bluuebunny/crossref_metadata_2025_split huggingface dataset:
A linear mixed model with temporal covariance structures in modelling catch per unit effort of Baltic herring
Authors: Mikkonen S. , Rahikainen M. , Virtanen J. , Lehtonen R. , Kuikka S. , Ahvonen A. 
Published: August 2008

Abstract
Mikkonen, S., Rahikainen, M., Virtanen, J., Lehtonen, R., Kuikka, S., and Ahvonen, A. 2008. A linear mixed model with temporal covariance structures in modelling catch per unit effort of Baltic herring. – ICES Journal of Marine Science, 65: 1645–1654. Changes in the structure and attributes of a fleet over time will break down the proportionality of catch per unit effort (cpue) and stock biomass. Moreover, logbook data from commercial fisheries are hierarchical and autocorrelated. Such features not only complicate the analysis of cpue data but also seriously limit the application of a generalized linear model approach, which nevertheless is applied commonly. We demonstrate a linear mixed model application for a large hierarchical dataset containing autocorrelated observations. In the analysis, the key idea is to explore the properties of the error term of the model. We modified the residual covariance matrix, allowing the introduction of assumed fisher behaviour, influencing the catch rate. Fisher behaviour consists of accumulated knowledge and learning processes from their earlier area- and time-specific catch rates. Also, we investigated the effects of vessel-specific parameters by introducing random intercepts and slopes in the model. A model with the autoregressive moving average residual covariance matrix structure was superior over the block-diagonal and autoregressive (AR1) structure for the data, having a time-dependent correlation among trawl hauls. The results address the benefits of statistically advanced methods in obtaining precise and unbiased estimates from cpue data, to be used further in stock assessment. Fisheries agencies are encouraged to monitor the relevant vessel and gear attributes, including engine power and gear size, and the deployment practices of the gear.
The Laterality Index in the Evaluation of Distal Sensorimotor Neuropathy
Authors: Lo Yew-Long , Leoh Teng-Hee , Lim Li-Ling , Fook-Chong Stephanie , Ng Yueh-Ling , Ratnagopal Pavanni 
Published: September 2008

Abstract

Objective:
Electrodiagnostic evaluation of distal sensorimotor neuropathy can be technically challenging. Conventional nerve conduction studies (NCS) often include unilateral upper and lower limb evaluation for patients with suspected sensorimotor peripheral neuropathy. For patients with predominantly lower extremity complaints, NCS of both lower limbs are performed occasionally. Side-to-side NCS parameters have not been adequately addressed.

Methods:
We performed NCS prospectively on 132 patients presenting with complaints of bilateral numbness or weakness in the extremities and 45 normal controls. The laterality index (LI) was defined as ratio of the smaller to the larger amplitude in a sensory or motor NCS, as a novel side-to-side comparison parameter.

Results:
Ten patients had at least 1 sensory or motor NCS with LIs exceeding that of normal controls. Patients 1-7 (group 1) had diagnoses of autoimmune or neoplasia-related conditions and all had 3 or more NCS with abnormal LIs. In contrast, patients 8-10 (group 2) had diabetes mellitus and all had 2 or less NCS with abnormal LIs (unpaired t test; P = 0.002). In group 1, patients 1-4, 6, and 7 all had both upper and lower limb LI abnormalities. In contrast, only 1 patient (patient 9) had upper limb LI abnormality in group 2.

Conclusions:
Patients with abnormal LIs were uncommon in our cohort. Patients with diabetes mellitus had significantly less abnormal LIs than those with autoimmune or neoplasia-related etiologies. There is evidence of vasculitic inflammation documented in diabetic neuropathy. However, this process may be significantly less prominent compared with the former 2 conditions. Our findings of predominantly lower limb LI abnormalities suggest the presence of a length-dependent distal neuropathic process in diabetes mellitus. The LI is a simple and useful adjunct to detect asymmetrical NCS abnormalities. It may also provide helpful information regarding the underlying etiology.
Tomato γ-Glutamylhydrolases: Expression, Characterization, and Evidence for Heterodimer Formation
Authors: Akhtar Tariq A. , McQuinn Ryan P. , Naponelli Valeria , Gregory Jesse F. , Giovannoni James J. , Hanson Andrew D. 
Published: August 2008

