Agroforestry perennials reduce nitrous oxide emissions and their live and dead trees increase ecosystem carbon storage.

Agroforestry systems (AFS) contribute to carbon (C) sequestration and reduction in greenhouse gas emissions from agricultural lands. However, previously understudied differences among AFS may underestimate their climate change mitigation potential. In this 3-year field study, we assessed various C stocks and greenhouse gas emissions across two common AFS (hedgerows and shelterbelts) and their component land uses: perennial vegetated areas with and without trees (woodland and grassland, respectively), newly planted saplings in grassland, and adjacent annual cropland in central Alberta, Canada. Between 2018 and 2020 (~April-October), nitrous oxide emissions were 89% lower under perennial vegetation relative to the cropland (0.02 and 0.18 g N m-2  year-1 , respectively). In 2020, heterotrophic respiration in the woodland was 53% lower in shelterbelts relative to hedgerows (279 and 600 g C m-2  year-1 , respectively). Within the woodland, deadwood C stock was particularly important in hedgerows (35 Mg C ha-1 or 7% of ecosystem C) relative to shelterbelts (2 Mg C ha-1 or <1% of ecosystem C), and likely affected C cycling differences between the woodland types by enhancing soil labile C and microbial biomass in hedgerows. Deadwood C stock was positively correlated with annual heterotrophic respiration and total (to ~100 cm depth) soil organic C, water-soluble organic C, and microbial biomass C. Total ecosystem C was 1.90-2.55 times greater within the woodland than all other land uses, with 176, 234, 237, and 449 Mg C ha-1 found in the cropland, grassland, planted saplings treatment, and woodland, respectively. Shelterbelt and hedgerow woodlands contained 2.09 and 3.03 times more C, respectively, than adjacent cropland. Our findings emphasize the importance of AFS for fostering C sequestration and reducing greenhouse gas emissions and, in particular, retaining hedgerows (legacy woodland) and their associated deadwood across temperate agroecosystems will help mitigate climate change.

Biochar and its manure-based feedstock have divergent effects on soil organic carbon and greenhouse gas emissions in croplands.

Applying organic amendments to soil can increase soil organic carbon (SOC) storage and reduce greenhouse gas (GHG) emissions generated by agriculture, helping to mitigate climate change. However, it is necessary to determine which type of amendment produces the most desirable results. We conducted a 3-y field study comparing one-time addition of manure compost and its biochar derivative to a control to assess their effects on SOC and GHG emissions at ten annually cropped sites in central Alberta, Canada. Manure compost and biochar were applied at equivalent carbon rates (7 Mg ha-1) and tilled into the surface 10 cm of soil. Two years post-treatment, biochar addition increased surface (0-10 cm) SOC by 12 and 10 Mg ha-1 relative to the control and manure addition, respectively. Therefore, biochar addition led to the sequestration of SOC at a rate of 2.5 Mg ha-1 y-1 relative to the control. No treatment effect on deeper (10-100 cm) or cumulative SOC was found. In 2018 and 2019, manure addition increased cumulative GHG (sum of CO2, CH4, and N2O) emissions by 33%, on average, due to greater CO2 emissions relative to both the control and biochar addition. In contrast, in 2020, biochar addition reduced cumulative GHG emissions by an average of 21% due to lower CO2 emissions relative to both the control and manure addition. Our study shows that the application of biochar, rather than its manure compost feedstock, increased surface SOC sequestration and had either no effect on (first two years) or reduced GHG emissions (year three) relative to the control. We recommend that policy and carbon sequestration initiatives focus on optimizing biochar production-application systems to fully realize the potential of biochar application as a viable climate change mitigation practice in agriculture.

Real-World Outcomes in Patients with Branch Retinal Vein Occlusion- (BRVO-) Related Macular Edema Treated with Anti-VEGF Injections Alone versus Anti-VEGF Injections Combined with Focal Laser.

The purpose of this study was to assess outcomes in a real-world nonclinical trial setting of antivascular endothelial growth factor (VEGF) injections alone vs. focal laser combined with anti-VEGF injections in patients with branch retinal vein occlusion- (BRVO-) related macular edema (ME). This study included 88 BRVO with ME patients who were treated over three years at both a tertiary referral center in the Birmingham metropolitan area and satellites in rural Alabama. One group received only anti-VEGF injections (n = 56); the other group received both anti-VEGF injections and focal laser (n = 32). The following outcome measures were evaluated: initial and final visual acuities (VA), initial central subfield thickness (CST) on OCT, number of injections, number of lasers, percentage of patients with a gain of 3 lines of VA, percentage of patients with VA better than or equal to 20/40, and percentage of patients with VA worse than or equal to 20/200. We found that there was no difference in initial VA (p=0.913) or CST (p=0.961) between the two groups. The injection only group required a median of 7 injections, while the combination group required a median of 4 injections, but this was not a statistically significant difference (p=0.117). There was no difference in final VA (p=0.414) or any of the other visual outcomes between the two groups. In conclusion, focal laser did not decrease the number of injections required or improve the VA in BRVO-related ME. Although visual outcomes were similar in both groups, focal laser does not appear to be of additional benefit in BRVO-related ME in the anti-VEGF era.

