bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary Reliability and Validity of the Grandparent Version of the Grandparent Support Scale for Teenage Mothers (GSSTM-G)
Authors: Maposa Sithokozile , SmithBattle Lee
Published: April 2008

This study demonstrates the preliminary reliability and validity of the grandparent version of the Grandparent Support Scale for Teenage Mothers (GSSTM-G), a measure designed to assess grandparents' perceptions of triadic relationships that support or imperil the teen mother's care of her baby. Grandparents ( N = 61) who participated in this study were parents and parent surrogates of teen mothers who completed a teen version of the scale (GSSTM-T). Principal axis factoring with oblique rotation resulted in a reduction of the GSSTM-G scale from 19 to 14 items. A two-factor solution was supported by item factor loadings and conceptual clarity. The GSSTM-G factors revealed two different patterns of family relationships, Responsive Family Relationships (α = .82) and Adversarial Family Relationships (α = .81), that correlated with other measures. Construct validity and internal consistency support further exploration of the GSSTM-G as a measure of family relationships, as related to the care of the infant, from grandparents' perspectives.
Reconsideration of Continuum Thermomechanical Quantities in Atomic Scale Simulations
Authors: Webb Edmund B. , Zimmerman Jonathan A. , Seel Steven C.
Published: April 2008

As motivation builds to consider mechanics of nanometer scale objects, it is increasingly advantageous to implement models with finer resolution than standard continuum approaches. For such exercises to prove fruitful, these models must be able to quantify continuum thermomechanical quantities; furthermore, it may be necessary to do so on a sub-system level in order to assess gradients or distributions in a given property. Herein we review the calculation of stress, heat flux, and temperature in atomic scale numerical simulations such as the molecular dynamics method.
The Size Effect of Thin Films on the Peierls Stress of Edge Dislocations
Authors: Lee Chin-Long , Shaofan Li
Published: April 2008

In this paper, we have developed a half-space Peierls—Nabarro (HSPN) model to evaluate dislocation mobility on material surface. The free-surface induced size effect on the mobility of an edge dislocation in thin films is investigated by using the model. The thickness of the thin layer between the dislocation and the free surface significantly influences the mobility of the dislocation. The Peierls stress of the edge dislocation in a thin film may be expressed as a function of the thickness of the thin film. A closed-form solution is obtained for the scaling factor, defined as the ratio of the modified Peierls stress to the conventional one in bulk materials, which allows for the characterization of the size (depth) effect on the Peierls stress of the edge dislocation in the half-space. Depending on the core size of the dislocation, the Peierls stress of a surface edge dislocation is about 5% to 25% less than that found in bulk materials.
Income Tax Preferences for the Elderly
Authors: Conway Karen Smith , Rork Jonathan C.
Published: April 2008

This research investigates the evolution of federal and state income tax preferences for the elderly during the past twenty-five years. Documenting how various types of income tax preferences have changed reveals that state tax policies are not simply mimicking federal tax law. It also shows a divergence in how the different types of state preferences have evolved. The authors explore two explanations for these patterns: the political power of the elderly and state tax competition. They construct a summary measure using representative household profiles created from the Current Population Survey and the TAXSIM calculator for 1977 to 2002. Several patterns emerge that are consistent with both explanations, but data limitations make it difficult to obtain definitive results. The most salient finding is that a proportionately large elderly population is associated with less generous tax preferences for the elderly, which is consistent with a ``program cost'' rather than ``preference'' effect of an aging population.
Policing the crisis revisited: The state, masculinity, fear of crime and racism
Authors: Jefferson Tony
Published: April 2008

E. P. Thompson once said, I forget where, that the most difficult part of writing was the opening sentence since that set the tone, or the `voice', for the whole piece. I think of his words almost every time I start a new piece, reminding myself that a morning spent playing with openings is not wasted, although it may feel so at the time. The problem of a starting point seems even more difficult when being asked to revisit something (co)written over 30 years ago, a time that has seen enormous changes in the theoretical landscape, in the state of the world, and, inevitably, in my own personal life. Given all this, I feel that the best I can manage is to tell the story, heavily edited of course and with the broadest of broad brushes, of how it was then and of how (with appropriate nods to serendipity, contingency and chance) I got from there to here. This will entail sticking with those elements of my work — namely, policing, masculinity, fear of crime and racism — that most resonate with the themes of Policing the Crisis ( PTC) (Hall et al., 1978).
Partners in crime
Authors: Jones Stephen
Published: April 2008

Criminologists have paid relatively little attention to the relationships between male and female co-offenders. Most of the published research has been published in the USA and relates to the street-level drugs economy. In this project, 50 sentenced adult women were interviewed in an English prison about their criminal involvement with co-defendants. The picture that emerged revealed the widespread use of devices by males ranging from various forms of manipulation to direct physical coercion in order to ensure female compliance with their criminal activities. These findings stand in contrast to statements in some of the more recent literature, which seek to emphasize women's agency in their offending behaviour. The implications of these findings for the criminal liability and sentencing of women are discussed.
Police effectiveness and police trustworthiness in Ghana: An empirical appraisal
Authors: Tankebe Justice
Published: April 2008

