Developing a broader scientific foundation for river restoration: Columbia River food webs

Well-functioning food webs are fundamental for sustaining rivers as ecosystems and maintaining associated aquatic and terrestrial communities. The current emphasis on restoring habitat structure—without explicitly considering food webs—has been less successful than hoped in terms of enhancing the status of targeted species and often overlooks important constraints on ecologically effective restoration. We identify three priority food web-related issues that potentially impede successful river restoration: uncertainty about habitat carrying capacity, proliferation of chemicals and contaminants, and emergence of hybrid food webs containing a mixture of native and invasive species. Additionally, there is the need to place these food web considerations in a broad temporal and spatial framework by understanding the consequences of altered nutrient, organic matter (energy), water, and thermal sources and flows, reconnecting critical habitats and their food webs, and restoring for changing environments. As an illustration, we discuss how the Columbia River Basin, site of one of the largest aquatic/riparian restoration programs in the United States, would benefit from implementing a food web perspective. A food web perspective for the Columbia River would complement ongoing approaches and enhance the ability to meet the vision and legal obligations of the US Endangered Species Act, the Northwest Power Act (Fish and Wildlife Program), and federal treaties with Northwest Indian Tribes while meeting fundamental needs for improved river management.Recent years have seen substantial expenditures and sustained efforts by government agencies, indigenous people, and nongovernmental organizations to restore rivers and their declining fish stocks. These activities are under increased scrutiny to show that goals and objectives are being met (1, 2). In general, past river restoration has focused on recreating structural attributes (e.g., channel width, complexity) based on the assumption that associated ecological functions will follow (3–6). However, contemporary evidence suggests that ecosystem structure alone does not necessarily reflect how it functions in supporting life. For example, field experiments in the US Pacific Northwest have shown that trophic manipulations (e.g., nutrient additions or salmon carcass introductions) that boost the abundance of potential prey organisms also boost subsequent fish growth (7–10). In contrast, restoration of physical habitats by creating pools or adding structures yields ambiguous evidence that such efforts increase subsequent fish abundance and biomass (11–17). Although it may be premature to conclude from these studies that food availability and species interactions are more limiting to fish than the quality or quantity of the physical habitat, evidence is mounting that many habitat restoration activities are not always as effective in meeting stated goals and objectives as originally anticipated.Nationwide, river restoration practices tend to target the effects of dams, flow manipulation, and channel structure. More than $1 billion/y has been spent since 1990 on river restoration in the United States, with limited evidence of success (1). It has been argued that successful restoration should focus on restoring processes that support ecosystem services and monitoring how processes respond within an adaptive management framework (3, 18, 19). We suggest here that a balance between physical habitat restoration and an understanding of trophic processes supporting biotic communities would improve restoration effectiveness.     

PARTIAL HYPOPITUITARISM IN KLINEFELTER'S SYNDROME

SUMMARY A patient with Klinefelter's syndrome, secondary hypothyroidism and absent growth hormone and prolactin reserves is described. This combination of pituitary hormone deficiency has not been reported previously in association with Klinefelter's syndrome.     

Depressive symptoms in relation to periodontal health in a Jordanian sample

Abstract:  Objectives : This cross-sectional study examines the relationship of depression symptoms to periodontal diseases and decayed (D), missing (M) and filled teeth (FT) in a sample of the Jordanian population. Methods : Subjects escorting dental patients attending two dental hospitals in North Jordan were included. Each subject received full periodontal examination, including probing pocket depth (PPD), clinical attachment level (CAL), gingival index (GI) and plaque index (PI). The numbers of M, D and F teeth were also recorded. The Zung Self-rating Depression Scale was used to determine susceptibility to depression. Results : The frequency of high susceptibility to depression among periodontitis-free subjects and those with periodontitis was found to be 48% and 50% respectively. There was no statistically significant association between susceptibility to depression symptoms and periodontal parameters, including PPD, CAL, PI and GI ( P  >   0.05 ) . However, subjects with low susceptibility to depression had significantly more FT than subjects highly susceptible to depression. Conclusions : High susceptibility to depression does not play a significant role in the aetiology and severity of periodontitis in the population studied.     

Critical and systematic evaluation of data for estimating human exposures to 2,4-dichlorophenoxyacetic acid (2,4-D) – quality and generalizability

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been commercially available since the 1940’s. Despite decades of data on 2,4-D in food, air, soil, and water, as well as in humans, the quality the quality of these data has not been comprehensively evaluated. Using selected elements of the Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument (temporal variability, avoidance of sample contamination, analyte stability, and urinary methods of matrix adjustment), the quality of 156 publications of environmental- and biomonitoring-based 2,4-D data was examined. Few publications documented steps were taken to avoid sample contamination. Similarly, most studies did not demonstrate the stability of the analyte from sample collection to analysis. Less than half of the biomonitoring publications reported both creatinine-adjusted and unadjusted urine concentrations. The scope and detail of data needed to assess temporal variability and sources of 2,4-D varied widely across the reviewed studies. Exposures to short-lived chemicals such as 2,4-D are impacted by numerous and changing external factors including application practices and formulations. At a minimum, greater transparency in reporting of quality control measures is needed. Perhaps the greatest challenge for the exposure community is the ability to reach consensus on how to address problems specific to short-lived chemical exposures in observational epidemiology investigations. More extensive conversations are needed to advance our understanding of human exposures and enable interpretation of these data to catch up to analytical capabilities. The problems defined in this review remain exquisitely difficult to address for chemicals like 2,4-D, with short and variable environmental and physiological half-lives and with exposures impacted by numerous and changing external factors.     

