Charred seeds in Mikkeli Orijärvi : A study of subsistence strategies of an Iron Age settlement in East Finland

In this study the over 350 macrofossil samples, containing over 2300 charred plant remains from an Iron Age settlement containing fossil fields in Mikkeli Orijärvi Kihlinpelto, were studied archaeobotanically. The aim was to get more information about subsistence strategies, especially agriculture and study differences in the plant combinations in the different structures and use the archaeobotanical theory to interpret these structures. The methodological question was to study the taphonomy of the charred plant material. The results gave a diverse impression of the agriculture and subsistence strategies of the settlement in Orijärvi, where barley was the most important cereal with rye, wheat and oat cultivated as minor crops. The arable weed assemblage indicates that the fields were situated in different kinds of soils and the crops were cultivated when different kind of weather conditions were prevailing. Ergot was found with the cereals, and it was growing on some of the arable crops and it also indicates wet climate. Hemp and flax were cultivated and wild plants were collected. The meadow and wetland plants found in the material derive most probably from animal fodder. Tubers of bulbous oat-grass were interesting, because they are usually found in graves. Comparison with other Iron Age settlements and graves indicates that the plant material found from the ancient field layers derives most probably from dwellings and graves, which were taken into cultivation.

Corona Aging Studies on Silicone Rubber Nanocomposites

In EHV and UHV power transmission lines, corona could occur even on well designed transmission line hardware and insulators especially under wet conditions. Corona if allowed to occur continuously can significantly damage the polymeric insulators used in such lines in the long run. This paper presents the experimental results of corona aging studies conducted on unfilled silicone rubber as well as filled silicone rubber nanocomposites. Corona aging studies were conducted on silicone rubber samples with filler concentrations of 0, 1, 2 and 3 % by wt of nanosilica for 25 h and 50 h. Needle-plane electrode geometry has been used to create the corona on the samples. Different characterization techniques such as Scanning Electron Microscopy, Energy Dispersive X-ray analysis, Hydrophobicity, Fourier Transform Infrared Spectroscopy, and Optical Profilometry have been used to assess the relative performance of the samples with respect to corona aging. Results indicate that at 3 wt %, the performance of the nanocomposite is much better than the unfilled silicon rubber which can be attributed to the modifications in the material caused by the size factor of the filler.

Carbon-13 NMR studies of lipid mobilization pattern in germinating groundnut (Arachis hypogaea L.) seeds

The products of lipid mobilization in groundnut (Arachis hypogaea L.) seeds as a function of time immediately after imbibition are monitored by 13C NMR. Different parts of the embryonic axis, namely,the radicle, hypocotyl, and plumule, exhibit characteristic time dependent 13C NMR spectra observed at 24-h intervals after imbibition. The various stages in the transformation of storage lipids present in different parts of the embryonic axis are clearly demonstrated. The transformaton of storage lipids is completed first in the radicle followed by the hypocotyl and finally the plumule. A mechanism of the transformation of the storage lipids is discussed.

Synthesis of Trilaurin by Developing Pisa Seeds (Actinodaphne hookeri)

