Systemic inhibition or global deletion of CaMKK2 protects against post-traumatic osteoarthritis

OBJECTIVE

To investigate the role of Ca^2+/calmodulin-dependent protein kinase 2 (CaMKK2) in post-traumatic osteoarthritis (PTOA).

METHODS

Destabilization of the medial meniscus (DMM) or sham surgeries were performed on 10-week-old male wild-type (WT) and Camkk2^-/- mice. Half of the DMM-WT mice and all other cohorts (n = 6/group) received tri-weekly intraperitoneal (i.p.) injections of saline whereas the remaining DMM-WT mice (n = 6/group) received i.p. injections of the CaMKK2 inhibitor STO-609 (0.033 mg/kg body weight) thrice a week. Study was terminated at 8- or 12-weeks post-surgery, and knee joints processed for microcomputed tomography imaging followed by histology and immunohistochemistry. Primary articular chondrocytes were isolated from knee joints of 4-6-day-old WT and Camkk2^-/- mice, and treated with 10 ng/ml interleukin-1β (IL)-1β for 24 or 48 h to investigate gene and protein expression.

RESULTS

CaMKK2 levels and activity became elevated in articular chondrocytes following IL-1β treatment or DMM surgery. Inhibition or absence of CaMKK2 protected against DMM-associated destruction of the cartilage, subchondral bone alterations and synovial inflammation. When challenged with IL-1β, chondrocytes lacking CaMKK2 displayed attenuated inflammation, cartilage catabolism, and resistance to suppression of matrix synthesis. IL-1β-treated CaMKK2-null chondrocytes displayed decreased IL-6 production, activation of signal transducer and activator of transcription 3 (Stat3) and matrix metalloproteinase 13 (MMP13), indicating a potential mechanism for the regulation of inflammatory responses in chondrocytes by CaMKK2.

CONCLUSIONS

Our findings reveal a novel function for CaMKK2 in chondrocytes and highlight the potential for its inhibition as an innovative therapeutic strategy in the prevention of PTOA.

Ecosystem services in vineyard landscapes: a focus on aboveground carbon storage and accumulation

BACKGROUND

Organic viticulture can generate a range of ecosystem services including supporting biodiversity, reducing the use of conventional pesticides and fertilizers, and mitigating greenhouse gas emissions through long-term carbon (C) storage. Here we focused on aboveground C storage rates and accumulation using a one-year increment analysis applied across different winegrape varietals and different-aged vineyard blocks. This produced a chronosequence of C storage rates over what is roughly the productive lifespan of most vines (aged 2-30 years). To our knowledge, this study provides the first estimate of C storage rates in the woody biomass of vines. Additionally, we assessed C storage in wildland buffers and adjacent oak-dominated habitats over a 9-year period.

RESULTS

Carbon storage averaged 6.5 Mg/Ha in vines. We found the average annual increase in woody C storage was 43% by mass. Variation correlated most strongly with vine age, where the younger the vine, the greater the relative increase in annual C. Decreases in C increment rates with vine age were more than offset by the greater overall biomass of older vines, such that C on the landscape continued to increase over the life of the vines at 18.5% per year on average. Varietal did not significantly affect storage rates or total C stored. Carbon storage averaged 81.7 Mg/Ha in native perennial buffer vegetation; we found an 11% increase in mass over 9 years for oak woodlands and savannas.

CONCLUSIONS

Despite a decrease in the annual rate of C accumulation as vines age, we found a net increase in aboveground C in the woody biomass of vines. The results indicate the positive role that older vines play in on-farm (vineyard) C and overall aboveground accumulation rates. Additionally, we found that the conservation of native perennial vegetation as vineyard buffers and edge habitats contributes substantially to overall C stores. We recommend that future research consider longer time horizons for increment analysis, as this should improve the precision of C accumulation rate estimates, including in belowground (i.e., soil) reservoirs.

