bluuebunny/crossref_metadata_2025 huggingface dataset:
Regulation of Centromere Localization of the Drosophila Shugoshin MEI-S332 and Sister-Chromatid Cohesion in Meiosis
Authors: Nogueira Cristina , Kashevsky Helena , Pinto Belinda , Clarke Astrid , Orr-Weaver Terry L
Published: August 2014

The Shugoshin (Sgo) protein family helps to ensure proper chromosome segregation by protecting cohesion at the centromere by preventing cleavage of the cohesin complex. Some Sgo proteins also influence other aspects of kinetochore-microtubule attachments. Although many Sgo members require Aurora B kinase to localize to the centromere, factors controlling delocalization are poorly understood and diverse. Moreover, it is not clear how Sgo function is inactivated and whether this is distinct from delocalization. We investigated these questions in Drosophila melanogaster, an organism with superb chromosome cytology to monitor Sgo localization and quantitative assays to test its function in sister-chromatid segregation in meiosis. Previous research showed that in mitosis in cell culture, phosphorylation of the Drosophila Sgo, MEI-S332, by Aurora B promotes centromere localization, whereas Polo phosphorylation promotes delocalization. These studies also suggested that MEI-S332 can be inactivated independently of delocalization, a conclusion supported here by localization and function studies in meiosis. Phosphoresistant and phosphomimetic mutants for the Aurora B and Polo phosphorylation sites were examined for effects on MEI-S332 localization and chromosome segregation in meiosis. Strikingly, MEI-S332 with a phosphomimetic mutation in the Aurora B phosphorylation site prematurely dissociates from the centromeres in meiosis I. Despite the absence of MEI-S332 on meiosis II centromeres in male meiosis, sister chromatids segregate normally, demonstrating that detectable levels of this Sgo are not essential for chromosome congression, kinetochore biorientation, or spindle assembly.
Sporadic Distribution of Prion-Forming Ability of Sup35p from Yeasts and Fungi
Authors: Edskes Herman K , Khamar Hima J , Winchester Chia-Lin , Greenler Alexandria J , Zhou Albert , McGlinchey Ryan P , Gorkovskiy Anton , Wickner Reed B
Published: August 2014

Sup35p of Saccharomyces cerevisiae can form the [PSI+] prion, an infectious amyloid in which the protein is largely inactive. The part of Sup35p that forms the amyloid is the region normally involved in control of mRNA turnover. The formation of [PSI+] by Sup35p’s from other yeasts has been interpreted to imply that the prion-forming ability of Sup35p is conserved in evolution, and thus of survival/fitness/evolutionary value to these organisms. We surveyed a larger number of yeast and fungal species by the same criteria as used previously and find that the Sup35p from many species cannot form prions. [PSI+] could be formed by the Sup35p from Candida albicans, Candida maltosa, Debaromyces hansenii, and Kluyveromyces lactis, but orders of magnitude less often than the S. cerevisiae  Sup35p converts to the prion form. The Sup35s from Schizosaccharomyces pombe and Ashbya gossypii clearly do not form [PSI+]. We were also unable to detect [PSI+] formation by the Sup35ps from Aspergillus nidulans, Aspergillus fumigatus, Magnaporthe grisea, Ustilago maydis, or Cryptococcus neoformans. Each of two C. albicans SUP35 alleles can form [PSI+], but transmission from one to the other is partially blocked. These results suggest that the prion-forming ability of Sup35p is not a conserved trait, but is an occasional deleterious side effect of a protein domain conserved for another function.
Expansion of CAG Repeats in Escherichia coli Is Controlled by Single-Strand DNA Exonucleases of Both Polarities
Authors: Jackson Adam , Okely Ewa A , Leach David R F
Published: August 2014

The expansion of CAG·CTG repeat tracts is responsible for several neurodegenerative diseases, including Huntington disease and myotonic dystrophy. Understanding the molecular mechanism of CAG·CTG repeat tract expansion is therefore important if we are to develop medical interventions limiting expansion rates. Escherichia coli provides a simple and tractable model system to understand the fundamental properties of these DNA sequences, with the potential to suggest pathways that might be conserved in humans or to highlight differences in behavior that could signal the existence of human-specific factors affecting repeat array processing. We have addressed the genetics of CAG·CTG repeat expansion in E. coli and shown that these repeat arrays expand via an orientation-independent mechanism that contrasts with the orientation dependence of CAG·CTG repeat tract contraction. The helicase Rep contributes to the orientation dependence of repeat tract contraction and limits repeat tract expansion in both orientations. However, RuvAB-dependent fork reversal, which occurs in a rep mutant, is not responsible for the observed increase in expansions. The frequency of repeat tract expansion is controlled by both the 5′–3′ exonuclease RecJ and the 3′–5′ exonuclease ExoI, observations that suggest the importance of both 3′and 5′ single-strand ends in the pathway of CAG·CTG repeat tract expansion. We discuss the relevance of our results to two competing models of repeat tract expansion.
A Genome-Wide Survey of Sexually Dimorphic Expression of Drosophila miRNAs Identifies the Steroid Hormone-Induced miRNA let-7 as a Regulator of Sexual Identity
Authors: Fagegaltier Delphine , König Annekatrin , Gordon Assaf , Lai Eric C , Gingeras Thomas R , Hannon Gregory J , Shcherbata Halyna R
Published: August 2014

