bluuebunny/crossref_metadata_2025 huggingface dataset:
Genome mining reveals the genus Xanthomonas to be a promising reservoir for new bioactive non-ribosomally synthesized peptides
Authors: Royer Monique , Koebnik Ralf , Marguerettaz Mélanie , Barbe Valérie , Robin Guillaume P , Brin Chrystelle , Carrere Sébastien , Gomez Camila , Hügelland Manuela , Völler Ginka H , Noëll Julie , Pieretti Isabelle , Rausch Saskia , Verdier Valérie , Poussier Stéphane , Rott Philippe , Süssmuth Roderich D , Cociancich Stéphane
Published: September 2013

Background

Various bacteria can use non-ribosomal peptide synthesis (NRPS) to produce peptides or other small molecules. Conserved features within the NRPS machinery allow the type, and sometimes even the structure, of the synthesized polypeptide to be predicted. Thus, bacterial genome miningvia in silicoanalyses of NRPS genes offers an attractive opportunity to uncover new bioactive non-ribosomally synthesized peptides.Xanthomonasis a large genus of Gram-negative bacteria that cause disease in hundreds of plant species. To date, the only known small molecule synthesized by NRPS in this genus is albicidin produced byXanthomonas albilineans. This study aims to estimate the biosynthetic potential ofXanthomonasspp. byin silicoanalyses of NRPS genes with unknown function recently identified in the sequenced genomes ofX. albilineansand related species ofXanthomonas.

Results

We performedin silicoanalyses of NRPS genes present in all published genome sequences ofXanthomonasspp., as well as in unpublished draft genome sequences ofXanthomonas oryzaepv. oryzaestrain BAI3 andXanthomonasspp. strain XaS3. These two latter strains, together withX. albilineansstrain GPE PC73 andX. oryzaepv.oryzaestrains X8-1A and X11-5A, possess novel NRPS gene clusters and share related NRPS-associated genes such as those required for the biosynthesis of non-proteinogenic amino acids or the secretion of peptides.In silicoprediction of peptide structures according to NRPS architecture suggests eight different peptides, each specific to its producing strain. Interestingly, these eight peptides cannot be assigned to any known gene cluster or related to known compounds from natural product databases. PCR screening of a collection of 94 plant pathogenic bacteria indicates that these novel NRPS gene clusters are specific to the genusXanthomonasand are also present inXanthomonas translucensandX. oryzaepv.oryzicola. Further genome mining revealed other novel NRPS genes specific toX. oryzaepv.oryzicolaorXanthomonas sacchari.

Conclusions

This study revealed the significant potential of the genusXanthomonasto produce new non-ribosomally synthesized peptides. Interestingly, this biosynthetic potential seems to be specific to strains ofXanthomonasassociated with monocotyledonous plants, suggesting a putative involvement of non-ribosomally synthesized peptides in plant-bacteria interactions.
Mimotope vaccination for epitope-specific induction of anti-VEGF antibodies
Authors: Li Weina , Ran Yonggang , Li Meng , Zhang Kuo , Qin Xin , Xue Xiaochang , Zhang Cun , Hao Qiang , Zhang Wei , Zhang Yingqi
Published: September 2013

Background

Tumor angiogenesis is critical for tumor growth, infiltration and metastasis. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor and targeting it is important in reducing angiogenesis. Bevacizumab (Avastin), a monoclonal antibody that reacts directly against VEGF, has been demonstrated to be an effective treatment for various cancers such as rectal cancer, colon carcinoma, and non-small cell lung cancer, etc.

Results

In the current study, we used the phage display technique to generate mimotopes that complemented the screening Avastin antibody (Ab). The candidate mimotopes of VEGF were isolated from a 12-mer peptide library. The phage displaying peptide DHTLYTPYHTHP (designated as 12P) exhibited high affinity to Avastin. The chemically synthesized 12P was conjugated to keyhole limpet hemocyanin (KLH) by glutaraldehyde (GA) to form vaccine KLH-12 peptide (KLH-12P). This epitope vaccine significantly induced humoral immunity in mice. The blood serum from KLH-12P-immunized mice associated with VEGF and blocked its binding to VEGFR, thus inhibiting vascular endothelial cell proliferation and migration.

Conclusions

Our data indicate that the isolated mimotope 12P reported here could potentially elicit specific antibodies against VEGF and result in the induction of anti-angiogenesis responses.
Sleep medicine education and knowledge among medical students in selected Saudi Medical Schools
Authors: Almohaya Abdulellah , Qrmli Abdulaziz , Almagal Naeif , Alamri Khaled , Bahammam Salman , Al-Enizi Mashhour , Alanazi Atif , Almeneessier Aljohara S , Sharif Munir M , BaHammam Ahmed S
Published: September 2013

Background

Limited information is available regarding sleep medicine education worldwide. Nevertheless, medical education has been blamed for the under-recognition of sleep disorders among physicians. This study was designed to assess the knowledge of Saudi undergraduate medical students about sleep and sleep disorders and the prevalence of education on sleep medicine in medical schools as well as to identify the obstacles to providing such education.