Although police researchers have often assumed that perceptions of police effectiveness enhance police legitimacy, there has been very little empirical support for this assumption. Employing the legitimacy scale developed by Sunshine and Tyler, this study sought to fill this gap in our criminological knowledge using data from a representative public survey in Accra, Ghana ( N= 374). The article reports a lack of reliability, in the Ghanaian context, for the overall Sunshine—Tyler scale, and therefore focuses attention on a sub-scale labelled `perceptions of police trustworthiness'. The findings show that though perceptions of police effectiveness exercise a direct impact on perceived police trustworthiness, the relationship is stronger if the police are also perceived to be procedurally fair. The findings are significant as they show that building public trust in the police requires democratic reforms that simultaneously improve the capacity of the police to achieve both substantive effectiveness and procedural fairness.
Neutrophil stress and apoptosis underlie myeloid dysfunction in glycogen storage disease type Ib
Authors: Kim So Youn , Jun Hyun Sik , Mead Paul A. , Mansfield Brian C. , Chou Janice Y.
Published: April 2008

Glycogen storage disease type Ib (GSD-Ib) is caused by a deficiency in the glucose-6-phosphate (G6P) transporter (G6PT) that works with a liver/kidney/intestine–restricted glucose-6-phosphatase-α (G6Pase-α) to maintain glucose homeostasis between meals. Clinically, GSD-Ib patients manifest disturbed glucose homeostasis and neutrophil dysfunctions but the cause of the latter is unclear. Neutrophils express the ubiquitously expressed G6PT and G6Pase-β that together transport G6P into the endoplasmic reticulum (ER) lumen and hydrolyze it to glucose. Because we expected G6PT-deficient neutrophils to be unable to produce endogenous glucose, we hypothesized this would lead to ER stress and increased apoptosis. Using GSD-Ib mice, we showed that GSD-Ib neutrophils exhibited increased production of ER chaperones and oxidative stress, consistent with ER stress, increased annexin V binding and caspase-3 activation, consistent with an increased rate of apoptosis. Bax activation, mitochondrial release of proapoptotic effectors, and caspase-9 activation demonstrated the involvement of the intrinsic mitochondrial pathway in these processes. The results demonstrate that G6P translocation and hydrolysis are required for normal neutrophil functions and support the hypothesis that neutrophil dysfunction in GSD-Ib is due, at least in part, to ER stress and increased apoptosis.
Reliable identification of mycobacterial species by PCR-restriction enzyme analysis (PRA)-hsp65 in a reference laboratory and elaboration of a sequence-based extended algorithm of PRA-hsp65patterns
Authors: Chimara Erica , Ferrazoli Lucilaine , Ueky Suely Yoko Misuka , Martins Maria Conceição , Durham Alan Mitchel , Arbeit Robert D , Leão Sylvia Cardoso
Published: April 2008

Background

Identification of nontuberculous mycobacteria (NTM) based on phenotypic tests is time-consuming, labor-intensive, expensive and often provides erroneous or inconclusive results. In the molecular method referred to as PRA-hsp65, a fragment of the hsp65 gene is amplified by PCR and then analyzed by restriction digest; this rapid approach offers the promise of accurate, cost-effective species identification. The aim of this study was to determine whether species identification of NTM using PRA-hsp65 is sufficiently reliable to serve as the routine methodology in a reference laboratory.

Results

A total of 434 NTM isolates were obtained from 5019 cultures submitted to the Institute Adolpho Lutz, Sao Paulo Brazil, between January 2000 and January 2001. Species identification was performed for all isolates using conventional phenotypic methods and PRA-hsp65. For isolates for which these methods gave discordant results, definitive species identification was obtained by sequencing a 441 bp fragment of hsp65. Phenotypic evaluation and PRA-hsp65 were concordant for 321 (74%) isolates. These assignments were presumed to be correct. For the remaining 113 discordant isolates, definitive identification was based on sequencing a 441 bp fragment of hsp65. PRA-hsp65 identified 30 isolates with hsp65 alleles representing 13 previously unreported PRA-hsp65 patterns. Overall, species identification by PRA-hsp65 was significantly more accurate than by phenotype methods (392 (90.3%) vs. 338 (77.9%), respectively; p < .0001, Fisher's test). Among the 333 isolates representing the most common pathogenic species, PRA-hsp65 provided an incorrect result for only 1.2%.

Conclusion

PRA-hsp65 is a rapid and highly reliable method and deserves consideration by any clinical microbiology laboratory charged with performing species identification of NTM.
The influence of in vitro fitness defects on pneumococcal ability to colonize and to cause invasive disease
Authors: Fernebro Jenny , Blomberg Christel , Morfeldt Eva , Wolf-Watz Hans , Normark Staffan , Normark Birgitta Henriques
Published: April 2008

Background

Streptococcus pneumoniaeis a genetically diverse major human pathogen, yet a common colonizer of the nasopharynx. Here we analyzed the influence of defects affectingin vitrogrowth rate, on the ability ofS. pneumoniaeto colonize and to cause invasive diseasein vivo.

Results

Of eleven different clinical isolates one serotype 14 carrier isolate showed a significantly longer generation time as compared to other isolates, and was severely attenuated in mice. To directly investigate the impact of growth rate on virulence, a panel of mutants in five non-essential housekeeping genes was constructed in the virulent TIGR4 background by insertion-deletion mutagenesis. Three of these mutants (ychF,hemKandyebC) were, to different degrees, growth defective, and showed a reduced invasiveness in an intranasal murine challenge model that correlated to theirin vitrogrowth rate, but remained capable of colonizing the upper airways. The growth defect, as well as virulence defect of thehemKinsertion-deletion mutant, was mediated by polarity effects on the downstreamyrdCgene, encoding a probable chaperone in ribosome assembly.

