Three-year Interval Research Articles

Precision and Consistency of the Taphonomic Signature of Predation by Crowned Hawk-Eagles (Stephanoaetus coronatus) in Kibale National Park, Uganda

Abstract Prey material, which was collected from beneath the nests of two pairs of crowned hawk-eagles (Stephanoaetus coronatus) in the Ngogo study area, Kibale National Park, Uganda, was analyzed to identify the taphonomic features diagnostic of eagle predation. Material from a recent three-year collection interval was compared to an earlier three-year collection subsample to determine signal consistency over time. The bulk of the assemblage is comprised of cercopithecoid monkey remains, reflecting the taxonomic composition of the Ngogo area. Taxonomic composition of the assemblage remains highly consistent over the collection period. Bone survivability and fragmentation profiles, as well as damage patterns, also were investigated. Crowned hawk-eagles inflict much less damage to prey skeletons than do mammalian carnivores. Crania, scapulae, and hindlimb elements are most likely to survive predation by crowned hawk-eagles and to be concentrated at nest sites, but these elements (especially crania) show ag...

Preface

Abstract The 14th International Symposium on Carotenoids was held in Edinburgh, Scotland, UK 17-22 July 2005, under the chairmanship of Dr. George Britton. The International Symposium on Carotenoids is the official symposium for the International Carotenoid Society (http://carotenoidsociety.org), which supported the symposium as did IUPAC. Financial support was gratefully received from DSM Nutritional Products, BASF Ag, Cognis Deutschland, Fuji Chemical Company Ltd., Inexa Industria Extractora CA, Valensa International, Nu Skin International Inc., Cargill Inc., The Alcon Foundation Inc., Kemin Health, Access Business Group, and LycoRed Natural Products Industries Ltd. The first International Symposium took place in Trondheim, Norway in 1966, and such meetings have continued at three-year intervals since then. Over that period of almost 40 years, the carotenoids field has expanded tremendously and diversified into many fields of study, especially human nutrition and health. There have also been continued advances in our understanding of the roles of carotenoids in photosynthesis and photochemistry, the regulation of their formation, de novo chemical synthesis, and the analytical techniques available for detailed structural analyses. The commercial importance of carotenoids has also significantly increased over the years; the current market was estimated to be around $887 million for 2004 and is expected to rise at an average annual growth rate of 2.9 % to just over $1 billion. These areas were fully reflected in the 220 invited lectures, oral communications, and poster sessions. The seven articles that appear in this issue embody the themes of the symposium, namely: - Carotenoids and Health: a series of themed sessions focusing on protection against disease, the eye, molecular and cellular processes, and nutrition - Carotenoid Oxidation and Breakdown Products and Metabolites - Carotenoids in Photosynthesis - Carotenoid Biosynthesis - Commercial Production and Applications - Carotenoids and Nature: ecology, etc. - Molecular Interactions of Carotenoids Finally, we would like to thank everyone who contributed to a most successful symposium, including the local organizing committee, and look forward to the next meeting in 2008, which will be held in Okinawa, Japan and will be chaired by Prof. Hideki Hashimoto. Richard J. Cogdell Peter M. Bramley Conference Editors

Magazine Prices Revisited

This paper examines price adjustment behavior in the magazine industry. In a frequently cited study, Cecchetti (1986) constructs a reduced-form (S,s) model for firms. Cecchetti assumes that a firm's pricing rules are fixed for non-overlapping three-year intervals and estimates the model using a conditional logit specification from Chamberlain (1980). The estimates are inconsistent, however, due to the state-dependent specification of the model. I illustrate the econometric problems in Cecchetti's results through a Monte Carlo exercise and then suggest a method for producing consistent estimates based upon Heckman and Singer (1984). The corrected results provide strong support for models of state-dependent pricing.

