bluuebunny/crossref_metadata_2025 huggingface dataset:
TRANSITIVE RESPONDING IN HOODED CROWS REQUIRES LINEARLY ORDERED STIMULI
Authors: Lazareva Olga F. , Smirnova Anna A. , Bagozkaja Maria S. , Zorina Zoya A. , Rayevsky Vladimir V. , Wasserman Edward A.
Published: March 2006

Eight crows were taught to discriminate overlapping pairs of visual stimuli (A+ B‐, B+ C‐, C+ D‐, and D+ E‐). For 4 birds, the stimuli were colored cards with a circle of the same color on the reverse side whose diameter decreased from A to E (ordered feedback group). These circles were made available for comparison to potentially help the crows order the stimuli along a physical dimension. For the other 4 birds, the circles corresponding to the colored cards had the same diameter (constant feedback group). In later testing, a novel choice pair (BD) was presented. Reinforcement history involving stimuli B and D was controlled so that the reinforcement/nonreinforcement ratios for the latter would be greater than for the former. If, during the BD test, the crows chose between stimuli according to these reinforcement/nonreinforcement ratios, then they should prefer D; if they chose according to the diameter of the feedback stimuli, then they should prefer B. In the ordered feedback group, the crows strongly preferred B over D; in the constant feedback group, the crows' choice did not differ significantly from chance. These results, plus simulations using associative models, suggest that the orderability of the postchoice feedback stimuli is important for crows' transitive responding.
SCIENTIFIC PEER REVIEW: A CASE STUDY FROM LOCAL AND GLOBAL ANALYSES
Authors: Shimp Charles P.
Published: March 2006

The dialog between Staddon (2001, 2004) and Baum (2004) raises general questions about the nature of scientific peer review. Their dialog displays effects on peer review of differences of opinion about the relative merits of local and global analyses. Baum (1995, 1997, 2001, 2002) favors global analyses as a paradigm different, newer, and better than the local, dynamic, real‐time approach that plays a significant role in Staddon (2001). According to the Kuhnian perspective (Kuhn, 1996) Baum advocates, we can better understand his review of Staddon (2001) by considering the implications for it of his commitment to the idea that a global analysis is a superior scientific paradigm. This commentary examines some characteristics of local and global analyses, as well as some of their possible implications for peer review in the context of a reviewer's belief in the Kuhnian idea of incommensurability: According to this idea, a reviewer who either is, or who believes he is, from one paradigm is unlikely, for better or worse, to understand or perhaps even tolerate work from a different paradigm. It is recommended that a process be developed to encourage “truth in peer reviewing” to reduce possible conflicts of interest embedded in the current conception of scientific peer review.
CONTINGENCIES OF REINFORCEMENT IN A FIVE‐PERSON PRISONER'S DILEMMA
Authors: Yi Richard , Rachlin Howard
Published: March 2006

As in studies of self‐control, a tit‐for‐tat contingency in an iterated prisoner's dilemma game creates a conflict between maximization of local and global reinforcement. The present experiments examine this conflict in a multiplayer prisoner's dilemma game. Versus tit for tat, cooperation corresponds to self‐control; defection, always immediately reinforced, corresponds to impulsiveness. Three experiments examined sensitivity of behavior to the global reinforcement contingency imposed by tit for tat. Undergraduates played a five‐player prisoner's dilemma game against four dummy players programmed to play tit for tat or randomly. With tit for tat, a player's cooperation (or defection) increased dummy players' cooperation (or defection) on subsequent trials—reinforcing cooperation and punishing defection in the long run. Participants cooperated at a higher rate when the dummy players played tit for tat than when the dummy players played randomly. These results are consistent with findings in corresponding studies of self‐control. Some participants, caught in a trap of mutual defection with the tit‐for‐tat playing dummy players, came to cooperate when the tit‐for‐tat contingency was reset (“forgiving” participants' previous defections) during a pause in the game. This increase was a result of the combined effects of a pause and reset; neither pausing nor resetting independently resulted in an increase in cooperation.
ON THE ORIGIN AND PRESERVATION OF CUMULATIVE RECORD IN ITS STRUGGLE FOR LIFE AS A FAVORED TERM
Authors: Morris Edward K. , Smith Nathaniel G.
Published: March 2006

This paper offers a case study of the origins, emergence, and evolution of the term cumulative record as the name for the means by which B. F. Skinner brought his behavior under the control of his subject matter. Our methods included on‐line searches, reviews of Skinner's publications, and journal codings and counts. The results reveal that the term is not originally attributable to Skinner, but emerged earlier in ordinary language and in another discipline—education. It was not even original to Skinner in print in his own science. Still, the term was once original to him, which we address with additional analyses of his having originated and advanced it. We conclude with a discussion the constraints of our methods, suggestions for future research, and the variable appreciation of technology and terminology in science studies.
EFFECTS OF GABAAMODULATORS ON THE REPEATED ACQUISITION OF RESPONSE SEQUENCES IN SQUIRREL MONKEYS
Authors: Campbell Una C. , Winsauer Peter J. , Stevenson Michael W. , Moerschbaecher Joseph M.
Published: March 2006

