bluuebunny/crossref_metadata_2025 huggingface dataset:
Dedicated Widows in Codex Theodosianus 9.25?
Authors: Wilkinson Kevin W.
Published: March 2012

Two fourth-century laws dealing with raptus , "abduction," preserved in title 9.25 of the Codex Theodosianus , have traditionally been read as protections for Christian virgins and widows who had taken vows of continence. A careful examination of these laws suggests something quite different. C. Th. 9.25.1 appears merely to extend existing penalties for the abduction of unwed girls to cover the abduction of widows of any sort. C. Th. 9.25.2 is corrupt in our manuscripts. The version printed in the standard critical edition, which includes mention of dedicated widows, is poorly attested and almost certainly incorrect. In its original form, this law censured only the abduction or seduction of dedicated virgins. There is therefore no legislation in the Code that refers to a class of widow who was vowed to God. This is as expected, for canonical and legal recognition of the widow's vow (as a binding oath that conferred a new status) only begins to emerge in the fifth century, at a point roughly contemporary with the compilation of the Code .
The roles of verb semantics, entrenchment, and morphophonology in the retreat from dative argument-structure overgeneralization errors
Authors: Ambridge Ben , Pine Julian M. , Rowland Caroline F. , Chang Franklin
Published: March 2012

Children (aged five-to-six and nine-to-ten years) and adults rated the acceptability of well-formed sentences and argument-structure overgeneralization errors involving the prepositional-object and double-object dative constructions (e.g. Marge pulled the box to Homer /* Marge pulled Homer the box ). In support of the entrenchment hypothesis, a negative correlation was observed between verb frequency and the acceptability of errors, across all age groups. Adults additionally displayed sensitivity to narrow-range semantic constraints on the alternation, rejecting double-object dative uses of novel verbs consistent with prepositional-dative-only classes and vice versa. Adults also provided evidence for the psychological validity of a proposed morphophonological constraint prohibiting Latinate verbs from appearing in the double-object dative. These findings are interpreted in the light of a recent account of argument-structure acquisition, under which children retreat from error by incrementally learning the semantic, phonological, and pragmatic properties associated with particular verbs and particular construction slots.
A test of the relation between working-memory capacity and syntactic island effects
Authors: Sprouse Jon , Wagers Matt , Phillips Colin
Published: March 2012

The source of syntactic island effects has been a topic of considerable debate within linguistics and psycholinguistics. Explanations fall into three basic categories: grammatical theories, which posit specific grammatical constraints that exclude extraction from islands; grounded theories, which posit grammaticized constraints that have arisen to adapt to constraints on learning or parsing; and reductionist theories, which analyze island effects as emergent consequences of non-grammatical constraints on the sentence parser, such as limited processing resources. In this article we present two studies designed to test a fundamental prediction of one of the most prominent reductionist theories: that the strength of island effects should vary across speakers as a function of individual differences in processing resources. We tested over three hundred native speakers of English on four different island-effect types ( whether , complex NP, subject, and adjunct islands) using two different acceptability rating tasks (seven-point scale and magnitude estimation) and two different measures of working-memory capacity (serial recall and n -back). We find no evidence of a relationship between working-memory capacity and island effects using a variety of statistical analysis techniques, including resampling simulations. These results suggest that island effects are more likely to be due to grammatical constraints or grounded grammaticized constraints than to limited processing resources.
A novel experimental paradigm for distinguishing between what is said and what is implicated
Authors: Doran Ryan , Ward Gregory , Larson Meredith , McNabb Yaron , Baker Rachel E.
Published: March 2012

That there is a theoretical distinction between context-dependent and context-independent aspects of utterance interpretation has become a standard assumption in current theories of meaning; however, how and where to draw this distinction has been the subject of considerable debate. In the current study, we investigate whether speakers can systematically distinguish between what is said and what is implicated (Grice 1989 [1967]) using a novel truth-value judgment paradigm across a wide range of implicature types. We found that, by providing participants with a clear set of judgment criteria, including the adoption of an objective third-person perspective, we were able to enhance their ability to distinguish conversational implicature from truth-conditional meaning. In addition, we found that none of the implicature types we investigated was either consistently incorporated into or consistently excluded from what is said. Instead, our findings revealed considerable variation in frequency of incorporation across implicature types in ways that do not correspond straightforwardly to the various taxonomies of implicature types proposed in the literature.
Endangered language families
Authors: Whalen D. H. , Simons Gary F.
Published: March 2012