Methods

We surveyed medical schools that were established more than 10 years ago, asking fourth- and fifth-year medical students (men and women) to participate. Seven medical schools were selected. To assess knowledge on sleep and sleep disorders, we used the Assessment of Sleep Knowledge in Medical Education (ASKME) Survey, which is a validated 30-item questionnaire. The participants were separated into two groups: those who scored ≥60% and those who scored <60%. To assess the number of teaching hours dedicated to sleep medicine in the undergraduate curricula, the organizers of the major courses on sleep disorders were contacted to obtain the curricula for those courses and to determine the obstacles to education.

Results

A total of 348 students completed the survey (54.9% male). Among the participants, 27.7% had a specific interest in sleep medicine. More than 80% of the study sample had rated their knowledge in sleep medicine as below average. Only 4.6% of the respondents correctly answered ≥60% of the questions. There was no difference in the scores of the respondents with regard to university, gender, grade-point average (GPA) or student academic levels. Only five universities provided data on sleep medicine education. The time spent teaching sleep medicine in the surveyed medical schools ranged from 0-8 hours with a mean of 2.6 ±2.6 hours. Identified obstacles included the following: (1) sleep medicine has a lower priority in the curriculum (53%) and (2) time constraints do not allow the incorporation of sleep medicine topics in the curriculum (47%).

Conclusions

Medical students in the surveyed institutions possess poor knowledge regarding sleep medicine, which reflects the weak level of education in this field of medicine. To improve the recognition of sleep disorders among practicing physicians, medical schools must provide adequate sleep medicine education.
Group X secreted phospholipase A2 induces lipid droplet formation and prolongs breast cancer cell survival
Authors: Pucer Anja , Brglez Vesna , Payré Christine , Pungerčar Jože , Lambeau Gérard , Petan Toni
Published: September 2013

Background

Alterations in lipid metabolism are inherent to the metabolic transformations that support tumorigenesis. The relationship between the synthesis, storage and use of lipids and their importance in cancer is poorly understood. The human group X secreted phospholipase A2 (hGX sPLA2) releases fatty acids (FAs) from cell membranes and lipoproteins, but its involvement in the regulation of cellular FA metabolism and cancer is not known.

Results

Here we demonstrate that hGX sPLA2 induces lipid droplet (LD) formation in invasive breast cancer cells, stimulates their proliferation and prevents their death on serum deprivation. The effects of hGX sPLA2 are shown to be dependent on its enzymatic activity, are mimicked by oleic acid and include activation of protein kinase B/Akt, a cell survival signaling kinase. The hGX sPLA2-stimulated LD biogenesis is accompanied by AMP-activated protein kinase (AMPK) activation, up-regulation of FA oxidation enzymes and the LD-coating protein perilipin 2, and suppression of lipogenic gene expression. Prolonged activation of AMPK inhibited hGX sPLA2-induced LD formation, while etomoxir, an inhibitor of FA oxidation, abrogated both LD formation and cell survival. The hGX sPLA2-induced changes in lipid metabolism provide a minimal immediate proliferative advantage during growth under optimal conditions, but they confer to the breast cancer cells a sustained ability to resist apoptosis during nutrient and growth factor limitation.

Conclusion

Our results identify hGX sPLA2 as a novel modulator of lipid metabolism that promotes breast cancer cell growth and survival by stimulating LD formation and FA oxidation.
Detection of interfraction displacement and volume variance during radiotherapy of primary thoracic esophageal cancer based on repeated four-dimensional CT scans
Authors: Wang Jin Zhi , Li Jian Bin , Wang Wei , Qi Huan Peng , Ma Zhi Fang , Zhang Ying Jie , Fan Ting Yong , Shao Qian , Xu Min
Published: September 2013

Background

To investigate the interfraction displacement and volume variation of primary thoracic esophagus carcinoma with enhanced four-dimensional computed tomography (4DCT) scanning during fractionated radiotherapy.

Methods

4DCT data sets were acquired at the time of treatment simulation and every ten fraction for each of 32 patients throughout treatment. Scans were registered to baseline (simulation) 4DCT scans by using bony landmarks. The gross tumor volumes (GTVs) were delineated on each data set. Coordinates of the GTV centroids were acquired on each respiration phase. Distance between center of the GTV contour on the simulation scan and the centers on subsequent scans were used to assess interfraction displacement between fractions. Volumes were constructed using three approaches: The GTV delineated from the maximum intensity projection (MIP) was defined IGTVMIP, all 10 GTVs were combined to form IGTV10, GTVmean was the average of all 10 phases of each GTV.

Results

Interfraction displacement in left-right (LR), anterior-posterior (AP), superior-inferior (SI) directions and 3D vector were 0.13 ± 0.09 cm, 0.16 ± 0.12 cm, 0.34 ± 0.26 cm and 0.43 ± 0.24 cm, respectively between the tenth fraction and simulation 4DCT scan. 0.14 ± 0.09 cm, 0.19 ± 0.16 cm, 0.45 ± 0.43 cm and 0.56 ± 0.40 cm in LR, AP, SI and 3D vector respectively between the twentieth fraction and simulation 4DCT scan. Displacement in SI direction was larger than LR and AP directions during treatment. For distal esophageal cancer, increased interfraction displacements were observed in SI direction and 3D vector (P = 0.002 and P = 0.001, respectively) during radiotherapy. The volume of GTVmean, IGTVMIP, and IGTV10 decreased significantly at the twentieth fraction for middle (median: 34.01%, 33.09% and 28.71%, respectively) and distal (median: 22.76%, 25.27% and 23.96%, respectively) esophageal cancer, but for the upper third, no significant variation were observed during radiotherapy.