The present study investigated the effects of positive and negative GABAAmodulators under three different baselines of repeated acquisition in squirrel monkeys in which the monkeys acquired a three‐response sequence on three keys under a second‐order fixed‐ratio (FR) schedule of food reinforcement. In two of these baselines, the second‐order FR schedule and the discriminative stimuli for the response sequence were manipulated (“chain‐strained” and “tandem‐strained”). In the third baseline condition, response‐independent tail shock was presented during acquisition of the response sequence. All of these baselines maintained high error levels and produced slow rates of acquisition. Under both the chain‐strained and tandem‐strained conditions, the positive GABAAmodulator triazolam (0.0032–0.1 mg/kg) and the negative GABAAmodulators β‐CCE (ethyl‐β‐carboline‐3‐carboxylate; 0.01–1 mg/kg), β‐CCM (methyl‐β‐carboline‐3‐carboxylate; 0.0032–0.1 mg/kg), and FG‐7142 (methyl‐β‐carboline‐3‐carboxamide; 0.18–10 mg/kg) dose‐dependently decreased overall response rate compared to administration of saline (control). Under the same two conditions, triazolam and the negative GABAAmodulators also increased the percentage of errors; however, the effects on accuracy frequently depended on the baseline condition and the particular modulator. In contrast, triazolam only decreased errors and enhanced acquisition in the presence of concurrent response‐independent tail shock when compared to saline administration under this condition. The neutral GABAAmodulator, flumazenil (1 mg/kg), had no effect on rate or accuracy of responding when administered alone, but antagonized the rate‐decreasing and error‐increasing effects produced by the negative GABAAmodulators. Together, these data suggest that the effects of both the positive and negative GABAAmodulators on acquisition can be similar in squirrel monkeys (i.e., both types of modulator may produce rate‐decreasing and error‐increasing effects) and that their effects on acquisition depend, in part, on the environmental conditions maintaining acquisition.
THE ACCIDENTAL BEHAVIORIST: A REVIEW OF THE NEW BEHAVIORISM BY JOHN STADDON
Authors: Baum William M.
Published: March 2006

Staddon contends that behavior analysis may profit from theory, by which he means theory that includes assumed elemental processes allowing derivation of observed patterns of results. Behavior analysts who consider that our field has matured to the point where we are secure in our descriptive grasp of a range of phenomena will tend to agree. Unfortunately, the book's positive message is almost lost in a morass of distracting criticisms of Skinner and behavior analysis in general. Instead of recognizing the growth and maturation of the field, Staddon writes as if the field has stagnated and blames that stagnation on what he takes to be Skinner's antipathy toward theory. Neither has behavior analysis become stagnated, nor should Skinner be blamed for any shortcomings. Instead of acknowledging Skinner's foundational contributions to the field, however, Staddon devotes most of this book to bashing Skinner and fails to distinguish his own view of theory based on internal states from theory in cognitive psychology, treating theoretical models and unseen processes as the “true” subject of inquiry and behavior as only an indicator.
EFFECTS OF METHYLPHENIDATE AND MORPHINE ON DELAY‐DISCOUNT FUNCTIONS OBTAINED WITHIN SESSIONS
Authors: Pitts Raymond C. , McKinney A. Patrick
Published: March 2006

Four rats responded under a “self‐control” procedure designed to obtain delay‐discount functions within sessions. Each session consisted of seven blocks, with seven trials within each block. Each block consisted of two initial forced‐choice trials followed by five free‐choice trials. On choice trials, the rats could press either of two retractable levers. A press on one lever was followed by presentation of a smaller reinforcer (a single dipper presentation of a sucrose solution); a press on the other lever was followed by presentation of a larger reinforcer (four consecutive dipper presentations). The delay associated with the smaller reinforcer always was 0 s, whereas the signaled delay associated with the larger reinforcer increased across blocks (from 0 to 50 s). Under these conditions, the percentage of choices of the larger reinforcer decreased across blocks, and relatively reliable delay‐discount functions were obtained within sessions. Doses of methylphenidate (1.0 to 17.0 mg/kg) and morphine (0.3 to 17.0 mg/kg) were then administered prior to selected sessions. Typically, intermediate doses of methylphenidate shifted the discount functions to the right (increased choices of the larger reinforcer). For 2 of the rats, this effect was pronounced; for the other 2 rats, this effect occurred after the range of delays for the larger reinforcer was decreased (0 to 20 s). On the other hand, in most cases morphine produced a slight leftward shift in the discount function (decreased choices of the larger reinforcer). The present procedure appears to be a useful and efficient method to characterize drug effects on an entire delay‐discount function. As with many procedures used to study self‐control choices, however, sources of control other than reinforcement delay and amount may have been operating in the present study, and these sources must be considered when interpreting drug effects.
EFFECTS OF REINFORCER PROBABILITY, DELAY, AND RESPONSE REQUIREMENTS ON THE CHOICES OF RATS AND PIGEONS: POSSIBLE SPECIES DIFFERENCES
Authors: Mazur James E.
Published: March 2006

