bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrashort Time-to-Echo MRI of the Cartilaginous Endplate: Technique and Association with Intervertebral Disk Degeneration
Authors: Law T. , Anthony M. P. , Samartzis D. , Chan Q. , Kim M. , Cheung K. , Khong P.
Published: June 2012

Introduction

An association between cartilaginous endplate (CEP) defects and intervertebral disk (IVD) degeneration has been previously suggested in animal and cadaveric studies. There have been no previous reports in the literature that describe the use of ultrashort time-to-echo (UTE) magnetic resonance imaging (MRI) to assess the CEP in humans in vivo. As such, the purpose of this study was to report the feasibility of the UTE MRI technique to assess CEP defects in humans in vivo using and to assess their relationship with IVD degeneration.

Materials and Methods

Nine volunteer subjects (mean age 43.9 years; range: 22 to 61 years) were recruited, representing 54 IVDs and 108 CEPs. The subjects underwent T2-weighted and UTE MRI to assess for the presence and severity of IVD degeneration, and for the presence of CEP defects, respectively, from T12 to S1. Intervertebral disk degeneration was graded according to the Schneiderman et al classification on T2-weighted MRI. CEP defects were defined on UTE MRI as discontinuity of high-signal over 4 consecutive images and were independently assessed by two observers.

Results

Total 37% out of 108 (34.3%) CEPs had defects, which mainly occurred at T12/L1, L1/L2, and L4/L5 ( p = 0.008). Multivariate logistic regression revealed that lower BMI ( p = 0.009) and younger ( p = 0.034) individuals had a decreased likelihood of having CEP defects. A statistically significant association was found to exist between the presence of CEP defects and IVD degeneration ( p = 0.036).A higher prevalence of degenerated IVDs with CEP defects were found at L4/5 and L5/S1, while degenerated IVDs with no CEP defects were found throughout the whole lumbar region. Mean IVD degeneration scores of the L4/5 and L5/S1 levels with CEP defects were higher in comparison to those with no CEP defects.

Conclusion

Our study demonstrates the feasibility of using UTE MRI in humans in vivo to assess the integrity of the CEP. A statistically significant association was found to exist between the presence of CEP defects and IVD degeneration. In the lower lumbar region, more severe degeneration was found to occur in the IVDs with CEP defects than in those without defects. Such imaging technology may broaden the understanding of IVD degeneration and facilitate management options that target IVD repair/regeneration. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared
Interspinous Dynamic Stabilization Using Diam Device at L5-S1 Level
Authors: Aleynik A. , Mlyavikh S. , Bokov A. , Ushakov A. , Perlmutter O.
Published: June 2012

Introduction

Interspinous stabilization has limited indications especially at L5-S1 level. But there's no description of level anatomy of L5-S1 hopeful for DIAM (Medtronic, Memphis, TN, USA) insertion in the literature.

Materials and Methods

We have suggested that short number of CT parameters could be used to check if level anatomy satisfied the requirements of good interspinous stabilization. The parameters are as follows: sagittal size of the spinous process “working part” (from yellow ligament to curved part)>13 mm, it's width from 4 to7 mm, sagittal translation of the vertebra ≤4 mm, segmental angle from 5 to 20°, interspinous height ≤14 mm, density of spinous process (Hounsfield) >200 units, height of the disk>50% (compared to the upper one), S1 spinous process slope (angle among S1 endplate line and upper edge of it's spinous process)<35°. We performed retrospective study among patients operated on L5-S1 level with DIAM device according to offered parameters (Group A - 52 patients 24 men, 28 women, mean age 39,4 ± 9,1) and group of patients, treated with decompressive operation at L5-S1 alone (Group B - 52 patients 19 men, 33 women, mean age 42.7 ± 10.1). Indication for surgery were: disсal herniations, segmental hypermobility, and lateral recess stenosis. Symptoms of leg and back pain and fail of the conservative treatment for 4 weeks were also necessary. Decompressive operations were: microdiscectomy, laminotomy, and medial facet resection. We have compared close (10 days after surgery) and remote results (24 month after surgery) by visual analog scale of pain, Oswestry disability index, patients satisfaction rate, operation time, and blood loss.

Results

In Group A, no reoperations, no unsatisfactory results, 3 satisfactory results, 49 good and excellent results, no implant failure. In Group B, 2 reoperations (unsatisfactory results), 7 satisfactory results, 43 good and excellent results. Visual analog scale for back pain; before the surgery: Group A-52.13 ± 23.5; Group B-48.09 ± 22.49 (no difference: p = 0.39); 10 days after surgery: Group A-19.8 ± 8.74, Group B-16.2 ± 8.44(difference at p = 0.02); 24 month after surgery: Group A-13.31 ± 10.73, Group B-20.17 ± 12.52 (difference at p = 0.00043). Oswestry index; before the operation: Group A 46.26 ± 15.62, Group B-51.27 ± 22.54 ( p = 0.27); 24 month after surgery: Group Я-10.26 ± 7.28, Group B-15.02 ± 10.9 ( p = 0.032). Blood loss at Group Я-110.7 ± 35.2 mL, Group B-67.4 ± 15.5 Мл( p = 0.0018). Operative time; Group A-115.5 ± 39.6 minutes, Group B-84.6 ± 26.7 minutes ( p < 0.001).