MiRNAs bear an increasing number of functions throughout development and in the aging adult. Here we address their role in establishing sexually dimorphic traits and sexual identity in male and female Drosophila. Our survey of miRNA populations in each sex identifies sets of miRNAs differentially expressed in male and female tissues across various stages of development. The pervasive sex-biased expression of miRNAs generally increases with the complexity and sexual dimorphism of tissues, gonads revealing the most striking biases. We find that the male-specific regulation of the X chromosome is relevant to miRNA expression on two levels. First, in the male gonad, testis-biased miRNAs tend to reside on the X chromosome. Second, in the soma, X-linked miRNAs do not systematically rely on dosage compensation. We set out to address the importance of a sex-biased expression of miRNAs in establishing sexually dimorphic traits. Our study of the conserved let-7-C miRNA cluster controlled by the sex-biased hormone ecdysone places let-7 as a primary modulator of the sex-determination hierarchy. Flies with modified let-7 levels present doublesex-related phenotypes and express sex-determination genes normally restricted to the opposite sex. In testes and ovaries, alterations of the ecdysone-induced let-7 result in aberrant gonadal somatic cell behavior and non-cell-autonomous defects in early germline differentiation. Gonadal defects as well as aberrant expression of sex-determination genes persist in aging adults under hormonal control. Together, our findings place ecdysone and let-7 as modulators of a somatic systemic signal that helps establish and sustain sexual identity in males and females and differentiation in gonads. This work establishes the foundation for a role of miRNAs in sexual dimorphism and demonstrates that similar to vertebrate hormonal control of cellular sexual identity exists in Drosophila.
Family-Centered Developmentally Supportive Care
Authors: Westrup Björn
Published: August 2014

The prematurely born infant is probably the most vulnerable patient in our hospitals due to his or her immaturity. Over recent years, the importance of neurodevelopmentally supportive care has become more obvious. In addition, to provide the best possible treatment and environmental conditions for the vital functions of the infant to properly develop, we also have to support the psychological processes of bonding and attachment between parents and infant, which are so crucial for long-term health and development. By integrating scientific findings from natural and behavioral sciences, multidisciplinary developmentally supportive interventions programs, recommendations for redesigning nurseries, and integrating families have developed to meet these challenges. It not only is “infant and family friendly” but has economic benefits and improves the long-term development of the child. The basis of family-centered, developmentally supportive care interventions is the recognition that the newborn infant is a human being in his or her own right, and letting the caregivers be guided by the current needs of the individual infant and family. Care and intervention based on the infant's own behavior makes good biological sense and is also ethically attractive.
Biotic impacts of energy development from shale: research priorities and knowledge gaps
Authors: Souther Sara , Tingley Morgan W , Popescu Viorel D , Hayman David TS , Ryan Maureen E , Graves Tabitha A , Hartl Brett , Terrell Kimberly
Published: August 2014

Although shale drilling operations for oil and natural gas have increased greatly in the past decade, few studies directly quantify the impacts of shale development on plants and wildlife. We evaluate knowledge gaps related to shale development and prioritize research needs using a quantitative framework that includes spatial and temporal extent, mitigation difficulty, and current level of understanding. Identified threats to biota from shale development include: surface and groundwater contamination; diminished stream flow; stream siltation; habitat loss and fragmentation; localized air, noise, and light pollution; climate change; and cumulative impacts. We find the highest research priorities to be probabilistic threats (underground chemical migration; contaminant release during storage, during disposal, or from accidents; and cumulative impacts), the study of which will require major scientific coordination among researchers, industry, and government decision makers. Taken together, our research prioritization outlines a way forward to better understand how energy development affects the natural world.
Meta‐Analysis of the Effect of Nitrogen Fertilization on Annual Cereal–Legume Intercrop Production
Authors: Pelzer Elise , Hombert Nicolas , Jeuffroy Marie-Hélène , Makowski David
Published: August 2014

Numerous studies have been performed to study the effect of N fertilization on cereal–legume intercrops, and their results are sometimes conflicting. Our objective was to do a meta‐analysis on cereal–legume intercrops testing the effects of N fertilization on land equivalent ration (LER; partial and total LER), yield ratio, and proportion of legume in the mixture of crop grains. This analysis was based on 17 published studies reporting the results of experiments performed in 15 countries on six species of cereals and 10 species of legumes. Experiments were generally based on replacement (50–50, i.e., in the intercrop, each species is sown at half the sowing rate used for the sole crop) or full substitutive (100–100, i.e., the sowing rate for each crop in the intercrop is identical to that for sole crops) designs. Nitrogen fertilization rates ranged from 0 to 180 kg N ha−1. The effect of N fertilization and its inter‐study variability were analyzed with mixed‐effect statistical models, including study as a random effect. Results showed that N fertilization had non‐significant effects on average LER and average yield ratio but that the inter‐study variability of these effects was large. Nitrogen fertilization was found to significantly decrease the grain proportion of the legume in the mixture and the partial LER of the legume in studies based on C3 cereal intercrops. The database used for the meta‐analysis is freely available (http://www6.versailles‐grignon.inra.fr/agronomie/Meta‐analysis‐in‐agronomy/Datasets/Dataset‐Intercrop).
Full‐Season Retrospectives on Causes of Plant‐to‐Plant Variability in Maize Grain Yield Response to Nitrogen and Tillage
Authors: Kovács Péter , Vyn Tony J.
Published: August 2014