In Experiment 1 with rats, a left lever press led to a 5‐s delay and then a possible reinforcer. A right lever press led to an adjusting delay and then a certain reinforcer. This delay was adjusted over trials to estimate an indifference point, or a delay at which the two alternatives were chosen about equally often. Indifference points increased as the probability of reinforcement for the left lever decreased. In some conditions with a 20% chance of food, a light above the left lever was lit during the 5‐s delay on all trials, but in other conditions, the light was only lit on those trials that ended with food. Unlike previous results with pigeons, the presence or absence of the delay light on no‐food trials had no effect on the rats' indifference points. In other conditions, the rats showed less preference for the 20% alternative when the time between trials was longer. In Experiment 2 with rats, fixed‐interval schedules were used instead of simple delays, and the presence or absence of the fixed‐interval requirement on no‐food trials had no effect on the indifference points. In Experiment 3 with rats and Experiment 4 with pigeons, the animals chose between a fixed‐ratio 8 schedule that led to food on 33% of the trials and an adjusting‐ratio schedule with food on 100% of the trials. Surprisingly, the rats showed less preference for the 33% alternative in conditions in which the ratio requirement was omitted on no‐food trials. For the pigeons, the presence or absence of the ratio requirement on no‐food trials had little effect. The results suggest that there may be differences between rats and pigeons in how they respond in choice situations involving delayed and probabilistic reinforcers.
THE EFFECTS OF INTERVAL DURATION ON TEMPORAL TRACKING AND ALTERNATION LEARNING
Authors: Ludvig Elliot A. , Staddon John E. R.
Published: March 2006

On cyclic‐interval reinforcement schedules, animals typically show a postreinforcement pause that is a function of the immediately preceding time interval (temporal tracking). Animals, however, do not track single‐alternation schedules—when two different intervals are presented in strict alternation on successive trials. In this experiment, pigeons were first trained with a cyclic schedule consisting of alternating blocks of 12 short intervals (5 s or 30 s) and 12 long intervals (180 s), followed by three different single‐alternation interval schedules: (a) 30 s and 180 s, (b) 5 s and 180 s, and (c) 5 s and 30 s. Pigeons tracked both schedules with alternating blocks of 12 intervals. With the single‐alternation schedules, when the short interval duration was 5 s, regardless of the duration of the longer interval, pigeons learned the alternation pattern, and their pause anticipated the upcoming interval. When the shorter interval was 30 s, even when the ratio of short to long intervals was kept at 6:1, pigeons did not initially show anticipatory pausing—a violation of the principle of timescale invariance.
The Effect of Combination of Recombinant Human Bone Morphogenetic Protein‐2 and Basic Fibroblast Growth Factor or Insulin‐Like Growth Factor‐I on Dental Implant Osseointegration by Confocal Laser Scanning Microscopy
Authors: Lan Jing , Wang Zhifeng , Wang Yining , Wang Jiawei , Cheng Xiangrong
Published: March 2006

Background: The healing period of bone‐implant osseointegration usually varies from 3 to 6 months or even longer. Failure may occur during this time. This study aimed to investigate whether osseointegration of dental implants can be enhanced by the combination of growth factors.

Methods: Sixty‐four implants were coated with polylactic acid and divided into four groups. Group I was applied with 1.0 mg recombinant human bone morphogenetic protein‐2 (rhBMP‐2) and 200 μg recombinant human basic fibroblast growth factor (rhbFGF), group II with 1.0 mg rhBMP‐2 and 250 μg recombinant human insulin‐like growth factor‐I (rhIGF‐I), group III with 1.0 mg rhBMP‐2, and group IV without growth factors as control. In total, 16 rabbits were used, and two osteotomies were drilled on each side of the femur, in which four different groups were randomly placed. Four weeks after implanting, 20 mg calcein green/kg body weight was administered intravenously, and 8 weeks after implanting, 20 mg alizarin/kg body weight was administered intravenously. Twelve weeks after implanting, the animals were sacrificed. The block of bone with implants was embedded in methylmethacrylate and sectioned, and the percentage of new bone surrounding the implant was analyzed by confocal laser scanning microscopy.

Results: There was a statistical difference in bone formation between rhBMP‐2–applied groups and the non‐applied group at 4 or 8 weeks, and no significant difference between groups I and II (although bone formation in group II was greater than that in group I at 4 weeks). The bone formation in group II was greater than that in group III at 4 or 8 weeks. The formed bone in group I was also greater than the one in group III at 8 weeks, but there was no difference at 4 weeks.

Conclusions: rhBMP‐2 could increase new bone formation, and it acted synergistically with rhbFGF and rhIGF‐I to improve bone‐implant osseointegration. The combination of rhBMP‐2 and rhbFGF (group 1) showed faster growth of new bone than other groups at 8 months.
Peri‐Implant Papilla Reconstruction: Realities and Limitations
Authors: Pradeep A.R. , Karthikeyan B.V.
Published: March 2006

In recent years, esthetic demands in dentistry have been climbing ever higher, driven by an enhanced awareness of beauty and physical appearance. Because gingival esthetics has become an important factor in the overall success of most implant‐supported restorations, the loss of the peri‐implant papilla leads to an esthetic handicap known as black hole disease. Today, one of the most challenging aspects of periodontal reconstructive surgery is to obtain a predictable peri‐implant papilla in the esthetic zone. Starting with the facts about the morphology of the peri‐implant tissues, to the various parameters influencing papilla reconstruction around implants, this article gives a brief overview of various papilla preservation and reconstruction techniques around implants.
Effect of a Controlled‐Release Chlorhexidine Chip on Clinical and Microbiological Parameters and Prostaglandin E2 Levels in Gingival Crevicular Fluid
Authors: Mızrak Tansel , Güncü Güliz N. , Çağlayan Feriha , Balcı Tansel Ansal , Aktar Gülseren Samancı , İpek Fikret
Published: March 2006

Background: The aim of the present study was to determine the effect of a chlorhexidine chip on crevicular prostaglandin E2 (PGE2) levels and on the clinical and microbiological parameters of periodontitis when used as adjunctive therapy to scaling and root planing (SRP) in patients with chronic periodontitis.

