bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo imaging of CD8+T cell-mediated elimination of malaria liver stages
Authors: Cockburn Ian A. , Amino Rogerio , Kelemen Reka K. , Kuo Scot C. , Tse Sze-Wah , Radtke Andrea , Mac-Daniel Laura , Ganusov Vitaly V. , Zavala Fidel , Ménard Robert
Published: May 2013

CD8+T cells are specialized cells of the adaptive immune system capable of finding and eliminating pathogen-infected cells. To date it has not been possible to observe the destruction of any pathogen by CD8+T cells in vivo. Here we demonstrate a technique for imaging the killing of liver-stage malaria parasites by CD8+T cells bearing a transgenic T cell receptor specific for a parasite epitope. We report several features that have not been described by in vitro analysis of the process, chiefly the formation of large clusters of effector CD8+T cells around infected hepatocytes. The formation of clusters requires antigen-specific CD8+T cells and signaling by G protein-coupled receptors, although CD8+T cells of unrelated specificity are also recruited to clusters. By combining mathematical modeling and data analysis, we suggest that formation of clusters is mainly driven by enhanced recruitment of T cells into larger clusters. We further show various death phenotypes of the parasite, which typically follow prolonged interactions between infected hepatocytes and CD8+T cells. These findings stress the need for intravital imaging for dissecting the fine mechanisms of pathogen recognition and killing by CD8+T cells.
Tissue plasminogen activator regulates Purkinje neuron development and survival
Authors: Li Jianxue , Yu Lili , Gu Xuesong , Ma Yinghua , Pasqualini Renata , Arap Wadih , Snyder Evan Y. , Sidman Richard L.
Published: May 2013

Significance

Cerebellar Purkinje neurons (PNs) strongly affect motor coordination and learning. PN study has contributed significantly to fundamental concepts of modern neuroscience. The present investigation defines distinctive molecular signaling pathways through which tissue plasminogen activator/plasmin-based proteolysis regulates postnatal PN dendrite development, synapse formation, mitochondrial morphology and function, and PN survival. These pathways involve differentially acting downstream constituents, including protein kinase Cγ, brain-derived neurotrophic factor, and a voltage-dependent anion channel. The metabolic mechanisms established here may apply to the development and degeneration of PNs and additional types of neurons in many animal and human brain diseases in which PNs are notably vulnerable.
Direct interaction between the TnsA and TnsB subunits controls the heteromeric
Tn7
transposase
Authors: Choi Ki Young , Li Ying , Sarnovsky Robert , Craig Nancy L.
Published: May 2013

Significance

DNA transposons move by excision and reintegration mediated by the element-encoded transposase. Unlike most transposases, the transposon
Tn7
transposase is heteromeric, containing TnsB protein, which recognizes the transposon ends and mediates 3′ end breakage and joining, and TnsA protein, which mediates 5′ end breakage. We show that TnsA and TnsB interact and that TnsA can stimulate two key TnsB activities, end binding and end pairing. We also show that an end-pairing deficiency underlies the inability of a
Tn7
containing two left ends to transpose. These findings reveal new aspects of protein–protein and protein–DNA interactions that underlie
Tn7
transposition.
Distinct quaternary structures of the AAA+ Lon protease control substrate degradation
Authors: Vieux Ellen F. , Wohlever Matthew L. , Chen James Z. , Sauer Robert T. , Baker Tania A.
Published: May 2013

Significance

Lon protease degrades unfolded or damaged proteins as well as numerous cellular regulatory proteins. How these different classes of substrates are recognized is poorly understood. We find that Lon hexamers assemble via a matrix of N-domain interactions to form a dodecamer with altered substrate-degradation properties. Access of protein substrates to the degradation machinery in the dodecamer appears to require passage through equatorial portals. As a consequence, large substrates that are efficiently degraded by hexamers seem to be preferentially excluded from dodecamers. This gating mechanism allows the substrate repertoire of Lon to be adjusted by its assembly state.
Dynamic FtsA and FtsZ localization and outer membrane alterations during polar growth and cell division in
Agrobacterium tumefaciens
Authors: Zupan John R. , Cameron Todd A. , Anderson-Furgeson James , Zambryski Patricia C.
Published: May 2013

Growth and cell division in rod-shaped bacteria have been primarily studied in species that grow predominantly by peptidoglycan (PG) synthesis along the length of the cell. Rhizobiales species, however, predominantly grow by PG synthesis at a single pole. Here we characterize the dynamic localization of several
Agrobacterium tumefaciens
components during the cell cycle. First, the lipophilic dye FM 4-64 predominantly stains the outer membranes of old poles versus growing poles. In cells about to divide, however, both poles are equally labeled with FM 4-64, but the constriction site is not. Second, the cell-division protein FtsA alternates from unipolar foci in the shortest cells to unipolar and midcell localization in cells of intermediate length, to strictly midcell localization in the longest cells undergoing septation. Third, the cell division protein FtsZ localizes in a cell-cycle pattern similar to, but more complex than, FtsA. Finally, because PG synthesis is spatially and temporally regulated during the cell cycle, we treated cells with sublethal concentrations of carbenicillin (Cb) to assess the role of penicillin-binding proteins in growth and cell division. Cb-treated cells formed midcell circumferential bulges, suggesting that interrupted PG synthesis destabilizes the septum. Midcell bulges contained bands or foci of FtsA-GFP and FtsZ-GFP and no FM 4-64 label, as in untreated cells. There were no abnormal morphologies at the growth poles in Cb-treated cells, suggesting unipolar growth uses Cb-insensitive PG synthesis enzymes.
Nose-pointing
Authors: Cooperrider Kensy , Núñez Rafael
Published: May 2013

