bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Variability in Puccinia psidii Populations as Revealed by PCR-DGGE and T-RFLP Markers
Authors: Quecine Maria Carolina , Bini Andressa Peres , Romagnoli Emiliana R. , Andreote Fernando Dini , Moon David Henry , Labate Carlos Alberto
Published: December 2013

Eucalyptus rust caused by Puccinia psidii is responsible for losses of approximately 20% of young Eucalyptus plants, depending on the environmental conditions and the geographic location. Despite its economic importance, there are few studies describing the genetic variability in P. psidii populations that infect different host plants. In the present study, we evaluated the ribosomal DNA internal transcribed spacer region (rDNA-ITS) using polymerase chain reaction denaturing gradient gel electrophoresis and terminal restriction fragment length polymorphism to assess the genetic variability in P. psidii populations infecting different Eucalyptus spp. and hybrids, as well as guava, jabuticaba, and syzygium. These culture-independent methods were efficient in differentiating populations based on the host species from which they were collected. In general, the results from both techniques showed that the populations collected from guava, jabuticaba, and syzygium were different from and had a greater level of diversity than the Eucalyptus rust populations. The sequencing of cloned rDNA-ITS fragments confirmed that the vast majority of the profiles generated were from P. psidii. This analysis also revealed interesting single-nucleotide polymorphisms. Therefore, these culture-independent methods are suitable for the rapid assessment of genetic variability within and between populations of this biotrophic fungus on a variety of host species and could be a tool to study the evolution of this pathogen and its interactions with host plants.
Slow-Rusting Resistance in Native Spearmint to Puccinia menthae
Authors: Johnson Dennis A.
Published: December 2013

Rust, caused by Puccinia menthae, is often a serious yield-reducing problem on native and Scotch spearmint in south-central Washington State. Rust resistant mint cultivars would reduce a dependence on fungicides for disease management; however, conventional breeding practices are not possible because commercial mint plants are sterile. Mutant Scotch and native spearmint lines induced by irradiation were evaluated for partial resistance to rust. Latent period and number of uredinia per leaf from urediniospore inoculations in the greenhouse and aecial and uredinial development in the field were quantified. Length of latent period, number of uredinia per leaf, incidence of shoots with aecia, and area under the disease progress curve (AUDPC) for uredinia development all varied significantly among lines and standard cultivars. Length of latent period was significantly longer and number of uredinia per leaf was significantly lower for native spearmint line N87-1 than for most of the other mutant lines, native spearmint, and Scotch spearmint. Line N87-1 had the lowest AUDPC values of all lines and standard cultivars for 3 years in the field. However, line N87-1 had a relatively high incidence of shoots with aecia both of two years in the field. Length of latent period was significantly and negatively correlated with AUDPC 2 of 3 years. Mean incidence of shoots with aecia was not correlated with AUDPC or with length of latent period after urediniospore infection. Rust in native spearmint in south-central Washington State could be satisfactorily managed with slow-rusting resistance when coupled with good irrigation water management and sanitation tactics that limit aecia development on early spring mint foliage.
The FupA/B protein uniquely facilitates transport of ferrous iron and siderophore-associated ferric iron across the outer membrane of Francisella tularensis live vaccine strain
Authors: Ramakrishnan Girija , Sen Bhaswati
Published: December 2013

Francisella tularensisis a highly infectious Gram-negative pathogen that replicates intracellularly within the mammalian host. One of the factors associated with virulence ofF. tularensisis the protein FupA that mediates high-affinity transport of ferrous iron across the outer membrane. Together with its paralogue FslE, a siderophore–ferric iron transporter, FupA supports survival of the pathogen in the host by providing access to the essential nutrient iron. The FupA orthologue in the attenuated live vaccine strain (LVS) is encoded by the hybrid genefupA/B, the product of an intergenic recombination event that significantly contributes to attenuation of the strain. We used55Fe transport assays with mutant strains complemented with the different paralogues to show that the FupA/B protein of LVS retains the capacity for high-affinity transport of ferrous iron, albeit less efficiently than FupA of virulent strain Schu S4.55Fe transport assays using purified siderophore and siderophore-dependent growth assays on iron-limiting agar confirmed previous findings that FupA/B also contributes to siderophore-mediated ferric iron uptake. These assays further demonstrated that the LVS FslE protein is a weaker siderophore–ferric iron transporter than the orthologue from Schu S4, and may be a result of the sequence variation between the two proteins. Our results indicate that iron-uptake mechanisms in LVS differ from those in Schu S4 and that functional differences in the outer membrane iron transporters have distinct effects on growth under iron limitation.
Influence of walking speed on locomotor time production
Authors: Megrot Fabrice , Megrot Carole
Published: December 2013

The aim of the present study was to determine whether or not walking speed affects temporal perception. It was hypothesized that fast walking would reduce the perceived length of time while slow walking increase production estimates. 16 healthy subjects were included. After a first « calibration » phase allowing the determination of different walking speeds, the subjects were instructed to demonstrate periods of time or « target times » of 3s and 7s, by a walking movement. Then, subjects were asked to simulate walking by raising one foot after the other without advancing. Finally, a third condition, Motionless, involved producing the target times while standing without movement. The results of this study suggest that movement does influence the perception of time, causing an overestimation of time. In agreement with the results of Denner et al. (1963) the subjects produced times which were longer than the target times.
Plantation Forestry under Global Warming: Hybrid Poplars with Improved Thermotolerance Provide New Insights on the in Vivo Function of Small Heat Shock Protein Chaperones
Authors: Merino Irene , Contreras Angela , Jing Zhong-Ping , Gallardo Fernando , Cánovas Francisco M. , Gómez Luis
Published: December 2013