Methods: This randomized single‐blind study was carried out in parallel design. The test group received SRP plus chlorhexidine chip, whereas the control group received SRP alone. Thirty‐four subjects, aged 20 to 55 years, with chronic periodontitis were recruited. Clinical indices, microbiological samples, and gingival crevicular fluid (GCF) samples were evaluated at baseline and after 1, 3, and 6 months. Microbiological samples were evaluated under a light microscope. GCF PGE2 levels were determined using radioimmunoassay.

Results: Significant improvements could be found for all clinical variables in both groups over the study period. The mean changes in probing depth obtained by SRP plus chlorhexidine chip were greater than those obtained by the SRP alone group at 3 and 6 months. In the test group, there was also significant gain in clinical attachment level at 6 months. When data were combined from all groups, significant reductions in GCF PGE2 levels and number of microorganisms were noted at all time points. However, in the test group, reduction was greater at 6 months for crevicular PGE2 level and at 3 and 6 months for proportions of spirochetes.

Conclusion: Based on the findings of this study, the chlorhexidine chip reduced GCF PGE2 levels and had positive effects on clinical parameters and subgingival flora when used as adjunctive therapy to SRP in patients with chronic periodontitis.
Effects of a Mineralized Human Cancellous Bone Allograft in Regeneration of Mandibular Class II Furcation Defects
Authors: Tsao Yi‐Pin , Neiva Rodrigo , Al‐Shammari Khalaf , Oh Tae‐Ju , Wang Hom‐Lay
Published: March 2006

Background: A solvent‐preserved, mineralized human cancellous bone allograft (MBA) was recently developed. However, its effect in regenerating furcation defects remains to be determined. Hence, the aim of the study is to evaluate the effects of this newly introduced MBA, with and without a bioabsorbable collagen membrane, for the treatment of mandibular class II furcation defects.

Methods: Thirty subjects with Hamp's Class II buccal or lingual furcation defects in lower molars were randomly assigned to open flap debridement (OFD), MBA, or MBA with a bioabsorbable collagen membrane (guided tissue regeneration [GTR] + MBA) groups. Clinical and defect measurements were obtained at the initial visit and at 6‐month reentry surgeries. The data were analyzed for intra‐ and intergroup comparisons and associations of treatment with probability of clinical improvement.

Results: Out of a total of 30 subjects, 27 individuals completed the study. Vertical bone fill (VBF) was −1.6 ± 2.1 mm in OFD, 1.9 ± 1.4 mm in MBA, and 0.7 ± 0.9 mm in GTR + MBA groups. VBF in MBA and GTR + MBA groups was significantly higher than that in the OFD group (P <0.05). Horizontal bone fill (HBF) was 0.2 ± 1.7 mm, 1.1 ± 0.9 mm, and 1.1 ± 0.9 mm for OFD, MBA, and GTR + MBA groups, respectively. However, HBF, recession, clinical attachment level gain, and probing depth reduction at furcations showed no differences among groups.

Conclusions: Results obtained from this study indicate that solvent‐preserved, mineralized human cancellous allograft, with or without collagen membrane, can significantly improve bone fill in mandibular Class II furcation defects. In addition, initial vertical defect depth was found to be the only factor that was associated with a higher probability of clinical improvement.
Demographic Variables Affecting Patient Referrals From General Practice Dentists to Periodontists
Authors: Zemanovich Mark Roy , Bogacki Russell E. , Abbott David M. , Maynard J. Gary , Lanning Sharon K.
Published: March 2006

Background: Within dentistry, a limited body of literature exists regarding the referral relationships between general practitioners (GPs) and specialists. The purpose of this study was to investigate the referral relationship between GPs and periodontists within the state of Virginia.

Methods: A survey was developed that focused on the demographic variables in the referral relationship between GPs and periodontists. The survey was mailed to 800 dentists throughout the state of Virginia. Descriptive statistics were completed along with multivariate logistic regression analysis comparing the responses with the number of patients referred per month to periodontists.

Results: Female respondents were more likely to refer three or more patients per month to a periodontist than a male respondent (P <0.02). Those dentists who practiced with one other dentist were twice as likely to refer more frequently when compared to solo practitioners or larger group practices (P <0.03). Dentists employing two hygienists were more likely to refer patients than those with fewer hygienists (P <0.02). Those whose practices were >5 miles from the nearest periodontist were more likely to refer patients compared to dentists geographically closer to a periodontist (P <0.02). No other variables had a significant effect on the referral of more patients per month to a periodontist.

Conclusions: This study indicates that four demographic variables have a statistical influence on the number of referrals per month from a GP to a periodontist. These variables are as follows: female gender, practicing with one other dentist, employing two or more hygienists, and being >5 miles away from the nearest periodontist.
Risk Assessment for Severe Clinical Attachment Loss in an Adult Population
Authors: Bouchard Philippe , Boutouyrie Pierre , Mattout Catherine , Bourgeois Denis
Published: March 2006

Background: This study was carried out to identify variables related to severe clinical attachment loss (CAL) in an adult French population.