This article describes a previously undocumented deictic facial gesture of Papua New Guinea, which we call nose-pointing. Based on a video corpus of examples produced by speakers of Yupno, an indigenous language of Papua New Guinea’s Finisterre Range, we characterize the gesture’s morphology — which involves an effortful scrunching together of the face, or S-action, in combination with a deictic head movement — and illustrate its use in different interactive contexts. Yupno speakers produce the nose-pointing gesture in alternation with more familiar pointing morphologies, such as index finger and head-pointing, suggesting that the gesture carries a distinctive meaning. Interestingly, the facial morphological component of nose-pointing — the S-action — is also widely used non-deictically by Yupno speakers, and we propose that such uses provide crucial clues to the meaning of nose-pointing. We conclude by highlighting questions for further research, including precisely how nose-pointing relates to non-deictic uses of the S-action and what cultural and communicative pressures might have shaped the gesture.
Interpreting in small-group bilingual videoconferences
Authors: Braun Sabine
Published: May 2013

When interpreting takes place in a videoconference setting, the intrinsic technological challenges and the very remoteness of the
interpreters’ location compound the complexity of the task. Existing research on remote interpreting and the problems it entails focusses on
remote conference interpreting, in which the interpreters are physically separated from the conference site while the
primary interlocutors are together on site as usual. In an effort to broaden the scope of research in the area of remote interpreting to
include other types and to address other questions, in particular that of the interpreters’ adaptability to new working conditions, this
paper analyses small-group videoconferences in which the primary interlocutors as well as the interpreters all work from
different locations. The findings from an empirical case study (based on recordings of videoconference sessions as well as introspective
data) are used to identify and exemplify different types of interpreter adaptation.
Predicting proficiency in signed language interpreting
Authors: López Gómez María José , Bajo Molina Teresa , Padilla Benítez Presentación , Santiago de Torres Julio
Published: May 2013

An empirical study was designed to identify which perceptual-motor, cognitive and personality factors may underlie both acquisition of a
signed language as a B language and development of signed language interpreting skills. If abilities that are potentially needed are found,
a previous assessment of candidates’ potential for developing signed-language interpreting skills could be useful in identifying which
students are likely to obtain good results during training. Perceptual-motor and cognitive skills, personality factors and academic
background were hypothesized as possible predictors of success. Results showed that perceptual-motor and cognitive abilities are more
important than personality traits in predicting proficiency in learning a signed language and developing signed-language interpreting
abilities. Perceptual-motor coordination is the most reliable factor for predicting signed language proficiency, followed by other cognitive
and personal factors.
The silver lining
Authors: Gorm Hansen Inge , Shlesinger Miriam
Published: May 2013

In an attempt to offset the negative effects of reduced contact hours, teachers of interpreting are encouraged to take advantage of
cost-effective methods, including technology-assisted self-study sessions and offline practice. This paper describes the use of new
pedagogical tools and equipment (ultra-modern labs, innovative software packages) to support the teaching of (mostly consecutive)
interpreting at the Copenhagen Business School. We report on various interventions that were tried over a period of several years, in the
interest of enhancing student performance. Aside from streamlining the teaching process, the new tools have been found to offset the anxiety
so typical of interpreting students. The different types of materials — including those available on a dedicated e-learning platform —
facilitate self-paced and self-monitored practice, and encourage independent practice among students whose motivation in the conventional
setting had been far more limited. Dramatic improvements in the final exam success rates highlight the effectiveness of the new
approach.
Intergroup and intragroup antiphonal songs in wild male Mueller’s gibbons (Hylobates muelleri)
Authors: Inoue Yoichi , Sinun Waidi , Yosida Shigeto , Okanoya Kazuo
Published: May 2013

Mueller’s gibbons (Hylobates muelleri) sing both sex-specific and duet songs. These songs are thought to be involved in territory maintenance, as well as the maintenance of pair or family bonds. However, few observational studies have examined how gibbons interact with their neighbors through song in the wild. We have been conducting field observations of wild gibbon groups in northeast Borneo since 2001. In the Borneo Rainforest Lodge (BRL) and Danum Valley Field Center (DVFC) at the Danum Valley Conservation Area (DVCA), we observed seven episodes of alternating songs between males. Here, we describe the process of song exchange between males. During male interactions, song bouts rarely overlapped and were alternately emitted. Several studies have reported antiphonal vocalizations in New World and Old World primate species, but rarely in apes. Our observations of antiphonal songs in gibbons indicate that gibbons not only unilaterally advertise information, but also interactively communicate with neighbors and family members through songs. Since gibbons are phylogenetically similar to humans, and turn-taking has an important role in human conversation, our research on gibbon communication may provide insight into the evolution of human language.
“Grab a pen and paper”
Authors: Thornborrow Joanna , Fitzgerald Richard
Published: May 2013

