Ebolavirus is evolving but not changing: No evidence for functional change in EBOV from 1976 to the 2014 outbreak

The 2014 epidemic of Ebola virus disease (EVD) has had a devastating impact in West Africa. Sequencing of ebolavirus (EBOV) from infected individuals has revealed extensive genetic variation, leading to speculation that the virus may be adapting to humans, accounting for the scale of the 2014 outbreak. We computationally analyze the variation associated with all EVD outbreaks, and find none of the amino acid replacements lead to identifiable functional changes. These changes have minimal effect on protein structure, being neither stabilizing nor destabilizing, are not found in regions of the proteins associated with known functions and tend to cluster in poorly constrained regions of proteins, specifically intrinsically disordered regions. We find no evidence that the difference between the current and previous outbreaks is due to evolutionary changes associated with transmission to humans. Instead, epidemiological factors are likely to be responsible for the unprecedented spread of EVD

Ultra-bright Photoactivatable Fluorophores Created by Reductive Caging

Sub-diffraction-limit imaging can be achieved by sequential localization of photoactivatable fluorophores, where the image resolution depends on the number of photons detected per localization. Here, we report a strategy for fluorophore caging that creates photoactivatable probes with high photon yields. Upon photoactivation, these probes can provide 104–106 photons per localization and allow imaging of fixed samples with resolutions of several nanometers. This strategy can be applied to many fluorophores across the visible spectrum

Isotropic 3D Super-resolution Imaging with a Self-bending Point Spread Function

Airy beams maintain their intensity profiles over a large propagation distance without substantial diffraction and exhibit lateral bending during propagation1-5. This unique property has been exploited for micromanipulation of particles6, generation of plasma channels7 and guidance of plasmonic waves8, but has not been explored for high-resolution optical microscopy. Here, we introduce a self-bending point spread function (SB-PSF) based on Airy beams for three-dimensional (3D) super-resolution fluorescence imaging. We designed a side-lobe-free SB-PSF and implemented a two-channel detection scheme to enable unambiguous 3D localization of fluorescent molecules. The lack of diffraction and the propagation-dependent lateral bending make the SB-PSF well suited for precise 3D localization of molecules over a large imaging depth. Using this method, we obtained super-resolution imaging with isotropic 3D localization precision of 10-15 nm over a 3 μm imaging depth from ∼2000 photons per localization

Polysaccharides from Portulaca oleracea L Improve Exercise Endurance and Decrease Oxidative Stress in Forced Swimming Mice

Purpose: To explore the effects of polysaccharides from Portulaca oleracea L. (POP) on exercise endurance and oxidative stress in forced-swimming mice.Methods: Forty-eight mice were divided into four groups of twelve animals each. All treatments were administered orally and daily for 28 days. Group A received isotonic saline solution (50 ml/kg bodyweight) as control group; B, C and D groups received 100, 200 and 400 mg/kg body wt. of POP as treatment groups, respectively. After the final treatment with POP, the mice were subjected to swimming to exhaustion and the exhaustive swimming time, blood lactic acid (BLA), blood glucose, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were measured.Results: The exhaustive swimming time of the POP-treated groups (967.3 ± 79.2, 1234.8 ± 97.6 and 1314.3 ± 107.3 s) was significantly longer than that of the control group (513.6 ± 41.2 s) (p < 0.05). After the exhaustive swimming exercise, BLA levels of the POP-treated groups (8.63 ± 0.91, 8.04 ± 0.86 and 7.51 ± 0.78 mmol/L) were significantly lower than that of the control group (11.39 ± 1.17 mmol/L) (p < 0.05). MDA levels of the POP-treated groups (2.69 ± 0.21, 2.41 ± 0.17 and 2.37 ± 0.23 U/mg.pro) were significantly lower than that of the control group (3.21 ± 0.29 U/mg.pro) (p < 0.05). On the other hand, blood glucose levels of the POP-treated groups (5.47 ± 0.48, 5.74 ± 0.57 and 6.04 ± 0.51 mmol/L) were significantly higher than that of the control group (4.89 ± 0.32 mmol/L) (p < 0.05). SOD levels of the POP-treated groups (124.36 ± 14.87, 136.39±13.48 and 145.87 ± 17.39 U/mg.pro) were significantly higher than that of the control group (108.41 ± 11.63 U/mg.pro) (p < 0.05). GPx levels of the POPtreated groups (68.24 ± 4.68, 71.33 ± 5.29 and 72.64 ± 5.99 U/mg.pro) were significantly higher than that of the control group (53.17 ± 5.24 U/mg.pro) (p < 0.05). CAT levels of the POP-treated groups (23.57 ± 1.71, 24.28 ± 2.14 and 26.72 ± 2.21 U/mg.pro) were significantly higher than that of the control group (19.48 ± 2.03 U/mg.pro) (p < 0.05).Conclusion: This study provides compelling evidence that POP can improve exercise endurance and decrease oxidative stress in forced swimming mice.Keywords: Polysaccharides, Portulaca oleracea L., Oxidative stress, Swimming, Exercise endurance

Supplying Improved Seed to Farmers in Rural Kenya: The Case of Freshco Kenya Ltd.

Freshco, a small producer and distributor of hybrid maize seed and macadamia seedlings, was one of the first private companies to enter the Kenya seed market after its liberalization. Currently, the company produces and markets six high yielding maize varieties that are suited for diverse agro-ecological conditions. Despite the company’s encouraging growth in the local maize seed market, Freshco’s executives recognize the need to scale up operations to stay competitive. The company’s challenge is to recognize business opportunities and customer needs in an environment susceptible to ecological, political, and socioeconomic change.Kenya, seed industry, smallholder farmers, scenario planning, Crop Production/Industries, Farm Management, Research Methods/ Statistical Methods, Q10, Q12,

Hazard posed by metals and As in PM2.5 in air of five megacities in the Beijing-Tianjin-Hebei region of China during APEC

Airborne fine particulate matter (PM2.5) from five megacities including Beijing, Tianjin, Shijiazhuang, Baoding, and Jinan were collected during November 2014 and compared with similar periods in 2012 and 2013. The November 2014 period coincided with the Asia Pacific Economic Cooperation (APEC) Leaders Meeting during which measures to control pollution of the air were introduced. Concentrations of 11 elements in PM2.5 were quantified by inductively coupled plasma–mass spectrometry (ICP-MS) after microwave-assisted digestion. Potential effects of five toxic trace metals including Mn, Ni, Cu, Zn, Pb, and the metalloid As on health were assessed. In 2014, concentrations of PM2.5 were significantly less than during the same period in 2012 and 2013. Mean concentrations of six elements ranked in decreasing order, Zn > Pb > Cu ≈ Mn > As > Ni, and spatial concentrations ranked in decreasing order, Shijiazhuang > Baoding > Tianjin > Jinan > Beijing. Risks of the five metals and the metalloid As to health of humans were small, except for Mn in Shijiazhuang. Risks to health posed by other elements were less during the period of study. Risks posed by the five metals and As in Beijing were greater to varying degrees after the APEC meeting. Risks to health of humans during the APEC were overall lesser than the same period in 2012 and 2013, mostly due to lesser emissions due to the short-term control measures