Linguists have increased their documentation efforts in response to the sharp decline in the number of languages. Greater awareness and new sources of funding have led to an upsurge in language documentation. While individual languages make unique contributions to the world’s linguistic heritage, language families, by virtue of their shared heritage, have related contributions to make. The endangerment of entire families, while implied by the loss of language, has not been explored to date. Here, we examine estimates of how many linguistic stocks (the largest subgroups of related languages that are reconstructable) consist entirely of endangered languages and thus are endangered themselves. Our data set includes 372 stocks that had at least one living language in 1950. Our finding is that since that time, 15% of the world’s linguistic stocks have become extinct and another 27% are now moribund in that direct estimates of endangerment indicate that no member languages are being learned by children. For cases where direct estimates were not found, we used population as a proxy for endangerment. If, as many predict, a further 50% of the world’s languages become extinct or moribund in this century, then an additional 25% of the linguistic stocks would be at risk of being lost. If 90% share this fate, only 11% of stocks would have at least one presumably ‘safe’ language. A comparison of the vitality of linguistic stocks by world areas yields the following ranking from worst to best: Americas, Pacific, Asia, Africa, Europe. Finally, some aspects of language that are unique to disappearing language stocks are outlined. Renewed efforts at documenting members of such stocks seem justified.
A usage-based theory of grammatical status and grammaticalization
Authors: Boye Kasper , Harder Peter
Published: March 2012

This article proposes a new way of understanding grammatical status and grammaticalization as distinctive types of linguistic phenomena. The approach is usage-based and links up structural and functional, as well as synchronic and diachronic, aspects of the issue. The proposal brings a range of previously disparate phenomena into a motivated relationship, while certain well-entrenched criteria (such as ‘closed paradigms’) are shown to be incidental to grammatical status and grammaticalization. The central idea is that grammar is constituted by expressions that by linguistic convention are ancillary and as such discursively secondary in relation to other linguistic expressions, and that grammaticalization is the kind of change that gives rise to such expressions.
Rhetorical Forms of Symbolic Labor: The Evolution of Iconic Representations in China’s Model Worker Awards
Authors: Butterfield Rya
Published: March 2012

As the steadily expanding cyberpublic presents both obstacles and opportunities for Communist Party rule in China, the party has responded by adapting the rhetorical strategies of the Model Worker (MW) commendations to a changing political environment. Using role model representations to encourage particular kinds of citizen labor, the system has changed from Maoist single-lane authoritarianism to a multilane interaction between the public and the party. This essay investigates the epideictic function, adaptation, and modification of MW awards via Kenneth Burke’s symbolic labor. Tracing the awards through the periods of leadership from Mao Zedong to Deng Xiaoping to Hu Jintao, I explore how the structure of the MW program has evolved into a rhetorical strategy capable of stabilizing party power through the moralization of party initiatives and the promulgation of party ideals despite increases in new media forms and institutions.
Race, Rhetoric, and Running for President: Unpacking the Significance of Barack Obama’s “A More Perfect Union” Speech
Authors: Dilliplane Susanna
Published: March 2012

Barack Obama’s “A More Perfect Union” speech was widely viewed as a key rhetorical moment in the 2008 presidential campaign. The purpose of this essay is to unpack reasons why the speech was significant, focusing particularly on the complex historical and contemporary dynamics of African American oratory, black churches, race relations, and American politics. I argue that the significance of the speech lies in the specific rhetorical challenges posed by the immediate context, the rhetorical strategy that Obama used to negotiate those challenges, and the way in which this strategy resonated more broadly with the rhetorical themes underlying Obama’s candidacy.
The Conservative Canon and Its Uses
Authors: Lee Michael J.
Published: March 2012

In this essay, I aim to locate the scriptural force of American conservatism’s secular canon. My basic claim is that the canon created and managed the potential for symbolic fusion and fracture among conservatives. The canon provided the tools to weather the rocky marriage between various conservative sects: traditionalists, libertarians, neoconservatives, and others; the canon afforded resources for each faction to establish their bona fides and to protect their version of authentic conservatism from impostors and apostates. I conclude by analyzing the link between the principles of classical conservatism and canonical politics.
Contact Rhetoric: Bodies and Love in Deus Caritas Est
Authors: Radwan Jon
Published: March 2012

A close textual analysis of Pope Benedict XVI’s inaugural encyclical Deus Caritas Est—God is Love is offered from the perspective of Platonic and contemporary rhetorical theory. An acclaimed inspirational success, this letter proposes loving “encounter” and “response” as the fundamental dynamic of Christian communication; God is “felt” and made manifest in concrete love-of-neighbor. Benedict’s “contact” orientation has significant implications for contemporary theory—humanity becomes ontologically contiguous, subjects are holistically embodied, Truth is grounded in co-felt exchange, and discourse is decentered by direct public engagement. Deus Caritas Est draws attention to ethical limits in Dramatism and Logology and advances embodied, invitational, and theological perspectives on rhetorical theory by showing how genuine love initiates and feeds a divine dynamic that can transcend divisions and unite humanity.
The Promise of Angiogenic Markers for the Early Diagnosis and Prediction of Preeclampsia
Authors: Hagmann Henning , Thadhani Ravi , Benzing Thomas , Karumanchi S Ananth , Stepan Holger
Published: March 2012

BACKGROUND

An imbalance in circulating factors that regulate blood vessel formation and health, referred to as angiogenic factors, plays a central role in the pathogenesis of preeclampsia.

