bluuebunny/crossref_metadata_2025 huggingface dataset:
Left atrium and the imaging of atrial fibrosis: catch it if you can!
Authors: Tan Timothy C. , Koutsogeorgis ΙIlias D. , Grapsa Julia , Papadopoulos Costas , Katsivas Apostolos , Nihoyannopoulos Petros
Published: July 2014

Atrial fibrillation is a sustained arrhythmia commonly encountered in clinical practice. It has a high prevalence among the elderly and contributes significantly to the global socio‐economic burden. Among many risk factors predisposing to atrial fibrillation is left atrial remodelling and wall fibrosis. Frequently, pathological left atrial wall remodelling and fibrosis results in low atrial compliance and elastance significantly increase the risk of developing permanent atrial fibrillation. We reviewed all literature which employs imaging and left atrial fibrosis and we present all available imaging modalities. Current imaging tools may play a role in the detection of atrial fibrosis, hence providing valuable information for risk stratification and management of patients with atrial fibrillation.
Late gadolinium enhancement CMR in primary mitral regurgitation
Authors: Van De Heyning Caroline M. , Magne Julien , Piérard Luc A. , Bruyère Pierre‐Julien , Davin Laurent , De Maeyer Catherine , Paelinck Bernard P. , Vrints Christiaan J. , Lancellotti Patrizio
Published: July 2014

Aims

The appropriate timing for surgery in severe asymptomatic primary mitral regurgitation (MR) remains controversial. It has been shown that late gadolinium enhancement on cardiovascular magnetic resonance (LGE CMR), which may identify myocardial fibrosis, is associated with a worse outcome in various cardiomyopathies. We sought to investigate the prevalence and significance of delayed enhancement in primary MR.

Methods

We prospectively included 41 patients with at least moderate primary MR and without overt signs of left ventricular (LV) dysfunction. Patients with evidence of coronary artery disease, arrhythmias or significant concomitant valvular disease were excluded. All patients were scheduled for transthoracic echocardiography and LGE CMR.

Results

A total of 39 patients had interpretable LGE CMR images. Among them, 12 (31%) had late contrast uptake of the LV wall. LGE CMR showed an infarct pattern in three patients, a pattern of mid‐wall fibrosis in seven patients and two patients had a combined pattern. Patients with delayed enhancement on CMR had significant higher LV diameters (LV end‐systolic diameter 39 ± 4 vs. 34 ± 5 mm, P = 0·002; LV end‐diastolic diameter 57 ± 5 vs. 50 ± 5 mm, P = 0·001). There was a trend towards a higher indexed left atrial volume (55 ± 21 vs. 44 ± 13 mL/m², P = 0·06). By contrast, there was no significant association between myocardial contrast uptake and age, LV ejection fraction and MR severity.

Conclusion

Left ventricular remodelling seems to be associated with the presence of delayed enhancement on CMR in primary MR. Further data are needed to determine whether LGE CMR can predict a less favourable outcome or could improve risk stratification in asymptomatic primary MR.
ON THE HETEROGENEOUS EMPLOYMENT EFFECTS OF OFFSHORING: IDENTIFYING PRODUCTIVITY AND DOWNSIZING CHANNELS
Authors: Moser Christoph , Urban Dieter , Weder Di Mauro Beatrice
Published: July 2014

This article examines the channels through which offshoring affects employment in a representative sample of German establishments, using a difference‐in‐differences matching approach. Offshoring is measured by an increase in the share of foreign to total intermediate inputs at the plant‐level. We identify a positive productivity effect and isolate a negative downsizing effect from offshoring on employment, by exploiting differences between offshoring plants that do and do not simultaneously restructure. Furthermore, we cannot find evidence of negative indirect employment effects on domestic suppliers or competitors. (JEL F16, J23, F23, C21)
Responses of swamp bay, Persea palustris, and avocado, Persea americana, to various concentrations of the laurel wilt pathogen, Raffaelea lauricola
Authors: Hughes M. A. , Inch S. A. , Ploetz R. C. , Er H. L. , van Bruggen A. H. C. , Smith J. A.
Published: July 2014

Laurel wilt, caused by the fungus Raffaelea lauricola and transmitted by the exotic ambrosia beetle Xyleborus glabratus, has killed members of the Lauraceae plant family throughout the southeast United States. A series of experiments were conducted to examine the effects of inoculum concentration on the development of laurel wilt in swamp bay, Persea palustris, and avocado, Persea americana. In each experiment, host plants were inoculated with aqueous suspensions of 102, 103, 104 or 105 conidia of R. lauricola, and plants were rated periodically for external symptom development (wilting and foliar dieback). At the end of experiments, plants were rated for internal symptoms of the disease (discoloration of sapwood) and assayed for R. lauricola on a semi‐selective medium. Symptom severity in swamp bay was significantly lower for the 102 treatment than at higher (103–105) concentrations, whereas 102 and 103 conidia caused less disease than 104 and 105 conidia in avocado. At the lowest inoculum concentration, 67% of the swamp bay plants and 20% of the avocados died by the time the respective experiments were terminated. The pathogen was recovered from a high proportion of the symptomatic sapwood of swamp bay (100%) and avocado (94%), and sapwood discoloration and recovery of R. lauricola from inoculated stems of swamp bay were highly correlated with recovery of the pathogen and symptom development in roots. Clearly, swamp bay and avocado are very sensitive to R. lauricola. The ability of only 100 conidia of this pathogen to kill these hosts suggests that few individuals of X. glabratus or other ambrosia beetles that carry low levels of the pathogen would be sufficient to transmit conidia that infect and lead to disease development. The results are also relevant to the development of disease‐tolerant host selections, as they indicate levels of the pathogen appropriate for use in screening plants for disease resistance.
Selective increase of in vivo firing frequencies in DA SN neurons after proteasome inhibition in the ventral midbrain
Authors: Subramaniam Mahalakshmi , Kern Beatrice , Vogel Simone , Klose Verena , Schneider Gaby , Roeper Jochen
Published: July 2014