Conclusion

We conclude that large fitness defects are needed to completely prevent pneumococci from causing invasive disease after intranasal challenge. However, even severe growth defects still allow pneumococci to persistently colonize the upper airways.
The IBR5 phosphatase promotes Arabidopsis auxin responses through a novel mechanism distinct from TIR1-mediated repressor degradation
Authors: Strader Lucia C , Monroe-Augustus Melanie , Bartel Bonnie
Published: April 2008

Background

In Arabidopsis, INDOLE-3-BUTYRIC ACID RESPONSE5 (IBR5), a putative dual-specificity protein phosphatase, is a positive regulator of auxin response. Mutations in IBR5 result in decreased plant height, defective vascular development, increased leaf serration, fewer lateral roots, and resistance to the phytohormones auxin and abscisic acid. However, the pathways through which IBR5 influences auxin responses are not fully understood.

Results

We analyzed double mutants of ibr5 with other mutants that dampen auxin responses and found that combining ibr5 with an auxin receptor mutant, tir1, enhanced auxin resistance relative to either parent. Like other auxin-response mutants, auxin-responsive reporter accumulation was reduced in ibr5. Unlike other auxin-resistant mutants, the Aux/IAA repressor reporter protein AXR3NT-GUS was not stabilized in ibr5. Similarly, the Aux/IAA repressor IAA28 was less abundant in ibr5 than in wild type. ibr5 defects were not fully rescued by overexpression of a mutant form of IBR5 lacking the catalytic cysteine residue.

Conclusion

Our genetic and molecular evidence suggests that IBR5 is a phosphatase that promotes auxin responses, including auxin-inducible transcription, differently than the TIR1 auxin receptor and without destabilizing Aux/IAA repressor proteins. Our data are consistent with the possibility that auxin-responsive transcription can be modulated downstream of TIR1-mediated repressor degradation.
Overexpression of mtDNA-associated AtWhy2 compromises mitochondrial function
Authors: Maréchal Alexandre , Parent Jean-Sébastien , Sabar Mohammed , Véronneau-Lafortune Félix , Abou-Rached Charbel , Brisson Normand
Published: April 2008

Background

StWhy1, a member of the plant-specific Whirly single-stranded DNA-binding protein family, was first characterized as a transcription factor involved in the activation of the nuclear PR-10a gene following defense-related stress in potato. In Arabidopsis thaliana, Whirlies have recently been shown to be primarily localized in organelles. Two representatives of the family, AtWhy1 and AtWhy3 are imported into plastids while AtWhy2 localizes to mitochondria. Their function in organelles is currently unknown.

Results

To understand the role of mitochondrial Whirlies in higher plants, we produced A. thaliana lines with altered expression of the atwhy2 gene. Organellar DNA immunoprecipitation experiments demonstrated that AtWhy2 binds to mitochondrial DNA. Overexpression of atwhy2 in plants perturbs mitochondrial function by causing a diminution in transcript levels and mtDNA content which translates into a low activity level of respiratory chain complexes containing mtDNA-encoded subunits. This lowered activity of mitochondria yielded plants that were reduced in size and had distorted leaves that exhibited accelerated senescence. Overexpression of atwhy2 also led to early accumulation of senescence marker transcripts in mature leaves. Inactivation of the atwhy2 gene did not affect plant development and had no detectable effect on mitochondrial morphology, activity of respiratory chain complexes, transcription or the amount of mtDNA present. This lack of phenotype upon abrogation of atwhy2 expression suggests the presence of functional homologues of the Whirlies or the activation of compensating mechanisms in mitochondria.

Conclusion

AtWhy2 is associated with mtDNA and its overexpression results in the production of dysfunctional mitochondria. This report constitutes the first evidence of a function for the Whirlies in organelles. We propose that they could play a role in the regulation of the gene expression machinery of organelles.
Implication of Xenobiotic Metabolizing Enzyme gene (CYP2E1, CYP2C19, CYP2D6, mEH and NAT2) Polymorphisms in Breast Carcinoma
Authors: Khedhaier Achraf , Hassen Elham , Bouaouina Noureddine , Gabbouj Sallouha , Ahmed Slim Ben , Chouchane Lotfi
Published: April 2008

Background

Xenobiotic Metabolizing Enzymes (XMEs) contribute to the detoxification of numerous cancer therapy-induced products. This study investigated the susceptibility and prognostic implications of the CYP2E1, CYP2C19, CYP2D6, mEH and NAT2 gene polymorphisms in breast carcinoma patients.

Methods

The authors used polymerase chain reaction and restriction enzyme digestion to characterize the variation of the CYP2E1, CYP2C19, CYP2D6, mEH and NAT2 gene in a total of 560 unrelated subjects (246 controls and 314 patients).

