bluuebunny/crossref_metadata_2025 huggingface dataset:
Three‐Dimensional Echocardiographic Delineation of an Acquired Aorto‐Left Atrial Fistula Complicating Native Aortic Valve Endocarditis – “Advantage of Three Dimensions”
Authors: Chandra Sharad , Ameta Deepak , Kharwar Rajiv Bharat , Goyal Mukesh , Kumar Devesh , Dwivedi Sudhanshu Kumar , Saran Ram Kirti
Published: August 2013

Mini‐Abstract

Aorto‐atrial fistulas are rare, but important complications resulting from aortic valve infective endocarditis, aortic valve surgery, or aortic dissection. We hereby report a case of 20‐year‐old male, referred to us with infective endocarditis of the native aortic valve with severe aortic regurgitation and symptoms of heart failure. Detailed evaluation with two‐dimensional and three‐dimensional transthoracic echocardiography revealed aorto‐left atrial fistula secondary to the involvement of the mitral–aortic intervalvular fibrosa (MAIVF) region. The patient underwent successful removal of the vegetations, closure of the defect along with aortic valve replacement and mitral valve repair.
The dopamine patchwork of the rat nucleus accumbens core
Authors: Shu Zhan , Taylor I. Mitch , Michael Adrian C.
Published: August 2013

The dopamine (DA) terminal field in the rat dorsal striatum is organized as a patchwork of domains that show distinct DA kinetics. The rate and short‐term plasticity of evoked DA release, the rate of DA clearance and the actions of several dopaminergic drugs are all domain‐dependent. The patchwork arises in part from local variations in the basal extracellular concentration of DA, which establishes an autoinhibitory tone in slow but not fast domains. The present study addressed the hypothesis that a domain patchwork might also exist in the nucleus accumbens core (NAcc), a DA terminal field that is deeply involved in reward processing and the mechanisms underlying substance abuse. DA recordings in the NAcc by fast‐scan voltammetry during electrical stimulation of the medial forebrain bundle confirmed that the NAcc contains a patchwork of fast and slow domains showing significantly different rates of evoked DA release and DA clearance. Moreover, the NAcc domains are substantially different from those in the dorsal striatum. There were no signs in the NAcc of short‐term plasticity of DA release during multiple consecutive stimuli, and no signs of a domain‐dependent autoinhibitory tone. Thus, the NAcc domains are distinct from each other and from the domains of the dorsal striatum.
Female Annual Killifish Austrolebias reicherti (Cyprinodontiformes, Rivulidae) Attend to Male Chemical Cues
Authors: Passos Carlos , Reyes Federico , Tassino Bettina , Rosenthal Gil G. , González Andrés
Published: August 2013

Chemical communication is an important mediator of social interactions in fish, including mate recognition, mate choice and intrasexual competition. We used a simultaneous‐choice design to test the response of adult females of the annual killifish, Austrolebias reicherti, towards male‐conditioned water, both crude and fractionated into its polar and non‐polar components. Females preferred male‐conditioned water when tested both against control water and female‐conditioned water. The polar and non‐polar fractions of the male‐conditioned water were not significantly attractive, although a tendency was observed towards the non‐polar fraction. Our study shows that annual fish respond to the chemical cues of potential mates. The chemical channel is likely to be particularly important in the muddy ephemeral ponds in which they occur.
The effect of insertional suspensory branch desmitis on racing performance in juvenile Thoroughbred racehorses
Authors: Plevin S. , McLellan J.
Published: August 2013

Reasons for performing the study

Limited information exists regarding the prognosis for juvenile racehorses sustaining injury to the suspensory ligament branch insertion (JISBI).

Objectives

To investigate the effect of JISBI on racing performance; and to assess whether the severity of JISBI is prognostically important.

Study design

Retrospective cohort study.

Methods

Records were reviewed for 896 juvenile Thoroughbreds in training, to identify horses with JISBI limited to one branch (cases). The ability of cases to start a race was compared to their cohorts. Race records of maternal siblings were compared to cases.

Results

The prevalence of JISBI for this population was 9.5%. Cohorts were 3.2 times more likely to start as a 2‐year‐old and 3.6 times more likely to start as a 3‐year‐old compared to horses with JISBI. Of 58 cases that were compared to maternal siblings, the total earnings per start (EPS), 2‐ and 3‐year‐old EPS were all reduced (P<0.01). Cases raced a mean of 3.8 times compared to 7.4 races for controls over the study period and were 113.2 days older by the time of first start (P<0.01). ‘Speed figures’ and EPS were, however, similar between cases that had raced and controls. Cases with a moderate–severe lesion (≥ Grade 2) were at significantly greater risk of reinjury than mild cases (P<0.05).

