bluuebunny/crossref_metadata_2025 huggingface dataset:
On the strength of β-sheet crystallites of
Bombyx mori
silk fibroin
Authors: Cheng Yuan , Koh Leng-Duei , Li Dechang , Ji Baohua , Han Ming-Yong , Zhang Yong-Wei
Published: April 2014

Silk fibroin, a natural multi-domain protein, has attracted great attention due to its superior mechanical properties such as ultra-high strength and stretchability, biocompatibility, as well as its versatile biodegradability and processability. It is mainly composed of β-sheet crystallites and amorphous domains. Although its strength is well known to be controlled by the dissociation of protein chains from β-sheet crystallites, the way that water as the solvent affects its strength and the reason that its theoretically predicted strength is several times higher than experimental measurement remain unclear. We perform all-atom molecular dynamics simulations on a β-sheet crystallite of
Bombyx mori
silk. We find that water solvent reduces the number and strength of hydrogen bonds between β-chains, and thus greatly weakens the strength of silk fibroin. By dissociating protein chains at different locations from the crystallite, we also find that the pulling strength for the interior chains is several times higher than that for the surface/corner chains, with the former being consistent with the theoretically predicted value, while the latter on par with the experimental value. It is shown that the weakest rupture strength controls the failure strength of silk fibre. Hence, this work sheds light on the role of water in the strength of silk fibroin and also provides clues on the origin of the strength difference between theory and experiment.
Hydrodynamics of diatom chains and semiflexible fibres
Authors: Nguyen Hoa , Fauci Lisa
Published: April 2014

Diatoms are non-motile, unicellular phytoplankton that have the ability to form colonies in the form of chains. Depending upon the species of diatoms and the linking structures that hold the cells together, these chains can be quite stiff or very flexible. Recently, the bending rigidities of some species of diatom chains have been quantified. In an effort to understand the role of flexibility in nutrient uptake and aggregate formation, we begin by developing a three-dimensional model of the coupled elastic–hydrodynamic system of a diatom chain moving in an incompressible fluid. We find that simple beam theory does a good job of describing diatom chain deformation in a parabolic flow when its ends are tethered, but does not tell the whole story of chain deformations when they are subjected to compressive stresses in shear. While motivated by the fluid dynamics of diatom chains, our computational model of semiflexible fibres illustrates features that apply widely to other systems. The use of an adaptive immersed boundary framework allows us to capture complicated buckling and recovery dynamics of long, semiflexible fibres in shear.
Scaling theory of electric-field-assisted tunnelling
Authors: Michaels Thomas C. T. , Cabrera H. , Zanin D. A. , De Pietro L. , Ramsperger U. , Vindigni A. , Pescia D.
Published: April 2014

Recent experiments report the current (
I
) versus voltage (
V
) characteristics of a tunnel junction consisting of a metallic tip placed at a distance
d
from a planar electrode,
d
varying over six orders of magnitude, from few nanometres to few millimetres. In the ‘electric-field-assisted’ (or ‘field emission’) regime, as opposed to the direct tunnelling regime used in conventional scanning tunnelling microscopy, all
I
–
V
curves are found to collapse onto one single graph when
d
is suitably rescaled, suggesting that the current
I
=
I
(
V
,
d
) is in reality a generalized homogeneous function of one single variable, i.e.

I
=

I

(
V
⋅

d

−
λ

)

, where λ being some characteristic exponent and

I

(
x
)

being a scaling function. In this paper, we provide a comprehensive explanation—based on analytical arguments, numerical simulations and further experimental results—for the scaling behaviour that we show to emerge for a variety of tip–plane geometries and thus seems to be a general feature of electric-field-assisted tunnelling.
Wave power extraction from a bottom-mounted oscillating water column converter with a V-shaped channel
Authors: Deng Zhengzhi , Huang Zhenhua , Law Adrian W. K.
Published: April 2014

An analytical theory is developed for an oscillating water column (OWC) with a V-shaped channel to improve the pneumatic efficiency of wave energy extraction. An eigenfunction expansion method is used in a cylindrical coordinate system to investigate wave interaction with the OWC converter system. Auxiliary functions are introduced to capture the singular behaviours in the velocity field near the salient corners and cusped edges. Effects of the OWC dimensions, the opening angle and length of the V-shaped channel, as well as the incident wave direction, on the pneumatic efficiency of wave energy extraction are examined. Compared with a system without the V-shaped channel, our results show that the V-shaped channel can significantly increase the conversion efficiency and widen the range of wave frequency over which the OWC system can operate at a high efficiency. For typical coastal water depths, the OWC converter system can perform efficiently when the diameter of the OWC chamber is in the range of