Methods: This cross‐sectional survey employed 2,132 subjects of the First National Periodontal and Systemic Examination Survey (NPASES I) aged 35 to 64 years, each with at least six teeth. A nationally representative sample was obtained from September 2002 to June 2003 by a quota method stratified on age, gender, socioeconomic status, and geographic areas. The subjects had a complete full‐mouth periodontal examination of four sites per tooth, assessment of missing teeth, and a number of laboratory tests and questionnaires. The periodontal status of each subject was assessed by criteria based on the severity and extent of CAL. The data were analyzed by univariable and multivariable models using logistic regression analyses.

Results: Nineteen and seven‐tenths percent (19.7%) of the subjects had CAL >5 mm. When dental variables were not included in the analysis (model 1), age (odds ratio [OR] = 1.8), male gender (OR = 1.7), body mass index (OR = 1.2), and white blood cell count (OR = 2.2) showed significant association with severe CAL. A significantly higher risk was also present in non‐drinkers and regular drinkers compared to occasional drinkers (OR = 1.6). Model 2, including dental variables in addition to model 1 variables, showed that a significantly higher risk for severe CAL was also present with age (OR = 1.6) and in males (OR = 1.7). The number of teeth (OR = 1.1), and the mean gingival bleeding index (OR = 1.7) were the dental variables significantly associated with severe CAL.

Conclusions: The results indicated that age and gender are powerful independent predictors of clinical attachment loss, as is the mean gingival bleeding index. To a lesser extent, the number of missing teeth was a good predictive variable. The patient profile for severe clinical attachment loss also included body mass index and white blood cell count. Occasional drinking may be associated with decreased severity of CAL.
Short‐Term Side Effects of 0.2% Alcohol‐Free Chlorhexidine Mouthrinse Used as an Adjunct to Non‐Surgical Periodontal Treatment: A Double‐Blind Clinical Study
Authors: Gürgan Cem A. , Zaim Eylem , Bakirsoy Işıl , Soykan Emel
Published: March 2006

Background: The aims of this clinical study were to evaluate the short‐term subjective (by means of questionnaire) and objective (by means of clinical examination) side effects of 0.2% chlorhexidine (CHX) mouthrinse without alcohol used as an adjunct to non‐surgical periodontal treatment and to elucidate the relationship between the subjective and objective evaluations.

Methods: This was a randomized, double‐blind, placebo‐controlled clinical trial with two groups: 1) the test group, rinsing with the test product (0.2% CHX without alcohol) twice per day for 1 week, and 2) the control (placebo) group, rinsing with a placebo solution twice per day for 1 week. Following the start of rinsing, patients were subjectively and objectively evaluated for the presence and severity of side effects (pain, burning sensation, pruritus, dryness of mouth, taste disturbance, mucosal irritations, and discoloration of tooth and tongue surfaces) at days 1, 3, and 7 of the rinsing period. The presence of subjective and objective side effects of the groups was compared via use of χ2 and Fisher exact tests. Analysis of the subjective and objective side effects within the evaluation periods was done by McNemar test. Spearman correlation analysis was used to assess the relationships between the subjective and objective side effects.

Results: None of the patients in either group complained of dryness of the mouth. The most commonly reported side effect was the change in color of the labial and buccal mucosa, particularly of the gingiva, after day 3 of rinsing. There were significant (r = 0.308 to 0.835; P <0.05) correlations between the discolorations of tongue and tooth surfaces reported by the patients and clinically detected at all evaluation periods. There was a significant and positive relationship between the subjective side effects and the soft tissue irritations when the duration of rinsing increased.

Conclusion: Within the limits of this clinical evaluation, rinsing with 0.2% alcohol‐free CHX for 1 week caused more irritation to oral mucosa, greater burning sensation, and increased altered taste perception compared to the placebo rinse.
The Role of Individual and Neighborhood Social Factors on Periodontitis: The Third National Health and Nutrition Examination Survey
Authors: Borrell Luisa N. , Burt Brian A. , Warren Rueben C. , Neighbors Harold W.
Published: March 2006

Background: This study investigates whether race/ethnicity, individual income, education, and neighborhood socioeconomic characteristics are independently associated with periodontitis in adults ≥18 years of age who participated in the third National Health and Nutrition Examination Survey (NHANES III).

Methods: Analyses were limited to participants in NHANES III who self‐identified as non‐Hispanic black, non‐Hispanic white, or Mexican American, received a periodontal examination, and whose records were linked to the 1990 U.S. Census data (N = 13,090). Periodontitis was investigated using a combination of clinical attachment loss and probing depth. Marginal logistic regression models were used to assess the association of race/ethnicity, individual income, education, and neighborhood socioeconomic characteristics with periodontitis before and after adjusting for selected covariates. A survey program was used to account for the survey sampling design and for the intraneighborhood correlation of outcomes of participants selected from the same neighborhood.

Results: Race/ethnicity, education, and neighborhood socioeconomic conditions were associated with periodontitis before and after controlling for selected covariates. After adjustment, blacks were twice (1.58 to 2.53) as likely to have periodontitis as whites. Compared to those with more than a high school education, those with less than a high school diploma were twice (1.48 to 2.89) as likely to have periodontitis. Individuals living in a neighborhood in the lowest tertile of the socioeconomic score were 1.81 times (1.36 to 2.41) more likely to have periodontitis than those living in a neighborhood in the highest tertile of the socioeconomic score.

