Observations of increased tropical rainfall preceded by air passage over forests.

Vegetation affects precipitation patterns by mediating moisture, energy and trace-gas fluxes between the surface and atmosphere. When forests are replaced by pasture or crops, evapotranspiration of moisture from soil and vegetation is often diminished, leading to reduced atmospheric humidity and potentially suppressing precipitation. Climate models predict that large-scale tropical deforestation causes reduced regional precipitation, although the magnitude of the effect is model and resolution dependent. In contrast, observational studies have linked deforestation to increased precipitation locally but have been unable to explore the impact of large-scale deforestation. Here we use satellite remote-sensing data of tropical precipitation and vegetation, combined with simulated atmospheric transport patterns, to assess the pan-tropical effect of forests on tropical rainfall. We find that for more than 60 per cent of the tropical land surface (latitudes 30 degrees south to 30 degrees north), air that has passed over extensive vegetation in the preceding few days produces at least twice as much rain as air that has passed over little vegetation. We demonstrate that this empirical correlation is consistent with evapotranspiration maintaining atmospheric moisture in air that passes over extensive vegetation. We combine these empirical relationships with current trends of Amazonian deforestation to estimate reductions of 12 and 21 per cent in wet-season and dry-season precipitation respectively across the Amazon basin by 2050, due to less-efficient moisture recycling. Our observation-based results complement similar estimates from climate models, in which the physical mechanisms and feedbacks at work could be explored in more detail.

Impact on short-lived climate forcers (SLCFs) from a realistic land-use change scenario via changes in biogenic emissions.

More than one quarter of natural forests have been cleared by humans to make way for other land-uses, with changes to forest cover projected to continue. The climate impact of land-use change (LUC) is dependent upon the relative strength of several biogeophysical and biogeochemical effects. In addition to affecting the surface albedo and exchanging carbon dioxide (CO2) and moisture with the atmosphere, vegetation emits biogenic volatile organic compounds (BVOCs), altering the formation of short-lived climate forcers (SLCFs) including aerosol, ozone (O3) and methane (CH4). Once emitted, BVOCs are rapidly oxidised by O3, and the hydroxyl (OH) and nitrate (NO3) radicals. These oxidation reactions yield secondary organic products which are implicated in the formation and growth of aerosol particles and are estimated to have a negative radiative effect on the climate (i.e. a cooling). These reactions also deplete OH, increasing the atmospheric lifetime of CH4, and directly affect concentrations of O3; the latter two being greenhouse gases which impose a positive radiative effect (i.e. a warming) on the climate. Our previous work assessing idealised deforestation scenarios found a positive radiative effect due to changes in SLCFs; however, since the radiative effects associated with changes to SLCFs result from a combination of non-linear processes it may not be appropriate to scale radiative effects from complete deforestation scenarios according to the deforestation extent. Here we combine a land-surface model, a chemical transport model, a global aerosol model, and a radiative transfer model to assess the net radiative effect of changes in SLCFs due to historical LUC between the years 1850 and 2000.

Multiannual observations of acetone, methanol, and acetaldehyde in remote tropical atlantic air: implications for atmospheric OVOC budgets and oxidative capacity.

