Natural Aging Conditions Research Articles

Identification of QTLs for seed storability in rice under natural aging conditions using two RILs with the same parent Shennong 265

Seed storability (SS) is an important trait for agronomic production and germplasm preservation in rice (Oryza sativa L.). Quantitative trait locus (QTL) for seed storability in three storage periods was identified using two sets of recombinant inbred lines (RILs) derived from the crosses with a common female parent Shennong 265 (SN265). Ten QTLs for seed storability were detected on chromosomes 1, 2, 3, 4, 6, 8, and 12 in SL-RILs (SN265/Lijiangxingtuanheigui (LTH)), and a total of 12 QTLs were identified on chromosomes 2, 3, 4, 6, 9, and 10 in SH-RILs (SN265/Luhui 99 (LH99)) in different storage periods. Among these QTLs, five major QTLs were identified in more than one storage period. The qSS3-1, qSS3-2, qSS12-1, and qSS12-2 were detected in SL-RILs. Similarly, qSS2-2, qSS2-3, qSS6-2, qSS6-3, qSS6-4, qSS9-1, and qSS9-2 were detected in SH-RILs. In addition, the maximum phenotypic variation was derived from the qSS6-1 and qSS9-2, explaining 53.58 and 29.09%, respectively, while qSS6-1 was a new stable QTL for seed storability. These results provide an opportunity for pyramiding and map-based cloning major QTLs for seed storability in rice.

Development of Al-Mg-Si-(Cu) Alloys for Automotive Body Panels and the Related Ageing Behaviours

In this work, Al-Mg-Si-Cu alloys for automotive body panels were designed and the related ageing behaviours were discussed in detail to help understand natural ageing and pre-ageing, as well as their influence on the subsequent paint-bake response. The clustering behavior of these Al-Mg-Si-Cu alloys in different ageing conditions was investigated by hardness / yield strength and electrical conductivity testing. The microstructure was investigated by using Electron Backscattered Diffraction (EBSD) technique, along with Scanning Electron Microscopy with Backscattered Electron Detector (BSE). The results show that the paint bake response is strongly influenced by the pre-ageing and natural ageing conditions. Both alloys show serrated yielding in a short natural ageing condition. Immediate high-temperature pre-ageing treatments were found to give a promising hardening response during the subsequent artificial ageing/ paint baking at 170oC.

Arabidopsis COGWHEEL1 links light perception and gibberellins with seed tolerance to deterioration.

Light is a major regulator of plant growth and development by antagonizing gibberellins (GA), and we provide evidence for a role of light perception and GA in seed coat formation and seed tolerance to deterioration. We have identified two activation-tagging mutants of Arabidopsis thaliana, cog1-2D and cdf4-1D, with improved seed tolerance to deterioration linked to increased expression of COG1/DOF1.5 and CDF4/DOF2.3, respectively. These encode two homologous DOF transcription factors, with COG1 most highly expressed in seeds. Improved tolerance to seed deterioration was reproduced in transgenic plants overexpressing these genes, and loss of function from RNA interference resulted in opposite phenotypes. Overexpressions of COG1 and CDF4 have been described to attenuate various light responses mediated by phytochromes. Accordingly, we found that phyA and phyB mutants exhibit increased seed tolerance to deterioration. The phenotype of tolerance to deterioration conferred by gain of function of COG1 and by loss of function of phytochromes is of maternal origin, is also observed under natural aging conditions and correlates with a seed coat with increased suberin and reduced permeability. In developing siliques of the cog1-2D mutant the expression of the GA biosynthetic gene GA3OX3 and levels of GA1 are higher than in the wild type. These results explain the antagonism between phytochromes and COG1 in terms of the inhibition and the activation, respectively, of GA action.

Experimental Investigation of the Early Stage of Precipitation on Binary Al-Li, Al-Cu Alloys and Ternary Al-Li-Cu Alloys by Means of Atom Probe Tomography