Conclusions

Interfractional displacements in SI direction were larger than LR and AP directions. For distal location, significant changes were observed in SI direction and 3D vector during radiotherapy. For middle and distal locations, the best time to reset position should be selected at the twentieth fraction when the primary tumor target volume changed significantly, and it was preferable to guide target correction and planning modification.
Genome replication engineering assisted continuous evolution (GREACE) to improve microbial tolerance for biofuels production
Authors: Luan Guodong , Cai Zhen , Li Yin , Ma Yanhe
Published: September 2013

Background

Microbial production of biofuels requires robust cell growth and metabolism under tough conditions. Conventionally, such tolerance phenotypes were engineered through evolutionary engineering using the principle of “Mutagenesis followed-by Selection”. The iterative rounds of mutagenesis-selection and frequent manual interventions resulted in discontinuous and inefficient strain improvement processes. This work aimed to develop a more continuous and efficient evolutionary engineering method termed as “Genome Replication Engineering Assisted Continuous Evolution” (GREACE) using “Mutagenesis coupled-with Selection” as its core principle.

Results

The core design of GREACE is to introduce an in vivo continuous mutagenesis mechanism into microbial cells by introducing a group of genetically modified proofreading elements of the DNA polymerase complex to accelerate the evolution process under stressful conditions. The genotype stability and phenotype heritability can be stably maintained once the genetically modified proofreading element is removed, thus scarless mutants with desired phenotypes can be obtained.

Kanamycin resistance of E. coli was rapidly improved to confirm the concept and feasibility of GREACE. Intrinsic mechanism analysis revealed that during the continuous evolution process, the accumulation of genetically modified proofreading elements with mutator activities endowed the host cells with enhanced adaptation advantages. We further showed that GREACE can also be applied to engineer n-butanol and acetate tolerances. In less than a month, an E. coli strain capable of growing under an n-butanol concentration of 1.25% was isolated. As for acetate tolerance, cell growth of the evolved E. coli strain increased by 8-fold under 0.1% of acetate. In addition, we discovered that adaptation to specific stresses prefers accumulation of genetically modified elements with specific mutator strengths.

Conclusions

We developed a novel GREACE method using “Mutagenesis coupled-with Selection” as core principle. Successful isolation of E. coli strains with improved n-butanol and acetate tolerances demonstrated the potential of GREACE as a promising method for strain improvement in biofuels production.
Prevalence of gastrointestinal nematodes and Fasciola hepatica in sheep in the northwest of Spain: relation to climatic conditions and/or man-made environmental modifications
Authors: Martínez-Valladares María , Robles-Pérez David , Martínez-Pérez Jose Manuel , Cordero-Pérez Coral , Famularo Ma del Rosario , Fernández-Pato Nélida , González-Lanza Camino , Castañón-Ordóñez Luciano , Rojo-Vázquez Francisco A
Published: September 2013

Background

In the present study we studied and updated the prevalence of the infections caused by gastrointestinal nematodes (GIN) and Fasciola hepatica in grazing sheep in the northwest (NW) of Spain for the last six years (2006–2011), and its relationship with the current climatic conditions.

Methods

We analyzed faecal samples from 110 flocks located in four different provinces of the Autonomous Community of Castilla y León: 76.4% of them were situated in León, 12.7% in Zamora, 9.1% in Palencia and 1.8% in Valladolid.

Results

The prevalence of GIN was 100% and the mean of eggs per gram (epg) in faeces was 237.2 (± 375.9) per flock. Regarding climatic conditions, we found a direct relationship between the GIN infection level and the maximum humidity (p<0.05) but inverse with the degree of solar radiation (p<0.05). The prevalence of fasciolosis was 59.3%, with a mean epg of 17.5 (± 33.9) per flock; these values were correlated with the minimum humidity and precipitations (p<0.05). Comparing our results in León with previous studies during the early 1990s, the mean epg of GIN was increased slightly (134.3 epg); regarding fasciolosis, the prevalence rose significantly, from 26.7% to 60.5%. Since the 1990s we observed that the maximum temperature is nowadays 0.45°C higher (17.0°C) and the minimum 0.5°C lower (5.2°C); the rainfall values were very similar in both decades but at the present time the humidity is higher (75.9%).