1
5

–

1
2

times the water depth, the opening angle of the V-shaped channel is in the range of [
π
/2, 3
π
/4] and the length of the V-shaped channel is in the range of 1–1.5 times the water depth.
Wave farm modelling of oscillating wave surge converters
Authors: Sarkar Dripta , Renzi Emiliano , Dias Frederic
Published: April 2014

A mathematical model is described to analyse the hydrodynamic behaviour of a wave energy farm consisting of oscillating wave surge converters in oblique waves. The method is a highly efficient semi-analytical approach based on the linear potential flow theory. Wave farms with a large number of such devices are studied for various configurations. For an inline configuration with normally incident waves, the occurrence of a near-resonant behaviour, already known for small arrays, is confirmed. A strong wave focusing effect is observed in special configurations comprising a large number of devices. The effects of the arrangement and of the distance of separation between the flaps are also studied extensively. In general, the flaps lying on the front of the wave farm are found to exhibit an enhanced performance behaviour in average, owing to the mutual interactions arising within the array. A random sea analysis shows that a slightly staggered arrangement can be an ideal layout for a wave farm of this device. The hydrodynamics of two flaps that oscillate back to back is also discussed.
Brittle fracture in a periodic structure with internal potential energy. Spontaneous crack propagation
Authors: Ayzenberg-Stepanenko Mark , Mishuris Gennady , Slepyan Leonid
Published: April 2014

Spontaneous brittle fracture is studied based on the model of a body, recently introduced by two of the authors, where only the prospective crack path is specified as a discrete set of alternating initially stretched and compressed bonds. In such a structure, a bridged crack destroying initially stretched bonds may propagate under a certain level of the internal energy without external sources. The general analytical solution with the crack speed–energy relation is presented in terms of the crack-related dynamic Green's function. For anisotropic chains and lattices considered earlier in quasi-statics, the dynamic problems are examined and discussed in detail. The crack speed is found to grow unboundedly as the energy approaches its upper limit. The steady-state sub- and supersonic regimes found analytically are confirmed by numerical simulations. In addition, irregular growth, clustering and crack speed oscillation modes are detected at a lower bound of the internal energy. It is observed, in numerical simulations, that the spontaneous fracture can occur in the form of a pure bridged, partially bridged or fully open crack depending on the internal energy level.
Dynamic response and localization in strongly damaged waveguides
Authors: Carta G. , Brun M. , Movchan A. B.
Published: April 2014

In this paper, we investigate the formation of band-gaps and localization phenomena in an elastic strip nearly disintegrated by an array of transverse cracks. We analyse the eigenfrequencies of finite, strongly damaged, elongated solids with reference to the propagation bands of an infinite strip with a periodic damage. Subsequently, we determine analytically the band-gaps of the infinite strip by using a lower-dimensional model, represented by a periodically damaged beam in which the small ligaments between cracks are modelled as ‘elastic junctions’. The effective rotational and translational stiffnesses of the elastic junctions are obtained from anad hocasymptotic analysis. We show that, for a finite frequency range, the dispersion curves for the reduced beam model agree with the dispersion data determined numerically for the two-dimensional elastic strip. Exponential localization, boundary layers and standing waves in strongly damaged systems are discussed in detail.
Effects of resource variation during early life and adult social environment on contest outcomes in burying beetles: a context-dependent silver spoon strategy?
Authors: Hopwood Paul E. , Moore Allen J. , Royle Nick J.
Published: April 2014

Good early nutritional conditions may confer a lasting fitness advantage over individuals suffering poor early conditions (a ‘silver spoon’ effect). Alternatively, if early conditions predict the likely adult environment, adaptive plastic responses might maximize individual performance when developmental and adult conditions match (environmental-matching effect). Here, we test for silver spoon and environmental-matching effects by manipulating the early nutritional environment of
Nicrophorus vespilloides
burying beetles. We manipulated nutrition during two specific early developmental windows: the larval environment and the post-eclosion environment. We then tested contest success in relation to variation in adult social environmental quality experienced (defined according to whether contest opponents were smaller (good environment) or larger (poor environment) than the focal individual). Variation in the larval environment influenced adult body size but not contest success
per se
for a given adult social environment experienced (an ‘indirect’ silver spoon effect). Variation in post-eclosion environment affected contest success dependent on the quality of the adult environment experienced (a context-dependent ‘direct’ silver spoon effect). By contrast, there was no evidence for environmental-matching. The results demonstrate the importance of social environmental context in determining how variation in nutrition in early life affects success as an adult.
Bumblebees (
Bombus terrestris
) use social information as an indicator of safety in dangerous environments
Authors: Dawson Erika H. , Chittka Lars
Published: April 2014