Maize (Zea maysL.) plant‐to‐plant variability at different plant densities and N fertilizer rates has been studied previously, but little attention has been devoted to consequences of different N placement and tillage management on plant variability in kernel number (KN) and grain yield. This study investigated effects of pre‐plant N placement relative to intended maize rows on the origin and magnitude of plant‐to‐plant variability in per‐plant grain weights (GW). Field studies compared two “shallow” anhydrous ammonia (NH3) placement directions (diagonal to future row vs. parallel but 15‐cm offset from the row) in both no‐till and conventional tillage systems at two N rates (145 and 202 kg N ha−1). Maize was planted with starter fertilizer (20 kg N ha−1) within 6 d following NH3application. Aboveground growth and development was monitored on bar‐coded plants from seedling emergence to maturity. Plant‐to‐plant uniformity in GW and KN was not improved by parallel NH3placement, conventional tillage, or a higher N rate; however, all three factors resulted in a slight shift towards higher mean GW and KN. Within‐row plant spacing and relative seedling emergence time had little influence on relative GW. Within‐row differences in silk emergence timing and estimated stem volumes were the most highly correlated parameters to per‐plant GW. Regression models confirmed that either of these mid‐silking factors explained >50% of such GW variations within most treatment combinations. Even in management systems with conventional tillage and precision N fertilizer placements, precision seed placement alone will not guarantee low variability in per‐plant GW.
Stover Quality and Soil Organic Carbon in Long‐Term Nitrogen‐Fertilized Maize
Authors: Melchiori Ricardo J. M. , Novelli Leonardo E. , Gregorutti Viviana C. , Caviglia Octavio P.
Published: August 2014

Nitrogen fertilization often increases maize (Zea mays L.) grain yield but reduces the C/N ratio of stover returned to the soil, which may affect the soil organic carbon (SOC) balance. This study evaluated the long‐term effect of N fertilization on maize grain yield, stover quality in terms of its C/N ratio, and its effect on SOC. In addition, a simulation approach was used to account for the effect of stover quality on its mineralization and SOC balance. Maize grain yield, stover production and quality, and SOC stock were measured during a 6‐yr period (2006–2012) in a long‐term N fertilization experiment under continuous maize since 1994 in Paraná, Argentina. On average, grain yield ranged from 5.06 in 2011 to 9.10 Mg ha−1in 2009. The N effect on grain yield, significant in all seasons, was more important than the effect on C stover production. In contrast, stover C/N ratio showed a linear decrease as a function of N fertilization. Changes in the stover C/N ratio were inversely proportional to the difference between the N rate and the agronomical optimum nitrogen rate (AONR). Although N fertilization increased stover C inputs in 3 out of 6 yr, SOC stock remained unchanged. Simulation results indicate that the required stover amount to maintain the SOC stock increased as the C/N ratio decreased. Our results contribute to better understanding of the previous, controversial results of the N effect on SOC and provide useful insights to develop or improve simulation models for SOC dynamics.
Impaired Judgment: The Effects of Asset Impairment Reversibility and Cognitive Dissonance on Future Investment
Authors: Rennekamp Kristina , Rupar Kathy K. , Seybert Nicholas
Published: August 2014

This paper examines how the reversibility of the accounting effect of asset impairments affects managers' investment decisions. We conduct two experiments in which participants act as CEO of a multi-division electronics company that suffers a large asset impairment at one of the divisions. Drawing on prior psychology research involving cognitive dissonance and decision reversibility, we predict and find that managers who are responsible for the decision to record the asset impairment invest more in the impaired division when the accounting effect of the impairment is reversible than when it is irreversible. This is consistent with the idea that reversible accounting effects encourage behavioral attempts to alter the cash flow outcome, while irreversible accounting effects encourage belief revision to rationalize the cash flow outcome. Also in line with cognitive dissonance theory, we show that managers who are not responsible for the decision to impair the asset, or managers who are given the opportunity to deny responsibility for the asset impairment, do not differ in their investment in the impaired division, regardless of impairment reversibility.
The Effect of Sandblasting and Different Primers on Shear Bond Strength Between Yttria-tetragonal Zirconia Polycrystal Ceramic and a Self-adhesive Resin Cement
Authors: Yi Y-A , Ahn J-S , Park Y-J , Jun S-H , Lee I-B , Cho B-H , Son H-H , Seo D-G
Published: August 2014

Purpose

To evaluate the effect of zirconia primers, air-abrasion, and tribochemical surface treatment methods on the shear bond strength between yttria-tetragonal zirconia polycrystal (Y-TZP) ceramic and self-adhesive resin cement.

Methods and Materials

Y-TZP ceramic surfaces were ground flat with 600-grit silicon carbide paper and then divided into seven groups of 10 and treated as follows: untreated (control), Monobond Plus, Z-PRIME Plus, ESPE Sil with CoJet, air-abrasion, Monobond Plus with air-abrasion, and Z-PRIME Plus with air-abrasion. Self-adhesive resin cement was placed onto the treated Y-TZP specimens for each group. All specimens were thermocycled and subjected to a shear bond strength test. Scanning electron microscope images of the fractured areas and x-ray diffraction (XRD) analysis of the surface-treated Y-TZP specimens were performed. Data were statistically analyzed using one-way analysis of variance and the Student-Newman-Keuls multiple comparison test (p<0.05).

