East Antarctica near the Eocene‐Oligocene transition (~34 Ma), which suggests that ice coverage influenced high‐latitude atmospheric circulation patterns through albedo effects from the earliest Oligocene onward.
Obliquity and long eccentricity pacing of the Middle Miocene climate transition
Authors: Tian Jun , Yang Mei , Lyle Mitchell W. , Wilkens Roy , Shackford Julia K.
Published: March 2013

The Middle Miocene East Antarctic ice sheet expansion (EAIE), which is indicated by an abrupt ~1‰ increase in global benthic foraminiferal δ18O at ~13.8 Ma, marks the Middle Miocene climate transition (MMCT) and has been related to astronomically modulated changes in the global carbon cycle. Here, we present high resolution (3–4 kyr) benthic foraminiferal δ18O and δ13C records from IODP Site U1337 in the central equatorial Pacific, which spans the period 12.2–15.8 Ma. The isotopic records clearly demonstrate significant imprints from periodic variations in the Earth's orbital parameters, particularly the obliquity (40 kyr) and the long eccentricity (400 kyr) cycles. While the benthic δ18O and δ13C exhibit nearly identical amplitudes for glacial‐interglacial cycles from 15.8 to 12.2 Ma, the long‐term trends in the benthic δ18O and δ13C had started to reverse after the beginning of the EAIE. Within the 400‐kyr band, the benthic −δ18O and δ13C displays a constant phase relationship between 15.8 and 12.2 Ma. At the 41‐kyr band, however, a phase reversal reaching >180° between −δ18O and δ13C occurs from 13.8 Ma to 14.0 Ma during the period of the EAIE. A similar phase relationship of benthic foraminiferal −δ18O and δ13C at the 400‐kyr band and the 41‐kyr band is also observed at ODP Site 1146 from the northern South China Sea. This phase jump occurs when the long‐term trends in δ18O and δ13C split, suggesting a decoupling of the global ice volume and ocean carbon reservoir changes during the Middle Miocene.
Seismic gap beneath Logachev Seamount: Indicator for melt focusing at an ultraslow mid‐ocean ridge?
Authors: Schlindwein Vera , Demuth Andrea , Geissler Wolfram H. , Jokat Wilfried
Published: March 2013

Ultraslow spreading mid‐ocean ridges have a low magma budget and melt is distributed unevenly along the ridge axis. There is little or no basaltic crust between isolated magmatic centers. The processes that focus melts to segments of robust magmatism are not yet understood. During a seismic survey of the ultraslow spreading Knipovich Ridge in the Norwegian‐Greenland Sea with ocean bottom seismometers, we discovered a seismic gap in the upper mantle beneath Logachev Seamount, where micro‐earthquakes clearly delineate a shallowing of the maximum depth of faulting. A topography of the lithosphere that allows melts to travel laterally along its base and rise in areas of thin lithosphere has been proposed as a possible mechanism to explain the focusing of melts at volcanic centers, but has never been confirmed observationally. Our results are the first geophysical evidence for an along‐axis variation of the lithospheric thickness at an ultraslow spreading ridge.
Interaction of dense shelf water cascading and open‐sea convection in the northwestern Mediterranean during winter 2012
Authors: Durrieu de Madron X. , Houpert L. , Puig P. , Sanchez‐Vidal A. , Testor P. , Bosse A. , Estournel C. , Somot S. , Bourrin F. , Bouin M. N. , Beauverger M. , Beguery L. , Calafat A. , Canals M. , Cassou C. , Coppola L. , Dausse D. , D'Ortenzio F. , Font J. , Heussner S. , Kunesch S. , Lefevre D. , Le Goff H. , Martín J. , Mortier L. , Palanques A. , Raimbault P.
Published: March 2013

The winter of 2012 experienced peculiar atmospheric conditions that triggered a massive formation of dense water on the continental shelf and in the deep basin of the Gulf of Lions. Multiplatforms observations enabled a synoptic view of dense water formation and spreading at basin scale. Five months after its formation, the dense water of coastal origin created a distinct bottom layer up to a few hundreds of meters thick over the central part of the NW Mediterranean basin, which was overlaid by a layer of newly formed deep water produced by open‐sea convection. These new observations highlight the role of intense episodes of both dense shelf water cascading and open‐sea convection to the progressive modification of the NW Mediterranean deep waters.
Effect of travel distance on household demand for typhoid vaccines: implications for planning
Authors: Kim Dohyeong , Lauria Donald T. , Poulos Christine , Dong Baiqing , Whittington Dale
Published: March 2013

Typhoid fever causes millions of illnesses and hundreds of thousands of deaths yearly. Vaccinations would mitigate this problem, but the users would probably have to pay some or most of the cost. Several willingness‐to‐pay studies have assessed the effect of price on private demand to provide a basis for financial planning of campaigns, but the effect of travel distance, which is a potentially important determinant of demand, has not been studied. This paper thus has two objectives: (i) conduct a willingness‐to‐pay survey to assess the effects of distance, price and other variables on the private demand for typhoid vaccinations in a rural township of China where a campaign is under consideration; and (ii) embed the demand function in a mathematical model to address three planning questions; should each village have its own clinic, would one clinic be best or should the number of clinics be something in‐between? Private vaccine demand was found to depend on and be inelastic with respect to both price and travel distance. A 1‐km increase in distance caused the number of vaccinations demanded to decrease the same as a $0.5 increase in price. Thus, the marginal rate of substitution was $0.5 per km. A single clinic would be best for the township only if diseconomies of scale in supplying vaccinations exceeded the marginal rate of substitution. Otherwise, multiple clinics close to users would be optimal. Thus, deciding the number, location and capacities of clinics for vaccination planning is as important as deciding what price(s) to charge. Copyright © 2013 John Wiley & Sons, Ltd.
Local‐scale and watershed‐scale determinants of summertime urban stream temperatures
Authors: Booth Derek B. , Kraseski Kristin A. , Rhett Jackson C.
Published: March 2013