Abstract
Folates typically have γ-linked polyglutamyl tails that make them better enzyme substrates and worse transport substrates than the unglutamylated forms. The tail can be shortened or removed by the vacuolar enzyme γ-glutamyl hydrolase (GGH). It is known that GGH is active only as a dimer and that plants can have several GGH genes whose homodimeric products differ functionally. However, it is not known whether GGH dimers dissociate under in vivo conditions, whether heterodimers form, or how heterodimerization impacts enzyme activity. These issues were explored using the GGH system of tomato (Solanum lycopersicum). Tomato has three GGH genes that, like those in other eudicots, apparently diverged recently. LeGGH1 and LeGGH2 are expressed in fruit and all other organs, whereas LeGGH3 is expressed mainly in flower buds. LeGGH1 and LeGGH2 homodimers differ in bond cleavage preference; the LeGGH3 homodimer is catalytically inactive. Homodimers did not dissociate in physiological conditions. When coexpressed in Escherichia coli, LeGGH1 and LeGGH2 formed heterodimers with an intermediate bond cleavage preference, whereas LeGGH3 formed heterodimers with LeGGH1 or LeGGH2 that had one-half the activity of the matching homodimer. E. coli cells expressing LeGGH2 showed approximately 85% reduction in folate polyglutamates, but cells expressing LeGGH3 did not, confirming that LeGGH2 can function in vivo and LeGGH3 cannot. The formation of LeGGH1-LeGGH2 heterodimers was demonstrated in planta using bimolecular fluorescence complementation. Plant GGH heterodimers thus appear to form wherever different GGH genes are expressed simultaneously and to have catalytic characteristics midway between those of the corresponding homodimers.
ArabidopsisTONNEAU1 Proteins Are Essential for Preprophase Band Formation and Interact with Centrin
Authors: Azimzadeh Juliette , Nacry Philippe , Christodoulidou Anna , Drevensek Stéphanie , Camilleri Christine , Amiour Nardjis , Parcy François , Pastuglia Martine , Bouchez David 
Published: August 2008

AbstractPlant cells have specific microtubule structures involved in cell division and elongation. The tonneau1 (ton1) mutant of Arabidopsis thaliana displays drastic defects in morphogenesis, positioning of division planes, and cellular organization. These are primarily caused by dysfunction of the cortical cytoskeleton and absence of the preprophase band of microtubules. Characterization of the ton1 insertional mutant reveals complex chromosomal rearrangements leading to simultaneous disruption of two highly similar genes in tandem, TON1a and TON1b. TON1 proteins are conserved in land plants and share sequence motifs with human centrosomal proteins. The TON1 protein associates with soluble and microsomal fractions of Arabidopsis cells, and a green fluorescent protein–TON1 fusion labels cortical cytoskeletal structures, including the preprophase band and the interphase cortical array. A yeast two-hybrid screen identified Arabidopsis centrin as a potential TON1 partner. This interaction was confirmed both in vitro and in plant cells. The similarity of TON1 with centrosomal proteins and its interaction with centrin, another key component of microtubule organizing centers, suggests that functions involved in the organization of microtubule arrays by the centrosome were conserved across the evolutionary divergence between plants and animals.
The Cold-Inducible CBF1 Factor–Dependent Signaling Pathway Modulates the Accumulation of the Growth-Repressing DELLA Proteins via Its Effect on Gibberellin Metabolism
Authors: Achard Patrick , Gong Fan , Cheminant Soizic , Alioua Malek , Hedden Peter , Genschik Pascal 
Published: August 2008