CONTENT

Several studies have demonstrated a strong association between altered circulating angiogenic factors and preeclampsia. These factors include circulating antiangiogenic proteins such as soluble fms-like tyrosine kinase 1 and soluble endoglin and proangiogenic protein such as placental growth factor. Abnormalities in these circulating angiogenic factors are not only present during clinical disease, but also antedate clinical signs and symptoms by several weeks. These alterations are particularly prominent in patients who present with preeclamptic signs and symptoms prematurely and/or in patients with severe preeclampsia. The availability of automated platforms for the rapid measurement of circulating angiogenic proteins in blood samples has now allowed researchers and clinicians to evaluate the utility of these assays in the diagnosis of the disease, in the stratification of patients in clinical trials, or in the monitoring of therapies. In this review we highlight the various studies that have been performed, with a focus on large validation studies.

Measurement of circulating angiogenic proteins for the diagnosis and prediction of preeclampsia is still at an early stage but is rapidly evolving. Standardization across the various automated platforms and prospective studies that demonstrate clinical utility are needed.
Increased Cardiac Troponin I As Measured by a High-Sensitivity Assay Is Associated with High Odds of Cardiovascular Death: The Minnesota Heart Survey
Authors: Apple Fred S , Steffen Lyn M , Pearce Lesly A , Murakami MaryAnn M , Luepker Russell V
Published: March 2012

BACKGROUND

We examined several novel biomarkers of different pathophysiologic pathways as predictors of cardiovascular mortality in participants enrolled in the Minnesota Heart Survey (MHS), a population-based study of cardiovascular disease (CVD) risk factors.

METHODS

In a nested case-control study within MHS, 7 biomarkers were assayed in serum samples from 211 patients identified after 8–15 years of follow-up who died of cardiovascular causes (cardiovascular heart disease, stroke, congestive heart failure) and 253 controls matched on age, sex, and study year. Logistic regression analysis, adjusted for age, race, sex, education, study year, smoking, abdominal obesity, diabetes, serum total cholesterol, systolic blood pressure, previous hospitalization for a CVD event, and other significant biomarkers, was used to evaluate the relations of biomarkers relative to the odds of CVD mortality.

RESULTS

Cases survived a median of 7.2 years after enrollment. Increased N-terminal pro-B type natriuretic peptide (NT-proBNP) (19% vs 4.3%), increased high-sensitivity C-reactive protein (hs-CRP) (71% vs 51%), and increased high-sensitivity cardiac troponin I (hs-cTnI) (8.7% vs 1.0%) were more common among cases than among controls (all P < 0.001 in unadjusted analyses). The adjusted odds of death were greater among cases compared to controls for increased NT-proBNP [odds ratio (OR) 5.67, 95% CI 2.17–15], hs-CRP (OR 1.73, 95% CI 1.03–2.89), and hs-cTnI (OR 8.53, 95% CI 1.68–43), and decreased ST2 (OR 1.92, 95% CI 1.05–3.48).

CONCLUSIONS

When measured by an hs-cTnI assay, cTnI is a key biomarker associated with increased cardiovascular death in a community sample when evaluated in a multiple biomarker analysis.
Modeling a New Rotational Reciprocating Plate Impeller Using Computational Fluid Dynamics
Authors: Lin Yun , Thibault Jules , Zhang Zisheng
Published: March 2012

A new impeller, the rotational reciprocating plate impeller (RRPI), designed to handle highly viscous fermentation broth, was modeled using computational fluid dynamics (CFD) to gain more insight into its performance. A standard Rushton turbine was first simulated using CFD software Fluent(r) for validation purposes. Under experimental conditions, the prediction of the power number obtained from CFD simulation agrees qualitatively with the experimental data. Multiphase simulation was used to better represent the gas-liquid interactions using Eulerian multiphase model. The rotational reciprocating movement of the RRPI was approximated using small time steps, each of which has a different rotation speed. Water and carboxymethyl cellulose (CMC) solutions were used as model fluids to represent the different stages of a typical fermentation with a rheologically-evolving broth. By comparing the simulation results to experimental data, the efficiency of the toothed belt used to drive the Rushton turbine impeller was confirmed to be high as expected, while the efficiency of the three-arm linkage system used to achieve the rotational reciprocation of the RRPI was estimated to be around 80%. The uniformity of mixing with the 3-Rushton impeller and the RRPI was compared to each other by investigating the distribution of liquid velocity, shear rate, and broth viscosity. The simulation results proved that the RRPI eliminated the dead zones that usually form when the Rushton turbines are used in viscous medium.
The effect of cancer procoagulant on expression of metastatic and angiogenic markers in breast cancer and embryonic stem cell lines
Authors: Kee Nalise Low Ah , Naudé Ryno J. , Blatch Gregory L. , Frost Carminita L.
Published: March 2012