Results

The mEH (C/C) mutant and the NAT2 slow acetylator genotypes were significantly associated with breast carcinoma risk (p = 0.02; p = 0.01, respectively). For NAT2 the association was more pronounced among postmenopausal patients (p = 0.006). A significant association was found between CYP2D6 (G/G) wild type and breast carcinoma risk only in postmenopausal patients (p = 0.04). Association studies of genetic markers with the rates of breast carcinoma specific overall survival (OVS) and the disease-free survival (DFS) revealed among all breast carcinoma patients no association to DFS but significant differences in OVS only with the mEH gene polymorphisms (p = 0.02). In addition, the mEH wild genotype showed a significant association with decreased OVS in patients with axillary lymph node-negative patients (p = 0.03) and with decreasesd DFS in patients with axillary lymph node-positive patients (p = 0.001). However, the NAT2 intermediate acetylator genotype was associated with decreased DFS in axillary lymph node-negative patients.

Conclusion

The present study may prove that polymorphisms of some XME genes may predict the onset of breast carcinoma as well as survival after treatment.
Selective Activation of Microglia in Spinal Cord but Not Higher Cortical Regions Following Nerve Injury in Adult Mouse
Authors: Zhang Fuxing , Vadakkan Kujumon I , Kim Susan S , Wu Long-Jun , Shang Yuze , Zhuo Min
Published: April 2008

Neuronal plasticity along the pathway for sensory transmission including the spinal cord and cortex plays an important role in chronic pain, including inflammatory and neuropathic pain. While recent studies indicate that microglia in the spinal cord are involved in neuropathic pain, a systematic study has not been performed in other regions of the central nervous system (CNS). In the present study, we used heterozygous Cx3cr1 GFP+ mice to characterize the morphological phenotypes of microglia following common peroneal nerve (CPN) ligation. We found that microglia showed a uniform distribution throughout the CNS, and peripheral nerve injury selectively activated microglia in the spinal cord dorsal horn and related ventral horn. In contrast, microglia was not activated in supraspinal regions of the CNS, including the anterior cingulate cortex (ACC), prefrontal cortex (PFC), primary and secondary somatosensory cortex (S1 and S2), insular cortex (IC), amygdala, hippocampus, periaqueductal gray (PAG) and rostral ventromedial medulla (RVM). Our results provide strong evidence that nerve injury primarily activates microglia in the spinal cord of adult mice, and pain-related cortical plasticity is likely mediated by neurons.
Survival time in severe hemorrhagic shock after perioperative hemodilution is longer with PEG-conjugated human serum albumin than with HES 130/0.4: a microvascular perspective
Authors: Martini Judith , Cabrales Pedro , K Ananda , Acharya Seetharama A , Intaglietta Marcos , Tsai Amy G
Published: April 2008

Introduction

Preoperative hemodilution is an established practice that is applied to reduce surgical blood loss. It has been proposed that polyethylene glycol (PEG) surface decorated proteins such as PEG-conjugated human serum albumin may be used as non-oxygen-carrying plasma expanders. The purpose of this study was to determine whether there is any difference in survival time after severe hemorrhagic shock following extreme hemodilution using a conventional hydroxyethyl starch (HES)-based plasma expander or PEG-albumin.

Methods

Experiments were performed using the hamster skinfold window preparation. Human serum albumin that was surface decorated with PEG was compared with Voluven 6% (Fresenius Kabi, Austria; a starch solution that is of low molecular weight and has a low degree of substitution; HES). These plasma expanders were used for a 50% (blood volume) exchange transfusion to simulate preoperative hemodilution. Exchange transfusion was followed by a 60% (blood volume) hemorrhage to reproduce a severe surgical bleed over a 1 hour period. Observation of the animal was continued for another hour during the shock phase.

Results

The PEG-albumin group exhibited significantly greater survival rate than did the HES group, in which none of the animals survived the hemorrhage phase of the experiment. Among the treatment groups there were no changes in mean arterial pressure and heart rate from baseline after hemodilution. Both groups experienced gradual increases in arterial oxygen tension and disturbance in acid-base balance, but this response was more pronounced in the HES group during the shock period. Mean arterial pressure remained elevated after the initial hemorrhage period in the PEG-albumin group but not in the HES group. Maintenance of a greater mean arterial pressure during the initial stages of hemorrhage is proposed to be in part due to the improved volume expansion with PEG-albumin, as indicated by the significant decrease in systemic hematocrit compared with the HES group. PEG-albumin treatment yielded higher functional capillary density during the initial stages of hemorrhage as compared with HES treatment.

Conclusion

The ability of PEG-albumin to prolong maintenance of microvascular function better than HES is a finding that would be significant in a clinical setting involving preoperative blood management and extreme blood loss.
Combined simulation and inversion of SP and resistivity logs for the estimation of connate-water resistivity and Archie’s cementation exponent
Authors: Salazar Jesús M. , Li Wang Gong , Torres-Verdín Carlos , Jae Lee Hee
Published: April 2008