Conclusion: This study indicates that race/ethnicity, individual education, and neighborhood socioeconomic circumstances are important for periodontal health.
Gingival Involvement in a Case Series of Patients With Acquired Immunodeficiency Syndrome‐Related Kaposi Sarcoma
Authors: Kalpidis Christos D.R. , Lysitsa Stella N. , Lombardi Tommaso , Kolokotronis Alexandros E. , Antoniades Demetrios Z. , Samson Jacky
Published: March 2006

Background: This case series presents the polymorphic clinical characteristics of gingival acquired immunodeficieny syndrome (AIDS)‐related Kaposi sarcoma (KS), a malignancy that is gradually becoming uncommon in developed nations. An up‐to‐date overview of the related epidemiology, etiopathogenesis, histopathology, and treatment is provided, along with a pictorial guide to ease clinical diagnosis.

Methods: The oral/maxillofacial pathology records at Aristotle University and the University of Geneva were retrospectively reviewed. Thirty‐two cases diagnosed with oral AIDS‐related KS were retrieved between 1991 and 2004. KS diagnosis was established histologically by incisional biopsies from intraoral lesions. All charts contained clinical oral examination data, radiological images, and detailed photographic records.

Results: Thirteen patients (12 males and one female) presented with KS gingival involvement (40.6%). Eleven of the male patients were homosexual/bisexual men. The mean age of the patients at the time of intraoral KS diagnosis was 42.1 years, and the mean CD4 cell count was 103 (0 to 481). Gingival epidemic KS presented with various degrees of pigmentation and a wide range of clinical patterns, from relatively flat macules (early stage) to tumors with variable nodular morphology (advanced disease). Solitary or multiple gingival involvement may appear concomitantly with palatal and/or cutaneous lesions.

Conclusions: Even though the incidence of intraoral KS had fallen precipitously in developed countries after the mid‐1990s, gingival KS should be considered in the differential diagnosis of every pigmented gingival lesion. Periodontists are in a unique position to identify gingival involvement of intraoral KS and facilitate early diagnosis.
Soil Nitrate Nitrogen Dynamics after Biosolids Application in a Tobosagrass Desert Grassland
Authors: Jurado‐Guerra Pedro , Wester David B. , Fish Ernest B.
Published: March 2006

Dormant‐season application of biosolids increases desert grass production more than growing season application in the first growing season after application. Differential patterns of NO3–N (plant available N) release following seasonal biosolids application may explain this response. Experiments were conducted to determine soil nitrate nitrogen dynamics following application of biosolids during two seasons in a tobosagrass [Hilaria mutica (Buckl.) Benth.] Chihuahuan Desert grassland. Biosolids were applied either in the dormant (early April) or growing (early July) season at 0, 18, or 34 dry Mg ha−1 A polyester–nylon mulch was also applied to serve as a control that approximated the same physical effects on the soil surface as the biosolids but without any chemical effects. Supplemental irrigation was applied to half of the plots. Soil NO3–N was measured at two depths (0–5 and 5–15 cm) underneath biosolids (or mulch) and in interspace positions relative to surface location of biosolids (or mulch). Dormant‐season biosolids application significantly increased soil NO3–N during the first growing season, and also increased soil NO3–N throughout the first growing season compared to growing‐season biosolids application in a year of higher‐than‐average spring precipitation. In a year of lower‐than‐average spring precipitation, season of application did not affect soil NO3–N. Soil NO3–N was higher at both biosolids rates for both seasons of application than in the control treatment. Biosolids increased soil NO3–N compared to the inert mulch. Irrigation did not significantly affect soil NO3–N. Soil NO3–N was not significantly different underneath biosolids and in interspace positions. Surface soil NO3–N was higher during the first year of biosolids application, and subsurface soil NO3–N increased during the second year. Results showed that biosolids rate and season of application affected soil NO3–N measured during the growing season. Under dry spring–normal summer precipitation conditions, season of application did not affect soil NO3–N; in contrast, dormant season application increased soil NO3–N more than growing season application under wet spring–dry summer conditions.
Optimizing Organic Fertilizer Applications under Steady‐State Conditions
Authors: Crohn David M.
Published: March 2006

Because organic N fertilizers must be mineralized before they become plant‐available, application designs should consider time and temperature effects on N release as well as crop N requirements. This study presents deterministic (DOpt) and stochastic (SOpt) linear optimization models to determine sustainable land application schedules. The easily solved models minimize the amount of N that is applied while assuring than crop N demands are met as they develop. Temperature effects on N mineralization were included by using the Arrhenius equation to create a temperature‐adjusted time series. Uncertainties associated with mineralization rates and the temperature‐adjustment (Q10) factor are considered by SOpt. Examples are presented for a summer maize (Zea mays L.) and winter triticale (Triticum aestivum L. × Secale cereale L.) rotation operated by a hypothetical dairy operation in Stanislaus County, California. Monte Carlo simulations were used to test the models. A closed‐form solution for estimating the time until steady state is presented and steady‐state conditions were reached within 7 yr after applications were initiated. Because of temperature effects, DOpt solutions were 12% greater during the winter and 29% lower during the summer than a reference approach that applied liquid manure at 130% of the crop N demand. Stochastic linear optimization values were 1.7% greater than DOpt values in the summer and 6.2% greater in the winter. Surplus N estimates from Monte Carlo simulations averaged 104 kg ha−1 for DOpt and 126 ka ha−1 for SOpt, but SOpt was much less likely to result in crop N deficits. Linear optimization is a viable tool for scheduling organic N applications.
Soil and Surface Runoff Phosphorus Relationships for Five Typical USA Midwest Soils
Authors: Allen B. L. , Mallarino A. P. , Klatt J. G. , Baker J. L. , Camara M.
Published: March 2006

