bluuebunny/crossref_metadata_2025 huggingface dataset:
Validity of the Stroke Rehabilitation Assessment of Movement Scale in Acute Rehabilitation: A Comparison With the Functional Independence Measure and Stroke Impact Scale‐16
Authors: Ward Irene , Pivko Susan , Brooks Gary , Parkin Kate
Published: November 2011

Objective

To demonstrate sensitivity to change of the Stroke Rehabilitation Assessment of Movement (STREAM) as well as the concurrent and predictive validity of the STREAM in an acute rehabilitation setting.

Design

Prospective cohort study.

Setting

Acute, in‐patient rehabilitation department within a tertiary‐care teaching hospital in the United States.

Participants

Thirty adults with a newly diagnosed, first ischemic stroke.

Methods

Clinical assessments were conducted on admission and then again on discharge from the rehabilitation hospital with the STREAM (total STREAM and upper extremity, lower extremity, and mobility subscales), Functional Independence Measure (FIM), and Stroke Impact Scale‐16 (SIS‐16). Sensitivity to change was determined with the Wilcoxon signed rank test and by the calculation of standardized response means. Spearman correlations were used to assess concurrent validity of the total STREAM and STREAM subscales with the FIM and SIS‐16 on admission and discharge. We determined predictive validity for all instruments by correlating admission scores with actual and predicted length of stay and by testing associations between admission scores and discharge destination (home vs subacute facility).

Main Outcomes

Not applicable.

Results

For all instruments, there was statistically significant improvement from admission to discharge. The standardized response means for the total STREAM and STREAM subscales were large. Spearman correlations between the total STREAM and STREAM subscales and the FIM and SIS‐16 were moderate to excellent, both on admission and discharge. Among change scores, only the SIS‐16 correlated with the total STREAM. All 3 instruments were significantly associated with discharge destination; however, the associations were strongest for the total STREAM and STREAM subscales. All instruments showed moderate‐to‐excellent correlations with predicted and actual length of stay.

Conclusions

The STREAM is sensitive to change and demonstrates good concurrent and predictive validity as compared with the FIM and SIS‐16 in the acute inpatient rehabilitation population.
Responding to patient anger: Development and evaluation of an oncology communication skills training module
Authors: Bialer Philip A. , Kissane David , Brown Richard , Levin Tomer , Bylund Carma
Published: November 2011

Objective:

The purpose of this study was to develop a communication skills training (CST) module for oncology healthcare professionals on how to more effectively respond to patient anger. We also sought to evaluate the module in terms of participant self-efficacy and satisfaction.

Method:

The development of this module was based on a systematic review of the literature and followed the Comskil model previously used for other doctor–patient CST. Using an anonymous 5-point Likert scale, participants rated their pre-post self-efficacy in responding to patient anger as well as their satisfaction with the course. Data were analyzed using a paired sample t test.

Results:

During the academic years 2006–2009, 275 oncology healthcare professionals participated in a CST that focused on responding to patient anger. Participants' confidence in responding to patient anger increased significantly (p < 0.001) after attending the workshop. They also agreed or strongly agreed to five out of six items assessing course satisfaction 92–97% of the time.

Significance of results:

We have developed a CST module on how to respond to patient anger, which is both effective and useful. Training healthcare professionals to respond more effectively to patient anger may have a positive impact on the patient–physician relationship.
Perspectives of staff providing care at the end of life for people with progressive long-term neurological conditions
Authors: Wilson Eleanor , Seymour Jane , Aubeeluck Aimee
Published: November 2011

Objective:

This article examines the views and opinions of staff from a larger study exploring the palliative and end-of-life care needs of patients with progressive long-term neurological conditions (PLTNC).

Method:

Eighty staff, in a range of professions from three types of care services provided to people with PLTNC in England, took part in 14 focus groups and 3 individual interviews. Sites included six long-term residential neurological care centers, an inpatient service at an urban hospice, and a multi-disciplinary outpatient service for people with Huntington's disease.

Results:

Findings show a concordance between the views of staff from across the three types of participating services. Staff placed particular emphasis on teamwork, support from community-based resources, and developing rapport with patients in order to provide high quality palliative and end-of-life care. All staff perceived that identifying the dying phase was a particular challenge, sometimes resulting in patients being admitted to hospital at the end of life in contravention of their expressed advance wishes for place of death.

Significance of results:

This article adds to a small body of literature that seeks staff views and opinions about the rewards and challenges of providing palliative and end-of-life care to people with complex needs arising from long-term conditions. Although this article focuses primarily on the challenges of caring for people with neurological conditions, many issues reported are of wider relevance for the delivery of palliative and end-of-life care in other conditions.
Seismotectonics of northeastern Taiwan: Kinematics of the transition from waning collision to subduction and postcollisional extension
Authors: Huang Hsin‐Hua , Shyu J. Bruce H. , Wu Yih‐Min , Chang Chien‐Hsin , Chen Yue‐Gau
Published: November 2011