Oxygenated volatile organic compounds (OVOCs) in the atmosphere are precursors to peroxy acetyl nitrate (PAN), affect the tropospheric ozone budget, and in the remote marine environment represent a significant sink of the hydroxyl radical (OH). The sparse observational database for these compounds, particularly in the tropics, contributes to a high uncertainty in their emissions and atmospheric significance. Here, we show measurements of acetone, methanol, and acetaldehyde in the tropical remote marine boundary layer made between October 2006 and September 2011 at the Cape Verde Atmospheric Observatory (CVAO) (16.85° N, 24.87° W). Mean mixing ratios of acetone, methanol, and acetaldehyde were 546 ± 295 pptv, 742 ± 419 pptv, and 428 ± 190 pptv, respectively, averaged from approximately hourly values over this five-year period. The CAM-Chem global chemical transport model reproduced annual average acetone concentrations well (21% overestimation) but underestimated levels by a factor of 2 in autumn and overestimated concentrations in winter. Annual average concentrations of acetaldehyde were underestimated by a factor of 10, rising to a factor of 40 in summer, and methanol was underestimated on average by a factor of 2, peaking to over a factor of 4 in spring. The model predicted summer minima in acetaldehyde and acetone, which were not apparent in the observations. CAM-Chem was adapted to include a two-way sea-air flux parametrization based on seawater measurements made in the Atlantic Ocean, and the resultant fluxes suggest that the tropical Atlantic region is a net sink for acetone but a net source for methanol and acetaldehyde. Inclusion of the ocean fluxes resulted in good model simulations of monthly averaged methanol levels although still with a 3-fold underestimation in acetaldehyde. Wintertime acetone levels were better simulated, but the observed autumn levels were more severely underestimated than in the standard model. We suggest that the latter may be caused by underestimated terrestrial biogenic African primary and/or secondary OVOC sources by the model. The model underestimation of acetaldehyde concentrations all year round implies a consistent significant missing source, potentially from secondary chemistry of higher alkanes produced biogenically from plants or from the ocean. We estimate that low model bias in OVOC abundances in the remote tropical marine atmosphere may result in up to 8% underestimation of the global methane lifetime due to missing model OH reactivity. Underestimation of acetaldehyde concentrations is responsible for the bulk (∼70%) of this missing reactivity.

Assessing costs of Indonesian fires and the benefits of restoring peatland.

Deforestation and drainage has made Indonesian peatlands susceptible to burning. Large fires occur regularly, destroying agricultural crops and forest, emitting large amounts of CO2 and air pollutants, resulting in adverse health effects. In order to reduce fire, the Indonesian government has committed to restore 2.49 Mha of degraded peatland, with an estimated cost of US$3.2-7 billion. Here we combine fire emissions and land cover data to estimate the 2015 fires, the largest in recent years, resulted in economic losses totalling US$28 billion, whilst the six largest fire events between 2004 and 2015 caused a total of US$93.9 billion in economic losses. We estimate that if restoration had already been completed, the area burned in 2015 would have been reduced by 6%, reducing CO2 emissions by 18%, and PM2.5 emissions by 24%, preventing 12,000 premature mortalities. Peatland restoration could have resulted in economic savings of US$8.4 billion for 2004-2015, making it a cost-effective strategy for reducing the impacts of peatland fires to the environment, climate and human health.

Impact on short-lived climate forcers increases projected warming due to deforestation.

The climate impact of deforestation depends on the relative strength of several biogeochemical and biogeophysical effects. In addition to affecting the exchange of carbon dioxide (CO2) and moisture with the atmosphere and surface albedo, vegetation emits biogenic volatile organic compounds (BVOCs) that alter the formation of short-lived climate forcers (SLCFs), which include aerosol, ozone and methane. Here we show that a scenario of complete global deforestation results in a net positive radiative forcing (RF; 0.12 W m-2) from SLCFs, with the negative RF from decreases in ozone and methane concentrations partially offsetting the positive aerosol RF. Combining RFs due to CO2, surface albedo and SLCFs suggests that global deforestation could cause 0.8 K warming after 100 years, with SLCFs contributing 8% of the effect. However, deforestation as projected by the RCP8.5 scenario leads to zero net RF from SLCF, primarily due to nonlinearities in the aerosol indirect effect.

Interventions to improve antibiotic prescribing practices in ambulatory care.

