bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of maintaining apical patency on canal transportation
Authors: Tsesis I. , Amdor B. , Tamse A. , Kfir A.
Published: February 2008

Aim  To evaluate, ex vivo, the effect of maintaining apical patency on the original canal shape during preparation of curved roots by two different techniques.

Methodology  Forty extracted human maxillary and mandibular molars were evaluated. Occlusal surfaces were ground and roots sectioned to the level of the cemento‐enamel junction to allow only one root to remain for evaluation in each tooth. Specimens were divided into four experimental groups (10 canals each): Group 1 – root canals prepared using the balanced force technique with stainless steel K‐files, and patency established with size 10 K‐files between each instrument; Group 2 – same as Group 1 but without the use of a patency file; Group 3 – canals instrumented with LightSpeed® instruments and patency established with size 10 K‐files between each instrument; and Group 4 – same as Group 3 but without the use of a patency file. Specimens were mounted and a series of radiographs taken. Initial and post‐preparation digital images were superimposed and the distance between two central axes at 1, 2 and 4 mm from the working length (WL) was measured to obtain an indication of the degree of apical transportation. Results were subjected to statistical analysis using two‐way analysis of variance (anova).

Results  No significant differences were found in degree of apical transportation at different levels of the root canal (P > 0.05) nor in loss of WL between groups (P > 0.05).

Conclusion  In this laboratory study, maintaining apical patency did not influence canal transportation in the apical 4 mm.
Accuracy of two electronic apex locators in primary teeth with and without apical resorption: a laboratory study
Authors: Tosun G. , Erdemir A. , Eldeniz A. U. , Sermet U. , Sener Y.
Published: February 2008

Aim  To evaluate the accuracy of the Root ZX (J Morita Corp., Kyoto, Japan) and Tri Auto ZX (J Morita Corp.) devices for measuring root canal length in primary teeth with and without apical resorption.

Methodology  Thirty‐four extracted human primary molar teeth with resorption and 19 primary teeth without resorption were collected. After endodontic access preparation, the actual lengths of the teeth were determined. The teeth were then embedded in an alginate model to determine the electronic working length measurement. Statistical evaluation was completed using Student’s t‐tests.

Results  For the Root ZX, there was no significant difference between those teeth with root resorption and those without. However, for the Tri Auto ZX, there was a significant difference in the electronic measurements between those teeth with root resorption and those without (P < 0.05). Significant differences were found amongst the measurements of the two apex locators (P < 0.05). For root canals with resorption, the respective accuracy rates (within ±0.5 mm) of Root ZX and Tri Auto ZX were 83.33% and 89.47%; within ±1 mm, the Root ZX and Tri Auto ZX demonstrated 98.95% and 100% accuracy, respectively. For root canals with no resorption, the percentage of measurements within ±0.5 mm of the apical construction was 89.28% for the Root ZX and 80.35% for the Tri Auto ZX. The accuracy within ±1 mm of the Root ZX and the Tri Auto ZX was 98.22% and 100%, respectively.

Conclusion  Within the limitations of this laboratory study, the presence of resorption affected the performance of the Tri Auto ZX more than the Root ZX.
Cortical processing of residual ano‐rectal sensation in patients with spinal cord injury: an fMRI study
Authors: Wietek B. M. , Baron Ch. , Erb M. , Hinninghofen H. , Badtke A. , Kaps H.‐p. , Grodd W. , Enck P.
Published: February 2008

Abstract  Eleven paraplegic patients with complete traumatic spinal cord injuries (SCI) [according to American Spinal Injury Association (ASIA) criteria] at different levels (Th3–L3) were investigated during non‐painful stimulation of the distal rectum and anal canal, using event related functional magnetic resonance imaging. Although a complete lesion was clinically diagnosed in all, four of them experienced reproducible sensations during anal and/or rectal stimulation. In six patients, individual data analysis revealed significant activation in the right secondary somatosensory cortex SII, the posterior cingular gyrus, the prefrontal cortex, and the left posterior cerebellar lobe during either anal or rectal stimulation or both. A Region of interest analysis using a data mask from healthy controls confirmed that SCI patients demonstrate cortical activation in areas similar to those activated in healthy volunteers, but to a less extensive degree. This supports the notion that the diagnosis of complete spinal cord transsection by ASIA criteria alone may be insufficient for assessment of ‘completeness’ of cord lesions, and that visceral sensitivity testing may be required in addition.
Neonatal vaccination with Bacillus Calmette‐Guérin elicits long‐term protection in mouse‐allergic responses
Authors: Shen H. , Huang H. , Wang J. , Ye S. , Li W. , Wang K. , Zhang G. , Wang P.
Published: February 2008

Background:  Mycobacterium bovis Bacillus Calmette‐Guérin (BCG) vaccination has been shown to inhibit allergic airway inflammation in animal models, associated with the regulation of allergen‐specific T‐cell immunity. However, little is known about whether neonatal BCG treatment could inhibit allergic inflammation by regulating allergen‐specific T‐cell response in aged mice. This study was aimed to investigate the impact of neonatal BCG treatment on allergic asthma and possible mechanism(s) underlying the action of BCG in different ages of mice.