The northeastern region of Taiwan is one of the few places on Earth that experienced a transition from collision to subduction and back‐arc opening in a young orogenic belt. This provides us a rare opportunity to study the structural characteristics in such a transition. We attempt to analyze the seismicity and stress patterns in this transitional region using data obtained from a dense and high‐quality seismic network. Our results show that from south to north, fault types change from thrust to strike‐slip, then to normal faulting. The transitional domain between Ilan and Hualien is dominated by left‐lateral strike‐slip faulting with a NNW‐SSE minimum principal stress axis, consistent with the opening of the Okinawa Trough. To the north, the Ilan Plain is formed by structural activities of a series of normal fault systems. To the south, the spatial distribution of an earthquake cluster north of Taiwan's Coastal Range appears to parallel the subducting interface between the Philippine Sea and Eurasian plates. This implies the northern extension of the Coastal Range has subducted. Consequently, the opening of the Okinawa Trough becomes an important tectonic driving force in northeastern Taiwan. The westernmost Ryukyu arc is pushed by the opening Okinawa Trough, and moves southward. The northern part of Taiwan's Central Range moves with the arc to bend southeastward, and the Ilan Plain forms in the space north of the range. The bending of the Central Range belt results in bedding plane slip with left‐lateral strike‐slip earthquakes in the transitional domain to accommodate the deformation.
Can vertical migrations of dinoflagellates explain observed bioluminescence patterns during an upwelling event in Monterey Bay, California?
Authors: Shulman Igor , Penta Bradley , Moline Mark A. , Haddock Steven H. D. , Anderson Stephanie , Oliver Matthew J. , Sakalaukus Peter
Published: November 2011

Extensive AUVs surveys showed that during the development of upwelling, bioluminescent dinoflagellates from the northern part of the Monterey Bay, California (called the upwelling shadow area), were able to avoid advection by southward flowing currents along the entrance to the Bay, while non‐bioluminescent phytoplankton were advected by currents. It is known that vertical swimming of dinoflagellates to deeper layers helps them avoid losses due to advection. In the present paper, we investigate if modeling dinoflagellates' vertical swimming can explain the observed dinoflagellates' ability to avoid advection during the upwelling development. The dynamics of a dinoflagellate population is modeled with the tracer model with introduced vertical swimming velocity. Three swimming behaviors are considered: sinking, swimming to the target depth and diel vertical migration. Velocities in all swimming cases are considered in the ranges of documented velocities for the observed dinoflagellates species during the upwelling development in the Monterey Bay. Our modeling confirmed that observed bioluminescent dinoflagellates' avoidance of advection during the upwelling development can be explained by their vertical swimming ability. In the case of swimming with 20 m/day (which is half of observed maximum swimming velocity), around 40% of dinoflagellates population from the northern part of the Bay were advected along the entrance to the Bay in comparison to the case without swimming. This is in agreement with the ratio of around 45% of observed mean bioluminescence intensity at the entrance to the Bay to the observed mean intensity in the northern part of the Bay. This mechanism also helps explain the general persistence of dinoflagellates in this part of the coastline.
Structure and dynamics of the midshelf front in the New York Bight
Authors: Ullman D. S. , Codiga D. L. , Hebert D. , Decker L. B. , Kincaid C. R.
Published: November 2011

The structure and variability of the wintertime midshelf front in the New York Bight is examined using moored observations of currents and hydrography during 2007. The front is located near the 50 m isobath, inshore of the shelf break front and offshore of estuarine outflow plume fronts. It spans the water column and is the boundary between cooler, fresher, and less dense inner shelf water and warmer, saltier, and denser outer shelf water. The mean hydrographic front slopes upward offshore, and there is an associated equatorward along‐shelf 5–10 cm/s surface‐intensified current jet. The mean across‐shelf circulation is offshore near the surface and onshore at depth. The across‐shelf velocity is convergent and strengthens across‐shelf property gradients with a time scale for gradient doubling of approximately 8 days. Tidal analysis of currents and temperatures suggests that tidal shear dispersion is not an important mechanism for midshelf front formation. The frontal structure and location are roughly consistent with the theory of bottom boundary layer advected fronts, suggesting that multiple estuarine outflows are collectively responsible. Pulses of strong offshore wind cause the breakdown of the across‐shelf thermal wind balance, which has been commonly assumed to hold in shelf environments. Observed shear significantly exceeds thermal wind shear at middepths, where observation of low‐gradient Richardson number indicates the importance of vertical mixing. The response of currents to wind fluctuations is asymmetric, whereby the combination of upwelling favorable and offshore winds or downwelling favorable and onshore winds produces a stronger response than winds from the remaining quadrants.
Palmitoylation and trafficking of GAD65 are impaired in a cellular model of Huntington's disease
Authors: Rush Daniel B. , Leon Rebecca T. , McCollum Mark H. , Treu Ryan W. , Wei Jianning
Published: November 2011

HD (Huntington's disease) is caused by an expanded polyQ (polyglutamine) repeat in the htt (huntingtin protein). GABAergic medium spiny neurons in the striatum are mostly affected in HD. However, mhtt (mutant huntingtin)-induced molecular changes in these neurons remain largely unknown. The present study focuses on the effect of mhtt on the subcellular localization of GAD (glutamic acid decarboxylase), the enzyme responsible for synthesizing GABA (γ-aminobutyric acid). We report that the subcellular distribution of GAD is significantly altered in two neuronal cell lines that express either the N-terminus of mhtt or full-length mhtt. GAD65 is predominantly associated with the Golgi membrane in cells expressing normal htt; however, it diffuses in the cytosol of cells expressing mhtt. As a result, vesicle-associated GAD65 trafficking is impaired. Since palmitoylation of GAD65 is required for GAD65 trafficking, we then demonstrate that palmitoylation of GAD65 is reduced in the HD model. Furthermore, overexpression of HIP14 (huntingtin-interacting protein 14), the enzyme responsible for palmitoylating GAD65 in vivo, could rescue GAD65 palmitoylation and vesicle-associated GAD65 trafficking. Taken together, our data support the idea that GAD65 palmitoylation is important for the delivery of GAD65 to inhibitory synapses and suggest that impairment of GAD65 palmitoylation by mhtt may lead to altered inhibitory neurotransmission in HD.
Traitements orthodontiques accélérés par piézocision : une alternative mini-invasive aux corticotomies alvéolaires
Authors: Sebaoun Jean-David M. , Surmenian Jérôme , Dibart Serge
Published: November 2011

