bluuebunny/crossref_metadata_2025 huggingface dataset:
A cross‐cultural study of students’ approaches to professional dilemmas: sticks or ripples
Authors: Ho Ming‐Jung , Lin Chi‐Wei , Chiu Yu‐Ting , Lingard Lorelei , Ginsburg Shiphra
Published: February 2012

Medical Education 2012:

46
: 245–256

Context  Medical educators internationally are faced with the challenge of teaching and assessing professionalism in their students. Some studies have drawn attention to contextual factors that influence students’ responses to professional dilemmas. Although culture is a significant contextual factor, no research has examined student responses to professional dilemmas across different cultures.

Methods  Semi‐structured interviews inquiring into reactions towards, and reasoning about, five video clips depicting students facing professional dilemmas were conducted with 24 final‐year medical students in Taiwan. The interviews were transcribed and analysed according to the theoretical framework used in prior Canadian studies using the same videos and interview questions.

Results  The framework from previous Canadian research, including the components of principles, affect and implications, was generally applicable to the decision making of Taiwanese students, with some distinctions. Taiwanese students cited a few more avowed principles. Taiwanese students emphasised an additional unavowed principle that pertained to following the advice of more senior trainees. In addition to implications for patients, team members or themselves, Taiwanese students considered the impact of their responses on multiple relationships, including those with patients’ families and alumni residents. Cultural norms were also cited by Taiwanese students.

Conclusions  Medical educators must acknowledge students’ reasoning in professionally challenging situations and guide students to balance considerations of principles, implications, affects and cultural norms. The prominence of Confucian relationalism in this study, exhibited by students’ considerations of the rippling effects of their behaviours on all their social relationships, calls for further cross‐cultural studies on medical professionalism to move the field beyond a Western individualist focus.
The legacy of altruism in health care: the promotion of empathy, prosociality and humanism
Authors: Burks Derek J , Kobus Amy M
Published: February 2012

Medical Education 2012: 46: 317–325

Objectives  This study aimed to examine concepts of altruism and empathy among medical students and professionals in conjunction with health care initiatives designed to support the maintenance of these qualities.

Methods  We searched for the terms ‘altruism’, ‘altruistic’, ‘helping’, ‘prosocial behaviour’ and ‘empathy’ in the English‐language literature published from 1980 to the present within the Ovid MEDLINE, PsycInfo and PubMed databases. We used conceptual analysis to examine the relationships among altruism, empathy and related prosocial concepts in health care in order to understand how such factors may relate to emotional and career burnout, cynicism, decreased helping and decreased patient‐centredness in care.

Results  Altruistic ideals and qualities of empathy appear to decrease among some medical students as they progress through their education. During this process, students face increasingly heavy workloads, deal with strenuous demands and become more acquainted with non‐humanistic informal practices inherent in the culture of medicine. In combination, these factors increase the likelihood that emotional suppression, detachment from patients, burnout and other negative consequences may result, perhaps as a means of self‐preservation. Alternatively, by making a mindful and intentional choice to endeavour for self‐care and a healthy work–life balance, medical students can uphold humanistic and prosocial attitudes and behaviours.

Conclusions  Promoting altruism in the context of a compensated health care career is contradictory and misguided. Instead, an approach to clinical care that is prosocial and empathic is recommended. Training in mindfulness, self‐reflection and emotion skills may help medical students and professionals to recognise, regulate and behaviourally demonstrate empathy within clinical and professional encounters. However, health care initiatives to increase empathy and other humanistic qualities will be limited unless more practical and feasible emotion skills training is offered to and accepted by medical students. Success will be further moderated by the culture of medicine’s full acceptance of empathy and humanism into its customs, beliefs, values, interactions and daily practices.
Learning during simulation training is prone to retroactive interference
Authors: Fraser Kristin , Ma Irene , Teteris Elise , Lee Murray , Wright Bruce , McLaughlin Kevin
Published: February 2012

Medical Education 2012: 46: 299–305

Context  Retroactive interference occurs when newly acquired information inhibits recall of previously learned information. This has been shown to influence recall of sounds, tastes and word associations, and is typically seen when learners receive training on one area of content and are then exposed to new content before being evaluated on the original content. Thus far, retroactive interference has received little attention in medical education and has not been studied during simulation training. Our objective was to evaluate whether retroactive interference occurs during simulation training.

Methods  We randomised 167 Year 1 medical students to one of two training protocols. After training on a cardiac murmur, participants were tested either on the same cardiac murmur followed by a novel murmur (the non‐interference protocol), or on the novel murmur followed by the training murmur (the interference protocol). We evaluated performance on both murmurs at 1 hour and 6 weeks post‐training.

Results  We found a significant interaction between training protocol and diagnostic performance on training versus novel murmurs at both testing time‐points. Students in the non‐interference protocol had increased odds of achieving success on the training murmur relative to the novel murmur at 1 hour (odds ratio [OR] 4.96; p < 0.001) and at 6 weeks (OR 4.23; p = 0.001) after training. By comparison, students in the interference protocol did not demonstrate improved performance on the training murmur relative to the novel murmur at either evaluation (1 hour post‐training: OR 0.56 [p = 0.08]; 6 weeks post‐training: OR 0.66 [p = 0.23]).