The influence of urbanization on the temperature of small streams is widely recognized, but these effects are confounded by the great natural variety of their contributing watersheds. To evaluate the relative importance of local‐scale and watershed‐scale factors on summer temperatures in urban streams, hundreds of near‐instantaneous temperature measurements throughout the central Puget Lowland, western Washington State, were collected during a single 2‐h period in August in each of the years 1998–2001. Stream temperatures ranged from 8.9 to 27.5 °C, averaging 15.4 °C. Pairwise correlation coefficients between stream temperature and four watershed variables (total watershed area and the watershed percentages of urban development, upstream lakes, and permeable glacial outwash soils as an indicator of groundwater exchange) were uniformly very low. Akaike's information criterion was applied to determine the best‐supported sets of watershed‐scale predictor variables for explaining the variability of stream temperatures. For the full four‐year dataset, the only well‐supported model was the global model (using all watershed variables); for the most voluminous single‐year (1999) data, Akaike's information criterion showed greatest support for per cent outwash (Akaike weight of 0.44), followed closely by per cent urban development + per cent outwash, per cent lake area only, and the global model. Upstream lakes resulted in downstream warming of up to 3 °C; variability in riparian shading imposed a similar temperature range. Watershed urbanization itself is not the most important determining factor for summer temperatures in this region; even the long‐recognized effects of riparian shading can be no more influential than those imposed by other local‐scale and watershed‐scale factors. Copyright © 2013 John Wiley & Sons, Ltd.
Book Reviews
Authors: PROCITA LEONARD
Published: March 2013

Book reviewed in this article:

Fundamental Concepts in Drug‐Receptor Interactions. J. F. Danielli, J. F. Moran, and D. J. Triggle, editors.

Current Dermatologic Management. Stuart Maddin, editor.

Drugs and Cerebral Function. W. L. Smith and G. A. Ulett, editors.

The Psychodynamic Implications of the Physiological Studies on Psychomimetic Drugs. L. Madow and L. H. Snow, editors.

Marijuana, The Second Trip. Revised Ed. Edward R. Bloomquist.

Cancer Chemotherapy. F. Elkerbout, P. Thomas, and A. Zwaveling, Eds.
Book Reviews
Authors: PROCITA LEONARD
Published: March 2013

Book reviewed in this article:

Cardiovascular Therapy, The Art and the Science. H. I. Russek and B. L. Zohman, editors.

Steroid‐Protein Interactions (Monographs on Endocrinology). U. Westphal, editor.

Fundamentals of Drug Metabolism and Drug Disposition. B. N. LaDu, H. G. Mandel, and E. L. Way, editors.

Monitoring Birth Defects and Environment. The Problem of Surveillance. E. B. Hook, D. T. Janerich, and I. H. Porter, editors.
A Pharmacokinetic—Pharmacodynamic Model of d‐Sotalol Q‐Tc Prolongation During Intravenous Administration to Healthy Subjects
Authors: Salazar Daniel E. , Much David R. , Nichola Peter S. , Seibold James R. , Shindler Daniel , Slugg Peter H.
Published: March 2013

The objective of this study was to assess the pharmacokinetics and pharmacodynamics of the dextro (d‐) isomer of sotalol, a class III antiarrhythmic agent, in healthy young men and women after a single intravenous bolus dose. The design was open‐label, randomized, parallel group. Each group (4 men and 4 women) received either 0.5, 1.5, or 3.0 mg/kg d‐sotalol as an intravenous infusion for 2 minutes. Serial measurements of the d‐sotalol plasma concentration and the Q‐Tc interval data were recorded before, during, and for 72 hours after drug administration. The pharmacokinetics of d‐sotalol were found to be well described by a three‐compartment model with linear elimination clearance from the central compartment. There were no significant differences in the elimination clearance or volume of the central compartment between dose levels or between men and women. However, women were found to have a lower steady‐state volume of distribution than men (1.20 L/kg versus 1.43 L/kg). The Q‐Tc versus d‐sotalol plasma concentration data were fitted to a model that assumed a distinct “effect compartment” and sigmoidal Emax response. The baseline Q‐Tc, determined from the fittings, was found to be significantly higher in women (0.40 versus 0.38 seconds). The effect compartment clearance was found to be highly variable, with a median of 12.3 (range, 0.2‐671,300) L/h. There were statistically significant differences in the effect compartment clearance by dose among men and by gender at a dose of 1.5 mg/kg. There were no significant differences detected between dose groups or genders for the d‐sotalol effect site concentration at one half the maximum Q‐Tc prolongation from baseline (EC50), EMAX, (the maximum Q‐Tc prolongation from baseline) or the Hill coefficient. In conclusion, the pharmacokinetics of d‐sotalol after intravenous administration are independent of dose and gender, because the difference between men and women in volume of distribution at steady‐state is not clinically significant. The pharmacodynamics of Q‐Tc prolongation produced by d‐sotalol appear to be independent of dose and gender; however, there is considerable variability in the time course of effects on Q‐Tc between individuals.
Alumina as a Support and Catalyst for the Synthesis of Benzothiazoles in Solvent‐free Condition
Authors: Ding Mei‐Fang , Chen Chia‐Pei , Lin Shaw‐Tao
Published: March 2013