In this paper we analyse the discursive frameworks for interaction in a UK political radio phone-in between 2001 and 2010, and the implications of those frameworks for public engagement with politicians. The BBC Radio 4 phone-in program Election Call, broadcast in the run-up to a general election, has experimented with ‘new’ interactive technology (TV simulcast, web broadcasting and e-mail) in its attempt to provide listeners with the opportunity to engage with politicians and political parties live on air. By 2010 however, the program had returned to the original ‘old’ media format of telephone interaction only. Building on previous research in the discourse of radio phone-in broadcasts (Hutchby 1996; Thornborrow 2001a, 2001b, 2002; Hester & Fitzgerald 1999; Fitzgerald & Housley 2002; Thornborrow & Fitzgerald 2002), our analysis focuses on the empirical implementation of the 2010 shift in editorial policy which explicitly invited callers to engage with issues rather than just giving opinions. We will argue that while interactivity may broaden access to democratic debate, it is through live interaction that callers are best able to challenge politicians and hold them to account.
Tracing trajectories
Authors: Carroll Mary , Weimar Katja , Flecken Monique , Lambert Monique , von Stutterheim Christiane
Published: May 2013

Although the typological contrast between Romance and Germanic languages as verb-framed versus satellite-framed (Talmy 1985) forms the background for many empirical studies on L2 acquisition, the inconclusive picture to date calls for more differentiated, fine-grained analyses. The present study goes beyond explanations based on this typological contrast and takes into account the sources from which spatial concepts are mainly derived in order to shape the trajectory traced by the entity in motion when moving through space: the entity in V-languages versus features of the ground in S-languages. It investigates why advanced French learners of English and German have difficulty acquiring the use of spatial concepts typical of the L2s to shape the trajectory, although relevant concepts can be expressed in their L1. The analysis compares motion event descriptions, based on the same sets of video clips, of L1 speakers of the three languages to L1 French-L2 English and L1 French-L2 German speakers, showing that the learners do not fully acquire the use of L2-specific spatial concepts. We argue that encoded concepts derived from the entity in motion vs. the ground lead to a focus on different aspects of motion events, in accordance with their compatibility with these sources, and are difficult to restructure in L2 acquisition.
Thinking for Speaking and linguistic relativity among bilinguals
Authors: Treffers-Daller Jeanine
Published: May 2013

This article evaluates how the different papers in this special issue fill a gap in our understanding of cognitive processes that are being activated when second language learners or bilinguals prepare to speak. All papers are framed in Slobin’s (1987) Thinking for Speaking theory, and aim to test whether the conceptualisation patterns that were learned in early childhood can be relearned or restructured in L2 acquisition. In many papers the focus is on identifying constraints on this restructuring process. Among these constraints, the role of typological differences between languages is investigated in great depth. The studies involve different types of learners, language combinations and tasks. As all informants were given verbal rather than non-verbal tasks, the focus is here on the effects of conceptual transfer from one language on another, and not on the effects of language on non-linguistic cognition. The paper also sketches different avenues for further research in this field and proposes that researchers working in this field might want to take up the challenge of investigating whether speakers of different languages perceive motion outside explicitly verbal contexts differently, as this will enable us to gain an understanding of linguistic relativity effects in this domain. Studying which teaching methods can help learners to restructure their conceptualisation patterns may also shed new light on the aspects of discourse organization and motion event construal that are most difficult for learners.
Visualization of ‘Candidatus Liberibacter asiaticus’ Cells in the Vascular Bundle of Citrus Seed Coats with Fluorescence In Situ Hybridization and Transmission Electron Microscopy
Authors: Hilf Mark E. , Sims Kenneth R. , Folimonova Svetlana Y. , Achor Diann S.
Published: May 2013