Methods:  C57BL/6 neonates were vaccinated with BCG on days 1, 7 and 14, sensitized with ovalbumin (OVA) at 5 and 7 weeks of age, and then challenged with allergen at 9 or 45 weeks of age for early‐ or late‐challenged asthma. Their airway inflammation and allergen‐specific T‐cell responses were characterized.

Results:  Following early‐challenge, BCG vaccination inhibited airway hyper‐responsiveness (AHR), infiltration of eosinophils and mucous overproduction (P < 0.05), and shifted OVA‐specific predominant Th2‐ to Th1‐type cytokine responses in both the bronchoalveolar lavage fluid and the splenocyte supernatants (P < 0.05). In late‐challenged mice, neonatal BCG treatment attenuated AHR and eosinophilia (P < 0.05), but failed to modulate allergen‐specific cytokine responses.

Conclusions:  Our data suggest that neonatal BCG vaccination has a long‐term effect on inhibiting AHR and eosinophilia, which is associated with the modulation of Th1/Th2 cytokine production in early‐, but not in late‐challenged mice. Thus, different mechanisms may mediate the long‐term protective effect of BCG neonatal vaccination differently in younger adult and aged mice.
Filaggrin null mutations are associated with increased asthma exacerbations in children and young adults
Authors: Basu K. , Palmer C. N. A. , Lipworth B. J. , Irwin McLean W. H. , Terron‐Kwiatkowski A. , Zhao Y. , Liao H. , Smith F. J. D. , Mitra A. , Mukhopadhyay S.
Published: February 2008

Background:  Filaggrin (FLG) null mutations are important genetic predisposing factors for atopic asthma and have recently been shown to influence controller and reliever medication needs in asthmatic children. Our objective was to study the role of FLG null alleles in asthma exacerbations.

Methods:  FLG mutations R501X and 2282del4 were assayed in 1135 individuals ranging from 3 to 22 years old with asthma from Tayside and Dumfries, Scotland. Asthma exacerbations over the previous 6 months were also studied.

Results:  The FLG mutations were significantly associated with greater risk of exacerbations in children with asthma. Exacerbations were significant for the R501X but not the 2282del4 mutation and the combined genotype compared to the wild‐type with odds ratios of 1.97 (95% CI, 1.19–3.22; P = 0.009) and 1.61 (95% CI, 1.08–2.40; P = 0.021), respectively. Individuals with FLG null alleles were more likely to require oral steroids (31.4%vs 19.5%; OR = 1.89; P = 0.021) for their exacerbations. There was also a 1.71‐fold increased risk (42.6%vs 30%; P = 0.041) of school absence owing to asthma exacerbations in asthmatic individuals with FLG null mutation. On sub‐group analysis, the effect of FLG mutations on asthma exacerbations is significant (P = 0.045) only for participants with relatively mild asthma controlled on inhaled steroids, with inhaled albuterol according to need.

Conclusion:  In addition to their effect on asthma medication requirements reported previously, there is an association between the presence of FLG null mutations and the risk of asthma exacerbations in asthmatic children and young adults.
Efficacy and safety of fluticasone propionate 0.005% ointment in the long‐term maintenance treatment of children with atopic dermatitis: Differences between boys and girls?
Authors: Glazenburg Eltjo J. , Wolkerstorfer Albert , Gerretsen Anton L. , Mulder Paul G. H. , Oranje Arnold P.
Published: February 2008

Treatment of atopic dermatitis (AD) in children tends to stabilize the condition in the short term. ‘Maintenance’ treatment options in children are limited. To assess the efficacy and safety of twice daily treatment with fluticasone propionate 0.005% (FP) ointment during 4 wk and the efficacy and safety of twice weekly maintenance treatment with FP in preventing exacerbations or remissions of AD during a 16 wk follow‐up period. Ninety children (aged 4–10 yr) with moderate to severe AD were included in a randomized, multi‐centre study and received FP ointment twice daily during the acute phase. Children whose AD was in remission after 4 wk of treatment, entered the maintenance phase. In addition to twice daily emollient, children were randomly allocated to receive FP or placebo ointment twice weekly on consecutive days. Efficacy was assessed by the objective SCORAD. Eighty‐seven (97%) completed the 4‐wk acute study period. Extensive remission was achieved in 78 (87%) children, and 75 children entered the maintenance phase. Intermittent treatment with FP resulted in less severe AD and significantly reduced risk of further relapse as compared with placebo. The risk of an exacerbation of AD was more than twice as high in the placebo group as in the FP group (hazard ratio 2.182, 95% CI). AD in girls was better controlled than in boys. This long‐term study shows that the addition of twice weekly FP to standard maintenance therapy significantly reduces the risk of relapse in children with moderate severe AD.
Photosynthesis, nitrogen allocation and specific leaf area in invasive Eupatorium adenophorum and native Eupatorium japonicum grown at different irradiances
Authors: Feng Yu‐Long
Published: February 2008