Cancer procoagulant is present only in malignant tumours and the undifferentiated tissues of human placenta. Its possible role in angiogenesis and metastasis was investigated. Cancer procoagulant increased the steady-state mRNA level of L1 cell adhesion molecule (L1CAM) in MCF-7 breast cancer cells and E14 mouse embryonic stem cells (MESCs), while an increase in angiogenin mRNA was observed in MDA-MB-231 breast cancer cells. Furthermore, production of vascular endothelial growth factor (VEGF) protein in MCF-7 breast cancer cells and E14 MESCs, but decreased in MDA-MB-231 breast cancer cells. We conclude that cancer procoagulant could potentially play a part in angiogenesis in cancer and vascular development during embryonic development.
Prenatal and Passive Smoke Exposure and Incidence of Asthma and Wheeze: Systematic Review and Meta-analysis
Authors: Burke Hannah , Leonardi-Bee Jo , Hashim Ahmed , Pine-Abata Hembadoon , Chen Yilu , Cook Derek G. , Britton John R. , McKeever Tricia M.
Published: March 2012

OBJECTIVES:

Exposure to passive smoke is a common and avoidable risk factor for wheeze and asthma in children. Substantial growth in the prospective cohort study evidence base provides an opportunity to generate new and more detailed estimates of the magnitude of the effect. A systematic review and meta-analysis was conducted to provide estimates of the prospective effect of smoking by parents or household members on the risk of wheeze and asthma at different stages of childhood.

METHODS:

We systematically searched Medline, Embase, and conference abstracts to identify cohort studies of the incidence of asthma or wheeze in relation to exposure to prenatal or postnatal maternal, paternal, or household smoking in subjects aged up to 18 years old. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were estimated by using random effects model.

RESULTS:

We identified 79 prospective studies. Exposure to pre- or postnatal passive smoke exposure was associated with a 30% to 70% increased risk of incident wheezing (strongest effect from postnatal maternal smoking on wheeze in children aged ≤2 years, OR = 1.70, 95% CI = 1.24–2.35, 4 studies) and a 21% to 85% increase in incident asthma (strongest effect from prenatal maternal smoking on asthma in children aged ≤2 years, OR = 1.85, 95% CI = 1.35–2.53, 5 studies).

CONCLUSIONS:

Building upon previous findings, exposure to passive smoking increases the incidence of wheeze and asthma in children and young people by at least 20%. Preventing parental smoking is crucially important to the prevention of asthma.
Implications of Childhood Autism for Parental Employment and Earnings
Authors: Cidav Zuleyha , Marcus Steven C. , Mandell David S.
Published: March 2012

OBJECTIVE:

To examine changes in parental labor force participation, hours of work, and annual earnings associated with childhood autism spectrum disorders (ASD).

METHODS:

We used the 2002–2008 Medical Expenditure Panel Survey to examine parental labor market outcomes of children with ASD relative to children with another health limitation and children without health limitations. A logit model was used to estimate parental labor force participation. A tobit model was used to estimate parental hours of work and earnings.

RESULTS:

On average, mothers of children with ASD earn 35% ($7189) less than the mothers of children with another health limitation and 56% ($14 755) less than the mothers of children with no health limitation. They are 6% less likely to be employed and work 7 hours less per week, on average, than mothers of children with no health limitation. There were no statistically significant differences in fathers’ labor market outcomes across 3 groups. On average, children with ASD are 9% less likely to have both parents working. Family earnings of children with ASD are 21% ($10 416) less than those of children with another health limitation and 28% ($17 763) less than those of children with no health limitation. Family weekly hours of work are an average of 5 hours less than those of children with no health limitation.

CONCLUSIONS:

Families of children with ASD face significant economic burden. Given the substantial health care expenses associated with ASD, the economic impact of having lower income in addition to these expenses is substantial. It is essential to design universal health care and workplace policies that recognize the full impact of autism.
A Phonetic Investigation of Single Word versus Connected Speech Production in Children with Persisting Speech Difficulties Relating to Cleft Palate
Authors: Howard Sara
Published: March 2012

Objective

To investigate the phonetic and phonological parameters of speech production associated with cleft palate in single words and in sentence repetition in order to explore the impact of connected speech processes, prosody, and word juncture on word production across contexts.

Participants

Two boys (aged 9 years 5 months and 11 years 0 months) with persisting speech impairments related to a history of unilateral cleft lip and palate formed the main focus of the study; three typical adult male speakers provided control data.

Method

Audio, video, and electropalatographic recordings were made of the participants producing single words and repeating two sets of sentences. The data were transcribed and the electropalatographic recordings were analyzed to explore lingual-palatal contact patterns across the different speech conditions. Acoustic analysis was used to further inform the perceptual analysis and to make specific durational measurements.

Results

The two boys’ speech production differed across the speech conditions. Both boys showed typical and atypical phonetic features in their connected speech production. One boy, although often unintelligible, resembled the adult speakers more closely prosodically and in his specific connected speech behaviors at word boundaries. The second boy produced developmentally atypical phonetic adjustments at word boundaries that appeared to promote intelligibility at the expense of naturalness.

