Effects of Acidification, Sodium Chloride, and Moisture Levels on Wheat Dough: I. Modeling of Rheological and Microstructural Properties

The rheological attributes of polymers as wheat dough are strongly related to its microstructure. To quantify dough protein microstructure confocal laser scanning microscopy combined with image analysis was used. The effect of three experimental factors pH (addition of lactic acid and sodium hydroxide), water addition, and sodium chloride (NaCl) addition on empirical and fundamental rheological properties as well as microstructural protein properties were studied and modeled by applying a response surface methodology. The obtained models revealed high correlations between the experimental factors and the complex shear modulus (R ²?=?0.97), dough resistance (R_max ^k; R ²?=?0.91) and stickiness (R ²?=?0.93). Furthermore it was possible to determine microstructural attributes as the area fraction (R ²?=?0.88) and Feret??s diameter (R ²?=?0.86) as a function of pH, water and NaCl addition. Especially measures of R^k _max revealed highly significant correlations with the protein microstructure as the branching index (r?=?0.79).     

温度、土壤水分和NaCl对黄顶菊种子萌以的影响

光照和黑暗条件下的黄顶菊种子萌发无显著差异;种子萌发的适宜温度为25～35℃:种子萌发率随着NaCl浓度的升高而下降;种子萌发的最佳土壤含水量为35%～45%.在最适温度下,种子萌发耐受NaCI的临界值为89.919 mmol·L-1,极限值为218.92 mm01.L-1;不同温度和NaCl以及二者共同作用使黄顶菊种子萌发受到的抑制都极显著.     

Effect of Potassium Chloride vs. Potassium Sulphate Fertilization at Different Soil Moisture on Take-All of Wheat

A pot experiment was conducted with two moisture levels to study the influence of KC1vs. K₂SO₄ fertilization on the growth of healthy and take-all infected spring wheat.Transpiration and diffusive resistance were measured in the flag leaves. The flag leaves of healthy plants had the highest rate of transpiration.Transpiration declined with higher incidence of Gaeumannomyces grminis var. trutici (Ggt).With low soil moisture and also with sulphate fertilization transpiration tended to be lower.The difference between sulphate and chloride fertilization was relatively greater in more severely affected than in healthy plants, in particular with lower soil moisture. The flag leaves of plants were maintained in a green state for a longer period of time by chloride fertilization. This indicates a higher and prolonged metabolic activity which is reflected in the grains yields. Yield depressions as a consequence of Ggt infection were smaller with KC1 than with K₂SO₄ fertilization and more marked under water stress than with optimal water supply.     

Effects of Potassium Chloride and Sodium Chloride on the Thermal Properties of Gellan Gum Gels

The exothermic and endothermic peaks in cooling and heating curves of differential scanning calorimetry (DSC) for gellan gum gels without and with potassium chloride and sodium chloride were analyzed. The gelling and melting temperatures shifted to higher temperatures with increasing gellan and salt concentration in the concentration range of gellan from 0.3 to 2.0% (w/w). The exothermic and endothermic enthalpy increased with increasing gellan and salt concentrations. Cooling DSC curves showed one exothermic peak for samples with salts and at low gellan concentration. Heating DSC curves showed many peaks for all samples except 0.3% (w/w) gellan gum gels. The sol-gel transition of samples was examined numerically by using a zipper model approach. The introduction of cations increases the number of junction zones or zippers and decreases the rotational freedom of parallel links. This makes the structure of junction zones more heat resistant, and increases the elastic modulus of the gel.     

Effect of pH, Sodium Chloride, and Sodium Nitrite on Enterotoxin A Production

The combined effects of pH, sodium chloride, and sodium nitrite were studied by using a dialysis sac technique in brain heart infusion broth. Growth and enterotoxin A production by Staphylococcus aureus strain 100 were found to decrease with the addition of sodium nitrite, with a decrease in pH from 7.0, and with an increase in sodium chloride concentration. The significance of these results is discussed in relation to cured meats.     