Arylbenzothiazole (4) and benzothiazolylcoumarins (5) were prepared by the condensation of 2‐aminothiophenol (1) and hydroxybenzaldehydes (2) and 3‐ethoxycarbonylcoumarinnin (3), respectively, in solvent‐free condition. Of the solid support used, γ‐Al2O3 demonstrated the best activity. A linear regression line obtained from correlation between relative formation rate and Hammett constants with slope of 0.653 suggested that this condensation process is less sensitive to the substituents on the phenyl ring due to low efficacy of polarization in the solid state. In general, good yields (>80% yield) were obtained for the formation of 4. Conversely, yields of 5 were poor, because of γ‐Al2O3 catalytic decomposition of 3 to form 2 (without P2O5) and coumarin (with P2O5).
In vitro Photo‐Oxidation of Pyruvate to Acetyl: A Main Source for the Formation of Acetyl Coenzyme A in the Citric Acid Cycle to Perform Biochemical Reactions
Authors: Farrukh Muhammad Akhyar , Naz Sana
Published: March 2013

The kinetics of photooxidation of pyruvate was investigated in presence of zinc oxide catalyst under illumination of visible light. The influence of different parameters such as concentrations of reactants, amount of catalyst and irradiation time was studied on the redox reaction under pseudo‐first order conditions. The results indicated that amount of catalyst, presence of electron accepter in solution and irradiation time was the key factors influencing the efficiency of photo‐oxidation of pyruvate to acetyl.
Controlled Friedel‐Crafts Acylation of 3,6‐Disubstituted‐9H‐carbazole
Authors: Lee Ting‐Yu , Yeh Ming‐Che , Chang Ling‐Chueh , Ong Chi‐Wi , Lin Che‐Yu , Huang Jui‐Hsien
Published: March 2013

1,8‐Dicarbonylcarbazoles are important starting materials for various applications, especially for pincer‐type ligands. The convenient synthesis of a series of 1,8‐diacyl‐3,6‐di‐tert‐butyl‐9H‐carbazoles (2) by the direct Friedel‐Crafts acylation of 3,6‐di‐tert‐butyl‐9H‐carbazole (1) is described. During the reaction, the dealkylation also occurred, and 1,8‐diacetyl‐3‐tert‐butyl‐9H‐carbazole (4) was isolated as well as characterized by an X‐ray diffraction analysis. In addition, the steric bulkiness of the acyl chlorides strongly affects the yields of 1,8‐diacylation of 1.
Photochemical and microbial alteration of dissolved organic matter in temperate headwater streams associated with different land use
Authors: Lu Yuehan , Bauer James E. , Canuel Elizabeth A. , Yamashita Youhei , Chambers R. M. , Jaffé Rudolf
Published: March 2013

Photochemical and microbial transformations of DOM were evaluated in headwater streams draining forested and human‐modified lands (pasture, cropland, and urban development) by laboratory incubations. Changes in DOC concentrations, DOC isotopic signatures, and DOM fluorescence properties were measured to assess the amounts, sources, ages, and properties of reactive and refractory DOM under the influence of photochemistry and/or bacteria. DOC in streams draining forest‐dominated watersheds was more photoreactive than in streams draining mostly human‐modified watersheds, possibly due to greater contributions of terrestrial plant‐derived DOC and lower amounts of prior light exposure in forested streams. Overall, the percentage of photoreactive DOC in stream waters was best predicted by the relative content of terrestrial fluorophores. The bioreactivity of DOC was similar in forested and human‐modified streams, but variations were correlated with temperature and may be further controlled by the diagenetic status of organic matter. Alterations to DOC isotopes and DOM fluorescence properties during photochemical and microbial incubations were similar between forested and human‐modified streams and included (1) negligible effects of microbial alteration on DOC isotopes and DOM fluorescence properties, (2) selective removal of 13C‐depleted and 14C‐enriched DOC under the combined influence of photochemical and microbial processes, and (3) photochemical alteration of DOM resulting in a preferential loss of terrestrial humic fluorescence components relative to microbial fluorescence components. This study provides a unique comparison of DOC reactivity in a regional group of streams draining forested and human‐modified watersheds and indicates the importance of land use on the photoreactivity of DOC exported from upstream watersheds.
The Structure of Claw‐Free Perfect Graphs
Authors: Chudnovsky Maria , Plumettaz Matthieu
Published: March 2013