The developing seeds of Actinodaphne hookeri were investigated to delineate their ability to synthesize large amounts of trilaurin. Until 88 days after flowering the embryos contained 71% neutral lipids (NL) and 29% phospholipids (PL) and both these components contained C-16:0, C-18:0, C-18:2, and C-18:3 as the major fatty acids (FA). At 102 days after flowering the seeds began to accumulate triacylglycerols (TAG) and to synthesize lauric acid (C-12:0). By 165 days after flowering, when the seeds were mature, they contained about 99% NL and 1% FL. At this stage the TAG contained exclusively C-12:0, while the PL consisted of long-chain fatty acids (LCFA) only. Leaf lipids in contrast did not contain any C-12:0. Experiments on [1-C-14]acetate incorporation into developing seed slices showed that at 88 days after flowering only 4% of the label was in TAG, 1% in diacylglycerols (DAG), and 87% in FL. One hundred two days after flowering seeds incorporated only 2% of the label into TAG, 30% into DAG, and 64% into FL. In contrast at 114 days after flowering 71% of the label was incorporated into TAG, 25% into DAG, and only 2% into FL. Analysis of labeled FA revealed that up to 102 days after flowering it was incorporated only into LCFA, whereas at 114 days after flowering it was incorporated exclusively into C-12:0. Furthermore, 67% of the label in PL at 114 days after flowering was found to be dilaurylglycerophosphate. Analysis of the label in DAG at this stage showed that it was essentially in dilaurin species. These observations indicate the induction of enzymes of Kennedy pathway for the specific synthesis of trilaurin at about 114 days after flowering, Homogenates of seeds (114 days after flowering) incubated with labeled FA in the presence of glycerol-3-phosphate and coenzymes A and ATP incorporated 84% of C-12:0 and 61% of C-14:0, but not C-16:0, C-18:2, and C-18:3, into TAG. In contrast the LCFA were incorporated preferentially into FL. It is concluded that, between 102 and 114 days after flowering, a switch occurs in A. hookeri for the synthesis of C-12:0 and trilaurin which is tissue specific. Since the seed synthesizes exclusively C-12:0 at 114 days after flowering onwards and incorporates specifically into TAG, this system appears to be ideal for identifying the enzymes responsible for medium-chain fatty acid as well as trilaurin synthesis and for exploiting them for genetic engineering. (C) 1994 Academic Press, Inc.

Long-term Accelerated Weathering of Outdoor Silicone Rubber Insulators

Multistress aging/weathering of outdoor composite polymeric insulators has been a topic of interest for power transmission research community in the last few decades. This paper deals with the long-term accelerated weathering of full-scale distribution class silicone rubber composite insulators. To evaluate the long-term synergistic effect of electric stress, temperature and UV radiation on insulators, they were subjected to accelerated weathering in a specially designed multistress-aging chamber for 30,000 h. All the insulators were subjected to the same level of electrical and thermal stresses but different UV radiation levels. Chemical, physical and electrical changes due to degradation have been assessed using various techniques. It was found that there was a monotonous reduction of the content of low molecular weight (LMW) molecules with the duration of the weathering. Further, due to oxidation and weathering there is an appreciable increase in surface roughness and atomic percentage of oxygen. There is no change in the leakage current of new and aged insulators under both wet and dry conditions at the end of the aging. The results also indicate that there is no influence of UV radiation on the silicone rubber for the durations and conditions under which the studies were made.

Crystallization and preliminary X-ray diffraction analysis of a galactose-specific lectin from the seeds of Butea monosperma

The galactose-specific lectin from the seeds of Butea monosperma has been crystallized by the hanging-drop vapour-diffusion technique. The crystals belonged to space group P1, with unit-cell parameters a = 78.45, b = 78.91, c = 101.85 A, alpha = 74.30, beta = 76.65, gamma = 86.88 degrees. X-ray diffraction data were collected to a resolution of 2.44 A under cryoconditions (100 K) using a MAR image-plate detector system mounted on a rotating-anode X-ray generator. Molecular-replacement calculations carried out using the coordinates of several structures of legume lectins as search models indicate that the galactose-specific lectin from B. monosperma forms an octamer.

Sibling rivalry between seeds within a fruit: Some population genetic models

Competition between seeds within a fruit for parental resources is described using one-locus-two-allele models. While a �normal� allele leads to an equitable distribution of resources between seeds (a situation which also corresponds to the parental optimum), the �selfish� allele is assumed to cause the seed carrying it to usurp a higher proportion of the resources. The outcome of competition between �selfish� alleles is also assumed to lead to an asymmetric distribution of resources, the �winner� being chosen randomly. Conditions for the spread of an initially rare selfish allele and the optimal resource allocation corresponding to the evolutionarily stable strategy, derived for species with n-seeded fruits, are in accordance with expectations based on Hamilton�s inclusive fitness criteria. Competition between seeds is seen to be most intense when there are only two seeds, and decreases with increasing number of seeds, suggesting that two-seeded fruits would be rarer than one-seeded or many-seeded ones. Available data from a large number of plant species are consistent with this prediction of the model.