Results

The Z-PRIME Plus treatment in combination with air-abrasion produced the highest bond strength (16.50±2.26 MPa), followed by air-abrasion (10.56±3.32 MPa), and then Monobond Plus combined with air-abrasion (8.93±3.13 MPa), ESPE Sil after CoJet application (8.54±3.98 MPa), and the Z-PRIME Plus group (8.27±2.79 MPa). The control (3.91±0.72 MPa) and Monobond Plus (4.86±1.77 MPa) groups indicated the lowest results (p<0.05). The XRD results showed the peaks of the monoclinic phase for the air-abrasion and CoJet treatment groups compared with the Y-TZP control.

Conclusion

Z-PRIME Plus primer application after air-abrasion presented the best results for improving the bond strength between Y-TZP ceramic and self-adhesive resin cement.
Evaluation of Flexural, Diametral Tensile, and Shear Bond Strength of Composite Repairs
Authors: Imbery TA , Gray T , DeLatour F , Boxx C , Best AM , Moon PC
Published: August 2014

Objective

Repairing composite restorations may be a more conservative treatment than replacing the entire restoration. The objective of this in vitro study was to determine the best repair method by measuring flexural, diametral tensile, and shear bond strength of repaired composites in which the surfaces were treated with chemical primers (Add & Bond or Silane Bond Enhancer), a bonding agent (Optibond Solo Plus [OBSP]), or mechanical retention with a bonding agent.

Methods

Filtek Supreme Ultra shade B1B was placed in special molds to fabricate specimens that served to test the flexural, diametral tensile, or shear strength of the inherent resin substrate. The same molds were modified to make specimens for testing repair strength of the resin. Repairs were made immediately or after aging in deionized water at 37°C for seven days. All repair sites were finished with coarse Sof-Lex discs to simulate finishing new restorations or partially removing aged restorations. Repair surfaces were treated with one of the following: 1) phosphoric-acid etching and OBSP; 2) Add & Bond; 3) phosphoric-acid etching, Silane Bond Enhancer, and OBSP; or 4) quarter round bur, phosphoric-acid etching, and OBSP. Specimens were placed back in the original molds to fabricate specimens for diametral tensile or flexural testing or in an Ultradent jig to make specimens for shear bond testing. Composite resin in shade B5B was polymerized against the treated surfaces to make repairs. Two negative control groups for the three testing methods consisted of specimens in which repairs were made immediately or after aging without any surface treatments. Controls and experimental repairs were aged (water 37°C, 24 hours) before flexural, diametral tensile, or shear testing in an Instron Universal testing machine at a crosshead speed of 0.5 mm/min.

Results

Experimental flexural repair strengths ranged from 26.4% to 88.6% of the inherent substrate strength. Diametral tensile repair strengths ranged from 40% to 80% of the inherent substrate strength, and shear bond strength repairs ranged from 56% to 102%. Geometric means were statistically analyzed with two-way analysis of variance on their log-transformed values. Significant differences were determined using Tukey honestly significant difference (p<0.05).

Conclusions

Depending on the mechanical property being tested, surface treatments produced different results. OBSP produced more consistent results than chemical primers.
Pelvic-Floor Muscle Rehabilitation in Erectile Dysfunction and Premature Ejaculation
Authors: Lavoisier Pierre , Roy Pascal , Dantony Emmanuelle , Watrelot Antoine , Ruggeri Jean , Dumoulin Sébastien
Published: August 2014

Background

In men, involuntary or voluntary ischiocavernosus muscle contractions after erection lead to intracavernous blood pressures far higher than the systolic pressure, which builds and maintains penile rigidity. Thus, erectile dysfunction may be partly due to ischiocavernosus muscle atrophy and may be treated by rehabilitation interventions.

Objective

The purpose of this study was to determine whether pelvic-floor muscle strengthening interventions could be associated with increases in intracavernous pressure that would increase penile rigidity.

Design

An observational study was conducted.

Methods

One hundred twenty-two men with isolated erectile dysfunction and 108 men with isolated premature ejaculation participated (no neuromuscular diseases or previous perineal rehabilitation). Thirty-minute sessions of voluntary contractions coupled with electrical stimulation were designed to increase ischiocavernosus muscle strength (monitored through intracavernous pressure increase). A linear mixed-effects model per group analyzed separately, then jointly, the maximum change in pressure (ΔP) and the maximum baseline (ie, respectively, the average contraction-generated difference in intracavernous pressure and the intracavernous pressure plateau at full erection, both measured during the highest moving average of the best 2 minutes of each session).

Results

Over 20 sessions, the maximum ΔP increased in erectile dysfunction as well as in premature ejaculation (87% and 88%, respectively, in men with positive trends). The maximum baseline also increased (99% and 72%, respectively, in men with positive trends). The joint modeling indicated that the mean expected progressions of the intracavernous pressure after 5 sessions in erectile dysfunction and premature ejaculation were 62.85 and 64.15 cm H2O, respectively.

Limitations

Indirect measurements were obtained of intracavernous pressure and ischiocavernosus muscle force.

