bluuebunny/crossref_metadata_2025 huggingface dataset:
VI. Observations upon four Mosaic Pavements discovered in the County of Hants; by Sir Richard Colt Hoare, Bart. F.R.S. and S.A. in a Letter to Nicholas Carlisle, Esq. F.R.S. Secretary
Authors: Hoare Richard Colt
Published: June 2012

As every circumstance relating either to British or Roman Antiquities must be interesting to your Society, I beg leave to transmit to you some account of four Mosaic Pavements discovered in the county of Hants, and which, I believe, have not yet been described in the Archæologia.
XVII. Observations upon an ancient Bracelet of bronze, found upon the Sand-hills near Altyre, on the Coast of Murrayshire: in a Letter from Henry Ellis, Esq. F.R.S. Secretary, addressed to the Right Honourable the Earl of Aberdeen, K.T. President
Authors: Ellis Henry
Published: June 2012

The Bracelet found upon the Sand-hills of Murrayshire, which was exhibited to the Society of Antiquaries at their last Meeting through your Lordship's hands, by Lady Gordon Cumming, having occasioned some Inquiry, and several of the Members expressing a doubt, in consequence of the narrowness of the circle and the extreme weight of the ornament, whether such could really have been either used or intended for a Bracelet, I have selected from the passages which occur in ancient writers, both sacred and profane, a few which illustrate the wearing of that Ornament, as well as the other uses to which it was applied. And I now lay the result of my research before your Lordship.
SAXIFRAGA MINUTISSIMA, A NEW SPECIES FROM THE GARHWAL HIMALAYA, INDIA, AND ITS IMPLICATIONS FOR THE TAXONOMY OF THE GENUS SAXIFRAGA (SAXIFRAGACEAE)
Authors: Gornall R. J. , Rawat D. S. , Zhang Zhuoxin
Published: June 2012

Saxifraga minutissima D.S.Rawat, a new and extremely small species of Saxifraga (Saxifragaceae), is described from the Garhwal Himalaya, India. It differs from all other species of Saxifraga, except Saxifraga bicuspidata, in having five stamens and lacking petals. It can be distinguished from Saxifraga bicuspidata in having leaves and sepals entire. The finely striate pollen exine pattern of Saxifraga minutissima indicates that the species belongs to Saxifraga section Ciliatae. Its prostrate, axillary leafy shoots and lack of crisped, rufous hairs strongly suggests a place in Saxifraga subsection Serpyllifoliae, where one of its closest relatives may be Saxifraga stella-aurea.
An Entrance to Exit Polling: Strategies for Using Exit Polls as Experiential Learning Projects
Authors: Berry Michael J. , Robinson Tony
Published: June 2012

Engaging students in the design, administration, and postelection analysis of an exit poll can be an excellent experiential learning activity. Lelieveldt and Rossen (2009) argue that exit polls are a “perfect teaching tool” because they provide students with a cooperative (rather than competitive) learning experience; help students better connect theory, methodology, and course substance; and allow students to move outside of the classroom by branching out into the community. As professors at the University of Colorado, Denver (UCD), we have organized student exit polling during the 2008 and 2010 elections in the Denver area for research methods and elections classes. Although we have found these exit polls to be rewarding experiences for instructors and students alike, the reality is that conducting an exit poll with a group of polling neophytes, in the confines of a single semester, can be challenging. In this article, we discuss strategies and issues for instructors to consider when using an exit poll as an experiential learning exercise.
2012 APSA Teaching and Learning Conference and Track Summaries
Authors: Mealy Kimberly A.
Published: June 2012

The ninth annual APSA Teaching and Learning Conference was held in Washington, DC, February 17–19, 2012. This year's theme was “Teaching Political Science: Relevance in a Changing World.”
APSA Africa Workshops: 2012 Program Update and FAQs
Authors: Super Betsy , Stinson Andrew
Published: June 2012

Regular readers of the International Programs section of PS will be familiar with APSA's Africa Workshop program, an academic conference series funded by the Andrew W. Mellon foundation, now going into its 5th annual iteration. This summer, approximately 30 scholars from across Africa and the United States will gather at the University of Botswana in Gaborone for this year's workshop “Local Communities and the State in Africa.”
Monitoring armed non-state actor compliance with humanitarian norms: a look at international mechanisms and the Geneva Call Deed of Commitment
Authors: Bongard Pascal , Somer Jonathan
Published: June 2012

Armed non-state actors are involved in most armed conflicts today, yet international law provides few mechanisms to ensure that they comply with humanitarian norms applicable to them. In particular, monitoring and verification mechanisms that address the conduct of armed non-state actors rarely appear in multilateral treaties, and, even when they do, are weak and not applied in practice. Over the past few years, a number of alternative mechanisms have been developed to better monitor respect of humanitarian norms during internal armed conflicts and verify allegations of violations. This article examines the strength of these various mechanisms and then focuses on the Deed of Commitment, an innovative instrument developed by the Swiss-based non-governmental organization Geneva Call, to hold armed non-state actors accountable. Experience with the Deed of Commitment on the prohibition of anti-personnel mines shows that these alternative mechanisms can be effective in ensuring better compliance with at least some humanitarian norms.
Ozone source apportionment (OSAT) to differentiate local regional and super‐regional source contributions in the Pearl River Delta region, China
Authors: Li Y. , Lau A. K.‐H. , Fung J. C.‐H. , Zheng J. Y. , Zhong L. J. , Louie P. K. K.
Published: June 2012

