bluuebunny/crossref_metadata_2025_split huggingface dataset:
How to make a sexy snake: estrogen activation of female sex pheromone in male red-sided garter snakes
Authors: Parker M. Rockwell , Mason Robert T. 
Published: February 2012

SUMMARY
Vertebrates indicate their genetic sex to conspecifics using secondary sexual signals, and signal expression is often activated by sex hormones. Among vertebrate signaling modalities, the least is known about how hormones influence chemical signaling. Our study species, the red-sided garter snake (Thamnophis sirtalis parietalis), is a model vertebrate for studying hormonal control of chemical signals because males completely rely on the female sex pheromone to identify potential mates among thousands of individuals. How sex hormones can influence the expression of this crucial sexual signal is largely unknown. We created two groups of experimental males for the first experiment: Sham (blank implants) and E2 (17β-estradiol implants). E2 males were vigorously courted by wild males in outdoor bioassays, and in a Y-maze E2 pheromone trails were chosen by wild males over those of small females and were indistinguishable from large female trails. Biochemically, the E2 pheromone blend was similar to that of large females, and it differed significantly from Shams. For the second experiment, we implanted males with 17β-estradiol in 2007 but removed the implants the following year (2008; Removal). That same year, we implanted a new group of males with estrogen implants (Implant). Removal males were courted by wild males in 2008 (implant intact) but not in 2009 (removed). Total pheromone quantity and quality increased following estrogen treatment, and estrogen removal re-established male-typical pheromone blends. Thus, we have shown that estrogen activates the production of female pheromone in adult red-sided garter snakes. This is the first known study to quantify both behavioral and biochemical responses in chemical signaling following sex steroid treatment of reptiles in the activation/organization context. We propose that the homogametic sex (ZZ, male) may possess the same targets for activation of sexual signal production, and the absence of the activator (17β-estradiol in this case) underlies expression of the male phenotype.
Is solid always best? Cranial performance in solid and fenestrated caecilian skulls
Authors: Kleinteich Thomas , Maddin Hillary C. , Herzen Julia , Beckmann Felix , Summers Adam P. 
Published: February 2012

SUMMARYCaecilians (Lissamphibia: Gymnophiona) are characterized by a fossorial lifestyle that appears to play a role in the many anatomical specializations in the group. The skull, in particular, has been the focus of previous studies because it is driven into the substrate for burrowing. There are two different types of skulls in caecilians: (1) stegokrotaphic, where the squamosal completely covers the temporal region and the jaw closing muscles, and (2) zygokrotaphic, with incomplete coverage of the temporal region by the squamosal. We used 3-D imaging and modeling techniques to explore the functional consequences of these skull types in an evolutionary context. We digitally converted stegokrotaphic skulls into zygokrotaphic skulls and vice versa. We also generated a third, akinetic skull type that was presumably present in extinct caecilian ancestors. We explored the benefits and costs of the different skull types under frontal loading at different head angles with finite element analysis (FEA). Surprisingly, the differences in stress distributions and bending between the three tested skull types were minimal and not significant. This suggests that the open temporal region in zygokrotaphic skulls does not lead to poorer performance during burrowing. However, the results of the FEA suggest a strong relationship between the head angle and skull performance, implying there is an optimal head angle during burrowing.
Can General Practitioner Commissioning Deliver Equity and Excellence? Evidence from Two Studies of Service Improvement in the English NHS
Authors: Gridley Kate , Spiers Gemma , Aspinal Fiona , Bernard Sylvia , Atkin Karl , Parker Gillian 
Published: February 2012