Climate-driven heat stress is a key factor affecting forest plantation yields. While its effects are expected to worsen during this century, breeding more tolerant genotypes has proven elusive. We report here a substantial and durable increase in the thermotolerance of hybrid poplar (Populus tremula × Populus alba) through overexpression of a major small heat shock protein (sHSP) with convenient features. Experimental evidence was obtained linking protective effects in the transgenic events with the unique chaperone activity of sHSPs. In addition, significant positive correlations were observed between phenotype strength and heterologous sHSP accumulation. The remarkable baseline levels of transgene product (up to 1.8% of total leaf protein) have not been reported in analogous studies with herbaceous species. As judged by protein analyses, such an accumulation is not matched either by endogenous sHSPs in both heat-stressed poplar plants and field-grown adult trees. Quantitative real time-polymerase chain reaction analyses supported these observations and allowed us to identify the poplar members most responsive to heat stress. Interestingly, sHSP overaccumulation was not associated with pleiotropic effects that might decrease yields. The poplar lines developed here also outperformed controls under in vitro and ex vitro culture conditions (callus biomass, shoot production, and ex vitro survival), even in the absence of thermal stress. These results reinforce the feasibility of improving valuable genotypes for plantation forestry, a field where in vitro recalcitrance, long breeding cycles, and other practical factors constrain conventional genetic approaches. They also provide new insights into the biological functions of the least understood family of heat shock protein chaperones.
Market Failure and Japanese Farmland Rents
Authors: Dawson P. J.
Published: December 2013

Since the early 1950s, Japanese farmland rents have been regulated and a consensus emerged that rent control led to market failure. Hypothesising a rent‐formation model where rents are determined by prices, this paper estimates a threshold autoregressive model which integrates three tests of market failure, namely, inefficiency, bias and asymmetry. There are four results. First, a long‐run relationship exists between rents and prices, and the Japanese farmland rental market is efficient. Second, the rent‐price elasticity is unity and the market is unbiased. Third, rents are Granger‐caused by prices which supports the rent‐formation model. Fourth, asymmetry exists where more rapid error‐correction occurs immediately after policy reform when rent growth exceeds price growth by 3.6% or more, and rent control has benefitted tenants.
Spatial distribution of Vespa velutina individuals hunting at domestic honeybee hives: heterogeneity at a local scale
Authors: Monceau Karine , Bonnard Olivier , Moreau Jérôme , Thiéry Denis
Published: December 2013

Since its recent introduction into Europe, the yellow‐legged hornet, Vespa velutina, has become a major predator of the domestic honeybee, Apis mellifera, but little is known about its hunting behavior. We studied V. velutina hunting behavior by a capture‐mark‐recapture procedure in an experimental apiary. A total of 360 hornets were captured and tagged, and we determined: (i) the number of hornets visiting the apiary and the changes in time, (ii) the average number of individual visits per half‐day and the time elapsed between consecutive recaptures, and (iii) the individual and global distribution of the hornets in the apiary. More than 50% of the marked hornets were recaptured at least once, this increased to 74% in considering the first marked individuals. We estimated 350 hornets visiting the patch daily with at least 1 visit per half‐day. The number of marked hornets decreased over time while the number of unmarked ones increased, suggesting a turnover of individuals. The reduction of the delay between consecutive visits indicates that hornets became more efficient over time. Most of the hornets (88%) were recaptured in front of different hives but, overall, the global distribution was aggregative. Hornets were mainly recaptured in front of 1 hive which was neither the smallest nor the biggest colony, suggesting that the major cue used by hornets is not the amount of food. We hypothesize that the defensive behavior of the honeybee colony could explain our results which may be promising to further studies.
Identification of quantitative trait loci affecting gastrointestinal parasite resistance in an experimental Angus population
Authors: Kim Eui‐Soo , Sonstegard Tad S. , Silva Marcos Vinicius G. B. , Gasbarre Louis C. , Van Tassell Curtis P.
Published: December 2013