Conclusions  Consistent with the theory of retroactive interference, students who encountered a novel murmur between training and evaluation on the murmur on which they had been trained showed no improvement in diagnostic performance following simulation training. These findings should serve to warn educators to consider retroactive interference when designing simulation training sessions.
The RS domain of Arabidopsis splicing factor RRC1 is required for phytochrome B signal transduction
Authors: Shikata Hiromasa , Shibata Mami , Ushijima Tomokazu , Nakashima Moeko , Kong Sam‐Geun , Matsuoka Ken , Lin Chentao , Matsushita Tomonao
Published: February 2012

Plants monitor the light environment through informational photoreceptors that include phytochromes. In seedling de‐etiolation, phytochrome B (phyB), which is the most important member of the phytochrome family, interacts with transcription factors to regulate gene expression and transduce light signals. In this study, we identified rrc1 (reduced red‐light responses in cry1cry2 background 1), an Arabidopsis mutant that is impaired in phyB‐mediated light responses. A genetic analysis demonstrated that RRC1 affected light signaling in a phyB‐dependent manner. RRC1 encodes an ortholog of the human potential splicing factor SR140. The RRC1 polypeptide contains a C‐terminal arginine/serine‐rich (RS) domain that is important for the regulation of alternative splicing. Although the complete loss of RRC1 caused pleiotropic developmental abnormalities, the deletion of the RS domain specifically reduced phyB signaling and caused aberrant alternative splicing of several SR protein genes. Moreover, semi‐quantitative RT‐PCR analysis revealed that the alternative splicing patterns of some of the SR protein genes were altered in a red‐light‐dependent manner, and that these responses were reduced in both phyB and rrc1 mutants. These findings suggest that the regulation of alternative splicing by the RS domain of RRC1 plays an important role in phyB signal transduction.
Transcriptome analysis and gene expression atlas for Panicum hallii var. filipes, a diploid model for biofuel research
Authors: Meyer Eli , Logan Tierney L. , Juenger Thomas E.
Published: February 2012

Panicum hallii is an emerging model for genetic studies of agronomic traits in Panicum, presenting a tractable diploid alternative study system to the tetra‐ or octaploid biofuel crop switchgrass (Panicum virgatum). To characterize the gene complement in P. hallii var. filipes and enable gene expression analysis in this system we sequenced, assembled, and annotated the transcriptome. Over 300 Mb of normalized cDNA prepared from multiple tissues and treatments was sequenced using 454‐Titanium, producing an annotated assembly including 15 422 unique gene names. Comparison with other grass genomes identified putative P. hallii homologs for >14 000 previously characterized genes. We also developed an atlas of gene expression across tissues and stages using RNA‐Seq (the quantitative analysis of short cDNA reads). SOLiD sequencing and quantitative analysis of more than 40 million cDNA tags identified substantial variation in expression profiles among tissues, consistent with known functional differences. Putative homologs were found for all enzymes in the phenylpropanoid pathway leading to lignin biosynthesis, including genes with known effects on biomass conversion efficiency. The resources developed here will enable studies of the genes underlying variation in cell wall composition, drought tolerance, and biomass production in Panicum.
Above‐ and below‐ground responses of Calamagrostis purpurea to UV‐B radiation and elevated CO2 under phosphorus limitation
Authors: Bussell Jenny S. , Gwynn‐Jones Dylan , Griffith Gareth W. , Scullion John
Published: February 2012

UV‐B radiation and elevated CO2 may impact rhizosphere processes through altered below‐ground plant resource allocation and root exudation, changes that may have implications for nutrient acquisition. As nutrients limit plant growth in many habitats, their supply may dictate plant response under elevated CO2. This study investigated UV‐B exposure and elevated CO2 effects, including interactions, on plant growth, tissue chemistry and rooting responses relating to P acquisition. The sub‐arctic grass Calamagrostis purpurea was subjected to UV‐B (0 or 3.04 kJ m−2day−1) and CO2 (ambient 380 or 650 ppmv) treatments in a factorial glasshouse experiment, with sparingly soluble P (0 or 0.152 mg P per plant as FePO4) a further factor. It was hypothesized that UV‐B exposure and elevated CO2 would change plant resource allocation, with CO2 mitigating adverse responses to UV‐B exposure and aiding P uptake. Plant biomass and morphology, tissue composition and rhizosphere leachate properties were measured. UV‐B directly affected chemical composition of shoots and interacted with CO2 to give a greater root biomass. Elevated CO2 altered the composition of both shoots and roots and increased shoot biomass and secondary root length, while leachate pH decreased. Below‐ground responses to CO2 did not affect P acquisition although P limitation progressively reduced leachate pH and increased secondary root length. Although direct plant growth, foliar composition and below‐ground nutrient acquisition responses were dominated by CO2 treatments, UV‐B modified these CO2 responses significantly. These interactions have implications for plant responses to future atmospheric conditions.
Rubisco activity is associated with photosynthetic thermotolerance in a wild rice (Oryza meridionalis)
Authors: Scafaro Andrew P. , Yamori Wataru , Carmo‐Silva A. Elizabete , Salvucci Michael E. , von Caemmerer Susanne , Atwell Brian J.
Published: February 2012