The impairment of protein degradation via the ubiquitin‐proteasome system (UPS) is present in sporadic Parkinson's disease (PD), and might play a key role in selective degeneration of vulnerable dopamine (DA) neurons in the substantia nigra pars compacta (SN). Further evidence for a causal role of dysfunctional UPS in familial PD comes from mutations in parkin, which results in a loss of function of an E3‐ubiquitin‐ligase. In a mouse model, genetic inactivation of an essential component of the 26S proteasome lead to widespread neuronal degeneration including DA midbrain neurons and the formation of alpha‐synuclein‐positive inclusion bodies, another hallmark of PD. Studies using pharmacological UPS inhibition in vivo had more mixed results, varying from extensive degeneration to no loss of DA SN neurons. However, it is currently unknown whether UPS impairment will affect the neurophysiological functions of DA midbrain neurons. To answer this question, we infused a selective proteasome inhibitor into the ventral midbrain in vivo and recorded single DA midbrain neurons 2 weeks after the proteasome challenge. We found a selective increase in the mean in vivo firing frequencies of identified DA SN neurons in anesthetized mice, while those in the ventral tegmental area (VTA) were unaffected. Our results demonstrate that a single‐hit UPS inhibition is sufficient to induce a stable and selective hyperexcitability phenotype in surviving DA SN neurons in vivo. This might imply that UPS dysfunction sensitizes DA SN neurons by enhancing ‘stressful pacemaking’.
Prenatal alcohol exposure and adolescent stress – unmasking persistent attentional deficits in rats
Authors: Comeau Wendy L. , Winstanley Catharine A. , Weinberg Joanne
Published: July 2014

Prenatal alcohol exposure (PAE) can produce a myriad of deficits. Unfortunately, affected individuals may also be exposed to the stress of an adverse home environment, contributing to deficits of attentional processes that are the hallmark of optimal executive function. Male offspring of ad‐libitum‐fed Control (Con), Pairfed (PF), and PAE dams were randomly assigned to either a 5‐day period of variable chronic mild stress (CMS) or no CMS in adolescence. In adulthood, rats were trained in a non‐match to sample task (T‐maze), followed by extensive assessment in the five‐choice serial reaction time task. Once rats acquired the five‐choice serial reaction time task (stable accuracy), they were tested in three challenge conditions: (i) increased sustained attention, (ii) selective attention and, (iii) varying doses of d‐amphetamine, an indirect dopamine and norepinephrine agonist. At birth and throughout the study, PAE offspring showed reduced body weight. Moreover, although PAE animals were similar to Con animals in task acquisition, they were progressively less proficient with transitions to shorter stimulus durations (decreased accuracy and increased omissions). Five days of adolescent CMS increased basal corticosterone levels in adolescence and disrupted cognitive performance in adulthood. Further, CMS augmented PAE‐related disturbances in acquisition and, to a lesser extent, also disrupted attentional processes in Con and PF animals. Following task acquisition, challenges unmasked persistent attentional difficulties resulting from both PAE and adolescent CMS. In conclusion, PAE, adolescent CMS, and their interaction produced unique behavioural profiles that suggest vulnerability in select neurobiological processes at different stages of development.
Body shape shifting during growth permits tests that distinguish between competing geometric theories of metabolic scaling
Authors: Hirst Andrew G. , Glazier Douglas S. , Atkinson David
Published: July 2014

Metabolism fuels all of life's activities, from biochemical reactions to ecological interactions. According to two intensely debated theories, body size affects metabolism via geometrical influences on the transport of resources and wastes. However, these theories differ crucially in whether the size dependence of metabolism is derived from material transport across external surfaces, or through internal resource‐transport networks. We show that when body shape changes during growth, these models make opposing predictions. These models are tested using pelagic invertebrates, because these animals exhibit highly variable intraspecific scaling relationships for metabolic rate and body shape. Metabolic scaling slopes of diverse integument‐breathing species were significantly positively correlated with degree of body flattening or elongation during ontogeny, as expected from surface area theory, but contradicting the negative correlations predicted by resource‐transport network models. This finding explains strong deviations from predictions of widely adopted theory, and underpins a new explanation for mass‐invariant metabolic scaling during ontogeny in animals and plants.
Reflections on how wound healing‐promoting effects of the hair follicle can be translated into clinical practice
Authors: Jimenez Francisco , Poblet Enrique , Izeta Ander
Published: July 2014