Aluminum-based alloys play a key role in modern engineering and are widely used in construction components in aircraft, automobiles and other means of transportation due to their light weight and superior mechanical properties. Introduction of different nano-structure features can improve the service and the physical properties of such alloys. An improvement of an Al-based alloy has been performed based on the understanding of the relationships among compositions, processing, microstructural characteristics and properties. Knowledge of the decomposition process of the microstructure during the precipitation reaction is particularly important for future technical developments. The objective of this study is to investigate the nano-scale chemical composition in the Al-Cu, Al-Li and Al-Li-Cu alloys during the early stage of the precipitation sequence and to describe whether this compositional difference correlates with variations in the observed precipitation kinetics. Investigation of the fine scale segregation effects of dilute solutes in aluminum alloys which were experienced different heat treatments by using atom probe tomography has been achieved. The results show that an Al-1.7 at.% Cu alloy requires a long ageing time of approximately 8 h at 160°C to allow the diffusion of Cu atoms into Al matrix. For the Al-8.2 at.% Li alloy, a combination of both the natural ageing condition (48 h at room temperature) and a short artificial ageing condition (5 min at 160°C) induces increasing on the number density of the Li clusters and hence increase number of precipitated particles. Applying this combination of natural ageing and short artificial ageing conditions onto the ternary Al-4 at.% Li-1.7 at.% Cu alloy induces the formation of a Cu-rich phase. Increasing the Li content in the ternary alloy up to 8 at.% and increasing the ageing time to 30 min resulted in the precipitation processes ending with δ' particles. Thus the results contribute to the understanding of Al-alloy design.

Seed invigoration treatments in different seed sizes of sunflower (<italic>Helianthus annuus</italic> L.) for maintenance of vigour, viability and yield potential

Pre-storage dry treatment of freshly harvested (high-vigour) sunflower (Helianthus annuus L.) seeds in different seed sizes (viz. composite, large, medium and small) with red chilli powder (@ 1 g/kg of seed) and bleaching powder (@ 2g/kg of seed) significantly slowed down seed deterioration under natural ageing conditions and increased field performance and productivity along with reduced leakage of electrolytes, lower volatile aldehyde production with higher dehydrogenase enzyme activity over their respective untreated control. Among the seed sizes, large seeds showed higher post-storage germinability as well as field performance and productivity than the other categories of seeds. Interaction effects were non-significant which indicated that the treatment effects are independent of seed sizes. On the basis of the present investigation, pre-storage dry treatments in large sized seeds with red chilli powder and bleaching powder may be suggested for improved germinability and yield potential of stored high-vigour sunflower seeds.

Effect of botanicals and insecticides seed treatment and containers on seed longevity of black gram under natural ageing conditions

Good storage is the basic requirement in seed production programme as maintenance of high seed viability and vigour from harvest to planting is of utmost importance in a seed production programme. Therefore, inexpensive, simple and practicable technology to prolong the shelf life of seeds under ambient condition is immensely needed. Hence, an experiment was carried out to study the effect of seed treatment with neem oil, nimbicidin, emamectin benzoate 5 SG, deltamethrin 2.8 EC, novuluron EC on black gram seed quality under ambient conditions. The seeds without any seed treatment were included as control. The treated and untreated seeds were stored in cloth bag and polylined cloth bag. The results revealed that, botanicals and emamectin benzoate seed treatments were significantly superior in controlling the storage insect and maintaining higher seed quality up to 10 months of storage when compared to control. Among the chemicals, the emamectin benzoate 5 SG @ 40 mg kg-1 of seed found better by recording significantly higher germination percentage (80.28), vigour index I (2124) and dry weight of seedlings (43.14 mg) and lower electrical conductivity (0.939 dSm-1) and seed damage (0.00 %) compared to control (78.78%, 2012, 38.90 mg, 0.942 dSm-1, respectively) at the end of 10th month of storage. The emamectin benzoate 5 SG and nimbicidintreated seeds stored in polylined cloth bags were considered as effective seed storage management approach in blackgram.

Dating of Iron Gall Ink Using the Dissolution‐Diffusion Method

In many criminal and civil cases, some questioned documents are written with iron gall ink. Determining the date when an iron gall ink entry was written can be important to assess the authenticity of a document. A dissolution-diffusion method was successfully employed to draw aging curves of iron gall ink entries stored in controlled conditions over 40months. Calibration curves were created to indicate the relationship between the average dissolution-diffusion rate of ink components and the age of ink entries stored under natural aging conditions. As preliminary findings of this study, the mixed solution of dimethyl formamide (DMF) and anhydrous ethanol was suitable to dissolve the dye of iron gall ink strokes made at different time. It was also determined that brands of iron gall inks, types of paper, and thickness of iron gall ink strokes had varying impacts on estimating the dates of iron gall ink strokes.

Extraction percentage analysis of inkpad seals stored under different conditions

Inkpad seals are often placed on important documents in China. Determining the date when a seal was affixed can be important in assessing the authenticity of a document. In this paper, an extraction percentage analysis method was employed to date the inkpad seals. Calibration curves were created to express the relationship between the extraction percentage of inkpad seal components and the age of inkpad seal entries stored under heat (thermal) ageing and UV-induced ageing conditions. The correspondence between the natural ageing, heat ageing and UV-induced ageing conditions was also established.

