Effects of water level and nutrients on spatial distribution of soil mesofauna in peatlands drained for forestry in Finland

Peer reviewe

Physical growing media characteristics of Sphagnum biomass dominated by Sphagnum fuscum (Schimp.) Klinggr

The surface biomass of moss dominated by Sphagnum fuscum (Schimp.) Klinggr. (Rusty Bog-moss) was harvested from a sparsely drained raised bog. Physical properties of the Sphagnum moss were determined and compared with those of weakly and moderately decomposed peats. Water retention curves (WRC) and saturated hydraulic conductivities (K-s) are reported for samples of Sphagnum moss with natural structure, as well as for samples that were cut to selected fibre lengths or compacted to different bulk densities. The gravimetric water retention results indicate that, on a dry mass basis, Sphagnum moss can hold more water than both types of peat under equal matric potentials. On a volumetric basis, the water retention of Sphagnum moss can be linearly increased by compacting at a gravimetric water content of 2 (g water / g dry mass). The bimodal water retention curve of Sphagnum moss appears to be a consequence of the natural double porosity of the moss matrix. The 6-parameter form of the double-porosity van Genuchten equation is used to describe the volumetric water retention of the moss as its bulk density increases. Our results provide considerable insight into the physical growing media properties of Sphagnum moss biomass.Peer reviewe

Proapoptotic, anti-cell proliferative, anti-inflammatory and antiangiogenic potential of carnosic acid during 7,12 dimethylbenz[a]anthracene-induced hamster buccal pouch carcinogenesis

ERRATUMRajasekaran et al., Afr., J. Tradit Complement Altern Med. 2013; 10(1): 102–112Published online 2012 Oct 1.doi: 10.4314/ajtcam.v10i1.1

Proapoptotic, Anti-Cell Proliferative, Anti-Inflammatory And Antiangiogenic Potential Of Carnosic Acid During 7,12 Dimethylbenz[A]Anthracene-Induced Hamster Buccal Pouch Carcinogenesis

The present study has investigated the modulating effect of carnosic acid on the expression pattern of cell proliferative (proliferating cell nuclear antigen (PCNA) cyclin D1 and a transcription factor c-fos), apoptotic (p53, Bcl-2, Bax caspase -3 and 9), inflammatory (Nuclear factor kappa B (NFκB) and cyclooxygenase-2 (COX- 2) and angiogenic (vascular endothelial growth factor (VEGF) markers during 7,12-dimethylbenz[a]anthracene (DMBA)-induced hamster buccal pouch carcinogenesis. Oral tumors were developed in the hamsters buccal pouches by painting with 0.5% DMBA in liquid paraffin three times a week for 14 weeks. Hundred per cent tumour formation (well-differentiated squamous cell carcinoma) accompanied by deregulation in the above mentioned molecular markers was noticed in hamsters treated with DMBA alone (tumour bearing hamsters). Oral administration of carnosic acid at dose of 10mg/kg bw to hamsters treated with DMBA not only completely prevented the tumour formation, but also corrected the abnormalities in the expression pattern of molecular markers. The present study suggests that carnosic acid might have inhibited the tumour formation by exerting anti-cell-proliferative, anti-inflammatory, anti-angiogenic and apoptotic potential during DMBA-induced hamster buccal pouch carcinogenesis

Na2.4Al0.4Mn2.6O7 anionic redox cathode material for sodium ion batteries- a combined experimental and theoretical approach to elucidate its charge storage mechanism

Here we report the synthesis via ceramic methods of the high-performance Mn-rich Na2.4Al0.4Mn2.6O7 oxygen-redox cathode material for Na-ion batteries which we use as a testbed material to study the effects of Al substitution and subsequent Na excess in the high-capacity, anionic redox-based cathode material Na2Mn3O7. The material shows a stable electrochemical performance, with a specific capacity of 200 mAh g-1 in the 1.5 - 4.7 voltage window at C/20 and capacity retention of 90 % after 40 cycles. Using a combination of electrochemical and structural analysis together with hybrid density functional theory calculations we explain the behaviour of this material with changes in Mn/anionic redox reactions and associated O2 release reactions occurring in the material during electrochemical cycling (Na insertion/extraction) and compare these findings to Na2Mn3O7. We expect that these results will advance understanding of the effect of dopants in Mn-rich cathode materials with oxygen redox activity to pave their way towards real applications in high-performing sodium-ion battery applications