Avoiding predation is one of the most important challenges that an animal faces. Several anti-predation behaviours can be employed, yet simply using the presence of conspecifics can be a good signal of safety in an environment with potential predation hazards. Here, we show, for the first time, that past experience of predation causes bumblebees (
Bombus terrestris
) to aggregate with conspecifics, facilitating the identification of safe foraging patches. Bees were trained to differentiate between flowers that harboured predators and flowers that were predator free. When test subjects were subsequently presented solely with the previously predator-infested flower species, there was a significant preference to only land on flowers occupied by other feeding conspecifics. Yet, when safe flowers were made available to subjects previously entrained to discriminate safe from predator-occupied flowers, subjects ignored other bees and the social information potentially provided by them, demonstrating that attraction towards conspecifics is confined to dangerous situations. Our findings demonstrate a previously unknown social interaction in pollinators which may have important implications for plant–pollinator interactions.
How choosy should I be? The relative searching time predicts evolution of choosiness under direct sexual selection
Authors: Etienne Loïc , Rousset François , Godelle Bernard , Courtiol Alexandre
Published: April 2014

Most theoretical research in sexual selection has focused on indirect selection. However, empirical studies have not strongly supported indirect selection. A well-established finding is that direct benefits and costs exert a strong influence on the evolution of mate choice. We present an analytical model in which unilateral mate choice evolves solely by direct sexual selection on choosiness. We show this is sufficient to generate the evolution of all possible levels of choosiness, because of the fundamental trade-off between mating rate and mating benefits. We further identify the relative searching time (RST, i.e. the proportion of lifetime devoted to searching for mates) as a predictor of the effect of any variable affecting the mating rate on the evolution of choosiness. We show that the RST: (i) allows one to make predictions about the evolution of choosiness across a wide variety of mating systems; (ii) encompasses all alternative variables proposed thus far to explain the evolution of choosiness by direct sexual selection; and (iii) can be empirically used to infer qualitative differences in choosiness.
Short-term variation in sperm competition causes sperm-mediated epigenetic effects on early offspring performance in the zebrafish
Authors: Zajitschek Susanne , Hotzy Cosima , Zajitschek Felix , Immler Simone
Published: April 2014

The inheritance of non-genetic factors is increasingly seen to play a major role in ecology and evolution. While the causes and consequences of epigenetic effects transmitted from the mother to the offspring have received ample attention, much less is known about how variation in the condition of the father affects the offspring. Here, we manipulated the intensity of sperm competition experienced by male zebrafish
Danio rerio
to investigate the potential for sperm-mediated epigenetic effects over a relatively short period of time. We found that the rapid responses of males to varying intensity of sperm competition not only affected sperm traits as shown previously, but also the performance of the resulting offspring. We observed that males exposed to high intensity of sperm competition produced faster swimming and more motile sperm, and sired offspring that hatched over a narrower time frame but exhibited a lower survival rate than males exposed to low intensity of sperm competition. Our results provide striking evidence for short-term paternal effects and the possible fitness consequences of such sperm-mediated non-genetic factors not only for the resulting offspring but also for the female.
Trans-generational immune priming in honeybees
Authors: Hernández López Javier , Schuehly Wolfgang , Crailsheim Karl , Riessberger-Gallé Ulrike
Published: April 2014

Maternal immune experience acquired during pathogen exposure and passed on to progeny to enhance resistance to infection is called trans-generational immune priming (TgIP). In eusocial insects like honeybees, TgIP would result in a significant improvement of health at individual and colony level. Demonstrated in invertebrates other than honeybees, TgIP has not yet been fully elucidated in terms of intensity and molecular mechanisms underlying this response. Here, we immune-stimulated honeybee queens withPaenibacillus larvae(Pl), a spore-forming bacterium causing American Foulbrood, the most deadly bee brood disease worldwide. Subsequently, offspring of stimulated queens were exposed to spores ofPland mortality rates were measured to evaluate maternal transfer of immunity. Our data substantiate the existence of TgIP effects in honeybees by direct evaluation of offspring resistance to bacterial infection. A further aspect of this study was to investigate a potential correlation between immune priming responses and prohaemocytes–haemocyte differentiation processes in larvae. The results point out that a priming effect triggers differentiation of prohaemocytes to haemocytes. However, the mechanisms underlying TgIP responses are still elusive and require future investigation.
Production and consumption of nitrous oxide in nitrate-ammonifying Wolinella succinogenes cells
Authors: Luckmann Monique , Mania Daniel , Kern Melanie , Bakken Lars R. , Frostegård Åsa , Simon Jörg
Published: April 2014