BACKGROUND: The development of resistance to antibiotics by many important human pathogens has been linked to exposure to antibiotics over time. The misuse of antibiotics for viral infections (for which they are of no value) and the excessive use of broad spectrum antibiotics in place of narrower spectrum antibiotics have been well-documented throughout the world. Many studies have helped to elucidate the reasons physicians use antibiotics inappropriately. OBJECTIVES: To systematically review the literature to estimate the effectiveness of professional interventions, alone or in combination, in improving the selection, dose and treatment duration of antibiotics prescribed by healthcare providers in the outpatient setting; and to evaluate the impact of these interventions on reducing the incidence of antimicrobial resistant pathogens. SEARCH STRATEGY: We searched the Cochrane Effective Practice and Organisation of Care Group (EPOC) specialized register for studies relating to antibiotic prescribing and ambulatory care. Additional studies were obtained from the bibliographies of retrieved articles, the Scientific Citation Index and personal files. SELECTION CRITERIA: We included all randomised and quasi-randomised controlled trials (RCT and QRCT), controlled before and after studies (CBA) and interrupted time series (ITS) studies of healthcare consumers or healthcare professionals who provide primary care in the outpatient setting. Interventions included any professional intervention, as defined by EPOC, or a patient-based intervention. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted data and assessed study quality. MAIN RESULTS: Thirty-nine studies examined the effect of printed educational materials for physicians, audit and feedback, educational meetings, educational outreach visits, financial and healthcare system changes, physician reminders, patient-based interventions and multi-faceted interventions. These interventions addressed the overuse of antibiotics for viral infections, the choice of antibiotic for bacterial infections such as streptococcal pharyngitis and urinary tract infection, and the duration of use of antibiotics for conditions such as acute otitis media. Use of printed educational materials or audit and feedback alone resulted in no or only small changes in prescribing. The exception was a study documenting a sustained reduction in macrolide use in Finland following the publication of a warning against their use for group A streptococcal infections. Interactive educational meetings appeared to be more effective than didactic lectures. Educational outreach visits and physician reminders produced mixed results. Patient-based interventions, particularly the use of delayed prescriptions for infections for which antibiotics were not immediately indicated effectively reduced antibiotic use by patients and did not result in excess morbidity. Multi-faceted interventions combining physician, patient and public education in a variety of venues and formats were the most successful in reducing antibiotic prescribing for inappropriate indications. Only one of four studies demonstrated a sustained reduction in the incidence of antibiotic-resistant bacteria associated with the intervention. AUTHORS' CONCLUSIONS: The effectiveness of an intervention on antibiotic prescribing depends to a large degree on the particular prescribing behaviour and the barriers to change in the particular community. No single intervention can be recommended for all behaviours in any setting. Multi-faceted interventions where educational interventions occur on many levels may be successfully applied to communities after addressing local barriers to change. These were the only interventions with effect sizes of sufficient magnitude to potentially reduce the incidence of antibiotic-resistant bacteria. Future research should focus on which elements of these interventions are the most effective. In addition, patient-based interventions and physician reminders show promise and innovative methods such as these deserve further study.

Variable morbidity of respiratory syncytial virus infection in patients with underlying lung disease: a review of the PICNIC RSV database. Pediatric Investigators Collaborative Network on Infections in Canada.

OBJECTIVE: We wished to compare outcomes of respiratory syncytial virus (RSV) infection in children with bronchopulmonary dysplasia (BPD) with those with other pulmonary disorders: cystic fibrosis, recurrent aspiration pneumonitis, pulmonary malformation, neurogenic disorders interfering with pulmonary toilet, and tracheoesophageal fistula. METHODS: Children with RSV infection hospitalized at seven Canadian pediatric tertiary care hospitals in 1993 through 1994 and 9 hospitals in 1994 through 1995 were enrolled and prospectively followed. This study is a secondary analysis of data from this prospective cohort. RESULTS: Of the 1516 patients enrolled the outcomes of 159 with preexisting lung disorders before RSV lower respiratory tract infection constitute this report. There were no significant differences among the 7 groups (BPD, cystic fibrosis, recurrent aspiration pneumonitis, pulmonary malformation, neurogenic disorders interfering with pulmonary toilet, tracheoesophageal fistula, other) for the morbidity measures: duration of hospitalization, intensive care unit (ICU) admission, duration of ICU stay, mechanical ventilation and duration of mechanical ventilation. Patients using home oxygen were more likely to be admitted to the ICU than those who had never or previously used home oxygen (current 57.1%, past 23.8%, never 33.3%, P = 0.03). CONCLUSIONS: Children with other underlying diseases have morbidity similar to those with BPD. Prophylactic interventions against RSV should also be studied in these groups.

