Soil Bacterial Assemblage Across a Production Landscape: Agriculture Increases Diversity While Revegetation Recovers Community Composition.

Aboveground ecological impacts associated with agricultural land use change are evident as natural plant communities are replaced with managed production systems. These impacts have been extensively studied, unlike those belowground, which remain poorly understood. Soil bacteria are good candidates to monitor belowground ecological dynamics due to their prevalence within the soil system and ability to survive under harsh and changing conditions. Here, we use soil physicochemical assessment and 16S rRNA gene sequencing to investigate the soil physical and bacterial assemblage changes across a mixed-use agricultural landscape. We assess soil from remnant vegetation (Eucalyptus mallee), new and old vineyards, old pasture, and recently revegetated areas. Elevated concentrations of nitrogen (NO3-) and plant-available (Colwell) phosphorus were identified in the managed vineyard systems, highlighting the impact of agricultural inputs on soil nutrition. Alpha diversity comparison revealed a significant difference between the remnant mallee vegetation and the vineyard systems, with vineyards supporting highest bacterial diversity. Bacterial community composition of recently revegetated areas was similar to remnant vegetation systems, suggesting that bacterial communities can respond quickly to aboveground changes, and that actions taken to restore native plant communities may also act to recover natural microbial communities, with implications for soil and plant health. Findings here suggest that agriculture may disrupt the correlation between above- and belowground diversities by altering the natural processes that otherwise govern this relationship (e.g. disturbance, plant production, diversity of inputs), leading to the promotion of belowground microbial diversity in agricultural systems.

Topical treatments for chronic plaque psoriasis of the scalp: a systematic review.

BACKGROUND: Chronic plaque psoriasis is the most common type of psoriasis and is characterized by redness, thickness and scaling. First-line management is with topical treatments. OBJECTIVES: Our objective was to establish the effectiveness, tolerability and safety of topical treatments for people with chronic plaque psoriasis of the scalp, assessing placebo-controlled trials of all treatments and head-to-head trials that assessed vitamin D analogues. METHODS: As part of a Cochrane review of topical treatments for psoriasis, we systematically searched electronic databases for randomized controlled trials. The review included 26 randomized controlled trials of treatments for psoriasis of the scalp with 8020 participants. Trials used several measures to assess changes in psoriasis severity: these were combined using the standardized mean difference metric and interpreted by reporting as a six-point global improvement score. RESULTS: On effectiveness grounds, very potent or potent steroid treatments should be preferred to vitamin D3 analogue with approximately an average 10% additional improvement on a six-point scale. Vitamin D3 analogue combined with potent steroid appears slightly more effective than potent steroid monotherapy (3% additional improvement on a six-point scale). Rates of withdrawal from treatment and adverse events in trials were generally low and similar to those for placebo. There remains uncertainty about the atrophic potential of corticosteroid treatments for scalp psoriasis. CONCLUSIONS: Corticosteroids are more effective than vitamin D analogues and similarly tolerated. However, further research is needed to inform long-term maintenance treatment and provide appropriate safety data.

Topical preparations for the treatment of psoriasis: a systematic review.

BACKGROUND: There is clinical uncertainty about the appropriate use of first-line topical treatments for psoriasis. OBJECTIVES: To assess the relative effectiveness and tolerability of topical treatments for psoriasis suitable for use both in primary and secondary care. METHODS: All major medical databases of published literature were searched electronically; references of trial reports and recent reviews were searched; authors and companies were contacted for missing data from published reports. The study selection comprised: (1) randomized placebo-controlled trials of topical treatments for psoriasis; and (2) randomized head-to-head studies of the new vitamin D3 derivative treatments for psoriasis that reported clinical outcome using a Total Severity Score (TSS), Psoriasis Area Severity Index or Investigator Assessment of Global Improvement. Eligibility and validity were assessed and data extracted independently by two authors. Clinical outcomes were pooled using a random effect standardized weighted mean difference (SWMD) metric, including 3380 patients randomized in 41 placebo (vehicle)-controlled trials and 4898 patients randomized in 28 head-to-head studies. RESULTS: There was a significant benefit in favour of active treatments against vehicle, SWMD: -1.06 (95% confidence interval [CI]: -1.26 to -0.86), approximately a 2-point improvement on a 12-point TSS after 6-8 weeks of treatment. The only significantly different benefit was for very potent corticosteroids: SWMD: -1.51 (95% CI: -1.76 to -1.25), approximately a 3-point improvement on a 12-point TSS. Head-to-head studies support these findings, except that calcipotriol was estimated to be more effective than dithranol, coal tar and other vitamin D3 derivatives. Polytherapy, using a potent steroid and calcipotriol, was more effective than calcipotriol alone: SWMD 0.42 (95% CI: 0.12-0.72 ) approximately a 0.8-point improvement on a 12-point TSS. No important differences in withdrawal or reporting of adverse events were identified. CONCLUSIONS: Trials of short duration neither adequately inform the management of chronic disease nor describe the sequelae of treatment. The evidence base for long-term care, reflecting the disease pathway, should be improved. Combination therapy with topical vitamin D analogues and steroids, and maintenance therapy following treatment response merit further investigation.