DNA markers associated with quantitative trait loci (QTL) affecting host tolerance to gastrointestinal (GI) parasite infection are ideal targets for marker‐assisted selection. However, few studies in cattle have attempted to identify this type of QTL due to the difficulty of generating accurate phenotypic data from a resource population with adequate statistical power for detection. For this effort, we amassed fecal egg count (FEC) measures from annual natural field challenges with GI nematodes that spanned 12 different contemporary groups of Angus calves (1992–2000) derived from a closed breeding population. FEC and blood pepsinogen measures were taken weekly over a 26‐week period post‐weaning, and the FEC data were Box‐Cox transformed to normalize the distribution of phenotypes. These 305 test animals and more than 100 founding animals from the extended pedigree were genotyped across 190 microsatellites markers. The genome‐wide analyses identified a suggestive genome‐wide QTL on bovine chromosome (Chr) 8 (P < 0.002) and nominal QTL on Chr 4, 12 and 17 (P < 0.05). These findings were unique for cattle, and some corresponded to previously identified QTL locations for parasite‐related traits in sheep to provide genome locations for further fine mapping of parasite resistance/susceptibility in Angus cattle.
Genome‐wide analysis of Italian sheep diversity reveals a strong geographic pattern and cryptic relationships between breeds
Authors: Ciani E. , Crepaldi P. , Nicoloso L. , Lasagna E. , Sarti F. M. , Moioli B. , Napolitano F. , Carta A. , Usai G. , D'Andrea M. , Marletta D. , Ciampolini R. , Riggio V. , Occidente M. , Matassino D. , Kompan D. , Modesto P. , Macciotta N. , Ajmone‐Marsan P. , Pilla F.
Published: December 2013

Italy counts several sheep breeds, arisen over centuries as a consequence of ancient and recent genetic and demographic events. To finely reconstruct genetic structure and relationships between Italian sheep, 496 subjects from 19 breeds were typed at 50K single nucleotide polymorphism loci. A subset of foreign breeds from the Sheep HapMap dataset was also included in the analyses. Genetic distances (as visualized either in a network or in a multidimensional scaling analysis of identical by state distances) closely reflected geographic proximity between breeds, with a clear north–south gradient, likely because of high levels of past gene flow and admixture all along the peninsula. Sardinian breeds diverged more from other breeds, a probable consequence of the combined effect of ancient sporadic introgression of feral mouflon and long‐lasting genetic isolation from continental sheep populations. The study allowed the detection of previously undocumented episodes of recent introgression (Delle Langhe into the endangered Altamurana breed) as well as signatures of known, or claimed, historical introgression (Merino into Sopravissana and Gentile di Puglia; Bergamasca into Fabrianese, Appenninica and, to a lesser extent, Leccese). Arguments that would question, from a genomic point of view, the current breed classification of Bergamasca and Biellese into two separate breeds are presented. Finally, a role for traditional transhumance practices in shaping the genetic makeup of Alpine sheep breeds is proposed. The study represents the first exhaustive analysis of Italian sheep diversity in an European context, and it bridges the gap in the previous HapMap panel between Western Mediterranean and Swiss breeds.
Patient frailty: the elephant in the operating room
Authors: Hubbard R. E. , Story D. A.
Published: December 2013

For most surgeons and many anaesthetists, patient frailty is currently the ‘elephant in the (operating) room’: it is easy to spot, but is often ignored. In this paper, we discuss different approaches to the measurement of frailty and review the evidence regarding the effect of frailty on peri‐operative outcomes. We explore the limitations of ‘eyeballing’ patients to quantify frailty, and consider why the frail older patient, challenged by seemingly minor insults in the postoperative period, may suffer falls or delirium. Frailty represents a state of increased vulnerability to stressors, and older inpatients are exposed to multiple stressors in the peri‐operative setting. Quantifying frailty is likely to increase the precision of peri‐operative risk assessment. The Frailty Index derived from Comprehensive Geriatric Assessment is a simple and robust way to quantify frailty, but is yet to be systematically investigated in the pre‐operative setting. Furthermore, the optimal care for frail patients and the reversibility of frailty with prehabilitation are fertile areas for future research.
Emergency surgery: the big three – abdominal aortic aneurysm, laparotomy and hip fracture
Authors: Stoneham M. , Murray D. , Foss N.
Published: December 2013

National reports recommended that peri‐operative care should be improved for elderly patients undergoing emergency surgery. Postoperative mortality and morbidity rates remain high, and indicate that emergency ruptured aneurysm repair, laparotomy and hip fracture fixation are high‐risk procedures undertaken on elderly patients with limited physiological reserve. National audits have reported variations in care quality, data that are increasingly being used to drive quality improvement through professional guidance. Given that the number of elderly patients presenting for emergency surgery is likely to rise as the population ages, this review summarises the evidence on which such guidance is based, and provides information about how anaesthetists might participate in audit and research aimed at improving local and national outcomes for these most vulnerable of patients.
A survey of zeb1, twist and claudin 1 and 4 expression during placental development and disease
Authors: Pirinen Elina , Soini Ylermi
Published: December 2013

We investigated zeb1, twist and claudins 1 and 4 in normal and diseased placental tissues. Eighty cases of placental tissues from all three trimesters and from different diseases were studied immunohistochemically to determine the expression of zeb1, twist and claudins 1 and 4. Zeb1 was more strongly expressed in endothelial and mesenchymal cells of the villous structures during the last two trimesters, suggesting that it plays a role in the development of placental blood vessels. In contrast, twist was more strongly expressed in the trophoblastic cells during these trimesters. The endothelial and stromal expression of zeb1 and the epithelial expression of twist were disturbed in those placentas with chromosomal aberrations. Claudin 4 was strongly expressed in trophoblastic cells during all trimesters. Its expression was especially strong in molar disease, suggesting that it could participate in trophoblastic aggregation and disturbed attachment of trophoblastic cells in the expanded villi. Claudin 4 expression was also increased in the placentas of diabetic mothers and in toxaemia. Claudin 1 did not show any specific disease associations. The study implicates that twist and zeb1 are involved in placental maturation, whereas claudin 4 appears to be connected with placental diseases such as diabetes, toxaemia or molar disease.
Conceptualising the role of information and communication technologies in the design of higher education teaching models used in the UK
Authors: Caird Sally , Lane Andy
Published: December 2013