Explaining Change Over Time in Quality of Life of Adult Patients With Anorectal Malformations or Hirschsprung's Disease

The aim of this study was to examine changes in the quality of life of adult patients with anorectal malformations or Hirschsprung's disease over a three-year interval and to identify demographic, clinical, and psychosocial variables that explain possible quality-of-life changes. Understanding the factors that affect changes in quality of life over time is particularly important to provide adequate care. Questionnaires were administered to 261 patients (77 percent), with a three-year interval. Background characteristics, including demographic and clinical variables, and psychosocial variables (i.e., self-esteem, mastery, social support, disease cognition) were measured on one occasion. Generic and disease-specific quality of life were measured twice. On average patients indicated no change in quality-of-life level after three years. However, variance in the change scores revealed individual variation, indicating the presence of patients who improved and patients who deteriorated. Patients who were female, older, have other congenital diseases, or a stoma reported poorer quality of life over time. The psychosocial variable "disease cognition" most strongly affected the change in quality of life of patients with anorectal malformations or Hirschsprung's disease. Our results could alert clinicians to patients who are at risk for quality-of-life deterioration and might therefore be in need for extra care. Our findings illustrate the importance of psychosocial functioning for enhancing the quality of life over time of these patients.

Biological Criteria for Municipal Wastewater Effluent Monitoring Programs

Abstract As part of the long-term strategy for addressing issues related to municipal wastewater effluents (MWWE), Environment Canada is developing environmental quality objectives (EQOs) for the aquatic receiving environment. Recommended biological monitoring components of the aquatic ecosystem include fish communities, benthic macroinvertebrate communities, sentinel fish species and primary producers (macrophytes, attached algae, phytoplankton). A set of criteria was developed for measurable attributes (indicators) of each of those components. Recommended numeric and narrative criteria could be used to determine when MWWE should be managed. Warning-level criteria for indices of benthic community composition are considered effects on indices of composition that deviate from the mean reference response by more than ±2 standard deviations. For sentinel fish population parameters, warning-level effects are considered >25% differences from reference in gonad or liver size, growth, or age, or a >10% change in condition factor. For primary producers, warning-level effects are considered those that coincide with anticipated changes in fish communities based on existing models. Where warning-level criteria are exceeded, it is recommended that monitoring be repeated at two- to three-year intervals. Where continued monitoring demonstrates an increase in the extent or magnitude of effects on indices of benthic community composition, or sentinel fish population parameters, it is recommended that effects be considered unacceptable and that the cause of effects be identified and managed. Losses of non-rare species or shifts in dominance are considered severe fish-community effects that should trigger management (i.e., identification and elimination of causative agents). Domination of the benthic community by one or a few tolerant taxa normally coincides with effects on fish communities, and should also be considered a severe effect that triggers management.

The Relationship Between Birth Predictedness and Violence During Pregnancy Among Women in La Paz and El Alto, Bolivia

The main objectives were to estimate the prevalence of predicted and unpredicted last births using a prospective approach and to estimate the prevalence of violence during the last pregnancy. In addition, the relationship between birth predictedness and violence during pregnancy was examined. The target population for this study was women who had participated in the 1994 Demographic and Health Survey (DHS) and lived in El Alto and La Paz Bolivia (n = 1308). In 1997, 816 women were located and re-interviewed. During this three-year interval, 127/816 women had given birth to their last child. Of the last births that occurred during the three-year interval, 82% were unpredicted (18% were to women who stated in 1994 that they wanted to postpone childbirth for more than three years and 64% were to women who stated they wanted to wanted to forego childbearing entirely). Twenty-eight percent of women reported that they had experienced violence during their last pregnancy. No statistically significant relationship was found between birth predictedness and violence during their pregnancy. The majority of births that occurred in the three-year study interval were unpredicted. The prevalence of violence during pregnancy was alarmingly high among this sample of women. Further investigation on violence during pregnancy is needed and should be expanded to examine how violence during pregnancy impacts maternal and infant outcomes, which have remained poor in this country. In addition, the high rates of unpredicted births illustrate that work remains to be done in addressing women's ability to control their fertility.

Reproducibility and sensitivity to change of various methods to measure joint space width in osteoarthritis of the hip: a double reading of three different radiographic views taken with a three-year interval

