Influence of liming on residual soil respiration and chemical properties in a tropical no-tillage system

Because of the climate changes occurring across the planet, especially global warming, the different forms of agricultural soil use have attracted researchers´ attention. Changes in soil management may influence soil respiration and, consequently, C sequestration. The objectives of this study were to evaluate the long-term influence of liming on soil respiration and correlate it with soil chemical properties after two years of liming in a no-tillage system. A randomized complete block design was used with six replications. The experimental treatments consisted of four lime rates and a control treatment without lime. Two years after liming, soil CO2 emission was measured and the soil sampled (layers 0-5, 5-10, 10-20, and 20-30 cm). The P, Ca2+ e Mg2+ soil contents and pH and base saturation were determined. CO2 emission from soil limed at the recommended rate was 24.1 % higher, and at twice the recommended rate, 47.4 % higher than from unlimed soil. Liming improved the chemical properties, and the linear increase in soil respiration rate correlated positively with the P, Ca2+ and Mg2+ soil contents, pH and base saturation, and negatively with H + Al and Al3+ contents. The correlation coefficient between soil respiration rate and chemical properties was highest in the 10-20 cm layer.

Potential influence of the chemical composition of water on the stable oxygen isotope composition of continental ostracods

Many studies in continental areas have successfully used the oxygen isotope composition of fossil ostracod valves to reconstruct past hydrological conditions associated with large changes in climate. Yet, ostracods are known to crystallise their valves out of isotopic equilibrium for oxygen and they generally have higher 18O contents compared to inorganic calcite grown at equilibrium under the same condi- tions. A review of vital offsets determined for continental ostracods indicates that vital offsets might change from site to site, questioning a potential influence of environmental conditions on oxygen isotope fractionation in ostracods. Results from the literature suggest that pH has no influence on ostracod vital offset. A re-evaluation of results from Li and Liu (J Paleolimnol 43:111-120, 2010) suggests that salin- ity may influence oxygen isotope fractionation in ostracods, with lower vital offsets for higher salinities. Such a relationship was also observed for the vital offsets determined by Chivas et al. (The ostracoda- applications in quaternary research. American Geo- physical Union, Washington, DC, 2002). Yet, when results of all studies are compiled, the correlation between vital offsets and salinity is low while the correlation between vital offsets and host water Mg/Ca is higher, suggesting that ionic composition of water and/or relative abundance of major ions may also control oxygen isotope fractionation in ostracods. Lack of data on host water ionic composition for the different studies precludes more detailed examination at this stage. Further studies such as natural or laboratory cultures done under strictly controlled conditions are needed to better understand the potential influence of varying environmental condi- tions on oxygen isotope compositions of ostracod valves.

Influence of compliance to respiratory weaning consensus conference criteria on respiratory outcome within 48h after planned extubation