Conclusions

Pelvic-floor muscle rehabilitation was found to be beneficial in erectile dysfunction. However, its effects on symptoms of premature ejaculation, despite intracavernous pressure gains, were much more difficult to assess. The definitive proof of its benefits requires rather difficult-to-design clinical trials.
Effects of Moderate- Versus High-Intensity Exercise Training on Physical Fitness and Physical Function in People With Type 2 Diabetes: A Randomized Clinical Trial
Authors: Taylor J. David , Fletcher James P. , Mathis Ruth Ann , Cade W. Todd
Published: August 2014

Background

Exercise training is effective for improving physical fitness and physical function in people with type 2 diabetes. However, limited research has been conducted on the optimal exercise training intensity for this population.

Objective

The primary study objective was to investigate the effects of moderate- versus high-intensity exercise training on physical fitness and physical function in people with type 2 diabetes.

Design

This was a randomized clinical trial.

Setting

The setting was a university campus.

Participants

Twenty-one people with type 2 diabetes were randomly allocated to receive either moderate-intensity training (MOD group) or high-intensity training (HIGH group).

Intervention

The MOD group performed resistance training at an intensity of 75% of the 8-repetition maximum (8-RM) and aerobic training at an intensity of 30% to 45% of the heart rate reserve (HRR). The HIGH group performed resistance training at an intensity of 100% of the 8-RM and aerobic training at an intensity of 50% to 65% of the HRR.

Measurements

Muscle strength (peak torque [newton-meters]), exercise capacity (graded exercise test duration [minutes]), and physical function (Patient-Specific Functional Scale questionnaire) were measured at baseline and 3 months later. Acute exercise-induced changes in glucose levels were assessed immediately before exercise, immediately after exercise, and 1 hour after exercise during the first exercise training session.

Results

Although both groups showed improvements in physical fitness and physical function, the between-group effect sizes were not statistically significant (exercise capacity estimated marginal mean [EMM] difference=2.1, 95% confidence interval [95% CI]=−0.2, 4.5; muscle strength EMM difference=20.8, 95% CI=−23.3, 65.0; and physical function EMM difference=0.1, 95% CI=−0.6, 0.9). Mean percent changes in glucose levels measured immediately before exercise and immediately after exercise, immediately after exercise and 1 hour after exercise, and immediately before exercise and 1 hour after exercise for the MOD group were −11.4%, −5.0%, and −15.8%, respectively; those for the HIGH group were −21.5%, 7.9%, and −15.3%, respectively.

Limitations

Sample size, lack of outcome assessor masking, and physical function measurement subjectivity were limitations.

Conclusions

Moderate- and high-intensity exercise training, as defined in this study, may lead to similar improvements in physical fitness and physical function in people with type 2 diabetes.
Four treatment failures of pharyngeal gonorrhoea with ceftriaxone (500 mg) or cefotaxime (500 mg), Sweden, 2013 and 2014
Authors: Golparian D , Ohlsson A K , Janson H , Lidbrink P , Richtner T , Ekelund O , Fredlund H , Unemo M
Published: August 2014

We describe four cases in Sweden of verified treatment failures of pharyngeal gonorrhoea with ceftriaxone (500 mg; n=3) or cefotaxime (500 mg; n=1) monotherapy. All the ceftriaxone treatment failures were caused by the internationally spreading multidrug-resistant gonococcal NG-MAST genogroup 1407 clone. Increased awareness of treatment failures is crucial particularly when antimicrobial monotherapy is used. Frequent test of cure and appropriate verification/falsification of suspected treatment failures, as well as implementation of recommended dual antimicrobial therapy are imperative.
Non-fatal case of Crimean-Congo haemorrhagic fever imported into the United Kingdom (ex Bulgaria), June 2014
Authors: Lumley S , Atkinson B , Dowall S D , Pitman J K , Staplehurst S , Busuttil J , Simpson A J , Aarons E J , Petridou C , Nijjar M , Glover S , Brooks T J , Hewson R
Published: August 2014

Crimean-Congo haemorrhagic fever (CCHF) was diagnosed in a United Kingdom traveller who returned from Bulgaria in June 2014. The patient developed a moderately severe disease including fever, headaches and petechial rash. CCHF was diagnosed following identification of CCHF virus (CCHFV) RNA in a serum sample taken five days after symptom onset. Sequence analysis of the CCHFV genome showed that the virus clusters within the Europe 1 clade, which includes viruses from eastern Europe.
Biomechanical analysis of anterior versus posterior instrumentation following a thoracolumbar corpectomy
Authors: Viljoen Stephanus V. , DeVries Watson Nicole A. , Grosland Nicole M. , Torner James , Dalm Brian , Hitchon Patrick W.
Published: August 2014

Object

The objective of this study was to evaluate the biomechanical properties of lateral instrumentation compared with short- and long-segment pedicle screw constructs following an L-1 corpectomy and reconstruction with an expandable cage.

Methods

Eight human cadaveric T10–L4 spines underwent an L-1 corpectomy followed by placement of an expandable cage. The spines then underwent placement of lateral instrumentation consisting of 4 monoaxial screws and 2 rods with 2 cross-connectors, short-segment pedicle screw fixation involving 1 level above and below the corpectomy, and long-segment pedicle screw fixation (2 levels above and below). The order of instrumentation was randomized in the 8 specimens. Testing was conducted for each fixation technique. The spines were tested with a pure moment of 6 Nm in all 6 degrees of freedom (flexion, extension, right and left lateral bending, and right and left axial rotation).

