Vegetation response to prescribed fire in the Kenai Mountains, Alaska

The Chugach National Forest has been using prescribed fire as a wildlife habitat management tool since l977. Between 1977 and 1997 about 4,000 hectares have been burned on the Kenai Peninsula to promote regeneration of woody plant species used by moose (Alces alces). Browse species include paper birch (Betula papyrifera), cottonwood (Populus balsamifera subsp. balsamifera and Populus balsamifera subsp. trichocarpa), aspen (Populus tremuloides), Scouler willow (Salix scouleriana), Barclay willow (Salix barclayi) and other tall shrub willows (Salix spp.). The purpose of this study was to evaluate the results of 20 years of prescribed fire in order to assess vegetation response to burning and provide managers with information on future prescribed burn planning. This analysis evaluated relationships among initial vegetation composition, physical site characteristics, browse species abundance, competitive herbaceous vegetation, and fire severity. With few exceptions, browse species increased in abundance after burning where they were present in the initial composition (measurements were made 15 to 20 years post-burn). Early successional grasses and forbs such as Epilobium angustfolium and Calamagrostis canadensis also tended to increase. Late successional species and forest associated species tended to decrease; these species include conifer seedlings, saplings, and trees (Tsuga mertensiana and Picea x lutzii), Rubus pedatus, Linnaea borealis, Drypoteris dilatata, and Menziesia ferruginea. Dwarf shrubs such as Vaccinium uliginosum, V. vitis-idaea, and Empetrum nigrum tended to decrease. Browse species abundance was inversely related to C. canadensis abundance. C. canadensis abundance increases with increasing depth of loamy mineral soil and increasing moisture (but C. canadensis does not occur abundantly on boggy sites with organic soils). Soils with deep loamy surface horizons tend to occur on depositional slopes such as fluvial valley bottoms and toe slopes. Sites with these features generally show large increases in C. canadensis cover after prescribed burning, even when C. canadensis cover is low (3%) prior to burning. The most important pre-burn variables for predicting post-burn browse species abundance are pre-burn C. canadensis cover and type of surficial deposit. Site conditions that are favorable to C. canadensis may be problematic for successful regeneration of browse species, especially if browse species are not present in the initial composition

Assessing the feasibility, acceptability, and fidelity of a tele-retinopathy-based intervention to encourage greater attendance to diabetic retinopathy screening in immigrants living with diabetes from China and African-Caribbean countries in Ottawa, Canada: a protocol

Background: Diabetic retinopathy is a leading cause of preventable blindness in Canada. Clinical guidelines recommend annual diabetic retinopathy screening for people living with diabetes to reduce the risk and progression of vision loss. However, many Canadians with diabetes do not attend screening. Screening rates are even lower in immigrants to Canada including people from China, Africa, and the Caribbean, and these groups are also at higher risk of developing diabetes complications. We aim to assess the feasibility, acceptability, and fidelity of a co-developed, linguistically and culturally tailored tele-retinopathy screening intervention for Mandarin-speaking immigrants from China and French-speaking immigrants from African-Caribbean countries living with diabetes in Ottawa, Canada, and identify how many from each population group attend screening during the pilot period. // Methods: We will work with our health system and patient partners to conduct a 6-month feasibility pilot of a tele-retinopathy screening intervention in a Community Health Centre in Ottawa. We anticipate recruiting 50–150 patients and 5–10 health care providers involved in delivering the intervention for the pilot. Acceptability will be assessed via a Theoretical Framework of Acceptability-informed survey with patients and health care providers. To assess feasibility, we will use a Theoretical Domains Framework-informed interview guide and to assess fidelity, and we will use a survey informed by the National Institutes of Health framework from the perspective of health care providers. We will also collect patient demographics (i.e., age, gender, ethnicity, health insurance status, and immigration information), screening outcomes (i.e., patients with retinopathy identified, patients requiring specialist care), patient costs, and other intervention-related variables such as preferred language. Survey data will be descriptively analyzed and qualitative data will undergo content analysis. // Discussion: This feasibility pilot study will capture how many people living with diabetes from each group attend the diabetic retinopathy screening, costs, and implementation processes for the tele-retinopathy screening intervention. The study will indicate the practicability and suitability of the intervention in increasing screening attendance in the target population groups. The study results will inform a patient-randomized trial, provide evidence to conduct an economic evaluation of the intervention, and optimize the community-based intervention