Conclusions

JISBI causes decreased racing ability as a 2‐year‐old. Mild cases perform similarly to controls by their 3‐year‐old season, but more severe cases demonstrate reduced ability as a 3‐year‐old, with an increased likelihood of reinjury. Although the wastage was higher in case horses with JISBI, individual cases that make it to a race have similar earnings per start as their controls.
Biogenesis of yeast Mia40 – uncoupling folding from import and atypical recognition features
Authors: Chatzi Afroditi , Sideris Dionisia P. , Katrakili Nitsa , Pozidis Charalampos , Tokatlidis Kostas
Published: August 2013

The discovery of the mitochondrial intermembrane space assembly (MIA) pathway was followed by studies that focused mainly on the typical small substrates of this disulfide relay system and the interactions between its two central partners: the oxidoreductase Mia40 and the FAD‐protein Erv1. Recent studies have revealed that more complex proteins utilize this pathway, including Mia40 itself. In the present study, we dissect the Mia40 biogenesis in distinct stages, supporting a kinetically coordinated sequence of events, starting with (a) import and insertion through the Tim23 translocon, followed by (b) folding of the core of imported Mia40 assisted by the endogenous Mia40 and (c) final interaction with Erv1. The interaction with endogenous Mia40 and the subsequent interaction with Erv1 represent kinetically distinguishable steps that rely on completely different determinants. Interaction with Mia40 proceeds very early (within 30 s) and is characterized by no Cys‐specificity, an increased tolerance to mutations of the hydrophobic substrate‐binding cleft and no apparent dependence on glutathione as a proofreading mechanism. All of these features illustrate a very atypical behaviour for the Mia40 precursor compared to other substrates of the MIA pathway. By contrast, interaction with Erv1 occurs after 5 min of import and relies on a more stringent specificity.
Environmental effects on biofilm bacterial communities: a comparison of natural and anthropogenic factors in New Zealand streams
Authors: Washington Vidya J. , Lear Gavin , Neale Martin W. , Lewis Gillian D.
Published: August 2013

We investigated the resident bacterial communities within the biofilm of 252 streams in New Zealand with the aim of assessing the community variation associated with natural and anthropogenic‐influenced environmental characteristics. This work is part of a larger project investigating the use of bacterial communities as biological indicators, and here we assess how predictable the variation in bacterial community is in response to environmental influences.

Samples of epilithic biofilm were collected in the Austral Summer of 2010, and bacterial communities were characterised using the DNA‐fingerprinting technique automated ribosomal intergenic spacer analysis (ARISA).

Multivariate analysis of the ARISA data revealed that geographical location (region) was a better predictor of bacterial community structure than land use.

Our finding that taxon richness varied with geographical location, decreasing along a north to south (increasing latitude) gradient, and that land use had no significant effect on taxon richness suggests that bacterial communities have great potential to act as biological indicators of stream health. In particular, the maintenance of taxon richness at impacted sites is a key advantage since the local extinction of many traditional indicator organisms, such as fish or macroinvertebrates, often precludes their further use.

Our conceptual model of bacterial community structure proposes that stream biofilm communities are comprised of four broad groups of bacteria: ubiquitous bacteria (found at all sites), region‐specific bacteria (those representative of geographical areas), natural‐state bacteria (those associated with unmodified systems) and impact‐related bacteria (those associated with human activities). The proportion of these four groups at a particular sample site would provide the basis of a novel bacterial community index of stream health.
A manipulative study of macroinvertebrate grazers in Hong Kong streams: do snails compete with insects?
Authors: Yeung Alex C. Y. , Dudgeon David
Published: August 2013

Sulcospira hainanensis (Pachychilidae) is the most abundant snail in Hong Kong streams. It constitutes about 1% of total benthic macroinvertebrate abundance but, because of its relatively large size, can comprise over one‐third of standing biomass. This snail may have the potential to depress periphytic algae and thereby compete for food with insect grazers.

Possible competitive interactions were investigated by manipulating snail densities in 4 streams under different shading conditions (2 shaded, 2 unshaded). Since previous work in Hong Kong streams indicated that algal standing stocks were depleted by wet‐season spates, manipulations were carried out during both the wet and dry seasons to investigate the extent of variability in interaction intensity.

Insect colonisation on artificial substrata (tiles) was compared between treatments where wire mesh barriers limited snail access, and under control conditions of natural snail densities. The exclusion treatment reduced snail densities by about 30–50% relative to controls during both seasons. Algal densities were lower during the wet season in two streams, probably reflecting spate‐induced disturbance, but snail densities remained relatively stable throughout the study.

Strong effects of S. hainanensis on algae and insects were observed during the dry season, with higher algal biomass and insect densities (especially mayflies) in snail‐exclusion treatments. Differences between treatments during the wet season were generally minor. Snails depressed algae more severely in shaded streams, but this did not result in greater increases in insect abundance in snail‐exclusion treatments.

Evidently snails did exert competitive effects on insects, but spate‐induced disturbance during the wet season appeared to override this biotic interaction, in agreement with predictions of the harsh‐benign hypothesis. Competition intensity was unaffected by shading conditions, perhaps because other environmental factors moderated interaction intensity in shaded streams.
Genetic variation in oxytocin rs2740210 and early adversity associated with postpartum depression and breastfeeding duration
Authors: Jonas W. , Mileva‐Seitz V. , Girard A. W. , Bisceglia R. , Kennedy J. L. , Sokolowski M. , Meaney M. J. , Fleming A. S. , Steiner M. ,   ; on behalf of the MAVAN Research Team
Published: August 2013

