Changeability in Retama raetam essential oils chemical composition,antioxidant and antimicrobial properties as affected by the physiological stage

Abstract

Retama raetam essential oils (EOs) composition and biological activities were assessed during three developmental periods. The essential oil yield varied significantly among the developmental stages and the optimal was detected at the fresh fruiting stage (0.34%). In addition, EOs composition varied significantly (p < 0.05) according to the different developmental stages. In fact, 2-Methoxy-4-vinylphenol, linalool, and 1-octen-3-ol were the main compounds in the vegetative, flowering, and the fresh fruiting stages, respectively. Developmental stage had also a strong effect on EOs antioxidant and antimicrobial activities. In fact, during the fresh fruiting stage, IC₅₀ and EC₅₀ values of the antioxidant assays were 2 to 3 times inferior to all others stages. Concerning the determination of the diameter of inhibition, a slight to high antimicrobial activity was revealed against 12 bacteria and 4 yeasts. Once again, EOs from the fresh fruiting stage had higher bactericidal effect than those from the flowering and vegetative ones (IZ varied from 10 to 13 mm). The results of this investigation showed for the first time the high accumulation of EOs at the early stages of fruit development making the fresh fruiting optimal stage for the extraction of powerful antioxidant and antimicrobial EOs.     

Interactive effects of soil warming and fertilization on root production, mortality, and longevity in a Norway spruce stand in Northern Sweden

The effects of soil warming and nitrogen availability on root production, longevity and mortality were studied using minirhizotrons in irrigation (C), fertilized (F), heated (H), and heated‐fertilized (HF) plots in a Norway spruce stand in northern Sweden from October 1996 to October 1997. Irrigation was included in all treatment plots. Heating cables were used to maintain the soil temperature in heated plots at 5°C above that in unheated plots during the growing season. A Kaplan–Meier approach was used to estimate the longevity of fine roots and Cox proportional hazards regression to analyze the effects of the H, F, and HF treatments on the risk of root mortality. The proportion of annual root length production contributed by winter–spring production amounted to 52% and 49% in heated plots and heated‐fertilized plots, respectively. The annual root length production in C plots was significantly higher than in other treatments, while the HF treatment gave significantly greater production compared with the F treatment. The risk of mortality (hazard ratio) relative to C plots was higher in H plots (358%) and F plots (191%). The interaction between heating and fertilizing was strongly significant. The increase in the risk of root mortality in combined fertilization and heating (103%) was lower than that in the H or F plots. The results show that nitrogen addition combined with warmer temperatures decreases the risk of root mortality, and fine root production is a function of the length of the growing season. In the future, fertilization combined with the warmer temperatures expected to follow predicted climatic change may increase root production in boreal forests at low fertility sites.     

Time dependent modifications of Hep G2 cells during exposure to static magnetic fields

Morphological modifications, i.e., cell shape, cell surface sugar residues, cytoskeleton, and apoptosis of Hep G2 cells during 24 h exposure to 6 mT static magnetic field (static MF) were studied by means of light and electron microscopy and cytochemistry. Progressive modifications of cell shape and surface were observed during the entire period of exposure to static MF. Control cells were polyhedric with short microvilli covering the cell surface, while those exposed to static MF, were elongated with many irregular microvilli randomly distributed on the cell surface. At the end of the exposure period, the cells had a less flat shape due to partial detachment from the culture dishes. However, throughout the period of exposure under investigation, the morphology of the organelles remained unmodified and cell proliferation was only partially affected. In parallel with cell shape changes, the microfilaments and microtubules, as well as the quantity and distribution of surface ConA-FITC and Ricinus communnis-FITC labeling sites, were modified in a time dependent manner. Apoptosis, which was almost negligible at the beginning of experiment, increased to about 20% after 24 h of continuous exposure. The induction of apoptosis was likely due to the increment of [Ca2+]i during exposure. In conclusion, the data reported in the present work indicates that 6 mT static MF exposure exerts time dependent biological effects on Hep G2 cells.     

The effect of resistance level and stability demands on recruitment patterns and internal loading of spine in dynamic flexion and extension using a simple trunk model

The effects of external resistance on the recruitment of trunk muscles in sagittal movements and the coactivation mechanism to maintain spinal stability were investigated using a simple computational model of iso-resistive spine sagittal movements. Neural excitation of muscles was attained based on inverse dynamics approach along with a stability-based optimisation. The trunk flexion and extension movements between 60° flexion and the upright posture against various resistance levels were simulated. Incorporation of the stability constraint in the optimisation algorithm required higher antagonistic activities for all resistance levels mostly close to the upright position. Extension movements showed higher coactivation with higher resistance, whereas flexion movements demonstrated lower coactivation indicating a greater stability demand in backward extension movements against higher resistance at the neighbourhood of the upright posture. Optimal extension profiles based on minimum jerk, work and power had distinct kinematics profiles which led to recruitment patterns with different timing and amplitude of activation.     