Clinicians have long reported that hair‐bearing areas tend to heal more rapidly than those lacking hair follicles. In the past decade, numerous scientific studies have corroborated clinical evidence, showing a direct nexus between the human hair follicle and the wound healing process. The migration of epithelial follicular stem cells to the skin surface to help in the wound re‐epithelialization and the effect of the hair cycle on the wound healing rate underline the influence of the hair follicle in the healing process. In clinical practice, non‐healing wounds are pathologies of high prevalence with significant associated burden costs for the healthcare system. As the population ages, the prevalence of this pathology is expected to increase in future years. The recent advances in understanding the biology of hair follicle stem cells have created the challenges of using this newly acquired knowledge in practical therapeutic applications. Chronic leg ulcers are an example of the targeted pathologies that urgently need better therapies. In this essay, our aim is to raise interest in this question, reviewing what is known in relation to the connections between hair follicles and wound healing, and elaborating on future directions that the field might take, including implications for clinical practice.
Association of promoter polymorphism −765G>C in the PTGS2 gene with malignant melanoma in Italian patients and its correlation to gene expression in dermal fibroblasts
Authors: Gomez‐Lira Macarena , Ferronato Silvia , Malerba Giovanni , Santinami Mario , Maurichi Andrea , Sangalli Antonella , Turco Alberto , Perego Paola , Rodolfo Monica
Published: July 2014

Prostaglandins, especially prostaglandin E synthetase (PGE2), influence carcinogenesis by promoting cell proliferation, inhibiting apoptosis, stimulating angiogenesis and mediating immune suppression. Cyclooxygenase‐2, coded by the PTGS2 gene, is the key enzyme in the production of prostaglandins. In melanoma, Cox‐2 is over expressed in primary malignant melanoma (MM) and in their corresponding metastases. Polymorphisms in the promoter region of PTGS2 gene can modulate gene expression and could modify individual susceptibility to MM. Two hundred and forty melanoma patients and 342 controls were genotyped for polymorphisms −765G>C (rs20417) and −1195A>G (rs689466). Allele −765C frequency was significantly higher in melanoma patients. No allele frequency differences for −1195A>G polymorphism were observed. Haplotype analysis revealed that the haplotypes carrying the minor alleles were associated to a higher risk of melanoma (P = 0.02). Expression analysis showed that allele −765C is associated to a higher gene expression and could represent a risk allele by affecting the functionality of the promoter.
Cxcr4 is transiently expressed in both epithelial and mesenchymal compartments of nascent hair follicles but is not required for follicle formation
Authors: Sennett Rachel , Rezza Amélie , Dauber Katherine L. , Clavel Carlos , Rendl Michael
Published: July 2014

Hair follicle (HF) morphogenesis relies on the coordinated exchange of signals between mesenchymal and epithelial compartments of embryonic skin. Chemokine receptor Cxcr4 expression was recently identified in dermal condensates (DCs) of nascent HFs, but its role in promoting HF morphogenesis remains unknown. Our analyses confirmed Cxcr4 expression in condensate cells, and additionally revealed transient Cxcr4 expression in incipient epithelial hair placodes. Placodal Cxcr4 appeared prior to detection in DCs, representing a switch of expression between epithelial and mesenchymal compartments. To explore the functional role of this receptor in both compartments for early HF formation, we conditionally ablated Cxcr4 with condensate‐targeting Tbx18cre knock‐in and epidermis‐targeting Krt14‐cre transgenic mice. Conditional knockouts for both crosses were viable throughout embryogenesis and into adulthood. Morphological and biochemical marker analyses revealed comparable numbers of HFs forming in knockout embryos compared to wild‐type littermate controls in both cases, suggesting that neither dermal nor epithelial Cxcr4 expression is required for early HF morphogenesis. We conclude that Cxcr4 expression and chemokine signaling through this receptor in embryonic mouse skin is dispensable for HF formation.
Black fly larvae facilitate community recovery in a mountain stream
Authors: Hammock Bruce G. , Bogan Michael T.
Published: July 2014

Early colonising ecosystem engineers modify habitats and alter the abundance of basal resources following disturbances. These changes can have profound effects on ecosystem recovery via facilitative or inhibitory effects on subsequent colonists.

We quantified how black fly larvae, which can be pioneer species during secondary succession in streams, influence initial community recovery following a simulated drying disturbance.

Black fly larvae anchor themselves to the stream substratum with silk, and diatoms adhere to the silk of black flies. Therefore, we hypothesised that black flies speed community recovery following disturbances by increasing the accrual rate of basal resources with their silk.

We compared algal and detrital resource abundance and invertebrate community recovery on recently submerged cobbles across three treatments: increased black fly abundance, added black fly silk plus ambient black fly abundance and ambient black fly abundance (control).

After 24 h, the increased black fly treatment had more chlorophyll a, detritus and greater invertebrate abundance and richness, and replicates had more self‐similar communities than the control treatment.

The added silk treatment responded similarly to the increased black fly treatment, supporting the hypothesis that black flies increase the rate of basal resource accrual with their silk, increasing the colonisation rates of other invertebrate species.