AbstractPlants have evolved robust mechanisms to respond and adapt to unfavorable environmental conditions, such as low temperature. The C-repeat/drought-responsive element binding factor CBF1/DREB1b gene encodes a transcriptional activator transiently induced by cold that controls the expression of a set of genes responding to low temperature (the CBF regulon). Constitutive expression of CBF1 confers freezing tolerance but also slows growth. Here, we propose that low temperature–induced CBF1 expression restrains growth at least in part by allowing the accumulation of DELLAs, a family of nuclear growth-repressing proteins, the degradation of which is stimulated by gibberellin (GA). We show that cold/CBF1 enhances the accumulation of a green fluorescent protein (GFP)–tagged DELLA protein (GFP-RGA) by reducing GA content through stimulating expression of GA-inactivating GA 2-oxidase genes. Accordingly, transgenic plants that constitutively express CBF1 accumulate less bioactive GA and as a consequence exhibit dwarfism and late flowering. Both phenotypes are suppressed when CBF1 is expressed in a line lacking two DELLA proteins, GA-INSENSITIVE and REPRESSOR OF GA1-3. In addition, we show that DELLAs contribute significantly to CBF1-induced cold acclimation and freezing tolerance by a mechanism that is distinct from the CBF regulon. We conclude that DELLAs are components of the CBF1-mediated cold stress response.
Molecular Remodeling of Photosystem II during State Transitions inChlamydomonas reinhardtii
Authors: Iwai Masakazu , Takahashi Yuichiro , Minagawa Jun 
Published: August 2008

AbstractState transitions, or the redistribution of light-harvesting complex II (LHCII) proteins between photosystem I (PSI) and photosystem II (PSII), balance the light-harvesting capacity of the two photosystems to optimize the efficiency of photosynthesis. Studies on the migration of LHCII proteins have focused primarily on their reassociation with PSI, but the molecular details on their dissociation from PSII have not been clear. Here, we compare the polypeptide composition, supramolecular organization, and phosphorylation of PSII complexes under PSI- and PSII-favoring conditions (State 1 and State 2, respectively). Three PSII fractions, a PSII core complex, a PSII supercomplex, and a multimer of PSII supercomplex or PSII megacomplex, were obtained from a transformant of the green alga Chlamydomonas reinhardtii carrying a His-tagged CP47. Gel filtration and single particles on electron micrographs showed that the megacomplex was predominant in State 1, whereas the core complex was predominant in State 2, indicating that LHCIIs are dissociated from PSII upon state transition. Moreover, in State 2, strongly phosphorylated LHCII type I was found in the supercomplex but not in the megacomplex. Phosphorylated minor LHCIIs (CP26 and CP29) were found only in the unbound form. The PSII subunits were most phosphorylated in the core complex. Based on these observations, we propose a model for PSII remodeling during state transitions, which involves division of the megacomplex into supercomplexes, triggered by phosphorylation of LHCII type I, followed by LHCII undocking from the supercomplex, triggered by phosphorylation of minor LHCIIs and PSII core subunits.
Themilkweed pod1Gene Encodes a KANADI Protein That Is Required for Abaxial/Adaxial Patterning in Maize Leaves
Authors: Candela Héctor , Johnston Robyn , Gerhold Abigail , Foster Toshi , Hake Sarah 
Published: August 2008

AbstractLeaf primordia initiate from the shoot apical meristem with inherent polarity; the adaxial side faces the meristem, while the abaxial side faces away from the meristem. Adaxial/abaxial polarity is thought to be necessary for laminar growth of leaves, as mutants lacking either adaxial or abaxial cell types often develop radially symmetric lateral organs. The milkweed pod1 (mwp1) mutant of maize (Zea mays) has adaxialized sectors in the sheath, the proximal part of the leaf. Ectopic leaf flaps develop where adaxial and abaxial cell types juxtapose. Ectopic expression of the HD-ZIPIII gene rolled leaf1 (rld1) correlates with the adaxialized regions. Cloning of mwp1 showed that it encodes a KANADI transcription factor. Double mutants of mwp1-R with a microRNA-resistant allele of rld1, Rld1-N1990, show a synergistic phenotype with polarity defects in sheath and blade and a failure to differentiate vascular and photosynthetic cell types in the adaxialized sectors. The sectored phenotype and timing of the defect suggest that mwp1 is required late in leaf development to maintain abaxial cell fate. The phenotype of mwp1; Rld1 double mutants shows that both genes are also required early in leaf development to delineate leaf margins as well as to initiate vascular and photosynthetic tissues.
Rpl33, a Nonessential Plastid-Encoded Ribosomal Protein in Tobacco, Is Required under Cold Stress Conditions
Authors: Rogalski Marcelo , Schöttler Mark A. , Thiele Wolfram , Schulze Waltraud X. , Bock Ralph 
Published: August 2008