Global warming is moving more and more into the public consciousness. Besides the commonly mentioned carbon dioxide and methane, nitrous oxide (N2O) is a powerful greenhouse gas in addition to its contribution to depletion of stratospheric ozone. The increasing concern about N2O emission has focused interest on underlying microbial energy-converting processes and organisms harbouring N2O reductase (NosZ), such as denitrifiers and ammonifiers of nitrate and nitrite. Here, the epsilonproteobacterial model organismWolinella succinogenesis investigated with regard to its capacity to produce and consume N2O during growth by anaerobic nitrate ammonification. This organism synthesizes an unconventional cytochromecnitrous oxide reductase (cNosZ), which is encoded by the first gene of an atypicalnosgene cluster. However,W. succinogeneslacks a nitric oxide (NO)-producing nitrite reductase of the NirS- or NirK-type as well as an NO reductase of the Nor-type. Using a robotized incubation system, the wild-type strain and suitable mutants ofW. succinogenesthat either produced or lackedcNosZ were analysed as to their production of NO, N2O and N2in both nitrate-sufficient and nitrate-limited growth medium using formate as electron donor. It was found that cells growing in nitrate-sufficient medium produced small amounts of N2O, which derived from nitrite and, most likely, from the presence of NO. Furthermore, cells employingcNosZ were able to reduce N2O to N2. This reaction, which was fully inhibited by acetylene, was also observed after adding N2O to the culture headspace. The results indicate thatW. succinogenescells are competent in N2O and N2production despite being correctly grouped as respiratory nitrate ammonifiers. N2O production is assumed to result from NO detoxification and nitrosative stress defence, while N2O serves as a terminal electron acceptor in anaerobic respiration. The ecological implications of these findings are discussed.
EARLY FLOWERING3 Regulates Flowering in Spring Barley by Mediating Gibberellin Production and FLOWERING LOCUS T Expression
Authors: Boden Scott A. , Weiss David , Ross John J. , Davies Noel W. , Trevaskis Ben , Chandler Peter M. , Swain Steve M.
Published: April 2014

EARLY FLOWERING3 (ELF3) is a circadian clock gene that contributes to photoperiod-dependent flowering in plants, with loss-of-function mutants in barley (Hordeum vulgare), legumes, and Arabidopsis thaliana flowering early under noninductive short-day (SD) photoperiods. The barley elf3 mutant displays increased expression of FLOWERING LOCUS T1 (FT1); however, it remains unclear whether this is the only factor responsible for the early flowering phenotype. We show that the early flowering and vegetative growth phenotypes of the barley elf3 mutant are strongly dependent on gibberellin (GA) biosynthesis. Expression of the central GA biosynthesis gene, GA20oxidase2, and production of the bioactive GA, GA1, were significantly increased in elf3 leaves under SDs, relative to the wild type. Inhibition of GA biosynthesis suppressed the early flowering of elf3 under SDs independently of FT1 and was associated with altered expression of floral identity genes at the developing apex. GA is also required for normal flowering of spring barley under inductive photoperiods, with chemical and genetic attenuation of the GA biosynthesis and signaling pathways suppressing inflorescence development under long-day conditions. These findings illustrate that GA is an important floral promoting signal in barley and that ELF3 suppresses flowering under noninductive photoperiods by blocking GA production and FT1 expression.
STM/BP-Like KNOXI Is Uncoupled from ARP in the Regulation of Compound Leaf Development inMedicago truncatula
Authors: Zhou Chuanen , Han Lu , Li Guifen , Chai Maofeng , Fu Chunxiang , Cheng Xiaofei , Wen Jiangqi , Tang Yuhong , Wang Zeng-Yu
Published: April 2014

Class I KNOTTED-like homeobox (KNOXI) genes are critical for the maintenance of the shoot apical meristem. The expression domain of KNOXI is regulated by ASYMMETRIC LEAVES1/ROUGHSHEATH2/PHANTASTICA (ARP) genes, which are associated with leaf morphology. In the inverted repeat-lacking clade (IRLC) of Fabaceae, the orthologs of LEAFY (LFY) function in place of KNOXI to regulate compound leaf development. Here, we characterized loss-of-function mutants of ARP (PHAN) and SHOOTMERISTEMLESS (STM)- and BREVIPEDICELLUS (BP)-like KNOXI in the model IRLC legume species Medicago truncatula. The function of ARP genes is species specific. The repression of STM/BP-like KNOXI genes in leaves is not mediated by PHAN, and no suppression of PHAN by STM/BP-like KNOXI genes was observed either, indicating that STM/BP-like KNOXI genes are uncoupled from PHAN in M. truncatula. Furthermore, comparative analyses of phenotypic output in response to ectopic expression of KNOXI and the M. truncatula LFY ortholog, SINGLE LEAFLET1 (SGL1), reveal that KNOXI and SGL1 regulate parallel pathways in leaf development. We propose that SGL1 probably functions in a stage-specific manner in the regulation of the indeterminate state of developing leaves in M. truncatula.
Structural insight into glucose dehydrogenase from the thermoacidophilic archaeonThermoplasma volcanium
Authors: Kanoh Yoshitaka , Uehara Seiichiroh , Iwata Hideyuki , Yoneda Kazunari , Ohshima Toshihisa , Sakuraba Haruhiko
Published: April 2014

