Stem Photosynthesis—A Key Element of Grass Pea (Lathyrus sativus L.) Acclimatisation to Salinity

Grass pea (Lathyrus sativus) is a leguminous plant of outstanding tolerance to abiotic stress. The aim of the presented study was to describe the mechanism of grass pea (Lathyrus sativus L.) photosynthetic apparatus acclimatisation strategies to salinity stress. The seedlings were cultivated in a hydroponic system in media containing various concentrations of NaCl (0, 50, and 100 mM), imitating none, moderate, and severe salinity, respectively, for three weeks. In order to characterise the function and structure of the photosynthetic apparatus, Chl a fluorescence, gas exchange measurements, proteome analysis, and Fourier-transform infrared spectroscopy (FT-IR) analysis were done inter alia. Significant differences in the response of the leaf and stem photosynthetic apparatus to severe salt stress were observed. Leaves became the place of harmful ion (Na⁺) accumulation, and the efficiency of their carboxylation decreased sharply. In turn, in stems, the reconstruction of the photosynthetic apparatus (antenna and photosystem complexes) activated alternative electron transport pathways, leading to effective ATP synthesis, which is required for the efficient translocation of Na⁺ to leaves. These changes enabled efficient stem carboxylation and made them the main source of assimilates. The observed changes indicate the high plasticity of grass pea photosynthetic apparatus, providing an effective mechanism of tolerance to salinity stress.     

A New Triazole-Thiol Compound Organofunctionalized on the Silica Gel Surface: Chemical Properties and Copper Sorption in Ethanol / Water Media

Silicon - This study describes the preparation and characterization of 3-chloropropyl silica gel with 4-amino-5-(4pyridyl)-4H-1,2,4-triazole-3-thiol (SGA) for copper adsorption in different media....     

Small Noncoding RNAs in Knee Osteoarthritis: The Role of MicroRNAs and tRNA-Derived Fragments

Knee osteoarthritis (OA) is a degenerative knee joint disease that results from the breakdown of joint cartilage and underlying bone, affecting about 3.3% of the world’s population. As OA is a multifactorial disease, the underlying pathological process is closely associated with genetic changes in articular cartilage and bone. Many studies have focused on the role of small noncoding RNAs in OA and identified numbers of microRNAs that play important roles in regulating bone and cartilage homeostasis. The connection between other types of small noncoding RNAs, especially tRNA-derived fragments and knee osteoarthritis is still elusive. The observation that there is limited information about small RNAs different than miRNAs in knee OA was very surprising to us, especially given the fact that tRNA fragments are known to participate in a plethora of human diseases and a portion of them are even more abundant than miRNAs. Inspired by these findings, in this review we have summarized the possible involvement of microRNAs and tRNA-derived fragments in the pathology of knee osteoarthritis.     

Optimization of osmotic dehydration of yacon slices

Osmotic dehydration assisted by ultrasound (ODAU) at low temperatures reduces water activity (a_w) and maintains nutrients. The influence of solution concentration (SC; 20 to 60° Brix, xylitol and sorbitol) and ultrasound application time (t_us, 0 to 40 min) in ODAU of yacon was studied with the aid of a response surface method. The optimum condition with respect to mass transfer parameters, a_w, and fructan retention was SC of 60° Brix for both solutions and t_us of 2.67 min for xylitol samples and 0 min for sorbitol samples. The application of ultrasound improved dehydration but resulted in depolymerization of fructans.     

Optimal recovery schemes in fault tolerant distributed computing

Clusters and distributed systems offer fault tolerance and high performance through load sharing. When all n computers are up and running, we would like the load to be evenly distributed among the computers. When one or more computers break down, the load on these computers must be redistributed to other computers in the system. The redistribution is determined by the recovery scheme. The recovery scheme is governed by a sequence of integers modulo n. Each sequence guarantees minimal load on the computer that has maximal load even when the most unfavorable combinations of computers go down. We calculate the best possible such recovery schemes for any number of crashed computers by an exhaustive search, where brute force testing is avoided by a mathematical reformulation of the problem and a branch-and-bound algorithm. The search nevertheless has a high complexity. Optimal sequences, and thus a corresponding optimal bound, are presented for a maximum of twenty one computers in the distributed system or cluster.Received: 26 May 2004, Published online: 14 March 2005     