Trait-based climate vulnerability of native rodents in southwestern Mexico

AIM

Incorporate species' trait information together with climate projections for associated habitat to assess the potential vulnerability of rodent taxa to climate change.

LOCATION

Oaxaca State, Mexico.

METHODS

We used a trait-based approach together with climate exposure models to evaluate the vulnerability of rodent species to projected climate conditions in the study region. Vulnerability was estimated based on three factors: (a) Level of climatic exposure that species are projected to experience across their current statewide range; (b) inherent species-specific sensitivity to stochastic events; and (c) species' capacity to cope with climate change effects. We defined species as inherently sensitive if they had any of the following: restricted geographic distribution in Mexico; narrow altitudinal range; low dispersal ability; or long generation length.

RESULTS

Vulnerability varied depending on the climate change scenario applied. Under the MPI general circulation model and current emissions trends, by 2099, all species evaluated were projected to have some level of threat (vulnerable for at least one factor), with 4 out of 55 species vulnerable for all three factors, 29 for two factors, and 22 for one factor. Six out of ten rodent species endemic to Oaxaca were vulnerable for two or more factors. We found that species with narrow and restricted-range distributions combined with low adaptive capacity were projected to be particularly vulnerable.

MAIN CONCLUSIONS

By including species-specific trait information in climate exposure assessments, researchers can contextualize and enhance their understanding about how climate change is likely to affect individual taxa in an area of interest. As such, studies like this one provide more relevant threat assessment information than exposure analyses alone and serve as a starting point for considering how climatic changes interact with an array of other variables to affect native species across their range.

Spinal cord syndromes in patients with systemic lupus erythematosus: differentiating lupus myelitis, neuromyelitis optica, and multiple sclerosis

OBJECTIVE

Non-infectious myelitis in systemic lupus erythematosus (SLE) may be due to SLE myelitis, comorbid multiple sclerosis (MS), or neuromyelitis optica (NMO). We compared characteristics of these three conditions in SLE patients at a large academic institution.

METHODS

We searched for neurologic diagnoses of SLE myelitis, NMO myelitis, and MS myelitis among 2297 patients with at least four 1997 American College of Rheumatology revised criteria for SLE between 2000 and 2015. Each subject was reviewed by a neurologist to confirm the underlying neurologic diagnosis. Demographic, clinical, laboratory, and radiographic data were extracted and compared using Fisher's exact test, analysis of variance, and Wilcoxon rank-sum test.

RESULTS

Fifteen of the 2297 subjects with SLE (0.7%) met criteria for a spinal cord syndrome: seven had SLE myelitis, three had AQP4 seropositive NMO, and five had MS. The median SLE Disease Activity Index 2000 score at time of neurologic syndrome presentation was higher in SLE myelitis subjects (8, interquartile range (IQR) 7-16) compared with subjects with NMO (6, IQR 0-14) or MS (2, IQR 0-4), p = 0.02. Subjects with SLE myelitis were also more likely to have elevated anti-dsDNA antibodies at presentation (86%) compared with subjects with NMO (33%) or MS (0%), p = 0.03.

CONCLUSION

Myelitis occurs rarely among patients with SLE. Compared with subjects with SLE + NMO and subjects with SLE + MS, subjects with SLE myelitis had higher SLE disease activity at presentation.

The importance of productivity and seasonality for structuring small rodent diversity across a tropical elevation gradient