Mothers vary in duration of breastfeeding. These individual differences are related to a variety of demographic and individual maternal factors including maternal hormones, mood and early experiences. However, little is known about the role of genetic factors. We studied single‐nucleotide polymorphisms (SNPs) in the OXT peptide gene (rs2740210; rs4813627) and the OXT receptor gene (OXTR rs237885) in two samples of mothers from the Maternal adversity, Vulnerability and Neurodevelopment study (MAVAN), a multicenter (Hamilton and Montreal, Canada) study following mothers and their children from pregnancy until 7 years of age. Data from the Hamilton site was the primary sample (n = 201) and data from Montreal was the replication sample (n = 151). Breastfeeding duration, maternal mood (measured by the CES‐D scale) and early life adversity (measured by the CTQ scale) were established during 12 months postpartum. In our primary sample, polymorphisms in OXT rs2740210, but not the other SNPs, interacted with early life adversity to predict variation in breastfeeding duration (overall F8,125 = 2.361, P = 0.021; interaction effect b = −8.12, t = −2.3, P = 0.023) and depression (overall F8,118 = 5.751, P ≤ 0.001; interaction effect b = 6.06, t = 3.13, P = 0.002). A moderated mediation model showed that higher levels of depression mediated the inverse relation of high levels of early life adversity to breastfeeding duration, but only in women possessing the CC genotype [effect a′ = −3.3401, 95% confidence interval (CI) = −7.9466 to −0.0015] of the OXT SNP and not in women with the AA/AC genotype (a′ = −1.2942, ns). The latter findings (moderated mediation model) were replicated in our Montreal sample (a′ = −0.277, 95% CI = −0.7987 to −0.0348 for CC; a′ = −0.1820, ns for AA/AC).
Alternative replication factor C protein, Elg1, maintains chromosome stability by regulating PCNA levels on chromatin
Authors: Shiomi Yasushi , Nishitani Hideo
Published: August 2013

Proliferating cell nuclear antigen (PCNA) is loaded on chromatin upon initiation of the S phase and acts as a platform for a large number of proteins involved in chromosome duplication at the replication fork. As duplication is completed, PCNA dissociates from chromatin, and thus, chromatin‐bound PCNA levels are regulated during the cell cycle. Although the mechanism of PCNA loading has been extensively investigated, the unloading mechanism has remained unclear. Here, we show that Elg1, an alternative replication factor C protein, is required for the regulation of chromatin‐bound PCNA levels. When Elg1 was depleted by small interfering RNA, chromatin‐bound PCNA levels were extremely increased during the S phase. The number of PCNA foci, regions in the nucleus normally representing DNA replication sites, was increased and PCNA remained on chromatin after DNA replication. Various chromatin‐associated protein levels on chromatin were affected, and chromatin loop size was increased. During mitosis, cells with aberrant chromosomes and lagging chromosomes were frequently detected. Our findings suggest that Elg1 has an important role in maintaining chromosome integrity by regulating PCNA levels on chromatin, thereby acting as a PCNA unloading factor.
Synthesis of Calcium Phosphate Nanoparticle‐Based Docetaxel Delivery System and its In Vitro Anticancer Activity
Authors: Yang Chao , Han Lina , Ma Fei , Zhou Lin , Zhou Jiahong , Wei Shaohua , Huang Guiqin , Shen Jian , Li Fuyou
Published: August 2013

A new docetaxel (DTX) delivery system has been prepared based on calcium phosphate nanoparticles (CaP NPs) and obtained DTX‐adsorbed CaP NPs. The DTX‐adsorbed CaP NPs were nearly spherical with mean diameter about 200 nm and a negative zeta potential of −18.8 ± 0.5 mV. They can be well dispersed and stable in water for a long time. In addition, the DTX‐adsorbed CaP NPs showed higher cytotoxicity in human nonsmall‐cell lung cancer (NSCLC) cell lines than that of DTX at the same experimental conditions. Thus, it could be concluded that CaP NPs can be a promising DTX delivery vehicle in NSCLC chemotherapy.
Hibiscus sabdariffaL. confesctionery gels,in vitrodigestion, antioxidant activity and phenolic compounds quantification: a nutraceutical application
Authors: Villanueva‐Carvajal Adriana , Dominguez‐Lopez Aurelio , Bernal‐Martínez Luz Raquel , Díaz‐Bandera Daniel
Published: August 2013

DehydratedHibiscus sabdariffa(Roselle) is usually used as the raw material of popular beverages, where the exhausted calyx, still rich in polyphenols and fibre, is discarded. The aim of the present study is to evaluate the possibility of adding Roselle's whole calyx to a confectionery product elaborated with gelatin, quantifying the concentration of released polyphenols (Folin–Ciocalteu) during anin vitrodigestion and the expression of antioxidant activity [Ferric reducing antioxidant power (FRAP) andN,N‐dimethyl‐p‐phenylenediamine dihydrochloride (DMPD)] during this process. Results show that hardness and elongation ofRoselle‐gelatin gums respond to a quadratic model where single components and binary mixtures show significant contributions to hardness and elongation behaviour respectively. Ten grams ofRoselle‐gelatin gum express a higher antioxidant activity (FRAP) than 250 mL of the infusion prepared by a traditionally procedure. A significant proportion of the radical scavenging (DMPD) activity could have been lost during the elaboration process of the gums, and although more studies should be done, a hypothesis explaining this effect is included.
Influence of hot‐air treatment, superatmospheric O2 and elevated CO2 on bioactive compounds and storage properties of fresh‐cut pomegranate arils
Authors: Maghoumi Mahshad , Mostofi Younes , Zamani Zabihollah , Talaie Alireza , Boojar Masoud , Gómez Perla A.
Published: August 2013