It is well‐known that ground‐level ozone is not just a local or regional air quality problem; emission sources from super‐regional (sources outside the PRD region) scales are known to contribute significantly to local ozone concentrations. However, source apportionment studies differentiating the relative contributions of local, regional, and super‐regional ozone precursors are still limited. In this paper, using the Pearl River Delta (PRD) as an example, we have conducted a detailed apportionment (by source categories and by source regions) study of surface ozone using photochemical model source apportionment tools. Our results show that, while the super‐regional contribution is dominant under mean ozone conditions, elevated local and regional sources are the causative factor for the formation of high ozone episodes. In particular, the local and PRD regional contributions increase from about 30% during non‐episode days to about 50% during high ozone episode days in the autumn (November 2006) and even up to about 70% during high ozone episodes in the summer (July 2006). These results suggest that local and regional controls of ozone precursors are still very important for ozone reduction, particularly for episodic events. Furthermore, our results show that mobile emission is by far the highest contributing source category to ozone levels in the PRD for episodic ozone events. Moreover, we find substantial seasonal variations in the way ozone precursors from neighboring areas affect ozone levels in any particular city, suggesting that regional collaborations are important for developing effective long‐term strategies to reduce ozone over the PRD region.
Magmatic lithospheric heating and weakening during continental rifting: A simple scaling law, a 2‐D thermomechanical rifting model and the East African Rift System
Authors: Schmeling Harro , Wallner Herbert
Published: June 2012

Continental rifting is accompanied by lithospheric thinning and decompressional melting. After extraction, melt is intruded at shallower depth thereby heating and weakening the lithosphere. In a feedback mechanism this weakening may assist rifting and melt production. A one‐dimensional kinematic lithospheric thinning model is developed including decompressional melting and intrusional magma deposition. The intrusional heating effect is determined as a function of thinning rate and amount, melting parameters, potential temperature, and the depth range of emplacement. The temperature increases approximately proportionally to the square root of the thinning rate and to the square of the supersolidus potential temperature. Simple scaling laws are derived allowing predicting these effects and the surface heat flux for arbitrary scenarios. Two‐dimensional thermomechanical extension models are carried out for a multicomponent (crust‐mantle) two‐phase (melt‐matrix) system with a rheology based on laboratory data including magmatic weakening. In good agreement with the 1‐D kinematic models it is found that the lithosphere may heat up by several 100 K. This heating enhances viscous weakening by one order of magnitude or more. In a feedback mechanism rifting is dynamically enforced, leading to a significant increase of rift induced melt generation. Including the effect of lateral focusing of magma toward the rift axis the laws are applied to different segments of the East African Rift System. The amount of intrusional heating increases with maturity of the rift from O(10 K) to up to 200 K or 400 K at the Afar Rift depending on the depth range of the magmatic emplacement.
Geographical and environmental drivers of regional differences in the lake pCO2 versus DOC relationship across northern landscapes
Authors: Lapierre Jean‐François , del Giorgio Paul A.
Published: June 2012

Several recent studies have identified dissolved organic carbon (DOC) as playing a key role in determining surface water partial pressure of CO2 (pCO2) in northern lakes and, in particular, in shaping the commonly observed patterns of CO2 supersaturation. The nature of this role is unclear, however, and appears to vary regionally, as evidenced by the contrasting strength and shape of the diverse pCO2 versus DOC (pCO2‐DOC) relationships. Here we combine original data on lakepCO2 from six boreal and temperate regions of Québec (Canada) with 13 studies from northern temperate and boreal aquatic landscapes published in the past 15 years to explore the factors that explain the differences in regional pCO2 baselines (pCO2 at low DOC) and in the slopes of the pCO2‐DOC relationships. Mean elevation was the best predictor of the regionalpCO2 baselines, suggesting that lake position in the landscape determines the contribution of terrestrially derived CO2 to lake pCO2. In contrast, the slope of the pCO2‐DOC relationships was strongly negatively correlated to the mean regional TP:DOC ratio. The relationship between DOC and TP varied at the cross‐regional scale, and there was a large increase in the TP:DOC ratio at TP > 20μg L−1, resulting in negative slopes of the pCO2‐DOC relationships for regions situated in that part of the TP gradient. These results highlight the interplay that exists between geographical gradients, large‐scale biogeochemical patterns in regional lake trophic status, and the associated metabolic balance in determiningpCO2 dynamics in northern lakes.
Comment on the article “Solitary waves and double layers in an ultra-relativistic degenerate dusty electron-positron-ion plasma” [Phys. Plasmas 19, 033705 (2012)]
Authors: Akbari-Moghanjoughi M.
Published: June 2012

More recently, Roy et al. [Phys. Plasmas 19, 033705 (2012)] have investigated the occurrence of nonlinear solitary and double-layers in an ultrarelativistic dusty electron-positron-ion degenerate plasma using a Sagdeev potential method. They have considered a full parametric examination on Mach-number criteria for existence of such nonlinear excitations using the specific degeneracy limits of Chandrasekhar equation of state (EoS) for Fermi-Dirac plasmas. In this comment, we point-out a misleading extension of polytropic EoS to study the Fermi-Dirac relativistically degenerate plasmas.
Electromagnetic hydrophone with tomographic system for absolute velocity field mapping
Authors: Grasland-Mongrain Pol , Mari Jean-Martial , Gilles Bruno , Chapelon Jean-Yves , Lafon Cyril
Published: June 2012

