bluuebunny/crossref_metadata_2025_split huggingface dataset:
The leader in midlife
Authors: Leider Richard J. 
Published: May 2008

PurposeThis paper aims to frame and open up a new, often hidden conversation that leaders often have privately … namely which way to go in the second half of life to legitimize the need to build the “self‐leadership” topic into leadership development models and programs.Design/methodology/approachThe author is a coach and seminar leader who has spoken to over 100,000 people in over 50 corporations. The message is gleaned from that work plus his own studies, formal and informal of adult development.FindingsThe key concept is how to sustain productivity and commitment over a ten year career. When this topic is discussed openly and legitimately in organizational settings, it engenders “natural productivity”. When it is hidden, contracted, or not discussed, it engenders burnout, fatigue and lack of commitment.Originality/valueProvides a viewpoint on leadership development.
Purification and Characterization of a Novel Recombinant Highly Enantioselective Short-Chain NAD(H)-Dependent Alcohol Dehydrogenase from
Thermus thermophilus
Authors: Pennacchio Angela , Pucci Biagio , Secundo Francesco , La Cara Francesco , Rossi Mosè , Raia Carlo A. 
Published: May 2008

ABSTRACT

The gene encoding a novel alcohol dehydrogenase (ADH) that belongs to the short-chain dehydrogenase/reductase (SDR) superfamily was identified in the extremely thermophilic, halotolerant gram-negative eubacterium
Thermus thermophilus
HB27. The
T. thermophilus
ADH gene (
adh
Tt
) was heterologously overexpressed in
Escherichia coli
, and the protein (ADH
Tt
) was purified to homogeneity and characterized. ADH
Tt
is a tetrameric enzyme consisting of identical 26,961-Da subunits composed of 256 amino acids. The enzyme has remarkable thermophilicity and thermal stability, displaying activity at temperatures up to ∼73°C and a 30-min half-inactivation temperature of ∼90°C, as well as good tolerance to common organic solvents. ADH
Tt
has a strict requirement for NAD(H) as the coenzyme, a preference for reduction of aromatic ketones and α-keto esters, and poor activity on aromatic alcohols and aldehydes. This thermophilic enzyme catalyzes the following reactions with Prelog specificity: the reduction of acetophenone, 2,2,2-trifluoroacetophenone, α-tetralone, and α-methyl and α-ethyl benzoylformates to (
S
)-(−)-1-phenylethanol (>99% enantiomeric excess [ee]), (
R
)-α-(trifluoromethyl)benzyl alcohol (93% ee), (
S
)-α-tetralol (>99% ee), methyl (
R
)-(−)-mandelate (92% ee), and ethyl (
R
)-(−)-mandelate (95% ee), respectively, by way of an efficient in situ NADH-recycling system involving 2-propanol and a second thermophilic ADH. This study further supports the critical role of the D37 residue in discriminating NAD(H) from NADP(H) in members of the SDR superfamily.
WolbachiaInfection Alters Olfactory-Cued Locomotion inDrosophilaspp
Authors: Peng Yu , Nielsen John E. , Cunningham J. Paul , McGraw Elizabeth A. 
Published: May 2008

ABSTRACTWolbachia pipientisis an endosymbiotic bacterium present in diverse insect species. Although it is well studied for its dramatic effects on host reproductive biology, little is known about its effects on other aspects of host biology, despite its presence in a wide array of host tissues. This study examined the effects of threeWolbachiastrains on two differentDrosophilaspecies, using a laboratory performance assay for insect locomotion in response to olfactory cues. The results demonstrate thatWolbachiainfection can have significant effects on host responsiveness that vary with respect to theWolbachiastrain-host species combination. ThewRi strain, native toDrosophila simulans, increases the basal activity level of the host insect as well as its responsiveness to food cues. In contrast, thewMel strain and the virulentwMelPop strain, native toDrosophila melanogaster, cause slight decreases in responsiveness to food cues but do not alter basal activity levels in the host. Surprisingly, the virulentwMelPop strain has very little impact on host responsiveness inD. simulans. This novel strain-host relationship was artificially created previously by transinfection. These findings have implications for understanding the evolution and spread ofWolbachiainfections in wild populations and forWolbachia-based vector-borne disease control strategies currently being developed.
Identification of thel,d-Transpeptidases for Peptidoglycan Cross-Linking inEscherichia coli
Authors: Magnet Sophie , Dubost Lionel , Marie Arul , Arthur Michel , Gutmann Laurent 
Published: May 2008