‘Candidatus Liberibacter asiaticus’ is the bacterium implicated as a causal agent of the economically damaging disease of citrus called huanglongbing (HLB). Vertical transmission of the organism through seed to the seedling has not been demonstrated. Previous studies using real-time polymerase chain reaction assays indicated abundant bacterial 16S rRNA sequences in seed coats of citrus seed but the presence of intact bacterial cells was not demonstrated. We used microscopy to verify that intact bacterial cells were present in citrus seed coats. Bacterial cells with the morphology and physical dimensions appropriate for ‘Ca. L. asiaticus’ were seen in phloem sieve elements in the vascular bundle of grapefruit seed coats using transmission electron microscopy (TEM). Fluorescence in situ hybridization (FISH) analyses utilizing probes complementary to the ‘Ca. L. asiaticus’ 16S rRNA gene revealed bacterial cells in the vascular tissue of intact seed coats of grapefruit and pummelo and in fragmented vascular bundles excised from grapefruit seed coats. The physical measurements and the morphology of individual bacterial cells were consistent with those ascribed in the literature to ‘Ca. L. asiaticus’. No bacterial cells were observed in preparations of seed from fruit from noninfected trees. A small library of clones amplified from seed coats from a noninfected tree using degenerate primers targeting prokaryote 16S rRNA gene sequences contained no ‘Ca. L. asiaticus’ sequences, whereas 95% of the sequences in a similar library from DNA from seed coats from an infected tree were identified as ‘Ca. L. asiaticus’, providing molecular genetic corroboration that the bacterial cells observed by TEM and FISH in seed coats from infected trees were ‘Ca. L. asiaticus’.
Computational fluid dynamic simulations of image-based stented coronary bifurcation models
Authors: Chiastra Claudio , Morlacchi Stefano , Gallo Diego , Morbiducci Umberto , Cárdenes Rubén , Larrabide Ignacio , Migliavacca Francesco
Published: May 2013

One of the relevant phenomenon associated with in-stent restenosis in coronary arteries is an altered haemodynamics in the stented region. Computational fluid dynamics (CFD) offers the possibility to investigate the haemodynamics at a level of detail not always accessible within experimental techniques. CFD can quantify and correlate the local haemodynamics structures which might lead to in-stent restenosis. The aim of this work is to study the fluid dynamics of realistic stented coronary artery models which replicate the complete clinical procedure of stent implantation. Two cases of pathologic left anterior descending coronary arteries with their bifurcations are reconstructed from computed tomography angiography and conventional coronary angiography images. Results of wall shear stress and relative residence time show that the wall regions more prone to the risk of restenosis are located next to stent struts, to the bifurcations and to the stent overlapping zone for both investigated cases. Considering a bulk flow analysis, helical flow structures are generated by the curvature of the zone upstream from the stent and by the bifurcation regions. Helical recirculating microstructures are also visible downstream from the stent struts. This study demonstrates the feasibility to virtually investigate the haemodynamics of patient-specific coronary bifurcation geometries.
Joint kinematics and kinetics of overground accelerated running versus running on an accelerated treadmill
Authors: Van Caekenberghe Ine , Segers Veerle , Aerts Peter , Willems Patrick , De Clercq Dirk
Published: May 2013

Literature shows that running on an accelerated motorized treadmill is mechanically different from accelerated running overground. Overground, the subject has to enlarge the net anterior–posterior force impulse proportional to acceleration in order to overcome linear whole body inertia, whereas on a treadmill, this force impulse remains zero, regardless of belt acceleration. Therefore, it can be expected that changes in kinematics and joint kinetics of the human body also are proportional to acceleration overground, whereas no changes according to belt acceleration are expected on a treadmill. This study documents kinematics and joint kinetics of accelerated running overground and running on an accelerated motorized treadmill belt for 10 young healthy subjects. When accelerating overground, ground reaction forces are characterized by less braking and more propulsion, generating a more forward-oriented ground reaction force vector and a more forwardly inclined body compared with steady-state running. This change in body orientation as such is partly responsible for the changed force direction. Besides this, more pronounced hip and knee flexion at initial contact, a larger hip extension velocity, smaller knee flexion velocity and smaller initial plantarflexion velocity are associated with less braking. A larger knee extension and plantarflexion velocity result in larger propulsion. Altogether, during stance, joint moments are not significantly influenced by acceleration overground. Therefore, we suggest that the overall behaviour of the musculoskeletal system (in terms of kinematics and joint moments) during acceleration at a certain speed remains essentially identical to steady-state running at the same speed, yet acting in a different orientation. However, because acceleration implies extra mechanical work to increase the running speed, muscular effort done (in terms of power output) must be larger. This is confirmed by larger joint power generation at the level of the hip and lower power absorption at the knee as the result of subtle differences in joint velocity. On a treadmill, ground reaction forces are not influenced by acceleration and, compared with overground, virtually no kinesiological adaptations to an accelerating belt are observed. Consequently, adaptations to acceleration during running differ from treadmill to overground and should be studied in the condition of interest.
Built for rowing: frog muscle is tuned to limb morphology to power swimming
Authors: Richards Christopher T. , Clemente Christofer J.
Published: May 2013