In 1988, Chvátal and Sbihi (J Combin Theory Ser B 44(2) (1988), 154–176) proved a decomposition theorem for claw‐free perfect graphs. They showed that claw‐free perfect graphs either have a clique‐cutset or come from two basic classes of graphs called elementary and peculiar graphs. In 1999, Maffray and Reed (J Combin Theory Ser B 75(1) (1999), 134–156) successfully described how elementary graphs can be built using line‐graphs of bipartite graphs using local augmentation. However, gluing two claw‐free perfect graphs on a clique does not necessarily produce claw‐free graphs. In this article, we give a complete structural description of claw‐free perfect graphs. We also give a construction for all perfect circular interval graphs.
Displaced dual‐mode imaging with desorption electrospray ionization for simultaneous mass spectrometry imaging in both polarities and with several scan modes
Authors: Janfelt Christian , Wellner Niels , Hansen Harald S. , Hansen Steen H.
Published: March 2013

Displaced dual‐mode imaging (DDI) is introduced as a method for simultaneous imaging in positive and negative‐ion mode on the same sample with desorption electrospray ionization imaging, as well as a method for simultaneous imaging in full‐scan and tandem mass spectrometry (MS/MS) mode. DDI is performed by using a smaller row distance in the y‐direction than the desired image resolution and recording for example every second row in positive‐ion mode and the other half of the rows in negative‐ion mode, thus resulting in two separate images. This causes some degree of oversampling, which is thus utilized to obtain complementary mass spectrometric of the sample. Imaging with both polarities is exemplified on an imprint of a Hypericum perforatum leaf containing secondary metabolites which ionize in both polarites and a mouse kidney containing phospholipids which ionize in positive or negative mode only. Simultaneous full‐scan and MS/MS imaging was demonstrated on the same mouse kidney, as the mouse had been given a relatively low dose of the antidepressive drug amitriptyline. While the full‐scan data allowed imaging of the endogenous phospholipids, the drug and its metabolites were only visible in the MS/MS images. The latter approach is useful, for example in whole‐body imaging experiments where the full‐scan data gives an overview of the tissue, and the MS/MS mode provides the sensitivity to image trace amounts of drugs and metabolites. Copyright © 2013 John Wiley & Sons, Ltd.
Nitric oxide boosts TLR‐4 mediated lipocalin 2 expression in chondrocytes
Authors: Gómez Rodolfo , Scotece Morena , Conde Javier , Lopez Veronica , Pino Jesus , Lago Francisca , Gómez‐Reino Juan J. , Gualillo Oreste
Published: March 2013

Lipocalin 2 (LCN2) has recently emerged as a novel adipokine involved in different processes including arthritis and chondrocyte inflammatory response. However, little is known about its activity on chondrocyte homeostasis and its regulation by nitric oxide (NO) Hence, we performed a set of experiments aimed to achieve a better understanding of this relationship. Cell vitality was tested in the ATDC5 cell line by the MTT colorimetric assay. Protein expression and gene expression was evaluated by Western blot and real time RT‐PCR, respectively. NO production (determined as nitrite accumulation) was assayed by the Griess reaction. First, we demonstrated that LCN2 decreased murine chondrocytes vitality. Next, LCN2 co‐stimulation with LPS enhanced NOS2 protein expression by murine chondrocytes. In addition, inhibition of LPS‐induced nitric oxide production by aminoguanidine, a selective NOS2 inhibitor, significantly reduced LPS‐mediated LCN2 expression. In contrast, treatment of murine chondrocytes with sodium nitroprussiate (SNP), a classic NO donor, scarcely induced LCN2 expression. Intriguingly, SNP addition to LPS‐challenged chondrocytes, treated with aminoguanidine, provoked a strong induction of LCN2 expression. Finally, murine ATDC5 cells, co‐cultured with LPS pre‐challenged macrophages, had higher LCN2 expression in comparison with murine chondrocytes co‐cultured with non pre‐challenged macrophages. In this work we have described for the first time that NO is able to exert a control on LCN2 expression, suggesting the existence of a feedback loop regulating its expression. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1046–1052, 2013
Endogenous TGF‐β activity limits TSLP expression in the intervertebral disc tissue by suppressing NF‐κB activation
Authors: Zhu Yong , Ohba Tetsuro , Ando Takashi , Fujita Koji , Koyama Kensuke , Nakamura Yuki , Katoh Ryohei , Haro Hirotaka , Nakao Atsuhito
Published: March 2013

Thymic stromal lymphopoietin (TSLP), an IL‐7‐like cytokine, is highly expressed in herniated disc (HD) tissue and may act as a key molecule for the initiation of macrophage recruitment into the tissue and natural resorption of HD. However, it remains unclear how TSLP expression is regulated in the intervertebral discs. This study showed that expression of TSLP and phosphorylated NF‐κB in HD tissue samples was inversely correlated with expression of phosphorylated Smad2/3 (an indicator of active TGF‐β signaling) and vice versa in posterior lumbar spinal fusion samples. The pharmacological blockades of endogenous TGF‐β activity induced TSLP expression in mouse intervertebral disc tissue culture, which was inhibited by NF‐κB inhibitors. Additionally, phosphorylation of Smad2/3 was constitutively detected in mouse intervertebral disc tissue in the steady states. Collectively, these results suggest that endogenous TGF‐β activity limits TSLP expression in intervertebral disc tissue in the steady states by suppressing NF‐κB activation. The findings reveal a regulatory mechanism how TSLP expression is induced in the intervertebral disc tissue and suggest a novel role of TGF‐β in maintaining the homeostasis of intervertebral disc tissue. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1144–1149, 2013
Absence of Cx43 selectively from osteocytes enhances responsiveness to mechanical force in mice
Authors: Bivi Nicoletta , Pacheco‐Costa Rafael , Brun Lucas R. , Murphy Thomas R. , Farlow Nathan R. , Robling Alexander G. , Bellido Teresita , Plotkin Lilian I.
Published: March 2013