The Alaska Arctic Vegetation Archive (AVA-AK)

The Alaska Arctic Vegetation Archive (AVA-AK, GIVD-ID: NA-US-014) is a free, publically available database archive of vegetation-plot data from the Arctic tundra region of northern Alaska. The archive currently contains 24 datasets with 3,026 non-overlapping plots. Of these, 74% have geolocation data with 25-m or better precision. Species cover data and header data are stored in a Turboveg database. A standardized Pan Arctic Species List provides a consistent nomenclature for vascular plants, bryophytes, and lichens in the archive. A web-based online Alaska Arctic Geoecological Atlas (AGA-AK) allows viewing and downloading the species data in a variety of formats, and provides access to a wide variety of ancillary data. We conducted a preliminary cluster analysis of the first 16 datasets (1,613 plots) to examine how the spectrum of derived clusters is related to the suite of datasets, habitat types, and environmental gradients. Here, we present the contents of the archive, assess its strengths and weaknesses, and provide three supplementary files that include the data dictionary, a list of habitat types, an overview of the datasets, and details of the cluster analysis

Moderating Effect of Depression on Glycemic Control in an eHealth Intervention Among Black Youth With Type 1 Diabetes: Findings From a Multicenter Randomized Controlled Trial

Background: Black adolescents with type 1 diabetes (T1D) are at increased risk for suboptimal diabetes health outcomes; however, evidence-based interventions for this population are lacking. Depression affects a high percentage of youth with T1D and increases the likelihood of health problems associated with diabetes. Objective: Our aim was to test whether baseline levels of depression moderate the effects of a brief eHealth parenting intervention delivered to caregivers of young Black adolescents with T1D on youths' glycemic control. Methods: We conducted a multicenter randomized controlled trial at 7 pediatric diabetes clinics located in 2 large US cities. Participants (N=149) were allocated to either the intervention group or a standard medical care control group. Up to 3 intervention sessions were delivered on a tablet computer during diabetes clinic visits over a 12-month period. Results: In a linear mixed effects regression model, planned contrasts did not show significant reductions in hemoglobin A1c (HbA1c) for intervention adolescents compared to controls. However, adolescents with higher baseline levels of depressive symptoms who received the intervention had significantly greater improvements in HbA1c levels at 6-month follow-up (0.94%; P=.01) and 18-month follow-up (1.42%; P=.002) than those with lower levels of depression. Within the intervention group, adolescents had a statistically significant reduction in HbA1c levels from baseline at 6-month and 18-month follow-up. Conclusions: A brief, culturally tailored eHealth parenting intervention improved health outcomes among Black adolescents with T1D and depressive symptoms. Trial registration: ClinicalTrials.gov NCT03168867; https://clinicaltrials.gov/study/NCT03168867.</p

Association of human immunodeficiency virus and hepatitis C virus infection with long-term outcomes post-ST segment elevation myocardial infarction in a disadvantaged urban community