Rowing is demanding, in part, because drag on the oars increases as the square of their speed. Hence, as muscles shorten faster, their force capacity falls, whereas drag rises. How do frogs resolve this dilemma to swim rapidly? We predicted that shortening velocity cannot exceed a terminal velocity where muscle and fluid torques balance. This terminal velocity, which is belowVmax, depends on gear ratio (GR = outlever/inlever) and webbed foot area. Perhaps such properties of swimmers are ‘tuned’, enabling shortening speeds of approximately 0.3Vmaxfor maximal power. Predictions were tested using a ‘musculo-robotic’Xenopus laevisfoot driven either by a livingin vitroor computationalin silicoplantaris longus muscle. Experiments verified predictions. Our principle finding is that GR ranges from 11.5 to 20 near the predicted optimum for rowing (GR ≈ 11). However, gearing influences muscle power more strongly than foot area. No single morphology is optimal for producing muscle power. Rather, the ‘optimal’ GR decreases with foot size, implying that rowing ability need not compromise jumping (andvice versa). Thus, despite our neglect of additional forces (e.g. added mass), our model predicts pairings of physiological and morphological properties to confer effective rowing. Beyond frogs, the model may apply across a range of size and complexity from aquatic insects to human-powered rowing.
Modelling seasonal influenza: the role of weather and punctuated antigenic drift
Authors: Yaari R. , Katriel G. , Huppert A. , Axelsen J. B. , Stone L.
Published: May 2013

Seasonal influenza appears as annual oscillations in temperate regions of the world, yet little is known as to what drives these annual outbreaks and what factors are responsible for their inter-annual variability. Recent studies suggest that weather variables, such as absolute humidity, are the key drivers of annual influenza outbreaks. The rapid, punctuated, antigenic evolution of the influenza virus is another major factor. We present a new framework for modelling seasonal influenza based on a discrete-time, age-of-infection, epidemic model, which allows the calculation of the model's likelihood function in closed form. This framework may be used to perform model inference and parameter estimation rigorously. The modelling approach allows us to fit 11 years of Israeli influenza data, with the best models fitting the data with unusually high correlations in which
r
> 0.9. We show that using actual weather to modulate influenza transmission rate gives better results than using the inter-annual means of the weather variables, providing strong support for the role of weather in shaping the dynamics of influenza. This conclusion remains valid even when incorporating a more realistic depiction of the decay of immunity at the population level, which allows for discrete changes in immunity from year to year.
A variational formulation of vertical slice models
Authors: Cotter C. J. , Holm D. D.
Published: May 2013

A variational framework is defined for vertical slice models with three-dimensional velocity depending only on
x
and
z
. The models that result from this framework are Hamiltonian, and have a Kelvin–Noether circulation theorem that results in a conserved potential vorticity in the slice geometry. These results are demonstrated for the incompressible Euler–Boussinesq equations with a constant temperature gradient in the
y
-direction (the Eady–Boussinesq model), which is an idealized problem used to study the formation and subsequent evolution of weather fronts. We then introduce a new compressible extension of this model. Unlike the incompressible model, the compressible model does not produce solutions that are also solutions of the three-dimensional equations, but it does reduce to the Eady–Boussinesq model in the low Mach number limit. Hence, the new model could be used in asymptotic limit error testing for compressible weather models running in a vertical slice configuration.
The role of additive and multiplicative noise in filtering complex dynamical systems
Authors: Gottwald Georg A. , Harlim John
Published: May 2013

Covariance inflation is an ad hoc treatment that is widely used in practical real-time data assimilation algorithms to mitigate covariance underestimation owing to model errors, nonlinearity, or/and, in the context of ensemble filters, insufficient ensemble size. In this paper, we systematically derive an effective ‘statistical’ inflation for filtering multi-scale dynamical systems with moderate scale gap,

, to the case of no scale gap with

, in the presence of model errors through reduced dynamics from rigorous stochastic subgrid-scale parametrizations. We will demonstrate that for linear problems, an effective covariance inflation is achieved by a systematically derived additive noise in the forecast model, producing superior filtering skill. For nonlinear problems, we will study an analytically solvable stochastic test model, mimicking turbulent signals in regimes ranging from a turbulent energy transfer range to a dissipative range to a laminar regime. In this context, we will show that multiplicative noise naturally arises in addition to additive noise in a reduced stochastic forecast model. Subsequently, we will show that a ‘statistical’ inflation factor that involves mean correction in addition to covariance inflation is necessary to achieve accurate filtering in the presence of intermittent instability in both the turbulent energy transfer range and the dissipative range.
Integrating genealogical and dynamical modelling to infer escape and reversion rates in HIV epitopes
Authors: Palmer Duncan , Frater John , Phillips Rodney , McLean Angela R. , McVean Gil
Published: May 2013

The rates of escape and reversion in response to selection pressure arising from the host immune system, notably the cytotoxic T-lymphocyte (CTL) response, are key factors determining the evolution of HIV. Existing methods for estimating these parameters from cross-sectional population data using ordinary differential equations (ODEs) ignore information about the genealogy of sampled HIV sequences, which has the potential to cause systematic bias and overestimate certainty. Here, we describe an integrated approach, validated through extensive simulations, which combines genealogical inference and epidemiological modelling, to estimate rates of CTL escape and reversion in HIV epitopes. We show that there is substantial uncertainty about rates of viral escape and reversion from cross-sectional data, which arises from the inherent stochasticity in the evolutionary process. By application to empirical data, we find that point estimates of rates from a previously published ODE model and the integrated approach presented here are often similar, but can also differ several-fold depending on the structure of the genealogy. The model-based approach we apply provides a framework for the statistical analysis and hypothesis testing of escape and reversion in population data and highlights the need for longitudinal and denser cross-sectional sampling to enable accurate estimate of these key parameters.
Infection deflection: hosts control parasite location with behaviour to improve tolerance
Authors: Sears B. F. , Snyder P. W. , Rohr J. R.
Published: May 2013