Results

In flexion, extension, and left/right lateral bending, posterior long-segment instrumentation had significantly less motion compared with the intact state. Additionally, posterior long-segment instrumentation was significantly more rigid than short-segment and lateral instrumentation in flexion, extension, and left/right lateral bending. In axial rotation, the posterior long-segment construct as well as lateral instrumentation were not significantly more rigid than the intact state. The posterior long-segment construct was the most rigid in all 6 degrees of freedom.

Conclusions

In the setting of highly unstable fractures requiring anterior reconstruction, and involving all 3 columns, long-segment posterior pedicle screw constructs are the most rigid.
Repeat microvascular decompression for recurrent idiopathic trigeminal neuralgia
Authors: Bakker Nicolaas A. , Van Dijk J. Marc C. , Immenga Steven , Wagemakers Michiel , Metzemaekers Jan D. M.
Published: August 2014

Object

Microvascular decompression (MVD) is considered the method of choice to treat idiopathic trigeminal neuralgia (TN) refractory to medical treatment. However, repeat MVD for recurrent TN is not well established. In this paper, the authors describe a large case series in which patients underwent repeat MVD for recurrent TN, focusing on outcome, risk factors, and complication rates.

Methods

Between 1990 and 2012, a total of 33 consecutive patients underwent repeat MVD for recurrent TN at the University Medical Center Groningen. The authors performed a retrospective chart review and telephone interviews. Risk factors were analyzed by binary logistic regression analysis.

Results

After 12 months of follow-up, 22 (67%) operations were successful, of which 19 patients were completely free of pain without medication. With multivariate analysis significant risk factors for success were older age (OR 1.11, p < 0.01) and direct absence of pain after repeat MVD (OR 25.2, p < 0.01). Previous neurodestructive procedures did not influence success rates. Facial numbness occurred in 9 patients (27%), while other morbidity was minimal. There was no mortality.

Conclusions

This study demonstrates that repeat MVD is a feasible therapeutic option with good chances of success, even in patients who have undergone neurodestructive procedures. Complication rates, particularly facial numbness, can be avoided if only a limited neurolysis is performed.
Catalase Activity of Sulfate-Reducing Bacteria Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 Isolated from Human Large Intestine
Authors: Kushkevych Ivan V , Fafula Roman V , Antonyak Halyana L
Published: August 2014

Catalase activity of the sulfate-reducing bacteria Desulfovibrio piger Vib-7 and Desulfomicrobium sp. Rod-9 isolated from the human large intestine was studied. The high activity of the enzyme in cell-free extracts of both bacterial strains was determined (1745.21±154.67 and 873.11±72.23 U×mg-1 protein for D. piger Vib-7 and Desulfomicrobium sp. Rod-9, respectively). The effect of different temperature and pH as well as H2O2 concentration and time of incubation on the catalase activity in the cell-free extracts of D. piger Vib-7 and Desulfomicrobium sp. Rod-9 were examined. The maximum catalase activity for both bacterial strains at +30ºC temperature was determined. The highest activity of the studied enzyme in the cell-free extracts of D. piger Vib-7 at pH 7.5 and Desulfomicrobium sp. Rod-9 at pH 7.0 was measured. Based on experimental data, the analysis of the kinetic properties of the catalase by the studied bacteria was carried out. Increasing of hydrogen peroxide concentrations from 0.5 to 5.0 mM causes a monotonic rise of studied enzyme activity and the activity was maintained on an unchanged level (plateau) under substrate concentrations over 5.0 mM. The catalase activity, initial (instantaneous) reaction rate (V0) and maximum rate of the catalase reaction (Vmax) were significantly higher in D. piger Vib-7 than in Desulfomicrobium sp. Rod-9 cells. Michaelis constants (Km) of the catalase reaction were 8.01±0.77 and 10.33±0.98 mM for D. piger Vib-7 and Desulfomicrobium sp. Rod-9, respectively. DOI: http://dx.doi.org/10.3329/mh.v3i1.19776 Microbes and Health, June 2014. 3(1): 15-20
Neonatal Human Dermal Fibroblasts Immobilized in RGD–Alginate Induce Angiogenesis
Authors: Guerreiro Susana G. , Oliveira Maria J. , Barbosa Mário A. , Soares Raquel , Granja Pedro L.
Published: August 2014

Promoting angiogenesis in a damaged tissue is a major challenge for tissue regeneration. Recent findings in tissue engineering suggest that fibroblasts (FBs) play an important role in orchestrating the angiogenic process. Fibroblasts maintain the structural integrity of connective tissue by continuously secreting growth factors and extracellular matrix precursors, which are essential for endothelial cell (EC) adhesion and spreading, thus playing a crucial role in angiogenesis. We hypothesized that FBs immobilized in alginate gels grafted with the RGD peptidic sequence could influence the recruitment of ECs to improve vascularization. In this work, the modulation of immobilized human FBs within the 3D synthetic extracellular matrix was assessed. Experiments using cocultures of ECs and FBs in indirect contact as well as angiogenic assays were performed to assess the influence of FBs immobilized in RGD–alginate in ECs' viability, stabilization, sprouting, and assembly into capillary-like structures. This study demonstrates the ability of FBs immobilized within RGD–alginate microspheres to modulate and support capillary-like structures' assembly. These findings indicate that the microenvironment created by these stromal cells in the scaffold modulates capillary morphogenesis, thus stimulating angiogenesis in situ and can potentially be used in regenerative medicine in clinical scenarios where vascularization is essential.
Use of TETRA Networks in Crisis Situations for Health Information Transfer Strategies
Authors: Lazakidou A. , Ioannou A. , Ioannou K. , Kitsios F.
Published: August 2014