Effect of Sodium Nitrite, Sodium Chloride, and Sodium Nitrate on Germination and Outgrowth of Anaerobic Spores

The effects of meat-curing agents on germination and outgrowth of putrefactive anaerobe 3679h (PA 3679h) spores were studied in microcultures. Nitrite concentrations up to 0.06% at pH 6.0 or between 0.8 and 1% at pH 7.0 allowed emergence and elongation of vegetative cells but blocked cell division. The newly emerged cells then lysed. With more than 0.06% nitrite at pH 6.0 or more than 0.8 to 1% at pH 7.0, the spores lost refractility and swelled, but vegetative cells did not emerge. Even as much as 4% nitrite failed to prevent germination (complete loss of refractility) and swelling of the spores. Sodium chloride concentrations above 6% prevented complete germination (i.e., the spores retained a refractile core). In the presence of 3 to 6% sodium chloride, most of the spores germinated and produced vegetative cells, but cell division was often blocked. Sodium nitrate had no apparent effect on germination and outgrowth at concentrations up to 2%.     

Effects of Sodium Chloride on Water Status and Growth of Sugar Beet

The effects of sodium chloride on the water status, growth,and physiology of sugar beet subjected to a range of soil waterpotentials were studied under controlled conditions. Sodiumchloride increased plant dry weight and the area, thickness,and succulence of the leaves. It increased the water capacityof the plant, mainly the shoot, but there was no evidence thatit altered the relationships between leaf relative water contentand the leaf water, osmotic, and turgor potentials or changedthe way stomatal conductance and photosynthesis responded todecreasing leaf water potential. The greater leaf expansionin sodium-treated plants is thought to be the consequence ofadjustments made by leaf cells to accommodate changes in ionsand water in a way that minimizes change in water and turgorpotentials. It is also suggested that the greater water capacityof treated plants buffers them against deleterious changes inleaf relative water content and water potential under conditionsof moderate stress.     

Microorganisms of the San Francisco Sour Dough Bread Process: II. Isolation and Characterization of Undescribed Bacterial Species Responsible for the Souring Activity

A medium was developed which permitted isolation, apparently for the first time, of the bacteria responsible for the acid production in the 100-year-old San Francisco sour dough French bread process. Some of the essential ingredients of this medium included a specific requirement for maltose at a high level, Tween 80, freshly prepared yeast extractives, and an initial pH of not over 6.0. The bacteria were gram-positive, nonmotile, catalase-negative, short to medium slender rods, indifferent to oxygen, and producers of lactic and acetic acids with the latter varying from 3 to 26% of the total. Carbon dioxide was also produced. Their requirement for maltose for rapid and heavy growth and a proclivity for forming involuted, filamentous, and pleomorphic forms raises a question as to whether they should be properly grouped with the heterofermentative lactobacilli.     

The Kinetics of Sodium Transport in the Toad Bladder : II. Dual effects of vasopressin

In the accompanying paper, a compartmental model for the toad bladder sodium transport system was developed. In the present paper, the model is tested by determining the effects of antidiuretic hormone on the pools and fluxes. It is shown that this hormone affects only that sodium pool previously designated as the transport pool, and that the effects are on two separate sites. In the first place, the hormone stimulates entry at the mucosal side of the transport compartment, and by this means brings about an increase in the amount of sodium contained in the compartment. Second, the hormone has a distinct stimulatory effect on the rate coefficient for efflux across the serosal boundary, the pump rate coefficient. Evidence is presented that under control conditions, the pump rate coefficient is a decreasing function of the pool size, a characteristic feature of a saturating system. Therefore, the effect of vasopressin in increasing both the pool size and the pump rate coefficient must be construed as a direct effect on the pump, and not one which is secondary to the increase in the pool size. Furthermore, it is shown that the effect of the hormone on the sodium pump is not dependent on the presence of sodium in the serosal medium.     

Some Effects of Sodium Chloride on Germination and Seedling Growth of Sugar Beet

Soaking sugar-beet seed in 1.0 M sodium chloride solution killed6 per cent of the seeds but the remainder germinated when transferredto more dilute (< 0.28 M) solutions. Small differences inthe concentration of dilute sodium chloride did not change thenumber of seeds which germinated but greatly affected wateruptake and seedling growth. For example, after 10 days at 15?C, radical length decreased almost linearly from 50 to 5 mmwhen the concentration increased from 0 to 0.2 M. Presoakingseed in water increased the concentration tolerated withoutreduction in growth. Advancing seed (presoaking followed byairdrying) increased seedling yield by 70 per cent by decreasingthe time taken to emerge, increasing the number of seeds whichgerminated and eliminating the detrimental effects of smallamounts of sodium chloride. Advancing seed also marginally reducedthe variation in seedling yield in laboratory and controlledenvironment experiments. To minimize the risk of killing seedsor decreasing seedling growth it seems that no more than therecommended quantity (377 kg ha^–1) of sodium chlorideshould be applied to sugar-beet crops.     