The velocity and pressure of an ultrasonic wave can be measured by an electromagnetic hydrophone made of a thin wire and a magnet. The ultrasonic wave vibrates the wire inside a magnetic field, inducing an electrical current. Previous articles reported poor spatial resolution of comparable hydrophones along the axis of the wire. In this study, submillimetric spatial resolution has been achieved by using a tomographic method. Moreover, a physical model is presented for obtaining absolute measurements. A pressure differential of 8% has been found between piezoelectric and electromagnetic hydrophone measurements. These characteristics show this technique as an alternative to standard hydrophones.
Thermochemical modeling of temperature controlled shock-induced chemical reactions in multifunctional energetic structural materials under shock compression
Authors: Zhang X. F. , Shi A. S. , Zhang J. , Qiao L. , He Y. , Guan Z. W.
Published: June 2012

Multifunctional energetic structural materials (MESMs) are a new class of energetic materials which release energy due to exothermic chemical reactions initiated under shock loading conditions. In order to analyze shock-induced chemical reactions (SICR) for MESMs, theoretical models have been developed to calculate the Hugoniot data which include the heat released by shock temperature controlled reactions. The temperature rise of porous materials due to shock compression is first calculated using a constant volume and pressure adjustment. Then the Arrhenius reaction rate and Avrami-Erofeev kinetic models are used to calculate the extent of reaction of MESMs under shock compression. Thermochemical models for shock-induced reactions, in which the reaction efficiency is considered, are given by combining the shock temperature rise with the chemical reaction kinetics. The Hugoniot relations and temperatures are calculated by using the proposed method. The models developed have been validated against the experimental SICR data involving Fe2O3/Al, Al/Ni, and Ti/Ni mixtures. It has been shown that the theoretical calculations correlate reasonably well with the corresponding experimental and simulation results. The models presented can be used to predict the reaction results of MESMs over a wide range of pressure satisfactorily.
A fundamental numerical and theoretical study for the vibrational properties of nanowires
Authors: Zhan H. F. , Gu Y. T.
Published: June 2012

Based on the molecular dynamics (MD) simulation and the classical Euler-Bernoulli beam theory, a fundamental study of the vibrational performance of the Ag nanowire (NW) is carried out. A comprehensive analysis of the quality (Q)-factor, natural frequency, beat vibration, as well as high vibration mode is presented. Two excitation approaches, i.e., velocity excitation and displacement excitation, have been successfully implemented to achieve the vibration of NWs. Upon these two kinds of excitations, consistent results are obtained, i.e., the increase of the initial excitation amplitude will lead to a decrease to the Q-factor, and moderate plastic deformation could increase the first natural frequency. Meanwhile, the beat vibration driven by a single relatively large excitation or two uniform excitations in both two lateral directions is observed. It is concluded that the nonlinear changing trend of external energy magnitude does not necessarily mean a non-constant Q-factor. In particular, the first order natural frequency of the Ag NW is observed to decrease with the increase of temperature. Furthermore, comparing with the predictions by Euler-Bernoulli beam theory, the MD simulation provides a larger and smaller first vibration frequencies for the clamped-clamped and clamped-free thin Ag NWs, respectively. Additionally, for thin NWs, the first order natural frequency exhibits a parabolic relationship with the excitation magnitudes. The frequencies of the higher vibration modes tend to be low in comparison to Euler-Bernoulli beam theory predictions. A combined initial excitation is proposed which is capable to drive the NW under a multi-mode vibration and arrows the coexistence of all the following low vibration modes. This work sheds lights on the better understanding of the mechanical properties of NWs and benefits the increasing utilities of NWs in diverse nano-electronic devices.
Exploration of nano-element array architectures for substrate solar cells using an a-Si:H absorber
Authors: Jun Nam Wook , Ji Liming , Varadan Vasundara V. , Fonash Stephen J.
Published: June 2012

Architectures involving Ag and transparent conducting oxide (TCO) nano-element arrays for light and photocarrier collection management in substrate solar cells are numerically explored and compared. Some architectures with TCO nano-elements are shown to perform better than the best reported Ag arrays and (1) increase JSC at least 57% over that of a planar 200 nm a-Si:H control, (2) attain absorber utilization <7 mg/W, and (3) have only 224 nm as the longest collection length. Photonic effects are the cause of the light trapping enhancement in these devices. While the computations were done for a-Si:H, the insight provided is equally applicable to other absorbers.
Conduction in core/shell nano-composites
Authors: Moorthy G. , Daneshvar K.
Published: June 2012

The conductivity trends exhibited by 3D disordered arrays of two different types of core/shell structures—one with a metal core/metal oxide shell, and another with a metal core/insulator shell; over a wide range of temperatures have been compared. A striking difference is observed among the conductivities of both samples. While the metal/metal oxide sample displays a sharp increase in conductivity after a certain threshold temperature, the metal/insulator sample does not reflect such abrupt transition. This dissimilar behavior of charge transport is suspected to be a result of tunneling and polaron hopping mechanisms predominating in different core/shell structures. Theoretical models have been used to try and interpret these results to account for the deviation in conductivity trends.
Characterization of surface and nonlinear elasticity in wurtzite ZnO nanowires
Authors: Yvonnet J. , Mitrushchenkov A. , Chambaud G. , He Q.-C. , Gu S.-T.
Published: June 2012