INTRODUCTION. A two-step assessment (readiness to wean (RW) followed by spontaneousbreathing trial (SBT)) of predefined criteria is recommended before planned extubation(PE)1.OBJECTIVES. We aimed to evaluate if compliance to all guideline criteria was associatedwith better respiratory outcome within 48 h after PE.METHODS. The data (extracted from our clinical information system) of 458 consecutivepatients who underwent PE after C48 h of invasive ventilation in our medico-surgical ICUwere analyzed. We evaluated compliance with guidelines [1] regarding respiratory rate, tidalvolume, PaO2, FiO2, PEEP, PaCO2, pH, heart rate, systolic arterial pressure and arrhythmiaduringRWand SBT assessment (RW and SBT within 2 h). A patient was classified as RW+ ifallRWcriteria were fulfilled andRW-if at least 1 criterion was violated. The same approachwas used to define SBT+ and SBT- patients. During the 48 h following PE, we assessed theoccurrence of post-PE respiratory failure (PRF) (defined as the presence of at least 1 consensuscriterion of respiratory failure [1]), reintubation (after NIV failure or because of immediateintubation criteria) and cumulative duration of post-PE ventilation (PPEV = Post-PE invasive+ non-invasive ventilation). ICU mortality was recorded. Comparisons for variousoutcomes were performed by Chi-square and t tests.RESULTS. All consensus criteria were fulfilled in 77.3% of the patients during RW and in68.1% of the patients during SBT.[Compliance to weaning criteria and outcome]N = 458 PRF (%) Reintubation (%) PPEV (min) ICU mortality (%)All patients 53.5 10.0 542 ± 664 6.1RW+ 50.0 9.3 490 ± 626 5.4RW- 65.4* 12.5 718 ± 757** 8.7SBT+ 52.6 8.0 498 ± 594 6.7SBT- 55.5 14.4*** 637 ± 788**** 4.8Occurrence of PRF only was not associated with increased ICU mortality: 4.2 versus 7.8%,p = 0.11. By contrast, ICU mortality was significantly increased in patients requiring reintubation:21.7 versus 4.4%. p\0.001; * p = 0.006 RW+ versus RW-; ** p = 0.003RW+ versus RW-; *** p = 0.035 SBT+ versus SBT-; **** p = 0.030 SBT+ versusSBTCONCLUSIONS.In our ICU, compliance to all criteria of the two-step published approach ofrespiratory weaning was not optimal but reintubation rate was comparable to published data.Compliance with consensus conference guidelines was associated with lower reintubation rateand shorter PPEV but not with ICU mortality. As mortality was increased by reintubation,more sensitive and specific criteria to predict the risk of reintubation are probably needed.REFERENCE. Boles JM, et al. Eur Respir J 2007;29:1033-56.

Influence of the diketonato ligand on the cytotoxicities of [Ru(eta(6)-p-cymene)-(R(2)acac)(PTA)](+) complexes (PTA=1,3,5-triaza-7-phosphaadamantane)

A series of compounds of general formula [Ru(eta(6)-p-cymene) (R(2)acac)(PTA)][X] (R(2)acac = Me(2)acac, tBu(2)acac, Ph(2)acac, Me(2)acac-Cl; PTA = 1,3,5-triaza-7-phosphaadamantane; X = BPh4, BF4), and the precursor to the Me2acac-Cl derivative [Ru(eta(6)-p-cymene)(Me(2)acac-Cl)Cl], have been prepared and characterised spectroscopically. Five of the compounds have also been characterised in the solid state by X-ray crystallography. The tetrafluoroborate salts are water-soluble, quite resistant to hydrolysis, and have been evaluated for cytotoxicity against A549 lung carcinoma and A2780 human ovarian cancer cells. The compounds are cytotoxic towards the latter cell line, and relative activities are discussed in terms of hydrolysis (less important) and lipophilicity, which appears to exert the dominating influence.

The role of counterions in the membrane-disruptive properties of pH-sensitive lysine-based surfactants

Surfactants are among the most versatile and widely used excipients in pharmaceuticals. This versatility, together with their pH-responsive membrane-disruptive activity and low toxicity, could also enable their potential application in drug delivery systems. Five anionic lysine-based surfactants which differ in the nature of their counterion were studied. Their capacity to disrupt the cell membrane was examined under a range of pH values, concentrations and incubation times, using a standard hemolysis assay as a model for endosomal membranes. The surfactants showed pH-sensitive hemolytic activity and improved kinetics at the endosomal pH range. Low concentrations resulted in negligible hemolysis at physiological pH and high membrane lytic activity at pH 5.4, which is in the range characteristic of late endosomes. With increasing concentration, the surfactants showed an enhanced capacity to lyse cell membranes, and also caused significant membrane disruption at physiological pH. This observation indicates that, at high concentrations, surfactant behavior is independent of pH. The mechanism of surfactant-mediated membrane destabilization was addressed, and scanning electron microscopy studies were also performed to evaluate the effects of the compounds on erythrocyte morphology as a function of pH. The in vitro cytotoxicity of the surfactants was assessed by MTT and NRU assays with the 3T3 cell line. The influence of different types of counterion on hemolytic activity and the potential applications of these surfactants in drug delivery are discussed. The possibility of using pH-sensitive surfactants for endosome disruption could hold great promise for intracellular drug delivery systems in future therapeutic applications.