The impact of heat treatment using hot air (HT 45 °C and 55 °C for 1 h) and two active modified atmosphere packaging (MAP) conditions of high oxygen atmosphere (HOA: 80 kPa O2, 20 kPa N2) and high CO2 atmosphere (HCA: 20 kPa CO2, 80 kPa N2), individually or combined, on the antioxidant capacity, polyphenols, vitamin C content, total anthocyanins, polyphenoloxydase (PPO) activity and shelf life of fresh‐cut (FC) pomegranate arils stored for 14 days at 4 °C was studied. The results indicate that HT 45 °C along with HOA inhibited PPO activity and prevented loss of antioxidant capacity, vitamin C and phenolic compounds in arils, in comparison with control and HT 55 °C. All treatments reduced the accumulation of anthocyanins, but HCA‐treated arils lost more anthocyanins besides having worse a* colour parameter values. No significant differences in titrable acidity (TA) and total soluble solids (TSS) were observed between treatments. The combination of HOA and HT 45 °C enhanced the benefits of applying each treatment separately and could be useful to improve and extend postharvest life of pomegranate FC arils.
Effect of postharvest storage conditions on the colour and freshness parameters of raw honey
Authors: Visquert Mario , Vargas Maria , Escriche Isabel
Published: August 2013

The influence of temperature (25, 30, 35 and 40 °C) and storage time (up to 62 or 104 days) on colour; hydroxymethyl furfural (HMF) content; and diastase index (ID) of citrus, rosemary, eucalyptus, polyfloral and honeydew honey was evaluated. Decreases in luminosity, whiteness index, hue and chroma with the increase in temperature and storage time were observed to different extents depending on the botanical origin of the honey. At all temperatures, the highest values of chromatic parameters throughout the whole period of storage corresponded to citrus honey. Honeydew honey showed the lowest values and the fewest colour differences. Principal component analysis explained 89% of the variations. PC1 (73%) separated honey types at lower temperatures in terms of colour parameters. PC2 (16%) described variations in HMF and ID in relation to storage conditions. Honey type had a much greater influence on HMF, ID and colour than storage conditions. The evaluated postharvest treatments did not alter the characteristic colour of each type of honey as long as the commercial requirements for freshness parameters were met.
Efficiency of the FT‐IR ATR spectrometry for the prediction of the physicochemical characteristics of Melipona subnitida honey and study of the temperature's effect on those properties
Authors: de Almeida‐Muradian Ligia Bicudo , Stramm Klaus Martin , Estevinho Leticia M.
Published: August 2013

The efficiency of ATR FT‐IR spectrometry was compared with recommended methodologies for physicochemical parameters of eighteen samples of Melipona subnitida honey. Significant differences were found between the values obtained using those techniques for hydroxymethylfurfural, ash and electrical conductivity. The results for the other parameters did not differ significantly, suggesting that this rapid and nondestructive methodology may predict parameters usually used to assess honeys’ quality. The effects of different storage conditions (room temperature, fridge and freezer) on the quality parameters of the product stored during 12 months were studied. Darkening of the honey was observed, particularly in the fridge and freezer. However, the changes occurring in the honey kept on the fridge were not statistically different from those occurring in the product kept on the freezer, except for free acidity. The results obtained for the honey stored at room temperature, best way to preserve, differed significantly from those obtained for the honey kept under the other conditions.
Extraction, identification and enzymatic synthesis of acylated derivatives of anthocyanins from jaboticaba (Myrciaria cauliflora) fruits
Authors: de Castro Vanessa Cristina , da Silva Paulo Henrique Alves , de Oliveira Eduardo Basílio , Desobry Stéphane , Humeau Catherine
Published: August 2013

Polyphenols were extracted from the skin of jabuticaba fruits (Myrciaria cauliflora). Their total concentration and in vitro antioxidant activity were analysed by the DPPH and ABTS methods. The corresponding results (dry basis) were 1290 mg gallic acid equivalent (GAE)∙(100 g)−1, 98% of DPPH radical inhibition and 120 μm TEAC∙g−1 (ABTS method). All these values are at least as higher as average values reported in the literature for other fruits. A more specific analysis of the fractions of phenolic compounds was also performed by HPLC‐MS. Ellagic acid, quercetin, rutin, delphinidin‐3‐glucoside and cyanidin‐3‐glucoside were the main compounds detected; the latter two were the most abundant. The crude extract was subjected to enzymatic acylation assays in order to synthesise new esters with new potential techno‐functionalities. Palmitic acid was used as acyl donor and lipase B of Candida antactica (CALB) as biocatalyst. HPLC‐MS evidenced the formation of palmitic monoesters in connection with the delphinidin‐3‐glucoside and cyanidin‐3‐glucoside fractions.
Characterisation of black cumin, pomegranate and flaxseed meals as sources of phenolic acids
Authors: Krimer Malešević Vera , Vaštag Žužana , Popović Ljiljana , Popović Senka , Peričin‐Starčevič Ivana
Published: August 2013

