bluuebunny/crossref_metadata_2025_split huggingface dataset:
The nuclear hormone receptor DAF‐12 has opposing effects on Caenorhabditis elegans lifespan and regulates genes repressed in multiple long‐lived worms
Authors: Fisher Alfred L. , Lithgow Gordon J. 
Published: March 2006

SummaryThe orphan nuclear hormone receptor gene daf‐12 in Caenorhabditis elegans plays a key role in the regulation of development and determination of adult longevity. To understand the effects of daf‐12 on aging we characterized the lifespan of loss‐of‐function and gain‐of‐function daf‐12 alleles that have been identified on the basis of their effects on dauer development. We find that these mutations have opposing effects on longevity and resistance to oxidative and thermal stress which makes daf‐12 the first gene with alleles that can extend or shorten lifespan. We find that the shortened lifespan of the loss‐of‐function mutation is due to accelerated aging in young adulthood rather than an adverse effect of the mutation on development. Microarray analysis of worms carrying the two alleles revealed a relatively small number of genes differentially expressed between the two genotypes. Comparison of the expression profiles with the profiles associated with dauer formation and long‐lived daf‐2 mutants revealed that while the profiles are largely different, there is significant overlap among the genes down‐regulated, but not up‐regulated, in all profiles. Several of these genes down‐regulated in multiple long‐lived worms have known effects on lifespan, and many of the genes belong to a family of poorly characterized genes that are strongly down‐regulated in dauers, daf‐2 mutants, and long‐lived daf‐12 mutants. Our results point to daf‐12 modulating aging and stress responses in part through the repression of specific genes, and emphasize the role that the repression of genes that curtail maximal lifespan plays in lifespan determination.
Aging networks in Caenorhabditis elegans: AMP‐activated protein kinase (aak‐2) links multiple aging and metabolism pathways
Authors: Curtis Rory , O'Connor Greg , DiStefano Peter S. 
Published: March 2006

SummaryMolecular genetics in lower organisms has allowed the elucidation of pathways that modulate the aging process. In certain instances, evolutionarily conserved genes and pathways have been shown to regulate lifespan in mammals as well. Many gene products known to affect lifespan are intimately involved in the control of energy metabolism, including the fuel sensor AMP‐activated protein kinase (AMPK). We have shown previously that over‐expression of an AMPK α subunit in Caenorhabditis elegans, designated aak‐2, increases lifespan. Here we show the interaction of aak‐2 with other pathways known to control aging in worms. Lifespan extension caused by daf‐2/insulin‐like signaling mutations was highly dependent on aak‐2, as was the lifespan extension caused by over‐expression of the deacetylase, sir‐2.1. Similarly, there was partial requirement for aak‐2 in lifespan extension by mitochondrial mutations (isp‐1 and clk‐1). Conversely, aak‐2 was not required for lifespan extension in mutants lacking germline stem cells (glp‐1) or mutants of the eating response (eat‐2). These results show that aging is controlled by overlapping but distinct pathways and that AMPK/aak‐2 represents a node in a network of evolutionarily conserved biochemical pathways that control aging.
Alleviation of soil compaction: requirements, equipment and techniques
Authors: Spoor G. 
Published: March 2006

AbstractThe nature of soil disturbance required to alleviate soil compaction in a range of agricultural and land restoration situations is identified. Implement geometry and adjustments required to achieve the desired brittle or tensile deformation of compacted soil are discussed. Field operating procedures to achieve the required degrees of soil fissuring, loosening or soil unit rearrangement using the power units and equipment available are described. A new progressive loosening technique is identified for use within deep, extremely compacted soil profiles. Emphasis is given to the importance of making visual field checks across the loosened soil zone at an early stage, to check the desired disturbance is being achieved. Care must be taken during subsequent trafficking operations, to minimize the risk of recompaction.
Soil compaction: identification directly in the field
Authors: Batey T. , McKenzie D. C. 
Published: March 2006