Conclusion

For older children with persisting speech impairments, it is particularly important to examine specific features of connected speech production, including word juncture and prosody. Sentence repetition data provide useful information to this end, but further investigations encompassing detailed perceptual and instrumental analysis of real conversational data are warranted.
Fire resistance of hybrid fibre-reinforced, ultra-high-strength concrete columns with compressive strength from 120 to 200 MPa
Authors: Lee J.-H. , Sohn Y.-S. , Lee S.-H.
Published: March 2012

This study investigated fire resistance performance for ultra-high-strength concrete (120∼200 MPa) columns incorporating various types of fibres such as polypropylene, nylon and steel. First, 24 small columns were tested with a standard heating curve of ISO 834 for 3 h. The main parameters were the length of the polypropylene fibres and the content ratios of each fibre. In addition, the effects of aggregate types between natural and electric arc furnace oxidising slag aggregates were studied. The fire resistance performance of the specimens was classified by spalling degree, based on the weight loss, the spalling depth and the spalling area. The test results showed that the hybrid fibre reinforcement of polypropylene, nylon and steel fibres were the most effective in spalling protection. After the fire tests on small columns, full-scale columns with compressive strength of approximately 200 MPa were constructed and tested under column loads and subjected to severe fire condition using the ISO-834 fire curve. Superior fire resistance of ultra-high-strength concrete columns was found to be obtained by hybrid fibre reinforcement of 0·2, 0·2 and 0·5 vol.% of polypropylene, nylon and steel fibres, respectively.
Safety formats for non-linear analysis of concrete structures
Authors: Schlune Hendrik , Plos Mario , Gylltoft Kent
Published: March 2012

For realistic modelling of reinforced concrete structures, non-linear models are often inevitable, which raises the question of an appropriate safety format for non-linear analysis. This paper gives an overview of available safety formats and discusses their advantages and disadvantages. An analysis of available round robin tests and modelling competitions shows that current safety formats do not properly account for the modelling uncertainty of non-linear analysis. Based on this observation a new safety format was proposed which allows one to explicitly account for the modelling uncertainty. To avoid any interaction of the modelled response with the safety format, the mean in situ material parameters should be used in the non-linear analysis and a resistance safety factor is used to assure the intended reliability level. The application of the new safety format to beam sections loaded in bending showed that it offers a reliability level that is in good agreement with the target reliability.
Prey–predator dynamics in rotifers: density‐dependent consequences of spatial heterogeneity due to surface attachment
Authors: Vadstein Olav , Olsen Lasse M. , Andersen Tom
Published: March 2012

Classical models of prey–predator interactions assume that per capita prey consumption is dependent on prey density alone and that prey consumption (functional response) and consumer proliferation (numerical response) operate on the same timescales and without time lags. Several modifications have been proposed for resolving this timescale discrepancy, including variants where the functional response depends on both prey and predator densities. A microcosm system with the rotiferBrachionus‘Nevada' feeding on the prasinophyteTetraselmissp. showed significant (P< 0.0005) increases in steady‐state biomasses of both prey and predators with increasing carrying capacity (represented by total phosphorus of the growth medium), which is inconsistent with predictions based on the traditional prey‐only‐dependent functional response. We provide data indicating that surfaces where the predator can attach provide a high‐quality habitat for rotifers, which can result in a predator‐dependent functional response. We also show that partitioning between the attached and free‐swimming habitats was fast compared to the timescale of the numerical response. When attached to surfaces, rotifers maximized net energy gain by avoiding the high cost of swimming and by increased food capture due to reduced viscous drag. A mathematical model with prey‐dependent functional response and wall‐attached and free‐swimming fractions of the population describes our data adequately. We discuss the implications of this finding for extrapolating microcosm experiments to systems with other surface‐to‐volume ratios, and to what extent our findings may apply to other popular model organisms for prey–predator interaction.
Gingival State and Dental Calculus in Early‐Onset Periodontitis
Authors: Albandar Jasim M. , Brown L. Jackson , Brunelle Janet A. , Löe Harald
Published: March 2012

This study was undertaken to 1) compare the prevalence of gingival inflammation and dental calculus in adolescents with early‐onset periodontitis and their matched controls and 2) assess and compare the relationship between the presence of dental calculus and the extent of gingival bleeding and attachment loss in these subjects. The study group consisted of 1,285 13 to 20 year‐old individuals, 651 males and 634 females, selected from a national survey of the oral health of U.S. adolescents in 1986/1987. It included 709 (55.2%) Blacks, 224 (17.4%) Hispanics, and 352 (27.4%) Whites. Eighty‐nine subjects had localized or generalized juvenile periodontitis (JP), 218 had incidental attachment loss (IAL), and 978 were without clinical attachment loss (controls). The controls were matched to cases on gender, race, age, and geographic location. The subjects were examined clinically to assess the percentage of sites with gingival bleeding and supragingival calculus only and subgingival calculus with or without supragingival calculus. The IAL and JP groups had significantly more gingival bleeding and subgingival calculus than the controls. Also, the JP group had significantly higher prevalence of both conditions than the IAL group. The percentage of sites with supragingival calculus was not different between the groups, but varied by ethnicity. Hispanics with JP had the highest percentage of sites with gingival bleeding and subgingival calculus, and the lowest percentage of sites with only supragingival calculus. The results demonstrate that gingival inflammation and subgingival calculus are associated with early periodontal breakdown, and contradict earlier reports of early‐onset periodontitis not being associated with these factors. J Periodontol 1996;67:953–959.
Severe Periodontitis and Risk for Poor Glycemic Control in Patients with Non‐Insulin‐Dependent Diabetes Mellitus
Authors: Taylor George W. , Burt Brian A. , Becker Mark P. , Genco Robert J. , Shlossman Marc , Knowler William C. , Pettitt David J.
Published: March 2012