Despite the widespread availability of information and communication technologies (ICTs) and some research into specific pedagogical practices using them, there has been little research on the role of these technologies in shaping broader pedagogical approaches in higher education (HE). Increased experimentation in using ICTs raises questions about their pedagogical role in teaching, learning and assessment provision, and in creating innovative pedagogies. An accepted approach is needed to compare the different ways ICTs and rich media are used in HE teaching models. Within the SusTEACH HE sustainability research project this was needed to support the carbon‐based environmental assessment of HE courses using ICTs. Building on a review of learning design theories and models, and ICTs used for pedagogical purposes, this paper considers several approaches to conceptualising the role of ICTs in HE courses, leading to the development of the Teaching Models Rating Tool designed to examine the role of ICTs in course provision. This tool characterises courses as using Face‐to‐Face Teaching Models, Distance Teaching Models, ICT‐Enhanced Blended Teaching Models or Online Teaching Models. Whilst this tool was designed to support research on sustainable HE teaching models in the UK, it has wider applications to support comparative assessments of pedagogical and economic impacts. Further developments will be informed by the complex and evolving role of ICTs in HE teaching models.
First detection of glacial meltwater signature in tree‐ring δ18O: Reconstructing past major glacier runoff events at Lago Verde (Miage Glacier, Italy)
Authors: Leonelli Giovanni , Pelfini Manuela , Battipaglia Giovanna , Saurer Matthias , Siegwolf Rolf T. W. , Cherubini Paolo
Published: December 2013

With the aim of evaluating the influence of glacial meltwater signature on tree‐ring stable isotopes, we analysed δ18O and δ13C in the tree rings of Larix decidua Mill. specimens growing in the area of an ice‐contact lake (Lago Verde, at Miage Glacier, European Alps). Additionally, we analysed δ18O in the glacial meltwater of the lake and of the glacier stream and compared it with the δ18O of precipitation predicted by a spatial model. We found that tree‐ring cellulose of trees fed by glacial meltwaters (LVW site) is significantly more depleted in δ18O than at a control site LVM (−0.91‰) fed only by precipitation, thus reflecting the measured higher depletion of glacial meltwaters with respect to local precipitation. δ13C values did not show significant differences in mean values between the two sites but an anomalous correlation with summer temperature was found at the LVW site, probably due to the different responses of trees stomatal conductance. Over the 30‐year period of analysis, four years at LVW (1992, 1995, 2003 and 2009) were markedly depleted in δ18O. These years are those when the highest summer temperatures were recorded in the area (the ones during which glacier ablation usually increases and more depleted meltwaters fill the lake), with the exception of 1995 during which high water levels occurred following the year with the second highest summer temperature (1994). Overall, our analysis demonstrates that tree‐ring δ18O, driven by the glacial meltwater signature in the lake, can be used for detecting past major glacier runoff events. The proposed approach could also be used for quantifying past glacier runoff and for defining past distribution areas of glacial meltwaters in glacier forefields, thus contributing to past environmental reconstructions and to hazard assessment.
A role for PPARα in the medial prefrontal cortex in formalin‐evoked nociceptive responding in rats
Authors: Okine B N , Rea K , Olango W M , Price J , Herdman S , Madasu M K , Roche M , Finn D P
Published: December 2013

Background and Purpose

The nuclear hormone receptor, PPARα, and its endogenous ligands, are involved in pain modulation. PPARα is expressed in the medial prefrontal cortex (mPFC), a key brain region involved in both the cognitive‐affective component of pain and in descending modulation of pain. However, the role of PPARα in the mPFC in pain responding has not been investigated. Here, we investigated the effects of pharmacological modulation of PPARα in the rat mPFC on formalin‐evoked nociceptive behaviour and the impact of formalin‐induced nociception on components of PPARα signalling in the mPFC.

Experimental Approach

The effects of intra‐mPFC microinjection of a PPARα agonist (GW7647) or a PPARα antagonist (GW6471) on formalin‐evoked nociceptive behaviour in rats were studied. Quantitative real‐time PCR and LC‐MS/MS were used to study the effects of intraplantar injection of formalin on PPARα mRNA expression and levels of endogenous ligands, respectively, in the mPFC.

Key Results

Intra‐mPFC administration of GW6471, but not GW7647, resulted in delayed onset of the early second phase of formalin‐evoked nociceptive behaviour. Furthermore, formalin‐evoked nociceptive behaviour was associated with significant reductions in mPFC levels of endogenous PPARα ligands (N‐palmitoylethanolamide and N‐oleoylethanolamide) and a 70% reduction in PPARα mRNA but not protein expression.

Conclusions and Implications

These data suggest that endogenous ligands may act at PPARα in the mPFC to play a facilitatory/permissive role in second phase formalin‐evoked nociceptive behaviour in rats.