Anti-parasite behaviour can reduce parasitic infections, but little is known about how such behaviours affect infection location within the host's body and whether parasite distribution ultimately affects tolerance of infection. To assess these questions, we exposed both anaesthetized (no behaviour) and non-anaesthetized
Hyla femoralis
tadpoles to plagiorchiid cercariae (larval trematodes), and quantified resistance, tolerance (relationship between mass change and infection intensity) and encystment location. Non-anaesthetized tadpoles had significantly more infections in their tail region than anaesthetized tadpoles, which had the majority of their infections in the head. This pattern indicates that parasites preferred to infect the head, but that hosts shunted infections to the tail when possible. Furthermore, there was a significant effect of encystment location on tolerance, with head-infected tadpoles having poorer tolerance to infection than tail-infected tadpoles. Variance partitioning suggests that, among infected tadpoles, behaviour contributed more to tolerance than resistance. These results suggest that, in addition to using behaviour to resist parasites,
H. femoralis
tadpoles also use behaviour to enhance infection tolerance by deflecting infections posteriorly, away from their vital sensory organs. These findings highlight the need to assess how widespread and important behaviour is to the tolerance of infections.
Loss of Plastoglobule Kinases ABC1K1 and ABC1K3 Causes Conditional Degreening, Modified Prenyl-Lipids, and Recruitment of the Jasmonic Acid Pathway
Authors: Lundquist Peter K. , Poliakov Anton , Giacomelli Lisa , Friso Giulia , Appel Mason , McQuinn Ryan P. , Krasnoff Stuart B. , Rowland Elden , Ponnala Lalit , Sun Qi , van Wijk Klaas J.
Published: May 2013

Plastoglobules (PGs) are plastid lipid-protein particles. This study examines the function of PG-localized kinases ABC1K1 and ABC1K3 in Arabidopsis thaliana. Several lines of evidence suggested that ABC1K1 and ABC1K3 form a protein complex. Null mutants for both genes (abc1k1 and abc1k3) and the double mutant (k1 k3) displayed rapid chlorosis upon high light stress. Also, k1 k3 showed a slower, but irreversible, senescence-like phenotype during moderate light stress that was phenocopied by drought and nitrogen limitation, but not cold stress. This senescence-like phenotype involved degradation of the photosystem II core and upregulation of chlorophyll degradation. The senescence-like phenotype was independent of the EXECUTER pathway that mediates genetically controlled cell death from the chloroplast and correlated with increased levels of the singlet oxygen–derived carotenoid β-cyclocitral, a retrograde plastid signal. Total PG volume increased during light stress in wild type and k1 k3 plants, but with different size distributions. Isolated PGs from k1 k3 showed a modified prenyl-lipid composition, suggesting reduced activity of PG-localized tocopherol cyclase (VTE1), and was consistent with loss of carotenoid cleavage dioxygenase 4. Plastid jasmonate biosynthesis enzymes were recruited to the k1 k3  PGs but not wild-type PGs, while pheophytinase, which is involved in chlorophyll degradation, was induced in k1 k3 and not wild-type plants and was localized to PGs. Thus, the ABC1K1/3 complex contributes to PG function in prenyl-lipid metabolism, stress response, and thylakoid remodeling.
Analyzing web citations availability and half‐life in medical journals
Authors: Jalalifard Mariam , Norouzi Yaghoub , Isfandyari‐Moghaddam Alireza
Published: May 2013

Purpose

The aim of this study is to compare the situation of internet resource citations in scientific articles of the journals of Shahid Beheshti University of Medical Sciences from 2005‐2009.

Design/methodology/approach

The research method is an analytical survey with webometrics and citation analysis. The internet was used as a tool for accessing articles. They are separately analyzed on the basis of journal name and publication year. The analysis is done using MATLAB and Excel software.

Findings

A total of 717 articles from seven journals during five years were reviewed. Of 13,448 citations extracted, 120 internet references were found. The final results indicated that the sum of web citations is less than 1 per cent of total citations and only 52 per cent of internet citations in studied journal articles are available. The average half‐life for the medical journals is estimated to be 1.02 years.

Practical implications

To increase the rate of URLs availability, publishers should oblige authors to utilize online archives such as WebCite to preserve expected information for all of the citations referred to in their articles.

Originality/value

This research would be valuable since it is the first that studies stability and persistence of URL domains of medical journals published in Shahid Beheshti University of Medical Sciences according to type of domain names and file extensions. Moreover, this is the first time that the half‐life for medical universities web citations is calculated.
Conceptualizing perceived affordances in social media interaction design
Authors: Zhao Yuxiang , Liu Jiang , Tang Jian , Zhu Qinghua
Published: May 2013

Purpose

The purpose of this paper is to theoretically develop the concept of perceived affordance based on the existing studies, and to construct a conceptual framework to show how perceived affordances can facilitate the interaction design of social media.

