Summary
The relationships between bacterial community diversity and stability were investigated by perturbing soils, with naturally differing levels of diversity, to equivalent toxicity using copper ...sulfate and benzene. Benzene amendment led to large decreases in total bacterial numbers and biomass in both soils. Benzene amendment of an organo‐mineral/improved pasture soil altered total soil bacterial community structure but, unlike amendment of the mineral/arable soil, maintained genetic diversity, based on polymerase chain reaction‐denaturing gradient gel electrophoresis (PCR‐DGGE ) analysis targeting DNA and RNA, until week 9 of the perturbation experiment. Assuming equivalent toxicity, the genetic diversity of the naturally more diverse soil was more resistant to benzene perturbation than the less diverse soil. The broad scale function (mineralization of 14C‐labelled wheat shoot) of both benzene‐ and copper‐treated soil communities was unaffected. However, narrow niche function (mineralization of 14C‐labelled 2,4‐dichlorophenol) was impaired for both benzene‐polluted soils. The organo‐mineral soil recovered this function by the end of the experiment but the mineral soil did not, suggesting greater resilience in the more diverse soil. Despite a large reduction in bacterial numbers and biomass in the copper‐treated soils, only small differences in bacterial community diversity were observed by week 9 in the copper‐polluted soils. The overall community structure was little altered and functionality, measured by mineralization rates, remained unchanged. This suggested a non‐selective pressure and a degree of genetic and functional resistance to copper perturbation, despite a significant reduction in bacterial numbers and biomass. However, initial shifts in physiological profiles of both copper‐polluted soils were observed but rapidly returned to those of the controls. This apparent functional recovery, accompanied by an increase in culturability, possibly reflects adaptation by the surviving communities to perturbation. The findings indicate that, although soil communities may be robust, relationships between diversity and stability need to be considered in developing a predictive understanding of response to environmental perturbations.
Diabet. Med. 29, 453–463 (2012)
Aims To estimate remaining life expectancy (RLE), quality‐adjusted life expectancy (QALE), causes of death and lifetime cumulative incidence of ...microvascular/macrovascular complications of diabetes for youths diagnosed with Type 2 diabetes.
Methods A Markov‐like computer model simulated the life course for a hypothetical cohort of adolescents/young adults in the USA, aged 15–24 years, newly diagnosed with Type 2 diabetes following either conventional or intensive treatment based on the UK Prospective Diabetes Study. Outcomes included RLE, discounted QALE in quality‐adjusted life years (QALYs), cumulative incidence of microvascular/macrovascular complications and causes of death.
Results Compared with a mean RLE of 58.6 years for a 20‐year‐old in the USA without diabetes, conventional treatment produced an average RLE of 43.09 years and 22.44 discounted QALYs. Intensive treatment afforded an incremental 0.98 years and 0.44 discounted QALYs. Intensive treatment led to lower lifetime cumulative incidence of all microvascular complications and lower mortality from microvascular complications (e.g. end‐stage renal disease (ESRD) death 19.4% vs. 25.2%). Approximately 5% with both treatments had ESRD within 25 years. Lifetime cumulative incidence of coronary heart disease (CHD) increased with longer RLE and greater severity of CHD risk factors. Incorporating disutility (loss in health‐related quality of life) of intensive treatment resulted in net loss of QALYs.
Conclusions Adolescents/young adults with Type 2 diabetes lose approximately 15 years from average RLE and may experience severe, chronic complications of Type 2 diabetes by their 40s. The net clinical benefit of intensive treatment may be sensitive to preferences for treatment. A comprehensive management plan that includes early and aggressive control of cardiovascular risk factors is likely needed to reduce lifetime risk of CHD.
The optimal strategy for the vaccinating against herpes zoster (HZ) vaccine remains unknown. Cost-effectiveness analyses provide insight to the most cost-effective age groups but results vary across ...studies. The optimal strategy is important given that vaccine efficacy and duration vary depending on vaccination age. Therefore, small changes from the optimal age can affect long-term outcomes and produce sub-optimal results. The objective of this research was to determine the optimal timing policy for HZ vaccination. We simulated cohorts of men and women and use stochastic dynamic programming to evaluate the decision to vaccinate or defer each year from age 50 to 100. If the decision was to defer, the cohort risked developing HZ. If HZ occurred, the cohort was subjected to cost and quality-adjusted life year (QALY) loss for a typical HZ infection (including complications) at that age. If HZ did not occur, the decision was evaluated at the next age. Then, we extend the model to consider the case in which a booster vaccine is available. A set of probabilistic sensitivity analyses were conducted to check model robustness. Results show the optimal policy for women is to vaccinate between ages 66 and 77, and for men between ages 66 and 74, assuming a willingness to pay (WTP) of $100,000 per QALY. It becomes optimal to vaccinate earlier if a booster vaccine is available, and women have a wider range of ages than men. This research is the first to examine exactly when the HZ vaccine should be administered. It is also the first study, to our knowledge, that used stochastic dynamic programming to examine the question of a second dose for any vaccine. This research provides the first simple policy on when to vaccinate and re-vaccinate against HZ.