Glucose dehydrogenase from the thermoacidophilic archaeonThermoplasma volcanium(tvGlcDH) is highly active towards D-glucose and D-galactose, but does not utilize aldopentoses such as D-xylose as substrates. In the present study, the crystal structures of substrate/cofactor-free tvGlcDH and of a tvGlcDH T277F mutant in a binary complex with NADP and in a ternary complex with D-glucose and nicotinic acid adenine dinucleotide phosphate, an NADP analogue, were determined at resolutions of 2.6, 2.25 and 2.33 Å, respectively. The overall structure of each monomer showed notable similarity to that of the enzyme fromSulfolobus solfataricus(ssGlcDH-1), which accepts a broad range of C5 and C6 sugars as substrates. However, the amino-acid residues of tvGlcDH involved in substrate binding markedly differed from those of ssGlcDH-1. Structural comparison revealed that a decreased number of interactions between the C3-hydroxyl group of the sugar and the enzyme are likely to be responsible for the lack of reactivity of tvGlcDH towards D-xylose.
Structure of a three-dimensional domain-swapped dimer of theHelicobacter pyloritype IV secretion system pilus protein CagL
Authors: Barden Stephan , Schomburg Benjamin , Conradi Jens , Backert Steffen , Sewald Norbert , Niemann Hartmut H.
Published: April 2014

A new crystal form of theHelicobacter pyloritype IV secretion system (T4SS) pilus protein CagL is described here. In contrast to two previously reported monomeric structures, CagL forms a three-dimensional domain-swapped dimer. CagL dimers can arise during refolding from inclusion bodies or can form spontaneously from purified monomeric CagL in the crystallization conditions. Monomeric CagL forms a three-helix bundle, with which the N-terminal helix is only loosely associated. In the new crystal form, the N-terminal helix is missing. The domain swap is owing to exchange of the C-terminal helix between the two protomers of a dimer. A loop-to-helix transition results in a long helix of 108 amino acids comprising the penultimate and the last helix of the monomer. The RGD motif of dimeric CagL adopts an α-helical conformation. In contrast to the previously reported structures, the conserved and functionally important C-terminal hexapeptide is resolved. It extends beyond the three-helix bundle as an exposed helical appendage. This new crystal form contributes to the molecular understanding of CagL by highlighting rigid and flexible regions in the protein and by providing the first view of the C-terminus. Based on the structural features, a previously unrecognized homology between CagL and CagI is discussed.
Flexible torsion-angle noncrystallographic symmetry restraints for improved macromolecular structure refinement
Authors: Headd Jeffrey J. , Echols Nathaniel , Afonine Pavel V. , Moriarty Nigel W. , Gildea Richard J. , Adams Paul D.
Published: April 2014

One of the great challenges in refining macromolecular crystal structures is a low data-to-parameter ratio. Historically, knowledge from chemistry has been used to help to improve this ratio. When a macromolecule crystallizes with more than one copy in the asymmetric unit, the noncrystallographic symmetry relationships can be exploited to provide additional restraints when refining the working model. However, although globally similar, NCS-related chains often have local differences. To allow for local differences between NCS-related molecules, flexible torsion-based NCS restraints have been introduced, coupled with intelligent rotamer handling for protein chains, and are available inphenix.refinefor refinement of models at all resolutions.
In cellulostructure determination of a novel cypovirus polyhedrin
Authors: Axford Danny , Ji Xiaoyun , Stuart David I. , Sutton Geoff
Published: April 2014

This work demonstrates that with the use of a microfocus synchrotron beam the structure of a novel viral polyhedrin could be successfully determined from microcrystals within cells, removing the preparatory step of sample isolation and maintaining a favourable biological environment. The data obtained are of high quality, comparable to that obtained from isolated crystals, and enabled a facile structure determination. A small but significant difference is observed between the unit-cell parameters and the mosaic spread ofin celluloand isolated crystals, suggesting that even these robust crystals are adversely affected by removal from the cell.
The structure of a class 3 nonsymbiotic plant haemoglobin fromArabidopsis thalianareveals a novel N-terminal helical extension
Authors: Reeder Brandon J. , Hough Michael A.
Published: April 2014