Oryza meridionalis is a wild species of rice, endemic to tropical Australia. It shares a significant genome homology with the common domesticated rice Oryza sativa. Exploiting the fact that the two species are highly related but O. meridionalis has superior heat tolerance, experiments were undertaken to identify the impact of temperature on key events in photosynthesis. At an ambient CO2 partial pressure of 38 Pa and irradiance of 1500 µmol quanta m−2 s−1, the temperature optimum of photosynthesis was 33.7 ± 0.8°C for O. meridionalis, significantly higher than the 30.6 ± 0.7°C temperature optimum of O. sativa. To understand the basis for this difference, we measured gas exchange and rubisco activation state between 20 and 42°C and modeled the response to determine the rate‐limiting steps of photosynthesis. The temperature response of light respiration (Rlight) and the CO2 compensation point in the absence of respiration (Γ*) were determined and found to be similar for the two species. C3 photosynthesis modeling showed that despite the difference in susceptibility to high temperature, both species had a similar temperature‐dependent limitation to photosynthesis. Both rice species were limited by ribulose‐1,5‐bisphosphate (RuBP) regeneration at temperatures of 25 and 30°C but became RuBP carboxylation limited at 35 and 40°C. The activation state of rubisco in O. meridionalis was more stable at higher temperatures, explaining its greater heat tolerance compared with O. sativa.
Activity, polypeptide and gene identification of thylakoid Ndh complex in trees: potential physiological relevance of fluorescence assays
Authors: Serrot Patricia H. , Sabater Bartolomé , Martín Mercedes
Published: February 2012

Three evergreen (Laurus nobilis, Viburnum tinus and Thuja plicata) and two autumnal abscission deciduous trees (Cydonia oblonga and Prunus domestica) have been investigated for the presence (zymogram and immunodetection) and functionality (post‐illumination chlorophyll fluorescence) of the thylakoid Ndh complex. The presence of encoding ndh genes has also been investigated in T. plicata. Western assays allowed tentative identification of zymogram NADH dehydrogenase bands corresponding to the Ndh complex after native electrophoresis of solubilized fractions from L. nobilis, V. tinus, C. oblonga and P. domestica leaves, but not in those of T. plicata. However, Ndh subunits were detected after SDS‐PAGE of thylakoid solubilized proteins of T. plicata. The leaves of the five plants showed the post‐illumination chlorophyll fluorescence increase dependent on the presence of active Ndh complex. The fluorescence increase was higher in autumn in deciduous, but not in evergreen trees, which suggests that the thylakoid Ndh complex could be involved in autumnal leaf senescence. Two ndhB genes were sequenced from T. plicata that differ at the 350 bp 3′ end sequence. Comparison with the mRNA revealed that ndhB genes have a 707‐bp type II intron between exons 1 (723 bp) and 2 (729 bp) and that the UCA 259th codon is edited to UUA in mRNA. Phylogenetically, the ndhB genes of T. plicata group close to those of Metasequoia, Cryptomeria, Taxodium, Juniperus and Widdringtonia in the cupresaceae branch and are 5′ end shortened by 18 codons with respect to that of angiosperms.
Influence of additional language learning on first language learning in children with language disorders
Authors: To Carol K. S. , Law Thomas , Li Xin‐xin
Published: February 2012

Abstract  Background: Multilingualism can bring about various positive outcomes to typically developing children. Its effect on children with language difficulties is not yet clear.

Aim: The aim of this study was to examine the effects of multilingual learning as a medium of instruction (MOI) on first language (L1) acquisition of children with language disorders (LD).

Methods & Procedures: Nineteen Cantonese‐speaking students aged 5;8–6;8 who were diagnosed with LD were recruited from a school that used Putonghua (an alternative Chinese dialect) as the MOI when learning Chinese language and were compared with 18 age‐and‐gender‐matched Cantonese‐speaking students with LD from a school that used Cantonese as the MOI when learning Chinese language. All the students also learned English (L2) as a subject at school. Proficiency in Cantonese was tested at the beginning and the end of the semester in Grade One in terms of: (1) grammar, (2) expressive vocabulary, (3) auditory textual comprehension, (4) word definition and (5) narration.

Outcomes & Results: Mixed‐model ANOVAs revealed an effect of time on language proficiency indicating positive gains in both groups. Interaction effects between time and group were not significant. There was a trend that children learning Putonghua showed slightly more improvement in auditory textual comprehension.

Conclusions & Implications: Proficiency gains were similar across groups. The study found no evidence that a multilingual learning environment hinders the language proficiency in L1 in students who have LD.
Dynamic Assessment of Sentence Structure (DASS): design and evaluation of a novel procedure for the assessment of syntax in children with language impairments
Authors: Hasson Natalie , Dodd Barbara , Botting Nicola
Published: February 2012

Abstract  Background: Sentence construction and syntactic organization are known to be poor in children with specific language impairments (SLI), but little is known about the way in which children with SLI approach language tasks, and static standardized tests contribute little to the differentiation of skills within the population of children with language impairments (LI). Information about the nature and intensity of prompts that facilitate sentence construction for a particular child may be useful in planning effective intervention.

Aims: This paper describes the development of a dynamic assessment (DA) task which requires implicit knowledge of syntactic structure. The aim was to formulate a valid and reliable procedure for the DA of sentence formulation that could yield useful information for planning intervention for children with LI.