Bacterial community structure and diversity in rhizospheres in two types of grassland, distinguished by both plant species and fertilization regimen, were assessed by performing a 16S ribosomal DNA ...(rDNA) sequence analysis of DNAs extracted from triplicate soil plots. PCR products were cloned, and 45 to 48 clones from each of the six libraries were partially sequenced. Phylogenetic analysis of the resultant 275 clone sequences indicated that there was considerable variation in abundance in replicate unfertilized, unimproved soil samples and fertilized, improved soil samples but that there were no significant differences in the abundance of any phylogenetic group. Several clone sequences were identical in the 16S rDNA region analyzed, and the clones comprised eight pairs of duplicate clones and two sets of triplicate clones. Many clones were found to be most closely related to environmental clones obtained in other studies, although three clones were found to be identical to culturable species in databases. The clones were clustered into operational taxonomic units at a level of sequence similarity of >97% in order to quantify diversity. In all, 34 clusters containing two or more sequences were identified, and the largest group contained nine clones. A number of diversity, dominance, and evenness indices were calculated, and they all indicated that diversity was high, reflecting the low coverage of rDNA libraries achieved. Differences in diversity between sample types were not observed. Collector's curves, however, indicated that there were differences in the underlying community structures; in particular, there was reduced diversity of organisms of the a subdivision of the class Proteobacteria (alpha-proteobacteria) in improved soils.
We characterised the spatial structure of soil microbial communities in an unimproved grazed upland grassland in the Scottish Borders. A range of soil chemical parameters, cultivable microbes, ...protozoa, nematodes, phospholipid fatty acid (PLFA) profiles, community-level physiological profiles (CLPP), intra-radical arbuscular mycorrhizal community structure, and eubacterial, actinomycete, pseudomonad and ammonia-oxidiser 16S rRNA gene profiles, assessed by denaturing gradient gel electrophoresis (DGGE) were quantified. The botanical composition of the vegetation associated with each soil sample was also determined. Geostatistical analysis of the data revealed a gamut of spatial dependency with diverse semivariograms being apparent, ranging from pure nugget, linear and non-linear forms. Spatial autocorrelation generally accounted for 40–60% of the total variance of those properties where such autocorrelation was apparent, but accounted for 97% in the case of nitrate-N. Geostatistical ranges extending from approximately 0.6–6 m were detected, dispersed throughout both chemical and biological properties. CLPP data tended to be associated with ranges greater than 4.5 m. There was no relationship between physical distance in the field and genetic similarity based on DGGE profiles. However, analysis of samples taken as close as 1 cm apart within a subset of cores suggested some spatial dependency in community DNA-DGGE parameters below an 8 cm scale. Spatial correlation between the properties was generally weak, with some exceptions such as between microbial biomass C and total N and C. There was evidence for scale-dependence in the relationships between properties. PLFA and CLPP profiling showed some association with vegetation composition, but DGGE profiling did not. There was considerably stronger association between notional sheep urine patches, denoted by soil nutrient status, and many of the properties. These data demonstrate extreme spatial variation in community-level microbiological properties in upland grasslands, and that despite considerable numeric ranges in the majority of properties, overarching controlling factors were not apparent.
Aims
To evaluate the effectiveness of automated symptom and side effect monitoring on quality of life among individuals with symptomatic diabetic peripheral neuropathy.
Methods
We conducted a ...pragmatic, cluster randomized controlled trial (July 2014 to July 2016) within a large healthcare system. We randomized 1834 primary care physicians and prospectively recruited from their lists 1270 individuals with neuropathy who were newly prescribed medications for their symptoms. Intervention participants received automated telephone‐based symptom and side effect monitoring with physician feedback over 6 months. The control group received usual care plus three non‐interactive diabetes educational calls. Our primary outcomes were quality of life (EQ‐5D) and select symptoms (e.g. pain) measured 4–8 weeks after starting medication and again 8 months after baseline. Process outcomes included receiving a clinically effective dose and communication between individuals with neuropathy and their primary care provider over 12 months. Interviewers collecting outcome data were blinded to intervention assignment.
Results
Some 1252 participants completed the baseline measures mean age (sd): 67 (11.7), 53% female, 57% white, 8% Asian, 13% black, 20% Hispanic. In total, 1179 participants (93%) completed follow‐up (619 control, 560 intervention). Quality of life scores (intervention: 0.658 ± 0.094; control: 0.653 ± 0.092) and symptom severity were similar at baseline. The intervention had no effect on primary EQ‐5D: −0.002 (95% CI −0.01, 0.01), P = 0.623; pain: 0.295 (−0.75, 1.34), P = 0.579; sleep disruption: 0.342 (−0.18, 0.86), P = 0.196; lower extremity functioning: −0.079 (−1.27, 1.11), P = 0.896; depression: −0.462 (−1.24, 0.32); P = 0.247 or process outcomes.
Conclusions
Automated telephone monitoring and feedback alone were not effective at improving quality of life or symptoms for people with symptomatic diabetic peripheral neuropathy.
Trial Registration: ClinicalTrials.gov (NCT02056431).
What's new?