AbstractThe compaction of soil alters its structure, increases its bulk density and decreases its porosity. These changes can be detected by careful and systematic visual and tactile examination directly in the field. These changes also reduce the permeability of soil to water and air and may alter the pattern of root growth. Further signs of compaction may be induced such as the creation of waterlogged zones or of dry zones caused by shallow rooting denying access to deeper reserves of water. Furthermore, there may be a reduction in nutrient uptake from dry soil. Under wet conditions anoxic pockets may form with associated biochemical changes, some of which are visible. Changes in mineral nitrogen may take place through denitrification and a reduction in nitrification. The criteria used to identify compaction in the field include patterns of crop growth, pale leaf colours, waterlogging on the surface or in subsurface layers above compaction, an increase in soil strength, changes to soil structure, soil colour and the distribution of roots and of soil moisture. Manifestation of soil compaction in crops is also dependent on the weather and is influenced by crop type and variety, and stage of growth. Many soil‐borne diseases are made worse by stress to the crop which might be induced by compaction caused by drier or wetter conditions in the root zone. Where, when and how to identify compaction in the field are discussed and the techniques used are described. Specific examples of the identification of compaction are given, covering a wide range of situations.
Influence of aggregate size on phosphorus loss and ryegrass yield in a soil cultivated intermittently
Authors: McDowell R. W. , Scott J. T. , Condron L. M. 
Published: March 2006

AbstractIntermittent cultivation for forage cropping and subsequent grazing by dairy cattle during winter is practiced in southern New Zealand to protect remaining pastures from poaching damage by cattle. However, this practice may degrade soil aggregate structure affecting pasture yield and nutrient loss. A study was conducted to determine the ability of different aggregate sizes to supply phosphorus (P) to ryegrass in a soil used for winter forage cropping and grazed by dairy cattle 2 out of 7 years. Over 35 weeks ryegrass was grown in pots containing one of six wet‐sieved soil aggregate size classes and leached every 2 weeks. Soil analyses included water soluble P, inorganic and organic P fractions, and P in leachate. Results showed that organic P was preferentially lost in leachate or mineralized and used by ryegrass with decreasing aggregate size, although this did not affect yield. Ryegrass yield was best correlated with bicarbonate extractable P in aggregates, and P loss with water soluble inorganic P after minimum disturbance. These findings suggest that although intermittent cultivation did not affect yield, if this practice decreases aggregate size in the future, it may increase the risk of P loss.
Comparison of two automated periodontal probes and two probes with a conventional readout in periodontal maintenance patients
Authors: Barendregt D. S. , Van der Velden U. , Timmerman M. F. , Van Der Weijden G. A. 
Published: March 2006

AbstractAim: The aim of the present study was to test in periodontal maintenance patients whether the systems for pressure control that have been commercially developed contribute to more reproducible probing depth measurements as compared with a manual probe.Material and Methods: In 12 patients duplicate measurements were made at day 0 and 1 week later. In each patient four teeth with the deepest pockets were measured at six sites. In total 288 sites were available for comparisons. The Florida Probe® (FP) (159 N/cm2), the Jonker Probe® (JP) (153 N/cm2), the Brodontic® probe (BP) (255 N/cm2) and the manual probe (MP) were used in a randomized scheme.Results: Mean probing measurements showed for the FP and the JP lower recordings than for the BP and manual probe. The FP, the BP and the MP showed no differences between the duplicate measurements, except for the JP where the second measurement was deeper. Correlation coefficients between measurements at day 0 and 1 week show for the BP and the MP are 0.90 and 0.89, respectively, while for the FP and the JP they are 0.76 and 0.75, respectively.Conclusion: The BP and the MP appear to be reliable tools for reproducible pocket depth measurements in periodontal maintenance patients.
The effect of smoking on periodontal treatment response: a review of clinical evidence
Authors: Heasman L. , Stacey F. , Preshaw P. M. , McCracken G. I. , Hepburn S. , Heasman P. A. 
Published: March 2006