The mechanisms underlying biological invasions are still not well elucidated. In this study, ecophysiological traits of invasive Eupatorium adenophorum and native E. japonicum were compared at 10 irradiances in field. I hypothesized that the invader may allocate a higher fraction of leaf nitrogen (N) to photosynthesis and have higher light‐saturated photosynthetic rate (Pmax) and specific leaf area (SLA) than E. japonicum. The invader had a significantly higher ability to acclimate to high irradiance than E. japonicum, while it showed a similar shade‐tolerant ability. The invader indeed allocated a higher fraction of leaf N to photosynthesis than E. japonicum, which, with its high leaf N content (NA), resulted in a higher N content in photosynthesis (NP), contributing to its higher biochemical capacity for photosynthesis and Pmax. However, the invader had a significantly lower SLA than E. japonicum, contributing to its higher Pmax but increasing its area‐based leaf construction cost. The abilities to acclimate to a wider range of irradiance and to allocate a higher fraction of leaf N to photosynthesis, and the higher Pmax, NA, NP and leaf area ratio may contribute to the invasion of the invader. High SLA is not always necessary for invasive species.
Experimental infection magnifies inbreeding depression in house mice
Authors: ILMONEN P. , PENN D. J. , DAMJANOVICH K. , CLARKE J. , LAMBORN D. , MORRISON L. , GHOTBI L. , POTTS W. K.
Published: February 2008

It is often assumed that inbreeding reduces resistance to pathogens, yet there are few experimental tests of this idea in vertebrates, and no tests for the effects of moderate levels of inbreeding more commonly found in nature. We mated wild‐derived mice with siblings or first cousins and compared the resistance of their offspring to Salmonella infection with outbred controls under laboratory and seminatural conditions. In the laboratory, full‐sib inbreeding reduced resistance to Salmonella and survivorship, whereas first‐cousin inbreeding had no detectable effects. In competitive population enclosures, we found that first‐cousin inbreeding reduced male fitness by 57% in infected vs. only 34% in noninfected control populations. Our study provides experimental evidence that inbreeding reduces resistance and ability to survive pathogenic infection, and moreover, it shows that even moderate inbreeding can cause significant fitness declines under naturalistic conditions of social stress, and especially with exposure to infectious agents.
Existence of a pattern of reproductive character displacement inHomobasidiomycotabut not inAscomycota
Authors: GAC M. LE , GIRAUD T.
Published: February 2008

Generally, stronger reproductive isolation is expected between sympatric than between allopatric sibling species. Such reproductive character displacement should predominantly affect premating reproductive isolation and can be due to several mechanisms, including population extinction, fusion of insufficiently isolated incipient species and reinforcement of reproductive isolation in response to low hybrid fitness. Experimental data on several taxa have confirmed these theoretical expectations on reproductive character displacement, but they are restricted to animals and a few plants. Using results reported in the literature on crossing experiments in fungi, we compared the degree and the nature of reproductive isolation between allopatric and sympatric species pairs. In accordance with theoretical expectations, we found a pattern of enhanced premating isolation among sympatric sibling species inHomobasidiomycota. By contrast, we did not find evidence for reproductive character displacement inAscomycotaat similar genetic distances. Both allopatric and sympatric species ofAscomycotahad similarly low levels of reproductive isolation, being mostly post‐zygotic. This suggests that some phylogeny‐dependent life‐history trait may strongly influence the evolution of reproductive isolation between closely related species. A significant correlation was found between degree of reproductive isolation and genetic divergence among allopatric species ofHomobasidiomycota, but not among sympatric ones or amongAscomycotaspecies.
Lamellar keratoplasty with a graft of lyophilized acellular porcine corneal stroma in the rabbit
Authors: Lin Xu‐Chu , Hui Yan‐Nian , Wang Yu‐Sheng , Meng Hao , Zhang Yong‐Jie , Jin Yan
Published: February 2008

Objective  To evaluate the efficacy of lamellar keratoplasty in the rabbit using a graft of lyophilized acellular porcine corneal stroma (APCS).

Animal studied  Twelve adult 2–2.5 kg Zealand white rabbits were studied.

Procedure  The cell components of the porcine cornea were removed by the means of enzymatic digestion, freezing, and thawing and then APCS was lyophilized. The 6.5 mm diameter APCS was implanted on a 6.0‐mm diameter keratectomy wound each of 12 rabbits. The postoperative clinical and histological evaluations were performed in the early, intermediate, and late periods.

Results  All corneal wounds healed. Ten of the 12 grafts of APCS were integrated completely with the receptive cornea except two grafts scraped partially off by the eyelid. The blepharospasm, ocular discharge, and edema of the cornea were marked 1 week after transplantation. New vessels invaded the graft after week 2 and regressed after week 8. The cornea became transparent gradually. The histological evaluation showed that the epithelium on the graft stratified normally post surgery. The keratocytes of the recipient grew into the graft and were proliferative at week 4. The inflammatory cells and new vessels were observed before week 8. The fibrosis in the graft was revealed at week 4 and lessened at week 8. The histological structure of the cornea after surgery was similar to the normal cornea at week 32.

Conclusions  APCS can recover the integrity of the rabbit's cornea and become transparent in vivo. APCS is an effective graft for lamellar keratoplasty in the rabbit.
Surgical management of a progressive iris melanocytoma in a Mustang
Authors: Scotty Nicole C. , Barrie Kathleen B. , Brooks Dennis E. , Taylor David
Published: February 2008

Case description A 7‐year‐old gray Mustang gelding weighing 454 kg was presented for evaluation of a brown mass within the left eye (OS) of 1 year's duration with recent enlargement.