Methods & Procedures: The Dynamic Assessment of Sentence Structure (DASS) was employed on 24 children aged 8–10 years, with identified language impairments, who were tested four times, at 4 monthly intervals.

Outcomes & Results: A range of scores was elicited with no limiting ceiling or floor effects, and the test showed high internal reliability of α= 0.833. Inter‐rater reliability was high. Concurrent validity was demonstrated by significant correlation with scores obtained on the CELF‐3(UK) and predictive validity of the measure was also found to exceed that of the standardized test measure. Information about the ability of the children to use strategies and less directive prompts, and to transfer learning between items was elicited, and the information was thought to be useful by speech and language therapists involved in their management.

Conclusions & Implications: The application of DA principles to the assessment of children previously diagnosed with LI, for the purposes of finding out more information about their potential to benefit from language intervention, was found to be effective. The tool developed was shown to be valid and reliable, and it has potentially important applications for the planning of individual intervention programmes and service delivery.
The Influence of Reflected Solar Glare Caused by the Glass Cladding of a Building: Application of Caustic Curve Analysis
Authors: Brzezicki Marcin
Published: February 2012

Abstract:  The purpose of this study is to investigate the effects of glare reflection on the surroundings from differently shaped glossy façades. The first stage of the research involved studying various forms of building façades, including rectangular and angular as well as concave and convex shapes. For the second stage, concave façades were selected, as they had been shown to generate the highest luminance values. This detailed examination of concave façades includes a mathematical analysis of the caustic curve and the formulation of geometrical conditions for its formation with supporting, custom‐made software. In conclusion, this study suggests how designers can either avoid caustic curve formation or how to predict its precise position in the building's surroundings.
Characterization of cerebral glucose dynamics in vivo with a four‐state conformational model of transport at the blood–brain barrier
Authors: Duarte João M. N. , Gruetter Rolf
Published: February 2012

J. Neurochem. (2012) 121, 396–406.

Determination of brain glucose transport kinetics in vivo at steady‐state typically does not allow distinguishing apparent maximum transport rate (Tmax) from cerebral consumption rate. Using a four‐state conformational model of glucose transport, we show that simultaneous dynamic measurement of brain and plasma glucose concentrations provide enough information for independent and reliable determination of the two rates. In addition, although dynamic glucose homeostasis can be described with a reversible Michaelis–Menten model, which is implicit to the large iso‐inhibition constant (Kii) relative to physiological brain glucose content, we found that the apparent affinity constant (Kt) was better determined with the four‐state conformational model of glucose transport than with any of the other models tested. Furthermore, we confirmed the utility of the present method to determine glucose transport and consumption by analysing the modulation of both glucose transport and consumption by anaesthesia conditions that modify cerebral activity. In particular, deep thiopental anaesthesia caused a significant reduction of both Tmax and cerebral metabolic rate for glucose consumption. In conclusion, dynamic measurement of brain glucose in vivo in function of plasma glucose allows robust determination of both glucose uptake and consumption kinetics.
Which plant traits predict species loss in calcareous grasslands with extinction debt?
Authors: Saar Liina , Takkis Krista , Pärtel Meelis , Helm Aveliina
Published: February 2012

Aim  Habitat loss and degradation pose a major threat to biodiversity, which can result in the extinction of habitat characteristic species. However, many species exhibit a delayed response to environmental changes because of the slow intrinsic dynamics of populations, resulting in extinction debt. We assess directly the changes in habitat characteristic species composition by comparing historical (1923) and current inventories in highly fragmented grasslands. We aim to characterize the species that constitute extinction debt in European calcareous grasslands.

Location  Europe, Estonia, 59–60° N, 24–25° E.

Methods  We related eleven life‐history traits and selected habitat preferences to local extinctions of populations in grasslands where extinction debt has been largely paid. Traits were chosen to describe species dispersal and persistence abilities and were quantified from databases.

Results  The studied grasslands have lost 90% of their area and 30% of their characteristic plant populations in 90 years. Species more prone to local population extinction were characterized by shorter life span, self‐pollination, a lack of clonal growth, fewer seeds per shoot, lower average height, lower soil nitrogen preference and higher requirements for light, indicating a limited ability to tolerate the range of changes in biotic and abiotic conditions of the sites. Locally extinct populations were also characterized by wind‐dispersed seeds, lower seed weight and lower terminal velocity of seeds, suggesting that species strategies for long‐distance dispersal are not favoured in highly fragmented landscapes. Thus, both increased habitat isolation and decreased habitat quality are important in determining local population extinction.