Conclusion

Interspinous dynamic stabilization using DIAM device is useful at L5-S1 level in cases where level anatomy lets you to set the device. CT is a method of choice for preoperative planning of the interspinous stabilization. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared
Can Adjacent Segment Degeneration be Reduced? Hybrid Fusions with Dynamic Topping-off versus 2-Level TLIF: Outcomes, Revisions and Complications of 104 Cases
Authors: Tuschel A. , Becker P. , Eder C. , Ogon M.
Published: June 2012

Introduction

Pedicle screw-based dynamic implants are considered to be a possibility to obtain stability and at the same time reduce the risk of the development of adjacent segment disease (ASD) in the lumbar spine. The aim of this study was to compare hybrid constructs (TLIF + adjacent dynamic stabilization) with rigid fusions (TLIF) in the lumbar spine, regarding clinical outcome, adjacent segment disease, and possible complications.

Materials and Methods

Between June 2008 and April 2010, a total of 104 patients underwent either 2-level hybrid surgery (TLIF + adjacent dynamic stabilization) (51 patients) or 2-level fusion (TLIF) (53 patients) in the lumbar spine for lumbar spinal stenosis with or without mild instability. Preoperatively, no significant differences regarding demographic factors, diagnosis or baseline outcome parameters could be found between the groups. To assess clinical outcome, SF36, Oswestry, and VAS pain scores were obtained preoperatively at last follow-up. Any revision surgery for symptomatic adjacent level degeneration and for complications was recorded. Mean follow-up was 27 months.

Results

Clinical outcome Clinical outcome parameters showed significant improvement from baseline after surgery in both groups; the difference of improvement between the two groups was statistically not significant. Adjacent segment disease In the fusion-group, the revision rate because of ASD was 7.5% compared with 5.9% in the dynamic-group. Fisher exact test showed no statistical difference in the ASD-related revision rates between both groups ( p = 0.513) Mean time until revision surgery was 15.8 months in the fusion-group and 24.3 months in the dynamic group. Complications Fusion Group: Apart from revisions due to ASD, two patients had to undergo revision surgery (1 x infection, 1 x further decompression). No failure of the hardware was noticed in the fusion-group. In the dynamic group, apart from revisions due to ASD, one patient had to undergo revision surgery due to screw-loosening after 15 months. Furthermore, one of the patients with ASD in the dynamic group had an additional loosening of the dynamic part of the rod. Another patient showed a broken dynamic rod at 12 months follow-up. Due to lack of symptoms he did not undergo revision surgery up to now. All together the implant failure rate in the dynamic group was 5.9%

Conclusion

At a mean follow-up of 27 months, clinical outcomes and ASD-related revision rates of 2-level TLIF and 2-level hybrid fusions with adjacent dynamic stabilization seem to be very comparable. There was a trend towards earlier revisions in the fusion group, but at the same time a trend towards a higher implant-failure rate could be observed in the dynamic group. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared
Generation of Wear Debris and Inflammatory Reaction around Cervical Disk Prosthesis after a Minimum of 18 Months in Vivo
Authors: Kabir K. , Deml M. , Pflugmacher R. , Wirtz D. C.
Published: June 2012

Introduction

Cervical disk replacement seems to be a promising alternative to anterior cervical fusion. However, there is still lack of information about the generation of wear particles and local reaction to these particles in human cervical spine under in vivo conditions. The authors report clinical outcome and histological findings of three revised cervical prosthesis after a minimum of 18 months in function.

Materials and Methods

We report three patients who underwent revision of their cervical disk prosthesis after a minimum of 18 months in vivo. All patients were asymptomatic for a minimum of 6 months after initial procedure. Cervicobrachialgia was the most common presentation. Pain was measured using the self-reporting Visual Analogue pain Scale (VAS). The preoperative diagnostic algorithm consists of functional X-ray, cervical MRI, myelographie, postmyelo-CT, 3-phase bone scintigraphy, and SPECT-CT. All implants were retrieved and the surrounded soft tissue was histological evaluated. All patients were fused in the affected segment.

Results

The preoperative VAS-Score was 7, 3 + /−1. All implants were retrieved without any complications. All the prostheses were surrounded by a soft fibrotic tissue. Metal and PE debris with signs of foreign body inflammatory reaction was found within the surrounding soft tissue shell of the segment. The soft tissue toward epidural space caused narrowing of epidural space. Only one patient had a loosening of one endplate, which was visible in the preoperative scintigraphy. Two patients were pain free and one patient had minor neck pain (VAS 3) without radicular pain after the revision surgery.

Conclusion

Despite the limits of our case series, the results show that generation of wear debris and inflammatory reaction to these particles exist after cervical disk replacement. Revision surgery is promising in such patients after a standardized diagnostic algorithm. One goal of the next generation of cervical disk replacement should be low generation of wear particles and less biological active wear particles. I confirm having declared any potential conflict of interest for all authors listed on this abstract No Disclosure of Interest None declared
Influence of Autologous Mononuclear Stem-Cells over Symptomatic Disk Disease in Experimental Animal Model
Authors: Vialle E. , Vialle L. , Arruda A. , Amarante C.
Published: June 2012

Introduction

Various therapeutic strategies have been used for controlling or at least slowing the degenerative cascade that leads to symptomatic disk degeneration. In this context, given its regenerative capability, stem cells (SC) therapy has shown promising results acting early on the degenerative cascade. This study aims to evaluate the influence of autologous adult mononuclear SC on the histological changes of experimentally induced disk degeneration.