Our study suggests that black flies are akin to other organisms that facilitate recovery following disturbance (e.g. alders fixing nitrogen following glacial retreat). Further research is needed to determine the effect of black flies on long‐term patterns of recovery and the applicability of our results to natural disturbances in streams.
A critical analysis of the implementation of service user involvement in primary care research and health service development using normalization process theory
Authors: Tierney Edel , McEvoy Rachel , O'Reilly‐de Brún Mary , de Brún Tomas , Okonkwo Ekaterina , Rooney Michelle , Dowrick Chris , Rogers Anne , MacFarlane Anne
Published: July 2014

Background

There have been recent important advances in conceptualizing and operationalizing involvement in health research and health‐care service development. However, problems persist in the field that impact on the scope for meaningful involvement to become a routine – normalized – way of working in primary care. In this review, we focus on current practice to critically interrogate factors known to be relevant for normalization – definition, enrolment, enactment and appraisal.

Method

Ours was a multidisciplinary, interagency team, with community representation. We searched EBSCO host for papers from 2007 to 2011 and engaged in an iterative, reflexive approach to sampling, appraising and analysing the literature following the principles of a critical interpretive synthesis approach and using Normalization Process Theory.

Findings

Twenty‐six papers were chosen from 289 papers, as a purposeful sample of work that is reported as service user involvement in the field. Few papers provided a clear working definition of service user involvement. The dominant identified rationale for enrolling service users in primary care projects was linked with policy imperatives for co‐governance and emancipatory ideals. The majority of methodologies employed were standard health services research methods that do not qualify as research with service users. This indicates a lack of congruence between the stated aims and methods. Most studies only reported positive outcomes, raising questions about the balance or completeness of the published appraisals.

Conclusion

To improve normalization of meaningful involvement in primary care, it is necessary to encourage explicit reporting of definitions, methodological innovation to enhance co‐governance and dissemination of research processes and findings.
Predictors for chronic pain‐related health care utilization: a cross‐sectional nationwide study in Iceland
Authors: Jonsdottir Thorbjorg , Jonsdottir Helga , Lindal Eirikur , Oskarsson Gudmundur K. , Gunnarsdottir Sigridur
Published: July 2014

Background

Individuals with chronic pain are among the most frequent users of health care. Still, a significant percentage does not utilize health care for pain. A range of factors predict chronic pain‐related health care utilization.

Design

A cross‐sectional study aimed at identifying predictors of chronic pain‐related health care utilization and comparing predictors between men and women.

Methods

A postal questionnaire measuring sociodemographic variables, pain characteristics, health‐related quality of life (HRQoL) and pain‐related health care utilization, was sent to a sample of 4500 individuals randomly drawn from the national population of Iceland. The relationships between sociodemographic and pain‐related factors and pain‐related health care utilization among participants reporting chronic pain (≥3 months) were tested by using bivariate and multivariate statistical analysis.

Results

Among participants reporting chronic pain, 53.2% had consulted a health care provider for pain during the previous 6 months. Predictors for chronic pain‐related health care utilization differed between men and women. Interference with life and pain pattern was the strongest predictors among women, as compared with interference with life and the physical components of HRQoL for men. Pain‐related health care utilization was not linked to sociodemographic factors.

Conclusions

Pain‐related variables are better predictors of chronic pain‐related health care utilization than sociodemographic factors. Even though gender does not predict chronic pain‐related health care utilization, there are gender differences in the relationships between pain‐related variables and health care utilization. Men tend to postpone health care consultations for chronic pain longer than women.
Heat shock protein 90 maintains the stability and function of transcription factor Broad Z7 by interacting with its Broad‐Complex‐Tramtrack‐Bric‐a‐brac domain
Authors: Cai M.‐J. , Li X.‐R. , Pei X.‐Y. , Liu W. , Wang J.‐X. , Zhao X.‐F.
Published: July 2014

Heat shock protein 90 (Hsp90) is a highly conserved chaperone protein that interacts with various client proteins to mediate their folding and stability. The Broad‐Complex‐Tramtrack‐Bric‐a‐brac (BTB) domain, also known as poxvirus and zinc finger (POZ) domain, exists widely in different proteins and is highly conserved. However, the stability mechanism of BTB domain‐containing proteins has not been fully understood. Co‐immunoprecipitation and a protein pull‐down assay were performed to investigate the interaction between Hsp90 and the transcription factor Broad isoform Z7 (BrZ7) in vivo and in vitro. The middle domain of Hsp90 directly associated with the BTB domain of BrZ7. The Hsp90 inhibitor 17‐(Allylamino)‐17‐demethoxygeldanamycin (17‐AAG) interrupted the interaction between Hsp90 and BrZ7 and decreased the protein level of BrZ7 but did not affect the mRNA level of BrZ7. The addition of the proteasome inhibitor peptide aldehyde Cbz‐leu‐leu leucinal suppressed the 17‐AAG‐induced degradation of BrZ7. BTB domain deletion and 17‐AAG treatment resulted in inhibition of BrZ7 function in gene expression in the 20‐hydroxyecdysone and juvenile hormone pathways. These results reveal that the middle domain of Hsp90 associates with the BTB domain of BrZ7 to prevent BrZ7 degradation and maintain BrZ7 function in gene expression in the lepidopteran insect Helicoverpa armigera.
Industrial–Organizational Psychologists in Business Schools: Brain Drain or Eye Opener?
Authors: Aguinis Herman , Bradley Kyle J. , Brodersen Apryl
Published: July 2014