Main conclusions  Populations more prone to local extinction were characterized by a number of life‐history traits, demonstrating a greater extinction risk for species with poorer abilities for local persistence and competition. Our results can be applied to less degraded grasslands where the extinction debt is not yet paid to determine those species most susceptible to future extinction.
Predicting to new environments: tools for visualizing model behaviour and impacts on mapped distributions
Authors: Zurell Damaris , Elith Jane , Schröder Boris
Published: February 2012

Data limitations can lead to unrealistic fits of predictive species distribution models (SDMs) and spurious extrapolation to novel environments. Here, we want to draw attention to novel combinations of environmental predictors that are within the sampled range of individual predictors but are nevertheless outside the sample space. These tend to be overlooked when visualizing model behaviour. They may be a cause of differing model transferability and environmental change predictions between methods, a problem described in some studies but generally not well understood. We here use a simple simulated data example to illustrate the problem and provide new and complementary visualization techniques to explore model behaviour and predictions to novel environments. We then apply these in a more complex real‐world example. Our results underscore the necessity of scrutinizing model fits, ecological theory and environmental novelty.
Contrasting patterns in species richness of birds, butterflies and plants along riparian corridors in an urban landscape
Authors: Dallimer Martin , Rouquette James R. , Skinner Andrew M. J. , Armsworth Paul R. , Maltby Lorraine M. , Warren Philip H. , Gaston Kevin J.
Published: February 2012

Aim  Urbanization is a major driver of global land‐use change, substantially modifying patterns of biodiversity. Managing these impacts has become a conservation priority. The creation and maintenance of greenways, such as river corridors, is frequently promoted as a strategy for mitigating habitat fragmentation in urban areas by bringing semi‐natural habitat cover into city centres. However, there is little evidence to support this assertion. Here, we examine whether riparian zones maintain semi‐natural habitat cover in urban areas and how species richness varies along such zones.

Location  Sheffield, Northern England.

Methods  Multiple taxonomic groups (birds, butterflies, plants) were surveyed at 105 sites spanning seven riparian corridors that transect the study system. For all groups, we model the relationships between species richness and environmental variables pertinent to an urban system. To test whether riparian zones can act to maintain semi‐natural habitats within a city, we modelled the proportion of semi‐natural land cover within 250 m grid squares that do, and do not, contain a river.

Results  Species richness varied markedly in relation to distance from the urban core. Trends differed both between taxonomic groups and between rivers, reflecting the complex patterns of environmental variation associated with cities. This suggests that biodiversity surveys that focus on a single group or transect cannot reliably be used as surrogates even within the same city. Nonetheless, there were common environmental predictors of species richness. Plant, avian and butterfly richness all responded positively to Habitat Diversity and the latter two declined with increases in sealed surface.

Main conclusions  Multiple transects and taxonomic groups are required to describe species richness responses to urbanization as no single pattern is evident. Although riparian zones are an important component of the mosaic of urban habitats, we find that river corridors do not disproportionately support tree and Natural Surface Cover when compared to non‐riverine urban areas.
Study on the dyeing properties of hemicyanine dyes. II. Cationic dyeable polyester
Authors: Ren Zhiping , Qin Chuanxiang , Tang Ren‐Cheng , Chen Guoqiang
Published: February 2012

The absorption spectra of two hemicyanine fluorescent dyes, namely, trans‐4‐[p‐(N,N‐di(2‐hydroxyethyl))‐amino‐styryl]‐N‐ethyl pyridinium bromide (DHEASPBr‐C2) and trans‐4‐[p‐(N,N‐di(2‐hydroxyethyl))‐amino‐styryl]‐N‐octyl pyridinium bromide (DHEASPBr‐C8), were studied at various levels of pH and high temperatures, and were then employed to dye cationic dyeable polyester. Their dyeing properties, fluorescent reflectance and colorimetric properties were explored. The novel fluorescent dyes existed in two forms of monocation and dication in solutions at low pH and high temperature. Overall, the influence of pH on colour depth and the maximum reflectance of dyed cationic dyeable polyester was extremely small. The adsorption mechanism of DHEASPBr‐C2 and DHEASPBr‐C8 on cationic dyeable polyester fibres was in good accord with the Langmuir type. Compared with DHEASPBr‐C2, DHEASPBr‐C8 exhibited comparatively faster adsorption rate, higher affinity and dye uptake, while its fluorescence shown by cationic dyeable polyester was slightly weak.
Acetaldehyde Oral Self‐Administration: Evidence from the Operant‐Conflict Paradigm
Authors: Cacace Silvana , Plescia Fulvio , Barberi Ignazio , Cannizzaro Carla
Published: February 2012

Background:

Acetaldehyde (ACD), ethanol's first metabolite, has been reported to interact with the dopaminergic reward system, and with the neural circuits involved in stress response. Rats self‐administer ACD directly into cerebral ventricles, and multiple intracerebroventricular infusions of ACD produce conditioned place preference. Self‐administration has been largely employed to assess the reinforcing and addictive properties of most drugs of abuse. In particular, operant conditioning is a valid model to investigate drug‐seeking and drug‐taking behavior in rats.

Methods:

This study was aimed at the evaluation of (i) the motivational properties of oral ACD in the induction and maintenance of an operant‐drinking behavior; (ii) ACD effect in a conflict situation employing the punishment‐based Geller–Seifter procedure; and (iii) the onset of a relapse drinking behavior, following ACD deprivation. The lever‐pressing procedure in a sound‐attenuated operant‐conditioning chamber was scheduled into 3 different periods: (i) training—rewarded responses with a fixed ratio 1; (ii) conflict—rewarded responses periodically associated with a 0.2 mA foot‐shock; and (iii) relapse—rewarded lever presses following 1‐week ACD abstinence.

Results:

Our results show that oral self‐administrated ACD induced: a higher rate of punished responses in Geller–Seifter procedures; and the establishment of a relapse behavior following ACD deprivation.