The osteocyte network is crucial for the response of bone to mechanical force. Within this network, connexin43 (Cx43) is thought to mediate the communication of osteocytes and osteoblasts among themselves and the exchange of small molecules with the extracellular milieu. Despite recent advances in understanding Cx43 role for the response of bone cells to mechanical stimulation, the contribution of Cx43 specifically in osteocytes to mechanotransduction in vivo is not well‐known. We examined the anabolic response to ulnar axial loading of mice lacking Cx43 in osteocytes (Cx43ΔOt). Loading induced a greater increase in periosteal bone formation rate in Cx43ΔOt mice compared to control littermates, resulting from higher mineralizing surface and enhanced mineral apposition rate. Expression of β‐catenin protein, a molecule implicated in mechanotransduction, was higher in bones from Cx43ΔOt mice, compared to littermate controls. In addition, MLO‐Y4 osteocytic cells knocked‐down for Cx43 exhibited higher β‐catenin protein expression and enhanced response to mechanical stimulation. These findings suggest that osteocytes lacking Cx43 are “primed” to respond to mechanical stimulation and that absence of Cx43 in osteocytes unleashes bone formation, by a mechanism that might involve accumulation of β‐catenin. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1075–1081, 2013
Habitat used by common and king eiders in spring in the southeast Beaufort Sea and overlap with resource exploration
Authors: Dickson D. Lynne , Smith Paul A.
Published: March 2013

The southeast Beaufort Sea is a critical spring staging area for common and king eiders (Somateria mollissima v‐nigrum,S. spectabilis), and is for many the final stop before they reach their breeding grounds throughout the western Canadian Arctic. The region also has significant oil and gas potential, and the recent approval of a pipeline through the Mackenzie Valley may make development of these resources economically viable. We used satellite telemetry to determine the distribution and habitat use of eiders staging in the southeast Beaufort Sea in spring, and the overlap of eiders with oil and gas exploration. From 2004 to 2009, we monitored 51 eiders equipped with platform terminal transmitters (PTTs) throughout spring migration (May–June). We compared the marine habitats used by each species, and evaluated habitat preferences using resource selection functions. The location and extent of the flaw lead (open water along the interface between mobile pack ice and stationary landfast ice) at the time when eiders were staging varied among years, but both species showed a strong preference for use of flaw lead habitats. This preference was stronger for common eiders than for king eiders, which also used pack ice extensively. Common eiders generally occurred near the landfast ice edge, whereas king eiders were just as often nearer to the pack ice edge of the flaw lead. Average water depth (±SE) for common eiders was 22 ± 2 m compared to 30 ± 1 m for king eiders. Kernel density estimators showed that eiders generally occurred in lower densities in areas of otherwise suitable habitat off the Mackenzie River delta. We suggest that this is a result of the highly turbid water discharged by the Mackenzie River, which limits visibility. Oil and gas exploration overlapped significantly with the areas used by eiders. The high density of birds using the restricted and ice‐rich flaw lead habitats indicates that an accidental spill in the region could be catastrophic for Canada's western Arctic eider populations. © 2013 The Wildlife Society.
Challenges and surgical nuances in reconstruction of large planum sphenoidale tuberculum sellae defects after endoscopic endonasal resection of parasellar skull base tumors
Authors: Eloy Jean Anderson , Shukla Pratik A. , Choudhry Osamah J. , Singh Rahul , Liu James K.
Published: March 2013

Objectives/Hypothesis

Endoscopic endonasal transplanum transtuberculum (EETT) resection of parasellar skull base (SB) tumors often results in large SB defects with intraoperative high‐flow cerebrospinal fluid (CSF) leaks. Reconstruction of these defects can be challenging because of the large defects size, communication with the suprasellar cistern, and close proximity to the optic nerves and chiasm. Recent studies have postulated that transplanum defects may be associated with increased postoperative CSF leakage. We review our experience with reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Challenges encountered during these repairs and our operative nuances for successful reconstruction are discussed.

Methods

A retrospective analysis was performed between March 2010 and February 2012 on patients undergoing reconstruction of transplanum defects after EETT resection of parasellar SB tumors. Repair materials, defect sizes, postoperative CSF leakage, postoperative CSF diversion, and demographic data were collected.

Results

Nineteen patients who underwent 22 repairs with a pedicled nasoseptal flap (PNSF) were identified. The mean age was 47.6 years (range, 12–68years). Average defect size was 5.6 cm2 (range, 2.2–10.4 cm2). Three failed repairs necessitated a revision procedure. All three revisions were successfully reconstructed with the previously used PNSF. The mean follow‐up period was 13.5 months (range, 1–26 months). The overall success rate was 86.4% for transplanum defects alone, as compared to 97.0% for our comprehensive PNSF experience in 99 repairs.