We conducted a quantitative and a qualitative study to assess the extent to which industrial and organizational (I–O) psychology has moved to business schools, understand the nature of this move, and offer a balanced discussion of positive and negative consequences of this phenomenon. In quantitative Study 1, we provide evidence that I–O psychologists affiliated with business schools currently constitute a majority of editorial board members and authors of articles published inJournal of Applied PsychologyandPersonnel Psychologybut that I–O psychology, as a field, is growing. These results suggest that it is not the field of I–O psychology but some of the most active and influential I–O psychology researchers who are moving to business schools. In qualitative Study 2, we gathered perspectives from 144 SIOP Fellows and 27 SIOP presidents suggesting different views on Study 1's results ranging from very negative (i.e., “brain drain”) to very positive (i.e., “eye opener”) depending on the affiliation of the respondent. On the basis of these results, we offer 10 admittedly provocative predictions to stimulate follow-up research and serve as a catalyst for an important conversation, as well as the development of action plans, regarding the future of I–O psychology as a field.
Technostress: negative effect on performance and possible mitigations
Authors: Tarafdar Monideepa , Pullins Ellen Bolman. , Ragu‐Nathan T. S.
Published: July 2014

We investigate the effect of conditions that create technostress, on technology‐enabled innovation, technology‐enabled performance and overall performance. We further look at the role of technology self‐efficacy, organizational mechanisms that inhibit technostress and technology competence as possible mitigations to the effects of technostress creators. Our findings show a negative association between technostress creators and performance. We find that, while traditional effort‐based mechanisms such as building technology competence reduce the impact of technostress creators on technology‐enabled innovation and performance, more empowering mechanisms such as developing technology self‐efficacy and information systems (IS) literacy enhancement and involvement in IS initiatives are required to counter the decrease in overall performance because of technostress creators. Noting that the professional sales context offers increasingly high expectations for technology‐enabled performance in an inherently interpersonal‐oriented and relationship‐oriented environment with regard to overall performance, and high failure rates for IS acceptance/use, the study uses survey data collected from 237 institutional sales professionals.
Getting evidence‐based pressure ulcer prevention into practice: a multi‐faceted unit‐tailored intervention in a hospital setting
Authors: Sving Eva , Högman Marieann , Mamhidir Anna‐Greta , Gunningberg Lena
Published: July 2014

The aim of the study was to evaluate whether a multi‐faceted, unit‐tailored intervention using evidenced‐based pressure ulcer prevention affects (i) the performance of pressure ulcer prevention, (ii) the prevalence of pressure ulcers and (iii) knowledge and attitudes concerning pressure ulcer prevention among registered and assistant nurses. A quasi‐experimental, clustered pre‐ and post‐test design was used. Five units at a hospital setting were included. The intervention was based on the PARIHS framework and included a multi‐professional team, training and repeated quality measurements. An established methodology was used to evaluate the prevalence and prevention of pressure ulcers. Nurses' knowledge and attitudes were evaluated using a validated questionnaire. A total of 506 patients were included, of whom 105 patients had a risk to develop pressure ulcer. More patients were provided pressure ulcer prevention care (P = 0·001) and more prevention care was given to each patient (P = 0·021) after the intervention. Corresponding results were shown in the group of patients assessed as being at risk for developing pressure ulcers. Nurses' knowledge about pressure ulcer prevention increased (P < 0·001). Positive attitudes towards pressure ulcer prevention remained high between pre‐ and post‐test surveys. This multi‐faceted unit‐tailored intervention affected pressure ulcer prevention. Facilitation and repeated quality measurement together with constructed feedback of results seemed to be the most important factor for pressure ulcer prevention.
Structural interactions between actin, tropomyosin, caldesmon and calcium binding protein and the regulation of smooth muscle thin filaments
Authors: MARSTON S. , BURTON D. , COPELAND O. , FRASER I. , GAO Y. , HODGKINSON J. , HUBER P. , LEVINE B. , EL‐MEZGUELDI M. , NOTARIANNI G.
Published: July 2014

The basic structure and functional properties of smooth muscle thin filaments were established about 10 years ago. Since then we and others have been working on the details of how tropomyosin, caldesmon and the Ca2+‐binding protein regulate actin interaction with myosin. Our work has tended to emphasize the similarities between caldesmon and troponin function whilst others have been more concerned with the differences. The need to resolve the resulting differences has stimulated us to find new and more direct ways of investigating the mechanism of thin filament regulation. In recent years an apparent divergence has opened up between functional measurements, which indicate an allosteric‐cooperative regulatory mechanism in which caldesmon and Ca2+‐binding protein control actin—tropomyosin state in the same way as troponin, and structural measurements which show thin filament structures unlike striated muscle thin filaments. The challenge is to interpret function in terms of structure. We have combined functional studies with expression and mutagenesis of caldesmon and with structural methods including X‐ray crystalography of tropomyosin—caldesmon crystals, electron microscopy and helical reconstruction of actin—tropomyosincaldesmon complexes and high resolution nuclear magnetic resonance spectroscopy of the C‐terminus of caldesmon in interaction with actin and calmodulin. We have used this information to propose a structural mechanism for caldesmon regulation of the smooth muscle thin filament.
A common pathway for regulation of nutritive blood flow to the brain: arterial muscle membrane potential and cytochrome P450 metabolites
Authors: HARDER D.R. , ROMAN R.J. , GEBREMEDHIN D. , BIRKS E.K. , LANGE A.R.
Published: July 2014