Plant nonsymbiotic haemoglobins fall into three classes, each with distinct properties but all with largely unresolved physiological functions. Here, the first crystal structure of a class 3 nonsymbiotic plant haemoglobin, that fromArabidopsis thaliana, is reported to 1.77 Å resolution. The protein forms a homodimer, with each monomer containing a two-over-two α-helical domain similar to that observed in bacterial truncated haemoglobins. A novel N-terminal extension comprising two α-helices plays a major role in the dimer interface, which occupies the periphery of the dimer–dimer face, surrounding an open central cavity. The haem pocket contains a proximal histidine ligand and an open sixth iron-coordination site with potential for a ligand, in this structure hydroxide, to form hydrogen bonds to a tyrosine or a tryptophan residue. The haem pocket appears to be unusually open to the external environment, with another cavity spanning the entrance of the two haem pockets. The final 23 residues of the C-terminal domain are disordered in the structure; however, these domains in the functional dimer are adjacent and include the only two cysteine residues in the protein sequence. It is likely that these residues form disulfide bondsin vitroand it is conceivable that this C-terminal region may act in a putative complex with a partner moleculein vivo.
IDL framework to integrate disparate digital library systems: a case study
Authors: Alipour-Hafezi Mehdi
Published: May 2014

Purpose

– The main purpose of this article is to provide a focal framework with the aim of making integrated digital libraries in technical and content level of syntactic interoperability between digital libraries.

Design/methodology/approach

– Literature review, library research method and analytical approach were used in the first step of this research in order to design IDL framework. Then a survey of 11 Iranian digital library applications was conducted for testing the proposed framework. Finally, based on the findings, conceptual integration architecture was proposed based on the framework.

Findings

– Based on the literature a framework for integration of digital library applications in syntax level is proposed which includes four core layers: models, protocols, metadata formats, and context-based layer. Based on the findings of the survey, integration architecture is proposed which includes all the mentioned layers in the IDL framework. So as to decrease cost of installing the architecture, cloud base technology architecture introduced to be used inverse.

Originality/value

– A gap exists between research and practice in the field of integrated digital libraries. In fact this article is an attempt to cover this gap by proposing a framework that can be implemented.
Design and implementation of a weighted features model for the evaluation of archival websites
Authors: Faba Pérez Cristina , María Sanz Caballero Isabel
Published: May 2014

Purpose

– The purpose of the present work was to design a comprehensive weighted features model for the specific evaluation of archival websites, and to apply it in practice to the particular population of Spain's web archives, ranking them in terms of quality based on the features they include.

Design/methodology/approach

– The design of the weighted features model is based on two parameters: the weight assigned to each feature according to its relevance for information retrieval from archival websites, and the archival website's degree of compliance with that feature.

Findings

– The results of the practical application of the model to the case of Spanish web archives showed that, contrary to prior expectation, factors which are intrinsic to the geographical region of Spain that the archive belongs to, such as economic level or degree of commitment to specific archival legislation, do not directly influence its website's quality ranking. Instead, the authors conclude that the population of archival websites presents its own particular behaviour.

Originality/value

– There has been a general lack of research specific to the analysis of the features of archival websites. The present work represents a certain advance in this regard in its proposal of a comprehensive weighted model of indicators for the specific evaluation of archival websites.
Critical success factors of an effective repairs and maintenance service for social housing in the UK
Authors: Tucker Matthew , Turley Martin , Holgate Sam
Published: April 2014

Purpose

– The purpose of this paper is to investigate the critical success factors of an effective repairs service by initially identifying what the important considerations are.

Design/methodology/approach

– Using quantitative research methods the study then examines how important each of the factors is considered from the perspective of those responsible for such services in the Northwest of England, the level of implementation throughout the region is also examined.

Findings

– Respondents felt that all 11 factors are perceived as “very” important but only nine are “always” implemented within their place of work. Sustainability and innovation are identified as the two factors that are least critical. It can also be said that although important and well implemented, the in-house skills factor does not appear to be considered as critical in comparison to the other factors.

Originality/value

– The UK housing sector is under an enormous amount of pressure to meet the needs of a growing population in extremely uncertain financial conditions. Social housing is a potential solution but providers are currently contending with reduced budgets and cuts to staffing levels together with an expectation that service levels will be maintained and value for money maximised. Repairs and maintenance of their stock is at the forefront of their challenge to meet these expectations and it is therefore vital that the service they provide is effective.
How related are technical and subjective measures of building conditions?
Authors: O. Hopland Arnt
Published: April 2014

Purpose

– The purpose of this paper is to investigate the link between technical school building conditions and student satisfaction with the school buildings. Learning more about the relationship between the measures will be useful for researchers who are studying the effect from physical work conditions on student achievement.

Design/methodology/approach

– The paper aims to study the correlation between technical condition and user satisfaction with school buildings using two different data sources. The first source is administrative data, where the local governments have reported the condition of their school buildings to a national investigation of school building conditions. The second source is survey data where students in Norwegian primary schools report their satisfaction with their learning environment, including the school buildings. Combining the two data sources provides a unique data set for a large number of Norwegian primary schools.

Findings

– The measures of technical and subjective condition are significantly correlated, but the correlation is far from 100 percent. Hence, it will be of great interest for researchers to look more into potential effects from subjective measures of building condition.