Conclusions

We found that the prevalence of GIN and F. hepatica infections was directly influenced by the humidity and also by precipitations in the case of F. hepatica. Comparing the current prevalence with studies carried out in the same area for the early 1990s, we observed that nowadays the mean epg of GIN is higher with a possible cause being the differences in climatic conditions depending on the sampling year. Regarding F. hepatica infection, its prevalence rose significantly probably favoured by an increase in irrigated areas in the area of study.
TNF-α and IFN-γ promote lymphocyte adhesion to endothelial junctional regions facilitating transendothelial migration
Authors: Jaczewska Justyna , Abdulreda Midhat H , Yau Chi Y , Schmitt Martin M , Schubert Irene , Berggren Per-Olof , Weber Christian , Koenen Rory R , Moy Vincent T , Wojcikiewicz Ewa P
Published: September 2013

Inflammatory conditions induce redistribution of junctional adhesion receptors toward the apical regions of endothelial cells promoting lymphocyte TEM. Much of the molecular structures of TEM have been revealed; however, the biophysical mechanisms underlying this process remain to be fully elucidated. Here, we used immunofluorescence microscopy and AFM to study endothelial distribution of adhesion molecules upon lymphocyte activation and transmigration. Our immunofluorescence results revealed redistribution of JAM-A and PECAM-1 but not ICAM-1 or VCAM-1 toward the apical junctional regions of HUVECs following a 6-h stimulation with TNF-α and IFN-γ. Consistently, our SCFS studies revealed that Jurkat cell adhesion to stimulated HUVEC monolayers was significantly greater in junctional regions. Enhanced adhesion was mediated mostly by JAM-A receptors. Further AFM adhesion mapping of the homophilic JAM-A/JAM-A interaction on the surfaces of HUVECs revealed a greater number of JAM-A receptors available for binding along junctional regions after TNF-α and IFN-γ stimulation. Our data reveal for the first time that adhesion “hot spots” of JAM-A receptors are involved in initiating lymphocyte TEM under inflammatory conditions.
Predicting future violence among individuals with psychopathy
Authors: Coid Jeremy W. , Ullrich Simone , Kallis Constantinos
Published: September 2013

Structured risk assessment aims to help clinicians classify offenders according to likelihood of future violent and criminal behaviour. We investigated how confident clinicians can be using three commonly used instruments (HCR-20, VRAG, OGRS-II) in individuals with different diagnoses. Moderate to good predictive accuracy for future violence was achieved for released prisoners with no mental disorder, low to moderate for clinical syndromes and personality disorder, but accuracy was no better than chance for individuals with psychopathy. Comprehensive diagnostic assessment should precede an assessment of risk. Risk assessment instruments cannot be relied upon when managing public risk from individuals with psychopathy.
Increase in cardiac myosin heavy-chain (MyHC) alpha protein isoform in hibernating ground squirrels, with echocardiographic visualization of ventricular wall hypertrophy and prolonged contraction.
Authors: Nelson O. Lynne , Rourke Bryan
Published: September 2013

Deep hibernators such as golden-mantled ground squirrels (Callospermophilus lateralis) have multiple challenges to cardiac function during low temperature torpor and subsequent arousals. As heart rates fall from over 300 beats per minute to less than 10, chamber dilation and reduced cardiac output could lead to congestive myopathy. We performed echocardiography on a cohort of individuals prior to, and after several months of hibernation. The left ventricular chamber exhibited eccentric and concentric hypertrophy during hibernation and thus calculated ventricular mass was ~30% greater. Ventricular ejection fraction was mildly reduced during hibernation but stroke volumes were greater due to the eccentric hypertrophy and dramatically increased diastolic filling volumes. Globally, the systolic phase in hibernation was approximately 9.5x longer, and the diastolic phase was 28x longer. Left atrial ejection generally was not observed during hibernation. Atrial ejection returned weakly during early arousal. Strain echocardiography assessed the velocity and total movement distance, of contraction and relaxation, of regional ventricular segments in active and early arousal states. Myocardial systolic strain during early arousal was significantly greater than the active state, indicating greater total contractile movement. This mirrored the increased ventricular ejection fraction noted with early arousal. However, strain rates were slower during early arousal compared to the active period, particularly systolic strain which was 33% of active, compared to the rate of diastolic strain, which was 67% of active. As heart rate rose during the arousal period, myocardial velocities and strain rates also increased; this was matched closely by cardiac output. Curiously, though heart rates were only 26% of active heart rates during early arousal, the cardiac output was nearly 40% of the active state, suggesting an efficient pumping system. We further analyzed proportions of cardiac myosin heavy-chain (MyHC) isoforms in a separate cohort of squirrels over five months, including timepoints before hibernation, during hibernation, and just prior to emergence. Hibernating individuals were maintained in both a 4°C cold room, and a 20°C warm room. Measured by SDS-PAGE, relative percentages of cardiac MyHC alpha were increased during hibernation, at both hibernacula temperatures. A potential increase in contractile speed, and power, from more abundant MyHC alpha may aid force generation at low temperature, and at low heart rates. Unlike many models of cardiomyopathies where the alpha isoform is replaced by the beta isoform in order to reduce oxygen consumption, ground squirrels demonstrate a potential cardioprotective mechanism to maintain cardiac output during torpor.
Functional implications of ontogenetic and sexual dimorphic dentition in the eastern shovelnose ray Aptychotrema rostrata (Shaw & Nodder, 1794)
Authors: Gutteridge Adrian , Bennett Mike
Published: September 2013