Photosynthetic productivity is a key determinant of the abundance and distribution of biodiversity around the world. The effect of this productivity on the distribution patterns of mammals is frequently invoked; however, it is seldom measured directly. In this study, we used Sherman live traps set in dry and rainy seasons across a 2300-m elevation gradient in southwestern Mexico to assess small rodent species distributions, and to relate these patterns to habitat structure, climate, and a well-accepted measure of photosynthetic productivity: the normalized difference vegetation index (NDVI). While habitat structure and climate helped explain some of the patterns observed, NDVI proved to be the most important contributing variable for most of the distribution models. We also found that partitioning the gradient-distribution model by trapping season revealed strong differences in terms of the effect of NDVI and the other explanatory variables. For example, lower elevations were associated with seasonal and year-round reductions in rodent diversity and were composed almost exclusively of granivore-based species assemblages. By contrast, the middle and upper elevations were more species rich, less affected by seasonality, and characterized by omnivorous species. Our results suggest that the positive productivity-diversity relationship found may be due, at least in part, to increased food resources and niche opportunities at more productive elevations. Increased diversity at the higher elevations may also be partially due to reductions in competition that result from productivity increases, as well as from the broader spectrum of feeding guild representation that it and the lack of seasonality allow.

Pesticide exposure and risk of systemic lupus erythematosus in an urban population of predominantly African-American women

OBJECTIVE

Past studies have reported associations between pesticide exposure and the risk of systemic lupus erythematosus (SLE). Residential pesticide exposure has been less well studied than agricultural exposure. The purpose of this study was to assess SLE risk associated with residential pesticide exposure in an urban population of predominantly African-American women.

METHODS

Adult women with SLE were identified from six hospital databases and community screening in three neighborhoods in Boston, Massachusetts, USA. Controls were adult women volunteers from the same neighborhoods who were screened for the absence of connective tissue disease and anti-nuclear antibodies. Subjects were considered exposed to pesticides if they had ever had an exterminator for an ant, cockroach, or termite problem prior to SLE diagnosis or corresponding reference age in controls. Risks associated with pesticide exposure were analyzed using multivariable logistic regression models, adjusted for sociodemographic factors.

RESULTS

We identified 93 SLE subjects and 170 controls with similar baseline characteristics. Eighty-three per cent were African-American. Pesticide exposure was associated with SLE, after controlling for potential confounders (odds ratio 2.24, 95% confidence interval 1.28-3.93).

CONCLUSION

Residential exposure to pesticides in an urban population of predominantly African-American women was associated with increased SLE risk. Additional studies are needed to corroborate these findings.

From berries to blocks: carbon stock quantification of a California vineyard

BACKGROUND

Quantifying terrestrial carbon (C) stocks in vineyards represents an important opportunity for estimating C sequestration in perennial cropping systems. Considering 7.2 M ha are dedicated to winegrape production globally, the potential for annual C capture and storage in this crop is of interest to mitigate greenhouse gas emissions. In this study, we used destructive sampling to measure C stocks in the woody biomass of 15-year-old Cabernet Sauvignon vines from a vineyard in California's northern San Joaquin Valley. We characterize C stocks in terms of allometric variation between biomass fractions of roots, aboveground wood, canes, leaves and fruits, and then test correlations between easy-to-measure variables such as trunk diameter, pruning weights and harvest weight to vine biomass fractions. Carbon stocks at the vineyard block scale were validated from biomass mounds generated during vineyard removal.

RESULTS

Total vine C was estimated at 12.3 Mg C ha^-1, of which 8.9 Mg C ha^-1 came from perennial vine biomass. Annual biomass was estimated at 1.7 Mg C ha^-1 from leaves and canes and 1.7 Mg C ha^-1 from fruit. Strong, positive correlations were found between the diameter of the trunk and overall woody C stocks (R² = 0.85), pruning weights and leaf and fruit C stocks (R² = 0.93), and between fruit weight and annual C stocks (R² = 0.96).

CONCLUSIONS

Vineyard C partitioning obtained in this study provides detailed C storage estimations in order to understand the spatial and temporal distribution of winegrape C. Allometric equations based on simple and practical biomass and biometric measurements could enable winegrape growers to more easily estimate existing and future C stocks by scaling up from berries and vines to vineyard blocks.