BackgroundHIV and HCV have been linked to an increased risk of cardiovascular disease (CVD). Their impact on long-term outcomes following ST-segment myocardial infarction (STEMI) has not been previously studied.MethodsWe leveraged data from a STEMI registry (n&nbsp;=&nbsp;1208) at an inner-city health system to assess the influence of HIV and HCV on post-STEMI outcomes. Cox regression was used to compare HIV-monoinfected (n&nbsp;=&nbsp;22), HCV-monoinfected (n&nbsp;=&nbsp;26) and HIV-HCV-coinfected patients (n&nbsp;=&nbsp;8) with the neither-infected group (n&nbsp;=&nbsp;1152) with regard to death, death or any readmission, and death or CVD readmission.ResultsThe cohort was majority black or Hispanic. Median follow-up was 4.3 years. Compared to the neither-infected group, the HIV-monoinfected group showed near-significantly higher risks of death or any readmission (HR&nbsp;=&nbsp;1.62, 95% CI&nbsp;=&nbsp;0.96, 2.74) and death or CVD readmission (HR&nbsp;=&nbsp;1.82, 95% CI&nbsp;=&nbsp;0.98, 3.39) after full adjustment. On similar comparison, the HCV-monoinfected group exhibited significantly higher risks of death (HR&nbsp;=&nbsp;2.09, 95% CI&nbsp;=&nbsp;1.05, 4.15) and death or any readmission (HR&nbsp;=&nbsp;1.68, 95% CI&nbsp;=&nbsp;1.07, 2.65), whereas the HIV-HCV-coinfected group showed higher risk of death (HR&nbsp;=&nbsp;6.51, 95% CI&nbsp;=&nbsp;2.28, 18.61).ConclusionsIn this cohort composed mostly of race-ethnic minorities, HIV monoinfection tended to be associated with 1.6-to-1.8-fold higher risk of death or readmission for any cause or CVD over long-term follow-up compared to neither infection, whereas HCV monoinfection was associated with 1.7-to-2.1-fold higher risk of death and death or any readmission, and HIV-HCV coinfection with 6.5-fold higher risk of death. These associations require further study in larger populations, but highlight the importance of identifying and treating HIV and HCV in patients presenting with STEMI

Multiphase Catalytic Hydrodehalogenation: A new PCDD/PCDF detoxification method

(ISSN: 1026-4892

Organ-specific over-sulfation of glycosaminoglycans and altered extracellular matrix in a mouse model of cystic fibrosis

Cystic fibrosis (CF) is a fatal inherited disease caused by the loss of function of a plasma membrane chloride channel-the cystic fibrosis transmembrane conductance regulator (CFTR). It is characterized by viscous mucous secretions which have abnormal glycosylation and sulfation. The development of a CFTR knockout mouse has allowed in vivo experiments aimed at investigating the over-sulfation phenomenon reported for CF glycoconjugates. Four CF and five control mice injected with [35S]sulfate were examined for differences in the sulfation of glycosaminoglycans (GAGs) synthesized by 12 tissues after 48 h. The liver and pancreas of CF mice incorporated significantly higher amounts of [35S]sulfate into GAGs (dpm/microg) than the controls, while the ileum, jejunum, colon, cecum, spleen, trachea, and gall bladder of CF mice exhibited higher incorporation levels that were not significant. The lung and nasal septum were not different, and the nasal mucosa of CF mice was significantly lower (P < 0.05). Structural analysis of the chondroitin/dermatan sulfate component by strong anion-exchange HPLC revealed that the liver and ileum of CF mice incorporated significantly more total sulfate than controls. However, for other organs, the explanation for higher isotope incorporation was a 40-50% higher specific activity of [35S]sulfate within GAGs. This finding implied different uptake kinetics of sulfate from the circulation or that CF mice have altered sulfate pools. CF mice also had altered proportions of chondroitin/dermatan sulfate to heparan sulfate in the ileum and gall bladder (P < 0.05). We conclude that extracellular matrix architecture in some CF organs may be abnormal and that sulfation of glycoconjugates by some organs and sulfate utilization in others have been affected by the loss of CFTR. This study provides the first in vivo evidence for an influence of CFTR on glycoconjugate sulfation and suggests other secondary manifestations of CFTR dysfunction associated with abnormalities of the extracellular matrix.Warren G. Hill, Gregory S. Harper, Tina Rozaklis, Richard C. Boucher, John J. Hopwoo