Objectives To explore some of the key assumptions underpinning the continued development of general practitioner-led commissioning in health services. Methods Qualitative data from two studies of service improvement in the English NHS were considered against England's plans for GP-led commissioning. These data were collected through in-depth interviews with a total of 187 professionals and 99 people affected by services in 10 different primary care trust areas across England between 2008 and 2009. Results Internationally, GPs are seen to have a central position in health systems. In keeping with this, the English policy places emphasis on the ‘pivotal role’ of general practitioners, considered to be ideally placed to commission in the best interests of their patients. However, our evidence suggests that general practitioners do not always have a pivotal role for all patients. Moreover, it is planned that the new commissioning groups in England will not be subject to top-down performance management and this raises the question of how agreed quality standards will be met under the proposed new system. Conclusions This paper questions the assumption that GPs are best placed to commission health services in a way that meets quality standards and leads to equitable outcomes. There is little evidence to suggest that GPs will succeed where others have failed and a risk that, without top-down performance management, service improvement will be patchy, leading to greater, not reduced, inequity.
Investigating the Governance of Autonomous Public Hospitals in England: Multi-Site Case Study of NHS Foundation Trusts
Authors: Allen Pauline , Keen Justin , Wright John , Dempster Paul , Townsend Jean , Hutchings Andrew , Street Andrew , Verzulli Rossella 
Published: February 2012

Objective To investigate the external and internal governance of NHS foundation trusts (FTs), which have increased autonomy, and local members and governors unlike other NHS trusts. Methods In depth, three-year case studies of four FTs; and analysis of national quantitative data on all FT hospitals and NHS Trust hospitals to give national context. Data included 111 interviews with managers, clinicians, governors and members, and local purchasers; observation of meetings; and analysis of FTs' documents. Results The four case study FTs were similar to other FTs. They had used their increased autonomy to develop more business-like practices. The FT regulator, Monitor, intervened only when there were reported problems in FT performance. National targets applying to the NHS also had a large effect on FT behaviour. FTs saw themselves as part of the local health economy and tried to maintain good relationships with local organisations. Relationships between governors and the FTs' executives were still developing, and not all governors felt able to hold their FT to account. The skills and experience of staff members and governors were under-used in the new governance structures. Conclusions It is easier to increase autonomy for public hospitals than to increase local accountability. Hospital managers are likely to be interested in making decisions with less central government control, whilst mechanisms for local accountability are notoriously difficult to design and operate. Further consideration of internal governance of FTs is needed. In a deteriorating financial climate, FTs should be better placed to make savings, due to their more business-like practices.
Does plugging unused combination screw holes improve the fatigue life of fixation with locking plates in comminuted supracondylar fractures of the femur?
Authors: Firoozabadi R. , McDonald E. , Nguyen T-Q. , Buckley J. M. , Kandemir U. 
Published: February 2012

Filling the empty holes in peri-articular locking plates may improve the fatigue strength of the fixation. The purpose of this in vitro study was to investigate the effect of plugging the unused holes on the fatigue life of peri-articular distal femoral plates used to fix a comminuted supracondylar fracture model.A locking/compression plate was applied to 33 synthetic femurs and then a 6 cm metaphyseal defect was created (AO Type 33-A3). The specimens were then divided into three groups: unplugged, plugged with locking screw only and fully plugged holes. They were then tested using a stepwise or run-out fatigue protocol, each applying cyclic physiological multiaxial loads.All specimens in the stepwise group failed at the 770 N load level. The mean number of cycles to failure for the stepwise specimen was 25 500 cycles (sd 1500), 28 800 cycles (sd 6300), and 26 400 cycles (sd 2300) cycles for the unplugged, screw only and fully plugged configurations, respectively (p = 0.16). The mean number of cycles to failure for the run-out specimens was 42 800 cycles (sd 10 700), 36 000 cycles (sd 7200), and 36 600 cycles (sd 10 000) for the unplugged, screw only and fully plugged configurations, respectively (p = 0.50). There were also no differences in axial or torsional stiffness between the constructs. The failures were through the screw holes at the level of comminution.In conclusion, filling the empty combination locking/compression holes in peri-articular distal femur locking plates at the level of supracondylar comminution does not increase the fatigue life of the fixation in a comminuted supracondylar femoral fracture model (AO 33-A3) with a 6 cm gap.
A prospective study comparing the functional outcome of computer-assisted and conventional total knee replacement
Authors: Hoffart H-E. , Langenstein E. , Vasak N. 
Published: February 2012