Surface elasticity and nonlinear effects are reported in ZnO nanowires and characterized by ab initio calculations. Fully anisotropic elastic and stress coefficients related to (101¯0) surfaces are provided and used to construct a continuum model of nanowires based on the Gurtin-Murdoch surface elasticity theory, able to capture mechanical size effects. Nonlinear elasticity is observed through non-zero third order energy derivative terms with respect to axial strain in the direction of the nanowire. The associated material parameters are found to be themselves size-dependent.
HfO2 dielectrics engineering using low power SF6 plasma on InP and In0.53Ga0.47As metal-oxide-semiconductor field-effect-transistors
Authors: Wang Yanzhen , Chen Yen-Ting , Xue Fei , Zhou Fei , Lee Jack C.
Published: June 2012

In this work, we demonstrate that device characteristics could be significantly improved by incorporating more fluorine (F) into HfO2 dielectrics layer using low power SF6 plasma treatment at different positions of gate oxide. Fluorine was incorporated in three ways: 4 min treatment from the top of 6 nm HfO2, 4 min treatment in the middle of 6 nm HfO2, or 2 min treatment each in the middle and from the top of HfO2 layer. Drive current (Id) and effective channel mobility could be improved by 70% and 51%, respectively, for devices with treatment both in the middle and from the top of HfO2 high κ layer compared to those of devices without SF6 treatment. The impact of SF6 plasma treatment on devices with HfO2/In0.53Ga0.47As stack is also presented.
Stability and optical limiting properties of a single wall carbon nanotubes dispersion in a binary water-glycerol solvent
Authors: Venediktova Anastasiya V. , Vlasov Andrey Yu. , Obraztsova Elena D. , Videnichev Dmitry A. , Kislyakov Ivan M. , Sokolova Ekaterina P.
Published: June 2012

We report the temporal stability of the dispersion of single-wall carbon nanotubes in a binary solvent “water + glycerol” having eutectic composition (ca. 67% wt.) with sodium dodecylbenzene sulfonate as a dispersant. The system procures good temporal and thermal stability: its absorption spectra demonstrate no changes during one-year storage with temperature spanning −40 to +40 °C. The system provides non-linear optical power limiting of the incident laser radiation (532 nm) in a one-shot and pulse-periodic regimes of its applying.
Repeatable low-temperature negative-differential resistance from Al0.18Ga0.82N/GaN resonant tunneling diodes grown by molecular-beam epitaxy on free-standing GaN substrates
Authors: Li D. , Tang L. , Edmunds C. , Shao J. , Gardner G. , Manfra M. J. , Malis O.
Published: June 2012

Low-aluminum composition AlGaN/GaN double-barrier resonant tunneling structures were grown by plasma-assisted molecular-beam-epitaxy on free-standing c-plane GaN substrates grown by hydride-vapor phase epitaxy. Clear, exactly reproducible, negative-differential resistance signatures were observed from 4 × 4 μm2 devices at 1.5 V and 1.7 V at 77 K. The relatively small value of the maximum peak-to-valley ratio (1.03) and the area dependence of the electrical characteristics suggest that charge transport is affected by leakage paths through dislocations. However, the reproducibility of the data indicates that electrical traps play no significant role in the charge transport in resonant tunneling diodes grown by molecular-beam-epitaxy under Ga-rich conditions on free-standing GaN substrates.
Investigation of green InGaN light-emitting diodes with asymmetric AlGaN composition-graded barriers and without an electron blocking layer
Authors: Chang Yi-An , Chang Jih-Yuan , Kuo Yih-Ting , Kuo Yen-Kuang
Published: June 2012

In this study, a green InGaN light-emitting diode with asymmetric AlGaN composition-graded barriers and without the use of an AlGaN electron blocking layer is presented to possess markedly enhanced optical and electrical performance. The simulation results show that the output power is increased by 10.0% and 33.2%, which corresponds to an increment of 7% and 29.4% in internal quantum efficiency, at 100 mA when the conventional GaN barriers are replaced by the asymmetric AlGaN composition-graded barriers and the commonly used AlGaN electron blocking layer is removed. The simulation results suggest that the improved device performance is due mainly to the markedly enhanced injection of holes into the active region.
Fast electron transfer from PbSe quantum dots to TiO2
Authors: Masumoto Yasuaki , Takagi Hayato , Umino Hikaru , Suzumura Eri
Published: June 2012

Fast electron transfer from PbSe quantum dots (QDs) to the porous anatase TiO2 film was observed in transient absorption and luminescence, when the lowest unoccupied molecular orbital level of PbSe QDs is higher than that of TiO2. In PbSe QDs 2.7 nm in diameter linked to the TiO2 film the bleaching recovery and the luminescence decay shortened to 1 ps and 4.2 ns from 650 ps and 1.3 μs observed in the non-linked PbSe QDs, respectively. The electron transfer from both the quantum state and the localized state in PbSe QDs to TiO2 takes place fast and efficiently.
Separating the effects of internal friction and transition state energy to explain the slow, frustrated folding of spectrin domains
Authors: Wensley Beth G. , Kwa Lee Gyan , Shammas Sarah L. , Rogers Joseph M. , Browning Stuart , Yang Ziqi , Clarke Jane
Published: June 2012