Avec un nombre croissant d’adultes se présentant en consultation orthodontique, la demande d’un traitement de courte durée revient de manière récurrente de la part des patients. Afin de répondre à ces attentes, plusieurs techniques ortho-chirurgicales visant à accélérer les mouvements dentaires ont été publiées mais se sont révélées relativement invasives. Nous introduisons ici une technique ortho-chirurgicale novatrice, minimalement invasive, sans lambeau muco-periosté, combinant micro-incisions, incisions corticales piézoélectriques et tunnelisation sélective permettant des greffes osseuses et gingivales. En associant plan de traitement consciencieux et compréhension des phénomènes biologiques impliqués, le métabolisme osseux alvéolaire peut ainsi être localement manipulé par cette nouvelle technique afin d’obtenir des résultats orthodontiques stables et rapides. La piézocision permet la correction rapide de malocclusions sévères sans présenter les inconvénients des approches chirurgicales extensives et traumatiques des corticotomies alvéolaires classiques.
Oscillatory and stationary convective patterns in a reaction driven gravity current
Authors: Miholics Orsika , Rica Tamás , Horváth Dezső , Tóth Ágota
Published: November 2011

Horizontally propagating chemical fronts are studied in a thin solution layer of the acid-catalyzed chlorite-tetrathionate reaction. Unusual cellular patterns develop when significant amount of autocatalyst is bound to polyelectrolyte with low mobility: both oscillatory and stationary patterns evolve as a result of the interaction between the reaction front and the superposed gravity current. The concentration of the polyelectrolyte regulating the velocity of front propagation serves as a bifurcation parameter for switching between the two basic patterns.
Multi-component non-stationary exponential distributions of the breakdown voltages and time delays in neon ramp breakdown experiments
Authors: Stamenković S. N. , Gocić S. R. , Marković V. Lj. , Jovanović A. P.
Published: November 2011

The concept of physically based distributions used in studies concerning gas electrical breakdowns is introduced in this paper. The non-stationary exponential distribution of the breakdown voltages and time delays with time dependent distribution parameter is theoretically derived based on physical grounds starting from a binomial distribution for electron occurrence in the interelectrode gap. The experimental distributions of breakdown voltages Ub and time delays td are obtained by applying linearly rising (ramp) voltage pulses to the discharge tube with a hard galvanic layer of gold on the cathode and modeled by multi-component non-stationary exponential distribution, as well as by a Weibull distribution for the sake of comparison. In order to fit the experimental data, the multi-component voltage/time dependent distribution parameter YP is introduced, where Y is electron yield (number of generated electrons in the interelectrode gap per second), and P is breakdown probability (the probability of one electron to cause a breakdown). It is shown that multi-component non-stationary exponential distribution is suitable for modeling of the experimental data when time varying voltage pulses are applied to the discharge tube.
Suppression of nonradiative recombination process in directly Si-doped InAs/GaAs quantum dots
Authors: Kita Takashi , Hasagawa Ryuichi , Inoue Tomoya
Published: November 2011

We carried out direct impurity doping in InAs/GaAs quantum dots (QDs) by selecting the self-assembled growth steps. The photoluminescence (PL) intensity of the Si-doped QDs is enhanced, and thermal quenching of the PL intensity is found to be considerably suppressed, whereas such improvement was not confirmed in Be-doped QDs. The excitation energy dependences of the PL intensity and the time-resolved PL indicate a reduction in the nonradiative recombination probability during the thermalization of carriers generated by high-energy photons. From these results, excess electrons in doped QDs neutralize and, therefore, inactivate the nonradiative recombination centers created by electron traps.
Plasmon-induced local photocurrent changes in GaAs photovoltaic cells modified with gold nanospheres: A near-field imaging study
Authors: Harada Yosuke , Imura Kohei , Okamoto Hiromi , Nishijima Yoshiaki , Ueno Kosei , Misawa Hiroaki
Published: November 2011

Modification of photovoltaic devices with metallic nanoparticles is expected to be one of the key methods for development of high performance devices as a future energy source. To clarify the mechanism of photocurrent changes induced by surface plasmon resonances of metal nanoparticles, we measured near-field photocurrent excitation images for a GaAs photodiode modified with gold nanospheres (diameter 100 nm) with a spatial resolution higher than 100 nm. The relationship between the photovoltaic efficiency and the plasmons of the gold nanospheres was investigated through the measurements of incident wavelength and polarization dependence of the near-field photocurrent images. Isolated nanospheres deposited on the GaAs active surface caused local photocurrent suppressions at the plasmon resonance wavelengths. In the case of assemblies (dimers and trimers) of the spheres, a remarkable decrease of photocurrent at the gap site between the spheres was observed. From the results, it turned out that the enhanced optical fields created via the plasmons on the metal nanostructures do not improve the photovoltaic efficiency and that forward scattering of photons by the gold nanoparticles is considered to be more important than the enhanced field effect at the particles for the GaAs photovoltaic device studied.
Vertical transport through GaAs/InGaP multi-quantum-wells p-i-n diode with evidence of tunneling effects
Authors: Gombia Enos , Parisini Antonella , Ghezzi Carlo , Tarricone Luciano , Baldini Michele , Vantaggio Salvatore
Published: November 2011