Materials and Methods

After local Ethical Committee approval, 16 rabbits-New Zealand, male, 3.5 to 4.5 kg-underwent needle puncture of the three caudal lumbar intervertebral discs using a previously validated technique, and the remaining discs were used as controls. The animals received either autologous mesenchymal SC or saline solution after 2 weeks (group 1) or 2 months (group 2). Animals underwent euthanasia 8 weeks after the cell administration, and the discs were harvested for analysis. The slides were analyzed on hematoxylin-eosin stains for the presence of degeneration by a previously validated score, and by automated color morphometry, also previously validated by the authors, defining cellular size and cellular population within the nucleus pulposus (NP).

Results

Total 91 intervertebral discs (IVDs) were obtained for histological analysis, extracted from 16 animals-4 animals were excluded due to inadequate tissue preparation. The study group was divided as follows: 55 control-not punctured-IVDs and 36 experimental IVDs; were 21 have received SC and 15, isotonic saline solution. The microscopically characteristic alterations of the experimental disk degeneration have been observed in all punctured IVDs; however, some slides suggested a less intensive degeneration process and normal areas inside de nucleus pulposus, meaning recovery areas in the IVDs which have received mononuclear stem cells. Through color morphometry, significant differences favoring the SC group regarding number of cells and especially nuclear size ( p = 0.03) give indirect evidence that the injected cells survived within the NP. There was also a trend favoring the group receiving SC earlier (2 weeks).

Conclusion

Injection of SC was not able to interrupt the degenerative process triggered by disk puncture. However, the histological changes were less severe in the groups receiving cell therapy. Color morphometry showed clusters of cells within the NP, not seen in the control groups. I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes Disclosure of Interest None declared
Insights on the influence of surface roughness on photovoltaic properties of state of the art copper indium gallium diselenide thin films solar cells
Authors: Jehl Z. , Bouttemy M. , Lincot D. , Guillemoles J. F. , Gerard I. , Etcheberry A. , Voorwinden G. , Powalla M. , Naghavi N.
Published: June 2012

The influence of Cu(In,Ga)Se2 (CIGSe) surface roughness on the photovoltaic parameters of state of the art devices is reported, highlighting the importance of the roughness of the as-grown CIGSe absorbers on solar cell efficiencies. As-grown CIGSe surface is progressively smoothed using a chemical etch, and characterized by SEM, AFM, XPS, μ-Raman spectroscopy, x-ray diffraction (XRD), and reflectivity. The decrease of roughness has no marked influence on crystal structure and surface composition of the absorber. The main effect is that the total reflectivity of the CIGSe surface increases with decreasing roughness. The samples are processed into solar cells and characterized by current-voltage measurements. While the open circuit voltage (Voc) and fill factor remain constant, the short circuit current (Jsc) decreases markedly with decreasing roughness, resulting in a reduction of the solar cell efficiency from 14% down to 11%, which exceeds the expected decrease from increased reflectivity. Quantum efficiency and reflectivity measurements on complete cells are performed to analyze those effects. The influence of surface roughness on the theorical effective space charge region and diffusion length is based on a simple theoretical model. This paper discusses the comparison of CIGSe solar cells with n-i-p structures.
Observation of trapped-modes excited in double-layered symmetric electric ring resonators
Authors: Seo Bo-jeong , Kim Kwanghoon , Gug Kim Sung , Kim Areun , Cho HyungJoon , Choi EunMi
Published: June 2012

We report on experimental observations of trapped-mode resonances in double-layered symmetric electric ring resonators separated by dielectric inserts. The resulting metamaterial introduces trapped-mode resonances that were thought to be produced only by asymmetric metamaterial unit cells. Experimental verification of the newly observed trapped modes, along with the analysis of the stacked metamaterial geometry reported in this paper, opens an alternative way of forming sharp resonances in a symmetric metamaterial structure extended in all three dimensions.
InGaN solar cell requirements for high-efficiency integrated III-nitride/non-III-nitride tandem photovoltaic devices
Authors: Toledo Nikholas G. , Mishra Umesh K.
Published: June 2012

The use of InGaN photovoltaic devices as a top cell in a tandem solar cell has the potential to improve the power conversion efficiency of multi-junction devices. The effects of the InGaN top cell’s external quantum efficiency, voltage offset, and fill factor on the integrated III-nitride/non-III-nitride solar cell’s power conversion efficiency are presented. The results are summarized into the III-nitride device parameter requirements for top cell applications. The minimum acceptable area ratio between the III-nitride and non-III-nitride subcells in a 3- or 4-terminal device is also determined.
Spin-glass freezing of maghemite nanoparticles prepared by microwave plasma synthesis
Authors: Nadeem K. , Krenn H. , Traussnig T. , Würschum R. , Szabó D. V. , Letofsky-Papst I.
Published: June 2012

Magnetic properties of 6 nm maghemite nanoparticles (prepared by microwave plasma synthesis) have been studied by ac and dc magnetic measurements. Structural characterization includes x-ray diffraction and transmission electron microscopy. The temperature scans of zero field cooled/field cooled (ZFC/FC) magnetization measurements show a maximum at 75 K. The ZFC/FC data are fitted to the Brown-Néel relaxation model using uniaxial anisotropy and a log-normal size-distribution function to figure out the effective anisotropy constant Keff. Keff turns out to be larger than the anisotropy constant of bulk maghemite. Fitting of the ac susceptibility to an activated relaxation process according to the Arrhenius law provides unphysical values of the spin-flip time and activation energy. A power-law scaling shows a satisfactory fit to the ac susceptibility data and the dynamic critical exponent (zv ≈ 10) takes value between 4 and 12 which is typical for the spin-glass systems. The temperature dependence of coercivity and exchange bias shows a sharp increase toward low temperatures which is due to enhanced surface anisotropy. The source of this enhanced magnetic anisotropy comes from the disordered surface spins which get frozen at low temperatures. Memory effects and thermoremanent magnetization experiments also support the existence of spin-glass behaviour. All these magnetic measurements signify either magnetic blocking or surface spin-glass freezing at high and low temperatures, respectively.
Charge accumulation at organic semiconductor interfaces due to a permanent dipole moment and its orientational order in bilayer devices
Authors: Noguchi Yutaka , Miyazaki Yukimasa , Tanaka Yuya , Sato Naoki , Nakayama Yasuo , Schmidt Tobias D. , Brütting Wolfgang , Ishii Hisao
Published: June 2012