The elongated three-helix bundle domains spectrin R16 and R17 fold some two to three orders of magnitude more slowly than their homologue R15. We have shown that this slow folding is due, at least in part, to roughness in the free-energy landscape of R16 and R17. We have proposed that this roughness is due to a frustrated search for the correct docking of partly preformed helices. However, this accounts for only a small part of the slowing of folding and unfolding. Five residues on the A helix of R15, when inserted together into R16 or R17, increase the folding rate constants, reduce landscape roughness, and alter the folding mechanism to one resembling R15. The effect of each of these mutations individually is investigated here. No one mutation causes the behavior seen for the five in combination. However, two mutations, E18F and K25V, significantly increase the folding and unfolding rates of both R16 and R17 but without a concomitant loss in landscape roughness. E18F has the greatest effect on the kinetics, and a Φ-value analysis of the C helix reveals that the folding mechanism is unchanged. For both E18F and K25V the removal of the charge and resultant transition state stabilization is the main origin of the faster folding. Consequently, the major cause of the unusually slow folding of R16 and R17 is the non-native burial of the two charged residues in the transition state. The slowing due to landscape roughness is only about fivefold.
Follistatin-mediated skeletal muscle hypertrophy is regulated by Smad3 and mTOR independently of myostatin
Authors: Winbanks Catherine E. , Weeks Kate L. , Thomson Rachel E. , Sepulveda Patricio V. , Beyer Claudia , Qian Hongwei , Chen Justin L. , Allen James M. , Lancaster Graeme I. , Febbraio Mark A. , Harrison Craig A. , McMullen Julie R. , Chamberlain Jeffrey S. , Gregorevic Paul
Published: June 2012

Follistatin is essential for skeletal muscle development and growth, but the intracellular signaling networks that regulate follistatin-mediated effects are not well defined. We show here that the administration of an adeno-associated viral vector expressing follistatin-288aa (rAAV6:Fst-288) markedly increased muscle mass and force-producing capacity concomitant with increased protein synthesis and mammalian target of rapamycin (mTOR) activation. These effects were attenuated by inhibition of mTOR or deletion of S6K1/2. Furthermore, we identify Smad3 as the critical intracellular link that mediates the effects of follistatin on mTOR signaling. Expression of constitutively active Smad3 not only markedly prevented skeletal muscle growth induced by follistatin but also potently suppressed follistatin-induced Akt/mTOR/S6K signaling. Importantly, the regulation of Smad3- and mTOR-dependent events by follistatin occurred independently of overexpression or knockout of myostatin, a key repressor of muscle development that can regulate Smad3 and mTOR signaling and that is itself inhibited by follistatin. These findings identify a critical role of Smad3/Akt/mTOR/S6K/S6RP signaling in follistatin-mediated muscle growth that operates independently of myostatin-driven mechanisms.
Internet Addiction Phenomenon in Early Adolescents in Hong Kong
Authors: Shek Daniel T. L. , Yu Lu
Published: June 2012

The present study investigated the prevalence and demographic correlates of Internet addiction in Hong Kong adolescents as well as the change in related behavior at two time points over a one-year interval. Two waves of data were collected from a large sample of students (Wave 1: 3,328 students, age=12.59±0.74years; Wave 2: 3,580 students, age=13.50±0.75years) at 28 secondary schools in Hong Kong. Comparable to findings at Wave 1 (26.4%), 26.7% of the participants met the criterion of Internet addiction at Wave 2 as measured by Young’s 10-item Internet Addiction Test. The behavioral pattern of Internet addiction was basically stable over time. While the predictive effects of demographic variables including age, gender, family economic status, and immigration status were not significant, Internet addictive behaviors at Wave 1 significantly predicted similar behaviors at Wave 2. Students who met the criterion of Internet addiction at Wave 1 were 7.55 times more likely than other students to be classified as Internet addicts at Wave 2. These results suggest that early detection and intervention for Internet addiction should be carried out.
Identification of moesin as NKCC2‐interacting protein and analysis of its functional role in the NKCC2 apical trafficking
Authors: Carmosino Monica , Rizzo Federica , Procino Giuseppe , Zolla Lello , Timperio Anna Maria , Basco Davide , Barbieri Claudia , Torretta Silvia , Svelto Maria
Published: June 2012

Background information

The renal Na+–K+–2Cl− co‐transporter (NKCC2) is expressed in kidney thick ascending limb cells, where it mediates NaCl re‐absorption regulating body salt levels and blood pressure.

Results

In this study, we used a well‐characterised NKCC2 construct (c‐NKCC2) to identify NKCC2‐interacting proteins by an antibody shift assay coupled with blue native/SDS‐PAGE and mass spectrometry. Among the interacting proteins, we identified moesin, a protein belonging to ezrin, eadixin and moesin family. Co‐immunoprecipitation experiments confirmed that c‐NKCC2 interacts with the N‐terminal domain of moesin in LLC‐PK1 cells. Moreover, c‐NKCC2 accumulates in intracellular and sub‐apical vesicles in cells transfected with a moesin dominant negative green fluorescent protien (GFP)‐tagged construct. In addition, moesin knock‐down by short interfering RNA decreases by about 50% c‐NKCC2 surface expression. Specifically, endocytosis and exocytosis assays showed that moesin knock‐down does not affect c‐NKCC2 internalisation but strongly reduces exocytosis of the co‐transporter.