What is the evidence for changes in cognition and functioning over the lifespan in patients with schizophrenia?

Cognitive deficits in schizophrenia are important predictors of impairment in most functional domains and are a critical therapeutic target. These deficits appear at or before the onset of illness, are stable across time in most patients, and can be improved by cognitive remediation treatments. Recent evidence, however, suggests that cognitive function does not necessarily follow a pattern of age-related decline. Several studies evaluated this pattern of decline in schizophrenia patients compared to both natural aging and degenerative conditions such as Alzheimer's disease. Age-related differences were not comparable to either normal aging or Alzheimer's disease. Older patients with an extensive history of illness and protracted institutionalization have shown a greater progressive decline. These deficits were also observed in older patients who were no longer institutionalized, with these patients demonstrating decline in functional capacity across time compared to healthy controls and patients with no lengthy institutional stay. There were 2 clear conclusions from this body of data. First, there appear to be 2 separate periods of deterioration in schizophrenia patients. These patients appear to decline the most at 2 key time points; the first occurs some time prior to the first psychotic episode and the second begins at approximately 65 years of age. The second important conclusion is that these 2 important periods of time may be the time point at which an aggressive intervention may have the greatest impact.

Skin Autofluorescence, 5-Year Mortality, and Cardiovascular Events in Peripheral Arterial Disease

The hunt for predictive biomarkers in diseases of the cardio-, cerebro-, and peripheral vascular systems is an ongoing effort and one whose importance cannot be overstated. The identification of subjects most at risk for death or major adverse cardiovascular events may provide a means to stratify diagnostic and therapeutic interventions based on validated predictive algorithms. In this issue of Arteriosclerosis, Thrombosis, and Vascular Biology , de Vos et al1 report that in 252 eligible subjects with documented peripheral arterial disease (PAD) studied at a single center, the measurement of skin autofluorescence (SAF) was independently associated with all-cause mortality and fatal or nonfatal major adverse cardiovascular events after a follow-up period of 5 years. Importantly, the authors excluded subjects with hemodialysis, kidney transplantation, recent myocardial infarction, or recent stroke and report that even after adjustment for cardiovascular risk factors and the use of lipid-lowering drugs, increased SAF remained associated with increased risk for death and major adverse cardiovascular events. A previous report from these authors compared subjects with PAD versus control PAD-free subjects and showed that increased SAF was significantly associated with PAD in a manner independent of traditional cardiovascular risk factors, although such risk factors were associated with further increases in SAF.2 See accompanying article on page 933 The AGE reader was used as a biological marker of advanced glycation endproducts (AGEs) in the skin and is usually tested in the forearm. AGEs are the products of nonenzymatic glycation and oxidation of proteins and lipids. AGEs are increased not only in diabetes mellitus but also in natural aging, oxidative stress, and inflammatory conditions, and in renal failure.3 AGEs form on lysine and arginine residues and are heterogeneous; some AGEs are associated with crosslinking (such as pentosidine), and some AGEs do not fluoresce, such as the carboxy methyl …

Dating of Seals Produced with Stamp‐Pad Ink Using Gas Chromatography Method

Seals are often placed on important documents, and determining the date when a seal was affixed can be important to assess the authenticity of a document. In this study, thirty-seven different brands of stamp-pad inks and three different types of paper were used to make diachronic samples of the seals. The volatile components of stamp-pad ink were determined, and the stamp-pad ink was classified by gas chromatography with a flame ionization detector. Calibration curves were created to show the relationship between the content of volatile stamp-pad ink components and the age of stamp-pad ink entries stored under natural aging, UV-induced aging, and heating aging conditions. The experimental results showed that GC was useful in the analysis of stamp-pad ink and applicable for determining the relative age of stamp-pad ink entries in some cases where the seal was placed on the document within 3 months.