Conclusions:

In conclusion, our results indicate that ACD is able to induce an operant‐drinking behavior, which is also maintained besides the conflict procedure and enhanced by the deprivation effect, supporting the hypothesis that ACD itself possesses motivational properties, such as alcohol and other substances of abuse.
Roy’s Safety‐First Portfolio Principle in Financial Risk Management of Disastrous Events
Authors: Chiu Mei Choi , Wong Hoi Ying , Li Duan
Published: February 2012

Roy pioneers the concept and practice of risk management of disastrous events via his safety‐first principle for portfolio selection. More specifically, his safety‐first principle advocates an optimal portfolio strategy generated from minimizing the disaster probability, while subject to the budget constraint and the mean constraint that the expected final wealth is not less than a preselected disaster level. This article studies the dynamic safety‐first principle in continuous time and its application in asset and liability management. We reveal that the distortion resulting from dropping the mean constraint, as a common practice to approximate the original Roy’s setting, either leads to a trivial case or changes the problem nature completely to a target‐reaching problem, which produces a highly leveraged trading strategy. Recognizing the ill‐posed nature of the corresponding Lagrangian method when retaining the mean constraint, we invoke a wisdom observed from a limited funding‐level regulation of pension funds and modify the original safety‐first formulation accordingly by imposing an upper bound on the funding level. This model revision enables us to solve completely the safety‐first asset‐liability problem by a martingale approach and to derive an optimal policy that follows faithfully the spirit of the safety‐first principle and demonstrates a prominent nature of fighting for the best and preventing disaster from happening.
Concern About HIV and AIDS Among Older People in the Slums of Nairobi, Kenya
Authors: Chepngeno‐Langat Gloria , Falkingham Jane C. , Madise Nyovani J. , Evandrou Maria
Published: February 2012

The article explores the way that social networks and personal experiences affect perceived HIV‐related concerns among people aged 50 years or older living in a low resource neighborhood with high HIV prevalence in Nairobi, Kenya. Multiple logistic regression is used to model the association between the reporting of an HIV‐related concern and individual‐level characteristics, personal experiences, and social interaction. The main concerns regarding HIV reported by older people in the study included caring for orphaned children (65%), caring for people with AIDS (48%), and losing material and social support from adult children (36%). Interestingly, 38% of respondents voiced concerns about HIV infection among older people. Respondents who had been individually affected by HIV and AIDS, who were part of a wide social network, or who participated in community activities were frequently more likely to report a concern. The findings highlight the significance of the role of social interaction and social networks in the diffusion of information and knowledge. These findings have implications for HIV and AIDS policy and programs, highlighting the potential for social networks and community‐level interventions to educate and increase awareness about HIV and AIDS among older people. Community leaders can make good peer educators and communication agents for HIV/AIDS campaigns. Additionally, the recognized high level of personal vulnerability to HIV infection among older people suggests the need for targeted sexual behavior change programs among this often neglected group.
Unquestioned Answers or Unanswered Questions: Beliefs About Science Guide Responses to Uncertainty in Climate Change Risk Communication
Authors: Rabinovich Anna , Morton Thomas A.
Published: February 2012

In two experimental studies we investigated the effect of beliefs about the nature and purpose of science (classical vs. Kuhnian models of science) on responses to uncertainty in scientific messages about climate change risk. The results revealed a significant interaction between both measured (Study 1) and manipulated (Study 2) beliefs about science and the level of communicated uncertainty on willingness to act in line with the message. Specifically, messages that communicated high uncertainty were more persuasive for participants who shared an understanding of science as debate than for those who believed that science is a search for absolute truth. In addition, participants who had a concept of science as debate were more motivated by higher (rather than lower) uncertainty in climate change messages. The results suggest that achieving alignment between the general public's beliefs about science and the style of the scientific messages is crucial for successful risk communication in science. Accordingly, rather than uncertainty always undermining the effectiveness of science communication, uncertainty can enhance message effects when it fits the audience's understanding of what science is.
3D Reconstruction of the Glycocalyx Structure in Mammalian Capillaries using Electron Tomography
Authors: ARKILL KENTON P. , NEAL CHRIS R. , MANTELL JUDITH M. , MICHEL CHARLES C. , QVORTRUP KLAUS , ROSTGAARD JØRGEN , BATES DAVE O. , KNUPP CARLO , SQUIRE JOHN M.
Published: February 2012

Please cite this paper as: Arkill KP, Neal CR, Mantell JM, Michel CC, Qvortrup K, Rostgaard J, Bates DO, Knupp C, Squire JM. 3D reconstruction of the glycocalyx structure in mammalian capillaries using electron tomography. Microcirculation 19: 343–351, 2012.

Objective:  Visualising the molecular strands making up the glycocalyx in the lumen of small blood vessels has proved to be difficult using conventional transmission electron microscopy techniques. Images obtained from tissue stained in a variety of ways have revealed a regularity in the organisation of the proteoglycan components of the glycocalyx layer (fundamental spacing about 20 nm), but require a large sample number. Attempts to visualise the glycocalyx face‐on (i.e. in a direction perpendicular to the endothelial cell layer in the lumen and directly applicable for permeability modelling) has had limited success (e.g. freeze fracture). A new approach is therefore needed.