Abstract
Plastid genomes contain a conserved set of genes encoding components of the translational apparatus. While knockout of plastid translation is lethal in tobacco (Nicotiana tabacum), it is not known whether each individual component of the plastid ribosome is essential. Here, we used reverse genetics to test whether several plastid genome–encoded ribosomal proteins are essential. We found that, while ribosomal proteins Rps2, Rps4, and Rpl20 are essential for cell survival, knockout of the gene encoding ribosomal protein Rpl33 did not affect plant viability and growth under standard conditions. However, when plants were exposed to low temperature stress, recovery of Rpl33 knockout plants was severely compromised, indicating that Rpl33 is required for sustaining sufficient plastid translation capacity in the cold. These findings uncover an important role for plastid translation in plant tolerance to chilling stress.
Internet access in UK public libraries: notes and queries from a small scale study
Authors: McMenemy David 
Published: August 2008

PurposeThe purpose of this editorial is to discuss the findings of a small scale study of internet access in UK public libraries. It aims to examine all aspects of access, from the moment the service is requested, to the acceptable use policy (AUP) for each library, to specific Internet sites that are banned.Design/methodology/approachThe methodology involved unobtrusive testing, commonly referred to as mystery shopping. A total of 14 different library authorities spread across the UK were visited by the researcher.FindingsVariances in access to the internet in public libraries in the UK exist. Of concern was the lack of time staff in most libraries allocated to explaining the AUP the library was asking the researcher to sign. In some libraries the AUP was actually bypassed by the staff member entirely. Other concerns related to the differences in internet filtering adopted in the libraries visited, with legitimate sites blocked in some and not others. The quality of the experience was also lessened by inadequately designed front‐ends and the lack of helpful guides on using the internet.Originality/valueThe paper should be of interest to public librarians and others interested in the implementation of internet services in public libraries.
Aligning library assessment processes to the library's service environment
Authors: Nash White Larry 
Published: August 2008

PurposeThe purpose of this paper is to understand the alignment of assessment processes in libraries and develop a conceptual model of aligning library performance assessment for effective reporting of library value and performance to stakeholders.Design/methodology/approachThe paper reviews of library performance assessment literature and current practice research to identify the need and value of aligned performance assessment processes for libraries, the primary contributing alignment factors affecting the library assessment process, and potential benefits of improved alignment of the assessment process for libraries.FindingsLibraries can improve the reporting and value of their assessment processes by improving the alignment of their assessment processes in two ways: internally through the use of consistent and innovative processes, metrics, and culture within the library and externally by embracing the alignment factors of the library's service environment. The library must develop more effective assessment alignment processes by progressively elevating the alignment of the library's assessment processes from internal non‐alignment of assessment to the total alignment of assessment to the library’ service environment and the dynamic environmental factors driving today's libraries.Practical implicationsIncreasing the alignment of a library's assessment processes can improve the efficiency of assessment processes, the effectiveness of the results of the assessment processes, and the library stakeholder's appreciation and understanding of the results of the assessment processes.Originality/valueProvides a conceptual model applicable to all types of libraries to increase the alignment of assessment and the library's ability to report value and impact.
Environmental scanning: an essential tool for twenty‐first century librarianship
Authors: Castiglione James 
Published: August 2008