Knowledge of initial water saturation is necessary to estimate original hydrocarbon in place. A reliable assessment of this petrophysical property is possible when rock-core measurements of Archie’s parameters, such as saturation exponent [Formula: see text] and cementation exponent [Formula: see text], are available. In addition, chemical analysis of formation water is necessary to measure connate-water resistivity [Formula: see text]. Such measurements are seldom available in most applications; if they are available, their reliability may be questionable. We describe a new inversion method to estimate [Formula: see text] and Archie’s cementation exponent from the combined use of borehole spontaneous-potential (SP) and raw array-induction resistivity measurements acquired in water-bearing depth intervals. Combined inversion of resistivity and SP measurements is performed assuming a piston-like invasion profile. In so doing, the reservoiris divided into petrophysical layers to account for vertical heterogeneities. Inversion products are values of invaded and virgin formation resistivity, radius of invasion, and static spontaneous potential (SSP). Connate-water resistivity is calculated by assuming membrane and diffusion potentials as the main contributors to the SSP. Archie’s or dual-water equations enable the estimation of [Formula: see text]. The new combined estimation method has been successfully applied to a data set acquired in a clastic formation. Data were acquired in a high permeability and moderately high-salt-concentration reservoir. Values of [Formula: see text] and [Formula: see text] yielded by the inversion are consistent with those obtained with a traditional interpretation method, thereby confirming the reliability of the estimation. The method is an efficient, rigorous alternative to conventional interpretation techniques for performing petrophysical analysis of exploratory and appraisal wells wherein rock-core measurements may not be available.
Estradiol-Induced Synaptic Remodeling of Tyrosine Hydroxylase Immunopositive Neurons in the Rat Arcuate Nucleus
Authors: Csakvari Eszter , Kurunczi Anita , Hoyk Zsofia , Gyenes Andrea , Naftolin Frederick , Parducz Arpad
Published: April 2008

Gonadal steroids induce synaptic plasticity in several areas of the adult nervous system. In the arcuate nucleus of adult female rats, 17β-estradiol triggers synaptic remodeling, resulting in a decrease in the number of inhibitory synaptic inputs, an increase in the number of excitatory synapses, and an enhancement of the frequency of neuronal firing. In the present paper, we studied the specificity of hormonal effects by determining the changes in synaptic connectivity of tyrosine hydroxylase (TH) immunoreactive (IR) neurons in the arcuate nucleus. We combined pre-embedding TH and post-embedding γ-aminobutyric acid (GABA) immunostaining, and performed unbiased stereological measurements in gonadectomized and 17β-estradiol-treated rats. We conclude that the synaptic connectivity of the TH-IR neurons is different from the other, nonlabeled population, and the response to estradiol is not uniform. TH-IR (dopaminergic) arcuate neurons of both male and female rats have more GABAergic (inhibitory) axosomatic inputs than the nondopaminergic population. Our study shows that the effect of 17β-estradiol is sex and cell specific in the sense that not all arcuate neurons are affected by the structural synaptic remodeling. In ovariectomized females hormone treatment decreased the numerical density of GABAergic axosomatic synapses on TH-IR, but not on nondopaminergic, neurons, whereas in orchidectomized males, 17β-estradiol treatment increased inhibitory synapses onto nondopaminergic neurons but did not affect the number of inhibitory terminals onto TH-IR neurons. The hormone-induced plastic changes in synaptic connectivity of TH-IR neurons may serve as the morphological basis for the cyclical regulation of the anterior pituitary.
Characterization of Nuclear Import of the Domain-Specific Androgen Receptor in Association with the Importin α/β and Ran-Guanosine 5′-Triphosphate Systems
Authors: Kaku Natsuko , Matsuda Ken-ichi , Tsujimura Atsushi , Kawata Mitsuhiro
Published: April 2008

Androgen induces androgen receptor (AR) nuclear import, which allows AR to act as a transcriptional factor and ultimately leads to biological activity. However, the mechanism of AR translocation to the nucleus is still unclear. In the present study, we assessed the nuclear import abilities of each domain of AR and their mechanisms related to Ran and importin α/β using green fluorescent protein real-time imaging. The localization of AR to the nucleus in the absence and presence of ligands was dependent upon a complex interplay of the amino terminal transactivation domain (NTD), the DNA binding domain (DBD), and the ligand binding domain (LBD). NTD and DBD showed ligand-independent nuclear import ability, whereas LBD had ligand-dependent transport. In addition, AR deletion mutant lacking DBD was distributed in the cytoplasm regardless of ligand existence, suggesting that the remaining domains, NTD and LBD, are responsible for AR cytoplasmic localization. Cotransfection with a dominant negative form of Ran dramatically inhibited the nuclear import of all AR domains, and a dominant negative form of importin α prevented AR and DBD import. Importin β-knockdown strongly blocked DBD import. These results indicate that there are two additional nuclear localization signals (NLSs) in the NTD and LBD, and there are distinct pathways used to attain domain-specific AR nuclear import: the NLS of DBD is Ran and importin α/β-dependent, whereas the NLSs of NTD and LBD are Ran dependent but importin α/β-independent. Our data suggest that the nuclear import of AR is regulated by the interplay between each domain of the AR.
Notch Inhibits Osteoblast Differentiation and Causes Osteopenia
Authors: Zanotti Stefano , Smerdel-Ramoya Anna , Stadmeyer Lisa , Durant Deena , Radtke Freddy , Canalis Ernesto
Published: April 2008