Methods:  Here we demonstrate the effectiveness of using the relatively novel electron microscopy technique of 3D electron tomography on two differently stained glycocalyx preparations. A tannic acid staining method and a novel staining technique using Lanthanum Dysprosium Glycosamino Glycan adhesion (the LaDy GAGa method).

Results:  3D electron tomography reveals details of the architecture of the glycocalyx just above the endothelial cell layer. The LaDy GAGa method visually appears to show more complete coverage and more depth than the Tannic Acid staining method.

Conclusion:  The tomographic reconstructions show a potentially significant improvement in determining glycocalyx structure over standard transmission electron microscopy.
Chloroquine enhances the chemotherapeutic activity of 5‐fluorouracil in a colon cancer cell line via cell cycle alteration
Authors: Choi Jung‐Hye , Yoon Jin Sun , Won Young‐Woong , Park Byeong‐Bae , Lee Young Yiul
Published: February 2012

Autophagy is a conserved catabolic process that degrades cytoplasmic proteins and organelles for recycling. The role of autophagy in tumorigenesis is controversial because autophagy can be either protective or damaging to tumor cells, and its effects may change during tumor progression. A number of cancer cell lines have been exposed to chloroquine, an anti‐malarial drug, with the aim of inhibiting cell growth and inducing cell death. In addition, chloroquine inhibits a late phase of autophagy. This study was conducted to investigate the anti‐cancer effect of autophagy inhibition, using chloroquine together with 5‐fluorouracil (5‐FU) in a colon cancer cell line. Human colon cancer DLD‐1 cells were treated with 5‐FU (10 μΜ) or chloroquine (100 μΜ), or a combination of both. Autophagy was evaluated by western blot analysis of microtubule‐associated protein light chain3 (LC3). Proliferative activity, alterations of the cell cycle, and apoptosis were measured by MTT assays, flow cytometry, and western blotting. LC3‐II protein increased after treatment with 5‐FU, and chloroquine potentiated the cytotoxicity of 5‐FU. MTT assays showed that 5‐FU inhibited proliferation of the DLD‐1 cells and that chloroquine enhanced this inhibitory effect of 5‐FU. The combination of 5‐FU and chloroquine induced G1 arrest, up‐regulation of p27 and p53, and down‐regulation of CDK2 and cyclin D1. These results suggest that chloroquine may potentiate the anti‐cancer effect of 5‐FU via cell cycle inhibition. Chloroquine potentiates the anti‐cancer effect of 5‐FU in colon cancer cells. Supplementation of conventional chemotherapy with chloroquine may provide a new cancer therapy modality.
Type III apparatus of Pseudomonas aeruginosa as a tool to diagnose pulmonary infection in cystic fibrosis patients
Authors: Cruz Aline C. , Neves Bianca C. , Higa Laurinda Y. S. , Folescu Tânia , Marques Elizabeth A. , Milagres Lucimar G.
Published: February 2012

Pseudomonas aeruginosa is associated with increased mortality in cystic fibrosis (CF) patients, and expresses type III secretion system proteins (TTSP), which is a common mechanism used by gram‐negative pathogens for delivery of anti‐host factors. Our aim was to investigate whether or not these antigens (TTSP) would be recognized by CF sera, by Western blot reaction. We have showed herein that all patients (n = 11) not chronically infected by P. aeruginosa had their first serum positive for TTSP (ExoS, ExoT, PopB, and/or PopD). All chronic patients had a strong positive serology to TTSP, although relatively weak reactions to TTSP were observed for some individuals in the negative control group. Therefore, TTSP that were early produced in P. aeruginosa infected CF patients, induced a detectable antibody response in those patients and were easily detected by Western‐blot reaction.
The green tea polyphenol (−)‐epigallocatechin gallate precipitates salivary proteins including alpha‐amylase: biochemical implications for oral health
Authors: Hara Kumiko , Ohara Masaru , Hayashi Ikue , Hino Takamune , Nishimura Rumi , Iwasaki Yoriko , Ogawa Tetsuji , Ohyama Yoshihiko , Sugiyama Masaru , Amano Hideaki
Published: February 2012

Hara K, Ohara M, Hayashi I, Hino T, Nishimura R, Iwasaki Y, Ogawa T, Ohyama Y, Sugiyama M, Amano H. The green tea polyphenol (−)‐epigallocatechin gallate precipitates salivary proteins including alpha‐amylase: biochemical implications for oral health.
 
Eur J Oral Sci 2012; 120: 132–139. © 2012 Eur J Oral Sci

Green tea is a popular drink throughout the world, and it contains various components, including the green tea polyphenol (−)‐epigallocatechin gallate (EGCG). Tea interacts with saliva upon entering the mouth, so the interaction between saliva and EGCG interested us, especially with respect to EGCG–protein binding. SDS‐PAGE revealed that several salivary proteins were precipitated after adding EGCG to saliva. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) peptide mass fingerprinting indicated that the major proteins precipitated by EGCG were alpha‐amylase, S100, and cystatins. Surface plasmon resonance revealed that EGCG bound to alpha‐amylase at dissociation constant (Kd) = 2.74 × 10−6 M, suggesting that EGCG interacts with salivary proteins with a relatively strong affinity. In addition, EGCG inhibited the activity of alpha‐amylase by non‐competitive inhibition, indicating that EGCG is effective at inhibiting the formation of fermentable carbohydrates involved in caries formation. Interestingly, alpha‐amylase reduced the antimicrobial activity of EGCG against the periodontal bacterium Aggregatibacter actinomycetemcomitans. Therefore, we considered that EGCG–salivary protein interactions might have both protective and detrimental effects with respect to oral health.
Microbial profiles in saliva from children with and without caries in mixed dentition
Authors: Luo AH , Yang DQ , Xin BC , Paster BJ , Qin J
Published: February 2012

Oral Diseases (2012) 18, 595–601

Objective:  The purpose of this study was to determine the bacterial profiles in saliva of the isolated children for studying caries etiology.