New Dental Accreditation Standard on Critical Thinking: A Call for Learning Models, Outcomes, Assessments

This opinion article applauds the recent introduction of a new dental accreditation standard addressing critical thinking and problem-solving, but expresses a need for additional means for dental schools to demonstrate they are meeting the new standard because articulated outcomes, learning models, and assessments of competence are still being developed. Validated, research-based learning models are needed to define reference points against which schools can design and assess the education they provide to their students. This article presents one possible learning model for this purpose and calls for national experts from within and outside dental education to develop models that will help schools define outcomes and assess performance in educating their students to become practitioners who are effective critical thinkers and problem-solvers.

Semantic generalization in implicit language learning

Despite many years of investigation into implicit learning in nonlinguistic domains, the potential for implicit learning to deliver the kinds of generalizations that underlie natural language competence remains unclear. In a series of experiments, we investigated implicit learning of the semantic preferences of novel verbs, specifically, whether they collocate with abstract or concrete nouns. After reading sentences containing the verbs, participants were required to judge the familiarity of pairs of novel verbs and nouns and to indicate their confidence or the basis of their judgment (i.e., guess, intuition, memory). Although all of the words had occurred in the texts, none of the critical items had actually occurred together. However, endorsement rates were significantly higher for pairs that respected the semantic preference rules than those that did not. Through analysis of subjective measures and verbal report, we argue that, for the majority of participants, this effect was based on unconscious knowledge. We argue that implicit learning of the kind of generalizations underlying semantic preferences is possible even after limited exposure.

Automatic perceptual simulation of first language meanings during second language sentence processing in bilinguals

Research supports the claim that, when understanding language, people perform mental simulation using those parts of the brain which support sensation, action, and emotion. A major criticism of the findings quoted as evidence for embodied simulation, however, is that they could be a result of conscious image generation strategies. Here we exploit the well-known fact that bilinguals routinely and automatically activate both their languages during comprehension to test whether this automatic process is, in turn, modulated by embodied simulatory processes. Dutch participants heard English sentences containing interlingual homophones and implying specific distance relations, and had to subsequently respond to pictures of objects matching or mismatching this implied distance. Participants were significantly slower to reject critical items when their perceptual features matched said distance relationship. These results suggest that bilinguals not only activate task-irrelevant meanings of interlingual homophones, but also automatically simulate these meanings in a detailed perceptual fashion. Our study supports the claim that embodied simulation is not due to participants' conscious strategies, but is an automatic component of meaning construction.

Forest structure, stand composition, and climate-growth response in montane forests of Jiuzhaigou National Nature Reserve, China

Montane forests of western China provide an opportunity to establish baseline studies for climate change. The region is being impacted by climate change, air pollution, and significant human impacts from tourism. We analyzed forest stand structure and climate-growth relationships from Jiuzhaigou National Nature Reserve in northwestern Sichuan province, along the eastern edge of the Tibetan plateau. We conducted a survey to characterize forest stand diversity and structure in plots occurring between 2050 and 3350 m in elevation. We also evaluated seedling and sapling recruitment and tree-ring data from four conifer species to assess: 1) whether the forest appears in transition toward increased hardwood composition; 2) if conifers appear stressed by recent climate change relative to hardwoods; and 3) how growth of four dominant species responds to recent climate. Our study is complicated by clear evidence of 20(th) century timber extraction. Focusing on regions lacking evidence of logging, we found a diverse suite of conifers (Pinus, Abies, Juniperus, Picea, and Larix) strongly dominate the forest overstory. We found population size structures for most conifer tree species to be consistent with self-replacement and not providing evidence of shifting composition toward hardwoods. Climate-growth analyses indicate increased growth with cool temperatures in summer and fall. Warmer temperatures during the growing season could negatively impact conifer growth, indicating possible seasonal climate water deficit as a constraint on growth. In contrast, however, we found little relationship to seasonal precipitation. Projected warming does not yet have a discernible signal on trends in tree growth rates, but slower growth with warmer growing season climates suggests reduced potential future forest growth.