Pulsed Vacuum Osmotic Dehydration of Beetroot,Carrot and Eggplant Slices: Effect of Vacuum Pressure on the Quality Parameters

Pulsed vacuum osmotic dehydration (PVOD) is a widely used technique for reducing moisture content and water activity in biological products. This study aimed to analyze the effect of vacuum application (VA) on PVOD of beetroot, carrot, and eggplant slices, with respect to chemical (moisture, water activity, specific pigments, polyphenols, and sodium content), optical (color), mechanical (shrinkage, maximum stress, and elasticity), and structural (microstructure) properties. PVOD was conducted at three different vacuum pressures (0, 40, and 80 kPa, for 10 min), during a total process time of 300 min. Osmotic processing was performed at 35 °C by using a ternary osmotic solution [40% sucrose +?10% sodium chloride (w/w)]. Eggplant and carrot samples were more sensitive to VA, compared to beetroot. This was related to their porous and less compact structure. In general, VA reduced the moisture content and water activity and preserved the carotenoid content. VA caused loss of betalain and phenolic acid, favored sodium uptake, and induced significant changes in the optical, mechanical, and structural properties, compared to the osmotic processing conducted at atmospheric pressure.     

Zn(II) adsorption from synthetic solution and kaolin wastewater onto vermicompost

The adsorption of Zn(II) from both synthetic solution and kaolin industry wastewater by cattle manure vermicompost was studied. The adsorption process was dependent on the various operating variables, viz., solution pH, particle size of the vermicompost, mass of vermicompost/volume of the Zn(II) solution ratio, contact time and temperature. The optimum conditions for Zn adsorption were pH 6.0, particle size of < or = 250 microm, 1 g per 10 mL adsorbent dose, contact time of 4h and temperature of 25 degrees C. Langmuir and Freundlich adsorption isotherms fit well in the experimental data and their constants were evaluated, with R(2) values from 0.95 to 0.99. In synthetic solution, the maximum adsorption capacity of the vermicompost for Zn(2+) ions was 20.48 mg g(-1) at 25 degrees C when the vermicompost dose was 1 g 10 mL(-1) and the initial adjusted pH was 2. The batch adsorption studies of Zn(II) on vermicompost using kaolin wastewater have shown the maximum adsorption capacity was 2.49 mg g(-1) at pH 2 (natural pH of the wastewater). The small values of the constant related to the energy of adsorption (from 0.07 to 0.163 L mg(-1)) indicated that Zn(2+) ions were binded strongly to vermicompost. The values of the separation factor, R(L), which has been used to predict affinity between adsorbate and adsorbent were between 0 and 1, indicating that sorption was very favorable for Zn(II) in synthetic solution and kaolin wastewater. The thermodynamic parameter, the Gibbs free energy, was calculated for each system and the negative values obtained confirm that the adsorption processes are spontaneous. The DeltaG degrees values were -19.656 kJ mol(-1) and -16.849 kJ mol(-1) for Zn(II) adsorption on vermicompost in synthetic solution at pH 6 and 2, respectively, and -13.275 kJ mol(-1) in kaolin wastewater at pH 2.     

Resident Perceptions of the 2010 FIFA Soccer World Cup Stadia Development in Cape Town

The 2010 Federation Internationale de Football (FIFA) World Cup to be hosted in South Africa is expected to provide an opportunity to further the country’s objectives of using sporting events to signal international recognition and promote socio-economic development. Studies on sport tourism events tend to focus on economic impacts and neglect social issues (Ritchie and Adair 2004). In particular, residents’ perceptions are overlooked although they are often directly impacted by sport events, especially when they reside in close proximity to the event location. The 2010 FIFA World Cup is heralded as a once-in-a-lifetime opportunity with significant legacy benefits for South Africans. However, generally, the actual voices of local residents are absent in relation to debates pertaining to this event and concomitant anticipated benefits (Swart and Bob 2007). One hundred residents in each location were interviewed. The focus of the study was to examine the perceptions of the residents towards the proposed stadia development and potential impacts of the 2010 World Cup. The findings reveal that there is considerable support and positive perceptions relating to South Africa’s hosting of the 2010 World Cup. However, there were several concerns raised in relation to the distribution of anticipated benefits and the impacts of the stadia on their lives.