Tensile Properties of Al-Cu 206 Cast Alloys with Various Iron Contents

The Al-Cu 206 cast alloys with varying alloy compositions (i.e., different levels of Fe, Mn, and Si) were investigated to evaluate the effect of the iron-rich intermetallics on the tensile properties. It is found that the tensile strength decreases with increasing iron content, but its overall loss is less than 10 pct over the range of 0.15 to 0.5 pct Fe at 0.3 pct Mn and 0.3 pct Si. At similar iron contents, the tensile properties of the alloys with dominant Chinese script iron-rich intermetallics are generally higher than those with the dominant platelet phase. In the solution and artificial overaging condition (T7), the tensile strength of the 206 cast alloys with more than 0.15 pct Fe is satisfactory, but the elongation does not sufficiently meet the minimum requirement of ductility (>7 pct) for critical automotive applications. However, it was found that both the required ductility and tensile strength can be reached at high Fe levels of 0.3 to 0.5 pct for the alloys with well-controlled alloy chemistry and microstructure in the solution and natural aging condition (T4), reinforcing the motivation for developing recyclable high-iron Al-Cu 206 cast alloys.

GC Analysis of Black Gel Pen Ink Stored under Different Conditions

In many criminal and civil cases in China, the most commonly questioned documents are those written with gel pen ink. An important task for forensic document examiners is to identify whether two or more ink entries in one or more documents were written with the same ink type. The identification of the age of gel ink entries made poses an important and difficult problem for forensic document examiners. In this paper, the volatile components of gel ink were determined and the gel ink was classified by gas chromatography with a flame ionization detector. Calibration curves were created to express the relationship between the content of volatile gel ink components and the age of gel ink entries stored under natural and UV-induced aging conditions. The correspondence between the natural and UV-induced aging conditions was also established. The experimental results showed that GC was useful in the analysis of black gel ink and applicable for determining the relative age of gel ink entries under certain conditions.

Dating of black gel pen ink using the dissolution–diffusion method

In many criminal and civil cases in China, the most commonly questioned documents are those written with gel pen ink. An important task for forensic document examiners is to identify whether two or more ink entries in one or more documents were written with the same ink type. The identification of the age of gel ink entries made poses an important and difficult problem for forensic document examiners. In this paper, a dissolution–diffusion method was successfully employed to estimate the relative age of gel ink entries by comparing dissolution–diffusion rates. Using extensive tests, the mixed solution of dimethyl formamide (DMF) and anhydrous ethanol proved to be a suitable solvent and was used to dissolve the dye of gel ink strokes made at different times. As preliminary findings of this study, calibration curves were created to indicate the relationship between the average dissolution–diffusion rate of soluble gel ink components and the age of gel ink entries stored under natural aging conditions. It was also determined that brands of gel inks, types of paper and thickness of gel ink strokes had varying impacts on estimating the dates of gel ink strokes. Experimental results showed that dissolution–diffusion method was applicable for determining the relative age of gel ink entries under certain conditions.

Is cellulose degradation due to β-elimination processes a threat in mass deacidification of library books?

As papers become acidic and brittle over time, libraries apply mass deacidification processes to their collections in order to neutralize acids and deposit an alkaline reserve in the paper. Books commonly treated by mass deacidification have undergone natural aging of up to 150 years. The risk of alkali-induced degradation of cellulosic material upon mass deacidification remains uncertain. In the present study, the extent of β-elimination-type degradation reactions was investigated by comparing deacidified and non-deacidified counterparts, using deacidified library materials and identical issues of non-deacidified books from second-hand book shops. The study dealt with only naturally-aged papers focusing on investigation of immediate effects of mass deacidification rather than a long-term impact. Gel permeation chromatography coupled with carbonyl group labeling gave insight into cellulose chain cleavage as well as into the behavior of oxidized functionalities. Processes occurring under natural aging conditions were compared to those upon artificial oxidation of model pulps. Library books did not show a significant reduction in molecular weight after mass deacidification compared to the non-deacidified controls, which stands in contrast to oxidized model pulps. The models showed a more pronounced loss of molecular weight upon deacidification treatments. A decrease in carbonyl groups other than reducing ends was found to occur. Thus, oxidized functionalities were found to be reactive in mass-deacidification reactions; the different behavior was traced down to particular regions of oxidative damage along the cellulose chains. In general, β-elimination processes did not pose a large risk factor upon mass deacidification treatments of the naturally-aged library material tested.