Effects of Chlorocholine Chloride and Water Regime on Growth, Yield, and Water Use of Spring Wheat

When CCC was applied as a spray to the leaves of Brassica oleraceaL. (Brussels sprout) grown in pots, plant height and mean internodelength were reduced. The effects appeared more slowly and wereless pronounced than those previously observed when CCC hadbeen applied to the soil; other differences were that root growthwas not inhibited, stem weight was only significantly reducedat the highest rate of application (2 per cent), and stomatalnumber per unit area of lower leaf epidermis was not affected.In common with soil applications, leaf thickness, stem diameter,and the percentage moisture contents of the leaves were allincreased by foliar applications.In a further experiment theprogress of wilting was observed in untreated plants and inplants treated with CCC applied either to the leaves or to thesoil. The rates of water loss and the moisture contents of theleaf laminae of the treated plants, after a period of wilting,were not significantly different from the controls. The treatedplants, however, looked less ‘wilted‘ for the changein angle of the leaf lamina to the stem was less and their leaveswere therefore held more upright.     

Differential Effects of Sodium Butyrate and Lithium Chloride on Rhesus Monkey Trophoblast Differentiation

Trophoblast differentiation during early placental development is critical for successful pregnancy and aberrant differentiation causes preeclampsia and early pregnancy loss. During the first trimester, cytotrophoblasts are exposed to low oxygen tension (equivalent to~2%-3% O₂) and differentiation proceeds along an extravillous pathway (giving rise to invasive extravillous cytotrophoblasts) and a villous pathway (giving rise to multinucleated syncytiotrophoblast). Interstitial extravillous cytotrophoblasts invade the decidua, while endovascular extravillous cytotrophoblasts are involved in re-modelling uterine spiral arteries. We tested the idea that sodium butyrate (an epigenetic modulator) induces trophoblast differentiation in early gestation rhesus monkey trophoblasts through activation of the Wnt/β-catenin pathway. The results show that syncytiotrophoblast formation was increased by butyrate, accompanied by nuclear accumulation of β-catenin, and increased expression of EnvV2 and galectin-1 (two factors thought to be involved in trophoblast fusion). Surprisingly, the expression of GCM1 and syncytin-2 was not affected by sodium butyrate. When trophoblasts were incubated with lithium chloride, a GSK3 inhibitor that mimics Wnt activation, nuclear accumulation of β-catenin also occurred but differentiation into syncytiotrophoblast was not observed. Instead the cells differentiated to mononucleated spindle-shaped cells and showed molecular and behavioral characteristics of endovascular trophoblasts. Another highly specific inhibitor of GSK3, CHIR99021, failed to induce endovascular trophoblast characteristics. These observations suggest that activation of the Wnt/β-catenin pathway correlates with both trophoblast differentiation pathways, but that additional factors determine specific cell fate decisions. Other experiments suggested that the differential effects of sodium butyrate and lithium chloride might be explained by their effects on TNFα production. The results provide valuable tools to manipulate trophoblast differentiation in vitro and to better understand the differentiation pathways that occur during early gestation.     

Effects of Sodium Chloride Stress on Callus Cultures of Cicer arietinum L. cv. BG-203: Growth and Ion Accumulation

Growth and ion accumulation were measured in callus culturesof Cicer arietinum L. cv. BG-203, grown on media supplementedwith 0–200 mol m^–3 NaCl. Fresh and dry weights decreasedat concentrations ranging from 100–200 mol m^–3,the reduction being greater during the third and fourth weeksof culture. Slight stimulation of growth was observed at 25and 50 mol m^–3 NaCl. There was also a decrease in tissuewater content (fresh weight: dry weight) at 100–200 molm^–3 NaCl. The concentration of Na⁺ and Cl^– in thetissue increased with increasing salinity of the medium. Mostof the accumulation of these ions occurred by the first weekwhile significant growth inhibition became apparent by onlythe third week of culture. Tissue K⁺ and Mg²⁺ decreased withincreasing salinization, the decrease being greater in K⁺ levels.Levels of Ca²⁺, however, were maintained throughout the experimentalrange. Key words: Cicer arietinum, NaCl stress, Callus cultures, Ion accumulation     