Clinical findings A nonpainful, 8 mm diameter, brown, vascularized mass was identified in the anterior chamber of the OS. Ocular B‐scan ultrasound confirmed iris involvement and corneal endothelial contact. Histopathology confirmed the presumptive diagnosis of a uveal melanocytic neoplasm, and revealed 1–3 mitotic figures per high power (400×) field.

Treatment and outcome The mass was removed via sector iridectomy without complications, but without complete margins. Three cutaneous melanocytomas noted 1.5 months postoperatively were completely excised. No tumor regrowth was noted 15 months postoperatively, supporting a diagnosis of melanocytoma for the iridal mass.

Clinical relevance Sector iridectomy is a reasonable treatment option for uncomplicated iridal melanocytomas in horses. Mitotic index and presence of cutaneous melanocytic neoplasms may be irrelevant to the prognosis of equine iridal melanocytic neoplasms.
Normal features of superficial nondesquamating cells of the rabbit corneal epithelium assessed by scanning electron microscopy
Authors: Doughty Michael J.
Published: February 2008

Objective  To quantitatively assess surface features of corneal epithelial cells with particular emphasis on regional differences in cell size or shape.

Animals studied  Female New Zealand White rabbits, aged 11–12 weeks.

Procedures  Animals were exposed to a light : dark cycle of 14 : 10 h for 2 weeks and then the corneas prepared for scanning electron microscopy (SEM) at 1500 h. Images were taken at central location (C), mid‐periphery (MP), and periphery (P) of the cornea. On prints at 5000×, cell–cell borders were marked, and long (L) and short (S) dimensions measured, and the surface ring‐shaped features outlined and counted.

Results  Across the epithelial surface cells had from 3 to 11 bordering cells (sides), with 5‐sided cells being more common (mean 32.7 ± 11.3%, SD). L dimensions averaged 26.7, 30.9, and 33.9 µm at the C, MP, and P locations, while S dimensions were 18.5, 21.8, and 24.0 µm, respectively. The L : S ratio was1.523, with averages of 1.567, 1.501, and 1.487 at the three locations. Using an averaged cell dimension, cell density was estimated and found to be 7376, 4405, and 3071 cells/mm2 at C, MP, and P locations. Almost all cells were decorated with ring‐shaped features (craters), with the number increasing in relation to cell size and were much higher on more peripheral cells.

Conclusions  The non‐exfoliating corneal epithelial surface is composed of flat polygonal cells often with 5‐sides cells, which are progressively larger towards the peripheral cornea and more decorated with ring‐shaped features.
Ocular morphology of the Leatherback sea turtle (Dermochelys coriacea)
Authors: Brudenall Denise K. , Schwab Ivan R. , Fritsches Kerstin A.
Published: February 2008

Objective  The Leatherback sea turtle is the largest extant reptile and the sole member of the family Dermochelyidae. Here, the eye of this critically endangered marine turtle was investigated to determine the anatomy, optics, and optical sensitivity.

Animals studied  Three Leatherback sea turtles, Dermochelys coriacea.

Results  The eye is small in proportion to body size of the adult compared to other vertebrates, with prominence of the retractor bulbi and pyramidalis muscles. The nictitans shows extensive folding of the bulbar conjunctiva as an apparent mechanism to increase the surface area for mucus secretion. The intraocular anatomy is consistent with an eye adapted to aquatic vision with minimal curvature of the cornea, a near‐spherical lens, deep ciliary cleft and highly vascularized ciliary body. The optical sensitivity, a measure of the sensitivity to light of a given optical system, is higher than in other marine turtles studied but lower than those found in teleost fish that share a habitat with the Leatherback sea turtle.

Conclusions  The Leatherback sea turtle shows ocular features that are characteristic of Chelonians with similarities to aquatic mammals. The calculated optical sensitivity suggests that compared to pelagic fishes, for instance, the Leatherback sea turtle eye is not particularly well adapted for vision in dim light even though this species is known to venture into deep, dark waters, and might feed at night.
Corneal epithelial inclusion cyst in a Llama
Authors: Pirie Chris G. , Pizzirani Stefano , Parry Nicola M.
Published: February 2008

A 13‐year‐old, female Llama presented for evaluation of a limbal based corneal mass involving the OD of 4 months duration. The mass was excised en bloc by a nonpenetrating keratectomy, followed by placement of a conjunctival advancement flap covering the keratectomy site. The mass was submitted for histological evaluation. Histopathology identified the mass to be a corneal epithelial inclusion cyst filled with necrotic squamous and neutrophilic debris. Surgical excision was complete and considered curative with no signs of recurrence 3 months postoperatively. There was no known prior ocular trauma; however, a previously performed corneal biopsy for evaluation of recurrent epithelial erosions may have been an initiating cause.
Corneal transplantation for inflammatory keratopathies in the horse: Visual outcome in 206 cases (1993–2007)
Authors: Brooks D. E. , Plummer C. E. , Kallberg M. E. , Barrie K. P. , Ollivier F. J. , Hendrix D. V. H. , Baker A. , Scotty N. C. , Utter M. E. , Blackwood S. E. , Nunnery C. M. , Ben‐Shlomo G. , Gelatt K. N.
Published: February 2008

Objective  To evaluate the visual outcome of three techniques of corneal transplantation surgery in treating severe inflammatory keratopathies in the horse.

