Seed germination of Agave species as influenced by substrate water potential

Background

Plants of Agave spp. perform Crassulacean acid metabolism (CAM) and are highly drought-tolerant, but little is known concerning seed germination under low water availability. The aim of this study was to assess the effect of substrate water potential (Ψ_W) on seed germination and contrast hydrotime parameters of seven valuable and commercially-important Agave species from different geographical distributions and climatic regions of Mexico. Our hypothesis was that seed germination of Agave species is not affected by low water availability independently of seed biomass and the climate of their distribution area.

Results

Seed germination (at 25°C and in the dark) between 85 and 100% for all species occurred within 80–180 h at -0.03 MPa and 250–430 h at -1.0 MPa. Seed germination at -1.5 MPa declined to less than 50% (p < 0.05) for A. asperrima and A. cupreata but did not change significantly for A. americana var. marginata, A. lechuguilla and A. striata, although they showed the lowest mean base water potential (-2.01 to -2.64 MPa). Seed germination of 40% Agave species, from arid and semi-arid climates in this study, was not affected by the lower Ψ_W.

Conclusion

Germination of seeds of Agave species is moderately affected by low water availability, is partially dependent of their ecological distribution, and is independent of seed mass.     

The kSORT Assay to Detect Renal Transplant Patients at High Risk for Acute Rejection: Results of the Multicenter AART Study

BackgroundDevelopment of noninvasive molecular assays to improve disease diagnosis and patient monitoring is a critical need. In renal transplantation, acute rejection (AR) increases the risk for chronic graft injury and failure. Noninvasive diagnostic assays to improve current late and nonspecific diagnosis of rejection are needed. We sought to develop a test using a simple blood gene expression assay to detect patients at high risk for AR.ConclusionsThe kSORT blood QPCR assay is a noninvasive tool to detect high risk of AR of renal transplants.Please see later in the article for the Editors'' Summary     

Role of Neurotoxin Associated Proteins in the Low pH Induced Structural Changes in the Botulinum Neurotoxin Complex

Botulinum Neurotoxin (BoNT) produced by the bacterium Clostridium botulinum as a complex with NAPs causes botulism. It has been known that the NAPs protect the toxin from both extremes of pHs and proteases of the GI tract. In an attempt to emulate the physiological conditions encountered by the toxin, we examined BoNT/A, BoNT/A complex, and NAPs under different pH conditions and monitored their structural characteristics by far-UV CD and thermal denaturation analysis. BoNT/A complex showed the maximum CD signal with a mean residue weight ellipticity of ?1.8 × 10⁵° cm²/dmol at 222 nm at both acidic and neutral pHs. Thermal denaturation analysis revealed NAPs to be the most stable amongst the three protein samples examined. Interestingly and quite uniquely, at pH 2.5, there was an increase in CD signal for BoNT complex as a function of temperature, which correlated with the NAPs profile, indicating a shielding effect of NAPs on BoNT complex at low pH. Calculation of the weighted mean of the ellipticities at the T_m for thermal unfolding of toxin and NAPs at neutral and acidic pHs showed variation with that of BoNT complex, suggesting structural reorganization in BoNT complex upon the association of NAPs and BoNT. In conclusion, this study reveals the structural behavior of BoNT complex and NAPs with pH changes substantially, which could be quite relevant for BoNT survival under extreme pH conditions in vivo.     

Exploring the impact of neutral evolution on intrapopulation genetic differentiation in functional traits in a long-lived plant

Most plant species, particularly long-lived plants, harbor a large amount of genetic variation within populations. A central issue in evolutionary ecology is to explore levels of genetic variation and understand the mechanisms that influence them. In this study, our goals were to examine the impact of neutral evolutionary processes on the genetic variance and functional diversity within three populations of a long-lived plant (Quercus suber L.). For this purpose, we genotyped the progeny of 45 open-pollinated mother trees from three populations originating from Spain, Portugal, and Morocco using six microsatellite markers. Seedlings were planted in a common garden trial and were phenotypically characterized by seven leaf functional traits. Molecular analyses revealed weak genetic differences between Iberian and Moroccan populations. Nevertheless, high genetic differentiation was observed among maternal families within populations. Differentiation between particular maternal families from the same population reached values of 29.2 %, which far exceeds the values reported between the most genetically distant populations for this species (11.7 %). Maternal families differed also in phenology, leaf size, and shape traits. In the Moroccan population, there were correlations among matrices of distances for molecular markers, leaf shape traits (e.g., leaf circularity index), and phenology, indicating that maternal families with contrasting phenologies were genetically and functionally distinct. This, together with the moderate heritability for phenology in Moroccan population, suggests that besides selective forces, neutral evolutionary processes have promoted intrapopulation genetic divergence and contribute to maintain high levels of genetic variation within this population. Overall, our results reinforce the importance of intrapopulation studies in long-lived plants under an evolutionary context.     