The article focuses on the extraction of ten phenolic acids from black cumin (Nigella sativa L.), pomegranate (Punica granatum L.) and flax (Linum usitatissimum L.) seed meals. The extracts have been fractionated as free, esterified and insoluble‐bound phenolic compounds and quantitatively determined by HPLC–PDA. The analysed meals can be utilised for obtaining valuable phenolic acids. However, the distribution of phenolic compounds varies depending on the meal source. The insoluble‐bound fraction has been the richest for the black cumin meal, both qualitatively and quantitatively, containing all ten analysed phenolics. In the pomegranate meal, the main phenolic has been gallic acid, accounting for nearly 48% in free form. The esterified form of the flaxseed meal has been abundant with ferulic (1025.44 ± 3.99 mg kg−1 dry weight), caffeic and p‐coumaric acids. The total amount of phenolic acids would be underestimated if only free fractions would be taken into account, while neglecting esterified (for the pomegranate and flax meals) and insoluble‐bound fractions (for the black cumin and pomegranate meals).
Problem-based learning: an exploration of student opinions on its educational role in one UK pharmacy undergraduate curriculum
Authors: Wright David , Wickham Jane , Sach Tracey
Published: August 2013

Objective

Problem-based learning (PBL) was introduced into the first 3 years of the undergraduate degree course at the University of East Anglia (UEA) to both enhance the student learning experience and to enable it to meet external course accreditation criteria. Evidence to support both of these assertions is required. The objective was to determine student opinions on the value of PBL and the PBL learning process at one UK school of pharmacy.

Method

Utilising the professional accreditation criteria for UK schools of pharmacy a questionnaire was devised and piloted before being given to all UEA undergraduate pharmacy students for self-completion. The most appropriate method of dissemination was determined from a student-led focus group.

Key findings

A total of 201/329 (61.1%) students responded. The majority of students agreed that PBL improved their team working (83.1%), oral communication (89.1%) and problem-solving skills (61.7%). Additionally PBL improved students’ ability to identify and address ethical dilemmas (74.5%) as well as enhancing their ability to manage their own learning (67.6%). Male students and those with a stated preference for team working were found to prefer PBL.

Conclusion

Students generally believe that PBL develops a number of key skills and consequently inclusion of PBL alongside traditional teaching methods enables the school to meet a number of degree accreditation criteria. Male students, those who enjoyed team working and working with their current group were more positive about PBL. Further work is required to improve the experience for all students.
Evaluating cross‐national variations in the extent and nature of informal employment in theEuropeanUnion
Authors: Williams Colin C.
Published: August 2013

This article evaluates critically the contrasting explanations for the cross‐national variations in the prevalence and nature of informal employment, which variously view such work as more prevalent in poorer, under‐developed economies; driven by high taxes, corruption and state interference that lead workers to exit formal employment; or driven by inadequate state intervention leading to the exclusion of workers from formal employment and state welfare provision. By analysing cross‐national variations across the European Union in the size of informal employment using indirect measurement methods and in its varying character using evidence from a 2007 Eurobarometer survey, it was found that wealthier, less corrupt and more equal economies with higher levels of labour market intervention, social protection and redistribution via social transfers have lower levels of informal employment, much of which is conducted to exit formal employment. The paper concludes by exploring the theoretical and policy implications.
Effect of Switching Atmospheric Conditions during Crystallization on the Phase Evolution of Solution‐Derived Lead Zirconate Titanate Thin Films
Authors: Mhin Sungwook , Cozzan Clayton , Nittala Krishna , Wanninkhof Patrick , Ihlefeld Jon F. , Brennecka Geoff L. , Jones Jacob L.
Published: August 2013

The crystallization behavior of solution‐derived lead zirconate titanate (PZT) thin films in different atmospheric environments was studied using in situ X‐ray diffraction. The stability of the transient intermetallic Pt3Pb phase and perovskite PZT is dependent on oxygen partial pressure during crystallization. Based on the relationship between oxygen partial pressure and the resultant phase stability of intermediate phases, a new route to produce PZT thin films was developed. The new route involves switching atmospheres during crystallization and is shown to mitigate the formation of the transient intermetallic Pt3Pb phase and to promote the perovskite PZT phase. The route evidences a new and significant variable controlling film synthesis and film microstructure.
In and out of Mesoamerica: temporal divergence ofAmaziliahummingbirds pre‐dates the orthodox account of the completion of theIsthmus ofPanama
Authors: Ornelas Juan Francisco , González Clementina , de los Monteros Alejandro Espinosa , Rodríguez‐Gómez Flor , García‐Feria Luis M.
Published: August 2013

Aim

We used mitochondrialDNAsequences to reconstruct the phylogenetic relationships of MesoamericanAmaziliahummingbirds (Trochilidae). The phylogeny was used to identify vicariance scenarios, reconstruct ancestral biogeographical areas, and investigate the role of geological events in generating genetic divergence through vicariance events.

Location

Mesoamerica.

Methods

Molecular sequence data were gathered from three mitochondrial genes (ND2,ND5and12S) for samples taken within the Mesoamerican region and analysed using maximum parsimony, maximum‐likelihood andBayesian approaches. Statistical dispersal–vicariance analysis (S‐DIVA) was used to reconstruct biogeographical areas and changes in distribution during the evolutionary history ofAmazilia. The phylogeny was calibrated using fossil dates, mean substitution rates and coalescent‐based divergence time inference.