ABSTRACTThree active-site cysteinel,d-transpeptidases can individually anchor the Braun lipoprotein to theEscherichia colipeptidoglycan. We show here that two additional enzymes of the same family form peptide bonds between the third residues of peptidoglycan stems, generatingmeso-DAP3→meso-DAP3unusual cross-links. This activity partially replaces thed,d-transpeptidase activity of penicillin-binding proteins.
Two-State Allosteric Modeling Suggests Protein Equilibrium as an Integral Component for Cyclic AMP (cAMP) Specificity in the cAMP Receptor Protein ofEscherichia coli
Authors: Youn Hwan , Koh Junseock , Roberts Gary P. 
Published: May 2008

ABSTRACTActivation of the cAMP receptor protein (CRP) fromEscherichia coliis highly specific to its allosteric ligand, cAMP. Ligands such as adenosine and cGMP, which are structurally similar to cAMP, fail to activate wild-type CRP. However, several cAMP-independent CRP variants (termed CRP*) exist that can be further activated by both adenosine and cGMP, as well as by cAMP. This has remained a puzzle because the substitutions in many of these CRP* variants lie far from the cAMP-binding pocket (>10 Å) and therefore should not directly affect that pocket. Here we show a surprising similarity in the altered ligand specificity of four CRP* variants with a single substitution in D53S, G141K, A144T, or L148K, and we propose a common basis for this phenomenon. The increased active protein population caused by an equilibrium shift in these variants is hypothesized to preferentially stabilize ligand binding. This explanation is completely consistent with the cAMP specificity in the activation of wild-type CRP. The model also predicts that wild-type CRP should be activated even by the lower-affinity ligand, adenosine, which we experimentally confirmed. The study demonstrates that protein equilibrium is an integral factor for ligand specificity in an allosteric protein, in addition to the direct effects of ligand pocket residues.
Model studies of socketed caissons in soft rock
Authors: Dykeman P , Valsangkar A J 
Published: May 2008

Results of centrifuge modelling of socketed caissons in a weak model rock made of cement, sand, bentonite, and water are presented. The model socketed caissons were made from aluminium tubing with a structural stiffness closely identical to a solid concrete pile. In the first series of tests, model sockets were tested in axial compression to determine the effect of socket roughness on side resistance. In the second series, model sockets were subjected to lateral loading. The experimental results are compared with existing design methods used to predict ultimate capacity and load deformation response. Data obtained from other model studies and full-scale tests are also presented and compared with the centrifuge modelling data. Key words: socketed caissons, centrifuge modelling, weak rock, lateral deformation, axial deformation.
Determination of bentonite content in soilbentonite liners by X-ray diffraction
Authors: Chapuis Robert P , Pouliot Gaston 
Published: May 2008