Linked Articles

This article is part of a themed section on Cannabinoids 2013. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2014.171.issue‐6
Genetic variants of immunoglobulin γ and κ chains influence humoral immunity to the cancer-testis antigen XAGE-1b (GAGED2a) in patients with non-small cell lung cancer
Authors: Pandey J P , Namboodiri A M , Ohue Y , Oka M , Nakayama E
Published: December 2013

GM (γ marker) allotypes, genetic variants of immunoglobulin γ chains, have been reported to be associated strongly with susceptibility to lung cancer, but the mechanism(s) underlying this association is not known. One mechanism could involve their contribution to humoral immunity to lung tumour-associated antigens. In this study, we aimed to determine whether particular GM and KM (κ marker) allotypes were associated with antibody responsiveness to XAGE-1b, a highly immunogenic lung tumour-associated cancer-testis antigen. Sera from 89 patients with non-small cell lung cancer (NSCLC) were allotyped for eight GM and two KM determinants and characterized for antibodies to a synthetic XAGE-1b protein. The distribution of various GM phenotypes was significantly different between XAGE-1b antibody-positive and -negative patients (P = 0·023), as well as in the subgroup of XAGE-1b antigen-positive advanced NSCLC (P = 0·007). None of the patients with the GM 1,17 21 phenotype was positive for the XAGE-1b antibody. In patients with antigen-positive advanced disease, the prevalence of GM 1,2,17 21 was significantly higher in the antibody-positive group than in those who lacked the XAGE-1b antibody (P = 0·026). This phenotype also interacted with a particular KM phenotype: subjects with GM 1,2,17 21 and KM 3,3 phenotypes were almost four times (odds ratio = 3·8) as likely to be positive for the XAGE-1b antibody as the subjects who lacked these phenotypes. This is the first report presenting evidence for the involvement of immunoglobulin allotypes in immunity to a cancer-testis antigen, which has important implications for XAGE-1b-based immunotherapeutic interventions in lung adenocarcinoma.
The influence of the periodontal biotype on peri‐implant tissues around immediate implants with and without xenografts. Clinical and micro‐computerized tomographic study in small Beagle dogs
Authors: Maia Luciana P. , Reino Danilo M. , Muglia Valdir A. , de Souza Sérgio L. S. , Palioto Daniela B. , Novaes Arthur B.
Published: December 2013

Objective

Soft tissues and buccal bone plate remodeling after immediate implantation in sockets with thin buccal bone, using the flapless approach with or without bone graft into the buccal gap, was compared between sites with thin and normal gingiva.

Material and methods

Eight dogs had the gingiva of one side of the mandible thinned, the mandibular premolars were extracted without flaps, and 4 implants were installed in each side, positioned 1.5 mm from the buccal bone. The sites were randomly assigned into: TG (test group) = thin gingiva; TG + GM (TG with grafting material); CG (control group) = normal gingiva; and CG + GM (CG with grafting material). Buccal bone thickness (BBT), thickness of keratinized tissue (TKT), alveolar thickness (AT), gingival recession (GR), and probing depth (PD) were clinically evaluated. Within 12 weeks the dogs were sacrificed and the samples were analyzed by micro‐computerized tomography.

Results

A thin BBT was observed in all the dogs. The presurgical procedures reduced TKT in the test group, with minimal changes of the AT. There were no statistically significant differences among the groups for the clinical parameters and the tomographic analysis showed similar linear and tri‐dimensional bone reduction in all the groups.

Conclusion

The thickness of the buccal bone was a fundamental factor in buccal bone plate resorption, even with flapless implantation. The decrease in gingival thickness or the addition of a biomaterial in the gap did not influence the results.
Lotus petal perforator flap for reconstruction of an extended chronic presacral defect after radiotherapy and rectal cancer resection
Authors: van der Meer J. G. , Moerman E. , van de Kar A. L. , Vermaas M. , Gerhards M. F.
Published: December 2013

Aim

As a result of their extent and complexity, pelvic wounds after surgery for anorectal malignancy often require a multidisciplinary approach to accomplish closure. This report describes a successful reconstruction using the lotus petal perforator flap.

Method

This flap is based on perforators of the internal pudendal artery and was partially depithelialized for plugging the defect.

Results

Wound healing was achieved after 12 days.

Conclusion

The lotus petal flap is a relatively simple and successful choice for reconstruction of an extended chronic presacral defect after radiotherapy and rectal cancer resection.
Early Effect of Essential Hypertension on the Left Ventricular Twist‐Displacement Loop by Two‐Dimensional Ultrasound Speckle Tracking Imaging
Authors: Qin Chuan , David Meggo‐Quiroz L. , Nanda Navin C. , Wang Xinfang , Xie Mingxing
Published: December 2013

Objective

To investigate two‐dimensional (2D) ultrasound speckle tracking imaging (STI) in the evaluation of the early changes in the left ventricular (LV) twist‐displacement loop in patients with hypertension (EH).