AbstractBackground: Smoking has been identified as a significant risk factor for periodontal diseases and is regarded as being responsible for incomplete or delayed healing in patients following treatment.Aim and Method: The aim of this conventional review was to review, collate and tabulate the relative effectiveness of treatments of chronic periodontitis in smokers, non‐smokers and ex‐smokers.Observations: The majority of clinical trials show significantly greater reductions in probing depths and bleeding on probing, and significantly greater gain of clinical attachment following non‐surgical and surgical treatments in non‐smokers compared with smokers. This benefit is also seen at class I and II furcation sites and in patients prescribed systemic or local antimicrobial treatments.Conclusions: Data from epidemiological, cross‐sectional and case–control studies strongly suggest that quitting smoking is beneficial to patients following periodontal treatments. The periodontal status of ex‐smokers following treatment suggests that quitting the habit is beneficial although there are only limited data from long‐term longitudinal clinical trials to demonstrate unequivocally the periodontal benefit of quitting smoking.
Tooth loss in treated periodontitis patients responsible for their supportive care arrangements
Authors: Leung W. K. , Ng Daniel K. C. , Jin Lijian , Corbet Esmonde F. 
Published: March 2006

AbstractAim: To identify risk indicators associated with tooth loss and periodontitis in treated patients responsible for arranging supportive periodontal care (SPC).Materials and Methods: Ninety‐seven Chinese subjects (34–77 years) who showed favourable responses to periodontal therapy provided in a teaching hospital 5–12 years previously were recalled. They were advised to seek regular SPC on discharge. Background information, general health status, smoking, oral hygiene habits, follow‐up dental care, tooth loss, and periodontal parameters were investigated. Multiple regression analysis was performed.Results: Two hundred and fifty‐six teeth had been lost, 195 because of self‐reported periodontal reasons. Up to 26.8% sites were with pockets 6 mm. Positive correlations were found between total/periodontal tooth loss and (i) smoking pack‐years, (ii) time spent on oral hygiene, (iii) years since therapy's conclusion, (iv) age, and negative correlations with (v) inter‐dental brush use, and (vi) education levels. Tooth loss by arch was correlated with wearing of removable partial denture in that arch. Percentage sites with pockets 6 mm were significantly negatively correlated with percentage sites without bleeding on probing.Conclusions: Smokers, more elderly patients, removable partial denture wearers, and patients with lower education levels or not using inter‐dental brushes ought to be targeted for clinic‐based SPC.
Cathepsin K levels in the crevicular fluid of dental implants: a pilot study
Authors: Strbac Georg D. , Monov Gabriel , Cei Silvia , Kandler Barbara , Watzek Georg , Gruber Reinhard 
Published: March 2006

AbstractObjective: To determine the concentration of cathepsin K secreted into the crevicular fluid around dental implants and its correlation with clinical parameters of healthy implants and implants showing clinical signs of peri‐implantitis.Material and Methods: Nineteen patients with 40 implants with and without peri‐implantitis were enrolled in the study. Peri‐implantitis was diagnosed by the pocket probing depth (PD), the modified bleeding index (MBI), the modified plaque index (MPI) and by radiographic signs of bone loss. Gingival crevicular fluid collected from the buccal and lingual sites was adsorbed to filter strips. Cathepsin K levels and total protein within the crevicular fluid were determined by immunoassay and the bicinchoninic method, respectively.Results: Cathepsin K per filter strip normalized to the time of collection was 10.1 (0–33.5) pmol/sample around control implants and 22.4 (3.7–56.3) pmol/sample in the peri‐implantitis group. The difference between the medians was significant (p<0.01). Absolute cathepsin K levels in the crevicular fluid of all implants investigated showed a positive correlation with PD (R=0.25; p=0.03), MPI (R=0.28; p=0.01) and MBI (R=0.32; p<0.01). Absolute cathepsin K levels in the crevicular fluid also correlated with the adsorbed volume of gingival crevicular fluid (R=0.51; p<0.01). When normalized to the adsorbed volume of gingival crevicular fluid, the concentration of cathepsin K was 2.2 (0.01–6.4) nM around control implants and 1.7 (0.4–4.6) nM in the peri‐implantitis group (p=0.33). Patients' age correlated with sample volume and with cathepsin K normalized to the adsorbed volume of gingival crevicular fluid (R=0.39; p<0.01). Moreover, significant differences between male and female (p<0.01, p<0.01), and between mandible and maxilla (p<0.05, p<0.01), but not between buccal and lingual sites (p=0.99, p=0.93), were observed when analysed for the parameters adsorbed volume and absolute cathepsin K levels.Conclusion: Clinical parameters of peri‐implantitis are associated with a higher amount of cathepsin K and a higher volume adsorbed to filters strips. To establish cathepsin K as a biochemical parameter to monitor peri‐implant tissue health, age, sex and collection site should be considered to avoid interfering influences because of sample inhomogenity. Also a prospective study over time including more patients would be necessary.
Clinical and microbiological effects of different antimicrobials on generalized aggressive periodontitis
Authors: Xajigeorgiou Christiana , Sakellari Dimitra , Slini Theodora , Baka Anneta , Konstantinidis Antonis 
Published: March 2006