The aim of this prospective single-centre study was to assess the difference in clinical outcome between total knee replacement (TKR) using computerised navigation and that of conventional TKR. We hypothesised that navigation would give a better result at every stage within the first five years. A total of 195 patients (195 knees) with a mean age of 70.0 years (39 to 89) were allocated alternately into two treatment groups, which used either conventional instrumentation (group A, 97 knees) or a navigation system (group B, 98 knees). After five years, complete clinical scores were available for 121 patients (62%). A total of 18 patients were lost to follow-up. Compared with conventional surgery, navigated TKR resulted in a better mean Knee Society score (p = 0.008). The difference in mean Knee Society scores over time between the two groups was not constant (p = 0.006), which suggests that these groups differed in their response to surgery with time. No significant difference in the frequency of malalignment was seen between the two groups.In summary, computerised navigation resulted in a better functional outcome at five years than conventional techniques. Given the similarity in mechanical alignment between the two groups, rotational alignment may prove to be a better method of identifying differences in clinical outcome after navigated surgery.
Incidence of venous thromboembolism in elective foot and ankle surgery with and without aspirin prophylaxis
Authors: Griffiths J. T. , Matthews L. , Pearce C. J. , Calder J. D. F. 
Published: February 2012

The incidence of deep-vein thrombosis (DVT) and pulmonary embolism (PE) is thought to be low following foot and ankle surgery, but the routine use of chemoprophylaxis remains controversial. This retrospective study assessed the incidence of symptomatic venous thromboembolic (VTE) complications following a consecutive series of 2654 patients undergoing elective foot and ankle surgery. A total of 1078 patients received 75 mg aspirin as routine thromboprophylaxis between 2003 and 2006 and 1576 patients received no form of chemical thromboprophylaxis between 2007 and 2010. The overall incidence of VTE was 0.42% (DVT, 0.27%; PE, 0.15%) with 27 patients lost to follow-up. If these were included to create a worst case scenario, the overall VTE rate was 1.43%. There was no apparent protective effect against VTE by using aspirin. We conclude that the incidence of VTE following foot and ankle surgery is very low and routine use of chemoprophylaxis does not appear necessary for patients who are not in the high risk group for VTE.
The relationship between microbiology results in the second of a two-stage exchange procedure using cement spacers and the outcome after revision total joint replacement for infection
Authors: Sorlí L. , Puig L. , Torres-Claramunt R. , González A. , Alier A. , Knobel H. , Salvadó M. , Horcajada J. P. 
Published: February 2012

Patients with infected arthroplasties are normally treated with a two-stage exchange procedure using polymethylmethacrylate bone cement spacers impregnated with antibiotics. However, spacers may act as a foreign body to which micro-organisms may adhere and grow. In this study it was hypothesised that subclinical infection may be diagnosed with sonication of the surface biofilm of the spacer. The aims were to assess the presence of subclinical infection through sonication of the spacer at the time of a second-stage procedure, and to determine the relationship between subclinical infection and the clinical outcome. Of 55 patients studied, 11 (20%) were diagnosed with subclinical infection. At a mean follow-up of 12 months (interquartile range 6 to 18), clinical failure was found in 18 (32.7%) patients. Of the patients previously diagnosed with subclinical infection, 63% (7 of 11) had failed compared with 25% (11 of 44) of those without subclinical infection (odds ratio 5.25, 95% confidence interval 1.29 to 21.4, p = 0.021). Sonication of the biofilm of the surface of the spacer is useful in order to exclude subclinical infection and therefore contributes to improving the outcome after two-stage procedures.
Use of multimodal intra-operative monitoring in averting nerve injury during complex hip surgery
Authors: Sutter M. , Hersche O. , Leunig M. , Guggi T. , Dvorak J. , Eggspuehler A. 
Published: February 2012

Peripheral nerve injury is an uncommon but serious complication of hip surgery that can adversely affect the outcome. Several studies have described the use of electromyography and intra-operative sensory evoked potentials for early warning of nerve injury. We assessed the results of multimodal intra-operative monitoring during complex hip surgery. We retrospectively analysed data collected between 2001 and 2010 from 69 patients who underwent complex hip surgery by a single surgeon using multimodal intra-operative monitoring from a total pool of 7894 patients who underwent hip surgery during this period. In 24 (35%) procedures the surgeon was alerted to a possible lesion to the sciatic and/or femoral nerve. Alerts were observed most frequently during peri-acetabular osteotomy. The surgeon adapted his approach based on interpretation of the neurophysiological changes. From 69 monitored surgical procedures, there was only one true positive case of post-operative nerve injury. There were no false positives or false negatives, and the remaining 68 cases were all true negative. The sensitivity for predicting post-operative nerve injury was 100% and the specificity 100%. We conclude that it is possible and appropriate to use this method during complex hip surgery and it is effective for alerting the surgeon to the possibility of nerve injury.
Sleep Problems and Early Developmental Delay: Implications for Early Intervention Programs
Authors: Bonuck Karen , Grant Roy 
Published: February 2012