Design Retrospective medical records study.

Animals studied  Medical records of 206 horses that received corneal transplantation surgery at the University of Florida Veterinary Medical Center from 1993 to 2007 were reviewed.

Procedure  Data collected from the medical records included signalment, types of ocular lesions, type of transplant surgery performed, length of follow‐up, complications, and visual outcomes.

Results  Full thickness penetrating keratoplasty (PK) was performed in 86 horses for melting ulcers, iris prolapse/descemetoceles, and medically nonresponsive full thickness stromal abscesses (SA). Posterior lamellar keratoplasty (PLK) and deep lamellar endothelial keratoplasty (DLEK) are split thickness penetrating keratoplasties that were utilized for medically nonresponsive deep stromal abscesses (DSA) in 54 and 66 eyes, respectively. The most common postoperative surgical complication was graft rejection and varying degrees of graft opacification. Wound dehiscence and aqueous humor leakage was also a common postoperative problem. A positive visual outcome was achieved for PK, PLK, and DLEK in 77.9%, 98.1%, and 89.4%, respectively.

Conclusions  Corneal transplantation is a tectonically viable surgery in the horse with an overall success rate of 88.5% in maintaining vision when treating vascularized and infected corneal disease in the horse.
VULNERABILITY IN RESEARCH AND HEALTH CARE; DESCRIBING THE ELEPHANT IN THE ROOM?
Authors: HURST SAMIA A.
Published: February 2008

Despite broad agreement that the vulnerable have a claim to special protection, defining vulnerable persons or populations has proved more difficult than we would like. This is a theoretical as well as a practical problem, as it hinders both convincing justifications for this claim and the practical application of required protections. In this paper, I review consent‐based, harm‐based, and comprehensive definitions of vulnerability in healthcare and research with human subjects. Although current definitions are subject to critique, their underlying assumptions may be complementary. I propose that we should define vulnerability in research and healthcare as an identifiably increased likelihood of incurring additional or greater wrong. In order to identify the vulnerable, as well as the type of protection that they need, this definition requires that we start from the sorts of wrongs likely to occur and from identifiable increments in the likelihood, or to the likely degree, that these wrongs will occur. It is limited but appropriately so, as it only applies to special protection, not to any protection to which we have a valid claim. Using this definition would clarify that the normative force of claims for special protection does not rest with vulnerability itself, but with pre‐existing claims when these are more likely to be denied. Such a clarification could help those who carry responsibility for the protection of vulnerable populations, such as Institutional Review Boards, to define the sort of protection required in a more targeted and effective manner.
ONE DANGER OF BIOMEDICAL ENHANCEMENTS
Authors: RAJCZI ALEX
Published: February 2008

In the near future, our society may develop a vast array of medical enhancements. There is a large debate about enhancements, and that debate has identified many possible harms. This paper describes a harm that has so far been overlooked. Because of some particular features of enhancements, we could come to place more value on them than we actually should. This over‐valuation would lead us to devote time, energy, and resources to enhancements that could be better spent somewhere else. That mistake might not be trivial. By spending too much time, energy, and resources on enhancements, we could set back our pursuit of our deepest goals such as living happily and leading ethical lives.
Embodied Technical Change and the Fluctuations of Unemployment and Wages
Authors: Reiter Michael
Published: February 2008

A matching model where technological change is partially embodied in the job match is shown to be successful in explaining the variability of unemployment and vacancies. If we incorporate long‐term wage contracts into the model, it also explains a number of stylized facts on the dynamics of real wages, which have been found in the empirical labor literature.
Labor‐market Volatility in Matching Models with Endogenous Separations*
Authors: Mortensen Dale , Nagypál Éva
Published: February 2008

The business‐cycle behavior of a matching model with endogenous separations is studied in this paper. We show that whether aggregate productivity shocks have a larger effect on the vacancy–unemployment ratio than in a model with exogenous separations depends on whether worker productivity stochastically increases with tenure. The difference in the response is quantitatively small, however. We also show that the cleansing effect introduced by allowing for endogenous separations can help in reconciling the model with observed fluctuations in the unemployment rate, but not with those in the vacancy rate.
The Macroeconomic Consequences of Reciprocity in Labor Relations*
Authors: Danthine Jean‐Pierre , Kurmann André
Published: February 2008

We develop and analyze a structural model of efficiency wages founded on reciprocity. Workers are assumed to face an explicit trade‐off between the disutility of providing effort and the psychological benefit of reciprocating the gift of a wage offer above some reference level. The model provides a rationale for rent sharing—a feature that is very much present in the data but absent from previous formulations of the efficiency wage hypothesis. This firm‐internal perspective on efficiency wages has potentially important macroeconomic consequences: rent‐sharing considerations promote wage rigidity, internal amplification and differential responses to technology and demand shocks.
U.S. Labor Market Dynamics Revisited
Authors: Yashiv Eran
Published: February 2008

The picture of U.S. labor market dynamics is opaque. This paper aims at its clarification by (i) listing data facts that can be agreed upon; these indicate that there is considerable cyclicality and volatility of both accessions to and separations from employment and hence both are important for the understanding of the business cycle; (ii) presenting the business‐cycle facts of key series; (iii) pointing to specific gaps in the data picture, showing that the definite characterization of labor market dynamics depends upon the closing of these data gaps.
Children's Attachment Relationships with Day Care Caregivers: Associations with Positive Caregiving and the Child's Temperament
Authors: De Schipper J. Clasien , Tavecchio Louis W. C. , Van IJzendoorn Marinus H.
Published: February 2008

