Establishing IUCN Red List criteria for threatened ecosystems.

The potential for conservation of individual species has been greatly advanced by the International Union for Conservation of Nature's (IUCN) development of objective, repeatable, and transparent criteria for assessing extinction risk that explicitly separate risk assessment from priority setting. At the IV World Conservation Congress in 2008, the process began to develop and implement comparable global standards for ecosystems. A working group established by the IUCN has begun formulating a system of quantitative categories and criteria, analogous to those used for species, for assigning levels of threat to ecosystems at local, regional, and global levels. A final system will require definitions of ecosystems; quantification of ecosystem status; identification of the stages of degradation and loss of ecosystems; proxy measures of risk (criteria); classification thresholds for these criteria; and standardized methods for performing assessments. The system will need to reflect the degree and rate of change in an ecosystem's extent, composition, structure, and function, and have its conceptual roots in ecological theory and empirical research. On the basis of these requirements and the hypothesis that ecosystem risk is a function of the risk of its component species, we propose a set of four criteria: recent declines in distribution or ecological function, historical total loss in distribution or ecological function, small distribution combined with decline, or very small distribution. Most work has focused on terrestrial ecosystems, but comparable thresholds and criteria for freshwater and marine ecosystems are also needed. These are the first steps in an international consultation process that will lead to a unified proposal to be presented at the next World Conservation Congress in 2012.

Effect of simply recording colonoscopy withdrawal time on polyp and adenoma detection rates.

BACKGROUND: According to national recommendations, colonoscopy withdrawal time (WT) on negative screening examinations should average more than 6 minutes because this time is associated with a higher rate of polyp detection. Attempts have been made to increase the WT; however, simply knowing that a quality measure, such as the WT, is being monitored, by itself, may improve the quality of an examination. OBJECTIVE: To measure changes in the polyp detection rate associated with recording the WT. DESIGN: Retrospective. SETTING: Single tertiary care center. PATIENTS: Patients undergoing colonoscopy within 5 months immediately before (group A) and after (group B) initiation of WT recording. Colonoscopies were excluded if procedure times were incomplete, missing, or nonsensical. MAIN OUTCOME MEASUREMENTS: Polyp detection, compared by using the chi(2) test and logistic regression multivariate analyses; pathology manually reviewed from a sample of 200 consecutive polyp cases (100 per group). RESULTS: The average WT in group B was 14.5 minutes (11.0 minutes in negative screening examinations). In group A, polyps were detected in 530 (37.7%) of 1405 colonoscopies compared with 571 (41.2%) of 1387 colonoscopies in group B (difference 3.5%; 95% CI, -0.2% to 7.1%), a nonsignificant 9.3% relative increase. Longer procedure time, age, sex, and indication were significant predictors; monitoring the WT was not. Nonsignificantly, more polyp examinations in group B found all nonadenomas compared with group A (36% vs 27%; P = .17), and polyps were nonsignificantly smaller (P = .30). LIMITATIONS: Retrospective database data, pathology performed only on a subsample. CONCLUSION: WT recording was associated with a nonsignificant increase in polyp detection, but this was likely attributable to a slight increase in the detection of (smaller) nonadenomatous polyps.

Period 2 mutation accelerates ApcMin/+ tumorigenesis.

Colorectal cancer risk is increased in shift workers with presumed circadian disruption. Intestinal epithelial cell proliferation is gated throughout each day by the circadian clock. Period 2 (Per2) is a key circadian clock gene. Per2 mutant (Per2(m/m)) mice show an increase in lymphomas and deregulated expression of cyclin D and c-Myc genes that are key to proliferation control. We asked whether Per2 clock gene inactivation would accelerate intestinal and colonic tumorigenesis. The effects of PER2 on cell proliferation and beta-catenin were studied in colon cancer cell lines by its down-regulation following RNA interference. The effects of Per2 inactivation in vivo on beta-catenin and on intestinal and colonic polyp formation were studied in mice with Per2 mutation alone and in combination with an Apc mutation using polyp-prone Apc(Min/+) mice. Down-regulation of PER2 in colon cell lines (HCT116 and SW480) increases beta-catenin, cyclin D, and cell proliferation. Down-regulation of beta-catenin along with Per2 blocks the increase in cyclin D and cell proliferation. Per2(m/m) mice develop colonic polyps and show an increase in small intestinal mucosa beta-catenin and cyclin D protein levels compared with wild-type mice. Apc(Min/+)Per2(m/m) mice develop twice the number of small intestinal and colonic polyps, with more severe anemia and splenomegaly, compared with Apc(Min/+) mice. These data suggest that Per2 gene product suppresses tumorigenesis in the small intestine and colon by down-regulation of beta-catenin and beta-catenin target genes, and this circadian core clock gene may represent a novel target for colorectal cancer prevention and control.