This study tested the hypothesis that severe periodontitis in persons with non‐insulin‐dependent diabetes mellitus (NIDDM) increases the risk of poor glycemic control. Data from the longitudinal study of residents of the Gila River Indian Community were analyzed for dentate subjects aged 18 to 67, comprising all those: 1) diagnosed at baseline with NIDDM (at least 200 mg/dL plasma glucose after a 2‐hour oral glucose tolerance test); 2) with baseline glycosylated hemoglobin (HbA1) less than 9%; and 3) who remained dentate during the 2‐year follow‐up period. Medical and dental examinations were conducted at 2‐year intervals. Severe periodontitis was specified two ways for separate analyses: 1) as baseline periodontal attachment loss of 6 mm or more on at least one index tooth; and 2) baseline radiographic bone loss of 50% or more on at least one tooth. Clinical data for loss of periodontal attachment were available for 80 subjects who had at least one follow‐up examination, 9 of whom had two follow‐up examinations at 2‐year intervals after baseline. Radiographic bone loss data were available for 88 subjects who had at least one follow‐up examination, 17 of whom had two follow‐up examinations. Poor glycemic control was specified as the presence of HbA1 of 9% or more at follow‐up. To increase the sample size, observations from baseline to second examination and from second to third examinations were combined. To control for non‐independence of observations, generalized estimating equations (GEE) were used for regression modeling. Severe periodontitis at baseline was associated with increased risk of poor glycemic control at follow‐up. Other statistically significant covariates in the GEE models were: 1) baseline age; 2) level of glycemic control at baseline; 3) having more severe NIDDM at baseline; 4) duration of NIDDM; and 5) smoking at baseline. These results support considering severe periodontitis as a risk factor for poor glycemic control and suggest that physicians treating patients with NIDDM should be alert to the signs of severe periodontitis in managing NIDDM. J Periodontol 1996;67:1085–1093.
Analysis of Consecutively Placed Loaded Root‐Form and Plate‐Form Implants in Adult Macaca mulatta Monkeys
Authors: Fritz Michael E. , Braswell Laura D. , Koth David , Jeffcoat Marjorie , Reddy Michael , Brogan Donna , Cotsonis George , Winter Marvin , Lemons Jack E.
Published: March 2012

The present paper describes 36 consecutively treated non‐human primates (Macaca mulatta) as part of a balanced block design study to examine osseointegration in root‐and plate‐form implants prepared by atraumatic preparation of bone. Clinical measurements around selected teeth and digital radiology were utilized to monitor periodontal disease and bone loss around root‐ and plate‐form implants which were loaded with a fixed prosthesis. Results indicate that once monthly regimen of scaling and root planing can prevent attachment loss in natural teeth, serving as abutments of loaded bridges. Root‐form implants exhibited a significant loss of crestal bone height during the first year (P < 0.03) while plate‐form implants showed less loss in bone height. There was an increase in bone mass over time for root‐form or plate‐form implants. Both root‐form and plate‐form implants provided radiographic evidence of osseointegration in loaded bridges. J Periodontol 1996;67:1322–1328.
Microbiota Associated With Consecutively Placed Loaded Root‐Form and Plate‐Form Implants in Adult Macaca mulatta Monkeys
Authors: Eke Paul I. , Braswell Laura D. , Fritz Michael E.
Published: March 2012

This study describes the microbiota associated with consecutively placed rootform and plate‐form implants placed in similar mandibular arches of rhesus (Macaca mulatta) monkeys and loaded with similar prostheses. The teeth and implants were maintained by monthly scaling and root planing. Twenty‐four round (root‐form) and 24 flat (plate‐form) implants were placed in the loci of #18 and #31 in 36 adult monkeys. The microbiota around implants and mandibular molar teeth were studied quarterly from the day prostheses were loaded (Day 0) for 12 months. The microbiota were characterized by culture and dark field microscopy. Overall, levels of putative peri‐implant pathogens studied declined or remained statistically unchanged at implant or mandibular molar sites. Levels of spirochetes and Porphyromonas species declined at mandibular molar teeth but increased at dental implant sites. Levels of A. actinomycetemcomitans declined significantly at implants and mandibular tooth sites during the period. No statistically significant difference was detected between levels of microorganisms colonizing root‐form and plate‐form implants. This study finds no significant increase in levels of putative peri‐implant pathogens at root‐form and plateform implants sites in the first 12 months after prosthetic loading when maintained by monthly scaling. J Periodontol 1996;67:1329–1334.
Regeneration of Rat Calvarial Defects Using a Bioabsorbable Membrane Technique: Influence of Collagen Cross‐linking
Authors: Brunel Gérard , Piantoni Philippe , Elharar Frédéric , Benqué Edmond , Marin Pierre , Zahedi Shahram
Published: March 2012