Notch receptors are determinants of cell fate decisions. To define the role of Notch in the adult skeleton, we created transgenic mice overexpressing the Notch intracellular domain (NICD) under the control of the type I collagen promoter. First-generation transgenics were small and osteopenic. Bone histomorphometry revealed that NICD caused a decrease in bone volume, secondary to a reduction in trabecular number; osteoblast and osteoclast number were decreased. Low fertility of founder mice and lethality of young pups did not allow the complete establishment of transgenic lines. To characterize the effect of Notch overexpression in vitro, NICD was induced in osteoblasts and stromal cells from Rosanotch mice, in which a STOP cassette flanked by loxP sites is upstream of NICD, by transduction with an adenoviral vector expressing Cre recombinase (Cre) under the control of the cytomegalovirus (CMV) promoter (Ad-CMV-Cre). NICD impaired osteoblastogenesis and inhibited Wnt/β-catenin signaling. To determine the effects of notch1 deletion in vivo, mice in which notch1 was flanked by loxP sequences (notch1loxP/loxP) were mated with mice expressing Cre recombinase under the control of the osteocalcin promoter. Conditional null notch1 mice had no obvious skeletal phenotype, possibly because of rescue by notch2; however, 1-month-old females exhibited a modest increase in osteoclast surface and eroded surface. Osteoblasts from notch1loxP/loxP mice, transduced with Ad-CMV-Cre and transfected with Notch2 small interfering RNA, displayed increased alkaline phosphatase activity. In conclusion, Notch signaling in osteoblasts causes osteopenia and impairs osteo-blastogenesis by inhibiting the Wnt/β-catenin pathway.
The influence of ontogeny and light environment on the expression of visual pigment opsins in the retina of the black bream,Acanthopagrus butcheri
Authors: Shand Julia , Davies Wayne L. , Thomas Nicole , Balmer Lois , Cowing Jill A. , Pointer Marie , Carvalho Livia S. , Trezise Ann E. O. , Collin Shaun P. , Beazley Lyn D. , Hunt David M.
Published: April 2008

The correlation between ontogenetic changes in the spectral absorption characteristics of retinal photoreceptors and expression of visual pigment opsins was investigated in the black bream, Acanthopagrus butcheri. To establish whether the spectral qualities of environmental light affected the complement of visual pigments during ontogeny, comparisons were made between fishes reared in: (1) broad spectrum aquarium conditions; (2) short wavelength-reduced conditions similar to the natural environment; or (3) the natural environment (wild-caught). Microspectrophotometry was used to determine the wavelengths of spectral sensitivity of the photoreceptors at four developmental stages: larval, post-settlement, juvenile and adult. The molecular sequences of the rod (Rh1) and six cone (SWS1, SWS2A and B, Rh2Aα and β, and LWS) opsins were obtained and their expression levels in larval and adult stages examined using quantitative RT-PCR. The changes in spectral sensitivity of the cones were related to the differing levels of opsin expression during ontogeny. During the larval stage the predominantly expressed opsin classes were SWS1, SWS2B and Rh2Aα, contrasting with SWS2A, Rh2Aβ and LWS in the adult. An increased proportion of long wavelength-sensitive double cones was found in fishes reared in the short wavelength-reduced conditions and in wild-caught animals, indicating that the expression of cone opsin genes is also regulated by environmental light.
Sugars are complementary resources to ethanol in foods consumed by Egyptian fruit bats
Authors: Sánchez Francisco , Kotler Burt P. , Korine Carmi , Pinshow Berry
Published: April 2008

Food resources are complementary for a forager if their contribution to fitness is higher when consumed together than when consumed independently,e.g. ingesting one may reduce the toxic effects of another. The concentration of potentially toxic ethanol, [EtOH], in fleshy fruit increases during ripening and affects food choices by Egyptian fruit bats, becoming deterrent at high concentrations (⩾1%). However, ethanol toxicity is apparently reduced when ingested along with some sugars; more with fructose than with sucrose or glucose. We predicted (1) that ingested ethanol is eliminated faster by bats eating fructose than by bats eating sucrose or glucose, (2)that the marginal value of fructose-containing food (food+fructose) increases with increasing [EtOH] more than the marginal value of sucrose- or glucose-containing food (food+sucrose, food+glucose), and (3) that by increasing [EtOH] the marginal value of food+sucose is incremented more than that of food+glucose. Ethanol in bat breath declined faster after they ate fructose than after eating sucrose or glucose. When food [EtOH] increased, the marginal value of food+fructose increased relative to food+glucose. However,the marginal value of food+sucrose increased with increasing [EtOH] more than food+fructose or food+glucose. Although fructose enhanced the rate at which ethanol declined in Egyptian fruit bat breath more than the other sugars, the bats treated both fructose and sucrose as complementary to ethanol. This suggests that in the wild, the amount of ethanol-containing fruit consumed or rejected by Egyptian fruit bats may be related to the fruit's own sugar content and composition, and/or the near-by availability of other sucrose- and fructose-containing fruits.
Effects of maternal carotenoid availability in relation to sex, parasite infection and health status of nestling kestrels (Falco tinnunculus)
Authors: De Neve Liesbeth , Fargallo Juan A. , Vergara Pablo , Lemus Jesús A. , Jarén-Galán Manuel , Luaces Inés
Published: April 2008