Formation, persistence, and identification of DNA adducts formed by the carcinogenic environmental pollutant o-anisidine in rats

2-Methoxyaniline (o-anisidine) is an industrial and environmental pollutant causing tumors of urinary bladder in rodents. Here, we investigated the formation and persistence of DNA adducts in the Wistar rat. Using the (32)P-postlabeling method, three o-anisidine-derived DNA adducts were found in several organs of rats treated with a total dose of 0.53 mg o-anisidine/kg body wt (0.15, 0.18, and 0.2 mg/kg body wt ip in the first, second, and third day, respectively), of which the urinary bladder had the highest levels. At four posttreatment times (1 day, 13 days, 10 weeks, and 36 weeks), DNA adducts in bladder, liver, kidney, and spleen of rats were analyzed to study their persistence. In all time points, the highest total adduct levels were found in urinary bladder (39 adducts per 10(7) nucleotides after 1 day and 15 adducts per 10(7) nucleotides after 36 weeks) where 39% adducts remained. In contrast to the urinary bladder, no persistence was detected in other organs. All three DNA adducts were identified as deoxyguanosine adducts. When deoxyguanosine was reacted with the oxidative metabolite of o-anisidine, N-(2-methoxyphenyl)hydroxylamine, three adducts could be separated by high-performance liquid chromatography (HPLC) and were identified by mass spectroscopy and/or nuclear magnetic resonance spectrometry. All adducts are products of the nitrenium/carbenium ions, the reactive species generated from N-(2-methoxyphenyl)hydroxylamine. The major adduct was identified to be N-(deoxyguanosin-8-yl)-2-methoxyaniline. Using cochromatography on HPLC, this adduct was found to be identical to the major adduct generated by activation of o-anisidine in vitro and in vivo.     

School Lunch Timing and Children's Physical Activity During Recess: An Exploratory Study

ObjectiveTo examine the relationship between school lunch timing (before vs after recess) on physical activity (PA) during recess and energy balance and food intake at lunch.MethodsA cross-sectional study design was used to examine lunch intake and PA during recess among fourth- and fifth-graders (n = 103) over 5 school days. Lunch and PA were measured using a weighted plate waste technique and accelerometry, respectively.ResultsChildren who received lunch before recess accumulated lower residual energy (ie, energy intake at lunch minus energy expenditure during recess) and consumed a greater proportion of milk servings. No timing effects were observed for other lunch and PA variables.Conclusions and ImplicationsLunch intake and activity during recess are related to lunch timing policy. Findings warrant further examination using experimental and quasi-experimental studies to better understand the impact of timing on health behaviors.     

Second malignancy following high-dose therapy and autologous stem cell transplantation: incidence and risk factor analysis

To establish incidence and risk factors for development of second malignant neoplasms after high-dose chemo/radiotherapy (HDT) and autologous hematopoietic stem cell transplantation (AHSCT), the case files of 800 consecutive patients who underwent AHSCT at our institution between June 1982 and December 2000 were reviewed. In all, 26 patients developed 29 second malignancies (nine myelodysplastic syndrome (MDS)/acute myelogenous leukemia (AML), 16 solid tumors and four lymphoproliferative disorders (LPDs)) for a 15-year cumulative incidence of 11% (95% confidence interval (CI), 5-18%). These second tumors occurred at a median of 68 (range 1.5-177) months following AHSCT. The relative risk (RR) compared to the general population of developing a second malignancy following AHSCT was 3.3 (CI 2.2-4.7) P<0.001. The RR of developing MDS/AML, LPD and a solid tumor was 47.2 (CI 21.5-89.5) P<0.001, 8.1 (2.2-20.7) P=0.002 and 1.98 (1.1-3.2) P=0.009, respectively. In multivariate analysis, age >or=35 years at the time of AHSCT (P=0.001) and an interval from diagnosis to AHSCT >or=36 months (P=0.03) were associated with a greater risk of developing a second malignancy. Patients who have undergone HDT and AHSCT are at significant risk for developing a second malignancy and should receive indefinite follow-up.     

碱化布吡卡因溶液对蟾蜍坐骨神经阻滞效能的研究

目的：了解布吡卡因碱化溶液的药效。方法：（１）离体坐骨神经法,取蟾蜍６０只,制备坐骨神经标本,分两组,实验组（碱化布吡卡因组）和对照组（盐酸布吡卡因组）各３０只,测定不同浓度的两组布吡卡因对离体坐骨神经动作电位（ＡＰ）幅度的影响;（２）在体坐骨神经丛法：取蟾蜍６０只,分组同上,破坏第三脊椎以上的脊髓后,将不同浓度的两种布吡卡因玫蟾蜍的腹腔内,测定其缩腿反射消失的时间。结果：实验一显示,实验组与对照