Abstract
Sleep disorders negatively impact behavior, cognition, and growth—the same areas targeted by early intervention. Conversely, developmental delays and disabilities may themselves precipitate sleep disorders. Young children with developmental delays experience sleep disorders at a higher rate than do typically developing children; the most common types are difficulties initiating or maintaining sleep and sleep disordered breathing. To date, attention has been focused on sleep problems in children with specific conditions (e.g., autism, genetic syndromes, prematurity, and seizure disorder). The authors review evidence of sleep problems' broader impact across the range of children screened for early intervention. Eligibility evaluations for early intervention address the five developmental domains: adaptive, motor, cognitive, communication, and socioemotional. Disordered sleep may be symptomatic of socioemotional and adaptive problems. Assessing sleep problems within the evaluation may help establish eligibility for early intervention services and would maximize developmental potential by ensuring timely identification, referral, and treatment.
Raman Spectrum Modification of CdSe/ZnS Quantum Dots at the Bio-conjugation to IgG Antibodies
Authors: Diaz Cano A. I. , Douda J. , Gonzalez Vargas C. R. , Gazarian K. 
Published: February 2012

ABSTRACTThe paper presents the analysis of Raman scattering spectra of non-conjugated and bio-conjugated CdSe/ZnS core–shell quantum dots in the range of Raman shifts of 80 - 2000 cm-1. Commercial CdSe/ZnS QDs covered by polymer and characterized by color emission with the maxima at 605 and 655 nm (1.89 and 2.04 eV) were used. Raman scattering spectra were measured at 300K and the excitation by the line 785.0 nm of a solid state LED. The analysis of Raman spectra has shown that the QD bio-conjugation to the immunoglobulin G (IgG) antibodies of the Pseudorabies virus is accompanied by the changes of the intensity of Raman lines related to the CdSe/ZnS core/shell QDs, PEG polymer covered QDs, the Si substrate and/or some organic groups of antibody molecules. The comparison of Raman spectra of CdSe/ZnS QDs with different sizes in non-conjugated and bio-conjugated states gives the opportunity to detect the bio-conjugation without mistake.
ZrO2 Doped with Cobalt Nanoparticles to Detect UV Radiatiion
Authors: Villa Sánchez Gerardo , Mendoza Anaya Demetrio , Gutiérrez-Wing Claudia , González Martínez. Pedro R. , Olea Mejía Oscar F. 
Published: February 2012

ABSTRACTThis paper reports the synthesis and characterization of the ZrO2:Co nanosystem, by incorporation of Co nanoparticles (CoNP) into tetragonal and monoclinic zirconia. ZrO2 was synthesized by a sol-gel process, while cobalt nanoparticles were obtained through a colloidal method by chemical reduction of a metal precursor. CoNP were incorporated by two different approaches: during the synthesis of the ZrO2 and by classical impregnation of CoNP on zirconium oxide. The size of Cobalt nanoparticles was controlled through the concentration of reducing agent (NaBH4) and passivanting agent (1-dodecanethiol). According to SEM and TEM analysis, the diameter of the zirconium oxide particles depends on the CoNP concentration added; the particle size for pure zirconia treated at 500°C is 200 nm and 180 nm for ZrO2:Co. X-Ray diffraction showed presence of the tetragonal and monoclinic zirconia, but the abundance of each one depends on the Co nanoparticles and thermally treatment.
ZrO2 Nanopowders Doped with Eu: SEM, XRD and UV Spectroscopy Studies
Authors: Villa Sánchez Gerardo , Mendoza Anaya Demetrio , Palma Palma Emmanuel , Gutiérrez Wing Claudia E. , Pérez Hernández Raúl , Olea Mejía Oscar F. , García Santibañez Federico 
Published: February 2012

