Conservation of carbon resources and values on public lands: A case study from the National Wildlife Refuge System.

Public lands in the United States are those land areas managed by federal, state, and county governments for public purposes such as preservation and recreation. Protecting carbon resources and increasing carbon sequestration capacity are compatible with public land management objectives for healthy and resilient habitats, i.e., managing habitats for the benefit of wildlife and ecosystem services can simultaneously capture and store carbon. To evaluate the effect of public land management on carbon storage and review carbon management as part of the land management objectives, we used existing data of carbon stock and net ecosystem carbon balance in a study of the National Wildlife Refuge System (NWRS), a public land management program of the U.S. Fish and Wildlife Service (Service). Total carbon storage of the 364 refuges studied was 16.6 PgC, with a mean value 42,981 gCm-2. We used mixed modeling with Bonferroni adjustment techniques to analyze the effect of time since refuge designation on carbon storage. In general, older refuges store more carbon per unit area than younger refuges. In addition to the age factor, carbon resources are variable by regions and habitat types protected in the refuges. Mean carbon stock and the rate of sequestration are higher within refuges than outside refuges, but the statistical comparison of 364 refuges analyzed in this study was not significant. We also used the social cost of carbon to analyze the annual benefits of sequestrating carbon in these publicly managed lands in the United States, which is over $976 million per year in avoided CO2 emissions via specific conservation management actions. We examine case studies of management, particularly with respect to Service cooperation activities with The Conservation Fund (TCF) Go Zero® Program, Trust for Public Land (TPL) and individuals. Additional opportunities exist in improving techniques to maximize carbon resources in refuges, while continuing to meet the core purpose and need of the NWRS.

Rapid identification of slow healing wounds.

Chronic nonhealing wounds have a prevalence of 2% in the United States, and cost an estimated $50 billion annually. Accurate stratification of wounds for risk of slow healing may help guide treatment and referral decisions. We have applied modern machine learning methods and feature engineering to develop a predictive model for delayed wound healing that uses information collected during routine care in outpatient wound care centers. Patient and wound data was collected at 68 outpatient wound care centers operated by Healogics Inc. in 26 states between 2009 and 2013. The dataset included basic demographic information on 59,953 patients, as well as both quantitative and categorical information on 180,696 wounds. Wounds were split into training and test sets by randomly assigning patients to training and test sets. Wounds were considered delayed with respect to healing time if they took more than 15 weeks to heal after presentation at a wound care center. Eleven percent of wounds in this dataset met this criterion. Prognostic models were developed on training data available in the first week of care to predict delayed healing wounds. A held out subset of the training set was used for model selection, and the final model was evaluated on the test set to evaluate discriminative power and calibration. The model achieved an area under the curve of 0.842 (95% confidence interval 0.834-0.847) for the delayed healing outcome and a Brier reliability score of 0.00018. Early, accurate prediction of delayed healing wounds can improve patient care by allowing clinicians to increase the aggressiveness of intervention in patients most at risk.

Frequency of debridements and time to heal: a retrospective cohort study of 312 744 wounds.

IMPORTANCE: Chronic wounds usually get trapped in the inflammatory stage of wound healing; however, aggressive debridement transforms chronic wounds to acute wounds and therefore complete healing. OBJECTIVE: To investigate healing outcomes and debridement frequency in a large wound data set. DESIGN: Retrospective cohort study. SETTING: Data collected from 525 wound care centers from June 1, 2008, through June 31, 2012, using a web-based clinical management system. PATIENTS: Referred sample of 154 644 patients with 312 744 wounds of all causes (of an initial data set of 364 534 wounds) participated. A total of 47.1% were male. Median age was 69 years (age range, 19-112 years), with 59.2% having one wound. Eligibility criteria included age older than 18 years, receiving at least 1 debridement, and having been discharged from the system. Advanced therapeutic treatment was ineligible. Because of incomplete, questionable, or ineligible data, 57 190 wounds were not included. Most wounds were diabetic foot ulcers (19.0%), venous leg ulcers (26.1%), and pressure ulcers (16.2%). INTERVENTION: Debridement (removal of necrotic tissue and foreign bodies from the wound) at different frequencies. MAIN OUTCOME AND MEASURE: Wound healing (completely epithelialized with dimensions at 0 × 0 × 0 cm). RESULTS: A total of 70.8% of wounds healed. The median number of debridements was 2 (range, 1-138). Frequent debridement healed more wounds in a shorter time (P < .001). In regression analysis, significant variables included male sex, physician category, wound type, increased patient age, and increased wound age, area, and depth. The odds ratio varied considerably for each variable. CONCLUSIONS AND RELEVANCE: The more frequent the debridements, the better the healing outcome. Although limited by retrospective data, this study's strength was the analysis of the largest wound data set to date.

Ultrasound-mediated oxygen delivery to lower extremity wounds.

Critical limb ischemia (CLI), an end result of peripheral ar- terial disease, remains a major clinical challenge. Wound healing in patients with CLI can be difficult due to diminished tissue oxygen- ation, often leading to recalcitrant ulcers and frequent limb loss. Nu- merous therapies, including hyperbaric oxygen therapy (HBOT), have been used to correct this regional ischemia, although often with mixed results. This case series investigates the effects of oxygen therapy de- livery augmented by low-frequency ultrasound, a device that combines surface acoustic waveform (SAW) low-frequency ultrasound with hyper- oxygenated saline to deliver oxygen to wounds. Participants included 7 patients (7 men, median age 63 years, all with hypertension) with CLI and full-thickness wounds. Baseline therapy PaO2 measurements were taken before therapy, after provision of hyper-oxygenated saline, and after sonification. The device was found to successfully oxygenate the wound beds; PaO2 levels increased by a median of 59.7%, a maximum of 116%, and a median absolute difference peaking at 10.8 mmHg PaO2 (P = 0.018). In conclusion, the treatment increases wound oxy- gen levels and may be an option in CLI therapy.