Telecommunications have been evolved dramatically during the last ten years, laying solid foundation for the next generation of Web Technologies and ultimate automated information cyberspace. As a result of this evolution and the users' demands, the current efforts of the researchers, in the areas of Health Information Transfer in Crisis Situations, promotes formation of inter-disciplinary international teams of experts, in order to create a new generation of technologies which will facilitate the future health information systems. The TETRA network can enable existing information and resources to be extended out to the point of care, helping medical professionals deliver top medical care in a more timely and efficient manner. In medicine, time savings equals hospital savings. The objective of this paper is to study how simply a medical specialist can collect physiological data from mobile-remote patients and how reliably health information can be transferred from emergency places to hospitals through TETRA.
Re-Engineering a Medical Devices Management Software System
Authors: Malataras P.G. , Bliznakov Z.B. , Pallikarakis N.E.
Published: August 2014

The primary aim of a hospital Clinical Engineering Department (CED) is to ensure a safe and cost-effective operation of the medical devices. In order to achieve this goal, it needs to implement and establish a comprehensive biomedical technology management program, which is a complex and multidimensional task. This work presents a medical devices management software system to assist the CED in healthcare, and it appears, as a result, of an effort to re-engineer and rebuild such an old, successful management system. The findings of this re-engineering attempt are presented. The goal was the incorporation of the new trends in clinical engineering and medical devices management and the exploitation of the new capabilities provided by the modern software tools and platforms. The system is expected to respond to the changing healthcare environment demands, the increased efforts required, and the respective broader role that CEDs have to play.
Accelerating Biomedical Research through Semantic Web Services
Authors: Chaleplioglou Artemis
Published: August 2014

In view of the fact that there is a lot of biomedical research data, rapidly accumulating to relevant repositories, there is an urgent need these data to be delivered, as soon as possible, to the specific scientific audience interesting in it. Unfortunately, the current database technologies often isolate data rather than making it easily and freely accessible. A considerable effort by the information scientists is needed to process the resources that meet the scientific query criteria as well as to index and present them as useful metadata. Taking into account that biomedical data are mostly hidden from the public eye, often stored in not indexed databases or libraries and inaccessible by standard search engines, the retrieval, storing, annotating, and qualification of health information remain major challenges. The evolution of the World Wide Web from a collection of unstructured and predominantly human readable data into the Semantic Web of knowledge with meaningful relationships between resources and machine readable data will significantly improve our ability to conduct bioinformatics analyses and to make better clinical decisions that positively affect healthcare outcomes. To this end novel semantic web services arise, which depend on markup ontologies in order to make biological and clinical data logical analysis computational and reasonable processed through the utilization of appropriate algorithms. Herein, we discuss the use of these technologies for the efficient and reliable retrieval of meaningful biomedical data from the relevant resources and repositories.
Reduction of Defect Misclassification of Electronic Board Using Multiple SVM Classifiers
Authors: Nakagawa Takuya , Iwahori Yuji , Bhuyan M. K.
Published: August 2014

This paper proposes a new method to improve the classification accuracy by multiple class classification using multiple SVM. The proposed approach classifies the true and pseudo defects by adding features to decrease the incorrect classification. This approach consists of two steps. First, detect the straight line by Hough Transform to the inspection image and condition is judged with the gradient. More than 80% of AOI images consist of images with the margin line between base part and lead line part which has the same direction. When detected line directions are almost the same directions, shifted image of inspection image is generated and used as the reference image. In case of different directions of detected lines (this case holds for less than 20% of AOI images), reference image is generated manually. After the reference image is prepared, the difference is taken between the inspection image and reference image. This leads to extract the defect candidate region with high accuracy and features are extracted to judge the defect and foreign material. Second, selected features are learned with multiple SVM and classified into the class. When the result has the multiple same voting counts to the same class, the judgment is treated as the difficult class for the classification. It is shown that the proposed approach gives efficient classification with the higher classification accuracy than the previous approaches through the real experiment.
Separating Fact From Factitious Hemoptysis: A Case Report
Authors: Mucha Susan M. , Varghese Linda A. , French Russell E. , Shade Daniel A.
Published: August 2014

A 61-year-old man with a history of testicular carcinoma and more recently diagnosed metastatic renal cell carcinoma was admitted because of recurrent submassive hemoptysis as evidenced by bright red blood in his bedside basin. Despite an exhaustive workup, including multiple invasive procedures, no cause of the bleeding was found. The diagnosis was Münchausen syndrome manifested as factitious hemoptysis via unusual and modern means. The case is a reminder to all members of the critical care team, from nurses to physicians: When dealing with the frustration of a recurrent problem with no clear answer, remain vigilant and remember the age-old advice to look at the patient… and trust your gut.
Too Much of a Good Thing? Tim-3 and TCR Signaling in T Cell Exhaustion
Authors: Ferris Robert L. , Lu Binfeng , Kane Lawrence P.
Published: August 2014