Conclusion

Repair of large transplanum defects after EETT resection of parasellar SB tumors presents a unique challenge. Using a PNSF along with meticulous multilayer closure may help decrease postoperative CSF leaks.
Primary tracheoesophageal puncture in salvage laryngectomy patients
Authors: Johnson Adam , Grammer Tracy , Medina Jesus
Published: March 2013

Objectives/Hypothesis

The purpose of this study was to determine the rate of complications in the immediate postoperative period following primary tracheoesophageal puncture (TEP) after salvage laryngectomy.

Study Design

Retrospective.

Methods

A retrospective review was done of 26 patients who underwent primary TEP with salvage total laryngectomy. To minimize variables, the patients included were operated on by a single surgeon and rehabilitated by a single speech‐language pathologist. The outcomes evaluated were the frequency of leakage around the TEP, dehiscence of the stoma, dislodging of the prosthesis, pharyngocutaneous fistula, time to initiation of oral intake, and length of hospital stay.

Results

The mean age of the patients was 60.8 years (range, 41–78 years). Previous treatment consisted of radiotherapy in 14 patients and chemotherapy and radiation in 12. Tumor site was glottic in 12 patients, supraglottic in seven, subglottic in two, vallecula in three, and overlapping in two. The pharynx was repaired primarily in all patients and then reinforced with a pectoralis muscle flap in 13. Leakage around the TEP was observed in 4% of the cases. There were no instances of dislodging of the TEP, and six patients (23%) developed pharyngocutaneous fistula; 12% had a wound dehiscence but none were around the stoma. The average time to begin oral feeding was 5.7 days (standard deviation, 1.93), and the average hospital stay was 8.4 days (standard deviation, 1.93).

Conclusions

Primary TEP in the setting of a salvage laryngectomy is associated with a low rate of complications. A pharyngocutaneous fistula occurred in 23% of the cases.

Level of Evidence

4.
Assessment of improvement of trainee surgical skills in the operating room for tonsillectomy
Authors: Ahmed Aadil , Ishman Stacey L. , Laeeq Kulsoom , Bhatti Nasir I.
Published: March 2013

Objectives/Hypothesis

To determine the feasibility, reliability, and validity of an objective surgical assessment tool designed to measure the development of tonsillectomy skills by resident trainees in the operating room. A tonsillectomy evaluation instrument created previously serves as a basis for this tool, which incorporates many similar concepts but was optimized to maximize feasibility and reliability with simplified anchors and inclusion of global and task‐specific sections.

Study Design

Prospective longitudinal validation study.

Methods

Faculty input via modified Delphi technique was used to develop a new objective structured assessment of technical skills–based instrument for tonsillectomy. The task‐specific checklist (TSC) and global rating scale (GRS) measured tonsillectomy technical skills and overall surgical performance, respectively. Twenty‐one otolaryngology–head and neck residents (ranging from postgraduate year 1 to 6) were evaluated for a period of 3 years by 11 faculty members.

Results

Eighty‐three evaluations were completed showing strong correlation between both instruments (r = 0.95, P < .001). Our tool demonstrated construct validity for both TSC and GRS, showing higher scores with increasing surgical experience. Both instruments showed high interitem reliability with Cronbach α coefficients of 0.97 for both parts.

Conclusions

This assessment tool is a feasible, reliable, and valid instrument for the assessment of surgical competency in tonsillectomy. It is effective in providing structured feedback at the end of each procedure, which encourages specific, targeted development. Laryngoscope, 2013
Impact of unilateral conductive hearing loss due to aural atresia on academic performance in children
Authors: Kesser Bradley W. , Krook Kaelyn , Gray Lincoln C.
Published: March 2013

Objectives/Hypothesis

This study evaluates the effect of unilateral conductive hearing loss secondary to aural atresia on elementary school children's academic performance.

Study Design

Case control survey and review of audiometric data.

Methods

One hundred thirty‐two surveys were mailed to families of children with aural atresia, and 48 surveys were sent to families of children with unilateral sensorineural hearing loss (SNHL) to identify rates of grade retention, use of any resource, and behavioral problems. Audiometric data of the cohort were tabulated.

Results

Of the 40 atresia patients, none repeated a grade, but 65% needed some resources: 12.5% currently use a hearing aid, 32.5% use(d) a frequency‐modulated system in school, 47.5% had an Individualized Education Plan, and 45% utilized speech therapy. Compared to the unilateral SNHL group and a cohort of children with unilateral SNHL in an earlier study,1 children with unilateral atresia were less likely to repeat a grade. Children in both unilateral atresia and SNHL groups were more likely to utilize some resource in the academic setting compared to the unilateral SNHL children in the prior study.

Conclusions

Unilateral conductive hearing loss due to aural atresia has an impact on academic performance in children, although not as profound when compared to children with unilateral SNHL. The majority of these children with unilateral atresia utilize resources in the school setting. Parents, educators, and health care professionals should be aware of the impact of unilateral conductive hearing loss and offer appropriate habilitative services.