Charge accumulation at the organic heterointerfaces in multilayer organic light-emitting diodes (OLEDs) is an important process for understanding their device operation, efficiency, and degradation properties. Charge accumulation behavior has typically been analyzed in terms of the energy barrier and difference of the charge carrier mobility across heterointerfaces. In this study, we demonstrate that permanent dipole moments and their orientational order also play a significant role in the charge behavior at organic semiconductor interfaces. The charge accumulation properties of bilayer devices composed of polar or nonpolar molecules deposited on a 4,4’-bis[N-(1-naphthyl)-N-phenylamino]-biphenyl layer between the anode and cathode were examined by displacement current measurement and impedance spectroscopy. In addition, Kelvin probe measurements for the corresponding bilayer structures excluding the cathode were performed to analyze the relationship between the potential profile and charge accumulation properties of the bilayer devices. We found that several polar molecules including tris-(8-hydroxyquinolate) aluminum, 1,3,5-tris(1-phenyl-1 H-benzimidazol-2-yl)benzene, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP), and 1,3-bis[2-(4-tert-butylphenyl)-1,3,4-oxadiazo-5-yl]benzene (OXD-7) are spontaneously ordered in evaporated films, and orientation polarization remains in bilayer devices. Orientation polarization leads to interface charge which determines the least amount of accumulated charge in the device under operation. The estimated interface charge density for these molecules ranged from −2.3 (OXD-7) to −0.5 (BCP) mC/m2. Furthermore, impedance spectroscopy revealed that the presence of a permanent dipole moment can suppress the charge dispersion along the interface probably owing to the microscopic potential fluctuation formed in the vicinity of the interface. These results indicate that the permanent dipole moment and orientation polarization contribute to the efficient charge accumulation at organic heterointerfaces and are important parameters for understanding and controlling the charge carrier dynamics in multilayer OLEDs.
Optical properties of edge dislocations on (11¯00) prismatic planes in wurtzite ZnO introduced at elevated temperatures
Authors: Ohno Y. , Tokumoto Y. , Yonenaga I. , Fujii K. , Yao T.
Published: June 2012

An arbitrary number (3×108−1×1010 cm−2) of edge dislocations on (11¯00) prismatic planes, with the Burgers vector of (a/3)[112¯0] and with the dislocation lines nearly parallel to [0001], were introduced intentionally in wurtzite ZnO bulk single crystals at elevated temperatures of 923–1073 K, and the optical properties were examined. After the introduction of the dislocations, the intensity of the intrinsic emissions existing in pre-dislocated crystals, i.e., near-band edge emissions and deep level emissions, was almost unchanged, and donor-acceptor pair (DAP) emissions with photon energies of 2.20 and 2.50 eV at temperature of 12 K appeared. The intensity of the DAP emissions increased with increasing the dislocation density. The origin of the DAP emissions was determined as acceptor levels of 0.9 and 1.2 eV depth introduced with the dislocations.
The study of structure, magnetism, electricity, and their correlations at martensitic transition for magnetostriction system Cu1−xMnxNMn3 (0 ≤ x ≤ 0.5)
Authors: Lin J. C. , Wang B. S. , Lin S. , Tong P. , Lu W. J. , Zhang L. , Zhao B. C. , Song W. H. , Sun Y. P.
Published: June 2012

The antiperovskite functional compound CuNMn3 exhibits magnetostriction below the non-collinear ferromagnetic (FM)-paramagnetic (PM) transition (accompanied by a martensitic transformation). After the substitution of Mn for Cu, martensitic transformation is decoupled from FM transition. Meanwhile, the tetragonality of the martensitic phase and the magnetostriction are weakened. The combined analysis indicates that the spin, charge, and lattice are closely coupled around martensitic transformation temperature (TMS). The low-temperature martensitic phase is associated with a metastable magnetic state characterized by small magnetocrystalline anisotropy. Additionally, the depression of TMS with introducing the Mn dopant is revelatory for the development of low-temperature negative thermal expansion material.
Non-linear injection level dependence of the excess carrier lifetime of p-type GaSb thin films: A two-layer model
Authors: Shura M. W. , Wagener V. , Botha J. R. , Wagener M. C.
Published: June 2012

The injection dependence of the excess carrier lifetime has been investigated for undoped and zinc doped p-type gallium antimonide thin films using steady-state photoconductivity measurements. Discrepancies between the observed lifetimes and the theoretical values are resolved using a two-layer generation/recombination model. Simulation of the room temperature experimental results yields values for the surface band bending, an upper limit to the surface recombination velocity and a lower limit to the Shockley-Read-Hall carrier lifetime.
Phylogenetic assessment of pollen characters in Myrtaceae
Authors: Thornhill Andrew H. , Crisp Michael D.
Published: June 2012