Jogos Paralímpicos Rio/2016 no Twitter

caracterizar conteúdos de narrativas transmidiáticas que foram produzidos e circularam acerca do esporte e dos atletas paralímpicos durante a abertura e encerramento dos JP Rio/2016 no Twitter. Mapeamos tweets das hashtags propostas pelas emissoras de tv oficiais do evento, TV Brasil (#VemPraPara) e SporTV (#JogosParalímpicosNoSporTV), e organizamos em três categorias: 1) prática e valores midiáticos-esportivos; 2) nacionalismo no esporte paralímpico; e 3) o senti mento paralímpic

Ultraviolet absorbance of Sphagnum magellanicum, S. fallax and S. fuscum extracts with seasonal and species-specific variation

Bryophytes, including Sphagnum, are common species in alpine and boreal regions especially on mires, where full sunlight exposes the plants to the damaging effects of UV radiation. Sphagnum species containing UV-protecting compounds might offer a biomass source for nature-based sunscreens to replace the synthetic ones. In this study, potential compounds and those linked in cell wall structures were obtained by using methanol and alkali extractions and the UV absorption of these extracts from three common Sphagnum moss species Sphagnum magellanicum, Sphagnum fuscum and Sphagnum fallax collected in spring and autumn from western Finland are described. Absorption spectrum screening (200–900 nm) and luminescent biosensor (Escherichia coli DPD2794) methodology were used to examine and compare the protection against UV radiation. Additionally, the antioxidant potential was evaluated using hydrogen peroxide scavenging (SCAV), oxygen radical absorbance capacity (ORAC) and ferric reducing absorbance capacity (FRAP). Total phenolic content was also determined using the Folin-Ciocalteu method. The results showed that methanol extractable compounds gave higher UV absorption with the used methods. Sphagnum fallax appeared to give the highest absorption in UV-B and UV-A wavelengths. In all assays except the SCAV test, the methanol extracts of Sphagnum samples collected in autumn indicated the highest antioxidant capacity and polyphenol content. Sphagnum fuscum implied the highest antioxidant capacity and phenolic content. There was low antioxidant and UV absorption provided by the alkali extracts of these three species

Optical properties of MoSe2_2 monolayer implanted with ultra-low energy Cr ions

The paper explores the optical properties of an exfoliated MoSe$_2$ monolayer implanted with Cr$^+$ ions, accelerated to 25 eV. Photoluminescence of the implanted MoSe$_2$ reveals an emission line from Cr-related defects that is present only under weak electron doping. Unlike band-to-band transition, the Cr-introduced emission is characterised by non-zero activation energy, long lifetimes, and weak response to the magnetic field. To rationalise the experimental results and get insights into the atomic structure of the defects, we modelled the Cr-ion irradiation process using ab-initio molecular dynamics simulations followed by the electronic structure calculations of the system with defects. The experimental and theoretical results suggest that the recombination of electrons on the acceptors, which could be introduced by the Cr implantation-induced defects, with the valence band holes is the most likely origin of the low energy emission. Our results demonstrate the potential of low-energy ion implantation as a tool to tailor the properties of 2D materials by doping

Nanomechanical absorption spectroscopy of 2D materials with femtowatt sensitivity

Nanomechanical spectroscopy (NMS) is a recently developed approach to determine optical absorption spectra of nanoscale materials via mechanical measurements. It is based on measuring changes in the resonance frequency of a membrane resonator vs. the photon energy of incoming light. This method is a direct measurement of absorption, which has practical advantages compared to common optical spectroscopy approaches. In the case of two-dimensional (2D) materials, NMS overcomes limitations inherent to conventional optical methods, such as the complications associated with measurements at high magnetic fields and low temperatures. In this work, we develop a protocol for NMS of 2D materials that yields two orders of magnitude improved sensitivity compared to previous approaches, while being simpler to use. To this end, we use mechanical sample actuation, which simplifies the experiment and provides a reliable calibration for greater accuracy. Additionally, the use of low-stress silicon nitride membranes as our substrate reduces the noise-equivalent power to fW , comparable to commercial semiconductor photodetectors. We use our approach to spectroscopically characterize a 2D transition metal dichalcogenide (WS2), a layered magnetic semiconductor (CrPS4), and a plasmonic super-crystal consisting of gold nanoparticles