Level of Evidence

3b. Laryngoscope, 123:2270–2275, 2013
A late recognition of tapia syndrome
Authors: Gevorgyan Artur , Nedzelski Julian M.
Published: March 2013

Tapia syndrome is characterized by concurrent paralysis of the recurrent laryngeal and hypoglossal nerves. The mechanism is associated with airway manipulation in 70% of patients and is attributed to compression or stretching of these nerves. Diagnosis is based on recognition of the concurrent paralyses and investigations to exclude central or vascular causes. Treatment is supportive, with emphasis on empiric corticosteroids and dysphagia therapy. Recovery is excellent in 30% of patients, incomplete in 39% of patients, and none in over 26% of patients. A case of a 48‐year‐old woman is described, who was diagnosed with Tapia syndrome 3 years after the suspected injury. Laryngoscope, 123:2423–2427, 2013
Access to Different Nanostructures via Self‐Assembly of Thiourea‐Containing PEGylated Amphiphiles
Authors: Venkataraman Shrinivas , Chowdhury Zarir Ashraf , Lee Ashlynn L. , Tong Yen Wah , Akiba Isamu , Yang Yi Yan
Published: March 2013

Readily water‐soluble PEGylated amphiphiles containing bis‐thiourea‐based molecular recognition units at the interface of hydrophobic and hydrophilic blocks are developed. Self‐assembly of these amphiphiles is found to be dependent on the exact chemical composition of the hydrophobic component. Elongated, spherical, and disk‐like micelles are formed with the change in hydrophobic group from stearyl (2A), oleyl (2B), and dodecanol (2C), respectively. The length of the rod‐like elongated micelles formed by 2A could be tuned by thermal treatment as well. Synthesis and detailed structural characterization of these amphiphiles by TEM, DSC, synchrotron SAXS techniques are reported. Organic solvent‐free direct aqueous encapsulation of doxorubicin, an anticancer drug into these nanostructures is demonstrated.

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Managerial Delegation Contracts under Centralized Unionization
Authors: Meccheri Nicola , Fanti Luciano
Published: March 2013

This paper studies how alternative managerial delegation contracts in a duopoly product market interact with wage decisions taken by a central (industry‐wide) union in the labor market. Interestingly, results prove to be more varied with respect to findings by the managerial delegation literature with exogenous production costs. Most notably, it is pointed out that, in equilibrium, both firm profitability and welfare outcomes can be superior under both sales delegation and relative profit delegation, depending on various factors such as the degree of product differentiation and the competition regime. Copyright © 2013 John Wiley & Sons, Ltd.
Validation of parkinsonian disease‐related metabolic brain patterns
Authors: Teune Laura K. , Renken Remco J. , Mudali Deborah , De Jong Bauke M. , Dierckx Rudi A. , Roerdink Jos B.T.M. , Leenders Klaus L.
Published: March 2013

Background

The objective of this study was to validate disease‐related metabolic brain patterns for Parkinson's disease, multiple system atrophy, and progressive supranuclear palsy.

Methods

The study included 20 patients with Parkinson's disease, 21 with multiple system atrophy, and 17 with progressive supranuclear palsy, all of whom had undergone a clinically motivated [18F]‐fluoro‐deoxyglucose positron emission tomography scan at an early stage of their disease. At a follow‐up time after the scan of 2–4 years, a clinical diagnosis was made according to established clinical research criteria. Patient groups were compared with 18 healthy controls using a multivariate covariance image analysis technique called scaled subprofile model/principal component analysis.

Results

Disease‐related metabolic brain patterns for these parkinsonian disorders were identified. Validation showed that these patterns were highly discriminative of the 3 disorders.

Conclusions

Early diagnosis of parkinsonian disorders is feasible when the expression of disease‐related metabolic brain patterns is quantified at a single‐subject level. © 2013 Movement Disorder Society
The inferior olivary nucleus: A postmortem study of essential tremor cases versus controls
Authors: Louis Elan D. , Babij Rachel , Cortés Etty , Vonsattel Jean‐Paul G. , Faust Phyllis L.
Published: March 2013

The pathogenesis of essential tremor is poorly understood. Historically, it has been hypothesized that the inferior olivary nucleus plays an important role in the generation of tremor in essential tremor, yet a detailed, controlled, anatomic‐pathological study of that brain region has yet to be conducted. A detailed postmortem study was undertaken of the microscopic changes in the inferior olivary nucleus of 14 essential tremor cases versus 15 age‐matched controls at the Essential Tremor Centralized Brain Repository. A series of metrics was used to quantify microscopic neuronal and glial changes in the inferior olivary nucleus and its input and output tracts. Olivary linear neuronal density also was assessed. Cases and controls did not differ from one another with respect to any of the assessed metrics (P values ranged from 0.23 to 1.0). Olivary linear neuronal density also was similar in cases and controls (P = 0.62). Paddle‐shaped neurons, a morphologic shape change in olivary neurons, which, to our knowledge, have not been previously recognized, occurred to an equal degree in essential tremor cases and controls (P = 0.89) and were correlated with several markers of neuronal loss and gliosis. A systematic postmortem study of the microscopic changes in the inferior olivary nucleus did not detect any differences between cases and controls. These data, along with positron emission tomography data, which have failed to identify any metabolic abnormality of the olive, indicate that, if the olive is involved in essential tremor, then there is no clearly identifiable structural or metabolic correlate. © 2013 Movement Disorder Society
Computational Investigation of SENP:SUMO Protein‐Protein Interaction for Structure Based Drug Design
Authors: Kumar Ashutosh , Zhang Kam Y. J.
Published: March 2013