AbstractAim: To evaluate and compare the effects of adjunctive metronidazole plus amoxicillin, doxycycline and metronidazole on clinical and microbiological parameters in patients with generalized aggressive periodontitis.Material and Methods: Forty‐three patients participated in this randomized clinical trial divided into four groups. Six weeks after scaling and root planning (SRP), groups 1–3 received adjunctive metronidazole, plus amoxicillin, doxycycline and metronidazole respectively, and group 4 acted as controls. Clinical recordings concerning probing depth, probing attachment level and bleeding on probing were performed at baseline, 6 weeks after SRP and 6 months from baseline. Subgingival samples were analysed using the ‘checkerboard’ DNA–DNA hybridization for Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Tannerella forsythia and Treponema denticola.Results: All treatments resulted in improvement of clinical parameters (ANOVA p>0.05). Systemic administration of metronidazole plus amoxicillin or metronidazole resulted in statistically significant greater reduction of the proportion of sites > 6mm than SRP (z‐test, p<0.05). These antimicrobials yielded a significant effect on levels of important periodontal pathogens for 6 months.Conclusion: Adjunctive metronidazole plus amoxicillin or metronidazole alone (when A.actinomycetemcomitans is not involved) is effective in deep pockets of aggressive periodontitis patients.
Nine‐ to fourteen‐year follow‐up of implant treatment. Part II: presence of peri‐implant lesions
Authors: Roos‐Jansåker Ann‐Marie , Lindahl Christel , Renvert Helena , Renvert Stefan 
Published: March 2006

AbstractObjectives: The aim of this study was to analyse the proportions of peri‐implant lesions at implants after 9–14 years of function.Material and Methods: Two hundred and ninety‐four patients underwent implant therapy during the years 1988–1992 in Kristianstad County. These individuals were recalled to the speciality clinic 1 and 5 years after placement of the suprastructure. Between 2000 and 2002, 218 patients with 999 implants were examined clinically and radiographically.Results: Forty‐eight per cent of the implants had probing depth 4 mm and bleeding on probing (peri‐implant mucositis). In 20.4% of the implants, the bone level was located 3.1 mm apical to the implant shoulder. Progressive bone loss (1.8 mm) during the observation period was found in 7.7% of the implants. Peri‐implantitis defined as bone loss 1.8 mm compared with 1‐year data (the apical border of the bony defect located at or apical to the third thread, i.e. a minimum of 3.1 mm apical to the implant shoulder), combined with bleeding on probing and or pus, were diagnosed among 16% of the patients and 6.6% of the implants.Conclusion: After 10 years in use without systematic supportive treatment, peri‐implant lesions is a common clinical entity adjacent to titanium implants.
Nine‐ to fourteen‐year follow‐up of implant treatment. Part I: implant loss and associations to various factors
Authors: Roos‐Jansåker Ann Marie , Lindahl Christel , Renvert Helena , Renvert Stefan 
Published: March 2006

AbstractObjectives: The aim of the present study was to evaluate the long‐term result of implant therapy, using implant loss as outcome variable.Material and Method: Two hundred and ninty‐four patients had received implant therapy (Brånemark System®) during the years of 1988–1992 in Kristianstad County, Sweden. The patients were recalled to the speciality clinic 1 and 5 years after placement of the suprastructure. Between 2000 and 2002, 9–14 years after implant placements, the patients were again called in for a complete clinical and radiographic examination.Results: Two hundred and eighteen patients treated with 1057 implants were examined. Twenty‐two patients had lost 46 implants and 12 implants were considered “sleeping implants”. The overall survival rate was 95.7%. Implant loss appeared in a cluster in a few patients and early failures were most common. Eight patients lost more than one fixture. A significant relationship was observed between implant loss and periodontal bone loss of the remaining teeth at implant placement. Maxillary, as opposed to mandibulary implants, showed more implant loss if many implants were placed in the jaw. A significant relationship between smoking habits and implant loss was not found.Conclusion: A history of periodontitis seems to be related to implant loss.
Nine‐ to fourteen‐year follow‐up of implant treatment. Part III: factors associated with peri‐implant lesions
Authors: Roos‐Jansåker Ann‐Marie , Renvert Helena , Lindahl Christel , Renvert Stefan 
Published: March 2006