The full-scale hydraulic performance of a soilbentonite liner depends on the homogeneity of bentonite content in the mix; any prediction must consider the distribution function of the local bentonite content, mainly that of below average values. The degree of homogeneity in the field depends on the mixing method and the sand characteristics. Several techniques, such as double hydrometer tests, or methylene blue tests, can evaluate the bentonite content in a sample. They are not reliable when the sand varies in gradation and mineralogy. This led to the investigation of whether X-ray diffraction could determine the bentonite content in a soilbentonite sample and a method was developed. First, the mix must be thermally treated to eliminate the variation in diffraction intensities resulting from the variable hydration of the montmorillonite. Then, an internal standard must be used to control the X-ray absorption. This paper presents the preliminary calibration work, the different steps to follow for quantitative determination of the bentonite content, its accuracy, and its application to a special project where the usual methods were not reliable due to a large variability in sand properties. The parameters needed to calculate the bentonite content in a mix depend on the type of bentonite but not on the type of sand. The accuracy depends on the variability in mineralogical quality of the bentonite powder. For one project, it is shown that the in situ mixing technique produced highly variable local bentonite contents, and that the average content was higher in the lower half of the lift than in its upper half. Key words: liner, bentonite, control, permeability.
Genomic imprinting of IGF2 in marsupials is methylation dependent
Authors: Lawton Betty R , Carone Benjamin R , Obergfell Craig J , Ferreri Gianni C , Gondolphi Christina M , VandeBerg John L , Imumorin Ikhide , O'Neill Rachel J , O'Neill Michael J 
Published: May 2008

Abstract

Background-
Parent-specific methylation of specific CpG residues is critical to imprinting in eutherian mammals, but its importance to imprinting in marsupials and, thus, the evolutionary origins of the imprinting mechanism have been the subject of controversy. This has been particularly true for the imprinted Insulin-like Growth Factor II (IGF2), a key regulator of embryonic growth in vertebrates and a focal point of the selective forces leading to genomic imprinting. The presence of the essential imprinting effector, DNMT3L, in marsupial genomes and the demonstration of a differentially methylated region (DMR) in the retrotransposon-derived imprinted gene, PEG10, in tammar wallaby argue for a role for methylation in imprinting, but several studies have found no evidence of parent-specific methylation at other imprinted loci in marsupials.

Results-
We performed the most extensive search to date for allele-specific patterns of CpG methylation within CpG isochores or CpG enriched segments across a 22 kilobase region surrounding the IGF2 gene in the South American opossum Monodelphis domestica. We identified a previously unknown 5'-untranslated exon for opossum IGF2, which is flanked by sequences defining a putative neonatal promoter, a DMR and an active Matrix Attachment Region (MAR). Demethylation of this DMR in opossum neonatal fibroblasts results in abherrant biallelic expression of IGF2.

Conclusion-
The demonstration of a DMR and an active MAR in the 5' flank of opossum IGF2 mirrors the regulatory features of the 5' flank of Igf2 in mice. However, demethylation induced activation of the maternal allele of IGF2 in opossum differs from the demethylation induced repression of the paternal Igf2 allele in mice. While it can now be concluded that parent-specific DNA methylation is an epigentic mark common to Marsupialia and Eutheria, the molecular mechanisms of transcriptional silencing at imprinted loci have clearly evolved along independent trajectories.
Characterization of CD4+CD25+ natural regulatory T cells in the inflammatory infiltrate of human chronic periodontitis
Authors: Cardoso Cristina Ribeiro , Garlet Gustavo Pompermaier , Moreira Ana Paula , Júnior Wálter Martins , Rossi Marcos Antônio , Silva João Santana 
Published: May 2008

AbstractPeriodontitis is an infectious disease, where putative periodontopathogens trigger chronic inflammatory and immune responses against periodontal structures, in which an unbalanced host response is also determinant to the disease outcome. It is reasonable to assume that patient susceptibility to periodontal tissue destruction could be determined by the balance between the response against periodontopathogens and regulatory mechanisms of these events mediated by suppressive T cells. In the present study, we identified and characterized natural regulatory T cells (Tregs) in the inflammatory infiltrate of human chronic periodontitis (CP) with emphasis on phenotypic analyses that were carried out to address the participation of Tregs in CP. Results showed that patients with CP presented increased frequency of T lymphocytes and CD4+CD25+ T cells in the inflammatory infiltrate of gingival tissues. These cells exhibited the phenotypic markers of Tregs such as forkhead box p3 (Foxp3), CTLA-4, glucocorticoid-inducible TNFR, CD103, and CD45RO and seemed to be attracted to the inflammation site by the chemokines CCL17 and CCL22, as their expression and its receptor CCR4 were increased in CP patients. Moreover, besides the increased detection of Foxp3 mRNA, diseased tissues presented high expression of the regulatory cytokines IL-10 and TGF-β. In addition, the inflammatory infiltrate in CP biopsies was composed of CD25+Foxp3+ and CD25+TGF-β+ cells, thus corroborating the hypothesis of the involvement of Tregs in the pathogenesis of CP. Finally, these results indicate that Tregs are found in the chronic lesions and must be involved in the modulation of local immune response in CP patients.
Human recombinant heat shock protein 70 affects the maturation pathways of dendritic cells in vitro and has an in vivo adjuvant activity
Authors: Valentinis Barbara , Capobianco Annalisa , Esposito Francesca , Bianchi Alessandro , Rovere-Querini Patrizia , Manfredi Angelo A , Traversari Catia 
Published: May 2008