Methods

Sixty‐five EH patients with left ventricular normal geometry (LVN) – including 33 cases with non‐left atrial enlargement (NLAE) and 32 cases with left atrial enlargement (LAE) – along with 45 healthy individuals were enrolled in this study. Basal and apical 2D LV short‐axis images were acquired and analyzed to obtain the LV rotation (LVrot) and LV radial displacement. Once the LV twist and LV radial displacement were calculated, an LV twist‐displacement loop was constructed. Group comparisons between peak twist (Ptw), twist at mitral valve opening (MVOtw), untwisting rate (Utw R), systolic radial displacement (SD), systolic slope (SS), isovolumic relaxation radial displacement (IVRD) and isovolumic relaxation slope (IVRS) were performed.

Results

(1) The Ptw and MVOTw were greater in the NLAE and LAE groups when compared to the normal group while the UTw R was lower in likewise comparison. (2) The LV twist was correlated to the radial displacement in systole and in the isovolumic relaxation period. The SS and IVRS were greater in the NLAE and LAE groups when compared to the normal group.

Conclusions

The LV twist‐displacement loop can be reconstructed noninvasively by 2D ultrasound STI. EH affects the systolic and early diastolic component of the twist‐displacement loop by increasing the LV twist and decreasing the LV untwisting respectively impairing LV relaxation. The assessment of the LV twist‐displacement loop may be useful in the evaluation of early features of LV dysfunction in EH patients.
Utility of Speckle Tracking Echocardiography to Characterize Dysfunctional Myocardium in Patients with Ischemic Cardiomyopathy Referred for Cardiac Resynchronization Therapy
Authors: Kydd Anna C. , Khan Fakhar , Gopalan Deepa , Ring Liam , Rana Bushra S. , Virdee Mohan S. , Dutka David P.
Published: December 2013

Background

Assessment of transmural scar at the site of latest mechanical activation is relevant to maximize outcomes in cardiac resynchronization therapy (CRT). Few studies have assessed the ability of speckle tracking echocardiography (STE)‐derived short‐axis strain to identify segmental myocardial scar, defined by contrast‐enhanced cardiac magnetic resonance imaging (CMR), in patients referred for CRT.

Methods

A total of 26 patients with ischemic cardiomyopathy who underwent preprocedure echocardiography and CMR were studied. Extent of transmural scar was assessed using contrast‐enhanced CMR and corresponding peak segmental radial and circumferential strains were derived using two‐dimensional (2D) STE. Total left ventricle (LV) scar volume was compared with parameters of global strain. CRT response was defined as >15% reduction in LV end systolic volume (LVESV) at 6 months.

Results

Speckle tracking short‐axis strain analysis was technically possible in over 90% of LV segments. Applying a segmental radial strain cutoff value of 10% distinguished segments with >50% scar area with a high negative predictive value (98%). Global longitudinal strain <−5% predicted CRT response.

Conclusions

Two‐dimensional STE offers potential to characterize dysfunctional myocardium and define segmental scar offering an integrated imaging approach to guide LV lead placement for CRT.
The Shadow Within: A Colossal Left Atrium
Authors: Varghese Mithun J. , Hussain Tajammul , George Paul V. , Pati Purendra K. , Jose Jacob V.
Published: December 2013

Mini‐Abstract

A 32‐year‐old male with rheumatic heart disease presented with atrial fibrillation and severe mitral regurgitation. His chest radiograph showed cardiomegaly and the distinctive shadow within shadow appearance of a distended left atrium (LA); echocardiogram revealed an LA dimension of 15.2 × 12.8 cm and cardiac magnetic resonance imaging disclosed a calculated LA volume of 1950 mL, representing one of the largest reported LA sizes in the current literature.
Nocturnal resource defence in aphid‐tending ants of northern Patagonia
Authors: LESCANO MARÍA N. , FARJI‐BRENER ALEJANDRO G. , GIANOLI ERNESTO
Published: December 2013

Interspecific competition plays a key role in the organisation of ant communities. In ant–plant interactions, individual host plants are usually occupied by a single ant colony, and co‐occurring ant species compete for hosts. Here indirect evidence of competition between three dominant ant species that tend aphids on two biennial thistles in northern Patagonia is described, and a novel defensive behaviour in temperate ant assemblages is reported.

This study has found that: (i) dominant ant species were not spatially segregated, thus enhancing the probability of fights and invasions of host plants; (ii) ant species did not show preferences for a thistle species or for any plant characteristic, and thus all plants have similar chances of being colonised by all dominant ant species; (iii) the resident ant species remained on the same plant during the whole plant life cycle, monopolising plant resources (aphids); and (iv) all dominant species, whose nests are on the ground, assigned some ants to stay on the host plant during the night, when the low temperatures typical of this temperate environment greatly reduce foraging activities. When these ‘nocturnal guards’ were experimentally removed from the host plant, other ants from the same colony rapidly appeared showing aggressive behaviours.