Joint space width (JSW) and narrowing (JSN) measurements on radiographs are currently the best way to assess disease severity or progression in hip osteoarthritis, yet we lack data regarding the most accurate and sensitive measurement technique. This study was conducted to determine the optimal radiograph and number of readers for measuring JSW and JSN. Fifty pairs of radiographs taken three years apart were obtained from patients included in a structure modification trial in hip osteoarthritis. Three radiographs were taken with the patient standing: pelvis, target hip anteroposterior (AP) and oblique views. Two trained readers, blinded to each other's findings, time sequence and treatment, each read the six radiographs gathered for each patient twice (time interval ≥15 days), using a 0.1 mm graduated magnifying glass. Radiographs were randomly coded for each reading. The interobserver and intraobserver cross-sectional (M0 and M36) and longitudinal (M0–M36) reproducibilities were assessed using the intraclass coefficient (ICC) and Bland–Altman method for readers 1 and 2 and their mean. Sensitivity to change was estimated using the standardized response mean (SRM = change/standard deviation of change) for M0–M36 changes. For interobserver reliability on M0–M36 changes, the ICCs (95% confidence interval [CI]) were 0.79 (0.65–0.88) for pelvic view, 0.87 (0.78–0.93) for hip AP view and 0.86 (0.76–0.92) for oblique view. Intraobserver reliability ICCs were 0.81 (0.69–0.89) for observer 1 and 0.97 (0.95–0.98) for observer 2 for the pelvic view; 0.87 (0.78–0.92) and 0.97 (0.96–0.99) for the hip AP view; and 0.73 (0.57–0.84) and 0.93 (0.88–0.96) for the oblique view. SRMs were 0.61 (observer 1) and 0.82 (observer 2) for pelvic view; 0.64 and 0.75 for hip AP view; and 0.77 and 0.70 for oblique view. All three views yielded accurate JSW and JSN. According to the best reader, the pelvic view performed slightly better. Both readers exhibited high precision, with SRMs of 0.6 or greater for assessing JSN over three years. Selecting a single reader was the most accurate method, with 0.3 mm precision. Using this cutoff, 50% of patients were classified as 'progressors'.

Predicting transitions in the use of informal and professional care by older adults

To prepare the care system for a rising population of older people, it is important to understand what factors predict the use of care. This paper reports a study of transitions in the use of informal and professional care using Andersen-Newman models of the predictive predisposing, enabling and need factors. The study has drawn on Longitudinal Ageing Study Amsterdam (LASA) data on the use of care and the contextual factors. The data were collected at three-yearly intervals from a random, sex- and age-stratified, population-based sample of adults aged 55–85 years. In summary, the findings for those who initially did not receive care were that almost one-third received some kind of care three years later, most of which was provided by informal care-givers. Need factors were important predictors of most transitions in care, and predisposing and enabling factors, such as age, partner status and income, also played a role. On the relationship between informal and professional care, evidence was found for both ‘compensatory processes ’, i.e. informal care substitutes for professional care, and ‘ bridging processes’, i.e. informal care facilitates professional care. In view of the increasing discrepancy between the demand for professional care and its supply, the significant impact of predisposing and enabling factors offers opportunities for intervention.

Publications in Dance Medicine and Science: A Bibliographer’s Perspective

The purpose of this study was to provide a statistical review of trends in dance medicine and science research over the last 38 years with regard to how much is being published, where it is being published, and what subject matter is attracting the most attention. All data were compiled through computer tabulations of entries in the authors’ Dance Medicine & Science Bibliography, 3rd Edition. When viewed in three-year intervals, the number of publications was seen to increase dramatically between 1977 and 1988, and decrease steadily at each interval through 2003. Over the time span in question, 141 authored books, 36 edited books, and 321 chapters have appeared, along with 405 articles in periodicals (led by Medical Problems of Performing Artists and the Journal of Dance Medicine & Science, with 151 and 136 articles, respectively). Eleven research subjects can be identified which have produced at least 100 references; the 3 most prolific subjects are Psychology/Personality/Perception/Memory/Stress, psychological (308); Technique/Teaching/Training (284); and Stress fracture/Overuse injury (241). Publications over the last 38 years in dance medicine and science portray it as a vigorous and diverse field, although there is potential cause for concern in the (at this time unexplained) decrease in number of publications since 1989.

AE: Acoustic emission testing of an HF acid sphere

The paper describes how an Acoustic Emission (AE) testing programme was used to detect environmental cracking in an HF storage sphere at an early stage, without the need for frequent internal inspections. The first AE test (in 1985) revealed a number of welding flaws in the top circumferential weld. These were verified by ultrasonic testing but repairs were not necessary. AE testing continued at approximate three-year intervals and recorded minimal levels of AE until the fourth (1995) test. This produced increased AE activity, giving the first indication of environmental damage. Follow-up examinations found fissuring and small blisters in the affected areas. This was not serious enough for immediate remedial action, so a follow-up AE test was scheduled to see if the condition changed after a further year of operation. This test, carried out in 1996, produced a further increase in AE activity and more areas were affected. The sphere was shut down for inspection and repair. Extensive cracking was found in the areas ofAE activity, most of these were removed by grinding but some weld repairs were needed. AE testing six-months after recommissioning showed AE activity had returned to the previous low levels.