AbstractHeat shock proteins (HSPs) are potent inducers of an antigen-specific immunological response. A role of chaperon of immunogenic peptides and a direct effect on APC activation and function have been described. However, the signal transduction events involved in the activation of human APCs are poorly characterized. We investigated, using human monocyte-derived dendritic cells (DCs), the signal transduction pathways activated by a human recombinant HSP70 (r)HSP70 purified from eukaryotic cells. rHSP70 effectively induced a partial maturation of DCs in vitro and a significant increase in the titers of antigen-specific IgG when used as a vaccine adjuvant in vivo. rHSP70 did not desensitize human DCs to LPS stimulation and retained its adjuvant properties in C3H/HeJ mice, which are LPS-resistant as a result of a mutation in TLR-4, ruling out the potential interference of LPS contamination. Effects on DC maturation and in vivo functions correlate to the ability of rHSP70 to activate IκB-α/NF-κB and ERK1/2 pathways in human DCs. No activation of p38 was induced in the same experimental conditions. Our data suggest that the IκB-α/NF-κB pathway has a critical role in the partial maturation of DCs induced by rHSP70.
Terminator 2, Judgment Day
Authors: Footring Ralph 
Published: May 2008

Scientific Editor, British Journal of PsychiatryHow would you feel about a sequel to One Flew Over the Cuckoo's Nest, set in the present? I am writing about the next best thing: Terminator 2, subtitled Judgment Day, sequel to the 1984 film Terminator, both starring Arnold Schwarzenegger in the eponymous role. Terminator 2, reputedly the most expensive film ever made, was released last August. Guild, its distributor, expect the film (certificate 15) in the UK to gross £17 million and to be seen by 6 million people, with a similar audience when it is released on video.
The landladies of Fishponds
Authors: Arnott Stephen , Smith Jeanette 
Published: May 2008

Over the last four decades there has been a substantial reduction in the number of psychiatric hospital beds. Alternative residential facilities in the community have been developed. These include staffed hostels, group homes and supportive lodgings providing bed and breakfast. While hostels and group homes are often integrated with psychiatric services and run by experienced staff, this may not be the case with the small privately run homes. Anstee (1978, 1985) described two supportive lodging schemes and suggested that such facilities were particularly helpful for people with schizophrenia. However, there has been little further research in this area even though supportive lodgings may constitute a significant proportion of long-stay residential facilities. We know little about the landladies, their background, training, experience and particularly the rewards and frustrations of their work. The extent of psychiatric morbidity and the overall burden of care for these landladies is also unknown.The aim of the present study was to gather information about the carers, the residents and the level of care provided in these facilities.
A Human Estrogen Receptor (ER)α Mutation with Differential Responsiveness to Nonsteroidal Ligands: Novel Approaches for Studying Mechanism of ER Action
Authors: Paulmurugan Ramasamy , Tamrazi Anobel , Katzenellenbogen John A. , Katzenellenbogen Benita S. , Gambhir Sanjiv S. 
Published: May 2008