Spatial distribution of oil in groundnut and sunflower seeds by nuclear magnetic resonance imaging

The nuclear magnetic resonance imaging technique has been used to obtain images of different transverse and vertical sections in groundnut and sunflower seeds. Separate images have been obtained for oil and water components in the seeds. The spatial distribution of oil and water inside the seed has been obtained from the detailed analysis of the images. In the immature groundnut seeds obtained commercially, complementary oil and water distributions have been observed. Attempts have been made to explain these results.

Crystallization and preliminary X-ray diffraction analysis of a galactose-specific lectin from the seeds of Butea monosperma

The galactose-specific lectin from the seeds of Butea monosperma has been crystallized by the hanging-drop vapour-diffusion technique. The crystals belonged to space group P1, with unit-cell parameters a = 78.45, b = 78.91, c = 101.85 A, alpha = 74.30, beta = 76.65, gamma = 86.88 degrees. X-ray diffraction data were collected to a resolution of 2.44 A under cryoconditions (100 K) using a MAR image-plate detector system mounted on a rotating-anode X-ray generator. Molecular-replacement calculations carried out using the coordinates of several structures of legume lectins as search models indicate that the galactose-specific lectin from B. monosperma forms an octamer.

Electrochemical Determination of L-Dopa in Mucuna pruriens Seeds, Leaves and Commercial Siddha Product Using Gold Modified Pencil Graphite Electrode

In the present work a gold modified pencil graphite electrode (GPGE) was used for the determination of L-dopa present in the aqueous extracts of Mucuna pruriens seeds (MPS), Mucuna pruriens leaves (MPL) and Commercial Siddha Product (CSP). The GPGE shows excellent electrocatalytic activity towards the oxidation of both L-dopa and ascorbic acid (AA), with the separation of peak potential of 98 mV. The differential pulse voltammetric (DPV) results indicated that the detection limit for L-dopa was 1.54 mu M (S/N=3). This method can be successfully applied for the determination of L-dopa in real samples.

Purification and partial characterization of acyl carrier proteins from developing oil seeds of pisa (Actinodaphne hookeri) and ground nut (Arachis hypogaea)

Acyl carrier proteins (ACP) were purified to homogeneity in the active form from developing seeds of pisa (Actinodaphne hookeri) which synthesizes exclusively trilaurin and from ground nut (Arachis hypogaea) which synthesizes triacylglycerols containing long chain fatty acids. Two major isoforms of ACPs were purified from developing pisa seeds using DEAE-cellulose, Superose-6 FPLC and C-4 reversed phase HPLC chromatographic methods. In contrast, only a single form of ACP was present in ground nut seeds which was purified by anion-exchange and activated thiol-Sepharose 4B affinity chromatography. The two isoforms of ACPs from pisa showed nearly the same specific activity of 6,706 and 7,175 pmol per min per mg protein while ground nut ACP showed a specific activity of 3,893 pmol per min per mg protein when assayed using E. coli acyl-ACP synthetase and [1-C-14]palmitic acid. When compared with E. coli ACP, the purified ACPs from both the seeds showed considerable difference in their mobility in native PAGE, but showed similar mobility in SDS-PAGE under reducing conditions. In the absence of reducing agents formation of dimers was quite prominent. The ACPs from both the seed sources were acid- and heat-stable. The major isoform of pisa seed ACP and the ground nut ACP contain 91 amino acids with M(r) 11,616 and 1,228 respectively. However, there is significant variation in their amino acid composition. A comparision of the amino acid sequence in the N-terminal region of pisa and ground nut seed ACPs showed considerable homology between themselves and with other plant ACPs but not with E. coli ACP.

Crystallization and preliminary X-ray studies of a galactose-specific lectin from the seeds of Spatholobus parviflorus

A galactose-specific seed lectin was purified from the legume Spatholobus parviflorus and crystallized using the hanging-drop vapour-diffusion technique. The crystals belonged to space group P1, with unit-cell parameters a = 60.998, b = 60.792, c = 78.179 angstrom, alpha = 101.32, beta = 91.38, gamma = 104.32 degrees. X-ray diffraction data were collected under cryoconditions (100 K) to a resolution of 2.04 angstrom using a MAR image-plate detector system mounted on a rotating-anode X-ray (Cu K alpha) generator. Molecular replacement using legume-lectin coordinates as a search model gave a tetrameric structure.