Distress proneness and cognitive decline in a population of older persons

The association between distress proneness and cognitive decline was examined in older residents of a biracial community in Chicago. At baseline, participants completed four cognitive tests that yielded a global measure (baseline mean=101.2; standard deviation (SD)=7.8), and a brief measure of the tendency to experience negative emotions (mean=16.5; SD=6.7) based on the Neuroticism scale of the NEO Five-Factor Inventory. Cognitive testing was repeated twice at three-year intervals. In mixed models that controlled age, sex, race, and education, for each point on the distress proneness scale, global cognitive score was 0.12 unit lower at baseline (p<0.001) and annual rate of decline increased by 0.01 unit (p=0.002), or about 2%. Thus, cognitive decline was about 30% faster in a person highly prone to distress (score=24, 90th percentile) compared to the one low in distress proneness (score=9, 10th percentile). This effect was unchanged after controlling for level of cognitive activity or excluding people with cognitive impairment at baseline, but it was reduced to a trend (p=0.059) after controlling for depressive symptoms. The results suggest that the tendency to experience psychological distress is associated with increased cognitive decline in old age.

Helicopter emergency medical services transport outcomes literature:: Annotated Review of Articles Published 2000–2003

Helicopter emergency medical services (HEMS) and its possible association with outcomes improvement continues to be a subject of debate. As is the case with other scientific endeavors, debate over HEMS usefulness should be framed around an evidence-based assessment of the relevant literature. In an effort to facilitate the academic pursuit of assessment of HEMS utility, in late 2000 the National Association of EMS Physicians' Air Medical Committee prepared annotated bibliographies of the HEMS-related outcomes literature. As a result of that work, two review articles—one covering HEMS use in nontrauma and the other in trauma—published in 2002 in Prehospital Emergency Care surveyed HEMS outcomes-related literature published between 1980 and mid-2000. Given the broad interest in the earlier reviews, and the increasing rate of publication of HEMS studies, the current project was executed with the intent of updating the annotated HEMS outcomes-related bibliography, covering a three-year time interval (through 2003) since the prior reviews.

Community integration in spinal cord injury of long duration

to examine longitudinal changes in community reintegration among people aging with spinal cord injury, and to determine if these changes are related to demographic variables and scores on psychosocial measures of stress, life satisfaction, depression, psychological well-being, and perceived quality of life. 178 members of a British population-based study of outcomes after spinal cord injury were evaluated at three-year intervals from 1990 to 1999. Participants responded to a questionnaire that included measures of community integration and perceived psychosocial status. Scores and results were analyzed to identify changes over time in community reintegration. The findings indicate a general decline in community reintegration over time in terms of physical independence, mobility, occupation and social integration. However, economic self-sufficiency appears to steadily improve as time passes. Life satisfaction also declined over time and was related to community reintegration. Measures of emotional distress were not important predictors of community reintegration. Community reintegration declined over time in this sample of British individuals aging with SCI. Although there were concurrent relationships between demographic variables of age and neurologic group, neither these factors nor duration of injury appeared to impact change in community reintegration. More significant was the relationship between perceived life satisfaction and community integration.

Changing psychosocial morbidity in people aging with spinal cord injury

to examine how scores on measures of stress, life satisfaction, depression, and psychological well-being relate to perceived quality of life among people with longstanding spinal cord injuries. 189 members of a British population-based study of outcomes after spinal cord injury were evaluated at three-year intervals from 1990 to 1999. Participants rated their quality of life at each interval, and completed various psychosocial measures. Scores and results were analyzed to identify changes over time and correlations with perceived quality of life. Self-ratings of quality of life were high and relatively stable over the duration of the longitudinal study. There were strong concurrent relationships between perceived quality of life and psychosocial outcomes. Across time periods, the outcomes studied did not seem to strongly predict later quality of life, but earlier perceived quality of life did predict later stress, depression, and psychological well-being. Perceived quality of life among this group of individual with long duration spinal cord injuries was high and relatively stable over time. Significant relationships identified between earlier quality of life and later perceived stress, depression, and well-being suggest that quality of life, typically thought of as a key outcome may itself be a predictor of other outcomes.