Identifying synapomorphic morphological characters is needed to select and then accurately place fossils as calibrations on a phylogeny in molecular-dating analyses. The plant family Myrtaceae, with 130 genera and 5500 species, has nine different pollen types, whereas the fossil pollen record of Myrtaceae, represented by the genus Myrtaceidites, putatively extends back to the Cretaceous and also contains at least nine distinct morphospecies. To reveal potential links between extant and fossil pollen, we optimised pollen characters scored from a recent family-wide review of extant Myrtaceae pollen using scanning electron microscopy (SEM) onto a phylogeny of 111 taxa inferred from two chloroplast (matK and ndhF) and one nuclear (internal transcribed spacer, ITS) loci. Our findings indicate the potential use of colpus morphology in diagnosing pollen types in Myrtaceae, whereas the majority of character states of exine pattern, presence of apocolpial island and pollen width appear to be homoplasious. The results of the present study have implications for understanding the relationship between fossil morphospecies and extant Myrtaceae species, and their reliable choice in molecular dating.
Leucopogon extremus (Styphelieae, Styphelioideae, Ericaceae), a remarkable new species that expands the morphological circumscription of Leucopogon sens. str.
Authors: Hislop Michael , Puente-Lelievre Caroline , Crayn Darren
Published: June 2012

Leucopogon extremus Hislop & Puente-Lelievre, a new species of Leucopogon s. str. with a remarkably anomalous morphology, is described, illustrated and its distribution mapped. Its placement within the genus is confirmed through phylogenetic analyses of the plastid rbcL, matK, atpB–rbcL and trnH–psbA sequences.
Reappraisal of the genera of Megalosporaceae (Teloschistales, Ascomycota)
Authors: Kantvilas G. , Lumbsch H. T.
Published: June 2012

The status of the genera of the lichen-forming fungal family Megalosporaceae is re-examined. DNA-sequence data utilising three loci and anatomical observations pertaining to the hymenium, asci and ascospores support Megaloblastenia as a distinct genus. Austroblastenia is not supported by molecular, morphological or anatomical data, which suggest that it should be subsumed within Megalospora. Consequently, the new combinations, Megalospora pauciseptata (Shirley) Kantvilas & Lumbsch and M. pupa (Sipman) Kantvilas & Lumbsch, are proposed.
Evolutionary and taxonomic relationships of Acacia s.l. (Leguminosae: Mimosoideae)
Authors: Miller Joseph T. , Seigler David
Published: June 2012

The species of Acacia s.l. are currently undergoing a taxonomic upheaval. This is due, in large part, to recent molecular work that has confirmed previous morphological studies and concluded that the genus is not monophyletic. At least five monophyletic lineages have been defined within the genus and, largely on the basis of molecular data, these are distributed throughout the tribes Acacieae, Ingeae and Mimoseae of the Mimosoideae. We provide new and review previous molecular data used to redefine the generic classification of the genus into five segregate genera. The present study doubles the number of plastid base pairs compared with previous studies, to over 7 kb of aligned sequence. These data confirm previous clades and the present is the first to identify robust support for relationships among clades on the backbone of the phylogeny. The support for Vachellia is stronger than for any subclade within it. However, the support for Senegalia s.s. is weaker than it is for each of two subclades within it. There is no support for the former tribal classification with the enlarged dataset. The nomenclatural implications of which clades are recognised at a generic level are discussed.
Energetic costs of digestion in Australian crocodiles
Authors: Gienger C. M. , Tracy Christopher R. , Brien Matthew L. , Manolis S. Charlie , Webb Grahame J. W. , Seymour Roger S. , Christian Keith A.
Published: June 2012

We measured standard metabolic rate (SMR) and the metabolic response to feeding in the Australian crocodiles, Crocodylus porosus and C. johnsoni. Both species exhibit a response that is characterised by rapidly increasing metabolism that peaks within 24 h of feeding, a postfeeding metabolic peak (peak O2) of 1.4–2.0 times SMR, and a return to baseline metabolism within 3–4 days after feeding. Postfeeding metabolism does not significantly differ between species, and crocodiles fed intact meals have higher total digestive costs (specific dynamic action; SDA) than those fed homogenised meals. Across a more than 100-fold range of body size (0.190 to 25.96 kg body mass), SMR, peak O2, and SDA all scale with body mass to an exponent of 0.85. Hatchling (≤1 year old) C. porosus have unexpectedly high rates of resting metabolism, and this likely reflects the substantial energetic demands that accompany the rapid growth of young crocodilians.
Low-resolution solution structures of Munc18:Syntaxin protein complexes indicate an open binding mode driven by the Syntaxin N-peptide
Authors: Christie Michelle P. , Whitten Andrew E. , King Gordon J. , Hu Shu-Hong , Jarrott Russell J. , Chen Kai-En , Duff Anthony P. , Callow Philip , Collins Brett M. , James David E. , Martin Jennifer L.
Published: June 2012