In this study, children's attachment relationships with their professional caregivers in center day care were observed for 48 children. We explored whether more positive caregiving was associated with a more secure attachment relationship and whether this association was stronger for more temperamentally irritable children compared to less irritable children. Trained observers coded the attachment relationship in the day care setting using the attachment Q‐sort. The observational record of the caregiving environment was used to assess children's individual experience of positive caregiver–child interaction in the classroom. When caregivers showed more frequent positive caregiving behavior, children showed more secure attachment behavior toward their primary professional caregiver. Temperament was not related to attachment security, nor did it serve as a moderator. Consequently, no support for Belsky's susceptibility hypothesis was found.
ECONOMIC GENERALITY VERSUS MATHEMATICAL GENERICITY: ACTIVITY‐LEVEL INDETERMINACY AND THE INDEX THEOREM IN CONSTANT RETURNS PRODUCTION ECONOMIES
Authors: Fratini Saverio M.
Published: February 2008

When the mathematical concept of genericity was arrived at in economics, it was meant more or less as a synonym for generality. Referring to constant return production economies, we will argue that this is not always the case. In particular, the representation of technology that is mathematically generic is not at all general for economists. We will see that in cases that are economically general, but not mathematically generic, activity‐level indeterminacy may occur. In these cases, Kehoe's index theorem, a well‐known result of the application of the differentiable approach to production economies, becomes unusable.
Humor as a Serious Strategy of Nonviolent Resistance to Oppression
Authors: Sorensen Majken Jul
Published: February 2008

This article explores how humor can be used as one aspect of a strategy of nonviolent resistance to oppression and dictatorship. It combines sociological and philosophical theories about humor's duality and incongruity with theories of nonviolent resistance to oppression in order to investigate the links between topics that have previously been considered unrelated. Experiences from the Serbian Otpor movement, which used humorous actions as a part of its strategy to bring down Slobodan Milošević from power, serve to illustrate the dynamics of humor as a form of resistance. Empirical examples and existing theory are combined to make an outline of an innovative theory of the functions of humor in nonviolent resistance.
Perspectives on organizational justice: Concept clarification, social context integration, time and links with morality
Authors: Fortin Marion
Published: February 2008

Organizational justice is concerned with people's fairness perceptions in organizations and has been a popular field of study in the social sciences for at least 25 years. This paper reviews the core concepts, models and questions of organizational justice research. Four research areas that are particularly critical for the future of the field will be highlighted: concept clarification, social context integration, time and links with morality. These areas have received increased attention lately, but there are still relatively few empirical studies and theoretical frameworks that grapple with these issues. Concept clarification is vital for improved consistency of the field and for internal validity of studies. Situating organizational justice in social contexts and in time will be crucial to improve external validity and the usability of organizational justice findings in organizations. Understanding the links between morality and justice at an individual level, and at the organizational and societal levels is necessary if justice researchers want to live up to the promise of their field for society. For each of these four areas, recent developments will be reviewed and avenues for future research discussed.
The determinants of export performance: A review of the research in the literature between 1998 and 2005
Authors: Sousa Carlos M.P. , Martínez‐López Francisco J. , Coelho Filipe
Published: February 2008

Considerable attention has been paid to the determinants of export performance. However, despite this research effort in identifying and examining the influence of such determinants, the literature is characterized by fragmentation and diversity, hindering theory development and practical advancement in the field. This paper attempts to review and synthesize the knowledge on the subject. As a result, this study reviews and evaluates 52 articles published between 1998 and 2005 to assess the determinants of export performance. The assessment reveals that: (a) more studies have been conducted outside the USA; (b) the majority of the studies focus on manufacturing firms, with relatively few studies examining the service sector; (c) the majority of the export studies continue to focus on small to medium‐sized firms; (d) there is a continuous increase in the sample size; (e) despite the problems that may arise from the use of single informants, it seems that none of the studies reviewed here collected data from more than one informant in the firm; (f) an increasing number of studies have been using the export venture as the unit of analysis; (g) the level of statistical sophistication has improved; (h) the use of control and moderating variables in export performance studies has increased; (i) more studies have started to include the external environment in their models, including domestic market characteristics; and (j) market orientation as a key determinant of export performance emerges in this review. Finally, conclusions are drawn, along with some suggestions for further research.
Age of SERPINA1 Gene PI Z Mutation: Swedish and Latvian Population Analysis
Authors: Lace B. , Sveger T. , Krams A. , Cernevska G. , Krumina A.
Published: February 2008

Alpha 1‐antitrypsin (A1AT) deficiency, one of the most common inborn errors of metabolism in Caucasians, is characterized by a low serum concentration of A1AT and a high risk of pulmonary emphysema and liver disease. The allelic frequency for the most common protease inhibitor (PI) Z mutation in the SERPINA1 gene is 2–5% in Caucasians of European descent.

The objective of our study was to estimate the PI Z mutation age using molecular analysis in Latvian and Swedish populations, which have the highest frequency of PI Z mutation.