HELICOPTER EMERGENCY MEDICAL SERVICES TRANSPORT OUTCOMES LITERATURE: ANNOTATED REVIEW OF ARTICLES PUBLISHED 2000–2003

Helicopter emergency medical services (HEMS) and its possible association with outcomes improvement continues to be a subject of debate. As is the case with other scientific endeavors, debate over HEMS usefulness should be framed around an evidence-based assessment of the relevant literature. In an effort to facilitate the academic pursuit of assessment of HEMS utility, in late 2000 the National Association of EMS Physicians' Air Medical Committee prepared annotated bibliographies of the HEMS-related outcomes literature. As a result of that work, two review articles—one covering HEMS use in nontrauma and the other in trauma—published in 2002 in Prehospital Emergency Care surveyed HEMS outcomes-related literature published between 1980 and mid-2000. Given the broad interest in the earlier reviews, and the increasing rate of publication of HEMS studies, the current project was executed with the intent of updating the annotated HEMS outcomes-related bibliography, covering a three-year time interval (through 2003) since the prior reviews.

Measuring the Impacts of Working-Age Adult Mortality on Small-Scale Farm Households in Kenya

Using a two-year panel of 1,422 Kenyan households surveyed in 1997 and 2000, we measure how working-age adult mortality affects rural households’ size and composition, crop production, asset levels, and off-farm income. We also use adult mortality rates from available data on an HIV-negative sample to predict the proportion of deaths observed during 1997–2000 due to AIDS. Difference-in-differences estimations indicate that the effects of adult mortality are highly sensitive to the gender and position of the deceased family member in the household and to the household’s initial asset levels. Results indicate that relatively poor households do not recover quickly from head-of-household adult mortality; effects on crop and nonfarm incomes do not decay at least over the three-year survey interval.

Race Differences in Depressive Symptoms: A Dynamic Perspective on Stress Exposure and Vulnerability

The existence, nature, and strength of race differences in mental health remain unclear after several decades of research. In this research, we examine black-white differences in the relationship between acute stressors and depressive symptoms. We reframe the stress exposure and differential vulnerability hypotheses in the context of long-term trajectories of stress and depression, and we hypothesize that trajectories of stress growth will be associated with trajectories of depressive symptom growth. Using latent growth curve analysis of a sample of 1,972 older persons interviewed three times at three-year intervals, we test the hypotheses that (1) growth in exposure to loss-related events will predict growth in depressive symptoms, and (2) African Americans will experience greater stress growth than whites. Results support the hypotheses. Stress growth exhibited a linear increase for blacks but not for whites, and predicted depression growth for both races, but explained more variance for blacks than for whites.

Late oncological occurrences following radical cystectomy in patients with bladder cancer.

To evaluate the prognoses and predictive factors of late oncological occurrences and its impact on follow-up strategy in patients with bladder tumours treated with radical cystectomy. Late oncological occurrences were considered when they took place after three years from cystectomy or when early recurrence was controlled with therapy and patients developed recurrence again after a three-year disease-free interval. Univariate and multivariate analysis of predictive factors for late oncological occurrences were carried out on 215 patients at risk of late oncological recurrences. Among 357 patients treated with cystectomy, 163 (45.6%) relapsed, 149 (41.7%) of them as early recurrence and 17 (4.7%) were considered as late oncological events. This incidence increased up to 8% when patients at risk were considered. Three patients with early recurrence reached a complete response after treatment and relapsed again as late recurrences. Distant metastases and local recurrence represented 78.5% of early recurrence as opposed to 11.7% in late oncological occurrences, whereas, extravesical urothelium recurrences represented 8.6% and 70% respectively (p<0.01). Among patients with late oncological occurrences, nine (53%) were disease-free, seven with urothelial recurrence and two of three with lymph-node recurrence whereas only eight (5.6%) patients with early recurrence were free of tumour (p<0.0001). Multiple tumours, prostate involvement and organ-confined tumours in cystectomy specimen were the independent variables for predicting late oncological occurrences in multivariate analysis. Recurrences in the remaining urothelium prevail as the pattern of late oncological occurrences. The prognosis of these events is significantly better than an early recurrence. Patients at risk of late oncological occurrences are those with multiple tumours, prostate involvement and with organ-confined tumours in cystectomy specimen. After three years from cystectomy, the follow-up schedule of these patients be limited to performing an annual CT-scan and urinary cytology to detect essentially upper urinary tract recurrence and extrapelvic lymph-nodal recurrence. Afterwards an annual intravenous urography might replace to CT-scan since lymph-nodal involvement was not detected.