When nerve cells communicate, vesicles from one neuron fuse with the presynaptic membrane releasing chemicals that signal to the next. Similarly, when insulin binds its receptor on adipocytes or muscle, glucose transporter-4 vesicles fuse with the cell membrane, allowing glucose to be imported. These essential processes require the interaction of SNARE proteins on vesicle and cell membranes, as well as the enigmatic protein Munc18 that binds the SNARE protein Syntaxin. Here, we show that in solution the neuronal protein Syntaxin1a interacts with Munc18-1 whether or not the Syntaxin1a N-peptide is present. Conversely, the adipocyte protein Syntaxin4 does not bind its partner Munc18c unless the N-peptide is present. Solution-scattering data for the Munc18-1:Syntaxin1a complex in the absence of the N-peptide indicates that this complex adopts the inhibitory closed binding mode, exemplified by a crystal structure of the complex. However, when the N-peptide is present, the solution-scattering data indicate both Syntaxin1a and Syntaxin4 adopt extended conformations in complexes with their respective Munc18 partners. The low-resolution solution structure of the open Munc18:Syntaxin binding mode was modeled using data from cross-linking/mass spectrometry, small-angle X-ray scattering, and small-angle neutron scattering with contrast variation, indicating significant differences in Munc18:Syntaxin interactions compared with the closed binding mode. Overall, our results indicate that the neuronal Munc18-1:Syntaxin1a proteins can adopt two alternate and functionally distinct binding modes, closed and open, depending on the presence of the N-peptide, whereas Munc18c:Syntaxin4 adopts only the open binding mode.
The N-end rule pathway counteracts cell death by destroying proapoptotic protein fragments
Authors: Piatkov Konstantin I. , Brower Christopher S. , Varshavsky Alexander
Published: June 2012

In the course of apoptosis, activated caspases cleave ∼500 to ∼1,000 different proteins in a mammalian cell. The dynamics of apoptosis involve a number of previously identified, caspase-generated proapoptotic protein fragments, defined as those that increase the probability of apoptosis. In contrast to activated caspases, which can be counteracted by inhibitor of apoptosis proteins, there is little understanding of antiapoptotic responses to proapoptotic protein fragments. One possibility is the regulation of proapoptotic fragments through their selective degradation. The previously identified proapoptotic fragments Cys-RIPK1, Cys-TRAF1, Asp-BRCA1, Leu-LIMK1, Tyr-NEDD9, Arg-BID, Asp-BCL
XL
, Arg-BIM
EL
, Asp-EPHA4, and Tyr-MET bear destabilizing N-terminal residues. Tellingly, the destabilizing nature (but not necessarily the actual identity) of N-terminal residues of proapoptotic fragments was invariably conserved in evolution. Here, we show that these proapoptotic fragments are short-lived substrates of the Arg/N-end rule pathway. Metabolic stabilization of at least one such fragment, Cys-RIPK1, greatly augmented the activation of the apoptosis-inducing effector caspase-3. In agreement with this understanding, even a partial ablation of the Arg/N-end rule pathway in two specific N-end rule mutants is shown to sensitize cells to apoptosis. We also found that caspases can inactivate components of the Arg/N-end rule pathway, suggesting a mutual suppression between this pathway and proapoptotic signaling. Together, these results identify a mechanistically specific and functionally broad antiapoptotic role of the Arg/N-end rule pathway. In conjunction with other apoptosis-suppressing circuits, the Arg/N-end rule pathway contributes to thresholds that prevent a transient or otherwise weak proapoptotic signal from reaching the point of commitment to apoptosis.
Determination of the Median Lethal Dose of Botulinum Serotype E in Channel Catfish Fingerlings
Authors: Chatla Kamalakar , Gaunt Patricia S. , Hanson Larry , Gao Dana X. , Wills Robert
Published: June 2012

The median lethal dose of botulinum serotype E in 5.3-g channel catfish Ictalurus punctatus fingerlings was determined. Five tanks (five fish/tank) were assigned to each of the following treatment groups: 70, 50, 35, 25, or 15 pg of purified botulinum serotype E. Fish were injected intracoelomically and observed for 96 h. Administration of the toxin resulted in initial hyperactivity followed by erratic swimming, paresis, and death. The cumulative mortality by treatment group was 100% at 70 pg, 96% at 50 pg, 100% at 35 pg, 88% at 25 pg, and 56% at 15 pg. The median lethal dose was calculated as 13.7 pg/fish (equivalent to a 0.81 median lethal dose for mice Mus musculus) using a logistic regression model. All fish were necropsied; lesions included exophthalmia, ascites, splenic congestion, intussusception of the intestines, congested spleen, and blanching of the intestinal tract. The resultant clinical signs and lesions were similar to those noted in the syndrome of visceral toxicosis of catfish. This study indicates that channel catfish are more sensitive to the effects of botulinum serotype E than laboratory mice, and the signs and lesions of visceral toxicosis of catfish were replicated by injecting catfish with the toxin.

Received October 13, 2011; accepted January 14, 2011
Comparison of Hatchery and Field Performance between a Whirling-Disease-Resistant Strain and the Ten Sleep Strain of Rainbow Trout
Authors: Wagner Eric J. , Bartley Matt , Arndt Ronney , Oplinger Randall W. , Routledge M. Douglas
Published: June 2012

A whirling-disease-resistant strain of rainbow trout Oncorhynchus mykiss (GRHL strain) derived from a backcross of an F1 hybrid of two strains (German strain × Harrison Lake strain) with German strain females, was compared with the Ten Sleep (TS) strain of rainbow trout. The GRHL strain had consistently superior growth and feed conversion in two consecutive hatchery trials. Hatching and mortality rates were similar between strains. Both strains were stocked into two Utah reservoirs (Hyrum, Porcupine), and a third, Causey Reservoir, was monitored as a control for seasonal variation in prevalence of Myxobolus cerebralis. A total of 1,323 salmonids captured by gill net in spring and fall sampling between 2006 and 2008 were tested for M. cerebralis via pepsin-trypsin digest methods. Only eight of these (<1% per species) had clinical signs consistent with whirling disease. In both reservoirs, GRHL survived better than the TS and had higher growth rates. The prevalence of M. cerebralis was significantly lower for GRHL (18.1%) than TS (50.0%) in Porcupine Reservoir. In Hyrum Reservoir the trend was similar, but prevalence was lower and did not significantly differ between GRHL (9.6%) and TS (23.1%). For infected fish, no significant differences were observed between strains in myxospore counts in either Hyrum (GRHL = 911–28,244 spores/fish [spf], TS = 1,822–155,800 spf) or Porcupine (GRHL = 333–426,667spf, TS = 333–230,511 spf) reservoirs. Unmarked rainbow trout in both reservoirs had significantly higher myxospore counts than stocked fish of either strain. There were significant differences in M. cerebralis prevalence and myxospore loads among other naturally reproducing salmonids in the reservoirs. The trend in susceptibility was cutthroat trout Oncorhynchus clarkii > kokanee Oncorhynchus nerka > brown trout Salmo trutta. The GRHL performed well in both hatchery and field settings and is recommended for stocking programs.