Conclusions

Our data clearly demonstrate that moesin plays a critical role in apical membrane insertion of NKCC2, suggesting a possible involvement of moesin in regulation of Na+ and Cl− absorption in the kidney.
The feasibility of using local general practice data to estimate the prevalence of childhood disabling conditions
Authors: Lingam R. , Ellis M. , Naqvi H. , Mytton J.
Published: June 2012

Aims  This study aimed to assess the feasibility of using general practice data to estimate the prevalence of potentially disabling conditions in young people aged 0–18 years.

Background  There are limited data that estimate the prevalence of disabling conditions in children and young people and are suitable to inform service planning. This has been highlighted by several government documents and parent groups. The current study analysed anonymized data from 5 general practices in Bristol, UK (n = 10 756 children and young people aged 0–18 years). A comprehensive Read Code list was created to identify children and young people with potentially disabling conditions and the severity of conditions was compared with General Practitioner completed free text within the computerized system.

Results  Across these practices an average 4.9% (95% confidence intervals 4.5–5.3) of children and young people had a significant physical or mental difficulty that could impact on their daily living. The most common disabling conditions in our sample were in the ICF category of mental function 36% (including general and specific developmental delays and mental health diagnoses).

Conclusion  This study suggests that routinely collected data may provide much needed robust information to inform service provision for some of the most vulnerable children and young people in our communities. It also highlights the need for improved data systems for disability services.
Focus on paediatric and adolescent varicocoele: a single institution experience
Authors: Cimador M. , Pensabene M. , Sergio M. , Caruso A. M. , De Grazia E.
Published: June 2012

The aim of this study was to report our long‐term diagnostic and surgical outcome during the last 18 years, in paediatric and adolescent management of varicocoele. The present retrospective study enrols 374 patients observed at our institution between 1994 and 2011. Patients were divided into three groups: Group A includes 142 youngsters and adolescents treated with open surgery for left varicocoele, in which a pre‐operative CDUS was not performed; Group B includes 65 patients treated with open surgery in which a pre‐operative CDUS evaluation was carried out, to assess varicocoele haemodynamic pattern and testicular volume. Group C includes 167 patients treated by laparoscopy and with pre‐operative CDUS assessment. For all groups post‐operative follow‐up consisted of CDUS evaluation performed 1, 3, 6, 12 months after surgical treatment, than every year. Persistence/recurrence of varicocoele, testicular volume and presence of hydrocele were evaluated. Recurrence rate was significatively higher in group A (11.2%) than B (no recurrence, p = 0.003) or C (no recurrence, p = 0.000). Post‐operative hydrocele was not significantly observed overall in group A in 9.8% of cases (13% if tunica vaginalis was left untouched, 4.2% if everted or resected p = 0.005), in group B in 3% and in group C in 7.1% of cases (p = NS). In conclusion, open and laparoscopic surgery offers similar results. In our opinion, the key‐point in paediatric and adolescent varicocoele is not the surgical approach to use, but the exact diagnosis. Careful CDUS evaluation is, in our opinion, a valid, safe, cost‐effective and immediate tool to accurately detect all refluxing venous system and for achieving a comprehensive evaluation of the vascular anatomy of varicocoele in paediatric and adolescent age. Laparoscopic Palomo or open subinguinal microsurgical varicocelectomy offer similar results in terms of recurrence; meanwhile the use of a lymphatic sparing surgery with or without blue‐dye is recommended to reduce post‐operative hydroceles.
The effects of two educational interventions on knowledge and competence of nurses with regard to conveying gastroscopy‐related information to patients
Authors: Kao Shu‐Hua , Hsu Li‐Ling , Hsieh Suh‐Ing , Huang Tzu‐Hsin
Published: June 2012

Kao S.‐H., Hsu L.‐L., Hsieh S.‐I. & Huang T.‐H. (2013) The effects of two educational interventions on knowledge and competence of nurses with regard to conveying gastroscopy‐related information to patients. Journal of Advanced Nursing 69(4), 793–804. doi: 10.1111/j.1365‐2648.2012.06062.x

Aim.  The study was to compare the effects of two different educational interventions on knowledge and competence of nurses regarding conveying gastroscopy‐related information to patients.

Background.  Nurses play an important role in helping patients undergo gastroscopy and must be familiar with the procedure to provide related patient education.

Design.  A quasi‐experimental study.

Methods.  This study in 2010 involved a pre‐test and two post‐tests. The experimental group (n = 25) received a multimedia CD‐ROM, and the comparator group (n = 40) received a pocket booklet. The effects of the two educational interventions were measured using the Knowledge Test Gastroscopy Nursing Instruction Scale, the Self‐Evaluation Gastroscopy Nursing Instruction Scale, and the Gastroscopy Nursing Instruction Learning Satisfaction Scale.

Results.  No overall significant difference in knowledge scores between the two groups was found, but subsequent post hoc analysis showed significantly higher scores in the experimental group than in the comparator group at week 6. A significant within‐subjects effect of the self‐evaluation gastroscopy nursing instruction scores from baseline–week 6 was dependent on the experimental group or the comparator group. There were significant between‐subjects effects overall, at week 3 and at week 6.