T cell exhaustion is thought to be a natural mechanism for limiting immune pathology, although it may be desirable to circumvent this mechanism to help eliminate viral reservoirs or tumors. Although there are no definitive markers, a fingerprint for exhausted T cells has been described that includes the transmembrane proteins PD-1, LAG3, and Tim-3. However, apart from the recruitment of tyrosine phosphatases to PD-1, little is known about the biochemical mechanisms by which these proteins contribute to the development or maintenance of exhaustion. Tim-3 contains no known motifs for the recruitment of inhibitory phosphatases, but it may actually increase signaling downstream of TCR/CD3, at least under acute conditions. Other studies showed that T cell exhaustion results from chronic stimulation that extends the effector phase of T cell activation, at the expense of T cell memory. We suggest that Tim-3 may contribute to T cell exhaustion by enhancing TCR-signaling pathways.
Helicopter Rotor Blade Flexibility Simulation for Aeroelasticity and Flight Dynamics Applications
Authors: Goulos Ioannis , Pachidis Vassilios , Pilidis Pericles
Published: August 2014

This paper presents a mathematical model for the simulation of rotor blade flexibility in real-time helicopter flight dynamics applications that also employs sufficient modeling fidelity for prediction of structural blade loads. A matrix/vector-based formulation is developed for the
treatment of elastic blade kinematics in the time domain. A novel, second-order-accurate, finite-difference scheme is employed for the approximation of the blade motion derivatives. The proposed method is coupled with a finite-state induced-flow model, a dynamic wake distortion model, and
an unsteady blade element aerodynamics model. The integrated approach is deployed to investigate trim controls, stability and control derivatives, nonlinear control response characteristics, and structural blade loads for a hingeless rotor helicopter. It is shown that the developed methodology
exhibits modeling accuracy comparable to that of non-real-time comprehensive rotorcraft codes. The proposed method is suitable for real-time flight simulation, with sufficient fidelity for simultaneous prediction of oscillatory blade loads.
Redes académicas transnacionales y la física argentina en las décadas de 1940 y 1950
Authors: Comastri Hernán
Published: August 2014

El presente artículo tiene como objetivo describir las consecuencias que la transformación de las redes académicas transnacionales, de mediados del siglo XX, tuvo para un país periférico a las mismas, como lo fue la Argentina de aquella época. Se tomará el caso específico de la física, y se estudiarán dos casos centrales en la institucionalización y modernización de la disciplina en el país: Enrique Gaviola, formado bajo los parámetros de la cultura académica alemana, y José Balseiro, formado en un contexto ya mucho más fuertemente influenciado por la cultura académica anglo-norteamericana y su particular forma de aproximación a la labor científica. El traspaso del centro de dicha red transnacional de Alemania hacia los Estados Unidos, luego de 1945, implicó un proceso de “selección” de la población académica, que también alcanzó a los nodos más alejados del centro, como fue el caso de la Argentina: diferencias culturales sobre la legitimidad y el rol social del científico impidieron una transferencia directa del capital acumulado e invertido en la academia alemana hacia los nuevos centros norteamericanos, y no todos los científicos supieron (o estuvieron dispuestos) a adaptarse a las nuevas condiciones y contextos sociales de trabajo.
Intelectualidad, habla e identidad étnica. El caso de dos intelectuales aymara de Arica y Parinacota
Authors: González Jaime
Published: August 2014

El presente artículo busca estudiar el nexo entre formas de intelectualidad étnica y tipos de identidad étnica. Con base a esta problemática inicial, se pretende analizar los casos de dos intelectuales aymara originarios de la región de Arica y Parinacota, que presentan semejanzas y diferencias en calidad de actores. Estas mismas propiedades tendrán consecuencias en la elaboración de identidades étnicas de esta colectividad. Se sugiere como hipótesis un vínculo entre tipos de intelectuales y formas de identidad étnica en los aymara de la XV región. Con base a esta primera formulación, sostenemos que la semejanza de ambos casos explica las similitudes en la elaboración de identidad. La base empírica del texto se apoyará principalmente en las voces de los sujetos de estudio, lo que no excluirá la alusión a notas de campo del comportamiento de estos agentes.
Studies of laterally heterogeneous structures using seismic refraction and reflection data
Authors: Green A G
Published: August 2014

In an attempt to delineate structures associated with ancient terrarte accretion and active plate convergence along the west coast of North America, a number of geophysical and geological surveys have been conducted across Vancouver Island and the adjacent
offshore continental margin. Early models based on gravity data and other information have been tested and refined by COCRUST using refraction methods, and by LITHOPROBE using multichannel seismic reflection, magnetotelluric, heat flow, seismicity, aeromagnetic and a range of geological/geochemical
techniques. A large block of underplated oceanic lithosphere, characterized by anomalously high densities and velocities have been mapped at crustal depths beneath Vancouver Island. The subducting Juan de Fuca oceanic plate lies below the underplated block, with northeasterly dip increasing from
about 3° under the offshore accretionary wedge to 10-15° under the northern part of the island.
Pontryagin’s Maximum Principle for the Loewner Equation in Higher Dimensions
Authors: Roth Oliver
Published: August 2014

In this paper we develop a variational method for the Loewner equation in higher dimensions. As a result we obtain a version of Pontryagin’s maximum principle from optimal control theory for the Loewner equation in several complex variables. Based on recent work of Arosio, Bracci, and
Wold, we then apply our version of the Pontryagin maximum principle to obtain first-order necessary
conditions for the extremal mappings for a wide class of extremal problems over the set of normalized
biholomorphic mappings on the unit ball in ℂn.