Longitudinal decline in lung function measurements among Saskatchewan grain workers.

To evaluate the relationship between the long term effects of grain dust and decline in lung function among grain elevator workers in Saskatchewan, studied over a 15-year period. The Grain Dust Medical Surveillance Program was started by Labour Canada in 1978 and longitudinally studied the respiratory health of Canadian grain elevator workers over a 15-year period (1978 to 1993). Data on respiratory symptoms and pulmonary function tests (forced expiratory volume in 1 s [FEV1], forced vital capacity [FVC]) were collected once every three years; each three-year interval was called a 'cycle'. Data from Saskatchewan were analyzed for this report. A transitional model using the generalized estimating equations approach was fitted using a SAS macro to predict the annual decline in FEV1 and FVC. Previous lung function, as one of the covariates in the transitional model, played an important role. Significant predictors of FEV1 were previous FEV1, base height, weight, years in the grain industry, current smoking status, cycle II, cycle III and cycle V. Significant predictors of FVC were previous FVC, base height, weight, years in the grain industry, cycle II, cycle III and cycle IV. The estimated annual decline in FEV1 and FVC increased according to length of time in the grain industry among nonsmoking, ex-smoking and smoking grain elevator workers. Lung function values improved after dust control, and yearly declines in FEV1 and FVC after dust control were smaller compared with yearly losses before dust control.

Screening for cervical cancer: new alternatives and research.

Evidence for the clinical utility of human papillomavirus (HPV) DNA testing has increased over the years and has now become very convincing. Some specific uses of HPV detection are a) triage of women with cytological determinations of atypical squamous cells of undetermined significance (ASC-US) and related management strategies, b) as a marker for test of cure post-treatment, and c) most importantly, as an adjunct to cytology in routine cervical disease screening programs. There are many studies that support each of these applications and include 8 studies on ASC-US triage, 10 on test of cure and 13 on adjunctive or stand-alone HPV screening. The most notable investigation of ASC-US triage was ALTS, a randomized controlled trial of 3,488 women. With respect to routine HPV screening the combined studies included 77,000 women, providing as a histological endpoint more than 1,000 cases of high-grade cervical intraepithelial neoplasia (CIN) or cancer. Testing methods were either the Hybrid Capture 2 (HC2) test or the polymerase chain reaction (PCR) test. HPV testing of women with ASC-US cytology had on average a higher sensitivity (90%) and specificity (70%) than repeating the cytological test (sensitivity 75%, specificity 60%) and was also more sensitive than colposcopy for follow-up. As an adjunct to the Papanicolaou (Pap) cytology test in routine screening, HPV DNA testing was a more sensitive indicator for prevalent high-grade CIN than either conventional or liquid cytology. A combination of HPV DNA and Papanicolaou testing had almost 100% sensitivity and negative predictive value. The specificity of the combined tests was slightly lower than the specificity of the Papanicolaou test. One "double-negative" HPV DNA and Papanicolaou test indicated a higher prognostic assurance against risk of future CIN 3 than three subsequent negative conventional Papanicolaou tests and may safely allow three-year or longer screening intervals for such low-risk women. It appears that HPV DNA testing is on the way to becoming a common testing strategy in cervical cancer prevention programs. Research continues into approaches for improving the performance and cost-effectiveness of HPV detection methods. Hybrid Capture 3 will offer improved HPV typing capabilities and the Rapid Capture machine allows for robot-assisted HPV DNA testing, permitting greater test throughput. PCR test improvements are expected to contribute to the growth of flexible accurate and cost-effective HPV DNA tests. It is likely that improved diagnostic technology along with HPV genotyping and quantitation may provide more value in future. A particularly promising approach is to combine HPV DNA testing with expression levels of other markers such as proliferative or cell cycle regulatory proteins to subdivide HPV-positive women into those who are at greater risk of cancer and those who can be safely followed by screening at longer intervals. This paper is available too at: http://www.insp.mx/salud/index.html.