Conclusion.  Both educational interventions improved nurses’ knowledge and competence in gastroscopy‐related information. However, the CD‐ROM‐based intervention had long‐term effects on knowledge and had short‐term and long‐term effects on competence.
The effect of continuing professional education on perioperative nurses’ relationships with medical staff: findings from a qualitative study
Authors: Tame Susan L.
Published: June 2012

Tame S.L. (2013) The effect of continuing professional education on perioperative nurses’ relationships with medical staff: findings from a qualitative study. Journal of Advanced Nursing 69(4), 817–827. doi: 10.1111/j.1365‐2648.2012.06065.x

Aims.  To report perceived changes to UK perioperative nurses’ relationships with medical staff following periods of formal, university‐based study.

Background.  Continuing professional development is considered important for nursing internationally; however, practice changes may not result following formal study. The literature did not describe perioperative nurses’ experiences of formal study, and it was believed differences may exist due to hierarchical interprofessional relationships in the operating theatre.

Design.  Descriptive, qualitative.

Methods.  Unstructured interviews (N = 23) were conducted between 2006–2007 with a purposive sample of perioperative nurses who had recent experience of continuing professional education. All participants were employed by one National Health Service Trust in the North of England, UK. Audio‐taped interviews were transcribed fully into the ethnograph computer‐assisted qualitative data analysis programme and data coded and analysed to identify themes.

Findings.  The findings indicated that whilst continuing professional education did not have a direct impact on practice, development of increased knowledge and confidence facilitated participants’ collaboration with and questioning of medical colleagues. Such increased interprofessional collaboration was attributed to indirectly enhancing patient care.

Conclusion.  Continuing professional education appeared to lead to intrinsic changes to practitioners rather than direct behavioural change. Nurses’ increased knowledge and confidence affected the balance of power in the doctor–nurse relationship in British perioperative environments. This paper is of significance to perioperative nursing and may be transferable to other areas of care.
Pathogen inactivation technology applied to a blood component collected from an asymptomatic carrier of Leishmania infantum: a case report
Authors: Jimenez‐Marco T. , Fisa R. , Riera C. , Girona‐Llobera E. , Sedeño M. , Saura A. , Iniesta L. , Guillen C. , Muncunill J.
Published: June 2012

Asymptomatic Leishmania infections have been the main cause of transfusion transmission in endemic areas. Polymerase chain reaction has been used to detect L. infantum DNA in the peripheral blood of asymptomatic Leishmania carriers. In our region, the prevalence of asymptomatic L. infantum infection in donors is markedly high (5·9% of donors studied). We investigated the ability of pathogen inactivation technology, using amotosalen and UVA illumination, to eliminate L. infantum in a blood component collected from an asymptomatic L. infantum infected donor. This is the first report of the INTERCEPT system being used to eliminate a parasite from a component collected from a donor.
Listening with care: using narrative methods to cultivate nurses’ responsive relationships in a home visiting intervention with teen mothers
Authors: SmithBattle Lee , Lorenz Rebecca , Leander Sheila
Published: June 2012

Effective public health nursing relies on the development of responsive and collaborative relationships with families. While nurse–family relationships are endorsed by home visitation programs, training nurses to follow visit‐to‐visit protocols may unintentionally undermine these relationships and may also obscure nurses’ clinical understanding and situated knowledge. With these issues in mind, we designed a home‐visiting intervention, titled Listening with Care, to cultivate nurses’ relationships with teen mothers and nurses’ clinical judgment and reasoning. Rather than using protocols, the training for the intervention introduced nurses to narrative methods and therapeutic tools. This mixed‐method pilot study included a quasi‐experimental design to examine the effect of the intervention on teen mothers’ depressive symptoms, self‐silencing, repeat pregnancy, and educational progress compared to teens who received usual care. Qualitative data were collected from the nurses to evaluate the feasibility and acceptability of the intervention and therapeutic tools. The nurses endorsed the therapeutic tools and expected to continue using them in their practice. Despite the lack of statistically significant differences in outcomes between groups, findings suggest that further study of the intervention is warranted. Future studies may have implications for strengthening hidden aspects of nursing that make a difference in the lives of teen mothers.
Treatment of retinopathy of prematurity in extremely premature infants over an 18‐year period
Authors: Gunn David J , Cartwright David W , Yuen Sonia A , Gole Glen A
Published: June 2012

Abstract

Background:  To report the efficacy of laser diode therapy in the treatment of retinopathy of prematurity (ROP) in extremely premature (EP) infants over an 18‐year period.

Design:  Retrospective study.

Participants:  One hundred twenty‐eight eyes in 66 infants treated between 23 and 25.6 weeks.

Methods:  Five hundred fifty‐four infants between 23 and 25.6 weeks gestational age (GA) were admitted to The Royal Brisbane and Women's Hospital Neonatal Intensive Care Unit (NICU) between 1992 and 2009. Three hundred seventy‐three patients survived to undergo screening, 304 were diagnosed with ROP, and 66 infants required diode laser therapy.

Main Outcome Measures:  Success of treatment, visual and refractive outcomes.