Excessively high soil P can increase P loss with surface runoff. This study used indoor rainfall simulations to characterize soil and runoff P relationships for five Midwest soils (Argiudoll, Calciaquaoll, Hapludalf, and two Hapludolls). Topsoil (15‐cm depth, 241–289 g clay kg−1 and pH 6.0–8.0) was incubated with five NH4H2PO4 rates (0–600 mg P kg−1) for 30 d. Total soil P (TPS) and soil‐test P (STP) measured with Bray‐P1 (BP), Mehlich‐3 (M3P), Olsen (OP), Fe‐oxide‐impregnated paper (FeP), and water (WP) tests were 370 to 1360, 3 to 530, 10 to 675, 4 to 640, 7 to 507, and 2 to 568 mg P kg−1, respectively. Degree of soil P saturation (DPS) was estimated by indices based on P sorption index (PSI) and STP (DPSSTP) and P, Fe, and Al extracted by ammonium oxalate (DPSox) or Mehlich‐3 (DPSM3). Soil was packed to 1.1 g cm−3 bulk density in triplicate boxes set at 4% slope. Surface runoff was collected during 75 min of 6.5 cm h−1 rain. Runoff bioavailable P (BAP) and dissolved reactive P (DRP) increased linearly with increased P rate, STP, DPSox, and DPSM3 but curvilinearly with DPSSTP Correlations between DRP or BAP and soil tests or saturation indices across soils were greatest (r ≥ 0.95) for FeP, OP, and WP and poorest for BP and TPS (r = 0.83–0.88). Excluding the calcareous soil (Calciaquoll) significantly improved correlations only for BP. Differences in relationships between runoff P and the soil tests were small or nonexistent among the noncalcareous soils. Routine soil P tests can estimate relationships between runoff P concentration and P application or soil P, although estimates would be improved by separate calibrations for calcareous and noncalcareous soils.
Organochlorine Residues in Fish and Water Samples from Lake Victoria, Uganda
Authors: Kasozi G. N. , Kiremire B. T. , Bugenyi F. W. B. , Kirsch N. H. , Nkedi‐Kizza P.
Published: March 2006

Nile tilapia and Nile perch samples from Lake Victoria were analyzed for lindane (gamma‐1,2,3,4,5,6‐hexachlorocyclohexane), aldrin (1,2,3,4,10,10‐hexachloro‐1,4,4a,5,8,8a‐hexahydro‐1,4:5,8‐dimethanonaphthalene), α‐endosulfan (6,7,8,9,10,10‐hexachloro‐1,5,5a,6,9,9a‐hexahydro‐6,9‐methano‐2,4,3‐ benzo(e) dioxathiepin‐3‐oxide), dieldrin (1,2,3,4,10,10‐hexachloro‐6,7‐epoxy‐1,4,4a,5,6,7,8,8a‐octahydro‐1,4,5,8‐dimethanonaphthalene), DDE (p,p′‐1,1‐dichloro‐2,2‐bis‐(4‐chlorophenyl)ethylene), and DDT (p,p′‐1,1,1‐trichloro‐2,2‐bis‐(4‐chlorophenyl)ethane). No significant difference (α = 0.05) in the residue levels between fish types for lindane, α‐endosulfan, p,p′‐DDE, p,p′‐DDT, and dieldrin was observed. The aldrin levels in Nile perch (Lates niloticus) were significantly higher than the levels in Nile tilapia (Oreochromis niloticus). No difference was observed in the distribution of residues in the different parts of Nile tilapia, although a difference for p,p′‐DDE was observed in the Nile perch. No significant difference was observed in the average fat content of the tissue of Nile perch and Nile tilapia; however, the distribution of fat was significantly different in the different parts of the fish, with the abdominal portion having the highest amount of fat. There was no correlation observed in this study between fat content and organochlorine concentration. Lower p,p′‐DDT residues levels compared with the p,p′‐DDE levels observed in this study indicate that DDT is no longer in use. The levels of organochlorine pesticide residues found in fish samples in this study were below the FAO, U.S. FDA, Australian, and German extraneous residue limits and maximum residue limits. The concentration of organochlorine residues in surface water within the Napoleon Gulf of Lake Victoria was below detection limit (0.1 μg L−1).
What is Soil Organic Matter Worth?
Authors: Sparling G. P. , Wheeler D. , Vesely E.‐T. , Schipper L. A.
Published: March 2006