Taking all these findings together, it is suggested that interspecific competition influences the distribution of ants on their host plants and involves nocturnal defensive behaviours despite unfavourable thermal conditions. This illustrates how habitat features, such as the short life cycle of thistles and the low night‐time temperatures that reduce ant foraging and thus make plants more vulnerable to invasion, might affect the distribution and behaviour of ants.
Biotic and abiotic regulation of a low‐density stream‐dwelling brown trout (Salmo truttaL.) population: effects on juvenile survival and growth
Authors: Richard Alexandre , Cattanéo Franck , Rubin Jean‐François
Published: December 2013

The effects of biotic (density‐dependent) and environmental (flow and temperature) factors on the apparent survival, mean length and size variation of a low‐density brown trout population in the juvenile stage, that is, from their first summer (0+) to the end of the second year (1+), were determined. Apparent survival was negatively related to the age class density during the three periods (first summer, first winter and second summer). A significant interaction between the mean flow and 0+ density highlighted a gradient towards strong density dependence acting on fish loss (i.e., mortality or migration) with decreasing summer flow. Conversely, no density dependence was reported at higher mean flows. The mean length was determined by density‐dependent and density‐independent (temperature and flow) factors throughout the study period. The negative relationship between fish length and intracohort density was highly significant during the three periods. The yearling (1+) density was negatively related to 0+ fish length measured after the first summer, suggesting intercohort effects. A positive effect of temperature on fish length was observed. Mean length after the summer seasons (0+ and 1+ fish) was also positively related to mean flow. Fish size variation around the mean measured with the coefficient of variation (CV) increased with increasing 0+ densities, both at the end of the first summer and the first winter. Results suggested that density‐dependent and density‐independent factors acted jointly on apparent survival and growth with a predominance of biotic processes. We discussed the potential implications of density‐dependent regulations on growth and survival for population resilience after catastrophic events.
Gender differences in suicidal behaviour in patients with first‐episode psychosis
Authors: Austad Gudrun , Joa Inge , Johannessen Jan Olav , Larsen Tor Ketil
Published: December 2013

Aim

Prior research shows contradictory gender patterns in suicidal behaviour among patients with first‐episode psychosis. The aim of this study was to investigate gender differences in the prevalence of suicidal behaviour (suicidal ideation, suicide plans and suicide attempts) and to delineate risk factors for suicidal behaviour among consecutively included male and female patients with first‐episode psychosis in the TIPS II early detection study.

Methods

Patients with first‐episode psychosis (n = 246) from a hospital catchment area with a system for early detection were assessed and compared on baseline sociodemographical and clinical variables according to gender. Current (past 1 month) and lifetime prevalence of suicidal behaviour were assessed.

Results

Current and lifetime rates of suicidal behaviour were high (50.8% and 65.9%, respectively) and higher among females (lifetime: 78.3 %, past month: 64.2 %) versus males (lifetime: 56.4 %, past month: 40.7 %). Depressive symptoms and female gender were associated with both lifetime and current risk for suicidal behaviour. Lifetime prevalence was also associated with a longer duration of untreated psychosis and young age after controlling for other risk factors.

Conclusions

Suicidal behaviour was frequent among patients with first‐episode psychosis, with a higher prevalence of suicidal behaviour in females. Depressive symptoms and female gender were significantly associated with suicidal behaviour.
Mechanisms underlying the basal forebrain enhancement of top‐down and bottom‐up attention
Authors: Avery Michael C. , Dutt Nikil , Krichmar Jeffrey L.
Published: December 2013

Both attentional signals from frontal cortex and neuromodulatory signals from basal forebrain (BF) have been shown to influence information processing in the primary visual cortex (V1). These two systems exert complementary effects on their targets, including increasing firing rates and decreasing interneuronal correlations. Interestingly, experimental research suggests that the cholinergic system is important for increasing V1's sensitivity to both sensory and attentional information. To see how the BF and top‐down attention act together to modulate sensory input, we developed a spiking neural network model of V1 and thalamus that incorporated cholinergic neuromodulation and top‐down attention. In our model, activation of the BF had a broad effect that decreases the efficacy of top‐down projections and increased the reliance of bottom‐up sensory input. In contrast, we demonstrated how local release of acetylcholine in the visual cortex, which was triggered through top‐down gluatmatergic projections, could enhance top‐down attention with high spatial specificity. Our model matched experimental data showing that the BF and top‐down attention decrease interneuronal correlations and increase between‐trial reliability. We found that decreases in correlations were primarily between excitatory–inhibitory pairs rather than excitatory–excitatory pairs and suggest that excitatory–inhibitory decorrelation is necessary for maintaining low levels of excitatory–excitatory correlations. Increased inhibitory drive via release of acetylcholine in V1 may then act as a buffer, absorbing increases in excitatory–excitatory correlations that occur with attention and BF stimulation. These findings will lead to a better understanding of the mechanisms underyling the BF's interactions with attention signals and influences on correlations.
Predicting the process of extinction in experimental microcosms and accounting for interspecific interactions in single‐species time series
Authors: Ferguson Jake M. , Ponciano José M.
Published: December 2013

Predicting population extinction risk is a fundamental application of ecological theory to the practice of conservation biology. Here, we compared the prediction performance of a wide array of stochastic, population dynamics models against direct observations of the extinction process from an extensive experimental data set. By varying a series of biological and statistical assumptions in the proposed models, we were able to identify the assumptions that affected predictions about population extinction. We also show how certain autocorrelation structures can emerge due to interspecific interactions, and that accounting for the stochastic effect of these interactions can improve predictions of the extinction process. We conclude that it is possible to account for the stochastic effects of community interactions on extinction when using single‐species time series.
Synchronisation and stability in river metapopulation networks
Authors: Yeakel J. D. , Moore J. W. , Guimarães P. R. , de Aguiar M. A. M.
Published: December 2013