Influence of chloride-mediated oxidation on the electrochemical degradation of the direct black 22 dye using boron-doped diamond and β-PbO2 anodes

The Direct Black 22 dye was electrooxidized at 30 mA cm-2 in a flow cell using a BDD or β-PbO2 anode, varying pH (3, 7, 11), temperature (10, 25, 45 °C), and [NaCl] (0 or 1.5 g L-1). In the presence of NaCl, decolorization rates were similar for all conditions investigated, but much higher than predicted through a theoretical model assuming mass-transport control; similar behavior was observed for COD removal (at pH 7, 25 °C), independently of the anode. With no NaCl, COD removals were also higher than predicted with a theoretical model, which suggests the existence of distinct dye degradation pathways.

The pH-dependent phase distribution of wood pitch components in papermaking processes

Wood contains only a very small amount of lipophilic extractives, commonly known as wood pitch. The pitch is known to cause severe problems in papermaking processes. The amount of pitch in process waters can be decreased by seasoning of the raw material prior to pulping, pulp washing, removal of pitch by flotation, adsorption of pitch onto various mineral surfaces, and retention of pitch to the fibre material by cationic polymers. The aim of this study was to determine the influence of pH on some of the methods used for pitch control. Experiments were performed using laboratory-made wood pitch emulsions with varying pH, salt concentration, hemicellulose concentration and pitch composition. These emulsions were used to study the phase distribution of resin and fatty acids, the colloidal stability of pitch with and without steric stabilisation by galactoglucomannans, and the interactions between wood pitch and mineral particles. Purification of unbleached and peroxidebleached mill process water was performed by froth flotation in combination with a foaming agent. The distribution of resin and fatty acids (RFAs) between colloidal pitch droplets and the water phase was very dependent on pH. At pH 3, almost all of the RFAs were attached to the pitch droplets, while increasing the pH led to increasing concentration of dissolved RFAs in the water phase. The presence of salt shifted the release of RFAs towards higher pH, while lower ratio of neutral pitch in the emulsion resulted in release of RFAs at lower pH. It was also seen that the dissolution and adsorption of RFAs at sudden pHchanges takes place very quickly. Colloidal pitch was more stable against electrolyte-induced aggregation at higher pH, due to its higher anionic charge. The concentration of cationic polymers needed to aggregate colloidal pitch also increased with increasing pH. The surface characteristics of solid particles, such as amount of charged groups, were very important for understanding their interactions with colloidal wood pitch. Water-soluble galactoglucomannans stabilised the colloidal pitch sterically against aggregation, but could not completely prevent interactions between wood pitch and hydrophilic particles. Froth flotation of unbleached and peroxidebleached process water showed that the pitch could be removed more effectively and selectively at low pH, compared to at neutral pH. The pitch was removed more effectively, using lower concentrations of foaming agent, from peroxide-bleached water than from unbleached water. The results show that pH has a major impact on various pulping and papermaking processes. It determines the anionic charge of the colloidal pitch and the solubility of certain pitch components. Because of this, the pH influences the effectiveness of pitch retention and removal of pitch. The results indicate that pitch problems could be diminished by acknowledging the importance of pH in various papermaking processes.

Influence of environmental factors on seed germination and seedling emergence of yellow sweet clover (Melilotus officinalis)

Laboratory and greenhouse experiments were conducted to determine the effects of drought and salinity stress, temperature, pH and planting depth on yellow sweet clover (Melilotus officinalis) germination and emergence. Base, optimum and ceiling germination temperatures were estimated as 0, 18.47 and 34.60 ºC, respectively. Seed germination was sensitive to drought stress and completely inhibited at a potential of -1 MPa, but it was tolerant to salinity. Salinity stress up to 90 mM had no effect over the M. officinalis seed germination, but the germination decreased by increasing the salt concentration. The drought and salinity required for 50% inhibition of maximum germination were 207 mM and -0.49 MPa, respectively. High percentage of seed germination (>92%) was observed at pH = 5-6 and decreased to 80% at acidic medium (pH 4) and to 42% at alkaline medium (pH 9) pH. Maximum seedling emergence occurred when the seeds were placed at 2 cm depth and decreased when increasing the depth of planting; no seed emerged from depths of 10 cm.