AbstractEstrogens, acting through the estrogen receptors (ERs), play crucial roles in regulating the function of reproductive and other systems under physiological and pathological conditions. ER activity in regulating target genes is modulated by the binding of both steroidal and synthetic nonsteroidal ligands, with ligand binding inducing ERs to adopt various conformations that control their interactions with transcriptional coregulators. Previously, we developed an intramolecular folding sensor with a mutant form of ERα (ERG521T) that proved to be essentially unresponsive to the endogenous ligand 17β-estradiol, yet responded very well to certain synthetic ligands. In this study, we have characterized this G521T-ER mutation in terms of the potency and efficacy of receptor response toward several steroidal and nonsteroidal ligands in two different ways: directly, by ligand effects on mutant ER conformation (by the split-luciferase complementation system), and indirectly, by ligand effects on mutant ER transactivation. Full-length G521T-ER shows no affinity for estradiol and does not activate an estrogen-responsive reporter gene. The synthetic pyrazole agonist ligand propyl-pyrazole-triol is approximately 100-fold more potent than estradiol in inducing intramolecular folding and reporter gene transactivation with the mutant ER, whereas both ligands have high potency on wild-type ER. This estradiol-unresponsive mutant ER can also specifically highlight the agonistic property of the selective ER modulator, 4-hydroxytamoxifen, by reporter gene transactivation, even in the presence of estradiol, and it can exert a dominant-negative effect on estrogen-stimulated wild-type ER. This system provides a model for ER-mutants that show differential ligand responsiveness to gene activation to gain insight into the phenomenon of hormone resistance observed in endocrine therapies of ER-positive breast cancers.
Variability in the encoding of spatial information by dancing bees
Authors: De Marco Rodrigo J. , Gurevitz Juan M. , Menzel Randolf 
Published: May 2008

SUMMARYA honeybee's waggle dance is an intriguing example of multisensory convergence, central processing and symbolic information transfer. It conveys to bees and human observers the position of a relatively small area at the endpoint of an average vector in a two-dimensional system of coordinates. This vector is often computed from a collection of waggle phases from the same or different dancers. The question remains, however, of how informative a small sample of waggle phases can be to the bees, and how the spatial information encoded in the dance is actually mapped to the followers' searches in the field. Certainly, it is the variability of a dancer's performance that initially defines the level of uncertainty that followers must cope with if they were to successfully decode information in the dance. Understanding how a dancer's behaviour is mapped to that of its followers initially relies on the analysis of both the accuracy and precision with which the dancer encodes spatial information in the dance. Here we describe within-individual variations in the encoding of the distance to and direction of a goal. We show that variations in the number of a dancer's wagging movements, a measure that correlates well with the distance to the goal, do not depend upon the dancer's travelled distance, meaning that there is a constant variance of wagging movements around the mean. We also show that the duration of the waggle phases and the angular dispersion and divergence of successive waggle phases co-vary with a dancer's orientation in space. Finally, using data from dances recorded through high-speed video techniques, we present the first analysis of the accuracy and precision with which an increasing number of waggle phases conveys spatial information to a human observer.
Electrocommunication signals in free swimming brown ghost knifefish, Apteronotus leptorhynchus
Authors: Hupé Ginette J. , Lewis John E. 
Published: May 2008

SUMMARY
Brown ghost knifefish, Apteronotus leptorhynchus, are a species of weakly electric fish that produce a continuous electric organ discharge (EOD)that is used in navigation, prey capture and communication. Stereotyped modulations of EOD frequency and amplitude are common in social situations and are thought to serve as communication signals. Of these modulations, the most commonly studied is the chirp. This study presents a quantitative analysis of chirp production in pairs of free-swimming, physically interacting male and female A. leptorhynchus. Under these conditions, we found that in addition to chirps, the fish commonly produce a second signal type, a type of frequency rise called abrupt frequency rises, AFRs. By quantifying the behaviours associated with signal production, we find that Type 2 chirps tend to be produced when the fish are apart, following periods of low aggression,whereas AFRs tend to be produced when the fish are aggressively attacking one another in close proximity. This study is the first to our knowledge that quantitatively describes both electrocommunication signalling and behavioural correlates on a subsecond time-scale in a wave-type weakly electric fish.