Degradation of rubber to metals bonds during its cathodic delamination, validation of an artificial ageing test

Rubber-metal assemblies used for submarine applications are often associated to cathodic protection which can lead to cathodic disbonding of the polymer/metal interface. The degradation mechanisms of polychloroprene/epoxy adhesive/copper–aluminium substrate systems associated to an accelerated ageing test are compared to the degradations resulting from natural ageing conditions in the Mediterranean sea. From destructives tests, a kinetic in four steps is identified for both ageing conditions. This kinetic is confirmed by Electrochemical Impedance Spectroscopy data during ageing. In order to further identify the failure mode, the disbonded surfaces on polymer and steel sides are analyzed using SEM and FTIR. Both ageing conditions present the same type of degradation which validates the fact that the accelerated ageing protocol reproduces the natural conditions. The chemical transformations in delaminated epoxy are very similar to the chemical transformation in epoxy coatings under high energy electron-beam irradiation. However, bidendate metal carboxylates rather than carboxylic acid chain ends are the main oxidation products due to the alkaline environment at the coating-metal interface. It was shown that the metal/polymer interface is not destroyed by an alkaline attack but by a strongly oxidative attack caused by the intermediates of the oxygen reduction.

Modeling and Analysis of Effect of Thermal Exposure on Fatigue Crack Growth of Al-Cu-Mg Alloys with Low Cu/Mg Ratio

Effect of thermal exposure on FCG of Al-Cu-Mg alloys with low Cu/Mg ratio in artificial and natural ageing conditions were modeled and analyzed. Three FCG rate models, namely Collipriest, Priddle, and Modified Forman model were examined to research the effect of thermal exposure on FCG of Al-Cu-Mg alloys with low Cu/Mg ratio in artificial and natural ageing conditions. The results showed that Priddle model provided the best fit. Priddle model was used to fit FCG data of (a) 170°C/30min ageing; (b)170°C/30min ageing +100°C/2000h exposure; (c)T351 ageing+100°C/2000h exposure; (d)T351 ageing. The fitted results indicated that the FCP resistance can be increased by slight artificial aging, and artificial aging can delay the degradation of the fatigue properties

Tensile Behavior of Ultrafine-Grained Al-4Zn-2Mg Alloy Produced by Cryorolling

An Al-4Zn-2Mg alloy was subjected to cryorolling (CR) followed by short annealing. An average grain size of ~100 nm was achieved. Cryorolled samples showed large reduction in grain size due to suppression of dynamic recovery and absence of annihilation of dislocations, as compared to room temperature rolled samples. Further, the ultrafine-grained (UFG) Al-4Zn-2Mg alloy when subjected to natural aging showed an improved strength of ~413 MPa with ductility of ~25%, as compared to ~360 MPa and 22% ductility in peak aged condition of coarse-grained alloy. However, UFG alloy in peak aging condition, exhibited a relatively strength (~375 MPa) and 24% ductility combinations than the natural aging condition. The latter is attributed to dynamic precipitation and stored energy. In the present study, it is demonstrated that simultaneous improvement in strength as well as ductility can be achieved for the Al-4Zn-2Mg alloy through CR and controlled heat treatment combinations.

Research on Bake Hardening Behavior of AA6016 Aluminum Alloy Sheets

The mechanical property and bake hardening behavior of two new-type automotive body AA6016 aluminum alloys under different artificial ageing processes are investigated comparatively,and the interrelated micro-mechanism is discussed.The optimal process is as follows:Solution hardening + pre-ageing + natural ageing + artificial ageing(bake hardening),which conduces to strengthening bake hardening.The results indicate that the bake hardening of aluminum alloy is mainly caused by the metastable precipitation of β′′ phase and the dislocations strengthening resulting from pre-deformation.The BH value is insensitive to natural ageing and rolling conditions,which couples with the speed of β′′ phase nucleation.The short-time baking process with high-temperature(2%～3% pre-deformation,170～180 ℃,less than 30 min) contributes to obtaining good bake hardening properties,the yield stress enhances 40～90 MPa.It is a good treatment schedule to promote the bake-hardening and formability of AA6016 aluminum alloys,which has guiding significance to practical application by enterprises.

Effect of Pre-Ageing on the Artificial Ageing Response of Al-Mg-Si(-Cu) Alloys

The effect of different pre-ageing treatments on the subsequent artificial ageing response of Al-Mg-Si(-Cu) alloys have been investigated using hardness, tensile and electrical conductivity testing. The microstructural evolution was characterised by differential scanning calorimetry (DSC) and 3-dimensional atom probe (3DAP) analysis. Pre-ageing treatments were carried out at 160-250°C for short times. Results show that the early stage artificial ageing response after 30 minutes at 170°C is strongly influenced by the pre-ageing and natural ageing conditions. A pre-ageing treatment performed for a short time at a high temperature and within a short delay after solution treatment and quenching was found to give a promising hardening response during subsequent artificial ageing. The mechanisms by which pre-ageing can reduce the detrimental effect of natural ageing on the artificial ageing response will be discussed in relation to the formation and distribution of clusters, GP zones and/or precipitates.