The aim of the present study was to examine the influence of cross‐linking on collagen membranes used for guided bone regeneration of calvarial defects in rats. In 48 Wistar rats, divided equally into 4 groups, 1 control and 3 experimental, standardized transosseous circular calvarial defects were made midparietally. In the control group, the defect was only covered by the soft tissue flap while in the 3 experimental groups, 3 differently cross‐linked collagen membranes were interposed between the osseous defect and the overlying flap before suturing. The healing was assessed at 10, 20, and 30 days after surgery. The results showed that augmenting the degree of collagen cross‐linking diminished the membrane resorption rate. Compared to the sham‐operated sites, the membrane protected defects showed significantly more bone regeneration (on average 4 times more) as attested by histology and measured by histomorphometric analysis. Although the bone gain seemed to augment with increasing degrees of cross‐linking, the results within the 3 experimental groups were not statistically different. Since longer healing periods might have been necessary to substantiate results within experimental groups, a study is currently undertaken to evaluate this aspect. This study demonstrated the efficacy of collagen membranes in guiding bone regeneration, as well as the importance of the type and degree of cross‐linking. J Periodontol 1996;67:1342–1348.
Molecular Genetics and the Analysis of Leukotoxin in A. actinomycetemcomitans
Authors: Kolodrubetz David
Published: March 2012

The primary pathogen involved in certain forms of early‐onset periodontitis is A. actinomycetemcomitans. Among its numerous potential virulence factors is a leukotoxin that kills certain host defense cells. In order to analyze the regulation and in vivo function of leukotoxin and other virulence factors in A. actinomycetemcomitans, molecular genetic approaches are being established. Although there has been significant progress in developing plasmids and bacteriophage as E. colilA. actinomycetemcomitans shuttle vectors, more work needs to be done. Tn5‐based transposon mutagenesis has been shown to work in this organism. Targeted mutagenesis is now possible in A. actinomycetemcomitans; exogenously introduced DNA recombines efficiently with the homologous chromosomal locus. These techniques have been applied to studies of leukotoxin. Targeted mutagenesis has been used to construct leukotoxin negative mutants that are otherwise isogenic with their leukotoxin‐producing parent strain. These mutants can be tested in animal models to ascertain the in vivo role of leukotoxin in A. actinomycetemcomitans pathogenesis. Gene targeting has also been used to make strains in which the leukotoxin promoter is regulating the synthesis of a β‐galactosidase reporter gene. Such strains have been used to show that leukotoxin synthesis increases in cells grown anaerobically, but that several other environmental changes had little effect on leukotoxin synthesis. Finally, plasmid shuttle vectors with leukotoxin promoters from various strains of A. actinomycetemcomitans fused to reporter genes have been used in cis/trans tests to show that leukotoxin promoter sequences and strain‐specific trans‐acting factors are important in determining why different strains of A. actinomycetemcomitans produce different levels of leukotoxin. J Periodontol 1996;67:309–316.
Genetic Risk Factors for Early‐Onset Periodontitis
Authors: Hart Thomas C.
Published: March 2012

Early‐onset periodontal diseases (EOP) are a heterogeneous group of diseases, sharing several characteristics including early onset and severe periodontal destruction. Although periodontopathogenic bacteria are primary etiologic agents in the disease process, familial aggregation of affected individuals suggests genetic factors also are important. Formal genetic studies suggest a pattern of disease transmission consistent with mendelian inheritance of a gene of major effect. This means that one or more genes could account for the observed familial pattern of some cases of early‐onset periodontitis. Clearly, both genetic and environmental risk factors are important in EOP. Epidemiological studies can identify risk factors for periodontitis on the population level. Although the association of a suspected risk factor can be studied with classic epidemiological techniques, these techniques are generally not applicable to the assessment of risk in individuals. Now with the advent of molecular epidemiology, it is possible to begin development of individual susceptibility profiles that may incorporate both host genetic and environmental components. Evidence for a central role of genetic risk factors in EOP makes these diseases a practical model for such studies. This review presents the primary support for genetic risk factors for EOP diseases and presents some of the potential genetic factors that may be useful in developing molecular epidemiological risk profiles for EOP. J Periodontol 1996;67:355–366.
The Association Between Estrogen Status and Alveolar Bone Density Changes in Postmenopausal Women With a History of Periodontitis
Authors: Payne Jeffrey B. , Zachs Neil R. , Reinhardt Richard A. , Nummikoski Pirkka V. , Patil Kashinath
Published: March 2012