Lesions of the dorsomedial amygdala, but not the nucleus accumbens, reduce the aversiveness of morphine withdrawal in rats.

Small lesions of the dorsomedial amygdala reduced the magnitude of the conditioned place aversion produced by naltrexone-precipitated morphine withdrawal, whereas large lesions of the ventral nucleus accumbens had no effect. This finding that the dorsomedial amygdala, which has not been implicated in opiate reward, is involved in mediating the aversiveness of opiate withdrawal is consistent with data indicating that amygdala lesions reduce the aversiveness of a variety of aversive events. In contrast, the nucleus accumbens, which is involved in mediating the rewarding effects of opiates, does not appear to be critically involved in mediating the aversive effects of opiate withdrawal. Together, these findings suggest that the neural structures that mediate the rewarding effects of opiates may be at least partially distinct from the structures that mediate the aversive effects of opiate withdrawal.

Congenital syphilis: A guide to diagnosis and management.

Although congenital syphilis is a rare disease in Canada, infected infants may experience severe sequelae, including cerebral palsy, hydrocephalus, sensorineural hearing loss and musculoskeletal deformity. Timely treatment of congenital syphilis during pregnancy may prevent all of the above sequelae. However, the diagnosis of suspected cases and management of congenital syphilis may be confusing, and the potential for severe disability is high when cases are missed. The present review provides assistance to practitioners in the diagnosis of suspected cases and management of children with presumed or confirmed infection.

Seckel-like syndrome in three siblings.

Seckel syndrome has been described as the prototype of the primordial bird-headed type of dwarfism. Since Seckel originally defined the disorder, less than 60 cases have been reported. In addition to the characteristic craniofacial dysmorphism and skeletal defects, abnormalities have been described in the cardiovascular, hematopoietic, endocrine, and central nervous systems. This pleiotropy has implied genetic heterogeneity and prompted reviews of previously reported cases of Seckel syndrome. As a result, the characteristic diagnostic features of Seckel syndrome have been highly debated. Although deletions in chromosome 2q have been described, to date, no genetic defect has been defined. We report three cases of Seckel-like syndrome in siblings from nonconsanguinous Caucasian parents. In addition to the typical Seckel phenotypic features, all three cases were characterized by severe hydrocephalus. We review the literature and propose that there is a spectrum of Seckel conditions that share some common key features, but also demonstrate a wide range of phenotypic features.

Antibiotic prescribing by pediatricians for respiratory tract infection in children.

To examine antimicrobial prescribing rates for viral respiratory tract infections by primary care pediatricians in the greater Toronto area, charts were reviewed for the week of 17-21 February 1997 at 61 pediatricians' offices. Antibiotics were considered appropriate if the diagnosis was compatible with bacterial infection. A total of 3,585 patient visits were reviewed. The common cold was the most common respiratory tract syndrome leading to an office visit (1,317 visits). The overall rate of appropriate antibiotic prescribing was 89.5%. There was no significant difference in prescribing when physicians were compared by year of graduation from medical school, sex, or location of training. Diagnostic codes (ICD-9 [International Classification of Diseases, 9th edition] codes) did not match the chart diagnosis in 41% of cases. Toronto primary care pediatricians appear to have a lower rate of inappropriate antibiotic prescribing than do primary care physicians in other regions of Canada and the United States.