PurposeThis article aims to highlight important aspects of environmental scanning (ES). As a managerial tool of high utility, ES may assist library professionals – at all levels – proactively assess and respond to change in the technological, demographic, economic and social environments that may have a future impact on the library profession and stakeholder services.Design/methodology/approachThis article deepens the library literature related to the methodology of ES with concepts and ideas derived from the relevant management literature.FindingsBased on an in‐depth review of the library literature, the evidence suggests that librarians have not the used ES techniques consistently or systematically to manage change.Research limitations/implicationsWhile the results of this literature review imply that ES is underutilized as a tool to manage change in the library environment, it is entirely possible that practicing librarians actually utilize ES far more frequently than a review of the library literature suggests. Additional survey‐studies addressing this concern will be required to resolve this important question.Originality/valueThis article provides useful information related to the importance of ES and the related methodology required to build a comprehensive ES initiative. In addition, the paper introduces the reader to the innovative goal of coordinating ES initiatives on a global scale. This is presented with a view toward developing cooperative programs and approaches that may increase the viability of our profession and strengthen our collective ability to increase stakeholder satisfaction.
Influence of fluor‐oligomers on the structural and tribological properties of steel surface at the rolling friction
Authors: Padgurskas Juozas , Rukuiza Raimundas , Amulevicius Arunas , Sipavicius Ceslovas , Mazeika Kestutis , Davidonis Rimantas , Daugvila Antanas , Cesiulis Henrikas 
Published: August 2008

PurposeThe purpose of this paper is to investigate the influence of fluor‐oligomeric coat on the mechanical properties of steel surface, as well as the chemical interaction of fluor‐oligomeric films with surface and theoretical‐phenomenological interpretation of structural processes in friction surface.Design/methodology/approachFour groups of specimens were studied: two groups of specimens without any wear tests – initial steel specimen as control version and a specimen which was ten times coated by fluor‐oligomer, and two groups of specimens, which were tribologically tested for one million cycles – without any coating and coated specimens. Closed kinematical profile scheme roller‐roller of steel 45 was chosen for tribological tests. Wear of friction surface after those tests was investigated. The interaction between fluor‐oligomer and iron was studied by means of Mössbauer spectroscopy. The micro‐hardness of matrix was also measured.FindingsAffecting the surface of steel by the fluor‐oligomer and friction produces the complicated processes of carbide decay and formation occur. The mechanisms are found which are related to the weakening of chemical bond in steel during the absorption, to the generation of microscopic ruptures, to the decrease (30‐50 per cent) of the amount of carbides and its increase during the friction (up to 50 per cent). The mechanical effect which causes the regeneration of carbides during friction is revealed. Tribological efficiency of fluor‐oligomeric coats (five times lower wear of coated specimens) is explained by the balance of three processes – the softening of matrix during adsorption, the detention of dislocations, and formation of hard particles in the matrix.Originality/valueThe complex mechanism of the increase of wear resistance is explained by filling of ductile matrix with carbide particles.
Esters of methylolcyclohexanols/ones as synthetic base lubricants
Authors: Tataroglu Seyidov Firdovsi , Mansoori Yagoub 
Published: August 2008

PurposeThe purpose of this paper is to examine the preparation of asymmetric mixed esters of methylolcyclohexanols in order to decrease the pour point and increase the thermal stability of base oils.Design/methodology/approachThe aldol condensation reaction of cyclohexanone with paraformaldehyde is modified to give mixture of alicyclic polyols. The obtained mixture was subsequently esterified by different pure and mixed linear mono carboxylic acids to give asymmetric mixture of esters of methylolcyclohexanols/ones.FindingsThe obtained base lubricants showed better wear preventive characteristcs (four‐ball rolling contact test) compared with previously reported and commercially available ester base lubricants.Research limitations/implicationsBecause of the complexity of the obtained mixture, it was impossible to study the structure and composition of the obtained products by modern techniques such as high field NMR spectroscopy.Practical implicationsThe obtained materials are slightly acidic and should be neutralized before use or formulation.Originality/valueThe paper presents a new process for obtaining synthetic ester base lubricants from mixed polyols of neo structure, which was obtained from aldol condensation reaction of cyclohexanone and paraformaldehyde, and linear aliphatic monocarboxylic acids. The key step in this process is modifying the reaction condition for obtaining mixture of polyols, and not pure 2,2,6,6‐tetramethylolcyclohexanol. This allows one to obtain asymmetrical and complex mixture of esterification products, which is favored in the production of synthetic ester base stocks, having excellent viscosity‐temperature properties, decreased pour point, and increased thermal stability. The synthesized ester base lubricants also show excellent viscosity‐temperature properties compared with ester base lubricants of the same family.