Design/methodology/approach

The paper provides a review of the relevant literature on affordance and perceived affordance, and conceptually proposes a typology of perceived affordances in social media and an integrative framework for interaction design from sociomateriality perspective. Furthermore, a brief empirical example on the interaction design of crowdsourcing systems is used to ground and illustrate the authors' conceptual framework.

Findings

The paper shows that the perceived affordances may have multi‐facet characteristics and the interaction design of social media should reflect the multi‐dimensional perceived affordances. The perceived affordances can support or facilitate the design of basic elements of social media, such as content and form, to enhance both usability (human‐computer interaction) and sociability (human‐human interaction). A position of constitutive entanglement does not privilege either users or social media artifacts, nor does it provide a rigid triangle among these three components. Instead, the perceived affordances play a critical role in integrating the key components in social media interaction design as an ensemble.

Originality/value

The paper attempts to explore and develop the concept of perceived affordance and employ it as a theoretical lens to underpin interaction design of social media. Overall, the authors' study contributes to the design science literature in the information management field by elaborating a new theoretical perspective and providing a conceptual framework for the researchers and designers.
Ninja Kitchen to the rescue
Authors: Quick Virginia , Corda Kirsten W. , Chamberlin Barbara , Schaffner Donald W. , Byrd‐Bredbenner Carol
Published: May 2013

Purpose

The purpose of this paper is to assess the effect of Ninja Kitchen, a food safety educational video game, on middle school students' food safety knowledge, psychographic characteristics, and usual and intended behaviors.

Design/methodology/approach

The experimental group (n=903) completed the following activities about one week apart from each other: pretest, played the game, posttest, and follow‐up test. The control group (n=365) completed the same activities at similar intervals but did not have access to the game until after the follow‐up test.

Findings

Linear mixed‐effects models, controlling for gender, grade, and geographic location revealed significant time by group effects for knowledge of safe cooking temperatures for animal proteins and danger zone hazard prevention, and usual produce washing behaviors. Pairwise comparisons, adjusted for multiple comparisons, indicated that after playing the game, the experimental group felt more susceptible to foodborne illness, had stronger attitudes toward the importance of handling food safely and handwashing, had greater confidence in their ability to practice safe food handling, and had greater intentions to practice handwashing and safe food handling. Teachers and students found the game highly acceptable.

Originality/value

The game has the potential to promote positive food safety behaviors among youth, in a fun and educational format.
UK consumer reactions to organic certification logos
Authors: Gerrard Catherine , Janssen Meike , Smith Laurence , Hamm Ulrich , Padel Susanne
Published: May 2013

Purpose

The purpose of this paper is to consider whether UK consumers recognise and trust organic certification logos and whether the presence of these logos on a product increases consumer willingness to pay for that product.

Design/methodology/approach

To ascertain the reaction of UK consumers to organic certification logos commonly used in the UK, this study makes use of three methods: focus groups, a consumer survey and a willingness to pay experiment (choice experiment).

Findings

These three approaches reveal that UK consumers associate certain benefits with organic foods but are generally unaware of how the industry is regulated. With regards to trust of the logo, the standards they think underlie the logo and the inspection system that they think is associated with the logo, UK consumers rate the Soil Association and Organic Farmers and Growers logos more highly than the EU logo or products labelled with just the word “organic”. They appear willing to pay a premium for the additional assurance that these two logos provide, suggesting that where they are recognised, certification logos are valued.

Originality/value

To the authors' knowledge, no previous studies exist on whether UK consumers recognise and trust different organic certification logos. These findings show that where such logos are recognised they can help to give some assurance to the UK consumer and this is reflected in a willingness to pay a premium for foods labelled with the Soil Association and Organic Farmers and Growers certification logos, as opposed to no logo or the (less well known) EU logo.
Development of sweet preparations with dietary fiber and low energy density
Authors: Tavares Carolina , Geraldo Ana Paula , Ramos Jamile , Elisabeth Pinto e Silva Maria
Published: May 2013

Purpose

The purpose of this study was to reduce the ED of sweet preparations through calorie reduction by replacing sucrose, reducing fat, and increasing the amount of dietary fiber.

Design/methodology/approach

Sweet preparations were chosen to reduce ED and increase dietary fiber. Sucrose was replaced by two types of sweeteners, white flour was partially replaced by whole grain flour and fat was reduced. Preparations that had the desired characteristics underwent sensorial analysis to assess their acceptability, and rated by the affective test with hedonic scale. Preparations rated with 50 percent of grades greater than or equal to 7 were considered accepted. Analysis and calculations were performed using FIZZ software. The percentage change in ED was calculated as the difference between the ED of those ingredients replaced and/or reduced.