Results:  One hundred twenty‐eight eyes from 66 infants (18.8% of those screened) underwent laser treatment with a mean GA of 24.3 weeks and mean birth weight of 711.4g. Fifty‐six eyes were treated at pre‐threshold disease, and 72 eyes at threshold disease. Over the study period, the number of laser spots and regression rate of ROP increased, while the frequency of re‐treatment decreased. At 40 weeks, 119 eyes had regressed ROP (93%), two advanced to stage 4a, three to stage 4b and four to stage 5. Aggressive posterior ROP (AP‐ROP) occurred in 15 eyes (11.7% of those treated). Forty‐three patients (65%) were followed up for a mean of 56.5 months. The number of laser spots correlated well with subsequent refractive error but poorly with corrected visual acuity.

Conclusions:  In EP infants, laser diode therapy is an effective technique to halt the progression of ROP in most cases. AP‐ROP is uncommon, even in this subgroup of extremely premature infants.
The bacterial thiopurine methyltransferase tellurite resistance process is highly dependent upon aggregation properties and oxidative stress response
Authors: Prigent‐Combaret Claire , Sanguin Hervé , Champier Ludovic , Bertrand Cédric , Monnez Claire , Colinon Céline , Blaha Didier , Ghigo Jean‐Marc , Cournoyer Benoit
Published: June 2012

Bacterial thiopurine methyltransferases (bTPMTs) can favour resistance towards toxic tellurite oxyanions through a pathway leading to the emission of a garlic‐like smell. Gene expression profiling completed by genetic, physiological and electron microscopy analyses was performed to identify key bacterial activities contributing to this resistance process. Escherichia coli strain MG1655 expressing the bTPMT was used as a cell model in these experiments. This strain produced a garlic‐like smell which was found to be due to dimethyl telluride, and cell aggregates in culture media supplemented with tellurite. Properties involved in aggregation were correlated with cell attachment to polystyrene, which increased with tellurite concentrations. Gene expression profiling supported a role of adhesins in the resistance process with 14% of the tellurite‐regulated genes involved in cell envelope, flagella and fimbriae biogenesis. Other tellurite‐regulated genes were, at 27%, involved in energy, carbohydrate and amino acid metabolism including the synthesis of antioxidant proteins, and at 12% in the synthesis of transcriptional regulators and signal transduction systems. Escherichia coli mutants impaired in tellurite‐regulated genes showed ubiquinone and adhesins synthesis, oxidative stress response, and efflux to be essential in the bTPMT resistance process. High tellurite resistance required a synergistic expression of these functions and an efficient tellurium volatilization by the bTPMT.
Identification of genes in the VirR regulon of Pectobacterium atrosepticum and characterization of their roles in quorum sensing‐dependent virulence
Authors: Monson Rita , Burr Tom , Carlton Timothy , Liu Hui , Hedley Peter , Toth Ian , Salmond George P.C.
Published: June 2012

In the economically important phytopathogen, Pectobacterium atrosepticum, expression of plant cell wall degrading enzymes and other virulence determinants is controlled in a cell density‐dependent fashion, termed quorum sensing (QS). Canonical QS systems in Gram‐negative bacteria contain a LuxI‐type protein, synthesizing a signalling molecule, and a LuxR‐type regulator, responding to the signalling molecule above threshold concentrations. In P. atrosepticum, the central LuxR‐type repressor of virulence, VirR, has been identified and its impacts on virulence characterized. Here we define the broader VirR regulon using chromatin immunoprecipitation (ChIP) and in planta microarrays. Ninety‐four direct VirR targets were identified by ChIP microarrays and a consensus VirR binding site was determined. Purified VirR was used in DNA gel shift assays on target promoters and VirR : promoter binding was disrupted by exogenous addition of the signalling molecule, N‐(3‐oxohexanoyl)‐l‐homoserine lactone (OHHL). VirR autorepressed, and directly activated the transcription of rsmA in the absence of OHHL. Finally, we showed that VirR directly regulated the production of siderophores and controlled swimming motility. This is the first report characterizing the direct targets of VirR and provides clear evidence that this LuxR‐type protein can act in vivo as both an activator and repressor of transcription in the absence of its cognate signalling molecule.
Colonic neoplasia in young patients with inflammatory bowel disease and primary sclerosing cholangitis
Authors: Imam M. H. , Thackeray E. W. , Lindor K. D.
Published: June 2012

Aim  Current guidelines recommend annual surveillance for colorectal cancer (CRC) in all patients with inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC). The aim of our study was to validate the need for annual surveillance for colon neoplasia in patients ≤ 45 of age with a combined diagnosis of PSC and IBD.

Method  We identified patients, ≤ 45 years of age with a combined diagnosis of PSC and IBD, who were seen at the Mayo Clinic between 1995 and 2010. We then reviewed the medical records of the patients who developed colonic neoplasia defined as cancer, high‐grade dysplasia (HGD) or dysplasia‐associated lesion or mass (DALM).

Results  In the population of 784 patients ≤ 45 years of age with a combined diagnosis of PSC and IBD, 10 (1.3%) of 784 developed colonic neoplasia during the follow‐up period. Seven patients had colon cancer, one had HGD and two had a DALM.

Conclusion  Colonic neoplasia is uncommon in young patients (≤ 45 years of age) with a combined diagnosis of PSC and IBD. We suggest delaying surveillance in young patients and propose that studies should be carried out to clarify the cost‐effectiveness of annual or biannual surveillance colonoscopies according to patient age.