Perfusion pressure to the brain must remain relatively constant to provide rapid and efficient distribution of blood to metabolically active neurones. Both of these processes are regulated by the level of activation and tone of cerebral arterioles. The active state of cerebral arterial muscle is regulated, to a large extent, by the level of membrane potential. At physiological levels of arterial pressure, cerebral arterial muscle is maintained in an active state owing to membrane depolarization, compared with zero pressure load. As arterial pressure changes, so does membrane potential. The membrane is maintained in a relatively depolarized state because of, in part, inhibition of K+ channel activity. The activity of K+ channels, especially the large conductance Ca2+‐activated K+ channel (KCa) is dependent upon the level of 20‐HETE produced by arterial muscle. As arterial pressure increases, so does cytochrome P450 (P4504A) activity. P4504A enzymes catalyse ω‐hydroxylation of arachidonic acid and formation of 20‐hydroxyeicosatetraenoic acid (20‐HETE). 20‐HETE is a potent inhibitor of KCa which maintains membrane depolarization and muscle cell activation. Astrocytes also metabolize AA via P450 enzymes of the 2C11 gene family to produce epoxyeicosatrienoic acids (EETs). Epoxyeicosatrienoic acids are released from astrocytes by glutamate which ‘spills over’ during neuronal activity. These locally released EETs shunt blood to metabolically active neurones providing substrate to support neuronal function. This short paper will discuss the findings which support the above scenario, the purpose of which is to provide a basis for future studies on the molecular mechanisms through which cerebral blood flow matches metabolism.
The role of phospholamban and SERCA3 in regulation of smooth muscle‐endothelial cell signalling mechanisms: evidence from gene‐ablated mice
Authors: PAUL R.J.
Published: July 2014

It is generally agreed that intracellular Ca2+ stores, the sarco(endo)plasmic‐reticulum (SER), affect Ca2+ homeostasis and thus contractility of vascular smooth muscle. There is, however, no general consensus as to the magnitude of the SER contribution to Ca2+ handling, the basis for isoforms of the SER Ca2+‐ATPases (SERCAs) or the role of an SER‐associated regulatory protein, phospholamban (PLB). Although the biochemical and cell biological roles of the SER have been intensely studied in vitro, the development of gene‐targeted and transgenic mouse models enables one to extend our information to the in vivo levels. A brief review of the role of PLB and SERCA function in vascular and endothelial cell function is presented. Studies on the PLB gene‐ablated mouse indicate that vascular contractility is considerably altered. This is mirrored by changes in intracellular Ca2+. Moreover, differences in contractility of the gene‐ablated tissues are eliminated by treatment with cyclopiazonic acid, which pharmacologically abolishes SER function by inhibiting the Ca2+‐ATPase. Thus PLB modulation of sarcoplasmic reticulum (SR) Ca2+ uptake plays a major role in modulating vascular contractility. It is interesting that endothelium‐dependent relaxation was decreased in the PLB‐deficient aorta. This is surprising in light of the PLB distribution, thought to be limited to cardiac, slow skeletal and smooth muscle. Our data indicate the presence of PLB in endothelial cells and point to an unrecognized pathway for modulation of endothelial cell [Ca2+]i and vascular contractility. Data from smooth muscle tissues of the SERCA3 gene‐ablated mouse demonstrate that this isoform affects endothelium‐dependent function, but not that of smooth muscle, consistent with its known distribution. This isoform appears to perform a modulatory function, rather than the more essential role of SERCA2. Gene‐targeted and transgenic models provide an important avenue for understanding the role of SER in vascular signalling.
Long‐term effects of intracellular calcium and growth factors on excitation and contraction in smooth muscle
Authors: HELLSTRAND P.
Published: July 2014

Modulation of vascular smooth muscle cells from a contractile to a synthetic phenotype is thought to be important in the development of the atherosclerotic lesion. Such modulation depends on growth factors and is influenced by cell—cell and cell—matrix interactions. Whereas smooth muscle cells in the vessel wall are contractile, dispersed cells in culture rapidly modulate to synthetic phenotype, which complicates long‐term in vitro studies. In contrast, vascular segments or smooth muscle strips in organ culture can maintain contractility for at least a week, sufficient for studies involving altered metabolism or protein expression. Examples are effects of endogenous polyamines on membrane ion channels and excitation—contraction coupling. While smooth muscle tissue is well preserved in serum‐free culture, growth stimulation with fetal calf serum (FCS) causes multiple effects, including decreased contractility, ultrastructural changes, decreased expression of l‐type Ca2+ channels, and increased SR release of Ca2+ via ryanodine receptors. These are all consequences of increased basal [Ca2+]i caused by FCS, as they are reversed by culture with verapamil in a concentration (1 μm) that does not inhibit stimulation of DNA and protein synthesis by FCS. The effects of FCS on contractility and Ca2+ channel expression are mimicked in serum‐free culture with increased [Ca2+]i. Contractile protein patterns, including myosin isoform composition, are unaffected by FCS, suggesting that reversal to synthetic phenotype is limited and not the immediate cause of decreased contractility.
Psychosocial factors related to smoking: The midlife study
Authors: Brook Judith S. , Zhang Chenshu , Brook David W.
Published: July 2014

Background

There is limited research on the correlates of cigarette smoking in women in late midlife.