Accuracy of Alcon WaveLight® EX500 optical pachymetry during LASIK.

PURPOSE: To study the accuracy and reliability of optical pachymetry using the Alcon WaveLight EX500 during laser-assisted in situ keratomileusis (LASIK). MATERIALS AND METHODS: This was a retrospective chart review of 90 eyes from 45 patients who had undergone LASIK (mean age 35.2±8.2 years; 19 males, 26 females). The WaveLight FS200 femtosecond laser was programmed to cut LASIK flaps at a desired depth of 120 µm. Optical low-coherence reflectometry (WaveLight EX500) was used to measure central corneal thickness prior to lifting the flap, and the residual stromal bed immediately after excimer ablation. Flap thickness (FT) was calculated using simple subtraction. Optical coherence tomography (OCT) was used to measure central corneal thickness, flap thickness, and residual stromal bed in the postoperative period and the results compared to intraoperative measurements. RESULTS: Mean programmed FS200 FT was 119 µm. Mean FT using EX500 optical pachymetry was 109 µm. The difference between FS200- programmed and EX500-measured FT was 9 µm (P<0.001). There was also a significant difference between the EX500 and OCT FT (109 µm vs 119 µm, respectively; P<0.001). CONCLUSION: FT values calculated using intraoperative EX500 optical pachymetry were significantly lower than programmed FS200 values or OCT measurements.

Spontaneous pneumomediastinum: A rare complication of methamphetamine use.

OBJECTIVE: To present an unusual case of spontaneous pneumomediastinum subsequent to recreational amphetamine use. CASE REPORT: A young African American adult male was admitted to internal medicine service for treatment of rhabdomyolysis secondary to methamphetamine use. On admission, he was complaining of chest pain in addition to nausea and generalized muscle aches. By his second hospital day, chest pain had resolved yet physical exam demonstrated crepitation of the anterior chest and left axilla. Portable chest x-ray revealed subcutaneous emphysema in addition to pneumomediastinum. CONCLUSION: Spontaneous pneumomediastinum is a rare complication of amphetamine use that is often associated with subcutaneous emphysema and can be diagnosed with chest x-ray. Management is conservative, with observation, pain control, and supplemental oxygen as needed.

Age-Associated ALU Element Instability in White Blood Cells Is Linked to Lower Survival in Elderly Adults: A Preliminary Cohort Study.

BACKGROUND: ALU element instability could contribute to gene function variance in aging, and may partly explain variation in human lifespan. OBJECTIVE: To assess the role of ALU element instability in human aging and the potential efficacy of ALU element content as a marker of biological aging and survival. DESIGN: Preliminary cohort study. METHODS: We measured two high frequency ALU element subfamilies, ALU-J and ALU-Sx, by a single qPCR assay and compared ALU-J/Sx content in white blood cell (WBCs) and skeletal muscle cell (SMCs) biopsies from twenty-three elderly adults with sixteen healthy sex-balanced young adults; all-cause survival rates of elderly adults predicted by ALU-J/Sx content in both tissues; and cardiovascular disease (CVD)- and cancer-specific survival rates of elderly adults predicted by ALU-J/Sx content in both tissues, as planned subgroup analyses. RESULTS: We found greater ALU-J/Sx content variance in WBCs from elderly adults than young adults (P < 0.001) with no difference in SMCs (P = 0.94). Elderly adults with low WBC ALU-J/Sx content had worse four-year all-cause and CVD-associated survival than those with high ALU-J/Sx content (both P = 0.03 and hazard ratios (HR) ≥ 3.40), while WBC ALU-J/Sx content had no influence on cancer-associated survival (P = 0.42 and HR = 0.74). SMC ALU-J/Sx content had no influence on all-cause, CVD- or cancer -associated survival (all P ≥ 0.26; HR ≤ 2.07). CONCLUSIONS: These initial findings demonstrate that ALU element instability occurs with advanced age in WBCs, but not SMCs, and imparts greater risk of all-cause mortality that is likely driven by an increased risk for CVD and not cancer.