National and Indiana dental workforce trends: IUSD DDS enrollment shaping

The IU School of Dentistry remains committed to serving its statewide mission to educate highly qualified individuals in preparation for the independent practice of dentistry. National dental workforce analyses indicate a stable number or slight decline in the number of dentists to 2025. Previous Indiana data indicate that 29 percent of nonresidents remain in the state following graduation. We believe our analysis strongly supports a need for DDS enrollment expansion consistent with the IUPUI Enrollment Shaping strategy if we are to achieve our goal of garnering new financial resources to construct a new dental building.

A national and Indiana perspective: the rising cost of dental education

Indiana University School of Dentistry remains committed to graduate competent general dentists. In the face of the cost of dental education, we are open to explore alternative educational and clinical models to enhance the educational experience for all students, while reducing the cost to provide that education. As dean, I welcome your thoughts and ideas to further reduce educational costs.

Assessment of carbon in woody plants and soil across a vineyard-woodland landscape

BACKGROUND

Quantification of ecosystem services, such as carbon (C) storage, can demonstrate the benefits of managing for both production and habitat conservation in agricultural landscapes. In this study, we evaluated C stocks and woody plant diversity across vineyard blocks and adjoining woodland ecosystems (wildlands) for an organic vineyard in northern California. Carbon was measured in soil from 44 one m deep pits, and in aboveground woody biomass from 93 vegetation plots. These data were combined with physical landscape variables to model C stocks using a geographic information system and multivariate linear regression.

RESULTS

Field data showed wildlands to be heterogeneous in both C stocks and woody tree diversity, reflecting the mosaic of several different vegetation types, and storing on average 36.8 Mg C/ha in aboveground woody biomass and 89.3 Mg C/ha in soil. Not surprisingly, vineyard blocks showed less variation in above- and belowground C, with an average of 3.0 and 84.1 Mg C/ha, respectively.

CONCLUSIONS

This research demonstrates that vineyards managed with practices that conserve some fraction of adjoining wildlands yield benefits for increasing overall C stocks and species and habitat diversity in integrated agricultural landscapes. For such complex landscapes, high resolution spatial modeling is challenging and requires accurate characterization of the landscape by vegetation type, physical structure, sufficient sampling, and allometric equations that relate tree species to each landscape. Geographic information systems and remote sensing techniques are useful for integrating the above variables into an analysis platform to estimate C stocks in these working landscapes, thereby helping land managers qualify for greenhouse gas mitigation credits. Carbon policy in California, however, shows a lack of focus on C stocks compared to emissions, and on agriculture compared to other sectors. Correcting these policy shortcomings could create incentives for ecosystem service provision, including C storage, as well as encourage better farm stewardship and habitat conservation.

Developing dental faculty for the future: ADEA/AAL Institute for Teaching and Learning, 2006-09

This report summarizes the history and curriculum of the American Dental Education Association/Academy for Academic Leadership Institute for Teaching and Learning (ADEA/AAL ITL) Program for Dental School Faculty, describes participant feedback, and reviews how the program serves the faculty development initiatives of the American Dental Education Association. The fifty-hour program (6.5 days), conducted in two phases at collaborating dental schools, enhances core academic competencies of new and transitional faculty, including faculty members whose responsibilities include predoctoral, allied, and postdoctoral dental education. The program's mission is to prepare participants to become more effective teachers and develop other skills that will facilitate confidence, job satisfaction, and professional growth in the academic environment. From 2005 to 2009, 174 individuals graduated from the program, representing forty-three schools of dentistry in the United States and Canada and twenty-nine private practices. A total of forty scholarships have been awarded to participants by the American Academy of Periodontology Foundation, the American Academy of Pediatric Dentistry, and the American Association of Orthodontists. In an online survey completed by 75 percent of ADEA/AAL ITL participants, 99 percent indicated they were positive or highly positive about their learning experience in this faculty development program. Ninety-six percent stated that the program had been important or very important in their effectiveness as a teacher. In 2010, the program will be held at the University of North Carolina at Chapel Hill School of Dentistry, with phase I occurring on August 19-22, 2010, and phase II on October 22-24, 2010. In summary, the ADEA/AAL ITL is addressing an unmet need through a formal professional development program designed to help new and potential faculty members thrive as educators and become future leaders in academic health care.