Findings

The preparations butter cookies, lemon pie topped with whipped cream and carrot cake with chocolate frosting were accepted by most of the tasters. It proved possible to reduce ED by approximately 4.0 kcal per gram and to increase the amount of total dietary fiber from 1.8 g/100 g to 3.6 g/100 g, without affecting acceptance.

Originality/value

It is an unpublished article that deals with reducing the ED and increasing the dietary fiber of sweet preparations, pointing out their difficulties and differences between different preparations created aiming at the prevention of chronic diseases.
Effect of thermal treatment on ochratoxin content of chickpea
Authors: Rahimi Khadije , Mohamadi Sani Ali , Gholampour Azizi Eisa
Published: May 2013

Purpose

The aim of this study was to investigate the presence of ochratoxin A (OTA) in chickpea samples in northern Iran and to study the effect of thermal treatment on ochratoxin content of the samples.

Design/methodology/approach

For this purpose, 32 chickpea samples were collected from retail stores of four cities in Mazandaran province in the north of Iran. Samples were soaked in potable water and cooked, respectively, for 3.5 and 4 h. Then the raw and cooked samples and the soaking water were analyzed for OTA determination by enzyme linked immunosorbent assay (ELISA) technique.

Findings

Results showed that six raw samples (18.75 per cent) contained detectable amounts of OTA by average concentration of 5.9±3.7 which is lower than national standards. The highest and lowest concentration of OTA in raw samples was 2.1 and 12.5 ppb, so chickpea is not a source for OTA poisoning. Increasing the time of cooking led to slight degradation of OTA but according to statistical analysis and LSD test, only after five hours, thermal treatment caused OTA to degrade significantly (p<0.05). During soaking and thermal processing, leakage of OTA to the water partly occurred so that the OTA content of soaking water is detectable.

Originality/value

Few research studies have been done on OTA detection in legumes and specially chickpea samples in the world and no research has been done to evaluate the effect of cooking process on OTA in chickpea.
Leadership as a balancing act between performance‐ and development‐orientation
Authors: Wallo Andreas , Ellström Per‐Erik , Kock Henrik
Published: May 2013

Purpose

The purpose of this article is to revisit data from a previous study of leadership in an industrial company that was in the process of implementing a process‐oriented, team‐based form of organisation. Based on these data, it aims to explore the assumption that process‐orientation implies “new” leadership behaviours and relationships with co‐workers. More specifically, it aims to focus on analysing how the managers and co‐workers understood and practised the ideas about leadership for learning and development that were introduced in connection with the new production organisation. The purpose is also to determine what factors constrained and facilitated these leadership practises.

Design/methodology/approach

The study was conducted with a large industrial company using case study methodology. The empirical material consists of 35 qualitative interviews with production managers (n=4), first‐line managers (n=14), and operators (n=17).

Findings

The results indicate that performance‐oriented leadership with a focus on facilitating adaptive learning is emphasised more than development‐oriented leadership, which facilitates critical reflection and innovative learning. Furthermore, the study suggests that the administrative workload greatly limits the potential for development‐oriented leadership. Overall, first‐line managers appear to have more in common with system administrators than leaders.

Practical implications

This study highlights the need to find a balance between performance and development in organisations. Specifically, there is a need for leaders to create opportunities and support for increased developmental learning at work. It is also necessary to emphasise critical reflection both in connection with daily operations and in the formal education of co‐workers and leaders.

Originality/value

This study demonstrates the gap between the rhetoric of new leadership and the organisational realities that leaders experience in their daily work. At the same time, the study points to the dual nature of leadership for learning and the constraints on its realisations in practise.
Ethical managers in ethical organisations? The leadership‐culture connection among Finnish managers
Authors: Huhtala Mari , Kangas Maiju , Lämsä Anna‐Maija , Feldt Taru
Published: May 2013

Purpose

The main aim of the present study is to discover whether the managers’ self‐evaluations of their ethical leadership style are associated with their assessments of the ethical organisational culture (measured with an eight‐dimensional Corporate Ethical Virtues‐model). It aims to hypothesise that the more ethical the managers evaluate their own leadership style to be, the higher evaluations they give on the ethical culture of their organisation. The underlying assumption is that ethical managers can enhance the ethical culture by behaving in accordance with their own values.

Design/methodology/approach

This quantitative research was based on a questionnaire study with 902 respondents throughout Finland. A linear regression analysis was conducted to examine how ethical leadership was related to ethical organisational culture.

Findings

Managers who appraised their own leadership style as ethical also evaluated the ethical culture of their organisations more positively. The result implies that an ethically behaving leader can develop the culture of his/her organisation towards more ethical practices. The results also showed that differences in evaluating both ethical leadership and culture emerged concerning background variables.

Research limitations/implications

The data collected were based only on self‐assessments from one data source, and therefore future studies, e.g. including employee ratings, are needed.

Practical implications

Promoting ethical virtues in organisations can lead to a virtuous circle, which supports both ethical culture and ethical leadership.

Originality/value

This empirical study contributes to the research on ethical leadership by examining it in relation to ethical organisational culture.