Unlike other elasmobranchs, batoids exhibit sexually dimorphic dentition. The functional implications of such dentition, however, remain understudied. For the present study ontogenetic and sexual dimorphism in tooth and jaw structure, together with the functional implications of this dimorphism, was determined in the eastern shovelnose ray, Aptychotrema rostrata (Shaw & Nodder, 1794). Sexually dimorphic dentition and jaw structure was first observed in sub-adult age classes, with males developing a pronounced lower jaw at the symphysis. Monognathic heterodonty was prominent in mature males, with teeth in the symphyseal region developing significantly greater tooth heights and tooth sharpness ratios in comparison to females. Ex vivo mechanical grip strength tests were used to determine simulated bite-grip tenacity. The mean peak pullout forces required to withdraw a section of a dissected pectoral fin from between jaws closed with a constant occlusal force was highest for mature males, intermediate for mature females and lowest for immature females and males. Although the species exhibits ontogenetic variations in diet, these were unrelated to sex. Rather, the larger and highly cuspidate teeth of mature males increased the bite-grip tenacity. This allowed for the pectoral fin of the females to be more firmly held, which likely aids in copulation.
Acute heat tolerance of cardiac excitation in the brown trout (Salmo trutta fario)
Authors: Vornanen Matti , Haverinen Jaakko , Egginton Stuart
Published: September 2013

The upper thermal tolerance and mechanisms of heat-induced cardiac failure in the brown trout (Salmo trutta fario) was examined. The point above which ion channel function and sinoatrial contractility in vitro, and electrocardiogram (ECG) in vivo, started to fail (break point temperature, BPT) was determined by acute temperature increases. In general, electrical excitation of the heart was most sensitive to heat in the intact animal (ECG) and least sensitive in isolated cardiac myocytes (ion currents). BPTs of Ca2+ and K+ currents of cardiac myocytes were much higher (>28°C) than BPT of in vivo heart rate (23.5±0.6°C) (P<0.05). A striking exception among sarcolemmal ion conductances was the Na+ current (INa), which was the most heat sensitive molecular function with a BPT of 20.9±0.5°C. The low heat tolerance of INa was reflected as a low BPT for the rate of action potential upstroke in vitro (21.7±1.2ºC) and the velocity of impulse transmission in vivo (21.9±2.2ºC). These findings from different levels of biological organization strongly suggest that heat-dependent deterioration of Na+ channel function disturbs normal spread of electrical excitation over the heart, leading to progressive variability of cardiac rhythmicity (missed beats, bursts of fast beating), reduction of heart rate and finally cessation of the normal heartbeat. Among the cardiac ion currents INa is ‘the weakest link’ and possibly a limiting factor for upper thermal tolerance of electrical excitation in the brown trout heart. Heat sensitivity of INa may result from functional requirements for very high flux rates and fast gating kinetics of the Na+ channels, i.e. a trade-off between high catalytic activity and thermal stability.
Combining an ancient tradition with modern developments: Latin and open access
Authors: Can Levent , Erol Osman , Şafak Nevin , Küçüker Orhan
Published: September 2013

In publishing names of new taxa of algae, fungi, and plants, it is argued that it is advantageous to retain the ancient tradition of Latin diagnoses in combination with the modern trend of publication in openly accessible electronic journals. Leading up to the XIX International Botanical Congress in 2017 in Shenzhen, China, we encourage that, even in the absence of a requirement, Latin continues to be used for diagnoses and consideration be given to making it a requirement that all valid publications of new taxa be freely accessible electronically. Retention of Latin diagnoses retains the discipline's link to the past and buffers against the rapid evolution modern languages are subject to, and Open access allows the discipline's results to be available to the widest possible audience.
Towards a phylogenetic classification of the climbing fern genus Arthropteris
Authors: Liu Hong-Mei , Jiang Ri-Hong , Guo Jian , Hovenkamp Peter , Perrie Leon R. , Shepherd Lara , Hennequin Sabine , Schneider Harald
Published: September 2013

We inferred the classification of the Paleotropical climbing fern genus Arthropteris and its close relative Psammiosorus, a monotypic genus endemic to Madagascar. The classification of these ferns has until now been poorly understood. To address this, we sampled more than half of the species diversity covering the whole range of the genus including the outlying occurrence at the Juan Fernández Islands. To reconstruct phylogenetic relationships, we obtained DNA sequences from up to six plastid genome regions, including coding and non–coding regions, for these two genera and representatives of all families of the eupolypod I clade, with an emphasis on the Tectariaceae. These data were analyzed using maximum parsimony, maximum likelihood, and Bayesian inference. We also obtained divergence time estimates. Three questions were addressed. (1) We established that Arthropteris and Psammiosorus form a well–supported clade representing a separate taxon based on their morphological distinctiveness, phylogenetic relationships, and separation since the Eocene from other accepted families of eupolypod ferns. (2) Psammiosorus was found to be nested within Arthropteris. (3) Our analyses supported recognition of a previously doubted species endemic to the karst regions of southern China and northern Vietnam. As a consequence of our results, we describe the new family Arthropteridaceae and introduce the new combination Arthropteris paucivenia for the Madagascan endemic previously treated under Psammiosorus.
Calla palustris (Araceae): New palynological insights with special regard to its controversial systematic position and to closely related genera
Authors: Ulrich Silvia , Hesse Michael , Bröderbauer David , Bogner Josef , Weber Martina , Halbritter Heidemarie
Published: September 2013