Influence of seed size and ecological factors on the germination and emergence of field bindweed (Convolvulus arvensis)

An understanding of seed germination ecology of weeds can assist in predicting their potential distribution and developing effective management strategies. Influence of environmental factors and seed size on germination and seedling emergence of Convolvulus arvensis (field bindweed) was studied in laboratory and greenhouse conditions. Germination occurred over a wide range of constant temperatures, between 15 and 40 ºC, with optimum germination between 20 and 25 ºC. Time to start germination, time to 50% germination and mean germination time increased while germination percentage and germination index decreased with an increase in temperature from 20 ºC, salinity and osmotic stress. However, germination was tolerant to low salt (25 mM) or osmotic stress (0.2 MPa), but as salinity and osmotic stress increased, germination percentage and germination index decreased. Seeds of C. arvensis placed at soil surface showed maximum emergence and decreased as seeding depth increased. Seeds of C. arvensis germinated over a wide range of pH (4 to 9) but optimum germination occurred at pH 6 to 8. Under highly alkaline and acidic pH, time to start germination, time to 50% germination and mean germination time increased while germination percentage and germination index decreased. Increase in field capacity caused decreased time to start germination, time to 50% germination and mean germination time but increased germination percentage and germination index. Bigger seeds had low time to start germination, time to 50% germination and mean germination time but high germination percentage and germination index. Smaller seeds were more sensitive to environmental factors as compared to larger or medium seeds. It can be concluded that except for pH, all environmental factors and seed sizes adversely affect C. arvensis as regards seed germination or emergence and germination or emergence traits, and larger seeds result in improved stand establishment and faster germination than small seeds, regardless of moisture stress or deeper seeding depth.

Allelopathic Influence of Residues from Sphagneticola trilobata on Weeds and Crops

The allelopathic effect studied in many cultures has currently generated great expectations that displayed a natural and environmentally friendly tool for weed management using bioherbicides. The objective of this work was to assess allelopathic influence of residues of S. trilobata on the germination and growth of weeds, as well as their relation with some crops and effects on soil properties. Results show that residues from S. trilobata have inhibited the germination of weeds (31.6 - 72%), increasingly with the applied dose. All residue doses of this specie have inhibited dicotyledonous germination, but only maximum concentration has affected monocotyledons. The residues did not affect onion germination, but stimulated it in radish and tomato, while the dose applied at 50% produced tomato stimulation and inhibition of cabbage. The effects of residues on hypocotyl growth in different crops showed changes in species response. For onion, the three doses had negative effects on the growth of hypocotyl, while tomato was stimulated. For radish, the growth was hindered by any dose applied, and were only different (50 and 100%) compared to control. For cabbage, only hypocotyl length was stimulated, when maximum dose (100%) was applied. For the radicle growth, in onion and radish no differences were found compared to control. While the tomato radicle growth was inhibited, in cabbage, all doses encouraged the elongation of the radicle. The dry mass of weed was affected by increased dose of residue (0.49 - 8.8 g m-2), however the soil microflora was stimulated, while the population of Azotobacter spp. was not affect. Some soil properties were affected, the level of organic material, Na+ and electrical conductivity were increased, while pH (H2O) decreased a bit, however it remained basic.