Originality/value

– The paper provides an investigation of the link between two different measures of building conditions that can both be relevant to use in studies of how school buildings affect student performance.
Critical success factors for building maintenance business: a Hong Kong case study
Authors: Tan Yongtao , Shen Liyin , Langston Craig , Lu Weisheng , C.H. Yam Michael
Published: April 2014

Purpose

– Thie purpose of this paper is to present the critical success factors (CSFs) for engaging in the building maintenance business in Hong Kong where maintenance is a major market sector.

Design/methodology/approach

– In this study, CSFs are identified for the business of building maintenance based on data collected from a questionnaire survey and interviews.

Findings

– A total of 12 CSFs are identified, such as client's satisfaction, certification of company, reliability of service, quality of service, and company reputation, and most are related to two principal factors, namely maintenance service and organization, and project management.

Originality/value

– This paper provides a review of building maintenance in Hong Kong and identifies a list of success factors for the business of building maintenance. The identified CSFs and principal factors provide useful reference for maintenance contractors to have a clear understanding of the expectations of the building maintenance market in Hong Kong.
KPIs for facility's performance assessment, Part I: identification and categorization of core indicators
Authors: Lavy Sarel , A. Garcia John , K. Dixit Manish
Published: April 2014

Purpose

– The purpose of this paper is to synthesize the previously established list of key performance indicators (KPIs), to identify and categorize the core performance indicators that are measurable and quantifiable.

Design/methodology/approach

– A literature-based qualitative approach is adopted for accumulating desired information on identifying and categorizing the core indicators. The list of KPIs established in an earlier paper is narrowed down considering the future research needs suggested by the literature.

Findings

– The quantifiable and measurable core indicators are identified and categorized in the form of a list. The core indicators are defined and the variables required to quantify them are described by citing peer-reviewed literature.

Research limitations/implications

– This paper represents the first step toward establishing a relevant list of quantifiable and measurable core KPIs. Future research papers could emphasize derivation of mathematical expressions for determining the identified core KPIs and validating these KPIs using simulation of real building data.

Practical implications

– The need to establish a concise and relevant list of quantifiable and measurable KPIs that could express more than one type of information about a facility's performance is identified in this paper. This paper presents and describes a narrowed down list of core KPIs, which could be utilized by facility management industry professionals while performing a holistic performance assessment.

Originality/value

– This paper provides a list of core KPIs that could express more than one aspect of a facility's performance and that is measurable and quantifiable.
An exploration of the challenges facing women starting business at fifty
Authors: Logan Julie
Published: April 2014

Purpose

– The paper aims to investigate the motivations, goals, challenges, successes and needs of older women starting new ventures.

Design/methodology/approach

– In-depth semi-structured interviews were conducted with ten successful female entrepreneurs who had created their businesses at age 50 or over. The key areas of focus included the women's motivation for starting a business, their previous work experience, potential barriers/enabling factors (including their human, social and financial capital), and the performance of their ventures. Responses were taped, transcribed, coded, grouped and analyzed.

Findings

– The primary trigger for older women to start a new venture appears to be the need to find a creative outlet (self-actualization). Further, more than half the women stated that because they now had significantly reduced family responsibilities, this was the time for them to pursue their own goals. Interestingly, a majority of the women had started new ventures in an area completely unrelated to their previous work experience. Family support, particularly from their spouse/partner, was acknowledged by virtually all the women as an important factor contributing to the success of their ventures. All the ventures were profitable and growing.

Research limitations/implications

– The findings suggest that well-trained mentors could make a significant difference to this older cohort of female entrepreneurs, particularly in terms of helping them to grow their businesses.

Originality/value

– This study fills a gap in the literature by providing an understanding of the motivations and needs of older female entrepreneurs.
Understanding the short- and long-run relationship between vacant allotment and established house prices
Authors: Rossini Peter , Kupke Valerie
Published: May 2014

Purpose

– The purpose of this paper is to address a key issue fundamental to the operation of land and housing markets, that is, the relationship between land and house prices. The study identifies possible causation between established house and vacant allotment prices using the metropolitan area of Adelaide, Australia as a case study.

Design/methodology/approach

– A key outcome of the study is the construction of a Site Adjusted Land Price Index against which a Quality Adjusted House Price Index is compared.

Findings

– The results show that there is a lagged effect of land prices on house prices and that this is significant at an interval of eight lag periods. The results also imply that the lead lag relationship between established house and vacant allotment prices is not unidirectional. This suggests that, while a change in house prices leads to a change in land prices in the short-run, the long-run position is for increasing land prices to lead to a delayed increase in house prices.

Research limitations/implications

– Rising house prices do not simply and solely reflect a shortage of land. There are suggested effects both immediate from house to land and delayed from land to house, particularly in a rising market.

