Uncertainties in mapping forest carbon in urban ecosystems.

Spatially explicit urban forest carbon estimation provides a baseline map for understanding the variation in forest vertical structure, informing sustainable forest management and urban planning. While high-resolution remote sensing has proven promising for carbon mapping in highly fragmented urban landscapes, data cost and availability are the major obstacle prohibiting accurate, consistent, and repeated measurement of forest carbon pools in cities. This study aims to evaluate the uncertainties of forest carbon estimation in response to the combined impacts of remote sensing data resolution and neighborhood spatial patterns in Charlotte, North Carolina. The remote sensing data for carbon mapping were resampled to a range of resolutions, i.e., LiDAR point cloud density - 5.8, 4.6, 2.3, and 1.2 pt s/m2, aerial optical NAIP (National Agricultural Imagery Program) imagery - 1, 5, 10, and 20 m. Urban spatial patterns were extracted to represent area, shape complexity, dispersion/interspersion, diversity, and connectivity of landscape patches across the residential neighborhoods with built-up densities from low, medium-low, medium-high, to high. Through statistical analyses, we found that changing remote sensing data resolution introduced noticeable uncertainties (variation) in forest carbon estimation at the neighborhood level. Higher uncertainties were caused by the change of LiDAR point density (causing 8.7-11.0% of variation) than changing NAIP image resolution (causing 6.2-8.6% of variation). For both LiDAR and NAIP, urban neighborhoods with a higher degree of anthropogenic disturbance unveiled a higher level of uncertainty in carbon mapping. However, LiDAR-based results were more likely to be affected by landscape patch connectivity, and the NAIP-based estimation was found to be significantly influenced by the complexity of patch shape.

Parenteral fish oil-associated burr cell anemia.

We report the development of burr cell anemia in an infant with short bowel syndrome who received parenteral fish oil (Omegaven, Fresenius-Kabi, Graz, Austria) after development of total parenteral nutrition-associated liver disease. Parenteral fish oil was discontinued, and the burr cell anemia disappeared, suggesting that parenteral fish oil might be associated with hemolytic anemia.

Pediatric gastroenterology fellows, class of 2007: how well are they prepared for the future?

OBJECTIVES: Pediatric gastroenterology fellows are expected to acquire skills as clinicians, researchers, and educators. An e-mail survey was conducted to examine training experiences of individual fellows; to understand how graduating fellows rate their abilities as clinicians, researchers, and teachers; and to answer whether the size of a pediatric gastroenterology training program affects a fellow's training and future position choice. MATERIALS AND METHODS: A survey was e-mailed to 76 third-year pediatric gastroenterology fellows. Respondents were ranked according to the size of their training program. RESULTS: Completed surveys were returned by 50 respondents. Of these, 75% planned to pursue careers in academic medicine and 16% in private practice. In all, 68% of trainees participated in some type of basic research and 64% in clinical research. As attending physicians, 22% of fellows hoped to conduct basic science research and 74% clinical research. The majority thought they were competent or proficient teachers, and rated themselves as advanced beginners or competent when asked to evaluate their research skills. The North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition recommends that fellows perform 100 colonoscopies, 20 liver biopsies, and 5 paracenteses to be considered competent. We found that regardless of program size, 48% of fellows performed fewer than 100 colonoscopies, 62% performed fewer than 20 liver biopsies, and 80% performed fewer than 5 paracenteses. CONCLUSIONS: The majority of fellows will pursue academic careers. Trainees may not be performing sufficient numbers of procedures. The number of procedures performed during fellowship was independent of program size.

A report of two children with Helicobacter heilmannii gastritis and review of the literature.

An 11-year-old boy with epigastric abdominal pain and a 2 year-old girl with failure to thrive underwent esophagogastroduodenoscopy. Endoscopic biopsies from the gastric antrum of both children revealed corkscrew-like spiral bacteria, consistent with the diagnosis of Helicobacter heilmannii infection. H. heilmannii is a rare finding in children and is thought to be present in approximately 0.3% of patients undergoing upper endoscopy. Clinical presentation, gross and histologic appearance, and treatment regimens are discussed. The clinical and histologic features of previously reported cases of H. heilmannii gastritis in children living in the United States are reviewed in table form.

Use of cholecystokinin-octapeptide for the prevention of parenteral nutrition-associated cholestasis.

OBJECTIVE: To determine whether cholecystokinin-octapeptide (CCK-OP) would prevent or ameliorate parenteral nutrition-associated cholestasis (PNAC) among high-risk neonates treated with total parenteral nutrition. STUDY DESIGN: This was a multicenter, double-blind, randomized, controlled trial conducted between 1996 and 2001. PATIENTS: Neonates at risk for the development of PNAC included very low birth weight neonates and those with major surgical conditions involving the gastrointestinal tract. SETTING: Tertiary care hospitals. INTERVENTION: Patients were randomized to receive CCK-OP (0.04 mug/kg per dose, twice daily) or placebo. Eligible infants were all <30 days of age. Patients were enrolled within 2 weeks after birth or within 7 days after surgery. OUTCOME MEASURES: The primary outcome measure was conjugated bilirubin (CB) levels, which were measured weekly. Secondary outcome measures included incidence of sepsis, times to achieve 50% and 100% of energy intake through the enteral route, number of ICU and hospital days, mortality rate, and incidences of biliary sludge and cholelithiasis. RESULTS: A total of 243 neonates were enrolled in the study. CCK-OP administration did not significantly affect CB levels (1.76 +/- 3.14 and 1.93 +/- 3.31 mg/dL for CCK-OP and placebo groups, respectively; mean +/- SD). Secondary outcome measures also were not significantly affected by the study drug. CONCLUSIONS: Use of CCK-OP failed to reduce significantly the incidence of PNAC or levels of CB. CCK-OP had no effect on other secondary measures and should not be recommended for the prevention of PNAC.