Almost all systematic treatments agree that Calla is a puzzling case, being a highly autapomorphic taxon with obscure relationships. In molecular–based classifications the variable placements of Calla within Aroideae conflict strongly with those in morphologically and anatomically based systematic classifications, which treat the genus as a subfamily (Calloideae) of its own. We studied the pollen morphology and ultrastructure of Calla by light and electron microscopy, and mapped the relevant pollen characters as well as some flower characters to the proposed placements of Calla within the Araceae as indicated in the various molecular phylogenies. Calla pollen is extraordinary within the entire Araceae. Pollen grains are small, and basically disulcate or with a ring–like aperture. The ornamentation is psilate to perforate, and the pollen wall consists of a sporopolleninous tectate–columellate exine. These pollen characters are shared with those of several earlier–diverging aroid taxa, especially with those of subfamily Zamioculcadoideae, whereas pollen characters in members of subfamily Aroideae deviate significantly. These findings are in accordance with other floral characters. Therefore, we propose that Calla is best placed in a transition zone between either subfamily Zamioculcadoideae (Stylochaeton clade) and subfamily Aroideae (Aroideae clade) or between subfamily Zamioculcadoideae (Stylochaeton clade) and subfamily Lasioideae.
Species diversity and reticulate evolution in the Asplenium normale complex (Aspleniaceae) in China and adjacent areas
Authors: Chang Yanfen , Li Jie , Lu Shugang , Schneider Harald
Published: September 2013

The Asplenium normale complex contains the widespread A. normale and several geographically restricted species: A. boreale, A. hobdyi, A. kiangsuense, A. oligophlebium and A. shimurae. The taxonomy of this group is unclear with some entities treated infraspecifically or as synonyms. Furthermore, the existence of diploids and tetraploids in this species complex is suggestive of reticulate evolution. In order to formulate a natural classification and to investigate the relationships in this complex, phylogenetic analyses of plastid and nuclear sequence data and inference of ploidy level were used to assess the distinctiveness of putative taxonomic units and their relationships. The Asplenium normale complex was recovered as a monophyletic group comprising six principal chloroplast lineages. The results support the hypothesis that A. normale s.l. contains several species. Based on our inferences, we outline an improved species classification recognizing three diploid and four tetraploid entities. Incongruence of chloroplast and nuclear phylogenies was interpreted to be a result of recurrent reticulation events in the A. normale complex.
A laboratory investigation to assess the influence of cement augmentation of screw and plate fixation in a simulation of distal femoral fracture of osteoporotic and non-osteoporotic bone
Authors: Wähnert D. , Lange J. H. , Schulze M. , Gehweiler D. , Kösters C. , Raschke M. J.
Published: September 2013

The augmentation of fixation with bone cement is increasingly being used in the treatment of severe osteoporotic fractures. We investigated the influence of bone quality on the mechanics of augmentation of plate fixation in a distal femoral fracture model (AO 33 A3 type). Eight osteoporotic and eight non-osteoporotic femoral models were randomly assigned to either an augmented or a non-augmented group. Fixation was performed using a locking compression plate. In the augmented group additionally 1 ml of bone cement was injected into the screw hole before insertion of the screw. Biomechanical testing was performed in axial sinusoidal loading. Augmentation significantly reduced the cut-out distance in the osteoporotic models by about 67% (non-augmented mean 0.30 mm (sd 0.08) vs augmented 0.13 mm (sd 0.06); p = 0.017). There was no statistical reduction in this distance following augmentation in the non-osteoporotic models (non-augmented mean 0.15 mm (sd 0.02) vs augmented 0.15 mm (sd 0.07); p = 0.915). In the osteoporotic models, augmentation significantly increased stability (p = 0.017).

Cite this article: Bone Joint J 2013;95-B:1406–9.
Neurological deterioration due to missed thoracic spinal stenosis after decompressive lumbar surgery
Authors: Fushimi K. , Miyamoto K. , Hioki A. , Hosoe H. , Takeuchi A. , Shimizu K.
Published: September 2013

There have been a few reports of patients with a combination of lumbar and thoracic spinal stenosis. We describe six patients who suffered unexpected acute neurological deterioration at a mean of 7.8 days (6 to 10) after lumbar decompressive surgery. Five had progressive weakness and one had recurrent pain in the lower limbs. There was incomplete recovery following subsequent thoracic decompressive surgery.

The neurological presentation can be confusing. Patients with compressive myelopathy due to lower thoracic lesions, especially epiconus lesions (T10 to T12/L1 disc level), present with similar symptoms to those with lumbar radiculopathy or cauda equina lesions. Despite the rarity of this condition we advise that patients who undergo lumbar decompressive surgery for stenosis should have sagittal whole spine MRI studies pre-operatively to exclude proximal neurological compression.

Cite this article: Bone Joint J 2013;95-B:1388–91.
Proximal tibial strain in medial unicompartmental knee replacements
Authors: Scott C. E. H. , Eaton M. J. , Nutton R. W. , Wade F. A. , Pankaj P. , Evans S. L.
Published: September 2013

As many as 25% to 40% of unicompartmental knee replacement (UKR) revisions are performed for pain, a possible cause of which is proximal tibial strain. The aim of this study was to examine the effect of UKR implant design and material on cortical and cancellous proximal tibial strain in a synthetic bone model. Composite Sawbone tibiae were implanted with cemented UKR components of different designs, either all-polyethylene or metal-backed. The tibiae were subsequently loaded in 500 N increments to 2500 N, unloading between increments. Cortical surface strain was measured using a digital image correlation technique. Cancellous damage was measured using acoustic emission, an engineering technique that detects sonic waves (‘hits’) produced when damage occurs in material.