Originality/value

– The lead lag relationships of both indexes are tested using Granger causality estimates to assess whether theoretical Ricardian concepts still hold in a modern urban land market.
Entering the world of sex offenders: an exploration of offending behaviour patterns of those with both internet and contact sex offences against children
Authors: Aslan Deniz , Edelmann Robert , Bray Diane , Worrell Marcia
Published: April 2014

Purpose

– The relationship between accessing indecent images online and the perpetration of contact child sex offences remains unclear. The purpose of this paper is to provide a better understanding of the offence process of offenders who have both such convictions.

Design/methodology/approach

– A total of eight semi-structured interviews were conducted with older adult males who had downloaded indecent images and also had a history of contact sex offences against children. Data analysis involved thematic coding based on guidelines suggested by Braun and Clarke (2006).

Findings

– Themes which emerged suggest some similarities (offence process behaviours), but also some differences (developmental factors) between the eight offenders. Data relevant to developmental factors formed two primary themes: childhood attachment difficulties and experiences of childhood abuse, both of which appeared to influence the offence process. Escalating factors generated a further three themes: adult relationships, personality problems and substance use. Five main categories also emerged with regard to offence behaviours: sexually deviant interests, lack of self-control, opportunity, the role of the internet (availability, easy access and anonymity), and cognitive distortions (justifications: interest in challenge and sexual frustration; denial: accidental access and denial of a victim, normalisation; blame: blame on the victim, new technologies and authorities and blame on other factors; and minimisation).

Practical implications

– A better understanding of the offence process would inform clinical practice with such offenders and aid in the process of prevention.

Originality/value

– This is the first research to date which explores the rationale provided for their behaviour by those convicted of both internet and contact child sex offences.
Frugal innovation: aligning theory, practice, and public policy
Authors: Soni Pavan , T. Krishnan Rishikesha
Published: May 2014

Purpose

– The paper aims to address two key gaps in the literature of frugal innovation. First, it disambiguates frugal innovations into its types, and into the various levels at which it happens. Second, it builds upon the theoretical foundations of resource-based view, new institutional economics, economics of location, and institutional theory to offer testable propositions on determinants of frugal innovations.

Design/methodology/approach

– This is a conceptual paper. The authors first systematically reviewed the extant literature on frugal innovation and related domains and categorized the existing understanding on the domain into various typologies of frugal innovation. The authors then justified why certain key theoretical lenses are tenable to understand the determinants of frugal innovation and then examined the conditions that enable such innovations.

Findings

– The paper has three key findings. First, frugal innovation comprises of a frugal mindset, a frugal process and a frugal outcome, which may be practiced distinctly. Second, frugal innovators are of three types: grassroots-level, domestic-enterprise level, and MNC-subsidiary level. Each has their distinctive incentives and styles of frugal innovation. Third, a frugal mindset is encouraged by a resource-scarce environments, weaker institutional intermediaries, and a higher tolerance for uncertainty. Frugal processes are espoused by poor property rights regime and a critical size of lead market; and frugal outcomes are influenced by the network-position of innovators, and the presence of critical lead-markets.

Research limitations/implications

– The propositions are though testable, but proxies need to be developed to measure the variables, such as a frugal mindset, and a frugal process. Further, the current view on various types and levels of frugal innovation is that of mutual exclusivity, whereas this may not always be the case. Hence, it might be useful to identify contingencies in which these distinctions fade away.

Originality/value

– The paper is valuable in two key aspects. First, it offers a much-needed theoretical underpinning to the phenomenon of frugal innovation, such that the phenomenon could be better understood and influenced. Second, it nuances the phenomenon by identifying distinct types of frugal innovators in terms of their motivation, institutional influences, and styles of innovation.
Effects of competitive psychological climate, work-family conflict and role conflict on customer orientation
Authors: Sahadev Sunil , Seshanna Sudarshan , Purani Keyoor
Published: May 2014

Purpose

– The purpose of this paper is to consider the impact of a competitive psychological climate on the levels of role conflict and work-family conflict in call center employees and their further impact on customer orientation.

Design/methodology/approach

– The conceptual model is developed through a review of literature and is then validated in the context of call center employees in India. A total of 281 responses were considered. The model is validated using a multi-group analysis in order to consider a possible influence of gender.

Findings

– The model is found to have a very good fit and four of the five hypothesized relationships are found to be significant. The study thus establishes the impact of a competitive psychological climate on the role conflict and work-life conflict in the case of service employees.

Research limitations/implications

– The study uses a self-reported measure of customer orientation as well as the sampling methodology is not random. These two aspects could limit the generalizability of the results.

Practical implications

– The paper gives empirical support against adoption of competition-based practices in service organizations. This is an important implication for practitioners.

Originality/value

– The study looks at the impact of competitive psychological climate in call centers, a construct hitherto not much analyzed. The analysis of the relationship between competitive psychological climate, role conflict and work-family conflict have also not been looked into in the previous literature.