Joint environmental and social benefits from diversified agriculture

Agricultural simplification continues to expand at the expense of more diverse forms of agriculture. This simplification, for example, in the form of intensively managed monocultures, poses a risk to keeping the world within safe and just Earth system boundaries. Here, we estimated how agricultural diversification simultaneously affects social and environmental outcomes. Drawing from 24 studies in 11 countries across 2655 farms, we show how five diversification strategies focusing on livestock, crops, soils, noncrop plantings, and water conservation benefit social (e.g., human well-being, yields, and food security) and environmental (e.g., biodiversity, ecosystem services, and reduced environmental externalities) outcomes. We found that applying multiple diversification strategies creates more positive outcomes than individual management strategies alone. To realize these benefits, well-designed policies are needed to incentivize the adoption of multiple diversification strategies in unison.

High porosity with tiny pore constrictions and unbending pathways characterize the 3D structure of intervessel pit membranes in angiosperm xylem

Pit membranes between xylem vessels play a major role in angiosperm water transport. Yet, their three-dimensional (3D) structure as fibrous porous media remains unknown, largely due to technical challenges and sample preparation artefacts. Here, we applied a modelling approach based on thickness measurements of fresh and fully shrunken pit membranes of seven species. Pore constrictions were also investigated visually by perfusing fresh material with colloidal gold particles of known sizes. Based on a shrinkage model, fresh pit membranes showed tiny pore constrictions of ca. 20 nm, but a very high porosity (i.e. pore volume fraction) of on average 0.81. Perfusion experiments showed similar pore constrictions in fresh samples, well below 50 nm based on transmission electron microscopy. Drying caused a 50% shrinkage of pit membranes, resulting in much smaller pore constrictions. These findings suggest that pit membranes represent a mesoporous medium, with the pore space characterized by multiple constrictions. Constrictions are much smaller than previously assumed, but the pore volume is large and highly interconnected. Pores do not form highly tortuous, bent, or zigzagging pathways. These insights provide a novel view on pit membranes, which is essential to develop a mechanistic, 3D understanding of air-seeding through this porous medium.

Vessel-associated cells in angiosperm xylem: Highly specialized living cells at the symplast-apoplast boundary

BACKGROUND

Vessel-associated cells (VACs) are highly specialized, living parenchyma cells that are in direct contact with water-conducting, dead vessels. The contact may be sparse or in large tight groups of parenchyma that completely surrounds vessels. VACs differ from vessel distant parenchyma in physiology, anatomy, and function and have half-bordered pits at the vessel-parenchyma juncture. The distinct anatomy of VACs is related to the exchange of substances to and from the water-transport system, with the cells long thought to be involved in water transport in woody angiosperms, but where direct experimental evidence is lacking.

SCOPE

This review focuses on our current knowledge of VACs regarding anatomy and function, including hydraulic capacitance, storage of nonstructural carbohydrates, symplastic and apoplastic interactions, defense against pathogens and frost, osmoregulation, and the novel hypothesis of surfactant production. Based on microscopy, we visually represent how VACs vary in dimensions and general appearance between species, with special attention to the protoplast, amorphous layer, and the vessel-parenchyma pit membrane.

CONCLUSIONS

An understanding of the relationship between VACs and vessels is crucial to tackling questions related to how water is transported over long distances in xylem, as well as defense against pathogens. New avenues of research show how parenchyma-vessel contact is related to vessel diameter and a new hypothesis may explain how surfactants arising from VAC can allow water to travel under negative pressure. We also reinforce the message of connectivity between VAC and other cells between xylem and phloem.

Indirect effects of a 7 year PCV7/PCV13 mass vaccination program in children on the incidence of pneumonia among adults: a comparative study based on two Polish cities

BACKGROUND AND OBJECTIVES

In 2006 the city of Kielce, Poland, introduced a mandatory PCV7 (replaced by PCV13 in 2011) vaccination program against S. pneumoanie for all children under 2 years old. At that time, the neighboring city of Ostrowiec Świętokrzyski had no such large-scale vaccination program in place. This created an opportunity to observe the results of the vaccination by comparing the incidence of pneumonia in these two cities. The aim of this study was to analyze how the incidence of pneumonia among adults was indirectly affected by the PCV7/PCV13 vaccination program in children during the 7 year follow-up period.

METHODS

We performed a retrospective study. PCV7/PCV13 vaccinations were delivered according to a 2 + 1 schedule. The vaccination rate in the analyzed period amounted to almost 99%. The following age groups were analyzed: 30-49, 50-64 and 65+. The Cochran-Armitage test was used to investigate the significance of the observed trend in pneumonia morbidity. The significance of deviations from a linear trend was also tested. In addition, the importance of the trend (in the case of deviations from linearity) was confirmed with the use of the Mantel test.

RESULTS

In the 65+ age group there was a decrease of 66.5% in the incidence of diagnosed pneumonia (p < 0.0001). This was followed by smaller, but statistically significant, declines in the other age groups: 30.75% in the 30-49 age group (p = 0.001) and 56.8% in the 50-64 age group (p < 0.0001). This decreasing trend continued for seven consecutive years of observation. In addition, we demonstrated a statistically significant higher rate of pneumonia in all age groups in the City of Ostrowiec Świętokrzyski.

CONCLUSIONS

The results clearly indicate that the indirect effectiveness of the PCV7/PCV13 vaccine program, performed according to the 2 + 1 schedule and applied in Kielce, Poland, is statistically significant.