DNA samples of heterozygous and homozygous PI Z allele carriers from Latvia (n = 21) and Sweden (n = 65) were analysed; 113 unrelated healthy donors from Latvia were used as a control group. MALDI‐TOF analysis was performed on all samples. Pairwise Fst was computed to compare the PI Z mutation ages between the two populations and controls. A p value less than 0.05 was considered significant.

Analysis of non‐recombinant SNPs revealed that the PI Z mutation age was 2902 years in Latvia (SD 1983) and 2362 years in Sweden (SD 1614) which correlates with previous studies based on microsatellite analysis.
Scottish toolkit for knowledge management
Authors: Caldwell Lynn , Davies Sandra , Stewart Fiona , Thain Annette , Wales Ann
Published: February 2008

Background : Using specific examples, this paper describes the tools, methods and resources used to develop Managed Knowledge Networks (MKNs) within the NHS Scotland e‐Library (http://www.elib.scot.nhs.uk). MKNs help to complete the knowledge management cycle by providing a place to share the learning and discuss the evidence for practice through combining the use of the published material (explicit knowledge) with the experience and knowledge held by individuals, communities and organizations (tacit knowledge).

Objectives : First of all, this paper outlines the e‐Library infrastructure, which provides an inter‐operable framework to manage the published knowledge using a metadata management system; and a knowledge‐sharing tool to support the development of MKNs. It then covers the various stages involved in developing an MKN: gathering and analysing information needs in a variety of ways; presenting and organizing the resources and services for the users as identified in the needs analysis; managing the tacit, personal and local knowledge.

Conclusion : The toolkit described enables the Knowledge Services Group to take the needs of users, transcribe these into Specialist e‐Libraries to provide access to the published information and to support this with accessing and sharing the knowledge of colleagues via MKNs.
Online anatomy and physiology: piloting the use of an anatomy and physiology e‐book–VLE hybrid in pre‐registration and post‐qualifying nursing programmes at the University of Salford
Authors: Raynor Michael , Iggulden Helen
Published: February 2008

Background : Anatomy and physiology (A&P) teaching and learning in nursing curricula poses problems for educators because of the often varying levels of students’ background knowledge. This study reports on a pilot project that attempted to normalize these differentials by delivering A&P teaching using an online interactive e‐book–virtual learning environment (VLE) hybrid.

Objectives : Evaluate the effectiveness of using an online interactive resource to deliver A&P teaching.

Methods : Data were collected from pre‐registration and post‐qualifying students by questionnaire and observation, and from lecturers by structured interviews. Scale‐up issues were identified and documented as part of support for the ongoing pilot.

Results : The pre‐registration group encountered problems accessing the resource and yielded evidence to suggest that inexperienced learners require a high level of direction to use the resource effectively. The post‐qualifying group benefited from the resource's interactive elements and 24/7 availability. There was clear evidence that the group were able to relate knowledge gained from the resource to practice.

Conclusions : This hybrid has great potential to add value to A&P learning on nursing programmes at post‐qualifying level. The resource could replace its printed equivalent; however, negotiations need to take place between institutions and publishers in order to resolve scale‐up issues.
Job hunting in the UK using the Internet: finding your next information professional role in the health care sector and the skills employers require
Authors: Davies Karen
Published: February 2008

Objectives:  The aim of this article is to analyse ‘professional’ health information vacancies advertised on three specific websites for 6 months from 1 April 2006 (to 30 September 2006). The objectives for this research were to identify the frequency of health information vacancies advertised on three specified websites and on an e‐mail discussion group.

Methods:  Each fortnight all health‐related vacancies advertised directly by the hiring organizations were identified. The job descriptions and person specifications for relevant vacancies were either downloaded or requested from the hiring organization. The main criteria for determining the relevance of a vacancy was that a degree or higher qualification in an information‐related subject was ‘essential’ or ‘desirable with previous experience’. The core skills and experiences required from the job descriptions and person specifications for professional health information posts were identified.

Results:  The results highlight the importance of the Internet in locating suitable vacancies. However, not one website listed all the potential job opportunities. The importance of information technology (IT) skills (including literature searching) and teaching skills were identified from the person specifications and job descriptions.

Conclusions:  The Internet is a useful tool for identifying health‐related employment opportunities. However, to obtain a full list of vacancies, several websites must be searched.
The Royal College of Nursing's information needs survey of nurses and health professionals
Authors: Bertulis Ros , Cheeseborough Jackie
Published: February 2008

Aims:  To find out about the nursing community's needs in the following areas: information or knowledge to improve practice in the clinical area; information to support lifelong learning and formal study.

Methods:  A questionnaire was circulated in summer 2004 containing questions on types of information source used for particular types of problem or question; specific sources used; ease of access to various information sources including computers and the Internet, and local health library; and workplace culture and environment.

Results:  A total of 1715 usable questionnaires were completed and returned. Significant numbers of the nursing community have currently no or limited access to computers. Nursing staff in the independent sector had less access to computers and the Internet than those working for the National Health Service (NHS). Workplace culture was as important as access to IT equipment.