Received December 28, 2011; accepted February 2, 2012
Rapid communication: Physical self-similarity enhances the gaze-cueing effect
Authors: Hungr Clara J. , Hunt Amelia R.
Published: June 2012

Important social information can be gathered from the direction of another person's gaze, such as their intentions and aspects of the environment that are relevant to those intentions. Previous work has examined the effect of gaze on attention through the gaze-cueing effect: an enhancement of performance in detecting targets that appear where another person is looking. The present study investigated whether the physical self-similarity of a face could increase its impact on attention. Self-similarity was manipulated by morphing participants' faces with those of strangers. The effect of gaze direction on target detection was strongest for faces morphed with the participant's face. The results support previous work suggesting that self-similar faces are processed differently from dissimilar faces. The data also demonstrate that a face's similarity to one's own face influences the degree to which that face guides our attention in the environment.
Metric dependence and asymptotic minimization of the expected number of critical points of random holomorphic sections
Authors: Baugher Benjamin
Published: June 2012

We prove the main conjecture from Douglas, Shiffman, and Zelditch (2006) concerning the metric dependence and asymptotic minimization of the expected number

N

N
,
h

crit

\mathcal {N}^{\operatorname {crit}}_{N,h}

of critical points of random holomorphic sections of the

N
N

th tensor power of a positive line bundle. The first non-topological term in the asymptotic expansion of

N

N
,
h

crit

\mathcal {N}^{\operatorname {crit}}_{N,h}

is the Calabi functional multiplied by the constant

β
2

(
m
)

\beta _2(m)

which depends only on the dimension of the manifold. We prove that

β
2

(
m
)

\beta _2(m)

is strictly positive in all dimensions, showing that the expansion is non-topological for all

m
m

, and that the Calabi extremal metric, when it exists, asymptotically minimizes

N

N
,
h

crit

\mathcal {N}^{\operatorname {crit}}_{N,h}

.
On the quasi-hereditary property for staggered sheaves
Authors: Achar Pramod
Published: June 2012

Let

G
G

be an algebraic group over an algebraically closed field, acting on a variety

X
X

with finitely many orbits. Staggered sheaves are certain complexes of

G
G

-equivariant coherent sheaves on

X
X

that seem to possess many remarkable properties. In this paper, we construct “standard” and “costandard” objects in the category of staggered sheaves, and we prove that that category has enough projectives and injectives.
Slicely countably determined Banach spaces
Authors: Avilés Antonio , Kadets Vladimir , Martín Miguel , Merí Javier , Shepelska Varvara
Published: June 2012

We introduce the class of slicely countably determined Banach spaces which contains in particular all spaces with the Radon-Nikodým property and all spaces without copies of

ℓ
1

\ell _1

. We present many examples and several properties of this class. We give some applications to Banach spaces with the Daugavet and the alternative Daugavet properties, lush spaces and Banach spaces with numerical index 

1
1

. In particular, we show that the dual of a real infinite-dimensional Banach space with the alternative Daugavet property contains

ℓ
1

\ell _1

and that operators which do not fix copies of

ℓ
1

\ell _1

on a space with the alternative Daugavet property satisfy the alternative Daugavet equation.
Cauchy problem of nonlinear Schrödinger equation with initial data in Sobolev space 𝑊^{𝑠,𝑝} for 𝑝<2
Authors: Zhou Yi
Published: June 2012

In this paper, we consider in

R
n

R^n

the Cauchy problem for the nonlinear Schrödinger equation with initial data in the Sobolev space

W

s
,
p

W^{s,p}

for

p
>
2

p>2

. It is well known that this problem is ill posed. However, we show that after a linear transformation by the linear semigroup the problem becomes locally well posed in

W

s
,
p

W^{s,p}

for

2
n

n
+
1

>
p
>
2

\frac {2n}{n+1}>p>2

and

s
>
n
(
1
−

1
p

)

s>n(1-\frac {1}{p})

. Moreover, we show that in one space dimension, the problem is locally well posed in

L
p

L^p

for any

1
>
p
>
2

1>p>2

.
Flows without wandering points on compact connected surfaces
Authors: Cobo Milton , Gutierrez Carlos , Llibre Jaume
Published: June 2012

Given a compact

2
2

–dimensional manifold

M
M

we classify all continuous flows

φ
\varphi

without wandering points on

M
M

. This classification is performed by finding finitely many pairwise disjoint open

φ
−

\varphi -

invariant subsets

{

U
1

,

U
2

,
…
,

U
n

}

\{U_1, U_2, \ldots , U_n\}

of

M
M

such that

⋃

i
=
1

n

U
i

¯

=
M

\bigcup _{i=1}^n{\overline {U_i}} = M

and each

U
i

U_i

is either a suspension of an interval exchange transformation, or a maximal open cylinder made up of closed trajectories of