While numerous studies have demonstrated a relationship between 17‐β‐estradiol (E2) deficiencies and skeletal bone loss in postmenopausal females, the influence of E2 deficiency on alveolar bone resorption is poorly understood. The purpose of this study was to examine the association between the estrogen status of postmenopausal women and alveolar bone density changes in a 1‐year longitudinal study. Twenty‐four postmenopausal women, within 7 years of menopause, were divided into 2 groups, E2‐sufficient (n = 10) and E2‐deficient (n = 14). Venous blood samples were taken at baseline, 6 months, and 1 year for radioimmunoassay determination of serum E2 levels. At baseline and 1 year, 4 vertical bite‐wing radiographs were taken for computerassisted densitometric image analysis (CADIA). Areas of interest (AOIs) for CADIA were crestal and subcrestal regions of posterior interproximal alveolar bone. Serum E2 levels were significantly higher at all 3 time points in the E2‐sufficient subjects (P < 0.002, repeated measures ANOVA). Overall, mean CADIA values (0.30 ± 0.07 for the E2‐sufficient women and ‐0.44 ± 0.07 for the E2‐deficient women) were statistically different between groups (P < 0.001, repeated measures ANOVA), indicating that the E2‐sufficient women displayed a mean net gain in alveolar bone density and the E2‐deficient women displayed a mean net loss in alveolar bone density. Furthermore, the E2‐sufficient women exhibited a higher frequency of sites demonstrating a gain in alveolar bone density, while the E2‐deficient women exhibited a higher frequency of sites demonstrating loss in alveolar bone density. These data suggest that estrogen status may influence alveolar bone density changes as demonstrated with CADIA. J Periodontol 1997;68:24–31.
The Effectiveness of an Aerosol Reduction Device for Ultrasonic Sealers
Authors: King Tracy B. , Muzzin Kathleen B. , Berry Charles W. , Anders Lisa M.
Published: March 2012

Intraoral use of ultrasonic scalers may generate aerosols that contain infectious microorganisms and therefore pose a hazard to the health of the dental professional. The purpose of this in vivo study was to determine if an aerosol reduction device for an ultrasonic sealer would be effective in reducing the amount of contaminated aerosols produced during ultrasonic instrumentation. Twelve adult subjects participated in the study. A split‐mouth design was utilized, and two treatments (in separate rooms) were performed on each subject: 1) ultrasonic scaling for 5 minutes with the aerosol reduction device; and 2) ultrasonic scaling for 5 minutes without the aerosol reduction device. The right or left side of the subject's mouth was randomly assigned to one of the two treatment groups. After instrumentation, the subject and operator remained motionless for 25 minutes during collection of aerosol particles. Air samples were collected on blood agar plates 6 inches from the subject's mouth. Replicate organism detection and counting plates were used to sample microorganisms present on the investigator's face shield. All plates were incubated for 3 days at 37°C. The results, using the paired t‐test (P < 0.001), indicate that the ultrasonic sealer without the aerosol reduction device had a significantly greater quantity of mean colony forming units (CFUs) 6 inches from the subject's mouth (45.1 ± 28.9) than the ultrasonic sealer with the aerosol reduction device (2.6 ± 3.6). No significant difference was evident in the number of CFUs found on the investigator's face shield. These data suggest that an aerosol reduction device is effective in reducing the number of microorganisms generated during ultrasonic scaling, therefore decreasing the risk of disease transmission. J Periodontol 1997;68:45–49.
Positive Correlation Between Blood Cyclosporin A Level and Severity of Gingival Overgrowth in Rats
Authors: Morisaki Ichijiro , Akiyama Yoriko M. , Miyawaki Yasuko N. , Mori Yuko
Published: March 2012

Cyclosporin a is a drug used to control rejection of organ transplantation and autoimmune diseases; however, it has also been implicated in gingival overgrowth. The present study investigates the relationship between severity of gingival overgrowth and blood cyclosporin A (CsA) levels in Fischer rats treated orally with CsA. Thirtysix 15‐day‐old male rats were divided into six experimental groups and given powdered rat chow containing 0, 50, 100, 200, 300, and 400 μg CsA/g diet ad libitum for 40 days. At the end of the 40‐day treatment period, whole blood samples were collected from each rat for assessment of CsA levels. The rats were then sacrificed and the gingival sulcus depth (pseudopocket) around mandibular molars measured to estimate gingival overgrowth. The blood levels of CsA in rats increased with increasing amounts of CsA provided in their food. A 100% incidence in gingival overgrowth was induced in all the rats treated orally with CsA. The overgrowth was more severe in buccal than in lingual gingiva. A significantly positive correlation was found between gingival sulcus depth and the blood CsA level (rs = 0.914, P < 0.0001; Spearman's correlation coefficient by rank). On histological examination, the overgrown gingiva consisted of a thickened epithelial layer and an accumulation of subepithelial fibrous connective tissue components without marked distortion of their proportion. J Periodontol 1997;68:7–11.