Vertical transport in p-i-n diodes containing InGaP/GaAs multi-quantum-wells (MQW) is investigated using current-voltage measurements under forward bias at different temperatures. At low injection, the experimental data are analyzed through a two diode model, by taking into account the non-complete depletion of the MQW region caused by unintentional p-type doping. The diffusion current results to be dominant at high temperatures, whereas the current due to non-radiative recombination through defects in the space charge region becomes more and more relevant as the temperature is reduced. At temperatures above T = 150 K and at high forward voltages, when the current is limited by the series resistance, the thermionic emission of holes over the InGaP barriers controls the transport through the whole MQW region. At lower temperatures resonant tunneling of holes takes place and a simple picture of the hole quantum levels permits to interpret the main details of the I(V) curves at T = 41 K, by supporting the hypothesis of a uniform electric field in the MQW region up to about 100 kV/cm.
Magnetic and dielectric properties of Eu-doped BiFeO3 nanoparticles by acetic acid-assisted sol-gel method
Authors: Chakrabarti Kaushik , Das Kajari , Sarkar Babusona , De S. K.
Published: November 2011

The BiFeO3 nanoparticles, having an average size of 13 nm, were synthesized by a simple sol-gel method. The samples possess single phase up to 2% Eu doping at the Bi site. The uncompensated spin moments on the surface and the modification of cycloidal spin structure due to the small size (13 nm) result in a ferromagnetic phase of the BiFeO3 nanoparticles. The successful doping of magnetically active Eu3+ ions in BiFeO3 nanoparticles improves the ferromagnetic property. The similar dependency of saturation magnetization, coercive field, and dielectric constant on Eu doping concentration reveals that a correlation between magnetic and dielectric properties exists in Eu-doped BiFeO3 nanoparticles.
Transparent organic light-emitting devices using a MoO3/Ag/MoO3 cathode
Authors: Tian Baolin , Williams Graeme , Ban Dayan , Aziz Hany
Published: November 2011

MoO3/Ag/MoO3 (MAM) stacks are investigated for utilization as transparent cathodes in organic light-emitting devices (OLEDs). The stacks can be fabricated using simple thermal evaporation at relatively low temperatures, and can be readily and safely utilized as top electrodes, without causing deposition damage to the organic layers. Results show that it is possible to achieve efficient electron injection from the MAM electrode into organic layers by means of incorporating a suitable electron injection layer (EIL) at the interface. Results also show that a MAM stack can exhibit high optical transmittance, amounting to about 65–80% in the 400–700 nm, and a low sheet resistance (9 Ω/□). A transparent OLED with a MAM cathode incorporated with a 10 nm Bphen: Cs2CO3 (10%) EIL is studied. By fine tuning the MAM structure, optimal OLED performance has been achieved: a total luminance of 1300 cd/m2 (representing ∼1000 cd/m2 and ∼300 cd/m2 from the bottom and the top, respectively) at 20 mA/cm2 and a corresponding driving voltage of 7.2 V. The OLED exhibits a peak transmittance of ∼90% in the 450–475 nm range, and a transmittance above 45% over the entire visible (i.e., 400–700 nm) range.
Direct measurement of energetic electron flow in Q-shu University experiment with steady-state spherical tokamak
Authors: Ishiguro Masaki , Hanada Kazuaki , Liu Haiqing , Zushi Hideki , Yoshida Naoaki , Tokunaga Tomonori , Nakamura Kazuo , Fujisawa Akihide , Idei Hiroshi , Sakamoto Mizuki , Hasegawa Makoto , Tashima Saya , Takase Yuichi , Maekawa Takashi , Kishimoto Yasuaki , Mitarai Osamu , Kawasaki Shoji , Nakashima Hisatoshi , Higashijima Aki
Published: November 2011

In magnetized plasmas, the presence of a significant number of energetic electrons has been observed but quantitative characteristics of these electrons are proving difficult to investigate. A Langmuir probe offers a means to provide quantitative measurement of these energetic electrons that takes into account electron emissions (secondary electron emission and electron reflection) from the probe tips and sheath expansion around the probe tips caused by a considerable negative potential. In this paper, these effects are experimentally confirmed and an analytical means to measure energetic electron characteristics are proposed. An analysis of plasmas produced by a high frequency wave is then applied leading to the successful detection of an asymmetric flow of energetic electrons. The estimated electron temperature and current density were approximately 4–5 keV and 2–3 kA/m2.
Kinetics of gas mediated electron beam induced etching
Authors: Randolph Steven , Toth Milos , Cullen Jared , Chandler Clive , Lobo Charlene
Published: November 2011

Electron beam induced etching (EBIE) is a high resolution, direct write, chemical dry etch process in which surface-adsorbed precursor molecules are activated by an electron beam. We show that nanoscale EBIE is rate limited through at least two mechanisms ascribed to adsorbate depletion and the transport of gaseous precursor molecules into an etch pit during etching, respectively. The latter has, to date, not been accounted for in models of EBIE and is needed to reproduce etch kinetics which govern the time-evolution of etch pits, EBIE throughput, and spatial resolution.
Two-dimensional electron gas related emissions in ZnMgO/ZnO heterostructures
Authors: Chen Hui , Gu Shulin , Liu Jiagao , Ye Jiandong , Tang Kun , Zhu Shunming , Zheng Youdou
Published: November 2011