Objectives

The present study examined the associations between risk factors in several psychosocial domains and current cigarette smoking among women in their mid‐60s. These domains included risks in personal attributes, family relationships, negative life events, financial stressors, contextual factors, and problematic alcohol use.

Methods

Data were from a cohort of women originally living in two upstate New York counties (N = 511) in late midlife (mean age = 65). Bivariate and multivariate logistic regression analyses were conducted.

Results

The results supported our hypotheses. The cumulative psychosocial risk index was significantly associated with a greater likelihood of cigarette smoking [A.O.R. = 1.53; 95% C.I. (1.3–.181); p < .001] after controlling for age and educational level.

Conclusions and Scientific Significance

It is important to reduce the number of psychosocial risk factors faced by women in their 60s in order to reduce the likelihood of continued cigarette smoking. (Am J Addict 2014;23:423–428)
Frequency and Temperature‐Independent Electrical Transport Properties of 2BaO–0.5Na2O–2.5Nb2O5–4.5B2O3 Glass‐Ceramics
Authors: Kundu Swarup , Varma Kalidindi B. R.
Published: July 2014

The temperature (300–973 K) and frequency (100 Hz–10 MHz) response of the dielectric and impedance characteristics of 2BaO‐0.5Na2O–2.5Nb2O5–4.5B2O3 glasses and glass nanocrystal composites were studied. The dielectric constant of the glass was found to be almost independent of frequency (100 Hz–10 MHz) and temperature (300–600 K). The temperature coefficient of dielectric constant was 8 ± 3 ppm/K in the 300–600 K temperature range. The relaxation and conduction phenomena were rationalized using modulus formalism and universal AC conductivity exponential power law, respectively. The observed relaxation behavior was found to be thermally activated. The complex impedance data were fitted using the least square method. Dispersion of Barium Sodium Niobate (BNN) phase at nanoscale in a glass matrix resulted in the formation of space charge around crystal‐glass interface, leading to a high value of effective dielectric constant especially for the samples heat‐treated at higher temperatures. The fabricated glass nanocrystal composites exhibited P versus E hysteresis loops at room temperature and the remnant polarization (Pr) increased with the increase in crystallite size.
Structure Evolution and Enhanced Microwave Dielectric Characteristics of (Sr1−xCax)La2Al2O7Ceramics
Authors: Yi Lei , Li Lei , Liu Xiao Qiang , Chen Xiang Ming
Published: July 2014

(Sr1−xCax)La2Al2O7(0.1 ≤ x ≤ 0.5) ceramics were prepared by a standard solid‐state reaction method. Their densification behavior and microwave dielectric properties were investigated together with the structural evolution. X‐ray diffraction analysis indicated that the major phase of Ruddlesden–Popper structure withn = 2 was obtained for all the compositions investigated here. PartialCasubstitution improved the sintering behavior ofSrLa2Al2O7ceramics. More importantly, microwave dielectric characteristics were enhanced in (Sr1−xCax)La2Al2O7ceramics with compositions ofx = 0.1~0.3. The stacking fault was confirmed by TEM observation in the present ceramics, and the microwave dielectric loss was influenced by it. The best combination of microwave dielectric characteristics was achieved for the composition ofx = 0.1: εr= 19.9,Qf = 135 400 GHz and τf = −18.5 ppm/°C.
Voluntary Benefits from Wrongdoing
Authors: Pasternak Avia
Published: July 2014

The principle of wrongful benefits prescribes that beneficiaries from wrongdoing incur duties towards the victims of the wrongdoing. The principle focuses on involuntary beneficiaries, demanding that they disgorge their tainted benefit. However, it overlooks the duties of beneficiaries who are not straightforwardly involuntary. The article addresses this gap in the literature. It explores the duties of ‘voluntary beneficiaries’, who could avoid receiving the tainted benefit; and the duties of ‘welcoming beneficiaries’, who cannot avoid receiving the tainted benefit but welcome it. The article demonstrates that in both cases, the duties of the beneficiary towards the victim of the original wrongdoing are not limited to the disgorgement of the benefit. Rather, voluntary and welcoming beneficiaries are themselves involved in the commission of wrongdoing against the victim of the original wrongdoing, and hence may owe the victim compensation that exceeds the level of their own benefit. This argument has various practical implications, e.g. in specifying the duties of companies who benefit from human rights violations down their supply chain.
The Priority of Solidarity to Justice
Authors: Kolers Avery
Published: July 2014