Influence of Pulsed-Electric Field Irradiation in Crystallization

The growing pharmaceutical interest, among others, in the polymorphic composition of the emerging solid end-products from production processes has been traced to the need for attainment of high product purity. This is more so as the presence of different polymorphs may constitute physical impurity of the product. Hence, the need for optimization of the yield of desired product component(s) through controlled crystallization kinetics for instance. This study was carried out to investigate the impact of pulsed electric field (PEF) irradiation on the crystal morphology of glycine obtained by cooling crystallization (without seeding) from commercial glycine sample in distilled deionized water solution. In doing so, three different pulse frequencies (294, 950 and 145 Hz) and a case without PEF were studied at three cooling rates (5, 10 and 20 ºC/h). The crystal products obtained were analyzed for polymorphic composition by powder x-ray diffraction (PXRD) and Fourier transform infrared (FTIR) spectroscopy while the particles characterization was done on Morphologi G3. The results obtained from this study showed that pulsed electric field irradiation had significant impact on metastability of the aqueous solution as well as on the polymorphic composition of the end product. With increasing PEF frequency applied, nucleation started earlier and the γ-glycine polymorph content of the product crystals increased. These were found to have been aided by cooling rate, as the most significant effect was observed at 5 ºC/h. It was also discovered that PEF application had no measurable impact on the pH of the aqueous solution as well as the size distribution of the particles. Cooling on the contrary was believed to be responsible for the broadening of the particle size distribution with a downward shift of the lower limit of the raw material from about 100 μm to between 10 and 50 μm.

Influence of chitosan addition on quality properties of vacuum-packaged pork sausages

The aim of the study was to evaluate the influence of the chitosan addition on the quality of vacuum packaged pork sausages. A variant of the product was elaborated with 1% (w/w) of chitosan in lactic acid solution at 1% (v/v) and it was compared to a control. Sausages were mechanically stuffed and manually conformed and vacuum packaged. Sausages were stored at 4 °C and microbiological evaluations, pH measurements, texture profile analysis and sensorial evaluation were performed. The chitosan addition in the formulation of the sausages did not reduce the microbiological counts. The pH values obtained in all samples were similar, which suggests that the chitosan addition did not influence the pH values of sausages. The added chitosan did not affect significantly (p < 0.05) the results of the texture profile analysis and sensorial attributes and therefore, the overall acceptance of the sausages.

The influence of achyrocline satureioides ("Marcela") extract on the lipid oxidation of salami

The effect of two levels (0.5 and 1%) of hydroalcoholic extract of Achyrocline satureioides on the safety (TBARS values) and quality (pH, water activity, colour, weight loss, and sensorial attributes) of salami was evaluated. The addition of Achyrocline satureioides extract decreased TBARS values significantly during the storage of salami when compared to the control, which was elaborated without Achyrocline satureioides extract. The treatment with 1% of "Marcela" extract showed larger lipid stability than that of the lot with 0.5%, However, it presented a decrease (p < 0.05) in the sensorial acceptance. The two levels of "Marcela" extract did not influence pH, water activity, colour, and weight loss significantly. This study indicates that the hydroalcoholic extract of "Marcela" was effective in decreasing the lipid oxidation and at 0.5% it did not alter the sensorial features; therefore, it may be used in salami to provide safer products for the consumers.

Restructuring Passiflora cincinnata fruit pulp: influence of hydrocolloids

This study evaluated the effect of mixtures of alginate, low methoxy pectin and gelatin on characteristics of P. cincinnata fruit gels, containing pulp with high soluble solids content (50 °Brix). The results of a central composite design showed that the models obtained, except for water activity and pH, were predictive. Gelatin was an important factor affecting firmness and colour parameters since higher concentrations of this hydrocolloid, combined with alginate concentrations greater than 1.3% and pectin quantity up to 1.26%, could be used to obtain clear yellow products with firmness greater that 1.2 kg.

Influence of passion fruit albedo, citric acid, and the pulp/sugar ratio on the quality of banana preserves

The objective of this research was to evaluate the effect of the citric acid concentration, pulp/sugar ratio, and albedo concentration of the passion fruit peel on physical, physiochemical, and sensorial characteristics of the 'Silver' banana preserves. A 2³ factorial design and 3 repetitions in the central point were used. The albedo concentration between 0 and 3% had significant influence on the reduction of the reducing sugars and on the decrease in titratable acidity. The increase in the pulp/sugar ratio exerted a negative effect on the pH and positive on the titratable acidity; the acid addition reduced the non-reducing sugar level. The sensorial evaluation and purchase intention indicated that the incorporation of a maximum of 1.5% albedo in formulations containing 50% pulp and 0.5% citric acid resulted in products with good acceptability in comparison with the formulation in which 60% pulp and an absence of acid or albedo is utilized.