Mothers can strongly influence the development of their offspring, and if maternal resources are limited, they may influence optimal reproductive strategies. In birds, maternally deposited carotenoids are a prominent component of egg yolk and are vital for the development of the embryo. However, results of long-lasting fitness consequences of this early nutritional environment have been scarce and inconsistent. In addition,sex-biased sensitivity to different egg components is one of the mechanisms postulated to account for sex-linked environmental vulnerability during early life. However, this important aspect is usually not accounted for when investigating maternal investment in carotenoids. In this study we gave carotenoid (lutein) supplements to female Eurasian kestrels (Falco tinnunculus) before and during egg laying. The experiment increased female plasma carotenoids, but this effect was not apparent in hatchling and fledgling plasma carotenoid concentration. Also, results showed that carotenoid supplementation increased the high density lipoprotein to low density lipoprotein ratio in adult females, suggesting that dietary carotenoids may influence lipid metabolism. Furthermore, the effect of the treatment was manifested in several nestling health state parameters. Nestlings of carotenoid-supplemented females were infested by less intestinal parasite groups, had higher lymphocyte concentrations in blood plasma, and were less stressed (heterophile to lymphocyte ratio) than control nestlings. In addition, an interaction between the experimental treatment and nestling sex was apparent for globulin concentrations, favouring the smaller male nestlings. Thereby, suggesting that males benefited more than females from an increase in maternal carotenoid investment. Our study shows that an increase in carotenoids in the maternal diet during egg laying favours nestling development in kestrels, and may also affect nestlings in a sex-specific way.
Comparative sequence analysis of myosin heavy chain proteins from congeneric shallow- and deep-living rattail fish (genus Coryphaenoides)
Authors: Morita Takami
Published: April 2008

The evolutionary adaptations of functional genes to life at high pressure are not well understood. To elucidate the mechanisms of protein adaptation to high pressure, we cloned the myosin heavy chain (MyHC) cDNA from skeletal muscle of two deep-sea fishes, Coryphaenoides yaquinae and C. armatus, and two non-deep-sea fishes, C. acrolepis and C. cinereus. The MyHCs of deep-sea fishes have a unique structure in two loop regions, loop-1 and loop-2, in comparison with those of non-deep-sea fishes. The loop-1 region of deep-sea fishes has a Pro residue and the loop-2 region, which is an actin-binding site, is shorter than the same region in non-deep-sea fishes. The amino acid substitution in the loop-1 region is expected to be mainly involved in ATPase activity, whereas the deletion in the loop-2 region affects the association of MyHC with actin filaments at high pressure. In addition, the MyHC of deep-sea fishes has biased amino acid substitutions at core positions in the coiled-coil structure of the rod region. These amino acid substitutions are likely to decrease the cavities in the coiled-coil structure and consequently make the structure more compact and unaffected by high pressure. Together, these results indicate that amino acid substitutions can adaptively alter the pressure sensitivity of a protein even if they do not directly influence core structure.
Dual Sales Channel Management with Service Competition
Authors: Chen Kay-Yut , Kaya Murat , Özer Özalp
Published: April 2008

We study a manufacturer's problem of managing his direct online sales channel together with an independently owned bricks-and-mortar retail channel, when the channels compete in service. We incorporate a detailed consumer channel choice model in which the demand faced in each channel depends on the service levels of both channels as well as the consumers' valuation of the product and shopping experience. The direct channel's service is measured by the delivery lead time for the product; the retail channel's service is measured by product availability. We identify optimal dual channel strategies that depend on the channel environment described by factors such as the cost of managing a direct channel, retailer inconvenience, and some product characteristics. We also determine when the manufacturer should establish a direct channel or a retail channel if he is already selling through one of these channels. Finally, we conduct a sequence of controlled experiments with human subjects to investigate whether our model makes reasonable predictions of human behavior. We determine that the model accurately predicts the direction of changes in the subjects' decisions, as well as their channel strategies in response to the changes in the channel environment. These observations suggest that the model can be used in designing channel strategies for an actual dual channel environment.1
Coming Forward: The Effects of Social and Regulatory Forces on the Voluntary Restatement of Earnings Subsequent to Wrongdoing
Authors: Pfarrer Michael D. , Smith Ken G. , Bartol Kathryn M. , Khanin Dmitry M. , Zhang Xiaomeng
Published: April 2008

We investigate the effects of social and regulatory forces on a firm's decision to disclose past wrongdoing by voluntarily restating its earnings. With an eight-year sample of more than 2,500 public firms, including 170 voluntary restaters, we find that firms are more likely to voluntarily restate their earnings in response to informal social pressures from other firms in their industry and less likely to do so in response to formal regulatory sanctions. We also show that the impact of these forces varies with firm status. We contribute to corporate governance and public policy research that examines the effectiveness of “hard” versus “soft” deterrence measures on firm compliance.
A Significant Reduction in Paediatric Post-Tonsillectomy Vomiting through Audit
Authors: Bennett AMD , Emery PJ
Published: April 2008

INTRODUCTION

Postoperative vomiting occurs more frequently after tonsillectomy than any other commonly performed paediatric operation. Postoperative vomiting is also the commonest cause of morbidity and re-admission following tonsillectomy. We present a successful completed audit cycle and literature review on the subject.

PATIENTS AND METHODS

Data on the risk factors for postoperative vomiting, whether the patient vomited and details of the patient's vomitus were collected prospectively on consecutive patients and compared with a gold standard. Changes in practice were agreed and a second cycle performed.

RESULTS

Two cycles and a total of 107 patients were included in the audit. A significant reduction in vomiting from 27% to 11% was achieved following the introduction of routine use of intravenous dexamethasone during surgery.