Spatial structure in landscapes impacts population stability. Two linked components of stability have large consequences for persistence: first, statistical stability as the lack of temporal fluctuations; second, synchronisation as an aspect of dynamic stability, which erodes metapopulation rescue effects. Here, we determine the influence of river network structure on the stability of riverine metapopulations. We introduce an approach that converts river networks to metapopulation networks, and analytically show how fluctuation magnitude is influenced by interaction structure. We show that river metapopulation complexity (in terms of branching prevalence) has nonlinear dampening effects on population fluctuations, and can also buffer against synchronisation. We conclude by showing that river transects generally increase synchronisation, while the spatial scale of interaction has nonlinear effects on synchronised dynamics. Our results indicate that this dual stability – conferred by fluctuation and synchronisation dampening – emerges from interaction structure in rivers, and this may strongly influence the persistence of river metapopulations.
Cervical extradural haematoma in an ataxic horse
Authors: Cunha dos Santos F. C. , de Lourdes Adrien Delgado M. , Fernandes C. G. , Nogueira C. E. W.
Published: December 2013

As neurological diseases in horses share many overlapping clinical signs, the veterinarian is required to know how to perform a focused evaluation of this system as well as how to carry out complementary examinations to establish an aetiological diagnosis. This is a case report of an ataxic horse presenting with an extradural haematoma in the region of the 7th cervical vertebra. The 7‐year‐oldCriollo mare presented with clinical signs of ataxiagrade 3(scale 1–5) in all limbs and a proprioceptive deficit. Radiological evaluation did not show bone changes or narrowing of the cervical canal. Samples of blood, serum and cerebrospinal fluid were collected and tested negative for antibodies to equine herpes virus type 1–4,Trypanosoma evansiandSarcocystis neurona. The disease evolution was followed over a 4‐week period, after which the animal showed worsening overall clinical signs, and thus euthanasia was performed. A necropsy did not reveal macroscopic changes in any organs, except for an extradural haematoma in the region of the 7th cervical vertebra causing spinal cord compression. Histological examinations showed that the nodular lesion consisted of fibrovascular tissue, granulation tissue at different stages of maturation, red blood cells, cellular debris, fibrin and macrophages. The white matter of the ventral horn of the spinal cord contained degenerative lesions. In addition, the brain tested negative for rabies virus encephalitis. Based on the history, the laboratory test results, anamnesis and the lesion observed at necropsy, it was concluded that the ataxia was due to spinal cord compression, which was caused by an extradural haematoma in the region of the 7th cervical vertebra. Evaluation of the equine neurological system is highly important in localising the area of lesions, and complementary examinations are useful in differentiating between diseases affecting this system. Spinal cord compression injuries, such as extradural haematomas, are rarely reported in the literature, and their pathophysiology is difficult to understand. Nevertheless, they should be included in the differential diagnosis of ataxia in horses.
An inertial sensor‐based system can objectively assess diagnostic anaesthesia of the equine foot
Authors: Maliye S. , Voute L. , Lund D. , Marshall J. F.
Published: December 2013

Reasons for performing study

In order for changes in lameness to be accurately and repeatably detected and recorded during diagnostic investigations, an objective measure of lameness is required.

Objectives

To ascertain whether an inertial sensor‐based system can distinguish between a positive and negative response to diagnostic anaesthesia of the foot and objectively assess the effect of a positive response on the trot.

Study design

Restrospective clinical study.

Methods

Data obtained during lameness investigations undertaken betweenAugust 2011 andDecember 2012 in which either a palmar digital or abaxial sesamoid nerve block was performed were retrospectively reviewed. Response to diagnostic anaesthesia was categorised as positive (n = 14) or negative (n = 9) by one of 2 evaluators before analysis of kinematic data (i.e. blinded). Changes in maximum and minimum head difference (ΔHDMaxandΔHDMin) and change in head movement asymmetry/change in pelvic movement asymmetry (ΔHMA/PMA, measure of asymmetry) allocated to each limb were calculated. AKruskal–Wallis one way analysis of variance on ranks was performed.Receiver operating characteristic (ROC) curves were generated forΔHDMax,ΔHDMinandΔHMAfor the blocked limb to identify cut‐off values to distinguish positive and negative responses to the block.

Results

MedianΔHDMaxandΔHDMinwere significantly greater after a positive response to diagnostic anaesthesia (P<0.01). Change in head movement asymmetry allocated to the blocked limb and contralateral forelimb andΔPMAallocated to the contralateral hindlimb were significantly greater in the positive response group (P<0.05). Change in head movement asymmetry allocated to the blocked limb andΔHDMaxandΔHDMinare useful diagnostic tests for identifying positive response to anaesthesia (area under the curve = 0.98, 0.83 and 0.96 respectively).

Conclusions

An inertial sensor‐based system can identify a positive response to diagnostic anaesthesia of the foot. Symmetry of movement allocated to the blocked limb, contralateral forelimb and contralateral hindlimb significantly improve, and head movement significantly decreases in horses with a positive response to the block. Cut‐off values for a positive response have been identified with good sensitivity and specificity. Forelimb lameness significantly affects contralateral hindlimb movement, which has implications for the investigation of multi‐limb lameness.