SUMO specific proteases (SENPs) are cysteine proteases that carry out the proteolytic processing of SUMO from its pro form as well as its deconjugation from substrate proteins. SENPs have been implicated in various cancers including prostate cancer, thyroid cancer and colon cancer. Therefore, the inhibition of SENPs is an attractive strategy for the treatment of cancer. However, the current SENP inhibitor development strategies target catalytic site and involve the usage of reactive functionalities to facilitate the covalent binding with a catalytic cysteine, which makes them less desirable for therapeutic purposes. Based on the available structural knowledge about the interaction of SENPs with various SUMO paralogues, an alternative approach for inhibiting SENPs could be via targeting SENP:SUMO protein‐protein interaction. Here we have investigated the protein‐protein interaction between SENP and SUMO as a target for structure based drug design using pocket prediction, ligand binding hotspot mapping, molecular dynamics simulation and in silico alanine mutagenesis. Finally, we have provided recommendations for the structure based design of SENP:SUMO protein‐protein interaction inhibitors. Our study indicates that the SENP inhibitors targeting SENP:SUMO protein‐protein interaction is a viable alternative strategy to existing inhibitors targeting the enzymatic site.
A comparison of magnetic resonance imaging methods for fluid content imaging in porous media
Authors: Muir Colleen E. , Balcom Bruce J.
Published: March 2013

Quantitative measurements are important for imaging fluid content in porous media. Conventional MRI methods suffer from contrast because of relaxation times in porous media, resulting in measurements of apparent fluid content, not the true fluid content. We compare four magnetic resonance imaging methods for fluid content imaging in several water‐saturated reservoir core plugs: frequency‐encoded spin echo, single point ramped imaging with T1 enhancement, hybrid spin echo single point imaging (SE‐SPI), and T2 mapping SE‐SPI. 1‐D profiles obtained with each method were compared in terms of image quality, image sensitivity, and quantification of water content. The image quality of short T2 lifetime samples suffered from blurring in hybrid SE‐SPI images. Image sensitivity was the highest in the profiles obtained with frequency‐encoded spin echo. The quantification of frequency‐encoded spin echo, T2 mapping SE‐SPI, and hybrid SE‐SPI suffered in core plugs with a significant population of short T2 components because of T2 attenuation. Overall, single point ramped imaging with T1 enhancement was found to be the most general method for fluid content imaging. Copyright © 2013 John Wiley & Sons, Ltd.
Festkörperchemie 2012
Authors: Adelhelm Philipp , Armbrüster Marc , Kraus Florian
Published: March 2013

Spannendes von den Elementen, neue Verbindungen mit überraschenden Bausteinen und Eigenschaften sowie die Lösung einiger “100‐jähriger Fragen” — die Festkörperchemie präsentiert sich in Bestform.
Lebensmittelchemie 2012
Authors: Berger Ralf G. , Schrader Jens , Schwab Wilfried , Wüst Matthias , Zorn Holger
Published: March 2013

Neben der Identifizierung von Aromastoffen durch die molekulare Sensorik sind die Aufklärung ihrer Biosynthese sowie ihre biotechnische Produktion ins Zentrum der Aromastoffforschung gerückt.
Comparison of different MRI sequences in lesion detection and early response evaluation of diffuse large B‐cell lymphoma – a whole‐body MRI and diffusion‐weighted imaging study
Authors: Wu Xingchen , Nerisho Seyoum , Dastidar Prasun , Ryymin Pertti , Järvenpää Ritva , Pertovaara Hannu , Eskola Hannu , Kellokumpu‐Lehtinen Pirkko‐Liisa
Published: March 2013

To compare different MRI sequences for the detection of lesions and the evaluation of response to chemotherapy in patients with diffuse large B‐cell lymphoma (DLBCL), 18 patients with histology‐confirmed DLBCL underwent 3‐T MRI scanning prior to and 1 week after chemotherapy. The MRI sequences included T1‐weighted pre‐ and post‐contrast, T2‐weighted with and without fat suppression, and a single‐shot echo‐planar diffusion‐weighted imaging (DWI) with two b values (0 and 800 s/mm2). Conventional MRI sequence comparisons were performed using the contrast ratio between tumor and normal vertebral body instead of signal intensity. The apparent diffusion coefficient (ADC) of the tumor was measured directly on the parametric ADC map. The tumor volume was used as a reference for the evaluation of chemotherapy response. The mean tumor volume was 374 mL at baseline, and decreased by 65% 1 week after chemotherapy (p < 0.01). The T2‐weighted image with fat suppression showed a significantly higher contrast ratio compared with images from all other conventional MRI sequences, both before and after treatment (p < 0.01, respectively). The contrast ratio of the T2‐weighted image with fat suppression decreased significantly (p < 0.01), and that of the T1‐weighted pre‐contrast image increased significantly (p < 0.01), after treatment. However, there was no correlation between the change in contrast ratio and tumor volume. The mean ADC value was 0.68 × 10–3 mm2/s at baseline; it increased by 89% after chemotherapy (p < 0.001), and the change in ADC value correlated with the change in tumor volume (r = 0.66, p < 0.01). The baseline ADC value also correlated inversely with the percentage change in ADC after treatment (r = −0.62, p < 0.01). In conclusion, this study indicates that T2‐weighted imaging with fat suppression is the best conventional sequence for the detection of lesions and evaluation of the efficacy of chemotherapy in DLBCL. DWI with ADC mapping is an imaging modality with both diagnostic and prognostic value that could complement conventional MRI. Copyright © 2013 John Wiley & Sons, Ltd.