Factors associated with early initiation of breastfeeding among Nepalese mothers: further analysis of Nepal Demographic and Health Survey, 2011

Background

Timely initiation of breastfeeding has been reported to reduce neonatal mortality by 19.1%. The World Health Organisation recommends early initiation of breastfeeding i.e. breastfeeding a newborn within the first hour of life. Knowledge on the rate and the determinants of early initiation of breastfeeding may help health program managers to design and implement effective breastfeeding promotion programs. The aim of this study was to determine the rate and the determinants of early initiation of breastfeeding in Nepal.

Methods

This study used the data from Nepal Demographic and Health Survey (NDHS) 2011 which is a nationally representative sample study. Chi square test and multiple logistic regression analysis were used to examine the factors associated with early initiation of breastfeeding (within one hour of birth).

Results

Of 4079 mothers, 66.4% initiated breastfeeding within one hour of delivery. Mothers with higher education (Odds Ratio (OR) 2.56; 95% CI : 1.26, 5.21), mothers of disadvantaged Janjati ethnicity (OR 1.43; 95% CI : 1.04, 1.94), mothers who were involved in agriculture occupation (OR 1.51; 95% CI : 1.16, 1.97), mothers who delivered in a health facility (OR 1.67; 95% CI : 1.25, 2.23), whose children were large at birth (OR 1.46; 95% CI : 1.07, 1.99) were more likely to initiate breastfeeding within the first hour of child birth.

Conclusions

Results suggest that two thirds of children in Nepal were breastfed within the first hour after birth. Although there was a higher prevalence of early initiation of breastfeeding among mothers who delivered in health facilities compared to mothers who delivered at home, universal practice of early initiation of breastfeeding should be a routine practice. The findings suggest the need of breastfeeding promotion programs among the mothers who are less educated, and not working. Such breastfeeding promotion programmes could be implemented via Nepal’s extensive network of community-based workers.

     

FEV1 inversely correlates with metalloproteinases 1, 7, 9 and CRP in COPD by biomass smoke exposure

Background

Matrix metalloproteinases (MMPs) and C-reactive protein (CRP) are involved in chronic obstructive pulmonary disease (COPD) pathogenesis. The aim of the present work was to determine plasma concentrations of MMPs and CRP in COPD associated to biomass combustion exposure (BE) and tobacco smoking (TS).

Methods

Pulmonary function tests, plasma levels of MMP-1, MMP-7, MMP-9, MMP-9/TIMP-1 and CRP were measured in COPD associated to BE (n = 40) and TS (n =40) patients, and healthy non-smoking (NS) healthy women (controls, n = 40).

Results

Plasma levels of MMP-1, MMP-7, MMP-9, and MMP-9/TIMP-1 and CRP were higher in BE and TS than in the NS healthy women (p <0.01). An inverse correlation between MMP-1, MMP-7, MMP-9, MMP-9/TIMP-1 and CRP plasma concentrations and FEV₁ was observed.

Conclusions

Increase of MMPs and CRP plasma concentrations in BE suggests a systemic inflammatory phenomenon similar to that observed in COPD associated to tobacco smoking, which may also play a role in COPD pathogenesis.     

Effect of photodynamic therapy on the skin using the ultrashort laser ablation

Photodynamic Therapy (PDT) with 5‐aminolevulinic acid (ALA) is known to be limited for applications in tumours of large volume mainly due to the limited penetration of topical photosensitization. The results show that micro‐holes created using a femtosecond laser before PDT significantly increased the depth of PDT effect in the healthy tissue. The combination of ultrashort laser ablation technique with PDT showed an important scientific breakthrough related to transportation and delivery of drugs into the deeper regions of the tissue. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)