AbstractObjective: The aim of the present paper was to analyse, on patient and implant basis, factors related to peri‐implant lesions.Material and Methods: Two hundred and eighteen patients treated with titanium implants were examined for biological complications at existing implants 9–14 years after initial therapy. The effects of several potentially explanatory variables, both on patient and on implant levels, were analysed.Results: On the implant level, the presence of keratinized mucosa (p=0.02) and plaque (p=0.005) was associated with mucositis (probing depth 4 mm+bleeding on probing). The bone level at implants was associated with the presence of keratinized mucosa (p=0.03) and the presence of pus (p<0.001). On the patient level, smoking was associated with mucositis, bone level and peri‐implantitis (p=0.02, <0.001 and 0.002, respectively). Peri‐implantitis was related to a previous history of periodontitis (p=0.05).Conclusions: Individuals with a history of periodontitis and individuals who smoke are more likely to develop peri‐implant lesions.
Joseph Conrad Criticism
Authors: Peters John G. 
Published: March 2006

ArticleThis essay is a brief survey of the history of commentary on the life and works of Joseph Conrad. Beginning with some of the early shorter and extended commentaries that appeared during the second decade of the twentieth century and ending with some of the most recent commentaries, this overview is intended to give the reader a clear idea of the significant issues that have arisen in the study of Conrad’s life and works. During the course of this essay, dominant movements will appear in Conrad studies: biographical/historical studies appearing during the 1920s and 1930s, psychological studies appearing during the 1950s and 1960s, poststructural and postcolonial studies appearing during the 1980s and 1990s, and gender studies appearing more recently. Furthermore, important individual commentaries will also be considered, so that the reader will have a good idea of where to go to investigate further various issues regarding Conrad’s life and works.
Making Time: Narrative Temporality in Twentieth‐Century Literature and Theory
Authors: Richardson Brian 
Published: March 2006

AbstractThis essay attempts to provide a brief survey of twentieth‐century constructions of narrative time in modernist, avant‐garde, and postmodern works and outlines the various theoretical positions these texts have engendered. Beginning with standard modernist practices that present a temporally scrambled story for the reader to reconstitute, I go on to identify some less well known but equally experimental uses of linear temporal order. This is followed by accounts more extreme, nonrealistic constructions of time in avant‐garde, postmodern, and science fiction texts. I conclude with an assessment of standard theories of narrative temporality and a brief look at current work in the field, including attempts to articulate the differing temporalities of serial, postmodern, gay, and postcolonial narratives.
Spoon River Anthology’s Heterosexual Heartland
Authors: Herring Scott 
Published: March 2006

AbstractCritics often assume Edgar Lee Masters’s best‐selling 1915 collection of poems, Spoon River Anthology, to be a damning account of small‐town corruption and sexual degeneration. This essay argues the counter‐intuitive claim that the anthology instead confirms a pastoral image of small town life even as it appears to negate this ideal. I suggest that Spoon River Anthology paradoxically confirms the idyllic image of the small Midwestern town through the collection’s representations of adultery, unrestrained lust, and promiscuity – activities that were often associated with an “unnatural” version of heterosexuality in the early twentieth‐century United States. To show that Masters’s critical account of Spoon River’s citizenry serves to substantiate representations of the heartland as an idyllic space for opposite‐sex couplings, I offer close readings of two poems –“Lucinda Matlock” and “Washington McNeely”– and illustrate how they each present readers with compulsory versions of heterosexual couplings that contrast to the “deviant” opposite‐sex activities that saturate the remainder of the text.