φ
\varphi

.
Quantum rotatability
Authors: Curran Stephen
Published: June 2012

Recently, Köstler and Speicher showed that de Finetti’s theorem on exchangeable sequences has a free analogue if one replaces exchangeability by the stronger condition of invariance of the joint distribution under quantum permutations. In this paper we study sequences of noncommutative random variables whose joint distribution is invariant under quantum orthogonal transformations. We prove a free analogue of Freedman’s characterization of conditionally independent Gaussian families; namely, the joint distribution of an infinite sequence of self-adjoint random variables is invariant under quantum orthogonal transformations if and only if the variables form an operator-valued free centered semicircular family with common variance. Similarly, we show that the joint distribution of an infinite sequence of random variables is invariant under quantum unitary transformations if and only if the variables form an operator-valued free centered circular family with common variance.

We provide an example to show that, as in the classical case, these results fail for finite sequences. We then give an approximation for how far the distribution of a finite quantum orthogonally invariant sequence is from the distribution of an operator-valued free centered semicircular family with common variance.
The homotopy fixed point spectra of profinite Galois extensions
Authors: Behrens Mark , Davis Daniel
Published: June 2012

LetEEbe akk-local profiniteGG-Galois extension of anE∞E_\infty-ring spectrumAA(in the sense of Rognes). We show thatEEmay be regarded as producing a discreteGG-spectrum. Also, we prove that ifEEis a profaithfulkk-local profinite extension which satisfies certain extra conditions, then the forward direction of Rognes’s Galois correspondence extends to the profinite setting. We show that the function spectrum<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper F Subscript upper A Baseline left-parenthesis left-parenthesis upper E Superscript h upper H Baseline right-parenthesis Subscript k Baseline comma left-parenthesis upper E Superscript h upper K Baseline right-parenthesis Subscript k Baseline right-parenthesis">FA((EhH)k,(EhK)k)F_A((E^{hH})_k, (E^{hK})_k)is equivalent to the localized homotopy fixed point spectrum((E[[G/H]])hK)k((E[[G/H]])^{hK})_k, whereHHandKKare closed subgroups ofGG. Applications to MoravaEE-theory are given, including showing that the homotopy fixed points defined by Devinatz and Hopkins for closed subgroups of the extended Morava stabilizer group agree with those defined with respect to a continuous action in terms of the derived functor of fixed points.
Outlet points and homogeneous continua
Authors: Krupski Paweł , Prajs Janusz R.
Published: June 2012

(1) A proof is presented for Bing’s conjecture that homogeneous, treelike continua are hereditarily indecomposable. As a consequence, each homogeneous curve admits the continuous decomposition into the maximal terminal, homeomorphic, homogeneous, hereditarily indecomposable, treelike subcontinua. (2) A homogeneous, hereditarily unicoherent continuum contains either an arc or arbitrarily small, nondegenerate, indecomposable subcontinua. (3) A treelike continuum with property

K
K

which is homogeneous with respect to confluent light mappings contains no two nondegenerate subcontinua with the one-point intersection.
Topological equivalence of foliations of homogeneous spaces
Authors: Witte Dave
Published: June 2012

For

i
=
1
,
2

i = 1,2

, let

Γ
i

{\Gamma _i}

be a lattice in a connected Lie group

G
i

{G_i}

, and let

X
i

{X_i}

be a connected Lie subgroup of

G
i

{G_i}

. The double cosets

Γ
i

g

X
i

{\Gamma _i}g{X_i}

provide a foliation

F

i

{\mathcal {F}_i}

of the homogeneous space

Γ
i

∖

G
i

{\Gamma _i}\backslash {G_i}

. Assume that

X
1

{X_1}

and

X
2

{X_2}

are unimodular and that

F

1

{\mathcal {F}_1}

has a dense leaf. If

G
1

{G_1}

and

G
2

{G_2}

are semisimple groups to which the Mostow Rigidity Theorem applies, or are simply connected nilpotent groups (or are certain more general solvable groups), we use an idea of D. Benardete to show that any topological equivalence of

F

1

{\mathcal {F}_1}

and

F

2

{\mathcal {F}_2}

must be the composition of two very elementary maps: an affine map and a map that takes each leaf to itself.
Rapidly decreasing functions in reduced 𝐶*-algebras of groups
Authors: Jolissaint Paul
Published: June 2012

Let

Γ
\Gamma

be a group. We associate to any length-function

L
L

on

Γ
\Gamma

the space

H
L
∞

(
Γ
)

H_L^\infty (\Gamma )

of rapidly decreasing functions on

Γ
\Gamma

(with respect to

L
L

), which coincides with the space of smooth functions on the

k
k

-dimensional torus when

Γ
=

Z

k

\Gamma = {{\bf {Z}}^k}

. We say that

Γ
\Gamma

has property (RD) if there exists a length-function

L
L

on

Γ
\Gamma

such that

H
L
∞

(
Γ
)

H_L^\infty (\Gamma )

is contained in the reduced

C
∗

{C^*}

-algebra

C
r
∗

(
Γ
)

C_r^*(\Gamma )

of

Γ
\Gamma

. We study the stability of property (RD) with respect to some constructions of groups such as subgroups, over-groups of finite index, semidirect and amalgamated products. Finally, we show that the following groups have property (RD): (1) Finitely generated groups of polynomial growth; (2) Discrete cocompact subgroups of the group of all isometries of any hyperbolic space.