Differences in staining of the unicellular algae Chlorococcales as a function of algaenan content

Algal strains belonging to the Chlorococcales (Chlorophyceae) show significant differences in the extent of staining with the commonly used dye, crystalline violet. This seems to depend on the cell wall composition and on the occurrence of the acetolysis-resistant biopolymer algaenan in the algal cells.Eighteen algal strains were investigated using 24 h staining with 0.2% crystalline violet and it was confirmed that algal strains which did not contain algaenan and had a trilaminar structure in the cell wall showed strong staining ability, while non-algaenan strains were stained very weakly, if at all. The simple method presented here may be helpful to distinguish both kinds of algal strains.

Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea in children: a randomized double-blind placebo-controlled trial

BACKGROUND

Co-treatment with Saccharomyces boulardii appears to lower the risk of antibiotic-associated diarrhoea in adults receiving broad-spectrum antibiotics.

AIM

To determine whether S. boulardii prevents antibiotic-associated diarrhoea in children.

METHODS

A total of 269 children (aged 6 months to 14 years) with otitis media and/or respiratory tract infections were enrolled in a double-blind, randomized placebo-controlled trial in which they received standard antibiotic treatment plus 250 mg of S. boulardii (experimental group, n = 132) or a placebo (control group, n = 137) orally twice daily for the duration of antibiotic treatment. Analyses were based on allocated treatment and included data from 246 children.

RESULTS

Patients receiving S. boulardii had a lower prevalence of diarrhoea (> or =3 loose or watery stools/day for > or =48 h occurring during or up to 2 weeks after the antibiotic therapy) than those receiving placebo [nine of 119 (8%) vs. 29 of 127 (23%), relative risk: 0.3, 95% confidence interval: 0.2-0.7]. S. boulardii also reduced the risk of antibiotic-associated diarrhoea (diarrhoea caused by Clostridium difficile or otherwise unexplained diarrhoea) compared with placebo [four of 119 (3.4%) vs. 22 of 127 (17.3%), relative risk: 0.2; 95% confidence interval: 0.07-0.5]. No adverse events were observed.

CONCLUSION

This is the first randomized-controlled trial evidence that S. boulardii effectively reduces the risk of antibiotic-associated diarrhoea in children.

Efficacy of Lactobacillus GG in prevention of nosocomial diarrhea in infants

OBJECTIVE

Nosocomial diarrhea is a major problem in pediatric hospitals worldwide. We evaluated the efficacy of orally administered Lactobacillus GG (LGG) in the prevention of this disease in young children.

STUDY DESIGN

Eighty-one children aged 1 to 36 months who were hospitalized for reasons other than diarrhea were enrolled in a double-blind trial and randomly assigned at admission to receive LGG (n = 45) at a dose of 6 x 10(9) colony-forming units or a comparable placebo (n = 36) twice daily orally for the duration of their hospital stay.

RESULTS

LGG reduced the risk of nosocomial diarrhea (> or =3 loose or watery stools/24 h) in comparison with placebo (6.7% vs 33.3%; relative risk: 0.2; [95% CI: 0.06-0.6]; number needed to treat: 4 [95% CI: 2-10]). The prevalence of rotavirus infection was similar in LGG and placebo groups (20% vs 27.8%, respectively; relative risk: 0.72; 95% CI: 0.33-1.56). However, the use of LGG compared with placebo significantly reduced the risk of rotavirus gastroenteritis (1/45 [2.2%] vs 6/36 [16.7%], respectively; relative risk: 0.13; 95% CI: 0.02-0.79; number needed to treat: 7; 95% CI: 3-40).

CONCLUSIONS

Prophylactic use of LGG significantly reduced the risk of nosocomial diarrhea in infants, particularly nosocomial rotavirus gastroenteritis.

Efficacy of Lactobacillus GG in prevention of nosocomial diarrhea in infants

OBJECTIVE

Nosocomial diarrhea is a major problem in pediatric hospitals worldwide. We evaluated the efficacy of orally administered Lactobacillus GG (LGG) in the prevention of this disease in young children.

STUDY DESIGN

Eighty-one children aged 1 to 36 months who were hospitalized for reasons other than diarrhea were enrolled in a double-blind trial and randomly assigned at admission to receive LGG (n = 45) at a dose of 6 x 10(9) colony-forming units or a comparable placebo (n = 36) twice daily orally for the duration of their hospital stay.

RESULTS

LGG reduced the risk of nosocomial diarrhea (> or =3 loose or watery stools/24 h) in comparison with placebo (6.7% vs 33.3%; relative risk: 0.2; [95% CI: 0.06-0.6]; number needed to treat: 4 [95% CI: 2-10]). The prevalence of rotavirus infection was similar in LGG and placebo groups (20% vs 27.8%, respectively; relative risk: 0.72; 95% CI: 0.33-1.56). However, the use of LGG compared with placebo significantly reduced the risk of rotavirus gastroenteritis (1/45 [2.2%] vs 6/36 [16.7%], respectively; relative risk: 0.13; 95% CI: 0.02-0.79; number needed to treat: 7; 95% CI: 3-40).

CONCLUSIONS

Prophylactic use of LGG significantly reduced the risk of nosocomial diarrhea in infants, particularly nosocomial rotavirus gastroenteritis.

Streptomyces coelicolor DNA homologous with acyltransferase domains of type I polyketide synthase gene complex

An acyltransferase-homologous DNA fragment was amplified in a PCR reaction on a cosmid DNA template from the genomic DNA library of the soil bacterium Streptomyces coelicolor A3(2). The putative amino acid sequence of the fragment resembles acyl-CoA:ACP acyltransferase domains from several bacterial enzymatic complexes of polyketide synthase. There is a high similarity with acyltransferase domains from so-called type I polyketide synthases. Such synthases catalyze production of the aglycone portion of macrolides and polyethers that are important as antibiotics or immunosuppressants. The amplified fragment is considered to be a part of a larger gene complex.