Anteromedial cortical surface strain showed significant differences between implants at 1500 N and 2500 N in the proximal 10 mm only (p < 0.001), with relative strain shielding in metal-backed implants. Acoustic emission showed significant differences in cancellous bone damage between implants at all loads (p = 0.001). All-polyethylene implants displayed 16.6 times the total number of cumulative acoustic emission hits as controls. All-polyethylene implants also displayed more hits than controls at all loads (p < 0.001), more than metal-backed implants at loads ≥ 1500 N (p < 0.001), and greater acoustic emission activity on unloading than controls (p = 0.01), reflecting a lack of implant stiffness. All-polyethylene implants were associated with a significant increase in damage at the microscopic level compared with metal-backed implants, even at low loads. All-polyethylene implants should be used with caution in patients who are likely to impose large loads across their knee joint.

Cite this article: Bone Joint J 2013;95-B:1339–47.
Achilles tendinopathy
Authors: Roche A. J. , Calder J. D. F.
Published: September 2013

The two main categories of tendo Achillis tendon disorder are broadly classified by anatomical location to include non-insertional and insertional conditions.

Non-insertional Achilles tendinopathy is often managed conservatively, and many rehabilitation protocols have been adapted and modified, with excellent clinical results. Emerging and popular alternative therapies, including a variety of injections and extracorporeal shockwave therapy, are often combined with rehabilitation protocols. Surgical approaches have developed, with minimally invasive procedures proving popular.

The management of insertional Achilles tendinopathy is improved by recognising coexisting pathologies around the insertion. Conservative rehabilitation protocols as used in non-insertional disorders are thought to prove less successful, but such methods are being modified, with improving results. Treatment such as shockwave therapy is also proving successful. Surgical approaches specific to the diagnosis are constantly evolving, and good results have been achieved.
Patient satisfaction with total knee replacement cannot be predicted from pre-operative variables alone
Authors: Baker P. N. , Rushton S. , Jameson S. S. , Reed M. , Gregg P. , Deehan D. J.
Published: September 2013

Pre-operative variables are increasingly being used to determine eligibility for total knee replacement (TKR). This study was undertaken to evaluate the relationships, interactions and predictive capacity of variables available pre- and post-operatively on patient satisfaction following TKR. Using nationally collected patient reported outcome measures and data from the National Joint Registry for England and Wales, we identified 22 798 patients who underwent TKR for osteoarthritis between August 2008 and September 2010. The ability of specific covariates to predict satisfaction was assessed using ordinal logistic regression and structural equational modelling. Only 4959 (22%) of 22 278 patients rated the results of their TKR as ‘excellent’, despite the majority (71%, n = 15 882) perceiving their knee symptoms to be much improved. The strongest predictors of satisfaction were post-operative variables. Satisfaction was significantly and positively related to the perception of symptom improvement (operative success) and the post-operative EuroQol-5D score. While also significant within the models pre-operative variables were less important and had a minimal influence upon post-operative satisfaction. The most robust predictions of satisfaction occurred only when both pre- and post-operative variables were considered together. These findings question the appropriateness of restricting access to care based on arbitrary pre-operative thresholds as these factors have little bearing on post-operative satisfaction.

Cite this article: Bone Joint J 2013;95-B:1359–65.
Boðhlaup kynslóðanna
Authors: Magnússon Gylfi
Published: September 2013

Grein þessi fjallar um þróun einkaneyslu, samneyslu, þjóðar- og landsframleiðslu og eignir Íslendinga frá árinu 1870 og til vorra daga auk þess að spá líklegri þróun 50 ár fram í tímann. Í ljós kemur að því síðar sem fólk fæðist á þeim tíma sem skoðaður er þeim mun meiri verður neysla þeirra að jafnaði. Mjög mikill munur er á neyslu einstakra kynslóða framan af tímabilinu. Hann fer síðan minnkandi en er þó áfram talsverður. Þannig geta börn fædd árið 2010 vænst þess að samanlögð einkaneysla þeirra alla ævina verði um 22% meiri en foreldranna og samneysla 78% meiri. Bæði einkaneysla og samneysla hafa aukist verulega frá einni kynslóð til annarrar en þó samneysla hlutfallslega meira. Í greininni er jafnframt lagt mat á verðmæti íslenska hagkerfisins í ljósi framleiðslugetu þess og er niðurstaðan um 51.100 milljarðar árið 2011. Það er sextugföldun frá árinu 1870.
When Should a Monopolist Improve Quality in a Network Industry?
Authors: Garcia Filomena
Published: September 2013

This article identifies the necessary and sufficient conditions under which a monopolist, producing a network good, benefits from introducing a higher quality in the market. It is shown that, if the network externality is higher than the intrinsic quality differential, quality improvement is not optimal. Also, we obtain that, for low levels of the network effect, the monopolist prefers not to cover the market, whereas for higher levels, optimal prices are such that all consumers buy one of the two qualities. Finally, there is an introductory price strategy which is optimal for the good that benefits from network externalities.
Convection Problems on Anisotropic Meshes
Authors: Kruse Carola , Maischak Matthias
Published: September 2013