ABSTRACTZirconia nanopowders doped with different concentrations of Eu were prepared by the solgel method followed by a thermal treatment at 500°C. Morphological and crystallographic characteristics were studied by scanning electron microscopy, X-Ray diffraction and UV spectroscopoy. Results showed a modification of the size of nanopowder particles when the concentration of Eu is increased from 0.0 to 4.0 wt%. Also, at lower concentration of Eu the tetragonal ZrO2 is the most abundant phase while high concentrations of Eu lead to the formation of the monoclinic phase. The UV spectroscopy of ZrO2 samples shows two main absorption peaks at 228 and 214 nm. The novel characteristics of the ZrO2 nanopowders doped with Eu allow us to propose them for use as solar UV radiation detectors.
Temperature and Time-Dependent Ion Diffusion Across Stainless Steel-Zirconium Film Interface Studied by Scanning Surface Potential.
Authors: Hawley M.E. , Hollis K.J. , Dickerson P.O. 
Published: February 2012

ABSTRACTZirconium is of interest in the development of high-density diffusion barriers in nuclear reactor applications because of its low thermal neutron absorption cross section and good thermal and mechanical properties. It is used in these applications to protect the low enriched fuel from interacting directly with the cladding material to prevent swelling and cracking of the fuel. In this work, we investigated the use of plasma spraying as a method to produce high quality, dense Zr barrier coatings over large surface areas. A thin sheet of 21Cr-6Ni-9Mn stainless steel (SS) was used as the substrate material. Both sides of the SS sheet were coated, one side at a time. A transfer arc (TA) current between a torch and the substrate was used to vary the substrate temperature to explore the effect of temperature and time on the film grain size, interface quality, and film porosity. The films were characterized using light optical microscopy (LOM), scanning probe microscopy (SPM) and Kelvin probe force microscopy (KPFM) and EDS-SEM Although the film quality did improved with temperature, at the elevated substrate temperatures used in this study, metal atoms from the substrate diffused into and, at the highest temperature and longest time, through the Zr coatings.
Characterization of InGaN and InAlN Epilayers by Microdiffraction X-Ray Reciprocal Space Mapping
Authors: Kachkanov V. , Dolbnya I.P. , O’Donnell K.P. , Lorenz K. , Pereira S. , Martin R.W. , Edwards P.R. , Watson I.M. 
Published: February 2012

ABSTRACTWe report a study of InGaN and InAlN epilayers grown on GaN/Sapphire substrates by microfocused three-dimensional X-ray Reciprocal Space Mapping (RSM). The analysis of the full volume of reciprocal space, while probing samples on the microscale with a focused X-ray beam, allows us to gain uniquely valuable information about the microstructure of III-N alloy epilayers. It is found that “seed” InGaN mosaic nanocrystallites are twisted with respect to the ensemble average and strain free. This indicates that the growth of InGaN epilayers follows the Volmer-Weber mechanism with nucleation of “seeds” on strain fields generated by thea-type dislocations which are responsible for the twist of underlying GaN mosaic blocks. In the case of InAlN epilayer formation of composition gradient was observed at the beginning of the epitaxial growth.
Enhanced Emission from InxGa1-xN-based LED Structures Using III-Nitride based Distributed Bragg Reflector
Authors: Lee K. , Kadiyala A. , Rodak L. E. , Goswami R. , Kumbham V. , Bearce B. A. , Justice J. , Peacock J. , Dawson J. M. , Hornak L. A. , Korakakis D. 
Published: February 2012

ABSTRACTInxGa1-xN-based LED structures were grown on digital AlxGa1-xN/GaN DBR substrate to enhance emission extraction. Same LED structure was grown on sapphire substrate as a comparison. LEDs grown on DBR substrate exhibited similar IV characteristics to that grown on sapphire substrate but emission-angle-dependent EL spectra were observed. Also, the resonant vertical cavity modes were observed in EL spectra of LEDs with DBR structure and compared to simulated results. Image processing analysis results show that light extraction of LEDs is enhanced with use of DBR substrate.