Frequent communication between individuals with diabetic peripheral neuropathy and primary care providers about symptoms and medication side effects is critical to optimizing medication dosing to treat painful diabetic peripheral neuropathy. Yet, there are considerable barriers to effective communication.
This cluster randomized controlled trial found that a brief intervention to automatically monitor person‐reported data on symptoms and side effects, and provide the information to physicians via an electronic health record was not effective in improving the outcomes valued by individuals with neuropathy.
Alerts alone are unlikely to change provider behaviour related to treatment intensification. More intensive interventions focused on individual activation or provider education may be more effective in changing prescribing behaviour and improving outcomes.
Bar-headed geese are renowned for migratory flights at extremely high altitudes over the world's tallest mountains, the Himalayas, where partial pressure of oxygen is dramatically reduced while ...flight costs, in terms of rate of oxygen consumption, are greatly increased. Such a mismatch is paradoxical, and it is not clear why geese might fly higher than is absolutely necessary. In addition, direct empirical measurements of high-altitude flight are lacking. We test whether migrating bar-headed geese actually minimize flight altitude and make use of favourable winds to reduce flight costs. By tracking 91 geese, we show that these birds typically travel through the valleys of the Himalayas and not over the summits. We report maximum flight altitudes of 7290 m and 6540 m for southbound and northbound geese, respectively, but with 95 per cent of locations received from less than 5489 m. Geese travelled along a route that was 112 km longer than the great circle (shortest distance) route, with transit ground speeds suggesting that they rarely profited from tailwinds. Bar-headed geese from these eastern populations generally travel only as high as the terrain beneath them dictates and rarely in profitable winds. Nevertheless, their migration represents an enormous challenge in conditions where humans and other mammals are only able to operate at levels well below their sea-level maxima.
Riparian vegetation can trap sediment and nutrients sourced from hillslopes and reduce stream bank erosion. This study presents results from a 10-year stream monitoring program (1991–2000), in a 6
km
...2 agricultural catchment near Albany, Western Australia. After 6 years, a 1.7
km stream reach was fenced, planted with eucalyptus species and managed independently from the adjacent paddocks. Streamflow, nutrient and sediment concentration data were collected at the downstream end of the fenced riparian area, so there are data for before and after improved riparian management. Suspended sediment (SS) concentrations fell dramatically following improved riparian management; the median event mean concentration (EMC) dropped from 147 to 9.9
mg
l
−1. Maximum SS concentrations dropped by an order of magnitude. As a result, sediment exports from the catchment decreased following improved riparian management, from over 100 to less than 10
kg
ha
−1
yr
−1. Observations suggest that this was the result of reduced bank erosion and increased channel stability. Riparian management had limited impact on total phosphorus (TP) concentrations or loads, but contributed to a change in phosphorus (P) form. Before improved riparian management, around half of the P was transported attached to sediment, but after, the median filterable reactive P (FRP) to TP ratio increased to 0.75. In addition, the median FRP EMC increased by 60% and the raw median FRP concentration increased from 0.18 to 0.35
mg
l
−1. These results suggest that there was a change in the dominant P form, from TP to FRP. Changes in total nitrogen (TN) following improved riparian management were less clear. There were reductions in TN concentrations at high flows, but little change in the loads or EMC. This study demonstrates the benefits of riparian management in reducing stream bank erosion, but suggests that in catchments with sandy, low P sorption soils, there may be limitations on the effectiveness of riparian buffers for reducing P and N exports.
The National Cholesterol Education Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel II) recommends treatment guidelines based on ...cholesterol level and number of risk factors.
To evaluate how the cost-effectiveness ratios of cholesterol-lowering therapies vary according to different risk factors.
Cost-effectiveness analysis.
Published data.
Women and men 35 to 84 years of age with low-density lipoprotein cholesterol levels of 4.1 mmol/L or greater (> or =160 mg/dL), divided into 240 risk subgroups according to age, sex, and the presence or absence of four coronary heart disease risk factors (smoking status, blood pressure, low-density lipoprotein cholesterol level, and high-density lipoprotein cholesterol level).
30 years.
Societal.
Step I diet, statin therapy, and no preventive treatment for primary and secondary prevention.
Incremental cost-effectiveness ratios.
Incremental cost-effectiveness ratios for primary prevention with step I diet ranged from $1900 per quality-adjusted life-year (QALY) gained to $500000 per QALY depending on risk subgroup characteristics. Primary prevention with a statin compared with diet therapy was $54000 per QALY to $1400000 per QALY. Secondary prevention with a statin cost less than $50000 per QALY for all risk subgroups.
The inclusion of niacin as a primary prevention option resulted in much less favorable incremental cost-effectiveness ratios for primary prevention with a statin (>$500000 per QALY).
Cost-effectiveness of treatment strategies varies significantly when adjusted for age, sex, and the presence or absence of additional risk factors. Primary prevention with a step I diet seems to be cost-effective for most risk subgroups but may not be cost-effective for otherwise healthy young women. Primary prevention with a statin may not be cost-effective for younger men and women with few risk factors, given the option of secondary prevention and of primary prevention in older age ranges. Secondary prevention with a statin seems to be cost-effective for all risk subgroups and is cost-saving in some high-risk subgroups.
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