The Galerkin and SDFEM methods are compared for a steady state convection
problem. The theoretical part of this work deals with the development of
approximation results for continuous solutions on the unit square containing
an edge singularity. In the numerical part we verify those
approximation results by considering continuous as well as discontinuous
solutions to the transport problem on an annular domain with a singularity at the inner circle.
A Fast Algorithm for Parameter Identification Problems Based on the Multilevel Augmentation Method
Authors: Cao Hui , Nair M. Thamban
Published: September 2013

A multilevel augmentation method is considered to solve parameter identification problems in elliptic systems. With the help of the natural linearization technique, the identification problems can be
transformed into a linear ill-posed operation equation, where noise
exists not only in RHS data but also in operators. Based on multiscale decomposition in solution space, the multilevel augmentation method leads to a fast algorithm for solving discretized ill-posed problems.
Combining with Tikhonov regularization, in the implementation of the multilevel augmentation method, one only needs to invert
the same matrix with a relatively small size and perform a matrix-vector multiplication at the linear computational complexity. As a result, the
computation cost is dramatically reduced. The a posteriori regularization
parameter choice rule and the convergence rate for the regularized
solution are also studied in this work. Numerical tests illustrate the proposed algorithm and the theoretical estimates.
Mechanisms and pathways underlying the therapeutic effect of transcranial magnetic stimulation
Authors: Medina Francisco Javier , Túnez Isaac
Published: September 2013

It has been almost 40 years since Barker, Jalinous, and Freeston designed and used the first device of transcranial magnetic stimulation (TMS). From then until now, this technique has evolved vertiginously, appearing a lot of new protocols and device modifications, which associated with new technologies complement and enhance the versatility of this technique. TMS has demonstrated to be a safe technology and become a key tool in the study of the complex brain processes. Despite this, it is as a therapeutic tool where this technique has caused a revolution. In this regard, this type of non-invasive brain stimulation has been proven useful in a variety of neurodegenerative and psychiatric disorders due to its biochemical, molecular, and cellular effects, with depression being the paradigm of the therapeutic effectiveness of this technique. This review focuses on a detailed vision of how this type of radiation modifies different biochemical and cellular processes that induce the mechanisms and pathways underlying the therapeutic effects of TMS.
Research Needs of Pediatric Hospitalists
Authors: Bekmezian Arpi , Teufel Ronald J. , Wilson Karen M.
Published: September 2013

Objective:

To assess the current state of research productivity, goals, obstacles, and needs of pediatric hospitalists.

Methods:

The American Academy of Pediatrics Section on Hospital Medicine performed a cross-sectional online survey of pediatric hospitalists. Questions assessed demographics, research productivity, system-level factors, research interests, goals and obstacles, and the perceived need for research training and support.

Results:

Two hundred twenty pediatric hospitalists in the United States completed the survey. Of these, 56% had presented at a national meeting, 24% were first authors of an article in a peer-reviewed journal, 8% had more than publications, and 12% had secured external grant support. While 90% of respondents had spent 10% or less time in research, 64% had an academic appointment at the assistant professor level or above. Nearly 40% felt that their institution expected them to do research, and 56% were interested and another 27% were very interested in conducting research. The main research interest was quality improvement (QI) evaluation. Common obstacles to research were lack of time, mentorship, and resources.

Conclusions:

Pediatric hospitalists want to conduct research to improve the quality of inpatient care but face significant obstacles including lack of dedicated time for research and mentorship. Coordinated efforts to improve access to academic resources are important for career development and academic growth of the field. National organizations and hospital programs interested in improving the quality of care for hospitalized children can provide support to meet the field’s professional needs for research.
Perceptions of Physician Bedside Handoff With Nurse and Family Involvement
Authors: Gosdin Craig H. , Vaughn Lisa
Published: September 2013

Objective:

Physician-to-physician handoffs have been identified as a high-risk area of patient care. Few data exist to support any specific handoff process as being superior. We developed a handoff process entitled physician bedside handoff (PBH), which is unique for allowing all stakeholders, including the parents of patients, to be involved in the handoff at the bedside. Our goal was to compare stakeholder perceptions of PBH with traditional physician handoff and to learn which factors stakeholders believe are important for improving handoffs in general.

Methods:

A convenience sample of 34 stakeholders (including attending physicians, residents, nurses, patient care attendants, patient parents, and medical students) participated in 1 of 3 group level assessments (GLAs), a participatory method in which valid data are generated regarding an issue of importance through an interactive and collaborative process.

Results:

In comparing PBH and traditional handoffs, participants uniformly perceived that both processes have value and that neither is superior in all cases; individual circumstances and parental preference should dictate which is used. Participation of all stakeholders was identified as being essential in improving handoffs in general. Other themes included that handoffs should occur in both verbal and written formats, and that providers and learners, specifcally medical students and residents, should be comfortable with both types of handoffs.

Conclusions:

Participants identified that including all stakeholders is essential to improve handoffs, that PBH is not superior to traditional handoffs, and that both processes have value. Further research should be conducted to determine if including all stakeholders in the handoff process results in improved quality of care and safety.