Proteomics screening of molecular targets of granulocyte colony stimulating factor in the mouse brain and PC12 cell line

Aims

Granulocyte colony stimulating factor (G-CSF), a new neuroprotective agent, binds to its specific receptors in the brain. In this study we hypothesized that at least a part of G-CSF's neuroprotective effect may be mediated through its interaction with other proteins in the brain.

Main methods

Using an immunoprecipitation (IP) kit, at first the antibody of G-CSF was covalently crosslinked to protein A/G agarose. Then the mouse brain or PC12 cell lysate mixed with G-CSF was added to the agarose beads plus antibody. After immunoaffinity isolation of target proteins, gel electrophoresis was performed and protein bands were identified using MALDI-TOF/TOF and MASCOT software.

Key findings

Our data show that G-CSF physically binds to cellular proteins like sodium/potassium-transporting ATPase, beta actin, aldehyde dehydrogenase, regucalcin and glutathione-s-transferase. These proteins are involved in membrane transportation, cell structure, signal transduction, enzymes involve in calcium related cell signaling and redox homeostasis.

Significance

Interaction of G-CSF with these proteins can explain some of its pharmacological effects in the CNS.     

A model of the basal ganglia in voluntary movement and postural reactions

A basal ganglia central pattern generator (CPG) is developed and its role in voluntary movements on the ground and postural reactions on a disturbed platform are studied and analysed by simulation. Biped dynamics and platform kinematics are utilised. The effects of agonist–antagonist muscular co-activation and joint stiffness are formulated. The implementation of the necessary counter-manoeuvres for maintaining balance and postural stability is studied. A control strategy, applicable to large systems, is formulated. The biped manoeuvres and transitions terminate in pre-specified intervals of time. Gravity is included and compensated for. Certain voluntary and postural adjustment strategies are the same but are initiated differently. Further experimental/computational research may identify the central nervous system and sensory paths that lead to the CPG. All actuator forces linearly evolve in time from their original values to their terminal values. There are no central continuous feedback loops present. Monitoring and sensing, however, are ongoing. The counter-manoeuvres are based on learned human-like voluntary movements that are triggered by the disturbance. The required central inputs to the musculoskeletal system are designed in the CPG. A functional structure for the CPG is proposed. The effect of certain disorders and malfunctions of the CPG are studied by simulation.     

Does liquid fertilization affect fine root dynamics and lifespan of mycorrhizal short roots?

We studied effects of nitrogen, other nutrients and water (liquid fertilization; LF) on fine root dynamics (production, mortality) and life span of mycorrhizal short roots in a Norway spruce stand, using minirhizotrons. Data were collected and analyzed during a two-year period at depths of 0–20 cm, 21–40 cm and 41–85 cm, six years after the start of treatment. Relative to control (C), root production was lower in LF plots at depth 0–20 cm. Root production increased significantly at depth 41–85 cm. Fine root mortality in LF plots was higher at all depths. Life span of mycorrhizal short roots in LF plots was significantly lower than C plots and at the end of the study no mycorrhizal short roots were alive. It is suggested that the water and nitrogen input lower longevity of mycorrhizal short roots and promote fine root production at deeper soil layers.     

IoTSteg: ensuring privacy and authenticity in internet of things networks using weighted pixels classification based image steganography

Cluster Computing - Internet of Things (IoT) networks are considered the great challenging by emerging technologies that try to solve the problems in modern life, while securing the information...     

Variation in fine root biomass of three European tree species: Beech (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst.), and Scots pine (Pinus sylvestris L.)

Abstract

Fine roots (<2 mm) are very dynamic and play a key role in forest ecosystem carbon and nutrient cycling and accumulation. We reviewed root biomass data of three main European tree species European beech, (Fagus sylvatica L.), Norway spruce (Picea abies L. Karst.) and Scots pine (Pinus sylvestris L.), in order to identify the differences between species, and within and between vegetation zones, and to show the relationships between root biomass and the climatic, site and stand factors. The collected literature consisted of data from 36 beech, 71 spruce and 43 pine stands. The mean fine root biomass of beech was 389 g m^?2, and that of spruce and pine 297 g m^?2 and 277 g m^?2, respectively. Data from pine stands supported the hypothesis that root biomass is higher in the temperate than in the boreal zone. The results indicated that the root biomass of deciduous trees is higher than that of conifers. The correlations between root biomass and site fertility characteristics seemed to be species specific. There was no correlation between soil acidity and root biomass. Beech fine root biomass decreased with stand age whereas pine root biomass increased with stand age. Fine root biomass at tree level correlated better than stand level root biomass with stand characteristics. The results showed that there exists a strong relationship between the fine root biomass and the above-ground biomass.