Dental education economics: challenges and innovative strategies

This article reviews current dental education economic challenges such as increasing student tuition and debt, decreasing funds for faculty salaries and the associated faculty shortage, and the high cost of clinic operations and their effect on the future of dentistry. Management tactics to address these issues are also reviewed. Despite recent efforts to change the clinical education model, implementation of proposed faculty recruitment and compensation programs, and creation of education- corporate partnerships, the authors argue that the current economics of public dental education is not sustainable. To remain viable, the dental education system must adopt transformational actions to re-engineer the program for long-term stability. The proposed re-engineering includes strategies in the following three areas: 1) educational process redesign, 2) reduction and redistribution of time in dental school, and 3) development of a regional curriculum. The intent of these strategies is to address the financial challenges, while educating adequate numbers of dentists at a reasonable cost to both the student and the institution in addition to maintaining dental education within research universities as a learned profession.

An analysis of preventive dental visits by provider type, 1996

BACKGROUND

Understanding preventive dental visit utilization patterns facilitates planning of the dental health services delivery system. The authors examine these patterns by analyzing the receipt of preventive dental services in the United States by type of dental provider.

METHODS

The authors analyzed data from the 1996 Medical Expenditure Panel Survey (MEPS) for the U.S. community-based population. They developed national estimates for the population with preventive dental visits by provider type, including the population with a preventive dental visit and mean number of preventive dental visits per person for socioeconomic and demographic categories.

RESULTS

Respondents who are white, are older, are female, have dental insurance, are from higher income and education backgrounds, and reside in small metropolitan areas were more likely (P < .05) to receive preventive care from a dental hygienist than from a dentist.

CONCLUSION

MEPS data showed that people's socioeconomic background and other demographic factors were associated with having a preventive dental visit with a dentist or dental hygienist. These factors also influence the per-person number of preventive visits by type of dental practitioner. These elements must be considered when planning for future dental work force needs.

PRACTICE IMPLICATIONS

Estimating future dental work force needs through this analysis assists dentists in meeting patient demand and maximizing the productive output of all services rendered in their practices, including preventive services.

Myocardial tumor necrosis factor-alpha expression does not correlate with clinical indices of heart failure in patients on left ventricular assist device support

BACKGROUND

Mechanical unloading with a left ventricular assist device (LVAD) can improve clinical indices of heart failure and alter myocardial tumor necrosis factor-alpha (TNFalpha) expression, but a correlation between clinical and molecular indices has not been established.

METHODS

We enrolled 14 patients with end-stage heart failure treated with drugs and mechanical unloading in a protocol including the collection of myocardial tissue samples at LVAD implantation and explantation. Ten nonfailing donor hearts served as controls. TNFalpha expression was measured by quantitative reverse transcription polymerase chain reaction. Clinical indices of heart failure were retrospectively analyzed and correlated with myocardial TNFalpha expression.

RESULTS

Left ventricular end-diastolic dimension decreased (p < 0.01) and cardiac index (p < 0.001) increased with unloading. Abnormal values of serum sodium, creatinine, blood urea nitrogen, glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, and albumin showed a trend toward normalization with mechanical unloading. TNFalpha expression was increased in 5 of 14 patients and decreased with mechanical unloading in 4 of them. Surprisingly, there was no correlation between mRNA levels of TNFalpha and any of the clinical indices studied.