Radiative recombination of two-dimensional electron gas (2DEG), induced by polarization and validated by Hall effect measurements, is investigated in ZnMgO/ZnO heterostructures grown by metal-organic chemical vapor deposition. The Mg composition, the depth profile distribution of Mg, the residual strain in ZnMgO caplayer, and the thickness of caplayer all significantly influence the 2DEG-related transitions in ZnMgO/ZnO heterostructures. Below or above ZnO donor bound exciton, three additional broad emissions persisting up to 100 K are assigned to the spatially indirect transitions from 2DEG electrons to the photoexcited holes towards the ZnO flat-band region or remaining at the heterointerface.
A strain sensor based on an aligned carbon particle string in a UV-cured polymer matrix
Authors: Høyer H. , Knaapila M. , Kjelstrup-Hansen J. , Liu X. , Helgesen G.
Published: November 2011

We demonstrate micro-mechanical strain sensors by aligning carbon black particles into single wirelike strings in a polymer matrix using an alternating electric field (dielectrophoresis) when the particle fraction is 0.1 vol. %. The strings are stabilized by UV-curing the polymer matrix and characterized electrically and electromechanically. Particle alignment makes the material conductive, and the stretching of such strings in polymer matrices gives a reversible change in resistivity. A gauge factor of about 150 is demonstrated. Nonaligned films containing 12 vol. % of carbon particles in the same polymer are conductive but not sensitive to similar stretching.
High Q electromechanics with InAs nanowire quantum dots
Authors: Solanki Hari S. , Sengupta Shamashis , Dubey Sudipta , Singh Vibhor , Dhara Sajal , Kumar Anil , Bhattacharya Arnab , Ramakrishnan S. , Clerk Aashish A. , Deshmukh Mandar M.
Published: November 2011

In this report, we study electromechanical properties of suspended InAs nanowire resonators. At low temperatures, the nanowire acts as the island of a single electron transistor, and a strong coupling between electron transport and mechanical modes is observed for resonant mechanical driving. Further, as a function of the mechanical drive frequency, the conductance exhibits a Fano lineshape. This arises from the interference between two contributions to potential of the single electron transistor coming from capacitively induced charges and the mechanical oscillation. The quality factor (Q) of these devices is ∼105 at 100 mK.
Temperature dependence of ultrafast phonon dynamics in graphite
Authors: Scheuch M. , Kampfrath T. , Wolf M. , von Volkmann K. , Frischkorn C. , Perfetti L.
Published: November 2011

Nonequilibrium optical phonons are generated in graphite following the excitation of electron-hole pairs with a femtosecond laser pulse. Their energy relaxation is probed by means of terahertz pulses. We find that the hot-phonon lifetime increases by a factor of 2 when the sample temperature decreases from 300 to 5 K. These results suggest that the energy relaxation in graphite at room temperature and above is dominated by the anharmonic decay of hot A1′ phonons at the K point into acoustic phonons with energies of about 10 meV.
Quantifying pulsed laser induced damage to graphene
Authors: Currie Marc , Caldwell Joshua D. , Bezares Francisco J. , Robinson Jeremy , Anderson Travis , Chun Hayden , Tadjer Marko
Published: November 2011

As an emerging optical material, graphene’s ultrafast dynamics are often probed using pulsed lasers yet the region in which optical damage takes place is largely uncharted. Here, femtosecond laser pulses induced localized damage in single-layer graphene on sapphire. Raman spatial mapping, SEM, and AFM microscopy quantified the damage. The resulting size of the damaged area has a linear correlation with the optical fluence. These results demonstrate local modification of sp2-carbon bonding structures with optical pulse fluences as low as 14 mJ/cm2, an order-of-magnitude lower than measured and theoretical ablation thresholds.
Cycads show no stomatal-density and index response to elevated carbon dioxide and subambient oxygen
Authors: Haworth Matthew , Fitzgerald Annmarie , McElwain Jennifer C.
Published: November 2011

The stomatal density (SD) and index (SI) of fossil plants are widely used in reconstructing palaeo-atmospheric CO2 concentration (palaeo-[CO2]). These stomatal reconstructions depend on the inverse relationship between atmospheric CO2 concentration ([CO2]) and SD and/or SI. Atmospheric oxygen concentration ([O2]) has also varied throughout earth history, influencing photosynthesis via the atmospheric CO2 : O2 ratio, and possibly affecting both SD and SI. Cycads formed a major component of Mesozoic floras, and may serve as suitable proxies of palaeo-[CO2]. However, little is known regarding SD and SI responses of modern cycads to [CO2] and [O2]. SD, SI and pore length were measured in six cycad species (Cycas revoluta, Dioon merolae, Lepidozamia hopei, Lepidozamia peroffskyana, Macrozamia miquelii and Zamia integrifolia) grown under elevated [CO2] (1500 ppm) and subambient [O2] (13.0%) in combination and separately, and compared with SD, SI and pore length under control atmospheric conditions of 380 ppm [CO2] and 20.9% [O2]. The cycad species analysed showed no significant SD, SI or pore-length response to changes in [CO2] or [O2].
Capillary electrophoresis characterisation of humic acids: application to diverse forest soil samples
Authors: Tatzber Michael , Mutsch Franz , Mentler Axel , Leitgeb Ernst , Englisch Michael , Gerzabek Martin H.
Published: November 2011