Conclusions:  As a result of the survey, the Royal College of Nursing (RCN) is working with the NHS and the independent health sector to improve access and provide complementary services for the whole nursing community.
The Journal of Ayub Medical College: a 10‐year bibliometric study
Authors: Ullah Midrar , Butt Idrees Farooq , Haroon Muhammad
Published: February 2008

Objective:  To conduct a bibliometric evaluation of the Journal of Ayub Medical College (JAMC), Abbottabad, Pakistan.

Methods  The data of articles, citations and authors of JAMC from 1997 to 2006 were collected and analysed in terms of bibliometric parameters.

Results:  The number of articles published per year ranges between 27 and 97; most of the articles (47.2%) have 11–20 citations. Three‐author contributions ranked the highest (134; 23.43%); the most prolific authors contributed seven articles; 295 (51.57%) of the authors are geographically affiliated to the North West Frontier Province (NWFP), Pakistan; the most popular subject is Internal Medicine; journal self‐cited references are 43; 7769 (77.94%) of the citations were from foreign journals; the most productive institution is Ayub Medical College, Abbottabad, Pakistan.

Conclusion:  The number of papers published in JAMC per issue has been increasing over the last 10 years, and the core region is NWFP, Pakistan. Original articles are the main type of papers for this journal. The publication is open for all fields of medical sciences.
Therapeutic effects of coenzyme Q10 (CoQ10) and reduced CoQ10 in the MPTP model of Parkinsonism
Authors: Cleren Carine , Yang Lichuan , Lorenzo Beverly , Calingasan Noel Y. , Schomer Andrew , Sireci Anthony , Wille Elizabeth J. , Beal M. Flint
Published: February 2008

J. Neurochem. (2008) 104, 1613–1621.

Coenzyme Q10 (CoQ10) is a promising agent for neuroprotection in neurodegenerative diseases. We tested the effects of various doses of two formulations of CoQ10 in food and found that administration in the diet resulted in significant protection against loss of dopamine (DA), which was accompanied by a marked increase in plasma concentrations of CoQ10. We further investigated the neuroprotective effects of CoQ10, reduced CoQ10 (ubiquinol), and CoQ10 emulsions in the (MPTP) model of Parkinson’s disease (PD). We found neuroprotection against MPTP induced loss of DA using both CoQ10, and reduced CoQ10, which produced the largest increases in plasma concentrations. Lastly, we administered CoQ10 in the diet to test its effects in a chronic MPTP model induced by administration of MPTP by Alzet pump for 1 month. We found neuroprotective effects against DA depletion, loss of tyrosine hydroxylase neurons and induction of alpha‐synuclein inclusions in the substantia nigra pars compacta. The finding that CoQ10 is effective in a chronic dosing model of MPTP toxicity, is of particular interest, as this may be more relevant to PD. These results provide further evidence that administration of CoQ10 is a promising therapeutic strategy for the treatment of PD.
Steady‐state increase of cAMP‐response element binding protein, Rac, and PAK signaling in presenilin‐deficient neurons
Authors: Barnes Natalie Y. , Shi Jun , Yajima Hiroshi , Thinakaran Gopal , Parent Angèle T.
Published: February 2008

J. Neurochem.(2008) 104, 1637–1648.

Mutations in the genes encoding presenilins (PS1 and PS2) account for the majority of cases of early‐onset Alzheimer’s disease. PS1 and PS2 form the catalytic center of γ‐secretase, an enzyme responsible for intramembraneous proteolysis of several type I transmembrane proteins. Many γ‐secretase substrates are coupled to intracellular signaling events such as cAMP‐response element binding protein and Rac1/p21‐activated kinase pathways, which are associated with synaptic function. Here, we have examined the activation of these pathways in neurons lacking PS1 expression or γ‐secretase activity. We found evidence for heightened steady‐state activation of cAMP‐response element binding protein, Rac1, and p21‐activated kinase signaling in PS‐deficient neurons. Our study highlights the importance of PS‐dependent proteolytic cleavage of γ‐secretase substrates in regulating neuronal signal transduction.
Multiple disease‐linked myotubularin mutations cause NFL assembly defects in cultured cells and disrupt myotubularin dimerization
Authors: Goryunov Dmitry , Nightingale Andrew , Bornfleth Lorelei , Leung Conrad , Liem Ronald K. H.
Published: February 2008

J. Neurochem.(2008) 104, 1536–1552.

Charcot‐Marie‐Tooth disease (CMT) is an inherited peripheral neuropathy that has been linked to mutations in multiple genes. Mutations in the neurofilament light (NFL) chain gene lead to the CMT2E form whereas mutations in the myotubularin‐related protein 2 and 13 (MTMR2 and MTMR13) genes lead to the CMT4B form. These two forms share characteristic pathological hallmarks on nerve biopsies including concentric sheaths (‘onion bulbs’) and, in at least one case, myelin loops. In addition, MTMR2 protein has been shown to interact physically with both NFL and MTMR13. Here, we present evidence that CMT‐linked mutations of MTMR2 can cause NFL aggregation in a cell line devoid of endogenous intermediate filaments, SW13vim−. Mutations in the protein responsible for X‐linked myotubular myopathy (myotubularin, MTM1) also induced NFL abnormalities in these cells. We also show that two MTMR2 mutant proteins, G103E and R283W, are unable to form dimers and undergo phosphorylation in vivo, implicating impaired complex formation in myotubularin‐related pathology.