Sugar Transport into Protoplasts Isolated from Developing Soybean Cotyledons : II. Sucrose Transport Kinetics, Selectivity, and Modeling Studies

The effects of metabolic inhibitors, pH, and temperature on the kinetics of sucrose uptake protoplasts isolated from developing soybean Glycine max L. cv Wye cotyledons were studied. Structural requirements for substrate recognition by the sucrose carrier were examined by observing the effects of potential alternate substrates for the saturable component on sucrose uptake.     

ATP Levels and their Effects on Plasmalemma Influxes of Potassium Chloride in Red Beet

Tissue ATP concentrations in slices of red beet increase progressively with time for up to 7 days after cutting the root. ATP levels are higher in slices taken from stored roots than in slices from fresh roots. ATP is reduced during incubation in salt solutions.     

渗透胁迫对小麦胚芽鞘内多胺的种类、形态和含量的影响

用高压液相色谱法研究了豫麦18（抗旱性较强）和扬麦9号（抗旱性较弱）小麦胚芽鞘中三种不同形态的多胺（polyamine,PA）：游离态多胺（PA）、高氯酸可溶性结合态多胺（ps结合态PA）和高氯酸不溶性结合态多胺（PIS结合态PA）与渗透胁迫的关系。结果发现：渗透胁迫2d,豫麦18胚芽鞘中的游离态Spd和游离态Spm的含量明显上升,而扬麦9号的游离态Put的上升明显。S-腺苷蛋氨酸脱羧酶（S—AMDC）的抑制剂——甲基乙二醛-双（鸟嘌呤腙）（MGBG）处理豫麦18,明显抑制了渗透胁迫诱导的游离态Spd和游离态Spm的增加,并且加重了渗透胁迫伤害,外源Spd处理扬麦9号明显促进了渗透胁迫诱导的游离态Spd和游离态Spm的增加,并且减缓了渗透胁迫的伤害。渗透胁迫下,豫麦18胚芽鞘中的PS结合态PA和PIS结合态PA的上升幅度都明显大于扬麦9号。菲咯啉（o—Phen）抑制渗透胁迫下PIS结合态PA的合成并加重了渗透胁迫对胚芽鞘的伤害。这些结果表明：小麦胚芽鞘中的游离态Spd、游离态Spm、PS结合态PA和PIS结合态PA的升高有利于增强渗透胁迫抗性。     

Modeling Hermissenda: II. Effects of variations in type-B cell excitability, synaptic strength, and network architecture

Because the Hermissenda eye is relatively simple and its cells well characterized, it provides an attractive preparation for detailed computational analysis. To examine the neural mechanisms of learning in this system, we developed multicompartmental models of the type-A and type-B photoreceptors, simulated the eye, and asked three questions: First, how do conductance changes affect cells in a network as compared with those in isolation; second, what are the relative contributions of increases in B-cell excitability and synaptic strength to network output; and third, how do these contributions vary as a function of network architecture? We found that reductions in the type-B cells of two K⁺ currents, I _A and I _C, differentially affected the type-B cells themselves, with I _C reductions increasing firing rate (excitability) in response to light, and I _A reductions increasing quantal output (synaptic strength) onto postsynaptic targets. Increases in either type-B cell excitability or synaptic strength, induced directly or indirectly, each suppressed A-cell photoresponses, and the combined effect of both changes occurring together was greater than either alone. To examine the effects of network architecture, we compared the full network with a simple feedforward B-A pair and intermediate configurations. Compared with a feedforward pair, the complete network exhibited greater A-cell sensitivity to B-cell changes. This was due to many factors, including an increased number of B-cells (which increased B-cell impact on A-cells), A-B feedback inhibition (which slowed both cell types and altered spike timing relationships), and B-B lateral inhibition (which reduced B-cell sensitivity to intrinsic biophysical modifications). These results suggest that an emergent property of the network is an increase both in the rate of information acquisition (“learning”) and in the amount of information that can be stored (“memory”).