Recognising and responding to injustices that benefit us is a pervasive problem of contemporary life, and arguably a mark of moral seriousness in anyone who presumes to take moral stands at all. In response, a number of authors have defended the view that such benefits normally bring with them prima facie obligations of compensation. This ‘wrongful‐benefits’ approach has considerable intuitive plausibility, much of it founded in the financial metaphor that gives it an appearance of precision. Yet while the compensation scenario works reasonably well in one‐off cases such as receiving stolen property, it yields incoherent results when facing ongoing structural injustices. In such cases ‘innocence’ is ambiguous and our status as beneficiaries and victims is complex. In contrast, solidarity — understood as a principle of equity requiring that we side with the least well off — provides a better account of duties to respond to structural injustice. In solidarity the agent follows the lead of organised out‐groups and defers to their judgment about collective actions to overcome injustice. Solidarity leads us to support the organised group that suffers from the greatest inequity. Solidarity does not use a financial metaphor and thus it neither requires full disgorgement, nor absolves us of further action when we reach the point of net‐zero benefit. Rather, solidarity is a principal means for ordinary citizens to promote equity by affirming the equal status of the victims, and to atone for having benefited from injustice, whether they did so willingly or otherwise.
Variation in nutrient use in ant assemblages along an extensive elevational gradient on Mt Kilimanjaro
Authors: Peters Marcell K. , Mayr Antonia , Röder Juliane , Sanders Nathan J. , Steffan‐Dewenter Ingolf
Published: July 2014

Aim

We used the extensive climatic and land‐use gradient on Mt Kilimanjaro, Tanzania, to study large‐scale variation of nutrient use in ground‐foraging ant communities. In particular, we tested the hypothesis that recruitment of ants to six different nutrients would vary with elevation and between land‐use regimes. We also tested whether the nutrient space (number and evenness of nutrients) used by ants decreases as species richness declines with elevation, a pattern expected because of complementarity in nutritional intake of species.

Location

Mt Kilimanjaro, Tanzania.

Methods

Standardized bait experiments with six nutrient treatments [carbohydrates (CHO), amino acid, CHO–amino acid mix, NaCl, H2O and lipids] were performed at a total of 48 study sites in natural and managed ecosystems along an elevational gradient from 860 to 4390 m a.s.l. We used generalized linear models, information theory‐based model inference and null model analyses to test hypotheses.

Results

The species richness of ant communities declined with elevation in natural ecosystems but peaked at mid‐elevations in managed ecosystems. We found that the use of four nutrients (NaCl, CHO, H2O and lipids) varied with elevation and, in the case of NaCl and H2O, with land use. Use of H2O and CHO decreased with elevation, while lipid use increased. NaCl use increased with elevation in natural ecosystems but decreased in managed ecosystems.

The nutrient space exploited by ant communities increased with ant species richness in natural ecosystems but decreased slightly in managed ecosystems. The difference could be because there are more trophic generalists in managed ecosystems and more specialists with complementary foraging niches in natural ecosystems.

Main conclusions

Ant communities in different environments appear to be limited by different types and numbers of nutrients. This spatial heterogeneity in nutritional ecology is probably determined by both the environmental availability of nutrients and the functional composition of ant communities.
Defining the spatial patterns of historical land use associated with the indigenous societies of eastern North America
Authors: Munoz Samuel E. , Mladenoff David J. , Schroeder Sissel , Williams John W.
Published: July 2014

Aim

To review and synthesize multiple lines of evidence that describe the spatial patterns of land use associated with prehistoric and early historical Native American societies in eastern North America in order to better characterize the type, spatial extent and temporal persistence of past land use.

Location

Temperate forests of eastern North America, and the Eastern Woodlands cultural region.

Methods

Ethnohistorical accounts, archaeological data, historical land surveys and palaeoecological records describing indigenous forms of silviculture and agriculture were evaluated across scales ranging from local (100 km) to regional (102 km) to produce a synthetic description of land‐use characteristics.

Results

Indigenous land‐use practices created patches of distinct ecological conditions within a heterogeneous mosaic of ecosystem types. At all scales, patch location was dynamic, and patches underwent recurrent periods of expansion, contraction and abandonment. Land‐use patches varied in their extent and persistence, and are broadly categorized as silvicultural (management of undomesticated woodland taxa) or agricultural (cultivation of domesticated taxa). Silvicultural patches persisted for centuries and extended kilometres to tens of kilometres around settlements and travel corridors. The dynamics of agricultural patches varied among groups, with persistence ranging from decades to centuries and extent ranging from less than a kilometre to tens of kilometres around settlements. Beyond patch boundaries, human impacts on ecosystems become indistinguishable from other drivers of environmental heterogeneity. These characteristics of patches are evident across scales and multiple lines of evidence.

Main conclusions

Our findings challenge the view that prehistoric human impacts on vegetation were widespread and ubiquitous, and build on previous work showing these impacts to be more localized and heterogeneous by providing quantitative descriptions of land‐use patch characteristics. Collaborative efforts that combine multiple data sources are needed to refine these descriptions and generate more precise measures of land‐use pattern to further investigate the history of human impacts on the Earth system.