Results

Amaziliacan be split into two divergent lineages, with high levels of sequence divergence within someMesoamerican species. Ancestral area reconstructions favour an ancestral distribution west of the Isthmus of Tehuantepec, with subsequent dispersals east of the isthmus and to South America. Divergence time estimations suggest that major diversification events occurred in theMiocene andPliocene, corresponding temporally and geographically to the formation of the mountain systems and establishment of the major biomes inMesoamerica.

Main conclusions

The diversification ofAmaziliacorresponds to vegetation shifts in combination with regional orogenesis. Intriguingly, the timing of the major diversification events and dispersal intoSouthAmerica pre‐dates the completion of thePanamanian isthmusc. 4 Ma before present.
PPARγ silencing enhances osteogenic differentiation of human adipose‐derived mesenchymal stem cells
Authors: Lee Mon‐Juan , Chen Hui‐Ting , Ho Mei‐Ling , Chen Chung‐Hwan , Chuang Shu‐Chun , Huang Sung‐Cheng , Fu Yin‐Chih , Wang Gwo‐Jaw , Kang Lin , Chang Je‐Ken
Published: August 2013

Peroxisome proliferator‐activated receptor gamma (PPARγ) is the master regulator of adipogenesis, and has been indicated as a potential therapeutic target to promote osteoblast differentiation. However, recent studies suggest that suppression of PPARγ inhibits adipogenesis, but does not promote osteogenic differentiation in human bone marrow‐derived mesenchymal stem cells (hBMSCs). It was reasoned that the osteogenic effect of PPARγ suppression may be masked by the strong osteogenesis‐inducing condition commonly used, resulting in a high degree of matrix mineralization in both control and experimental groups. This study investigates the role of PPARγ in the lineage commitment of human adipose‐derived mesenchymal stem cells (hADSCs) by interfering with the function of PPARγ mRNA through small interfering RNAs (siRNAs) specific for PPARγ2. By applying an osteogenic induction condition less potent than that used conventionally, we found that PPARγ silencing led to retardation of adipogenesis and stimulated a higher level of matrix mineralization. The mRNA level of PPARγ decreased to 47% of control 2 days after treatment with 50 nmol/l PPARγ2 siRNA, while its protein expression was 60% of mock control. In the meantime, osteogenic marker genes, including bone morphogenic protein 2 (BMP2), runt‐related transcription factor 2 (Runx2), alkaline phosphatase (ALP) and osteocalcin (OC), were up‐regulated under PPARγ silencing. Our results suggest that transient suppression of PPARγ promotes the onset of osteogenesis, and may be considered a new strategy to stimulate bone formation in bone tissue engineering using hADSCs.
Exploring patterns of variation in clutch size–density reaction norms in a wild passerine bird
Authors: Nicolaus M. , Brommer J. E. , Ubels R. , Tinbergen J. M. , Dingemanse N. J.
Published: August 2013

Negative density dependence of clutch size is a ubiquitous characteristic of avian populations and is partly due to within‐individual phenotypic plasticity. Yet, very little is known about the extent to which individuals differ in their degree of phenotypic plasticity, whether such variation has a genetic basis and whether level of plasticity can thus evolve in response to selection. Using 18 years of data of aDutch great tit population (Parus major), we show that females reduced clutch size with increasing population density (slopes of the reaction norms), differed strongly in their average clutch size (elevations of the reaction norms) at the population‐mean density and that the latter variation was partly heritable. In contrast, we could not detect individual variation in phenotypic plasticity (‘I × E’). Level of plasticity is thus not likely to evolve in response to selection in this population. Observed clutch sizes deviated more from the estimated individual reaction norms in certain years and densities, implying that the within‐individual between‐year variance (so‐called residual variance) of clutch size was heterogeneous with respect to these factors. Given the observational nature of this study, experimental manipulation of density is now warranted to confirm the causality of the observed density effects. Our analyses demonstrate that failure to acknowledge this heterogeneity would have inflated the estimate of ‘I × E’ and led to misinterpretation of the data. This paper thereby emphasizes the fact that heterogeneity in residuals can provide biologically insightful information about the ecological processes underlying the data.
The application of P–T–X(CO2) modelling in constraining metamorphism and hydrothermal alteration at the Damang gold deposit, Ghana
Authors: White A. J. R. , Waters D. J. , Robb L. J.
Published: August 2013