Environmental contextAnalysis of soil organic matter is important for understanding turnover and stabilisation processes of organic carbon in soils. Capillary electrophoresis is used here to investigate humic acids from soils of diverse forest sites, and show that the patterns of signals are indicative of soil characteristics. The method provides useful information of soil types and complements the existing set of methods for humic acid characterisation.
AbstractAnalyses of humic substances provide very useful information about turnover characteristics and stabilisation processes of soil organic matter in environmental soil samples. The present study investigates 113 samples of forest soils from three different layers (undecomposed litter (L), if present, mixed samples of F (intermediate decomposed) and H (highly decomposed) organic matter (FH) and upper mineral soil layers (Ah horizon) from 0 to 5 cm) by extracting humic acids (HAs) and recording electropherograms. Five signals of these electropherograms were evaluated and correlated with basic parameters from soil (organic carbon, Corg, and total nitrogen, Nt, and extraction yields of HAs) and HAs (total carbon, Ct, and Nt), and with signals from photometry, mid-infrared and fluorescence spectroscopy. The developed method was able to separate HAs from different soil layers by calculating a discriminant function based on the five evaluated electrophoretic signals. The dataset of this work opened the opportunity to correlate the observed electrophoretic signals with the other determined soil parameters and spectroscopic signals. This can be seen as a very important step in the direction to assignments of the obtained electrophoretic signals. Soil characteristics were reflected quite well by this method and, combined with the other approaches, it is suitable for applications in further studies.
How do rural GPs’ workloads and work activities differ with community size compared with metropolitan practice?
Authors: McGrail Matthew R. , Humphreys John S. , Joyce Catherine M. , Scott Anthony , Kalb Guyonne
Published: November 2011

Rural communities continue to experience shortages of doctors, placing increased work demands on the existing rural medical workforce. This paper investigates patterns of geographical variation in the workload and work activities of GPs by community size. Our data comes from wave 1 of the Medicine in Australia: Balancing Employment and Life longitudinal study, a national study of Australian doctors. Self-reported hours worked per usual week across eight workplace settings and on-call/ after-hours workload per usual week were analysed against seven community size categories. Our results showed that a GP’s total hours worked per week consistently increases as community size decreases, ranging from 38.6 up to 45.6 h in small communities, with most differences attributable to work activities of rural GPs in public hospitals. Higher on-call workload is also significantly associated with smaller rural communities, with the likelihood of GPs attending more than one callout per week ranging from 9% for metropolitan GPs up to 48–58% in small rural communities. Our study is the first to separate hours worked into different work activities whilst adjusting for community size and demographics, providing significantly greater insight to the increased hours worked, more diverse activities and significant after-hours demands experienced by current rural GPs.
Direct binding of triglyceride to fat storage-inducing transmembrane proteins 1 and 2 is important for lipid droplet formation
Authors: Gross David A. , Zhan Chenyang , Silver David L.
Published: November 2011

The process of lipid droplet (LD) formation is an evolutionarily conserved process among all eukaryotes and plays an important role in both cellular physiology and disease. Recently, fat storage-inducing transmembrane proteins 1 and 2 (FIT1/FITM1 and FIT2/FITM2) were discovered as an evolutionarily conserved family of proteins involved in fat storage. In mammals, FIT1 is expressed primarily in skeletal muscle and FIT2 is expressed primarily in adipose, raising the possibility that FIT1 and FIT2 have unique functions. These proteins are exclusively localized to the endoplasmic reticulum (ER) and mediate triglyceride-rich LD accumulation when overexpressed in cells, mouse liver, or muscle. Unlike the ER-resident diacylglycerol
O
-acyltransferase family of triglyceride-synthesizing enzymes, FITs do not synthesize triglyceride, but rather partition triglyceride into LDs. The mechanism by which FIT proteins mediate this process has not been determined. A simple hypothesis was tested that FIT proteins bind to triglyceride to mediate LD formation. Here, it is shown that FIT proteins purified in detergent micelles directly bind triolein with specificity and saturation-binding kinetics. A FIT2 gain-of-function mutant that formed larger LDs, FLL(157–9)AAA, showed increased binding to triolein relative to wild-type FIT2, whereas FIT1 and a FIT2 partial loss-of-function mutant, N80A, had significantly lower triolein binding and produced smaller LDs. In summary, FIT proteins are transmembrane domain-containing proteins shown to bind triglyceride. These findings indicate that FITs have a unique biochemical mechanism in mediating LD formation and implicates triglyceride binding as important for FIT-mediated LD formation.
Direct-coupling analysis of residue coevolution captures native contacts across many protein families
Authors: Morcos Faruck , Pagnani Andrea , Lunt Bryan , Bertolino Arianna , Marks Debora S. , Sander Chris , Zecchina Riccardo , Onuchic José N. , Hwa Terence , Weigt Martin
Published: November 2011