The conservation and restoration of soil organic matter are often advocated because of the generally beneficial effects on soil attributes for plant growth and crop production. More recently, organic matter has become important as a terrestrial sink and store for C and N. We have attempted to derive a monetary value of soil organic matter for crop production and storage functions in three contrasting New Zealand soil orders (Gley, Melanic, and Granular Soils). Soil chemical and physical characteristics of real‐life examples of three pairs of matched soils with low organic matter contents (after long‐term continuous cropping for vegetables or maize) or high organic matter content (continuous pasture) were used as input data for a pasture (grass–clover) production model. The differences in pasture dry matter yields (non‐irrigated) were calculated for three climate scenarios (wet, dry, and average years) and the yields converted to an equivalent weight and financial value of milk solids. We also estimated the hypothetical value of the C and N sequestered during the recovery phase of the low organic matter content soils assuming trading with C and N credits. For all three soil orders, and for the three climate scenarios, pasture dry matter yields were decreased in the soils with lower organic matter contents. The extra organic matter in the high C soils was estimated to be worth NZ$27 to NZ$150 ha−1 yr−1 in terms of increased milk solids production. The decreased yields from the previously cropped soils were predicted to persist for 36 to 125 yr, but with declining effect as organic matter gradually recovered, giving an accumulated loss in pastoral production worth around NZ$518 to NZ$1239 ha−1 This was 42 to 73 times lower than the hypothetical value of the organic matter as a sequestering agent for C and N, which varied between NZ$22 963 to NZ$90 849 depending on the soil, region, discount rates, and values used for carbon and nitrogen credits.
Survival of Cryptosporidium parvum Oocysts in Calf Housing Facilities in the New York City Watersheds
Authors: Collick A. S. , Fogarty E. A. , Ziegler P. E. , Walter M. T. , Bowman D. D. , Steenhuis T. S.
Published: March 2006

Pathogen contamination of the public drinking water supply in the New York City watersheds is a serious concern. New York City's Watershed Agriculture Program is working with dairy farms in the watersheds to implement management practices that will reduce the risk of pathogens contaminating the water supply. Solar calf housing (SCH) was suggested as a best management practice (BMP) to control Cryptosporidium parvum, a common protozoan parasite that causes disease in humans. This BMP targets young calves because they are the primary source of C. parvum in dairy herds. The objective of this project was to assess and compare the survivability of C. parvum in SCH and in conventional calf housing (CCH), usually located in the main barn. C. parvum oocysts were secured in sentinel chambers and placed in SCH and CCH bedding on four farms. The chambers were in thermal, chemical, and moisture equilibrium with their microenvironments. An oocyst‐filled control chamber, sealed from its surroundings, was placed near each chamber. Chambers and controls were sampled after 4, 6, and 8 wk. Oocyst viability in the chambers decreased to less than 10% in warm months and between 15 and 30% in the winter months. The viability of the control oocysts was similar to the chambers during warm months and generally higher during winter months. There was no significant (P > 0.05) difference in the viability decrease between SCH and CCH. Although oocyst viability was similar in both types of calf housing, SCH allow contaminated calf manure to be isolated from the main barn manure and potentially managed differently and in a way to decrease the number of viable oocysts entering the environment during field spreading.
Dredging of Drainage Ditches Increases Short‐Term Transport of Soluble Phosphorus
Authors: Smith Douglas R. , Warnemuende E. A. , Haggard B. E. , Huang C.
Published: March 2006

Managed drainage ditches are common in the midwestern United States. These ditches are designed to remove water from fields as quickly as possible, and sediment buildup necessitates dredging, to ensure adequate water removal. This laboratory study was conducted to determine the impact of ditch dredging on soluble phosphorus (P) transport. Ditch sediments were collected from a drainage ditch in northeastern Indiana immediately before and after dredging. The sediments were placed in a stream simulator, and stream water was loaded with 0.55 mMP for 5 d (adsorption experiment). Water was then removed, and “clean” water (no P added) was used for a desorption experiment, lasting 1 d. During the adsorption experiment, pre‐dredged sediments were able to remove P from the water column quicker, and P concentrations 120 h after introduction of high P water were lower for the pre‐dredged sediments (0.075 mMP) than the dredged sediments (0.111 mMP). During the desorption experiment, P was released to the water column slower in the pre‐dredged treatment than the dredged treatment (instantaneous flux att= 0 was 0.205 μMP h−1for pre‐dredged and 0.488 μMP h−1for dredged). This occurred despite higher Mehlich 3–extractable P in the pre‐dredged sediments than the dredged sediments. Equilibrium phosphorus concentrations (EPCo) were lower in the pre‐dredged sediments during both adsorption and desorption experiments. Transport of soluble P immediately after dredging will likely increase in drainage ditches; however, dredging is a necessary management tool to ensure adequate discharge of water from surrounding fields.
DNA as classical and quantum information system: Implication to gene expression in normal and cancer cells
Authors: Koruga Ðuro
Published: March 2006

Usually, we think about DNA as a molecular machinery system responsible to make proteins. Protein looks like a second side of DNA code because mapping function is based on a classical information system (chemical/physical) by code 43=64. However, in organisms like paramecium DNA works 95% as molecular machinery for proteins synthesis, while in humans it is only about 10%. Is 90% of human genetic structure "junk"? What does other 90% DNA work in human organism? What type of information system, different than classical, does DNA possess? To give answer to this question we are rethinking well-known facts of biomolecules from both classical and quantum information point of view. Basic element in our consideration is hydrogen bond, which possess both classical and quantum properties. Based on new vision of old data we develop synergetic (classical/quantum) model of DNA information processing, which may help for better understanding the functions of "junk" sequence in genetic code. We believe that "junk" sequences may be active regulatory factor of system complexity trough microtubules (centrioles) and water in living systems. Synergetic approach (classical/quantum) of information channels may open a new vision and understanding of the genomic programming and molecular interconnection on distance based on matching classical and quantum properties of hydrogen bonds and entanglement. .