CONCLUSIONS

This simple prospective audit of paediatric post-tonsillectomy vomiting has resulted in a statistically significant reduction in vomiting which would appear to be due to use of intra-operative steroids.
Injury to the Lateral Femoral Cutaneous Nerve During Minimally Invasive Hip Surgery: A Cadaver Study
Authors: Jameson Simon S , Howcroft Daniel WJ , McCaskie Andrew W , Gerrand Craig H
Published: April 2008

INTRODUCTION

A smaller skin incision as part of minimally invasive surgery (MIS) for total hip arthroplasty (THA) is thought to reduce local tissue trauma. Preservation of cutaneous nerves may reduce postoperative pain and improve rehabilitation. The standard lateral approach (SLA) and two MIS approaches (anterolateral [ALA] and posterior [PA]) were compared to determine which incision preserved cutaneous nerves.

PATIENTS AND METHODS

Fifteen cadaveric hip specimens were dissected to establish the course of branches of the lateral femoral cutaneous nerve. The number of branches divided by each of the three incisions was recorded.

RESULTS

The MIS incisions resulted in significantly less nerve division compared with the SLA. The mean difference between the SLA and the ALA was 4.4 (P < 0.0001), and between the SLA and the PA was 1.4 (P = 0.0005). The ALA divided significantly fewer nerves compared with the PA (mean difference = 3; P = 0.0001).

DISCUSSION

There is little evidence of the benefit of one MIS approach over another in the literature. The ALA preserved significantly more cutaneous nerves in this study. These results need corroboration with clinical outcomes to determine their significance.
Patient Decision Aids in Joint Replacement Surgery: A Literature Review and An Opinion Survey of Consultant Orthopaedic Surgeons
Authors: Adam JA , Khaw F-M , Thomson RG , Gregg PJ , Llewellyn-Thomas HA
Published: April 2008

INTRODUCTION

Patient decision aids could facilitate shared decision-making in joint replacement surgery. However, patient decision aids are not routinely used in this setting.

METHODS

With a view to developing a patient decision aid for UK hip/knee joint replacement practice, we undertook a systematic search of the literature for evidence on the use of shared decision-making and patient decision aids in orthopaedics, and a national survey of consultant orthopaedic surgeons on the potential acceptability and feasibility of patient decision aids.

RESULTS

We found little published evidence regarding shared decision-making or patient decision aids in orthopaedics. In the survey, 362 of 639 (57%) randomly selected consultant orthopaedic surgeons responded. Respondents appear representative of consultant orthopaedic surgeons in the UK. Of 272 valid responses, 79% (95% CI, 73–85%) thought patient decision aids a good or excellent idea. There was consensus on the potential helpfulness of patient decision aids and core content. A booklet to take home was the preferred medium/practice model.

CONCLUSIONS

Despite the increased emphasis on patient involvement in decision-making, there is little evidence in the medical literature relating to shared decision-making or the use of patient decision aids in orthopaedic surgery. Further research in this area of clinical practice is required. Our survey shows that consultant orthopaedic surgeons in the UK are generally positive about the use of patient decision aids for joint replacement surgery. Survey results could inform future development of patient decision aids for joint replacement practice in the UK.
Emergency Management of Malignant Acute Left-Sided Colonic Obstruction
Authors: Trompetas Vasileios
Published: April 2008

INTRODUCTION

The management of acute left-sided colonic obstruction still remains a challenging problem despite significant progress.

METHODS

A literature search was undertaken using PubMed and the Cochrane Library regarding the options in emergency management of left-sided colonic obstruction focusing on outcomes such as mortality, morbidity, long-term prognosis and cost effectiveness.

DISCUSSION

Colonic stenting is the best option either for palliation or as a bridge to surgery. It reduces morbidity and mortality rate and the need for colostomy formation. Stenting is likely to be cost effective, but data are variable depending on the individual healthcare system. Nevertheless, surgical management remains relevant as colonic stenting has a small rate of failure, and it is not always available. There are various surgical options. One-stage primary resection and anastomosis is the preferred choice for low-risk patients. Intra-operative colonic irrigation has no proven benefit. Subtotal colectomy is useful in cases of proximal bowel damage or synchronous tumours. Hartmann's procedure should be reserved for high-risk patients. Simple colostomy has no role other than for use in very ill patients who are not fit for any other procedure.
Toward a Framework for Assessing Covert Marketing Practices
Authors: Milne George R. , Bahl Shalini , Rohm Andrew
Published: April 2008

In an effort to make the marketing process seamless and more efficient, marketers are surreptitiously and inextricably coupling information gathering and marketing. To understand the welfare implications of these practices better, this essay extends the conceptualization of covert marketing to include both information gathering and marketing communications. The authors present a multistage exchange framework that helps identify factors affecting marketer and consumer welfare when covert practices are used. They use the framework to discuss the benefits and harms related to these types of covert marketing practices as well as consumer reactions to such practices.
The Stealth Influence of Covert Marketing and Much Ado about what May be Nothing
Authors: Rotfeld Herbert Jack
Published: April 2008

Most discussions of covert marketing stem from three basic statements: (1) People are generally skeptical of any business-provided sources of information, so publicity or even random endorsements by strangers on the street might provide consumers with more persuasive sales messages; (2) advertising creators repeatedly say that they need to “break out” from the increasingly cluttered mass media environment; and (3) news reports of any pervasive marketing activity include a direct assertion, or at least an implicit presumption, that business managers do it because they know it “works.” Management decisions to use any covert marketing tactic are driven by the first two beliefs, and public policy worries of its improper or deceptive influence on consumers flow from the third. However, most covert marketing efforts are undertaken with professional uncertainty of whether anything really works as they create new areas of consumer skepticism and even more commercial clutter.