The similarity in the three-dimensional structures of homologous proteins imposes strong constraints on their sequence variability. It has long been suggested that the resulting correlations among amino acid compositions at different sequence positions can be exploited to infer spatial contacts within the tertiary protein structure. Crucial to this inference is the ability to disentangle direct and indirect correlations, as accomplished by the recently introduced direct-coupling analysis (DCA). Here we develop a computationally efficient implementation of DCA, which allows us to evaluate the accuracy of contact prediction by DCA for a large number of protein domains, based purely on sequence information. DCA is shown to yield a large number of correctly predicted contacts, recapitulating the global structure of the contact map for the majority of the protein domains examined. Furthermore, our analysis captures clear signals beyond intradomain residue contacts, arising, e.g., from alternative protein conformations, ligand-mediated residue couplings, and interdomain interactions in protein oligomers. Our findings suggest that contacts predicted by DCA can be used as a reliable guide to facilitate computational predictions of alternative protein conformations, protein complex formation, and even the de novo prediction of protein domain structures, contingent on the existence of a large number of homologous sequences which are being rapidly made available due to advances in genome sequencing.
The Voronoi Implicit Interface Method for computing multiphase physics
Authors: Saye Robert I. , Sethian James A.
Published: November 2011

We introduce a numerical framework, the Voronoi Implicit Interface Method for tracking multiple interacting and evolving regions (phases) whose motion is determined by complex physics (fluids, mechanics, elasticity, etc.), intricate jump conditions, internal constraints, and boundary conditions. The method works in two and three dimensions, handles tens of thousands of interfaces and separate phases, and easily and automatically handles multiple junctions, triple points, and quadruple points in two dimensions, as well as triple lines, etc., in higher dimensions. Topological changes occur naturally, with no surgery required. The method is first-order accurate at junction points/lines, and of arbitrarily high-order accuracy away from such degeneracies. The method uses a single function to describe all phases simultaneously, represented on a fixed Eulerian mesh. We test the method’s accuracy through convergence tests, and demonstrate its applications to geometric flows, accurate prediction of von Neumann’s law for multiphase curvature flow, and robustness under complex fluid flow with surface tension and large shearing forces.
Arabidopsis
lysin-motif proteins LYM1 LYM3 CERK1 mediate bacterial peptidoglycan sensing and immunity to bacterial infection
Authors: Willmann Roland , Lajunen Heini M. , Erbs Gitte , Newman Mari-Anne , Kolb Dagmar , Tsuda Kenichi , Katagiri Fumiaki , Fliegmann Judith , Bono Jean-Jacques , Cullimore Julie V. , Jehle Anna K. , Götz Friedrich , Kulik Andreas , Molinaro Antonio , Lipka Volker , Gust Andrea A. , Nürnberger Thorsten
Published: November 2011

Recognition of microbial patterns by host pattern recognition receptors is a key step in immune activation in multicellular eukaryotes. Peptidoglycans (PGNs) are major components of bacterial cell walls that possess immunity-stimulating activities in metazoans and plants. Here we show that PGN sensing and immunity to bacterial infection in
Arabidopsis thaliana
requires three lysin-motif (LysM) domain proteins. LYM1 and LYM3 are plasma membrane proteins that physically interact with PGNs and mediate
Arabidopsis
sensitivity to structurally different PGNs from Gram-negative and Gram-positive bacteria.
lym1
and
lym3
mutants lack PGN-induced changes in transcriptome activity patterns, but respond to fungus-derived chitin, a pattern structurally related to PGNs, in a wild-type manner. Notably,
lym1
,
lym3
, and
lym3 lym1
mutant genotypes exhibit supersusceptibility to infection with virulent
Pseudomonas syringae
pathovar
tomato
DC3000. Defects in basal immunity in
lym3 lym1
double mutants resemble those observed in
lym1
and
lym3
single mutants, suggesting that both proteins are part of the same recognition system. We further show that deletion of CERK1, a LysM receptor kinase that had previously been implicated in chitin perception and immunity to fungal infection in
Arabidopsis
, phenocopies defects observed in
lym1
and
lym3
mutants, such as peptidoglycan insensitivity and enhanced susceptibility to bacterial infection. Altogether, our findings suggest that plants share with metazoans the ability to recognize bacterial PGNs. However, as
Arabidopsis
LysM domain proteins LYM1, LYM3, and CERK1 form a PGN recognition system that is unrelated to metazoan PGN receptors, we propose that lineage-specific PGN perception systems have arisen through convergent evolution.
Wnt/β-catenin signaling is differentially regulated by Gα proteins and contributes to fibrous dysplasia
Authors: Regard Jean B. , Cherman Natasha , Palmer Daniel , Kuznetsov Sergei A. , Celi Francesco S. , Guettier Jean-Marc , Chen Min , Bhattacharyya Nisan , Wess Jurgen , Coughlin Shaun R. , Weinstein Lee S. , Collins Michael T. , Robey Pamela G. , Yang Yingzi
Published: November 2011