Planning to Save a Species: the Jaguar as a Model.

International conservation planning at the end of the twentieth century is dominated by coarse-filter, supra-organismal approaches to conservation that may be insufficient to conserve certain species such as the jaguar ( Panthera onca). If we are to retain broadly distributed species into the next century, we need to plan explicitly for their survival across their entire geographic range and through political boundaries while recognizing the variety of ecological roles the species plays in different habitats. In March 1999 the Wildlife Conservation Society sponsored a priority-setting and planning exercise for the jaguar across its range, from northern Mexico to northern Argentina. Field scientists from 18 countries reached consensus on four types of information: (1) the spatial extent of their jaguar knowledge, (2) the known, currently occupied range of jaguars, (3) areas with substantial jaguar populations, adequate habitat, and a stable and diverse prey base, and (4) point localities where jaguars have been observed during the last 10 years. During the exercise, these experts also conducted a range-wide assessment of the long-term survival prospects of the jaguar and developed an algorithm for prioritizing jaguar conservation units occurring in major habitat types. From this work, we learned that the known, occupied range of the jaguar has contracted to approximately 46% of estimates of its 1900 range. Jaguar status and distribution is unknown in another 12% of the jaguar's former range, including large areas in Mexico, Colombia, and Brazil. But over 70% of the area where jaguars are thought to still occur was rated as having a high probability of supporting their long-term survival. Fifty-one jaguar conservation units representing 30 different jaguar geographic regions were prioritized as the basis for a comprehensive jaguar conservation program.

RESUMEN: La planeación de la conservación internacional al final del siglo veinte esta dominada por enfoques de grano grueso, supra-organísmicas que pueden ser insuficientes para conservar ciertas especies como el jaguar ( Panthera onca). Si hemos de mantener especies ampliamente distribuidas en el próximo siglo, necesitamos planificar su supervivencia explícitamente en todo su rango geográfico a través de límites políticos al mismo tiempo que se reconozca la variedad de funciones ecológicas de las especies en diferentes hábitats. En marzo de 1999 la Sociedad de Conservación de Vida Silvestre promovió un ejercicio de definición de prioridades y de planeación para el jaguar en todo su rango de distribución, desde el norte de México hasta el norte de Argentina. Científicos de 18 países llegaron a consensos en cuatro tipos de información: (1) la extensión espacial de su conocimiento del jaguar, (2) el rango conocido, actualmente ocupado por el jaguar, (3) áreas con poblaciones importantes, hábitat adecuado y una base de presas estable y diversa y (4) localidades en las que se han observado jaguares durante los últimos 10 años. Durante el ejercicio, estos expertos también hicieron una evaluación de la supervivencia a largo plazo del jaguar en todo su rango y desarrollaron un algoritmo para priorizar unidades de conservación del jaguar en los tipos de hábitat más importantes. De este trabajo, aprendimos que el rango del jaguar conocido y ocupado se ha contraído aproximadamente al 46% de su rango estimado circa de 1900. El estatus del jaguar y su distribución en otro 12% del rango anterior, incluyendo extensas áreas en México, Colombia y Brasil. Sin embargo, más del 70% del área donde se piensa que todavía ocurre el jaguar fue considerada con una alta probabilidad de soportar la supervivencia a largo plazo. Se priorizaron 51 unidades de conservación representando 30 regiones diferentes como la base para un sólido programa de conservación del jaguar.