Orogenic gold mineralization at the Damang deposit, Ghana, is associated with hydrothermal alteration haloes around gold‐bearing quartz veins, produced by the infiltration of a H2O–CO2–K2O–H2S fluid following regional metamorphism. Alteration assemblages are controlled by the protoliths with sedimentary rocks developing a typical assemblage of muscovite, ankerite and pyrite, while intrusive dolerite bodies contain biotite, ankerite and pyrrhotite, accompanied by the destruction of hornblende. Mineral equilibria modelling was undertaken with the computer program thermocalc, in subsets of the model system MnO–Na2O–CaO–K2O–FeO–MgO–Al2O3–SiO2–CO2–H2O–TiO2–Fe2O3, to constrain conditions of regional metamorphism and the subsequent gold mineralization event. Metapelites with well‐developed amphibolite facies assemblages reliably constrain peak regional metamorphism at ~595 °C and 5.5 kbar. Observed hydrothermal alteration assemblages associated with gold mineralization in a wide compositional range of lithologies are typically calculated to be stable within P–T–X(CO2) arrays that trend towards lower temperatures and pressures with increasing equilibrium fluid X(CO2). These independent P–T–X(CO2) arrays converge and the region of overlap at ~375–425 °C and 1–2 kbar is taken to represent the conditions of alteration approaching equilibrium with a common infiltrating fluid with an X(CO2) of ~0.7. Fluid‐rock interaction calculations with M–X(CO2) diagrams indicate that the observed alteration assemblages are consistent with the addition of a single fluid phase requiring minimum fluid/rock ratios on the order of 1.
Metabolic alterations associated with schizophrenia: a critical evaluation of proton magnetic resonance spectroscopy studies
Authors: Schwerk Anne , Alves Fabiana D. S. , Pouwels Petra J. W. , van Amelsvoort Therese
Published: August 2013

By reviewing the existing 1H‐magnetic resonance spectroscopy literature in schizophrenia, the relationship of different sample characteristics and applied methodologies with metabolite alterations is explored. Furthermore, we emphasize common pitfalls and discrepancies in the methodological framework of the reviewed studies that introduce unwanted variation in findings and complicate the comparison of studies. A total of 92 studies were reviewed. Articles were retrieved by searching the Pubmed database. Care was taken to note down reliability and validity measures of each included study. Despite many methodological differences and shortcomings, progressive NAA reductions could be seen in several brain regions implicated in the pathogenesis of schizophrenia. In terms of treatment effects, cross‐sectional evidence implicates a normalizing role for atypical antipsychotic medication; however, longitudinal studies remain inconclusive on this issue. Choline, creatine, and myo‐inositol levels remain largely unchanged and a time‐dependent role of glutamate finds confirmation in several spectroscopy studies. Other findings are less consistent and need further replication. Most studies lack power and methodological precision. Future studies should aim for standardization and for more distinguished study populations to gain more valid and reliable findings.
Unravelling the blood supply to the zebrafish pharyngeal jaws and teeth
Authors: Crucke Jeroen , Huysseune Ann
Published: August 2013

We describe the vascular supply to the pharyngeal jaws and teeth in zebrafish, from larval stages to juveniles, using serial high quality semithin sections and 3D reconstructions. We have identified that the arterial blood supply to the last pair of branchial arches, which carries the teeth, issues from the hypobranchial artery. Surprisingly, the arteries supplying the pharyngeal jaws show an asymmetric branching pattern that is modified over ontogeny. Moreover, the blood vessel pattern that serves each jaw can best be described as a sinusoidal cavity encircling the bases of both the functional and replacement teeth. Capillaries branching from this sinusoidal cavity enter the pulp and constitute the intrinsic blood supply to the attached teeth. The role of these blood vessels during tooth development (whether instructive or nutritive) remains to be determined and requires further study. However, we have provided a firm morphological basis that will aid in the interpretation of experiments addressing this question.
Breastfeeding and the prevention of breast cancer: a retrospective review of clinical histories
Authors: González‐Jiménez Emilio , García Pedro A , Aguilar María José , Padilla Carlos A , Álvarez Judit
Published: August 2013

Aims and objectives

To evaluate at what age parous and nonparous women were diagnosed with breast cancer. Factors taken into account for parous women were whether they had breastfed their children, and if so, the length of the lactation period. Other factors considered for both groups were obesity, family histories of cancer, smoking habits and alcohol consumption.

Background

Breast cancer is the most common form of cancer in younger women in Western countries. Its growing incidence as well as the increasingly early age of diagnosis led us to carefully analyse its possible causes and the preventive measures to be taken. This is a particularly important goal in epidemiological research.

Design

A retrospective study of the clinical histories of patients diagnosed with breast cancer at the San Cecilio University Hospital in Granada (Spain).

Methods

In this study, we analysed 504 medical records of female patients, 19–91 years of age, who had been diagnosed and treated for breast cancer from 2004–2009 at the San Cecilio University Hospital in Granada (Spain). Relevant data (age of diagnosis, period of lactation, family history of cancer, obesity, alcohol consumption and smoking habits) were collected from the clinical histories of each patient and analysed. A conditional inference tree was used to relate the age of diagnosis to smoking habits and the length of the lactation period.

Results

The conditional inference tree identified significant differences between the age of the patients at breast cancer diagnosis, smoking habits (p < 0·001) and lactation period if the subjects had breastfed their children for more than six months (p = 0·006), regardless of whether they had a family history of cancer.

Conclusions

Our study concluded that breastfeeding for over six months not only provides children with numerous health benefits, but also protects mothers from breast cancer when the mothers are nonsmokers.

Relevance to clinical practice

Nurses play a crucial role in encouraging new mothers to breastfeed their children, and this helps to prevent breast cancer.
Ultrasonographic measurement of amniochorionic membrane in asymptomatic pregnant women is not a useful tool for preterm birth prediction
Authors: Başaran Derman , Özyüncü Özgür , Kara Özgür , Şahin Nihal , Turğal Mert , Önderoğlu Lütfü S.
Published: August 2013

Aim

The objective of this study was to determine the accuracy of ultrasonographic measurement of amniochorionic membrane thickness (AMT) in the prediction of preterm birth among an asymptomatic pregnant population.