CONCLUSIONS

Although clinical indices of heart failure improve and elevated levels of myocardial TNFalpha expression decrease with mechanical unloading, there is no correlation between the two. Thus, clinical and molecular indices of heart failure in LVAD-supported patients do not always correlate.

The ethics of placebo-controlled trials in developing countries to prevent mother-to-child transmission of HIV

Placebo-trials on HIV-infected pregnant women in developing countries like Thailand and Uganda have provoked recent controversy. Such experiments aim to find a treatment that will cut the rate of vertical transmission more efficiently than existing treatments like zidovudine. This scenario is first stated as generally as possible, before three ethical principles found in the Belmont Report, itself a sharpening of the Helsinki Declaration, are stated. These three principles are the Principle of Utility, the Principle of Autonomy and the Principle of Justice. These are taken as voices of moral imperative. But although each has intuitive appeal, it can be shown that there are possible scenarios in which they give conflicting prescriptions. To achieve consistency, one must be subordinate to the others. The voice of utility is taken as subordinate to those of justice and autonomy and it is shown that given plausible assumptions about the level of poverty and education in the developing country targeted, the experiment is ruled morally wrong in the name of both justice and autonomy. Moreover, it is argued that no justification can be found for the inclusion of a placebo group, when strictly defined. By contrast, a 'no-treatment' control arm might be justified, but only when the demands of autonomy are satisfied, demands that are more stringent than they might appear. A utilitarian defence of the experiment is examined, namely that the would-be participants are in a no-loss situation, and it is shown that this defence is seriously flawed. Finally, it is concluded that there is no justification for amending the Declaration of Helsinki.

Lack of immunity in university students before an outbreak of serogroup C meningococcal infection

Immunity to meningococci was determined in infected and uninfected students before and during an outbreak of serogroup C meningococcal infection at a university in the United Kingdom. No immunity against the outbreak strain was detected in serum taken from infected students prior to the outbreak or at the time of admission; bactericidal activity developed during convalescence. Carriage of all strains of serogroup C meningococci in asymptomatic students was low (0.9%), and no carriage of the outbreak strain could be detected. Immunity in the at-risk student population before the outbreak was low: 90% of students had no significant bactericidal activity against the outbreak strain. A low prevalence of carriage of the outbreak strain, together with a low prevalence of protective immunity within the student population, was associated with a high incidence of invasive disease in those who acquired the outbreak strain.

Root trunk dimensions of 5 different tooth types

The primary purpose of this study was to document mean, standard deviation, and range of root trunk dimensions of multirooted tooth types. A total of 412 extracted teeth were examined and classified as: maxillary first molars, maxillary second molars, maxillary first premolars, mandibular first molars, and mandibular second molars. The distance from the cementoenamel junction (CEJ) to the root groove and from the CEJ to the root division was measured. Mean CEJ to root groove distances ranged from 1.35 to 1.65 mm for maxillary first molars, from 1.49 to 1.89 mm for maxillary second molars, from 1.71 to 1.73 mm for maxillary first premolars, from 1.16 to 1.22 mm for mandibular first molars, and from 1.53 to 1.76 mm for mandibular second molars.

Why is short-term sentence recall verbatim? An evaluation of the role of lexical priming

By showing that short-term sentence recall can be significantly affected by words encountered in an intervening distractor task, Potter and Lombardi (1990, Journal of Memory and Language, 29, 633-654) argue that short-term sentence recall is often verbatim because of the availability of recently activated lexical entries during the regeneration of the sentence from its conceptual representation. We show that similar effects can be obtained even when bilinguals perform an intervening task in a different language from that of sentence recall, or when monolinguals perform an intervening task upon pictures. Furthermore, we show that the presentation of a word in P&L's distractor task does not, in any case, affect subsequent retrieval of a semantically related word as measured in a picture-naming task. We suggest that the effects on recall reported here and by P&L should be explained in terms of conceptual level interference at the time of recall. We also discuss the implications of our suggestion for the issue of the verbatimness of short-term sentence recall.