Materials and methods:  Samples were collected from isolated children from 6 to 8 years old including 20 caries‐free (dmfs = 0) (healthy) and 30 caries‐active individuals (dmfs > 8) (patients). 16S rRNA genes were amplified by PCR from bacterial DNA of saliva sample and labeled via incorporation of Cy3‐dCTP in second nested PCR. After hybridization of labeled amplicons on HOMIM, the microarray slides were scanned and original data acquired from professional software.

Results:  Collectively, 94 bacterial species or clusters representing six bacterial phyla and 30 genera were detected. A higher bacterial diversity was observed in patients than in healthy samples. Statistical analyses revealed eight species or clusters were detected more frequently in diseased patients than in healthy samples, while six different species were detected more frequently in healthy as compared to diseased patients.

Conclusion:  The diversity of microbe within saliva derived from isolated population increased in caries‐active status, and there are some bacteria in salivary flora can be as candidate biomarkers for caries prognosis in mixed dentition. The imbalances in the resident microflora may be the ultimate mechanism of dental caries.
Role of phosphate in the central metabolism of two lactic acid bacteria – a comparative systems biology approach
Authors: Levering Jennifer , Musters Mark W. J. M. , Bekker Martijn , Bellomo Domenico , Fiedler Tomas , de Vos Willem M. , Hugenholtz Jeroen , Kreikemeyer Bernd , Kummer Ursula , Teusink Bas
Published: February 2012

Lactic acid‐producing bacteria survive in distinct environments, but show common metabolic characteristics. Here we studied the dynamic interactions of the central metabolism in Lactococcus lactis, extensively used as a starter culture in the dairy industry, and Streptococcus pyogenes, a human pathogen. Glucose‐pulse experiments and enzymatic measurements were performed to parameterize kinetic models of glycolysis. Significant improvements were made to existing kinetic models for L. lactis, which subsequently accelerated the development of the first kinetic model of S. pyogenes glycolysis. The models revealed an important role for extracellular phosphate in the regulation of central metabolism and the efficient use of glucose. Thus, phosphate, which is rarely taken into account as an independent species in models of central metabolism, should be considered more thoroughly in the analysis of metabolic systems in the future. Insufficient phosphate supply can lead to a strong inhibition of glycolysis at high glucose concentrations in both species, but this was more severe in S. pyogenes. S. pyogenes is more efficient at converting glucose to ATP, showing a higher tendency towards heterofermentative energy metabolism than L. lactis. Our comparative systems biology approach revealed that the glycolysis of L. lactis and S. pyogenes have similar characteristics, but are adapted to their individual natural habitats with respect to phosphate regulation.

Database

The mathematical models described here have been submitted to the Online Cellular Systems Modelling Database and can be accessed at http://jjj.biochem.sun.ac.za/database/Levering/index.html free of charge.
FMN fluorescence in inducible NOS constructs reveals a series of conformational states involved in the reductase catalytic cycle
Authors: Ghosh Dipak K. , Ray Krishanu , Rogers Albert J. , Nahm Nicholas J. , Salerno John C.
Published: February 2012

Nitric oxide synthases (NOSs) produce NO as a molecular signal in the nervous and cardiovascular systems and as a cytotoxin in the immune response. NO production in the constitutive isoforms is controlled by calmodulin regulation of electron transfer. In the tethered shuttle model for NOS reductase function, the FMN domain moves between NADPH dehydrogenase and oxygenase catalytic centers. Crystal structures of neuronal NOS reductase domain and homologs correspond to an ‘input state’, with FMN in close contact with FAD. We recently produced two domain ‘output state’ (oxyFMN) constructs showing calmodulin dependent FMN domain association with the oxygenase domain. FMN fluorescence is sensitive to enzyme conformation and calmodulin binding. The inducible NOS (iNOS) oxyFMN construct is more fluorescent than iNOS holoenzyme. The difference in steady state fluorescence is rationalized by the observation of a series of characteristic states in the two constructs, which we assign to FMN in different environments. OxyFMN and holoenzyme share open conformations with an average lifetime of ∼ 4.3 ns. The majority state in holoenzyme has a short lifetime of ∼ 90 ps, probably because of FAD–FMN interactions. In oxyFMN about 25–30% of the FMN is in a state with a lifetime of 0.9 ns, which we attribute to quenching by heme in the output state. Occupancy of the output state together with our previous kinetic results yields a heme edge to FMN distance estimate of 12–15 Å. These results indicate that FMN fluorescence is a valuable tool to study conformational states involved in the NOS reductase catalytic cycle.

Database
 NOS, EC 1.14.13.39