Methods

One hundred and ninety consecutive singleton pregnant women presenting for prenatal care between May 2010 and August 2011 were recruited for the study. AMT of the patients was measured once between 18 and 22 weeks of gestation and then again between 28 and 32 weeks of gestation with transabdominal ultrasound. The results of measurements were recorded and compared with the perinatal outcome related to prematurity.

Results

Thirteen of the 190 births were preterm. The mean AMT of the pregnant women who delivered at term were 0.79 ± 0.23 mm in the second trimester and 0.88 ± 0.27 mm in the third trimester. The mean AMT of pregnant women who delivered preterm were 0.77 ± 0.27 mm in the second trimester and 0.91 ± 0.20 mm in the third trimester. There were no statistically significant differences between the second and third trimester AMT of the preterm delivery group and term delivery group (P = 0.542 and P = 0.448, respectively).

Conclusion

In this study, ultrasonographic measurement of fetal membranes was not found to be a useful marker for prediction of preterm birth. The findings of our study may help in understanding ultrasonographic changes in fetal membranes in normal pregnancies.
Uterine preservation surgery for placental polyp
Authors: Hiraki Koichi , Khan Khaleque Newaz , Kitajima Michio , Fujishita Akira , Masuzaki Hideaki
Published: August 2013

Aim

To examine clinical and surgical performances of cases with placental polyps in which uterine preservation surgery was conducted.

Methods

During the period September 2002 to April 2009, we examined eight cases (hysteroscopic resection, six cases; laparotomy, one case; dilatation and curettage, one case) diagnosed with placental polyp that had been treated with polyp extraction surgery. Imaging evaluation was done using magnetic resonance imaging and 2‐D ultrasound.

Results

Three of the eight cases (37.5%) had been first‐time pregnancies. Most of our cases experienced minimal surgical manipulation after medical abortion. Among them, six cases (75%) were mid‐term medical abortions, one case (12.5%) received no treatment after spontaneous abortion, and one case (12.5%) had postsurgical abortion (dilatation and curettage). All cases showed variable amount of blood flow in the internal mass and myometrium by color Doppler ultrasound. Magnetic resonance imaging angiography showed contrast effects in the intrauterine cavity and myometrium in selected cases. The average duration from diagnosis to surgery was 32 days (range, 11–105). Color Doppler revealed a reduction in blood flow in five cases during the waiting period until surgery with an average blood loss of 10 g (range, 0–20) during surgery.

Conclusion

Use of color Doppler ultrasound may be useful in diagnosing placental polyp. Although hysteroscopic resection of placental polyp is effective in patients hoping for uterine preservation, delaying timing of surgery may reduce blood loss during operative procedure.
Psychological contract breach and voluntary turnover: Testing a multiple mediation model
Authors: Clinton Michael E. , Guest David E.
Published: August 2013

Ample evidence exists of an association between psychological contract (PC) breach and intention to quit. Although some studies report an association between breach and turnover behaviour, a meta‐analysis by Zhao et al. (2007, Personnel Psychology, 60, 647) failed to find any significant link. This seems counter‐intuitive, and therefore, to explore this relationship between breach and voluntary turnover more fully, we developed and tested a model that proposed exchange fairness and trust as mediators. Using data collected from over 6,000 British Royal Air Force personnel, we find a positive relationship between breach and subsequent voluntary turnover, which exchange fairness and trust fully mediate. The contribution of the study to our understanding of the relationship between PC breach and voluntary turnover is discussed.

Practitioner points

The study considers whether the psychological contract represents a useful tool for understanding employee turnover behaviour.

The findings indicate that if employers are able to fulfil their obligations to their employees, then employees are less likely to voluntarily quit the organization.

The reason why this relationship occurs is linked to employees' perceptions regarding the fairness of the exchange relationship and organizational trustworthiness.
Molecular Identification and Phylogenetic Analysis of Sugarcane Yellow Leaf Phytoplasma (SCYLP) in Egypt
Authors: ElSayed Abdelaleim Ismail , Boulila Moncef
Published: August 2013

Samples of sugarcane leaves were collected from different commercial fields and breeding stations in Egypt. Aetiology of sugarcane phytoplasma disease was investigated using nested PCR. Phytoplasma‐specific primers (P1/P7 and R16F2n/R16R2) were used to amplify a fragment of the 16S rRNA gene. Sequencing and restriction fragment length polymorphism analyses revealed that the tested phytoplasmas belonged to the 16SrI (aster yellows phytoplasma) group. Phylogenetic analyses of 60 screened accessions of 16S ribosomal RNA gene sequences of Candidatus phytoplasmas comprising those collected from Egypt (this study) and those extracted from GenBank showed that they split into two distinct clusters. All the phytoplasmas form a stable phylogenetic subcluster, as judged by branch length and bootstrap values of 100% in the 16S group cluster. Results of phylogenetic analyses indicated that these phytoplasmas are closely related and share a common ancestor. Conversely, based on the analysis of the 16S‐23S region, examined isolates segregated into four different clusters suggesting a notable heterogeneity between them. These results are the first record of the presence of phytoplasma in association with sugarcane yellow leaf in Egypt.