Skeletal dysplasias are common disabling disorders characterized by aberrant growth of bone and cartilage leading to abnormal skeletal structures and functions, often attributable to defects in skeletal progenitor cells. The underlying molecular and cellular mechanisms of most skeletal dysplasias remain elusive. Although the Wnt/β-catenin signaling pathway is required for skeletal progenitor cells to differentiate along the osteoblastic lineage, inappropriately elevated levels of signaling can also inhibit bone formation by suppressing osteoblast maturation. Here, we investigate interactions of the four major Gα protein families (Gαs, Gαi/o, Gαq/11, and Gα12/13) with the Wnt/β-catenin signaling pathway and identify a causative role of Wnt/β-catenin signaling in fibrous dysplasia (FD) of bone, a disease that exhibits abnormal differentiation of skeletal progenitor cells. The activating Gαsmutations that cause FD potentiated Wnt/β-catenin signaling, and removal ofGαsled to reduced Wnt/β-catenin signaling and decreased bone formation. We further show that activation of Wnt/β-catenin signaling in osteoblast progenitors results in an FD-like phenotype and reduction of β-catenin levels rescued differentiation defects of FD patient-derived stromal cells. Gα proteins may act at the level of β-catenin destruction complex assembly by binding Axin. Our results indicate that activated Gα proteins differentially regulate Wnt/β-catenin signaling but, importantly, are not required core components of Wnt/β-catenin signaling. Our data suggest that activated Gα proteins are playing physiologically significant roles during both skeletal development and disease by modulating Wnt/β-catenin signaling strength.
Truncated G protein-coupled mu opioid receptor MOR-1 splice variants are targets for highly potent opioid analgesics lacking side effects
Authors: Majumdar Susruta , Grinnell Steven , Le Rouzic Valerie , Burgman Maxim , Polikar Lisa , Ansonoff Michael , Pintar John , Pan Ying-Xian , Pasternak Gavril W.
Published: November 2011

Pain remains a pervasive problem throughout medicine, transcending all specialty boundaries. Despite the extraordinary insights into pain and its mechanisms over the past few decades, few advances have been made with analgesics. Most pain remains treated by opiates, which have significant side effects that limit their utility. We now describe a potent opiate analgesic lacking the traditional side effects associated with classical opiates, including respiratory depression, significant constipation, physical dependence, and, perhaps most important, reinforcing behavior, demonstrating that it is possible to dissociate side effects from analgesia. Evidence indicates that this agent acts through a truncated, six-transmembrane variant of the G protein-coupled mu opioid receptor MOR-1. Although truncated splice variants have been reported for a number of G protein-coupled receptors, their functional relevance has been unclear. Our evidence now suggests that truncated variants can be physiologically important through heterodimerization, even when inactive alone, and can comprise new therapeutic targets, as illustrated by our unique opioid analgesics with a vastly improved pharmacological profile.
Organelle–nucleus cross-talk regulates plant intercellular communication via plasmodesmata
Authors: Burch-Smith Tessa M. , Brunkard Jacob O. , Choi Yoon Gi , Zambryski Patricia C.
Published: November 2011

We use
Arabidopsis thaliana
embryogenesis as a model system for studying intercellular transport via plasmodesmata (PD). A forward genetic screen for altered PD transport identified
increased size exclusion limit
(
ise) 1
and
ise2
mutants with increased intercellular transport of fluorescent 10-kDa tracers. Both
ise1
and
ise2
exhibit increased formation of twinned and branched PD.
ISE1
encodes a mitochondrial DEAD-box RNA helicase, whereas
ISE2
encodes a DEVH-type RNA helicase. Here, we show that ISE2 foci are localized to the chloroplast stroma. Surprisingly, plastid development is defective in both
ise1
and
ise2
mutant embryos. In an effort to understand how RNA helicases that localize to different organelles have similar impacts on plastid and PD development/function, we performed whole-genome expression analyses. The most significantly affected class of transcripts in both mutants encode products that target to and enable plastid function. These results reinforce the importance of plastid-mitochondria-nucleus cross-talk, add PD as a critical player in the plant cell communication network, and thereby illuminate a previously undescribed signaling pathway dubbed organelle–nucleus-plasmodesmata signaling. Several genes with roles in cell wall synthesis and modification are also differentially expressed in both mutants, providing new targets for investigating PD development and function.
Molecular basis for the differential use of glucose and glutamine in cell proliferation as revealed by synchronized HeLa cells
Authors: Colombo Sergio L. , Palacios-Callender Miriam , Frakich Nanci , Carcamo Saul , Kovacs Istvan , Tudzarova Slavica , Moncada Salvador
Published: November 2011

During cell division, the activation of glycolysis is tightly regulated by the action of two ubiquitin ligases, anaphase-promoting complex/cyclosome–Cdh1 (APC/C-Cdh1) and SKP1/CUL-1/F-box protein–β-transducin repeat-containing protein (SCF-β-TrCP), which control the transient appearance and metabolic activity of the glycolysis-promoting enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase, isoform 3 (PFKFB3). We now demonstrate that the breakdown of PFKFB3 during S phase occurs specifically via a distinct residue (S
273
) within the conserved recognition site for SCF-β-TrCP. Glutaminase 1 (GLS1), the first enzyme in glutaminolysis, is also targeted for destruction by APC/C-Cdh1 and, like PFKFB3, accumulates after the activity of this ubiquitin ligase decreases in mid-to-late G1. However, our results show that GLS1 differs from PFKFB3 in that its recognition by APC/C-Cdh1 requires the presence of both a Lys-Glu-Asn box (KEN box) and a destruction box (D box) rather than a KEN box alone. Furthermore, GLS1 is not a substrate for SCF-β-TrCP and is not degraded until cells progress from S to G2/M. The presence of PFKFB3 and GLS1 coincides with increases in generation of lactate and in utilization of glutamine, respectively. The contrasting posttranslational regulation of PFKFB3 and GLS1, which we have verified by studies of ubiquitination and protein stability, suggests the different roles of glucose and glutamine at distinct stages in the cell cycle. Indeed, experiments in which synchronized cells were deprived of either of these substrates show that both glucose and glutamine are required for progression through the restriction point in mid-to-late G1, whereas glutamine is the only substrate essential for the progression through S phase into cell division.